TOPICAL REVIEW: Prosthetic interfaces with the visual system: biological issues

NASA Astrophysics Data System (ADS)

Cohen, Ethan D.

2007-06-01

The design of effective visual prostheses for the blind represents a challenge for biomedical engineers and neuroscientists. Significant progress has been made in the miniaturization and processing power of prosthesis electronics; however development lags in the design and construction of effective machine brain interfaces with visual system neurons. This review summarizes what has been learned about stimulating neurons in the human and primate retina, lateral geniculate nucleus and visual cortex. Each level of the visual system presents unique challenges for neural interface design. Blind patients with the retinal degenerative disease retinitis pigmentosa (RP) are a common population in clinical trials of visual prostheses. The visual performance abilities of normals and RP patients are compared. To generate pattern vision in blind patients, the visual prosthetic interface must effectively stimulate the retinotopically organized neurons in the central visual field to elicit patterned visual percepts. The development of more biologically compatible methods of stimulating visual system neurons is critical to the development of finer spatial percepts. Prosthesis electrode arrays need to adapt to different optimal stimulus locations, stimulus patterns, and patient disease states.

The importance of aerodynamics for prosthetic limb design used by competitive cyclists with an amputation: An introduction.

PubMed

Dyer, Bryce

2015-06-01

This study introduces the importance of the aerodynamics to prosthetic limb design for athletes with either a lower-limb or upper-limb amputation. The study comprises two elements: 1) An initial experiment investigating the stability of outdoor velodrome-based field tests, and 2) An experiment evaluating the application of outdoor velodrome aerodynamic field tests to detect small-scale changes in aerodynamic drag respective of prosthetic limb componentry changes. An outdoor field-testing method is used to detect small and repeatable changes in the aerodynamic drag of an able-bodied cyclist. These changes were made at levels typical of alterations in prosthetic componentry. The field-based test method of assessment is used at a smaller level of resolution than previously reported. With a carefully applied protocol, the field test method proved to be statistically stable. The results of the field test experiments demonstrate a noticeable change in overall athlete performance. Aerodynamic refinement of artificial limbs is worthwhile for athletes looking to maximise their competitive performance. A field-testing method illustrates the importance of the aerodynamic optimisation of prosthetic limb components. The field-testing protocol undertaken in this study gives an accessible and affordable means of doing so by prosthetists and sports engineers. Using simple and accessible field-testing methods, this exploratory experiment demonstrates how small changes to riders' equipment, consummate of the scale of a small change in prosthetics componentry, can affect the performance of an athlete. Prosthetists should consider such opportunities for performance enhancement when possible. © The International Society for Prosthetics and Orthotics 2014.

Does Seeing Ice Really Feel Cold? Visual-Thermal Interaction under an Illusory Body-Ownership

PubMed Central

Kanaya, Shoko; Matsushima, Yuka; Yokosawa, Kazuhiko

2012-01-01

Although visual information seems to affect thermal perception (e.g. red color is associated with heat), previous studies have failed to demonstrate the interaction between visual and thermal senses. However, it has been reported that humans feel an illusory thermal sensation in conjunction with an apparently-thermal visual stimulus placed on a prosthetic hand in the rubber hand illusion (RHI) wherein an individual feels that a prosthetic (rubber) hand belongs to him/her. This study tests the possibility that the ownership of the body surface on which a visual stimulus is placed enhances the likelihood of a visual-thermal interaction. We orthogonally manipulated three variables: induced hand-ownership, visually-presented thermal information, and tactically-presented physical thermal information. Results indicated that the sight of an apparently-thermal object on a rubber hand that is illusorily perceived as one's own hand affects thermal judgments about the object physically touching this hand. This effect was not observed without the RHI. The importance of ownership of a body part that is touched by the visual object on the visual-thermal interaction is discussed. PMID:23144814

Does seeing ice really feel cold? Visual-thermal interaction under an illusory body-ownership.

PubMed

Kanaya, Shoko; Matsushima, Yuka; Yokosawa, Kazuhiko

2012-01-01

Although visual information seems to affect thermal perception (e.g. red color is associated with heat), previous studies have failed to demonstrate the interaction between visual and thermal senses. However, it has been reported that humans feel an illusory thermal sensation in conjunction with an apparently-thermal visual stimulus placed on a prosthetic hand in the rubber hand illusion (RHI) wherein an individual feels that a prosthetic (rubber) hand belongs to him/her. This study tests the possibility that the ownership of the body surface on which a visual stimulus is placed enhances the likelihood of a visual-thermal interaction. We orthogonally manipulated three variables: induced hand-ownership, visually-presented thermal information, and tactically-presented physical thermal information. Results indicated that the sight of an apparently-thermal object on a rubber hand that is illusorily perceived as one's own hand affects thermal judgments about the object physically touching this hand. This effect was not observed without the RHI. The importance of ownership of a body part that is touched by the visual object on the visual-thermal interaction is discussed.

Contrast Sensitivity With a Subretinal Prosthesis and Implications for Efficient Delivery of Visual Information

PubMed Central

Goetz, Georges; Smith, Richard; Lei, Xin; Galambos, Ludwig; Kamins, Theodore; Mathieson, Keith; Sher, Alexander; Palanker, Daniel

2015-01-01

Purpose To evaluate the contrast sensitivity of a degenerate retina stimulated by a photovoltaic subretinal prosthesis, and assess the impact of low contrast sensitivity on transmission of visual information. Methods We measure ex vivo the full-field contrast sensitivity of healthy rat retina stimulated with white light, and the contrast sensitivity of degenerate rat retina stimulated with a subretinal prosthesis at frequencies exceeding flicker fusion (>20 Hz). Effects of eye movements on retinal ganglion cell (RGC) activity are simulated using a linear–nonlinear model of the retina. Results Retinal ganglion cells adapt to high frequency stimulation of constant intensity, and respond transiently to changes in illumination of the implant, exhibiting responses to ON-sets, OFF-sets, and both ON- and OFF-sets of light. The percentage of cells with an OFF response decreases with progression of the degeneration, indicating that OFF responses are likely mediated by photoreceptors. Prosthetic vision exhibits reduced contrast sensitivity and dynamic range, with 65% contrast changes required to elicit responses, as compared to the 3% (OFF) to 7% (ON) changes with visible light. The maximum number of action potentials elicited with prosthetic stimulation is at most half of its natural counterpart for the ON pathway. Our model predicts that for most visual scenes, contrast sensitivity of prosthetic vision is insufficient for triggering RGC activity by fixational eye movements. Conclusions Contrast sensitivity of prosthetic vision is 10 times lower than normal, and dynamic range is two times below natural. Low contrast sensitivity and lack of OFF responses hamper delivery of visual information via a subretinal prosthesis. PMID:26540657

Assistive peripheral phosphene arrays deliver advantages in obstacle avoidance in simulated end-stage retinitis pigmentosa: a virtual-reality study

NASA Astrophysics Data System (ADS)

Zapf, Marc Patrick H.; Boon, Mei-Ying; Lovell, Nigel H.; Suaning, Gregg J.

2016-04-01

Objective. The prospective efficacy of peripheral retinal prostheses for guiding orientation and mobility in the absence of residual vision, as compared to an implant for the central visual field (VF), was evaluated using simulated prosthetic vision (SPV). Approach. Sighted volunteers wearing a head-mounted display performed an obstacle circumvention task under SPV. Mobility and orientation performance with three layouts of prosthetic vision were compared: peripheral prosthetic vision of higher visual acuity (VA) but limited VF, of wider VF but limited VA, as well as centrally restricted prosthetic vision. Learning curves using these layouts were compared fitting an exponential model to the mobility and orientation measures. Main results. Using peripheral layouts, performance was superior to the central layout. Walking speed with both higher-acuity and wider-angle layouts was 5.6% higher, and mobility errors reduced by 46.4% and 48.6%, respectively, as compared to the central layout. The wider-angle layout yielded the least number of collisions, 63% less than the higher-acuity and 73% less than the central layout. Using peripheral layouts, the number of visual-scanning related head movements was 54.3% (higher-acuity) and 60.7% (wider-angle) lower, as compared to the central layout, and the ratio of time standing versus time walking was 51.9% and 61.5% lower, respectively. Learning curves did not differ between layouts, except for time standing versus time walking, where both peripheral layouts achieved significantly lower asymptotic values compared to the central layout. Significance. Beyond complementing residual vision for an improved performance, peripheral prosthetic vision can effectively guide mobility in the later stages of retinitis pigmentosa (RP) without residual vision. Further, the temporal dynamics of learning peripheral and central prosthetic vision are similar. Therefore, development of a peripheral retinal prosthesis and early implantation to alleviate VF constriction in RP should be considered to extend the target group and the time of benefit for potential retinal prosthesis implantees.

The role of vision processing in prosthetic vision.

PubMed

Barnes, Nick; He, Xuming; McCarthy, Chris; Horne, Lachlan; Kim, Junae; Scott, Adele; Lieby, Paulette

2012-01-01

Prosthetic vision provides vision which is reduced in resolution and dynamic range compared to normal human vision. This comes about both due to residual damage to the visual system from the condition that caused vision loss, and due to limitations of current technology. However, even with limitations, prosthetic vision may still be able to support functional performance which is sufficient for tasks which are key to restoring independent living and quality of life. Here vision processing can play a key role, ensuring that information which is critical to the performance of key tasks is available within the capability of the available prosthetic vision. In this paper, we frame vision processing for prosthetic vision, highlight some key areas which present problems in terms of quality of life, and present examples where vision processing can help achieve better outcomes.

Real-time three-dimensional transesophageal echocardiography in valve disease: comparison with surgical findings and evaluation of prosthetic valves.

PubMed

Sugeng, Lissa; Shernan, Stanton K; Weinert, Lynn; Shook, Doug; Raman, Jai; Jeevanandam, Valluvan; DuPont, Frank; Fox, John; Mor-Avi, Victor; Lang, Roberto M

2008-12-01

Recently, a novel real-time 3-dimensional (3D) matrix-array transesophageal echocardiographic (3D-MTEE) probe was found to be highly effective in the evaluation of native mitral valves (MVs) and other intracardiac structures, including the interatrial septum and left atrial appendage. However, the ability to visualize prosthetic valves using this transducer has not been evaluated. Moreover, the diagnostic accuracy of this new technology has never been validated against surgical findings. This study was designed to (1) assess the quality of 3D-MTEE images of prosthetic valves and (2) determine the potential value of 3D-MTEE imaging in the preoperative assessment of valvular pathology by comparing images with surgical findings. Eighty-seven patients undergoing clinically indicated transesophageal echocardiography were studied. In 40 patients, 3D-MTEE images of prosthetic MVs, aortic valves (AVs), and tricuspid valves (TVs) were scored for the quality of visualization. For both MVs and AVs, mechanical and bioprosthetic valves, the rings and leaflets were scored individually. In 47 additional patients, intraoperative 3D-MTEE diagnoses of MV pathology obtained before initiating cardiopulmonary bypass were compared with surgical findings. For the visualization of prosthetic MVs and annuloplasty rings, quality was superior compared with AV and TV prostheses. In addition, 3D-MTEE imaging had 96% agreement with surgical findings. Three-dimensional matrix-array transesophageal echocardiographic imaging provides superb imaging and accurate presurgical evaluation of native MV pathology and prostheses. However, the current technology is less accurate for the clinical assessment of AVs and TVs. Fast acquisition and immediate online display will make this the modality of choice for MV surgical planning and postsurgical follow-up.

Getting signals into the brain: visual prosthetics through thalamic microstimulation.

PubMed

Pezaris, John S; Eskandar, Emad N

2009-07-01

Common causes of blindness are diseases that affect the ocular structures, such as glaucoma, retinitis pigmentosa, and macular degeneration, rendering the eyes no longer sensitive to light. The visual pathway, however, as a predominantly central structure, is largely spared in these cases. It is thus widely thought that a device-based prosthetic approach to restoration of visual function will be effective and will enjoy similar success as cochlear implants have for restoration of auditory function. In this article the authors review the potential locations for stimulation electrode placement for visual prostheses, assessing the anatomical and functional advantages and disadvantages of each. Of particular interest to the neurosurgical community is placement of deep brain stimulating electrodes in thalamic structures that has shown substantial promise in an animal model. The theory of operation of visual prostheses is discussed, along with a review of the current state of knowledge. Finally, the visual prosthesis is proposed as a model for a general high-fidelity machine-brain interface.

Obstructed bi-leaflet prosthetic mitral valve imaging with real-time three-dimensional transesophageal echocardiography.

PubMed

Shimbo, Mai; Watanabe, Hiroyuki; Kimura, Shunsuke; Terada, Mai; Iino, Takako; Iino, Kenji; Ito, Hiroshi

2015-01-01

Real-time three-dimensional transesophageal echocardiography (RT3D-TEE) can provide unique visualization and better understanding of the relationship among cardiac structures. Here, we report the case of an 85-year-old woman with an obstructed mitral prosthetic valve diagnosed promptly by RT3D-TEE, which clearly showed a leaflet stuck in the closed position. The opening and closing angles of the valve leaflets measured by RT3D-TEE were compatible with those measured by fluoroscopy. Moreover, RT3D-TEE revealed, in the ring of the prosthetic valve, thrombi that were not visible on fluoroscopy. RT3D-TEE might be a valuable diagnostic technique for prosthetic mitral valve thrombosis. © 2014 Wiley Periodicals, Inc.

Image segmentation for enhancing symbol recognition in prosthetic vision.

PubMed

Horne, Lachlan; Barnes, Nick; McCarthy, Chris; He, Xuming

2012-01-01

Current and near-term implantable prosthetic vision systems offer the potential to restore some visual function, but suffer from poor resolution and dynamic range of induced phosphenes. This can make it difficult for users of prosthetic vision systems to identify symbolic information (such as signs) except in controlled conditions. Using image segmentation techniques from computer vision, we show it is possible to improve the clarity of such symbolic information for users of prosthetic vision implants in uncontrolled conditions. We use image segmentation to automatically divide a natural image into regions, and using a fixation point controlled by the user, select a region to phosphenize. This technique improves the apparent contrast and clarity of symbolic information over traditional phosphenization approaches.

Dynamic elasticity measurement for prosthetic socket design.

PubMed

Kim, Yujin; Kim, Junghoon; Son, Hyeryon; Choi, Youngjin

2017-07-01

The paper proposes a novel apparatus to measure the dynamic elasticity of human limb in order to help the design and fabrication of the personalized prosthetic socket. To take measurements of the dynamic elasticity, the desired force generated as an exponential chirp signal in which the frequency increases and amplitude is maintained according to time progress is applied to human limb and then the skin deformation is recorded, ultimately, to obtain the frequency response of its elasticity. It is referred to as a Dynamic Elasticity Measurement Apparatus (DEMA) in the paper. It has three core components such as linear motor to provide the desired force, loadcell to implement the force feedback control, and potentiometer to record the skin deformation. After measuring the force/deformation and calculating the dynamic elasticity of the limb, it is visualized as 3D color map model of the limb so that the entire dynamic elasticity can be shown at a glance according to the locations and frequencies. For the visualization, the dynamic elasticities measured at specific locations and frequencies are embodied using the color map into 3D limb model acquired by using 3D scanner. To demonstrate the effectiveness, the visualized dynamic elasticities are suggested as outcome of the proposed system, although we do not have any opportunity to apply the proposed system to the amputees. Ultimately, it is expected that the proposed system can be utilized to design and fabricate the personalized prosthetic socket in order for releasing the wearing pain caused by the conventional prosthetic socket.

Viability of Controlling Prosthetic Hand Utilizing Electroencephalograph (EEG) Dataset Signal

NASA Astrophysics Data System (ADS)

Miskon, Azizi; A/L Thanakodi, Suresh; Raihan Mazlan, Mohd; Mohd Haziq Azhar, Satria; Nooraya Mohd Tawil, Siti

2016-11-01

This project presents the development of an artificial hand controlled by Electroencephalograph (EEG) signal datasets for the prosthetic application. The EEG signal datasets were used as to improvise the way to control the prosthetic hand compared to the Electromyograph (EMG). The EMG has disadvantages to a person, who has not used the muscle for a long time and also to person with degenerative issues due to age factor. Thus, the EEG datasets found to be an alternative for EMG. The datasets used in this work were taken from Brain Computer Interface (BCI) Project. The datasets were already classified for open, close and combined movement operations. It served the purpose as an input to control the prosthetic hand by using an Interface system between Microsoft Visual Studio and Arduino. The obtained results reveal the prosthetic hand to be more efficient and faster in response to the EEG datasets with an additional LiPo (Lithium Polymer) battery attached to the prosthetic. Some limitations were also identified in terms of the hand movements, weight of the prosthetic, and the suggestions to improve were concluded in this paper. Overall, the objective of this paper were achieved when the prosthetic hand found to be feasible in operation utilizing the EEG datasets.

Advances in Retinal Prosthetic Research: A Systematic Review of Engineering and Clinical Characteristics of Current Prosthetic Initiatives.

PubMed

Cheng, Derrick L; Greenberg, Paul B; Borton, David A

2017-03-01

To date, reviews of retinal prostheses have focused primarily on devices undergoing human trials in the Western Hemisphere and fail to capture significant advances in materials and engineering research in countries such as Japan and Korea, as well as projects in early stages of development. To address these gaps, this systematic review examines worldwide advances in retinal prosthetic research, evaluates engineering characteristics and clinical progress of contemporary device initiatives, and identifies potential directions for future research in the field of retinal prosthetics. A literature search using PubMed, Google Scholar, and IEEExplore was conducted following the PRISMA Guidelines for Systematic Review. Inclusion criteria were peer-reviewed papers demonstrating progress in human or animal trials and papers discussing the prosthetic engineering design. For each initiative, a description of the device, its engineering considerations, and recent clinical results were provided. Ten prosthetic initiatives met our inclusion criteria and were organized by stimulation location. Of these initiatives, four have recently completed human trials, three are undergoing multi- or single-center human trials, and three are undergoing preclinical animal testing. Only the Argus II (FDA 2013, CE 2011) has obtained FDA approval for use in the United States; the Alpha-IMS (CE 2013) has achieved the highest visual acuity using a Landolt-C test to date and is the only device presently undergoing a multicenter clinical trial. Several distinct approaches to retinal stimulation have been successful in eliciting visual precepts in animals and/or humans. However, many clinical needs are still not met and engineering challenges must be addressed before a retinal prosthesis with the capability to fully and safely restore functional vision can be realized.

Electronic approaches to restoration of sight

NASA Astrophysics Data System (ADS)

Goetz, G. A.; Palanker, D. V.

2016-09-01

Retinal prostheses are a promising means for restoring sight to patients blinded by the gradual atrophy of photoreceptors due to retinal degeneration. They are designed to reintroduce information into the visual system by electrically stimulating surviving neurons in the retina. This review outlines the concepts and technologies behind two major approaches to retinal prosthetics: epiretinal and subretinal. We describe how the visual system responds to electrical stimulation. We highlight major differences between direct encoding of the retinal output with epiretinal stimulation, and network-mediated response with subretinal stimulation. We summarize results of pre-clinical evaluation of prosthetic visual functions in- and ex vivo, as well as the outcomes of current clinical trials of various retinal implants. We also briefly review alternative, non-electronic, approaches to restoration of sight to the blind, and conclude by suggesting some perspectives for future advancement in the field.

Electronic Approaches to Restoration of Sight

PubMed Central

Goetz, G A; Palanker, D V

2016-01-01

Retinal prostheses are a promising means for restoring sight to patients blinded by the gradual atrophy of photoreceptors due to retinal degeneration. They are designed to reintroduce information into the visual system by electrically stimulating surviving neurons in the retina. This review outlines the concepts and technologies behind two major approaches to retinal prosthetics: epiretinal and subretinal. We describe how the visual system responds to electrical stimulation. We highlight major differences between direct encoding of the retinal output with epiretinal stimulation, and network-mediated response with subretinal stimulation. We summarize results of pre-clinical evaluation of prosthetic visual functions in- and ex-vivo, as well as the outcomes of current clinical trials of various retinal implants. We also briefly review alternative, non-electronic, approaches to restoration of sight to the blind, and conclude by suggesting some perspectives for future advancement in the field. PMID:27502748

Replicating Physiological Patterns of Activity with Prosthetic Stimulation

DTIC Science & Technology

2008-07-01

from retinitis pigmentosa : Arch Ophthalmol, v. 122, p. 460-9. 8 Dacey, D. M., B. B. Peterson, F. R. Robinson, and P. D. Gamlin, 2003, Fireworks in...with DTL electrodes: a study in patients with retinitis pigmentosa , glaucoma, and homonymous visual field loss and normal subjects: Invest Ophthalmol...outcomes associated with retinal prosthetics. To accomplish this, we are investigating the mechanism(s) by which different types of retinal neurons

Simulated Prosthetic Vision: The Benefits of Computer-Based Object Recognition and Localization.

PubMed

Macé, Marc J-M; Guivarch, Valérian; Denis, Grégoire; Jouffrais, Christophe

2015-07-01

Clinical trials with blind patients implanted with a visual neuroprosthesis showed that even the simplest tasks were difficult to perform with the limited vision restored with current implants. Simulated prosthetic vision (SPV) is a powerful tool to investigate the putative functions of the upcoming generations of visual neuroprostheses. Recent studies based on SPV showed that several generations of implants will be required before usable vision is restored. However, none of these studies relied on advanced image processing. High-level image processing could significantly reduce the amount of information required to perform visual tasks and help restore visuomotor behaviors, even with current low-resolution implants. In this study, we simulated a prosthetic vision device based on object localization in the scene. We evaluated the usability of this device for object recognition, localization, and reaching. We showed that a very low number of electrodes (e.g., nine) are sufficient to restore visually guided reaching movements with fair timing (10 s) and high accuracy. In addition, performance, both in terms of accuracy and speed, was comparable with 9 and 100 electrodes. Extraction of high level information (object recognition and localization) from video images could drastically enhance the usability of current visual neuroprosthesis. We suggest that this method-that is, localization of targets of interest in the scene-may restore various visuomotor behaviors. This method could prove functional on current low-resolution implants. The main limitation resides in the reliability of the vision algorithms, which are improving rapidly. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Feedforward control strategies of subjects with transradial amputation in planar reaching.

PubMed

Metzger, Anthony J; Dromerick, Alexander W; Schabowsky, Christopher N; Holley, Rahsaan J; Monroe, Brian; Lum, Peter S

2010-01-01

The rate of upper-limb amputations is increasing, and the rejection rate of prosthetic devices remains high. People with upper-limb amputation do not fully incorporate prosthetic devices into their activities of daily living. By understanding the reaching behaviors of prosthesis users, researchers can alter prosthetic devices and develop training protocols to improve the acceptance of prosthetic limbs. By observing the reaching characteristics of the nondisabled arms of people with amputation, we can begin to understand how the brain alters its motor commands after amputation. We asked subjects to perform rapid reaching movements to two targets with and without visual feedback. Subjects performed the tasks with both their prosthetic and nondisabled arms. We calculated endpoint error, trajectory error, and variability and compared them with those of nondisabled control subjects. We found no significant abnormalities in the prosthetic limb. However, we found an abnormal leftward trajectory error (in right arms) in the nondisabled arm of prosthetic users in the vision condition. In the no-vision condition, the nondisabled arm displayed abnormal leftward endpoint errors and abnormally higher endpoint variability. In the vision condition, peak velocity was lower and movement duration was longer in both arms of subjects with amputation. These abnormalities may reflect the cortical reorganization associated with limb loss.

Facial identification in very low-resolution images simulating prosthetic vision.

PubMed

Chang, M H; Kim, H S; Shin, J H; Park, K S

2012-08-01

Familiar facial identification is important to blind or visually impaired patients and can be achieved using a retinal prosthesis. Nevertheless, there are limitations in delivering the facial images with a resolution sufficient to distinguish facial features, such as eyes and nose, through multichannel electrode arrays used in current visual prostheses. This study verifies the feasibility of familiar facial identification under low-resolution prosthetic vision and proposes an edge-enhancement method to deliver more visual information that is of higher quality. We first generated a contrast-enhanced image and an edge image by applying the Sobel edge detector and blocked each of them by averaging. Then, we subtracted the blocked edge image from the blocked contrast-enhanced image and produced a pixelized image imitating an array of phosphenes. Before subtraction, every gray value of the edge images was weighted as 50% (mode 2), 75% (mode 3) and 100% (mode 4). In mode 1, the facial image was blocked and pixelized with no further processing. The most successful identification was achieved with mode 3 at every resolution in terms of identification index, which covers both accuracy and correct response time. We also found that the subjects recognized a distinctive face especially more accurately and faster than the other given facial images even under low-resolution prosthetic vision. Every subject could identify familiar faces even in very low-resolution images. And the proposed edge-enhancement method seemed to contribute to intermediate-stage visual prostheses.

34 CFR 369.4 - What definitions apply to these programs?

Code of Federal Regulations, 2010 CFR

2010-07-01

... training in the use of prosthetic and orthotic devices; (3) Recreational therapy; (4) Physical and..., communication, self-care, self-direction, interpersonal skills, work tolerance, or work skills) in terms of an... to obtaining or retaining employment; (9) Eyeglasses and visual services, including visual training...

Pinch-force-magnification mechanism of low degree of freedom EMG prosthetic hand for children.

PubMed

Ye, Hesong; Sakoda, Shintaro; Jiang, Yinlai; Morishita, Soichiro; Yokoi, Hiroshi

2015-01-01

EMG prosthetic hands are being extensively studied for the disabled who need them not only for cosmesis but also for the functions to help them with basic daily activities. However, most EMG prosthetic hands are developed for adults. Since the early use of prosthetic hands is important for the children to accept and adapt to them, we are developing low degrees of freedom (DoF) prosthetic hand that is suitable for children. Due to the limited size of a child's hand, the servo motor which drives the MP joint are small-sized and low-power. Hence, a pinch-force-magnification mechanism is required to improve the pinch force of the EMG prosthetic hand. In this paper we designed a wire-driven mechanism which can magnify pinch force by increasing the length of the MP joint's moment arm. Pinch force measurement experiment validated that the pinch force of the prosthetic hand with the mechanism is more than twice of that of the hand with direct drive.

Simplification of Visual Rendering in Simulated Prosthetic Vision Facilitates Navigation.

PubMed

Vergnieux, Victor; Macé, Marc J-M; Jouffrais, Christophe

2017-09-01

Visual neuroprostheses are still limited and simulated prosthetic vision (SPV) is used to evaluate potential and forthcoming functionality of these implants. SPV has been used to evaluate the minimum requirement on visual neuroprosthetic characteristics to restore various functions such as reading, objects and face recognition, object grasping, etc. Some of these studies focused on obstacle avoidance but only a few investigated orientation or navigation abilities with prosthetic vision. The resolution of current arrays of electrodes is not sufficient to allow navigation tasks without additional processing of the visual input. In this study, we simulated a low resolution array (15 × 18 electrodes, similar to a forthcoming generation of arrays) and evaluated the navigation abilities restored when visual information was processed with various computer vision algorithms to enhance the visual rendering. Three main visual rendering strategies were compared to a control rendering in a wayfinding task within an unknown environment. The control rendering corresponded to a resizing of the original image onto the electrode array size, according to the average brightness of the pixels. In the first rendering strategy, vision distance was limited to 3, 6, or 9 m, respectively. In the second strategy, the rendering was not based on the brightness of the image pixels, but on the distance between the user and the elements in the field of view. In the last rendering strategy, only the edges of the environments were displayed, similar to a wireframe rendering. All the tested renderings, except the 3 m limitation of the viewing distance, improved navigation performance and decreased cognitive load. Interestingly, the distance-based and wireframe renderings also improved the cognitive mapping of the unknown environment. These results show that low resolution implants are usable for wayfinding if specific computer vision algorithms are used to select and display appropriate information regarding the environment. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

A methodology for coupling a visual enhancement device to human visual attention

NASA Astrophysics Data System (ADS)

Todorovic, Aleksandar; Black, John A., Jr.; Panchanathan, Sethuraman

2009-02-01

The Human Variation Model views disability as simply "an extension of the natural physical, social, and cultural variability of mankind." Given this human variation, it can be difficult to distinguish between a prosthetic device such as a pair of glasses (which extends limited visual abilities into the "normal" range) and a visual enhancement device such as a pair of binoculars (which extends visual abilities beyond the "normal" range). Indeed, there is no inherent reason why the design of visual prosthetic devices should be limited to just providing "normal" vision. One obvious enhancement to human vision would be the ability to visually "zoom" in on objects that are of particular interest to the viewer. Indeed, it could be argued that humans already have a limited zoom capability, which is provided by their highresolution foveal vision. However, humans still find additional zooming useful, as evidenced by their purchases of binoculars equipped with mechanized zoom features. The fact that these zoom features are manually controlled raises two questions: (1) Could a visual enhancement device be developed to monitor attention and control visual zoom automatically? (2) If such a device were developed, would its use be experienced by users as a simple extension of their natural vision? This paper details the results of work with two research platforms called the Remote Visual Explorer (ReVEx) and the Interactive Visual Explorer (InVEx) that were developed specifically to answer these two questions.

Concerns of anophthalmic patients-a comparison between cryolite glass and polymethyl methacrylate prosthetic eye wearers.

PubMed

Rokohl, Alexander C; Koch, Konrad R; Adler, Werner; Trester, Marc; Trester, Wolfgang; Pine, Nicola S; Pine, Keith R; Heindl, Ludwig M

2018-06-01

To compare the concerns of experienced cryolite glass and (poly)methyl methacrylate (PMMA) prosthetic eye wearers. One hundred six experienced cryolite glass and 63 experienced PMMA prosthetic eye wearers completed an anonymous questionnaire regarding general and specific prosthetic eye concerns at least 2 years after natural eye loss. From these independent anophthalmic populations, we identified 34 case-control pairs matched for the known influencing demographic variables of gender, occupation, age, and time since natural eye loss. The levels of concern were significantly lower in the cryolite glass group than those in the PMMA group for the following: loss of balance (p < 0.001), phantom sight vision (p < 0.001), pain (p < 0.001), receiving good advice (p = 0.001), fullness of orbit (p = 0.001), size (p = 0.007), direction of gaze relative to the healthy fellow eye (p = 0.005), eye lid contour (p = 0.037), comfort of the prosthetic eye (p < 0.001), colour relative to the healthy fellow eye (p < 0.001), and retention of the prosthetic eye (p < 0.001). Concerns about watering, crusting, discharge, visual perception, appearance, movement of the prosthetic eye, and health of the remaining eye were not significantly different between both groups. The results of this study showed that many general and specific levels of concern were significantly lower for cryolite glass prosthetic eye wearers than for PMMA prosthetic eye wearers. The question of why there are significant differences and to what extent the material of the prosthesis (cryolite glass or PMMA) has an impact on various concerns remains unanswered and should be addressed in a prospective comparative multicentre trial.

Acute failure of a St. Jude's prosthetic aortic valve: large pannus formation masked by a small thrombus.

PubMed

Hurwitz, Seth Eric; Waxman, Daniel; Hecht, Susan

2009-09-01

Pannus formation and valve thrombus can cause prosthetic valve failure. The authors report the case of a 50-year-old woman who presented to the emergency room with decompensated heart failure secondary to mechanical valve dysfunction. On two-dimensional and transesophageal echocardiography, the patient had severe aortic stenosis and regurgitation. A thrombus seen on the valve was felt to be the etiology of her prosthetic valve failure. She underwent emergent cardiac surgery for aortic valve replacement. Pathology revealed that although a small thrombus was present, extensive pannus was the underlying mechanism of valve dysfunction. Differentiation between pannus and thrombus may have important clinical implications, but this case illustrates that distinguishing between these entities by echocardiographic and clinical criteria may not be possible.

The effects of prosthetic foot type and visual alteration on postural steadiness in below-knee amputees

PubMed Central

2014-01-01

Background Achieving independent upright posture has known to be one of the main goals in rehabilitation following lower limb amputation. The purpose of this study was to compare postural steadiness of below knee amputees with visual alterations while wearing three different prosthetic feet. Methods Ten male below-knee amputees were instructed to stand quietly on the Biodex® balance platform while wearing solid ankle cushion heel (SACH), single axis (SA) and energy storage and release (ESAR) prosthetic foot under different visual input conditions (eyes-opened and eyes-closed). The overall stability index (OSI), anterior- posterior stability index (APSI), and medial-lateral stability index (MLSI) were computed. Perceived balance assessment of each foot was evaluated using Activities-specific Balance Confidence (ABC) score. Results The findings highlights that SACH showed lowest overall stability index (indicating less body sway) during eyes-opened (OSI: SACH = 1.09, SA = 1.58, ESAR = 1.59) and SA showed lowest overall stability index during eyes-closed (OSI: SACH = 2.52, SA = 2.30, ESAR = 2.76) condition. However, overall stability indexes between foot types did not differ significantly during eyes-opened or eyes-closed (p = 0.651). There was a trend of instability which occurred more in medial-lateral compared to anterior-posterior direction for all foot types, with significant result in ESAR foot(eyes-opened: MLSI = 1.59, APSI = 0.65, p = 0.034; eyes-closed: MLSI = 2.76, APSI = 1.80, p = 0.017, respectively). When comparing between visual conditions, stability score was significantly higher during eyes-closed compared to eyes-opened situations for SACH and ESAR foot (eyes-closed vs opened; SACH OSI: 3.43 vs 1.71, p = 0.018 and MLSI: 3.43 vs 1.71, p = 0.018; ESAR OSI: 3.58 vs 1.86, p = 0.043 and APSI: 1.80 vs 0.65, p = 0.027). Conclusions The results of this study suggested postural steadiness in below-knee amputees was not affected by the types of prosthetic foot during quiet upright standing, but was significantly affected when visual cues was absent. PMID:24597518

75 FR 59793 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-28

.... Joel W. Bryant Mr. Bryant, 53, has had a prosthetic right eye since 1990 due to a traumatic injury. The..., sustained traumatic injury to his left optic nerve at age 14. The best corrected visual acuity in his right... ruptured globe in his left eye due to a traumatic injury sustained in 2005. The best corrected visual...

77 FR 46793 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-06

..., had an enucleation of his left eye due to a traumatic injury sustained as a child. The visual acuity.... Johnsonbaugh, 42, has a prosthetic left eye due to a traumatic injury sustained in 1992. The visual acuity in... had retinal scarring in his left eye due to a traumatic injury sustained as a child. The best...

77 FR 60008 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-01

... in a CMV. Terry J. Edwards Mr. Edwards, 53, has a prosthetic right eye due to a traumatic injury... left eye due to a traumatic injury sustained at age 2. The best corrected visual acuity in his right... his right eye due to a traumatic injury sustained 10 years ago. The visual acuity in his right eye is...

75 FR 14656 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-26

... traumatic injury sustained during childhood. The best corrected visual acuity in his right eye is 20/20... moving violations in a CMV. Lane L. Savoie Mr. Savoie, 57, has a prosthetic left eye due to a traumatic injury sustained in 1995. The best corrected visual acuity in his right eye is 20/20. Following an...

76 FR 55465 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-07

... enucleation of his left eye due to a traumatic injury that he sustained in 1952. The best corrected visual... due to a traumatic injury that occurred in 1983. The best corrected visual acuity in his right eye is... Mr. Buckingham, 43, has a prosthetic left eye due to a traumatic injury that occurred more than 25...

77 FR 17109 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-23

... W. Doran, Jr. Mr. Doran, 51, has had a macular scar in his left eye due to a traumatic injury... prosthetic left eye due to a traumatic injury sustained 20 years ago. The best corrected visual acuity in... traumatic injury sustained at age 23. The best corrected visual acuity in left eye is 20/20. Following an...

Cyborg beast: a low-cost 3d-printed prosthetic hand for children with upper-limb differences.

PubMed

Zuniga, Jorge; Katsavelis, Dimitrios; Peck, Jean; Stollberg, John; Petrykowski, Marc; Carson, Adam; Fernandez, Cristina

2015-01-20

There is an increasing number of children with traumatic and congenital hand amputations or reductions. Children's prosthetic needs are complex due to their small size, constant growth, and psychosocial development. Families' financial resources play a crucial role in the prescription of prostheses for their children, especially when private insurance and public funding are insufficient. Electric-powered (i.e., myoelectric) and body-powered (i.e., mechanical) devices have been developed to accommodate children's needs, but the cost of maintenance and replacement represents an obstacle for many families. Due to the complexity and high cost of these prosthetic hands, they are not accessible to children from low-income, uninsured families or to children from developing countries. Advancements in computer-aided design (CAD) programs, additive manufacturing, and image editing software offer the possibility of designing, printing, and fitting prosthetic hands devices at a distance and at very low cost. The purpose of this preliminary investigation was to describe a low-cost three-dimensional (3D)-printed prosthetic hand for children with upper-limb reductions and to propose a prosthesis fitting methodology that can be performed at a distance. No significant mean differences were found between the anthropometric and range of motion measurements taken directly from the upper limbs of subjects versus those extracted from photographs. The Bland and Altman plots show no major bias and narrow limits of agreements for lengths and widths and small bias and wider limits of agreements for the range of motion measurements. The main finding of the survey was that our prosthetic device may have a significant potential to positively impact quality of life and daily usage, and can be incorporated in several activities at home and in school. This investigation describes a low-cost 3D-printed prosthetic hand for children and proposes a distance fitting procedure. The Cyborg Beast prosthetic hand and the proposed distance-fitting procedures may represent a possible low-cost alternative for children in developing countries and those who have limited access to health care providers. Further studies should examine the functionality, validity, durability, benefits, and rejection rate of this type of low-cost 3D-printed prosthetic device.

Real-time three-dimensional transesophageal echocardiography in the assessment of mechanical prosthetic mitral valve ring thrombosis.

PubMed

Ozkan, Mehmet; Gürsoy, Ozan Mustafa; Astarcıoğlu, Mehmet Ali; Gündüz, Sabahattin; Cakal, Beytullah; Karakoyun, Süleyman; Kalçık, Macit; Kahveci, Gökhan; Duran, Nilüfer Ekşi; Yıldız, Mustafa; Cevik, Cihan

2013-10-01

Although 2-dimensional (2D) transesophageal echocardiography (TEE) is the gold standard for the diagnosis of prosthetic valve thrombosis, nonobstructive clots located on mitral valve rings can be missed. Real-time 3-dimensional (3D) TEE has incremental value in the visualization of mitral prosthesis. The aim of this study was to investigate the utility of real-time 3D TEE in the diagnosis of mitral prosthetic ring thrombosis. The clinical outcomes of these patients in relation to real-time 3D transesophageal echocardiographic findings were analyzed. Of 1,263 patients who underwent echocardiographic studies, 174 patients (37 men, 137 women) with mitral ring thrombosis detected by real-time 3D TEE constituted the main study population. Patients were followed prospectively on oral anticoagulation for 25 ± 7 months. Eighty-nine patients (51%) had thrombi that were missed on 2D TEE and depicted only on real-time 3D TEE. The remaining cases were partially visualized with 2D TEE but completely visualized with real-time 3D TEE. Thirty-seven patients (21%) had thromboembolism. The mean thickness of the ring thrombosis in patients with thromboembolism was greater than that in patients without thromboembolism (3.8 ± 0.9 vs 2.8 ± 0.7 mm, p <0.001). One hundred fifty-five patients (89%) underwent real-time 3D TEE during follow-up. There were no thrombi in 39 patients (25%); 45 (29%) had regression of thrombi, and there was no change in thrombus size in 68 patients (44%). Thrombus size increased in 3 patients (2%). Thrombosis was confirmed surgically and histopathologically in 12 patients (7%). In conclusion, real-time 3D TEE can detect prosthetic mitral ring thrombosis that could be missed on 2D TEE and cause thromboembolic events. Copyright © 2013 Elsevier Inc. All rights reserved.

Visual performance with changes in eccentricity in PROSE device: a case report.

PubMed

Jagadeesh, Divya; Mahadevan, Rajeswari

2014-01-01

This case report describes the variations in visual performance of a subject with moderate keratoconus with changes in front surface eccentricities (FSEs) of PROSE (Prosthetic Replacement of Ocular Surface Ecosystem). PROSE device of 0.6 FSE provided maximum visual improvement and reduction in Higher Order Aberrations (HOAs) compared to 0, 0.3 and 0.8 FSEs in this clinical condition. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Undergraduate prosthetics and orthotics teaching methods: A baseline for international comparison.

PubMed

Aminian, Gholamreza; O'Toole, John M; Mehraban, Afsoon Hassani

2015-08-01

Education of Prosthetics and Orthotics is a relatively recent professional program. While there has been some work on various teaching methods and strategies in international medical education, limited publication exists within prosthetics and orthotics. To identify the teaching and learning methods that are used in Bachelor-level prosthetics and orthotics programs that are given highest priority by expert prosthetics and orthotics instructors from regions enjoying a range of economic development. Mixed method. The study partly documented by this article utilized a mixed method approach (qualitative and quantitative methods) within which each phase provided data for other phases. It began with analysis of prosthetics and orthotics curricula documents, which was followed by a broad survey of instructors in this field and then a modified Delphi process. The expert instructors who participated in this study gave high priority to student-centered, small group methods that encourage critical thinking and may lead to lifelong learning. Instructors from more developed nations placed higher priority on student's independent acquisition of prosthetics and orthotics knowledge, particularly in clinical training. Application of student-centered approaches to prosthetics and orthotics programs may be preferred by many experts, but there appeared to be regional differences in the priority given to different teaching methods. The results of this study identify the methods of teaching that are preferred by expert prosthetics and orthotics instructors from a variety of regions. This treatment of current instructional techniques may inform instructor choice of teaching methods that impact the quality of education and improve the professional skills of students. © The International Society for Prosthetics and Orthotics 2014.

The FDA's role in medical device clinical studies of human subjects

NASA Astrophysics Data System (ADS)

Saviola, James

2005-03-01

This paper provides an overview of the United States Food and Drug Administration's (FDA) role as a regulatory agency in medical device clinical studies involving human subjects. The FDA's regulations and responsibilities are explained and the device application process discussed. The specific medical device regulatory authorities are described as they apply to the development and clinical study of retinal visual prosthetic devices. The FDA medical device regulations regarding clinical studies of human subjects are intended to safeguard the rights and safety of subjects. The data gathered in pre-approval clinical studies provide a basis of valid scientific evidence in order to demonstrate the safety and effectiveness of a medical device. The importance of a working understanding of applicable medical device regulations from the beginning of the device development project is emphasized particularly for novel, complex products such as implantable visual prosthetic devices.

'Who is the ideal candidate?': decisions and issues relating to visual neuroprosthesis development, patient testing and neuroplasticity

NASA Astrophysics Data System (ADS)

Merabet, Lotfi B.; Rizzo, Joseph F., III; Pascual-Leone, Alvaro; Fernandez, Eduardo

2007-03-01

Appropriate delivery of electrical stimulation to intact visual structures can evoke patterned sensations of light in individuals who have been blind for many years. This pivotal finding has lent credibility to the concept of restoring functional vision by artificial means. As numerous groups worldwide pursue human clinical testing with visual prosthetic devices, it is becoming increasingly clear that there remains a considerable gap between the challenges of prosthetic device development and the rehabilitative strategies needed to implement this new technology in patients. An important area of future work will be the development of appropriate pre- and post-implantation measures of performance and establishing candidate selection criteria in order to quantify technical advances, guide future device design and optimize therapeutic success. We propose that the selection of an 'ideal' candidate should also be considered within the context of the variable neuroplastic changes that follow vision loss. Specifically, an understanding of the adaptive and compensatory changes that occur within the brain could assist in guiding the development of post-implantation rehabilitative strategies and optimize behavioral outcomes.

Possible sources of neuroprotection following subretinal silicon chip implantation in RCS rats

NASA Astrophysics Data System (ADS)

Pardue, Machelle T.; Phillips, Michael J.; Yin, Hang; Fernandes, Alcides; Cheng, Yian; Chow, Alan Y.; Ball, Sherry L.

2005-03-01

Current retinal prosthetics are designed to stimulate existing neural circuits in diseased retinas to create a visual signal. However, implantation of retinal prosthetics may create a neurotrophic environment that also leads to improvements in visual function. Possible sources of increased neuroprotective effects on the retina may arise from electrical activity generated by the prosthetic, mechanical injury due to surgical implantation, and/or presence of a chronic foreign body. This study evaluates these three neuroprotective sources by implanting Royal College of Surgeons (RCS) rats, a model of retinitis pigmentosa, with a subretinal implant at an early stage of photoreceptor degeneration. Treatment groups included rats implanted with active and inactive devices, as well as sham-operated. These groups were compared to unoperated controls. Evaluation of retinal function throughout an 18 week post-implantation period demonstrated transient functional improvements in eyes implanted with an inactive device at 6, 12 and 14 weeks post-implantation. However, the number of photoreceptors located directly over or around the implant or sham incision was significantly increased in eyes implanted with an active or inactive device or sham-operated. These results indicate that in the RCS rat localized neuroprotection of photoreceptors from mechanical injury or a chronic foreign body may provide similar results to subretinal electrical stimulation at the current output evaluated here.

Possibilities and limits of imaging endodontic structures with CBCT.

PubMed

Weber, Marie-Theres; Stratz, Nadja; Fleiner, Jonathan; Schulze, Dirk; Hannig, Christian

2015-01-01

An adequate portrayal of the root canal anatomy by diagnostic imaging is a prerequisite for a successful diagnosis and therapy in endodontics. The introduction of dental cone beam computed tomography (CBCT) has considerably expanded the scope of imaging diagnostics. The aim of the following study was to evaluate the imaging of endodontic structures with CBCT. One hundred and twenty teeth were examined with a CBCT device (ProMax 3D). Subsequently, the findings of the three-dimensional images were evaluated and compared to those of dental radiographs and tangential section preparations of the examined teeth. Results with high prevalence, such as existing roots and root canals, as well as results with low prevalence, e.g., extremely fine anatomical structures of the endodontic tissue, could be visualized precisely by dental CBCT; side canals, ramifications, communications, pulp stones, and obliterations could also be detected. Additionally, the length of curved root canals could be determined accurately. Likewise, root fractures were visualized reliably with CBCT. However, carious lesions could not be diagnosed adequately, and the evaluation of fillings and prosthetic restorations was complicated due to scattered X-ray artifacts. CBCT datasets qualify to visualize and diagnose small anatomical structures of the endodontic tissue.

Biomechanical characteristics, patient preference and activity level with different prosthetic feet: a randomized double blind trial with laboratory and community testing.

PubMed

Raschke, Silvia U; Orendurff, Michael S; Mattie, Johanne L; Kenyon, David E A; Jones, O Yvette; Moe, David; Winder, Lorne; Wong, Angie S; Moreno-Hernández, Ana; Highsmith, M Jason; J Sanderson, David; Kobayashi, Toshiki

2015-01-02

Providing appropriate prosthetic feet to those with limb loss is a complex and subjective process influenced by professional judgment and payer guidelines. This study used a small load cell (Europa™) at the base of the socket to measure the sagittal moments during walking with three objective categories of prosthetic feet in eleven individuals with transtibial limb loss with MFCL K2, K3 and K4 functional levels. Forefoot stiffness and hysteresis characteristics defined the three foot categories: Stiff, Intermediate, and Compliant. Prosthetic feet were randomly assigned and blinded from participants and investigators. After laboratory testing, participants completed one week community wear tests followed by a modified prosthetics evaluation questionnaire to determine if a specific category of prosthetic feet was preferred. The Compliant category of prosthetic feet was preferred by the participants (P=0.025) over the Stiff and Intermediate prosthetic feet, and the Compliant and Intermediate feet had 15% lower maximum sagittal moments during walking in the laboratory (P=0.0011) compared to the Stiff feet. The activity level of the participants did not change significantly with any of the wear tests in the community, suggesting that each foot was evaluated over a similar number of steps, but did not inherently increase activity. This is the first randomized double blind study in which prosthetic users have expressed a preference for a specific biomechanical characteristic of prosthetic feet: those with lower peak sagittal moments were preferred, and specifically preferred on slopes, stairs, uneven terrain, and during turns and maneuvering during real world use. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Design and clinical outcome of a novel 3D-printed prosthetic joint replacement for the human temporomandibular joint.

PubMed

Ackland, David; Robinson, Dale; Lee, Peter Vee Sin; Dimitroulis, George

2018-05-11

Stock prosthetic temporomandibular joint replacements come in limited sizes, and do not always encompass the joint anatomy that presents clinically. The aims of this study were twofold. Firstly, to design a personalized prosthetic total joint replacement for the treatment of a patient's end-stage temporomandibular joint osteoarthritis, to implant the prosthesis into the patient, and assess clinical outcome 12-months post-operatively; and secondly, to evaluate the influence of changes in prosthetic condyle geometry on implant load response during mastication. A 48-year-old female patient with Grade-5 osteoarthritis to the left temporomandibular joint was recruited, and a prosthesis developed to match the native temporomandibular joint anatomy. The prosthesis was 3D printed, sterilized and implanted into the patient, and pain and function measured 12-months post-operatively. The prosthesis load response during a chewing-bite and maximum-force bite was evaluated using a personalized multi-body musculoskeletal model. Simulations were performed after perturbing condyle thickness, neck length and head sphericity. Increases in prosthetic condyle neck length malaligned the mandible and perturbed temporomandibular joint force. Changes in condylar component thickness greatly influenced fixation screw stress response, while a more eccentric condylar head increased prosthetic joint-contact loading. Post-operatively, the prosthetic temporomandibular joint surgery reduced patient pain from 7/10 to 1/10 on a visual analog scale, and increased intercisal opening distance from 22 mm to 38 mm. This study demonstrates effectiveness of a personalized prosthesis that may ultimately be adapted to treat a wide-range of end-stage temporomandibular joint conditions, and highlights sensitivity of prosthesis load response to changes in condylar geometry. Copyright © 2018 Elsevier Ltd. All rights reserved.

First-in-man demonstration of a fully implanted myoelectric sensors system to control an advanced electromechanical prosthetic hand.

PubMed

Pasquina, Paul F; Evangelista, Melissa; Carvalho, A J; Lockhart, Joseph; Griffin, Sarah; Nanos, George; McKay, Patricia; Hansen, Morten; Ipsen, Derek; Vandersea, James; Butkus, Josef; Miller, Matthew; Murphy, Ian; Hankin, David

2015-04-15

Advanced motorized prosthetic devices are currently controlled by EMG signals generated by residual muscles and recorded by surface electrodes on the skin. These surface recordings are often inconsistent and unreliable, leading to high prosthetic abandonment rates for individuals with upper limb amputation. Surface electrodes are limited because of poor skin contact, socket rotation, residual limb sweating, and their ability to only record signals from superficial muscles, whose function frequently does not relate to the intended prosthetic function. More sophisticated prosthetic devices require a stable and reliable interface between the user and robotic hand to improve upper limb prosthetic function. Implantable Myoelectric Sensors (IMES(®)) are small electrodes intended to detect and wirelessly transmit EMG signals to an electromechanical prosthetic hand via an electro-magnetic coil built into the prosthetic socket. This system is designed to simultaneously capture EMG signals from multiple residual limb muscles, allowing the natural control of multiple degrees of freedom simultaneously. We report the status of the first FDA-approved clinical trial of the IMES(®) System. This study is currently in progress, limiting reporting to only preliminary results. Our first subject has reported the ability to accomplish a greater variety and complexity of tasks in his everyday life compared to what could be achieved with his previous myoelectric prosthesis. The interim results of this study indicate the feasibility of utilizing IMES(®) technology to reliably sense and wirelessly transmit EMG signals from residual muscles to intuitively control a three degree-of-freedom prosthetic arm. Copyright © 2014 Elsevier B.V. All rights reserved.

Characterisation of prosthetic feet used in low-income countries.

PubMed

Sam, M; Hansen, A H; Childress, D S

2004-08-01

Eleven kinds of prosthetic feet that were designed for use in low-income countries were mechanically characterised in this study. Masses of the different kinds of prosthetic feet varied substantially. Dynamic properties, including damping ratios and resonant frequencies, were obtained from step unloading tests of the feet while interacting with masses comparable to the human body. Data showed that for walking, the feet can be appropriately modeled using their quasistatic properties since natural frequencies were high compared to walking frequencies and since damping ratios were small. Roll-over shapes, the effective rocker (cam) geometries that the feet deform to under walking loads, were determined using a quasistatic loading technique and a spatial transformation of the ground reaction force's centre of pressure. The roll-over shapes for most of the prosthetic feet studied were similar to the roll-over shape of the SACH (solid-ankle cushioned heel) prosthetic foot. All roll-over shapes showed a lack of forefoot support, which may cause a "drop-off" experience at the end of single limb stance and shorter step lengths of the contralateral limb. The roll-over shapes of prosthetic feet appear useful in characterization of foot function.

Sensory feedback by peripheral nerve stimulation improves task performance in individuals with upper limb loss using a myoelectric prosthesis.

PubMed

Schiefer, Matthew; Tan, Daniel; Sidek, Steven M; Tyler, Dustin J

2016-02-01

Tactile feedback is critical to grip and object manipulation. Its absence results in reliance on visual and auditory cues. Our objective was to assess the effect of sensory feedback on task performance in individuals with limb loss. Stimulation of the peripheral nerves using implanted cuff electrodes provided two subjects with sensory feedback with intensity proportional to forces on the thumb, index, and middle fingers of their prosthetic hand during object manipulation. Both subjects perceived the sensation on their phantom hand at locations corresponding to the locations of the forces on the prosthetic hand. A bend sensor measured prosthetic hand span. Hand span modulated the intensity of sensory feedback perceived on the thenar eminence for subject 1 and the middle finger for subject 2. We performed three functional tests with the blindfolded subjects. First, the subject tried to determine whether or not a wooden block had been placed in his prosthetic hand. Second, the subject had to locate and remove magnetic blocks from a metal table. Third, the subject performed the Southampton Hand Assessment Procedure (SHAP). We also measured the subject's sense of embodiment with a survey and his self-confidence. Blindfolded performance with sensory feedback was similar to sighted performance in the wooden block and magnetic block tasks. Performance on the SHAP, a measure of hand mechanical function and control, was similar with and without sensory feedback. An embodiment survey showed an improved sense of integration of the prosthesis in self body image with sensory feedback. Sensory feedback by peripheral nerve stimulation improved object discrimination and manipulation, embodiment, and confidence. With both forms of feedback, the blindfolded subjects tended toward results obtained with visual feedback.

Proceedings, 13th Annual Conference on Manual Control

NASA Technical Reports Server (NTRS)

1977-01-01

Theoretical aspects of manual control theory are discussed. Specific topics covered include: tracking; performance, attention allocation, and mental load; surface vehicle control; monitoring behavior and supervisory control; manipulators and prosthetics; aerospace vehicle control; motion and visual cues; and displays and controls.

Functional added value of microprocessor-controlled knee joints in daily life performance of Medicare Functional Classification Level-2 amputees.

PubMed

Theeven, Patrick; Hemmen, Bea; Rings, Frans; Meys, Guido; Brink, Peter; Smeets, Rob; Seelen, Henk

2011-10-01

To assess the effects of using a microprocessor-controlled prosthetic knee joint on the functional performance of activities of daily living in persons with an above-knee leg amputation. To assess the effects of using a microprocessor-controlled prosthetic knee joint on the functional performance of activities of daily living in persons with an above-knee leg amputation. Randomised cross-over trial. Forty-one persons with unilateral above-knee or knee disarticulation limb loss, classified as Medicare Functional Classification Level-2 (MFCL-2). Participants were measured in 3 conditions, i.e. using a mechanically controlled knee joint and two types of microprocessor-controlled prosthetic knee joints. Functional performance level was assessed using a test in which participants performed 17 simulated activities of daily living (Assessment of Daily Activity Performance in Transfemoral amputees test). Performance time was measured and self-perceived level of difficulty was scored on a visual analogue scale for each activity. High levels of within-group variability in functional performance obscured detection of any effects of using a microprocessor-controlled prosthetic knee joint. Data analysis after stratification of the participants into 3 subgroups, i.e. participants with a "low", "intermediate" and "high" functional mobility level, showed that the two higher functional subgroups performed significantly faster using microprocessor-controlled prosthetic knee joints. MFCL-2 amputees constitute a heterogeneous patient group with large variation in functional performance levels. A substantial part of this group seems to benefit from using a microprocessor-controlled prosthetic knee joint when performing activities of daily living.

Psycho-physiological assessment of a prosthetic hand sensory feedback system based on an auditory display: a preliminary study.

PubMed

Gonzalez, Jose; Soma, Hirokazu; Sekine, Masashi; Yu, Wenwei

2012-06-09

Prosthetic hand users have to rely extensively on visual feedback, which seems to lead to a high conscious burden for the users, in order to manipulate their prosthetic devices. Indirect methods (electro-cutaneous, vibrotactile, auditory cues) have been used to convey information from the artificial limb to the amputee, but the usability and advantages of these feedback methods were explored mainly by looking at the performance results, not taking into account measurements of the user's mental effort, attention, and emotions. The main objective of this study was to explore the feasibility of using psycho-physiological measurements to assess cognitive effort when manipulating a robot hand with and without the usage of a sensory substitution system based on auditory feedback, and how these psycho-physiological recordings relate to temporal and grasping performance in a static setting. 10 male subjects (26+/-years old), participated in this study and were asked to come for 2 consecutive days. On the first day the experiment objective, tasks, and experiment setting was explained. Then, they completed a 30 minutes guided training. On the second day each subject was tested in 3 different modalities: Auditory Feedback only control (AF), Visual Feedback only control (VF), and Audiovisual Feedback control (AVF). For each modality they were asked to perform 10 trials. At the end of each test, the subject had to answer the NASA TLX questionnaire. Also, during the test the subject's EEG, ECG, electro-dermal activity (EDA), and respiration rate were measured. The results show that a higher mental effort is needed when the subjects rely only on their vision, and that this effort seems to be reduced when auditory feedback is added to the human-machine interaction (multimodal feedback). Furthermore, better temporal performance and better grasping performance was obtained in the audiovisual modality. The performance improvements when using auditory cues, along with vision (multimodal feedback), can be attributed to a reduced attentional demand during the task, which can be attributed to a visual "pop-out" or enhance effect. Also, the NASA TLX, the EEG's Alpha and Beta band, and the Heart Rate could be used to further evaluate sensory feedback systems in prosthetic applications.

Major lower limb amputations in the Marshall Islands: incidence, prosthetic prescription, and prosthetic use after 6-18 months.

PubMed

Harding, Katherine

2005-03-01

The Republic of the Marshall Islands has been recognised anecdotally to have high rates of major lower limb amputations secondary to diabetes. During 2001, a prosthetics service was introduced as part of the rehabilitation service at Majuro Hospital. 1. To determine the incidence of major lower limb amputations over a one year period from 2002 to 2003. 2. To evaluate the proportion of patients suitable for prosthetic fitting. 3. Determine survival rates and usage of prostheses six to eighteen months after prosthetic fitting. Amputation rates were established through review of the surgical logs at the two hospitals in the Marshall Islands. Prosthetic fitting rates were determined using records from Majuro hospital rehabilitation service. Follow up interviews were conducted with fifteen surviving patients who received prostheses during the study period, to investigate prosthetic use. The incidence of major lower limb amputation was found to be 79.5 per 100,000 population, with all forty-five amputations being associated with diabetes. Just over a third of these patients were discharged from rehabilitation with a prosthesis. Fifteen of the patients were followed up post discharge. All of the thirteen with transtibial amputations were found to be using their prosthesis at least some of the day. The two patients with transfemoral amputations had ceased to walk with their prosthesis. This study identified a very high rate of lower limb amputation in the Marshall Islands by world standards. Prosthetic fitting rates and follow up results were comparable to those reported by others, and indicate that small, geographically isolated island nations such as the Marshall Islands are able to provide a successful prosthetics and rehabilitation service locally.

A quasi-dynamic nonlinear finite element model to investigate prosthetic interface stresses during walking for trans-tibial amputees.

PubMed

Jia, Xiaohong; Zhang, Ming; Li, Xiaobing; Lee, Winson C C

2005-07-01

To predict the interface pressure between residual limb and prosthetic socket for trans-tibial amputees during walking. A quasi-dynamic finite element model was built based on the actual geometry of residual limb, internal bones and socket liner. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. Besides variable external loads and material inertia, the coupling between the large rigid displacement of knee joint and small elastic deformation of residual limb and prosthetic components were also considered. Interface pressure distribution was found to have the same profile during walking. The high pressures fall over popliteal depression, middle patella tendon, lateral tibia and medial tibia regions. Interface pressure predicted by static or quasi-dynamic analysis had the similar double-peaked waveform shape in stance phase. The consideration of inertial effects and motion of knee joint cause 210% average variation of the area between the pressure curve and the horizontal line of pressure threshold between two cases, even though there is only a small change in the peak pressure. The findings in this paper show that the coupling dynamic effects of inertial loads and knee flexion must be considered to study interface pressure between residual limb and prosthetic socket during walking.

Diagnosis of the prosthetic heart valve pannus formation with real-time three-dimensional transoesophageal echocardiography.

PubMed

Ozkan, Mehmet; Gündüz, Sabahattin; Yildiz, Mustafa; Duran, Nilüfer Eksi

2010-05-01

Prosthetic heart valve obstruction (PHVO) caused by pannus formation is an uncommon but serious complication. Although two-dimensional transesophageal echocardiography (2D-TEE) is the method of choice in the evaluation of PHVO, visualization of pannus is almost impossible with 2D-TEE. While demonstrating the precise aetiology of PHVO is essential for guiding the therapy, either thrombolysis for valve thrombosis or surgery for pannus formation, more sophisticated imaging techniques are needed in patients with suspected pannus formation. We present real-time 3D-TEE imaging in a patient with mechanical mitral PHVO, clearly demonstrating pannus overgrowth.

First-in-Man Demonstration of Fully Implanted Myoelectric Sensors for Control of an Advanced Electromechanical Arm by Transradial Amputees

PubMed Central

Pasquina, Paul F.; Evangelista, Melissa; Carvalho, Antonio J.; Lockhart, Joseph; Griffin, Sarah; Nanos, George; McKay, Patricia; Hansen, Morten; Ipsen, Derek; Vandersea, James; Butkus, Josef; Miller, Matthew; Murphy, Ian; Hankin, David

2014-01-01

Background Advanced motorized prosthetic devices are currently controlled by EMG signals generated by residual muscles and recorded by surface electrodes on the skin. These surface recordings are often inconsistent and unreliable, leading to high prosthetic abandonment rates for individuals with upper limb amputation. Surface electrodes are limited because of poor skin contact, socket rotation, residual limb sweating, and their ability to only record signals from superficial muscles, whose function frequently does not relate to the intended prosthetic function. More sophisticated prosthetic devices require a stable and reliable interface between the user and robotic hand to improve upper limb prosthetic function. New Method Implantable Myoelectric Sensors (IMES®) are small electrodes intended to detect and wirelessly transmit EMG signals to an electromechanical prosthetic hand via an electromagnetic coil built into the prosthetic socket. This system is designed to simultaneously capture EMG signals from multiple residual limb muscles, allowing the natural control of multiple degrees of freedom simultaneously. Results We report the status of the first FDA-approved clinical trial of the IMES® System. This study is currently in progress, limiting reporting to only preliminary results. Comparison with Existing Methods Our first subject has reported the ability to accomplish a greater variety and complexity of tasks in his everyday life compared to what could be achieved with his previous myoelectric prosthesis. Conclusion The interim results of this study indicate the feasibility of utilizing IMES® technology to reliably sense and wirelessly transmit EMG signals from residual muscles to intuitively control a three degree-of-freedom prosthetic arm. PMID:25102286

User surveys support designing a prosthetic wrist that incorporates the Dart Thrower's Motion.

PubMed

Davidson, Matthew; Bodine, Cathy; Weir, Richard F Ff

2018-03-07

Prosthetic devices are not meeting the needs of people with upper limb amputations. Due to controlsidelimitations, prosthetic wrists cannot yet be fully articulated. This study sought to determine which wrist motions users felt were most important for completing activities of daily living. We specifically invstigated whether adding a combinationof flexion and deviation known as the Dart Thrower's Motion to a prosthetic wrist would help improve functionality. Fifteen participants with a trans-radial amputation, aged 25-64 years, who use a prosthesis completed an online survey and answered interview questions to determine which types of tasks pose particular challenges. Participants were asked what kinds of improvements they would like to see in a new prosthesis. A subset of five participants were interviewed in-depth to provide further information about difficulties they face using their device. The survey showed that participants had difficulty performing activities of daily living that involve a combination of wrist flexion and deviation known as the "Dart Throwers Motion". Interview responses confirmed that users have difficulty performing these tasks, especially those that require tools. Additionally, users said that they were more interested in having flexion and deviation than rotation in a prosthetic wrist. This research indicates that including the Dart Thrower's Motion in future designs of prosthetic wrists would improve these devices and people with upper limb amputations would be excited to see this improvement in their devices. Implications for Rehabilitation • Over one third of people with upper limb amputations do not use a prosthesis because prosthetic devices do not meet their needs.• The number of motions possible in state of the art prosthetic devices is limited by the small number of control sites available.• The Dart Thrower?s Motion is a wrist motion used for many activities of daily living but unavailable in commercial prosthetics leading many prosthetics users to have difficulty with these tasks.• Prosthetic use, and therefore quality of life, could be improved by including the Dart Thrower's Motion in a prosthesis.

Sensory feedback add-on for upper-limb prostheses.

PubMed

Fallahian, Nader; Saeedi, Hassan; Mokhtarinia, Hamidreza; Tabatabai Ghomshe, Farhad

2017-06-01

Sensory feedback systems have been of great interest in upper-limb prosthetics. Despite tremendous research, there are no commercial modality-matched feedback systems. This article aims to introduce the first detachable and feedback add-on option that can be attached to in-use prostheses. A sensory feedback system was tested on a below-elbow myoelectric prosthesis. The aim was to have the amputee grasp fragile objects without crushing while other accidental feedback sources were blocked. A total of 8 successful trials (out of 10) showed that sensory feedback system decreased the amputee's visual dependency by improving awareness of his prosthesis. Sensory feedback system can be used either as post-fabrication (prosthetic add-on option) or para-fabrication (incorporated into prosthetic design). The use of these direct feedback systems can be explored with a current prosthesis before ordering new high-tech prosthesis. Clinical relevance This technical note introduces the first attach/detach-able sensory feedback system that can simply be added to in-use (myo)electric prosthesis, with no obligation to change prosthesis design or components.

[An attempt to use ultrasonic technique for confirming the diagnosis, planning and observation of long-term treatment results of painful temporo-mandibular joint dysfunction].

PubMed

Ey-Chmielewska, H

1998-01-01

The author presents an attempt of using ultrasonographic technique in diagnosis, planning and observation of treatment results of temporo-mandibular joint pain dysfunctions. Temporo-mandibular joint pain dysfunctions are interchangeably also called temporo-mandibular joint functional disorders. The assessment of pain symptoms in temporo-mandibular joint dysfunctions pain symptoms is principally based on a subjective estimation by the examining practitioner. There is no univocal definition of the disease or a simple index evidencing important symptoms in decision making. Additionally X-ray technique examinations, being hitherto used, in early stages of the disorder do not allow to diagnose it, and are also burdensome to a patient. The aim of this study was to confirm visibility of anatomical elements of the temporo-mandibular joint in an ultrasound examination, assess the mobility of the articular disc before, during and after prosthetic treatment with and without the use of ultrasound technique, and to determine the period of time necessary to obtain a therapeutic effect. The study material consisted of 180 patients, 128 women and 52 men, aged 20 to 60 years, treated by applying prostheses because of temporo-mandibular joint pain dysfunction, in the Department of Prosthetic Dentistry of the Pomeranian Medical Academy. The patients were divided into 2 groups, control and study group. The control group consisted of 90 patients, 63 women and 27 men. In this group prosthetic treatment planning and observation of results was based on a subjective estimation of the practitioner. The study group here comprised 90 patients, 65 women and 25 men, aged 26 to 60 years. In this group prosthetic treatment planning and observation of treatment results were carried on with the use of ultrasound technique. Data from both groups concerning history, results of examinations carried out by ultrasound technique, and the assessment of ultrasound examination were noted on standard examination records used in the Department of Prosthetic Dentistry. For the need of this study an own ultrasound technique was elaborated which allowed for analyzing the ultrasound image in a static situation and during functioning. The ultrasound examination was accomplished with the use of Acuson 128 XP apparatus, linear probe 7.5 MHz. In both groups prosthetic treatment was carried out using different prosthetic methods such as: splints, occlusal adjustment on fixed prosthetic restorations in therapeutical occulus et height in abnormal occlusion. In the study group the therapeutical occulus height was determined under the control of ultrasound technique. Statistical analysis of the obtained results was performed with the use of chi-square test and chi-square test with Yates correction. On the basis of the accomplished study it has been determined that the ultrasound technique makes it possible to visualize morphological elements and facilitates functional observation of the temporo-mandibular joint, articular disc, mandibular condyle and lateral pterygoid muscle in a degree which allows for planning the treatment and the observation of results (Tab. 1-6). The use of ultrasound technique in determining spatial position of the mandible in temporo-mandibular joint permitted to objectively estimate examination results in the study group. A small number of publications on the use of ultrasound technique in functional examination of the temporo-mandibular joint accessible in foreign literature and general reference on the subject in Polish literature do not allow for an objective comparison of obtained study results.

Art Practice as Prosthetic Visuality

ERIC Educational Resources Information Center

Garoian, Charles R.

2010-01-01

In this lecture I explore and conceptualize the anomalous spaces of perception and memory in art practice and research where experimental and alternative discourses and pedagogies can emerge. I argue that the instabilities and slippages between what is visible and invisible, known and unknown, in these spaces enable insightful and multivalent ways…

Transposed brachial-basilic arteriovenous fistulas versus prosthetic upper limb grafts: a meta-analysis.

PubMed

Lazarides, M K; Georgiadis, G S; Papasideris, C P; Trellopoulos, G; Tzilalis, V D

2008-11-01

Controversy exists regarding the best type of arteriovenous (AV) fistula to be formed in secondary and tertiary access procedures when primary fistulas have failed. This meta-analysis aimed to compare transposed brachial-basilic AV fistulas (BBAVFs) with upper limb AV prosthetic grafts. A literature search of the MEDLINE and SCOPUS databases was performed to identify comparative studies reporting outcomes for both BBAVFs with upper limb AV prosthetic grafts. Meta-analysis techniques were applied to identify differences in outcomes between the two groups regarding primary and secondary 1-year failure rates. Eleven relevant studies, involving 1509 patients, met the inclusion criteria and were incorporated in the final analysis; however, only one was randomised controlled trial. The pooled odds' ratio (OR) estimate for the primary and secondary failure rates at 1 year was 0.67 (CI 0.41-1.09) and 0.88 (CI 0.69-1.12), respectively, showing no difference in the outcome between the two groups. The re-intervention rate was higher for prosthetic grafts (0.54 per BBAVF versus 1.32 per graft). In a small subgroup of two studies comparing BBAVFs with forearm grafts the pooled estimate for 1-year primary failure rate was in favour of the BBAVF group (OR 0.3, CI 0.15-0.58, p=0.0004) suggesting that forearm grafts were inferior having a 3-fold risk of failure at 1 year. This analysis supports the use of BBAVF early in difficult access cases prior to the use of prosthetic grafts. However, the latter conclusion is debatable due to heterogeneity, small size and non-randomised design of the included studies.

Smartphones as image processing systems for prosthetic vision.

PubMed

Zapf, Marc P; Matteucci, Paul B; Lovell, Nigel H; Suaning, Gregg J

2013-01-01

The feasibility of implants for prosthetic vision has been demonstrated by research and commercial organizations. In most devices, an essential forerunner to the internal stimulation circuit is an external electronics solution for capturing, processing and relaying image information as well as extracting useful features from the scene surrounding the patient. The capabilities and multitude of image processing algorithms that can be performed by the device in real-time plays a major part in the final quality of the prosthetic vision. It is therefore optimal to use powerful hardware yet to avoid bulky, straining solutions. Recent publications have reported of portable single-board computers fast enough for computationally intensive image processing. Following the rapid evolution of commercial, ultra-portable ARM (Advanced RISC machine) mobile devices, the authors investigated the feasibility of modern smartphones running complex face detection as external processing devices for vision implants. The role of dedicated graphics processors in speeding up computation was evaluated while performing a demanding noise reduction algorithm (image denoising). The time required for face detection was found to decrease by 95% from 2.5 year old to recent devices. In denoising, graphics acceleration played a major role, speeding up denoising by a factor of 18. These results demonstrate that the technology has matured sufficiently to be considered as a valid external electronics platform for visual prosthetic research.

Visualization of small lesions in rat cartilage by means of laboratory-based x-ray phase contrast imaging

NASA Astrophysics Data System (ADS)

Marenzana, Massimo; Hagen, Charlotte K.; Das Neves Borges, Patricia; Endrizzi, Marco; Szafraniec, Magdalena B.; Ignatyev, Konstantin; Olivo, Alessandro

2012-12-01

Being able to quantitatively assess articular cartilage in three-dimensions (3D) in small rodent animal models, with a simple laboratory set-up, would prove extremely important for the development of pre-clinical research focusing on cartilage pathologies such as osteoarthritis (OA). These models are becoming essential tools for the development of new drugs for OA, a disease affecting up to 1/3 of the population older than 50 years for which there is no cure except prosthetic surgery. However, due to limitations in imaging technology, high-throughput 3D structural imaging has not been achievable in small rodent models, thereby limiting their translational potential and their efficiency as research tools. We show that a simple laboratory system based on coded-aperture x-ray phase contrast imaging (CAXPCi) can correctly visualize the cartilage layer in slices of an excised rat tibia imaged both in air and in saline solution. Moreover, we show that small, surgically induced lesions are also correctly detected by the CAXPCi system, and we support this finding with histopathology examination. Following these successful proof-of-concept results in rat cartilage, we expect that an upgrade of the system to higher resolutions (currently underway) will enable extending the method to the imaging of mouse cartilage as well. From a technological standpoint, by showing the capability of the system to detect cartilage also in water, we demonstrate phase sensitivity comparable to other lab-based phase methods (e.g. grating interferometry). In conclusion, CAXPCi holds a strong potential for being adopted as a routine laboratory tool for non-destructive, high throughput assessment of 3D structural changes in murine articular cartilage, with a possible impact in the field similar to the revolution that conventional microCT brought into bone research.

Closed-loop control of grasping with a myoelectric hand prosthesis: which are the relevant feedback variables for force control?

PubMed

Ninu, Andrei; Dosen, Strahinja; Muceli, Silvia; Rattay, Frank; Dietl, Hans; Farina, Dario

2014-09-01

In closed-loop control of grasping by hand prostheses, the feedback information sent to the user is usually the actual controlled variable, i.e., the grasp force. Although this choice is intuitive and logical, the force production is only the last step in the process of grasping. Therefore, this study evaluated the performance in controlling grasp strength using a hand prosthesis operated through a complete grasping sequence while varying the feedback variables (e.g., closing velocity, grasping force), which were provided to the user visually or through vibrotactile stimulation. The experiments were conducted on 13 volunteers who controlled the Otto Bock Sensor Hand Speed prosthesis. Results showed that vibrotactile patterns were able to replace the visual feedback. Interestingly, the experiments demonstrated that direct force feedback was not essential for the control of grasping force. The subjects were indeed able to control the grip strength, predictively, by estimating the grasping force from the prosthesis velocity of closing. Therefore, grasping without explicit force feedback is not completely blind, contrary to what is usually assumed. In our study we analyzed grasping with a specific prosthetic device, but the outcomes are also applicable for other devices, with one or more degrees-of-freedom. The necessary condition is that the electromyography (EMG) signal directly and proportionally controls the velocity/grasp force of the hand, which is a common approach among EMG controlled prosthetic devices. The results provide important indications on the design of closed-loop EMG controlled prosthetic systems.

Psycho-physiological assessment of a prosthetic hand sensory feedback system based on an auditory display: a preliminary study

PubMed Central

2012-01-01

Background Prosthetic hand users have to rely extensively on visual feedback, which seems to lead to a high conscious burden for the users, in order to manipulate their prosthetic devices. Indirect methods (electro-cutaneous, vibrotactile, auditory cues) have been used to convey information from the artificial limb to the amputee, but the usability and advantages of these feedback methods were explored mainly by looking at the performance results, not taking into account measurements of the user’s mental effort, attention, and emotions. The main objective of this study was to explore the feasibility of using psycho-physiological measurements to assess cognitive effort when manipulating a robot hand with and without the usage of a sensory substitution system based on auditory feedback, and how these psycho-physiological recordings relate to temporal and grasping performance in a static setting. Methods 10 male subjects (26+/-years old), participated in this study and were asked to come for 2 consecutive days. On the first day the experiment objective, tasks, and experiment setting was explained. Then, they completed a 30 minutes guided training. On the second day each subject was tested in 3 different modalities: Auditory Feedback only control (AF), Visual Feedback only control (VF), and Audiovisual Feedback control (AVF). For each modality they were asked to perform 10 trials. At the end of each test, the subject had to answer the NASA TLX questionnaire. Also, during the test the subject’s EEG, ECG, electro-dermal activity (EDA), and respiration rate were measured. Results The results show that a higher mental effort is needed when the subjects rely only on their vision, and that this effort seems to be reduced when auditory feedback is added to the human-machine interaction (multimodal feedback). Furthermore, better temporal performance and better grasping performance was obtained in the audiovisual modality. Conclusions The performance improvements when using auditory cues, along with vision (multimodal feedback), can be attributed to a reduced attentional demand during the task, which can be attributed to a visual “pop-out” or enhance effect. Also, the NASA TLX, the EEG’s Alpha and Beta band, and the Heart Rate could be used to further evaluate sensory feedback systems in prosthetic applications. PMID:22682425

75 FR 1835 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-13

.... John E. Cain Mr. Cain, 59, has a retinal detachment in his left eye due to a traumatic injury sustained... CMV. Curtis J. Crowston Mr. Crowston, 44, has a prosthetic left eye due to a traumatic injury... to a traumatic injury sustained during childhood. The best corrected visual acuity in his left eye is...

Changes in ganglion cell physiology during retinal degeneration influence excitability by prosthetic electrodes

NASA Astrophysics Data System (ADS)

Cho, Alice; Ratliff, Charles; Sampath, Alapakkam; Weiland, James

2016-04-01

Objective. Here we investigate ganglion cell physiology in healthy and degenerating retina to test its influence on threshold to electrical stimulation. Approach. Age-related Macular Degeneration and Retinitis Pigmentosa cause blindness via outer retinal degeneration. Inner retinal pathways that transmit visual information to the central brain remain intact, so direct electrical stimulation from prosthetic devices offers the possibility for visual restoration. Since inner retinal physiology changes during degeneration, we characterize physiological properties and responses to electrical stimulation in retinal ganglion cells (RGCs) of both wild type mice and the rd10 mouse model of retinal degeneration. Main results. Our aggregate results support previous observations that elevated thresholds characterize diseased retinas. However, a physiology-driven classification scheme reveals distinct sub-populations of ganglion cells with thresholds either normal or strongly elevated compared to wild-type. When these populations are combined, only a weakly elevated threshold with large variance is observed. The cells with normal threshold are more depolarized at rest and exhibit periodic oscillations. Significance. During degeneration, physiological changes in RGCs affect the threshold stimulation currents required to evoke action potentials.

Emergence of a Stable Cortical Map for Neuroprosthetic Control

PubMed Central

Ganguly, Karunesh; Carmena, Jose M.

2009-01-01

Cortical control of neuroprosthetic devices is known to require neuronal adaptations. It remains unclear whether a stable cortical representation for prosthetic function can be stored and recalled in a manner that mimics our natural recall of motor skills. Especially in light of the mixed evidence for a stationary neuron-behavior relationship in cortical motor areas, understanding this relationship during long-term neuroprosthetic control can elucidate principles of neural plasticity as well as improve prosthetic function. Here, we paired stable recordings from ensembles of primary motor cortex neurons in macaque monkeys with a constant decoder that transforms neural activity to prosthetic movements. Proficient control was closely linked to the emergence of a surprisingly stable pattern of ensemble activity, indicating that the motor cortex can consolidate a neural representation for prosthetic control in the presence of a constant decoder. The importance of such a cortical map was evident in that small perturbations to either the size of the neural ensemble or to the decoder could reversibly disrupt function. Moreover, once a cortical map became consolidated, a second map could be learned and stored. Thus, long-term use of a neuroprosthetic device is associated with the formation of a cortical map for prosthetic function that is stable across time, readily recalled, resistant to interference, and resembles a putative memory engram. PMID:19621062

Vestibular ablation and a semicircular canal prosthesis affect postural stability during head turns

PubMed Central

Thompson, Lara A.; Haburcakova, Csilla; Lewis, Richard F.

2016-01-01

In our study, we examined postural stability during head turns for two rhesus monkeys: one, single animal study contrasted normal and mild bilateral vestibular ablation and a second animal study contrasted severe bilateral vestibular ablation with and without prosthetic stimulation. The monkeys freely stood, unrestrained on a balance platform and made voluntary head turns between visual targets. To quantify each animals’ posture, motions of the head and trunk, as well as torque about the body’s center-of-mass, were measured. In the mildly ablated animal, we observed less foretrunk sway in comparison to the normal state. When the canal prosthesis provided electric stimulation to the severely ablated animal, it showed a decrease in trunk sway during head turns. Because the rhesus monkey with severe bilateral vestibular loss exhibited a decrease in trunk sway when receiving vestibular prosthetic stimulation, we propose that the prosthetic electrical stimulation partially restored head velocity information. Our results provide an indication that a semicircular canal prosthesis may be an effective way to improve postural stability in patients with severe peripheral vestibular dysfunction. PMID:27405997

Immediate effects of a new microprocessor-controlled prosthetic knee joint: a comparative biomechanical evaluation.

PubMed

Bellmann, Malte; Schmalz, Thomas; Ludwigs, Eva; Blumentritt, Siegmar

2012-03-01

To investigate the immediate biomechanical effects after transition to a new microprocessor-controlled prosthetic knee joint. Intervention cross-over study with repeated measures. Only prosthetic knee joints were changed. Motion analysis laboratory. Men (N=11; mean age ± SD, 36.7±10.2y; Medicare functional classification level, 3-4) with unilateral transfemoral amputation. Two microprocessor-controlled prosthetic knee joints: C-Leg and a new prosthetic knee joint, Genium. Static prosthetic alignment, time-distance parameters, kinematic and kinetic parameters, and center of pressure. After a half-day training and an additional half-day accommodation, improved biomechanical outcomes were demonstrated by the Genium: lower ground reaction forces at weight acceptance during level walking at various velocities, increased swing phase flexion angles during walking on a ramp, and level walking with small steps. Maximum knee flexion angle during swing phase at various velocities was nearly equal for Genium. Step-over-step stair ascent with the Genium knee was more physiologic as demonstrated by a more equal load distribution between the prosthetic and contralateral sides and a more natural gait pattern. When descending stairs and ramps, knee flexion moments with the Genium tended to increase. During quiet stance on a decline, subjects using Genium accepted higher loading of the prosthetic side knee joint, thus reducing same side hip joint loading as well as postural sway. In comparision to the C-Leg, the Genium demonstrated immediate biomechanical advantages during various daily ambulatory activities, which may lead to an increase in range and diversity of activity of people with above-knee amputations. Results showed that use of the Genium facilitated more natural gait biomechanics and load distribution throughout the affected and sound musculoskeletal structure. This was observed during quiet stance on a decline, walking on level ground, and walking up and down ramps and stairs. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

77 FR 27847 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-11

... vision in his right eye due to a traumatic injury sustained at age 14. The best corrected visual acuity... CMV. John C. Smith Mr. Smith, 54, has a prosthetic right eye due to a traumatic injury sustained in... CMV. John F. Lynch Mr. Lynch, 35, has complete loss of vision in his left eye due to a traumatic...

A dynamic model-based approach to motion and deformation tracking of prosthetic valves from biplane x-ray images.

PubMed

Wagner, Martin G; Hatt, Charles R; Dunkerley, David A P; Bodart, Lindsay E; Raval, Amish N; Speidel, Michael A

2018-04-16

Transcatheter aortic valve replacement (TAVR) is a minimally invasive procedure in which a prosthetic heart valve is placed and expanded within a defective aortic valve. The device placement is commonly performed using two-dimensional (2D) fluoroscopic imaging. Within this work, we propose a novel technique to track the motion and deformation of the prosthetic valve in three dimensions based on biplane fluoroscopic image sequences. The tracking approach uses a parameterized point cloud model of the valve stent which can undergo rigid three-dimensional (3D) transformation and different modes of expansion. Rigid elements of the model are individually rotated and translated in three dimensions to approximate the motions of the stent. Tracking is performed using an iterative 2D-3D registration procedure which estimates the model parameters by minimizing the mean-squared image values at the positions of the forward-projected model points. Additionally, an initialization technique is proposed, which locates clusters of salient features to determine the initial position and orientation of the model. The proposed algorithms were evaluated based on simulations using a digital 4D CT phantom as well as experimentally acquired images of a prosthetic valve inside a chest phantom with anatomical background features. The target registration error was 0.12 ± 0.04 mm in the simulations and 0.64 ± 0.09 mm in the experimental data. The proposed algorithm could be used to generate 3D visualization of the prosthetic valve from two projections. In combination with soft-tissue sensitive-imaging techniques like transesophageal echocardiography, this technique could enable 3D image guidance during TAVR procedures. © 2018 American Association of Physicists in Medicine.

Prosthetic aspects and patient satisfaction with resilient liner and clip attachments for bar- and implant-retained mandibular overdentures: a 3-year randomized clinical study.

PubMed

ELsyad, Moustafa Abdou

2012-01-01

This report aimed to compare prosthetic aspects and patient satisfaction during a 3-year randomized clinical trial of bar- and implant-retained mandibular overdentures attached with either resilient liners or clips. Thirty edentulous male patients (mean age: 62.5 years) received two implants in the anterior mandible after being allocated into two equal groups (according to attachment type received) using balanced randomization. After 3 months, implants were connected with resilient bars. New maxillary complete dentures were then constructed, and mandibular overdentures were retained to the bars with either clips (group I) or silicone resilient liners (group II). Subjects indicated satisfaction with their prostheses using a questionnaire and visual analog scale. Patient satisfaction and prosthetic complications were recorded for both attachments at 6 months and 1 and 3 years after overdenture insertion. Comfort and stability with the maxillary denture and ease of hygiene procedures were rated higher in group II, while ease of handling the dentures was rated higher in group I. No significant differences in other parameters of patient satisfaction between groups were noted after 3 years. The mean number of prosthetic adjustments and repairs in group I (11.9) was significantly higher (P = .00) compared to that in group II (4.8). The most common complication in group I was clip wear, while separation of the resilient liner from the denture base was the most common problem in group II. Hyperplasia under the bar and flabby ridge in the maxilla occurred significantly more often in group I compared to group II. Resilient liner-retained mandibular overdentures had comparable patient satisfaction, less prosthetic maintenance and costs, and less soft tissue complications when compared to clip-retained ones after 3 years.

Retinal Prosthetics, Optogenetics, and Chemical Photoswitches

PubMed Central

2015-01-01

Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral delivery of type 1 opsin genes from prokaryotes or eukaryote algae to restore light responses in survivor neurons. Targeting and expression remain major problems, but are potentially soluble. Importantly, optogenetics could provide the ultimate in high-resolution vision due to the long persistence of gene expression achieved in animal models. Nevertheless, optogenetics remains challenging to implement in human eyes with large volumes, complex disease progression, and physical barriers to viral penetration. Now, a new generation of photochromic ligands or chemical photoswitches (azobenzene-quaternary ammonium derivatives) can be injected into a degenerated mouse eye and, in minutes to hours, activate light responses in neurons. These photoswitches offer the potential for rapidly and reversibly screening the vision restoration expected in an individual patient. Chemical photoswitch variants that persist in the cell membrane could make them a simple therapy of choice, with resolution and sensitivity equivalent to optogenetics approaches. A major complexity in treating retinal degenerations is retinal remodeling: pathologic network rewiring, molecular reprogramming, and cell death that compromise signaling in the surviving retina. Remodeling forces a choice between upstream and downstream targeting, each engaging different benefits and defects. Prosthetics and optogenetics can be implemented in either mode, but the use of chemical photoswitches is currently limited to downstream implementations. Even so, given the high density of human foveal ganglion cells, the ultimate chemical photoswitch treatment could deliver cost-effective, high-resolution vision for the blind. PMID:25089879

Design of a high-resolution optoelectronic retinal prosthesis.

PubMed

Palanker, Daniel; Vankov, Alexander; Huie, Phil; Baccus, Stephen

2005-03-01

It has been demonstrated that electrical stimulation of the retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. However, current retinal implants provide very low resolution (just a few electrodes), whereas at least several thousand pixels would be required for functional restoration of sight. This paper presents the design of an optoelectronic retinal prosthetic system with a stimulating pixel density of up to 2500 pix mm(-2) (corresponding geometrically to a maximum visual acuity of 20/80). Requirements on proximity of neural cells to the stimulation electrodes are described as a function of the desired resolution. Two basic geometries of sub-retinal implants providing required proximity are presented: perforated membranes and protruding electrode arrays. To provide for natural eye scanning of the scene, rather than scanning with a head-mounted camera, the system operates similar to 'virtual reality' devices. An image from a video camera is projected by a goggle-mounted collimated infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. The goggles are transparent to visible light, thus allowing for the simultaneous use of remaining natural vision along with prosthetic stimulation. Optical delivery of visual information to the implant allows for real-time image processing adjustable to retinal architecture, as well as flexible control of image processing algorithms and stimulation parameters.

Design of a high-resolution optoelectronic retinal prosthesis

NASA Astrophysics Data System (ADS)

Palanker, Daniel; Vankov, Alexander; Huie, Phil; Baccus, Stephen

2005-03-01

It has been demonstrated that electrical stimulation of the retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. However, current retinal implants provide very low resolution (just a few electrodes), whereas at least several thousand pixels would be required for functional restoration of sight. This paper presents the design of an optoelectronic retinal prosthetic system with a stimulating pixel density of up to 2500 pix mm-2 (corresponding geometrically to a maximum visual acuity of 20/80). Requirements on proximity of neural cells to the stimulation electrodes are described as a function of the desired resolution. Two basic geometries of sub-retinal implants providing required proximity are presented: perforated membranes and protruding electrode arrays. To provide for natural eye scanning of the scene, rather than scanning with a head-mounted camera, the system operates similar to 'virtual reality' devices. An image from a video camera is projected by a goggle-mounted collimated infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. The goggles are transparent to visible light, thus allowing for the simultaneous use of remaining natural vision along with prosthetic stimulation. Optical delivery of visual information to the implant allows for real-time image processing adjustable to retinal architecture, as well as flexible control of image processing algorithms and stimulation parameters.

42 CFR 414.402 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... certified by either the American Board for Certification in Orthotics and Prosthetics, Inc., or the Board... bidding area. Network means a group of small suppliers that form a legal entity to provide competitively...

42 CFR 414.402 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... certified by either the American Board for Certification in Orthotics and Prosthetics, Inc., or the Board... bidding area. Network means a group of small suppliers that form a legal entity to provide competitively...

Image Processing Strategies Based on a Visual Saliency Model for Object Recognition Under Simulated Prosthetic Vision.

PubMed

Wang, Jing; Li, Heng; Fu, Weizhen; Chen, Yao; Li, Liming; Lyu, Qing; Han, Tingting; Chai, Xinyu

2016-01-01

Retinal prostheses have the potential to restore partial vision. Object recognition in scenes of daily life is one of the essential tasks for implant wearers. Still limited by the low-resolution visual percepts provided by retinal prostheses, it is important to investigate and apply image processing methods to convey more useful visual information to the wearers. We proposed two image processing strategies based on Itti's visual saliency map, region of interest (ROI) extraction, and image segmentation. Itti's saliency model generated a saliency map from the original image, in which salient regions were grouped into ROI by the fuzzy c-means clustering. Then Grabcut generated a proto-object from the ROI labeled image which was recombined with background and enhanced in two ways--8-4 separated pixelization (8-4 SP) and background edge extraction (BEE). Results showed that both 8-4 SP and BEE had significantly higher recognition accuracy in comparison with direct pixelization (DP). Each saliency-based image processing strategy was subject to the performance of image segmentation. Under good and perfect segmentation conditions, BEE and 8-4 SP obtained noticeably higher recognition accuracy than DP, and under bad segmentation condition, only BEE boosted the performance. The application of saliency-based image processing strategies was verified to be beneficial to object recognition in daily scenes under simulated prosthetic vision. They are hoped to help the development of the image processing module for future retinal prostheses, and thus provide more benefit for the patients. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Photovoltaic restoration of sight with high visual acuity

PubMed Central

Lorach, Henri; Goetz, Georges; Smith, Richard; Lei, Xin; Mandel, Yossi; Kamins, Theodore; Mathieson, Keith; Huie, Philip; Harris, James; Sher, Alexander; Palanker, Daniel

2015-01-01

Patients with retinal degeneration lose sight due to gradual demise of photoreceptors. Electrical stimulation of the surviving retinal neurons provides an alternative route for delivery of visual information. We demonstrate that subretinal arrays with 70 μm photovoltaic pixels provide highly localized stimulation, with electrical and visual receptive fields of comparable sizes in rat retinal ganglion cells. Similarly to normal vision, retinal response to prosthetic stimulation exhibits flicker fusion at high frequencies, adaptation to static images and non-linear spatial summation. In rats with retinal degeneration, these photovoltaic arrays provide spatial resolution of 64 ± 11 μm, corresponding to half of the normal visual acuity in pigmented rats. Ease of implantation of these wireless and modular arrays, combined with their high resolution opens the door to functional restoration of sight. PMID:25915832

Cerebral venous hypertension and blindness: a reversible complication.

PubMed

Cuadra, Salvador A; Padberg, Frank T; Turbin, Roger E; Farkas, Jeffrey; Frohman, Larry P

2005-10-01

A 57-year-old woman developed blindness during treatment for sarcoidosis-induced end-stage renal disease. An initial renal transplantation failed, and hemoaccess was maintained with multiple central catheters and upper extremity prosthetic arteriovenous grafts. A successful second transplantation eliminated her need for hemodialysis, but a right brachial to internal jugular graft remained patent. Progressive visual loss 2 years after transplantation prompted ophthalmic evaluation which initially revealed unilateral left optic nerve edema and visual loss, ultimately worsening over several months to no light perception in the left eye, 20/60 vision in the right eye, and bilateral papilledema. Arteriography demonstrated cerebral venous hypertension attributed to the functioning hemoaccess graft. Permanent graft occlusion normalized the papilledema, and visual field defects in the right eye and visual acuity returned to 20/20 in the right eye.

Development of a Prototype Over-Actuated Biomimetic Prosthetic Hand

PubMed Central

Williams, Matthew R.; Walter, Wayne

2015-01-01

The loss of a hand can greatly affect quality of life. A prosthetic device that can mimic normal hand function is very important to physical and mental recuperation after hand amputation, but the currently available prosthetics do not fully meet the needs of the amputee community. Most prosthetic hands are not dexterous enough to grasp a variety of shaped objects, and those that are tend to be heavy, leading to discomfort while wearing the device. In order to attempt to better simulate human hand function, a dexterous hand was developed that uses an over-actuated mechanism to form grasp shape using intrinsic joint mounted motors in addition to a finger tendon to produce large flexion force for a tight grip. This novel actuation method allows the hand to use small actuators for grip shape formation, and the tendon to produce high grip strength. The hand was capable of producing fingertip flexion force suitable for most activities of daily living. In addition, it was able to produce a range of grasp shapes with natural, independent finger motion, and appearance similar to that of a human hand. The hand also had a mass distribution more similar to a natural forearm and hand compared to contemporary prosthetics due to the more proximal location of the heavier components of the system. This paper describes the design of the hand and controller, as well as the test results. PMID:25790306

Late complication of open inguinal hernia repair: small bowel obstruction caused by intraperitoneal mesh migration.

PubMed

Ferrone, Roberto; Scarone, Pier Carlo; Natalini, Gianni

2003-09-01

We describe a case of small bowel obstruction due to prosthetic mesh migration. A 67-year-old male, who had undergone prosthetic repair of inguinal hernia 3 years before, was admitted for a mechanical small bowel obstruction. Laparotomy revealed the penultimate ileal loop choked by an adhesion drawing it towards a polypropylene mesh, firmly attached to the parietal peritoneum of the inguinal region. The intestinal loop was released; the mesh was embedded deep with continuous whip suture after folding the parietal peritoneum. The patient was dismissed on the 11th postoperative day surgically healed. The "tension-free" technique is undoubtedly the gold standard for hernia repair. However, it is not free of complications, mostly due to technical errors, of which the surgeon must be aware, both when he is responsible for correcting defects in the wall, as well as when he has to face an occlusion in a patient who has undergone plastic surgery for inguinal hernia.

Evolution of penile prosthetic devices

PubMed Central

Burnett, Arthur L.

2015-01-01

Penile implant usage dates to the 16th century yet penile implants to treat erectile dysfunction did not occur until nearly four centuries later. The modern era of penile implants has progressed rapidly over the past 50 years as physicians' knowledge of effective materials for penile prostheses and surgical techniques has improved. Herein, we describe the history of penile prosthetics and the constant quest to improve the technology. Elements of the design from the first inflatable penile prosthesis by Scott and colleagues and the Small-Carrion malleable penile prosthesis are still found in present iterations of these devices. While there have been significant improvements in penile prosthesis design, the promise of an ideal prosthetic device remains elusive. As other erectile dysfunction therapies emerge, penile prostheses will have to continue to demonstrate a competitive advantage. A particular strength of penile prostheses is their efficacy regardless of etiology, thus allowing treatment of even the most refractory cases. PMID:25763121

Evolution of penile prosthetic devices.

PubMed

Le, Brian; Burnett, Arthur L

2015-03-01

Penile implant usage dates to the 16th century yet penile implants to treat erectile dysfunction did not occur until nearly four centuries later. The modern era of penile implants has progressed rapidly over the past 50 years as physicians' knowledge of effective materials for penile prostheses and surgical techniques has improved. Herein, we describe the history of penile prosthetics and the constant quest to improve the technology. Elements of the design from the first inflatable penile prosthesis by Scott and colleagues and the Small-Carrion malleable penile prosthesis are still found in present iterations of these devices. While there have been significant improvements in penile prosthesis design, the promise of an ideal prosthetic device remains elusive. As other erectile dysfunction therapies emerge, penile prostheses will have to continue to demonstrate a competitive advantage. A particular strength of penile prostheses is their efficacy regardless of etiology, thus allowing treatment of even the most refractory cases.

Towards an assistive peripheral visual prosthesis for long-term treatment of retinitis pigmentosa: evaluating mobility performance in immersive simulations

NASA Astrophysics Data System (ADS)

Zapf, Marc Patrick H.; Boon, Mei-Ying; Matteucci, Paul B.; Lovell, Nigel H.; Suaning, Gregg J.

2015-06-01

Objective. The prospective efficacy of a future peripheral retinal prosthesis complementing residual vision to raise mobility performance in non-end stage retinitis pigmentosa (RP) was evaluated using simulated prosthetic vision (SPV). Approach. Normally sighted volunteers were fitted with a wide-angle head-mounted display and carried out mobility tasks in photorealistic virtual pedestrian scenarios. Circumvention of low-lying obstacles, path following, and navigating around static and moving pedestrians were performed either with central simulated residual vision of 10° alone or enhanced by assistive SPV in the lower and lateral peripheral visual field (VF). Three layouts of assistive vision corresponding to hypothetical electrode array layouts were compared, emphasizing higher visual acuity, a wider visual angle, or eccentricity-dependent acuity across an intermediate angle. Movement speed, task time, distance walked and collisions with the environment were analysed as performance measures. Main results. Circumvention of low-lying obstacles was improved with all tested configurations of assistive SPV. Higher-acuity assistive vision allowed for greatest improvement in walking speeds—14% above that of plain residual vision, while only wide-angle and eccentricity-dependent vision significantly reduced the number of collisions—both by 21%. Navigating around pedestrians, there were significant reductions in collisions with static pedestrians by 33% and task time by 7.7% with the higher-acuity layout. Following a path, higher-acuity assistive vision increased walking speed by 9%, and decreased collisions with stationary cars by 18%. Significance. The ability of assistive peripheral prosthetic vision to improve mobility performance in persons with constricted VFs has been demonstrated. In a prospective peripheral visual prosthesis, electrode array designs need to be carefully tailored to the scope of tasks in which a device aims to assist. We posit that maximum benefit might come from application alongside existing visual aids, to further raise life quality of persons living through the prolonged early stages of RP.

Influence of parafunctional loading and prosthetic connection on stress distribution: a 3D finite element analysis.

PubMed

Torcato, Leonardo Bueno; Pellizzer, Eduardo Piza; Verri, Fellippo Ramos; Falcón-Antenucci, Rosse Mary; Santiago Júnior, Joel Ferreira; de Faria Almeida, Daniel Augusto

2015-11-01

Clinicians should consider parafunctional occlusal load when planning treatment. Prosthetic connections can reduce the stress distribution on an implant-supported prosthesis. The purpose of this 3-dimensional finite element study was to assess the influence of parafunctional loading and prosthetic connections on stress distribution. Computer-aided design software was used to construct 3 models. Each model was composed of a bone and an implant (external hexagon, internal hexagon, or Morse taper) with a crown. Finite element analysis software was used to generate the finite element mesh and establish the loading and boundary conditions. A normal force (200-N axial load and 100-N oblique load) and parafunctional force (1000-N axial and 500-N oblique load) were applied. Results were visualized as the maximum principal stress. Three-way analysis of variance and Tukey test were performed, and the percentage of contribution of each variable to the stress concentration was calculated from sum-of squares-analysis. Stress was concentrated around the implant at the cortical bone, and models with the external hexagonal implant showed the highest stresses (P<.001). Oblique loads produced high tensile stress concentrations on the site opposite the load direction. Internal connection implants presented the most favorable biomechanical situation, whereas the least favorable situation was the biomechanical behavior of external connection implants. Parafunctional loading increased the magnitude of stress by 3 to 4 times. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Prosthetic Joint Infection

PubMed Central

Tande, Aaron J.

2014-01-01

SUMMARY Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided. PMID:24696437

Qualifying CT for wrist arthroplasty: extending techniques for total hip arthroplasty to total wrist arthroplasty

NASA Astrophysics Data System (ADS)

Alcala, Yvonne; Olivecrona, Henrik; Olivecrona, Lotta; Noz, Marilyn E.; Maguire, Gerald Q., Jr.; Zeleznik, Michael P.; Sollerman, Christer

2005-04-01

The purpose of this study was to extend previous work to detect migration of total wrist arthroplasty non-invasively, and with greater accuracy. Two human cadaverous arms, each with a cemented total wrist implant, were used in this study. In one of the arms, 1 mm tantalum balls were implanted, six in the carpal bones and five in the radius. Five CT scans of each arm were acquired, changing the position of the arm each time to mimic different positions patients might take on repeated examinations. Registration of CT volume data sets was performed using an extensively validated, 3D semi-automatic volume fusion tool in which co-homologous point pairs (landmarks) are chosen on each volume to be registered. Three sets of ten cases each were obtained by placing landmarks on 1) bone only (using only arm one), 2) tantalum implants only, and 3) bone and tantalum implants (both using only arm two). The accuracy of the match was assessed visually in 2D and 3D, and numerically by calculating the distance difference between the actual position of the transformed landmarks and their ideal position (i.e., the reference landmark positions). All cases were matched visually within one width of cortical bone and numerically within one half CT voxel (0.32 mm, p = 0.05). This method matched only the bone/arm and not the prosthetic component per se, thus making it possible to detect prosthetic movement and wear. This method was clinically used for one patient with pain. Loosening of the carpal prosthetic component was accurately detected and this was confirmed at surgery.

Improvement of chronic corneal opacity in ocular surface disease with prosthetic replacement of the ocular surface ecosystem (PROSE) treatment.

PubMed

Cressey, Anna; Jacobs, Deborah S; Remington, Crystal; Carrasquillo, Karen G

2018-06-01

To demonstrate clearing of chronic corneal opacities and improvement of visual acuity with the use of BostonSight prosthetic replacement of the ocular surface ecosystem (PROSE) treatment in ocular surface disease. We undertook retrospective analysis of the medical records of a series of patients who underwent PROSE treatment from August 2006 to December 2014. Patients were referred for ocular surface disease of various etiologies. Primary inclusion criterion was corneal opacity that improved with PROSE treatment. Patients were excluded if topical steroids or adjuvant therapy used once PROSE treatment was initiated. Underlying disease, prior treatment, clinical presentation, and clinical course were extracted from the medical record. Four patients are included in this series. There were three females and one male; median age at time of treatment initiation was 30 years (range = 0.5-58 years). Median duration of PROSE treatment at time of retrospective analysis was 3.5 years (range = 1-8 years). Two cases had corneal opacification in the context of neurotrophic keratopathy: a unilateral case due to presumed herpes simplex keratitis and a bilateral case due to congenital corneal anesthesia associated with familial dysautonomia. One case had corneal opacity from exposure related to seventh nerve palsy, and one had corneal opacification associated with recurrent surface breakdown, neurotrophic keratopathy, and limbal stem deficiency of uncertain etiology. After consistent wear of prosthetic devices used in PROSE treatment for support of the ocular surface, visual acuity improved and clearing of the opacities was observed, without use of topical steroids or adjuvant therapy. These cases demonstrate clearing of chronic corneal opacity with PROSE treatment for ocular surface disease. This clearing can occur with no adjuvant therapy, suggesting that restoration of ocular surface function and integrity allows for corneal remodeling.

Evaluation of prosthetic valve obstruction on electrocardiographically gated multidetector-row computed tomography--identification of subprosthetic pannus in the aortic position.

PubMed

Ueda, Tomohiro; Teshima, Hideki; Fukunaga, Shuji; Aoyagi, Shigeaki; Tanaka, Hiroyuki

2013-01-01

This study was performed to evaluate the diagnostic role of electrocardiographically gated multidetector-row computed tomography (MDCT) for prosthetic valve obstruction (PVO) in the aortic position. Between 2002 and 2006, 9 patients were diagnosed with PVO of an aortic bileaflet mechanical valve based on echocardiographic and cineradiographic criteria. These 9 patients were examined using MDCT before replacement of the mechanical valve, and intraoperative findings were compared to morphologic periprosthetic abnormalities observed on MDCT. CT attenuation (Hounsfield units; HU) of the periprosthetic abnormalities was measured to investigate the underlying cause of the PVO. MDCT showed subprosthetic masses extending beyond the prosthetic ring into the orifice of the valve. At reoperation, presence of subprosthetic pannus was confirmed in all of the 9 patients, but no periprosthetic thrombus was found. The mean CT attenuation of the subprosthetic pannus was 170 HU, and it was significantly greater than that obtained from the interventricular septum (108 HU; P<0.0001). MDCT can be used to clearly visualize subprosthetic pannus causing PVO and the mean CT attenuation of subprosthetic pannus is significantly higher than that of the interventricular septum on MDCT.

Integration of graphene sensor with electrochromic device on modulus-gradient polymer for instantaneous strain visualization

NASA Astrophysics Data System (ADS)

Yang, Tingting; Zhong, Yujia; Tao, Dashuai; Li, Xinming; Zang, Xiaobei; Lin, Shuyuan; Jiang, Xin; Li, Zhihong; Zhu, Hongwei

2017-09-01

In nature, some animals change their deceptive coloration for camouflage, temperature preservation or communication. This astonishing function has inspired scientists to replicate the color changing abilities of animals with artificial skin. Recently, some studies have focused on the smart materials and devices with reversible color changing or light-emitting properties for instantaneous strain visualization. However, most of these works only show eye-detectable appearance change when subjected to large mechanical deformation (100%-500% strain), and conspicuous color change at small strain remains rarely explored. In the present study, we developed a user-interactive electronic skin with human-readable optical output by assembling a highly sensitive resistive strain sensor with a stretchable organic electrochromic device (ECD) together. We explored the substrate effect on the electromechanical behavior of graphene and designed a strategy of modulus-gradient structure to employ graphene as both the highly sensitive strain sensing element and the insensitive stretchable electrode of the ECD layer. Subtle strain (0-10%) was enough to evoke an obvious color change, and the RGB value of the color quantified the magnitude of the applied strain. Such high sensitivity to smaller strains (0-10%) with color changing capability will potentially enhance the function of wearable devices, robots and prosthetics in the future.

SSVEP-based BCI for manipulating three-dimensional contents and devices

NASA Astrophysics Data System (ADS)

Mun, Sungchul; Cho, Sungjin; Whang, Mincheol; Ju, Byeong-Kwon; Park, Min-Chul

2012-06-01

Brain Computer Interface (BCI) studies have been done to help people manipulate electronic devices in a 2D space but less has been done for a vigorous 3D environment. The purpose of this study was to investigate the possibility of applying Steady State Visual Evoked Potentials (SSVEPs) to a 3D LCD display. Eight subjects (4 females) ranging in age between 20 to 26 years old participated in the experiment. They performed simple navigation tasks on a simple 2D space and virtual environment with/without 3D flickers generated by a Flim-Type Patterned Retarder (FPR). The experiments were conducted in a counterbalanced order. The results showed that 3D stimuli enhanced BCI performance, but no significant effects were found due to the small number of subjects. Visual fatigue that might be evoked by 3D stimuli was negligible in this study. The proposed SSVEP BCI combined with 3D flickers can allow people to control home appliances and other equipment such as wheelchairs, prosthetics, and orthotics without encountering dangerous situations that may happen when using BCIs in real world. 3D stimuli-based SSVEP BCI would motivate people to use 3D displays and vitalize the 3D related industry due to its entertainment value and high performance.

Availability of cosmetic treatment using novel cosmetics-based material on patients with craniofacial concavity.

PubMed

Koyama, Shigeto; Kanetaka, Hiroyasu; Sagehashi, Yoshinori; Sasaki, Keiichi; Sato, Naoko

2018-03-09

Patients treated with maxillofacial prosthetics often experience emotional problems because of the remaining facial skin concavity such as a surgical scar. In such cases, cosmetic treatment can potentially correct their skin tone imperfections and deformities. This study aimed to evaluate the clinical availability of novel cosmetics-based material for craniofacial small concavity by initiating a cosmetic treatment in a preliminary case. Eighteen patients with aesthetic problems such as craniofacial deformities, small defects, and concavities on their faces underwent cosmetic treatment that was performed by makeup practitioners. Data were collected from the patient's charts and a survey questionnaire. A visual analog scale was used to conduct a survey regarding the satisfaction levels of the patients following cosmetic treatment with a novel cosmetics-based material. The cosmetic treatment was performed for a concavity on the left midface of a 67-year-old woman with partial maxillectomy. The novel cosmetics-based material was manufactured from a semi-translucent oil base. The satisfaction level of the patient increased after undergoing the cosmetic treatment. Regarding clinical applications, the novel cosmetics-based material can help reduce their cosmetic disturbance and restore the small deformity. These results suggest that the cosmetic treatment with the novel cosmetics-based material can be used as a subsidiary method for facial prostheses or an independent new method for correcting patients' small craniofacial concavity and for reducing visible deformity. Copyright © 2018 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Clinical characteristics and outcomes of prosthetic joint infection caused by small colony variant staphylococci.

PubMed

Tande, Aaron J; Osmon, Douglas R; Greenwood-Quaintance, Kerryl E; Mabry, Tad M; Hanssen, Arlen D; Patel, Robin

2014-09-30

Small colony variants (SCVs) are naturally occurring subpopulations of bacteria. The clinical characteristics and treatment outcomes of patients with prosthetic joint infection (PJI) caused by staphylococcal SCVs are unknown. This study was a retrospective series of 113 patients with staphylococcal PJI, with prospective testing of archived sonicate fluid samples. SCVs were defined using two-investigator review. Treatment failure was defined as (i) subsequent revision surgery for any reason, (ii) PJI after the index surgery, (iii) prosthesis nonreimplantation due to ongoing infection, or (iv) amputation of the affected limb. There were 38 subjects (34%) with SCVs and 75 (66%) with only normal-phenotype (NP) bacteria. Subjects with SCVs were more likely to have been on chronic antimicrobials prior to surgery (P = 0.048), have had prior surgery for PJI (P = 0.03), have had a longer duration of symptoms (P = 0.0003), and have had a longer time since joint implantation (P = 0.007), compared to those with only NP bacteria. Over a median follow-up of 30.6 months, 9 subjects (24%) with SCVs and 23 (32%) with only NP bacteria experienced treatment failure (P = 0.51). Subjects infected with Staphylococcus aureus were more likely to fail than were those infected with Staphylococcus epidermidis (hazard ratio [HR], 4.03; 95% confidence interval [CI], 1.80 to 9.04). While frequently identified in subjects with PJI and associated with several potential predisposing factors, SCVs were not associated with excess treatment failure compared to NP infections in this study, where they were primarily managed with two-stage arthroplasty exchange. Bacteria with the small colony variant (SCV) phenotype are described in small case series as causing persistent or relapsing infection, but there are insufficient data to suggest that they should be managed differently than infection with normal-phenotype bacteria. In an effort to investigate the clinical importance of this phenotype, we determined whether SCVs were present in biofilms dislodged from the surfaces of arthroplasties of patients with staphylococcal prosthetic joint infection and assessed the clinical outcomes associated with detection of SCVs. We found that prosthetic joint infection caused by SCV staphylococci was associated with a longer duration of symptoms and more prior treatment for infection but not with an increased rate of treatment failure, compared to infection caused by normal-phenotype staphylococci. Copyright © 2014 Tande et al.

Live intramacrophagic Staphylococcus aureus as a potential cause of antibiotic therapy failure: observations in an in vivo mouse model of prosthetic vascular material infections.

PubMed

Boudjemaa, Rym; Steenkeste, Karine; Jacqueline, Cédric; Briandet, Romain; Caillon, Jocelyne; Boutoille, David; Le Mabecque, Virginie; Tattevin, Pierre; Fontaine-Aupart, Marie-Pierre; Revest, Matthieu

2018-06-12

To evaluate the significant role played by biofilms during prosthetic vascular material infections (PVMIs). We developed an in vivo mouse model of Staphylococcus aureus PVMI allowing its direct observation by confocal microscopy to describe: (i) the structure of biofilms developed on Dacron® vascular material; (ii) the localization and effect of antibiotics on these biostructures; and (iii) the interaction between bacteria and host tissues and cells during PVMI. In this model we demonstrated that the biofilm structures are correlated to the activity of antibiotics. Furthermore, live S. aureus bacteria were visualized inside the macrophages present at the biofilm sites, which is significant as antibiotics do not penetrate these immune cells. This intracellular situation may explain the limited effect of antibiotics and also why PVMIs can relapse after antibiotic therapy.

Biologically inspired multi-layered synthetic skin for tactile feedback in prosthetic limbs.

PubMed

Osborn, Luke; Nguyen, Harrison; Betthauser, Joseph; Kaliki, Rahul; Thakor, Nitish

2016-08-01

The human body offers a template for many state-of-the-art prosthetic devices and sensors. In this work, we present a novel, sensorized synthetic skin that mimics the natural multi-layered nature of mechanoreceptors found in healthy glabrous skin to provide tactile information. The multi-layered sensor is made up of flexible piezoresistive textiles that act as force sensitive resistors (FSRs) to convey tactile information, which are embedded within a silicone rubber to resemble the compliant nature of human skin. The top layer of the synthetic skin is capable of detecting small loads less than 5 N whereas the bottom sensing layer responds reliably to loads over 7 N. Finite element analysis (FEA) of a simplified human fingertip and the synthetic skin was performed. Results suggest similarities in behavior during loading. A natural tactile event is simulated by loading the synthetic skin on a prosthetic limb. Results show the sensors' ability to detect applied loads as well as the ability to simulate neural spiking activity based on the derivative and temporal differences of the sensor response. During the tactile loading, the top sensing layer responded 0.24 s faster than the bottom sensing layer. A synthetic biologically-inspired skin such as this will be useful for enhancing the functionality of prosthetic limbs through tactile feedback.

Advanced Prosthetic Gait Training Tool

DTIC Science & Technology

2015-12-01

motion capture sequences was provided by MPL to CCAD and OGAL. CCAD’s work focused on imposing these sequences on the SantosTM digital human avatar ...manipulating the avatar image. These manipulations are accomplished in the context of reinforcing what is the more ideal position and relating...focus on the visual environment by asking users to manipulate a static image of the Santos avatar to represent their perception of what they observe

Excessive strut wear allowing ball-poppet embolization in a DeBakey-Surgitool aortic valve prosthesis.

PubMed

Sutherland, R D; Guynes, W A; Nichols, C T; Martinez, H E

1982-01-01

Excessive cage strut wear allowing ball-poppet embolization caused the sudden death of a 47 year old lady in whom a DeBakey-Surgitool aortic prosthesis had been implanted nine years earlier. Patients with this type of prosthesis should have periodic valvular cine fluoroscopy with image intensification to allow visualization of significant strut wear or fracture, and appropriate prosthetic valve replacement.

Head mounted DMD based projection system for natural and prosthetic visual stimulation in freely moving rats.

PubMed

Arens-Arad, Tamar; Farah, Nairouz; Ben-Yaish, Shai; Zlotnik, Alex; Zalevsky, Zeev; Mandel, Yossi

2016-10-12

Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal's retina. Thorough system characterization and the investigation of the effect of various parameters on obtained image quality were performed using ZEMAX. Simulation results revealed that images with an MTF higher than 0.8 were obtained with little effect of the vertex distance. Increased image quality was obtained at an optimal pupil diameter and smaller field of view. Visual cortex activity data was recorded simultaneously with pattern projection, further highlighting the importance of the system for prosthetic vision studies. This novel head mounted projection system may prove to be a vital tool in studying natural and artificial vision in behaving animals.

Head mounted DMD based projection system for natural and prosthetic visual stimulation in freely moving rats

PubMed Central

Arens-Arad, Tamar; Farah, Nairouz; Ben-Yaish, Shai; Zlotnik, Alex; Zalevsky, Zeev; Mandel, Yossi

2016-01-01

Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal’s retina. Thorough system characterization and the investigation of the effect of various parameters on obtained image quality were performed using ZEMAX. Simulation results revealed that images with an MTF higher than 0.8 were obtained with little effect of the vertex distance. Increased image quality was obtained at an optimal pupil diameter and smaller field of view. Visual cortex activity data was recorded simultaneously with pattern projection, further highlighting the importance of the system for prosthetic vision studies. This novel head mounted projection system may prove to be a vital tool in studying natural and artificial vision in behaving animals. PMID:27731346

Head mounted DMD based projection system for natural and prosthetic visual stimulation in freely moving rats

NASA Astrophysics Data System (ADS)

Arens-Arad, Tamar; Farah, Nairouz; Ben-Yaish, Shai; Zlotnik, Alex; Zalevsky, Zeev; Mandel, Yossi

2016-10-01

Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal’s retina. Thorough system characterization and the investigation of the effect of various parameters on obtained image quality were performed using ZEMAX. Simulation results revealed that images with an MTF higher than 0.8 were obtained with little effect of the vertex distance. Increased image quality was obtained at an optimal pupil diameter and smaller field of view. Visual cortex activity data was recorded simultaneously with pattern projection, further highlighting the importance of the system for prosthetic vision studies. This novel head mounted projection system may prove to be a vital tool in studying natural and artificial vision in behaving animals.

Classifying prosthetic use via accelerometry in persons with transtibial amputations.

PubMed

Redfield, Morgan T; Cagle, John C; Hafner, Brian J; Sanders, Joan E

2013-01-01

Knowledge of how persons with amputation use their prostheses and how this use changes over time may facilitate effective rehabilitation practices and enhance understanding of prosthesis functionality. Perpetual monitoring and classification of prosthesis use may also increase the health and quality of life for prosthetic users. Existing monitoring and classification systems are often limited in that they require the subject to manipulate the sensor (e.g., attach, remove, or reset a sensor), record data over relatively short time periods, and/or classify a limited number of activities and body postures of interest. In this study, a commercially available three-axis accelerometer (ActiLife ActiGraph GT3X+) was used to characterize the activities and body postures of individuals with transtibial amputation. Accelerometers were mounted on prosthetic pylons of 10 persons with transtibial amputation as they performed a preset routine of actions. Accelerometer data was postprocessed using a binary decision tree to identify when the prosthesis was being worn and to classify periods of use as movement (i.e., leg motion such as walking or stair climbing), standing (i.e., standing upright with limited leg motion), or sitting (i.e., seated with limited leg motion). Classifications were compared to visual observation by study researchers. The classifier achieved a mean +/- standard deviation accuracy of 96.6% +/- 3.0%.

Classifying Prosthetic Use via Accelerometry in Persons with Trans-Tibial Amputations

PubMed Central

Redfield, Morgan T.; Cagle, John C.; Hafner, Brian J.; Sanders, Joan E.

2014-01-01

Knowledge of how persons with amputation use their prostheses and how this use changes over time may facilitate effective rehabilitation practices and enhance understanding of prosthesis functionality. Perpetual monitoring and classification of prosthesis use may also increase the health and quality of life for prosthetic users. Existing monitoring and classification systems are often limited in that they require the subject to manipulate the sensor (e.g., attach, remove, or reset a sensor), record data over relatively short time periods, and/or classify a limited number of activities and body postures of interest. In this study, a commercially-available three-axis accelerometer (ActiLife ActiGraph GT3X+) was used to characterize the activities and body postures of individuals with trans-tibial amputation. Accelerometers were mounted on prosthetic pylons of ten persons with trans-tibial amputation as they performed a preset routine of actions. Accelerometer data was post-processed using a Binary Decision Tree to identify when the prosthesis was being worn and to classify periods of use as movement (i.e., leg motion like walking or stair climbing), standing (i.e., standing upright with limited leg motion), or sitting (i.e., seated with limited leg motion). Classifications were compared to visual observation by study researchers. The classifier achieved a mean accuracy of 96.6% (SD=3.0%). PMID:24458961

Implementing a new curriculum for computer-assisted restorations in prosthetic dentistry.

PubMed

Schweyen, R; Beuer, F; Bochskanl, M; Hey, J

2018-05-01

Computer-aided design/computer-aided manufacturing (CAD/CAM) of fixed prosthetic restorations has gained popularity in the last decade. However, this field of dentistry has not been integrated in the dental curriculum at most universities. According to the method of Kern, a curriculum was designed and established on a voluntary basis in the prosthetic education of a German dental school. The success of the implementation was measured by evaluation carried out by the participants on a visual analogue scale. Furthermore, the clinical performance of the fabricated restorations was evaluated. Ninety-four percent of all students participated in the CAD/CAM curriculum indicating considerable interest. Nearly half of all students used the acquired knowledge to design crowns for their patients. All restorations fabricated by participants of the new CAD/CAM programme showed good clinical performance. By phasing-in the CAD/CAM training programme, independent CAD/CAM-based fabrication of all-ceramic crowns increased student's self-confidence in tooth preparation. A tendency was found that students using CAD/CAM technology prepared more teeth than their fellow students who did not use CAD/CAM technology. Further studies are required to investigate the influence of independent CAD/CAM-based single-crown fabrication on the quality of the preparation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

EDITORIAL: Special issue containing contributions from the Sixth Biennial Research Congress of The Eye and the Chip Special issue containing contributions from the Sixth Biennial Research Congress of The Eye and the Chip

NASA Astrophysics Data System (ADS)

Hessburg, Philip C.

2011-06-01

Once again Journal of Neural Engineering is devoting an issue to the field of visual neuro-prosthetics. These papers were presented at the Sixth Biennial Research Congress of The Eye and the ChipA 13 DVD set of all presentations at The Eye and the Chip 2010 is available from Carolyn Barth PhD, Detroit Institute of Ophthalmology, 15415 E Jefferson, Grosse Pointe Park MI 48230, USA, 313.824.4710, clbarth@dioeyes.org, held in Detroit in September 2010. In the last decade this field has metamorphosed from 'in all probability a foolish and impractical dream' to a device approved for implantation in Europe and pending approval in the United States, and from a handful of serious efforts to several dozen on every continent save for Antartica. A recent comprehensive volume, Visual Prosthetics [1], edited by Gislin Dagnelie of Johns Hopkins University School of Medicine, focuses closely on this subject and is a tremendous addition to the literature. In his preface Dr Dagnelie notes as follows. 'In the year 2000, the Detroit Institute of Ophthalmology had the inspiration to foster a new collaboration among visual prosthesis researchers, clinicians, and workers in low vision rehabilitation by creating and sponsoring a series of biennial meetings called 'The Eye and the Chip'. Successful beyond expectations, these meetings have become the premier gathering place for researchers from all parts of the world and from very different backgrounds. Invited speakers are scientists who are advancing the field, yet the scale and atmosphere allow all researchers, patients, and the media to come and be updated about progress over the past two years. More perhaps than at other scientific meetings, where investigators tend to gather within disciplines, participants at The Eye and the Chip are challenged to be open-minded, learn about and critique each other's work, and return home with fresh ideas for interdisciplinary approaches. The interdisciplinary character of this book reflects that same spirit.' A letter to us from our co-organizer of The Eye and the Chip, Joseph Rizzo MD, Harvard Medical School, furthers the point that the Research Congress Model is productive. This model is based on a belief that collegiality enhances collaboration and that collaboration accelerates progress. 'At the time of our first The Eye and the Chip meeting, now many years ago, the field of visual prosthetics was still in its infancy. The research community generally held a very skeptical attitude about the possible use of a bio-electronic implant to restore vision, despite the great success of cochlear implants. Over the last two decades our field has matured dramatically, and now there is widespread optimism about the potential for visual implants to help patients who are blind. 'The marked improvement in our status as a field is the result of excellent research from a large critical mass of scientists from throughout the world. It is the general opinion of researchers in our field that The Eye and the Chip meeting has provided the most vibrant source of scientific exchange for our field. The reasons for the success of this meeting relate to the fact that the meeting is devoted to a single topic, it is all-inclusive (anyone who is performing credible research in the field is invited to participate) and it provides a very substantial amount of time for open group discussions. These attributes expand the length of the meeting, which I understand increases the cost of the meeting, but the benefits have been remarkable for our field. Simply stated, The Eye and the Chip meeting provides the best venue for scientific and academic exchange in the world for the field of visual prosthetics.' And, furthermore, following a rather spirited discussion on the end points to be used in evaluating these devices on the third and final day of The Eye and the Chip last September, the Food and Drug Administration (FDA), under the leadership of the US National Eye Institute (NEI), held a fine one-day Congress, 'End Points' in Washington in early May. We, as leaders of The Eye and the Chip, are hopeful that the FDA will continue its meeting in the off-years between The Eye and the Chip research congresses. The field is now so important that an annual meeting exclusively devoted to the subject, especially if Journal of Neural Engineering continues to cover this important work, will not be excessive. References [1] Dagnelie G (ed) 2011 Visual Prosthetics (New York: Springer)

Probing the functional impact of sub-retinal prosthesis

PubMed Central

Roux, Sébastien; Matonti, Frédéric; Dupont, Florent; Hoffart, Louis; Takerkart, Sylvain; Picaud, Serge; Pham, Pascale; Chavane, Frédéric

2016-01-01

Retinal prostheses are promising tools for recovering visual functions in blind patients but, unfortunately, with still poor gains in visual acuity. Improving their resolution is thus a key challenge that warrants understanding its origin through appropriate animal models. Here, we provide a systematic comparison between visual and prosthetic activations of the rat primary visual cortex (V1). We established a precise V1 mapping as a functional benchmark to demonstrate that sub-retinal implants activate V1 at the appropriate position, scalable to a wide range of visual luminance, but with an aspect-ratio and an extent much larger than expected. Such distorted activation profile can be accounted for by the existence of two sources of diffusion, passive diffusion and activation of ganglion cells’ axons en passant. Reverse-engineered electrical pulses based on impedance spectroscopy is the only solution we tested that decreases the extent and aspect-ratio, providing a promising solution for clinical applications. DOI: http://dx.doi.org/10.7554/eLife.12687.001 PMID:27549126

Interface Prostheses With Classifier-Feedback-Based User Training.

PubMed

Fang, Yinfeng; Zhou, Dalin; Li, Kairu; Liu, Honghai

2017-11-01

It is evident that user training significantly affects performance of pattern-recognition-based myoelectric prosthetic device control. Despite plausible classification accuracy on offline datasets, online accuracy usually suffers from the changes in physiological conditions and electrode displacement. The user ability in generating consistent electromyographic (EMG) patterns can be enhanced via proper user training strategies in order to improve online performance. This study proposes a clustering-feedback strategy that provides real-time feedback to users by means of a visualized online EMG signal input as well as the centroids of the training samples, whose dimensionality is reduced to minimal number by dimension reduction. Clustering feedback provides a criterion that guides users to adjust motion gestures and muscle contraction forces intentionally. The experiment results have demonstrated that hand motion recognition accuracy increases steadily along the progress of the clustering-feedback-based user training, while conventional classifier-feedback methods, i.e., label feedback, hardly achieve any improvement. The result concludes that the use of proper classifier feedback can accelerate the process of user training, and implies prosperous future for the amputees with limited or no experience in pattern-recognition-based prosthetic device manipulation.It is evident that user training significantly affects performance of pattern-recognition-based myoelectric prosthetic device control. Despite plausible classification accuracy on offline datasets, online accuracy usually suffers from the changes in physiological conditions and electrode displacement. The user ability in generating consistent electromyographic (EMG) patterns can be enhanced via proper user training strategies in order to improve online performance. This study proposes a clustering-feedback strategy that provides real-time feedback to users by means of a visualized online EMG signal input as well as the centroids of the training samples, whose dimensionality is reduced to minimal number by dimension reduction. Clustering feedback provides a criterion that guides users to adjust motion gestures and muscle contraction forces intentionally. The experiment results have demonstrated that hand motion recognition accuracy increases steadily along the progress of the clustering-feedback-based user training, while conventional classifier-feedback methods, i.e., label feedback, hardly achieve any improvement. The result concludes that the use of proper classifier feedback can accelerate the process of user training, and implies prosperous future for the amputees with limited or no experience in pattern-recognition-based prosthetic device manipulation.

Comparison of gait after Syme and transtibial amputation in children: factors that may play a role in function.

PubMed

Jeans, Kelly A; Karol, Lori A; Cummings, Donald; Singhal, Kunal

2014-10-01

Preservation of maximal limb length during amputation is often recommended to maximize the efficiency and symmetry of gait. The goals of this study were to determine (1) whether there are gait differences between children with a Syme (or Boyd) amputation and those with a transtibial-level amputation, and (2) whether the type of prosthetic foot affects gait and PODCI (Pediatric Outcomes Data Collection Instrument) outcomes. Sixty-four patients (age range, 4.7 to 19.2 years) with unilateral below-the-knee prosthesis use (forty-one in the Syme group and twenty-three in the transtibial group) underwent gait analysis and review of data for the involved limb. The twelve prosthetic foot types were categorized as designed for a high, medium, or low activity level (e.g., Flex foot, dynamic response foot, or SACH). Statistical analyses were conducted. Kinematic differences of <4° in total prosthetic ankle motion and 8° in external hip rotation were seen between the Syme and transtibial groups. Ankle power was greater in the transtibial group, whereas the Syme group had greater coronal-plane hip power (p < 0.05). Prosthetic ankle motion was significantly greater in the high compared with the medium and low-performance feet. However, the PODCI happiness score was higher in patients with low compared with medium-performance feet (p < 0.05). Small differences in prosthetic ankle motion and power were found between children with Syme and transtibial amputations. Ankle motion was greater in patients using high-performance feet (9% of the total cohort) compared with medium-performance (59%) and low-performance (31%) feet. Despite the increased ankle motion achieved with high-performance dynamic feet, this advantage was not reflected in peak power of the prosthetic ankle or the PODCI sports/physical functioning subscale. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Optimization of pillar electrodes in subretinal prosthesis for enhanced proximity to target neurons

NASA Astrophysics Data System (ADS)

Flores, Thomas; Lei, Xin; Huang, Tiffany; Lorach, Henri; Dalal, Roopa; Galambos, Ludwig; Kamins, Theodore; Mathieson, Keith; Palanker, Daniel

2018-06-01

Objective. High-resolution prosthetic vision requires dense stimulating arrays with small electrodes. However, such miniaturization reduces electrode capacitance and penetration of electric field into tissue. We evaluate potential solutions to these problems with subretinal implants based on utilization of pillar electrodes. Approach. To study integration of three-dimensional (3D) implants with retinal tissue, we fabricated arrays with varying pillar diameter, pitch, and height, and implanted beneath the degenerate retina in rats (Royal College of Surgeons, RCS). Tissue integration was evaluated six weeks post-op using histology and whole-mount confocal fluorescence imaging. The electric field generated by various electrode configurations was calculated in COMSOL, and stimulation thresholds assessed using a model of network-mediated retinal response. Main results. Retinal tissue migrated into the space between pillars with no visible gliosis in 90% of implanted arrays. Pillars with 10 μm height reached the middle of the inner nuclear layer (INL), while 22 μm pillars reached the upper portion of the INL. Electroplated pillars with dome-shaped caps increase the active electrode surface area. Selective deposition of sputtered iridium oxide onto the cap ensures localization of the current injection to the pillar top, obviating the need to insulate the pillar sidewall. According to computational model, pillars having a cathodic return electrode above the INL and active anodic ring electrode at the surface of the implant would enable six times lower stimulation threshold, compared to planar arrays with circumferential return, but suffer from greater cross-talk between the neighboring pixels. Significance. 3D electrodes in subretinal prostheses help reduce electrode-tissue separation and decrease stimulation thresholds to enable smaller pixels, and thereby improve visual acuity of prosthetic vision.

Visual BOLD Response in Late Blind Subjects with Argus II Retinal Prosthesis

PubMed Central

Castaldi, E.; Cicchini, G. M.; Cinelli, L.; Rizzo, S.; Morrone, M. C.

2016-01-01

Retinal prosthesis technologies require that the visual system downstream of the retinal circuitry be capable of transmitting and elaborating visual signals. We studied the capability of plastic remodeling in late blind subjects implanted with the Argus II Retinal Prosthesis with psychophysics and functional MRI (fMRI). After surgery, six out of seven retinitis pigmentosa (RP) blind subjects were able to detect high-contrast stimuli using the prosthetic implant. However, direction discrimination to contrast modulated stimuli remained at chance level in all of them. No subject showed any improvement of contrast sensitivity in either eye when not using the Argus II. Before the implant, the Blood Oxygenation Level Dependent (BOLD) activity in V1 and the lateral geniculate nucleus (LGN) was very weak or absent. Surprisingly, after prolonged use of Argus II, BOLD responses to visual input were enhanced. This is, to our knowledge, the first study tracking the neural changes of visual areas in patients after retinal implant, revealing a capacity to respond to restored visual input even after years of deprivation. PMID:27780207

A new three-dimensional, print-on-demand temporomandibular prosthetic total joint replacement system: Preliminary outcomes.

PubMed

Dimitroulis, George; Austin, Stephen; Sin Lee, Peter Vee; Ackland, David

2018-05-16

The aim of this study is to present the preliminary clinical data on the OMX Temporomandibular Joint (TMJ) Prosthetic total joint replacement system. A prospective, cohort, clinical study was undertaken of consecutive adult patients with Category 5 end-stage joint disease who were implanted with the OMX TMJ prosthesis between May 2015 and April 2017. A total of 50 devices were implanted in 38 patients, with 12 patients receiving bilateral prosthetic joints. There were 31 females and 7 males in this cohort, who ranged in age from 20 to 66 years, with a mean of 43.8 years (±14.0 years). Ten of the 50 prosthetic joints (20%) were fully customized, while the remaining were patient matched using virtual planning software. Based on a mean follow-up period of 15.3 months (range 12-24 months) following the TMJ total joint replacement, preliminary results suggest the OMX TMJ prosthesis has made a positive impact on clinical outcomes, with a mean 74.4% reduction in joint pain levels and significant improvements (p < 0.05) in jaw function as measured by the visual analogue scales for mouth opening (30.8%), diet (77.1%), and function (59.2%). No device failures were reported during the study period. This study suggests that the print-on-demand OMX TMJ prosthesis, designed for rapid delivery of both patient-matched and fully customize devices, represents a safe, reliable and versatile implantable joint replacement system for the treatment of category 5 end-stage TMJ disease. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Focal activation of primary visual cortex following supra-choroidal electrical stimulation of the retina: Intrinsic signal imaging and linear model analysis.

PubMed

Cloherty, Shaun L; Hietanen, Markus A; Suaning, Gregg J; Ibbotson, Michael R

2010-01-01

We performed optical intrinsic signal imaging of cat primary visual cortex (Area 17 and 18) while delivering bipolar electrical stimulation to the retina by way of a supra-choroidal electrode array. Using a general linear model (GLM) analysis we identified statistically significant (p < 0.01) activation in a localized region of cortex following supra-threshold electrical stimulation at a single retinal locus. (1) demonstrate that intrinsic signal imaging combined with linear model analysis provides a powerful tool for assessing cortical responses to prosthetic stimulation, and (2) confirm that supra-choroidal electrical stimulation can achieve localized activation of the cortex consistent with focal activation of the retina.

Modeling of Prosthetic Limb Rotation Control by Sensing Rotation of Residual Arm Bone

PubMed Central

Kuiken, Todd A.

2011-01-01

We proposed a new approach to improve the control of prosthetic arm rotation in amputees. Arm rotation is sensed by implanting a small permanent magnet into the distal end of the residual bone, which produces a magnetic field. The position of the bone rotation can be derived from magnetic field distribution detected with magnetic sensors on the arm surface, and then conveyed to the prosthesis controller to manipulate the rotation of the prosthesis. Proprioception remains intact for residual limb skeletal structures; thus, this control system should be natural and easy-to-use. In this study, simulations have been conducted in an upper arm model to assess the feasibility and performance of sensing the voluntary rotation of residual humerus with an implanted magnet. A sensitivity analysis of the magnet size and arm size was presented. The influence of relative position of the magnet to the magnetic sensors, orientation of the magnet relative to the limb axis, and displacement of the magnetic sensors on the magnetic field was evaluated. The performance of shielding external magnetostatic interference was also investigated. The simulation results suggest that the direction and angle of rotation of residual humerus could be obtained by decoding the magnetic field signals with magnetic sensors built into a prosthetic socket. This pilot study provides important guidelines for developing a practical interface between the residual bone rotation and the prosthesis for control of prosthetic rotation. PMID:18713682

Reoperation for non-structural valvular dysfunction caused by pannus ingrowth in aortic valve prosthesis.

PubMed

Oh, Se Jin; Park, Samina; Kim, Jun Sung; Kim, Kyung-Hwan; Kim, Ki Bong; Ahn, Hyuk

2013-07-01

The authors' clinical experience is presented of non-structural valvular dysfunction of the prosthetic aortic valve caused by pannus ingrowth during the late postoperative period after previous heart valve surgery. Between January 1999 and April 2012, at the authors' institution, a total of 33 patients underwent reoperation for increased mean pressure gradient of the prosthetic aortic valve. All patients were shown to have pannus ingrowth. The mean interval from the previous operation was 16.7 +/- 4.3 years, and the most common etiology for the previous aortic valve replacement (AVR) was rheumatic valve disease. The mean effective orifice area index (EOAI) of the previous prosthetic valve was 0.97 +/- 0.11 cm2/m2, and the mean pressure gradient on the aortic prosthesis before reoperation was 39.1 +/- 10.7 mmHg. Two patients (6.1%) died in-hospital, and late death occurred in six patients (18.2%). At the first operation, 30 patients underwent mitral or tricuspid valve surgery as a concomitant procedure. Among these operations, mitral valve replacement (MVR) was combined in 24 of all 26 patients with rheumatic valve disease. Four patients underwent pannus removal only while the prosthetic aortic valve was left in place. The mean EOAI after reoperation was significantly increased to 1.16 +/- 0.16 cm2/m2 (p < 0.001), and the mean pressure gradient was decreased to 11.9 +/- 1.9 mmHg (p < 0.001). Non-structural valvular dysfunction caused by pannus ingrowth was shown in patients with a small EOAI of the prosthetic aortic valve and combined MVR for rheumatic disease. As reoperation for pannus overgrowth showed good clinical outcomes, an aggressive resection of pannus and repeated AVR should be considered in symptomatic patients to avoid the complications of other cardiac diseases.

Robotic hand with locking mechanism using TCP muscles for applications in prosthetic hand and humanoids

NASA Astrophysics Data System (ADS)

Saharan, Lokesh; Tadesse, Yonas

2016-04-01

This paper presents a biomimetic, lightweight, 3D printed and customizable robotic hand with locking mechanism consisting of Twisted and Coiled Polymer (TCP) muscles based on nylon precursor fibers as artificial muscles. Previously, we have presented a small-sized biomimetic hand using nylon based artificial muscles and fishing line muscles as actuators. The current study focuses on an adult-sized prosthetic hand with improved design and a position/force locking system. Energy efficiency is always a matter of concern to make compact, lightweight, durable and cost effective devices. In natural human hand, if we keep holding objects for long time, we get tired because of continuous use of energy for keeping the fingers in certain positions. Similarly, in prosthetic hands we also need to provide energy continuously to artificial muscles to hold the object for a certain period of time, which is certainly not energy efficient. In this work we, describe the design of the robotic hand and locking mechanism along with the experimental results on the performance of the locking mechanism.

Laparoscopic surgical treatment of umbilical hernia and small eventrations with prosthetic mesh using omentum overlay.

PubMed

Bratu, D; Sabău, A; Dumitra, A; Sabău, D; Miheţiu, A; Beli, L; Hulpuş, R

2014-01-01

Umbilical hernias and abdominal incisional hernias represent current pathologies which require numerous surgical alternative ways of treatment in prosthetic or non prosthetic,open or minimally invasive surgery. The method proposed by us is a less expensive option with no additional risks compared to other similar procedures as surgical technique. We conducted a retrospective study between 01.01.2008 - 01.06.2013 in which we considered a number of 23 patients with umbilical hernia and eventration, patients who received laparoscopic intraperitoneal polyester mesh covered with omentum, procedure applied at the IInd Surgery Clinic, Clinical County Emergency Hospital Sibiu. Out of 23 patients with postoperative umbilical hernia and eventration cases in which we used this surgical technique,16 were umbilical hernias and 7 post incisional hernias. The average time of surgery was 1 hour and 40 minutes, recording 4 postoperative complications remitted under conservative treatment, with a mean hospitalization of 4.1 days. Proepiploic laparoscopic treatment using omentum is a reliable alternative to a more expensive and difficult procedure involving Dual Mesh. Celsius.

Identifying the values and preferences of prosthetic users: a case study series using the repertory grid technique.

PubMed

Schaffalitzky, Elisabeth; NiMhurchadha, Sinead; Gallagher, Pamela; Hofkamp, Susan; MacLachlan, Malcolm; Wegener, Stephen T

2009-06-01

The matching of prosthetic devices to the needs of the individual is a challenge for providers and patients. The aims of this study are to explore the values and preferences that prosthetic users have of their prosthetic devices; to investigate users' perceptions of alternative prosthetic options and to demonstrate a novel method for exploring the values and preferences of prosthetic users. This study describes four case studies of upper limb and lower limb high tech and conventional prosthetic users. Participants were interviewed using the repertory grid technique (RGT), a qualitative technique to explore individual values and preferences regarding specific choices and events. The participants generated distinctive patterns of personal constructs and ratings regarding prosthetic use and different prosthetic options available. The RGT produced a unique profile of preferences regarding prosthetic technologies for each participant. User choice is an important factor when matching prosthetic technology to the user. The consumer's values regarding different prosthetic options are likely to be a critical factor in prosthetic acceptance and ultimate quality of life. The RGT offers a structured method of exploring these attitudes and values without imposing researcher or practitioner bias and identifies personalized dimensions for providers and users to evaluate the individuals' preferences in prosthetic technology.

Wavefront-Guided Scleral Lens Prosthetic Device for Keratoconus

PubMed Central

Sabesan, Ramkumar; Johns, Lynette; Tomashevskaya, Olga; Jacobs, Deborah S.; Rosenthal, Perry; Yoon, Geunyoung

2016-01-01

Purpose To investigate the feasibility of correcting ocular higher order aberrations (HOA) in keratoconus (KC) using wavefront-guided optics in a scleral lens prosthetic device (SLPD). Methods Six advanced keratoconus patients (11 eyes) were fitted with a SLPD with conventional spherical optics. A custom-made Shack-Hartmann wavefront sensor was used to measure aberrations through a dilated pupil wearing the SLPD. The position of SLPD, i.e. horizontal and vertical decentration relative to the pupil and rotation were measured and incorporated into the design of the wavefront-guided optics for the customized SLPD. A submicron-precision lathe created the designed irregular profile on the front surface of the device. The residual aberrations of the same eyes wearing the SLPD with wavefront-guided optics were subsequently measured. Visual performance with natural mesopic pupil was compared between SLPDs having conventional spherical and wavefront-guided optics by measuring best-corrected high-contrast visual acuity and contrast sensitivity. Results Root-mean-square of HOA(RMS) in the 11 eyes wearing conventional SLPD with spherical optics was 1.17±0.57μm for a 6 mm pupil. HOA were effectively corrected by the customized SLPD with wavefront-guided optics and RMS was reduced 3.1 times on average to 0.37±0.19μm for the same pupil. This correction resulted in significant improvement of 1.9 lines in mean visual acuity (p<0.05). Contrast sensitivity was also significantly improved by a factor of 2.4, 1.8 and 1.4 on average for 4, 8 and 12 cycles/degree, respectively (p<0.05 for all frequencies). Although the residual aberration was comparable to that of normal eyes, the average visual acuity in logMAR with the customized SLPD was 0.21, substantially worse than normal acuity. Conclusions The customized SLPD with wavefront-guided optics corrected the HOA of advanced KC patients to normal levels and improved their vision significantly. PMID:23478630

Electrical stimulation of the brain and the development of cortical visual prostheses: An historical perspective.

PubMed

Lewis, Philip M; Rosenfeld, Jeffrey V

2016-01-01

Rapid advances are occurring in neural engineering, bionics and the brain-computer interface. These milestones have been underpinned by staggering advances in micro-electronics, computing, and wireless technology in the last three decades. Several cortically-based visual prosthetic devices are currently being developed, but pioneering advances with early implants were achieved by Brindley followed by Dobelle in the 1960s and 1970s. We have reviewed these discoveries within the historical context of the medical uses of electricity including attempts to cure blindness, the discovery of the visual cortex, and opportunities for cortex stimulation experiments during neurosurgery. Further advances were made possible with improvements in electrode design, greater understanding of cortical electrophysiology and miniaturisation of electronic components. Human trials of a new generation of prototype cortical visual prostheses for the blind are imminent. This article is part of a Special Issue entitled Hold Item. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Development of closed-loop neural interface technology in a rat model: combining motor cortex operant conditioning with visual cortex microstimulation.

PubMed

Marzullo, Timothy Charles; Lehmkuhle, Mark J; Gage, Gregory J; Kipke, Daryl R

2010-04-01

Closed-loop neural interface technology that combines neural ensemble decoding with simultaneous electrical microstimulation feedback is hypothesized to improve deep brain stimulation techniques, neuromotor prosthetic applications, and epilepsy treatment. Here we describe our iterative results in a rat model of a sensory and motor neurophysiological feedback control system. Three rats were chronically implanted with microelectrode arrays in both the motor and visual cortices. The rats were subsequently trained over a period of weeks to modulate their motor cortex ensemble unit activity upon delivery of intra-cortical microstimulation (ICMS) of the visual cortex in order to receive a food reward. Rats were given continuous feedback via visual cortex ICMS during the response periods that was representative of the motor cortex ensemble dynamics. Analysis revealed that the feedback provided the animals with indicators of the behavioral trials. At the hardware level, this preparation provides a tractable test model for improving the technology of closed-loop neural devices.

Late leaflet fracture and embolization of a Duromedics mitral prosthesis.

PubMed

Sudo, K; Sasagawa, N; Ide, H; Nunokawa, M; Fujiki, T; Tonari, K

2000-08-01

A case of leaflet fracture and embolization of a mitral prosthetic valve is described. A 54-year-old man had received mitral valve replacement with an Edwards-Duromedics 29M prosthetic valve, at 10 years ago. Emergency mitral valve replacement was performed because the patient had severe congestive left heart failure with severe acute mitral regurgitation caused by a fracture in one of the mitral valve leaflets. The leaflet, which was fractured into 2 pieces, was removed from the right common iliac artery at 3 months after valve replacement. Visual inspection revealed that the leaflet contained a midline fracture. The fracture originated within a cavitary erosion pit near the major radius of the leaflet. The patient recovered from acute renal failure, requiring hemodialysis for 80 days, and is currently without complaints. We have used a Duromedics mitral valve in 11 patients, from April 1987 to April 1988. No subsequent valve failure has occurred. The diagnosis, treatment and cause of a mechanical valve fracture are discussed.

A Low-Cost, Open-Source, Compliant Hand for Enabling Sensorimotor Control for People with Transradial Amputations

PubMed Central

Akhtar, Aadeel; Choi, Kyung Yun; Fatina, Michael; Cornman, Jesse; Wu, Edward; Sombeck, Joseph; Yim, Chris; Slade, Patrick; Lee, Jason; Moore, Jack; Gonzales, Daniel; Wu, Alvin; Anderson, Garrett; Rotter, David; Shin, Cliff; Bretl, Timothy

2017-01-01

In this paper, we describe the design and implementation of a low-cost, open-source prosthetic hand that enables both motor control and sensory feedback for people with transradial amputations. We integrate electromyographic pattern recognition for motor control along with contact reflexes and sensory substitution to provide feedback to the user. Compliant joints allow for robustness to impacts. The entire hand can be built for around $550. This low cost makes research and development of sensorimotor prosthetic hands more accessible to researchers worldwide, while also being affordable for people with amputations in developing nations. We evaluate the sensorimotor capabilites of our hand with a subject with a transradial amputation. We show that using contact reflexes and sensory substitution, when compared to standard myoelectric prostheses that lack these features, improves grasping of delicate objects like an eggshell and a cup of water both with and without visual feedback. Our hand is easily integrated into standard sockets, facilitating long-term testing of sensorimotor capabilities. PMID:28261008

Rapid control and feedback rates enhance neuroprosthetic control

PubMed Central

Shanechi, Maryam M.; Orsborn, Amy L.; Moorman, Helene G.; Gowda, Suraj; Dangi, Siddharth; Carmena, Jose M.

2017-01-01

Brain-machine interfaces (BMI) create novel sensorimotor pathways for action. Much as the sensorimotor apparatus shapes natural motor control, the BMI pathway characteristics may also influence neuroprosthetic control. Here, we explore the influence of control and feedback rates, where control rate indicates how often motor commands are sent from the brain to the prosthetic, and feedback rate indicates how often visual feedback of the prosthetic is provided to the subject. We developed a new BMI that allows arbitrarily fast control and feedback rates, and used it to dissociate the effects of each rate in two monkeys. Increasing the control rate significantly improved control even when feedback rate was unchanged. Increasing the feedback rate further facilitated control. We also show that our high-rate BMI significantly outperformed state-of-the-art methods due to higher control and feedback rates, combined with a different point process mathematical encoding model. Our BMI paradigm can dissect the contribution of different elements in the sensorimotor pathway, providing a unique tool for studying neuroprosthetic control mechanisms. PMID:28059065

MR safety and compatibility of a noninvasively expandable total-joint endoprosthesis.

PubMed

Ogg, Robert J; McDaniel, C Brian; Wallace, Donald; Pitot, Pierre; Neel, Michael D; Kaste, Sue C

2005-09-01

A noninvasively expandable total-joint endoprosthesis is now available for pediatric patients; the prosthesis can be lengthened by external application of a magnetic field. We investigated the risks of unintentional heating or lengthening of the prosthesis during MR imaging and evaluated the effect of the device on the diagnostic efficacy of MR imaging of surrounding tissues. We performed MR imaging at 1.5 T by using standard pulse sequences and pulse sequences with high-gradient and high-radiofrequency duty cycle. MR imaging caused no measurable change in prosthesis length, and the temperature of the prosthesis increased by less than 1 degrees C during repeated 14-min exposures. Despite significant signal loss and image distortion around the prosthetic joint, clinically useful images were obtained as close as 12 cm from the ends of the prosthetic stems, measured toward the body of the device. Thus, the prosthesis can be safely exposed to MR imaging pulse sequences at 1.5 T, and the visualization of some tissue surrounding the device is clinically useful.

Rapid control and feedback rates enhance neuroprosthetic control

NASA Astrophysics Data System (ADS)

Shanechi, Maryam M.; Orsborn, Amy L.; Moorman, Helene G.; Gowda, Suraj; Dangi, Siddharth; Carmena, Jose M.

2017-01-01

Brain-machine interfaces (BMI) create novel sensorimotor pathways for action. Much as the sensorimotor apparatus shapes natural motor control, the BMI pathway characteristics may also influence neuroprosthetic control. Here, we explore the influence of control and feedback rates, where control rate indicates how often motor commands are sent from the brain to the prosthetic, and feedback rate indicates how often visual feedback of the prosthetic is provided to the subject. We developed a new BMI that allows arbitrarily fast control and feedback rates, and used it to dissociate the effects of each rate in two monkeys. Increasing the control rate significantly improved control even when feedback rate was unchanged. Increasing the feedback rate further facilitated control. We also show that our high-rate BMI significantly outperformed state-of-the-art methods due to higher control and feedback rates, combined with a different point process mathematical encoding model. Our BMI paradigm can dissect the contribution of different elements in the sensorimotor pathway, providing a unique tool for studying neuroprosthetic control mechanisms.

The Rhetoric of Disfigurement in First World War Britain

PubMed Central

Biernoff, Suzannah

2011-01-01

Summary During the First World War, the horror of facial mutilation was evoked in journalism, poems, memoirs and fiction; but in Britain it was almost never represented visually outside the professional contexts of clinical medicine and medical history. This article asks why, and offers an account of British visual culture in which visual anxiety and aversion are of central importance. By comparing the rhetoric of disfigurement to the parallel treatment of amputees, an asymmetrical picture emerges in which the ‘worst loss of all’—the loss of one's face—is perceived as a loss of humanity. The only hope was surgery or, if that failed, prosthetic repair: innovations that were often wildly exaggerated in the popular press. Francis Derwent Wood was one of several sculptors whose technical skill and artistic ‘wizardry’ played a part in the improvised reconstruction of identity and humanity.

Image analysis for microelectronic retinal prosthesis.

PubMed

Hallum, L E; Cloherty, S L; Lovell, N H

2008-01-01

By way of extracellular, stimulating electrodes, a microelectronic retinal prosthesis aims to render discrete, luminous spots-so-called phosphenes-in the visual field, thereby providing a phosphene image (PI) as a rudimentary remediation of profound blindness. As part thereof, a digital camera, or some other photosensitive array, captures frames, frames are analyzed, and phosphenes are actuated accordingly by way of modulated charge injections. Here, we present a method that allows the assessment of image analysis schemes for integration with a prosthetic device, that is, the means of converting the captured image (high resolution) to modulated charge injections (low resolution). We use the mutual-information function to quantify the amount of information conveyed to the PI observer (device implantee), while accounting for the statistics of visual stimuli. We demonstrate an effective scheme involving overlapping, Gaussian kernels, and discuss extensions of the method to account for shortterm visual memory in observers, and their perceptual errors of omission and commission.

Anthropomorphic cardiac ultrasound phantom.

PubMed

Smith, S W; Rinaldi, J E

1989-10-01

A new phantom is described which simulates the human cardiac anatomy for applications in ultrasound imaging, ultrasound Doppler, and color-flow Doppler imaging. The phantom consists of a polymer left ventricle which includes a prosthetic mitral and aortic valve and is connected to a mock circulatory loop. Aerated tap water serves as a blood simulating fluid and ultrasound contrast medium within the circulatory loop. The left ventricle is housed in a Lexan ultrasound visualization chamber which includes ultrasound viewing ports and acoustic absorbers. A piston pump connected to the visualization chamber by a single port pumps degassed water within the chamber which in turn pumps the left ventricle. Real-time ultrasound images and Doppler studies measure flow patterns through the valves and within the left ventricle.

Artificial organs: recent progress in artificial hearing and vision.

PubMed

Ifukube, Tohru

2009-01-01

Artificial sensory organs are a prosthetic means of sending visual or auditory information to the brain by electrical stimulation of the optic or auditory nerves to assist visually impaired or hearing-impaired people. However, clinical application of artificial sensory organs, except for cochlear implants, is still a trial-and-error process. This is because how and where the information transmitted to the brain is processed is still unknown, and also because changes in brain function (plasticity) remain unknown, even though brain plasticity plays an important role in meaningful interpretation of new sensory stimuli. This article discusses some basic unresolved issues and potential solutions in the development of artificial sensory organs such as cochlear implants, brainstem implants, artificial vision, and artificial retinas.

Visualizing anatomical evidences on atrioventricular conduction system for TAVI.

PubMed

Kawashima, Tomokazu; Sato, Fumi

2014-06-01

Visualizing the anatomy of the atrioventricular (AV) conduction axis substantiates that there is remarkable inter-individual variation at the macro- and microscopic levels, and that the atrioventricular bundle and left bundle branch are located more anteriorly, distally, and cranially and much closer to the aortic root complex than previously thought. The AV conduction system may therefore be compromised during implantation of a transcatheter aortic valve prosthesis, which may account for the relatively high incidence of new cardiac conduction abnormalities when conventional prosthetic valves are used. The design of the newer JenaValve® may afford advantages over more conventional valves by avoiding the high-risk implantation area and the potential for coronary ostia obstruction. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Expert training with standardized operative technique helps establish a successful penile prosthetics program for urologic resident education.

PubMed

King, Ashley B; Klausner, Adam P; Johnson, Corey M; Moore, Blake W; Wilson, Steven K; Grob, B Mayer

2011-10-01

The challenge of resident education in urologic surgery programs is to overcome disparity imparted by diverse patient populations, limited training times, and inequalities in the availability of expert surgical educators. Specifically, in the area of prosthetic urology, only a small proportion of programs have full-time faculty available to train residents in this discipline. To examine whether a new model using yearly training sessions from a recognized expert can establish a successful penile prosthetics program and result in better outcomes, higher case volumes, and willingness to perform more complex surgeries. A recognized expert conducted one to two operative training sessions yearly to teach standardized technique for penile prosthetics to residents. Each session consisted of three to four operative cases performed under the direct supervision of the expert. Retrospective data were collected from all penile prosthetic operations before (February, 2000 to June, 2004: N = 44) and after (July, 2004 to October, 2007: N = 79) implementation of these sessions. Outcomes reviewed included patient age, race, medical comorbidities, operative time, estimated blood loss, type of prosthesis, operative approach, drain usage, length of stay, and complications including revision/explantation rates. Statistical analysis was performed using Student's t-tests, Fisher's tests, and survival curves using the Kaplan-Meier technique (P value ≤ 0.05 to define statistical significance). Patient characteristics were not significantly different pre- vs. post-training. Operative time and estimated blood loss significantly decreased. Inflatable implants increased from 19/44 (43.2%, pre-training) to 69/79 (87.3%, post-training) (P < 0.01). Operations per year increased from 9.96 (pre-training) to 24 (post-training) (P < 0.01). Revision/explantation occurred in 11/44 patients (25%, pre-training) vs. 7/79 (8.9%, post-training) (P < 0.05). These data demonstrate that yearly sessions with a recognized expert can improve surgical outcomes, type, and volume of implants and can reduce explantation/revision rates. This represents an excellent model for improved training of urologic residents in penile prosthetics surgery. © 2011 International Society for Sexual Medicine.

Experimental and failure analysis of the prosthetic finger joint implants

NASA Astrophysics Data System (ADS)

Naidu, Sanjiv H.

Small joint replacement arthroplasty of the hand is a well accepted surgical procedure to restore function and cosmesis in an individual with a crippled hand. Silicone elastomers have been used as prosthetic material in various small hand joints for well over three decades. Although the clinical science aspects of silicone elastomer failure are well known, the physical science aspects of prosthetic failure are scant and vague. In the following thesis, using both an animal model, and actual retrieved specimens which have failed in human service, experimental and failure analysis of silicone finger joints are presented. Fractured surfaces of retrieved silicone trapezial implants, and silicone finger joint implants were studied with both FESEM and SEM; the mode of failure for silicone trapezium is by wear polishing, whereas the finger joint implants failed either by fatigue fracture or tearing of the elastomer, or a combination of both. Thermal analysis revealed that the retrieved elastomer implants maintained its viscoelastic properties throughout the service period. In order to provide for a more functional and physiologic arthroplasty a novel finger joint (Rolamite prosthesis) is proposed using more recently developed thermoplastic polymers. The following thesis also addresses the outcome of the experimental studies of the Rolamite prosthesis in a rabbit animal model, in addition to the failure analysis of the thermoplastic polymers while in service in an in vivo synovial environment. Results of retrieved Rolamite specimens suggest that the use for thermoplastic elastomers such as block copolymer based elastomers in a synovial environment such as a mammalian joint may very well be limited.

The relationship between elastomer opacity, colorimeter beam size, and measured colorimetric response.

PubMed

Rugh, E H; Johnston, W M; Hesse, N S

1991-01-01

The effect of opacity on the colorimetric responses of large-area and small-area colorimeters was determined using an elastomer intended for maxillofacial prosthetics use and containing various pigments at different concentrations. Opacity was determined by calculating the contrast ratio of 2-mm-thick specimens against black and white backings, using Kubelka-Munk analyses to correct for thickness and backing color variations. The measure of comparison of the two colorimeters was the relative difference in tristimulus reflectance, with the tristimulus reflectance of the large-area colorimeter as the basis of the relative difference. A significant quadratic relationship was found between contrast ratio and the relative difference in tristimulus reflectance. This relationship may be used to describe opacity without the need to make optical observations or measurements of a thin layer of material on contrasting backings. The small-area colorimeter produced color parameters that are a measure of the combined effects of both color and opacity. The importance of beam size considerations of optical measuring devices for translucent natural and prosthetic materials was emphasized.

Improved synthesis of [¹⁸F]FS-PTAD as a new tyrosine-specific prosthetic group for radiofluorination of biomolecules.

PubMed

Al-Momani, Ehab; Israel, Ina; Buck, Andreas K; Samnick, Samuel

2015-10-01

A novel prosthetic group, 4-(p-([(18)F]fluorosulfonyl)phenyl)-1,2,4-triazoline-3,5-dione ([(18)F]FS-PTAD) for site-specific radiofluorination of tyrosine residue in small molecules is described. Coupling of [(18)F]FS-PTAD with L-tyrosine, N-acetyl-L-tyrosine methyl amide and phenol as model compounds were achieved in buffered aqueous solution at room temperature, resulting in the corresponding fluorinated tyrosine and phenol derivatives. The total synthesis time including radiosynthesis, HPLC purification and formulation was less than 60 min (n=15) with ≥98% radio chemical purity. An initial in vitro evaluation of [(18)F]FS-PTAD-tyrosine in glioma cell lines revealed moderate uptake. Copyright © 2015 Elsevier Ltd. All rights reserved.

21 CFR 870.3945 - Prosthetic heart valve sizer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of the...

21 CFR 870.3945 - Prosthetic heart valve sizer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of the...

21 CFR 870.3945 - Prosthetic heart valve sizer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of the...

21 CFR 870.3945 - Prosthetic heart valve sizer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of the...

21 CFR 870.3945 - Prosthetic heart valve sizer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of the...

The effects of transverse rotation angle on compression and effective lever arm of prosthetic feet during simulated stance.

PubMed

Major, Matthew J; Howard, David; Jones, Rebecca; Twiste, Martin

2012-06-01

Unlike sagittal plane prosthesis alignment, few studies have observed the effects of transverse plane alignment on gait and prosthesis behaviour. Changes in transverse plane rotation angle will rotate the points of loading on the prosthesis during stance and may alter its mechanical behaviour. This study observed the effects of increasing the external transverse plane rotation angle, or toe-out, on foot compression and effective lever arm of three commonly prescribed prosthetic feet. The roll-over shape of a SACH, Flex and single-axis foot was measured at four external rotation angle conditions (0°, 5°, 7° and 12° relative to neutral). Differences in foot compression between conditions were measured as average distance between roll-over shapes. Increasing the transverse plane rotation angle did not affect foot compression. However, it did affect the effective lever arm, which was maximized with the 5° condition, although differences between conditions were small. Increasing the transverse plane rotation angle of prosthetic feet by up to 12° beyond neutral has minimal effects on their mechanical behaviour in the plane of walking progression during weight-bearing.

A Prosthetic Foot Emulator to Optimize Prescription of Prosthetic Feet in Veterans and Service Members with Leg Amputations

DTIC Science & Technology

2017-09-01

AWARD NUMBER: W81XWH-16-1-0569 TITLE: A Prosthetic Foot Emulator to Optimize Prescription of Prosthetic Feet in Veterans and Service Members...Headquarters Services , Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202- 4302...GRANT NUMBER A Prosthetic Foot Emulator to Optimize Prescription of Prosthetic Feet in Veterans and Service Members with Leg Amputations 5c

Prosthesis use in adult acquired major upper-limb amputees: patterns of wear, prosthetic skills and the actual use of prostheses in activities of daily life.

PubMed

Østlie, Kristin; Lesjø, Ingrid Marie; Franklin, Rosemary Joy; Garfelt, Beate; Skjeldal, Ola Hunsbeth; Magnus, Per

2012-11-01

To describe patterns of prosthesis wear and perceived prosthetic usefulness in adult acquired upper-limb amputees (ULAs). To describe prosthetic skills in activities of daily life (ADL) and the actual use of prostheses in the performance of ADL tasks. To estimate the influence of prosthetic skills on actual prosthesis use and the influence of background factors on prosthetic skills and actual prosthesis use. Cross-sectional study analysing population-based questionnaire data (n = 224) and data from interviews and clinical testing in a referred/convenience sample of prosthesis-wearing ULAs (n = 50). Effects were analysed using linear regression. 80.8% wore prostheses. 90.3% reported their most worn prosthesis as useful. Prosthetic usefulness profiles varied with prosthetic type. Despite demonstrating good prosthetic skills, the amputees reported actual prosthesis use in only about half of the ADL tasks performed in everyday life. In unilateral amputees, increased actual use was associated with sufficient prosthetic training and with the use of myoelectric vs cosmetic prostheses, regardless of amputation level. Prosthetic skills did not affect actual prosthesis use. No background factors showed significant effect on prosthetic skills. Most major ULAs wear prostheses. Individualised prosthetic training and fitting of myoelectric rather than passive prostheses may increase actual prosthesis use in ADL.

Iris reconstruction using artificial iris prosthesis for management of aniridia.

PubMed

Mostafa, Yehia S; Osman, Amr A; Hassanein, Dina H; Zeid, Ashraf M; Sherif, Ahmed M

2018-01-01

To discuss the limitations and benefits of the BrightOcular prosthetic artificial iris device in management of aniridia associated with aphakia or cataract. This is a retrospective study including 5 eyes of 4 patients who underwent implantation of the BrightOcular iris prosthesis (Stellar Devices) for total or partial aniridia. The cases included 2 eyes of 1 patient with congenital aniridia associated with congenital cataract and 3 eyes with traumatic aniridia: 1 with subluxated cataractous lens and 2 with aphakia. In all cases, the iris prosthesis was implanted after a 3-piece acrylic intraocular lens was implanted. We evaluated the clinical course with a minimum follow-up period of 6 months, the intraoperative and postoperative complications, and the cosmetic satisfaction of patients. All patients had improved uncorrected distance visual acuity and best-corrected distance visual acuity. All patients had a transient corneal edema that resolved within the first postoperative week. Only the patient with congenital aniridia had a permanent increase in intraocular pressure and developed a band keratopathy throughout a 2-year follow-up period. The prosthesis was well-centered in all eyes except for one case that required scleral suture fixation after 3 months. All patients had a satisfactory cosmetic appearance. BrightOcular iris prosthesis is a safe and useful tool to correct aniridia associated with pseudophakia or aphakia. Being foldable, it is easy to be implanted through a small incision and placed in the ciliary sulcus without sutures when properly sized. Cosmetic results are satisfactory. Sizing methods should be improved.

Rothia mucilaginosa Prosthetic Device Infections: a Case of Prosthetic Valve Endocarditis

PubMed Central

Tokarczyk, Mindy J.; Jungkind, Donald; DeSimone, Joseph A.

2013-01-01

Rothia mucilaginosa is increasingly recognized as an emerging opportunistic pathogen associated with prosthetic device infections. Infective endocarditis is one of the most common clinical presentations. We report a case of R. mucilaginosa prosthetic valve endocarditis and review the literature of prosthetic device infections caused by this organism. PMID:23467598

Towards photorealistic and immersive virtual-reality environments for simulated prosthetic vision: integrating recent breakthroughs in consumer hardware and software.

PubMed

Zapf, Marc P; Matteucci, Paul B; Lovell, Nigel H; Zheng, Steven; Suaning, Gregg J

2014-01-01

Simulated prosthetic vision (SPV) in normally sighted subjects is an established way of investigating the prospective efficacy of visual prosthesis designs in visually guided tasks such as mobility. To perform meaningful SPV mobility studies in computer-based environments, a credible representation of both the virtual scene to navigate and the experienced artificial vision has to be established. It is therefore prudent to make optimal use of existing hardware and software solutions when establishing a testing framework. The authors aimed at improving the realism and immersion of SPV by integrating state-of-the-art yet low-cost consumer technology. The feasibility of body motion tracking to control movement in photo-realistic virtual environments was evaluated in a pilot study. Five subjects were recruited and performed an obstacle avoidance and wayfinding task using either keyboard and mouse, gamepad or Kinect motion tracking. Walking speed and collisions were analyzed as basic measures for task performance. Kinect motion tracking resulted in lower performance as compared to classical input methods, yet results were more uniform across vision conditions. The chosen framework was successfully applied in a basic virtual task and is suited to realistically simulate real-world scenes under SPV in mobility research. Classical input peripherals remain a feasible and effective way of controlling the virtual movement. Motion tracking, despite its limitations and early state of implementation, is intuitive and can eliminate between-subject differences due to familiarity to established input methods.

Toward high-resolution optoelectronic retinal prosthesis

NASA Astrophysics Data System (ADS)

Palanker, Daniel; Huie, Philip; Vankov, Alexander; Asher, Alon; Baccus, Steven

2005-04-01

It has been already demonstrated that electrical stimulation of retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. Current retinal implants provide very low resolution (just a few electrodes), while several thousand pixels are required for functional restoration of sight. We present a design of the optoelectronic retinal prosthetic system that can activate a retinal stimulating array with pixel density up to 2,500 pix/mm2 (geometrically corresponding to a visual acuity of 20/80), and allows for natural eye scanning rather than scanning with a head-mounted camera. The system operates similarly to "virtual reality" imaging devices used in military and medical applications. An image from a video camera is projected by a goggle-mounted infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. Such a system provides a broad field of vision by allowing for natural eye scanning. The goggles are transparent to visible light, thus allowing for simultaneous utilization of remaining natural vision along with prosthetic stimulation. Optical control of the implant allows for simple adjustment of image processing algorithms and for learning. A major prerequisite for high resolution stimulation is the proximity of neural cells to the stimulation sites. This can be achieved with sub-retinal implants constructed in a manner that directs migration of retinal cells to target areas. Two basic implant geometries are described: perforated membranes and protruding electrode arrays. Possibility of the tactile neural stimulation is also examined.

Clinical Presentation, Risk Factors, and Outcomes of Hematogenous Prosthetic Joint Infection in Patients with Staphylococcus aureus Bacteremia.

PubMed

Tande, Aaron J; Palraj, Bharath Raj; Osmon, Douglas R; Berbari, Elie F; Baddour, Larry M; Lohse, Christine M; Steckelberg, James M; Wilson, Walter R; Sohail, M Rizwan

2016-02-01

Staphylococcus aureus bacteremia is a life-threatening condition that may lead to metastatic infection, including prosthetic joint infection. To assess clinical factors associated with hematogenous prosthetic joint infection, we retrospectively reviewed all patients with a joint arthroplasty in place at the time of a first episode of S. aureus bacteremia over a 5-year period at our institution. Patients with postsurgical prosthetic joint infection without hematogenous prosthetic joint infection were excluded. There were 85 patients (143 arthroplasties) with either no prosthetic joint infection (n = 50; 58.8%) or hematogenous prosthetic joint infection in at least one arthroplasty (n = 35; 41.2%). The odds of hematogenous prosthetic joint infection was significantly increased among patients with community-acquired S. aureus bacteremia (odds ratio [OR] 18.07; 95% confidence interval [CI] 2.64-infinity; P = .001), as compared with nosocomial S. aureus bacteremia, in which there were no patients with hematogenous prosthetic joint infection. After adjusting for S. aureus bacteremia classification, the presence of ≥3 joint arthroplasties in place was associated with a nearly ninefold increased odds of hematogenous prosthetic joint infection as compared with those with 1-2 joint arthroplasties in place (OR 8.55; 95% CI 1.44-95.71; P = .012). All but one joint with prosthetic joint infection demonstrated at least one clinical feature suggestive of infection. There were 4 additional S. aureus prosthetic joint infections diagnosed during a median of 3.4 years of follow-up post hospitalization for S. aureus bacteremia. Prosthetic joint infection is frequent in patients with existing arthroplasties and concomitant S. aureus bacteremia, particularly with community-acquired S. aureus bacteremia and multiple prostheses. In contrast, occult S. aureus prosthetic joint infection without clinical features suggestive of prosthetic joint infection at the time of S. aureus bacteremia is rare. Copyright © 2016 Elsevier Inc. All rights reserved.

A system verification platform for high-density epiretinal prostheses.

PubMed

Chen, Kuanfu; Lo, Yi-Kai; Yang, Zhi; Weiland, James D; Humayun, Mark S; Liu, Wentai

2013-06-01

Retinal prostheses have restored light perception to people worldwide who have poor or no vision as a consequence of retinal degeneration. To advance the quality of visual stimulation for retinal implant recipients, a higher number of stimulation channels is expected in the next generation retinal prostheses, which poses a great challenge to system design and verification. This paper presents a system verification platform dedicated to the development of retinal prostheses. The system includes primary processing, dual-band power and data telemetry, a high-density stimulator array, and two methods for output verification. End-to-end system validation and individual functional block characterization can be achieved with this platform through visual inspection and software analysis. Custom-built software running on the computers also provides a good way for testing new features before they are realized by the ICs. Real-time visual feedbacks through the video displays make it easy to monitor and debug the system. The characterization of the wireless telemetry and the demonstration of the visual display are reported in this paper using a 256-channel retinal prosthetic IC as an example.

Learning to see again: biological constraints on cortical plasticity and the implications for sight restoration technologies

NASA Astrophysics Data System (ADS)

Beyeler, Michael; Rokem, Ariel; Boynton, Geoffrey M.; Fine, Ione

2017-10-01

The ‘bionic eye’—so long a dream of the future—is finally becoming a reality with retinal prostheses available to patients in both the US and Europe. However, clinical experience with these implants has made it apparent that the visual information provided by these devices differs substantially from normal sight. Consequently, the ability of patients to learn to make use of this abnormal retinal input plays a critical role in whether or not some functional vision is successfully regained. The goal of the present review is to summarize the vast basic science literature on developmental and adult cortical plasticity with an emphasis on how this literature might relate to the field of prosthetic vision. We begin with describing the distortion and information loss likely to be experienced by visual prosthesis users. We then define cortical plasticity and perceptual learning, and describe what is known, and what is unknown, about visual plasticity across the hierarchy of brain regions involved in visual processing, and across different stages of life. We close by discussing what is known about brain plasticity in sight restoration patients and discuss biological mechanisms that might eventually be harnessed to improve visual learning in these patients.

Psychophysical testing of visual prosthetic devices: a call to establish a multi-national joint task force

NASA Astrophysics Data System (ADS)

Rizzo, Joseph F., III; Ayton, Lauren N.

2014-04-01

Recent advances in the field of visual prostheses, as showcased in this special feature of Journal of Neural Engineering , have led to promising results from clinical trials of a number of devices. However, as noted by these groups there are many challenges involved in assessing vision of people with profound vision loss. As such, it is important that there is consistency in the methodology and reporting standards for clinical trials of visual prostheses and, indeed, the broader vision restoration research field. Two visual prosthesis research groups, the Boston Retinal Implant Project (BRIP) and Bionic Vision Australia (BVA), have agreed to work cooperatively to establish a multi-national Joint Task Force. The aim of this Task Force will be to develop a consensus statement to guide the methods used to conduct and report psychophysical and clinical results of humans who receive visual prosthetic devices. The overarching goal is to ensure maximum benefit to the implant recipients, not only in the outcomes of the visual prosthesis itself, but also in enabling them to obtain accurate information about this research with ease. The aspiration to develop a Joint Task Force was first promulgated at the inaugural 'The Eye and the Chip' meeting in September 2000. This meeting was established to promote the development of the visual prosthetic field by applying the principles of inclusiveness, openness, and collegiality among the growing body of researchers in this field. These same principles underlie the intent of this Joint Task Force to enhance the quality of psychophysical research within our community. Despite prior efforts, a critical mass of interested parties could not congeal. Renewed interest for developing joint guidelines has developed recently because of a growing awareness of the challenges of obtaining reliable measurements of visual function in patients who are severely visually impaired (in whom testing is inherently noisy), and of the importance of comparing outcomes amongst the many research teams that have entered this field, all of which are using different devices implanted at various locations within the visual system and different methods of assessing efficacy. Researchers at the BRIP and BVA believe that use of common methods for testing and for reporting results would benefit all scientists and clinicians in the field, the agencies that regulate human testing, corporations that are invested in the success of this field, and, most importantly, potential patients. The Task Force will be formed with the intent of developing substantive recommendations to provide a measure of consistency and quality control within the field. The guidelines will offer recommendations for the assessment of the: (1) baseline (pre-implant) visual status of potential patients (including specification of the disease diagnosis and impact on visual functioning) and (2) post-operative visual function. The guidelines will be available to the public, research groups and companies. Any groups that choose to adopt the recommendations would be encouraged to include a formal statement of compliance in their presentations and publications. The Task Force will develop these guidelines with the understanding that the ability to perform experiments in the suggested manner might be limited by the particular engineering design and functionality of different prosthesis devices. It is not the intent of the Task Force to write strict test protocols for all parties to follow, but instead to work cooperatively as a research field to develop guidelines about the types of tests that should be implemented, and how they could be reported in a similar format between groups. The opportunity to participate on the Task Force is open to all researchers, clinicians and other specialists who work in the fields of sensory prostheses (both visual and cochlear implants), molecular therapy, stem cells, optogenetics or other fields that share a similar goal of restoring vision to the blind. Decisions about the guidelines will be made democratically, with precautions to prevent any one group or company from having a more dominant voice than any other. One or more smaller working groups may be established to delve more deeply into specific issues, like the ethics of testing or governance structure, and to develop specific wording for recommendations that would be voted on by the entire Task Force group. Ultimately, the various recommendations, once approved democratically, will serve as the consensus document for the Multi-National Joint Task Force. The full list of members of the Task Force and the rules of governance will be published to promote transparency. The Joint Task force will post its guidelines with all signatories on a dedicated page within the website of the Henry Ford Department of Ophthalmology (Detroit). This site was chosen in recognition of the consistent support that Phillip Hessburg MD and the Board of Directors of the Detroit Institute of Ophthalmology, which has recently merged with the Henry Ford Department of Ophthalmology, have so generously and selflessly provided to our field over the past 14 years. This website will also contain a list of all human psychophysical testing that has been performed in the visual prosthetic field, with designations for those studies that were performed in accordance with the guidelines of the Multi-National Task Force, which will assume responsibility for the accuracy of the material. For those who wish to join this Task Force or have further questions, Dr Rizzo and Dr Ayton can be contacted at the email addresses listed above. The founding members of the Task Force anticipate that this digital resource will prove valuable to anyone who has interest in learning more about the achievements in our field, especially our prospective patients, to whom we dedicate our work.

Factors Associated with Prosthetic Looseness in Lower Limb Amputees.

PubMed

Phonghanyudh, Thong; Sutpasanon, Taweesak; Hathaiareerug, Chanasak; Devakula, M L Buddhibongsa; Kumnerddee, Wipoo

2015-12-01

To determine the factors associated with prosthetic looseness in lower limb amputees in Sisaket province. The present was a cross-sectional descriptive study. Subjects were lower limb amputees who previously obtained prostheses and required prosthetic replacements at the mobile prosthetic laboratory unit under the Prostheses Foundation of H.R.H. the Princess Mother at Khun Han Hospital, Sisaket province, in February 2013. Data including participant characteristics, prosthetic looseness data, and various variables were collected by direct semi-structured interview. Energy expenditures in physical activities were measured using the Thai version of the short format international physical activity questionnaire. Data between participants with and without prosthetic looseness were compared to determine prosthetic loosening associated factors. Among 101 participants enrolled, 33 (32.7%) had prosthetic looseness with average onset of 1.76 ± 1.67 years. Diabetes mellitus was the only significant factor associated with prosthetic looseness from both univariate and multivariate analyses (HR = 7.05, p = 0.002 and HR = 5.93, p = 0.007 respectively). Among the lower limb amputees in Sisaket province, diabetes mellitus was the only factor associated with prosthetic looseness. Therefore, diabetic screening should be supplemented in lower limb amputee assessment protocol. In addition, we recommend that amputees with diabetes mellitus should receive prosthesis check out at approximately

Threshold concepts in prosthetics.

PubMed

Hill, Sophie

2017-12-01

Curriculum documents identify key concepts within learning prosthetics. Threshold concepts provide an alternative way of viewing the curriculum, focussing on the ways of thinking and practicing within prosthetics. Threshold concepts can be described as an opening to a different way of viewing a concept. This article forms part of a larger study exploring what students and staff experience as difficult in learning about prosthetics. To explore possible threshold concepts within prosthetics. Qualitative, interpretative phenomenological analysis. Data from 18 students and 8 staff at two universities with undergraduate prosthetics and orthotics programmes were generated through interviews and questionnaires. The data were analysed using an interpretative phenomenological analysis approach. Three possible threshold concepts arose from the data: 'how we walk', 'learning to talk' and 'considering the person'. Three potential threshold concepts in prosthetics are suggested with possible implications for prosthetics education. These possible threshold concepts involve changes in both conceptual and ontological knowledge, integrating into the persona of the individual. This integration occurs through the development of memories associated with procedural concepts that combine with disciplinary concepts. Considering the prosthetics curriculum through the lens of threshold concepts enables a focus on how students learn to become prosthetists. Clinical relevance This study provides new insights into how prosthetists learn. This has implications for curriculum design in prosthetics education.

Advanced upper limb prosthetic devices: implications for upper limb prosthetic rehabilitation.

PubMed

Resnik, Linda; Meucci, Marissa R; Lieberman-Klinger, Shana; Fantini, Christopher; Kelty, Debra L; Disla, Roxanne; Sasson, Nicole

2012-04-01

The number of catastrophic injuries caused by improvised explosive devices in the Afghanistan and Iraq Wars has increased public, legislative, and research attention to upper limb amputation. The Department of Veterans Affairs (VA) has partnered with the Defense Advanced Research Projects Agency and DEKA Integrated Solutions to optimize the function of an advanced prosthetic arm system that will enable greater independence and function. In this special communication, we examine current practices in prosthetic rehabilitation including trends in adoption and use of prosthetic devices, financial considerations, and the role of rehabilitation team members in light of our experiences with a prototype advanced upper limb prosthesis during a VA study to optimize the device. We discuss key challenges in the adoption of advanced prosthetic technology and make recommendations for service provision and use of advanced upper limb prosthetics. Rates of prosthetic rejection are high among upper limb amputees. However, these rates may be reduced with sufficient training by a highly specialized, multidisciplinary team of clinicians, and a focus on patient education and empowerment throughout the rehabilitation process. There are significant challenges emerging that are unique to implementing the use of advanced upper limb prosthetic technology, and a lack of evidence to establish clinical guidelines regarding prosthetic prescription and treatment. Finally, we make recommendations for future research to aid in the identification of best practices and development of policy decisions regarding insurance coverage of prosthetic rehabilitation. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

AB0 blood types: impact on development of prosthetic mechanical valve thrombosis

PubMed Central

Astarcıoğlu, Mehmet Ali; Kalçık, Macit; Yesin, Mahmut; Gürsoy, Mustafa Ozan; Şen, Taner; Karakoyun, Süleyman; Gündüz, Sabahattin; Özkan, Mehmet

2016-01-01

Objective: The non-O alleles of the ABO genotype have been associated with an increased risk of thrombosis. We aimed to assess the association between blood group status and prosthetic valve thrombosis. Methods: The association between AB0 blood group status and prosthetic valve thrombosis was assessed in this retrospective study. Transesophageal echocardiography was performed in 149 patients with a diagnosis of prosthetic valve thrombosis and in 192 control subjects. Results: Non-0 blood group type (p<0.001), presence of NYHA class III-IV status (p<0.001), and central nervous system (p<0.001) and non-central nervous system (p<0.001) emboli were significantly more prevalent in prosthetic valve thrombosis patients than in the control subjects. The incidence of ineffective anticoagulation was higher in patients with prosthetic valve thrombosis than in controls (p<0.001), as was the presence of moderate to severe left atrial spontaneous echo contrast (p<0.001). The non-0 blood prosthetic valve thrombosis subgroup had a higher incidence of obstructive thrombi and central nervous system thrombotic events than having 0 blood prosthetic valve thrombosis subgroup. Non-0 blood group, ineffective anticoagulation, left atrial spontaneous echo contrast, and a poor NYHA functional capacity were identified to be the predictors of prosthetic valve thrombosis. Conclusion: Our data demonstrate that patients with non-0 compared with 0 blood groups have higher incidence of prosthetic valve thrombosis and central nervous system embolism and similar rates of non-central nervous system embolism at presentation compared with 0 blood group type. Thus, non-O blood group may be a risk factor that may be prone to the development of prosthetic valve thrombosis in patients with prosthetic heart valves. PMID:27488753

The Effect of Prosthetic Foot Push-off on Mechanical Loading Associated with Knee Osteoarthritis in Lower Extremity Amputees

PubMed Central

Morgenroth, David C.; Segal, Ava D.; Zelik, Karl E.; Czerniecki, Joseph M.; Klute, Glenn K.; Adamczyk, Peter G.; Orendurff, Michael S.; Hahn, Michael E.; Collins, Steven H.; Kuo, Art D.

2011-01-01

Lower extremity amputation not only limits mobility, but also increases the risk of knee osteoarthritis of the intact limb. Dynamic walking models of non-amputees suggest that pushing-off from the trailing limb can reduce collision forces on the leading limb. These collision forces may determine the peak knee external adduction moment (EAM), which has been linked to the development of knee OA in the general population. We therefore hypothesized that greater prosthetic push-off would lead to reduced loading and knee EAM of the intact limb in unilateral transtibial amputees. Seven unilateral transtibial amputees were studied during gait under three prosthetic foot conditions that were intended to vary push-off. Prosthetic foot-ankle push-off work, intact limb knee EAM and ground reaction impulses for both limbs during step-to-step transition were measured. Overall, trailing limb prosthetic push-off work was negatively correlated with leading intact limb 1st peak knee EAM (slope = −0.72 +/− 0.22; p=0.011). Prosthetic push-off work and 1st peak intact knee EAM varied significantly with foot type. The prosthetic foot condition with the least push-off demonstrated the largest knee EAM, which was reduced by 26% with the prosthetic foot producing the most push-off. Trailing prosthetic limb push-off impulse was negatively correlated with leading intact limb loading impulse (slope = −0.34 +/− 0.14; p=.001), which may help explain how prosthetic limb push-off can affect intact limb loading. Prosthetic feet that perform more prosthetic push-off appear to be associated with a reduction in 1st peak intact knee EAM, and their use could potentially reduce the risk and burden of knee osteoarthritis in this population. PMID:21803584

The effect of prosthetic foot push-off on mechanical loading associated with knee osteoarthritis in lower extremity amputees.

PubMed

Morgenroth, David C; Segal, Ava D; Zelik, Karl E; Czerniecki, Joseph M; Klute, Glenn K; Adamczyk, Peter G; Orendurff, Michael S; Hahn, Michael E; Collins, Steven H; Kuo, Art D

2011-10-01

Lower extremity amputation not only limits mobility, but also increases the risk of knee osteoarthritis of the intact limb. Dynamic walking models of non-amputees suggest that pushing-off from the trailing limb can reduce collision forces on the leading limb. These collision forces may determine the peak knee external adduction moment (EAM), which has been linked to the development of knee OA in the general population. We therefore hypothesized that greater prosthetic push-off would lead to reduced loading and knee EAM of the intact limb in unilateral transtibial amputees. Seven unilateral transtibial amputees were studied during gait under three prosthetic foot conditions that were intended to vary push-off. Prosthetic foot-ankle push-off work, intact limb knee EAM and ground reaction impulses for both limbs during step-to-step transition were measured. Overall, trailing limb prosthetic push-off work was negatively correlated with leading intact limb 1st peak knee EAM (slope=-.72±.22; p=.011). Prosthetic push-off work and 1st peak intact knee EAM varied significantly with foot type. The prosthetic foot condition with the least push-off demonstrated the largest knee EAM, which was reduced by 26% with the prosthetic foot producing the most push-off. Trailing prosthetic limb push-off impulse was negatively correlated with leading intact limb loading impulse (slope=-.34±.14; p=.001), which may help explain how prosthetic limb push-off can affect intact limb loading. Prosthetic feet that perform more prosthetic push-off appear to be associated with a reduction in 1st peak intact knee EAM, and their use could potentially reduce the risk and burden of knee osteoarthritis in this population. Published by Elsevier B.V.

Perceived self-efficacy and specific self-reported outcomes in persons with lower-limb amputation using a non-microprocessor-controlled versus a microprocessor-controlled prosthetic knee.

PubMed

Möller, Saffran; Hagberg, Kerstin; Samulesson, Kersti; Ramstrand, Nerrolyn

2018-04-01

To measure self-efficacy in a group of individuals who have undergone a lower-limb amputation and investigate the relationship between self-efficacy and prosthetic-specific outcomes including prosthetic use, mobility, amputation-related problems and global health. A second purpose was to examine if differences exist in outcomes based upon the type of prosthetic knee unit being used. Cross-sectional study using the General Self-Efficacy (GSE) Scale and the Questionnaire for Persons with a Transfemoral Amputation (Q-TFA). Forty-two individuals participated in the study. Twenty-three used a non-microprocessor-controlled prosthetic knee joint (non-MPK) and 19 used a microprocessor-controlled prosthetic knee joint (MPK). The study sample had quite high GSE scores (32/40). GSE scores were significantly correlated to the Q-TFA prosthetic use, mobility and problem scores. High GSE scores were related to higher levels of prosthetic use, mobility, global scores and negatively related to problem score. No significant difference was observed between individuals using a non-MPK versus MPK joints. Individuals with high self-efficacy used their prosthesis to a higher degree and high self-efficacy was related to higher level of mobility, global scores and fewer problems related to the amputation in individuals who have undergone a lower-limb amputation and were using a non-MPK or MPK knee. Implications for rehabilitation Perceived self-efficacy has has been shown to be related to quality of life, prosthetic mobility and capability as well as social activities in daily life. Prosthetic rehabilitation is primary focusing on physical improvement rather than psychological interventions. More attention should be directed towards the relationship between self-efficacy and prosthetic related outcomes during prosthetic rehabilitation after a lower-limb amputation.

Development of a model osseo-magnetic link for intuitive rotational control of upper-limb prostheses.

PubMed

Rouse, Elliott J; Nahlik, David C; Peshkin, Michael A; Kuiken, Todd A

2011-04-01

The lack of proprioceptive feedback is a serious deficiency of current prosthetic control systems. The Osseo-Magnetic Link (OML) is a novel humeral or wrist rotation control system that could preserve proprioception. It utilizes a magnet implanted within the residual bone and sensors mounted in the prosthetic socket to detect magnetic field vectors and determine the bone's orientation. This allows the use of volitional bone rotation to control a prosthetic rotator. We evaluated the performance of the OML using a physical model of a transhumeral residual limb. A small Neodymium-Iron-Boron magnet was placed in a model humerus, inside a model upper arm. Four three-axis Hall-effect sensors were mounted on a ring 3 cm distal to the magnet. An optimization algorithm based on Newton's method determined the position and orientation of the magnet within the model humerus under various conditions, including bone translations, interference, and magnet misalignment. The orientation of the model humerus was determined within 3° for rotations centered in the arm; an additional 6° error was found for translations 20 mm from center. Adjustments in sensor placement may reduce these errors. The results demonstrate that the OML is a feasible solution for providing prosthesis rotation control while preserving rotational proprioception.

Target of physiological gait: Realization of speed adaptive control for a prosthetic knee during swing flexion.

PubMed

Cao, Wujing; Yu, Hongliu; Zhao, Weiliang; Li, Jin; Wei, Xiaodong

2018-01-01

Prosthetic knee is the most important component of lower limb prosthesis. Speed adaptive for prosthetic knee during swing flexion is the key method to realize physiological gait. This study aims to discuss the target of physiological gait, propose a speed adaptive control method during swing flexion and research the damping adjustment law of intelligent hydraulic prosthetic knee. According to the physiological gait trials of healthy people, the control target during swing flexion is defined. A new prosthetic knee with fuzzy logical control during swing flexion is designed to realize the damping adjustment automatically. The function simulation and evaluation system of intelligent knee prosthesis is provided. Speed adaptive control test of the intelligent prosthetic knee in different velocities are researched. The maximum swing flexion of the knee angle is set between sixty degree and seventy degree as the target of physiological gait. Preliminary experimental results demonstrate that the prosthetic knee with fuzzy logical control is able to realize physiological gait under different speeds. The faster the walking, the bigger the valve closure percentage of the hydraulic prosthetic knee. The proposed fuzzy logical control strategy and intelligent hydraulic prosthetic knee are effective for the amputee to achieve physiological gait.

Reduced prosthetic stiffness lowers the metabolic cost of running for athletes with bilateral transtibial amputations.

PubMed

Beck, Owen N; Taboga, Paolo; Grabowski, Alena M

2017-04-01

Inspired by the springlike action of biological legs, running-specific prostheses are designed to enable athletes with lower-limb amputations to run. However, manufacturer's recommendations for prosthetic stiffness and height may not optimize running performance. Therefore, we investigated the effects of using different prosthetic configurations on the metabolic cost and biomechanics of running. Five athletes with bilateral transtibial amputations each performed 15 trials on a force-measuring treadmill at 2.5 or 3.0 m/s. Athletes ran using each of 3 different prosthetic models (Freedom Innovations Catapult FX6, Össur Flex-Run, and Ottobock 1E90 Sprinter) with 5 combinations of stiffness categories (manufacturer's recommended and ± 1) and heights (International Paralympic Committee's maximum competition height and ± 2 cm) while we measured metabolic rates and ground reaction forces. Overall, prosthetic stiffness [fixed effect (β) = 0.036; P = 0.008] but not height ( P ≥ 0.089) affected the net metabolic cost of transport; less stiff prostheses reduced metabolic cost. While controlling for prosthetic stiffness (in kilonewtons per meter), using the Flex-Run (β = -0.139; P = 0.044) and 1E90 Sprinter prostheses (β = -0.176; P = 0.009) reduced net metabolic costs by 4.3-4.9% compared with using the Catapult prostheses. The metabolic cost of running improved when athletes used prosthetic configurations that decreased peak horizontal braking ground reaction forces (β = 2.786; P = 0.001), stride frequencies (β = 0.911; P < 0.001), and leg stiffness values (β = 0.053; P = 0.009). Remarkably, athletes did not maintain overall leg stiffness across prosthetic stiffness conditions. Rather, the in-series prosthetic stiffness governed overall leg stiffness. The metabolic cost of running in athletes with bilateral transtibial amputations is influenced by prosthetic model and stiffness but not height. NEW & NOTEWORTHY We measured the metabolic rates and biomechanics of five athletes with bilateral transtibial amputations while running with different prosthetic configurations. The metabolic cost of running for these athletes is minimized by using an optimal prosthetic model and reducing prosthetic stiffness. The metabolic cost of running was independent of prosthetic height, suggesting that longer legs are not advantageous for distance running. Moreover, the in-series prosthetic stiffness governs the leg stiffness of athletes with bilateral leg amputations.

Treating amblyopia in adults with prosthetic occluding contact lenses.

PubMed

Garcia-Romo, Esperanza; Perez-Rico, Consuelo; Roldán-Díaz, Isabel; Arévalo-Serrano, Juan; Blanco, Román

2018-05-01

To investigate the feasibility, effectiveness and acceptability of using prosthetic occluding contact lenses (OCLs) to treat moderate amblyopia in adults and of the role of the multifocal visual evoked potential (mfVEP) as a predictor of postamblyopic therapy. A comparative, prospective, interventional, case series pilot study with amblyopic adults (mean age: 40 years, range 20-50 years) allocated into two intervention groups: eye patching and OCL. The primary outcome variable was logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA), and secondary outcomes were mfVEP amplitude and latency and patients' health-related quality of life National Eye Institute Visual Function Questionnaire (NEI VFQ-25). Significant improvements in pre- to postamblyopic therapy BCVA were seen at 1.5 months in the OCL group [0.29 logMAR, 95% confidence interval (CI): 0.10-0.47 versus 0.11 logMAR, 95% CI: 0.02-0.19; p < 0.001] and eye patching group (0.29 logMAR, 95% CI: 0.17-0.40 versus 0.18 logMAR, 95% CI: 0.12-0.23; p < 0.01). Post-treatment BCVA was inversely related to age (R: 0.009, 95% CI: -0.02 to -0.001; p = 0.04) and the presence of strabismus (R: -0.3, 95% CI: -0.434 to -0.17; p = 0.001). No significant changes in the number and size of the abnormal mfVEP amplitude and latency defects were observed after occlusion. The NEI VFQ-25 composite score showed significant improvement in the OCL users at 12 months compared to eye patching. Significant vision improvement can be achieved, making occlusion with OCLs an effective and more acceptable therapy for adults with amblyopia. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Federal regulation of vision enhancement devices for normal and abnormal vision

NASA Astrophysics Data System (ADS)

Drum, Bruce

2006-09-01

The Food and Drug Administration (FDA) evaluates the safety and effectiveness of medical devices and biological products as well as food and drugs. The FDA defines a device as a product that is intended, by physical means, to diagnose, treat, or prevent disease, or to affect the structure or function of the body. All vision enhancement devices fulfill this definition because they are intended to affect a function (vision) of the body. In practice, however, FDA historically has drawn a distinction between devices that are intended to enhance low vision as opposed to normal vision. Most low vision aids are therapeutic devices intended to compensate for visual impairment, and are actively regulated according to their level of risk to the patient. The risk level is usually low (e.g. Class I, exempt from 510(k) submission requirements for magnifiers that do not touch the eye), but can be as high as Class III (requiring a clinical trial and Premarket Approval (PMA) application) for certain implanted and prosthetic devices (e.g. intraocular telescopes and prosthetic retinal implants). In contrast, the FDA usually does not actively enforce its regulations for devices that are intended to enhance normal vision, are low risk, and do not have a medical intended use. However, if an implanted or prosthetic device were developed for enhancing normal vision, the FDA would likely decide to regulate it actively, because its intended use would entail a substantial medical risk to the user. Companies developing such devices should contact the FDA at an early stage to clarify their regulatory status.

Neuroengineering tools/applications for bidirectional interfaces, brain-computer interfaces, and neuroprosthetic implants - a review of recent progress.

PubMed

Rothschild, Ryan Mark

2010-01-01

The main focus of this review is to provide a holistic amalgamated overview of the most recent human in vivo techniques for implementing brain-computer interfaces (BCIs), bidirectional interfaces, and neuroprosthetics. Neuroengineering is providing new methods for tackling current difficulties; however neuroprosthetics have been studied for decades. Recent progresses are permitting the design of better systems with higher accuracies, repeatability, and system robustness. Bidirectional interfaces integrate recording and the relaying of information from and to the brain for the development of BCIs. The concepts of non-invasive and invasive recording of brain activity are introduced. This includes classical and innovative techniques like electroencephalography and near-infrared spectroscopy. Then the problem of gliosis and solutions for (semi-) permanent implant biocompatibility such as innovative implant coatings, materials, and shapes are discussed. Implant power and the transmission of their data through implanted pulse generators and wireless telemetry are taken into account. How sensation can be relayed back to the brain to increase integration of the neuroengineered systems with the body by methods such as micro-stimulation and transcranial magnetic stimulation are then addressed. The neuroprosthetic section discusses some of the various types and how they operate. Visual prosthetics are discussed and the three types, dependant on implant location, are examined. Auditory prosthetics, being cochlear or cortical, are then addressed. Replacement hand and limb prosthetics are then considered. These are followed by sections concentrating on the control of wheelchairs, computers and robotics directly from brain activity as recorded by non-invasive and invasive techniques.

Neuroengineering Tools/Applications for Bidirectional Interfaces, Brain–Computer Interfaces, and Neuroprosthetic Implants – A Review of Recent Progress

PubMed Central

Rothschild, Ryan Mark

2010-01-01

The main focus of this review is to provide a holistic amalgamated overview of the most recent human in vivo techniques for implementing brain–computer interfaces (BCIs), bidirectional interfaces, and neuroprosthetics. Neuroengineering is providing new methods for tackling current difficulties; however neuroprosthetics have been studied for decades. Recent progresses are permitting the design of better systems with higher accuracies, repeatability, and system robustness. Bidirectional interfaces integrate recording and the relaying of information from and to the brain for the development of BCIs. The concepts of non-invasive and invasive recording of brain activity are introduced. This includes classical and innovative techniques like electroencephalography and near-infrared spectroscopy. Then the problem of gliosis and solutions for (semi-) permanent implant biocompatibility such as innovative implant coatings, materials, and shapes are discussed. Implant power and the transmission of their data through implanted pulse generators and wireless telemetry are taken into account. How sensation can be relayed back to the brain to increase integration of the neuroengineered systems with the body by methods such as micro-stimulation and transcranial magnetic stimulation are then addressed. The neuroprosthetic section discusses some of the various types and how they operate. Visual prosthetics are discussed and the three types, dependant on implant location, are examined. Auditory prosthetics, being cochlear or cortical, are then addressed. Replacement hand and limb prosthetics are then considered. These are followed by sections concentrating on the control of wheelchairs, computers and robotics directly from brain activity as recorded by non-invasive and invasive techniques. PMID:21060801

77 FR 14989 - Medicare Program; Revisions to the Durable Medical Equipment, Prosthetics, Orthotics, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

... wheelchairs. Prosthetic devices are included in the definition of ``medical and other health services'' in section 1861(s)(8) of the Act. Prosthetic devices are defined as devices (other than dental) which replace... examples of prosthetic devices include cardiac pacemakers, cochlear implants, electrical continence aids...

75 FR 52629 - Medicare Program; Establishing Additional Medicare Durable Medical Equipment, Prosthetics...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-27

... wheelchairs. Prosthetic devices are included in the definition of ``medical and other health services'' under section 1861(s)(8) of the Act. Prosthetic devices are defined in this section of the Act as ``devices... insertion of an intraocular lens.'' Other examples of prosthetic devices include cardiac pacemakers...

Cerebral hemorrhage in infective endocarditis caused by Actinobacillus actinomycetemcomitans.

PubMed

Lin, Gen-Min; Chu, Kai-Min; Juan, Chun-Jung; Chang, Feng-Yee

2007-11-01

Cerebral hemorrhage occurs rarely in endocarditis caused by Actinobacillus actinomycetemcomitans. A 51-year-old man with a prosthetic mitral valve, who had been prophylactically treated (7 years) with warfarin, presented with intermittent fever. On admission, a Levine grade II/VI systolic cardiac murmur was detected. A transthoracic echocardiogram was negative for valve vegetation. Cefepime (1 g every 8 hours) was administered intravenously. On day 4, culturing of Gram-negative bacilli from blood and a transesophageal echocardiogram revealed a small oscillating filament attached to lateral mitral prosthetic ring on the atrial side. Ceftriaxone (2 g once daily) was started. Gait instability and left-side weakness developed abruptly 2 weeks later; brain magnetic resonance imaging revealed a hematoma over the right parietal-occipital lobe. Ceftriaxone was adjusted to 2 g every 12 hours. Actinobacillus actinomycetemcomitans was identified 3 weeks later. Recovery was achieved, with significant interval improvement and resolution of the cerebral lesions evident on CT.

Update on Bioactive Prosthetic Material for the Treatment of Hernias.

PubMed

Edelman, David S; Hodde, Jason P

2011-12-01

The use of mesh in the repair of hernias is commonplace. Synthetic mesh, like polypropylene, has been the workhorse for hernia repairs since the 1980s. Surgisis® mesh (Cook Surgical, Bloomington, IN), a biologic hernia graft material composed of purified porcine small intestinal submucosa (SIS), was first introduced to the United States in 1998 as an alternative to synthetic mesh materials. This mesh, composed of extracellular matrix collagen, fibronectin and associated glycosaminoglycans and growth factors, has been extensively investigated in animal models and used clinically in many types of surgical procedures. SIS acts as a scaffold for natural growth and strength. We reported our initial results in this publication in July 2006. Since then, there have been many more reports and numerous other bioactive prosthetic materials (BPMs) released. The object of this article is to briefly review some of the current literature on the use of BPM for inguinal hernias, sports hernias, and umbilical hernias.

Virtual Preoperative Planning and Intraoperative Navigation in Facial Prosthetic Reconstruction: A Technical Note.

PubMed

Verma, Suzanne; Gonzalez, Marianela; Schow, Sterling R; Triplett, R Gilbert

This technical protocol outlines the use of computer-assisted image-guided technology for the preoperative planning and intraoperative procedures involved in implant-retained facial prosthetic treatment. A contributing factor for a successful prosthetic restoration is accurate preoperative planning to identify prosthetically driven implant locations that maximize bone contact and enhance cosmetic outcomes. Navigational systems virtually transfer precise digital planning into the operative field for placing implants to support prosthetic restorations. In this protocol, there is no need to construct a physical, and sometimes inaccurate, surgical guide. The report addresses treatment workflow, radiologic data specifications, and special considerations in data acquisition, virtual preoperative planning, and intraoperative navigation for the prosthetic reconstruction of unilateral, bilateral, and midface defects. Utilization of this protocol for the planning and surgical placement of craniofacial bone-anchored implants allows positioning of implants to be prosthetically driven, accurate, precise, and efficient, and leads to a more predictable treatment outcome.

21 CFR 895.101 - Prosthetic hair fibers.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic hair fibers. 895.101 Section 895.101 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES BANNED DEVICES Listing of Banned Devices § 895.101 Prosthetic hair fibers. Prosthetic hair fibers are devices intended for implantation...

38 CFR 17.122 - Payment or reimbursement of the expenses of repairs to prosthetic appliances and similar devices...

Code of Federal Regulations, 2010 CFR

2010-07-01

... of the expenses of repairs to prosthetic appliances and similar devices furnished without prior... Payment or reimbursement of the expenses of repairs to prosthetic appliances and similar devices furnished without prior authorization. The expenses of repairs to prosthetic appliances, or similar appliances...

76 FR 18472 - Medicare Program; Revisions to the Durable Medical Equipment, Prosthetics, Orthotics, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-04

....Prosthetic devices are included in the definition of ``medical and other health services'' under section 1861(s)(8) of the Act. Prosthetic devices are defined in this section of the Act as ``devices (other than... intraocular lens.'' Other examples of prosthetic devices include cardiac pacemakers, cochlear implants...

The effect of anti-gravity treadmill training for prosthetic rehabilitation of a case with below-knee amputation.

PubMed

Mikami, Yukio; Fukuhara, Kouki; Kawae, Toshihiro; Kimura, Hiroaki; Ochi, Mitsuo

2015-12-01

The aim of this case study was to verify the efficacy and safety of anti-gravity treadmill training for prosthetic rehabilitation following below-knee amputation. The patient underwent left below-knee amputation as a result of diabetic foot gangrene. Since his physical strength and vitality had declined during the perioperative period, anti-gravity treadmill training was introduced for his outpatient prosthetic rehabilitation. Stable prosthetic gait exercise could be carried out under guidance on the anti-gravity treadmill, quickly resulting in improved gait. Furthermore, the patient's self-efficacy and exercise tolerance were elevated after the period of anti-gravity treadmill training. At the final evaluation following 6 weeks of rehabilitation with the anti-gravity treadmill, he had acquired prosthetic gait with the assistance of a T-cane. The anti-gravity treadmill was found to be a useful instrument for prosthetic rehabilitation following below-knee amputation. Anti-gravity treadmill training has the potential to support the prosthetic rehabilitation of below-knee amputees, especially for patients whose physical strength and vitality are decreased. © The International Society for Prosthetics and Orthotics 2014.

Kinematics in the terminal swing phase of unilateral transfemoral amputees: microprocessor-controlled versus swing-phase control prosthetic knees.

PubMed

Mâaref, Khaled; Martinet, Noël; Grumillier, Constance; Ghannouchi, Slaheddine; André, Jean Marie; Paysant, Jean

2010-06-01

To analyze the spatiotemporal parameters in the terminal swing phase of the prosthetic limb in unilateral transfemoral amputees (TFAs) compared with a group of asymptomatic subjects, and to identify a latency period (LP) in the TFA between the full extension of the prosthetic knee and the initial ground contact of the ipsilateral foot. To study the correlation between the LP and the duration of the swing phase. To evaluate the influence of the type of knee, the time since amputation, and the amputation level on the latency period. Three-dimensional gait analysis with an optoelectronic device. Gait analysis laboratory of a re-education and functional rehabilitation service. TFA (n=29) and able-bodied (n=15) subjects. Not applicable. Spatiotemporal and kinematics gait parameters. The swing phase and the LP of the prosthetic limb, associated with a consequently longer single-limb stance phase in the intact limb, were significantly longer than those measured in the intact limbs of these subjects, as well as those measured on both lower limbs of the able-bodied subjects (P<.05). There is a positive correlation (P<.05; r(2)=.58 between the LP and the swing phase on the TFA's prosthetic side. The LP measured in the prosthetic limb of TFA with a swing-phase control prosthetic knee is significantly greater than in those using the microprocessor-controlled prosthetic knee (P<.05). Of negligible duration in able-bodied subjects and in the intact limb of TFA, the LP is significantly greater in the prosthetic limb. It can explain the lengthened swing phase on the prosthetic side of those subjects. The use of a microprocessor-controlled prosthetic knee allows the LP to be reduced. This LP appears to be necessary to insure the stability of the prosthetic knee. We suggest calling this time "confidence time." Copyright 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Advanced Prosthetic Gait Training Tool

DTIC Science & Technology

2014-10-01

AWARD NUMBER: W81XWH-10-1-0870 TITLE: Advanced Prosthetic Gait Training Tool...October 2014 2. REPORT TYPE Annual Report 3. DATES COVERED 20 Sep 2013 to 19 Sep 2014 4. TITLE AND SUBTITLE Advanced Prosthetic Gait Training...produce a computer-based Advanced Prosthetic Gait Training Tool to aid in the training of clinicians at military treatment facilities providing care

Prosthetic Consideration in Implant-supported Prosthesis: A Review of Literature

PubMed Central

Gowd, Manga Snigdha; Shankar, Thatapudi; Ranjan, Rajeev; Singh, Arpita

2017-01-01

Modern dentistry has changed tremendously with implant therapy. For the successful implant therapy, making a proper treatment plan considering both surgical and prosthetic part in mind is the key of success. Often practitioners tend to create a treatment plan overlooking the basic principles of prosthetic part. This present review has discussed various prosthetic consideration of implant-supported prosthesis. A step-by-step detailed prosthetic option with their indications has been discussed to help all dental implant practitioners in making of an optimal treatment plan for each case. PMID:28713760

Intracardiac echocardiographic guidance for hemodynamic assessment in a patient with congenital abnormalities and a prosthetic aortic valve.

PubMed

Papafaklis, M I; Ligthart, J M R; Vaina, S; Witsenburg, M; Bogers, A J J C; Serruys, P W

2005-01-01

In this case report, we present the use of intracardiac echocardiography (ICE) for guiding the cardiac catheterization and subsequent hemodynamic investigation in an unusual patient case with multiple congenital abnormalities (bicuspid aortic valve, left cervical aortic arch, two aortic coarctations) and two aortic valve replacement operations in the past. The ICE catheter (AcuNav) permitted us to accurately and safely puncture the interatrial septum and place the Swan-Ganz catheter in the left ventricle; additionally, visualization of the aortic coarctation in the ascending aorta was also achieved.

Use of multidetector-row computed tomography scan to detect pannus formation in prosthetic mechanical aortic valves.

PubMed

Aladmawi, Mohamed A; Pragliola, Claudio; Vriz, Olga; Galzerano, Domenico

2017-04-01

Obstruction of a mechanical aortic valve by pannus formation at the subvalvular level is a major long-term complication of aortic valve replacement (AVR). In fact, pannus is sometime difficult to differentiate from patient-prosthesis mismatch or valve thrombosis. In most cases cine-angiography and echocardiography, either transthoracic or transesophageal, cannot correctly visualize the complication when the leaflets show a normal mobility. Recent technological refinements made this difficult diagnosis possible by ECG-gated computed tomography (CT) scan which shows adequate images in 90% of the cases and can differentiate pannus from fresh and organized thrombus.

Learning to see again: Biological constraints on cortical plasticity and the implications for sight restoration technologies

PubMed Central

Beyeler, Michael; Rokem, Ariel; Boynton, Geoffrey M.; Fine, Ione

2018-01-01

The “bionic eye” – so long a dream of the future – is finally becoming a reality with retinal prostheses available to patients in both the US and Europe. However, clinical experience with these implants has made it apparent that the vision provided by these devices differs substantially from normal sight. Consequently, the ability to learn to make use of this abnormal retinal input plays a critical role in whether or not some functional vision is successfully regained. The goal of the present review is to summarize the vast basic science literature on developmental and adult cortical plasticity with an emphasis on how this literature might relate to the field of prosthetic vision. We begin with describing the distortion and information loss likely to be experienced by visual prosthesis users. We then define cortical plasticity and perceptual learning, and describe what is known, and what is unknown, about visual plasticity across the hierarchy of brain regions involved in visual processing, and across different stages of life. We close by discussing what is known about brain plasticity in sight restoration patients and discuss biological mechanisms that might eventually be harnessed to improve visual learning in these patients. PMID:28612755

Case study: survey of patient satisfaction with prosthesis quality and design among below-knee prosthetic leg socket users.

PubMed

Mohd Hawari, Nurhanisah; Jawaid, Mohammad; Md Tahir, Paridah; Azmeer, Raja Ahmad

2017-11-01

The aim of this case study was to explore patient satisfaction with the quality of prosthetic leg sockets intended for persons with lower limb amputations. A qualitative study based on in-depth interviews, preceded by a questionnaire session, was carried out with patients from the Rehabilitation Center and Hospital in Malaysia. Twelve out-patient and in-patient amputees with lower limb amputations, specifically below-knee amputations, were chosen randomly. The analysis of patients' narratives aimed to identify the functional and esthetic characteristics of currently used prosthetic leg sockets and any problems related to them. The obtained results indicated that out of the 12 participants, 41.7% and 25% were satisfied and somewhat satisfied with their current prosthetic sockets. Durability and comfort were rated by the participants as the most important characteristics of prosthetic sockets, with 83.3%. As regards the esthetic appearance of the socket, 66.7% of the respondents considered that the most important feature was the material from which the socket was fabricated. Thus, we conclude that current satisfaction levels with the quality of prosthetic sockets among amputees in Malaysia are suitable, prosthesis being preferred by many amputees. The results can be used to direct future research on cosmesis and functionality of prosthetic socket design. Implications for Rehabilitation Case study will help participants to get cost effective prosthetic leg socket. Develop prosthetic leg socket comfortable as comparative to existing one. Help Malaysian government to make policy to develop local prosthetic leg socket at affordable price.

Microcomputer-based artificial vision support system for real-time image processing for camera-driven visual prostheses

NASA Astrophysics Data System (ADS)

Fink, Wolfgang; You, Cindy X.; Tarbell, Mark A.

2010-01-01

It is difficult to predict exactly what blind subjects with camera-driven visual prostheses (e.g., retinal implants) can perceive. Thus, it is prudent to offer them a wide variety of image processing filters and the capability to engage these filters repeatedly in any user-defined order to enhance their visual perception. To attain true portability, we employ a commercial off-the-shelf battery-powered general purpose Linux microprocessor platform to create the microcomputer-based artificial vision support system (μAVS2) for real-time image processing. Truly standalone, μAVS2 is smaller than a deck of playing cards, lightweight, fast, and equipped with USB, RS-232 and Ethernet interfaces. Image processing filters on μAVS2 operate in a user-defined linear sequential-loop fashion, resulting in vastly reduced memory and CPU requirements during execution. μAVS2 imports raw video frames from a USB or IP camera, performs image processing, and issues the processed data over an outbound Internet TCP/IP or RS-232 connection to the visual prosthesis system. Hence, μAVS2 affords users of current and future visual prostheses independent mobility and the capability to customize the visual perception generated. Additionally, μAVS2 can easily be reconfigured for other prosthetic systems. Testing of μAVS2 with actual retinal implant carriers is envisioned in the near future.

Microcomputer-based artificial vision support system for real-time image processing for camera-driven visual prostheses.

PubMed

Fink, Wolfgang; You, Cindy X; Tarbell, Mark A

2010-01-01

It is difficult to predict exactly what blind subjects with camera-driven visual prostheses (e.g., retinal implants) can perceive. Thus, it is prudent to offer them a wide variety of image processing filters and the capability to engage these filters repeatedly in any user-defined order to enhance their visual perception. To attain true portability, we employ a commercial off-the-shelf battery-powered general purpose Linux microprocessor platform to create the microcomputer-based artificial vision support system (microAVS(2)) for real-time image processing. Truly standalone, microAVS(2) is smaller than a deck of playing cards, lightweight, fast, and equipped with USB, RS-232 and Ethernet interfaces. Image processing filters on microAVS(2) operate in a user-defined linear sequential-loop fashion, resulting in vastly reduced memory and CPU requirements during execution. MiccroAVS(2) imports raw video frames from a USB or IP camera, performs image processing, and issues the processed data over an outbound Internet TCP/IP or RS-232 connection to the visual prosthesis system. Hence, microAVS(2) affords users of current and future visual prostheses independent mobility and the capability to customize the visual perception generated. Additionally, microAVS(2) can easily be reconfigured for other prosthetic systems. Testing of microAVS(2) with actual retinal implant carriers is envisioned in the near future.

Design and Evaluation of a Prosthetic Knee Joint Using the Geared Five-Bar Mechanism.

PubMed

Sun, Yuanxi; Ge, Wenjie; Zheng, Jia; Dong, Dianbiao

2015-11-01

This paper presents the mechanical design, dynamics analysis and ankle trajectory analysis of a prosthetic knee joint using the geared five-bar mechanism. Compared with traditional four-bar or six-bar mechanisms, the geared five-bar mechanism is better at performing diverse movements and is easy to control. This prosthetic knee joint with the geared five-bar mechanism is capable of fine-tuning its relative instantaneous center of rotation and ankle trajectory. The centrode of this prosthetic knee joint, which is mechanically optimized according to the centrode of human knee joint, is better in the bionic performance than that of a prosthetic knee joint using the four-bar mechanism. Additionally, the stability control of this prosthetic knee joint during the swing and stance phase is achieved by a motor. By adjusting the gear ratio of this prosthetic knee joint, the ankle trajectories of both unilateral and bilateral amputees show less deviations from expected than that of the four-bar knee joint.

Developing prescribing guidelines for microprocessor-controlled prosthetic knees in the South East England.

PubMed

Sedki, Imad; Fisher, Keren

2015-06-01

Microprocessor-controlled prosthetic knees have gained increasing popularity over the last decade. Research supports their provision to address specific problems or to achieve certain rehabilitation goals. However, there are yet no agreed protocols or prescribing criteria to assist clinicians in the identification and appropriate selection of suitable users. The aim is to reach professionals' agreement on specific prescribing guidelines for microprocessor-controlled prosthetic knees. The study involved multidisciplinary teams from the Inter Regional Prosthetic Audit Group, representing nine Prosthetic Rehabilitation Centres in the South East England region. We used the Delphi technique with a total of three rounds to reach professionals' agreement. The prescribing guidelines were agreed and will be reviewed and updated depending on new research evidence and technical advances. This project is highly useful for professionals in a clinic setting to aid in appropriate patient selection and to justify the cost of prescribing microprocessor-controlled prosthetic knees. © The International Society for Prosthetics and Orthotics 2014.

Deep learning-based artificial vision for grasp classification in myoelectric hands.

PubMed

Ghazaei, Ghazal; Alameer, Ali; Degenaar, Patrick; Morgan, Graham; Nazarpour, Kianoush

2017-06-01

Computer vision-based assistive technology solutions can revolutionise the quality of care for people with sensorimotor disorders. The goal of this work was to enable trans-radial amputees to use a simple, yet efficient, computer vision system to grasp and move common household objects with a two-channel myoelectric prosthetic hand. We developed a deep learning-based artificial vision system to augment the grasp functionality of a commercial prosthesis. Our main conceptual novelty is that we classify objects with regards to the grasp pattern without explicitly identifying them or measuring their dimensions. A convolutional neural network (CNN) structure was trained with images of over 500 graspable objects. For each object, 72 images, at [Formula: see text] intervals, were available. Objects were categorised into four grasp classes, namely: pinch, tripod, palmar wrist neutral and palmar wrist pronated. The CNN setting was first tuned and tested offline and then in realtime with objects or object views that were not included in the training set. The classification accuracy in the offline tests reached [Formula: see text] for the seen and [Formula: see text] for the novel objects; reflecting the generalisability of grasp classification. We then implemented the proposed framework in realtime on a standard laptop computer and achieved an overall score of [Formula: see text] in classifying a set of novel as well as seen but randomly-rotated objects. Finally, the system was tested with two trans-radial amputee volunteers controlling an i-limb Ultra TM prosthetic hand and a motion control TM prosthetic wrist; augmented with a webcam. After training, subjects successfully picked up and moved the target objects with an overall success of up to [Formula: see text]. In addition, we show that with training, subjects' performance improved in terms of time required to accomplish a block of 24 trials despite a decreasing level of visual feedback. The proposed design constitutes a substantial conceptual improvement for the control of multi-functional prosthetic hands. We show for the first time that deep-learning based computer vision systems can enhance the grip functionality of myoelectric hands considerably.

Deep learning-based artificial vision for grasp classification in myoelectric hands

NASA Astrophysics Data System (ADS)

Ghazaei, Ghazal; Alameer, Ali; Degenaar, Patrick; Morgan, Graham; Nazarpour, Kianoush

2017-06-01

Objective. Computer vision-based assistive technology solutions can revolutionise the quality of care for people with sensorimotor disorders. The goal of this work was to enable trans-radial amputees to use a simple, yet efficient, computer vision system to grasp and move common household objects with a two-channel myoelectric prosthetic hand. Approach. We developed a deep learning-based artificial vision system to augment the grasp functionality of a commercial prosthesis. Our main conceptual novelty is that we classify objects with regards to the grasp pattern without explicitly identifying them or measuring their dimensions. A convolutional neural network (CNN) structure was trained with images of over 500 graspable objects. For each object, 72 images, at {{5}\\circ} intervals, were available. Objects were categorised into four grasp classes, namely: pinch, tripod, palmar wrist neutral and palmar wrist pronated. The CNN setting was first tuned and tested offline and then in realtime with objects or object views that were not included in the training set. Main results. The classification accuracy in the offline tests reached 85 % for the seen and 75 % for the novel objects; reflecting the generalisability of grasp classification. We then implemented the proposed framework in realtime on a standard laptop computer and achieved an overall score of 84 % in classifying a set of novel as well as seen but randomly-rotated objects. Finally, the system was tested with two trans-radial amputee volunteers controlling an i-limb UltraTM prosthetic hand and a motion controlTM prosthetic wrist; augmented with a webcam. After training, subjects successfully picked up and moved the target objects with an overall success of up to 88 % . In addition, we show that with training, subjects’ performance improved in terms of time required to accomplish a block of 24 trials despite a decreasing level of visual feedback. Significance. The proposed design constitutes a substantial conceptual improvement for the control of multi-functional prosthetic hands. We show for the first time that deep-learning based computer vision systems can enhance the grip functionality of myoelectric hands considerably.

Patient satisfaction and prosthetic aspects with mini-implants retained mandibular overdentures. A 5-year prospective study.

PubMed

Elsyad, Moustafa Abdou

2016-07-01

This study aimed to evaluate patient satisfaction and prosthetic aspects during a 5-year prospective clinical study of mini dental implants (MDIs) retaining mandibular overdentures. This observational prospective clinical study was conducted on a group of completely edentulous patients (n = 28) with retention problems of conventional mandibular dentures. All patients received new maxillary and mandibular conventional dentures. A total of 112 MDIs (four per patient) were inserted using the flapless surgical approach and immediately loaded by the new mandibular dentures (overdentures). Patients indicated satisfaction with their prosthesis using a questionnaire and a visual analogue scale (VAS). Patient satisfaction and prosthetic complications were recorded 6 months (T6 m ), 1 (T1), 3 (T3), and 5 (T5) years after overdenture insertion. The patient satisfaction with eating (hard/soft) food (P < 0.001), talking (P < 0.001), appearance (P = 0.001), comfort (P < 0.001), healing process (P = 0.013), socialization (P < 0.001), stability/retention of mandibular dentures (P = 0.001), ease of oral hygiene (P = 0.008), and ease of handling the dentures (P < 0.001) increased significantly with time. After 5 years, the most common complication was wear/damage of O/rings (n = 235), O/ring replacement (n = 125), maxillary denture relining times (n = 13), worn teeth (n = 10), overdentures relines (n = 10), detachment of the metal housings (n = 9), and fracture of mandibular overdentures (n = 8). Mucositis, soreness, and decubitis ulcer under overdenture occurred most often at T6 m and decreased significantly with time (P = 0.002, 0.005, and 0.024, respectively). Within the limitations of this clinical study, patient satisfaction with mini-implant retained mandibular overdentures increased significantly with time. However, this treatment required a considerable amount of prosthetic maintenance and repair after 5 years of service. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mechanical design and performance specifications of anthropomorphic prosthetic hands: a review.

PubMed

Belter, Joseph T; Segil, Jacob L; Dollar, Aaron M; Weir, Richard F

2013-01-01

In this article, we set forth a detailed analysis of the mechanical characteristics of anthropomorphic prosthetic hands. We report on an empirical study concerning the performance of several commercially available myoelectric prosthetic hands, including the Vincent, iLimb, iLimb Pulse, Bebionic, Bebionic v2, and Michelangelo hands. We investigated the finger design and kinematics, mechanical joint coupling, and actuation methods of these commercial prosthetic hands. The empirical findings are supplemented with a compilation of published data on both commercial and prototype research prosthetic hands. We discuss numerous mechanical design parameters by referencing examples in the literature. Crucial design trade-offs are highlighted, including number of actuators and hand complexity, hand weight, and grasp force. Finally, we offer a set of rules of thumb regarding the mechanical design of anthropomorphic prosthetic hands.

Additive Manufacturing of Biomaterials, Tissues, and Organs.

PubMed

Zadpoor, Amir A; Malda, Jos

2017-01-01

The introduction of additive manufacturing (AM), often referred to as three-dimensional (3D) printing, has initiated what some believe to be a manufacturing revolution, and has expedited the development of the field of biofabrication. Moreover, recent advances in AM have facilitated further development of patient-specific healthcare solutions. Customization of many healthcare products and services, such as implants, drug delivery devices, medical instruments, prosthetics, and in vitro models, would have been extremely challenging-if not impossible-without AM technologies. The current special issue of the Annals of Biomedical Engineering presents the latest trends in application of AM techniques to healthcare-related areas of research. As a prelude to this special issue, we review here the most important areas of biomedical research and clinical practice that have benefited from recent developments in additive manufacturing techniques. This editorial, therefore, aims to sketch the research landscape within which the other contributions of the special issue can be better understood and positioned. In what follows, we briefly review the application of additive manufacturing techniques in studies addressing biomaterials, (re)generation of tissues and organs, disease models, drug delivery systems, implants, medical instruments, prosthetics, orthotics, and AM objects used for medical visualization and communication.

Abstract and proportional myoelectric control for multi-fingered hand prostheses.

PubMed

Pistohl, Tobias; Cipriani, Christian; Jackson, Andrew; Nazarpour, Kianoush

2013-12-01

Powered hand prostheses with many degrees of freedom are moving from research into the market for prosthetics. In order to make use of the prostheses' full functionality, it is essential to study efficient ways of high dimensional myoelectric control. Human subjects can rapidly learn to employ electromyographic (EMG) activity of several hand and arm muscles to control the position of a cursor on a computer screen, even if the muscle-cursor map contradicts directions in which the muscles would act naturally. But can a similar control scheme be translated into real-time operation of a dexterous robotic hand? We found that despite different degrees of freedom in the effector output, the learning process for controlling a robotic hand was surprisingly similar to that for a virtual two-dimensional cursor. Control signals were derived from the EMG in two different ways, with a linear and a Bayesian filter, to test how stable user intentions could be conveyed through them. Our analysis indicates that without visual feedback, control accuracy benefits from filters that reject high EMG amplitudes. In summary, we conclude that findings on myoelectric control principles, studied in abstract, virtual tasks can be transferred to real-life prosthetic applications.

[Intra-prosthetic dislocation of the Bousquet dual mobility socket].

PubMed

Lecuire, F; Benareau, I; Rubini, J; Basso, M

2004-05-01

The Bousquet system is a dual mobility head-polyethylene polyethylene-metal cup socket. The polyethylene insert retaining the femoral head moves in the noncemented metal cup, increasing both mobility and stability. Between 1989 and 1997, seven cases of intra-prosthetic dislocation (six patients) were observed. The femoral head escaped from the polyethylene insert due to wear. On the average, this complication occurred ten Years after implantation. Risk of dislocation was high in six of the seven hips. All patients had a large sized stem screwed into the femoral neck. There was a characteristic radiological aspect with loss of the concentric head metal cup configuration. The head was applied against the upper wall of the metal cup. Surgical replacement was undertaken early in six patients by simply changing the insert without modifying the other stable components. Outcome remained good at three to eight Years. One patient underwent late surgery. The insert and the cup were replaced with a classical implant. Functional outcome was good but recurrent dislocation occurred. At mid-term, intra-prosthetic dislocation of dual mobility sockets appears to be exceptional. Dislocation results from polyethylene wear leading to failure of the insert to retain the prosthetic head. Wear is favored by direct phenomena (direct contact between neck and insert which can occur early if there is a small difference in the head and neck diameters) or indirect phenomena (factors limiting polyethylene metal-cup mobility). Surgical treatment is necessary. If undertaken early, replacement with a modular head and insert can be sufficient if the prosthesis has not loosened but the metal cup may have to be replaced in the event of metal-metal contact between the head and the cup. Prosthesis loosening, wear of the metal cup, or an identified cause of dislocation imply replacing the failing implants. Implantation of the dual mobility system is particularly interesting for patients with a high risk of dislocation or a chronically unstable hip prosthesis. Careful technique is required to reduce or retard the risk of intra-prosthetic dislocation. Intra-prosthetic dislocation of a dual mobility socket is an exceptional complication at mid-term. Surgical treatment is required but may be limited to simple insert replacement. Systematic use of this type of implant in young subjects must be carefully examined, but for us, the risk of dislocation does not outweigh the advantages of this original concept of dual mobility. This type of socket remains an useful preventive technique for high-risk hips or for curative treatment of recurrent dislocation.

Microprocessor prosthetic knees.

PubMed

Berry, Dale

2006-02-01

This article traces the development of microprocessor prosthetic knees from early research in the 1970s to the present. Read about how microprocessor knees work, functional options, patient selection, and the future of this prosthetic.

Nanowire arrays restore vision in blind mice.

PubMed

Tang, Jing; Qin, Nan; Chong, Yan; Diao, Yupu; Yiliguma; Wang, Zhexuan; Xue, Tian; Jiang, Min; Zhang, Jiayi; Zheng, Gengfeng

2018-03-06

The restoration of light response with complex spatiotemporal features in retinal degenerative diseases towards retinal prosthesis has proven to be a considerable challenge over the past decades. Herein, inspired by the structure and function of photoreceptors in retinas, we develop artificial photoreceptors based on gold nanoparticle-decorated titania nanowire arrays, for restoration of visual responses in the blind mice with degenerated photoreceptors. Green, blue and near UV light responses in the retinal ganglion cells (RGCs) are restored with a spatial resolution better than 100 µm. ON responses in RGCs are blocked by glutamatergic antagonists, suggesting functional preservation of the remaining retinal circuits. Moreover, neurons in the primary visual cortex respond to light after subretinal implant of nanowire arrays. Improvement in pupillary light reflex suggests the behavioral recovery of light sensitivity. Our study will shed light on the development of a new generation of optoelectronic toolkits for subretinal prosthetic devices.

Outdoor weathering of facial prosthetic elastomers differing in Durometer hardness.

PubMed

Willett, Emily S; Beatty, Mark W

2015-03-01

Facial prosthetic elastomers with wide ranges in hardness are available, yet material weatherability is unknown. The purpose of this study was to assess color, Durometer hardness, and tensile property changes after 3000 hours of outdoor weathering. Unpigmented elastomers with Durometer hardness 5, 30, 50, 70, and A-2186 were polymerized into dumbbells (ASTM D412) and disks, 34 mm in diameter by 6 mm thick. Materials were subjected to outdoor or time passage environments for 3000 hours. CIELab color (n=5), Durometer hardness (n=5), and tensile mechanical properties (n=10) were measured at 0 and 3000 hours, and group differences were assessed by material and weathering condition (ANOVA/Tukey, α=.05). Except for A-2186, the mean Durometer changes for all materials were 1 unit or less, with no significant differences observed between time passage and weathered groups (P≥.05). Three-thousand-hour tensile mechanical property results demonstrated nonsignificant differences between time passage and weathered materials but significantly changed properties from immediately tested materials (P<.001). Outdoor weathering induced perceptible but acceptable color changes (1.7≤ΔE*≤2.6) for elastomers with Durometer hardness 5 and 30 and A-2186. With a few exceptions, outdoor weathering produced relatively small changes in color, Durometer hardness, or tensile properties compared with time passage. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Cost analysis of debridement and retention for management of prosthetic joint infection.

PubMed

Peel, T N; Dowsey, M M; Buising, K L; Liew, D; Choong, P F M

2013-02-01

Prosthetic joint infection remains one of the most devastating complications of arthroplasty. Debridement and retention of the prosthesis is an attractive management option in carefully selected patients. Despite this, there are no data investigating the cost of this management modality for prosthetic joint infections. The aim of this case-control study was to calculate the cost associated with debridement and retention for management of prosthetic joint infection compared with primary joint replacement surgery without prosthetic joint infection. From 1 January 2008 to 30 June 2010, there were 21 prosthetic joint infections matched to 42 control patients. Controls were matched to cases according to the arthroplasty site, age and sex. Cases had a greater number of unplanned readmissions (100% vs. 7.1%; p <0.001), more additional surgery (3.3 vs. 0.07; p <0.001) and longer total bed days (31.6 vs. 7.9 days; p <0.001). In addition they had more inpatient, outpatient and emergency department visits (p <0.001, respectively). For patients with prosthetic joint infection the total cost, including index operation and costs of management of the prosthetic joint infection, was 3.1 times the cost of primary arthoplasty; the mean cost for cases was Australian dollars (AUD) $69,414 (±29,869) compared with $22,085 (±8147) (p <0.001). The demand for arthroplasty continues to grow and with that, the number of prosthetic joint infections will also increase, placing significant burden on the health system. Our study adds significantly to the growing body of evidence highlighting the substantial costs associated with prosthetic joint infection. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

Dynamic tracking of prosthetic valve motion and deformation from bi-plane x-ray views: feasibility study

NASA Astrophysics Data System (ADS)

Hatt, Charles R.; Wagner, Martin; Raval, Amish N.; Speidel, Michael A.

2016-03-01

Transcatheter aortic valve replacement (TAVR) requires navigation and deployment of a prosthetic valve within the aortic annulus under fluoroscopic guidance. To support improved device visualization in this procedure, this study investigates the feasibility of frame-by-frame 3D reconstruction of a moving and expanding prosthetic valve structure from simultaneous bi-plane x-ray views. In the proposed method, a dynamic 3D model of the valve is used in a 2D/3D registration framework to obtain a reconstruction of the valve. For each frame, valve model parameters describing position, orientation, expansion state, and deformation are iteratively adjusted until forward projections of the model match both bi-plane views. Simulated bi-plane imaging of a valve at different signal-difference-to-noise ratio (SDNR) levels was performed to test the approach. 20 image sequences with 50 frames of valve deployment were simulated at each SDNR. The simulation achieved a target registration error (TRE) of the estimated valve model of 0.93 +/- 2.6 mm (mean +/- S.D.) for the lowest SDNR of 2. For higher SDNRs (5 to 50) a TRE of 0.04 mm +/- 0.23 mm was achieved. A tabletop phantom study was then conducted using a TAVR valve. The dynamic 3D model was constructed from high resolution CT scans and a simple expansion model. TRE was 1.22 +/- 0.35 mm for expansion states varying from undeployed to fully deployed, and for moderate amounts of inter-frame motion. Results indicate that it is feasible to use bi-plane imaging to recover the 3D structure of deformable catheter devices.

Dynamic tracking of prosthetic valve motion and deformation from bi-plane x-ray views: feasibility study.

PubMed

Hatt, Charles R; Wagner, Martin; Raval, Amish N; Speidel, Michael A

2016-01-01

Transcatheter aortic valve replacement (TAVR) requires navigation and deployment of a prosthetic valve within the aortic annulus under fluoroscopic guidance. To support improved device visualization in this procedure, this study investigates the feasibility of frame-by-frame 3D reconstruction of a moving and expanding prosthetic valve structure from simultaneous bi-plane x-ray views. In the proposed method, a dynamic 3D model of the valve is used in a 2D/3D registration framework to obtain a reconstruction of the valve. For each frame, valve model parameters describing position, orientation, expansion state, and deformation are iteratively adjusted until forward projections of the model match both bi-plane views. Simulated bi-plane imaging of a valve at different signal-difference-to-noise ratio (SDNR) levels was performed to test the approach. 20 image sequences with 50 frames of valve deployment were simulated at each SDNR. The simulation achieved a target registration error (TRE) of the estimated valve model of 0.93 ± 2.6 mm (mean ± S.D.) for the lowest SDNR of 2. For higher SDNRs (5 to 50) a TRE of 0.04 mm ± 0.23 mm was achieved. A tabletop phantom study was then conducted using a TAVR valve. The dynamic 3D model was constructed from high resolution CT scans and a simple expansion model. TRE was 1.22 ± 0.35 mm for expansion states varying from undeployed to fully deployed, and for moderate amounts of inter-frame motion. Results indicate that it is feasible to use bi-plane imaging to recover the 3D structure of deformable catheter devices.

The Persian version of satisfaction assessment module of Orthotics and Prosthetics Users' Survey.

PubMed

Hadadi, Mohammad; Ghoseiri, Kamiar; Fardipour, Shima; Kashani, Reza Vahab; Asadi, Farnoosh; Asghari, Azizeh

2016-01-01

Orthotics and Prosthetics User's Survey (OPUS) was developed to measure patient satisfaction in Prosthetic and Orthotic (P&O) field. To translate the satisfaction assessment module of OPUS (OPUS-SM) into Persian language (Persian OPUS-SM) and investigate its psychometric properties. For cross-cultural adaptation of the OPUS-SM, the guideline suggested by the World Health Organization was recruited. A sample of 116 Persian-speaking people who received P&O devices and services, participated in this study. During the first session, participants filled out the Persian OPUS-SM and the Visual Analog Scale (VAS) regarding their satisfaction from delivered devices and services. Drawing from the above sample of 116 participants, 41 participants retook the Persian OPUS-SM 5-7 days after their first time. The results of the first and second administration sessions were analyzed to assess internal consistency, test-retest reliability, item-subscale correlation, minimal detectable change, floor and ceiling effects, criterion validity, and dimensionality of the Persian OPUS-SM. The Cronbach's alphas of the Persian OPUS-SM were 0.71 and 0.89 for device and service satisfaction subscales, respectively. The intraclass correlation coefficients were 0.76 and 0.90 for device and service satisfaction subscales, respectively. The SEM and MDC for device satisfaction were 6.21 and ±17.21, respectively. The SEM and MDC for service satisfaction were 2.25 and ±6.22, respectively. There was a strong correlation between VAS and satisfaction subscales of the Persian OPUS-SM. Dimensionality assessment revealed that Persian OPUS-SM is a unidimensional measure. The adapted and translated Persian OPUS-SM is a reliable and validated measure. Copyright © 2016 Elsevier Inc. All rights reserved.

Sensor fusion and computer vision for context-aware control of a multi degree-of-freedom prosthesis

NASA Astrophysics Data System (ADS)

Markovic, Marko; Dosen, Strahinja; Popovic, Dejan; Graimann, Bernhard; Farina, Dario

2015-12-01

Objective. Myoelectric activity volitionally generated by the user is often used for controlling hand prostheses in order to replicate the synergistic actions of muscles in healthy humans during grasping. Muscle synergies in healthy humans are based on the integration of visual perception, heuristics and proprioception. Here, we demonstrate how sensor fusion that combines artificial vision and proprioceptive information with the high-level processing characteristics of biological systems can be effectively used in transradial prosthesis control. Approach. We developed a novel context- and user-aware prosthesis (CASP) controller integrating computer vision and inertial sensing with myoelectric activity in order to achieve semi-autonomous and reactive control of a prosthetic hand. The presented method semi-automatically provides simultaneous and proportional control of multiple degrees-of-freedom (DOFs), thus decreasing overall physical effort while retaining full user control. The system was compared against the major commercial state-of-the art myoelectric control system in ten able-bodied and one amputee subject. All subjects used transradial prosthesis with an active wrist to grasp objects typically associated with activities of daily living. Main results. The CASP significantly outperformed the myoelectric interface when controlling all of the prosthesis DOF. However, when tested with less complex prosthetic system (smaller number of DOF), the CASP was slower but resulted with reaching motions that contained less compensatory movements. Another important finding is that the CASP system required minimal user adaptation and training. Significance. The CASP constitutes a substantial improvement for the control of multi-DOF prostheses. The application of the CASP will have a significant impact when translated to real-life scenarious, particularly with respect to improving the usability and acceptance of highly complex systems (e.g., full prosthetic arms) by amputees.

Gaze Compensation as a Technique for Improving Hand–Eye Coordination in Prosthetic Vision

PubMed Central

Titchener, Samuel A.; Shivdasani, Mohit N.; Fallon, James B.; Petoe, Matthew A.

2018-01-01

Purpose Shifting the region-of-interest within the input image to compensate for gaze shifts (“gaze compensation”) may improve hand–eye coordination in visual prostheses that incorporate an external camera. The present study investigated the effects of eye movement on hand-eye coordination under simulated prosthetic vision (SPV), and measured the coordination benefits of gaze compensation. Methods Seven healthy-sighted subjects performed a target localization-pointing task under SPV. Three conditions were tested, modeling: retinally stabilized phosphenes (uncompensated); gaze compensation; and no phosphene movement (center-fixed). The error in pointing was quantified for each condition. Results Gaze compensation yielded a significantly smaller pointing error than the uncompensated condition for six of seven subjects, and a similar or smaller pointing error than the center-fixed condition for all subjects (two-way ANOVA, P < 0.05). Pointing error eccentricity and gaze eccentricity were moderately correlated in the uncompensated condition (azimuth: R2 = 0.47; elevation: R2 = 0.51) but not in the gaze-compensated condition (azimuth: R2 = 0.01; elevation: R2 = 0.00). Increased variability in gaze at the time of pointing was correlated with greater reduction in pointing error in the center-fixed condition compared with the uncompensated condition (R2 = 0.64). Conclusions Eccentric eye position impedes hand–eye coordination in SPV. While limiting eye eccentricity in uncompensated viewing can reduce errors, gaze compensation is effective in improving coordination for subjects unable to maintain fixation. Translational Relevance The results highlight the present necessity for suppressing eye movement and support the use of gaze compensation to improve hand–eye coordination and localization performance in prosthetic vision. PMID:29321945

Sensor fusion and computer vision for context-aware control of a multi degree-of-freedom prosthesis.

PubMed

Markovic, Marko; Dosen, Strahinja; Popovic, Dejan; Graimann, Bernhard; Farina, Dario

2015-12-01

Myoelectric activity volitionally generated by the user is often used for controlling hand prostheses in order to replicate the synergistic actions of muscles in healthy humans during grasping. Muscle synergies in healthy humans are based on the integration of visual perception, heuristics and proprioception. Here, we demonstrate how sensor fusion that combines artificial vision and proprioceptive information with the high-level processing characteristics of biological systems can be effectively used in transradial prosthesis control. We developed a novel context- and user-aware prosthesis (CASP) controller integrating computer vision and inertial sensing with myoelectric activity in order to achieve semi-autonomous and reactive control of a prosthetic hand. The presented method semi-automatically provides simultaneous and proportional control of multiple degrees-of-freedom (DOFs), thus decreasing overall physical effort while retaining full user control. The system was compared against the major commercial state-of-the art myoelectric control system in ten able-bodied and one amputee subject. All subjects used transradial prosthesis with an active wrist to grasp objects typically associated with activities of daily living. The CASP significantly outperformed the myoelectric interface when controlling all of the prosthesis DOF. However, when tested with less complex prosthetic system (smaller number of DOF), the CASP was slower but resulted with reaching motions that contained less compensatory movements. Another important finding is that the CASP system required minimal user adaptation and training. The CASP constitutes a substantial improvement for the control of multi-DOF prostheses. The application of the CASP will have a significant impact when translated to real-life scenarious, particularly with respect to improving the usability and acceptance of highly complex systems (e.g., full prosthetic arms) by amputees.

A computational method for comparing the behavior and possible failure of prosthetic implants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nielsen, C.; Hollerbach, K.; Perfect, S.

1995-05-01

Prosthetic joint implants currently in use exhibit high Realistic computer modeling of prosthetic implants provides an opportunity for orthopedic biomechanics researchers and physicians to understand possible in vivo failure modes, without having to resort to lengthy and costly clinical trials. The research presented here is part of a larger effort to develop realistic models of implanted joint prostheses. The example used here is the thumb carpo-metacarpal (cmc) joint. The work, however, can be applied to any other human joints for which prosthetic implants have been designed. Preliminary results of prosthetic joint loading, without surrounding human tissue (i.e., simulating conditions undermore » which the prosthetic joint has not yet been implanted into the human joint), are presented, based on a three-dimensional, nonlinear finite element analysis of three different joint implant designs.« less

Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis.

PubMed

Jin, H; Yuan, L; Li, C; Kan, Y; Hao, R; Yang, J

2014-03-01

The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty. A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection. Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis. In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

Development of Subischial Prosthetic Sockets with Vacuum-Assisted Suspension for Highly Active Persons with Transfemoral Amputations

DTIC Science & Technology

2014-10-01

Award Number: W81XWH-10-1-0744 TITLE: Development of Subischial Prosthetic Sockets with Vacuum...REPORT TYPE Annual 3. DATES COVERED 15 Sep 2013 – 14 Sep 2014 4. TITLE AND SUBTITLE Development of Subischial Prosthetic Sockets with Vacuum...to develop a highly flexible sub-ischial prosthetic socket with assisted-vacuum suspension for highly active persons with transfemoral amputation. The

Comparison of prosthetic feet prescribed to active individuals using ISO standards.

PubMed

Mason, Zachary D; Pearlman, Jon; Cooper, Rory A; Laferrier, Justin Z

2011-12-01

Little research has been done on the robustness of prosthetic feet prescribed to military personnel, and manufacturers are not required to test their products prior to sale. This is problematic because the prosthetic feet used by active individuals are subjected to loading conditions not seen in normal gait. To evaluate whether commercially available heavy-duty prosthetic feet intended for use by military personnel meet ISO 10328 standards. Bench testing of heavy-duty prosthetic feet using ISO 10328 standards. Prosthetic feet from three different manufacturers were tested according to ISO 10328 standards, using a testing frame fitted with axial load and displacement transducers. Pass/fail information was recorded as well as the stiffness and creep of each foot before and after cyclic testing. All feet passed the ISO 10328 standards at the highest loading level, and some significant differences were found within a given model of prosthesis when comparing stiffness and creep before and after cyclic testing. This study demonstrated that manufacturers of heavy-duty prosthetic feet adhere to the voluntary ISO 10328 standards. However, these standards may be insufficient because the tests simulate only idealized gait. Further development of the standards may be necessary to reproduce the circumstances that occur during extreme usage to ensure that prosthetic feet do not fail.

Circuit For Control Of Electromechanical Prosthetic Hand

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr.

1995-01-01

Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

Artificial vision: needs, functioning, and testing of a retinal electronic prosthesis.

PubMed

Chader, Gerald J; Weiland, James; Humayun, Mark S

2009-01-01

Hundreds of thousands around the world have poor vision or no vision at all due to inherited retinal degenerations (RDs) like retinitis pigmentosa (RP). Similarly, millions suffer from vision loss due to age-related macular degeneration (AMD). In both of these allied diseases, the primary target for pathology is the retinal photoreceptor cells that dysfunction and die. Secondary neurons though are relatively spared. To replace photoreceptor cell function, an electronic prosthetic device can be used such that retinal secondary neurons receive a signal that simulates an external visual image. The composite device has a miniature video camera mounted on the patient's eyeglasses, which captures images and passes them to a microprocessor that converts the data to an electronic signal. This signal, in turn, is transmitted to an array of electrodes placed on the retinal surface, which transmits the patterned signal to the remaining viable secondary neurons. These neurons (ganglion, bipolar cells, etc.) begin processing the signal and pass it down the optic nerve to the brain for final integration into a visual image. Many groups in different countries have different versions of the device, including brain implants and retinal implants, the latter having epiretinal or subretinal placement. The device furthest along in development is an epiretinal implant sponsored by Second Sight Medical Products (SSMP). Their first-generation device had 16 electrodes with human testing in a Phase 1 clinical trial beginning in 2002. The second-generation device has 60+ electrodes and is currently in Phase 2/3 clinical trial. Increased numbers of electrodes are planned for future versions of the device. Testing of the device's efficacy is a challenge since patients admitted into the trial have little or no vision. Thus, methods must be developed that accurately and reproducibly record small improvements in visual function after implantation. Standard tests such as visual acuity, visual field, electroretinography, or even contrast sensitivity may not adequately capture some aspects of improvement that relate to a better quality of life (QOL). Because of this, some tests are now relying more on "real-world functional capacity" that better assesses possible improvement in aspects of everyday living. Thus, a new battery of tests have been suggested that include (1) standard psychophysical testing, (2) performance in tasks that are used in real-life situations such as object discrimination, mobility, etc., and (3) well-crafted questionnaires that assess the patient's own feelings as to the usefulness of the device. In the Phase 1 trial of the SSMP 16-electrode device, six subjects with severe RP were implanted with ongoing, continuing testing since then. First, it was evident that even limited sight restoration is a slow, learning process that takes months for improvement to become evident. However, light perception was restored in all six patients. Moreover, all subjects ultimately saw discrete phosphenes and could perform simple visual spatial and motion tasks. As mentioned above, a Phase 2/3 trial is now ongoing with a 60+ device. A 250+ device is on the drawing board, and one with over 1000 electrodes is being planned. Each has the possibility of significantly improving a patient's vision and QOL, being smaller and safer in design and lasting for the lifetime of the patient. From theoretical modeling, it is estimated that a device with approximately 1000 electrodes could give good functional vision, i.e., face recognition and reading ability. This could be a reality within 5-10 years from now. In summary, no treatments are currently available for severely affected patients with RP and dry AMD. An electrical prosthetic device appears to offer hope in replacing the function of degenerating or dead photoreceptor neurons. Devices with new, sophisticated designs and increasing numbers of electrodes could allow for long-term restoration of functional sight in patients with improvement in object recognition, mobility, independent living, and general QOL.

Periprosthetic joint infection: are patients with multiple prosthetic joints at risk?

PubMed

Jafari, S Mehdi; Casper, David S; Restrepo, Camilo; Zmistowski, Benjamin; Parvizi, Javad; Sharkey, Peter F

2012-06-01

Patients who present with a periprosthetic joint infection in a single joint may have multiple prosthetic joints. The risk of these patients developing a subsequent infection in another prosthetic joint is unknown. Our purposes were (1) to identify the risk of developing a subsequent infection in another prosthetic joint and (2) to describe the time span and organism profile to the second prosthetic infection. We retrospectively identified 55 patients with periprosthetic joint infection who had another prosthetic joint in place at the time of presentation. Of the 55 patients, 11 (20%) developed a periprosthetic joint infection in a second joint. The type of organism was the same as the first infection in 4 (36%) of 11 patients. The time to developing a second infection averaged 2.0 years (range, 0-6.9 years). Copyright © 2012 Elsevier Inc. All rights reserved.

Review of Prosthetic Joint Infection from Listeria monocytogenes.

PubMed

Bader, Gilbert; Al-Tarawneh, Mohammed; Myers, James

2016-12-01

Prosthetic joint infection from Listeria monocytogenes is rare. We decided to shed light on this illness and review the reported cases to better understand its characteristics. We conducted a comprehensive review of the English literature using PubMed. We also included one case that we had managed. We found 25 cases of prosthetic joint infection from L. monocytogenes reported individually and a retrospective study of 43 cases of joint and bone listerial infection, including 34 with prosthetic joint infection, conducted in France. We have described their clinical and para-clinical features and tried to elaborate on the pathophysiology, treatment, and prevention. Prosthetic joint infection from L. monocytogenes is mainly late. Systemic inflammation may be absent. Although rare, it must be suspected in patients at high risk for both prosthetic joint and listerial infections. In addition, those patients must be instructed on appropriate preventive measures.

Characterizing the Mechanical Properties of Running-Specific Prostheses

PubMed Central

Beck, Owen N.; Taboga, Paolo; Grabowski, Alena M.

2016-01-01

The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10°-25°) compared to neutral (0°) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness. PMID:27973573

An extremely lightweight fingernail worn prosthetic interface device

NASA Astrophysics Data System (ADS)

Yetkin, Oguz; Ahluwalia, Simranjit; Silva, Dinithi; Kasi-Okonye, Isioma; Volker, Rachael; Baptist, Joshua R.; Popa, Dan O.

2016-05-01

Upper limb prosthetics are currently operated using several electromyography sensors mounted on an amputee's residual limb. In order for any prosthetic driving interface to be widely adopted, it needs to be responsive, lightweight, and out of the way when not being used. In this paper we discuss the possibility of replacing such electrodes with fingernail optical sensor systems mounted on the sound limb. We present a prototype device that can detect pinch gestures and communicate with the prosthetic system. The device detects the relative position of fingers to each other by measuring light transmitted via tissue. Applications are not limited to prosthetic control, but can be extended to other human-machine interfaces.

Upper Extremity Amputations and Prosthetics

PubMed Central

Ovadia, Steven A.; Askari, Morad

2015-01-01

Upper extremity amputations are most frequently indicated by severe traumatic injuries. The location of the injury will determine the level of amputation. Preservation of extremity length is often a goal. The amputation site will have important implications on the functional status of the patient and options for prosthetic reconstruction. Advances in amputation techniques and prosthetic reconstructions promote improved quality of life. In this article, the authors review the principles of upper extremity amputation, including techniques, amputation sites, and prosthetic reconstructions. PMID:25685104

Influence of the prosthetic arm length (palatal position) of zygomatic implants upon patient satisfaction

PubMed Central

Pellicer-Chover, Hilario; Cervera-Ballester, Juan; Peñarrocha-Oltra, David; Bagán, Leticia; Peñarrocha-Diago, María

2016-01-01

Background To assess the influence of the prosthetic arm length (palatal position) of zygomatic implants upon patient comfort and stability, speech, functionality and overall satisfaction. Material and Methods A retrospective clinical study was made of patients subjected to rehabilitation of atrophic maxilla with complete maxillary implant-supported fixed prostheses involving a minimum of two zygomatic implants (one on each side) in conjunction with premaxillary implants, and with 12 months of follow-up after implant loading. Subjects used a VAS to score general satisfaction, comfort and stability, speech and functionality, and the results were analyzed in relation to the prosthetic arm length of the zygomatic implants 12 months after prosthetic delivery. Results Twenty-two patients participated in the study, receiving 22 prostheses anchored on 148 implants (44 were zygomatic and 94 were conventional implants). The mean right and left prosthetic arm length was 5.9±2.4 mm and 6.1±2.7 mm, respectively, with no statistically significant differences between them (p=0.576). The mean scores referred to comfort/retention, speech, functionality and overall satisfaction were high - no correlation being found between prosthetic arm length and patient satisfaction (p=0.815). Conclusions No relationship could be identified between prosthetic arm length (palatal position) and patient satisfaction. Key words:Zygomatic implants, patient satisfaction, zygomatic prosthesis, prosthetic arm length. PMID:26946206

Standing on slopes - how current microprocessor-controlled prosthetic feet support transtibial and transfemoral amputees in an everyday task.

PubMed

Ernst, Michael; Altenburg, Björn; Bellmann, Malte; Schmalz, Thomas

2017-11-16

Conventional prosthetic feet like energy storage and return feet provide only a limited range of ankle motion compared to human ones. In order to overcome the poor rotational adaptability, prosthetic manufacturers developed different prosthetic feet with an additional rotational joint and implemented active control in different states. It was the aim of the study to investigate to what extent these commercially available microprocessor-controlled prosthetic feet support a natural posture while standing on inclines and which concept is most beneficial for lower limb amputees. Four unilateral transtibial and four unilateral transfemoral amputees participated in the study. Each of the subjects wore five different microprocessor-controlled prosthetic feet in addition to their everyday feet. The subjects were asked to stand on slopes of different inclinations (level ground, upward slope of 10°, and downward slope of -10°). Vertical ground reaction forces, joint torques and joint angles in the sagittal plane were measured for both legs separately for the different situations and compared to a non-amputee reference group. Differences in the biomechanical parameters were observed between the different prosthetic feet and compared to the reference group for the investigated situations. They were most prominent while standing on a downward slope. For example, on the prosthetic side, the vertical ground reaction force is reduced by about 20%, and the torque about the knee acts to flex the joint for feet that are not capable of a full adaptation to the downward slope. In contrast, fully adaptable feet with an auto-adaptive dorsiflexion stop show no changes in vertical ground reaction forces and knee extending torques. A prosthetic foot that provides both, an auto-adaptive dorsiflexion stop and a sufficient range of motion for fully adapting to inclinations appears to be the key element in the prosthetic fitting for standing on inclinations in lower limb amputees. In such situations, this prosthetic concept appears superior to both, conventional feet with passive structures as well as feet that solely provide a sufficient range of motion. The results also indicate that both, transfemoral and transtibial amputees benefit from such a foot.

38 CFR 17.150 - Prosthetic and similar appliances.

Code of Federal Regulations, 2010 CFR

2010-07-01

... appliances. 17.150 Section 17.150 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Prosthetic, Sensory, and Rehabilitative Aids § 17.150 Prosthetic and similar appliances... appliances including invalid lifts and therapeutic and rehabilitative devices, and special clothing made...

Smart Sensing and Dynamic Fitting for Enhanced Comfort and Performance of Prosthetics

DTIC Science & Technology

2016-10-01

ACCOMPLISHMENTS  What were the major goals of the project? The three aims of the projects are: 1) Demonstrating real-time measurements of interfacial...that demonstrates simultaneous measurement of shear and pressure stresses (by July 2015) – experiment is completed. Manuscript preparation under way...beam has a slot at the center so that the strain gauges bonded on the outer walls of the slot have sufficient sensitivity to measure small compression

Fused Filament Fabrication of Prosthetic Components for Trans-Humeral Upper Limb Prosthetics

NASA Astrophysics Data System (ADS)

Lathers, Steven M.

Presented below is the design and fabrication of prosthetic components consisting of an attachment, tactile sensing, and actuator systems with Fused Filament Fabrication (FFF) technique. The attachment system is a thermoplastic osseointegrated upper limb prosthesis for average adult trans-humeral amputation with mechanical properties greater than upper limb skeletal bone. The prosthetic designed has: a one-step surgical process, large cavities for bone tissue ingrowth, uses a material that has an elastic modulus less than skeletal bone, and can be fabricated on one system. FFF osseointegration screw is an improvement upon the current two-part osseointegrated prosthetics that are composed of a fixture and abutment. The current prosthetic design requires two invasive surgeries for implantation and are made of titanium, which has an elastic modulus greater than bone. An elastic modulus greater than bone causes stress shielding and overtime can cause loosening of the prosthetic. The tactile sensor is a thermoplastic piezo-resistive sensor for daily activities for a prosthetic's feedback system. The tactile sensor is manufactured from a low elastic modulus composite comprising of a compressible thermoplastic elastomer and conductive carbon. Carbon is in graphite form and added in high filler ratios. The printed sensors were compared to sensors that were fabricated in a gravity mold to highlight the difference in FFF sensors to molded sensors. The 3D printed tactile sensor has a thickness and feel similar to human skin, has a simple fabrication technique, can detect forces needed for daily activities, and can be manufactured in to user specific geometries. Lastly, a biomimicking skeletal muscle actuator for prosthetics was developed. The actuator developed is manufactured with Fuse Filament Fabrication using a shape memory polymer composite that has non-linear contractile and passive forces, contractile forces and strains comparable to mammalian skeletal muscle, reaction time under one second, low operating temperature, and has a low mass, volume, and material costs. The actuator improves upon current prosthetic actuators that provide rigid, linear force with high weight, cost, and noise.

Correctness of multi-detector-row computed tomography for diagnosing mechanical prosthetic heart valve disorders using operative findings as a gold standard.

PubMed

Tsai, I-Chen; Lin, Yung-Kai; Chang, Yen; Fu, Yun-Ching; Wang, Chung-Chi; Hsieh, Shih-Rong; Wei, Hao-Ji; Tsai, Hung-Wen; Jan, Sheng-Ling; Wang, Kuo-Yang; Chen, Min-Chi; Chen, Clayton Chi-Chang

2009-04-01

The purpose was to compare the findings of multi-detector computed tomography (MDCT) in prosthetic valve disorders using the operative findings as a gold standard. In a 3-year period, we prospectively enrolled 25 patients with 31 prosthetic heart valves. MDCT and transthoracic echocardiography (TTE) were done to evaluate pannus formation, prosthetic valve dysfunction, suture loosening (paravalvular leak) and pseudoaneurysm formation. Patients indicated for surgery received an operation within 1 week. The MDCT findings were compared with the operative findings. One patient with a Björk-Shiley valve could not be evaluated by MDCT due to a severe beam-hardening artifact; thus, the exclusion rate for MDCT was 3.2% (1/31). Prosthetic valve disorders were suspected in 12 patients by either MDCT or TTE. Six patients received an operation that included three redo aortic valve replacements, two redo mitral replacements and one Amplatzer ductal occluder occlusion of a mitral paravalvular leak. The concordance of MDCT for diagnosing and localizing prosthetic valve disorders and the surgical findings was 100%. Except for images impaired by severe beam-hardening artifacts, MDCT provides excellent delineation of prosthetic valve disorders.

Effects of a flat prosthetic foot rocker section on balance and mobility.

PubMed

Hansen, Andrew; Nickel, Eric; Medvec, Joseph; Brielmaier, Steven; Pike, Alvin; Weber, Marilyn

2014-01-01

Previous studies have shown that the effective rocker shape of the physiologic ankle-foot system during standing and fore-aft swaying is much flatter than that used during walking, which indicates a more stable base of support for the standing/swaying activity. Previous work suggests that flat regions within the effective rocker shapes of prosthetic ankle-foot systems could provide enhanced stability for standing balance tasks. An experimental prosthetic foot was altered to provide three different flat region lengths within its effective rocker shape. It was hypothesized that longer flat regions of the effective rocker shape would lead to improved standing balance outcomes and reduced walking performance for unilateral transtibial prosthesis users. However, no significant changes were seen in the balance and mobility outcomes of 12 unilateral transtibial prosthesis users when using the three prosthetic foot conditions. Subjects in the study significantly preferred prosthetic feet with relatively low to moderate flat regions over those with long flat regions. All the subjects without loss of light touch or vibratory sensation selected the prosthetic foot with the shortest flat region. More work is needed to investigate the effects of prosthetic foot properties on balance and mobility of prosthesis users.

Rapidly growing non-tuberculous mycobacteria infection of prosthetic knee joints: A report of two cases.

PubMed

Kim, Manyoung; Ha, Chul-Won; Jang, Jae Won; Park, Yong-Beom

2017-08-01

Non-tuberculous mycobacteria (NTM) cause prosthetic knee joint infections in rare cases. Infections with rapidly growing non-tuberculous mycobacteria (RGNTM) are difficult to treat due to their aggressive clinical behavior and resistance to antibiotics. Infections of a prosthetic knee joint by RGNTM have rarely been reported. A standard of treatment has not yet been established because of the rarity of the condition. In previous reports, diagnoses of RGNTM infections in prosthetic knee joints took a long time to reach because the condition was not suspected, due to its rarity. In addition, it is difficult to identify RGNTM in the lab because special identification tests are needed. In previous reports, after treatment for RGNTM prosthetic infections, knee prostheses could not be re-implanted in all cases but one, resulting in arthrodesis or resection arthroplasty; this was most likely due to the aggressiveness of these organisms. In the present report, two cases of prosthetic knee joint infection caused by RGNTM (Mycobacterium abscessus) are described that were successfully treated, and in which prosthetic joints were finally reimplanted in two-stage revision surgery. Copyright © 2017 Elsevier B.V. All rights reserved.

Rotationplasty with vascular reconstruction for prosthetic knee joint infection.

PubMed

Fujiki, Masahide; Miyamoto, Shimpei; Nakatani, Fumihiko; Kawai, Akira; Sakuraba, Minoru

2015-01-01

Rotationplasty is used most often as a function-preserving salvage procedure after resection of sarcomas of the lower extremity; however, it is also used after infection of prosthetic knee joints. Conventional vascular management during rotationplasty is to preserve and coil major vessels, but recently, transection and reanastomosis of the major vessels has been widely performed. However, there has been little discussion regarding the optimal vascular management of rotationplasty after infection of prosthetic knee joints because rotationplasty is rarely performed for this indication. We reviewed four patients who had undergone resection of osteosarcomas of the femur, placement of a prosthetic knee joint, and rotationplasty with vascular reconstruction from 2010 to 2013. The mean interval between prosthetic joint replacement and rotationplasty was 10.4 years and the mean interval between the diagnosis of prosthesis infection and rotationplasty was 7.9 years. Rotationplasty was successful in all patients; however, in one patient, arterial thrombosis developed and necessitated urgent surgical removal and arterial reconstruction. All patients were able to walk independently with a prosthetic limb after rehabilitation. Although there is no consensus regarding the most appropriate method of vascular management during rotationplasty for revision of infected prosthetic joints, vascular transection and reanastomosis is a useful option.

Isolated Lactobacillus chronic prosthetic knee infection.

PubMed

Bennett, David M; Shekhel, Tatyana; Radelet, Matt; Miller, Michael D

2014-01-01

Lactobacillus is a gram-positive rod bacteria found primarily in the gastrointestinal and female genital tracts. Prosthetic infections in implants are being increasingly reported. The authors present a case of a 58-year-old patient with Lactobacillus septic prosthetic knee joint infection. To the authors’ knowledge, this is the first reported case of chronic prosthetic knee infection with isolated Lactobacillus species. Lactobacillus has been most commonly implicated with bacteremia and endocarditis and rarely with pneumonia, meningitis, and endovascular infection, and a vast majority of the cases are reported in immunocompromised patients. In the current case, diabetes mellitus, hepatitis, malnutrition, anemia, and liver failure were comorbid conditions, placing the patient at increased risk of infection. The findings suggest that further case series are necessary to establish the significance of Lactobacillus as an etiologic agent in chronic low-virulence, and potentially vancomycin-resistant, prosthetic joint infection. The need also exists for further research aimed at the risk of prosthetic joint infection with oral intake of certain probiotic foods and supplements. The goal of this case report is to bring to light the potential of this organism to be a cause of subtle chronic prosthetic joint infection.

Control of a visual keyboard using an electrocorticographic brain-computer interface.

PubMed

Krusienski, Dean J; Shih, Jerry J

2011-05-01

Brain-computer interfaces (BCIs) are devices that enable severely disabled people to communicate and interact with their environments using their brain waves. Most studies investigating BCI in humans have used scalp EEG as the source of electrical signals and focused on motor control of prostheses or computer cursors on a screen. The authors hypothesize that the use of brain signals obtained directly from the cortical surface will more effectively control a communication/spelling task compared to scalp EEG. A total of 6 patients with medically intractable epilepsy were tested for the ability to control a visual keyboard using electrocorticographic (ECOG) signals. ECOG data collected during a P300 visual task paradigm were preprocessed and used to train a linear classifier to subsequently predict the intended target letters. The classifier was able to predict the intended target character at or near 100% accuracy using fewer than 15 stimulation sequences in 5 of the 6 people tested. ECOG data from electrodes outside the language cortex contributed to the classifier and enabled participants to write words on a visual keyboard. This is a novel finding because previous invasive BCI research in humans used signals exclusively from the motor cortex to control a computer cursor or prosthetic device. These results demonstrate that ECOG signals from electrodes both overlying and outside the language cortex can reliably control a visual keyboard to generate language output without voice or limb movements.

Intracardiac echocardiography to diagnose pannus formation after aortic valve replacement.

PubMed

Yamamoto, Yoshiya; Ohara, Takahiro; Funada, Akira; Takahama, Hiroyuki; Amaki, Makoto; Hasegawa, Takuya; Sugano, Yasuo; Kanzaki, Hideaki; Anzai, Toshihisa

2016-03-01

A 66-year-old female, under regular follow-up for 20 years after aortic valve replacement (19-mm Carbomedics), presented dyspnea on effort and hypotension during hemodialysis. A transthoracic echocardiogram showed elevation of transvalvular velocity up to 4 m/s, but the structure around the aortic prosthesis was difficult to observe due to artifacts. Fluoroscopy revealed normal motion of the leaflets of the mechanical valve. Intracardiac echocardiography (ICE) revealed a pannus-like structure in the left ventricular outflow tract. Transesophageal echocardiogram also revealed this structure. ICE can visualize structural abnormalities around a prosthetic valve after cardiac surgery even in patients in whom conventional imaging modalities failed.

Use of multidetector-row computed tomography scan to detect pannus formation in prosthetic mechanical aortic valves

PubMed Central

Aladmawi, Mohamed A.; Vriz, Olga; Galzerano, Domenico

2017-01-01

Obstruction of a mechanical aortic valve by pannus formation at the subvalvular level is a major long-term complication of aortic valve replacement (AVR). In fact, pannus is sometime difficult to differentiate from patient-prosthesis mismatch or valve thrombosis. In most cases cine-angiography and echocardiography, either transthoracic or transesophageal, cannot correctly visualize the complication when the leaflets show a normal mobility. Recent technological refinements made this difficult diagnosis possible by ECG-gated computed tomography (CT) scan which shows adequate images in 90% of the cases and can differentiate pannus from fresh and organized thrombus. PMID:28540078

38 CFR 3.810 - Clothing allowance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... prosthetic or orthopedic appliance (including, but not limited to, a wheelchair) which tends to wear or tear... service-connected disability or disabilities, wears or uses one qualifying prosthetic or orthopedic... allowance for each prosthetic or orthopedic appliance (including, but not limited to, a wheelchair) or...

Prosthetic Aortic Valves: Challenges and Solutions

PubMed Central

Musumeci, Lucia; Jacques, Nicolas; Hego, Alexandre; Nchimi, Alain; Lancellotti, Patrizio; Oury, Cécile

2018-01-01

Aortic Valve Disease (AVD) is the most common Valvular Heart Disease (VHD), affecting millions of people worldwide. Severe AVD is treated in most cases with prosthetic aortic valve replacement, which involves the substitution of the native aortic valve with a prosthetic one. In this review we will discuss the different types of prosthetic aortic valves available for implantation and the challenges faced by patients, medical doctors, researchers and manufacturers, as well as the approaches that are taken to overcome them. PMID:29868612

Remote transient Lactobacillus animalis bacteremia causing prosthetic hip joint infection: a case report.

PubMed

Somayaji, R; Lynch, T; Powell, J N; Gregson, D

2016-11-04

Lactobacillus spp. are uncommon pathogens in immunocompetent hosts, and even rarer causes of prosthetic device infections. A case of chronic hip prosthetic joint infection (PJI) caused by L. animalis is described. This occurred 5 years after a transient bacteremia with the same organism. Whole genome sequencing of both isolates proved this PJI infection resulted from this remote bacteremia. We document that prosthetic joint infections may be a consequence of bacteremia as much as 3 years before the onset of symptoms.

Good quality of life outcomes after treatment of prosthetic joint infection with debridement and prosthesis retention.

PubMed

Aboltins, Craig; Dowsey, Michelle; Peel, Trish; Lim, Wen K; Choong, Peter

2016-05-01

Patients treated for early prosthetic joint infection (PJI) with surgical debridement and prosthesis retention have a rate of successful infection eradication that is similar to patients treated with the traditional approach of prosthesis exchange. It is therefore important to consider other outcomes after prosthetic joint infection treatment that may influence management decisions, such as quality of life (QOL). Our aim was to describe infection cure rates and quality of life for patients with prosthetic joint infection treated with debridement and prosthesis retention and to determine if treatment with this approach was a risk factor for poor quality of life outcomes. Prospectively collected pre and post-arthroplasty data were available for 2,134 patients, of which PJI occurred in 41. For patients treated for prosthetic joint infection, the 2-year survival free of treatment failure was 87% (95%CI 84-89). Prosthetic joint infection cases treated with debridement and retention had a similar improvement from pre-arthroplasty to 12-months post-arthroplasty as patients without PJI in QOL according to the SF-12 survey. Prosthetic joint infection treated with debridement and retention was not a risk factor for poor quality of life on univariate or multivariate analysis. Prosthetic joint infection treated with debridement and prosthesis retention results in good cure rates and quality of life. Further studies are required that directly compare quality of life for different surgical approaches for prosthetic joint infection to better inform management decisions. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:898-902, 2016. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Analysis of the acoustic spectral signature of prosthetic heart valves in patients experiencing atrial fibrillation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scott, D.D.; Jones, H.E.

1994-05-06

Prosthetic heart valves have increased the life span of many patients with life threatening heart conditions. These valves have proven extremely reliable adding years to what would have been weeks to a patient`s life. Prosthetic valves, like the heart however, can suffer from this constant work load. A small number of valves have experienced structural fractures of the outlet strut due to fatigue. To study this problem a non-intrusive method to classify valves has been developed. By extracting from an acoustic signal the opening sounds which directly contain information from the outlet strut and then developing features which are suppliedmore » to an adaptive classification scheme (neural network) the condition of the valve can be determined. The opening sound extraction process has proved to be a classification problem itself. Due to the uniqueness of each heart and the occasional irregularity of the acoustic pattern it is often questionable as to the integrity of a given signal (beat), especially one occurring during an irregular beat pattern. A common cause of these irregular patterns is a condition known as atrial fibrillation, a prevalent arrhythmia among patients with prosthetic hear valves. Atrial fibrillation is suspected when the ECG shows no obvious P-waves. The atria do not contract and relax correctly to help contribute to ventricular filling during a normal cardiac cycle. Sometimes this leads to irregular patterns in the acoustic data. This study compares normal beat patterns to irregular patterns of the same heart. By analyzing the spectral content of the beats it can be determined whether or not these irregular patterns can contribute to the classification of a heart valve or if they should be avoided. The results have shown that the opening sounds which occur during irregular beat patterns contain the same spectral information as the opening which occur during a normal beat pattern of the same heart and these beats can be used for classification.« less

Graft-Sparing Strategy for Thoracic Prosthetic Graft Infection.

PubMed

Uchino, Gaku; Yoshida, Takeshi; Kakii, Bunpachi; Furui, Masato

2018-04-01

 Thoracic prosthetic graft infection is a rare but serious complication with no standard management. We reported our surgical experience on graft-sparing strategy for thoracic prosthetic graft infection.  This study included patients who underwent graft-sparing surgery for thoracic prosthetic graft infection at Matsubara Tokushukai Hospital in Japan from January 2000 to October 2017.  There were 17 patients included in the analyses, with a mean age at surgery of 71.0 ± 10.5 years; 11 were men. In-hospital mortality was observed in five patients (29.4%).  Graft-sparing surgery for thoracic prosthetic graft infection is an alternative option particularly for early graft infection after hemiarch replacement. Georg Thieme Verlag KG Stuttgart · New York.

Development of inexpensive prosthetic feet for high-heeled shoes using simple shoe insole model.

PubMed

Meier, Margrit R; Tucker, Kerice A; Hansen, Andrew H

2014-01-01

The large majority of prosthetic feet are aimed at low-heeled shoes, with a few models allowing a heel height of up to 5 cm. However, a survey by the American Podiatric Medical Association indicates that most women wear heels over 5 cm; thus, current prosthetic feet limit most female prosthesis users in their choice. Some prosthetic foot components are heel-height adjustable; however, their plantar surface shapes do not change to match the insole shapes of the shoes with different heel heights. The aims of the study were therefore (1) to develop a model that allows prediction of insole shape for various heel height shoes in combination with different shoe sizes and (2) to develop and field-test low-cost prototypes of prosthetic feet whose insole shapes were based on the new model. An equation was developed to calculate insole shapes independent of shoe size. Field testing of prototype prosthetic feet fabricated based on the equation was successful and demonstrated the utility of the equation.

Provision of Prosthetic Services Following Lower Limb Amputation in Malaysia

PubMed Central

Arifin, Nooranida; Hasbollah, Hasif Rafidee; Hanafi, Muhammad Hafiz; Ibrahim, Al Hafiz; Rahman, Wan Afezah Wan Abdul; Aziz, Roslizawati Che

2017-01-01

The incidence of lower limb amputation is high across the globe and continues to be a major threat to morbidity and mortality. Consequently, the provision of high quality and effective prosthetics services have been known as an essential component for a successful rehabilitation outcome. In Malaysia, amputation prevalence has been increasing in which several main components of service delivering aspects (such as service intervention, prosthetic personnel) should be anticipated to accommodate for the increasing demand. This article highlights the hurdles experienced in providing prosthetic services in Malaysia from multiple aspects such as financial burden to acquire the prosthesis and lack of expertise to produce quality prosthesis. This paramount issues consequently justify for the urgency to carry out national level survey on the current statistics of lower limb amputation and to ascertain the available workforce to provide a quality prosthetics services. Only with accurate and current information from the national survey, strategies and policies aimed at enhancing the outcome from prosthetics services can be achieved. PMID:29386978

Provision of Prosthetic Services Following Lower Limb Amputation in Malaysia.

PubMed

Arifin, Nooranida; Hasbollah, Hasif Rafidee; Hanafi, Muhammad Hafiz; Ibrahim, Al Hafiz; Rahman, Wan Afezah Wan Abdul; Aziz, Roslizawati Che

2017-10-01

The incidence of lower limb amputation is high across the globe and continues to be a major threat to morbidity and mortality. Consequently, the provision of high quality and effective prosthetics services have been known as an essential component for a successful rehabilitation outcome. In Malaysia, amputation prevalence has been increasing in which several main components of service delivering aspects (such as service intervention, prosthetic personnel) should be anticipated to accommodate for the increasing demand. This article highlights the hurdles experienced in providing prosthetic services in Malaysia from multiple aspects such as financial burden to acquire the prosthesis and lack of expertise to produce quality prosthesis. This paramount issues consequently justify for the urgency to carry out national level survey on the current statistics of lower limb amputation and to ascertain the available workforce to provide a quality prosthetics services. Only with accurate and current information from the national survey, strategies and policies aimed at enhancing the outcome from prosthetics services can be achieved.

Embodied prosthetic arm stabilizes body posture, while unembodied one perturbs it.

PubMed

Imaizumi, Shu; Asai, Tomohisa; Koyama, Shinichi

2016-10-01

Senses of ownership (this arm belongs to me) and agency (I am controlling this arm) originate from sensorimotor system. External objects can be integrated into the sensorimotor system following long-term use, and recognized as one's own body. We examined how an (un)embodied prosthetic arm modulates whole-body control, and assessed the components of prosthetic embodiment. Nine unilateral upper-limb amputees participated. Four frequently used their prosthetic arm, while the others rarely did. Their postural sway was measured during quiet standing with or without their prosthesis. The frequent users showed greater sway when they removed the prosthesis, while the rare users showed greater sway when they fitted the prosthesis. Frequent users reported greater everyday feelings of postural stabilization by prosthesis and a larger sense of agency over the prosthesis. We suggest that a prosthetic arm maintains or perturbs postural control, depending on the prosthetic embodiment, which involves sense of agency rather than ownership. Copyright © 2016 Elsevier Inc. All rights reserved.

Will musculoskeletal and visual stress change when Visual Display Unit (VDU) operators move from small offices to an ergonomically optimized office landscape?

PubMed

Helland, Magne; Horgen, Gunnar; Kvikstad, Tor Martin; Garthus, Tore; Aarås, Arne

2011-11-01

This study investigated the effect of moving from small offices to a landscape environment for 19 Visual Display Unit (VDU) operators at Alcatel Denmark AS. The operators reported significantly improved lighting condition and glare situation. Further, visual discomfort was also significantly reduced on a Visual Analogue Scale (VAS). There was no significant correlation between lighting condition and visual discomfort neither in the small offices nor in the office landscape. However, visual discomfort correlated significantly with glare in small offices i.e. more glare is related to more visual discomfort. This correlation disappeared after the lighting system in the office landscape had been improved. There was also a significant correlation between glare and itching of the eyes as well as blurred vision in the small offices, i.e. more glare more visual symptoms. Experience of pain was found to reduce the subjective assessment of work capacity during VDU tasks. There was a significant correlation between visual discomfort and reduced work capacity in small offices and in the office landscape. When moving from the small offices to the office landscape, there was a significant reduction in headache as well as back pain. No significant changes in pain intensity in the neck, shoulder, forearm, and wrist/hand were observed. The pain levels in different body areas were significantly correlated with subjective assessment of reduced work capacity in small offices and in the office landscape. By careful design and construction of an office landscape with regard to lighting and visual conditions, transfer from small offices may be acceptable from a visual-ergonomic point of view. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Bi-layered zirconia/fluor-apatite bridges supported by ceramic dental implants: a prospective case series after thirty months of observation.

PubMed

Spies, Benedikt Christopher; Witkowski, Siegbert; Butz, Frank; Vach, Kirstin; Kohal, Ralf-Joachim

2016-10-01

The aim of this study was to determine the success and survival rate of all-ceramic bi-layered implant-supported three-unit fixed dental prostheses (IS-FDPs) 3 years after implant placement. Thirteen patients (seven males, six females; age: 41-78 years) received two one-piece ceramic implants (alumina-toughened zirconia) each in the region of the premolars or the first molar and were finally restored with adhesively cemented bi-layered zirconia-based IS-FDPs (3 in the maxilla, 10 in the mandible) composed of CAD/CAM-fabricated zirconia frameworks pressed-over with fluor-apatite glass-ceramic ingots. At prosthetic delivery and the follow-ups after 1, 2 and 3 years, the restorations were evaluated using modified United States Public Health Service (USPHS) criteria. Restorations with minor veneer chippings, a small-area occlusal roughness, slightly soundable restoration margins, minimal contour deficiencies and tolerable color deviations were regarded as success. In case of more distinct defects that could, however, be repaired to a clinically acceptable level, IS-FDPs were regarded as surviving. Kaplan-Meier plots were used for the success/survival analyses. To verify an impact on subjective patients' perceptions, satisfaction was evaluated by visual analog scales (VAS). All patients were seen 3 years after implant installation. No IS-FDP had to be replaced, resulting in 100% survival after a mean observation period of 29.5 months (median: 30.7). At the 3-year follow-up, 7/13 IS-FDPs showed a veneer chipping, 13/13 an occlusal roughness and 12/13 minimal deficiencies of contour/color. Since six restorations showed a major chipping and/or a major occlusal roughness, the Kaplan-Meier success rate was 53.8%. However, patients' significantly improved perceptions of function, esthetics, sense, and speech at prosthetic delivery remained stable over time. Bi-layered zirconia/fluor-apatite IS-FDPs entirely survived the observation period but showed a high frequency of technical complications. Nevertheless, the treatment highly satisfied patients' expectations. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Attenuation of centre-of-pressure trajectory fluctuations under the prosthetic foot when using an articulating hydraulic ankle attachment compared to fixed attachment.

PubMed

De Asha, Alan R; Johnson, Louise; Munjal, Ramesh; Kulkarni, Jai; Buckley, John G

2013-02-01

Disruptions to the progress of the centre-of-pressure trajectory beneath prosthetic feet have been reported previously. These disruptions reflect how body weight is transferred over the prosthetic limb and are governed by the compliance of the prosthetic foot device and its ability to simulate ankle function. This study investigated whether using an articulating hydraulic ankle attachment attenuates centre-of-pressure trajectory fluctuations under the prosthetic foot compared to a fixed attachment. Twenty active unilateral trans-tibial amputees completed walking trials at their freely-selected, comfortable walking speed using both their habitual foot with either a rigid or elastic articulating attachment and a foot with a hydraulic ankle attachment. Centre-of-pressure displacement and velocity fluctuations beneath the prosthetic foot, prosthetic shank angular velocity during stance, and walking speed were compared between foot conditions. Use of the hydraulic device eliminated or reduced the magnitude of posteriorly directed centre-of-pressure displacements, reduced centre-of-pressure velocity variability across single-support, increased mean forward angular velocity of the shank during early stance, and increased freely chosen comfortable walking speed (P ≤ 0.002). The attenuation of centre-of-pressure trajectory fluctuations when using the hydraulic device indicated bodyweight was transferred onto the prosthetic limb in a smoother, less faltering manner which allowed the centre of mass to translate more quickly over the foot. Copyright © 2012 Elsevier Ltd. All rights reserved.

Salmonella Typhimurium gastroenteritis leading to chronic prosthetic vascular graft infection.

PubMed

Cullinan, Milo; Clarke, Michael; Dallman, Tim; Peart, Steven; Wilson, Deborah; Weiand, Daniel

2017-08-01

Introduction. It is estimated up to 6 % of prosthetic vascular grafts become infected. Staphylococcus aureus is predominant in early infection and coagulase-negative staphylococci are predominant in late infections. Enterobacteriaceae cause 14-40 % of prosthetic vascular graft infections. This is, to our knowledge the first reported case of Salmonella gastroenteritis causing chronic prosthetic vascular graft infection (PVGI). Case presentation. A 57 years old lady presented with signs and symptoms of prosthetic vascular graft infection. Three years earlier, she had undergone a prosthetic axillo-femoral bypass graft for critical limb ischaemia. The infected prosthetic vascular graft was removed and Salmonella Typhimurium was isolated on culture. In the intervening period, Salmonella Typhimurium was isolated from a faecal specimen, collected during an episode of acute gastroenteritis. Whole-genome sequencing (WGS) showed that the respective Salmonella Typhimurium isolates differed by only a single nucleotide polymorphism (SNP). Salmonella Typhimurium was not isolated on culture of a faecal specimen collected five days following cessation of antimicrobial therapy. Six months after removal of the prosthetic graft, the patient remains under follow-up for her peripheral vascular disease, which currently requires no further surgical intervention. Conclusion. This case has clear implications for the management of chronic PVGI. It is vital to collect high-quality surgical specimens for microbiological analysis and empirical choices of antibiotics are unlikely to cover all potential pathogens. It may also be prudent to enquire about a history of acute gastroenteritis when assessing patients presenting with chronic PVGI.

21 CFR 890.3420 - External limb prosthetic component.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false External limb prosthetic component. 890.3420 Section 890.3420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3420...

21 CFR 890.3025 - Prosthetic and orthotic accessory.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Prosthetic and orthotic accessory. 890.3025 Section 890.3025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3025...

21 CFR 890.3025 - Prosthetic and orthotic accessory.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Prosthetic and orthotic accessory. 890.3025 Section 890.3025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3025...

21 CFR 890.3025 - Prosthetic and orthotic accessory.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prosthetic and orthotic accessory. 890.3025 Section 890.3025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3025...

21 CFR 890.3420 - External limb prosthetic component.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false External limb prosthetic component. 890.3420 Section 890.3420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3420...

21 CFR 890.3420 - External limb prosthetic component.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External limb prosthetic component. 890.3420 Section 890.3420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3420...

21 CFR 890.3025 - Prosthetic and orthotic accessory.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prosthetic and orthotic accessory. 890.3025 Section 890.3025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3025...

21 CFR 890.3420 - External limb prosthetic component.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false External limb prosthetic component. 890.3420 Section 890.3420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3420...

21 CFR 890.3420 - External limb prosthetic component.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false External limb prosthetic component. 890.3420 Section 890.3420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3420...

21 CFR 890.3025 - Prosthetic and orthotic accessory.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic and orthotic accessory. 890.3025 Section 890.3025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3025...

Evaluation of a Powered Ankle-Foot Prosthesis during Slope Ascent Gait

PubMed Central

2016-01-01

Passive prosthetic feet lack active plantarflexion and push-off power resulting in gait deviations and compensations by individuals with transtibial amputation (TTA) during slope ascent. We sought to determine the effect of active ankle plantarflexion and push-off power provided by a powered prosthetic ankle-foot (PWR) on lower extremity compensations in individuals with unilateral TTA as they walked up a slope. We hypothesized that increased ankle plantarflexion and push-off power would reduce compensations commonly observed with a passive, energy-storing-returning prosthetic ankle-foot (ESR). We compared the temporal spatial, kinematic, and kinetic measures of ten individuals with TTA (age: 30.2 ± 5.3 yrs) to matched abled-bodied (AB) individuals during 5° slope ascent. The TTA group walked with an ESR and separately with a PWR. The PWR produced significantly greater prosthetic ankle plantarflexion and push-off power generation compared to an ESR and more closely matched AB values. The PWR functioned similar to a passive ESR device when transitioning onto the prosthetic limb due to limited prosthetic dorsiflexion, which resulted in similar deviations and compensations. In contrast, when transitioning off the prosthetic limb, increased ankle plantarflexion and push-off power provided by the PWR contributed to decreased intact limb knee extensor power production, lessening demand on the intact limb knee. PMID:27977681

Evaluation of a Powered Ankle-Foot Prosthesis during Slope Ascent Gait.

PubMed

Rábago, Christopher A; Aldridge Whitehead, Jennifer; Wilken, Jason M

2016-01-01

Passive prosthetic feet lack active plantarflexion and push-off power resulting in gait deviations and compensations by individuals with transtibial amputation (TTA) during slope ascent. We sought to determine the effect of active ankle plantarflexion and push-off power provided by a powered prosthetic ankle-foot (PWR) on lower extremity compensations in individuals with unilateral TTA as they walked up a slope. We hypothesized that increased ankle plantarflexion and push-off power would reduce compensations commonly observed with a passive, energy-storing-returning prosthetic ankle-foot (ESR). We compared the temporal spatial, kinematic, and kinetic measures of ten individuals with TTA (age: 30.2 ± 5.3 yrs) to matched abled-bodied (AB) individuals during 5° slope ascent. The TTA group walked with an ESR and separately with a PWR. The PWR produced significantly greater prosthetic ankle plantarflexion and push-off power generation compared to an ESR and more closely matched AB values. The PWR functioned similar to a passive ESR device when transitioning onto the prosthetic limb due to limited prosthetic dorsiflexion, which resulted in similar deviations and compensations. In contrast, when transitioning off the prosthetic limb, increased ankle plantarflexion and push-off power provided by the PWR contributed to decreased intact limb knee extensor power production, lessening demand on the intact limb knee.

Multi-Disciplinary Antimicrobial Strategies for Improving Orthopaedic Implants to Prevent Prosthetic Joint Infections in Hip and Knee

PubMed Central

Getzlaf, Matthew A.; Lewallen, Eric A.; Kremers, Hilal M.; Jones, Dakota L.; Bonin, Carolina A.; Dudakovic, Amel; Thaler, Roman; Cohen, Robert C.; Lewallen, David G.; van Wijnen, Andre J.

2016-01-01

Like any foreign object, orthopaedic implants are susceptible to infection when introduced into the human body. Without additional preventative measures, the absolute number of annual prosthetic joint infections will continue to rise, and may exceed the capacity of health care systems in the near future. Bacteria are difficult to eradicate from synovial joints due to their exceptionally diverse taxonomy, complex mechanistic attachment capabilities, and tendency to evolve antibiotic resistance. When a primary orthopaedic implant fails from prosthetic joint infection, surgeons are generally challenged by limited options for intervention. In this review, we highlight the etiology and taxonomic groupings of bacteria known to cause prosthetic joint infections, and examine their key mechanisms of attachment. We propose that antimicrobial strategies should focus on the most harmful bacteria taxa within the context of occurrence, taxonomic diversity, adhesion mechanisms, and implant design. Patient-specific identification of organisms that cause prosthetic joint infections will permit assessment of their biological vulnerabilities. The latter can be targeted using a range of antimicrobial techniques that exploit different colonization mechanisms including implant surface attachment, biofilm formation, and/or hematogenous recruitment. We anticipate that customized strategies for each patient, joint, and prosthetic component will be most effective at reducing prosthetic joint infections, including those caused by antibiotic-resistant and polymicrobial bacteria. PMID:26449208

Increasing prosthetic foot energy return affects whole-body mechanics during walking on level ground and slopes.

PubMed

Childers, W Lee; Takahashi, Kota Z

2018-03-29

Prosthetic feet are designed to store energy during early stance and then release a portion of that energy during late stance. The usefulness of providing more energy return depends on whether or not that energy transfers up the lower limb to aid in whole body propulsion. This research examined how increasing prosthetic foot energy return affected walking mechanics across various slopes. Five people with a uni-lateral transtibial amputation walked on an instrumented treadmill at 1.1 m/s for three conditions (level ground, +7.5°, -7.5°) while wearing a prosthetic foot with a novel linkage system and a traditional energy storage and return foot. The novel foot demonstrated greater range of motion (p = 0.0012), and returned more energy (p = 0.023) compared to the traditional foot. The increased energy correlated with an increase in center of mass (CoM) energy change during propulsion from the prosthetic limb (p = 0.012), and the increased prosthetic limb propulsion correlated to a decrease in CoM energy change (i.e., collision) on the sound limb (p < 0.001). These data indicate that this novel foot was able to return more energy than a traditional prosthetic foot and that this additional energy was used to increase whole body propulsion.

Biomechanics principle of elbow joint for transhumeral prostheses: comparison of normal hand, body-powered, myoelectric & air splint prostheses.

PubMed

Abd Razak, Nasrul Anuar; Abu Osman, Noor Azuan; Gholizadeh, Hossein; Ali, Sadeeq

2014-09-10

Understanding of kinematics force applied at the elbow is important in many fields, including biomechanics, biomedical engineering and rehabilitation. This paper provides a comparison of a mathematical model of elbow joint using three different types of prosthetics for transhumeral user, and characterizes the forces required to overcome the passive mechanical of the prosthetics at the residual limb. The study modeled the elbow as a universal joint with intersecting axes of x-axis and y-axis in a plain of upper arm and lower arm. The equations of force applied, torque, weight and length of different type of prosthetics and the anthropometry of prosthetics hand are discussed in this study. The study also compares the force, torque and pressure while using all three types of prosthetics with the normal hand. The result was measured from the elbow kinematics of seven amputees, using three different types of prosthetics. The F-Scan sensor used in the study is to determine the pressure applied at the residual limb while wearing different type of prostheses. These technological advances in assessment the biomechanics of an elbow joint for three different type of prosthetics with the normal hand bring the new information for the amputees and prosthetist to choose the most suitable device to be worn daily.

Autologous alternative veins may not provide better outcomes than prosthetic conduits for below-knee bypass when great saphenous vein is unavailable.

PubMed

Avgerinos, Efthymios D; Sachdev, Ulka; Naddaf, Abdallah; Doucet, Dannielle R; Mohapatra, Abhisekh; Leers, Steven A; Chaer, Rabih A; Makaroun, Michel S

2015-08-01

There is a need to better define the role of alternative autologous vein (AAV) segments over contemporary prosthetic conduits in patients with critical limb ischemia when great saphenous vein (GSV) is not available for use as the bypass conduit. Consecutive patients who underwent bypass to infrageniculate targets between 2007 and 2011 were categorized in three groups: GSV, AAV, and prosthetic. The primary outcome was graft patency. The secondary outcome was limb salvage. Cox proportional hazards regression was used to adjust for baseline confounding variables. A total of 407 infrainguinal bypasses to below-knee targets were analyzed; 255 patients (63%) received a single-segment GSV, 106 patients (26%) received an AAV, and 46 patients (11%) received a prosthetic conduit. Baseline characteristics were similar among groups, with the exception of popliteal targets and anticoagulation use being more frequent in the prosthetic group. Primary patency at 2 and 5 years was estimated at 47% and 32%, respectively, for the GSV group; 24% and 23% for the AAV group; and 43% and 38% for the prosthetic group. Primary assisted patency at 2 and 5 years was estimated at 71% and 55%, respectively, for the GSV group; 53% and 51% for the AAV group; and 45% and 40% for the prosthetic group. Secondary patency at 2 and 5 years was estimated at 75% and 60%, respectively, for the GSV group; 57% and 55% for the AAV group; and 46% and 41% for the prosthetic group. In Cox analysis, primary patency (hazard ratio [HR], 0.55; P < .001; 95% confidence interval [CI], 0.404-0.758), primary assisted patency (HR, 0.57; P = .004; 95% CI, 0.388-0.831), and secondary patency (HR, 0.56; P = .005; 95% CI, 0.372-0.840) were predicted by GSV compared with AAV, but there was no difference between AAV and prosthetic grafts except for the primary patency, for which prosthetic was protective (HR, 0.38; P < .001; 95% CI, 0.224-0.629). Limb salvage was similar among groups. AAV conduits may not offer a significant patency advantage in midterm follow-up over prosthetic bypasses. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Prosthetic model, but not stiffness or height, affects the metabolic cost of running for athletes with unilateral transtibial amputations.

PubMed

Beck, Owen N; Taboga, Paolo; Grabowski, Alena M

2017-07-01

Running-specific prostheses enable athletes with lower limb amputations to run by emulating the spring-like function of biological legs. Current prosthetic stiffness and height recommendations aim to mitigate kinematic asymmetries for athletes with unilateral transtibial amputations. However, it is unclear how different prosthetic configurations influence the biomechanics and metabolic cost of running. Consequently, we investigated how prosthetic model, stiffness, and height affect the biomechanics and metabolic cost of running. Ten athletes with unilateral transtibial amputations each performed 15 running trials at 2.5 or 3.0 m/s while we measured ground reaction forces and metabolic rates. Athletes ran using three different prosthetic models with five different stiffness category and height combinations per model. Use of an Ottobock 1E90 Sprinter prosthesis reduced metabolic cost by 4.3 and 3.4% compared with use of Freedom Innovations Catapult [fixed effect (β) = -0.177; P < 0.001] and Össur Flex-Run (β = -0.139; P = 0.002) prostheses, respectively. Neither prosthetic stiffness ( P ≥ 0.180) nor height ( P = 0.062) affected the metabolic cost of running. The metabolic cost of running was related to lower peak (β = 0.649; P = 0.001) and stance average (β = 0.772; P = 0.018) vertical ground reaction forces, prolonged ground contact times (β = -4.349; P = 0.012), and decreased leg stiffness (β = 0.071; P < 0.001) averaged from both legs. Metabolic cost was reduced with more symmetric peak vertical ground reaction forces (β = 0.007; P = 0.003) but was unrelated to stride kinematic symmetry ( P ≥ 0.636). Therefore, prosthetic recommendations based on symmetric stride kinematics do not necessarily minimize the metabolic cost of running. Instead, an optimal prosthetic model, which improves overall biomechanics, minimizes the metabolic cost of running for athletes with unilateral transtibial amputations. NEW & NOTEWORTHY The metabolic cost of running for athletes with unilateral transtibial amputations depends on prosthetic model and is associated with lower peak and stance average vertical ground reaction forces, longer contact times, and reduced leg stiffness. Metabolic cost is unrelated to prosthetic stiffness, height, and stride kinematic symmetry. Unlike nonamputees who decrease leg stiffness with increased in-series surface stiffness, biological limb stiffness for athletes with unilateral transtibial amputations is positively correlated with increased in-series (prosthetic) stiffness.

Brain-machine interfaces: electrophysiological challenges and limitations.

PubMed

Lega, Bradley C; Serruya, Mijail D; Zaghloul, Kareem A

2011-01-01

Brain-machine interfaces (BMI) seek to directly communicate with the human nervous system in order to diagnose and treat intrinsic neurological disorders. While the first generation of these devices has realized significant clinical successes, they often rely on gross electrical stimulation using empirically derived parameters through open-loop mechanisms of action that are not yet fully understood. Their limitations reflect the inherent challenge in developing the next generation of these devices. This review identifies lessons learned from the first generation of BMI devices (chiefly deep brain stimulation), identifying key problems for which the solutions will aid the development of the next generation of technologies. Our analysis examines four hypotheses for the mechanism by which brain stimulation alters surrounding neurophysiologic activity. We then focus on motor prosthetics, describing various approaches to overcoming the problems of decoding neural signals. We next turn to visual prosthetics, an area for which the challenges of signal coding to match neural architecture has been partially overcome. Finally, we close with a review of cortical stimulation, examining basic principles that will be incorporated into the design of future devices. Throughout the review, we relate the issues of each specific topic to the common thread of BMI research: translating new knowledge of network neuroscience into improved devices for neuromodulation.

In vitro reproduction of incisal/occlusal cupping/cratering.

PubMed

Dzakovich, John J; Oslak, Robert R

2013-06-01

Occlusal cupping/cratering (depressed dentin surrounded by elevated rims of enamel) has been postulated to be the result of abrasion, bruxism, attrition, acid erosion, stress corrosion, or a combination of these. The primary etiology or the multifactorial sequence of occlusal cupping/cratering remains scientifically unsubstantiated. The purpose of this study was to reproduce occlusal/incisal cupping/cratering in vitro. This study was designed to create cupping/cratering on the occlusal surfaces of extracted human teeth rather than to quantify the amount of lost tooth structure caused by abrasion. One name-brand toothbrush was tested with 2 different dentifrices (of different abrasive potentials [low and high]) and water only (nonabrasive) on extracted human teeth. Six specimens of 4 teeth each (24 teeth) were subjected to horizontal brushing in a 1:1 toothpaste/water slurry and water only. The control group, brushed with water only, demonstrated no visible loss of tooth structure. Each of the specimens brushed with toothpaste, regardless of the degree of abrasivity, demonstrated visible wear of the dentin, resulting in occlusal/incisal cupping/cratering. Pronounced cupping/cratering was caused by horizontal brushing with commercial toothpastes. Brushing in water demonstrated no visual loss of occlusal tooth structure. (J Prosthet Dent 2013;109:384-391). Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Enhancement of a prosthetic knee with a microprocessor-controlled gait phase switch reduces falls and improves balance confidence and gait speed in community ambulators with unilateral transfemoral amputation.

PubMed

Fuenzalida Squella, Sara Agueda; Kannenberg, Andreas; Brandão Benetti, Ângelo

2018-04-01

Despite the evidence for improved safety and function of microprocessor stance and swing-controlled prosthetic knees, non-microprocessor-controlled prosthetic knees are still standard of care for persons with transfemoral amputations in most countries. Limited feature microprocessor-control enhancement of such knees could stand to significantly improve patient outcomes. To evaluate gait speed, balance, and fall reduction benefits of the new 3E80 default stance hydraulic knee compared to standard non-microprocessor-controlled prosthetic knees. Comparative within-subject clinical study. A total of 13 young, high-functioning community ambulators with a transfemoral amputation underwent assessment of performance-based (e.g. 2-min walk test, timed ramp/stair tests) and self-reported (e.g. falls, Activities-Specific Balance Confidence scale, Prosthesis Evaluation Questionnaire question #1, Satisfaction with the Prosthesis) outcome measures for their non-microprocessor-controlled prosthetic knees and again after 8 weeks of accommodation to the 3E80 microprocessor-enhanced knee. Self-reported falls significantly declined 77% ( p = .04), Activities-Specific Balance Confidence scores improved 12 points ( p = .005), 2-min walk test walking distance increased 20 m on level ( p = .01) and uneven ( p = .045) terrain, and patient satisfaction significantly improved ( p < .01) when using the 3E80 knee. Slope and stair ambulation performance did not differ between knee conditions. The 3E80 knee reduced self-reported fall incidents and improved balance confidence. Walking performance on both level and uneven terrains also improved compared to non-microprocessor-controlled prosthetic knees. Subjects' satisfaction was significantly higher than with their previous non-microprocessor-controlled prosthetic knees. The 3E80 may be considered a prosthetic option for improving gait performance, balance confidence, and safety in highly active amputees. Clinical relevance This study compared performance-based and self-reported outcome measures when using non-microprocessor and a new microprocessor-enhanced, default stance rotary hydraulic knee. The results inform rehabilitation professionals about the functional benefits of a limited-feature, microprocessor-enhanced hydraulic prosthetic knee over standard non-microprocessor-controlled prosthetic knees.

Systematic variation of prosthetic foot spring affects center-of-mass mechanics and metabolic cost during walking.

PubMed

Zelik, Karl E; Collins, Steven H; Adamczyk, Peter G; Segal, Ava D; Klute, Glenn K; Morgenroth, David C; Hahn, Michael E; Orendurff, Michael S; Czerniecki, Joseph M; Kuo, Arthur D

2011-08-01

Lower-limb amputees expend more energy to walk than non-amputees and have an elevated risk of secondary disabilities. Insufficient push-off by the prosthetic foot may be a contributing factor. We aimed to systematically study the effect of prosthetic foot mechanics on gait, to gain insight into fundamental prosthetic design principles. We varied a single parameter in isolation, the energy-storing spring in a prototype prosthetic foot, the controlled energy storage and return (CESR) foot, and observed the effect on gait. Subjects walked on the CESR foot with three different springs. We performed parallel studies on amputees and on non-amputees wearing prosthetic simulators. In both groups, spring characteristics similarly affected ankle and body center-of-mass (COM) mechanics and metabolic cost. Softer springs led to greater energy storage, energy return, and prosthetic limb COM push-off work. But metabolic energy expenditure was lowest with a spring of intermediate stiffness, suggesting biomechanical disadvantages to the softest spring despite its greater push-off. Disadvantages of the softest spring may include excessive heel displacements and COM collision losses. We also observed some differences in joint kinetics between amputees and non-amputees walking on the prototype foot. During prosthetic push-off, amputees exhibited reduced energy transfer from the prosthesis to the COM along with increased hip work, perhaps due to greater energy dissipation at the knee. Nevertheless, the results indicate that spring compliance can contribute to push-off, but with biomechanical trade-offs that limit the degree to which greater push-off might improve walking economy. © 2011 IEEE

Systematic variation of prosthetic foot spring affects center-of-mass mechanics and metabolic cost during walking

PubMed Central

Zelik, Karl E.; Collins, Steven H.; Adamczyk, Peter G.; Segal, Ava D.; Klute, Glenn K.; Morgenroth, David C.; Hahn, Michael E.; Orendurff, Michael S.; Czerniecki, Joseph M.; Kuo, Arthur D.

2014-01-01

Lower-limb amputees expend more energy to walk than non-amputees and have an elevated risk of secondary disabilities. Insufficient push-off by the prosthetic foot may be a contributing factor. We aimed to systematically study the effect of prosthetic foot mechanics on gait, to gain insight into fundamental prosthetic design principles. We varied a single parameter in isolation, the energy-storing spring in a prototype prosthetic foot, the Controlled Energy Storage and Return (CESR) foot, and observed the effect on gait. Subjects walked on the CESR foot with three different springs. We performed parallel studies on amputees and on non-amputees wearing prosthetic simulators. In both groups, spring characteristics similarly affected ankle and body center-of-mass (COM) mechanics and metabolic cost. Softer springs led to greater energy storage, energy return and prosthetic limb COM push-off work. But metabolic energy expenditure was lowest with a spring of intermediate stiffness, suggesting biomechanical disadvantages to the softest spring despite its greater push-off. Disadvantages of the softest spring may include excessive heel displacements and COM collision losses. We also observed some differences in joint kinetics between amputees and non-amputees walking on the prototype foot. During prosthetic push-off, amputees exhibited reduced energy transfer from the prosthesis to the COM along with increased hip work, perhaps due to greater energy dissipation at the knee. Nevertheless, the results indicate that spring compliance can contribute to push-off, but with biomechanical trade-offs that limit the degree to which greater push-off might improve walking economy. PMID:21708509

An evaluation of dental prosthetic status and prosthetic needs among eunuchs (trans genders) residing in bhopal city, madhya pradesh, India: a cross-sectional study.

PubMed

Hongal, S; Torwane, Na; Chandrashekhar, Br; Saxena, V; Chavan, Kr

2014-11-01

Eunuchs are considered as the most vulnerable, frustrated, and insecure community. The accessibility to medical and dental facilities for the eunuchs is nearly nonexistent. Due to these reasons, they might be at a high risk of developing severe dental problems like tooth loss. The present cross-sectional study aimed to evaluate the dental prosthetic status and prosthetic needs among eunuchs residing in Bhopal city, Madhya Pradesh, India. On the basis of convenient nonprobability snowball sampling technique, all the self-identified eunuchs residing in the city of Bhopal along with a matched control consisting of cross section of the general population residing in the same locality was examined to evaluate the prosthetic status and prosthetic needs of the population. All the obtained data were entered into a personal computer on Microsoft excel sheet and analyzed using the software; Statistical Package for Social Science version 20. Data comparison was done by applying Chi-square test. A total of 639 subjects comprised of 207 eunuchs, 218 males and 214 females. Among all participants, 2.8% (18/639) were having prosthesis. The overall prosthetic status among males was 3.2% (7/218) followed by 2.9% (6/207) eunuchs and 2.3% (5/214) females. However, need for multi-unit and combination of one and more unit prosthesis for upper and lower jaws was higher in males compared to females and eunuchs, but the difference was not statistically significant. The findings of this study clearly demonstrate a high unmet need for prosthetic care among the population surveyed.

The clinical significance of perivalvular pannus in prosthetic mitral valves: Can cardiac CT be helpful?

PubMed

Chang, Suyon; Suh, Young Joo; Han, Kyunghwa; Kim, Jin Young; Kim, Young Jin; Chang, Byung-Chul; Choi, Byoung Wook

2017-12-15

The clinical significance of pannus in the prosthetic mitral valve (MV) is not well documented. To investigate the clinical significance of pannus on cardiac computed tomography (CT) in patients with a prosthetic MV. A total of 130 patients with previous MV replacement who underwent cardiac CT were retrospectively included in this study. The presence of pannus, paravalvular leak (PVL) around the prosthetic MV and limitation of motion (LOM) of the MV were analyzed using CT. Between patients with MV pannus and those without pannus, CT, echocardiographic, and redo-surgery findings were compared. The diagnostic performance of CT and transesophageal echocardiography (TEE) for the detection of MV pannus was also compared, using surgical findings as a standard reference. MV pannus was observed on cardiac CT in 32.3% of the study population. Patients with MV pannus detected on CT more commonly had LOM (28.2% vs. 15.2%) and less frequently had PVL of the prosthetic MV (16.7% vs. 25%) than patients without MV pannus (P>0.05). Prosthetic valve obstruction (PVO) due prosthetic MV pannus requiring redo-surgery was present in only five patients (11.9%). Cardiac CT detected MV pannus with sensitivity of 65.2% and specificity of 80.9% and showed better diagnostic performance than TEE (P<0.05). Prosthetic MV pannus can frequently be seen on cardiac CT. However, its clinical significance should be assessed with careful consideration, because PVO due to MV pannus is relatively uncommon, and pannus can be seen in patients without any clinical problems. Copyright © 2017 Elsevier B.V. All rights reserved.

21 CFR 870.3935 - Prosthetic heart valve holder.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic heart valve holder. 870.3935 Section... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a replacement heart valve while it is being sutured into place. (b) Classification. Class I. The device is...

21 CFR 870.3935 - Prosthetic heart valve holder.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Prosthetic heart valve holder. 870.3935 Section... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a replacement heart valve while it is being sutured into place. (b) Classification. Class I. The device is...

21 CFR 870.3935 - Prosthetic heart valve holder.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prosthetic heart valve holder. 870.3935 Section... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a replacement heart valve while it is being sutured into place. (b) Classification. Class I. The device is...

21 CFR 870.3935 - Prosthetic heart valve holder.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prosthetic heart valve holder. 870.3935 Section... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a replacement heart valve while it is being sutured into place. (b) Classification. Class I. The device is...

21 CFR 870.3935 - Prosthetic heart valve holder.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Prosthetic heart valve holder. 870.3935 Section... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a replacement heart valve while it is being sutured into place. (b) Classification. Class I. The device is...

Options in virtual 3D, optical-impression-based planning of dental implants.

PubMed

Reich, Sven; Kern, Thomas; Ritter, Lutz

2014-01-01

If a 3D radiograph, which in today's dentistry often consists of a CBCT dataset, is available for computerized implant planning, the 3D planning should also consider functional prosthetic aspects. In a conventional workflow, the CBCT is done with a specially produced radiopaque prosthetic setup that makes the desired prosthetic situation visible during virtual implant planning. If an exclusively digital workflow is chosen, intraoral digital impressions are taken. On these digital models, the desired prosthetic suprastructures are designed. The entire datasets are virtually superimposed by a "registration" process on the corresponding structures (teeth) in the CBCTs. Thus, both the osseous and prosthetic structures are visible in one single 3D application and make it possible to consider surgical and prosthetic aspects. After having determined the implant positions on the computer screen, a drilling template is designed digitally. According to this design (CAD), a template is printed or milled in CAM process. This template is the first physically extant product in the entire workflow. The article discusses the options and limitations of this workflow.

Development of novel 3D-printed robotic prosthetic for transradial amputees.

PubMed

Gretsch, Kendall F; Lather, Henry D; Peddada, Kranti V; Deeken, Corey R; Wall, Lindley B; Goldfarb, Charles A

2016-06-01

Upper extremity myoelectric prostheses are expensive. The Robohand demonstrated that three-dimensional printing reduces the cost of a prosthetic extremity. The goal of this project was to develop a novel, inexpensive three-dimensional printed prosthesis to address limitations of the Robohand. The prosthesis was designed for patients with transradial limb amputation. It is shoulder-controlled and externally powered with an anthropomorphic terminal device. The user can open and close all five fingers, and move the thumb independently. The estimated cost is US$300. After testing on a patient with a traumatic transradial amputation, several advantages were noted. The independent thumb movement facilitated object grasp, the device weighed less than most externally powered prostheses, and the size was easily scalable. Limitations of the new prosthetic include low grip strength and decreased durability compared to passive prosthetics. Most children with a transradial congenital or traumatic amputation do not use a prosthetic. A three-dimensional printed shoulder-controlled robotic prosthesis provides a cost effective, easily sized and highly functional option which has been previously unavailable. © The International Society for Prosthetics and Orthotics 2015.

Myoelectric control of prosthetic hands: state-of-the-art review

PubMed Central

Geethanjali, Purushothaman

2016-01-01

Myoelectric signals (MES) have been used in various applications, in particular, for identification of user intention to potentially control assistive devices for amputees, orthotic devices, and exoskeleton in order to augment capability of the user. MES are also used to estimate force and, hence, torque to actuate the assistive device. The application of MES is not limited to assistive devices, and they also find potential applications in teleoperation of robots, haptic devices, virtual reality, and so on. The myoelectric control-based prosthetic hand aids to restore activities of daily living of amputees in order to improve the self-esteem of the user. All myoelectric control-based prosthetic hands may not have similar operations and exhibit variation in sensing input, deciphering the signals, and actuating prosthetic hand. Researchers are focusing on improving the functionality of prosthetic hand in order to suit the user requirement with the different operating features. The myoelectric control differs in operation to accommodate various external factors. This article reviews the state of the art of myoelectric prosthetic hand, giving description of each control strategy. PMID:27555799

Upper extremity limb loss: functional restoration from prosthesis and targeted reinnervation to transplantation.

PubMed

Carlsen, Brian T; Prigge, Pat; Peterson, Jennifer

2014-01-01

For several decades, prosthetic use was the only option to restore function after upper extremity amputation. Recent years have seen advances in the field of prosthetics. Such advances include prosthetic design and function, activity-specific devices, improved aesthetics, and adjunctive surgical procedures to improve both form and function. Targeted reinnervation is one exciting advance that allows for more facile and more intuitive function with prosthetics following proximal amputation. Another remarkable advance that holds great promise in nearly all fields of medicine is the transplantation of composite tissue, such as hand and face transplantation. Hand transplantation holds promise as the ultimate restorative procedure that can provide form, function, and sensation. However, this procedure still comes with a substantial cost in terms of the rehabilitation and toxic immunosuppression and should be limited to carefully selected patients who have failed prosthetic reconstruction. Hand transplantation and prosthetic reconstruction should not be viewed as competing options. Rather, they are two treatment options with different risk/benefit profiles and different indications and, hence vastly different implications. Copyright © 2014 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Pannus-related prosthetic valve dysfunction. Case report

PubMed Central

MOLDOVAN, MARIA-SÎNZIANA; BEDELEANU, DANIELA; KOVACS, EMESE; CIUMĂRNEAN, LORENA; MOLNAR, ADRIAN

2016-01-01

Pannus-related prosthetic valve dysfunction, a complication of mechanical prosthetic valve replacement, is rare, with a slowly progressive evolution, but it can be acute, severe, requiring surgical reintervention. We present the case of a patient with a mechanical single disc aortic prosthesis, with moderate prosthesis-patient mismatch, minor pannus found on previous ultrasound examinations, who presented to our service with angina pain with a duration of 1 hour, subsequently interpreted as non-ST segment elevation myocardial infarction (NSTEMI) syndrome. Coronarography showed normal epicardial coronary arteries, an ample movement of the prosthetic disc, without evidence of coronary thromboembolism, and Gated Single-Photon Emission Computerized Tomography (SPECT) with Technetium (Tc)-99m detected no perfusion defects. Transthoracic echocardiography (TTE) evidenced a dysfunctional prosthesis due to a subvalvular mass; transesophageal echocardiography (TOE) showed the interference of this mass, with a pannus appearance, with the closure of the prosthetic disc. Under conditions of repeated angina episodes, under anticoagulant treatment, surgery was performed, with the intraoperative confirmation of pannus and its removal. Postoperative evolution was favorable. This case reflects the diagnostic and therapeutic management problems of pannus-related prosthetic valve dysfunction. PMID:27004041

Pannus-related prosthetic valve dysfunction. Case report.

PubMed

Moldovan, Maria-Sînziana; Bedeleanu, Daniela; Kovacs, Emese; Ciumărnean, Lorena; Molnar, Adrian

2016-01-01

Pannus-related prosthetic valve dysfunction, a complication of mechanical prosthetic valve replacement, is rare, with a slowly progressive evolution, but it can be acute, severe, requiring surgical reintervention. We present the case of a patient with a mechanical single disc aortic prosthesis, with moderate prosthesis-patient mismatch, minor pannus found on previous ultrasound examinations, who presented to our service with angina pain with a duration of 1 hour, subsequently interpreted as non-ST segment elevation myocardial infarction (NSTEMI) syndrome. Coronarography showed normal epicardial coronary arteries, an ample movement of the prosthetic disc, without evidence of coronary thromboembolism, and Gated Single-Photon Emission Computerized Tomography (SPECT) with Technetium (Tc)-99m detected no perfusion defects. Transthoracic echocardiography (TTE) evidenced a dysfunctional prosthesis due to a subvalvular mass; transesophageal echocardiography (TOE) showed the interference of this mass, with a pannus appearance, with the closure of the prosthetic disc. Under conditions of repeated angina episodes, under anticoagulant treatment, surgery was performed, with the intraoperative confirmation of pannus and its removal. Postoperative evolution was favorable. This case reflects the diagnostic and therapeutic management problems of pannus-related prosthetic valve dysfunction.

Hydrodynamic endurance test of the prosthetic valve used in the various types of the ventricular assist device.

PubMed

Nitta, S; Yambe, T; Katahira, Y; Sonobe, T; Saijoh, Y; Naganuma, S; Akiho, H; Kakinuma, Y; Tanaka, M; Miura, M

1991-12-01

To evaluate the various basic designs of the pump chambers used in the ventricular assist devices (VADs), hydrodynamic endurance test was performed from the viewpoint of the durability of the prosthetic valves used in the VAD. For the hydrodynamic analysis, we designed three basic types of pump (sac type, diaphragm type, and pusher plate type) using the same material and having the same capacity and shape. Prosthetic valves in these VADs were tested from the standpoint of the water hammer effect, which affects the valve durability, to determine which pump design would be most durable as a prosthetic valve in the VAD. The water-hammer phenomenon was evaluated using the maximum pressure gradient (MPG) across the prosthetic valve in the moc circulatory loop. Maximum pump output was recorded when we used the diaphragm type model, and minimum MPG in the commonly used driving condition of the VAD were recorded when we used the sac type model. The results suggest that the sac type VAD model is the most durable design for the prosthetic value.

Rehand: Realistic electric prosthetic hand created with a 3D printer.

PubMed

Yoshikawa, Masahiro; Sato, Ryo; Higashihara, Takanori; Ogasawara, Tsukasa; Kawashima, Noritaka

2015-01-01

Myoelectric prosthetic hands provide an appearance with five fingers and a grasping function to forearm amputees. However, they have problems in weight, appearance, and cost. This paper reports on the Rehand, a realistic electric prosthetic hand created with a 3D printer. It provides a realistic appearance that is same as the cosmetic prosthetic hand and a grasping function. A simple link mechanism with one linear actuator for grasping and 3D printed parts achieve low cost, light weight, and ease of maintenance. An operating system based on a distance sensor provides a natural operability equivalent to the myoelectric control system. A supporter socket allows them to wear the prosthetic hand easily. An evaluation using the Southampton Hand Assessment Procedure (SHAP) demonstrated that an amputee was able to operate various objects and do everyday activities with the Rehand.

Finite element analysis of the contact interface between trans-femoral stump and prosthetic socket.

PubMed

Zhang, Linlin; Zhu, Ming; Shen, Ling; Zheng, Feng

2013-01-01

Transfemoral amputees need prosthetic devices after amputation surgery, and the interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. The purpose of this study was to build a nonlinear finite element model to investigate the interface pressure between the above-knee residual limb and its prosthetic socket. The model was three-dimensional (3D) with consideration of nonlinear boundary conditions. Contact analysis was used to simulate the friction conditions between skin and the socket. The normal stresses up to 80.57 kPa at the distal end of the soft tissue. The longitudinal and circumferential shear stress distributions at the limb-socket interface were also simulated. This study explores the influences of load transfer between trans-femoral residual limb and its prosthetic socket.

Progressive upper limb prosthetics.

PubMed

Lake, Chris; Dodson, Robert

2006-02-01

The field of upper extremity prosthetics is a constantly changing arena as researchers and prosthetists strive to bridge the gap between prosthetic reality and upper limb physiology. With the further development of implantable neurologic sensing devices and targeted muscle innervation (discussed elsewhere in this issue), the challenge of limited input to control vast outputs promises to become a historical footnote in the future annals of upper limb prosthetics. Soon multidextrous terminal devices, such as that found in the iLimb system(Touch EMAS, Inc., Edinburgh, UK), will be a clinical reality (Fig. 22). Successful prosthetic care depends on good communication and cooperation among the surgeon, the amputee, the rehabilitation team, and the scientists harnessing the power of technology to solve real-life challenges. If the progress to date is any indication, amputees of the future will find their dreams limited only by their imagination.

Innovations in prosthetic interfaces for the upper extremity.

PubMed

Kung, Theodore A; Bueno, Reuben A; Alkhalefah, Ghadah K; Langhals, Nicholas B; Urbanchek, Melanie G; Cederna, Paul S

2013-12-01

Advancements in modern robotic technology have led to the development of highly sophisticated upper extremity prosthetic limbs. High-fidelity volitional control of these devices is dependent on the critical interface between the patient and the mechanical prosthesis. Recent innovations in prosthetic interfaces have focused on several control strategies. Targeted muscle reinnervation is currently the most immediately applicable prosthetic control strategy and is particularly indicated in proximal upper extremity amputations. Investigation into various brain interfaces has allowed acquisition of neuroelectric signals directly or indirectly from the central nervous system for prosthetic control. Peripheral nerve interfaces permit signal transduction from both motor and sensory nerves with a higher degree of selectivity. This article reviews the current developments in each of these interface systems and discusses the potential of these approaches to facilitate motor control and sensory feedback in upper extremity neuroprosthetic devices.

Directional plasticity rapidly improves 3D vestibulo-ocular reflex alignment in monkeys using a multichannel vestibular prosthesis.

PubMed

Dai, Chenkai; Fridman, Gene Y; Chiang, Bryce; Rahman, Mehdi A; Ahn, Joong Ho; Davidovics, Natan S; Della Santina, Charles C

2013-12-01

Bilateral loss of vestibular sensation can be disabling. We have shown that a multichannel vestibular prosthesis (MVP) can partly restore vestibular sensation as evidenced by improvements in the 3-dimensional angular vestibulo-ocular reflex (3D VOR). However, a key challenge is to minimize misalignment between the axes of eye and head rotation, which is apparently caused by current spread beyond each electrode's targeted nerve branch. We recently reported that rodents wearing a MVP markedly improve 3D VOR alignment during the first week after MVP activation, probably through the same central nervous system adaptive mechanisms that mediate cross-axis adaptation over time in normal individuals wearing prisms that cause visual scene movement about an axis different than the axis of head rotation. We hypothesized that rhesus monkeys would exhibit similar improvements with continuous prosthetic stimulation over time. We created bilateral vestibular deficiency in four rhesus monkeys via intratympanic injection of gentamicin. A MVP was mounted to the cranium, and eye movements in response to whole-body passive rotation in darkness were measured repeatedly over 1 week of continuous head motion-modulated prosthetic electrical stimulation. 3D VOR responses to whole-body rotations about each semicircular canal axis were measured on days 1, 3, and 7 of chronic stimulation. Horizontal VOR gain during 1 Hz, 50 °/s peak whole-body rotations before the prosthesis was turned on was <0.1, which is profoundly below normal (0.94 ± 0.12). On stimulation day 1, VOR gain was 0.4-0.8, but the axis of observed eye movements aligned poorly with head rotation (misalignment range ∼30-40 °). Substantial improvement of axis misalignment was observed after 7 days of continuous motion-modulated prosthetic stimulation under normal diurnal lighting. Similar improvements were noted for all animals, all three axes of rotation tested, for all sinusoidal frequencies tested (0.05-5 Hz), and for high-acceleration transient rotations. VOR asymmetry changes did not reach statistical significance, although they did trend toward slight improvement over time. Prior studies had already shown that directional plasticity reduces misalignment when a subject with normal labyrinths views abnormal visual scene movement. Our results show that the converse is also true: individuals receiving misoriented vestibular sensation under normal viewing conditions rapidly adapt to restore a well-aligned 3D VOR. Considering the similarity of VOR physiology across primate species, similar effects are likely to occur in humans using a MVP to treat bilateral vestibular deficiency.

Active confocal imaging for visual prostheses

PubMed Central

Jung, Jae-Hyun; Aloni, Doron; Yitzhaky, Yitzhak; Peli, Eli

2014-01-01

There are encouraging advances in prosthetic vision for the blind, including retinal and cortical implants, and other “sensory substitution devices” that use tactile or electrical stimulation. However, they all have low resolution, limited visual field, and can display only few gray levels (limited dynamic range), severely restricting their utility. To overcome these limitations, image processing or the imaging system could emphasize objects of interest and suppress the background clutter. We propose an active confocal imaging system based on light-field technology that will enable a blind user of any visual prosthesis to efficiently scan, focus on, and “see” only an object of interest while suppressing interference from background clutter. The system captures three-dimensional scene information using a light-field sensor and displays only an in-focused plane with objects in it. After capturing a confocal image, a de-cluttering process removes the clutter based on blur difference. In preliminary experiments we verified the positive impact of confocal-based background clutter removal on recognition of objects in low resolution and limited dynamic range simulated phosphene images. Using a custom-made multiple-camera system, we confirmed that the concept of a confocal de-cluttered image can be realized effectively using light field imaging. PMID:25448710

Pre-Prosthetic surgical alterations in maxillectomy to enhance the prosthetic prognoses as part of rehabilitation of oral cancer patient

PubMed Central

El Fattah, Hisham; Zaghloul, Ashraf; Escuin, Tomas

2012-01-01

Objectives: After maxillectomy, prosthetic restoration of the resulting defect is an essential step because it signals the beginning of patient’s rehabilitation. The obturator used to restore the defect should be comfortable, restore adequate speech, deglutition, mastication, and be cosmetically acceptable, success will depend on the size and location of the defect and the quantity and integrity of the remaining structures, in addition to pre-prosthetic surgical preparation of defect site. Preoperative cooperation between the oncologist surgeon and the maxillofacial surgeon may allow obturation of a resultant defect by preservation of the premaxilla or the tuberosity on the defect side and maintaining the alveolar bone or teeth adjacent to the defect. This study evaluates the importance of pre-prosthetic surgical alterations at the time maxillectomy on the enhancement of the prosthetic prognoses as part of the rehabilitation of oral cancer patient. Study Design: The study was carried out between 2003- 2008, on 66 cancer patients(41 male-25 female) age ranged from 33 to 72 years, at National Cancer Institute, Cairo University, whom underwent maxillectomy surgery to remove malignant tumor as a part of cancer treatment. Patients were divided in two groups. Group A: Resection of maxilla followed by preprosthetic surgical preparation. Twenty-four cancer patients (13 male – 11 female). Group B: Resection of maxilla without any preprosthetic surgical preparation. Forty-two cancer patients (28 male-14 female). Results: Outcome variables measured included facial contour and aesthetic results, speech understandability, ability to eat solid foods, oronasal separation, socializing outside the home, and return-to-work status. Flap success and donor site morbidity were also studied. Conclusions: To improve the prosthetic restoration of maxillary defect resulting maxillary resection as part treatment of maxillofacial tumor depends on the close cooperation between prosthodontist and surgeon, by combination of pre-prosthetic surgery during maxillectomy and prosthodontic technique. Key words:Maxillectomy, pre-prosthetic surgery, quality of life, oral cancer. PMID:22143710

Extrinsic mechanism obstructing the opening of a prosthetic mitral valve: an unusual case of suture entrapment.

PubMed

Ozkan, Mehmet; Astarcioglu, Mehmet Ali; Karakoyun, Suleyman; Balkanay, Mehmet

2012-02-01

Obstruction to a prosthetic cardiac valve is a well-recognized complication of cardiac valve replacement. Malfunction of the mobile component of a prosthetic valve to open or close correctly may occur in consequence of intrinsic or extrinsic causes (thrombus, vegetation, entrapment of left ventricular myocardium, suture entanglement, and pannus formation) that may result prosthetic valve stenosis and/or insufficiency. In the case we report a 48-year-old female with valve dysfunction occurred early after surgery, as one valve leaflet was only able to partially open due to suture entrapment. © 2011, Wiley Periodicals, Inc.

a Review of Retinal Prosthesis Approaches

NASA Astrophysics Data System (ADS)

Kien, Tran Trung; Maul, Tomas; Bargiela, Andrzej

Age-related macular degeneration and retinitis pigmentosa are two of the most common diseases that cause degeneration in the outer retina, which can lead to several visual impairments up to blindness. Vision restoration is an important goal for which several different research approaches are currently being pursued. We are concerned with restoration via retinal prosthetic devices. Prostheses can be implemented intraocularly and extraocularly, which leads to different categories of devices. Cortical Prostheses and Optic Nerve Prostheses are examples of extraocular solutions while Epiretinal Prostheses and Subretinal Prostheses are examples of intraocular solutions. Some of the prostheses that are successfully implanted and tested in animals as well as humans can restore basic visual functions but still have limitations. This paper will give an overview of the current state of art of Retinal Prostheses and compare the advantages and limitations of each type. The purpose of this review is thus to summarize the current technologies and approaches used in developing Retinal Prostheses and therefore to lay a foundation for future designs and research directions.

A review of functional outcomes related to prosthetic treatment after maxillary and mandibular reconstruction in patients with head and neck cancer.

PubMed

Tang, Judith A Lam; Rieger, Jana M; Wolfaardt, Johan F

2008-01-01

This review examined literature that reported functional outcomes across 3 categories of prosthetic treatment after microvascular reconstruction of the maxilla and mandible: (1) conventional dental/tissue-supported prosthesis, (2) implant-retained prosthesis, and (3) no prosthesis. Library databases were searched for articles related to reconstruction of the maxilla and mandible, and references of selected articles were hand searched. Relevant literature was identified and reviewed with criteria specified a priori. Forty-nine articles met the inclusion criteria. Twelve articles reported on function after maxillary reconstruction, with the majority of articles reporting on outcomes for 1 to 6 subjects. Thirty-nine articles reported on function after mandibular reconstruction. Speech outcomes were satisfactory across all groups. Swallowing reports indicated that many patients who received either type of prosthetic rehabilitation resumed a normal diet, whereas those without prosthetic rehabilitation were often restricted to liquid diets or feeding tubes. Patients without prosthetic rehabilitation reportedly had poor masticatory ability, whereas conventional prosthetic treatment allowed some recovery of mastication and implant-retained prosthetic treatment resulted in the most favorable masticatory outcomes. Quality-of-life outcomes were similar across all patients. Several limitations of the current literature prevented definitive conclusions from being reached within this review, especially regarding maxillary reconstruction. However, recognition of these limitations can direct functional assessment for the future.

Analysis of maxillofacial prosthetics at university dental hospitals in the capital region of Korea

PubMed Central

Lee, Jong-Ho

2016-01-01

PURPOSE The purpose of this study was to investigate the demographic patterns of maxillofacial prosthetic treatment to identify the characteristics and geographic distribution of patients with maxillofacial prosthetics in the capital region of Korea. MATERIALS AND METHODS This retrospective analytical multicenter study was performed by chart reviews. This study included patients who visited the department of prosthodontics at four university dental hospitals for maxillofacial prosthetic rehabilitation. Patients with facial and congenital defects or with insufficient medical data were excluded. The patients were classified into three categories based on the location of the defect. Patients' sex, age, and residential area were analyzed. Pearson's chi-square test with a significance level of 0.05 was used to analyze the variables. RESULTS Among 540 patients with maxillofacial prosthetics, there were 284 (52.59%) male patients and 256 (47.41%) female patients. The number of the patients varied greatly by hospital. Most patients were older than 70, and the most common defect was a hard palate defect. Chi-square analysis did not identify any significant differences in sex, age, and distance to hospital for any defect group (P>.05). CONCLUSION The results of this study indicated that there was imbalance in the distribution of patients with maxillofacial prosthetic among the hospitals in the capital region of Korea. Considerations on specialists and insurance policies for the improvement of maxillofacial prosthetics in Korea are required. PMID:27350859

Outdoor dynamic subject-specific evaluation of internal stresses in the residual limb: hydraulic energy-stored prosthetic foot compared to conventional energy-stored prosthetic feet.

PubMed

Portnoy, Sigal; Kristal, Anat; Gefen, Amit; Siev-Ner, Itzhak

2012-01-01

The prosthetic foot plays an important role in propelling, breaking, balancing and supporting body loads while the amputee ambulates on different grounds. It is therefore important to quantify the effect of the prosthetic foot mechanism on biomechanical parameters, in order to prevent pressure ulcers and deep tissue injury. Our aim was to monitor the internal stresses in the residuum of transtibial amputation (TTA) prosthetic-users ambulating on different terrains, which the amputees encounter during their daily activities, i.e. paved floor, grass, ascending and descending stairs and slope. We specifically aimed to compare between the internal stresses in the TTA residuum of amputees ambulating with a novel hydraulic prosthetic foot compared to conventional energy storage and return (ESR) prosthetic feet. Monitoring of internal stresses was accomplished using a portable subject-specific real-time internal stress monitor. We found significant decrease (p<0.01) in peak internal stresses and in the loading rate of the amputated limb, while walking with the hydraulic foot, compared to walking with ESR feet. The loading rate calculated while ambulating with the hydraulic foot was at least three times lower than the loading rate calculated while ambulating with the ESR foot. Although the average decrease in internal stresses was ≈ 2-fold larger when replacing single-toe ESR feet with the hydraulic foot than when replacing split-toed ESR feet with the hydraulic foot, the differences were statistically insignificant. Our findings suggest that using a hydraulic prosthetic foot may protect the distal tibial end of the TTA residuum from high stresses, therefore preventing pressure-related injury and pain. Copyright © 2011 Elsevier B.V. All rights reserved.

The effects of a controlled energy storage and return prototype prosthetic foot on transtibial amputee ambulation

PubMed Central

Segal, Ava D.; Zelik, Karl E.; Klute, Glenn K.; Morgenroth, David C.; Hahn, Michael E.; Orendurff, Michael S.; Adamczyk, Peter G.; Collins, Steven H.; Kuo, Arthur D.; Czerniecki, Joseph M.

2015-01-01

The lack of functional ankle musculature in lower limb amputees contributes to the reduced prosthetic ankle push-off, compensations at other joints and more energetically costly gait commonly observed in comparison to non-amputees. A variety of energy storing and return prosthetic feet have been developed to address these issues but have not been shown to sufficiently improve amputee biomechanics and energetic cost, perhaps because the timing and magnitude of energy return is not controlled. The goal of this study was to examine how a prototype microprocessor-controlled prosthetic foot designed to store some of the energy during loading and return it during push-off affects amputee gait. Unilateral transtibial amputees wore the Controlled Energy Storage and Return prosthetic foot (CESR), a conventional foot (CONV), and their previously prescribed foot (PRES) in random order. Three-dimensional gait analysis and net oxygen consumption were collected as participants walked at constant speed. The CESR foot demonstrated increased energy storage during early stance, increased prosthetic foot peak push-off power and work, increased prosthetic limb center of mass (COM) push-off work and decreased intact limb COM collision work compared to CONV and PRES. The biological contribution of the positive COM work for CESR was reduced compared to CONV and PRES. However, the net metabolic cost for CESR did not change compared to CONV and increased compared to PRES, which may partially reflect the greater weight, lack of individualized size and stiffness and relatively less familiarity for CESR and CONV. Controlled energy storage and return enhanced prosthetic push-off, but requires further design modifications to improve amputee walking economy. PMID:22100728

Energy flow analysis of amputee walking shows a proximally-directed transfer of energy in intact limbs, compared to a distally-directed transfer in prosthetic limbs at push-off.

PubMed

Weinert-Aplin, R A; Howard, D; Twiste, M; Jarvis, H L; Bennett, A N; Baker, R J

2017-01-01

Reduced capacity and increased metabolic cost of walking occurs in amputees, despite advances in prosthetic componentry. Joint powers can quantify deficiencies in prosthetic gait, but do not reveal how energy is exchanged between limb segments. This study aimed to quantify these energy exchanges during amputee walking. Optical motion and forceplate data collected during walking at a self-selected speed for cohorts of 10 controls, 10 unilateral trans-tibial, 10 unilateral trans-femoral and 10 bilateral trans-femoral amputees were used to determine the energy exchanges between lower limb segments. At push-off, consistent thigh and shank segment powers were observed between amputee groups (1.12W/kg vs. 1.05W/kg for intact limbs and 0.97W/kg vs. 0.99W/kg for prosthetic limbs), and reduced prosthetic ankle power, particularly in trans-femoral amputees (3.12W/kg vs. 0.87W/kg). Proximally-directed energy exchange was observed in the intact limbs of amputees and controls, while prosthetic limbs displayed distally-directed energy exchanges at the knee and hip. This study used energy flow analysis to show a reversal in the direction in which energy is exchanged between prosthetic limb segments at push-off. This reversal was required to provide sufficient energy to propel the limb segments and is likely a direct result of the lack of push-off power at the prosthetic ankle, particularly in trans-femoral amputees, and leads to their increased metabolic cost of walking. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

The effects of a controlled energy storage and return prototype prosthetic foot on transtibial amputee ambulation.

PubMed

Segal, Ava D; Zelik, Karl E; Klute, Glenn K; Morgenroth, David C; Hahn, Michael E; Orendurff, Michael S; Adamczyk, Peter G; Collins, Steven H; Kuo, Arthur D; Czerniecki, Joseph M

2012-08-01

The lack of functional ankle musculature in lower limb amputees contributes to the reduced prosthetic ankle push-off, compensations at other joints and more energetically costly gait commonly observed in comparison to non-amputees. A variety of energy storing and return prosthetic feet have been developed to address these issues but have not been shown to sufficiently improve amputee biomechanics and energetic cost, perhaps because the timing and magnitude of energy return is not controlled. The goal of this study was to examine how a prototype microprocessor-controlled prosthetic foot designed to store some of the energy during loading and return it during push-off affects amputee gait. Unilateral transtibial amputees wore the Controlled Energy Storage and Return prosthetic foot (CESR), a conventional foot (CONV), and their previously prescribed foot (PRES) in random order. Three-dimensional gait analysis and net oxygen consumption were collected as participants walked at constant speed. The CESR foot demonstrated increased energy storage during early stance, increased prosthetic foot peak push-off power and work, increased prosthetic limb center of mass (COM) push-off work and decreased intact limb COM collision work compared to CONV and PRES. The biological contribution of the positive COM work for CESR was reduced compared to CONV and PRES. However, the net metabolic cost for CESR did not change compared to CONV and increased compared to PRES, which may partially reflect the greater weight, lack of individualized size and stiffness and relatively less familiarity for CESR and CONV. Controlled energy storage and return enhanced prosthetic push-off, but requires further design modifications to improve amputee walking economy. Published by Elsevier B.V.

Marker-based method to measure movement between the residual limb and a transtibial prosthetic socket.

PubMed

Childers, Walter Lee; Siebert, Steven

2016-12-01

Limb movement between the residuum and socket continues to be an underlying factor in limb health, prosthetic comfort, and gait performance yet techniques to measure this have been underdeveloped. Develop a method to measure motion between the residual limb and a transtibial prosthetic socket. Single subject, repeated measures with mathematical modeling. The gait of a participant with transtibial amputation was recorded using a motion capture system using a marker set that included arrays on the anterior distal tibia and the lateral epicondyle of the femur. The proximal or distal translation, anterior or posterior translation, and angular movements were quantified. A random Monte Carlo simulation based on the precision of the motion capture system and a model of the bone moving under the skin explored the technique's accuracy. Residual limb tissue stiffness was modeled as a linear spring based on data from Papaioannou et al. Residuum movement relative to the socket went through ~30 mm, 18 mm, and 15° range of motion. Root mean squared errors were 5.47 mm, 1.86 mm, and 0.75° when considering the modeled bone-skin movement in the proximal or distal, anterior or posterior, and angular directions, respectively. The measured movement was greater than the root mean squared error, indicating that this method can measure motion between the residuum and socket. The ability to quantify movement between the residual limb and the prosthetic socket will improve prosthetic treatment through the evaluation of different prosthetic suspensions, socket designs, and motor control of the prosthetic interface. © The International Society for Prosthetics and Orthotics 2015.

Dental prosthetic status and prosthetic needs of institutionalised elderly population in oldage homes of jabalpur city, madhya pradesh, India.

PubMed

Deogade, Suryakant C; Vinay, S; Naidu, Sonal

2013-12-01

Oral disorders are cumulative throughout life and hence unfavourable outcomes are likely to be greatest among the elderly. A descriptive cross-sectional study was conducted among institutionalized geriatric population in old-age homes of Jabalpur city, Madhya Pradesh, to assess their prosthetic status and prosthetic needs. A cross-sectional survey was conducted in all the four old-age homes of Jabalpur city, Madhya Pradesh state, India. All residents aged 60 years and above formed the study population. The recording of prosthetic status and prosthetic needs was carried out according to the World Health Organisation (WHO) Oral Health Assessment Form (1997). A total of 224 individuals were included in the study of which 123 were females and 101 were males. Seventy five percent of the females and 55 % of the males had no prostheses in their upper arch and 61 % of the females and 76 % of the males had no prostheses in their lower arch. More number of males presented with 'Bridges' in their upper arch when compared to females (P value = 0.006). Highest prosthetic need in males was multi-unit prosthesis (42 % in upper arch and 41 % in lower arch) whereas, females' required full prosthesis (39 % in both the upper arch and lower arches). Ageing presents some formidable challenges, particularly with the institutionalised. This study clearly demonstrates a high insufficiency of prosthetic care among the institutionalized elderly population. Any preparation towards the provision of oral health care should not be limited to treatment alone but, more importantly focus on empowering this elderly community with information and education programmes.

100 top-cited scientific papers in limb prosthetics.

PubMed

Eshraghi, Arezoo; Osman, Noor Azuan Abu; Gholizadeh, Hossein; Ali, Sadeeq; Shadgan, Babak

2013-11-17

Research has tremendously contributed to the developments in both practical and fundamental aspects of limb prosthetics. These advancements are reflected in scientific articles, particularly in the most cited papers. This article aimed to identify the 100 top-cited articles in the field of limb prosthetics and to investigate their main characteristics. Articles related to the field of limb prosthetics and published in the Web of Knowledge database of the Institute for Scientific Information (ISI) from the period of 1980 to 2012. The 100 most cited articles in limb prosthetics were selected based on the citation index report. All types of articles except for proceedings and letters were included in the study. The study design and level of evidence were determined using Sackett's initial rules of evidence. The level of evidence was categorized either as a systematic review or meta-analysis, randomized controlled trial, cohort study, case-control study, case series, expert opinion, or design and development. The top cited articles in prosthetics were published from 1980 to 2012 with a citation range of 11 to 90 times since publication. The mean citation rate was 24.43 (SD 16.7) times. Eighty-four percent of the articles were original publications and were most commonly prospective (76%) and case series studies (67%) that used human subjects (96%) providing level 4 evidence. Among the various fields, rehabilitation (47%), orthopedics (29%), and sport sciences (28%) were the most common fields of study. The study established that studies conducted in North America and were written in English had the highest citations. Top cited articles primarily dealt with lower limb prosthetics, specifically, on transtibial and transradial prosthetic limbs. Majority of the articles were experimental studies.

The comparison of transfemoral amputees using mechanical and microprocessor- controlled prosthetic knee under different walking speeds: A randomized cross-over trial.

PubMed

Cao, Wujing; Yu, Hongliu; Zhao, Weiliang; Meng, Qiaoling; Chen, Wenming

2018-04-20

The microprocessor-controlled prosthetic knees have been introduced to transfemoral amputees due to advances in biomedical engineering. A body of scientific literature has shown that the microprocessor-controlled prosthetic knees improve the gait and functional abilities of persons with transfemoral amputation. The aim of this study was to propose a new microprocessor-controlled prosthetic knee (MPK) and compare it with non-microprocessor-controlled prosthetic knees (NMPKs) under different walking speeds. The microprocessor-controlled prosthetic knee (i-KNEE) with hydraulic damper was developed. The comfortable self-selected walking speeds of 12 subjects with i-KNEE and NMPK were obtained. The maximum swing flexion knee angle and gait symmetry were compared in i-KNEE and NMPK condition. The comfortable self-selected walking speeds of some subjects were higher with i-KNEE while some were not. There was no significant difference in comfortable self-selected walking speed between the i-KNEE and the NMPK condition (P= 0.138). The peak prosthetic knee flexion during swing in the i-KNEE condition was between sixty and seventy degree under any walking speed. In the NMPK condition, the maximum swing flexion knee angle changed significantly. And it increased with walking speed. There is no significant difference in knee kinematic symmetry when the subjects wear the i-KNEE or NMPK. The results of this study indicated that the new microprocessor-controlled prosthetic knee was suitable for transfemoral amputees. The maximum swing flexion knee angle under different walking speeds showed different properties in the NMPK and i-KNEE condition. The i-KNEE was more adaptive to speed changes. There was little difference of comfortable self-selected walking speed between i-KNEE and NMPK condition.

INTERVENTIONS TO MANAGE RESIDUAL LIMB ULCERATION DUE TO PROSTHETIC USE IN INDIVIDUALS WITH LOWER EXTREMITY AMPUTATION: A SYSTEMATIC REVIEW OF THE LITERATURE.

PubMed

Highsmith, M Jason; Kahle, Jason T; Klenow, Tyler D; Andrews, Casey R; Lewis, Katherine L; Bradley, Rachel C; Ward, Jessica M; Orriola, John J; Highsmith, James T

2016-09-01

Patients with lower extremity amputation (LEA) experience 65% more dermatologic issues than non-amputees, and skin problems are experienced by ≈75% of LEA patients who use prostheses. Continuously referring LEA patients to a dermatologist for every stump related skin condition may be impractical. Thus, physical rehabilitation professionals should be prepared to recognize and manage common non-emergent skin conditions in this population. The purpose of this study was to determine the quantity, quality, and strength of available evidence supporting treatment methods for prosthesis-related residual limb (RL) ulcers. Systematic literature review with evidence grading and synthesis of empirical evidence statements (EES) was employed. Three EESs were formulated describing ulcer etiology, conditions in which prosthetic continuance is practical, circumstances likely requiring prosthetic discontinuance, and the consideration of additional medical or surgical interventions. Continued prosthetic use is a viable option to manage minor or early-stage ulcerated residual limbs in compliant patients lacking multiple comorbidities. Prosthetic discontinuance is also a viable method of residual limb ulcer healing and may be favored in the presence of severe acute ulcerations, chronic heavy smoking, intractable pain, rapid volume and weight change, history of chronic ulceration, systemic infections, or advanced dysvascular etiology. Surgery or other interventions may also be necessary in such cases to achieve restored prosthetic ambulation. A short bout of prosthetic discontinuance with a staged re-introduction plan is another viable option that may be warranted in patients with ulceration due to poor RL volume management. High-quality prospective research with larger samples is needed to determine the most appropriate course of treatment when a person with LEA develops an RL ulcer that is associated with prosthetic use.

The influence of staff training and education on prosthetic and orthotic service quality: A scoping review.

PubMed

Forghany, Saeed; Sadeghi-Demneh, Ebrahim; Trinler, Ursula; Onmanee, Pornsuree; Dillon, Michael P; Baker, Richard

2018-06-01

Education and training in prosthetics and orthotics typically comply with International Society for Prosthetics and Orthotics standards based on three categories of prosthetic and orthotic professionals. This scoping study sought to describe the evidence base available to answer the question, How are prosthetic and orthotic services influenced by the training of staff providing them? Scoping review. A structured search of the peer-reviewed literature catalogued in major electronic databases yielded 3039 papers. Following review of title and abstract, 93 articles were considered relevant. Full-text review reduced this number to 25. Only two articles were identified as providing direct evidence of the effects of training and education on service provision. While both suggested that there was an impact, it is difficult to see how the more specific conclusions of either could be generalised. The other 23 articles provide a useful background to a range of issues including the specification of competencies that training programmes should deliver (3 articles), descriptions of a range of training programmes and the effects of training and education on student knowledge and skills. Although it is considered axiomatic, the service quality is dependent on practitioner education and training. There is insufficient evidence to establish whether levels of training and education in prosthetics and orthotics have an effect on the quality of prosthetic and orthotic services. Clinical relevance There is very little evidence about the effects of training and education of prosthetists and orthotists on service quality. While this is a somewhat negative finding, we feel that it is important to bring this to the attention of the prosthetics and orthotics community.

Photovoltaic restoration of sight in rodents with retinal degeneration (Conference Presentation)

NASA Astrophysics Data System (ADS)

Palanker, Daniel V.

2017-02-01

To restore vision in patients who lost their photoreceptors due to retinal degeneration, we developed a photovoltaic subretinal prosthesis which converts light into pulsed electric current, stimulating the nearby inner retinal neurons. Visual information is projected onto the retina by video goggles using pulsed near-infrared ( 900nm) light. This design avoids the use of bulky electronics and wiring, thereby greatly reducing the surgical complexity. Optical activation of the photovoltaic pixels allows scaling the implants to thousands of electrodes, and multiple modules can be tiled under the retina to expand the visual field. We found that similarly to normal vision, retinal response to prosthetic stimulation exhibits flicker fusion at high frequencies (>20Hz), adaptation to static images, and non-linear summation of subunits in the receptive fields. Photovoltaic arrays with 70um pixels restored visual acuity up to a single pixel pitch, which is only two times lower than natural acuity in rats. If these results translate to human retina, such implants could restore visual acuity up to 20/250. With eye scanning and perceptual learning, human patients might even cross the 20/200 threshold of legal blindness. In collaboration with Pixium Vision, we are preparing this system (PRIMA) for a clinical trial. To further improve visual acuity, we are developing smaller pixels - down to 40um, and on 3-D interface to improve proximity to the target neurons. Scalability, ease of implantation and tiling of these wireless modules to cover a large visual field, combined with high resolution opens the door to highly functional restoration of sight.

Corynebacterium minutissimum vascular graft infection: case report and review of 281 cases of prosthetic device-related Corynebacterium infection.

PubMed

Reece, Rebecca M; Cunha, Cheston B; Rich, Josiah D

2014-09-01

Corynebacterium spp. have proven their pathogenic potential in causing infections, particularly in the setting of immunosuppression and prosthetic devices. We conducted a PubMed literature review of all cases of Corynebacterium prosthetic device infections published in the English language through December 2013. The majority of cases involved peritoneal dialysis and central venous catheters, but prosthetic joints and central nervous system shunts/drains were also involved. The management of these cases in terms of retention or removal of the device was not uniform; however, the overall mortality remained the same among both groups. All of these prosthetic device infections pose potential problems in management when the device cannot be removed safely for the patient, especially with the lack of data on the pathogenicity of Corynebacterium species. However with better identification of species and sensitivities, successful treatment is possible even with retention of the device.

Molecular Identification of Human Fungal Pathogens

DTIC Science & Technology

2008-03-01

reported this period: Drees M, Wickes BL, Gupta M, Hadley S. Lecythophora mutabilis prosthetic valve endocarditis in a diabetic patient. Med Mycol. (2007...Wickes BL, Gupta M, Hadley S. 2007. Lecythophora mutabilis prosthetic valve endocarditis in a diabetic patient. Med Mycol. 45:463-467. 9...information: http://www.informaworld.com/smpp/title~content=t713694156 Lecythophora mutabilis prosthetic valve endocarditis in a diabetic patient Marci

Custom-made laser-welded titanium implant prosthetic abutment.

PubMed

Iglesia-Puig, Miguel A

2005-10-01

A technique to create an individually modified implant prosthetic abutment is described. An overcasting is waxed onto a machined titanium abutment, cast in titanium, and joined to it with laser welding. With the proposed technique, a custom-made titanium implant prosthetic abutment is created with adequate volume and contour of metal to support a screw-retained, metal-ceramic implant-supported crown.

A global perspective on mechanical prosthetic heart valve thrombosis: Diagnostic and therapeutic challenges

PubMed Central

Gürsoy, Mustafa Ozan; Kalçık, Macit; Yesin, Mahmut; Karakoyun, Süleyman; Bayam, Emrah; Gündüz, Sabahattin; Özkan, Mehmet

2016-01-01

Prosthetic valve thrombosis is one of the major causes of primary valve failure, which can be life-threatening. Multimodality imaging is necessary for determination of leaflet immobilization, cause of underlying pathology (thrombus versus pannus or both), and whether thrombolytic therapy attempt in the patient would be successful or surgery is needed. Current guidelines for the management of prosthetic valve thrombosis lack definitive class I recommendations due to lack of randomized controlled trials, and usually leave the choice of treatment to the clinician’s experience. In this review, we aimed to summarize the pathogenesis, diagnosis, and management of mechanical prosthetic valve thrombosis. PMID:28005024

Aerogel Use as a Skin Protective Liner In Space Suits and Prosthetic Limbs Project

NASA Technical Reports Server (NTRS)

Roberson, Luke Bennett

2014-01-01

Existing materials for prosthetic liners tend to be thick and airtight, causing perspiration to accumulate inside the liner and potentially causing infection and injury. The purpose of this project was to examine the suitability of aerogel for prosthetic liner applications for use in space suits and orthopedics. Three tests were performed on several types of aerogel to assess the properties of each material, and our initial findings demonstrated that these materrials would be excellent candidates for liner applications for prosthetics and space suits. The project is currently on hold until additional funding is obtained for application testing at the VH Hospitals in Tampa

Strength evaluation of prosthetic check sockets, copolymer sockets, and definitive laminated sockets.

PubMed

Gerschutz, Maria J; Haynes, Michael L; Nixon, Derek; Colvin, James M

2012-01-01

A prosthesis encounters loading through forces and torques exerted by the person with amputation. International Organization for Standardization (ISO) standard 10328 was designed to test most lower-limb prosthetic components. However, this standard does not include prosthetic sockets. We measured static failure loads of prosthetic sockets using a modified ISO 10328 and then compared them with the criteria set by this standard for other components. Check socket (CS) strengths were influenced by thickness, material choice, and fabrication method. Copolymer socket (CP) strengths depended on thickness and fabrication methods. A majority of the CSs and all of the CPs failed to pass the ISO 10328 ductile loading criterion. In contrast, the strengths of definitive laminated sockets (DLs) were influenced more by construction material and technique. A majority of the DLs failed to pass the ISO 10328 brittle loading criterion. Analyzing prosthetic sockets from a variety of facilities demonstrated that socket performance varies considerably between and within facilities. The results from this article provide a foundation for understanding the quality of prosthetic sockets, some insight into possible routes for improving the current care delivered to patients, and a comparative basis for future technology.

Experimental measurement of flexion-extension movement in normal and corpse prosthetic elbow joint.

PubMed

TarniŢă, Daniela; TarniŢă, DănuŢ Nicolae

2016-01-01

This paper presents a comparative experimental study of flexion-extension movement in healthy elbow and in the prosthetic elbow joint fixed on an original experimental bench. Measurements were carried out in order to validate the functional morphology and a new elbow prosthesis type ball head. The three-dimensional (3D) model and the physical prototype of our experimental bench used to test elbow endoprosthesis at flexion-extension and pronation-supination movements is presented. The measurements were carried out on a group of nine healthy subjects and on the prosthetic corpse elbow, the experimental data being obtained for flexion-extension movement cycles. Experimental data for the two different flexion-extension tests for the nine subjects and for the corpse prosthetic elbow were acquired using SimiMotion video system. Experimental data were processed statistically. The corresponding graphs were obtained for all subjects in the experimental group, and for corpse prosthetic elbow for both flexion-extension tests. The statistical analysis has proved that the flexion angles of healthy elbows were significantly close to the values measured at the prosthetic elbow fixed on the experimental bench. The studied elbow prosthesis manages to re-establish the mobility for the elbow joint as close to the normal one.

Influence of Prosthetic Screw Material on Joint Stability in Passive and Non-Passive Implant-Supported Dentures

PubMed Central

Spazzin, Aloísio Oro; Henriques, Guilherme Elias Pessanha; de Arruda Nóbilo, Mauro Antônio; Consani, Rafael Leonardo Xediek; Correr-Sobrinho, Lourenço; Mesquita, Marcelo Ferraz

2009-01-01

Objectives: This study evaluated the influence of prosthetic screw material on joint stability in implantsupported dentures at two levels of fit. Methods: Ten mandibular implant-supported dentures were fabricated. Twenty cast models were fabricated using these dentures. Four groups (n=10) were tested, according to the vertical fit of the dentures [passive and non-passive] and prosthetic screw materials [titanium (Ti) or gold (Au) alloy]. The one-screw test was performed to quantify the vertical misfits using an optic microscope. The loosening torque for the prosthetic screws was measured 24 hours after the tightening torque (10 Ncm) using a digital torque meter. Data were analyzed by two-way ANOVA and Tukey’s test (α=0.05). Results: Overall, dentures with passive fit and Ti screws resulted in significantly higher loosening torque of the prosthetic screws (p<0.05). No significant interaction was found between fit level and screw material (p=0.199). The prosthetic screw material and fit of implant-supported dentures have an influence on screw joint stability. Ti screws presented higher joint stability than Au screws and minimum of misfit should be found clinically to improve the mechanical behavior of the screw joint. PMID:20148135

A regenerative microchannel device for recording multiple single-unit action potentials in awake, ambulatory animals.

PubMed

Srinivasan, Akhil; Tipton, John; Tahilramani, Mayank; Kharbouch, Adel; Gaupp, Eric; Song, Chao; Venkataraman, Poornima; Falcone, Jessica; Lacour, Stéphanie P; Stanley, Garrett B; English, Arthur W; Bellamkonda, Ravi V

2016-02-01

Despite significant advances in robotics, commercially advanced prosthetics provide only a small fraction of the functionality of the amputated limb that they are meant to replace. Peripheral nerve interfacing could provide a rich controlling link between the body and these advanced prosthetics in order to increase their overall utility. Here, we report on the development of a fully integrated regenerative microchannel interface with 30 microelectrodes and signal extraction capabilities enabling evaluation in an awake and ambulatory rat animal model. In vitro functional testing validated the capability of the microelectrodes to record neural signals similar in size and nature to those that occur in vivo. In vitro dorsal root ganglia cultures revealed striking cytocompatibility of the microchannel interface. Finally, in vivo, the microchannel interface was successfully used to record a multitude of single-unit action potentials through 63% of the integrated microelectrodes at the early time point of 3 weeks. This marks a significant advance in microchannel interfacing, demonstrating the capability of microchannels to be used for peripheral nerve interfacing. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Preclinical Evaluation of 18F-PSMA-1007, a New Prostate-Specific Membrane Antigen Ligand for Prostate Cancer Imaging.

PubMed

Cardinale, Jens; Schäfer, Martin; Benešová, Martina; Bauder-Wüst, Ulrike; Leotta, Karin; Eder, Matthias; Neels, Oliver C; Haberkorn, Uwe; Giesel, Frederik L; Kopka, Klaus

2017-03-01

In recent years, several radiotracers targeting the prostate-specific membrane antigen (PSMA) have been introduced. Some of them have had a high clinical impact on the treatment of patients with prostate cancer. However, the number of 18 F-labeled tracers addressing PSMA is still limited. Therefore, we aimed to develop a radiofluorinated molecule resembling the structure of therapeutic PSMA-617. Methods: The nonradioactive reference compound PSMA-1007 and the precursor were produced by solid-phase chemistry. The radioligand 18 F-PSMA-1007 was produced by a 2-step procedure with the prosthetic group 6- 18 F-fluoronicotinic acid 2,3,5,6-tetrafluorophenyl ester. The binding affinity of the ligand for PSMA and its internalization properties were evaluated in vitro with PSMA-positive LNCaP (lymph node carcinoma of the prostate) cells. Further, organ distribution studies were performed with mice bearing LNCaP and PC-3 (prostate cancer cell line; PSMA-negative) tumors. Finally, small-animal PET imaging of an LNCaP tumor-bearing mouse was performed. Results: The identified ligand had a binding affinity of 6.7 ± 1.7 nM for PSMA and an exceptionally high internalization ratio (67% ± 13%) in vitro. In organ distribution studies, high and specific tumor uptake (8.0 ± 2.4 percentage injected dose per gram) in LNCaP tumor-bearing mice was observed. In the small-animal PET experiments, LNCaP tumors were clearly visualized. Conclusion: The radiofluorinated PSMA ligand showed promising characteristics in its preclinical evaluation, and the feasibility of prostate cancer imaging was demonstrated by small-animal PET studies. Therefore, we recommend clinical transfer of the radioligand 18 F-PSMA-1007 for use as a diagnostic PET tracer in prestaging and monitoring of prostate cancer. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Standardizing the evaluation criteria on treatment outcomes of mandibular implant overdentures: a systematic review

PubMed Central

Kim, Ha-Young; Shin, Sang-Wan

2014-01-01

PURPOSE The aim of this review was to analyze the evaluation criteria on mandibular implant overdentures through a systematic review and suggest standardized evaluation criteria. MATERIALS AND METHODS A systematic literature search was conducted by PubMed search strategy and hand-searching of relevant journals from included studies considering inclusion and exclusion criteria. Randomized clinical trials (RCT) and clinical trial studies comparing attachment systems on mandibular implant overdentures until December, 2011 were selected. Twenty nine studies were finally selected and the data about evaluation methods were collected. RESULTS Evaluation criteria could be classified into 4 groups (implant survival, peri-implant tissue evaluation, prosthetic evaluation, and patient satisfaction). Among 29 studies, 21 studies presented implant survival rate, while any studies reporting implant failure did not present cumulative implant survival rate. Seventeen studies evaluating peri-implant tissue status presented following items as evaluation criteria; marginal bone level (14), plaque Index (13), probing depth (8), bleeding index (8), attachment gingiva level (8), gingival index (6), amount of keratinized gingiva (1). Eighteen studies evaluating prosthetic maintenance and complication also presented following items as evaluation criteria; loose matrix (17), female detachment (15), denture fracture (15), denture relining (14), abutment fracture (14), abutment screw loosening (11), and occlusal adjustment (9). Atypical questionnaire (9), Visual analog scales (VAS) (4), and Oral Health Impact Profile (OHIP) (1) were used as the format of criteria to evaluate patients satisfaction in 14 studies. CONCLUSION For evaluation of implant overdenture, it is necessary to include cumulative survival rate for implant evaluation. It is suggested that peri-implant tissue evaluation criteria include marginal bone level, plaque index, bleeding index, probing depth, and attached gingiva level. It is also suggested that prosthetic evaluation criteria include loose matrix, female detachment, denture fracture, denture relining, abutment fracture, abutment screw loosening, and occlusal adjustment. Finally standardized criteria like OHIP-EDENT or VAS are required for patient satisfaction. PMID:25352954

Effect of the sinus of valsalva on the closing motion of bileaflet prosthetic heart valves.

PubMed

Ohta, Y; Kikuta, Y; Shimooka, T; Mitamura, Y; Yuhta, T; Dohi, T

2000-04-01

Conventional bileaflet prosthetic mechanical heart valves close passively with backflow. Naturally, the valve has problems associated with closure, such as backflow, water hammer effect, and fracture of the leaflet. On the other hand, in the case of the natural aortic valve, the vortex flow in the sinus of Valsalva pushes the leaflet to close, and the valve starts the closing motion earlier than the prosthetic valve as the forward flow decelerates. This closing mechanism is thought to decrease backflow at valve closure. In this study, we propose a new bileaflet mechanical valve resembling a drawbridge in shape, and the prototype valve was designed so that the leaflet closes with the help of the vortex flow in the sinus. The test valve was made of aluminum alloy, and its closing motion was compared to that of the CarboMedics (CM) valve. Both valves were driven by a computer controlled hydraulic mock circulator and were photographed at 648 frames/s by a high speed charge-coupled device (CCD) camera. Each frame of the valve motion image was analyzed with a personal computer, and the opening angles were measured. The flow rate was set as 5.0 L/min. The system was pulsed with 70 bpm, and the systolic/diastolic ratio was 0.3. Glycerin water was used as the circulation fluid at room temperature, and polystyrene particles were used to visualize the streamline. The model of the sinus of Valsalva was made of transparent silicone rubber. As a result, high speed video analysis showed that the test valve started the closing motion 41 ms earlier than the CM valve, and streamline analysis showed that the test valve had a closing mechanism similar to the natural one with the effect of vortex flow. The structure of the test valve was thought to be effective for soft closure and could solve problems associated with closure.

Modulation of neural activity by reward in medial intraparietal cortex is sensitive to temporal sequence of reward

PubMed Central

Rajalingham, Rishi; Stacey, Richard Greg; Tsoulfas, Georgios

2014-01-01

To restore movements to paralyzed patients, neural prosthetic systems must accurately decode patients' intentions from neural signals. Despite significant advancements, current systems are unable to restore complex movements. Decoding reward-related signals from the medial intraparietal area (MIP) could enhance prosthetic performance. However, the dynamics of reward sensitivity in MIP is not known. Furthermore, reward-related modulation in premotor areas has been attributed to behavioral confounds. Here we investigated the stability of reward encoding in MIP by assessing the effect of reward history on reward sensitivity. We recorded from neurons in MIP while monkeys performed a delayed-reach task under two reward schedules. In the variable schedule, an equal number of small- and large-rewards trials were randomly interleaved. In the constant schedule, one reward size was delivered for a block of trials. The memory period firing rate of most neurons in response to identical rewards varied according to schedule. Using systems identification tools, we attributed the schedule sensitivity to the dependence of neural activity on the history of reward. We did not find schedule-dependent behavioral changes, suggesting that reward modulates neural activity in MIP. Neural discrimination between rewards was less in the variable than in the constant schedule, degrading our ability to decode reach target and reward simultaneously. The effect of schedule was mitigated by adding Haar wavelet coefficients to the decoding model. This raises the possibility of multiple encoding schemes at different timescales and reinforces the potential utility of reward information for prosthetic performance. PMID:25008408

Modulation of neural activity by reward in medial intraparietal cortex is sensitive to temporal sequence of reward.

PubMed

Rajalingham, Rishi; Stacey, Richard Greg; Tsoulfas, Georgios; Musallam, Sam

2014-10-01

To restore movements to paralyzed patients, neural prosthetic systems must accurately decode patients' intentions from neural signals. Despite significant advancements, current systems are unable to restore complex movements. Decoding reward-related signals from the medial intraparietal area (MIP) could enhance prosthetic performance. However, the dynamics of reward sensitivity in MIP is not known. Furthermore, reward-related modulation in premotor areas has been attributed to behavioral confounds. Here we investigated the stability of reward encoding in MIP by assessing the effect of reward history on reward sensitivity. We recorded from neurons in MIP while monkeys performed a delayed-reach task under two reward schedules. In the variable schedule, an equal number of small- and large-rewards trials were randomly interleaved. In the constant schedule, one reward size was delivered for a block of trials. The memory period firing rate of most neurons in response to identical rewards varied according to schedule. Using systems identification tools, we attributed the schedule sensitivity to the dependence of neural activity on the history of reward. We did not find schedule-dependent behavioral changes, suggesting that reward modulates neural activity in MIP. Neural discrimination between rewards was less in the variable than in the constant schedule, degrading our ability to decode reach target and reward simultaneously. The effect of schedule was mitigated by adding Haar wavelet coefficients to the decoding model. This raises the possibility of multiple encoding schemes at different timescales and reinforces the potential utility of reward information for prosthetic performance. Copyright © 2014 the American Physiological Society.

The Effect of Preoperative Antimicrobial Prophylaxis on Intraoperative Culture Results in Patients with a Suspected or Confirmed Prosthetic Joint Infection: a Systematic Review

PubMed Central

Benito, Natividad; Soriano, Alex

2017-01-01

ABSTRACT Obtaining reliable cultures during revision arthroplasty is important to adequately diagnose and treat a prosthetic joint infection (PJI). The influence of antimicrobial prophylaxis on culture results remains unclear. Since withholding prophylaxis increases the risk for surgical site infections, clarification on this topic is critical. A systematic review was performed with the following research question: in patients who undergo revision surgery of a prosthetic joint, does preoperative antimicrobial prophylaxis affect the culture yield of intraoperative samples in comparison with nonpreoperative antimicrobial prophylaxis? Seven articles were included in the final analysis. In most studies, standard diagnostic culture techniques were used. In patients with a PJI, pooled analysis showed a culture yield of 88% (145/165) in the prophylaxis group versus 95% (344/362) in the nonprophylaxis group (P = 0.004). Subanalysis of patients with chronic PJIs showed positive cultures in 88% (78/89) versus 91% (52/57), respectively (P = 0.59). In patients with a suspected chronic infection, a maximum difference of 4% in culture yield between the prophylaxis and nonprophylaxis groups was observed. With the use of standard culture techniques, antimicrobial prophylaxis seems to affect cultures in a minority of patients. Along with the known risk of surgical site infections due to inadequate timing of antimicrobial prophylaxis, we discourage the postponement of prophylaxis until tissue samples are obtained in revision surgery. Future studies are necessary to conclude whether the small percentage of false-negative cultures after prophylaxis can be further reduced with the use of more-sensitive culture techniques, like sonication. PMID:28659322

How do prosthetic stiffness, height and running speed affect the biomechanics of athletes with bilateral transtibial amputations?

PubMed Central

Taboga, Paolo; Grabowski, Alena M.

2017-01-01

Limited available information describes how running-specific prostheses and running speed affect the biomechanics of athletes with bilateral transtibial amputations. Accordingly, we quantified the effects of prosthetic stiffness, height and speed on the biomechanics of five athletes with bilateral transtibial amputations during treadmill running. Each athlete performed a set of running trials with 15 different prosthetic model, stiffness and height combinations. Each set of trials began with the athlete running on a force-measuring treadmill at 3 m s−1, subsequent trials incremented by 1 m s−1 until they achieved their fastest attainable speed. We collected ground reaction forces (GRFs) during each trial. Prosthetic stiffness, height and running speed each affected biomechanics. Specifically, with stiffer prostheses, athletes exhibited greater peak and stance average vertical GRFs (β = 0.03; p < 0.001), increased overall leg stiffness (β = 0.21; p < 0.001), decreased ground contact time (β = −0.07; p < 0.001) and increased step frequency (β = 0.042; p < 0.001). Prosthetic height inversely associated with step frequency (β = −0.021; p < 0.001). Running speed inversely associated with leg stiffness (β = −0.58; p < 0.001). Moreover, at faster running speeds, the effect of prosthetic stiffness and height on biomechanics was mitigated and unchanged, respectively. Thus, prosthetic stiffness, but not height, likely influences distance running performance more than sprinting performance for athletes with bilateral transtibial amputations. PMID:28659414

Energy expenditure of wheeling and walking during prosthetic rehabilitation in a woman with bilateral transfemoral amputations.

PubMed

Wu, Y J; Chen, S Y; Lin, M C; Lan, C; Lai, J S; Lien, I N

2001-02-01

To compare the energy expenditure of locomotion by wheelchair with that required for prosthetic ambulation in a person with bilateral transfemoral (TF) amputations. Observational, single patient, descriptive. An 80-meter long rectangular hallway in a rehabilitation unit. A 41-year-old woman with bilateral TF amputations that were performed 79 days before her admission to the rehabilitation unit. The oxygen uptake, oxygen cost, heart rate, speed, cadence, and stride length of walking measured during a 4-month course of prosthetic rehabilitation. Five locomotion conditions were evaluated: (1) wheelchair propulsion, (2) walking with short-leg prostheses (stubbies) and a walker, (3) long-leg prostheses and a walker, (4) long-leg prostheses without knee mechanism and axillary crutches, and (5) long-leg prostheses with right polycentric knee and left locked knee and axillary crutches. A portable and telemetric system was used to measure the metabolic parameters. An arm ergometry graded exercise test was performed at the end of rehabilitation. Oxygen cost (range, 466%--707% of that of wheeling) and heart rate (range, 106%--116% of that of wheeling) were higher during walking with various combinations of prostheses and walking aids. The speed of prosthetic walking was only 24% to 33% of that of wheeling. Our patient preferred using a wheelchair to prosthetic walking after discharge. People with bilateral TF amputations require very high cardiorespiratory endurance to fulfill the energy demand during prosthetic rehabilitation. The high energy cost of prosthetic walking will limit its application in daily activities.

How do prosthetic stiffness, height and running speed affect the biomechanics of athletes with bilateral transtibial amputations?

PubMed

Beck, Owen N; Taboga, Paolo; Grabowski, Alena M

2017-06-01

Limited available information describes how running-specific prostheses and running speed affect the biomechanics of athletes with bilateral transtibial amputations. Accordingly, we quantified the effects of prosthetic stiffness, height and speed on the biomechanics of five athletes with bilateral transtibial amputations during treadmill running. Each athlete performed a set of running trials with 15 different prosthetic model, stiffness and height combinations. Each set of trials began with the athlete running on a force-measuring treadmill at 3 m s -1 , subsequent trials incremented by 1 m s -1 until they achieved their fastest attainable speed. We collected ground reaction forces (GRFs) during each trial. Prosthetic stiffness, height and running speed each affected biomechanics. Specifically, with stiffer prostheses, athletes exhibited greater peak and stance average vertical GRFs ( β = 0.03; p < 0.001), increased overall leg stiffness ( β = 0.21; p < 0.001), decreased ground contact time ( β = -0.07; p < 0.001) and increased step frequency ( β = 0.042; p < 0.001). Prosthetic height inversely associated with step frequency ( β = -0.021; p < 0.001). Running speed inversely associated with leg stiffness ( β = -0.58; p < 0.001). Moreover, at faster running speeds, the effect of prosthetic stiffness and height on biomechanics was mitigated and unchanged, respectively. Thus, prosthetic stiffness, but not height, likely influences distance running performance more than sprinting performance for athletes with bilateral transtibial amputations. © 2017 The Author(s).

Impact of a stance phase microprocessor-controlled knee prosthesis on level walking in lower functioning individuals with a transfemoral amputation.

PubMed

Eberly, Valerie J; Mulroy, Sara J; Gronley, JoAnne K; Perry, Jacquelin; Yule, William J; Burnfield, Judith M

2014-12-01

For individuals with transfemoral amputation, walking with a prosthesis presents challenges to stability and increases the demand on the hip of the prosthetic limb. Increasing age or comorbidities magnify these challenges. Computerized prosthetic knee joints improve stability and efficiency of gait, but are seldom prescribed for less physically capable walkers who may benefit from them. To compare level walking function while wearing a microprocessor-controlled knee (C-Leg Compact) prosthesis to a traditionally prescribed non-microprocessor-controlled knee prosthesis for Medicare Functional Classification Level K-2 walkers. Crossover. Stride characteristics, kinematics, kinetics, and electromyographic activity were recorded in 10 participants while walking with non-microprocessor-controlled knee and Compact prostheses. Walking with the Compact produced significant increase in velocity, cadence, stride length, single-limb support, and heel-rise timing compared to walking with the non-microprocessor-controlled knee prosthesis. Hip and thigh extension during late stance improved bilaterally. Ankle dorsiflexion, knee extension, and hip flexion moments of the prosthetic limb were significantly improved. Improvements in walking function and stability on the prosthetic limb were demonstrated by the K-2 level walkers when using the C-Leg Compact prosthesis. Understanding the impact of new prosthetic designs on gait mechanics is essential to improve prescription guidelines for deconditioned or older persons with transfemoral amputation. Prosthetic designs that improve stability for safety and walking function have the potential to improve community participation and quality of life. © The International Society for Prosthetics and Orthotics 2013.

Implant salvage in breast reconstruction with severe peri-prosthetic infection.

PubMed

Meybodi, Farid; Sedaghat, Negin; French, James; Keighley, Caitlin; Mitchell, David; Elder, Elisabeth

2017-12-01

Although treatment of mild peri-prosthetic infection in implant-based breast reconstruction results in high rates of resolution, successful management of severe peri-prosthetic infection remains a significant challenge. In this case series, a protocol utilizing a novel dressing - negative pressure wound therapy with instillation (NPWTi) - for the management of severe peri-prosthetic infection in breast reconstruction patients is described. This is an operative technique involving: (i) explantation of the breast prosthesis and application of the NPWTi dressing to the implant pocket; (ii) change of the NPWTi dressing; (iii) intraoperative fluid/tissue cultures; and (iv) reimplantation of the breast prosthesis when cultures yield no growth. This protocol was utilized in six cases of severe peri-prosthetic infection in five patients with immediate breast reconstruction for breast cancer or risk-reducing surgery. Cultures of fluid/tissue grew typical and/or unusual organisms. Only one case did not yield an organism. The hospital length of stay upon completion of the protocol ranged from 7-16 days (mean, 12 days). Successful implant salvage was achieved in five of six cases. The protocol was aborted in one case to allow for completion of adjuvant chemotherapy. Early findings from this case series suggest that in cases of severe peri-prosthetic infection this novel operative protocol may result in successful implant salvage for breast reconstruction patients. Further studies are needed to more fully elaborate the role of NPWTi to achieve implant salvage in challenging cases of peri-prosthetic infection. © 2015 Royal Australasian College of Surgeons.

Prosthetic vascular graft infection and prosthetic joint infection caused by Pseudomonas stutzeri.

PubMed

Bonares, Michael J; Vaisman, Alon; Sharkawy, Abdu

2016-01-01

Pseudomonas stutzeri is infrequently isolated from clinical specimens, and if isolated, more likely represents colonization or contamination rather than infection. Despite this, there are dozens of case reports which describe clinically significant P. stutzeri infections at variable sites. A 69-year-old man had a P. stutzeri infection of a prosthetic vascular graft infection, which he received in Panama City. He was successfully treated with a single antipseudomonal agent for 6 weeks and the removal of the infected vascular graft. A 70-year-old man had a P. stutzeri infection of a prosthetic joint, which was successfully treated with a single anti-pseudomonal agent for 6 weeks. There is only one other documented case of a prosthetic vascular graft infection secondary to P. stutzeri . There are 5 documented cases of P. stutzeri prosthetic joint infections. The previous cases were treated with antibiotics and variably, source control with the removal of prosthetic material. Most cases of P. stutzeri infection are due to exposure in health care settings. Immunocompromised states such as HIV or hematological and solid tumor malignancies are risk factors for P. stutzeri infection. Infections caused by P. stutzeri are far less frequent and less fatal than those caused by P. aeruginosa. The etiology of a P. stutzeri infection could be exposure to soil and water, but also contaminated material in the health care setting or an immunocompromised state. Iatrogenic infections that are secondary to health care tourism are a potential cause of fever in the returned traveler.

High-resolution remotely sensed small target detection by imitating fly visual perception mechanism.

PubMed

Huang, Fengchen; Xu, Lizhong; Li, Min; Tang, Min

2012-01-01

The difficulty and limitation of small target detection methods for high-resolution remote sensing data have been a recent research hot spot. Inspired by the information capture and processing theory of fly visual system, this paper endeavors to construct a characterized model of information perception and make use of the advantages of fast and accurate small target detection under complex varied nature environment. The proposed model forms a theoretical basis of small target detection for high-resolution remote sensing data. After the comparison of prevailing simulation mechanism behind fly visual systems, we propose a fly-imitated visual system method of information processing for high-resolution remote sensing data. A small target detector and corresponding detection algorithm are designed by simulating the mechanism of information acquisition, compression, and fusion of fly visual system and the function of pool cell and the character of nonlinear self-adaption. Experiments verify the feasibility and rationality of the proposed small target detection model and fly-imitated visual perception method.

Distal anastomotic vein adjunct usage in infrainguinal prosthetic bypasses.

PubMed

McPhee, James T; Goodney, Philip P; Schanzer, Andres; Shaykevich, Shimon; Belkin, Michael; Menard, Matthew T

2013-04-01

Single-segment saphenous vein remains the optimal conduit for infrainguinal revascularization. In its absence, prosthetic conduit may be used. Existing data regarding the significance of anastomotic distal vein adjunct (DVA) usage with prosthetic grafts are based on small series. This is a retrospective cohort analysis derived from the regional Vascular Study Group of New England as well as the Brigham and Women's hospital database. A total of 1018 infrainguinal prosthetic bypass grafts were captured in the dataset from 73 surgeons at 15 participating institutions. Propensity scoring and 3:1 matching was performed to create similar exposure groups for analysis. Outcome measures of interest included: primary patency, freedom from major adverse limb events (MALEs), and amputation free survival at 1 year as a function of vein patch utilization. Time to event data were compared with the log-rank test; multivariable Cox proportional hazard models were used to evaluate the adjusted association between vein cuff usage and the primary end points. DVA was defined as a vein patch, cuff, or boot in any configuration. Of the 1018 bypass operations, 94 (9.2%) had a DVA whereas 924 (90.8%) did not (no DVA). After propensity score matching, 88 DVAs (25%) and 264 no DVAs (75%) were analyzed. On univariate analysis of the matched cohort, the DVA and no DVA groups were similar in terms of mean age (70.0 vs 69.0; P = .55), male sex (58.0% vs 58.3%; P > .99), and preoperative characteristics such as living at home (93.2% vs 94.3%; P = .79) and independent ambulatory status (72.7% vs 75.7%; P = .64). The DVA and no DVA groups had similar rates of major comorbidities such as hypertension chronic obstructive pulmonary disease, diabetes mellitus, coronary artery disease, and dialysis dependence (P > .05 for all). Likewise, they had similar rates of distal origin grafts (13.6% vs 12.5%; P = .85), critical limb ischemia indications (P = .53), and prior arterial bypass (58% vs 47%; P = .08). The DVA group had a higher rate of completion angiogram performed (55.7% vs 37.5%; P =.002) and were more likely to be discharged on coumadin (53.4% vs 37.1%; P =.01). By multivariable analysis, use of a distal DVA was protective against MALEs (hazard ratio, 0.36; 95% confidence interval, 0.14-0.90; P = .03). This contemporary multi-institutional propensity-matched study demonstrates that patients that receive distal anastomotic vein adjuncts as part of infrainguinal prosthetic bypass operations in general have more extreme comorbidities and more technically challenging operations based on level of target vessel and prior bypass attempts. After propensity-matched analysis, the use of a DVA may protect against MALEs in prosthetic bypass surgery and should be considered when feasible. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Recurrent prosthetic valve endocarditis caused by Aspergillus delacroxii (formerly Aspergillus nidulans var. echinulatus)

PubMed Central

Uhrin, Gábor Balázs; Jensen, Rasmus Hare; Korup, Eva; Grønlund, Jens; Hjort, Ulla; Moser, Claus; Arendrup, Maiken Cavling; Schønheyder, Henrik Carl

2015-01-01

We report Aspergillus delacroxii (formerly Aspergillus nidulans var. echinulatus) causing recurrent prosthetic valve endocarditis. The fungus was the sole agent detected during replacement of a mechanical aortic valve conduit due to abscess formation. Despite extensive surgery and anti-fungal treatment, the patient had a cerebral hemorrhage 4 months post-surgery prompting a diagnosis of recurrent prosthetic valve endocarditis and fungemia. PMID:26909244

Proceedings on Combating the Unrestricted Warfare Threat: Integrating Strategy, Analysis, and Technology, 20-21 March 2007

DTIC Science & Technology

2007-03-01

Prosthetics to enable return to units without loss of capability Quantum...and will give us a big advantage in terms of unrestricted warfare. Figure 17 high-Productivity Computing System PRoSThETICS We have an exciting...program in prosthetics (Figure 18). It started with a monkey at Duke University. We put microelectronic implants into her brain, taught her

Prosthetic Joint Infections

PubMed Central

Aslam, Saima; Darouiche, Rabih O.

2012-01-01

Prosthetic joint infections represent a major therapeutic challenge for both healthcare providers and patients. This paper reviews the predisposing factors, pathogenesis, microbiology, diagnosis, treatment and prophylaxis of prosthetic joint infection. The most optimal management strategy should be identified based on a number of considerations including type and duration of infection, antimicrobial susceptibility of the infecting pathogen, condition of infected tissues and bone stock, patient wishes and functional status. PMID:22847032

A new cofactor in prokaryotic enzyme: Tryptophan tryptophylquinone as the redox prosthetic group in methylamine dehydrogenase

DOE Office of Scientific and Technical Information (OSTI.GOV)

McIntire, W.S.; Wemmer, D.E.; Chistoserdov, A.

Methylamine dehydrogenase (MADH), an {alpha}{sub 2}{beta}{sub 2} enzyme from numerous methylotrophic soil bacteria, contains a novel quinonoid redox prosthetic group that is covalently bound to its small {beta} subunit through two amino acyl residues. A comparison of the amino acid sequence deduced from the gene sequence of the small subunit for the enzyme from Methylobacterium extorquens AM1 with the published amino acid sequence obtained by Edman degradation method, allowed the identification of the amino acyl constituents of the cofactor as two tryptophyl residues. This information was crucial for interpreting {sup 1}H and {sup 13}C nuclear magnetic resonance, and mass spectralmore » data collected for the semicarbazide- and carboxymethyl-derivatized bis(tripeptidyl)-cofactor of MADH from bacterium W3A1. The cofactor is composed of two cross-linked tryptophyl residues. Although there are many possible isomers, only one is consistent with all the data: The first tryptophyl residue in the peptide sequence exists as an indole-6,7-dione, and is attached at its 4 position to the 2 position of the second, otherwise unmodified, indole side group. Contrary to earlier reports, the cofactor of MADH is not 2,7,9-tricarboxypyrroloquinoline quinone (PQQ), a derivative thereof, of pro-PQQ. This appears to be the only example of two cross-linked, modified amino acyl residues having a functional role in the active site of an enzyme, in the absence of other cofactors or metal ions.« less

Retrieval analysis of titanium nitride (TiN) coated prosthetic femoral heads articulating with polyethylene.

PubMed

Łapaj, Łukasz; Wendland, Justyna; Markuszewski, Jacek; Mróz, Adrian; Wiśniewski, Tomasz

2015-03-01

Data regarding in vivo performance of titanium nitride (TiN) coated prosthetic femoral heads is scarce, and available studies of older generations of implants demonstrated coating wear in vivo. That is why we conducted a retrieval analysis of 11 femoral heads (articulating in vivo for 1-56 months) with TiN film formed using physical vapor deposition (PVD), to verify if coating failure is a problem in contemporary implants. Retrieved implants were examined using scanning electron microscope, coating roughness was evaluated with a contact profilometer and adhesion was tested using a Rockwell HRC test according to VDI 3824 guideline. Although no gross failure of the TiN coating was observed in our retrievals, all implants had defects typical for PVD coatings, such as pinholes, small titanium droplets and blisters with delaminated coating. In some heads the coating was contaminated with small niobium (Nb) droplets uniformly scattered on the entire surface of the film. Presence of Nb contamination was associated with an increased number and area of other types of defects and poorer coating adhesion. In one component, subjected to multiple dislocations we found severe delamination and cracking of the coating, increased roughness and the presence of third bodies. Our results indicate, that although wear of the coating is lower than seen in older generations of implants, inconsistent quality of the TiN film among different implants indicates the need for strict monitoring of the manufacturing process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Advances in upper extremity prosthetics.

PubMed

Zlotolow, Dan A; Kozin, Scott H

2012-11-01

Until recently, upper extremity prostheses had changed little since World War II. In 2006, the Defense Advanced Research Projects Agency responded to an increasing number of military amputees with the Revolutionizing Prosthetics program. The program has yielded several breakthroughs both in the engineering of new prosthetic arms and in the control of those arms. Direct brain-wave control of a limb with 22° of freedom may be within reach. In the meantime, advances such as individually powered digits have opened the door to multifunctional full and partial hand prostheses. Restoring sensation to the prosthetic limb remains a major challenge to full integration of the limb into a patient's self-image. Copyright © 2012 Elsevier Inc. All rights reserved.

Afebrile Pannus-Induced Blood Culture-Negative Mechanical Valve Endocarditis.

PubMed

Matsukuma, Seiji; Eishi, Kiyoyuki; Tanigawa, Kazuyoshi; Miura, Takashi; Matsumaru, Ichiro; Hisatomi, Kazuki; Tsuneto, Akira

2016-12-01

The diagnosis of prosthetic valve endocarditis may be challenging in patients with an atypical clinical presentation. Virtually all infections associated with mechanical prosthetic valves are localized to the prosthesis-tissue junction at the sewing ring and are accompanied by tissue destruction around the prosthesis. Because the orifice of the mechanical prosthetic valve is made of metal and pyrolytic carbon, which do not enable the adherence of microorganisms, any vegetation originating from the interior of the valve orifice is usually rare. Here we present a rare case of pannus-induced mechanical prosthetic valve endocarditis that was difficult to diagnose. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Three-Dimensional Printing of Prosthetic Hands for Children.

PubMed

Burn, Matthew B; Ta, Anderson; Gogola, Gloria R

2016-05-01

Children with hand reductions, whether congenital or traumatic, have unique prosthetic needs. They present a challenge because of their continually changing size due to physical growth as well as changing needs due to psychosocial development. Conventional prosthetics are becoming more technologically advanced and increasingly complex. Although these are welcome advances for adults, the concomitant increases in weight, moving parts, and cost are not beneficial for children. Pediatric prosthetic needs may be better met with simpler solutions. Three-dimensional printing can be used to fabricate rugged, light-weight, easily replaceable, and very low cost assistive hands for children. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Echocardiographic Assessment of Heart Valve Prostheses

PubMed Central

Sordelli, Chiara; Severino, Sergio; Ascione, Luigi; Coppolino, Pasquale; Caso, Pio

2014-01-01

Patients submitted to valve replacement with mechanical or biological prosthesis, may present symptoms related either to valvular malfunction or ventricular dysfunction from other causes. Because a clinical examination is not sufficient to evaluate a prosthetic valve, several diagnostic methods have been proposed to assess the functional status of a prosthetic valve. This review provides an overview of echocardiographic and Doppler techniques useful in evaluation of prosthetic heart valves. Compared to native valves, echocardiographic evaluation of prosthetic valves is certainly more complex, both for the examination and the interpretation. Echocardiography also allows discriminating between intra- and/or peri-prosthetic regurgitation, present in the majority of mechanical valves. Transthoracic echocardiography (TTE) requires different angles of the probe with unconventional views. Transesophageal echocardiography (TEE) is the method of choice in presence of technical difficulties. Three-dimensional (3D)-TEE seems to be superior to 2D-TEE, especially in the assessment of paravalvular leak regurgitation (PVL) that it provides improved localization and analysis of the PVL size and shape. PMID:28465917

Structural Integration and Control of Peerless Human-like Prosthetic Hand

NASA Astrophysics Data System (ADS)

Dave, Ankit; Muthu, P.; Karthikraj, V.; Latha, S.

2018-04-01

Limb damage can create severe disturbance in movement and operative abilities wherein the prosthetic rehabilitation has the potential to replace function and enhance the quality of life. This paper presents a humanlike prosthetic hand using such unique design concept of hand model using artificial bones, ligaments, and tendons controlled using Arduino. Amongst various platforms available, Arduino is known for its adaptability, adoration and low cost. The design of prosthetic hand has a unique structure with all carpal, metacarpal, and phalanges which are bones of the hand. These bones are attached to each other following the pattern of human hand using the polymeric rubber as a functioning ligament. Furthermore, this structure of finger is driven by tendons attached to all fingers and passes through the ligaments working as pulley resulting in more degrees of freedom. The motor can twitch the tendons to achieve the action of fingers. Thus the servos, controlled by an Arduino, are used to regulate the movement mechanism of the prosthetic hand.

Control of a powered prosthetic device via a pinch gesture interface

NASA Astrophysics Data System (ADS)

Yetkin, Oguz; Wallace, Kristi; Sanford, Joseph D.; Popa, Dan O.

2015-06-01

A novel system is presented to control a powered prosthetic device using a gesture tracking system worn on a user's sound hand in order to detect different grasp patterns. Experiments are presented with two different gesture tracking systems: one comprised of Conductive Thimbles worn on each finger (Conductive Thimble system), and another comprised of a glove which leaves the fingers free (Conductive Glove system). Timing tests were performed on the selection and execution of two grasp patterns using the Conductive Thimble system and the iPhone app provided by the manufacturer. A modified Box and Blocks test was performed using Conductive Glove system and the iPhone app provided by Touch Bionics. The best prosthetic device performance is reported with the developed Conductive Glove system in this test. Results show that these low encumbrance gesture-based wearable systems for selecting grasp patterns may provide a viable alternative to EMG and other prosthetic control modalities, especially for new prosthetic users who are not trained in using EMG signals.

Categorization of compensatory motions in transradial myoelectric prosthesis users.

PubMed

Hussaini, Ali; Zinck, Arthur; Kyberd, Peter

2017-06-01

Prosthesis users perform various compensatory motions to accommodate for the loss of the hand and wrist as well as the reduced functionality of a prosthetic hand. Investigate different compensation strategies that are performed by prosthesis users. Comparative analysis. A total of 20 able-bodied subjects and 4 prosthesis users performed a set of bimanual activities. Movements of the trunk and head were recorded using a motion capture system and a digital video recorder. Clinical motion angles were calculated to assess the compensatory motions made by the prosthesis users. The video recording also assisted in visually identifying the compensations. Compensatory motions by the prosthesis users were evident in the tasks performed (slicing and stirring activities) as compared to the benchmark of able-bodied subjects. Compensations took the form of a measured increase in range of motion, an observed adoption of a new posture during task execution, and prepositioning of items in the workspace prior to initiating a given task. Compensatory motions were performed by prosthesis users during the selected tasks. These can be categorized into three different types of compensations. Clinical relevance Proper identification and classification of compensatory motions performed by prosthesis users into three distinct forms allows clinicians and researchers to accurately identify and quantify movement. It will assist in evaluating new prosthetic interventions by providing distinct terminology that is easily understood and can be shared between research institutions.

Performance of photovoltaic arrays in-vivo and characteristics of prosthetic vision in animals with retinal degeneration

PubMed Central

Lorach, Henri; Goetz, Georges; Mandel, Yossi; Lei, Xin; Kamins, Theodore I.; Mathieson, Keith; Huie, Philip; Dalal, Roopa; Harris, James S.; Palanker, Daniel

2014-01-01

Summary Loss of photoreceptors during retinal degeneration leads to blindness, but information can be reintroduced into the visual system using electrical stimulation of the remaining retinal neurons. Subretinal photovoltaic arrays convert pulsed illumination into pulsed electric current to stimulate the inner retinal neurons. Since required irradiance exceeds the natural luminance levels, an invisible near-infrared (915nm) light is used to avoid photophobic effects. We characterized the thresholds and dynamic range of cortical responses to prosthetic stimulation with arrays of various pixel sizes and with different number of photodiodes. Stimulation thresholds for devices with 140µm pixels were approximately half those of 70µm pixels, and with both pixel sizes, thresholds were lower with 2 diodes than with 3 diodes per pixel. In all cases these thresholds were more than two orders of magnitude below the ocular safety limit. At high stimulation frequencies (>20Hz), the cortical response exhibited flicker fusion. Over one order of magnitude of dynamic range could be achieved by varying either pulse duration or irradiance. However, contrast sensitivity was very limited. Cortical responses could be detected even with only a few illuminated pixels. Finally, we demonstrate that recording of the corneal electric potential in response to patterned illumination of the subretinal arrays allows monitoring the current produced by each pixel, and thereby assessing the changes in the implant performance over time. PMID:25255990

Periprosthetic Joint Infections: Clinical and Bench Research

PubMed Central

Legout, Laurence; Senneville, Eric

2013-01-01

Prosthetic joint infection is a devastating complication with high morbidity and substantial cost. The incidence is low but probably underestimated. Despite a significant basic and clinical research in this field, many questions concerning the definition of prosthetic infection as well the diagnosis and the management of these infections remained unanswered. We review the current literature about the new diagnostic methods, the management and the prevention of prosthetic joint infections. PMID:24288493

Smart Sensing and Dynamic Fitting for Enhanced Comfort and Performance of Prosthetics

DTIC Science & Technology

2017-10-01

studying microstrip resonators for bio- impedance measurement. For actuation, we have 1) improved and de -bugged the prosthetic interface control ...studying microstrip resonators for bio‐impedance measurement. For actuation, we have 1) improved and de -bugged the prosthetic interface control ...shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number

Prosthetic Smart Socket Technology to Improve Patient Interaction, Usability, Comfort, Fit and Function

DTIC Science & Technology

2017-10-01

AWARD NUMBER: W81XWH-16-1-0785 TITLE: Prosthetic Smart Socket Technology to Improve Patient Interaction, Usability, Comfort, Fit and Function...2016 - 29 Sep 2017 4. TITLE AND SUBTITLE Prosthetic Smart Socket Technology to Improve Patient Interaction, Usability, Comfort, Fit and Function 5a...discomfort. 2. KEYWORDS: Provide a brief list of keywords (limit to 20 words). Prosthesis, prosthesis fit, technology , skin problems, amputee

Current standard rules of combined anteversion prevent prosthetic impingement but ignore osseous contact in total hip arthroplasty.

PubMed

Weber, Markus; Woerner, Michael; Craiovan, Benjamin; Voellner, Florian; Worlicek, Michael; Springorum, Hans-Robert; Grifka, Joachim; Renkawitz, Tobias

2016-12-01

In this prospective study of 135 patients undergoing cementless total hip arthroplasty (THA) we asked whether six current definitions of combined anteversion prevent impingement and increase postoperative patient individual impingement-free range-of-motion (ROM). Implant position was measured by an independent, external institute on 3D-CT performed six weeks post-operatively. Post-operative ROM was calculated using a CT-based algorithm detecting osseous and/or prosthetic impingement by virtual hip movement. Additionally, clinical ROM was evaluated pre-operatively and one-year post-operatively by a blinded observer. Combined component position of cup and stem according to the definitions of Ranawat, Widmer, Dorr, Hisatome and Yoshimine inhibited prosthetic impingement in over 90 %, while combined osseous and prosthetic impingement still occurred in over 40 % of the cases. The recommendations by Jolles, Widmer, Dorr, Yoshimine and Hisatome enabled higher flexion (p ≤ 0.001) and internal rotation (p ≤ 0.006). Clinically, anteversion rules of Widmer and Yoshimine provided one-year post-operatively statistically but not clinically relevant higher internal rotation (p ≤0.034). Standard rules of combined anteversion detect prosthetic but fail to prevent combined osseous and prosthetic impingement in THA. Future models will have to account for the patient-individual anatomic situation to ensure impingement-free ROM.

Fatigue testing of energy storing prosthetic feet.

PubMed

Toh, S L; Goh, J C; Tan, P H; Tay, T E

1993-12-01

This paper describes a simple approach to the fatigue testing of prosthetic feet. A fatigue testing machine for prosthetic feet was designed as part of the programme to develop an energy storing prosthetic foot (ESPF). The fatigue tester does not simulate the loading pattern on the foot during normal walking. However, cyclic vertical loads are applied to the heel and forefoot during heel-strike and toe-off respectively, for 500,000 cycles. The maximum load applied was chosen to be 1.5 times that applied by the bodyweight of the amputee and the test frequency was chosen to be 2 Hz to shorten the test duration. Four prosthetic feet were tested: two Lambda feet (a newly developed ESPF), a Kingsley SACH foot and a Proteor SACH foot. It was found that the Lambda feet have very good fatigue properties. The Kingsley SACH foot performed better than the Proteor model, with no signs of wear at the heel. The results obtained using the simple approach was found to be comparable to the results from more complex fatigue machines which simulate the load pattern during normal walking. This suggests that simple load simulating machines, which are less costly and require less maintenance, are useful substitutes in studying the fatigue properties of prosthetic feet.

Speech and Swallowing Data in Individual Patients Who Underwent Glossectomy after Prosthetic Rehabilitation

PubMed Central

Sennes, Luiz Ubirajara

2016-01-01

Maintaining oral function in patients undergoing glossectomy boosts interventions such as prosthetic rehabilitation. However, current literature still fails in the presentation of results of prosthetic rehabilitation in relation to speech or swallowing. The objective of this research is to evaluate the effectiveness of prosthetic rehabilitation on voice, speech, and swallowing in patients undergoing glossectomy by performing a systematic literature review and meta-analysis of individual cases. Studies were identified by relevant electronic database and included all dates available. The criteria used were sample with any n; resection due to malignant tumors, restricted to tongue and/or floor of mouth; type of prosthetic rehabilitation; and description of the oral functions outcomes with prosthesis. For the meta-analysis of individual data, associations between the variables of interest and the type of prosthesis were evaluated. Thirty-three of 471 articles met the selection criteria. Results on speech and/or voice and swallowing were reported in 27 and 28 articles, respectively. There were improvement of speech intelligibility and swallowing in 96 patients and in 73 patients, respectively, with prosthesis. Based on the available evidences, this article showed that prosthetic rehabilitation was able to improve oral functions and can be a strategy used with surgical reconstruction in selected cases. PMID:28042295

Preferences for rehabilitation services among women with major limb amputations.

PubMed

Elnitsky, Christine A; Latlief, Gail A; Andrews, Erin E; Adams-Koss, Laurel B; Phillips, Samuel L

2013-01-01

We present five cases of adult females with major limb amputations, their concerns and preferences for services across the life span. A convenience sample of five veteran and nonveteran women aged 19-58 with major limb amputations participating in a regional VA Prosthetics Conference in 2010 took part in a panel interview. The concerns identified by these women as high priorities included independence and participation in a full range of life activities, limitations in access, patient decision-making and body image concerns, and preferences for selected services. Maximizing function and quality of life for women amputees requires identifying patient preferences for rehabilitation and prosthetic services. Lessons learned could inform development of clinic-based rehabilitation care, prosthetic services, and studies of women with major limb amputations. As the current conflicts in Iraq and Afghanistan wind down, the number of women veterans seeking rehabilitation and prosthetic services will increase. With this information, rehabilitation and prosthetic service providers and organizations will be uniquely positioned to provide prevention and treatment of amputations for this growing population of women veterans in national care delivery systems and in communities. An open-ended facilitated discussion among a panel of women with major limb amputations provided insights for providers and organizations with respect to needs, concerns, and preferences for rehabilitation and prosthetic services. © 2013 Association of Rehabilitation Nurses.

Prosthetic implant treatment of the edentulous maxilla with overdenture.

PubMed

Inversini, M

2006-10-01

The literature concerning the success of prosthetic implant treatment with maxillary overdenture is reviewed, and variables affecting treatment from the implant and prosthetic standpoint are analysed. Guidelines for the fabrication of maxillary overimplants comparable to those for mandibular overimplants are still lacking, as are evidence-based prosthetic design concepts. Individual methods and techniques have been described, but evaluation standards for the outcome of maxillary prosthetic-implant treatment are lacking or individually interpreted. The biomechanics involved in the proposed system are described, together with the advantages of telescopic crowns for the retention of removable partial prosthesis supported by maxillary implants. The positive influence, in terms of long-term prognosis, of the perio-protective design of removable partial prostheses supported by maxillary overimplants is also discussed. The proposed system not only provides stability, support and retention for removable partial prostheses supported by maxillary implants, but also enables implant survival rates to be improved, both for biomechanical reasons and due to improved oral hygiene. The simplification of fabrication procedures, repair, rebasing and re-operating also reduce the cost of follow-up and improve the cost/benefit ratio. However, additional studies are needed to clarify the number and most appropriate distribution of implants, as well as the most favourable prosthetic designs for maxillary overimplants.

[Tuberculous prosthetic knee joint infection: a case report and literature review].

PubMed

Lara-Oya, A; Liébana-Martos, M C; Rodríguez-Granger, J; Sampedro-Martínez, A; Aliaga-Martínez, L; Gutierrez-Fernández, J; Navarro-Marí, J M

2016-08-01

Prosthetic late infection occurs in the second month after surgery in the context of haematogenous spread from another source. Prosthetic mycobacterial infection is a rare complication whose clinical management is not standardized. Patient of 77 years with no personal history except for diabetes and a prosthetic replacement of right knee with osteoarthritis three years ago. Patient goes to hospital emergency box for 6 months pain in the right knee with mechanical inflammatory signs but no fever associated. After their return within 5 days and clinical worsening is reporting growth of Mycobacterium tuberculosis in knee aspirate and antitubercular treatment is established for 9 months. Nuclear magnetic resonance imaging studies also confirmed the diagnosis of tuberculosis spondylitis in the clinical context of the patients. After surgery, M. tuberculosis was again isolated from intraoperative samples and therefore the patient received another batch of treatment for 9 months. After a year of monitoring, the development was acceptable but few months later, the patient died for cardiovascular causes. In the literature review, 15 publications with a total of 17 clinical cases of prosthetic infection by M. tuberculosis were found from 1980 to 2014. Prosthetic tuberculous arthritis, although it is a rare presentation, it should be noted, especially in patients with predisposing conditions with a history of tuberculosis infection.

A three-dimensional finite element study on the stress distribution pattern of two prosthetic abutments for external hexagon implants.

PubMed

Moreira, Wagner; Hermann, Caio; Pereira, Jucélio Tomás; Balbinoti, Jean Anacleto; Tiossi, Rodrigo

2013-10-01

The purpose of this study was to evaluate the mechanical behavior of two different straight prosthetic abutments (one- and two-piece) for external hex butt-joint connection implants using three-dimensional finite element analysis (3D-FEA). Two 3D-FEA models were designed, one for the two-piece prosthetic abutment (2 mm in height, two-piece mini-conical abutment, Neodent) and another one for the one-piece abutment (2 mm in height, Slim Fit one-piece mini-conical abutment, Neodent), with their corresponding screws and implants (Titamax Ti, 3.75 diameter by 13 mm in length, Neodent). The model simulated the single restoration of a lower premolar using data from a computerized tomography of a mandible. The preload (20 N) after torque application for installation of the abutment and an occlusal loading were simulated. The occlusal load was simulated using average physiological bite force and direction (114.6 N in the axial direction, 17.1 N in the lingual direction and 23.4 N toward the mesial at an angle of 75° to the occlusal plan). The regions with the highest von Mises stress results were at the bottom of the initial two threads of both prosthetic abutments that were tested. The one-piece prosthetic abutment presented a more homogeneous behavior of stress distribution when compared with the two-piece abutment. Under the simulated chewing loads, the von Mises stresses for both tested prosthetic-abutments were within the tensile strength values of the materials analyzed which thus supports the clinical use of both prosthetic abutments.

A clinical survey about commercial games in lower limb prosthetic rehabilitation.

PubMed

Imam, Bita; Miller, William C; Finlayson, Heather C; Eng, Janice J; Jarus, Tal

2018-06-01

Despite the popularity of commercial games in lower limb prosthetic rehabilitation, data about their prevalence of use as well as therapists' perspectives about these games are still lacking. To learn about the prevalence of use of commercial games in lower limb prosthetic rehabilitation and therapists' perspectives about these games. Cross-sectional. An online survey was sent to physical and occupational therapists across prosthetic rehabilitation facilities in Canada. The survey had questions about the use of commercial games and therapists' perspectives. Data were collected from 82 therapists. Overall, 46.3% (38/82) reported that they use commercial games; of those, 94.7% (36/38) used the Nintendo Wii Fit. The most reported perceived benefits were the Wii Fit helping to improve weight shifting ( n = 76/82, 92.7%) and balance ( n = 75/82, 91.5%), and being motivating and complementing traditional therapy ( n = 75/82, 91.5%). The most reported perceived barriers/challenges were lack of time and familiarity with the games ( n = 58/82, 70.7%). Commercial games, particularly the Wii Fit, are commonly used in lower prosthetic rehabilitation in Canada. Most of the queried therapists view the Wii Fit positively. Knowledge translation activities and developing standard treatment protocols would be helpful in minimizing the barriers identified in this study. Clinical relevance The Wii Fit is prevalent in lower limb prosthetic rehabilitation in Canada and it is viewed positively by therapists as having the potential to improve balance and weight bearing, making rehabilitation more motivating, and complementing traditional therapy. Future studies should investigate the efficacy of the Wii Fit in prosthetic rehabilitation.

Bruxism and prosthetic treatment: a critical review.

PubMed

Johansson, Anders; Omar, Ridwaan; Carlsson, Gunnar E

2011-07-01

Based on the findings from available research on bruxism and prosthetic treatment published in the dental literature, an attempt was made to draw conclusions about the existence of a possible relationship between the two, and its clinical relevance. MEDLINE/PubMed searches were conducted using the terms 'bruxism' and 'prosthetic treatment', as well as combinations of these and related terms. The few studies judged to be relevant were critically reviewed, in addition to papers found during an additional manual search of reference lists within selected articles. Bruxism is a common parafunctional habit, occurring both during sleep and wakefulness. Usually it causes few serious effects, but can do so in some patients. The etiology is multifactorial. There is no known treatment to stop bruxism, including prosthetic treatment. The role of bruxism in the process of tooth wear is unclear, but it is not considered a major cause. As informed by the present critical review, the relationship between bruxism and prosthetic treatment is one that relates mainly to the effect of the former on the latter. Bruxism may be included among the risk factors, and is associated with increased mechanical and/or technical complications in prosthodontic rehabilitation, although it seems not to affect implant survival. When prosthetic intervention is indicated in a patient with bruxism, efforts should be made to reduce the effects of likely heavy occlusal loading on all the components that contribute to prosthetic structural integrity. Failure to do so may indicate earlier failure than is the norm. Copyright © 2011 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Prosthetics socket that incorporates an air splint system focusing on dynamic interface pressure.

PubMed

Razak, Nasrul Anuar Abd; Osman, Noor Azuan Abu; Gholizadeh, Hossein; Ali, Sadeeq

2014-08-01

The interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. This paper presents the design and performance of a new prosthetic socket that uses an air splint system. The air splint prosthetic socket system was implemented by combining the air splint with a pressure sensor that the transhumeral user controls through the use of a microcontroller. The modular construction of the system developed allows the FSR pressure sensors that are placed inside the air splint socket to determine the required size and fitting for the socket used. Fifteen transhumeral amputees participated in the study. The subject's dynamic pressure on the socket that's applied while wearing the air splint systems was recorded using F-socket transducers and microcontroller analysis. The values collected by the F-socket sensor for the air splint prosthetic socket system were determined accordingly by comparing the dynamic pressure applied using statically socket. The pressure volume of the air splint fluctuated and was recorded at an average of 38 kPa (2.5) to 41 kPa (1.3) over three hours. The air splint socket might reduce the pressure within the interface of residual limb. This is particularly important during the daily life activities and may reduce the pain and discomfort at the residual limb in comparison to the static socket. The potential development of an auto-adjusted socket that uses an air splint system as the prosthetic socket will be of interest to researchers involved in rehabilitation engineering, prosthetics and orthotics.

Prosthetics socket that incorporates an air splint system focusing on dynamic interface pressure

PubMed Central

2014-01-01

Background The interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee’s satisfaction and comfort. This paper presents the design and performance of a new prosthetic socket that uses an air splint system. Methods The air splint prosthetic socket system was implemented by combining the air splint with a pressure sensor that the transhumeral user controls through the use of a microcontroller. The modular construction of the system developed allows the FSR pressure sensors that are placed inside the air splint socket to determine the required size and fitting for the socket used. Fifteen transhumeral amputees participated in the study. Results The subject’s dynamic pressure on the socket that’s applied while wearing the air splint systems was recorded using F-socket transducers and microcontroller analysis. The values collected by the F-socket sensor for the air splint prosthetic socket system were determined accordingly by comparing the dynamic pressure applied using statically socket. The pressure volume of the air splint fluctuated and was recorded at an average of 38 kPa (2.5) to 41 kPa (1.3) over three hours. Conclusion The air splint socket might reduce the pressure within the interface of residual limb. This is particularly important during the daily life activities and may reduce the pain and discomfort at the residual limb in comparison to the static socket. The potential development of an auto-adjusted socket that uses an air splint system as the prosthetic socket will be of interest to researchers involved in rehabilitation engineering, prosthetics and orthotics. PMID:25085005

Incidence of Prosthetic Complications associated with Implant-borne Prosthesis in a Sleep Disorder Center.

PubMed

Suneel, Venkatesh B; Kotian, Santhosh; Jujare, Ravikanth H; Shetty, Adarsh K; Nidhi, Sneh; Grover, Shehkar

2017-09-01

Obstructive sleep apnea (OSA) is one of the common prevalent conditions present worldwide. The process of abnormal habits related to clenching and grinding of teeth is referred to as bruxism and is characterized under the heading of parafunctional activity of the masticatory system. Osseointegrated dental implants represent advancements in the field of odontology. Despite its high success rate, failure and complications are often associated with dental implant treatment due to a number of factors. Hence, we aimed for the present study to assess the incidence of prosthetic complications in patients rehabilitated with implant-borne prosthesis in a sleep disorder unit. The present study included the assessment of all the patients who underwent prosthetic rehabilitation by dental implants. An experienced registered prosthodontist was given duty for examination of all the cases from the record file data. Prosthetic complications in the patients were identified using photographs, radiographs, and all other relevant data of the patients obtained from the record files. All types of complications and other factors were recorded separately and analyzed. While correlating the prosthetic complications in OSA patients grouped based on number of dental implants, nonsignificant results were obtained. Significant correlation was observed while comparing the prosthetic complications divided based on type of prosthesis. Fracture of the porcelain was observed in four and eight cases respectively, of screwed and cemented dental implant cases. Some amount of significant correlation existed between the incidences of prosthetic complications and OSA. Proper history of the patients undergoing dental implant procedures should be taken to avoid failure.

[Incidence of hip and knee prosthetic infections in a specialized center of Mexico City].

PubMed

Franco-Cendejas, Rafael; Contreras-Córdova, Erika Lizbeth; Mondragón-Eguiluz, Jaime Arturo; Vanegas-Rodríguez, Edgar Samuel; Ilizaliturri-Sánchez, Víctor Manuel; Galindo-Fraga, Arturo

Hip and knee prosthetic replacements have proven to be the most appropriate treatment in the joints that do not benefit from medical or arthroscopic interventions; however, infections are the most feared complication. It is recommended that the incidence of infection should not exceed 2%. This was an observational, prospective, longitudinal and observational study conducted in patients fitted with a prosthetic joint from August 2011 to July 2012. Patients were followed up pre and post-surgery for one year to identify a prosthetic infection, diagnosed using international parameters. We calculated the incidence of prosthetic infection, as well as the incidence density. A total of 339 patients (179 hip and 160 knee) were included. Variations in the time of pre-operative antibiotics' administration were observed. Six prosthetic infections were identified with an incidence rate of 1.79/339 arthroplasties, 2.2/179 hip procedures, and 1.25/160 knee arthroplasties. An incidence density of 0.02/year for hip arthroplasties and 0.11/year for knee procedures was identified. There were 4 infections of hip and 2 of knee. Five infections were acute and one chronic. The isolated microorganisms were E. faecalis, S. epidermidis (2), S. mitis, S. aureus and P. stomatis. The incidence of prosthetic joint infection in the first year of follow-up at our centre is within the recommended parameters. Surgical techniques and organizational practices influence the results. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

Clinical characteristics, microbiology, and outcomes of prosthetic joint infection in Taiwan.

PubMed

Tsai, Jen-Chih; Sheng, Wang-Huei; Lo, Wan-Yu; Jiang, Ching-Chuan; Chang, Shan-Chwen

2015-04-01

Prosthetic joint infection (PJI) after total knee or hip replacement is a devastating complication associated with substantial morbidity and economic cost. The incidence of prosthetic joint infection is increasing as the use of mechanical joint replacement increases. The treatment approach to prosthetic joint infection is based on different clinical situations such as a patient's comorbidities, epidemic microbiology data, and surgical procedures. The aim of our study was to understand clinical characteristics of prosthetic joint infection, the microbiology of the prosthetic joint infection, and the outcomes of different treatment strategies during 2006-2011. We retrospectively collected cases of prosthetic joint infection in the National Taiwan University Hospital between January 1, 2006 and December 31, 2011. The patients' characteristics, microbiology, outcomes, and factors associated with treatment success were recorded. One hundred and forty-four patients were identified as having PJI. Of these, 92 patients were entered into per-protocol analysis. Staphylococcus aureus was the most common causative organism (29.9%), followed by coagulase-negative Staphylococci (16.7%), and Enterococci (9.7%). The overall treatment success rate was 50%. Patients who received a two-stage revision had a better outcome, compared to patients who underwent other types of surgeries (70% vs. 32.7%, respectively; p < 0.001). In multivariate analysis, the two-stage revision was significantly associated with treatment success (odds ratio = 3.923, 95% confidence interval = 1.53-10.04). Our study demonstrates that Staphylococcus aureus was the most common causative organisms in PJI. Performing two-stage revisions was significantly associated with a better outcome. Copyright © 2013. Published by Elsevier B.V.

Can We Achieve Intuitive Prosthetic Elbow Control Based on Healthy Upper Limb Motor Strategies?

PubMed Central

Merad, Manelle; de Montalivet, Étienne; Touillet, Amélie; Martinet, Noël; Roby-Brami, Agnès; Jarrassé, Nathanaël

2018-01-01

Most transhumeral amputees report that their prosthetic device lacks functionality, citing the control strategy as a major limitation. Indeed, they are required to control several degrees of freedom with muscle groups primarily used for elbow actuation. As a result, most of them choose to have a one-degree-of-freedom myoelectric hand for grasping objects, a myoelectric wrist for pronation/supination, and a body-powered elbow. Unlike healthy upper limb movements, the prosthetic elbow joint angle, adjusted prior to the motion, is not involved in the overall upper limb movements, causing the rest of the body to compensate for the lack of mobility of the prosthesis. A promising solution to improve upper limb prosthesis control exploits the residual limb mobility: like in healthy movements, shoulder and prosthetic elbow motions are coupled using inter-joint coordination models. The present study aims to test this approach. A transhumeral amputated individual used a prosthesis with a residual limb motion-driven elbow to point at targets. The prosthetic elbow motion was derived from IMU-based shoulder measurements and a generic model of inter-joint coordinations built from healthy individuals data. For comparison, the participant also performed the task while the prosthetic elbow was implemented with his own myoelectric control strategy. The results show that although the transhumeral amputated participant achieved the pointing task with a better precision when the elbow was myoelectrically-controlled, he had to develop large compensatory trunk movements. Automatic elbow control reduced trunk displacements, and enabled a more natural body behavior with synchronous shoulder and elbow motions. However, due to socket impairments, the residual limb amplitudes were not as large as those of healthy shoulder movements. Therefore, this work also investigates if a control strategy whereby prosthetic joints are automatized according to healthy individuals' coordination models can lead to an intuitive and natural prosthetic control. PMID:29456499

Pre-prosthetic surgical alterations in maxillectomy to enhance the prosthetic prognoses as part of rehabilitation of oral cancer patient.

PubMed

El Fattah, H; Zaghloul, A; Pedemonte, E; Escuin, T

2012-03-01

After maxillectomy, prosthetic restoration of the resulting defect is an essential step because it signals the beginning of patient's rehabilitation. The obturator used to restore the defect should be comfortable, restore adequate speech, deglutition, mastication, and be cosmetically acceptable, success will depend on the size and location of the defect and the quantity and integrity of the remaining structures, in addition to pre-prosthetic surgical preparation of defect site. Preoperative cooperation between the oncologist surgeon and the maxillofacial surgeon may allow obturation of a resultant defect by preservation of the premaxilla or the tuberosity on the defect side and maintaining the alveolar bone or teeth adjacent to the defect. This study evaluates the importance of pre-prosthetic surgical alterations at the time maxillectomy on the enhancement of the prosthetic prognoses as part of the rehabilitation of oral cancer patient. The study was carried out between 2003- 2008, on 66 cancer patients(41 male-25 female) age ranged from 33 to 72 years, at National Cancer Institute, Cairo University, whom underwent maxillectomy surgery to remove malignant tumor as a part of cancer treatment. Patients were divided in two groups. Group A: Resection of maxilla followed by preprosthetic surgical preparation. Twenty-four cancer patients (13 male - 11 female). Group B: Resection of maxilla without any preprosthetic surgical preparation. Forty-two cancer patients (28 male-14 female). Outcome variables measured included facial contour and aesthetic results, speech understandability, ability to eat solid foods, oronasal separation, socializing outside the home, and return-to-work status. Flap success and donor site morbidity were also studied. To improve the prosthetic restoration of maxillary defect resulting maxillary resection as part treatment of maxillofacial tumor depends on the close cooperation between prosthodontist and surgeon, by combination of pre-prosthetic surgery during maxillectomy and prosthodontic technique.

Prosthetic joint infection caused by Pasteurella multocida: a case series and review of literature.

PubMed

Honnorat, Estelle; Seng, Piseth; Savini, Hélène; Pinelli, Pierre-Olivier; Simon, Fabrice; Stein, Andreas

2016-08-20

Pasteurella multocida is a well-recognized zoonotic agent following dog or cat bites or scratches. Nevertheless, prosthetic joint infection caused by P. multocida are rarely reported. We report here a series of six cases of prosthetic joint infection caused by P. multocida managed at a referral centre for the treatment of bone and joint infection in southern France. We also reviewed the 26 cases reported in literature. The mean age of our cases was 74 years [±8.2, range 63-85]. In majority of our cases (5 cases) were associated with knee prostheses and one case with a hip prosthesis. Most of cases occurred after cat or dog scratches or licks or contact. Diagnoses of prosthetic joint infection caused by P. multocida were made by positive cultures of surgical biopsies or needle aspiration. Mean time delay between prosthetic joint implantation and infection onset was 7.6 years (±5.12 years, range 2-17). Local inflammation, which occurred in all six cases, was the most frequent clinical symptom, followed by pain in five cases, fever and swollen joints in four cases, and a fistula with purulent discharge inside the wound in two cases. The mean time of antibiotic therapy was 8 months. Surgical treatment with prosthesis removal was performed in three cases. Six of our cases were in remission without apparent relapse at 3 years after end of treatment. Prosthetic joint infections caused by P. multocida usually occur after animal scratches or bites, but can occasionally occur after a short animal lick. These infections are usually resulting from a contiguous infection and localized in the knee. An early antibiotic therapy after surgical debridement could avoid prosthetic withdrawal, notably in elderly patients. Patients with prosthetic joints should be warned that animals are potential sources of serious infection and urgent medical advice should be sought if they are bitten or scratched.

Incremental benefit of 3D transesophageal echocardiography: a case of a mass overlying a prosthetic mitral valve.

PubMed

Tauras, James M; Zhang, Zhihang; Taub, Cynthia C

2011-05-01

A young woman with a mechanical mitral valve and prosthetic mitral stenosis underwent multiple imaging modalities (including transthoracic ECHO, fluoroscopy, and two-dimensional transesophageal ECHO) to determine the cause of her stenosis. Only three-dimensional transesophageal echocardiography demonstrated the full size and extent of an obstructing mass on the strut and sewing ring of the prosthetic mitral valve. © 2011, Wiley Periodicals, Inc.

The Effect of a Microprocessor Prosthetic Foot on Function and Quality of Life in Transtibial Amputees Who Are Limited Community Ambulators

DTIC Science & Technology

2017-09-01

parallel, randomized, controlled clinical trial designed to determine if a microprocessor controlled prosthetic foot (MPF), with greater range of...clinical trial designed to determine if a microprocessor controlled prosthetic foot (MPF), with greater range of motion and active power, will...Department of the Army position, policy or decision unless so designated by other documentation. CONTRACTING ORGANIZATION: University of Tennessee

24 DOF EMG controlled hybrid actuated prosthetic hand.

PubMed

Atasoy, A; Kaya, E; Toptas, E; Kuchimov, S; Kaplanoglu, E; Ozkan, M

2016-08-01

A complete mechanical design concept of an electromyogram (EMG) controlled hybrid prosthetic hand, with 24 degree of freedom (DOF) anthropomorphic structure is presented. Brushless DC motors along with Shape Memory Alloy (SMA) actuators are used to achieve dexterous functionality. An 8 channel EMG is used for detecting 7 basic hand gestures for control purposes. The prosthetic hand will be integrated with the Neural Network (NNE) based controller in the next phase of the study.

Management of Prosthetic Joint Infection.

PubMed

Tande, Aaron J; Gomez-Urena, Eric O; Berbari, Elie F; Osmon, Douglas R

2017-06-01

Although uncommon, prosthetic joint infection is a devastating complication. This challenging condition requires a coordinated management approach to achieve good patient outcomes. This review details the general principles to consider when managing patients with prosthetic joint infection. The different medical/surgical treatment strategies and how to appropriately select a strategy are discussed. The data to support each strategy are presented, along with discussion of antimicrobial strategies in specific situations. Copyright © 2017 Elsevier Inc. All rights reserved.

Optical 3D methods for measurement of prosthetic wear of total hip arthroplasty: principles, verification and results.

PubMed

Rossler, Tomas; Mandat, Dusan; Gallo, Jiri; Hrabovsky, Miroslav; Pochmon, Michal; Havranek, Vitezslav

2009-07-20

Total hip arthroplasty (THA) significantly improves the quality of life in majority of patients with severe osteoarthritis. However, long-term outcomes of THAs are compromised by aseptic loosening and periprosthetic osteolysis which needs revision surgery. Both of these are causally linked to a prosthetic wear deliberated from the prosthetic articulating surfaces. As a result, there is a need to measure the mode and magnitude of wear. The paper evaluates three optical methods proposed for construction of a device for the non-contact prosthetic wear measurement. Of them, the scanning profilometry achieved promising combination of accuracy and repeatability. Simultaneously, it is time efficient to enable the development of a sensor for wear measurement.

Capnocytophaga canimorsus: a rare case of conservatively treated prosthetic valve endocarditis.

PubMed

Jalava-Karvinen, Päivi; Grönroos, Juha O; Tuunanen, Helena; Kemppainen, Jukka; Oksi, Jarmo; Hohenthal, Ulla

2018-05-01

We describe a rare case of prosthetic valve endocarditis caused by the canine bacterium Capnocytophaga canimorsus in a male aged 73 years. The diagnosis of infective endocarditis was unequivocal, as it blood cultures were positive for C. canimorsus and vegetations were detected on transesophageal echocardiography; the modified Duke criteria were fulfilled. PET-CT showed intense 18 F-FDG uptake of the prosthetic valve area. The patient was treated with antibiotics alone (no surgery), and is now on life-long suppressive antibiotic therapy. To our knowledge, this is the third reported case of prosthetic valve endocarditis caused by C. canimorsus and the first one to have been treated conservatively. © 2018 APMIS. Published by John Wiley & Sons Ltd.

[Overlay prosthetic solution in subtotal edentation treatment].

PubMed

Tatarciuc, M; Ursache, M; Grădinaru, I

2001-01-01

The preservation of the natural dental roots represents a big advantage for the overdenture prosthetic appliances. The realization of an overdenture needs a perfect correlation of all the clinical and technological factors, in all the prosthetics steps. Another important aspect is represented by the possibility of a correct treatment of the remaining roots. The remaining roots will be correctly endodontically treated. The root section will be prepared with two inclines bucally and orally located. A metallic cup will cover the root section. On the inner surface of the overdenture the dental technician will realize specific preparations corresponding to this cups. This kind of prosthetic treatment is indicated only for patients with a very good oral hygiene and a good general health.

Prosthetic aortic valve endocarditis complicated with annular abscess, sub-aortic obstruction and valve dehiscence.

PubMed

Hassoulas, Joannis; Patrianakos, Alexandros P; Parthenakis, Fragiskos I; Vardas, Panos E

2009-01-01

We present a 76-year-old woman with infective endocarditis of a prosthetic aortic valve. The course of her illness started with an ischaemic stroke and she was admitted with prolonged fever and an episode of loss of consciousness. Echocardiography revealed acute aortic regurgitation and dehiscence of the prosthetic valve with excessive "rocking motion", aortic abscesses and left ventricular outflow obstruction caused by a semilunar shelf of tissue probably due to endocarditis vegetations. She underwent an urgent surgical procedure that confirmed the echocardiographic findings. Our case report reinforces the value of early diagnosis in the presence of a high clinical suspicion of prosthetic valve endocarditis. An extended workup, including transoesophageal echocardiography, in such a patient with a mechanical valve is mandatory.

Spatial asymmetry in tactile sensor skin deformation aids perception of edge orientation during haptic exploration.

PubMed

Ponce Wong, Ruben D; Hellman, Randall B; Santos, Veronica J

2014-01-01

Upper-limb amputees rely primarily on visual feedback when using their prostheses to interact with others or objects in their environment. A constant reliance upon visual feedback can be mentally exhausting and does not suffice for many activities when line-of-sight is unavailable. Upper-limb amputees could greatly benefit from the ability to perceive edges, one of the most salient features of 3D shape, through touch alone. We present an approach for estimating edge orientation with respect to an artificial fingertip through haptic exploration using a multimodal tactile sensor on a robot hand. Key parameters from the tactile signals for each of four exploratory procedures were used as inputs to a support vector regression model. Edge orientation angles ranging from -90 to 90 degrees were estimated with an 85-input model having an R (2) of 0.99 and RMS error of 5.08 degrees. Electrode impedance signals provided the most useful inputs by encoding spatially asymmetric skin deformation across the entire fingertip. Interestingly, sensor regions that were not in direct contact with the stimulus provided particularly useful information. Methods described here could pave the way for semi-autonomous capabilities in prosthetic or robotic hands during haptic exploration, especially when visual feedback is unavailable.

Looking beyond first-world problems: an emerging global workplace is encouraging more biomedical engineers to address the health issues of the developing world.

PubMed

Tucker, Lindsay

2014-01-01

Each year, the developed world is flooded with complex new medical technologies, from robotic prosthetics to remote-controlled aspirin implants. Meanwhile, only about 10% of health research funds are spent addressing the pressing problems of developing nations, although these countries make up 93% of the worldwide burden of disease. In short, while a small fraction of the world pops brand-name pharmaceuticals, the majority suffers from poor sanitation, contaminated drinking water, preventable disease, and child mortality.

Cervical lung hernia

PubMed Central

Lightwood, Robin G.; Cleland, W. P.

1974-01-01

Lightwood, R. G., and Cleland, W. P. (1974).Thorax, 29, 349-351. Cervical lung hernia. Lung hernias occur in the cervical position in about one third of cases. The remainder appear through the chest wall. Some lung hernias are congenital, but trauma is the most common cause. The indications for surgery depend upon the severity of symptoms. Repair by direct suture can be used for small tears in Sibson's (costovertebral) fascia while larger defects have been closed using prosthetic materials. Four patients with cervical lung hernia are described together with an account of their operations. PMID:4850946

Rehabilitation and Prosthetic Services

MedlinePlus

... VA Learning University (VALU) SimLearn Libraries (VALNET) VA Software Documentation Library (VDL) About VHA Learn about VHA Forms & ... & Sensory Aids Service (PSAS) Our Mission The mission of the Prosthetic & ...

Current antibiotic management of prosthetic joint infections in Italy: the 'Udine strategy'.

PubMed

Bassetti, Matteo; Cadeo, Barbara; Villa, Giovanni; Sartor, Assunta; Cainero, Vanni; Causero, Araldo

2014-09-01

The rate of prosthetic joint infections followed and cured at our institution is constantly increasing, in line with epidemiological data from the recent literature. This is probably related to the greater number of knee and hip prostheses implanted every year. For intermediate and late infections, only the two-stage approach is applied, as this demonstrates the best outcome in our experience. Particular attention is paid to microbiological isolation of the pathogen: multiple samples of tissue are collected during the interventions, and kept in culture for a longer period of time than usual. Sonication of prosthetic devices is used to enhance the sensitivity and specificity of the microbiological cultures. Histological examination influences surgical choices either towards implantation of a new prosthesis or replacement of the spacer. An empirical antibiotic backbone of a glycopeptide/lipopeptide and rifampicin is chosen, due to the leading role of Gram-positive bacteria in this setting and the high incidence of methicillin resistance in our centre (>30%), followed by an antibiotic regimen containing linezolid. If specific risk factors are present, an anti-Gram-negative drug is added to the regimen. Duration of therapy depends upon the approach that is chosen, usually being 6 weeks when the prosthesis is removed. Despite at the moment being limited by its small sample size, data from our experience confirms that our empirical approach may represent a valid choice during the early phase of treatment, by keeping linezolid for a step-down therapy of shorter duration (4 weeks). © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Brucella melitensis prosthetic joint infection in a traveller returning to the UK from Thailand: Case report and review of the literature.

PubMed

Lewis, Joseph M; Folb, Jonathan; Kalra, Sanjay; Squire, S Bertel; Taegtmeyer, Miriam; Beeching, Nick J

Brucella spp. prosthetic joint infections are infrequently reported in the literature, particularly in returning travellers, and optimal treatment is unknown. We describe a prosthetic joint infection (PJI) caused by Brucella melitensis in a traveller returning to the UK from Thailand, which we believe to be the first detailed report of brucellosis in a traveller returning from this area. The 23 patients with Brucella-related PJI reported in the literature are summarised, together with our case. The diagnosis of Brucella-related PJI is difficult to make; only 30% of blood cultures and 75% of joint aspiration cultures were positive in the reported cases. Culture of intraoperative samples provides the best diagnostic yield. In the absence of radiological evidence of joint loosening, combination antimicrobial therapy alone may be appropriate treatment in the first instance; this was successful in 6/7 [86%] of patients, though small numbers of patients and the likelihood of reporting bias warrant caution in drawing any firm conclusions about optimal treatment. Aerosolisation of synovial fluid during joint aspiration procedures and nosocomial infection has been described. Brucella-related PJI should be considered in the differential of travellers returning from endemic areas with PJI, including Thailand. Personal protective equipment including fit tested filtering face piece-3 (FFP3) mask or equivalent is recommended for personnel carrying out joint aspiration when brucellosis is suspected. Travellers can reduce the risk of brucellosis by avoiding unpasteurised dairy products and animal contact (particularly on farms and abattoirs) in endemic areas and should be counselled regarding these risks as part of their pre-travel assessment. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

The Effect of Preoperative Antimicrobial Prophylaxis on Intraoperative Culture Results in Patients with a Suspected or Confirmed Prosthetic Joint Infection: a Systematic Review.

PubMed

Wouthuyzen-Bakker, Marjan; Benito, Natividad; Soriano, Alex

2017-09-01

Obtaining reliable cultures during revision arthroplasty is important to adequately diagnose and treat a prosthetic joint infection (PJI). The influence of antimicrobial prophylaxis on culture results remains unclear. Since withholding prophylaxis increases the risk for surgical site infections, clarification on this topic is critical. A systematic review was performed with the following research question: in patients who undergo revision surgery of a prosthetic joint, does preoperative antimicrobial prophylaxis affect the culture yield of intraoperative samples in comparison with nonpreoperative antimicrobial prophylaxis? Seven articles were included in the final analysis. In most studies, standard diagnostic culture techniques were used. In patients with a PJI, pooled analysis showed a culture yield of 88% (145/165) in the prophylaxis group versus 95% (344/362) in the nonprophylaxis group ( P = 0.004). Subanalysis of patients with chronic PJIs showed positive cultures in 88% (78/89) versus 91% (52/57), respectively ( P = 0.59). In patients with a suspected chronic infection, a maximum difference of 4% in culture yield between the prophylaxis and nonprophylaxis groups was observed. With the use of standard culture techniques, antimicrobial prophylaxis seems to affect cultures in a minority of patients. Along with the known risk of surgical site infections due to inadequate timing of antimicrobial prophylaxis, we discourage the postponement of prophylaxis until tissue samples are obtained in revision surgery. Future studies are necessary to conclude whether the small percentage of false-negative cultures after prophylaxis can be further reduced with the use of more-sensitive culture techniques, like sonication. Copyright © 2017 American Society for Microbiology.

Effects of a 3D segmental prosthetic system for tricuspid valve annulus remodelling on the right coronary artery: a human cadaveric coronary angiography study.

PubMed

Riki-Marishani, Mohsen; Gholoobi, Arash; Sazegar, Ghasem; Aazami, Mathias H; Hedjazi, Aria; Sajjadian, Maryam; Ebrahimi, Mahmoud; Aghaii-Zade Torabi, Ahmad

2017-09-01

A prosthetic system to repair secondary tricuspid valve regurgitation was developed. The conceptual engineering of the current device is based on 3D segmental remodelling of the tricuspid valve annulus in lieu of reductive annuloplasty. This study was designed to investigate the operational safety of the current prosthetic system with regard to the anatomical integrity of the right coronary artery (RCA) in fresh cadaveric human hearts. During the study period, from January to April 2016, the current prosthetic system was implanted on the tricuspid valve annulus in fresh cadaveric human hearts that met the study's inclusion criteria. The prepared specimens were investigated via selective coronary angiography of the RCA in the catheterization laboratory. The RCA angiographic anatomies were categorized as normal, distorted, kinked or occluded. Sixteen specimens underwent implantation of the current prosthetic system. The mean age of the cadaveric human hearts was 43.24 ± 15.79 years, with vehicle accident being the primary cause of death (59%). A dominant RCA was noticed in 62.5% of the specimens. None of the specimens displayed any injury, distortion, kinking or occlusion in the RCA due to the implantation of the prostheses. In light of the results of the present study, undertaken on fresh cadaveric human heart specimens, the current segmental prosthetic system for 3D remodelling of the tricuspid valve annulus seems to be safe vis-à-vis the anatomical integrity of the RCA. Further in vivo studies are needed to investigate the functional features of the current prosthetic system with a view to addressing the complex pathophysiology of secondary tricuspid valve regurgitation. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

The use of a direct manufacturing prosthetic socket system in a rural community in South Africa: A pilot study and lessons for future research.

PubMed

Ennion, Liezel; Johannesson, Anton; Rhoda, Anthea

2017-10-01

Challenges exist with the provision of appropriate mobility assistive devices in rural areas. The use of the direct manufacturing prosthetic socket system is a possible solution to these challenges. The objective of this study was to test and explore the clients' perspectives with the application of this device. Within a mixed-methods approach, a longitudinal sequential explanatory design was applied. The Orthotic and Prosthetic User's Survey was administered to explore the use of the direct manufacturing prosthetic socket system in terms of function, health-related quality of life and client satisfaction. A conveniently selected sample of 21 individuals who suffered a unilateral trans-tibial amputation was included. Data were collected at 1, 3 and 6 months post fitting, and two focus group discussions were also administered. Of the 21 participants recruited, 11 returned for follow up. Although participants reported favourably about the prosthesis, their scores were generally worse than the norms with regard to function and quality of life. Participants highlighted the need for improvement in the cosmetic appearance of the prosthesis. The direct manufacturing prosthetic socket system could be considered as an alternative technique of socket manufacturing for individuals living in rural areas due to the shorter manufacture time and promising initial results, but further research on this topic with a bigger sample is recommended. Clinical relevance The direct manufacturing prosthetic socket system may be considered as an alternative to the traditional prosthetic socket manufacturing technique used in South Africa. As this device requires only one visit and therefore decreased travel by the patients to the hospitals, it could be applicable to more amputees who cannot return to hospital post discharge.

Pilot Study on the Influence of Nutritional Counselling and Implant Therapy on the Nutritional Status in Dentally Compromised Patients

PubMed Central

Wöstmann, Bernd; Simon, Teresa; Neuhäuser-Berthold, Monika; Rehmann, Peter

2016-01-01

Objectives To investigate the impact of implant-prosthetic rehabilitation combined with nutritional counseling on the nutritional status of patients with severely reduced dentitions. Design An explorative intervention study including an intra-individual comparison of 20 patients with severely reduced dentitions in terms of nutrition- and quality of life-related parameters recorded at baseline and at six and twelve months after implant-prosthetic rehabilitation. Participants Twenty patients from the Department of Prosthetic Dentistry of Justus-Liebig University of Giessen, with an mean age of 63 years, who had fewer than ten pairs of antagonists. Measurements The baseline data collection included dental status, a chewing ability test, laboratory parameters, anthropometric data (body mass index), energy supply, a 3-day dietary record, an analysis of the oral health-related quality of life (OHRQoL) with the OHIP-G14, the Mini-Mental Status (MMS) and Mini Nutritional Assessment (MNA). Six months after implantation and prosthetic rehabilitation, individual nutritional counseling was performed by a dietician. Data were again collected and analyzed. A final follow-up was conducted 12 months after prosthetic rehabilitation. Results Despite the highly significant improvement in masticatory ability and OHRQoL after implant-prosthetic rehabilitation, no significant changes were observed regarding MNA, anthropometric data or energy supply. Except for cholinesterase (p = 0.012), ferritin (p = 0.003), folic acid (p = 0.019) and vitamin A (p = 0.004), no laboratory parameter changed significantly during the investigation period. In addition, no general significant differences were observed for nutrient intake or food choice. Conclusion The present study does not confirm the assumption that the implant-prosthetic rehabilitation of patients with severely reduced residual dentitions with or without an individual nutritional counseling influences nutritional status. PMID:26821352

Pilot Study on the Influence of Nutritional Counselling and Implant Therapy on the Nutritional Status in Dentally Compromised Patients.

PubMed

Wöstmann, Bernd; Simon, Teresa; Neuhäuser-Berthold, Monika; Rehmann, Peter

2016-01-01

To investigate the impact of implant-prosthetic rehabilitation combined with nutritional counseling on the nutritional status of patients with severely reduced dentitions. An explorative intervention study including an intra-individual comparison of 20 patients with severely reduced dentitions in terms of nutrition- and quality of life-related parameters recorded at baseline and at six and twelve months after implant-prosthetic rehabilitation. Twenty patients from the Department of Prosthetic Dentistry of Justus-Liebig University of Giessen, with an mean age of 63 years, who had fewer than ten pairs of antagonists. The baseline data collection included dental status, a chewing ability test, laboratory parameters, anthropometric data (body mass index), energy supply, a 3-day dietary record, an analysis of the oral health-related quality of life (OHRQoL) with the OHIP-G14, the Mini-Mental Status (MMS) and Mini Nutritional Assessment (MNA). Six months after implantation and prosthetic rehabilitation, individual nutritional counseling was performed by a dietician. Data were again collected and analyzed. A final follow-up was conducted 12 months after prosthetic rehabilitation. Despite the highly significant improvement in masticatory ability and OHRQoL after implant-prosthetic rehabilitation, no significant changes were observed regarding MNA, anthropometric data or energy supply. Except for cholinesterase (p = 0.012), ferritin (p = 0.003), folic acid (p = 0.019) and vitamin A (p = 0.004), no laboratory parameter changed significantly during the investigation period. In addition, no general significant differences were observed for nutrient intake or food choice. The present study does not confirm the assumption that the implant-prosthetic rehabilitation of patients with severely reduced residual dentitions with or without an individual nutritional counseling influences nutritional status.

Prosthetists' and Orthotists' experience of their work and workspace - characterising the physical and organisational environment: Focus group findings.

PubMed

Anderson, Sarah; Stuckey, Rwth; Oakman, Jodi R

2016-12-01

Little research has been undertaken into occupational health and safety in the Prosthetics and Orthotics profession. To identify physical, psychosocial and environmental workplace experiences of Prosthetists and Orthotists in organisational settings. Qualitative methodology, cross-sectional design, using thematically analysed data collected from focus groups. Focus groups explored workplace and work experiences across varied Prosthetic and Orthotic settings. Data were thematically analysed to identify physical, psychosocial and environmental workplace experiences. Three major themes, Demands of Work Practice, Impacts on the Individual and Job Design, were identified as problematic. A latent theme Perceptions of Others of P&O highlighted a lack of understanding of the Prosthetics and Orthotics job role outside the profession. This first study of occupational health and safety in the Prosthetics and Orthotics profession identifies a number of important physical and psychosocial issues, including characteristics that have been previously identified as risk factors for work-related musculoskeletal disorders. Findings from the study indicate that some Australian organisations lack understanding of the Prosthetics and Orthotics job role, which results in inappropriate expectations of Prosthetics and Orthotics professionals. Preventing injuries and retaining experienced Prosthetists and Orthotists in the workplace is vital for the profession, and as a result, issues raised in this study require further exploration and then development of appropriate management strategies. This is the first study characterising the experiences of work and risk of injuries in Prosthetists and Orthotists. Preventing injuries and retaining experienced Prosthetists and Orthotists in the workplace is vital for the international profession. Issues raised in this study require further exploration and then development of appropriate management strategies. © The International Society for Prosthetics and Orthotics 2015.

Oral health-related quality of life after prosthetic rehabilitation in patients with oral cancer: A longitudinal study with the Liverpool Oral Rehabilitation Questionnaire version 3 and Oral Health Impact Profile-14 questionnaire.

PubMed

Dholam, K P; Chouksey, G C; Dugad, J

2016-01-01

Prosthodontic rehabilitation helps to improve the oral health-related quality of life (OHRQOL). The Liverpool Oral Rehabilitation Questionnaire (LORQ) and Oral Health Impact Profile (OHIP) are specific tools that measure OHRQOL. The primary objective of this study was to assess the impact of oral rehabilitation on patients' OHRQOL following treatment for cancer of oral cavity using LORQ version 3 (LORQv3) and OHIP-14 questionnaire. Secondary objectives were to identify issues specific to oral rehabilitation, patients compliance to prosthetic rehabilitation, the effect of radiation treatment on prosthetic rehabilitation, to achieve meaningful differences over a time before & after prosthetic intervention, to carryout and document specific patient-deprived problem. Seventy-five oral cancer patients were studied. Patients were asked to rate their experience of dental problems before fabrication of prosthesis and after 1 year using LORQv3 and OHIP-14. The responses were compared on Likert scale. Patients reported with extreme problems before rehabilitation. After 1 year of prosthetic rehabilitation, there was improvement noticed in all the domain of LORQv3 and OHIP-14. Complete compliance to the use of prosthetic appliances for 1 year study period was noted. In response to the question no. 40 (LORQv3), only 15 patients who belonged to the obturator group, brought to notice the problems which were not addressed in the LORQv3 questionnaire. The study showed that the oral cancer patients coped well and adapted to near normal oral status after prosthetic rehabilitation. This contributed to the improved overall health-related quality of life.

Increased risk of prosthetic joint infection associated with esophago-gastro-duodenoscopy with biopsy.

PubMed

Coelho-Prabhu, Nayantara; Oxentenko, Amy S; Osmon, Douglas R; Baron, Todd H; Hanssen, Arlen D; Wilson, Walter R; Steckelberg, James M; Baddour, Larry M; Harmsen, William S; Mandrekar, Jay; Berbari, Elie F

2013-02-01

There are no prospective data regarding the risk of prosthetic joint infection following routine gastrointestinal endoscopic procedures. We wanted to determine the risk of prosthetic hip or knee infection following gastrointestinal endoscopic procedures in patients with joint arthroplasty. We conducted a prospective, single-center, case-control study at a single, tertiary-care referral center. Cases were defined as adult patients hospitalized for prosthetic joint infection of the hip or knee between December 1, 2001 and May 31, 2006. Controls were adult patients with hip or knee arthroplasties but without a diagnosis of joint infection, hospitalized during the same time period at the same orthopedic hospital. The main outcome measure was the odds ratio (OR) of prosthetic joint infection after gastrointestinal endoscopic procedures performed within 2 years before admission. 339 cases and 339 controls were included in the study. Of these, 70 cases (21%) cases and 82 controls (24%) had undergone a gastrointestinal endoscopic procedure in the preceding 2 years. Among gastrointestinal procedures that were assessed, esophago-gastro-duodenoscopy (EGD) with biopsy was associated with an increased risk of prosthetic joint infection (OR = 3, 95% CI: 1.1-7). In a multivariable analysis adjusting for sex, age, joint age, immunosuppression, BMI, presence of wound drain, prior arthroplasty, malignancy, ASA score, and prothrombin time, the OR for infection after EGD with biopsy was 4 (95% CI: 1.5-10). EGD with biopsy was associated with an increased risk of prosthetic joint infection in patients with hip or knee arthroplasties. This association will need to be confirmed in other epidemiological studies and adequately powered prospective clinical trials prior to recommending antibiotic prophylaxis in these patients.

Contact dermatitis to cobalt chloride with an unusual mechanism.

PubMed

Arslan, Sevket; Aksan, Serkan; Ucar, Ramazan; Caliskaner, Ahmet Zafer

2015-10-01

Contact dermatitis is a frequent inflammatory skin disease. A suspected diagnosis is based on clinical symptoms, a plausible contact to allergens and a suitable history of dermatitis. Therefore, careful diagnosis by patch testing is of great importance because the patch testing is important to find out which allergen/material causes the complaints. Metallic allergens such as cobalt are among the most common causes of allergic contact dermatitis, but frequencies of contact dermatitis to these allergens may vary in different skin areas. Here, we report an unusual case of cobalt allergy on the skin contact with the prosthetic leg of a 30-year-old female patient. The patient developed maculopapular and vesicular lesions on her contact region of residual limb to prosthetic leg. She underwent standard patch testing, which resulted in a strong positive reaction to cobalt chloride. This case report may serve to remind doctors to be aware of potential allergic reactions to prostheses and to enable them to recognize a metal allergy if it appears. Prosthetists should also be reminded of potential allergic reactions. Cobalt can be used as an accelerator in making a prosthetic socket. Several cases have been reported concerning allergies to components of the prosthetic socket. This is the first report of sensitization to cobalt which is used in making a prosthetic leg. © The International Society for Prosthetics and Orthotics 2014.

[The incidence and prevalence of complications after urogynaecological and reconstructive pelvic floor prosthetic surgery and management of these complications in women].

PubMed

Martan, A; Svabík, K; Masata, J

2007-12-01

The aim of this article is to review the incidence and prevalence of complications after prosthetic surgery for POP (pelvic organ prolaps) and USI (urodynamic stress incontinence) and to introduce diagnostic and therapeutic advice into clinical practice. Review article. Gynecological and Obstetric Clinic, 1st LF UK and VFN, Prague. Summary of complications, recent findings, opinions and specific diagnostic and therapeutic recommendations with special focus to vaginal erosion, post-operative voiding difficulties, persisting leakage of urine and de novo urgency. In the last decade the surgical treatment of female USI by prosthetic slings procedures has been shown to be effective with high cure rate and low morbidity. Similary, prosthetic reconstruction of pelvic organ prolapse through the different compartments has been introduced into clinical practice with good anatomical and promising functional results. The article is structured to the different sections, describing the epidemiology and management of complications after prosthetic slings procedures and after vaginal prosthetic treatment of pelvic organ prolapse. The effect of various operations of pelvic floor and USI using synthetic implants may differ, depending on the material of the implant used. Current recommendation for the implants material: a light-weight, flexible polypropylene; Amid's classification: type 1, i.e macro-porous, monofilament material. The advantage of surgical treatment of pelvic floor defect using implants comprises a low percentage of recurrence of the descensus.

Bionic hand exoprosthesis – Perspectives for the future in Romania

PubMed Central

Pogarasteanu, ME; Barbilian, AG

2014-01-01

Prosthetics is a modern area of interest and a challenge in Orthopedics. Over time, there has been a transition from an artisanal method of prosthetics production to modern concepts and materials, including a re-education through virtual reality. The conditions for an efficient fitting of a prosthesis include the necessity that the prosthesis respects the form and function of the lost limb, both anatomically and biomechanically. Prosthetics are made individually, personalized according to sex, age, physiological characteristics, profession and preference. In our country, thoracic limb prosthetics has a relatively short-recorded history of approximately a century, the most preeminent centers being in Iasi, Cluj and Bucharest. Currently, thoracic limb prosthetics, and particularly hand prosthetics, are in a period of development. A technique for amputation and stump reamputation called “circumferential osteoneuromioplasty” (CONM) is currently being used in the Orthopedics and Trauma Clinic of the Central Military University Emergency Hospital in Bucharest. The method was created with the purpose of obtaining distinct myoelectric signals of better quality, following the contraction of each muscle. The CONM method can be used in conjuncture with both the new hand prostheses that are currently available in Romania, and with the model that is being developed by a mixed team from the Polytechnic University in Bucharest, in collaboration with the Central Military University Emergency Hospital in Bucharest. PMID:25713630

The Effects of the Inertial Properties of Above-Knee Prostheses on Optimal Stiffness, Damping, and Engagement Parameters of Passive Prosthetic Knees.

PubMed

Narang, Yashraj S; Murthy Arelekatti, V N; Winter, Amos G

2016-12-01

Our research aims to design low-cost, high-performance, passive prosthetic knees for developing countries. In this study, we determine optimal stiffness, damping, and engagement parameters for a low-cost, passive prosthetic knee that consists of simple mechanical elements and may enable users to walk with the normative kinematics of able-bodied humans. Knee joint power was analyzed to divide gait into energy-based phases and select mechanical components for each phase. The behavior of each component was described with a polynomial function, and the coefficients and polynomial order of each function were optimized to reproduce the knee moments required for normative kinematics of able-bodied humans. Sensitivity of coefficients to prosthesis mass was also investigated. The knee moments required for prosthesis users to walk with able-bodied normative kinematics were accurately reproduced with a mechanical system consisting of a linear spring, two constant-friction dampers, and three clutches (R2=0.90 for a typical prosthetic leg). Alterations in upper leg, lower leg, and foot mass had a large influence on optimal coefficients, changing damping coefficients by up to 180%. Critical results are reported through parametric illustrations that can be used by designers of prostheses to select optimal components for a prosthetic knee based on the inertial properties of the amputee and his or her prosthetic leg.

Treatment Challenges of Prosthetic Hip Infection with Associated Iliacus Muscle Abscess: Report of 5 Cases and Literature Review.

PubMed

Lawrenz, Joshua M; Mesko, Nathan W; Higuera, Carlos A; Molloy, Robert M; Simpfendorfer, Claus; Babic, Maja

2017-01-01

Prosthetic joint infection is an unfortunate though well-recognized complication of total joint arthroplasty. An iliacus and/or iliopsoas muscle abscess is a rarely documented presentation of hip prosthetic joint infection. It is thought an unrecognized retroperitoneal nidus of infection can be a source of continual seeding of the prosthetic hip joint, prolonging attempts to eradicate infection despite aggressive debridement and explant attempts. The current study presents five cases demonstrating this clinical scenario, and discusses various treatment challenges. In each case we report the patient's clinical history, pertinent imaging, management and outcome. Diagnosis of the iliacus muscle abscess was made using computed tomography imaging. In brief, the mean number of total drainage procedures (open and percutaneous) per patient was 4.2, and outcomes consisted of one patient with a hip girdlestone, two patients with delayed revisions, and two patients with retained prosthesis. All patients ended with functional pain and on oral antibiotic suppression with an average follow up of 18 months. This article highlights an iliacus muscle abscess as an unrecognized source of infection to a prosthetic hip. It demonstrates resilience to standard treatment protocols for prosthetic hip infection, and is associated with poor patient outcomes. Aggressive surgical debridement appears to remain critical to treatment success, and early retroperitoneal debridement of the abscess should be considered.

Optical fiber Bragg grating-instrumented silicone liner for interface pressure measurement within prosthetic sockets of lower-limb amputees

NASA Astrophysics Data System (ADS)

Al-Fakih, Ebrahim; Arifin, Nooranida; Pirouzi, Gholamhossein; Mahamd Adikan, Faisal Rafiq; Shasmin, Hanie Nadia; Abu Osman, Noor Azuan

2017-08-01

This paper presents a fiber Bragg grating (FBG)-instrumented prosthetic silicone liner that provides cushioning for the residual limb and can successfully measure interface pressures inside prosthetic sockets of lower-limb amputees in a simple and practical means of sensing. The liner is made of two silicone layers between which 12 FBG sensors were embedded at locations of clinical interest. The sensors were then calibrated using a custom calibration platform that mimics a real-life situation. Afterward, a custom gait simulating machine was built to test the liner performance during an amputee's simulated gait. To validate the findings, the results were compared to those obtained by the commonly used F-socket mats. As the statistical findings reveal, both pressure mapping methods measured the interface pressure in a consistent way, with no significant difference (P-values ≥0.05). This pressure mapping technique in the form of a prosthetic liner will allow prosthetics professionals to quickly and accurately create an overall picture of the interface pressure distribution inside sockets in research and clinical settings, thereby improving the socket fit and amputee's satisfaction.

The Effect of the Prosthetic Group on the Pharmacologic Properties of 18F-labeled Rhodamine B, a Potential Myocardial Perfusion Agent for PET

PubMed Central

Bartholomä, Mark D.; Gottumukkala, Vijay; Zhang, Shaohui; Baker, Amanda; Dunning, Patricia; Fahey, Frederic H.; Treves, S. Ted; Packard, Alan B.

2013-01-01

We recently reported the development of the 2-[18F]fluoroethyl ester of rhodamine B as a potential positron emission tomography (PET) tracer for myocardial perfusion imaging. This compound, which was prepared using a [18F]fluoroethyl prosthetic group, has significant uptake in the myocardium in rats, but also demonstrates relatively high liver uptake and is rapidly hydrolyzed in vivo in mice. We have now prepared 18F-labeled rhodamine B using three additional prosthetic groups (propyl, diethylene glycol, and triethylene glycol) and found that the prosthetic group has a significant effect on the in vitro and in vivo properties of these compounds. Of the esters prepared to date, the diethylene glycol ester is superior in terms of in vitro stability and pharmacokinetics. These observations suggest that the prosthetic group plays a significant role in determining the pharmacological properties of 18F-labeled compounds. They also support the value of continued investigation of 18F-labeled rhodamines as PET radiopharmaceuticals for myocardial perfusion imaging. PMID:23210516

Effect of the prosthetic group on the pharmacologic properties of 18F-labeled rhodamine B, a potential myocardial perfusion agent for positron emission tomography (PET).

PubMed

Bartholomä, Mark D; Gottumukkala, Vijay; Zhang, Shaohui; Baker, Amanda; Dunning, Patricia; Fahey, Frederic H; Treves, S Ted; Packard, Alan B

2012-12-27

We recently reported the development of the 2-[(18)F]fluoroethyl ester of rhodamine B as a potential positron emission tomography (PET) tracer for myocardial perfusion imaging. This compound, which was prepared using a [(18)F]fluoroethyl prosthetic group, has significant uptake in the myocardium in rats but also demonstrates relatively high liver uptake and is rapidly hydrolyzed in vivo in mice. We have now prepared (18)F-labeled rhodamine B using three additional prosthetic groups (propyl, diethylene glycol, and triethylene glycol) and found that the prosthetic group has a significant effect on the in vitro and in vivo properties of these compounds. Of the esters prepared to date, the diethylene glycol ester is superior in terms of in vitro stability and pharmacokinetics. These observations suggest that the prosthetic group plays a significant role in determining the pharmacological properties of (18)F-labeled compounds. They also support the value of continued investigation of (18)F-labeled rhodamines as PET radiopharmaceuticals for myocardial perfusion imaging.

Assessment of adhesion formation to intra-abdominal polypropylene mesh and polytetrafluoroethylene mesh.

PubMed

Matthews, Brent D; Pratt, Broc L; Pollinger, Harrison S; Backus, Charles L; Kercher, Kent W; Sing, R F; Heniford, B Todd

2003-10-01

The development of intra-abdominal adhesions, bowel obstruction, and enterocutaneous fistulas are potentially severe complications related to the intraperitoneal placement of prosthetic biomaterials. The purpose of this study was to determine the natural history of adhesion formation to polypropylene mesh and two types of polytetrafluoroethylene (ePTFE) mesh when placed intraperitoneally in a rabbit model that simulates laparoscopic ventral hernia repair. Thirty New Zealand white rabbits were used for this study. A 10-cm midline incision was performed for intra-abdominal access and a 2 cm x 2 cm piece of mesh (n = 60) was sewn to an intact peritoneum on each side of the midline. Two types of ePTFE mesh (Dual Mesh and modified Dual Mesh, W.L. Gore & Assoc., Flagstaff, AZ) and polypropylene mesh were compared. The rate of adhesion formation was evaluated by direct visualization using microlaparoscopy (2-mm endoscope/trocar) at 7 days, 3 weeks, 9 weeks, and 16 weeks after mesh implantation. Adhesions to the prosthetic mesh were scored for extent (%) using the Modified Diamond Scale (0 = 0%, 1 50%). At necropsy the mesh was excised en bloc with the anterior abdominal wall for histological evaluation of mesothelial layer growth. The mean adhesion score for the polypropylene mesh was significantly greater (P < 0.05) than Dual Mesh at 9 weeks and 16 weeks and modified Dual Mesh at 7 days, 9 weeks, and 16 weeks. Fifty-five percent (n = 11) of the polypropylene mesh had adhesions to small intestine or omentum at necropsy compared to 30% (n = 6) of the Dual Mesh and 20% (n = 4) of the modified Dual Mesh. There was a significantly greater percentage (P < 0.003) of ePTFE mesh mesothelialized at explant (modified Dual Mesh 44.2%; Dual Mesh 55.8%) compared to the polypropylene mesh (12.9%). Serial microlaparoscopic evaluation of intraperitoneally implanted polypropylene mesh and ePTFE mesh in a rabbit model revealed a progression of adhesions to polypropylene mesh over a 16 week period. The pore size of mesh is critical in the development and maintenance of abdominal adhesions and tissue ingrowth. The macroporous polypropylene mesh promoted adhesion formation, while the microporous nature of the visceral side of the ePTFE served as a barrier to adhesions.

Prosthetic Engineering

MedlinePlus

... torque adapter in the pylons of transtibial amputees. Energy Storage & Release Many ambulatory lower limb amputees exhibit ... Future Directions Current Project Summaries Development of Controlled Energy Storage and Release Prosthetic Foot Development of Inverting- ...

Enterococcus faecalis Endogenous Endophthalmitis from Valvular Endocarditis

PubMed Central

Barge, Sidnei; Rothwell, Renata; Varandas, Rosário; Agrelos, Luís

2013-01-01

We report a case of a 74-year-old female, with a mitral heart valve, who presented with pain and blurred vision in the right eye for 2 days. Her visual acuity was light perception (LP) in the right eye and 20/40 in the left eye. Slit lamp examination showed corneal edema and hypopyon, and a view of the right fundus was impossible. Echography showed vitreous condensation. One day after presentation, the patient developed acute lung edema requiring hospitalization, so she was not submitted to vitreous tap and intravitreal treatment. The cardiac and systemic evaluations revealed a mitral endocarditis secondary to Enterococcus faecalis. The patient improved systemically with treatment with gentamicin, vancomycin, and linezolid. Her visual acuity remained as no LP, and her intraocular pressure (IOP) has been controlled with brimonidine bid despite developing a total cataract with 360° posterior synechia. A cardiac source for endogenous endophthalmitis should be considered in the presence of a prosthetic cardiac valve. The treatment and followup must be made in cooperation with a cardiologist specialist, but the ophthalmologist can play a key role in the diagnosis. PMID:23936701

A review of extra-articular prosthetic stabilization of the cranial cruciate ligament-deficient stifle.

PubMed

Tonks, C A; Lewis, D D; Pozzi, A

2011-01-01

Extra-articular prosthetic stabilization techniques have been used as a method of stabilization of the cranial cruciate ligament (CrCL)-deficient stifle for decades. During extra-articular prosthetic stabilization, the prosthesis is anchored to the femur and tibia, and tensioned in the attempt to resolve femorotibial instability. The position of the anchor points of the prosthesis is crucial for restoring a normal range of joint motion and mitigating alterations in prosthesis tension during motion. Recently developed techniques offer several innovations with potential advantages such as bone-to-bone fixation, prosthetic materials with better mechanical properties, and improved isometry of the anchor points. Whether these innovations provide clinically superior results to the traditional techniques such as lateral circumfabellar-tibial suture techniques has yet to be determined.

[Localized purpura revealing vascular prosthetic graft infection].

PubMed

Boureau, A S; Lescalie, F; Cassagnau, E; Clairand, R; Connault, J

2013-07-01

Prosthetic graft infection after vascular reconstruction is a rare but serious complication. We report a case of infection occurring late after implantation of an iliofemoral prosthetic vascular graft. The Staphylococcus aureus infection was revealed by vascular purpura localized on the right leg 7 years after implantation of a vascular prosthesis. This case illustrates an uncommonly late clinical manifestation presenting as an acute infection 7 years after the primary operation. In this situation, the presentation differs from early infection, which generally occurs within the first four postoperative months. Diagnosis and treatment remain a difficult challenge because prosthetic graft infection is a potentially life-threatening complication. Morbidity and mortality rates are high. Here we detail specific aspects of the clinical and radiological presentation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Toward more versatile and intuitive cortical brain machine interfaces

PubMed Central

Andersen, Richard A.; Kellis, Spencer; Klaes, Christian; Aflalo, Tyson

2015-01-01

Brain machine interfaces have great potential in neuroprosthetic applications to assist patients with brain injury and neurodegenerative diseases. One type of BMI is a cortical motor prosthetic which is used to assist paralyzed subjects. Motor prosthetics to date have typically used the motor cortex as a source of neural signals for controlling external devices. The review will focus on several new topics in the arena of cortical prosthetics. These include using 1) recordings from cortical areas outside motor cortex; 2) local field potentials (LFPs) as a source of recorded signals; 3) somatosensory feedback for more dexterous control of robotics; and 4) new decoding methods that work in concert to form an ecology of decode algorithms. These new advances hold promise in greatly accelerating the applicability and ease of operation of motor prosthetics. PMID:25247368

Amputation and Prosthetics

MedlinePlus

... Extremity Prosthetics Find a hand surgeon near you. Videos Figures Figure 1: Thumb Prosthesis - not attached Figure ... or "in." Also, avoid using media types like "video," "article," and "picture." Tip 4: Your results can ...

Applying Space Technology to Enhance Control of an Artificial Arm for Children and Adults With Amputations

NASA Technical Reports Server (NTRS)

Atkins, Diane J.

1998-01-01

The first single function myoelectric prosthetic hand was introduced in the 1960's. This hand was controlled by the electric fields generated by muscle contractions in the residual limb of the amputee user. Electrodes and amplifiers, embedded in the prosthetic socket, measured these electric fields across the skin, which increase in amplitude as the individual contracts their muscle. When the myoelectric signal reached a certain threshold amplitude, the control unit activated a motor which opened or closed a hand-like prosthetic terminal device with a pincher grip. Late in the 1990's, little has changed. Most current myoelectric prostheses still operate in this same, single-function way. To better understand the limitations of the current single-function myoelectric hand and the needs of those who use them, The Institute for Rehabilitation and Research (TIRR), sponsored by the National Institutes of Health (NUH), surveyed approximately 2,500 individuals with upper limb loss [1]. When asked to identify specific features of their current myoelectric prostheses that needed improvement, the survey respondents overwhelmingly identified the lack of wrist and finger movement, as well as poor control capability. However, simply building a mechanism with individual finger and wrist motion is not enough. In the 1960's and 1970's, engineers built a number of more dexterous prosthetic hands. Unfortunately, these were rejected during clinical trials due to a difficult and distracting control interface. The goal of this project, "Applying Space Technology to Enhance Control of an Artificial Arm for Children and Adults with Amputations," was to lay the foundation for a multi-function, intuitive myoelectric control system which requires no conscious thought to move the hand. We built an extensive myoelectric signal database for six motions from ten amputee volunteers, We also tested a control system based on new artificial intelligence techniques on the data from two of these subjects. This data is available to anyone doing myoelectric control research. Its availability is an important contribution to the prosthetics research community, as many researchers do not have access to amputee subjects. Since we collected myoelectric data from subjects' sound arms as well as their residual arms, this database will also prove useful to virtual reality and robotics researchers who want to explore myoelectric-based interfaces between any user and a machine. Currently, one small company (Intelligenta, Inc.) and one university (University of New Brunswick, Canada) are using this myoelectric database under other funding to develop multifunction control systems for prostheses. A prosthetics manufacturer (Liberty Technology, Inc.) is making plans to incorporate the results of their work into an artificial hand capable of several different movements to provide functionality only dreamed of by current myoelectric users. Methods Six adults and four children, all with unilateral, below-elbow amputations served as subjects. Five of the adults (3 male, 2 female, average age 34 years) had amputations due to traumatic injury, while one adult (female, age 32 years) and the four children (3 male, 1 female, average age 13 years) had congenital (i.e. from birth) limb deficiencies.

Rotational joint assembly for the prosthetic leg

NASA Technical Reports Server (NTRS)

Owens, L. J.; Jones, W. C. (Inventor)

1977-01-01

A rotational joint assembly for a prosthetic leg has been devised, which enables an artificial foot to rotate slightly when a person is walking, running or turning. The prosthetic leg includes upper and lower tubular members with the rotational joint assembly interposed between them. The assembly includes a restrainer mechanism which consists of a pivotably mounted paddle element. This device applies limiting force to control the rotation of the foot and also restores torque to return the foot back to its initial position.

A radiograph positioning technique to evaluate prosthetic misfit and bone loss around implants.

PubMed

Lin, Kevin C; Wadhwani, Chandur P K; Sharma, Arun; Finzen, Frederick

2014-02-01

A radiograph positioning device was developed to fit with commercially available film holders and implant systems. The device is indexed to the dental implant body and the adjacent dentition by using an implant placement driver and polyvinyl siloxane occlusal registration material. By fitting the device to a conventional film holder, accurate orthogonal radiographs can monitor changes in bone architecture and prosthetic misfit. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

A novel vacuum assisted closure therapy model for use with percutaneous devices.

PubMed

Cook, Saranne J; Nichols, Francesca R; Brunker, Lucille B; Bachus, Kent N

2014-06-01

Long-term maintenance of a dermal barrier around a percutaneous prosthetic device remains a common clinical problem. A technique known as Negative Pressure Wound Therapy (NPWT) uses negative pressure to facilitate healing of impaired and complex soft tissue wounds. However, the combination of using negative pressure with percutaneous prosthetic devices has not been investigated. The goal of this study was to develop a methodology to apply negative pressure to the tissues surrounding a percutaneous device in an animal model; no tissue healing outcomes are presented. Specifically, four hairless rats received percutaneous porous coated titanium devices implanted on the dorsum and were bandaged with a semi occlusive film dressing. Two of these animals received NPWT; two animals received no NPWT and served as baseline controls. Over a 28-day period, both the number of dressing changes required between the two groups as well as the pressures were monitored. Negative pressures were successfully applied to the periprosthetic tissues in a clinically relevant range with a manageable number of dressing changes. This study provides a method for establishing, maintaining, and quantifying controlled negative pressures to the tissues surrounding percutaneous devices using a small animal model. Published by Elsevier Ltd.

Technology efficacy in active prosthetic knees for transfemoral amputees: a quantitative evaluation.

PubMed

El-Sayed, Amr M; Hamzaid, Nur Azah; Abu Osman, Noor Azuan

2014-01-01

Several studies have presented technological ensembles of active knee systems for transfemoral prosthesis. Other studies have examined the amputees' gait performance while wearing a specific active prosthesis. This paper combined both insights, that is, a technical examination of the components used, with an evaluation of how these improved the gait of respective users. This study aims to offer a quantitative understanding of the potential enhancement derived from strategic integration of core elements in developing an effective device. The study systematically discussed the current technology in active transfemoral prosthesis with respect to its functional walking performance amongst above-knee amputee users, to evaluate the system's efficacy in producing close-to-normal user performance. The performances of its actuator, sensory system, and control technique that are incorporated in each reported system were evaluated separately and numerical comparisons were conducted based on the percentage of amputees' gait deviation from normal gait profile points. The results identified particular components that contributed closest to normal gait parameters. However, the conclusion is limitedly extendable due to the small number of studies. Thus, more clinical validation of the active prosthetic knee technology is needed to better understand the extent of contribution of each component to the most functional development.

A personalized 3D-printed prosthetic joint replacement for the human temporomandibular joint: From implant design to implantation.

PubMed

Ackland, David C; Robinson, Dale; Redhead, Michael; Lee, Peter Vee Sin; Moskaljuk, Adrian; Dimitroulis, George

2017-05-01

Personalized prosthetic joint replacements have important applications in cases of complex bone and joint conditions where the shape and size of off-the-shelf components may not be adequate. The objective of this study was to design, test and fabricate a personalized 3D-printed prosthesis for a patient requiring total joint replacement surgery of the temporomandibular joint (TMJ). The new 'Melbourne' prosthetic TMJ design featured a condylar component sized specifically to the patient and fixation screw positions that avoid potential intra-operative damage to the mandibular nerve. The Melbourne prosthetic TMJ was developed for a 58-year-old female recipient with end-stage osteoarthritis of the TMJ. The load response of the prosthesis during chewing and a maximum-force bite was quantified using a personalized musculoskeletal model of the patient's masticatory system developed using medical images. The simulations were then repeated after implantation of the Biomet Microfixation prosthetic TMJ, an established stock device. The maximum condylar stresses, screw stress and mandibular stress at the screw-bone interface were lower in the Melbourne prosthetic TMJ (259.6MPa, 312.9MPa and 198.4MPa, respectively) than those in the Biomet Microfixation device (284.0MPa, 416.0MPa and 262.2MPa, respectively) during the maximum-force bite, with similar trends also observed during the chewing bite. After trialing surgical placement and evaluating prosthetic TMJ stability using cadaveric specimens, the prosthesis was fabricated using 3D printing, sterilized, and implanted into the female recipient. Six months post-operatively, the prosthesis recipient had a normal jaw opening distance (40.0 mm), with no complications identified. The new design features and immediate load response of the Melbourne prosthetic TMJ suggests that it may provide improved clinical and biomechanical joint function compared to a commonly used stock device, and reduce risk of intra-operative nerve damage during placement. The framework presented may be useful for designing and testing customized devices for the treatment of debilitating bone and joint conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Designing and testing lightweight shoulder prostheses with hybrid actuators for movements involved in typical activities of daily living and impact absorption.

PubMed

Sekine, Masashi; Kita, Kahori; Yu, Wenwei

2015-01-01

Unlike forearm amputees, transhumeral amputees have residual stumps that are too small to provide a sufficient range of operation for their prosthetic parts to perform usual activities of daily living. Furthermore, it is difficult for small residual stumps to provide sufficient impact absorption for safe manipulation in daily living, as intact arms do. Therefore, substitution of upper limb function in transhumeral amputees requires a sufficient range of motion and sufficient viscoelasticity for shoulder prostheses under critical weight and dimension constraints. We propose the use of two different types of actuators, ie, pneumatic elastic actuators (PEAs) and servo motors. PEAs offer high power-to-weight performance and have intrinsic viscoelasticity in comparison with motors or standard industrial pneumatic cylinder actuators. However, the usefulness of PEAs in large working spaces is limited because of their short strokes. Servo motors, in contrast, can be used to achieve large ranges of motion. In this study, the relationship between the force and stroke of PEAs was investigated. The impact absorption of both types of actuators was measured using a single degree-of-freedom prototype to evaluate actuator compliance for safety purposes. Based on the fundamental properties of the actuators identified, a four degree-of-freedom robotic arm is proposed for prosthetic use. The configuration of the actuators and functional parts was designed to achieve a specified range of motion and torque calculated from the results of a simulation of typical movements performed in usual activities of daily living. Our experimental results showed that the requirements for the shoulder prostheses could be satisfied.

Association Between Montreal Cognitive Assessment Scores and Measures of Functional Mobility in Lower Extremity Amputees After Inpatient Rehabilitation.

PubMed

Frengopoulos, Courtney; Burley, Joshua; Viana, Ricardo; Payne, Michael W; Hunter, Susan W

2017-03-01

To determine whether scores on a cognitive measure are associated with walking endurance and functional mobility of individuals with transfemoral or transtibial amputations at discharge from inpatient prosthetic rehabilitation. Retrospective cohort study. Rehabilitation hospital. Consecutive admissions (N=176; mean age ± SD, 64.27±13.23y) with transfemoral or transtibial amputation that had data at admission and discharge from an inpatient prosthetic rehabilitation program. Not applicable. Cognitive status was assessed using the Montreal Cognitive Assessment (MoCA). The L Test and the 2-minute walk test (2MWT) were used to estimate functional mobility and walking endurance. The mean ± SD MoCA score was 24.05±4.09 (range, 6-30), and 56.3% of patients had scores <26. MoCA scores had a small positive correlation with the 2MWT (r=.29, P<.01), and a small negative correlation to the L Test (r=-.24, P<.01). In multivariable linear regression, compared with people with the highest MoCA score quartile, there was no difference on the 2MWT, but people in the lowest 2 quartiles took longer to complete the L Test. Cognitive impairment was very prevalent. The association between MoCA and functional mobility was statistically significant. These results highlight the potential for differences on complex motor tasks for individuals with cognitive impairment but does not indicate a need to exclude them from rehabilitation on the basis of cognitive impairment alone. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Rehabilitation and the Veterans' Administration

NASA Technical Reports Server (NTRS)

Meister, F.

1974-01-01

The Veteran's Administration health care system provides prosthetic and sensory aids for the rehabilitation of neurologically handicapped veterans. Research and development centers include prosthetic clinic teams, orthopedic shops, restoration clinics, bioengineering services, orthotics, etc.

75 FR 16511 - Pentron Clinical Technologies, a Wholly-Owned Subsidiary of Kerr Dental/Sybron Dental...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-01

... produce dental materials such as dental prosthetics, dental composites, dental impressions, dental... materials such as dental prosthetics, dental composites, dental impressions, dental adhesives, and other...

Toward more versatile and intuitive cortical brain-machine interfaces.

PubMed

Andersen, Richard A; Kellis, Spencer; Klaes, Christian; Aflalo, Tyson

2014-09-22

Brain-machine interfaces have great potential for the development of neuroprosthetic applications to assist patients suffering from brain injury or neurodegenerative disease. One type of brain-machine interface is a cortical motor prosthetic, which is used to assist paralyzed subjects. Motor prosthetics to date have typically used the motor cortex as a source of neural signals for controlling external devices. The review will focus on several new topics in the arena of cortical prosthetics. These include using: recordings from cortical areas outside motor cortex; local field potentials as a source of recorded signals; somatosensory feedback for more dexterous control of robotics; and new decoding methods that work in concert to form an ecology of decode algorithms. These new advances promise to greatly accelerate the applicability and ease of operation of motor prosthetics. Copyright © 2014 Elsevier Ltd. All rights reserved.

Remote monitoring of lower-limb prosthetic socket fit using wireless technologies.

PubMed

Sahandi, R; Sewell, P; Noroozi, S; Hewitt, M

2012-01-01

Accurate fitting of a lower-limb prosthetic socket is the most important factor affecting amputee satisfaction and rehabilitation. The technology is now available to allow real-time monitoring of in-service pressure distribution of prosthetic limbs. This paper proposes a remote interfacial pressure monitoring system necessary for the assessment of fit. The suitability of a wireless ZigBee network due to its relevant technical specification is investigated. The system enables remote monitoring of a prosthetic socket and its fit under different operating conditions thereby improving design, efficiency and effectiveness. The data can be used by prosthetists and may also be recorded for future training or for patient progress monitoring. This can minimize the number of iterations by getting it right first time, thereby minimizing the number of replacement prostheses. Copyright © 2012 Informa UK, Ltd.

Granulicatella adiacens prosthetic hip joint infection after dental treatment.

PubMed

Aweid, Osama; Sundararajan, Sabapathy; Teferi, Abraham

2016-06-01

Granulicatella adiacens is a Gram-positive bacteria and a normal component of oral flora. It is also found in dental plaques, endodontic abscesses and can rarely cause more serious infections. We describe a prosthetic hip joint infection in an 81-year-old fit and healthy man due to Granulicatella adiacens who underwent a prolonged dental intervention two days earlier without antibiotic prophylaxis. The infection was successfully treated with surgical intervention and a combination of antibiotics. The patient eventually succumbed to severe community-acquired pneumonia two months later. Current guidelines recommend avoidance of antibiotic prophylaxis prior to dental treatment in patients who have no co-morbidities and no prior operation on the index prosthetic joint. This case report indicates that infections of prosthetic joints may be associated with dental procedures even in fit and healthy patients without the recognized risk factors.

[Microbiological characteristics and patterns of resistance in prosthetic joint infections in a referral hospital].

PubMed

Ortega-Peña, Silvestre; Colín-Castro, Claudia; Hernández-Duran, Melissa; López-Jácome, Esaú; Franco-Cendejas, Rafael

2015-01-01

The prosthetic joint infection is the most feared and catastrophic complication for cause severe physical damage to patients and, generates high economic costs. To describe the microbiological characteristics and to determine the resistance pattern in prosthetic joint infections in a reference hospital in Mexico. Patients whose prosthetic devices were withdrawn due to suspicion of septic and aseptic loosening were included. Cultures were performed to identify microorganisms and susceptibility analysis. Of the 111 patients included, 55% were diagnosed with prosthetic joint infection, with the most frequent prosthesis being of the hip (43%). Positive cultures were obtained in 97% of the infected cases, of which 75% were monomicrobial infections. The most frequent bacterial species isolated were: Staphylococcus epidermidis (31%), Enterococcus faecalis (16%), Staphylococcus aureus (13%), and Escherichia coli (8%). The resistance patterns for the Staphylococcus genus were: oxacillin (79%), erythromycin (45%) and ciprofloxacin (37%). Enterococcus faecalis showed a high percentage of resistance to erythromycin and clindamycin (86%), and fluoroquinolones (43%). The large majority (86%) of Escherichia coli were extended spectrum beta-lactamases positive, in addition to having high resistance to fluoroquinolones (86%), trimethoprim/sulfamethoxazole (86%) and gentamicin (72%). The microbiological characteristics found in prosthetic joint infections vary according to the hospitals. In this series, a high proportion of coagulase-negative Staphylococci and Enterococcus spp. were found, as well as a high bacterial resistance. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

Evaluation of 3D printed anatomically scalable transfemoral prosthetic knee.

PubMed

Ramakrishnan, Tyagi; Schlafly, Millicent; Reed, Kyle B

2017-07-01

This case study compares a transfemoral amputee's gait while using the existing Ossur Total Knee 2000 and our novel 3D printed anatomically scalable transfemoral prosthetic knee. The anatomically scalable transfemoral prosthetic knee is 3D printed out of a carbon-fiber and nylon composite that has a gear-mesh coupling with a hard-stop weight-actuated locking mechanism aided by a cross-linked four-bar spring mechanism. This design can be scaled using anatomical dimensions of a human femur and tibia to have a unique fit for each user. The transfemoral amputee who was tested is high functioning and walked on the Computer Assisted Rehabilitation Environment (CAREN) at a self-selected pace. The motion capture and force data that was collected showed that there were distinct differences in the gait dynamics. The data was used to perform the Combined Gait Asymmetry Metric (CGAM), where the scores revealed that the overall asymmetry of the gait on the Ossur Total Knee was more asymmetric than the anatomically scalable transfemoral prosthetic knee. The anatomically scalable transfemoral prosthetic knee had higher peak knee flexion that caused a large step time asymmetry. This made walking on the anatomically scalable transfemoral prosthetic knee more strenuous due to the compensatory movements in adapting to the different dynamics. This can be overcome by tuning the cross-linked spring mechanism to emulate the dynamics of the subject better. The subject stated that the knee would be good for daily use and has the potential to be adapted as a running knee.

The effects of prosthetic foot roll-over shape arc length on the gait of trans-tibial prosthesis users.

PubMed

Hansen, Andrew H; Meier, Margrit R; Sessoms, Pinata H; Childress, Dudley S

2006-12-01

The Shape&Roll prosthetic foot was used to examine the effect of roll-over shape arc length on the gait of 14 unilateral trans-tibial prosthesis users. Simple modifications to the prosthetic foot were used to alter the effective forefoot rocker length, leaving factors such as alignment, limb length, and heel and mid-foot characteristics unchanged. Shortening the roll-over shape arc length caused a significant reduction in the maximum external dorsiflexion moment on the prosthetic side at all walking speeds (p < 0.001 for main effect of arc length), due to a reduction in forefoot leverage (moment arm) about the ankle. Roll-over shape arc length significantly affected the initial loading on the sound limb at normal and fast speeds (p = 0.001 for the main effect of arc length), with participants experiencing larger first peaks of vertical ground reaction forces on their sound limbs when using the foot with the shortest effective forefoot rocker arc length. Additionally, the difference between step lengths on the sound and prosthetic limbs was larger with the shortest arc length condition, although this difference was not statistically significant (p = 0.06 for main effect). It appears that prosthesis users may experience a drop-off effect at the end of single limb stance on prosthetic feet with short roll-over shape arc lengths, leading to increased loading and/or a shortened step on the contralateral limb.

ECONOMIC EVALUATIONS OF INTERVENTIONS FOR TRANSTIBIAL AMPUTEES: A SCOPING REVIEW OF COMPARATIVE STUDIES.

PubMed

Highsmith, M Jason; Kahle, Jason T; Lewandowski, Amanda; Klenow, Tyler D; Orriola, John J; Miro, Rebecca M; Hill, Owen T; Raschke, Sylvia Ursula; Orendurff, Michael S; Highsmith, James T; Sutton, Bryce S

2016-09-01

Transtibial amputation (TTA) is life-altering emotionally, functionally, and economically. The economic impact to all stakeholders is largely unknown, as is the cost-effectiveness of prosthetic intervention. This scoping report's purpose was to determine if there is sufficient evidence to conduct a formal systematic review or meta-analysis in any particular prosthetic intervention area and to determine if any evidence statements could be synthesized relative to economic evaluation of interventions provided to patients with TTA. The scoping review revealed six articles representing three topical areas of transtibial care: Care Models, Prosthetic Treatment, and Prosthetic Sockets. All six articles were cost-identification or cost-consequence design and included a total of 704 subjects. Presently, it can be concluded with moderate confidence that specific weight-bearing and total-contact sockets for transtibial amputees are functionally and economically equivalent in the short term when costs, delivery time, and all stakeholder perspectives are considered. Long-term socket outcomes are relatively unexplored. Further primary research is needed beyond this to determine cost-effectiveness for other areas of transtibial prosthetic care although clinical outcomes are somewhat established through systematic review and meta-analysis in other areas of care. Conversely, evaluation of narrative economic reports relative to transtibial care may be sufficient to warrant further analysis. Guidance from the profession may also be useful in devising a strategy for how to assure economic analyses are a routine element of future prosthetic science.

Beyond intuitive anthropomorphic control: recent achievements using brain computer interface technologies

NASA Astrophysics Data System (ADS)

Pohlmeyer, Eric A.; Fifer, Matthew; Rich, Matthew; Pino, Johnathan; Wester, Brock; Johannes, Matthew; Dohopolski, Chris; Helder, John; D'Angelo, Denise; Beaty, James; Bensmaia, Sliman; McLoughlin, Michael; Tenore, Francesco

2017-05-01

Brain-computer interface (BCI) research has progressed rapidly, with BCIs shifting from animal tests to human demonstrations of controlling computer cursors and even advanced prosthetic limbs, the latter having been the goal of the Revolutionizing Prosthetics (RP) program. These achievements now include direct electrical intracortical microstimulation (ICMS) of the brain to provide human BCI users feedback information from the sensors of prosthetic limbs. These successes raise the question of how well people would be able to use BCIs to interact with systems that are not based directly on the body (e.g., prosthetic arms), and how well BCI users could interpret ICMS information from such devices. If paralyzed individuals could use BCIs to effectively interact with such non-anthropomorphic systems, it would offer them numerous new opportunities to control novel assistive devices. Here we explore how well a participant with tetraplegia can detect infrared (IR) sources in the environment using a prosthetic arm mounted camera that encodes IR information via ICMS. We also investigate how well a BCI user could transition from controlling a BCI based on prosthetic arm movements to controlling a flight simulator, a system with different physical dynamics than the arm. In that test, the BCI participant used environmental information encoded via ICMS to identify which of several upcoming flight routes was the best option. For both tasks, the BCI user was able to quickly learn how to interpret the ICMSprovided information to achieve the task goals.

Comparison between microprocessor-controlled ankle/foot and conventional prosthetic feet during stair negotiation in people with unilateral transtibial amputation.

PubMed

Agrawal, Vibhor; Gailey, Robert S; Gaunaurd, Ignacio A; O'Toole, Christopher; Finnieston, Adam A

2013-01-01

Contrary to stance-phase dorsiflexion of conventional prosthetic feet, the microprocessor-controlled Proprio foot permits swing-phase dorsiflexion on stairs. The purpose of this study was to compare Symmetry in External Work (SEW) between a microprocessor-controlled foot and conventional prosthetic feet in two groups with unilateral transtibial amputation (Medicare Functional Classification Levels K-Level-2 and K-Level-3) during stair ascent and descent. Ten subjects were evaluated while wearing three conventional prosthetic feet- solid ankle cushion heel (SACH), stationary attachment flexible endoskeleton (SAFE), and Talux-and the Proprio foot using a study socket and were given a 10- to 14-day accommodation period with each foot. Ground reaction forces were collected using F-scan sensors during stair ascent and descent. The SEW between the intact and amputated limbs was calculated for each foot. During stair ascent, the Proprio foot resulted in a higher interlimb symmetry than conventional prosthetic feet, with significant differences between the Pro prio and SACH/SAFE feet. The swing-phase dorsiflexion appeared to promote greater interlimb symmetry because it facilitated forward motion of the body, resulting in a heel-to-toe center of pressure trajectory. During stair descent, all feet had low symmetry without significant differences between feet. The movement strategy used when descending stairs, which is to roll over the edge of a step, had a greater influence on symmetry than the dorsiflexion features of prosthetic feet.

Peri-prosthetic femoral fractures of hip or knee arthroplasty. Analysis of 34 cases and a review of Spanish series in the last 20 years.

PubMed

Gracia-Ochoa, M; Miranda, I; Orenga, S; Hurtado-Oliver, V; Sendra, F; Roselló-Añón, A

2016-01-01

To evaluate peri-prosthetic femoral fractures by analysing type of patient, treatment and outcomes, and to compare them with Spanish series published in the last 20 years. A retrospective review of the medical records of patients with peri-prosthetic femoral fractures treated in our hospital from 2010 to 2014, and telephone survey on the current status. A total of 34 peri-prosthetic femoral fractures were analysed, 20 in hip arthroplasty and 14 in knee arthroplasty. The mean age of the patients was 79.9 years, and 91% had previous comorbidity, with up to 36% having at least 3 prior systemic diseases. Mean hospital stay was 8.7 days, and was higher in surgically-treated than in conservative-treated patients. The majority (60.6%) of patients had complications, and mortality was 18%. Functional status was not regained in 61.5% of patients, and pain was higher in hip than in knee arthroplasty. Peri-prosthetic femoral fractures are increasing in frequency. This is due to the increasing number of arthroplasties performed and also to the increasing age of these patients. Treatment of these fractures is complex because of the presence of an arthroplasty component, low bone quality, and comorbidity of the patients. Peri-prosthetic femoral fractures impair quality of life. They need individualised treatment, and have frequent complications and mortality. Copyright © 2016 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Prosthetic joint infection caused by Granulicatella adiacens: a case series and review of literature.

PubMed

Quénard, Fanny; Seng, Piseth; Lagier, Jean-Christophe; Fenollar, Florence; Stein, Andreas

2017-06-23

Bone and joint infection involving Granulicatella adiacens is rare, and mainly involved in cases of bacteremia and infectious endocarditis. Here we report three cases of prosthetic joint infection involving G. adiacens that were successfully treated with surgery and prolonged antimicrobial treatment. We also review the two cases of prosthetic joint infection involving G. adiacens that are reported in the literature. Not all five cases of prosthetic joint infection caused by G. adiacens were associated with bacteremia or infectious endocarditis. Dental care before the onset of infection was observed in two cases. The median time delay between arthroplasty implantation and the onset of infection was of 4 years (ranging between 2 and 10 years). One of our cases was identified with 16srRNA gene sequencing, one case with MALDI-TOF mass spectrometry, and one case with both techniques. Two literature cases were diagnosed by 16srRNA gene sequencing. All five cases were cured after surgery including a two-stage prosthesis exchange in three cases, a one-stage prosthesis exchange in one case, and debridement, antibiotics, irrigation, and retention of the prosthesis in one case, and prolonged antimicrobial treatment. Prosthetic joint infection involving G. adiacens is probably often dismissed due to difficult culture or misdiagnosis, in particular in the cases of polymicrobial infection. Debridement, antibiotics, irrigation, and retention of the prosthesis associated with prolonged antimicrobial treatment (≥ 8 weeks) should be considered as a treatment strategy for prosthetic joint infection involving G. adiacens.

Development and preliminary evaluation of a new anatomically based prosthetic alignment method for below-knee prosthesis.

PubMed

Tafti, Nahid; Karimlou, Masoud; Mardani, Mohammad Ali; Jafarpisheh, Amir Salar; Aminian, Gholam Reza; Safari, Reza

2018-04-20

The objectives of current study were to a) assess similarities and relationships between anatomical landmark-based angles and distances of lower limbs in unilateral transtibial amputees and b) develop and evaluate a new anatomically based static prosthetic alignment method. First sub-study assessed the anthropometrical differences and relationships between the lower limbs in the photographs taken from amputees. Data were analysed via paired t-test and regression analysis. Results show no significant differences in frontal and transverse planes. In the sagittal plane, the anthropometric parameters of the amputated limb were significantly correlated to the corresponding variables of the sound limb. The results served as bases for the development of a new prosthetic alignment method. The method was evaluated on a single subject study. Prosthetic alignment carried out by an experienced prosthetist was compared with such alignment adjusted by an inexperienced prosthetist but with the use of the developed method. In sagittal and frontal planes, the socket angle was tuned with respect to the shin angle, and the position of the prosthetic foot was tuned in relation to the pelvic landmarks. Further study is needed to assess the proposed method on a larger sample of amputees and prosthetists.

Optical fiber Bragg grating-instrumented silicone liner for interface pressure measurement within prosthetic sockets of lower-limb amputees.

PubMed

Al-Fakih, Ebrahim; Arifin, Nooranida; Pirouzi, Gholamhossein; Mahamd Adikan, Faisal Rafiq; Shasmin, Hanie Nadia; Abu Osman, Noor Azuan

2017-08-01

This paper presents a fiber Bragg grating (FBG)-instrumented prosthetic silicone liner that provides cushioning for the residual limb and can successfully measure interface pressures inside prosthetic sockets of lower-limb amputees in a simple and practical means of sensing. The liner is made of two silicone layers between which 12 FBG sensors were embedded at locations of clinical interest. The sensors were then calibrated using a custom calibration platform that mimics a real-life situation. Afterward, a custom gait simulating machine was built to test the liner performance during an amputee's simulated gait. To validate the findings, the results were compared to those obtained by the commonly used F-socket mats. As the statistical findings reveal, both pressure mapping methods measured the interface pressure in a consistent way, with no significant difference (P-values ≥0.05). This pressure mapping technique in the form of a prosthetic liner will allow prosthetics professionals to quickly and accurately create an overall picture of the interface pressure distribution inside sockets in research and clinical settings, thereby improving the socket fit and amputee's satisfaction. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Incidence, severity, and impact of hyperhidrosis in people with lower-limb amputation.

PubMed

Hansen, Colby; Godfrey, Bradeigh; Wixom, Jody; McFadden, Molly

2015-01-01

To assess the incidence and severity of self-reported hyperhidrosis in patients with amputation and understand its effects on prosthetic fit or function, a cross-sectional survey of patients at two amputee clinics was performed. Responses from 121 subjects with lower-limb amputation were analyzed. Of these subjects, 66% reported sweating to a degree that it interfered with daily activities, as measured by the Hyperhidrosis Disease Severity Scale. There was a significant association between sweating and interference with prosthetic fit and function. Sweating was more severe in cases of transtibial amputations, patients under the age of 60, warm weather, and vigorous activity. There was no relationship between severity of sweating and time since amputation, etiology of amputation, duration of daily prosthetic use, or reported ability to perform functional tasks. Subjects reported trying multiple interventions, but the self-reported effectiveness of these treatments was low. Hyperhidrosis, a common problem associated with prosthetic usage, varies in severity and often interferes with daily activities. Sweating severity is associated with poor prosthetic fit and function. Risk factors include younger age and transtibial amputation status. Treatment strategies generally lack efficacy. The results of this study may provide guidance for future interventions and treatment options.

Device to monitor sock use in people using prosthetic limbs: technical report.

PubMed

Sanders, Joan E; Murthy, Revathi; Cagle, John C; Allyn, Katheryn J; Phillips, Reid H; Otis, Brian P

2012-01-01

A device using radio frequency identification (RFID) technology was developed to continuously monitor sock use in people who use prosthetic limbs. RFID tags were placed on prosthetic socks worn by subjects with transtibial limb loss, and a high-frequency RFID reader and antenna were placed in a portable unit mounted to the outside of the prosthetic socket. Bench testing showed the device to have a maximum read range between 5.6 cm and 12.7 cm, depending on the RFID tag used. Testing in a laboratory setting on three participants with transtibial amputation showed that the device correctly monitored sock presence during sitting, standing, and walking activity when one or two socks were worn but was less reliable when more socks were used. Accurate detection was sensitive to orientation of the tag relative to the reader, presence of carbon fiber in the prosthetic socket, pistoning of the limb in the socket, and overlap among the tags. Use of ultra-high-frequency RFID may overcome these limitations. With improvements, the technology may prove useful to practitioners prescribing volume accommodation strategies for patients by providing information about sock use between clinical visits, including timing and consistency of daily sock-ply changes.

Technical Report: A device to monitor sock use on people using prosthetic limbs

PubMed Central

Sanders, Joan; Murthy, Revathi; Cagle, John; Allyn, Katheryn; Phillips, Reid

2015-01-01

A device using radio frequency identification technology (RFID) was developed to continuously monitor sock use on people using prosthetic limbs. RFID tags were placed on prosthetic socks worn by subjects with transtibial limb loss, and a high-frequency (HF) RFID reader and antenna were placed in a portable unit mounted to the outside of the prosthetic socket. Bench testing showed the device to have a maximum read range between 5.6 cm and 12.7 cm, depending on the RFID tag used. Testing in a laboratory setting on three participants with transtibial amputation showed that the device correctly monitored sock presence during sitting, standing, and walking activity when one or two socks were worn but was less reliable when more socks were used. Accurate detection was sensitive to orientation of the tag relative to the reader, presence of carbon fiber in the prosthetic socket, pistoning of the limb in the socket, and overlap among the tags. Use of ultra high frequency (UHF) RFID may overcome these limitations. With improvements, the technology may prove useful to practitioners prescribing volume accommodation strategies for patients by providing information about sock use between clinical visits, including timing and consistency of daily sock ply changes. PMID:23341315

Allograft-prosthetic composite reverse total shoulder arthroplasty for reconstruction of proximal humerus tumor resections.

PubMed

King, Joseph J; Nystrom, Lukas M; Reimer, Nickolas B; Gibbs, C Parker; Scarborough, Mark T; Wright, Thomas W

2016-01-01

Proximal humerus reconstructions after resection of tumors are challenging. Early success of the reverse shoulder arthroplasty for reconstructions has recently been reported. The reverse allograft-prosthetic composite offers the advantage of improved glenohumeral stability compared with hemiarthroplasty for proximal humeral reconstructions as it uses the deltoid for stability. This article describes the technique for treating proximal humeral tumors, including preoperative planning, biopsy principles, resection pearls, soft tissue tensioning, and specifics about reconstruction using the reverse allograft-prosthetic composite. Two cases are presented along with the functional outcomes with use of this technique. Biomechanical considerations during reconstruction are reviewed, including techniques to improve the deltoid compression force. Reported instability rates are less with reverse shoulder arthroplasty reconstruction as opposed to hemiarthroplasty or total shoulder arthroplasty reconstructions of tumor resections. Reported functional outcomes are promising for the reverse allograft-prosthetic composite reconstructions, although complications are reported. Reverse allograft-prosthetic composites are a promising option for proximal humeral reconstructions, although nonunion of the allograft-host bone junction continues to be a challenge for this technique. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Design and characterization of a biologically inspired quasi-passive prosthetic ankle-foot.

PubMed

Mooney, Luke M; Lai, Cara H; Rouse, Elliott J

2014-01-01

By design, commonly worn energy storage and release (ESR) prosthetic feet cannot provide biologically realistic ankle joint torque and angle profiles during walking. Additionally, their anthropomorphic, cantilever architecture causes their mechanical stiffness to decrease throughout the stance phase of walking, opposing the known trend of the biological ankle. In this study, the design of a quasi-passive pneumatic ankle-foot prosthesis is detailed that is able to replicate the biological ankle's torque and angle profiles during walking. The prosthetic ankle is comprised of a pneumatic piston, bending spring and solenoid valve. The mechanical properties of the pneumatic ankle prosthesis are characterized using a materials testing machine and the properties are compared to those from a common, passive ESR prosthetic foot. The characterization spanned a range of ankle equilibrium pressures and testing locations beneath the foot, analogous to the location of center of pressure within the stance phase of walking. The pneumatic ankle prosthesis was shown to provide biologically appropriate trends and magnitudes of torque, angle and stiffness behavior, when compared to the passive ESR prosthetic foot. Future work will focus on the development of a control system for the quasi-passive device and clinical testing of the pneumatic ankle to demonstrate efficacy.

Retrieval of a leaflet escaped in a Tri-technologies bileaflet mechanical prosthetic valve.

PubMed

Cianciulli, Tomás F; Lax, Jorge A; Saccheri, María C; Guidoin, Robert; Salvado, César M; Fernández, Adrián J; Prezioso, Horacio A

2008-01-01

The escape of the prosthetic heart valve disc is one of the causes of prosthetic dysfunction that requires emergency surgery. The removal of the embolized disc should be carried out because of the risk of a progressive extrusion on the aortic wall. Several imaging techniques can be used for the detection of the missing disc localization. In this report we describe a 32-year-old man who underwent mitral valve replacement with a Tri-technologies bileaflet valve three years ago, and was admitted in cardiogenic shock. Transesophageal echocardiography showed acute-onset massive mitral regurgitation. The patient underwent emergency replacement of the prosthetic valve. Only one of the two leaflets remained in the removed prosthetic valve. The missing leaflet could not be found within the cardiac cavity. The abdominal fluoroscopic study and plain radiography were unable to detect the escaped leaflet. The abdominal computed tomography scan and the ultrasound showed the escaped leaflet in the terminal portion of the aortic bifurcation. To retrieve the embolized disc laparotomy and aortotomy were performed three months later. The escaped leaflet shows a fracture of one of the pivot systems caused by structural failure. This kind of failure mode is usually the result of high stress concentration.

Evaluation of function, performance, and preference as transfemoral amputees transition from mechanical to microprocessor control of the prosthetic knee.

PubMed

Hafner, Brian J; Willingham, Laura L; Buell, Noelle C; Allyn, Katheryn J; Smith, Douglas G

2007-02-01

To evaluate differences in function, performance, and preference between mechanical and microprocessor prosthetic knee control technologies. A-B-A-B reversal design. Home, community, and laboratory environments. Twenty-one unilateral, transfemoral amputees. Mechanical control prosthetic knee versus microprocessor control prosthetic knee (Otto Bock C-Leg). Stair rating, hill rating and time, obstacle course time, divided attention task accuracy and time, Amputee Mobility Predictor score, step activity, Prosthesis Evaluation Questionnaire score, Medical Outcomes Study 36-Item Short-Form Health Survey score, self-reported frequency of stumbles and falls, and self-reported concentration required for ambulation. Stair descent score, hill descent time, and hill sound-side step length showed significant (P<.01) improvement with the C-Leg. Users reported a significant (P<.05) decrease in frequency of stumbles and falls, frustration with falling, and difficulty in multitasking while using the microprocessor knee. Subject satisfaction with the C-Leg was significantly (P<.001) greater than the mechanical control prosthesis. The study population showed improved performance when negotiating stairs and hills, reduced frequency of stumbling and falling, and a preference for the microprocessor control C-Leg as compared with the mechanical control prosthetic knee.

Historical Aspects of Inner Ear Anatomy and Biology that Underlie the Design of Hearing and Balance Prosthetic Devices.

PubMed

Van De Water, Thomas R

2012-11-01

This review presents some of the major historical events that advanced the body of knowledge of the anatomy of the inner ear and its sensory receptors as well as the biology of these receptors that underlies the sensory functions of hearing and balance. This knowledge base of the inner ear's structure/function has been an essential factor for the design and construction of prosthetic devices to aid patients with deficits in their senses of hearing and balance. Prosthetic devices are now available for severely hearing impaired and deaf patients to restore hearing and are known as cochlear implants and auditory brain stem implants. A prosthetic device for patients with balance disorders is being perfected and is in an animal model testing phase with another prosthetic device for controlling intractable dizziness in Meniere's patients currently being evaluated in clinical testing. None of this would have been possible without the pioneering studies and discoveries of the investigators mentioned in this review and with the work of many other talented investigators to numerous to be covered in this review. Copyright © 2012 Wiley Periodicals, Inc.

A patterned microtexture to reduce friction and increase longevity of prosthetic hip joints

PubMed Central

Chyr, Anthony; Qiu, Mingfeng; Speltz, Jared; Jacobsen, Ronald L.; Sanders, Anthony P.; Raeymaekers, Bart

2014-01-01

More than 285,000 total hip replacement surgeries are performed in the US each year. Most prosthetic hip joints consist of a cobalt-chromium (CoCr) femoral head that articulates with a polyethylene acetabular component, lubricated with synovial fluid. The statistical survivorship of these metal-on-polyethylene prosthetic hip joints declines significantly after 10 to 15 years of use, primarily as a result of polyethylene wear and wear debris incited disease. The current engineering paradigm to increase the longevity of prosthetic hip joints is to improve the mechanical properties of the polyethylene component, and to manufacture ultra-smooth articulating surfaces. In contrast, we show that adding a patterned microtexture to the ultra-smooth CoCr femoral head reduces friction when articulating with the polyethylene acetabular liner. The microtexture increases the load-carrying capacity and the thickness of the joint lubricant film, which reduces contact between the articulating surfaces. As a result, friction and wear is reduced. We have used a lubrication model to design the geometry of the patterned microtexture, and experimentally demonstrate reduced friction for the microtextured compared to conventional smooth surrogate prosthetic hip joints. PMID:25013240

Comparison of mechanical energy profiles of passive and active below-knee prostheses: a case study.

PubMed

Takahashi, Kota Z; Horne, John R; Stanhope, Steven J

2015-04-01

With the recent technological advancements of prosthetic lower limbs, there is currently a great desire to objectively evaluate existing prostheses. Using a novel biomechanical analysis, the purpose of this case study was to compare the mechanical energy profiles of anatomical and two disparate prostheses: a passive prosthesis and an active prosthesis. An individual with a transtibial amputation who customarily wears a passive prosthesis (Elation, Össur) and an active prosthesis (BiOM, iWalk, Inc.) and 11 healthy subjects participated in an instrumented gait analysis. The total mechanical power and work of below-knee structures during stance were quantified using a unified deformable segment power analysis. Active prosthesis generated greater peak power and total positive work than passive prosthesis and healthy anatomical limbs. The case study will enhance future efforts to objectively evaluate prosthetic functions during gait in individuals with transtibial amputations. A prosthetic limb should closely replicate the mechanical energy profiles of anatomical limbs. The unified deformable (UD) analysis may be valuable to facilitate future clinical prescription and guide fine adjustments of prosthetic componentry to optimize gait outcomes. © The International Society for Prosthetics and Orthotics 2014.

Lateral geniculate body evoked potentials elicited by visual and electrical stimulation.

PubMed

Choi, Chang Wook; Kim, Pan Sang; Shin, Sun Ae; Yang, Ji Yeon; Yang, Yun Sik

2014-08-01

Blind individuals who have photoreceptor loss are known to perceive phosphenes with electrical stimulation of their remaining retinal ganglion cells. We proposed that implantable lateral geniculate body (LGB) stimulus electrode arrays could be used to generate phosphene vision. We attempted to refine the basic reference of the electrical evoked potentials (EEPs) elicited by microelectrical stimulations of the optic nerve, optic tract and LGB of a domestic pig, and then compared it to visual evoked potentials (VEPs) elicited by short-flash stimuli. For visual function measurement, VEPs in response to short-flash stimuli on the left eye of the domestic pig were assessed over the visual cortex at position Oz with the reference electrode at Fz. After anesthesia, linearly configured platinum wire electrodes were inserted into the optic nerve, optic track and LGB. To determine the optimal stimulus current, EEPs were recorded repeatedly with controlling the pulse and power. The threshold of current and charge density to elicit EEPs at 0.3 ms pulse duration was about ±10 µA. Our experimental results showed that visual cortex activity can be effectively evoked by stimulation of the optic nerve, optic tract and LGB using penetrating electrodes. The latency of P1 was more shortened as the electrical stimulation was closer to LGB. The EEPs of two-channel in the visual cortex demonstrated a similar pattern with stimulation of different spots of the stimulating electrodes. We found that the LGB-stimulated EEP pattern was very similar to the simultaneously generated VEP on the control side, although implicit time deferred. EEPs and VEPs derived from visual-system stimulation were compared. The LGB-stimulated EEP wave demonstrated a similar pattern to the VEP waveform except implicit time, indicating prosthetic-based electrical stimulation of the LGB could be utilized for the blind to perceive vision of phosphenes.

Restoration of vision in blind individuals using bionic devices: a review with a focus on cortical visual prostheses.

PubMed

Lewis, Philip M; Ackland, Helen M; Lowery, Arthur J; Rosenfeld, Jeffrey V

2015-01-21

The field of neurobionics offers hope to patients with sensory and motor impairment. Blindness is a common cause of major sensory loss, with an estimated 39 million people worldwide suffering from total blindness in 2010. Potential treatment options include bionic devices employing electrical stimulation of the visual pathways. Retinal stimulation can restore limited visual perception to patients with retinitis pigmentosa, however loss of retinal ganglion cells precludes this approach. The optic nerve, lateral geniculate nucleus and visual cortex provide alternative stimulation targets, with several research groups actively pursuing a cortically-based device capable of driving several hundred stimulating electrodes. While great progress has been made since the earliest works of Brindley and Dobelle in the 1960s and 1970s, significant clinical, surgical, psychophysical, neurophysiological, and engineering challenges remain to be overcome before a commercially-available cortical implant will be realized. Selection of candidate implant recipients will require assessment of their general, psychological and mental health, and likely responses to visual cortex stimulation. Implant functionality, longevity and safety may be enhanced by careful electrode insertion, optimization of electrical stimulation parameters and modification of immune responses to minimize or prevent the host response to the implanted electrodes. Psychophysical assessment will include mapping the positions of potentially several hundred phosphenes, which may require repetition if electrode performance deteriorates over time. Therefore, techniques for rapid psychophysical assessment are required, as are methods for objectively assessing the quality of life improvements obtained from the implant. These measures must take into account individual differences in image processing, phosphene distribution and rehabilitation programs that may be required to optimize implant functionality. In this review, we detail these and other challenges facing developers of cortical visual prostheses in addition to briefly outlining the epidemiology of blindness, and the history of cortical electrical stimulation in the context of visual prosthetics. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Facial recognition using simulated prosthetic pixelized vision.

PubMed

Thompson, Robert W; Barnett, G David; Humayun, Mark S; Dagnelie, Gislin

2003-11-01

To evaluate a model of simulated pixelized prosthetic vision using noncontiguous circular phosphenes, to test the effects of phosphene and grid parameters on facial recognition. A video headset was used to view a reference set of four faces, followed by a partially averted image of one of those faces viewed through a square pixelizing grid that contained 10x10 to 32x32 dots separated by gaps. The grid size, dot size, gap width, dot dropout rate, and gray-scale resolution were varied separately about a standard test condition, for a total of 16 conditions. All tests were first performed at 99% contrast and then repeated at 12.5% contrast. Discrimination speed and performance were influenced by all stimulus parameters. The subjects achieved highly significant facial recognition accuracy for all high-contrast tests except for grids with 70% random dot dropout and two gray levels. In low-contrast tests, significant facial recognition accuracy was achieved for all but the most adverse grid parameters: total grid area less than 17% of the target image, 70% dropout, four or fewer gray levels, and a gap of 40.5 arcmin. For difficult test conditions, a pronounced learning effect was noticed during high-contrast trials, and a more subtle practice effect on timing was evident during subsequent low-contrast trials. These findings suggest that reliable face recognition with crude pixelized grids can be learned and may be possible, even with a crude visual prosthesis.

Influence of malalignment on socket reaction moments during gait in amputees with transtibial prostheses.

PubMed

Boone, David A; Kobayashi, Toshiki; Chou, Teri G; Arabian, Adam K; Coleman, Kim L; Orendurff, Michael S; Zhang, Ming

2013-04-01

Alignment - the process and measured orientation of the prosthetic socket relative to the foot - is important for proper function of a transtibial prosthesis. Prosthetic alignment is performed by prosthetists using visual gait observation and amputees' feedback. The aim of this study was to investigate the effect of transtibial prosthesis malalignment on the moments measured at the base of the socket: the socket reaction moments. Eleven subjects with transtibial amputation were recruited from the community. An instrumented prosthesis alignment component was used to measure socket reaction moments during ambulation under 17 alignment conditions, including nominally aligned using conventional clinical methods, and angle perturbations of 3° and 6° (flexion, extension, abduction, and adduction) and translation perturbations of 5mm and 10mm (anterior, posterior, lateral, and medial) referenced from the nominal alignment. Coronal alignment perturbations caused systematic changes in the coronal socket reaction moments. All angle and translation perturbations revealed statistically significant differences on coronal socket reaction moments compared to the nominal alignment at 30% and 75% of stance phase (P<0.05). The effect of sagittal alignment perturbations on sagittal socket reaction moments was not as responsive as that of the coronal perturbations. The sagittal angle and translation perturbations of the socket led to statistically significant changes in minimum moment, maximum moment, and moments at 45% of stance phase in the sagittal plane. Therefore, malalignment affected the socket reaction moments in amputees with transtibial prostheses. Copyright © 2012 Elsevier B.V. All rights reserved.

Towards a real-time interface between a biomimetic model of sensorimotor cortex and a robotic arm

PubMed Central

Dura-Bernal, Salvador; Chadderdon, George L; Neymotin, Samuel A; Francis, Joseph T; Lytton, William W

2015-01-01

Brain-machine interfaces can greatly improve the performance of prosthetics. Utilizing biomimetic neuronal modeling in brain machine interfaces (BMI) offers the possibility of providing naturalistic motor-control algorithms for control of a robotic limb. This will allow finer control of a robot, while also giving us new tools to better understand the brain’s use of electrical signals. However, the biomimetic approach presents challenges in integrating technologies across multiple hardware and software platforms, so that the different components can communicate in real-time. We present the first steps in an ongoing effort to integrate a biomimetic spiking neuronal model of motor learning with a robotic arm. The biomimetic model (BMM) was used to drive a simple kinematic two-joint virtual arm in a motor task requiring trial-and-error convergence on a single target. We utilized the output of this model in real time to drive mirroring motion of a Barrett Technology WAM robotic arm through a user datagram protocol (UDP) interface. The robotic arm sent back information on its joint positions, which was then used by a visualization tool on the remote computer to display a realistic 3D virtual model of the moving robotic arm in real time. This work paves the way towards a full closed-loop biomimetic brain-effector system that can be incorporated in a neural decoder for prosthetic control, to be used as a platform for developing biomimetic learning algorithms for controlling real-time devices. PMID:26709323

Prediction of thrombus-related mechanical prosthetic valve dysfunction using transesophageal echocardiography

NASA Technical Reports Server (NTRS)

Lin, S. S.; Tiong, I. Y.; Asher, C. R.; Murphy, M. T.; Thomas, J. D.; Griffin, B. P.

2000-01-01

Identification of thrombus-related mechanical prosthetic valve dysfunction (MPVD) has important therapeutic implications. We sought to develop an algorithm, combining clinical and echocardiographic parameters, for prediction of thrombus-related MPVD in a series of 53 patients (24 men, age 52 +/- 16 years) who had intraoperative diagnosis of thrombus or pannus from 1992 to 1997. Clinical and echocardiographic parameters were analyzed to identify predictors of thrombus and pannus. Prevalence of thrombus and diagnostic yields relative to the number of predictors were determined. There were 22 patients with thrombus, 19 patients with pannus, and 12 patients with both. Forty-two of 53 masses were visualized using transesophageal echocardiography (TEE), including 29 of 34 thrombi or both thrombi and panni and 13 of 19 isolated panni. Predictors of thrombus or mixed presentation include mobile mass (p = 0.009), attachment to occluder (p = 0.02), elevated gradients (p = 0.04), and an international normalized ratio of < or = 2.5 (p = 0.03). All 34 patients with thrombus or mixed presentation had > or = 1 predictor. The prevalence of thrombus in the presence of < or = 1, 2, and > or = 3 predictors is 14%, 69%, and 91%, respectively. Thus, TEE is sensitive in the identification of abnormal mass in the setting of MPVD. An algorithm based on clinical and transesophageal echocardiographic predictors may be useful to estimate the likelihood of thrombus in the setting of MPVD. In the presence of > or = 3 predictors, the probability of thrombus is high.

Rehabilitation with 4 zygomatic implants with a new surgical protocol using ultrasonic technique.

PubMed

Mozzati, Marco; Mortellaro, Carmen; Arata, Valentina; Gallesio, Giorgia; Previgliano, Valter

2015-05-01

When the residual bone crest cannot allow the placement of standard implants, the treatment for complete arch rehabilitation of severely atrophic maxillae can be performed with 4 zygomatic implants (ZIs) and immediate function with predictable results in terms of aesthetics, function, and comfort for the patient. However, even if ZIs' rehabilitations showed a good success rate, this surgery is difficult and need a skillful operator. Complications in this kind of rehabilitation are not uncommon; the main difficulties can be related to the reduced surgical visibility and instrument control in a critical anatomic area. All the surgical protocols described in the literature used drilling techniques. Furthermore, the use of ultrasonic instruments in implant surgery compared with drilling instruments have shown advantages in many aspects of surgical procedures, tissues management, enhancement of control, surgical visualization, and healing. The aim of this study was to report on the preliminary experience using ultrasound technique for ZIs surgery in terms of safety and technical improvement. Ten consecutive patients with severely atrophic maxilla have been treated with 4 ZIs and immediate complete arch acrylic resin provisional prostheses. The patients were followed up from 30 to 32 months evaluating implant success, prosthetic success, and patient satisfaction with a questionnaire. No implants were lost during the study period, with a 100% implant and prosthetic success rate. Within the limitations of this preliminary study, these data indicate that ultrasonic implant site preparation for ZIs can be a good alternative to the drilling technique and an improvement for the surgeon.

Brachial plexus injury management through upper extremity amputation with immediate postoperative prostheses.

PubMed

Malone, J M; Leal, J M; Underwood, J; Childers, S J

1982-02-01

Management of patients with brachial plexus injuries requires a team approach so that all aspects of their care are addressed simultaneously. This report examines elective amputation and prosthetic rehabilitation in a patient with brachial plexus avulsion of the left arm. The best possibility for good prosthetic rehabilitation is the early application of prosthetic devices with intensive occupational therapy. Using this type of approach, we have achieved significant improvement in amputation rehabilitation of upper extremity amputees treated with immediate postoperative conventional electric and myoelectric prostheses.

High-density stretchable microelectrode arrays: An integrated technology platform for neural and muscular surface interfacing

NASA Astrophysics Data System (ADS)

Guo, Liang

2011-12-01

Numerous applications in neuroscience research and neural prosthetics, such as retinal prostheses, spinal-cord surface stimulation for prosthetics, electrocorticogram (ECoG) recording for epilepsy detection, etc., involve electrical interaction with soft excitable tissues using a surface stimulation and/or recording approach. These applications require an interface that is able to set up electrical communications with a high throughput between electronics and the excitable tissue and that can dynamically conform to the shape of the soft tissue. Being a compliant and biocompatible material with mechanical impedance close to that of soft tissues, polydimethylsiloxane (PDMS) offers excellent potential as the substrate material for such neural interfaces. However, fabrication of electrical functionalities on PDMS has long been very challenging. This thesis work has successfully overcome many challenges associated with PDMS-based microfabrication and achieved an integrated technology platform for PDMS-based stretchable microelectrode arrays (sMEAs). This platform features a set of technological advances: (1) we have fabricated uniform current density profile microelectrodes as small as 10 mum in diameter; (2) we have patterned high-resolution (feature as small as 10 mum), high-density (pitch as small as 20 mum) thin-film gold interconnects on PDMS substrate; (3) we have developed a multilayer wiring interconnect technology within the PDMS substrate to further boost the achievable integration density of such sMEA; and (4) we have invented a bonding technology---via-bonding---to facilitate high-resolution, high-density integration of the sMEA with integrated circuits (ICs) to form a compact implant. Taken together, this platform provides a high-resolution, high-density integrated system solution for neural and muscular surface interfacing. sMEAs of example designs are evaluated through in vitro and in vivo experimentations on their biocompatibility, surface conformability, and surface recording/stimulation capabilities, with a focus on epimysial (i.e. on the surface of muscle) applications. Finally, as an example medical application, we investigate a prosthesis for unilateral vocal cord paralysis (UVCP) based on simultaneous multichannel epimysial recording and stimulation.

3D Assessment of Features Associated With Transvalvular Aortic Regurgitation After TAVR: A Real-Time 3D TEE Study.

PubMed

Shibayama, Kentaro; Mihara, Hirotsugu; Jilaihawi, Hasan; Berdejo, Javier; Harada, Kenji; Itabashi, Yuji; Siegel, Robert; Makkar, Raj R; Shiota, Takahiro

2016-02-01

This study of 3-dimensional (3D) transesophageal echocardiography (TEE) aimed to demonstrate features associated with transvalvular aortic regurgitation (AR) after transcatheter aortic valve replacement (TAVR) and to confirm the fact that a gap between the native aortic annulus and prosthesis is associated with paravalvular AR. The mechanism of AR after TAVR, particularly that of transvalvular AR, has not been evaluated adequately. All patients with severe aortic stenosis who underwent TAVR with the Sapien device (Edwards Lifesciences, Irvine, California) had 3D TEE of the pre-procedural native aortic annulus and the post-procedural prosthetic valve. In the 201 patients studied, the total AR was mild in 67 patients (33%), moderate in 21 patients (10%), and severe in no patients. There were 20 patients with transvalvular AR and 82 patients with paravalvular AR. Fourteen patients had both transvalvular and paravalvular AR. Patients with transvalvular AR had larger prosthetic expansion (p <0.05), a more elliptical prosthetic shape at the prosthetic commissure level (p <0.01) and more anti-anatomical position (p <0.001), which was defined as malposition of the prosthetic commissures in relation to the native commissures, than the patients without transvalvular AR. Age (odds ratio [OR]: 1.05; 95% confidence interval [CI]: 1.01 to 1.09; p < 0.05) and effective area oversizing (OR: 0.97; 95% CI: 0.93 to 0.99, p <0.05) were associated with mild or greater paravalvular AR. 3D TEE successfully demonstrated the features associated with transvalvular AR, such as large prosthetic expansion, elliptical prosthetic shape, and anti-anatomical position of prosthesis. Additionally, effective area oversizing was associated with paravalvular AR. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Assessment of transfemoral amputees using a passive microprocessor-controlled knee versus an active powered microprocessor-controlled knee for level walking.

PubMed

Creylman, Veerle; Knippels, Ingrid; Janssen, Paul; Biesbrouck, Evelyne; Lechler, Knut; Peeraer, Louis

2016-12-19

In transfemoral (TF) amputees, the forward propulsion of the prosthetic leg in swing has to be mainly carried out by hip muscles. With hip strength being the strongest predictor to ambulation ability, an active powered knee joint could have a positive influence, lowering hip loading and contributing to ambulation mobility. To assess this, gait of four TF amputees was measured for level walking, first while using a passive microprocessor-controlled prosthetic knee (P-MPK), subsequently while using an active powered microprocessor-controlled prosthetic knee (A-MPK). Furthermore, to assess long-term effects of the use of an A-MPK, a 4-weeks follow-up case study was performed. The kinetics and kinematics of the gait of four TF amputees were assessed while walking with subsequently the P-MPK and the A-MPK. For one amputee, a follow-up study was performed: he used the A-MPK for 4 weeks, his gait was measured weekly. The range of motion of the knee was higher on both the prosthetic and the sound leg in the A-MPK compared to the P-MPK. Maximum hip torque (HT) during early stance increased for the prosthetic leg and decreased for the sound leg with the A-MPK compared to the P-MPK. During late stance, the maximum HT decreased for the prosthetic leg. The difference between prosthetic and sound leg for HT disappeared when using the A-MPK. Also, an increase in stance phase duration was observed. The follow-up study showed an increase in confidence with the A-MPK over time. Results suggested that, partially due to an induced knee flexion during stance, HT can be diminished when walking with the A-MPK compared to the P-MPK. The single case follow-up study showed positive trends indicating that an adaptation time is beneficial for the A-MPK.

Bariatric amputee: A growing problem?

PubMed

Kulkarni, Jai; Hannett, Dominic P; Purcell, Steven

2015-06-01

This study reviewed prevalence of patients with lower limb amputations with above normal weight profile, with body mass index over 25, in seven disablement services centres managing their amputee rehabilitation in the United Kingdom. To review two clinical standards of practice in amputee rehabilitation. Ambulant lower limb amputees should have their body weight recorded on an electronic information system, with identification of cohort with body weight >100 kg. Lower limb amputees to be provided with suitable weight-rated prosthesis. Observational study of clinical practice. Data were collected from the Clinical Information Management Systems. Inclusion criteria--subjects were ambulant prosthetic users with some prosthetic intervention in the last 5 years and had at least one lower limb amputation. In 96% of patients, the weight record profile was maintained. In addition, 86% were under 100 kg, which is the most common weight limit of prosthetic componentry. Of 15,204 amputation levels, there were 1830 transfemoral and transtibial sites in users with body weight over 100 kg. In 60 cases, the prosthetic limb build was rated to be below the user body weight. In 96% of our patients, body weight was documented, and in 97%, the prosthetic limb builds were within stated body weight limits, but this may not be the case in all the other disablement services centres in the United Kingdom. Also, the incidence of obesity in the United Kingdom is a growing problem, and the health issues associated with obesity are further compounded in the amputee population. Prosthetic componentry has distinct weight limits which must be considered during prescription. As people with amputation approach the limits of specific components, clinicians are faced with the challenge of continued provision in a safe and suitable manner. This article reviews the amputee population and the current national profile to consider trends in provision and the incidence of these challenges. © The International Society for Prosthetics and Orthotics 2014.

Playing checkers: detection and eye hand coordination in simulated prosthetic vision

NASA Astrophysics Data System (ADS)

Dagnelie, Gislin; Walter, Matthias; Yang, Liancheng

2006-09-01

In order to assess the potential for visual inspection and eye hand coordination without tactile feedback under conditions that may be available to future retinal prosthesis wearers, we studied the ability of sighted individuals to act upon pixelized visual information at very low resolution, equivalent to 20/2400 visual acuity. Live images from a head-mounted camera were low-pass filtered and presented in a raster of 6 × 10 circular Gaussian dots. Subjects could either freely move their gaze across the raster (free-viewing condition) or the raster position was locked to the subject's gaze by means of video-based pupil tracking (gaze-locked condition). Four normally sighted and one severely visually impaired subject with moderate nystagmus participated in a series of four experiments. Subjects' task was to count 1 to 16 white fields randomly distributed across an otherwise black checkerboard (counting task) or to place a black checker on each of the white fields (placing task). We found that all subjects were capable of learning both tasks after varying amounts of practice, both in the free-viewing and in the gaze-locked conditions. Normally sighted subjects all reached very similar performance levels independent of the condition. The practiced performance level of the visually impaired subject in the free-viewing condition was indistinguishable from that of the normally sighted subjects, but required approximately twice the amount of time to place checkers in the gaze-locked condition; this difference is most likely attributable to this subject's nystagmus. Thus, if early retinal prosthesis wearers can achieve crude form vision, then on the basis of these results they too should be able to perform simple eye hand coordination tasks without tactile feedback.

Effects of sociodemographic, treatment variables, and medical characteristics on quality of life of patients with maxillectomy restored with obturator prostheses.

PubMed

Artopoulou, Ioli Ioanna; Karademas, Evangelos C; Papadogeorgakis, Nikolaos; Papathanasiou, Ioannis; Polyzois, Gregory

2017-12-01

Restoration of maxillary defects resulting from tumor ablative surgery presents a difficult challenge, with both functional and esthetic issues. Whether rehabilitation with an obturator prosthesis could significantly contribute to improved quality of life in patients with maxillary resection has been scarcely studied, with relatively small study samples. The purpose of this survey study was to assess the overall functioning of the obturator prosthesis and the effect of specific sociodemographic, medical, and treatment variables on obturator functioning and quality of life in patients with maxillectomy. Global quality of life (QOL) and satisfaction with the obturator prosthesis of 57 patients who underwent maxillectomy and prosthetic rehabilitation at the National and Kapodistrian University of Athens were assessed using 3 questionnaires: European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire C30 (QLQ-C30), the EORTC QLQ-HN35, and the obturator functioning scale. The data were analyzed using the Kruskal-Wallis 1-way ANOVA on ranks, hierarchical multiple regression analysis, and the Spearman rank order correlation (α=.05). Satisfactory functioning of the obturator prosthesis was the most significant predictor of improved QOL (P<.05). QOL was significantly related to additional treatments (P<.05), the size of the primary tumor (P<.05), and the size of the maxillectomy defect (P<.05). The most significant predictors of good obturator functioning were additional treatments (P<.01), age at the time of surgery (P<.05), presence of mandibular teeth (P<.05), and previous maxillary removable prosthetic experience (P<.05). Obturator functioning scale appearance and insertion subscales (r=0.47, P<.01), followed by speech (r=0.42, P<.01), were significantly related to better QOL. A well-functioning obturator prosthesis was the most significant determinant for improved QOL in patients with maxillary resection. Age at the time of surgery, adjuvant treatments, presence of mandibular teeth, and previous maxillary removable prosthetic experience were the most significant predictors for better obturator functioning, whereas the size of the maxillectomy defect had a significant effect on QOL but did not influence the functional outcome. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Facilitating Children's Adjustment to Orthotic and Prosthetic Appliances.

ERIC Educational Resources Information Center

Fredrick, Jeff; Fletcher, Donna

1985-01-01

Guidelines are offered to help teachers understand the nature and use of orthotic and prosthetic appliances for disabled students. Classroom behavior observations are noted so that teachers can help monitor the child's adjustment to the appliance. (CL)

Rotationally Actuated Prosthetic Hand

NASA Technical Reports Server (NTRS)

Norton, William E.; Belcher, Jewell G., Jr.; Carden, James R.; Vest, Thomas W.

1991-01-01

Prosthetic hand attached to end of remaining part of forearm and to upper arm just above elbow. Pincerlike fingers pushed apart to degree depending on rotation of forearm. Simpler in design, simpler to operate, weighs less, and takes up less space.

Development of a Prosthesis for Urinary Control

NASA Technical Reports Server (NTRS)

Tenney, J. B.; Rabinowitz, R.; Tomkiewicz, Z.; Harrison, H. N.; Rogers, D. W.

1986-01-01

Report describes development and marketing of prosthetic sphincter for urinary control. With prosthetic device, patients void bladder every 3 to 4 hours. Periodic voiding keeps bladder muscles exercised and healthy and avoids bladder infections and kidney damage.

Early prosthetic aortic valve infection identified with the use of positron emission tomography in a patient with lead endocarditis.

PubMed

Amraoui, Sana; Tlili, Ghoufrane; Sohal, Manav; Bordenave, Laurence; Bordachar, Pierre

2016-12-01

18-Fluorodeoxyglucose positron emission tomography/computerized tomography (FDG PET/CT) scanning has recently been proposed as a diagnostic tool for lead endocarditis (LE). FDG PET/CT might be also useful to localize associated septic emboli in patients with LE. We report an interesting case of a LE patient with a prosthetic aortic valve in whom a trans-esophageal echocardiogram did not show associated aortic endocarditis. FDG PET/CT revealed prosthetic aortic valve infection. A second TEE performed 2 weeks after identified aortic vegetation. A longer duration of antimicrobial therapy with serial follow-up echocardiography was initiated. There was also increased uptake in the sigmoid colon, corresponding to focal polyps resected during a colonoscopy. FDG PET/CT scanning seems to be highly sensitive for prosthetic aortic valve endocarditis diagnosis. This promising diagnostic tool may be beneficial in LE patients, by identifying septic emboli and potential sites of pathogen entry.

Power feasibility of implantable digital spike sorting circuits for neural prosthetic systems.

PubMed

Zumsteg, Zachary S; Kemere, Caleb; O'Driscoll, Stephen; Santhanam, Gopal; Ahmed, Rizwan E; Shenoy, Krishna V; Meng, Teresa H

2005-09-01

A new class of neural prosthetic systems aims to assist disabled patients by translating cortical neural activity into control signals for prosthetic devices. Based on the success of proof-of-concept systems in the laboratory, there is now considerable interest in increasing system performance and creating implantable electronics for use in clinical systems. A critical question that impacts system performance and the overall architecture of these systems is whether it is possible to identify the neural source of each action potential (spike sorting) in real-time and with low power. Low power is essential both for power supply considerations and heat dissipation in the brain. In this paper we report that state-of-the-art spike sorting algorithms are not only feasible using modern complementary metal oxide semiconductor very large scale integration processes, but may represent the best option for extracting large amounts of data in implantable neural prosthetic interfaces.

Theoretical Study on the Mechanics of the Conjunct Gnatoprothetic Devices in the Context of Occlusive Function Rehabilitation

PubMed Central

POPESCU, M.R.; TRANĂ, F.; MANOLEA, H.; RAUTEN, ANE-MARIE; ȘURLIN, PETRA; DRAGOMIR, L.P.

2014-01-01

The partially intercalated edentation offers the practitioner the possibility of the functional rehabilitation of the dental arcades through conjunct gnato-prosthetic devices. The functions of the dento-maxilar device, disturbed by the presence of edentation, require a treatment approach so that, without pre-planning or estimating, the result can lead most of the times to failure in terms of functionality. Clinical evaluation associated with pre- and proprosthetic treatment can also impose, in some situations the evaluation of the dental units involved in prosthetic rehabilitation. The association and implementation of the prosthetic construction in the occlusive-articular ensemble, as well as the counterbalancing of the mastication forces per dental unit and whole interarch system, linked to the distribution of the forces at the level of the pillar teeth and prosthetic construction, represent the goal of this theoretical study. PMID:25729593

Theoretical study on the mechanics of the conjunct gnatoprothetic devices in the context of occlusive function rehabilitation.

PubMed

Popescu, M R; Trană, F; Manolea, H; Rauten, Ane-Marie; Șurlin, Petra; Dragomir, L P

2014-01-01

The partially intercalated edentation offers the practitioner the possibility of the functional rehabilitation of the dental arcades through conjunct gnato-prosthetic devices. The functions of the dento-maxilar device, disturbed by the presence of edentation, require a treatment approach so that, without pre-planning or estimating, the result can lead most of the times to failure in terms of functionality. Clinical evaluation associated with pre- and proprosthetic treatment can also impose, in some situations the evaluation of the dental units involved in prosthetic rehabilitation. The association and implementation of the prosthetic construction in the occlusive-articular ensemble, as well as the counterbalancing of the mastication forces per dental unit and whole interarch system, linked to the distribution of the forces at the level of the pillar teeth and prosthetic construction, represent the goal of this theoretical study.

Red flag in the emergency department: fracture and primary failure of a prosthetic valve.

PubMed

Ozsarac, Murat; Karcioglu, Ozgur; Ayrik, Cuneyt; Bozkurt, Seyran; Turkcuer, Ibrahim; Gumrukcu, Serhat

2005-07-01

This case report concerns a patient with fracture and primary dysfunction of a prosthetic valve. A 40-year-old man presented to the Emergency Department with a chief complaint of breakthrough pleuritic back pain and shortness of breath. Past surgical history was significant only for an aortic valve replacement and mitral valve replacement performed 16 years prior. The transthoracic echocardiography raised suspicion of prosthesis malposition. The patient was taken to the operating room by cardiothoracic surgeons for valve replacement. Operative findings revealed that a prosthetic valve leaflet in the mitral position had broken off. Primary prosthetic valve failure should not be overlooked in the differential diagnosis of patients with valve replacement and a rapidly deteriorating clinical course. Emergency echocardiography is a guide to convenient diagnosis and management. Early surgical consultation and early reparative surgery might prevent unnecessary morbidity and mortality.

Recurrent pannus formation causing prosthetic aortic valve dysfunction: Is excision without valve re-replacement applicable?

PubMed Central

2012-01-01

Prosthetic valve dysfunction at aortic position is commonly caused by pannus formation. The exact etiology is not known. It arises from ventricular aspect of the prosthesis encroaching its leaflets causing stenosis or it may remain localized causing left ventricular outflow tract obstruction without affecting valve function. The difference in location entails different approaches in management. Such a pathology requires surgical excision of the pannus with or without valve re-replacement. A recurrent pannus was observed in a female patient who needed repeated surgical intervention to excise a localized pannus without re-replacement of a well functioning prosthetic valve. Management of our case presents several questions, whether recurrence of pannus is caused by sparing the prosthetic valve, is it simply an exaggeration of an inflammatory healing process in certain individuals or is it ideal to re-replace the valve despite a well preserved function. PMID:22747790

Recurrent pannus formation causing prosthetic aortic valve dysfunction: is excision without valve re-replacement applicable?

PubMed

Darwazah, Ahmad K

2012-06-29

Prosthetic valve dysfunction at aortic position is commonly caused by pannus formation. The exact etiology is not known. It arises from ventricular aspect of the prosthesis encroaching its leaflets causing stenosis or it may remain localized causing left ventricular outflow tract obstruction without affecting valve function.The difference in location entails different approaches in management. Such a pathology requires surgical excision of the pannus with or without valve re-replacement.A recurrent pannus was observed in a female patient who needed repeated surgical intervention to excise a localized pannus without re-replacement of a well functioning prosthetic valve.Management of our case presents several questions, whether recurrence of pannus is caused by sparing the prosthetic valve, is it simply an exaggeration of an inflammatory healing process in certain individuals or is it ideal to re-replace the valve despite a well preserved function.

Ten questions on prosthetic shoulder infection

PubMed Central

Pinder, Elizabeth M; Ong, Joshua CY; Bale, R Stephen

2016-01-01

Prosthetic shoulder infection can cause significant morbidity secondary to pain and stiffness. Symptoms may be present for years before diagnosis because clinical signs are often absent and inflammatory markers may be normal. An emerging common culprit, Propionibacterium acnes, is hard to culture and so prolonged incubation is necessary. A negative culture result does not always exclude infection and new synovial fluid biochemical markers such as α defensin are less sensitive than for lower limb arthroplasty. A structured approach is necessary when assessing patients for prosthetic shoulder joint infection. This includes history, examination, serum inflammatory markers, plain radiology and aspiration and/or biopsy. A classification for the likelihood of prosthetic shoulder infection has been described based on culture, pre-operative and intra-operative findings. Treatment options include antibiotic suppression, debridement with component retention, one-stage revision, two-stage revision and excision arthroplasty. Revision arthroplasty is associated with the best outcomes. PMID:27583013

Ten questions on prosthetic shoulder infection.

PubMed

Pinder, Elizabeth M; Ong, Joshua Cy; Bale, R Stephen; Trail, Ian A

2016-07-01

Prosthetic shoulder infection can cause significant morbidity secondary to pain and stiffness. Symptoms may be present for years before diagnosis because clinical signs are often absent and inflammatory markers may be normal. An emerging common culprit, Propionibacterium acnes, is hard to culture and so prolonged incubation is necessary. A negative culture result does not always exclude infection and new synovial fluid biochemical markers such as α defensin are less sensitive than for lower limb arthroplasty. A structured approach is necessary when assessing patients for prosthetic shoulder joint infection. This includes history, examination, serum inflammatory markers, plain radiology and aspiration and/or biopsy. A classification for the likelihood of prosthetic shoulder infection has been described based on culture, pre-operative and intra-operative findings. Treatment options include antibiotic suppression, debridement with component retention, one-stage revision, two-stage revision and excision arthroplasty. Revision arthroplasty is associated with the best outcomes.

Efficiency of bowel preparation for capsule endoscopy examination: a meta-analysis.

PubMed

Niv, Yaron

2008-03-07

Good preparation before endoscopic procedures is essential for successful visualization. The small bowel is difficult to evaluate because of its length and complex configuration. A meta-analysis was conducted of studies comparing small bowel visualization by capsule endoscopy with and without preparation. Medical data bases were searched for all studies investigating the preparation for capsule endoscopy of the small bowel up to July 31, 2007. Studies that scored bowel cleanness and measured gastric and small bowel transit time and rate of cecum visualization were included. The primary endpoint was the quality of bowel visualization. The secondary endpoints were transit times and proportion of examinations that demonstrated the cecum, with and without preparation. Meta-analysis was performed with StatDirect Statistical software, version 2.6.1 (http://statsdirect.com). Eight studies met the inclusion criteria. Bowel visualization was scored as "good" in 78% of the examinations performed with preparation and 49% performed without (P<0.0001). There were no significant differences in transit times or in the proportion of examinations that demonstrated the cecum with and without preparation. Capsule endoscopy preparation improves the quality of small bowel visualization, but has no effect on transit times, or demonstration of the cecum.

Efficiency of bowel preparation for capsule endoscopy examination: A meta-analysis

PubMed Central

Niv, Yaron

2008-01-01

Good preparation before endoscopic procedures is essential for successful visualization. The small bowel is difficult to evaluate because of its length and complex configuration. A meta-analysis was conducted of studies comparing small bowel visualization by capsule endoscopy with and without preparation. Medical data bases were searched for all studies investigating the preparation for capsule endoscopy of the small bowel up to July 31, 2007. Studies that scored bowel cleanness and measured gastric and small bowel transit time and rate of cecum visualization were included. The primary endpoint was the quality of bowel visualization. The secondary endpoints were transit times and proportion of examinations that demonstrated the cecum, with and without preparation. Meta-analysis was performed with StatDirect Statistical software, version 2.6.1 (http://statsdirect.com). Eight studies met the inclusion criteria. Bowel visualization was scored as “good” in 78% of the examinations performed with preparation and 49% performed without (P < 0.0001). There were no significant differences in transit times or in the proportion of examinations that demonstrated the cecum with and without preparation. Capsule endoscopy preparation improves the quality of small bowel visualization, but has no effect on transit times, or demonstration of the cecum. PMID:18322940

Modular socket system versus traditionally laminated socket: a cost analysis.

PubMed

Normann, Elna; Olsson, Anna; Brodtkorb, Thor-Henrik

2011-03-01

Using the new modular socket system (MSS) to produce a prosthetic socket directly on the patient has the potential of being easier and quicker to manufacture but also incurring higher costs. The purpose of the study was to compare the costs of manufacturing a transtibial prosthetic socket using either a MSS or a standard laminated socket (PC). Concurrent controlled trial. A total of 20 patients at two orthopaedic facilities were followed with regards to the cost of manufacturing a prosthetic socket using either MSS or PC. Time aspects and material costs were considered in the cost analysis. Other factors studied include delivery time and number of visits. For the cost analysis, only direct costs pertaining to the prosthetic socket were considered. The total cost of MSS was found to be significantly higher (p < 0.01) compared to PC. However, the production and time cost was significantly lower. Delivery time to the patient was 1 day for MSS compared to 17 days for PC. Our study shows that the direct prosthetic cost of treating a patient using MSS is significantly higher than treating a patient using PC. However, the MSS prosthesis can be delivered significantly faster and with fewer visits. Further studies taking the full societal costs of MSS into account should therefore be performed. This study shows that the direct prosthetic cost of treating a patient with Modular Socket System is significantly higher than treating a patient with plastercasting with standard laminated socket. However, the Modular Socket System prosthesis can be delivered significantly faster and with fewer visits.

Analysis of colour stability of selected provisional prosthetic materials: an in vitro study.

PubMed

Koczorowski, Ryszard; Linkowska-Swidzińska, Kamila; Gedrange, Tomasz; Swidziński, Teodor

2009-08-01

Prosthetic restorative materials (that are) used for temporary fixed dentures tend to exhibit variable discolouration over several weeks of use. The aim of this study was to perform a spectrophotometric analysis of the influence of selected discolouring factors on the colour stability of provisional prosthetic materials in vitro. In the study, the following prosthetic materials for short-term use in the oral cavity were evaluated: Luxatemp, Structur 2S.C., Protemp II, Zhermacryl STC and Dentalon Plus. Samples of these materials were immersed in coffee, tea and dark fruit juice for 60 h at different pH values. Colour was evaluated by determining the monochromatic coefficients of light reflected by the samples, using a spectrophotometric method. Results received in artificial light (illuminant A) were compared with those obtained in daylight (illuminant D65). Changes in colour and its parameters according to the CIE L*a*b* system were analysed. The analysis (of the colour and colour parameters) of the tested materials in two types of light showed that Structur displayed the greatest tendency to discolouration and that the least tendency to discolouration was exhibited by Dentalon Plus. The fact that colour parameters obtained in two types of light were not identical suggests that changes in the colour of the same material may be perceived differently, depending on the illuminant. Provisional prosthetic materials show variable colour stability under different conditions in the oral cavity. The colour of prosthetic materials may be perceived differently, depending on the illuminant and the effect of the environment in which they are used.

Mechanical Properties and Simulated Aging of Silicone Maxillofacial Elastomers: Advancements in the Past 45 Years.

PubMed

Hatamleh, Muhanad M; Polyzois, Gregory L; Nuseir, Amjad; Hatamleh, Khaldoun; Alnazzawi, Ahmad

2016-07-01

To identify and discuss the findings of publications on mechanical behavior of maxillofacial prosthetic materials published since 1969. Original experimental articles reporting on mechanical properties of maxillofacial prosthetic materials were included. A two-stage search of the literature, electronic and hand search, identified relevant published studies up to May 2015. An extensive electronic search was conducted of databases including PubMed, Embase, Scopus, and Google Scholar. Included primary studies (n = 63) reported on tensile strength, tear strength, and hardness of maxillofacial prosthetic materials at baseline and after aging. The search revealed 63 papers, with more than 28 papers being published in the past 10 years, which shows an increased number of publications when compared to only 6 papers published in the 1970s. The increase is linear with significant correlation (r = 0.85). Such an increase reflects great awareness and continued developments and warrants more research in the field of maxillofacial prosthetic materials properties; however, it is difficult to directly compare results, as studies varied in maxillofacial prosthetic materials tested with various silicone elastomers being heavily investigated, standards followed in preparing test specimens, experimental testing protocols, and parameters used in setting simulated aging conditionings. It is imperative to overcome the existing variability by establishing unified national or international standards/specifications for maxillofacial prosthetic materials. Standardization organizations or bodies, the scientific community, and academia need to be coordinated to achieve this goal. In the meantime and despite all of these theoretically significant alternatives, clinical practice still faces problems with serviceability of maxillofacial prostheses. © 2016 by the American College of Prosthodontists.

[Influence of preoperative bone mass density in periprosthetic bone remodeling after implantation of ABG-II prosthesis: A 10-year follow-up].

PubMed

Aguilar Ezquerra, A; Panisello Sebastiá, J J; Mateo Agudo, J

2016-01-01

Preoperative bone mass index has shown to be an important factor in peri-prosthetic bone remodelling in short follow-up studies. Bone density scans (DXA) were used to perform a 10-year follow-up study of 39 patients with a unilateral, uncemented hip replacement. Bone mass index measurements were made at 6 months, one year, 3 years, 5 years, and 10 years after surgery. Pearson coefficient was used to quantify correlations between preoperative bone mass density (BMD) and peri-prosthetic BMD in the 7 Gruen zones at 6 months, one year, 3 years, 5 years, and 10 years. Pre-operative BMD was a good predictor of peri-prosthetic BMD one year after surgery in zones 1, 2, 4, 5 and 6 (Pearson index from 0.61 to 0.75). Three years after surgery it has good predictive power in zones 1, 4 and 5 (0.71-0.61), although in zones 3 and 7 low correlation was observed one year after surgery (0.51 and 0.57, respectively). At the end of the follow-up low correlation was observed in the 7 Gruen zones. Sex and BMI were found to not have a statistically significant influence on peri-prosthetic bone remodelling. Although preoperative BMD seems to be an important factor in peri-prosthetic remodelling one year after hip replacement, it loses its predictive power progressively, until not being a major factor in peri-prosthetic remodelling ten years after surgery. Copyright © 2015 SECOT. Published by Elsevier Espana. All rights reserved.

Attachment systems for mandibular implant overdentures: a systematic review

PubMed Central

Kim, Ha-Young; Lee, Jeong-Yol; Bryant, S. Ross

2012-01-01

PURPOSE The aim of this systematic review was to address treatment outcome according to attachment systems for mandibular implant overdentures in terms of implant survival rate, prosthetic maintenance and complications, and patient satisfaction. MATERIALS AND METHODS A systematic literature search was conducted using PubMed and hand searching of relevant journals considering inclusion and exclusion criteria. Clinical trial studies on mandibular implant overdentures until August, 2010 were selected if more than one type of overdenture attachment was reported. Twenty four studies from 1098 studies were finally included and the data on implant survival rate, prosthetic maintenance and complications, patient satisfaction were analyzed relative to attachment systems. RESULTS Four studies presented implant survival rates (95.8 - 97.5% for bar, 96.2 - 100% for ball, 91.7% for magnet) according to attachment system. Ten other studies presented an implant survival rate ranging from 93.3% to 100% without respect to the attachment groups. Common prosthetic maintenance and complications were replacement of an assay for magnet attachments, and activation of a matrix or clip for ball or bar attachments. Prosthetic maintenance and complications most commonly occurred in the magnet groups. Conflicting findings were found on the rate of prosthetic maintenance and complications comparing ball and bar attachments. Most studies showed no significant differences in patient satisfaction depending upon attachment systems. CONCLUSION The implant survival rate of mandibular overdentures seemed to be high regardless attachment systems. The prosthetic maintenance and complications may be influenced by attachment systems. However patient satisfaction may be independent of the attachment system. PMID:23236571

Representing high-dimensional data to intelligent prostheses and other wearable assistive robots: A first comparison of tile coding and selective Kanerva coding.

PubMed

Travnik, Jaden B; Pilarski, Patrick M

2017-07-01

Prosthetic devices have advanced in their capabilities and in the number and type of sensors included in their design. As the space of sensorimotor data available to a conventional or machine learning prosthetic control system increases in dimensionality and complexity, it becomes increasingly important that this data be represented in a useful and computationally efficient way. Well structured sensory data allows prosthetic control systems to make informed, appropriate control decisions. In this study, we explore the impact that increased sensorimotor information has on current machine learning prosthetic control approaches. Specifically, we examine the effect that high-dimensional sensory data has on the computation time and prediction performance of a true-online temporal-difference learning prediction method as embedded within a resource-limited upper-limb prosthesis control system. We present results comparing tile coding, the dominant linear representation for real-time prosthetic machine learning, with a newly proposed modification to Kanerva coding that we call selective Kanerva coding. In addition to showing promising results for selective Kanerva coding, our results confirm potential limitations to tile coding as the number of sensory input dimensions increases. To our knowledge, this study is the first to explicitly examine representations for realtime machine learning prosthetic devices in general terms. This work therefore provides an important step towards forming an efficient prosthesis-eye view of the world, wherein prompt and accurate representations of high-dimensional data may be provided to machine learning control systems within artificial limbs and other assistive rehabilitation technologies.

Prosthetic Hand Lifts Heavy Loads

NASA Technical Reports Server (NTRS)

Carden, James R.; Norton, William; Belcher, Jewell G.; Vest, Thomas W.

1991-01-01

Prosthetic hand designed to enable amputee to lift diverse heavy objects like rocks and logs. Has simple serrated end effector with no moving parts. Prosthesis held on forearm by system of flexible straps. Features include ruggedness, simplicity, and relatively low cost.

[Ectodermal Capdepont syndrome and oral prosthetic rehabilitation. About a clinical case].

PubMed

Kumpanya, P; Matshumba, M; Sekele, I B; Mayunga, M; Lutula, P S; Ntumba, M K

2015-03-01

The authors describe the ectodermal Capdepont syndrome as an anomaly characterized by anhidrosis, hypotrichosis and anodontia diagnosed in a 22 year-old adult. In front of this anodontia, oral prosthetic rehabilitation remains the only solution.

[Guywire dentures].

PubMed

Riakhovskiĭ, A N

2000-01-01

Analyzes possible complications and shortcomings of traditional prosthetic treatments. Presents a new approach to prosthetic treatment and describes the general design of guy dentures. Describes in brief the biomechanics, methods of making guy dentures, and discusses their advantages in comparison with the traditional dentures.

Differences in Military Obstacle Course Performance Between Three Energy-Storing and Shock-Adapting Prosthetic Feet in High-Functioning Transtibial Amputees: A Double-Blind, Randomized Control Trial.

PubMed

Highsmith, M Jason; Kahle, Jason T; Miro, Rebecca M; Lura, Derek J; Carey, Stephanie L; Wernke, Matthew M; Kim, Seok Hun; Quillen, William S

2016-11-01

Approximately 683 persons engaged in military service experienced transtibial amputation (TTA) related to recent war in Iraq and Afghanistan. Military TTAs function at a level beyond basic ambulation. No empirical data demonstrate which higher functioning prosthetic feet maximize injured service personnel's ability to continue performing at a level commensurate with return to duty. This study's purpose was to determine which of three high-functioning, energy-storing prosthetic feet maximize performance and preference in a field obstacle course (OC) and to quantify physical performance differences between TTAs and high-functioning nonamputees. A randomized, double-blind, repeated measures experimental design compared three prosthetic feet (Ossur Variflex, Endolite Elite Blade, and Ossur Re-Flex Rotate) during performance on a field OC. TTAs accommodated with study feet and the OC before assessment. 14 TTAs and 14 nonamputee controls completed the course. Subjective and objective performance differences were compared across feet conditions and between groups. Total OC completion times were similar between prosthetic feet: Elite-Blade (419 seconds ± 130), Variflex (425 seconds ± 144), and Re-Flex Rotate (444 seconds ± 220). Controls' OC completion time (287.2 seconds ± 58) was less (p ≤ 0.05) than TTA times. In total, controls had faster completion times (p ≤ 0.05) compared to all prosthetic feet conditions in 13/17 obstacles. Re-Flex Rotate had 2 additional obstacles different (p ≤ 0.05) than controls and required more time to complete. Median RPE values were lower (p ≤ 0.05) for controls than TTA regardless of foot. Regarding foot preference for OC completion, 7/14 (50%) preferred Elite Blade, 5/14 (36%) preferred Re-Flex Rotate, and the remaining 2/14 (14%) preferred Variflex. Controls completed the OC faster and with less effort than TTAs regardless of prosthetic foot. No clear differences in prosthetic feet emerged during OC completion; however, individual task performance, perceived effort, and preference resulted in trends of slight performance improvement with and preference for Elite Blade, a dual function energy-storing and return foot combined with vertical shock absorption. Understanding how to maximally improve performance in such functional tasks may allow service members to best sustain physical fitness, return to their military occupational specialty and possibly in-theater duty. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

The small eye phenotype in the EPIC-Norfolk eye study: prevalence and visual impairment in microphthalmos and nanophthalmos.

PubMed

Day, Alexander C; Khawaja, Anthony P; Peto, Tunde; Hayat, Shabina; Luben, Robert; Broadway, David C; Khaw, Kay-Tee; Foster, Paul J

2013-01-01

To describe the prevalence and phenotypic characteristics of small eyes in the European Prospective Investigation of Cancer (EPIC)-Norfolk Eye Study. Community cross-sectional study. East England population (Norwich, Norfolk and surrounding area). 8033 participants aged 48-92 years old from the EPIC-Norfolk Eye Study, Norfolk, UK with axial length measurements. Participants underwent a standardised ocular examination including visual acuity (LogMAR), ocular biometry, non-contact tonometry, autorefraction and fundal photography. A small eye phenotype was defined as a participant with one or both eyes with axial length of <21 mm. Prevalence of small eyes, proportion with visual impairment, demographic and biometric factors. Ninety-six participants (1.20%, 95% CI 0.98% to 1.46%) had an eye with axial length less than 21 mm, of which 74 (77%) were women. Prevalence values for shorter axial lengths were <20 mm: 0.27% (0.18% to 0.41%); <19 mm: 0.17% (0.11% to 0.29%); <18 mm: 0.14% (0.08% to 0.25%). Two participants (2.1%) had low vision (presenting visual acuity >0.48 LogMAR) and one participant was blind (>1.3 LogMAR). The prevalence of unilateral visual impairment was higher in participants with a small eye. Multiple logistic regression modelling showed presence of a small eye to be significantly associated with shorter height, lower body mass index, higher systolic blood pressure and lower intraocular pressure. The prevalence of people with small eyes is higher than previously thought. While small eyes were more common in women, this appears to be related to shorter height and lower body mass index. Participants with small eyes were more likely to be blind or to have unilateral visual impairment.

Magnetic Oculomotor Prosthetics for Acquired Nystagmus.

PubMed

Nachev, Parashkev; Rose, Geoff E; Verity, David H; Manohar, Sanjay G; MacKenzie, Kelly; Adams, Gill; Theodorou, Maria; Pankhurst, Quentin A; Kennard, Christopher

2017-10-01

Acquired nystagmus, a highly symptomatic consequence of damage to the substrates of oculomotor control, often is resistant to pharmacotherapy. Although heterogeneous in its neural cause, its expression is unified at the effector-the eye muscles themselves-where physical damping of the oscillation offers an alternative approach. Because direct surgical fixation would immobilize the globe, action at a distance is required to damp the oscillation at the point of fixation, allowing unhindered gaze shifts at other times. Implementing this idea magnetically, herein we describe the successful implantation of a novel magnetic oculomotor prosthesis in a patient. Case report of a pilot, experimental intervention. A 49-year-old man with longstanding, medication-resistant, upbeat nystagmus resulting from a paraneoplastic syndrome caused by stage 2A, grade I, nodular sclerosing Hodgkin's lymphoma. We designed a 2-part, titanium-encased, rare-earth magnet oculomotor prosthesis, powered to damp nystagmus without interfering with the larger forces involved in saccades. Its damping effects were confirmed when applied externally. We proceeded to implant the device in the patient, comparing visual functions and high-resolution oculography before and after implantation and monitoring the patient for more than 4 years after surgery. We recorded Snellen visual acuity before and after intervention, as well as the amplitude, drift velocity, frequency, and intensity of the nystagmus in each eye. The patient reported a clinically significant improvement of 1 line of Snellen acuity (from 6/9 bilaterally to 6/6 on the left and 6/5-2 on the right), reflecting an objectively measured reduction in the amplitude, drift velocity, frequency, and intensity of the nystagmus. These improvements were maintained throughout a follow-up of 4 years and enabled him to return to paid employment. This work opens a new field of implantable therapeutic devices-oculomotor prosthetics-designed to modify eye movements dynamically by physical means in cases where a purely neural approach is ineffective. Applied to acquired nystagmus refractory to all other interventions, it is shown successfully to damp pathologic eye oscillations while allowing normal saccadic shifts of gaze. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Anterior loop of the inferior alveolar nerve: Averages and prevalence based on CT scans.

PubMed

Juan, Del Valle Lovato; Grageda, Edgar; Gómez Crespo, Salvador

2016-02-01

The treatment of edentulous patients by using a complete implant-supported fixed prosthetic with distal extension has been widely studied; success is mainly dependent upon the placement of the distal implants. The location of the inferior alveolar nerve determines implant placement, but the length, prevalence, and symmetry between the left and right side of the anterior loop of the alveolar nerve are unknown. The purpose of this clinical study was to measure the anterior loop of the inferior alveolar nerve, which determines the placement of distal implants, in a group of 55 Mexican participants. The study expected to ascertain the average length, prevalence, and symmetry between left and right side and any sex differences. To differentiate the inferior alveolar nerve path, a new technique was applied using Hounsfield unit (HU) thresholds. The null hypothesis was that no significant differences would be found between the left and right sides or between men and women for the anterior loop of the inferior alveolar nerve. Fifty-five computed tomography (CT) scans were made (Somatom Sensation 16; Siemens Healthcare) and were visualized with InVesalius software. Anterior loop measurements were made on 3-dimensional surfaces. To determine statistical differences between the left and right side and between the sexes, the t test was used. The interclass correlation coefficient test was also applied to verify the reliability of the measurements. Ninety percent of participants showed the anterior loop of the inferior alveolar nerve. The length of the anterior loop ranged between 0 and 6.68 mm, with a mean of 2.19 mm. No significant differences were found between the left and right sides or between men and women. The mean length for the anterior loop in the sample was 2.19 mm. As the anterior loop length shows a high degree of variability, these findings suggest that a CT scan for each patient is recommended in order to visualize a safety zone before placing implants close to the mental foramen. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Rotational joint for prosthetic leg

NASA Technical Reports Server (NTRS)

Jones, W. C.; Owens, L. J.

1977-01-01

Device is installed in standard 30 millimeter tubing used for lower leg prosthetics. Unit allows proper rotation (about 3 degrees) of foot relative to the hip, during normal walking or running. Limited rotational movement with restoring force results in a more natural gait.

Mesofluidic controlled robotic or prosthetic finger

DOEpatents

Lind, Randall F; Jansen, John F; Love, Lonnie J

2013-11-19

A mesofluidic powered robotic and/or prosthetic finger joint includes a first finger section having at least one mesofluidic actuator in fluid communication with a first actuator, a second mesofluidic actuator in fluid communication with a second actuator and a second prosthetic finger section pivotally connected to the first finger section by a joint pivot, wherein the first actuator pivotally cooperates with the second finger to provide a first mechanical advantage relative to the joint point and wherein the second actuator pivotally cooperates with the second finger section to provide a second mechanical advantage relative to the joint point.

Re-operation for aortic and mitral prosthetic dysfunctions.

PubMed

Kaul, T K; Sastry, M R; Mercer, J L; Meade, J B

1985-01-01

The overall incidence of re-operation and prosthetic valve endocarditis was low in the present series as mechanical prostheses were used predominantly. The prosthetic dysfunctions were less frequent following the primary implantation with Bjork Shiley prostheses, but high operative risk was associated with the clotted Bjork Shiley prostheses. We also had unusual experience of strut fracture and sticking of Bjork Shiley discs in the closed position in both aortic and mitral positions. The early deaths were nil since the use of cardioplegic protection. Intra-operative bleeding due to adhesions can be minimised by using synthetic or heterologous pericardium during the primary operation.

A rare case of prosthetic endocarditis and dehiscence in a mechanical valved conduit

PubMed Central

Kannan, Arun; Smith, Cristy; Subramanian, Sreekumar; Janardhanan, Rajesh

2014-01-01

A middle-aged adult patient with a history of aortic root replacement with a mechanical valved conduit and remote chest trauma was referred to our institution with prosthetic endocarditis. Transoesophageal echocardiogram at our institution confirmed a near-complete dehiscence of the prosthetic aortic valve from the conduit, with significant perivalvular flow forming a pseudoaneurysm. The patient underwent a high-risk re-operation, involving redo aortic root replacement with a homograft after extensive debridement of the infected tissue. The patient was discharged to an outside facility after an uncomplicated hospital course, and remains stable. PMID:24510692

A rare case of prosthetic endocarditis and dehiscence in a mechanical valved conduit.

PubMed

Kannan, Arun; Smith, Cristy; Subramanian, Sreekumar; Janardhanan, Rajesh

2014-02-07

A middle-aged adult patient with a history of aortic root replacement with a mechanical valved conduit and remote chest trauma was referred to our institution with prosthetic endocarditis. Transoesophageal echocardiogram at our institution confirmed a near-complete dehiscence of the prosthetic aortic valve from the conduit, with significant perivalvular flow forming a pseudoaneurysm. The patient underwent a high-risk re-operation, involving redo aortic root replacement with a homograft after extensive debridement of the infected tissue. The patient was discharged to an outside facility after an uncomplicated hospital course, and remains stable.

Control factors in removable complete dentures: from the articulation quintet to kinetic contact

PubMed Central

Pompa, Giorgio; Giovannetti, Agostino; Gentile, Tina; Di Carlo, Stefano

2010-01-01

Summary Hanau’s laws and the so-called articulation quintet have contributed greatly to the evolution of the prosthetic dentistry and have been further elaborated by various authors. The main aim of this study was to establish the stability of prosthetic plates by attaining balanced occlusion. Several authors have addressed the problem of removable and fixed prostheses by classifying mandibular movements into functional and parafunctional movements which extends the classical occlusal mechanics for the modern occlusal feedback model. Moreover, they suggest the use of the angle of convergence as a reference plane when manufacturing prosthetic. PMID:22238706

Selected applications for current polymers in prosthetic dentistry - state of the art.

PubMed

Kawala, Maciej; Smardz, Joanna; Adamczyk, Lukasz; Grychowska, Natalia; Wieckiewicz, Mieszko

2018-05-10

Polymers are widely applied in medicine, including dentistry, i.e. in prosthodontics. The following paper is aimed at demonstrating the applications of selected modern polymers in prosthetic dentistry based on the reported literature. The study was conducted using the PubMed, SCOPUS and CINAHL databases in relation to documents published during 1999-2017. The following keywords were used: polymers with: prosthetic dentistry, impression materials, denture base materials, bite registration materials, denture soft liners, occlusal splint materials and 3D printing. Original papers and reviews which were significant from the modern clinical viewpoint and practical validity in relation to the possibility of using polymeric materials in prosthetic dentistry, were presented. Denture base materials were most commonly modified polymers. Modifications mainly concerned antimicrobial properties and reinforcement of the material structure by introducing additional fibers. Antimicrobial modifications were also common in case of relining materials. Polymeric materials have widely been used in prosthetic dentistry. Modifications of their composition allow achieving new, beneficial properties that affect quality of patients' life. Progress in science allows for a more methodologically-advanced research on the synthesis of new polymeric materials and incorporation of new substances into already known polymeric materials, that will require systematization and appropriate classification. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Differentiation between solid-ankle cushioned heel and energy storage and return prosthetic foot based on step-to-step transition cost.

PubMed

Wezenberg, Daphne; Cutti, Andrea G; Bruno, Antonino; Houdijk, Han

2014-01-01

Decreased push-off power by the prosthetic foot and inadequate roll-over shape of the foot have been shown to increase the energy dissipated during the step-to-step transition in human walking. The aim of this study was to determine whether energy storage and return (ESAR) feet are able to reduce the mechanical energy dissipated during the step-to-step transition. Fifteen males with a unilateral lower-limb amputation walked with their prescribed ESAR foot (Vari-Flex, Ossur; Reykjavik, Iceland) and with a solid-ankle cushioned heel foot (SACH) (1D10, Ottobock; Duderstadt, Germany), while ground reaction forces and kinematics were recorded. The positive mechanical work on the center of mass performed by the trailing prosthetic limb was larger (33%, p = 0.01) and the negative work performed by the leading intact limb was lower (13%, p = 0.04) when walking with the ESAR foot compared with the SACH foot. The reduced step-to-step transition cost coincided with a higher mechanical push-off power generated by the ESAR foot and an extended forward progression of the center of pressure under the prosthetic ESAR foot. Results can explain the proposed improvement in walking economy with this kind of energy storing and return prosthetic foot.

Prosthesis rejection in acquired major upper-limb amputees: a population-based survey.

PubMed

Østlie, Kristin; Lesjø, Ingrid Marie; Franklin, Rosemary Joy; Garfelt, Beate; Skjeldal, Ola Hunsbeth; Magnus, Per

2012-07-01

To estimate the rates of primary and secondary prosthesis rejection in acquired major upper-limb amputees (ULAs), to describe the most frequently reported reasons for rejection and to estimate the influence of background factors on the risk of rejection. Cross-sectional study analysing population-based questionnaire data (n = 224). Effects were analysed by logistic regression analyses and Cox regression analyses. Primary prosthesis rejection was found in 4.5% whereas 13.4% had discontinued prosthesis use. The main reasons reported for primary non-wear were a perceived lack of need and discrepancies between perceived need and the prostheses available. The main reasons reported for secondary prosthesis rejection were dissatisfaction with prosthetic comfort, function and control. Primary prosthesis rejection was more likely in ULAs amputated at high age and in ULAs with proximal amputations. Secondary prosthesis rejection was more likely in proximal ULAs and in women. Clinicians should be aware of the increased risk of rejection in proximal ULAs, elderly ULAs and in women. Emphasising individual needs will probably facilitate successful prosthetic fitting. Improved prosthesis quality and individualised prosthetic training may increase long-term prosthesis use. Further studies of the effect of prosthetic training and of the reasons for rejection of different prosthetic types are suggested.

Literature Review on Needs of Upper Limb Prosthesis Users.

PubMed

Cordella, Francesca; Ciancio, Anna Lisa; Sacchetti, Rinaldo; Davalli, Angelo; Cutti, Andrea Giovanni; Guglielmelli, Eugenio; Zollo, Loredana

2016-01-01

The loss of one hand can significantly affect the level of autonomy and the capability of performing daily living, working and social activities. The current prosthetic solutions contribute in a poor way to overcome these problems due to limitations in the interfaces adopted for controlling the prosthesis and to the lack of force or tactile feedback, thus limiting hand grasp capabilities. This paper presents a literature review on needs analysis of upper limb prosthesis users, and points out the main critical aspects of the current prosthetic solutions, in terms of users satisfaction and activities of daily living they would like to perform with the prosthetic device. The ultimate goal is to provide design inputs in the prosthetic field and, contemporary, increase user satisfaction rates and reduce device abandonment. A list of requirements for upper limb prostheses is proposed, grounded on the performed analysis on user needs. It wants to (i) provide guidelines for improving the level of acceptability and usefulness of the prosthesis, by accounting for hand functional and technical aspects; (ii) propose a control architecture of PNS-based prosthetic systems able to satisfy the analyzed user wishes; (iii) provide hints for improving the quality of the methods (e.g., questionnaires) adopted for understanding the user satisfaction with their prostheses.

Electromyography (EMG) signal recognition using combined discrete wavelet transform based adaptive neuro-fuzzy inference systems (ANFIS)

NASA Astrophysics Data System (ADS)

Arozi, Moh; Putri, Farika T.; Ariyanto, Mochammad; Khusnul Ari, M.; Munadi, Setiawan, Joga D.

2017-01-01

People with disabilities are increasing from year to year either due to congenital factors, sickness, accident factors and war. One form of disability is the case of interruptions of hand function. The condition requires and encourages the search for solutions in the form of creating an artificial hand with the ability as a human hand. The development of science in the field of neuroscience currently allows the use of electromyography (EMG) to control the motion of artificial prosthetic hand into the necessary use of EMG as an input signal to control artificial prosthetic hand. This study is the beginning of a significant research planned in the development of artificial prosthetic hand with EMG signal input. This initial research focused on the study of EMG signal recognition. Preliminary results show that the EMG signal recognition using combined discrete wavelet transform and Adaptive Neuro-Fuzzy Inference System (ANFIS) produces accuracy 98.3 % for training and 98.51% for testing. Thus the results can be used as an input signal for Simulink block diagram of a prosthetic hand that will be developed on next study. The research will proceed with the construction of artificial prosthetic hand along with Simulink program controlling and integrating everything into one system.

The History of Nontraditional or Ectopic Placement of Reservoirs in Prosthetic Urology.

PubMed

Perito, Paul; Wilson, Steven

2016-04-01

Reservoir placement during implantation of prosthetic urology devices has been problematic throughout the history of the surgical treatment of erectile dysfunction and urinary incontinence. We thought it would be interesting to review the history of reservoir placement leading up to current surgical techniques. To provide an overview of the past and present techniques for reservoir placement and discuss the evolutionary process leading to safe and effective placement of prosthetic reservoirs. We reviewed data pertaining to inflatable penile prosthesis (IPP) reservoirs and pressure-regulating balloons (PRB) in a chronological fashion, spanning 25 years. Main outcomes included a historical review of techniques for IPP reservoir and PRB placement leading to the subsequent incremental improvements in safety and efficacy when performing penile implants and artificial urinary sphincters. Prosthetic urologic reservoirs have traditionally been placed in the retropubic space. Over the years, urologists have attempted use of alternative spaces including peritoneal, epigastric, "ectopic," posterior to transversalis, and high submuscular. Current advances in prosthetic urologic reservoir placement allow safe and effective abdominal wall placement of reservoirs. These novel approaches appear to be so effective that urologists may now be able to cease using the traditional retropubic space for reservoir placement, even in the case of virgin pelves. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Microbiological Aetiology, Epidemiology, and Clinical Profile of Prosthetic Joint Infections: Are Current Antibiotic Prophylaxis Guidelines Effective?

PubMed Central

Cheng, Allen C.; Buising, Kirsty L.; Choong, Peter F. M.

2012-01-01

Prosthetic joint infections remain a major complication of arthroplasty. At present, local and international guidelines recommend cefazolin as a surgical antibiotic prophylaxis at the time of arthroplasty. This retrospective cohort study conducted across 10 hospitals over a 3-year period (January 2006 to December 2008) investigated the epidemiology and microbiological etiology of prosthetic joint infections. There were 163 cases of prosthetic joint infection identified. From a review of the microbiological culture results, methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci were isolated in 45% of infections. In addition, polymicrobial infections, particularly those involving Gram-negative bacilli and enterococcal species, were common (36%). The majority (88%) of patients received cefazolin as an antibiotic prophylaxis at the time of arthroplasty. In 63% of patients in this cohort, the microorganisms subsequently obtained were not susceptible to the antibiotic prophylaxis administered. The results of this study highlight the importance of ongoing reviews of the local ecology of prosthetic joint infection, demonstrating that the spectrum of pathogens involved is broad. The results should inform empirical antibiotic therapy. This report also provokes discussion about infection control strategies, including changing surgical antibiotic prophylaxis to a combination of glycopeptide and cefazolin, to reduce the incidence of infections due to methicillin-resistant staphylococci. PMID:22314530

Second-site prosthetic joint infection in patients with multiple prosthetic joints.

PubMed

Clesham, Kevin; Hughes, Andrew J; O' hEireamhoin, Sven; Fleming, Catherine; Murphy, Colin G

2018-04-10

Prosthetic joint infections (PJIs) are among the most serious complications in arthroplasty. A second-site PJI in patients with multiple prosthetic joints increases morbidity, with many requiring further revision procedures. We aimed to establish why some patients with multiple joints develop second-site infections. Our institution's arthroplasty database was reviewed from 2004 to 2017. All PJIs were identified, and all patients with more than one prosthetic joint in situ were included. We recorded risk factors, causative organisms, number of procedures and length of stay. Forty-four patients meeting the criteria were identified. Four patients (9.1%) developed second-site infection. Eight patients (18.2%) developed re-infection of the primary PJI. Positive MRSA carrier status and PJI of a total knee replacement were associated with an increased risk of a second episode of infection. Patients who developed further infection had more frequent admission and longer lengths of stay than isolated PJIs. Higher morbidity and use of hospital resources are associated with this cohort of patients. PJIs in total knee replacements and positive MRSA status are associated with higher rates of second infection. Identifying this vulnerable cohort of patients at an early stage is critical to ensure measures are taken to reduce the risks of further infection.

Single-stage revision for fungal peri-prosthetic joint infection: a single-centre experience.

PubMed

Klatte, T O; Kendoff, D; Kamath, A F; Jonen, V; Rueger, J M; Frommelt, L; Gebauer, M; Gehrke, T

2014-04-01

Fungal peri-prosthetic infections of the knee and hip are rare but likely to result in devastating complications. In this study we evaluated the results of their management using a single-stage exchange technique. Between 2001 and 2011, 14 patients (ten hips, four knees) were treated for a peri-prosthetic fungal infection. One patient was excluded because revision surgery was not possible owing to a large acetabular defect. One patient developed a further infection two months post-operatively and was excluded from the analysis. Two patients died of unrelated causes. After a mean of seven years (3 to 11) a total of ten patients were available for follow-up. One patient, undergoing revision replacement of the hip, had a post-operative dislocation. Another patient, undergoing revision replacement of the knee, developed a wound infection and required revision 29 months post-operatively following a peri-prosthetic femoral fracture. The mean Harris hip score increased to 74 points (63 to 84; p < 0.02) in those undergoing revision replacement of the hip, and the mean Hospital for Special Surgery knee score increased to 75 points (70 to 80; p < 0.01) in those undergoing revision replacement of the knee. A single-stage revision following fungal peri-prosthetic infection is feasible, with an acceptable rate of a satisfactory outcome.

Literature Review on Needs of Upper Limb Prosthesis Users

PubMed Central

Cordella, Francesca; Ciancio, Anna Lisa; Sacchetti, Rinaldo; Davalli, Angelo; Cutti, Andrea Giovanni; Guglielmelli, Eugenio; Zollo, Loredana

2016-01-01

The loss of one hand can significantly affect the level of autonomy and the capability of performing daily living, working and social activities. The current prosthetic solutions contribute in a poor way to overcome these problems due to limitations in the interfaces adopted for controlling the prosthesis and to the lack of force or tactile feedback, thus limiting hand grasp capabilities. This paper presents a literature review on needs analysis of upper limb prosthesis users, and points out the main critical aspects of the current prosthetic solutions, in terms of users satisfaction and activities of daily living they would like to perform with the prosthetic device. The ultimate goal is to provide design inputs in the prosthetic field and, contemporary, increase user satisfaction rates and reduce device abandonment. A list of requirements for upper limb prostheses is proposed, grounded on the performed analysis on user needs. It wants to (i) provide guidelines for improving the level of acceptability and usefulness of the prosthesis, by accounting for hand functional and technical aspects; (ii) propose a control architecture of PNS-based prosthetic systems able to satisfy the analyzed user wishes; (iii) provide hints for improving the quality of the methods (e.g., questionnaires) adopted for understanding the user satisfaction with their prostheses. PMID:27242413

EDITORIAL: The Eye and The Chip 2008 The Eye and The Chip 2008

NASA Astrophysics Data System (ADS)

Rizzo, Joseph F.; O'Malley, Edward R.; Hessburg, Philip C.

2009-06-01

Over the course of the past decade, The Eye and The Chip world congress on visual neuro-prosthetic devices has become a premier meeting for those who believe that 'artificial' vision will one day be used to improve the quality of life of visually impaired patients. Although substantial progress has been made, there are numerous unresolved issues, like the preferred methods for wireless communication, placement of devices, and materials and design among others. The Eye and The Chip meeting of 2008, held in Detroit on 12-14 June 2008, provided important new information about these and other important topics, and thus served to advance this field of scientific research. From a research seedling a decade ago to the crowd of superb presentations in Detroit last June, a very real sense of justifiable optimism has developed. The prospects of artificial vision are no longer remote. Many of the researchers expressed confidence that implantable devices will provide the hoped-for level of vision to justify their widespread use in the future. The often dramatic successes of cochlear implants continues to provide credence that artificial stimulation of nerve tissue is a plausible strategy to restore vision. The Eye and The Chip 2008 attracted researchers from four continents (North America, Europe, Asia and Australia). The meeting also benefited from the attendance and presentations by representatives of the FDA, who have been present for all The Eye and The Chip meetings. The 2008 meeting was also enhanced by the inclusion of a new and related scientific field that shares the goal of restoring vision to the blind—the field of molecular restoration of retinal function by insertion of channelrhodopsin. Just as the field of ophthalmology went from Ridley's primitive intraocular lens replacement to implants useful in virtually every cataract patient in one surgeon's clinical lifetime, the field of retinal prostheses seems to be following a very similar trajectory. Likewise, the field of visual prosthetics continues to amass evidence that suggests that its long-term future is promising. We are grateful to the scientists who made the congress a success, to the Journal of Neural Engineering for organizing this special issue, to the financial supporters who made the congress possible and to the Detroit Institute of Ophthalmology staff who worked tirelessly and without complaint to bring home a superb congress. We invite you to attend the next The Eye and The Chip meeting, which will be held in 2011.

A topology visualization early warning distribution algorithm for large-scale network security incidents.

PubMed

He, Hui; Fan, Guotao; Ye, Jianwei; Zhang, Weizhe

2013-01-01

It is of great significance to research the early warning system for large-scale network security incidents. It can improve the network system's emergency response capabilities, alleviate the cyber attacks' damage, and strengthen the system's counterattack ability. A comprehensive early warning system is presented in this paper, which combines active measurement and anomaly detection. The key visualization algorithm and technology of the system are mainly discussed. The large-scale network system's plane visualization is realized based on the divide and conquer thought. First, the topology of the large-scale network is divided into some small-scale networks by the MLkP/CR algorithm. Second, the sub graph plane visualization algorithm is applied to each small-scale network. Finally, the small-scale networks' topologies are combined into a topology based on the automatic distribution algorithm of force analysis. As the algorithm transforms the large-scale network topology plane visualization problem into a series of small-scale network topology plane visualization and distribution problems, it has higher parallelism and is able to handle the display of ultra-large-scale network topology.