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Sample records for accurate needle placement

  1. Improved targeting device and computer navigation for accurate placement of brachytherapy needles

    SciTech Connect

    Pappas, Ion P.I.; Ryan, Paul; Cossmann, Peter; Kowal, Jens; Borgeson, Blake; Caversaccio, Marco

    2005-06-15

    Successful treatment of skull base tumors with interstitial brachytherapy requires high targeting accuracy for the brachytherapy needles to avoid harming vital anatomical structures. To enable safe placement of the needles in this area, we developed an image-based planning and navigation system for brachytherapy, which includes a custom-made mechanical positioning arm that allows rough and fine adjustment of the needle position. The fine-adjustment mechanism consists of an XYZ microstage at the base of the arm and a needle holder with two fine-adjustable inclinations. The rotation axes of the inclinations cross at the tip of the needle so that the inclinational adjustments do not interfere with the translational adjustments. A vacuum cushion and a noninvasive fixation frame are used for the head immobilization. To avoid mechanical bending of the needles due to the weight of attached tracking markers, which would be detrimental for targeting accuracy, only a single LED marker on the tail of the needle is used. An experimental phantom-based targeting study with this setup demonstrated that a positioning accuracy of 1.4 mm (rms) can be achieved. The study showed that the proposed setup allows brachytherapy needles to be easily aligned and inserted with high targeting accuracy according to a preliminary plan. The achievable accuracy is higher than if the needles are inserted manually. The proposed system can be linked to a standard afterloader and standard dosimetry planning module. The associated additional effort is reasonable for the clinical practice and therefore the proposed procedure provides a promising tool for the safe treatment of tumors in the skull base area.

  2. Percutaneous Radiofrequency Ablation of Osteoid Osteomas with Use of Real-Time Needle Guidance for Accurate Needle Placement: A Pilot Study

    SciTech Connect

    Busser, Wendy M. H. Hoogeveen, Yvonne L.; Veth, Rene P. H.; Schreuder, H. W. Bart; Balguid, Angelique; Renema, W. KlaasJan; SchultzeKool, Leo J.

    2011-02-15

    Purpose: To evaluate the accuracy and technical success of positioning a radiofrequency ablation (RFA) electrode in osteoid osteomas by use of a new real-time needle guidance technology combining cone-beam computed tomography (CT) and fluoroscopy. Materials and Methods: Percutaneous RFA of osteoid osteomas was performed in five patients (median age 18 years), under general anesthesia, with the use of cone-beam CT and fluoroscopic guidance for electrode positioning. The outcome parameters were technical success, meaning correct needle placement in the nidus; accuracy defined as the deviation (in mm) from the center of the nidus; and clinical outcome at follow-up. Results: In all five cases, positioning was possible within 3 mm of the determined target location (median nidus size 6.8 mm; range 5-10.2 mm). All procedures were technically successful. All patients were free of pain at clinical follow-up. No complications were observed. Conclusion: Real-time fluoroscopy needle guidance based on cone-beam CT is a useful tool to accurately position radiofrequency needles for minimally invasive treatment of osteoid osteomas.

  3. CT-guided percutaneous needle placement in forensic medicine.

    PubMed

    Hyodoh, Hideki; Shimizu, Jyunya; Mizuo, Keisuke; Okazaki, Shunichiro; Watanabe, Satoshi; Inoue, Hiromasa

    2015-03-01

    We have developed a technique of CT-guided needle placement in the destructed human body in forensic practice. A sixty-year-old male was found in a burned car and he was also destructed severely. Although blood was needed for the external examination, it was difficult to approach the vessels because of the severely burned condition of the cadaver. Thus, we attempted to obtain a blood sample from a vessel using a CT-guided technique. Postmortem CT demonstrated the presence of blood-containing vessels in the pelvis. Indeed, CT-guided needle placement had no difficulty with surface markers, table location, or depth measurement from the surface. CT-guide needle placement is a feasible and reliable technique, so that when the tissue/blood sample is at risk of being spoiled, CT-guided needle placement could be a substitute for conventional sampling techniques.

  4. MRI-Compatible Pneumatic Robot for Transperineal Prostate Needle Placement

    PubMed Central

    Fischer, Gregory S.; Iordachita, Iulian; Csoma, Csaba; Tokuda, Junichi; DiMaio, Simon P.; Tempany, Clare M.; Hata, Nobuhiko; Fichtinger, Gabor

    2010-01-01

    Magnetic resonance imaging (MRI) can provide high-quality 3-D visualization of prostate and surrounding tissue, thus granting potential to be a superior medical imaging modality for guiding and monitoring prostatic interventions. However, the benefits cannot be readily harnessed for interventional procedures due to difficulties that surround the use of high-field (1.5T or greater) MRI. The inability to use conventional mechatronics and the confined physical space makes it extremely challenging to access the patient. We have designed a robotic assistant system that overcomes these difficulties and promises safe and reliable intraprostatic needle placement inside closed high-field MRI scanners. MRI compatibility of the robot has been evaluated under 3T MRI using standard prostate imaging sequences and average SNR loss is limited to 5%. Needle alignment accuracy of the robot under servo pneumatic control is better than 0.94 mm rms per axis. The complete system workflow has been evaluated in phantom studies with accurate visualization and targeting of five out of five 1 cm targets. The paper explains the robot mechanism and controller design, the system integration, and presents results of preliminary evaluation of the system. PMID:21057608

  5. MRI-Compatible Pneumatic Robot for Transperineal Prostate Needle Placement.

    PubMed

    Fischer, Gregory S; Iordachita, Iulian; Csoma, Csaba; Tokuda, Junichi; Dimaio, Simon P; Tempany, Clare M; Hata, Nobuhiko; Fichtinger, Gabor

    2008-06-01

    Magnetic resonance imaging (MRI) can provide high-quality 3-D visualization of prostate and surrounding tissue, thus granting potential to be a superior medical imaging modality for guiding and monitoring prostatic interventions. However, the benefits cannot be readily harnessed for interventional procedures due to difficulties that surround the use of high-field (1.5T or greater) MRI. The inability to use conventional mechatronics and the confined physical space makes it extremely challenging to access the patient. We have designed a robotic assistant system that overcomes these difficulties and promises safe and reliable intraprostatic needle placement inside closed high-field MRI scanners. MRI compatibility of the robot has been evaluated under 3T MRI using standard prostate imaging sequences and average SNR loss is limited to 5%. Needle alignment accuracy of the robot under servo pneumatic control is better than 0.94 mm rms per axis. The complete system workflow has been evaluated in phantom studies with accurate visualization and targeting of five out of five 1 cm targets. The paper explains the robot mechanism and controller design, the system integration, and presents results of preliminary evaluation of the system.

  6. Characteristics of Children Who Undergo Intraosseous Needle Placement.

    PubMed

    Reuter-Rice, Karin; Patrick, Dana; Kantor, Elizabeth; Nolin, Cathy; Foley, Jennifer

    2015-01-01

    Intraosseous (IO) access is a standard of care for pediatric emergencies in the absence of conventional intravenous access. Intraosseous needles provide access for resuscitation fluids and medications and are often placed in the emergency department. However, there are no studies to date that describe the characteristics of pediatric IO needle recipients or their dispositions and outcomes. This study examined the characteristics and disposition of children following IO needle placement by prehospital and emergency room teams before being transported to a children's hospital. We conducted a retrospective descriptive analysis of pediatric patients who had an IO needle placed as a part of their transport care. Data was extracted from a Level 1 trauma tertiary care children's hospital transport database from 1993 to 2009. We measured diagnosis, insertion reason, insertion time (day vs. night shift), complications, and disposition of patients after IO needle placement. There were 143 eligible patients in the study; 65% were males. Mean patient's age was 1.2 years (range: 0.01-13 years). Intraosseous needles were placed most often for patients with cardiopulmonary compromise. Of the 143 patients transported, 53% (n = 76) were placed for no intravenous access and 34% (n = 49) were placed for nonperfusing rhythm. The majority of the IO needles were placed during the daytime (0700-1900 hr), and most patients experienced no complications (n = 67; 47%). However, of those who experienced a complication, 27% were due to infiltration of the IO needle. Of those admitted to hospital, 58% (n = 83) were ultimately discharged home. Intraosseous access provides a safe and reliable method for rapidly achieving a route for administration of medications, fluids and blood products. It is a lifesaving measure with most IO needles successfully placed by referring facilities prior to transport, with few reported complications.

  7. Percutaneous needle placement using laser guidance: a practical solution

    NASA Astrophysics Data System (ADS)

    Xu, Sheng; Kapoor, Ankur; Abi-Jaoudeh, Nadine; Imbesi, Kimberly; Hong, Cheng William; Mazilu, Dumitru; Sharma, Karun; Venkatesan, Aradhana M.; Levy, Elliot; Wood, Bradford J.

    2013-03-01

    In interventional radiology, various navigation technologies have emerged aiming to improve the accuracy of device deployment and potentially the clinical outcomes of minimally invasive procedures. While these technologies' performance has been explored extensively, their impact on daily clinical practice remains undetermined due to the additional cost and complexity, modification of standard devices (e.g. electromagnetic tracking), and different levels of experience among physicians. Taking these factors into consideration, a robotic laser guidance system for percutaneous needle placement is developed. The laser guidance system projects a laser guide line onto the skin entry point of the patient, helping the physician to align the needle with the planned path of the preoperative CT scan. To minimize changes to the standard workflow, the robot is integrated with the CT scanner via optical tracking. As a result, no registration between the robot and CT is needed. The robot can compensate for the motion of the equipment and keep the laser guide line aligned with the biopsy path in real-time. Phantom experiments showed that the guidance system can benefit physicians at different skill levels, while clinical studies showed improved accuracy over conventional freehand needle insertion. The technology is safe, easy to use, and does not involve additional disposable costs. It is our expectation that this technology can be accepted by interventional radiologists for CT guided needle placement procedures.

  8. Accuracy of Needle Placement into the Intra-Articular Space of the Knee in Osteoarthritis Patients for Viscosupplementation

    PubMed Central

    Telikicherla, Manaswini

    2016-01-01

    Introduction Knee osteoarthritis is characterized by inflammation in the intra-articular space or synovial membrane, breakdown of articular cartilage, and sclerosis of the subchondral bone. Intra-articular injections of Sodium hyaluronate which have viscoelastic and protective effect on articular cartilage and restores normal articular homeostasis. The efficacy of these injections is diminished when they are placed inadvertently outside the joint. For the maximum benefit, injection of hyaluronic acid derivatives needs to be placed accurately into the knee joint. Aim The study was performed to know the correct placement of needle inside the knee joint prior to Viscosupplementation by fluoroscopy using a contrast material. Materials and Methods The accurate placement of needle was evaluated in a prospective series of 94 consecutive injections in patients without clinical knee effusion. All the injections were performed by single orthopaedic surgeon using a 5 cm 21-gauge needle through anterolateral, and lateral midpatellar portals. The needle placement in the knee joint was confirmed with fluoroscopy using the contrast material. Results The accuracy rates through Lateral midpatellar and Anterolateral portals were lower than expected rate (100%). A total of 43 out of 47 injections were intra-articular, indicating accuracy of 91.5% through lateral midpatellar portal, 41 out of 47 injections were intra-articular through anterolateral portal with accuracy of 87.4%. Conclusion Study showed that the accuracy of needle placement was higher through Lateral midpatellar than the Anterolateral portal. PMID:27042542

  9. Registration and motion compensation of a needle placement robot for CT-guided spinal procedures

    NASA Astrophysics Data System (ADS)

    Xu, Sheng; Cleary, Kevin R.; Stoianovici, Dan; Fichtinger, Gabor

    2005-04-01

    Computed tomography (CT) guided needle placement is an established practice in the medical field. The efficacy of these procedures is related to the accuracy of needle placement. Current free-hand techniques have limitations in accuracy, which is often affected by the patient motion. In response to these problems and as a testbed for future developments, we propose a robotically assisted needle placement system consisting of a mobile CT scanner, a needle insertion robot, and an optical localizer. This paper presents the overall system concept and concentrates on the system registration and compensation of the patient motion. Accuracy results using an abdominal phantom are also presented.

  10. Needle placement for piriformis injection using 3-D imaging.

    PubMed

    Clendenen, Steven R; Candler, Shawn A; Osborne, Michael D; Palmer, Scott C; Duench, Stephanie; Glynn, Laura; Ghazi, Salim M

    2013-01-01

    Piriformis syndrome is a pain syndrome originating in the buttock and is attributed to 6% - 8% of patients referred for the treatment of back and leg pain. The treatment for piriformis syndrome using fluoroscopy, computed tomography (CT), electromyography (EMG), and ultrasound (US) has become standard practice. The treatment of Piriformis Syndrome has evolved to include fluoroscopy and EMG with CT guidance. We present a case study of 5 successful piriformis injections using 3-D computer-assisted electromagnet needle tracking coupled with ultrasound. A 6-degree of freedom electromagnetic position tracker was attached to the ultrasound probe that allowed the system to detect the position and orientation of the probe in the magnetic field. The tracked ultrasound probe was used to find the posterior superior iliac spine. Subsequently, 3 points were captured to register the ultrasound image with the CT or magnetic resonance image scan. Moreover, after the registration was obtained, the navigation system visualized the tracked needle relative to the CT scan in real-time using 2 orthogonal multi-planar reconstructions centered at the tracked needle tip. Conversely, a recent study revealed that fluoroscopically guided injections had 30% accuracy compared to ultrasound guided injections, which tripled the accuracy percentage. This novel technique exhibited an accurate needle guidance injection precision of 98% while advancing to the piriformis muscle and avoiding the sciatic nerve. The mean (± SD) procedure time was 19.08 (± 4.9) minutes. This technique allows for electromagnetic instrument tip tracking with real-time 3-D guidance to the selected target. As with any new technique, a learning curve is expected; however, this technique could offer an alternative, minimizing radiation exposure.

  11. Development of an MRI-Guided Intra-Prostatic Needle Placement System

    DTIC Science & Technology

    2011-07-01

    and intra-operative imaging using techniques such as those described by Haker , et al. [18]. Target points for the needle insertion are selected... Haker , S., Fichtinger, G., Tem- pany, C.: Transperineal prostate biopsy under magnetic resonance image guid- ance: A needle placement accuracy study 26...clinically localized prostate cancer. Int J Radiat Oncol Biol Phys 42(3), 507–515 (1998) 9. DiMaio, S.P., Pieper, S., Chinzei, K., Hata, N., Haker , S.J

  12. An augmented reality simulator for ultrasound guided needle placement training.

    PubMed

    Magee, D; Zhu, Y; Ratnalingam, R; Gardner, P; Kessel, D

    2007-10-01

    Details are presented of a low cost augmented-reality system for the simulation of ultrasound guided needle insertion procedures (tissue biopsy, abscess drainage, nephrostomy etc.) for interventional radiology education and training. The system comprises physical elements; a mannequin, a mock ultrasound probe and a needle, and software elements; generating virtual ultrasound anatomy and allowing data collection. These two elements are linked by a pair of magnetic 3D position sensors. Virtual anatomic images are generated based on anatomic data derived from full body CT scans of live humans. Details of the novel aspects of this system are presented including; image generation, registration and calibration.

  13. Experimental platform for intra-uterine needle placement procedures

    NASA Astrophysics Data System (ADS)

    Madjidi, Yashar; Haidegger, Tamás.; Ptacek, Wolfgang; Berger, Daniel; Kirisits, Christian; Kronreif, Gernot; Fichtinger, Gabor

    2013-03-01

    A framework has been investigated to enable a variety of comparative studies in the context of needle-based gynaecological brachytherapy. Our aim was to create an anthropomorphic phantom-based platform. The three main elements of the platform are the organ model, needle guide, and needle drive. These have been studied and designed to replicate the close environment of brachytherapy treatment for cervical cancer. Key features were created with the help of collaborating interventional radio-oncologists and the observations made in the operating room. A phantom box, representing the uterus model, has been developed considering available surgical analogies and operational limitations, such as organs at risk. A modular phantom-based platform has been designed and prototyped with the capability of providing various boundary conditions for the target organ. By mimicking the female pelvic floor, this framework has been used to compare a variety of needle insertion techniques and configurations for cervical and uterine interventions. The results showed that the proposed methodology is useful for the investigation of quantifiable experiments in the intraabdominal and pelvic regions.

  14. Feasibility Study of Needle Placement in Percutaneous Vertebroplasty: Cone-Beam Computed Tomography Guidance Versus Conventional Fluoroscopy

    SciTech Connect

    Braak, Sicco J.; Zuurmond, Kirsten Aerts, Hans C. J.; Leersum, Marc van Overtoom, Timotheus T. Th. Heesewijk, Johannes P. M. van Strijen, Marco J. L. van

    2013-08-01

    ObjectiveTo investigate the accuracy, procedure time, fluoroscopy time, and dose area product (DAP) of needle placement during percutaneous vertebroplasty (PVP) using cone-beam computed tomography (CBCT) guidance versus fluoroscopy.Materials and MethodsOn 4 spine phantoms with 11 vertebrae (Th7-L5), 4 interventional radiologists (2 experienced with CBCT guidance and two inexperienced) punctured all vertebrae in a bipedicular fashion. Each side was randomization to either CBCT guidance or fluoroscopy. CBCT guidance is a sophisticated needle guidance technique using CBCT, navigation software, and real-time fluoroscopy. The placement of the needle had to be to a specific target point. After the procedure, CBCT was performed to determine the accuracy, procedure time, fluoroscopy time, and DAP. Analysis of the difference between methods and experience level was performed.ResultsMean accuracy using CBCT guidance (2.61 mm) was significantly better compared with fluoroscopy (5.86 mm) (p < 0.0001). Procedure time was in favor of fluoroscopy (7.39 vs. 10.13 min; p = 0.001). Fluoroscopy time during CBCT guidance was lower, but this difference is not significant (71.3 vs. 95.8 s; p = 0.056). DAP values for CBCT guidance and fluoroscopy were 514 and 174 mGy cm{sup 2}, respectively (p < 0.0001). There was a significant difference in favor of experienced CBCT guidance users regarding accuracy for both methods, procedure time of CBCT guidance, and added DAP values for fluoroscopy.ConclusionCBCT guidance allows users to perform PVP more accurately at the cost of higher patient dose and longer procedure time. Because procedural complications (e.g., cement leakage) are related to the accuracy of the needle placement, improvements in accuracy are clinically relevant. Training in CBCT guidance is essential to achieve greater accuracy and decrease procedure time/dose values.

  15. Pneumatically Operated MRI-Compatible Needle Placement Robot for Prostate Interventions.

    PubMed

    Fischer, Gregory S; Iordachita, Iulian; Csoma, Csaba; Tokuda, Junichi; Mewes, Philip W; Tempany, Clare M; Hata, Nobuhiko; Fichtinger, Gabor

    2008-06-13

    Magnetic Resonance Imaging (MRI) has potential to be a superior medical imaging modality for guiding and monitoring prostatic interventions. The strong magnetic field prevents the use of conventional mechatronics and the confined physical space makes it extremely challenging to access the patient. We have designed a robotic assistant system that overcomes these difficulties and promises safe and reliable intra-prostatic needle placement inside closed high-field MRI scanners. The robot performs needle insertion under real-time 3T MR image guidance; workspace requirements, MR compatibility, and workflow have been evaluated on phantoms. The paper explains the robot mechanism and controller design and presents results of preliminary evaluation of the system.

  16. Spectral tissue sensing to identify intra- and extravascular needle placement — A randomized single-blind controlled trial

    PubMed Central

    Balthasar, Andrea J. R.; van Geffen, Geert-Jan; van der Voort, Marjolein; Lucassen, Gerald W.; Roggeveen, Stefan; Bruaset, Ivar J.; Bruhn, Joergen

    2017-01-01

    Safe vascular access is a prerequisite for intravenous drug admission. Discrimination between intra- and extravascular needle position is essential for procedure safety. Spectral tissue sensing (STS), based on optical spectroscopy, can provide tissue information directly from the needle tip. The primary objective of the trial was to investigate if STS can reliably discriminate intra-vascular (venous) from non-vascular punctures. In 20 healthy volunteers, a needle with an STS stylet was inserted, and measurements were performed for two intended locations: the first was subcutaneous, while the second location was randomly selected as either subcutaneous or intravenous. The needle position was assessed using ultrasound (US) and aspiration. The operators who collected the data from the spectral device were blinded to the insertion and ultrasonographic visualization procedure and the physician was blinded to the spectral data. Following offline spectral analysis, a prediction of intravascular or subcutaneous needle placement was made and compared with the “true” needle tip position as indicated by US and aspiration. Data for 19 volunteers were included in the analysis. Six out of 8 intended vascular needle placements were defined as intravascular according to US and aspiration. The remaining two intended vascular needle placements were negative for aspiration. For the other 11 final needle locations, the needle was clearly subcutaneous according to US examination and no blood was aspirated. The Mann-Whitney U test yielded a p-value of 0.012 for the between-group comparison. The differences between extra- and intravascular were in the within-group comparison computed with the Wilcoxon signed-rank test was a p-value of 0.022. In conclusion, STS is a promising method for discriminating between intravascular and extravascular needle placement. The information provided by this method may complement current methods for detecting an intravascular needle position. PMID

  17. Pneumatically Operated MRI-Compatible Needle Placement Robot for Prostate Interventions

    PubMed Central

    Fischer, Gregory S.; Iordachita, Iulian; Csoma, Csaba; Tokuda, Junichi; Mewes, Philip W.; Tempany, Clare M.; Hata, Nobuhiko; Fichtinger, Gabor

    2011-01-01

    Magnetic Resonance Imaging (MRI) has potential to be a superior medical imaging modality for guiding and monitoring prostatic interventions. The strong magnetic field prevents the use of conventional mechatronics and the confined physical space makes it extremely challenging to access the patient. We have designed a robotic assistant system that overcomes these difficulties and promises safe and reliable intra-prostatic needle placement inside closed high-field MRI scanners. The robot performs needle insertion under real-time 3T MR image guidance; workspace requirements, MR compatibility, and workflow have been evaluated on phantoms. The paper explains the robot mechanism and controller design and presents results of preliminary evaluation of the system. PMID:21686038

  18. Dominant hand operating probe vs needle: a comparison study of ultrasound-guided needle placement in phantom models.

    PubMed

    Johnston, D F; Stafford, M

    2015-08-01

    We conducted a replicated crossover design study to assess if using one's dominant hand for operating a probe vs directing a needle would affect the time taken, the number of needle passes and the accuracy of an ultrasound-guided procedure in phantom models. Twenty ultrasound-novice participants completed the task 10 times for each hand arrangement (alternating between attempts). The time taken and number of needle passes required for both dominant hand-probe and hand-needle decreased over time (p = 0.001). Dominant hand-needle had a lower mean time used (p = 0.001) and fewer needle passes (p = 0.02) compared with hand-probe. Sixty-five per cent of participants preferred using their dominant hand to direct the needle. When learning ultrasound-guided needle procedures on phantom models, use of the dominant hand to operate the needle is associated with a shorter procedure time and fewer needle passes.

  19. Visualization tool for improved accuracy in needle placement during percutaneous radio-frequency ablation of liver tumors

    NASA Astrophysics Data System (ADS)

    Stüdeli, Thomas; Kalkofen, Denis; Risholm, Petter; Ali, Wajid; Freudenthal, Adinda; Samset, Eigil

    2008-03-01

    The European research network "Augmented reality in Surgery" (ARIS*ER) developed a system that supports percutaneous radio frequency ablation of liver tumors. The system provides interventionists, during placement and insertion of the RFA needle, with information from pre-operative CT images and real-time tracking data. A visualization tool has been designed that aims to support (1) exploration of the abdomen, (2) planning of needle trajectory and (3) insertion of the needle in the most efficient way. This work describes a first evaluation of the system, where user performances and feedback of two visualization concepts of the tool - needle view and user view - are compared. After being introduced to the system, ten subjects performed three needle placements with both concepts. Task fulfillment rate, time for completion of task, special incidences, accuracy of needle placement recorded and analyzed. The results show ambiguous results with beneficial and less favorable effects on user performance and workload of both concepts. Effects depend on characteristics of intra-operative tasks as well as on task complexities depending on tumor location. The results give valuable input for the next design steps.

  20. Preclinical evaluation of an MRI-compatible pneumatic robot for angulated needle placement in transperineal prostate interventions

    PubMed Central

    Tokuda, Junichi; Song, Sang-Eun; Fischer, Gregory S.; Iordachita, Iulian; Seifabadi, Reza; Cho, Bong Joon; Tuncali, Kemal; Fichtinger, Gabor; Tempany, Clare M.; Hata, Nobuhiko

    2013-01-01

    Purpose To evaluate the targeting accuracy of a small profile MRI-compatible pneumatic robot for needle placement that can angulate a needle insertion path into a large accessible target volume. Methods We extended our MRI-compatible pneumatic robot for needle placement to utilize its four degrees-of-freedom (4-DOF) mechanism with two parallel triangular structures and support transperineal prostate biopsies in a closed-bore magnetic resonance imaging (MRI) scanner. The robot is designed to guide a needle towards a lesion so that a radiologist can manually insert it in the bore. The robot is integrated with navigation software that allows an operator to plan angulated needle insertion by selecting a target and an entry point. The targeting error was evaluated while the angle between the needle insertion path and the static magnetic field was between −5.7° and 5.7° horizontally and between −5.7° and 4.3° vertically in the MRI scanner after sterilizing and draping the device. Results The robot positioned the needle for angulated insertion as specified on the navigation software with overall targeting error of 0.8 ± 0.5 mm along the horizontal axis and 0.8 ± 0.8 mm along the vertical axis. The two-dimensional root-mean-square targeting error on the axial slices as containing the targets was 1.4 mm. Conclusions Our preclinical evaluation demonstrated that the MRI-compatible pneumatic robot for needle placement with the capability to angulate the needle insertion path provides targeting accuracy feasible for clinical MRI-guided prostate interventions. The clinical feasibility has to be established in a clinical study. PMID:22678723

  1. Virtobot 2.0: the future of automated surface documentation and CT-guided needle placement in forensic medicine.

    PubMed

    Ebert, Lars Christian; Ptacek, Wolfgang; Breitbeck, Robert; Fürst, Martin; Kronreif, Gernot; Martinez, Rosa Maria; Thali, Michael; Flach, Patricia M

    2014-06-01

    In this paper we present the second prototype of a robotic system to be used in forensic medicine. The system is capable of performing automated surface documentation using photogrammetry, optical surface scanning and image-guided, post-mortem needle placement for tissue sampling, liquid sampling, or the placement of guide wires. The upgraded system includes workflow optimizations, an automatic tool-change mechanism, a new software module for trajectory planning and a fully automatic computed tomography-data-set registration algorithm. We tested the placement accuracy of the system by using a needle phantom with radiopaque markers as targets. The system is routinely used for surface documentation and resulted in 24 surface documentations over the course of 11 months. We performed accuracy tests for needle placement using a biopsy phantom, and the Virtobot placed introducer needles with an accuracy of 1.4 mm (±0.9 mm). The second prototype of the Virtobot system is an upgrade of the first prototype but mainly focuses on streamlining the workflow and increasing the level of automation and also has an easier user interface. These upgrades make the Virtobot a potentially valuable tool for case documentation in a scalpel-free setting that uses purely imaging techniques and minimally invasive procedures and is the next step toward the future of virtual autopsy.

  2. Accurate biopsy-needle depth estimation in limited-angle tomography using multi-view geometry

    NASA Astrophysics Data System (ADS)

    van der Sommen, Fons; Zinger, Sveta; de With, Peter H. N.

    2016-03-01

    Recently, compressed-sensing based algorithms have enabled volume reconstruction from projection images acquired over a relatively small angle (θ < 20°). These methods enable accurate depth estimation of surgical tools with respect to anatomical structures. However, they are computationally expensive and time consuming, rendering them unattractive for image-guided interventions. We propose an alternative approach for depth estimation of biopsy needles during image-guided interventions, in which we split the problem into two parts and solve them independently: needle-depth estimation and volume reconstruction. The complete proposed system consists of the previous two steps, preceded by needle extraction. First, we detect the biopsy needle in the projection images and remove it by interpolation. Next, we exploit epipolar geometry to find point-to-point correspondences in the projection images to triangulate the 3D position of the needle in the volume. Finally, we use the interpolated projection images to reconstruct the local anatomical structures and indicate the position of the needle within this volume. For validation of the algorithm, we have recorded a full CT scan of a phantom with an inserted biopsy needle. The performance of our approach ranges from a median error of 2.94 mm for an distributed viewing angle of 1° down to an error of 0.30 mm for an angle larger than 10°. Based on the results of this initial phantom study, we conclude that multi-view geometry offers an attractive alternative to time-consuming iterative methods for the depth estimation of surgical tools during C-arm-based image-guided interventions.

  3. Evaluation of nonholonomic needle steering using a robotic needle driver

    NASA Astrophysics Data System (ADS)

    Wilson, Emmanuel; Ding, Jeinan; Carignan, Craig; Krishnan, Karthik; Avila, Rick; Turner, Wes; Stoianovici, Dan; Yankelevitz, David; Banovac, Filip; Cleary, Kevin

    2010-02-01

    Accurate needle placement is a common need in the medical environment. While the use of small diameter needles for clinical applications such as biopsy, anesthesia and cholangiography is preferred over the use of larger diameter needles, precision placement can often be challenging, particularly for needles with a bevel tip. This is due to deflection of the needle shaft caused by asymmetry of the needle tip. Factors such as the needle shaft material, bevel design, and properties of the tissue penetrated determine the nature and extent to which a needle bends. In recent years, several models have been developed to characterize the bending of the needle, which provides a method of determining the trajectory of the needle through tissue. This paper explores the use of a nonholonomic model to characterize needle bending while providing added capabilities of path planning, obstacle avoidance, and path correction for lung biopsy procedures. We used a ballistic gel media phantom and a robotic needle placement device to experimentally assess the accuracy of simulated needle paths based on the nonholonomic model. Two sets of experiments were conducted, one for a single bend profile of the needle and the second set of tests for double bending of the needle. The tests provided an average error between the simulated path and the actual path of 0.8 mm for the single bend profile and 0.9 mm for the double bend profile tests over a 110 mm long insertion distance. The maximum error was 7.4 mm and 6.9 mm for the single and double bend profile tests respectively. The nonholonomic model is therefore shown to provide a reasonable prediction of needle bending.

  4. Comparison of CT Fluoroscopy-Guided Manual and CT-Guided Robotic Positioning System for In Vivo Needle Placements in Swine Liver

    SciTech Connect

    Cornelis, F.; Takaki, H.; Laskhmanan, M.; Durack, J. C.; Erinjeri, J. P.; Getrajdman, G. I.; Maybody, M.; Sofocleous, C. T.; Solomon, S. B.; Srimathveeravalli, G.

    2015-10-15

    PurposeTo compare CT fluoroscopy-guided manual and CT-guided robotic positioning system (RPS)-assisted needle placement by experienced IR physicians to targets in swine liver.Materials and MethodsManual and RPS-assisted needle placement was performed by six experienced IR physicians to four 5 mm fiducial seeds placed in swine liver (n = 6). Placement performance was assessed for placement accuracy, procedure time, number of confirmatory scans, needle manipulations, and procedure radiation dose. Intra-modality difference in performance for each physician was assessed using paired t test. Inter-physician performance variation for each modality was analyzed using Kruskal–Wallis test.ResultsPaired comparison of manual and RPS-assisted placements to a target by the same physician indicated accuracy outcomes was not statistically different (manual: 4.53 mm; RPS: 4.66 mm; p = 0.41), but manual placement resulted in higher total radiation dose (manual: 1075.77 mGy/cm; RPS: 636.4 mGy/cm; p = 0.03), required more confirmation scans (manual: 6.6; RPS: 1.6; p < 0.0001) and needle manipulations (manual: 4.6; RPS: 0.4; p < 0.0001). Procedure time for RPS was longer than manual placement (manual: 6.12 min; RPS: 9.7 min; p = 0.0003). Comparison of inter-physician performance during manual placement indicated significant differences in the time taken to complete placements (p = 0.008) and number of repositions (p = 0.04) but not in other study measures (p > 0.05). Comparison of inter-physician performance during RPS-assisted placement suggested statistically significant differences in procedure time (p = 0.02) and not in other study measures (p > 0.05).ConclusionsCT-guided RPS-assisted needle placement reduced radiation dose, number of confirmatory scans, and needle manipulations when compared to manual needle placement by experienced IR physicians, with equivalent accuracy.

  5. Precision grid and hand motion for accurate needle insertion in brachytherapy

    SciTech Connect

    McGill, Carl S.; Schwartz, Jonathon A.; Moore, Jason Z.; McLaughlin, Patrick W.; Shih, Albert J.

    2011-08-15

    Purpose: In prostate brachytherapy, a grid is used to guide a needle tip toward a preplanned location within the tissue. During insertion, the needle deflects en route resulting in target misplacement. In this paper, 18-gauge needle insertion experiments into phantom were performed to test effects of three parameters, which include the clearance between the grid hole and needle, the thickness of the grid, and the needle insertion speed. Measurement apparatus that consisted of two datum surfaces and digital depth gauge was developed to quantify needle deflections. Methods: The gauge repeatability and reproducibility (GR and R) test was performed on the measurement apparatus, and it proved to be capable of measuring a 2 mm tolerance from the target. Replicated experiments were performed on a 2{sup 3} factorial design (three parameters at two levels) and analysis included averages and standard deviation along with an analysis of variance (ANOVA) to find significant single and two-way interaction factors. Results: Results showed that grid with tight clearance hole and slow needle speed increased precision and accuracy of needle insertion. The tight grid was vital to enhance precision and accuracy of needle insertion for both slow and fast insertion speed; additionally, at slow speed the tight, thick grid improved needle precision and accuracy. Conclusions: In summary, the tight grid is important, regardless of speed. The grid design, which shows the capability to reduce the needle deflection in brachytherapy procedures, can potentially be implemented in the brachytherapy procedure.

  6. Ultrasound-guided core needle biopsy of the breast: does frozen section give an accurate diagnosis?

    PubMed

    Mueller-Holzner, Elisabeth; Frede, Thomas; Daniaux, Martin; Ban, Michael; Taucher, Susanne; Schneitter, Alois; Zeimet, Alain G; Marth, Christian

    2007-12-01

    Reducing the period of uncertainty between the discovery of a breast tumor and histological diagnosis alleviates the psychological impact of breast cancer to an important degree. We aimed to verify whether histological results obtained with frozen sections of core needle biopsies (CNBs) offer an accurate and reliable tool for minimising this period. In 2619 cases we compared histological diagnosis on frozen sections with those on paraffin sections of CNB and finally with the results of open biopsies. Of the cases 49% were proved malignant and 51% benign. In 99.3% of the malignant lesions preceding CNB was correctly classified as B5 (n = 1185, 92.9%) or at least B4 (n = 82, 6.4%) in frozen and in paraffin sections. There were seven false-negative cases in frozen (false-negative rate = 0.5%) and five false-negative cases (false-negative rate = 0.4%) in paraffin sections of CNB. On frozen sections complete sensitivity was 99.5% and the positive predictive value of B5 was 99.9%. There was one false-positive case in frozen sections and one in paraffin sections. False-positive rate = 0.08%, negative predictive value for B2 = 99.4% for frozen and 99.6% for paraffin sections; full specificity was 85.9 for frozen and 85.8 for paraffin sections of CNBs. Immediate investigation of CNB in frozen sections is an accurate diagnostic method and an important step in reducing psychological strain on patients with breast tumors and may be offered by specialised Breast Assessment Units.

  7. Imaging behind opaque obstacle: a potential method for guided in vitro needle placement

    PubMed Central

    Perinchery, Sandeep Menon; Shinde, Anant; Matham, Murukeshan Vadakke

    2016-01-01

    We report a simple real time optical imaging concept using an axicon lens to image the object kept behind opaque obstacles in free space. The proposed concept underlines the importance and advantages of using an axicon lens compared to a conventional lens to image behind the obstacle. The potential of this imaging concept is demonstrated by imaging the insertion of surgical needle in biological specimen in real time, without blocking the field of view. It is envisaged that this proposed concepts and methodology can make a telling impact in a wide variety of areas especially for diagnostics, therapeutics and microscopy applications. PMID:28018744

  8. Gene expression using an ultrathin needle enabling accurate displacement and low invasiveness

    SciTech Connect

    Han, SungWoong; Nakamura, Chikashi; E-mail: chikashi-nakamura@aist.go.jp; Obataya, Ikuo; Nakamura, Noriyuki; Miyake, Jun

    2005-07-08

    We have previously demonstrated a new cell manipulation technology by using an atomic force microscope (AFM) and ultrathin needles, named nanoneedles. The nanoneedle is an AFM tip etched by a focused ion beam (FIB) and is sharpened from 200 to 800 nm in diameter. In this study, we have evaluated the proper diameter of a needle required for insertion into human cells over a long period without causing cell death, and achieved highly efficient gene expression method for human cells using a nanoneedle and an AFM.

  9. Accurate defect die placement and nuisance defect reduction for reticle die-to-die inspections

    NASA Astrophysics Data System (ADS)

    Wen, Vincent; Huang, L. R.; Lin, C. J.; Tseng, Y. N.; Huang, W. H.; Tuo, Laurent C.; Wylie, Mark; Chen, Ellison; Wang, Elvik; Glasser, Joshua; Kelkar, Amrish; Wu, David

    2015-10-01

    Die-to-die reticle inspections are among the simplest and most sensitive reticle inspections because of the use of an identical-design neighboring-die for the reference image. However, this inspection mode can have two key disadvantages: (1) The location of the defect is indeterminate because it is unclear to the inspector whether the test or reference image is defective; and (2) nuisance and false defects from mask manufacturing noise and tool optical variation can limit the usable sensitivity. The use of a new sequencing approach for a die-to-die inspection can resolve these issues without any additional scan time, without sacrifice in sensitivity requirement, and with a manageable increase in computation load. In this paper we explore another approach for die-to-die inspections using a new method of defect processing and sequencing. Utilizing die-to-die double arbitration during defect detection has been proven through extensive testing to generate accurate placement of the defect in the correct die to ensure efficient defect disposition at the AIMS step. The use of this method maintained the required inspection sensitivity for mask quality as verified with programmed-defectmask qualification and then further validated with production masks comparing the current inspection approach to the new method. Furthermore, this approach can significantly reduce the total number of defects that need to be reviewed by essentially eliminating the nuisance and false defects that can result from a die-to-die inspection. This "double-win" will significantly reduce the effort in classifying a die-to-die inspection result and will lead to improved cycle times.

  10. Photoacoustic-guided focused ultrasound for accurate visualization of brachytherapy seeds with the photoacoustic needle

    NASA Astrophysics Data System (ADS)

    Singh, Mithun Kuniyil Ajith; Parameshwarappa, Vinay; Hendriksen, Ellen; Steenbergen, Wiendelt; Manohar, Srirang

    2016-12-01

    An important problem in minimally invasive photoacoustic (PA) imaging of brachytherapy seeds is reflection artifacts caused by the high signal from the optical fiber/needle tip reflecting off the seed. The presence of these artifacts confounds interpretation of images. In this letter, we demonstrate a recently developed concept called photoacoustic-guided focused ultrasound (PAFUSion) for the first time in the context of interstitial illumination PA imaging to identify and remove reflection artifacts. In this method, ultrasound (US) from the transducer is focused on the region of the optical fiber/needle tip identified in a first step using PA imaging. The image developed from the US diverging from the focus zone at the tip region visualizes only the reflections from seeds and other acoustic inhomogeneities, allowing identification of the reflection artifacts of the first step. These artifacts can then be removed from the PA image. Using PAFUSion, we demonstrate reduction of reflection artifacts and thereby improved interstitial PA visualization of brachytherapy seeds in phantom and ex vivo measurements on porcine tissue.

  11. Accurate measurement of optical properties of narrow leaves and conifer needles with a typical integrating sphere and spectroradiometer.

    PubMed

    Noda, Hibiki M; Motohka, Takeshi; Murakami, Kazutaka; Muraoka, Hiroyuki; Nasahara, Kenlo Nishida

    2013-10-01

    Accurate information on the optical properties (reflectance and transmittance spectra) of single leaves is important for an ecophysiological understanding of light use by leaves, radiative transfer models and remote sensing of terrestrial ecosystems. In general, leaf optical properties are measured with an integrating sphere and a spectroradiometer. However, this method is usually difficult to use with grass leaves and conifer needles because they are too narrow to cover the sample port of a typical integrating sphere. Although ways to measure the optical properties of narrow leaves have been suggested, they have problems. We propose a new measurement protocol and calculation algorithms. The protocol does not damage sample leaves and is valid for various types of leaves, including green and senescent. We tested our technique with leaves of Aucuba japonica, an evergreen broadleaved shrub, and compared the spectral data of whole leaves and narrow strips of the leaves. The reflectance and transmittance of the strips matched those of the whole leaves, indicating that our technique can accurately estimate the optical properties of narrow leaves. Tests of conifer needles confirmed the applicability.

  12. Are School Placement Recommendations Accurate? The Effect of Students' Ethnicity on Teachers' Judgments and Recognition Memory

    ERIC Educational Resources Information Center

    Glock, Sabine; Krolak-Schwerdt, Sabine; Pit-ten Cate, Ineke M.

    2015-01-01

    Educational research has provided evidence that racial and ethnic minority students are disadvantaged in today's educational systems. Teachers' stereotypical expectations are believed to contribute to these disadvantages because teachers make decisions about grades, special education, tracking, and school placement. Research so far has shown that…

  13. Collagen, type XI, alpha 1: an accurate marker for differential diagnosis of breast carcinoma invasiveness in core needle biopsies.

    PubMed

    Freire, Javier; Domínguez-Hormaetxe, Saioa; Pereda, Saray; De Juan, Ana; Vega, Alfonso; Simón, Laureano; Gómez-Román, Javier

    2014-12-01

    Accurate diagnosis of invasive breast lesions, when analyzed by Core Needle Biopsy, may suppose a major challenge for the pathologist. Various markers of invasiveness such as laminin, S-100 protein, P63 or calponin have been described; however, none of them is completely reliable. The use of a specific marker of the infiltrating tumor microenvironment seems vital to support the diagnosis of invasive against in situ lesions. At this point, Collagen, type XI, alpha 1 (COL11A1), might be helpful since it has been described to be associated to cancer associated fibroblasts in other tumors such as lung, pancreas or colorectal. This paper aims to analyze the role of COL11A1 as a marker of invasiveness in breast tumor lesions. Two hundred and one breast Core Needle Biopsy samples were analyzed by immunohistochemistry against pro-COL11A1. The results show a significant difference (p < 0.0001) when comparing the expression in infiltrative tumors (93%) versus immunostaining of non-invasive lesions (4%). Forty cases of underestimated DCIS were also stained for COL11A1, presenting a sensitivity of 90% when compared with p63 and calponin which not tagged invasion. In conclusion, pro-COL11A1 expression is a promising marker of invasive breast lesions, and may be included in immunohistochemical panels aiming at identifying infiltration in problematic breast lesions.

  14. Comparison of Spinal Needle Deflection in a Ballistic Gel Model

    PubMed Central

    Rand, Ethan; Christolias, George; Visco, Christopher; R. Singh, Jaspal

    2016-01-01

    Background Percutaneous diagnostic and therapeutic procedures are commonly used in the treatment of spinal pain. The success of these procedures depends on the accuracy of needle placement, which is influenced by needle size and shape. Objectives The purpose of this study is to examine and quantify the deviation of commonly used spinal needles based on needle tip design and gauge, using a ballistic gel tissue simulant. Materials and Methods Six needles commonly used in spinal procedures (Quincke, Short Bevel, Chiba, Tuohy, Hustead, Whitacre) were selected for use in this study. Ballistic gel samples were made in molds of two depths, 40mm and 80 mm. Each needle was mounted in a drill press to ensure an accurate needle trajectory. Distance of deflection was recorded for each needle. Results In comparing the mean deflection of 22 gauge needles of all types at 80 mm of depth, deflection was greatest among beveled needles [Short Bevel (9.96 ± 0.77 mm), Quincke (8.89 ± 0.17 mm), Chiba (7.71 ± 1.16 mm)], moderate among epidural needles [Tuohy (7.64 ± 0.16 mm) and least among the pencil-point needles [Whitacre (0.73 ± 0.34 mm)]. Increased gauge (25 g) led to a significant increase in deflection among beveled needles. The direction of deflection was away from the bevel with Quincke, Chiba and Short Beveled needles and toward the bevel of the Tuohy and Hustead needles. Deflection of the Whitacre pencil-point needle was minimal. Conclusions There is clinical utility in knowing the relative deflection of various needle tips. When a procedure requires a needle to be steered around obstacles, or along non-collinear targets, the predictable and large amount of deflection obtained through use of a beveled spinal needle may prove beneficial. PMID:27847693

  15. Towards synergistic control of hands-on needle insertion with automated needle steering for MRI-guided prostate interventions.

    PubMed

    Wartenberg, Marek; Patel, Niravkumar; Gang Li; Fischer, Gregory S

    2016-08-01

    A significant hurdle of accurate needle tip placement in percutaneous needle-based prostate interventions is unmodeled needle deflection and tissue deformation during insertion. This paper introduces a robotic platform for developing synergistic, cooperatively controlled needle insertion algorithms decoupled from closed-loop image-guided needle steering. Shared control of the surgical workspace through human-robot synergy creates a balance between the accuracy of robotic autonomy while still providing ultimate control of the procedure to the physician. Validation tests were performed using camera-based image-guided feedback control of needle steering with cooperative hands-on needle insertion. Locations were targeted inside a transparent gelatin phantom with an average total error of 2.68 ± 0.34mm and in-plane error of 2.59 ± 0.30mm.

  16. Finite element analysis of the effect of electrodes placement on accurate resistivity measurement in a diamond anvil cell with van der Pauw technique

    NASA Astrophysics Data System (ADS)

    Wu, Baojia; Huang, Xiaowei; Han, Yonghao; Gao, Chunxiao; Peng, Gang; Liu, Cailong; Wang, Yue; Cui, Xiaoyan; Zou, Guangtian

    2010-05-01

    The van der Pauw technique is widely used to determine resistivity of materials. In diamond anvil cell the compressed sample will make the contact placement change under high pressure. Using finite element analysis, we study the effect of contact placement error induced by pressure on the resistivity measurement accuracy of van der Pauw method. The results show the contact placement has a significant effect on determination accuracy. This method can provide accurate determination of sample resistivity when the spacing b between the contact center and sample periphery is less than D/9 (sample diameter). And the effect of contact placement error on accuracy rapidly increases as the contact location is closing to the sample center. For the same contact placement, the contact size error has a more obvious effect on the semiconductor sample.

  17. Finite element analysis of the effect of electrodes placement on accurate resistivity measurement in a diamond anvil cell with van der Pauw technique

    SciTech Connect

    Wu Baojia; Huang Xiaowei; Han Yonghao; Gao Chunxiao; Peng Gang; Liu Cailong; Wang Yue; Cui Xiaoyan; Zou Guangtian

    2010-05-15

    The van der Pauw technique is widely used to determine resistivity of materials. In diamond anvil cell the compressed sample will make the contact placement change under high pressure. Using finite element analysis, we study the effect of contact placement error induced by pressure on the resistivity measurement accuracy of van der Pauw method. The results show the contact placement has a significant effect on determination accuracy. This method can provide accurate determination of sample resistivity when the spacing b between the contact center and sample periphery is less than D/9 (sample diameter). And the effect of contact placement error on accuracy rapidly increases as the contact location is closing to the sample center. For the same contact placement, the contact size error has a more obvious effect on the semiconductor sample.

  18. C-arm Cone Beam Computed Tomographic Needle Path Overlay for Fluoroscopic-Guided Placement of Translumbar Central Venous Catheters

    SciTech Connect

    Tam, Alda; Mohamed, Ashraf; Pfister, Marcus; Rohm, Esther; Wallace, Michael J.

    2009-07-15

    C-arm cone beam computed tomography is an advanced 3D imaging technology that is currently available on state-of-the-art flat-panel-based angiography systems. The overlay of cross-sectional imaging information can now be integrated with real-time fluoroscopy. This overlay technology was used to guide the placement of three percutaneous translumbar inferior vena cava catheters.

  19. A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement.

    PubMed

    Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S

    2013-01-01

    Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scanner. The opto-electronic sensing system design was minimized to fit inside an MRI-compatible robot controller enclosure. A flexure mechanism was designed that integrates the FPI sensor fiber for measuring needle insertion force, and finite element analysis was performed for optimizing the correct force-deformation relationship. The compact, low-cost FPI sensing system was integrated into the robot and calibration was conducted. The root mean square (RMS) error of the calibration among the range of 0-10 Newton was 0.318 Newton comparing to the theoretical model which has been proven sufficient for robot control and teleoperation.

  20. A Fabry-Perot Interferometry Based MRI-Compatible Miniature Uniaxial Force Sensor for Percutaneous Needle Placement

    PubMed Central

    Shang, Weijian; Su, Hao; Li, Gang; Furlong, Cosme; Fischer, Gregory S.

    2014-01-01

    Robot-assisted surgical procedures, taking advantage of the high soft tissue contrast and real-time imaging of magnetic resonance imaging (MRI), are developing rapidly. However, it is crucial to maintain tactile force feedback in MRI-guided needle-based procedures. This paper presents a Fabry-Perot interference (FPI) based system of an MRI-compatible fiber optic sensor which has been integrated into a piezoelectrically actuated robot for prostate cancer biopsy and brachytherapy in 3T MRI scanner. The opto-electronic sensing system design was minimized to fit inside an MRI-compatible robot controller enclosure. A flexure mechanism was designed that integrates the FPI sensor fiber for measuring needle insertion force, and finite element analysis was performed for optimizing the correct force-deformation relationship. The compact, low-cost FPI sensing system was integrated into the robot and calibration was conducted. The root mean square (RMS) error of the calibration among the range of 0–10 Newton was 0.318 Newton comparing to the theoretical model which has been proven sufficient for robot control and teleoperation. PMID:25126153

  1. A model to predict deflection of bevel-tipped active needle advancing in soft tissue.

    PubMed

    Datla, Naresh V; Konh, Bardia; Honarvar, Mohammad; Podder, Tarun K; Dicker, Adam P; Yu, Yan; Hutapea, Parsaoran

    2014-03-01

    Active needles are recently being developed to improve steerability and placement accuracy for various medical applications. These active needles can bend during insertion by actuators attached to their bodies. The bending of active needles enables them to be steered away from the critical organs on the way to target and accurately reach target locations previously unachievable with conventional rigid needles. These active needles combined with an asymmetric bevel-tip can further improve their steerability. To optimize the design and to develop accurate path planning and control algorithms, there is a need to develop a tissue-needle interaction model. This work presents an energy-based model that predicts needle deflection of active bevel-tipped needles when inserted into the tissue. This current model was based on an existing energy-based model for bevel-tipped needles, to which work of actuation was included in calculating the system energy. The developed model was validated with needle insertion experiments with a phantom material. The model predicts needle deflection reasonably for higher diameter needles (11.6% error), whereas largest error was observed for the smallest needle diameter (24.7% error).

  2. Validation of the accuracy of needle placement as used in diagnostic local analgesia of the maxillary nerve for investigation of trigeminally mediated headshaking in horses.

    PubMed

    Wilmink, S; Warren-Smith, C M R; Roberts, V L H

    2015-02-07

    Diagnostic local anaesthesia of the maxillary nerve is a valuable aid in the diagnosis of trigeminally mediated headshaking in horses. Our objective is to validate the accuracy of needle placement in this procedure and to identify any correlation between accuracy of the technique and operator experience. Using a small volume of contrast medium, the procedure was performed bilaterally on 30 horse cadaver heads by three groups with different levels of experience with the technique. The location of deposition was then identified using computed tomography (CT). Contrast medium was deposited around the target site in 53.3% (32/60) of injections. An experienced operator succeeded in deposition around the target area significantly (p<0.05) more often (80%, 16/20) than did the less and non-experienced performers (40%, 16/40). A negative response to diagnostic local anaesthesia of the maxillary nerve does not disprove facial dysaesthesia as the cause of headshaking in that horse as a false negative response could arise due to failure to deposit local anaesthetic around the target area. Increased experience in performing the procedure decreases the probability of false negative results.

  3. Technical tips: verification of accurate placement and labeling of 10-10 scalp electrodes and intracranial grid/strip electrodes using documentation tools.

    PubMed

    Feravich, Susan M; Keller, Crystal M

    2012-06-01

    In some instances, evaluation of seizure activity may require the addition of 10-10 scalp electrodes or the placement of intracranial grids and strips. At any given time, different technologists may be responsible for placement, addition, and the care of electrodes for the same patient. The presence of extra surface electrodes or extensive coverage of brain with intracranial electrodes increases the risk of incorrect placement and labeling which can cause treatment errors based on inaccurate reading of EEG recordings. Procedures should be put into place with documentation tools to correctly place, label, and hook-up extra 10-10 scalp and intracranial electrodes without errors. By using written processes and documentation tools, staff are more capable of acquiring safe and accurate patient data which increase good patient outcomes. The processes for placement and hook up of 10-10 scalp electrodes and intracranial grid and strip electrodes are different and require separate procedures and documentation tools to ensure accuracy. For 10-10 scalp electrode placement, the use of a 10-10 map, labeled tape, and non-duplicating adjacent electrode colors reduces risk of error Documentation of intracranial grid/strip electrodes includes placement map, list of electrode locations in amplifier and a table of cables and corresponding grid/strips with colors. Accurate hook-up is verified by the technologist and the epileptologist and is documented on recording. With the use of documentation tools and verification procedures, the quality of patient outcomes increases while the potential for recording errors is reduced.

  4. A Prototype Body-Mounted MRI-Compatible Robot for Needle Guidance in Shoulder Arthrography

    PubMed Central

    Monfaredi, R.; Seifabadi, R.; Iordachita, I.; Sze, R.; Safdar, N. M.; Sharma, K.; Fricke, S.; Krieger, A.; Cleary, K.

    2014-01-01

    A novel compact and lightweight patient-mounted MRI-compatible robot has been designed for MRI image-guided interventions. This robot is intended to enable MRI-guided needle placement as done in shoulder arthrography. The robot could make needle placement more accurate and simplify the current workflow by converting the traditional two-stage arthrography procedure (fluoroscopy-guided needle insertion followed by a diagnostic MRI scan) to a one-stage procedure (streamlined workflow all in MRI suite). The robot has 4 degrees of freedom (DOF), two for orientation of the needle and two for needle positioning. The mechanical design was based on several criteria including rigidity, MRI compatibility, compact design, sterilizability, and adjustability. The proposed workflow is discussed and initial MRI compatibility experiments are presented. The results show that artifacts in the region of interest are minimal and that MRI images of the shoulder were not adversely affected by placing the robot on a human volunteer. PMID:25473653

  5. Full automatic fiducial marker detection on coil arrays for accurate instrumentation placement during MRI guided breast interventions

    NASA Astrophysics Data System (ADS)

    Filippatos, Konstantinos; Boehler, Tobias; Geisler, Benjamin; Zachmann, Harald; Twellmann, Thorsten

    2010-02-01

    With its high sensitivity, dynamic contrast-enhanced MR imaging (DCE-MRI) of the breast is today one of the first-line tools for early detection and diagnosis of breast cancer, particularly in the dense breast of young women. However, many relevant findings are very small or occult on targeted ultrasound images or mammography, so that MRI guided biopsy is the only option for a precise histological work-up [1]. State-of-the-art software tools for computer-aided diagnosis of breast cancer in DCE-MRI data offer also means for image-based planning of biopsy interventions. One step in the MRI guided biopsy workflow is the alignment of the patient position with the preoperative MR images. In these images, the location and orientation of the coil localization unit can be inferred from a number of fiducial markers, which for this purpose have to be manually or semi-automatically detected by the user. In this study, we propose a method for precise, full-automatic localization of fiducial markers, on which basis a virtual localization unit can be subsequently placed in the image volume for the purpose of determining the parameters for needle navigation. The method is based on adaptive thresholding for separating breast tissue from background followed by rigid registration of marker templates. In an evaluation of 25 clinical cases comprising 4 different commercial coil array models and 3 different MR imaging protocols, the method yielded a sensitivity of 0.96 at a false positive rate of 0.44 markers per case. The mean distance deviation between detected fiducial centers and ground truth information that was appointed from a radiologist was 0.94mm.

  6. Design of a Teleoperated Needle Steering System for MRI-guided Prostate Interventions.

    PubMed

    Seifabadi, Reza; Iordachita, Iulian; Fichtinger, Gabor

    2012-12-31

    Accurate needle placement plays a key role in success of prostate biopsy and brachytherapy. During percutaneous interventions, the prostate gland rotates and deforms which may cause significant target displacement. In these cases straight needle trajectory is not sufficient for precise targeting. Although needle spinning and fast insertion may be helpful, they do not entirely resolve the issue. We propose robot-assisted bevel-tip needle steering under MRI guidance as a potential solution to compensate for the target displacement. MRI is chosen for its superior soft tissue contrast in prostate imaging. Due to the confined workspace of the MRI scanner and the requirement for the clinician to be present inside the MRI room during the procedure, we designed a MRI-compatible 2-DOF haptic device to command the needle steering slave robot which operates inside the scanner. The needle steering slave robot was designed to be integrated with a previously developed pneumatically actuated transperineal robot for MRI-guided prostate needle placement. We describe design challenges and present the conceptual design of the master and slave robots and the associated controller.

  7. Design of a Teleoperated Needle Steering System for MRI-guided Prostate Interventions

    PubMed Central

    Seifabadi, Reza; Iordachita, Iulian; Fichtinger, Gabor

    2013-01-01

    Accurate needle placement plays a key role in success of prostate biopsy and brachytherapy. During percutaneous interventions, the prostate gland rotates and deforms which may cause significant target displacement. In these cases straight needle trajectory is not sufficient for precise targeting. Although needle spinning and fast insertion may be helpful, they do not entirely resolve the issue. We propose robot-assisted bevel-tip needle steering under MRI guidance as a potential solution to compensate for the target displacement. MRI is chosen for its superior soft tissue contrast in prostate imaging. Due to the confined workspace of the MRI scanner and the requirement for the clinician to be present inside the MRI room during the procedure, we designed a MRI-compatible 2-DOF haptic device to command the needle steering slave robot which operates inside the scanner. The needle steering slave robot was designed to be integrated with a previously developed pneumatically actuated transperineal robot for MRI-guided prostate needle placement. We describe design challenges and present the conceptual design of the master and slave robots and the associated controller. PMID:24649480

  8. Automatic Multiple-Needle Surgical Planning of Robotic-Assisted Microwave Coagulation in Large Liver Tumor Therapy

    PubMed Central

    Liu, Shaoli; Xia, Zeyang; Liu, Jianhua; Xu, Jing; Ren, He; Lu, Tong; Yang, Xiangdong

    2016-01-01

    The “robotic-assisted liver tumor coagulation therapy” (RALTCT) system is a promising candidate for large liver tumor treatment in terms of accuracy and speed. A prerequisite for effective therapy is accurate surgical planning. However, it is difficult for the surgeon to perform surgical planning manually due to the difficulties associated with robot-assisted large liver tumor therapy. These main difficulties include the following aspects: (1) multiple needles are needed to destroy the entire tumor, (2) the insertion trajectories of the needles should avoid the ribs, blood vessels, and other tissues and organs in the abdominal cavity, (3) the placement of multiple needles should avoid interference with each other, (4) an inserted needle will cause some deformation of liver, which will result in changes in subsequently inserted needles’ operating environment, and (5) the multiple needle-insertion trajectories should be consistent with the needle-driven robot’s movement characteristics. Thus, an effective multiple-needle surgical planning procedure is needed. To overcome these problems, we present an automatic multiple-needle surgical planning of optimal insertion trajectories to the targets, based on a mathematical description of all relevant structure surfaces. The method determines the analytical expression of boundaries of every needle “collision-free reachable workspace” (CFRW), which are the feasible insertion zones based on several constraints. Then, the optimal needle insertion trajectory within the optimization criteria will be chosen in the needle CFRW automatically. Also, the results can be visualized with our navigation system. In the simulation experiment, three needle-insertion trajectories were obtained successfully. In the in vitro experiment, the robot successfully achieved insertion of multiple needles. The proposed automatic multiple-needle surgical planning can improve the efficiency and safety of robot-assisted large liver tumor

  9. 3T MR Guided in bore transperineal prostate biopsy: A Comparison of robotic and manual needle-guidance templates

    PubMed Central

    Tilak, Gaurie; Tuncali, Kemal; Song, Sang-Eun; Tokuda, Junichi; Olubiyi, Olutayo; Fennessy, Fiona; Fedorov, Andriy; Penzkofer, Tobias; Tempany, Clare; Hata, Nobuhiko

    2014-01-01

    Purpose To demonstrate the utility of a robotic needle-guidance template device as compared to a manual template for in-bore 3T transperineal MR-guided prostate biopsy. Materials and Methods This two-arm mixed retrospective-prospective study included 99 cases of targeted transperineal prostate biopsies. The biopsy needles were aimed at suspicious foci noted on multiparametric 3T MRI using manual template (historical control) as compared with a robotic template. The following data was obtained: the accuracy of average and closest needle placement to the focus, histologic yield, percentage of cancer volume in positive core samples, complication rate, and time to complete the procedure. Results 56 cases were performed using the manual template, and 43 cases were performed using the robotic template. The mean accuracy of the best needle placement attempt was higher in the robotic group (2.39 mm) than the manual group (3.71 mm, p<0.027). The mean core procedure time was shorter in the robotic (90.82min) than the manual group (100.63min, p<0.030). Percentage of cancer volume in positive core samples was higher in robotic group (p<0.001). Cancer yields and complication rates were not statistically different between the two sub-groups (p = 0.557 and p=0.172 respectively). Conclusion The robotic needle-guidance template helps accurate placement of biopsy needles in MRI-guided core biopsy of prostate cancer. PMID:25263213

  10. Characterization of optically actuated MRI-compatible active needles for medical interventions

    NASA Astrophysics Data System (ADS)

    Black, Richard J.; Ryu, Seokchang; Moslehi, Behzad; Costa, Joannes M.

    2014-03-01

    The development of a Magnetic Resonance Imaging (MRI) compatible optically-actuated active needle for guided percutaneous surgery and biopsy procedures is described. Electrically passive MRI-compatible actuation in the small diameter needle is provided by non-magnetic materials including a shape memory alloy (SMA) subject to precise fiber laser operation that can be from a remote (e.g., MRI control room) location. Characterization and optimization of the needle is facilitated using optical fiber Bragg grating (FBG) temperature sensors arrays. Active bending of the needle during insertion allows the needle to be accurately guided to even relatively small targets in an organ while avoiding obstacles and overcoming undesirable deviations away from the planned path due to unforeseen or unknowable tissue interactions. This feature makes the needle especially suitable for use in image-guided surgical procedures (ranging from MRI to CT and ultrasound) when accurate targeting is imperative for good treatment outcomes. Such interventions include reaching small tumors in biopsies, delineating freezing areas in, for example, cryosurgery and improving the accuracy of seed placement in brachytherapy. Particularly relevant are prostate procedures, which may be subject to pubic arch interference. Combining diagnostic imaging and actuation assisted biopsy into one treatment can obviate the need for a second exam for guided biopsy, shorten overall procedure times (thus increasing operating room efficiencies), address healthcare reimbursement constraints and, most importantly, improve patient comfort and clinical outcomes.

  11. Validation system of MR image overlay and other needle insertion techniques.

    PubMed

    Fischer, Gregory S; Dyer, Eva; Csoma, Csaba; Deguet, Anton; Fichtinger, Gabor

    2007-01-01

    In order to develop accurate and effective augmented reality (AR) systems used in MR and CT guided needle placement procedures, a comparative validation environment is necessary. Clinical equipment is prohibitively expensive and often inadequate for precise measurement. Therefore, we have developed a laboratory validation system for measuring operator performance using different assistance techniques. Electromagnetically tracked needles are registered with the preoperative plan to measure placement accuracy and the insertion path. The validation system provides an independent measure of accuracy that can be applied to varying methods of assistance ranging from augmented reality guidance methods to tracked navigation systems and autonomous robots. In preliminary studies, this validation system is used to evaluate the performance of the image overlay, bi-plane laser guide, and traditional freehand techniques.

  12. Ultrasound/fluoroscopy-assisted placement of peritoneal dialysis catheters.

    PubMed

    Maya, Ivan D

    2007-01-01

    Peritoneal dialysis (PD) catheters may be inserted blindly, surgically, and either by laparoscopic, peritoneoscopic, or fluoroscopic approach. A modified fluoroscopic technique by adding ultrasound-assistance was performed in the present study to ensure entry into the abdominal cavity under direct ultrasound visualization. From March 2005 to May 2007, ultrasound-fluoroscopic guided placement of PD catheters was attempted in 32 end-stage renal disease (ESRD) patients. Preoperative evaluation was performed on all patients prior to the procedure. After initial dissection of the subcutaneous tissue anterior to the anterior rectus sheath, the needle was inserted into the abdominal cavity under the guidance of ultrasound. The position of the epigastric artery was also examined using ultrasonography to avoid the risk of arterial injury. PD catheters were successfully placed in 31 of the 32 ESRD patients using this technique. In all of these patients, the needle could be seen entering the abdominal cavity using an ultrasound. In one patient the procedure was abandoned because of bowel puncture by the micro-puncture needle that was inadvertently advanced into a loop of bowel. This patient did not develop acute abdomen nor needed any intervention. One patient died 4 days after placement of the catheter of unrelated causes. One patient was started on acute peritoneal dialysis the same day of catheter placement without any complications. The rest of the patients started peritoneal dialysis within 2-6 weeks of catheter placement. None of the patients had bleeding related to arterial injury as ultrasound was able to visualize the epigastric artery. Our experience shows that ultrasound-fluoroscopic technique is minimally invasive and allows for accurate assessment of the entry into the abdominal cavity. This technique can avoid the risk of vascular injury altogether.

  13. Recording triggered EMG thresholds from axillary chest wall electrodes: a new refined technique for accurate upper thoracic (T2-T6) pedicle screw placement.

    PubMed

    Regidor, Ignacio; de Blas, Gema; Barrios, Carlos; Burgos, Jesús; Montes, Elena; García-Urquiza, Sergio; Hevia, Edurado

    2011-10-01

    This study was aimed at evaluating the sensitivity and safety of a new technique to record triggered EMG thresholds from axillary chest wall electrodes when inserting pedicle screws in the upper thoracic spine (T2-T6). A total of 248 (36.6%) of a total of 677 thoracic screws were placed at the T2-T6 levels in 92 patients with adolescent idiopathic scoliosis. A single electrode placed at the axillary midline was able to record potentials during surgery from all T2-T6 myotomes at each side. Eleven screws were removed during surgery because of malposition according to intraoperative fluoroscopic views. Screw position was evaluated after surgery in the remaining 237 screws using a CT scan. Malposition was detected in 35 pedicle screws (14.7%). Pedicle medial cortex was breached in 24 (10.1%). Six screws (2.5%) were located inside the spinal canal. Mean EMG threshold was 24.44 ± 11.30 mA in well-positioned screws, 17.98 ± 8.24 mA (p < 0.01) in screws violating the pedicle medial cortex, and 10.38 ± 3.33 mA (p < 0.005) in screws located inside the spinal canal. Below a threshold of 12 mA, 33.4% of the screws (10/30) were malpositioned. Furthermore, 36% of the pedicle screws with t-EMG stimulation thresholds within the range 6-12 mA were malpositioned. In conclusion, assessment of upper thoracic pedicle screw placement by recording tEMG at a single axillary electrode was highly reliable. Thresholds below 12 mA should alert surgeons to suspect screw malposition. This technique simplifies tEMG potential recording to facilitate safe placement of pedicle screws at upper thoracic levels.

  14. Keyword: Placement

    ERIC Educational Resources Information Center

    Cassuto, Leonard

    2012-01-01

    The practical goal of graduate education is placement of graduates. But what does "placement" mean? Academics use the word without thinking much about it. "Placement" is a great keyword for the graduate-school enterprise. For one thing, its meaning certainly gives a purpose to graduate education. Furthermore, the word is a portal into the way of…

  15. Navigated marker placement for motion compensation in radiotherapy

    NASA Astrophysics Data System (ADS)

    Winterstein, A.; März, K.; Franz, A. M.; Hafezi, M.; Fard, N.; Sterzing, F.; Mehrabi, A.; Maier-Hein, L.

    2015-03-01

    Radiotherapy is frequently used to treat unoperated or partially resected tumors. Tumor movement, e.g. caused by respiration, is a major challenge in this context. Markers can be implanted around the tumor prior to radiation therapy for accurate tracking of tumor movement. However, accurate placement of these markers while keeping a secure margin around the target and while taking into account critical structures is a difficult task. Computer-assisted needle insertion has been an active field of research in the past decades. However, the challenge of navigated marker placement for motion compensated radiotherapy has not yet been addressed. This work presents a system to support marker implantation for radiotherapy under consideration of safety margins and optimal marker configuration. It is designed to allow placement of markers both percutaneously and during an open liver surgery. To this end, we adapted the previously proposed EchoTrack system which integrates ultrasound (US) imaging and electromagnetic (EM) tracking in a single mobile modality. The potential of our new marker insertion concept was evaluated in a phantom study by inserting sets of three markers around dedicated targets (n=22) simultaneously spacing the markers evenly around the target as well as placing the markers in a defined distance to the target. In all cases the markers were successfully placed in a configuration fulfilling the predefined criteria. This includes a minimum distance of 18.9 ± 2.4 mm between marker and tumor as well as a divergence of 2.1 ± 1.5 mm from the planned marker positions. We conclude that our system has high potential to facilitate the placement of markers in suitable configurations for surgeons without extensive experience in needle punctions as high quality configurations were obtained even by medical non-experts.

  16. Design and fabrication of a low-frequency (1-3 MHz) ultrasound transducer for accurate placement of screw implants in the spine

    NASA Astrophysics Data System (ADS)

    Manbachi, Amir; Lee, Mike; Foster, F. Stuart; Ginsberg, Howard J.; Cobbold, Richard S. C.

    2014-03-01

    In 2012 approximately 800,000 spinal fusion surgeries were performed in the United States, requiring the insertion of screws into the pedicles. Their exact placement is critical and made complex due to limited visibility of the spine, continuous bleeding in the exposed regions, and variability in morphologies. The alarmingly high rate of screw misplacements (up to 20%) reported in the literature is of major concern since such misplacements can place the surrounding vital structures at risk. A potential guidance method for determining the best screw trajectory is by the use of real-time ultrasound imaging similar to that used for intravascular imaging. An endovascular transducer could be inserted into the pedicle to image the anatomy from within and identify bone boundaries. A major challenge of imaging within bone is high signal attenuation. The rapid increase of attenuation with frequency requires much lower frequencies (1-3 MHz) than those used in intravascular imaging. This study describes the custom design and fabrication of 2 MHz ultrasound probes (3.5 mm diameter/ 11 Fr) for pedicle screw guidance. Three transducer designs are explored to provide improved sensitivity and signal to noise ratio, compared to the previously tested transducer within the pedicle. Experimental measurements are compared with the results obtained using various simulation tools. The work reported in this paper represents the first stage in our ultimate goal of developing a 32- element phased array that is capable of generating a radial B-mode image.

  17. Fiber-Optic Fabry-Pérot Interferometers for Axial Force Sensing on the Tip of a Needle

    PubMed Central

    Beekmans, Steven; Lembrechts, Thomas; van den Dobbelsteen, John; van Gerwen, Dennis

    2016-01-01

    A range of complex percutaneous procedures, such as biopsy or regional anesthesia, rely heavily on accurate needle insertion. Small variations in the mechanical properties of the pierced tissue can however cause deviations from the projected needle path and can thus result in inaccurate placement of the needle. Navigation of a rigid needle towards the target tissue is traditionally based on the surgeons capacity to interpret small variations in the needle insertion force. A more accurate measurement of these small force variations enables improvement in needle targeting, can potentially aid in enhancing force feedback in robotic needle placement and can provide valuable information on tissue-tool interaction. In this study we investigated several concepts for the design of a force sensor based on a fiber-optic Fabry-Pérot interferometer to measure needle-tissue interaction forces on the tip of a 18 G needle, where special attention was given to concepts for a sensor with (1), an intrinsic low cross-sensitivity to temperature and (2), elementary design and fabrication. Three concepts, using either a quartz capillary, an Invar capillary or a thin polyimide film as the force sensitive element were prototyped and subjected to both static and dynamic testing. The force transducer based on a quartz capillary presented the lowest cross-sensitivity to temperature (12 mN/∘C) and good accuracy (maximum measurement error of 65 mN/10 N) in a measurement of static forces. However, limited strength of the sensor is expected to prevent usage of the quartz capillary in small diameter needles. The concepts for a sensor based on an Invar capillary or a thin polyimide film proved a higher cross-sensitivity to temperature (50 mN/∘C and 220 mN/∘C, respectively) and higher maximum measurement error (350 mN/10 N, 800 mN/10 N), comparable to those of FBG-based sensors reported in literature, but are likely to be more suitable for integration in very small biopsy needles. PMID

  18. Fiber-Optic Fabry-Pérot Interferometers for Axial Force Sensing on the Tip of a Needle.

    PubMed

    Beekmans, Steven; Lembrechts, Thomas; van den Dobbelsteen, John; van Gerwen, Dennis

    2016-12-26

    A range of complex percutaneous procedures, such as biopsy or regional anesthesia, rely heavily on accurate needle insertion. Small variations in the mechanical properties of the pierced tissue can however cause deviations from the projected needle path and can thus result in inaccurate placement of the needle. Navigation of a rigid needle towards the target tissue is traditionally based on the surgeons capacity to interpret small variations in the needle insertion force. A more accurate measurement of these small force variations enables improvement in needle targeting, can potentially aid in enhancing force feedback in robotic needle placement and can provide valuable information on tissue-tool interaction. In this study we investigated several concepts for the design of a force sensor based on a fiber-optic Fabry-Pérot interferometer to measure needle-tissue interaction forces on the tip of a 18 G needle, where special attention was given to concepts for a sensor with (1), an intrinsic low cross-sensitivity to temperature and (2), elementary design and fabrication. Three concepts, using either a quartz capillary, an Invar capillary or a thin polyimide film as the force sensitive element were prototyped and subjected to both static and dynamic testing. The force transducer based on a quartz capillary presented the lowest cross-sensitivity to temperature ( 12 m N / ∘ C) and good accuracy (maximum measurement error of 65 m N /10 N ) in a measurement of static forces. However, limited strength of the sensor is expected to prevent usage of the quartz capillary in small diameter needles. The concepts for a sensor based on an Invar capillary or a thin polyimide film proved a higher cross-sensitivity to temperature ( 50 m N / ∘ C and 220 m N / ∘ C, respectively) and higher maximum measurement error (350 m N /10 N , 800 m N /10 N ), comparable to those of FBG-based sensors reported in literature, but are likely to be more suitable for integration in very small

  19. Robotic system for MRI-guided prostate biopsy: feasibility of teleoperated needle insertion and ex vivo phantom study

    PubMed Central

    Seifabadi, Reza; Song, Sang-Eun; Krieger, Axel; Cho, Nathan Bongjoon; Tokuda, Junichi; Fichtinger, Gabor; Iordachita, Iulian

    2012-01-01

    Purpose Magnetic Resonance Imaging (MRI) combined with robotic assistance has the potential to improve on clinical outcomes of biopsy and local treatment of prostate cancer. Methods We report the workspace optimization and phantom evaluation of a five Degree of Freedom (DOF) parallel pneumatically actuated modular robot for MRI-guided prostate biopsy. To shorten procedure time and consequently increase patient comfort and system accuracy, a prototype of a MRI-compatible master–slave needle driver module using piezo motors was also added to the base robot. Results Variable size workspace was achieved using appropriate link length, compared with the previous design. The 5-DOF targeting accuracy demonstrated an average error of 2.5mm (STD=1.37mm) in a realistic phantom inside a 3T magnet with a bevel-tip 18G needle. The average position tracking error of the master–slave needle driver was always below 0.1mm. Conclusion Phantom experiments showed sufficient accuracy for manual prostate biopsy. Also, the implementation of teleoperated needle insertion was feasible and accurate. These two together suggest the feasibility of accurate fully actuated needle placement into prostate while keeping the clinician supervision over the task. PMID:21698389

  20. Steerable real-time sonographically guided needle biopsy.

    PubMed

    Buonocore, E; Skipper, G J

    1981-02-01

    A method for dynamic real-time ultrasonic guidance for percutaneous needle biopsy has been successful in obtaining cytologic and histologic specimens from abdominal masses. The system depends on a real-time ultrasonic transducer that has been rigidly attached to a laterally placed steerable needle holder. Using simple trigonometric functions, a chart has been derived that gives the exact angulation and needle length to produce quick, reliable, guided needle placements. Examples of successful renal, hepatobiliary, and retroperitoneal biopsies are presented. Advantages of this technique include speed, accuracy, low cost, three-dimensional format, and the omission of contrast media and radiation.

  1. Modeling of Needle-Tissue Interaction Forces During Surgical Suturing

    PubMed Central

    Jackson, Russell C.; Çavuşoğlu, M. Cenk

    2013-01-01

    This paper presents a model of needle tissue interaction forces that a rigid suture needle experiences during surgical suturing. The needle-tissue interaction forces are modeled as the sum of lumped parameters. The model has three main components; friction, tissue compression, and cutting forces. The tissue compression force uses the area that the needle sweeps out during a suture to estimate both the force magnitude and force direction. The area that the needle sweeps out is a direct result of driving the needle in a way that does not follow the natural curve of the needle. The friction force is approximated as a static friction force along the shaft of the needle. The cutting force acts only on the needle tip. The resulting force and torque model is experimentally validated using a tissue phantom. These results indicate that the proposed lumped parameter model is capable of accurately modeling the forces experienced during a suture. PMID:24683499

  2. Disposable patient-mounted geared robot for image-guided needle insertion

    NASA Astrophysics Data System (ADS)

    Watkins, Charles; Kato, Takahisa; Hata, Nobuhiko

    2016-03-01

    Patient-mounted robotic needle guidance is an emerging method of needle insertion in percutaneous ablation therapies. During needle insertion, patient-mounted robots can account for patient body movement, unlike gantry or floor mounted devices, and still increase the accuracy and precision of needle placement. Patient-mounted robots, however, require repeated sterilisation, which is often a difficult process with complex devices; overcoming this challenge is therefore key to the success of a patient mounted robot. To eliminate the need for repeated sterilization, we have developed a disposable patient-mounted robot with two rings as a kinematic structure: an angled upper ring both rotates and revolves about the lower ring. Using this structure, the robot has a clinically suitable range of needle insertion angles with a remote center of motion. To achieve disposability, our structure applies a disposable gear transmission component which detachably interfaces with non-disposable driving motors. With a manually driven prototype of the gear trains, we assessed whether the kinematic structure of the two rings can be operated only by using input pinions locating at outside of the kinematic structure. Our tests confirmed that the input pinions were able to rotate both upper and lower rings independently. We also determined a linear relationship of rotation transmission with the gear trains and determined that the rotation transmission between the pinions and the two rings were within 3 % of error from the designed value. Our robot introduces a novel approach to patient-mounted robots, and has potential to enable sterile and accurate needle guidance in percutaneous ablation therapies.

  3. Emergency physician's needle holder.

    PubMed

    Abidin, M R; Towler, M A; Lombardi, S A; Becker, D G; Thacker, J G; McGregor, W; Edlich, R F

    1989-01-01

    A new needle holder is described that has jaws metallurgically bonded with tungsten carbide particles that enhance needle holding security without causing sutural damage during instrument ties. Scissors have also been incorporated into the needle holder to cut sutures. One ringlet on a handle has been offset to facilitate retrieval of the needle holder from a flat surface.

  4. Sensorless Motion Planning for Medical Needle Insertion in Deformable Tissues

    PubMed Central

    Alterovitz, Ron; Goldberg, Kenneth Y.; Pouliot, Jean; Hsu, I-Chow

    2009-01-01

    Minimally invasive medical procedures such as biopsies, anesthesia drug injections, and brachytherapy cancer treatments require inserting a needle to a specific target inside soft tissues. This is difficult because needle insertion displaces and deforms the surrounding soft tissues causing the target to move during the procedure. To facilitate physician training and preoperative planning for these procedures, we develop a needle insertion motion planning system based on an interactive simulation of needle insertion in deformable tissues and numerical optimization to reduce placement error. We describe a 2-D physically based, dynamic simulation of needle insertion that uses a finite-element model of deformable soft tissues and models needle cutting and frictional forces along the needle shaft. The simulation offers guarantees on simulation stability for mesh modications and achieves interactive, real-time performance on a standard PC. Using texture mapping, the simulation provides visualization comparable to ultrasound images that the physician would see during the procedure. We use the simulation as a component of a sensorless planning algorithm that uses numerical optimization to compute needle insertion offsets that compensate for tissue deformations. We apply the method to radioactive seed implantation during permanent seed prostate brachytherapy to minimize seed placement error. PMID:19126473

  5. Sensorless motion planning for medical needle insertion in deformable tissues.

    PubMed

    Alterovitz, Ron; Goldberg, Kenneth Y; Pouliot, Jean; Hsu, I-Chow Joe

    2009-03-01

    Minimally invasive medical procedures such as biopsies, anesthesia drug injections, and brachytherapy cancer treatments require inserting a needle to a specific target inside soft tissues. This is difficult because needle insertion displaces and deforms the surrounding soft tissues causing the target to move during the procedure. To facilitate physician training and preoperative planning for these procedures, we develop a needle insertion motion planning system based on an interactive simulation of needle insertion in deformable tissues and numerical optimization to reduce placement error. We describe a 2-D physically based, dynamic simulation of needle insertion that uses a finite-element model of deformable soft tissues and models needle cutting and frictional forces along the needle shaft. The simulation offers guarantees on simulation stability for mesh modifications and achieves interactive, real-time performance on a standard PC. Using texture mapping, the simulation provides visualization comparable to ultrasound images that the physician would see during the procedure. We use the simulation as a component of a sensorless planning algorithm that uses numerical optimization to compute needle insertion offsets that compensate for tissue deformations. We apply the method to radioactive seed implantation during permanent seed prostate brachytherapy to minimize seed placement error.

  6. [Discussion on needling sensation, arrival of qi and needling response (Deqi)].

    PubMed

    Zhang, Fang; Wang, Hong-Du

    2012-12-01

    The current appointed teaching material of Science of Acupuncture and Moxibustion holds that there is no difference among the needling sensation, arrival of qi and needling response. However, the author has a different understanding. Therefore, Neijing (Internal Classic), its annotation, exposition and understandings of ancient and modern famous experts are cited to analyze their meanings. And the result indicates that the needling sensation is subjective feelings and perceived responses of doctors and patients. Arrival of qi is the healing process of the organ through activating the anti-pathogenic qi to expel the pathogens. The needling response is the final aim of acupuncture therapy. Thus, the meaning of needling sensation, arrival of qi, and needling response are different. And an accurate understanding can better guide acupuncture treatment.

  7. Modeling and Control of Needles with Torsional Friction

    PubMed Central

    Reed, Kyle B.; Okamura, Allison M.; Cowan, Noah J.

    2010-01-01

    A flexible needle can be accurately steered by robotically controlling the bevel tip orientation as the needle is inserted into tissue. Friction between the long, flexible needle shaft and the tissue can cause a significant discrepancy between the orientation of the needle tip and the orientation of the base where the needle angle is controlled. Our experiments show that several common phantom tissues used in needle steering experiments impart substantial friction forces to the needle shaft, resulting in a lag of over 45° for a 10 cm insertion depth in some phantoms; clinical studies report torques large enough to cause similar errors during needle insertions. Such angle discrepancies will result in poor performance or failure of path planners and image-guided controllers, since the needles used in percutaneous procedures are too small for state-of-the-art imaging to accurately measure the tip angle. To compensate for the angle discrepancy, we develop an estimator using a mechanics-based model of the rotational dynamics of a needle being inserted into tissue. Compared to controllers that assume a rigid needle in a frictionless environment, our estimator-based controller improves the tip angle convergence time by nearly 50% and reduces the path deviation of the needle by 70%. PMID:19695979

  8. Mechanics of Flexible Needles Robotically Steered through Soft Tissue

    PubMed Central

    Misra, S.; Reed, K. B.; Schafer, B. W.; Ramesh, K. T.; Okamura, A. M.

    2010-01-01

    The tip asymmetry of a bevel-tip needle results in the needle naturally bending when it is inserted into soft tissue. This enables robotic needle steering, which can be used in medical procedures to reach subsurface targets inaccessible by straight-line trajectories. However, accurate path planning and control of needle steering requires models of needle-tissue interaction. Previous kinematic models required empirical observations of each needle and tissue combination in order to fit model parameters. This study describes a mechanics-based model of robotic needle steering, which can be used to predict needle behavior and optimize system design based on fundamental mechanical and geometrical properties of the needle and tissue. We first present an analytical model for the loads developed at the tip, based on the geometry of the bevel edge and material properties of soft-tissue simulants (gels). We then present a mechanics-based model that calculates the deflection of a bevel-tipped needle inserted through a soft elastic medium. The model design is guided by microscopic observations of needle-gel interactions. The energy-based formulation incorporates tissue-specific parameters, and the geometry and material properties of the needle. Simulation results follow similar trends (deflection and radius of curvature) to those observed in experimental studies of robotic needle insertion. PMID:21170164

  9. Ultrasound-Guided Needle Technique Accuracy

    PubMed Central

    Johnson, Angela N.; Peiffer, Jeffery S.; Halmann, Nahi; Delaney, Luke; Owen, Cindy A.; Hersh, Jeff

    2017-01-01

    Background and Objectives Ultrasound-guided regional anesthesia facilitates an approach to sensitive targets such as nerve clusters without contact or inadvertent puncture. We compared accuracy of needle placement with a novel passive magnetic ultrasound needle guidance technology (NGT) versus conventional ultrasound (CU) with echogenic needles. Methods Sixteen anesthesiologists and 19 residents performed a series of 16 needle insertion tasks each, 8 using NGT (n = 280) and 8 using CU (n = 280), in high-fidelity porcine phantoms. Tasks were stratified based on aiming to contact (target-contact) or place in close proximity with (target-proximity) targets, needle gauge (no. 18/no. 22), and in-plane (IP) or out-of-plane (OOP) approach. Distance to the target, task completion by aim, number of passes, and number of tasks completed on the first pass were reported. Results Needle guidance technology significantly improved distance, task completion, number of passes, and completion on the first pass compared with CU for both IP and OOP approaches (P ≤ 0.001). Average NGT distance to target was lower by 57.1% overall (n = 560, 1.5 ± 2.4 vs 3.5 ± 3.7 mm), 38.5% IP (n = 140, 1.6 ± 2.6 vs 2.6 ± 2.8 mm), and 68.2% OOP (n = 140, 1.4 ± 2.2 vs 4.4 ± 4.3 mm) (all P ≤ 0.01). Subgroup analyses revealed accuracy gains were largest among target-proximity tasks performed by residents and for OOP approaches. Needle guidance technology improved first-pass completion from 214 (76.4%) per 280 to 249 (88.9%) per 280, a significant improvement of 16.4% (P = 0.001). Conclusions Passive magnetic NGT can improve accuracy of needle procedures, particularly among OOP procedures requiring close approach to sensitive targets, such as nerve blocks in anesthesiology practice. PMID:28079754

  10. The improvement on the falling needle viscometer

    NASA Astrophysics Data System (ADS)

    Sha, Zhen-Shun

    1997-04-01

    To overcome the shortcomings of the conventional falling needle viscometer, many improvements have been made, e.g., adopting new design of needle structure, collector, and launcher. Furthermore, Hall magnetic sensors and single-board computer are used in the system, which makes the measurement automatic and intelligent. It is proved in the experiment that the instrument is accurate enough and has excellent performance. The technique can also be applied in falling ball viscometers.

  11. The research of knitting needle status monitoring setup

    NASA Astrophysics Data System (ADS)

    Liu, Lu; Liao, Xiao-qing; Zhu, Yong-kang; Yang, Wei; Zhang, Pei; Zhao, Yong-kai; Huang, Hui-jie

    2013-09-01

    In textile production, quality control and testing is the key to ensure the process and improve the efficiency. Defect of the knitting needles is the main factor affecting the quality of the appearance of textiles. Defect detection method based on machine vision and image processing technology is universal. This approach does not effectively identify the defect generated by damaged knitting needles and raise the alarm. We developed a knitting needle status monitoring setup using optical imaging, photoelectric detection and weak signal processing technology to achieve real-time monitoring of weaving needles' position. Depending on the shape of the knitting needle, we designed a kind of Glass Optical Fiber (GOF) light guides with a rectangular port used for transmission of the signal light. To be able to capture the signal of knitting needles accurately, we adopt a optical 4F system which has better imaging quality and simple structure and there is a rectangle image on the focal plane after the system. When a knitting needle passes through position of the rectangle image, the reflected light from needle surface will back to the GOF light guides along the same optical system. According to the intensity of signals, the computer control unit distinguish that the knitting needle is broken or curving. The experimental results show that this system can accurately detect the broken needles and the curving needles on the knitting machine in operating condition.

  12. Transbronchial needle aspiration with a new electromagnetically-tracked TBNA needle

    NASA Astrophysics Data System (ADS)

    Choi, Jae; Popa, Teo; Gruionu, Lucian

    2009-02-01

    Transbronchial needle aspiration (TBNA) is a common method used to collect tissue for diagnosis of different chest diseases and for staging lung cancer, but the procedure has technical limitations. These limitations are mostly related to the difficulty of accurately placing the biopsy needles into the target mass. Currently, pulmonologists plan TBNA by examining a number of Computed Tomography (CT) scan slices before the operation. Then, they manipulate the bronchoscope down the respiratory track and blindly direct the biopsy. Thus, the biopsy success rate is low. The diagnostic yield of TBNA is approximately 70 percent. To enhance the accuracy of TBNA, we developed a TBNA needle with a tip position that can be electromagnetically tracked. The needle was used to estimate the bronchoscope's tip position and enable the creation of corresponding virtual bronchoscopic images from a preoperative CT scan. The TBNA needle was made with a flexible catheter embedding Wang Transbronchial Histology Needle and a sensor tracked by electromagnetic field generator. We used Aurora system for electromagnetic tracking. We also constructed an image-guided research prototype system incorporating the needle and providing a user-friendly interface to assist the pulmonologist in targeting lesions. To test the feasibility of the accuracy of the newly developed electromagnetically-tracked needle, a phantom study was conducted in the interventional suite at Georgetown University Hospital. Five TBNA simulations with a custom-made phantom with a bronchial tree were performed. The experimental results show that our device has potential to enhance the accuracy of TBNA.

  13. Stereotaxic implantation of dispersed cell suspensions into brain. A systematic appraisal of cell placement and survival

    SciTech Connect

    Plunkett, R.J.; Weber, R.J.; Oldfield, E.H.

    1988-08-01

    The application of several recent advances in cell biology, brain implantation, and cell-mediated tumor immunotherapy requires successful and reproducible placement of viable cell suspensions into brain. Stereotaxic implantation is being used to inject cytotoxic lymphocytes into gliomas and to replace dopaminergic cells in parkinsonian models. Systematic assessment of the factors that influence success in implantation of cell suspensions into solid tissues is needed. A model was developed for investigation of stereotaxic implantation using radiolabeled rat lymphokine-activated killer (LAK) cells. Anesthetized rats received microliter injections of cell suspension into the right caudate nucleus. The injection volume, cell concentration, infusion rate, and needle size were varied systematically. The animals were sacrificed 1 hour after injection; the brain was removed and sectioned, and the radioactivity was counted. Three aliquots of the suspension were injected into counting tubes for control analysis. Recovery of radioactivity was expressed as the percent of mean counts per minute (cpm) in the right frontal lobe/mean cpm in the three control tubes. To assess the viability of implanted cells, the right frontal region was mechanically dissociated in media and centrifuged, and the pellet and supernatant were counted. By using small needles and slow infusion of volumes of 10 microliters or less, 85% to 90% of the radioactivity was recovered in the caudate nucleus. At least half of the implanted cells were viable. Consistent, accurate implantation of dispersed cells into brain over a range of volumes, cell concentrations, infusion rates, and needle sizes was achieved.

  14. Target Tracking, Approach, and Camera Handoff for Automated Instrument Placement

    NASA Technical Reports Server (NTRS)

    Bajracharya, Max; Diaz-Calderon, Antonio; Robinson, Matthew; Powell, Mark

    2005-01-01

    This paper describes the target designation, tracking, approach, and camera handoff technologies required to achieve accurate, single-command autonomous instrument placement for a planetary rover. It focuses on robust tracking integrated with obstacle avoidance during the approach phase, and image-based camera handoff to allow vision-based instrument placement. It also provides initial results from a complete system combining these technologies with rover base placement to maximize arm manipulability and image-based instrument placement.

  15. Observations on rotating needle insertions using a brachytherapy robot

    NASA Astrophysics Data System (ADS)

    Meltsner, M. A.; Ferrier, N. J.; Thomadsen, B. R.

    2007-09-01

    A robot designed for prostate brachytherapy implantations has the potential to greatly improve treatment success. Much of the research in robotic surgery focuses on measuring accuracy. However, there exist many factors that must be optimized before an analysis of needle placement accuracy can be determined. Some of these parameters include choice of the needle type, insertion velocity, usefulness of the rotating needle and rotation speed. These parameters may affect the force at which the needle interacts with the tissue. A reduction in force has been shown to decrease the compression of the prostate and potentially increase the accuracy of seed position. Rotating the needle as it is inserted may reduce frictional forces while increasing accuracy. However, needle rotations are considered to increase tissue damage due to the drilling nature of the insertion. We explore many of the factors involved in optimizing a brachytherapy robot, and the potential effects each parameter may have on the procedure. We also investigate the interaction of rotating needles in gel and suggest the rotate-cannula-only method of conical needle insertion to minimize any tissue damage while still maintaining the benefits of reduced force and increased accuracy.

  16. Coaxial needle insertion assistant with enhanced force feedback.

    PubMed

    De Lorenzo, Danilo; Koseki, Yoshihiko; De Momi, Elena; Chinzei, Kiyoyuki; Okamura, Allison M

    2013-02-01

    Many medical procedures involving needle insertion into soft tissues, such as anesthesia, biopsy, brachytherapy, and placement of electrodes, are performed without image guidance. In such procedures, haptic detection of changing tissue properties at different depths during needle insertion is important for needle localization and detection of subsurface structures. However, changes in tissue mechanical properties deep inside the tissue are difficult for human operators to sense, because the relatively large friction force between the needle shaft and the surrounding tissue masks the smaller tip forces. A novel robotic coaxial needle insertion assistant, which enhances operator force perception, is presented. This one-degree-of-freedom cable-driven robot provides to the operator a scaled version of the force applied by the needle tip to the tissue, using a novel design and sensors that separate the needle tip force from the shaft friction force. The ability of human operators to use the robot to detect membranes embedded in artificial soft tissue was tested under the conditions of 1) tip force and shaft force feedback, and 2) tip force only feedback. The ratio of successful to unsuccessful membrane detections was significantly higher (up to 50%) when only the needle tip force was provided to the user.

  17. Modulation of an optical needle's reflectivity alters the average photon path through scattering media.

    PubMed

    Simonson, Paul; D'Amico, Enrico; Gratton, Enrico

    2006-01-01

    We introduce the concept of deliberate placement of absorbers to alter the average path of photons through tissue for a biomedical optical device. By changing the reflectivity of a needle that separates a source and detector, the average photon path through a turbid medium can be changed. Totally reflective needles have photon scattering density functions similar to a point source and detector in an infinite medium. An absorbing needle moves the average photon path of photons that reach the detector away from the needle. Thus, by modulating the reflectivity of the needle, it is possible to modify the sensitive volume, and simple tomography data should be possible. These results are confirmed by Monte Carlo simulations and experiment. Experiments include moving a black target relative to an optical "needle" and measuring the resulting intensity and phase lag of light reaching a detector at the distal end of the needle.

  18. The Path-of-Probability Algorithm for Steering and Feedback Control of Flexible Needles

    PubMed Central

    Park, Wooram; Wang, Yunfeng; Chirikjian, Gregory S.

    2010-01-01

    In this paper we develop a new framework for path planning of flexible needles with bevel tips. Based on a stochastic model of needle steering, the probability density function for the needle tip pose is approximated as a Gaussian. The means and covariances are estimated using an error propagation algorithm which has second order accuracy. Then we adapt the path-of-probability (POP) algorithm to path planning of flexible needles with bevel tips. We demonstrate how our planning algorithm can be used for feedback control of flexible needles. We also derive a closed-form solution for the port placement problem for finding good insertion locations for flexible needles in the case when there are no obstacles. Furthermore, we propose a new method using reference splines with the POP algorithm to solve the path planning problem for flexible needles in more general cases that include obstacles. PMID:21151708

  19. Precessing Ferromagnetic Needle Magnetometer.

    PubMed

    Jackson Kimball, Derek F; Sushkov, Alexander O; Budker, Dmitry

    2016-05-13

    A ferromagnetic needle is predicted to precess about the magnetic field axis at a Larmor frequency Ω under conditions where its intrinsic spin dominates over its rotational angular momentum, Nℏ≫IΩ (I is the moment of inertia of the needle about the precession axis and N is the number of polarized spins in the needle). In this regime the needle behaves as a gyroscope with spin Nℏ maintained along the easy axis of the needle by the crystalline and shape anisotropy. A precessing ferromagnetic needle is a correlated system of N spins which can be used to measure magnetic fields for long times. In principle, by taking advantage of rapid averaging of quantum uncertainty, the sensitivity of a precessing needle magnetometer can far surpass that of magnetometers based on spin precession of atoms in the gas phase. Under conditions where noise from coupling to the environment is subdominant, the scaling with measurement time t of the quantum- and detection-limited magnetometric sensitivity is t^{-3/2}. The phenomenon of ferromagnetic needle precession may be of particular interest for precision measurements testing fundamental physics.

  20. Manually controlled steerable needle for MRI-guided percutaneous interventions.

    PubMed

    Henken, Kirsten R; Seevinck, Peter R; Dankelman, Jenny; van den Dobbelsteen, John J

    2017-02-01

    This study aims to develop and evaluate a manually controlled steerable needle that is compatible with and visible on MRI to facilitate full intra-procedural control and accurate navigation in percutaneous interventions. The steerable needle has a working channel that provides a lumen to a cutting stylet or a therapeutic instrument. A steering mechanism based on cable-operated compliant elements is integrated in the working channel. The needle can be steered by adjusting the orientation of the needle tip through manipulation of the handle. The steering mechanism is evaluated by recording needle deflection at constant steering angles. A steering angle of 20.3° results in a deflection of 9.1-13.3 mm in gelatin and 4.6-18.9 mm in porcine liver tissue at an insertion depth of 60 mm. Additionally, the possibility to control the needle path under MRI guidance is evaluated in a gelatin phantom. The needle can be steered to targets at different locations while starting from the same initial position and orientation under MRI guidance with generally available sequences. The steerable needle offers flexibility to the physician in control and choice of the needle path when navigating the needle toward the target position, which allows for optimization of individual treatment and may increase target accuracy.

  1. Biopsy Needle Artifact Localization in MRI-guided Robotic Transrectal Prostate Intervention

    PubMed Central

    Song, Sang-Eun; Cho, Nathan B.; Iordachita, Iulian; Guion, Peter; Fichtinger, Gabor; Kaushal, Aradhana; Camphausen, Kevin; Whitcomb, Louis L.

    2013-01-01

    Recently a number of robotic intervention systems for magnetic resonance image (MRI) guided needle placement in the prostate have been reported. In MRI-guided needle interventions, after a needle is inserted, the needle position is often confirmed with a volumetric MRI scan. Commonly used titanium needles are not directly visible in an MR image, but they generate a susceptibility artifact in the immediate neighborhood of the needle. This paper reports the results of a quantitative study of the relationship between the true position of titanium biopsy needle and the corresponding needle artifact position in MR images, thereby providing a better understanding of the influence of needle artifact on targeting errors. The titanium needle tip artifact extended 9 mm beyond the actual needle tip location with tendency to bend towards the scanner’s B0 magnetic field direction, and axially displaced 0.38 mm and 0.32 mm (mean) in scanner’s frequency and phase encoding direction, respectively. PMID:22481805

  2. A Placement Advisory Test

    ERIC Educational Resources Information Center

    Hughes, Chris

    2010-01-01

    The primary method of placement at Portland CC (PCC) is the Compass Placement test. For the most part, students are placed correctly, but there are cases when students feel that they have been placed too low. In such cases we use our newly created Placement Advisory Test (PAT) to help us place them appropriately. (Contains 2 figures.)

  3. Needle breakage: incidence and prevention.

    PubMed

    Malamed, Stanley F; Reed, Kenneth; Poorsattar, Susan

    2010-10-01

    Since the introduction of nonreusable, stainless steel dental local anesthetic needles, needle breakage has become an extremely rare complication of dental local anesthetic injections. But although rare, dental needle breakage can, and does, occur. Review of the literature and personal experience brings into focus several commonalities which, when avoided, can minimize the risk of needle breakage with the fragment being retained from occurring.

  4. Buffon's needle problem

    NASA Astrophysics Data System (ADS)

    Schröer, H.

    We accidentally let a needle fall with the length L on a table. On the table are drawn parallel lines with distance D. We assume L is smaller than D. We introduce the rotation probability. Then we generalize the Buffon's needle problem. We view a general convex set. We have to solve a two-dimensional integral. There is an english and a german edition.

  5. Cosmic Needles versus Cosmic Microwave Background Radiation

    NASA Astrophysics Data System (ADS)

    Li, Aigen

    2003-02-01

    It has been suggested by a number of authors that the 2.7 K cosmic microwave background (CMB) radiation might have arisen from the radiation of ``Population III'' objects thermalized by conducting cosmic graphite/iron needle-shaped dust. Due to a lack of an accurate solution to the absorption properties of exceedingly elongated grains, in existing literature which studies the CMB thermalizing process they are generally modeled as (1) needle-like spheroids in terms of the Rayleigh approximation, (2) infinite cylinders, and (3) antennae. We show here that the Rayleigh approximation is not valid since the Rayleigh criterion is not satisfied for highly conducting needles. We also show that the available intergalactic iron dust, if modeled as infinite cylinders, is not sufficient to supply the required opacity at long wavelengths to obtain the observed isotropy and Planckian nature of the CMB. If appealing to the antenna theory, conducting iron needles with exceedingly large elongations ( >104) appear able to provide sufficient opacity to thermalize the CMB within the iron density limit. But the applicability of the antenna theory to exceedingly thin needles of nanometer/micrometer thickness has not yet been verified.

  6. Vertical Small-Needle Caudal Epidural Injection Technique

    PubMed Central

    Maniquis Smigel, Liza; Dean Reeves, Kenneth; Jeffrey Rosen, Howard; Patrick Rabago, David

    2016-01-01

    Background Anecdotal evidence suggests that a vertical small-needle injection method enters the caudal epidural space with comparable efficacy to cephalad-directed methods, with less intravascular injection. Objectives Assess the success rate of vertical caudal epidural injection using epidurography and the frequency of intravascular injection using a vertical small-needle approach. Patients and Methods Participants had chronic generalized non-surgical low back pain and either gluteal and/or leg pain and were enrolled in a simultaneous clinical trial assessing the analgesic effect of 5% dextrose epidural injection. A 25 gauge 3.7 cm hypodermic needle was placed at the sacral hiatus using a fingertip-guided vertical technique without imaging assistance, followed by fluoroscopic epidurography. Minimal needle redirection was allowed up to 10 degrees from the vertical plane if the initial epidurogram showed an extradural pattern, followed by repeat epidurography. Results First needle placement without imaging resulted in blood return in 1/199 participants and positive epidurography in 179/199 (90%). Minimal needle repositioning resulted in a positive epidurogram in the remaining 19 attempts. No intravascular injection patterns were observed. Conclusions This compares favorably to published success rates of fluoroscopically-guided technique and was well tolerated. Vertical caudal epidural injection may be suitable for combination with ultrasound-guided methods with Doppler flow monitoring. PMID:27826539

  7. NOTE: Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants

    NASA Astrophysics Data System (ADS)

    Thompson, S. A.; Fung, A. Y. C.; Zaider, M.

    2002-08-01

    One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results.

  8. Computed tomography-guided S3 lead placement for sacral neuromodulation.

    PubMed

    Chung, Christopher P; Neese, Paul A; Le, Hoang Kim; Bird, Erin T

    2013-02-01

    Computed tomography (CT)-guided lead placement for sacral neuromodulation was used in a patient with arthritis and narrow S3 foramina. Bilateral S3 foramina were localized and guide needles were placed with CT guidance. Lead placement was further modified by placement of a tined, quadripolar lead through a dilated S3 tract without initial somatosensory testing. The lead was then interrogated to assess placement and to differentiate superiority of response between two leads. The patient has had greater than 50 % improvement in urinary symptoms by voiding diary. Using CT guidance, satisfactory localization of bilateral S3 foramina may be achieved where prior attempts with conventional fluoroscopy have failed.

  9. Needle Federated Search Engine

    SciTech Connect

    2009-12-01

    The Idaho National Laboratory (INL) has combined a number of technologies, tools, and resources to accomplish a new means of federating search results. The resulting product is a search engine called Needle, an open-source-based tool that the INL uses internally for researching across a wide variety of information repositories. Needle has a flexible search interface that allows end users to point at any available data source. A user can select multiple sources such as commercial databases (Web of Science, Engineering Index), external resources (WorldCat, Google Scholar), and internal corporate resources (email, document management system, library collections) in a single interface with one search query. In the future, INL hopes to offer this open-source engine to the public. This session will outline the development processes for making Needle™s search interface and simplifying the federation of internal and external data sources.

  10. Trigger Point Dry Needling.

    PubMed

    2017-03-01

    Increasingly, physical therapists in the United States and throughout the world are using dry needling to treat musculoskeletal pain, even though this treatment has been a controversial addition to practice. To better generalize to physical therapy practice the findings about dry needling thus far, the authors of a study published in the March 2017 issue of JOSPT identified the need for a systematic review examining the effectiveness of dry needling performed by physical therapists on people with musculoskeletal pain. Their review offers a meta-analysis of data from several included studies and assesses the evidence for risks of bias. J Orthop Sports Phys Ther 2017;47(3):150. doi:10.2519/jospt.2017.0502.

  11. Understanding the Heritage Language Student: Proficiency and Placement

    ERIC Educational Resources Information Center

    Thompson, Gregory L.

    2015-01-01

    Given the ever-growing number of Spanish heritage learners in both universities and colleges, the need has continued to grow for the development of placement exams that accurately measure language ability, are simple to evaluate, and are easy to administer to large numbers of students. This article analyzes the implementation of a placement exam…

  12. Optical Flow-Based Tracking of Needles and Needle-Tip Localization Using Circular Hough Transform in Ultrasound Images

    PubMed Central

    Ayvali, Elif; Desai, Jaydev P.

    2014-01-01

    Image-guided interventions have become the standard of care for needle-based procedures. The success of the image-guided procedures depends on the ability to precisely locate and track the needle. This work is primarily focused on 2D ultrasound-based tracking of a hollow needle (cannula) that is composed of straight segments connected by shape memory alloy actuators. An in-plane tracking algorithm based on optical flow was proposed to track the cannula configuration in real-time. Optical flow is a robust tracking algorithm that can easily run on a CPU. However, the algorithm does not perform well when it is applied to the ultrasound images directly due to the intensity variation in the images. The method presented in this work enables using the optical flow algorithm on ultrasound images to track features of the needle. By taking advantage of the bevel tip, Circular Hough transform was used to accurately locate the needle tip when the imaging is out-of-plane. Through experiments inside tissue phantom and ex-vivo experiments in bovine kidney, the success of the proposed tracking methods were demonstrated. Using the methods presented in this work, quantitative information about the needle configuration is obtained in real-time which is crucial for generating control inputs for the needle and automating the needle insertion. PMID:25503523

  13. A "Needling" Complication.

    PubMed

    Banerji, John S; Govier, Fred E

    2016-11-01

    Intracavernosal injection therapy with vasoactive agents for treatment of erectile dysfunction has been around for more than 3 decades since its advent in the early 1980s. Common complications include ecchymosis and hematoma at the site of injection, priapism, and fibrosis. We describe a rare but potentially dangerous complication of breakage of needle during administering of injections, and discuss its successful retrieval.

  14. NEEDLE TRADES, MATHEMATICS - I.

    ERIC Educational Resources Information Center

    COLICCHIO, ANTOINETTE J.

    THE NEEDLE TRADES INDUSTRY CONSISTS OF THREE TYPES OF ESTABLISHMENTS -- THE REGULAR MANUFACTURERS, THE APPAREL JOBBERS, AND THE CONTRACTORS. THE FUNCTIONS INCLUDED COVER A WIDE SCOPE FROM BUYING OF RAW MATERIAL TO SELLING OF THE FINISHED APPAREL. THE PURPOSE OF THIS STUDY GUIDE IS TO FURNISH BASIC KNOWLEDGE IN MATHEMATICS AND DEVELOP SKILL IN…

  15. Endoscopic ultrasonography-guided placement of a transhepatic portal vein stent in a live porcine model

    PubMed Central

    Park, Tae Young; Seo, Dong Wan; Kang, Hyeon-Ji; Cho, Min Keun; Song, Tae Jun; Park, Do Hyun; Lee, Sang Soo; Lee, Sung Koo; Kim, Myung-Hwan

    2016-01-01

    Background and Objectives: Percutaneous portal vein (PV) stent placement is used to manage PV occlusion or stenosis caused by malignancy. The use of endoscopic ultrasonography (EUS) has expanded to include vascular interventions. The aim of this study was to examine the technical feasibility and safety of EUS-guided transhepatic PV stent placement in a live porcine model. Materials and Methods: EUS-guided transhepatic PV stent placement was performed in six male miniature pigs under general anesthesia using forward-viewing echoendoscope. Under EUS guidance, the left intrahepatic PV was punctured with a 19-gauge fine-needle aspiration (FNA) needle and a 0.025 inch guidewire inserted through the needle and into the main PV. The FNA needle was then withdrawn and a needle-knife inserted to dilate the tract. Under EUS and fluoroscopic guidance, a noncovered metal stent was inserted over the guidewire and released into the main PV. Results: A PV stent was placed successfully in all six pigs with no technical problems or complications. The patency of the stent in the main PV was confirmed using color Doppler EUS and transhepatic portal venography. Necropsy of the first three animals revealed no evidence of bleeding and damage to intra-abdominal organs or vessels. No complications occurred in the remaining three animals during the 8 weeks observation period. Conclusions: EUS-guided transhepatic PV stent placement can be both technically feasible and safe in a live animal model. PMID:27803904

  16. Robot-Assisted Needle Steering

    PubMed Central

    Reed, Kyle B.; Majewicz, Ann; Kallem, Vinutha; Alterovitz, Ron; Goldberg, Ken; Cowan, Noah J.; Okamura, Allison M.

    2012-01-01

    Needle insertion is a critical aspect of many medical treatments, diagnostic methods, and scientific studies, and is considered to be one of the simplest and most minimally invasive medical procedures. Robot-assisted needle steering has the potential to improve the effectiveness of existing medical procedures and enable new ones by allowing increased accuracy through more dexterous control of the needle tip path and acquisition of targets not accessible by straight-line trajectories. In this article, we describe a robot-assisted needle steering system that uses three integrated controllers: a motion planner concerned with guiding the needle around obstacles to a target in a desired plane, a planar controller that maintains the needle in the desired plane, and a torsion compensator that controls the needle tip orientation about the axis of the needle shaft. Experimental results from steering an asymmetric-tip needle in artificial tissue demonstrate the effectiveness of the system and its sensitivity to various environmental and control parameters. In addition, we show an example of needle steering in ex vivo biological tissue to accomplish a clinically relevant task, and highlight challenges of practical needle steering implementation. PMID:23028210

  17. Using Multiple Measures to Make Math Placement Decisions: Implications for Access and Success in Community Colleges

    ERIC Educational Resources Information Center

    Ngo, Federick; Kwon, William W.

    2015-01-01

    Community college students are often placed in developmental math courses based on the results of a single placement test. However, concerns about accurate placement have recently led states and colleges across the country to consider using other measures to inform placement decisions. While the relationships between college outcomes and such…

  18. Development of 3D ultrasound needle guidance for high-dose-rate interstitial brachytherapy of gynaecological cancers

    NASA Astrophysics Data System (ADS)

    Rodgers, J.; Tessier, D.; D'Souza, D.; Leung, E.; Hajdok, G.; Fenster, A.

    2016-04-01

    High-dose-rate (HDR) interstitial brachytherapy is often included in standard-of-care for gynaecological cancers. Needles are currently inserted through a perineal template without any standard real-time imaging modality to assist needle guidance, causing physicians to rely on pre-operative imaging, clinical examination, and experience. While two-dimensional (2D) ultrasound (US) is sometimes used for real-time guidance, visualization of needle placement and depth is difficult and subject to variability and inaccuracy in 2D images. The close proximity to critical organs, in particular the rectum and bladder, can lead to serious complications. We have developed a three-dimensional (3D) transrectal US system and are investigating its use for intra-operative visualization of needle positions used in HDR gynaecological brachytherapy. As a proof-of-concept, four patients were imaged with post-insertion 3D US and x-ray CT. Using software developed in our laboratory, manual rigid registration of the two modalities was performed based on the perineal template's vaginal cylinder. The needle tip and a second point along the needle path were identified for each needle visible in US. The difference between modalities in the needle trajectory and needle tip position was calculated for each identified needle. For the 60 needles placed, the mean trajectory difference was 3.23 +/- 1.65° across the 53 visible needle paths and the mean difference in needle tip position was 3.89 +/- 1.92 mm across the 48 visible needles tips. Based on the preliminary results, 3D transrectal US shows potential for the development of a 3D US-based needle guidance system for interstitial gynaecological brachytherapy.

  19. Biopsy needle tips with markers--MR compatible needles for high-precision needle tip positioning.

    PubMed

    Müller-Bierl, Bernd M; Martirosian, Petros; Graf, Hansjörg; Boss, Andreas; König, Claudius; Pereira, Philippe L; Schick, Fritz

    2008-06-01

    Needle tip visualization is of high importance in magnetic resonance imaging (MRI) guided interventional procedures, for example for taking biopsies from suspicious lesions in the liver or kidney. The exact position of the needle tip is often obscured by image artifacts arising from the magnetic properties of the needle. The authors investigated two special biopsy needle tip designs using diamagnetic coatings. For common interventional MR sequences, the needle tip can be identified in the MR image by several equidistant dark spots arranged along a straight line. A dotted instead of a solid line allows for an improved control of the movement of the needle, not only if the needle is tilted toward the imaging plane, but also if the needle leaves an empty canal with signal extinction, which cannot be distinguished from the needle material itself. With the proposed design the position of the needle tip can be estimated with a precision of approximately 1 mm using conventional FLASH, FISP, and TSE sequences, as used for interventional MR. Furthermore, the size of the biopsy probe can be estimated from the artifact. In using needles with a properly designed tip coating, taking biopsies under MR control is beginning to be greatly simplified. The approach to design artifacts using diamagnetic material in combination with paramagnetic material paves the way toward new instruments and implants, suitably tailored to the needs of the interventional radiologist.

  20. Controlling a Robotically Steered Needle in the Presence of Torsional Friction

    PubMed Central

    Reed, Kyle B.; Okamura, Allison M.; Cowan, Noah J.

    2010-01-01

    A flexible needle can be accurately steered by robotically controlling the orientation of the bevel tip as the needle is inserted into tissue. Here, we demonstrate the significant effect of friction between the long, flexible needle shaft and the tissue, which can cause a significant discrepancy between the orientation of the needle tip and the orientation of the base where the needle is controlled. Our experiments show that several common phantom tissues used in needle steering experiments impart substantial frictional forces to the needle shaft, resulting in a lag of over 45° for a 10 cm insertion depth in some phantoms; clinical studies have reported torques large enough to could cause similar errors during needle insertions. Such angle discrepancies will result in poor performance or failure of path planners and image-guided controllers, since the needles used in percutaneous procedures are too small for state-of-the-art imaging to accurately measure the tip angle. To compensate for the angle discrepancy, we develop a model for the rotational dynamics of a needle being continuously inserted into tissue and show how a PD controller is sufficient to compensate for the rotational dynamics. PMID:21461175

  1. Integrated Planning and Image-Guided Control for Planar Needle Steering

    PubMed Central

    Reed, Kyle B.; Kallem, Vinutha; Alterovitz, Ron; Goldberg, Ken; Okamura, Allison M.; Cowan, Noah J.

    2010-01-01

    Flexible, tip-steerable needles promise to enhance physicians’ abilities to accurately reach targets and maneuver inside the human body while minimizing patient trauma. Here, we present a functional needle steering system that integrates two components: (1) a patient-specific 2D pre- and intra-operative planner that finds an achievable route to a target within a planar slice of tissue (Stochastic Motion Roadmap), and (2) a low-level image-guided feedback controller that keeps the needle tip within that slice. The planner generates a sequence of circular arcs that can be realized by interleaving pure insertions with 180° rotations of the needle shaft. This preplanned sequence is updated in realtime at regular intervals. Concurrently, the low-level image-based controller servos the needle to remain close to the desired plane between plan updates. Both planner and controller are predicated on a previously developed kinematic nonholonomic model of bevel-tip needle steering. We use slighly different needles here that have a small bend near the tip, so we extend the model to account for discontinuities of the tip position caused by 180° rotations. Further, during large rotations of the needle base, we maintain the desired tip angle by compensating for torsional compliance in the needle shaft, neglected in previous needle steering work. By integrating planning, control, and torsion compensation, we demonstrate both accurate targeting and obstacle avoidance. PMID:20640197

  2. ESL Placement and Schools

    PubMed Central

    Callahan, Rebecca; Wilkinson, Lindsey; Muller, Chandra; Frisco, Michelle

    2010-01-01

    In this study, the authors explore English as a Second Language (ESL) placement as a measure of how schools label and process immigrant students. Using propensity score matching and data from the Adolescent Health and Academic Achievement Study and the National Longitudinal Study of Adolescent Health, the authors estimate the effect of ESL placement on immigrant achievement. In schools with more immigrant students, the authors find that ESL placement results in higher levels of academic performance; in schools with few immigrant students, the effect reverses. This is not to suggest a one-size-fits-all policy; many immigrant students, regardless of school composition, generational status, or ESL placement, struggle to achieve at levels sufficient for acceptance to a 4-year university. This study offers several factors to be taken into consideration as schools develop policies and practices to provide immigrant students opportunities to learn. PMID:20617111

  3. Fiducial Marker Placement

    MedlinePlus

    ... Media Computed Tomography (CT) - Body General Ultrasound Ultrasound - Prostate Introduction to Cancer Therapy (Radiation Oncology) Proton Therapy Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiotherapy (SBRT) Images related to Fiducial Marker Placement Sponsored by ...

  4. Gastrostomy tube placement - slideshow

    MedlinePlus

    ... presentations/100125.htm Gastrostomy tube placement - series—Normal anatomy To use the sharing features on this page, ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated: ...

  5. Efficacy of the EZ-IO® needle driver for out-of-hospital intraosseous access - a preliminary, observational, multicenter study

    PubMed Central

    2011-01-01

    Background Intraosseous (IO) access represents a reliable alternative to intravenous vascular access and is explicitly recommended in the current guidelines of the European Resuscitation Council when intravenous access is difficult or impossible. We therefore aimed to study the efficacy of the intraosseous needle driver EZ-IO® in the prehospital setting. Methods During a 24-month period, all cases of prehospital IO access using the EZ-IO® needle driver within three operational areas of emergency medical services were prospectively recorded by a standardized questionnaire that needed to be filled out by the rescuer immediately after the mission and sent to the primary investigator. We determined the rate of successful insertion of the IO needle, the time required, immediate procedure-related complications, the level of previous experience with IO access, and operator's subjective satisfaction with the device. Results 77 IO needle insertions were performed in 69 adults and five infants and children by emergency physicians (n = 72 applications) and paramedics (n = 5 applications). Needle placement was successful at the first attempt in all but 2 adults (one patient with unrecognized total knee arthroplasty, one case of needle obstruction after placement). The majority of users (92%) were relative novices with less than five previous IO needle placements. Of 22 responsive patients, 18 reported pain upon fluid administration via the needle. The rescuers' subjective rating regarding handling of the device and ease of needle insertion, as described by means of an analogue scale (0 = entirely unsatisfied, 10 = most satisfied), provided a median score of 10 (range 1-10). Conclusions The EZ-IO® needle driver was an efficient alternative to establish immediate out-of-hospital vascular access. However, significant pain upon intramedullary infusion was observed in the majority of responsive patients. PMID:22029625

  6. Autonomous real-time interventional scan plane control with a 3-D shape-sensing needle.

    PubMed

    Elayaperumal, Santhi; Plata, Juan Camilo; Holbrook, Andrew B; Park, Yong-Lae; Pauly, Kim Butts; Daniel, Bruce L; Cutkosky, Mark R

    2014-11-01

    This study demonstrates real-time scan plane control dependent on three-dimensional needle bending, as measured from magnetic resonance imaging (MRI)-compatible optical strain sensors. A biopsy needle with embedded fiber Bragg grating (FBG) sensors to measure surface strains is used to estimate its full 3-D shape and control the imaging plane of an MR scanner in real-time, based on the needle's estimated profile. The needle and scanner coordinate frames are registered to each other via miniature radio-frequency (RF) tracking coils, and the scan planes autonomously track the needle as it is deflected, keeping its tip in view. A 3-D needle annotation is superimposed over MR-images presented in a 3-D environment with the scanner's frame of reference. Scan planes calculated based on the FBG sensors successfully follow the tip of the needle. Experiments using the FBG sensors and RF coils to track the needle shape and location in real-time had an average root mean square error of 4.2 mm when comparing the estimated shape to the needle profile as seen in high resolution MR images. This positional variance is less than the image artifact caused by the needle in high resolution SPGR (spoiled gradient recalled) images. Optical fiber strain sensors can estimate a needle's profile in real-time and be used for MRI scan plane control to potentially enable faster and more accurate physician response.

  7. Ultrasound probe and needle-guide calibration for robotic ultrasound scanning and needle targeting.

    PubMed

    Kim, Chunwoo; Chang, Doyoung; Petrisor, Doru; Chirikjian, Gregory; Han, Misop; Stoianovici, Dan

    2013-06-01

    Image-to-robot registration is a typical step for robotic image-guided interventions. If the imaging device uses a portable imaging probe that is held by a robot, this registration is constant and has been commonly named probe calibration. The same applies to probes tracked by a position measurement device. We report a calibration method for 2-D ultrasound probes using robotic manipulation and a planar calibration rig. Moreover, a needle guide that is attached to the probe is also calibrated for ultrasound-guided needle targeting. The method is applied to a transrectal ultrasound (TRUS) probe for robot-assisted prostate biopsy. Validation experiments include TRUS-guided needle targeting accuracy tests. This paper outlines the entire process from the calibration to image-guided targeting. Freehand TRUS-guided prostate biopsy is the primary method of diagnosing prostate cancer, with over 1.2 million procedures performed annually in the U.S. alone. However, freehand biopsy is a highly challenging procedure with subjective quality control. As such, biopsy devices are emerging to assist the physician. Here, we present a method that uses robotic TRUS manipulation. A 2-D TRUS probe is supported by a 4-degree-of-freedom robot. The robot performs ultrasound scanning, enabling 3-D reconstructions. Based on the images, the robot orients a needle guide on target for biopsy. The biopsy is acquired manually through the guide. In vitro tests showed that the 3-D images were geometrically accurate, and an image-based needle targeting accuracy was 1.55 mm. These validate the probe calibration presented and the overall robotic system for needle targeting. Targeting accuracy is sufficient for targeting small, clinically significant prostatic cancer lesions, but actual in vivo targeting will include additional error components that will have to be determined.

  8. An automated optimization tool for high-dose-rate (HDR) prostate brachytherapy with divergent needle pattern

    NASA Astrophysics Data System (ADS)

    Borot de Battisti, M.; Maenhout, M.; de Senneville, B. Denis; Hautvast, G.; Binnekamp, D.; Lagendijk, J. J. W.; van Vulpen, M.; Moerland, M. A.

    2015-10-01

    Focal high-dose-rate (HDR) for prostate cancer has gained increasing interest as an alternative to whole gland therapy as it may contribute to the reduction of treatment related toxicity. For focal treatment, optimal needle guidance and placement is warranted. This can be achieved under MR guidance. However, MR-guided needle placement is currently not possible due to space restrictions in the closed MR bore. To overcome this problem, a MR-compatible, single-divergent needle-implant robotic device is under development at the University Medical Centre, Utrecht: placed between the legs of the patient inside the MR bore, this robot will tap the needle in a divergent pattern from a single rotation point into the tissue. This rotation point is just beneath the perineal skin to have access to the focal prostate tumor lesion. Currently, there is no treatment planning system commercially available which allows optimization of the dose distribution with such needle arrangement. The aim of this work is to develop an automatic inverse dose planning optimization tool for focal HDR prostate brachytherapy with needle insertions in a divergent configuration. A complete optimizer workflow is proposed which includes the determination of (1) the position of the center of rotation, (2) the needle angulations and (3) the dwell times. Unlike most currently used optimizers, no prior selection or adjustment of input parameters such as minimum or maximum dose or weight coefficients for treatment region and organs at risk is required. To test this optimizer, a planning study was performed on ten patients (treatment volumes ranged from 8.5 cm3to 23.3 cm3) by using 2-14 needle insertions. The total computation time of the optimizer workflow was below 20 min and a clinically acceptable plan was reached on average using only four needle insertions.

  9. Lumbar Catheter Placement Using Paramedian Approach Under Fluoroscopic Guidance

    PubMed Central

    Qureshi, Adnan I.; Khan, Asif A.; Malik, Ahmed A.; Afzal, Mohammad Rauf; Herial, Nabeel A.; Qureshi, Mushtaq H.; Suri, M. Fareed K.

    2016-01-01

    Background Lumbar catheter placement under fluoroscopic guidance may reduce the rate of technical failures and associated complications seen with insertion guided by manually palpable landmarks. Methods We reviewed our experience with 43 attempted lumbar catheter placements using paramedian approach under fluoroscopic guidance and ascertained rates of technical success, and clinical events. Results Among the 43 patients, 18, 1, and 1 patients were on aspirin (with dipyrimadole in 2), clopidogrel, and combination of both, respectively. Lumbar catheter placement was successful in 42 of 43 attempted placements. Floroscopic guidance was critical in three patients; one patient had severe cerebrospinal fluid (CSF) depletion (empty thecal sac phenomenon) following pituitary surgery leading to no cerebrospinal fluid return despite correct placement confirmation under fluoroscopy. Two patients had spinal needle placement at the junction between epidural and cerebrospinal fluid spaces (junctional position) leading to cerebrospinal fluid return but inability to introduce the lumbar catheter. After confirmation of position by the injection of contrast or radiographic landmarks the needle was advanced by indenting the subcutaneous tissue or reinserting at a spinal level above the first insertion. The lumbar catheter remained in position over a mean period (±standard deviation) of 4.1(±2.3) days. Improvement in hydrocephalus was seen in two patients with intracranial mass lesions. One patient developed cerebrospinal fluid leakage through the insertion track following removal of catheter and required skin suturing at the site of insertion. Conclusions We observed a high technical success rate with low rate of complications even in patients with intracranial mass lesions, those on ongoing antiplatelet medications or in whom insertion would not be possible guided by manually palpable landmarks. PMID:26958156

  10. Needle bar for warp knitting machines

    DOEpatents

    Hagel, Adolf; Thumling, Manfred

    1979-01-01

    Needle bar for warp knitting machines with a number of needles individually set into slits of the bar and having shafts cranked to such an extent that the head section of each needle is in alignment with the shaft section accommodated by the slit. Slackening of the needles will thus not influence the needle spacing.

  11. Fine needle aspiration cytology.

    PubMed Central

    Lever, J V; Trott, P A; Webb, A J

    1985-01-01

    Fine needle aspiration cytology is an inexpensive, atraumatic technique for the diagnosis of disease sites. This paper describes the technique and illustrates how it may be applied to the management of tumours throughout the body. The limitations of the method, the dangers of false positive reports, and the inevitability of false negative diagnoses are emphasised. In a clinical context the method has much to offer by saving patients from inappropriate operations and investigations and allowing surgeons to plan quickly and more rationally. It is an economically valuable technique and deserves greater recognition. Images PMID:2578481

  12. Needling the early universe

    NASA Technical Reports Server (NTRS)

    Hawkins, Isabel; Wright, Edward L.

    1988-01-01

    The possibility that the whole microwave background can be produced by a bright population of pregalactic stars at a redshift of a few hundred is explored. The radiation is thermalized by a combination of amorphous silicate, amorphous carbon, graphite, and needle-shaped conducting grains which give rise to the opacity needed at wavelengths greater than 3 cm. The occurrence of distortion in a primordial microwave background spectrum due to its interaction with Population III stars and dust is investigated. The possibility of producing deviations small enough to be consistent with the best available observations, but still detectable by COBE, is considered.

  13. Ban on needle swaps.

    PubMed

    1999-10-01

    A District of Columbia appropriations bill banning spending for needle-exchange programs will be going to President Clinton for signature. The House voted to approve the bill, and the Senate voted to accept it. Politicians from both parties are lobbying the President about the bill. Clinton's budget director, Jacob J. Lew, and D.C. Del. Eleanor Holmes Norton, argue against signing the bill. Rep. Thomas M. Davis warns a veto would scuttle legislation that funds education reforms and cleanup of the Anacostia River.

  14. Ultrasound-guided catheterisation of the subclavian vein: freehand vs needle-guided technique.

    PubMed

    Maecken, T; Heite, L; Wolf, B; Zahn, P K; Litz, R J

    2015-11-01

    The objective of this prospective, randomised study was to examine the impact of a multi-angle needle guide for ultrasound-guided, in-plane, central venous catheter placement in the subclavian vein. One hundred and sixty patients were randomly allocated to two groups, freehand or needle-guided, and then 159 catheterisations were analysed. Cannulation of the first examined access site was successful in 96.9% of cases with no significant difference between groups. There were three arterial punctures and no other severe injuries. Catheter misplacements did not differ between the groups. Higher success rates within the first and second attempts in the needle-guided group were observed (p = 0.041 and p = 0.019, respectively). Use of the needle guide reduced the access time from a median (IQR [range]) of 30 (18-76 [6-1409]) s to 16 (10-30 [4-295]) s; p = 0.0001, and increased needle visibility from 31.8% (9.7%-52.2% [0-96.67]) to 86.2% (62.5%-100% [0-100]); p < 0.0001. A multi-angle needle guide significantly improved aligning the needle and ultrasound plane compared with the freehand technique when cannulating the subclavian vein. Use of the guide resulted in faster access times and increased success at the first and second attempts.

  15. College Placement in Today's Economy.

    ERIC Educational Resources Information Center

    Galloway, James L.

    1982-01-01

    Analyzed the effects of reduced financing on college placement items such as services, staffing, fees, conference attendance, travel, recruitment, and salaries. Placement personnel (N=224) responded to a questionnaire. Results indicated that budgets have generally remained the same. (RC)

  16. The Gothic arch (needle point) tracing and condylar inclination.

    PubMed

    el-Gheriani, A S; Winstanley, R B

    1987-11-01

    The records of 11 patients referred for treatment of TMJ disorders were used to compare condylar inclination found by drawing a tangent and by using a mathematic technique. Needle point tracing angles were also measured for the same patients and were compared with the condylar inclination. It can be concluded that (1) the mathematic technique outlined records a more accurate condylar angulation, and (2) there is a great variation in condylar inclination values between patients and between left and right sides of the same patient, and (3) there is no direct relationship between condylar inclination and the needle point tracing angle.

  17. 21 CFR 880.5580 - Acupuncture needle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to pierce the skin in the practice of acupuncture. The device consists of a solid, stainless steel needle....

  18. 21 CFR 880.5580 - Acupuncture needle.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to pierce the skin in the practice of acupuncture. The device consists of a solid, stainless steel needle....

  19. 21 CFR 880.5580 - Acupuncture needle.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to pierce the skin in the practice of acupuncture. The device consists of a solid, stainless steel needle....

  20. 21 CFR 880.5580 - Acupuncture needle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to pierce the skin in the practice of acupuncture. The device consists of a solid, stainless steel needle....

  1. 21 CFR 880.5580 - Acupuncture needle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Acupuncture needle. 880.5580 Section 880.5580 Food... § 880.5580 Acupuncture needle. (a) Identification. An acupuncture needle is a device intended to pierce the skin in the practice of acupuncture. The device consists of a solid, stainless steel needle....

  2. Transrectal Prostate Biopsy and Fiducial Marker Placement in a Standard 1.5T Magnetic Resonance Imaging Scanner

    PubMed Central

    Susil, Robert C.; Ménard, Cynthia; Krieger, Axel; Coleman, Jonathan A.; Camphausen, Kevin; Choyke, Peter; Fichtinger, Gabor; Whitcomb, Louis L.; Coleman, C. Norman; Atalar, Ergin

    2012-01-01

    Purpose We investigated the accuracy and feasibility of a system that provides transrectal needle access to the prostate concurrent with 1.5 Tesla MRI which previously has not been possible. Materials and Methods In 5 patients with previously diagnosed prostate cancer, MRI guided intraprostatic placement of gold fiducial markers (4 procedures) and/or prostate biopsy (3 procedures) was performed using local anesthesia. Results Mean procedure duration was 76 minutes and all patients tolerated the intervention well. Procedure related adverse events included self-limited hematuria and hematochezia following 3 of 8 procedures (all resolved in less than 1 week). Mean needle placement accuracy was 1.9 mm for the fiducial marker placement studies and 1.8 mm for the biopsy procedures. Mean fiducial marker placement accuracy was 4.8 mm and the mean fiducial marker placement accuracy transverse to the needle direction was 2.6 mm. All patients who underwent the procedure were able to complete their course of radiotherapy without delay or complication. Conclusions While studies of clinical usefulness are warranted, transrectal 1.5 T MRI guided prostate biopsy and fiducial marker placement is feasible using this system, providing new opportunities for image guided diagnostic and therapeutic prostate interventions. PMID:16406885

  3. Autonomous Real-Time Interventional Scan Plane Control With a 3-D Shape-Sensing Needle

    PubMed Central

    Plata, Juan Camilo; Holbrook, Andrew B.; Park, Yong-Lae; Pauly, Kim Butts; Daniel, Bruce L.; Cutkosky, Mark R.

    2016-01-01

    This study demonstrates real-time scan plane control dependent on three-dimensional needle bending, as measured from magnetic resonance imaging (MRI)-compatible optical strain sensors. A biopsy needle with embedded fiber Bragg grating (FBG) sensors to measure surface strains is used to estimate its full 3-D shape and control the imaging plane of an MR scanner in real-time, based on the needle’s estimated profile. The needle and scanner coordinate frames are registered to each other via miniature radio-frequency (RF) tracking coils, and the scan planes autonomously track the needle as it is deflected, keeping its tip in view. A 3-D needle annotation is superimposed over MR-images presented in a 3-D environment with the scanner’s frame of reference. Scan planes calculated based on the FBG sensors successfully follow the tip of the needle. Experiments using the FBG sensors and RF coils to track the needle shape and location in real-time had an average root mean square error of 4.2 mm when comparing the estimated shape to the needle profile as seen in high resolution MR images. This positional variance is less than the image artifact caused by the needle in high resolution SPGR (spoiled gradient recalled) images. Optical fiber strain sensors can estimate a needle’s profile in real-time and be used for MRI scan plane control to potentially enable faster and more accurate physician response. PMID:24968093

  4. Multi-resolution Gabor wavelet feature extraction for needle detection in 3D ultrasound

    NASA Astrophysics Data System (ADS)

    Pourtaherian, Arash; Zinger, Svitlana; Mihajlovic, Nenad; de With, Peter H. N.; Huang, Jinfeng; Ng, Gary C.; Korsten, Hendrikus H. M.

    2015-12-01

    Ultrasound imaging is employed for needle guidance in various minimally invasive procedures such as biopsy guidance, regional anesthesia and brachytherapy. Unfortunately, a needle guidance using 2D ultrasound is very challenging, due to a poor needle visibility and a limited field of view. Nowadays, 3D ultrasound systems are available and more widely used. Consequently, with an appropriate 3D image-based needle detection technique, needle guidance and interventions may significantly be improved and simplified. In this paper, we present a multi-resolution Gabor transformation for an automated and reliable extraction of the needle-like structures in a 3D ultrasound volume. We study and identify the best combination of the Gabor wavelet frequencies. High precision in detecting the needle voxels leads to a robust and accurate localization of the needle for the intervention support. Evaluation in several ex-vivo cases shows that the multi-resolution analysis significantly improves the precision of the needle voxel detection from 0.23 to 0.32 at a high recall rate of 0.75 (gain 40%), where a better robustness and confidence were confirmed in the practical experiments.

  5. Benchmarking of state-of-the-art needle detection algorithms in 3D ultrasound data volumes

    NASA Astrophysics Data System (ADS)

    Pourtaherian, Arash; Zinger, Svitlana; de With, Peter H. N.; Korsten, Hendrikus H. M.; Mihajlovic, Nenad

    2015-03-01

    Ultrasound-guided needle interventions are widely practiced in medical diagnostics and therapy, i.e. for biopsy guidance, regional anesthesia or for brachytherapy. Needle guidance using 2D ultrasound can be very challenging due to the poor needle visibility and the limited field of view. Since 3D ultrasound transducers are becoming more widely used, needle guidance can be improved and simplified with appropriate computer-aided analyses. In this paper, we compare two state-of-the-art 3D needle detection techniques: a technique based on line filtering from literature and a system employing Gabor transformation. Both algorithms utilize supervised classification to pre-select candidate needle voxels in the volume and then fit a model of the needle on the selected voxels. The major differences between the two approaches are in extracting the feature vectors for classification and selecting the criterion for fitting. We evaluate the performance of the two techniques using manually-annotated ground truth in several ex-vivo situations of different complexities, containing three different needle types with various insertion angles. This extensive evaluation provides better understanding on the limitations and advantages of each technique under different acquisition conditions, which is leading to the development of improved techniques for more reliable and accurate localization. Benchmarking results that the Gabor features are better capable of distinguishing the needle voxels in all datasets. Moreover, it is shown that the complete processing chain of the Gabor-based method outperforms the line filtering in accuracy and stability of the detection results.

  6. Evaluation of a Marker Clip System in Sonographically Guided Core Needle Biopsy for Breast Cancer Localization Before and After Neoadjuvant Chemotherapy

    PubMed Central

    Schulz-Wendtland, R.; Dankerl, P.; Bani, M. R.; Fasching, P. A.; Heusinger, K.; Lux, M. P.; Jud, S. M.; Rauh, C.; Bayer, C. M.; Schrauder, M. G.; Beckmann, M. W.; Uder, M.; Brehm, B.; Loehberg, C. R.

    2017-01-01

    Introduction The placement of intramammary marker clips has proven to be helpful for tumor localization in patients undergoing neoadjuvant chemotherapy and breast-conserving surgery. The purpose of our study was to investigate the feasibility of using a clip marker system for breast cancer localization and its influence on the imaging assessment of treatment responses after neoadjuvant chemotherapy. Patients and Methods Between March and June 2015, a total of 25 patients (n = 25), with a suspicion of invasive breast cancer with diameters of at least 2 cm (cT2), underwent preoperative sonographically guided core needle biopsy using a single-use breast biopsy system (HistoCore™) and intramammary clip marking using a directly adapted clip system based on the established O-Twist Marker™, before their scheduled preoperative neoadjuvant chemotherapy. Localization of the intramammary marker clip was controlled by sonography and digital breast tomosynthesis. Results Sonography detected no dislocation of intrammammary marker clips in 20 of 25 patients (80 %), while digital breast tomosynthesis showed accurate placement without dislocation in 24 patients (96 %) (p < 0.05). There was no evidence of significant clip migration during preoperative follow-up imaging after neoadjuvant chemotherapy. No complication related to the clip marking was noted and there was no difficulty in evaluating the treatment response to neoadjuvant chemotherapy. Among the breast-conserving surgeries performed, no cases were identified in which intraoperative loss of the marker clip had occurred. Conclusion Our study underscores the importance of intramammary marking clip systems before neoadjuvant chemotherapy. Placement of marker clips is advised to facilitate accurate tumor bed localization. With regard to digital breast tomosynthesis, its development continues to improve the quality of diagnostics and the therapy of breast cancer particularly for small breast cancer tumors or in

  7. Impacted material placement plans

    SciTech Connect

    Hickey, M.J.

    1997-01-29

    Impacted material placement plans (IMPP) are documents identifying the essential elements in placing remediation wastes into disposal facilities. Remediation wastes or impacted material(s) are those components used in the construction of the disposal facility exclusive of the liners and caps. The components might include soils, concrete, rubble, debris, and other regulatory approved materials. The IMPP provides the details necessary for interested parties to understand the management and construction practices at the disposal facility. The IMPP should identify the regulatory requirements from applicable DOE Orders, the ROD(s) (where a part of a CERCLA remedy), closure plans, or any other relevant agreements or regulations. Also, how the impacted material will be tracked should be described. Finally, detailed descriptions of what will be placed and how it will be placed should be included. The placement of impacted material into approved on-site disposal facilities (OSDF) is an integral part of gaining regulatory approval. To obtain this approval, a detailed plan (Impacted Material Placement Plan [IMPP]) was developed for the Fernald OSDF. The IMPP provides detailed information for the DOE, site generators, the stakeholders, regulatory community, and the construction subcontractor placing various types of impacted material within the disposal facility.

  8. Iron needles in supernova remnants?

    NASA Astrophysics Data System (ADS)

    Gomez (née Morgan), Haley L.; Dunne, Loretta; Eales, Stephen A.; Gomez, Edward L.; Edmunds, Michael G.

    2005-08-01

    It has been suggested by Dwek that iron needles could explain the submillimetre emission from the Cas A supernova remnant (SNR) with only a very small total mass. We investigate whether a similar model holds for the Kepler SNR, and find that its emission could indeed be explained by a dust mass of less than 10-2Msolar, dependent on the axial ratio l/a of the needles - which we constrain to be less than 700. But the implied needle model for Kepler is inconsistent with that suggested for Cas A since either the needles would have to have a resistivity one or two orders of magnitude greater than those in Cas A or the electron density in Kepler's shocked plasma must be 40 times greater than suggested by X-ray observations. An additional problem with the needle model is that the implied thickness of the needles seems to be implausibly small, if the emission properties are calculated under the usual approximations.

  9. Fabrication of tungsten wire needles

    SciTech Connect

    Roder, A.

    1983-02-01

    Fine point needles for field emissoin are conventionally produced by electrolytically or chemically etching tungsten wire. Points formed in this manner have a typical tip radius of about 0.5 microns and a cone angle of some 30 degrees. The construction of needle matrix detector chambers has created a need for tungsten needles whose specifications are: 20 mil tungsten wire, 1.5 inch total length, 3 mm-long taper (resulting in a cone angle of about 5 degrees), and 25 micron-radius point (similar to that found on sewing needles). In the process described here for producing such needles, tungsten wire, immersed in a NaOH solution and in the presence of an electrode, is connected first to an ac voltage and then to a dc supply, to form a taper and a point on the end of the wire immersed in the solution. The process parameters described here are for needles that will meet the above specifications. Possible variations will be discussed under each approprite heading.

  10. Computer-vision-based inspecting system for needle roller bearing

    NASA Astrophysics Data System (ADS)

    Li, Wei; He, Tao; Zhong, Fei; Wu, Qinhua; Zhong, Yuning; Shi, Teiling

    2006-11-01

    A Computer Vision based Inspecting System for Needle Roller Bearing (CVISNRB) is proposed in the paper. The characteristic of technology, main functions and principle of CVISNRB are also introduced. CVISNRB is composed of a mechanic transmission and an automatic feeding system, an imaging system, software arithmetic, an automatic selecting system of inspected bearing, a human-computer interaction, a pneumatic control system, an electric control system and so on. The computer vision technique is introduced in the inspecting system for needle roller bearing, which resolves the problem of the small needle roller bearing inspecting in bearing production business enterprise, raises the speed of the inspecting, and realizes the automatic untouched and on-line examination. The CVISNRB can effectively examine the loss of needle and give the accurate number. The accuracy can achieve 99.5%, and the examination speed can arrive 15 needle roller bearings each minute. The CVISNRB has none malfunction in the actual performance in the past half year, and can meet the actual need.

  11. Endoscopic Ultrasound Guided Rendezvous Drainage of Biliary Obstruction Using a New Flexible 19-Gauge Fine Needle Aspiration Needle

    PubMed Central

    Tang, Zhouwen; Igbinomwanhia, Efehi; Elhanafi, Sherif

    2016-01-01

    Background and Aim. A successful endoscopic ultrasound guided rendezvous (EUS-RV) biliary drainage is dependent on accurate puncture of the bile duct and precise guide wire manipulation across the ampulla of Vater. We aim to study the feasibility of using a flexible 19-gauge fine aspiration needle in the performance of EUS-RV biliary drainage. Method. This is a retrospective case series of EUS-RV biliary drainage procedures at a single center. Patients who failed ERCP during the same session for benign or malignant biliary obstruction underwent EUS-RV using a flexible, nitinol covered, 19-gauge needle for biliary access and guide wire manipulation. Result. 24 patients underwent EUS-RV biliary drainage via extrahepatic access while 1 attempt was via intrahepatic access. The technical success rate was 80%, including 83.3% of cases via extrahepatic access. There was no significant difference in success rate of inpatient and outpatient procedures, benign or malignant indications, or type of guide wire used. Adverse events included mild pancreatitis (3 patients) and cholangitis (1 patient). Conclusion. A flexible 19-gauge needle for biliary access can be safe and effective when used to perform EUS-RV biliary drainage. Direct comparison between the nitinol needle and conventional metal needles in the performance of EUS guided biliary drainage is needed. PMID:27822005

  12. Design of a mechanical clutch-based needle-insertion device

    PubMed Central

    Bassett, Erik K.; Slocum, Alexander H.; Masiakos, Peter T.; Pryor, Howard I.; Farokhzad, Omid C.; Karp, Jeffery M.

    2009-01-01

    Insertion of trocars, needles, and catheters into unintended tissues or tissue compartments results in hundreds of thousands of complications annually. Current methods for blood vessel cannulation or epidural, chest tube, and initial trocar placement often involve the blind pass of a needle through several layers of tissue and generally rely on distinguishable anatomic landmarks and a high degree of clinical skill. To address this simply and without the use of electronics, a purely mechanical clutch system was developed for use in medical devices that access tissue and tissue compartments. This clutch utilizes the surface contact of a buckled filament inside an S-shaped tube to transmit force from the filament (catheter/guide wire) to the tube (needle). Upon encountering sufficient resistance at the tip, such as dense tissue, the catheter buckles and locks within the tube, causing the filament and needle to advance as one. When the needle reaches the target tissue or fluid-filled cavity, the filament unlocks and slides freely into the target region while the needle remains stationary. A similar locking phenomenon has long been observed in drill strings inside drill shafts used by the oil-drilling industry, and oil industry models were adapted to describe the motion of this clutch system. A predictive analytical model was generated and validated with empirical data and used to develop prototypes of a complete device then tested in vitro on muscle tissue and in vivo on a porcine laparoscopic model with promising results. PMID:19307560

  13. Planning Fireworks Trajectories for Steerable Medical Needles to Reduce Patient Trauma.

    PubMed

    Xu, Jijie; Duindam, Vincent; Alterovitz, Ron; Pouliot, Jean; Cunha, J Adam M; Hsu, I-Chow; Goldberg, Ken

    Accurate insertion of needles to targets in 3D anatomy is required for numerous medical procedures. To reduce patient trauma, a "fireworks" needle insertion approach can be used in which multiple needles are inserted from a single small region on the patient's skin to multiple targets in the tissue. In this paper, we explore motion planning for "fireworks" needle insertion in 3D environments by developing an algorithm based on Rapidly-exploring Random Trees (RRTs). Given a set of targets, we propose an algorithm to quickly explore the configuration space by building a forest of RRTs and to find feasible plans for multiple steerable needles from a single entry region. We present two path selection algorithms with different optimality considerations to optimize the final plan among all feasible outputs. Finally, we demonstrate the performance of the proposed algorithm with a simulation based on a prostate cancer treatment environment.

  14. Planning Fireworks Trajectories for Steerable Medical Needles to Reduce Patient Trauma

    PubMed Central

    Xu, Jijie; Duindam, Vincent; Alterovitz, Ron; Pouliot, Jean; Cunha, J. Adam M.; Hsu, I-Chow; Goldberg, Ken

    2012-01-01

    Accurate insertion of needles to targets in 3D anatomy is required for numerous medical procedures. To reduce patient trauma, a “fireworks” needle insertion approach can be used in which multiple needles are inserted from a single small region on the patient’s skin to multiple targets in the tissue. In this paper, we explore motion planning for “fireworks” needle insertion in 3D environments by developing an algorithm based on Rapidly-exploring Random Trees (RRTs). Given a set of targets, we propose an algorithm to quickly explore the configuration space by building a forest of RRTs and to find feasible plans for multiple steerable needles from a single entry region. We present two path selection algorithms with different optimality considerations to optimize the final plan among all feasible outputs. Finally, we demonstrate the performance of the proposed algorithm with a simulation based on a prostate cancer treatment environment. PMID:25946259

  15. Low cost augmented reality for training of MRI-guided needle biopsy of the spine.

    PubMed

    George, Sandeep; Kesavadas, Thenkurussi

    2008-01-01

    In needle biopsy of the spine, an Augmented Reality (AR) image guidance system can be very effective in ensuring that while targeting the lesion with the biopsy needle, vital organs near the spine are not damaged and that the approach path is accurate. This procedure requires skill that is hard to master on patients. In this paper, we present a low cost AR based training set-up which consists of a software that uses one static single-camera tracking mechanism to locate the biopsy needle in the patient and which then augments the camera feed of the patient with virtual data providing real-time guidance to the surgeon for insertion of the biopsy needle. The setup is implemented using a phantom model consisting of a set of carefully modeled holes to simulate the needle insertion task. The lack of requirement of elaborate infrared tracking systems and high computing power makes this system very effective for educational and training purposes.

  16. Interactive simulation of needle insertion models.

    PubMed

    DiMaio, Simon P; Salcudean, Septimiu E

    2005-07-01

    A novel interactive virtual needle insertion simulation is presented. The simulation models are based on measured planar tissue deformations and needle insertion forces. Since the force-displacement relationship is only of interest along the needle shaft, a condensation technique is shown to reduce the computational complexity of linear simulation models significantly. As the needle penetrates or is withdrawn from the tissue model, the boundary conditions that determine the tissue and needle motion change. Boundary condition and local material coordinate changes are facilitated by fast low-rank matrix updates. A large-strain elastic needle model is coupled to the tissue models to account for needle deflection and bending during simulated insertion. A haptic environment, based on these novel interactive simulation techniques, allows users to manipulate a three-degree-of-freedom virtual needle as it penetrates virtual tissue models, while experiencing steering torques and lateral needle forces through a planar haptic interface.

  17. 7. View showing placement of timber deck placement on chord ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View showing placement of timber deck placement on chord and built up construction of top chord and continuous construction through top panel points, eye bar construction on bottom chord - Bridge No. 2.4, Spanning Boiling Fork Creek at Railroad Milepost JC-2.4, Decherd, Franklin County, TN

  18. Does Needle Rotation Improve Lesion Targeting?

    PubMed Central

    Badaan, Shadi; Petrisor, Doru; Kim, Chunwoo; Mozer, Pierre; Mazilu, Dumitru; Gruionu, Lucian; Patriciu, Alex; Cleary, Kevin; Stoianovici, Dan

    2011-01-01

    Background Image-guided robots are manipulators that operate based on medical images. Perhaps the most common class of image-guided robots are robots for needle interventions. Typically, these robots actively position and/or orient a needle guide, but needle insertion is still done by the physician. While this arrangement may have safety advantages and keep the physician in control of needle insertion, actuated needle drivers can incorporate other useful features. Methods We first present a new needle driver that can actively insert and rotate a needle. With this device we investigate the use of needle rotation in controlled in-vitro experiments performed with a specially developed revolving needle driver. Results These experiments show that needle rotation can improve targeting and may reduce errors by as much as 70%. Conclusion The new needle driver provides a unique kinematic architecture that enables insertion with a compact mechanism. Perhaps the most interesting conclusion of the study is that lesions of soft tissue organs may not be perfectly targeted with a needle without using special techniques, either manually or with a robotic device. The results of this study show that needle rotation may be an effective method of reducing targeting errors. PMID:21360796

  19. Superficial versus deep dry needling.

    PubMed

    Baldry, Peter

    2002-08-01

    Ninety percent of my patients with myofascial trigger point (MTrP) pain have this alone and are treated with superficial dry needling. Approximately 10% have concomitant MTrP pain and nerve root compression pain. These are treated with deep dry needling. SUPERFICIAL DRY NEEDLING (SDN): The activated and sensitised nociceptors of a MTrP cause it to be so exquisitely tender that firm pressure applied to it gives rise to a flexion withdrawal reflex (jump sign) and in some cases the utterance of an expletive (shout sign). The optimum strength of SDN at a MTrP site is the minimum necessary to abolish these two reactions. With respect to this patients are divided into strong, average and weak responders. The responsiveness of each individual is determined by trial and error. It is my practice to insert a needle (0.3mm x 30mm) into the tissues immediately overlying the MTrP to a depth of 5-10 mm and to leave it in situ long enough for the two reactions to be abolished. For an average reactor this is about 30secs. For a weak reactor it is several minutes. And for a strong reactor the insertion of the needle and its immediate withdrawal is all that is required. Following treatment muscle stretching exercises should be carried out, and any steps taken to eliminate factors that might lead to the reactivation of the MTrPs. DEEP DRY NEEDLING (DDN): This in my practice is only used either when primary MTrP activity causes shortening of muscle sufficient enough to bring about compression of nerve roots. Or when there is nerve compression pain usually from spondylosis or disc prolapse and the secondary development of MTrP activity. Unlike SDN, DDN is a painful procedure and one which gives rise to much post-treatment soreness.

  20. Magnetic needles and superparamagnetic cells

    PubMed Central

    Bryant, H C; Sergatskov, D A; Lovato, Debbie; Adolphi, Natalie L; Larson, Richard S; Flynn, Edward R

    2007-01-01

    Superparamagnetic nanoparticles can be attached in great numbers to pathogenic cells using specific antibodies so that the magnetically-labeled cells themselves become superparamagnets. The cells can then be manipulated and drawn out of biological fluids, as in a biopsy, very selectively using a magnetic needle. We examine the origins and uncertainties in the forces exerted on magnetic nanoparticles by static magnetic fields, leading to a model for trajectories and collection times of dilute superparamagnetic cells in biological fluids. We discuss the design and application of such magnetic needles and the theory of collection times. We compare the mathematical model to measurements in a variety of media including blood. PMID:17664592

  1. Toward effective needle steering in brain tissue.

    PubMed

    Engh, J A; Podnar, G; Kondziolka, D; Riviere, C N

    2006-01-01

    Recent research has exploited the inherent bending of a bevel-tipped needle during insertion, accomplishing steering of the needle by rotating the needle shaft. Combining this technique with the observation that a straight trajectory can be accomplished by spinning the needle at a constant rate during insertion, this paper presents a novel technique for proportional control of the curvature of the trajectory via duty-cycled spinning of the needle. In order to accommodate this technique to very soft tissues such as the brain, several custom needle prototypes have also been designed in order to increase the steering versatility of the system by maximizing the attainable curvature. The paper describes the needle-steering system and the needle prototypes, and presents preliminary results from tests in an artificial brain tissue substitute.

  2. 45 CFR 605.35 - Evaluation and placement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... administered to a student with impaired sensory, manual, or speaking skills, the test results accurately..., rather than reflecting the student's impaired sensory, manual, or speaking skills (except where those skills are the factors that the test purports to measure). (c) Placement procedures. In...

  3. 34 CFR 104.35 - Evaluation and placement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... administered to a student with impaired sensory, manual, or speaking skills, the test results accurately..., rather than reflecting the student's impaired sensory, manual, or speaking skills (except where those skills are the factors that the test purports to measure). (c) Placement procedures. In...

  4. 45 CFR 605.35 - Evaluation and placement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... administered to a student with impaired sensory, manual, or speaking skills, the test results accurately..., rather than reflecting the student's impaired sensory, manual, or speaking skills (except where those skills are the factors that the test purports to measure). (c) Placement procedures. In...

  5. 34 CFR 104.35 - Evaluation and placement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... administered to a student with impaired sensory, manual, or speaking skills, the test results accurately..., rather than reflecting the student's impaired sensory, manual, or speaking skills (except where those skills are the factors that the test purports to measure). (c) Placement procedures. In...

  6. 34 CFR 104.35 - Evaluation and placement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... administered to a student with impaired sensory, manual, or speaking skills, the test results accurately..., rather than reflecting the student's impaired sensory, manual, or speaking skills (except where those skills are the factors that the test purports to measure). (c) Placement procedures. In...

  7. 34 CFR 104.35 - Evaluation and placement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... administered to a student with impaired sensory, manual, or speaking skills, the test results accurately..., rather than reflecting the student's impaired sensory, manual, or speaking skills (except where those skills are the factors that the test purports to measure). (c) Placement procedures. In...

  8. 45 CFR 605.35 - Evaluation and placement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... administered to a student with impaired sensory, manual, or speaking skills, the test results accurately..., rather than reflecting the student's impaired sensory, manual, or speaking skills (except where those skills are the factors that the test purports to measure). (c) Placement procedures. In...

  9. 34 CFR 104.35 - Evaluation and placement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... administered to a student with impaired sensory, manual, or speaking skills, the test results accurately..., rather than reflecting the student's impaired sensory, manual, or speaking skills (except where those skills are the factors that the test purports to measure). (c) Placement procedures. In...

  10. 45 CFR 605.35 - Evaluation and placement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... administered to a student with impaired sensory, manual, or speaking skills, the test results accurately..., rather than reflecting the student's impaired sensory, manual, or speaking skills (except where those skills are the factors that the test purports to measure). (c) Placement procedures. In...

  11. 45 CFR 605.35 - Evaluation and placement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... administered to a student with impaired sensory, manual, or speaking skills, the test results accurately..., rather than reflecting the student's impaired sensory, manual, or speaking skills (except where those skills are the factors that the test purports to measure). (c) Placement procedures. In...

  12. MAPP: A Mathematics Placement Program.

    ERIC Educational Resources Information Center

    Doblin, Stephen A.

    1978-01-01

    MAPP (A Mathematics Placement Program) uses two COBOL programs to place entering freshmen in mathematics courses which are commensurate with their backgrounds and abilities. Having been used for three years, the program is considered to be a viable alternative to the traditional mathematics placement process. (Author/JKS)

  13. [Developmental Placement.] Collected Research References.

    ERIC Educational Resources Information Center

    Bjorklund, Gail

    Drawing on information and references in the ERIC system, this literature review describes research related to a child's developmental placement. The issues examined include school entrance age; predictive validity, reliability, and features of Gesell School Readiness Assessment; retention; and the effectiveness of developmental placement. A…

  14. Improvement of Job Placement Services.

    ERIC Educational Resources Information Center

    Mount San Antonio Community Coll. District, Walnut, CA.

    The Improvement of Job Placement Services Project was undertaken to examine and strengthen job placement services and programs in the California community colleges. Specific objectives of the project were to: (1) select and convene a 12-member representative advisory committee to oversee project operations working with the California Placement…

  15. Placement and Follow-up.

    ERIC Educational Resources Information Center

    Shippen, Samuel Joseph, Ed.; Wasil, Raymond A., Ed.

    This document contains a compilation of original manuscripts written by competent authorities in the field of job placement services for students. Viewing placement as both a product and an integral part of a developmental process, these papers are divided into the following six topical areas: (1) information, (2) exploration, (3) counseling, (4)…

  16. College Student Personnel Graduate Placement

    ERIC Educational Resources Information Center

    Greer, Richard M.; And Others

    1978-01-01

    This study reports results of ACPA Commission XII's survey of 101 college student personnel training institutions regarding their graduate placement. Graduates were identified according to degree, race, and sex. Percentages of graduates placed, specialty areas, types of institutions, areas of the country, and time and method of placement were…

  17. CT-Guided Placement of a Drainage Catheter Within a Pelvic Abscess Using a Transsacral Approach

    SciTech Connect

    Iguchi, Toshihiro Asami, Shinya; Kubo, Shinichiro; Kin, Hitoshi; Katusi, Kuniaki; Sakurai, Jun; Hiraki, Takao; Kanazawa, Susumu

    2007-11-15

    A 66-year-old man underwent CT-guided drainage catheter placement within a pelvic abscess with a diameter of 46 mm. We performed the drainage by a transsacral approach because it was considered the safest and most feasible approach. An 8G bone marrow biopsy needle was used to penetrate the sacrum to create a path for subsequent drainage catheter insertion. After withdrawal of the biopsy needle, a 6 Fr catheter was advanced into the abscess cavity through the path using the Seldinger technique. Except for bearable pain, no procedure-related complications occurred. Twenty-nine days after the placement, the catheter was withdrawn safely and the abscess cavity had shrunk remarkably.

  18. Biomechanics of a new atraumatic surgical needle holder.

    PubMed

    Towler, M A; Chen, N C; Moody, F P; McGregor, W; Thacker, J G; Rodeheaver, G T; Edlich, R F

    1991-01-01

    It is the purpose of this report to design, develop, and evaluate a needle holder whose jaws improve needle-holding security without altering the geometry of the curved surgical needle. The configuration of the jaws of this new needle holder is curved, conforming to the curvature of the surgical needle. A biomechanical study of this curved surgical needle holder demonstrates that it holds the curved needle securely without needle deformation.

  19. Core needle biopsy guidance based on EMOCT imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Iftimia, Nicusor V.; Park, Jesung; Maguluri, Gopi

    2016-03-01

    We present a novel method, based on encoder mapping OCT imaging, for real-time guidance of core biopsy procedures. This method provides real-time feedback to the interventional radiologist, such that he/she can reorient the needle during the biopsy and sample the most representative area of the suspicious mass that is being investigated. This aspect is very important for tailoring therapy to the specific cancer based on biomarker analysis, which will become one of the next big advances in our search for the optimal cancer therapy. To enable individualized treatment, the genetic constitution and the DNA repair status in the affected areas is needed for each patient. Thus, representative sampling of the tumor is needed for analyzing various biomarkers, which are used as a tool to personalize cancer therapy. The encoder-based OCT enables samping of large size masses and provides full control on the imaging probe, which is passed through the bore of the biopsy guidance needle. The OCT image is built gradually, based on the feedback of an optical encoder which senses the incremental movement of the needle with a few microns resolution. Tissue mapping is independent of the needle speed, while it is advanced through the tissue. The OCT frame is analyzed in real-time and tissue cellularity is reported in a very simple manner (pie chart). Our preliminary study on a rabbit model of cancer has demonstrated the capability of this technology for accurately differentiating between viable cancer and heterogeneous or necrotic tissue.

  20. Limitations of the Use of Pressure Waves to Verify Correct Epidural Needle Position in Dogs

    PubMed Central

    Bergadano, Alessandra; Spadavecchia, Claudia

    2013-01-01

    The use of pressure waves to confirm the correct position of the epidural needle has been described in several domestic species and proposed as a valid alternative to standard methods, namely, control radiographic exam and fluoroscopy. The object of this retrospective clinical study was to evaluate the sensitivity of the epidural pressure waves as a test to verify the correct needle placement in the epidural space in dogs, in order to determine whether this technique could be useful not only in the clinical setting but also when certain knowledge of needle's tip position is required, for instance when performing clinical research focusing on epidural anaesthesia. Of the 54 client-owned dogs undergoing elective surgeries and enrolled in this retrospective study, only 45% showed epidural pressure waves before and after epidural injection. Twenty-six percent of the animals showed epidural pressure waves only after the injection, whereas 29% of the dogs showed epidural pressure waves neither before nor after injection and were defined as false negatives. Our results show that the epidural pressure wave technique to verify epidural needle position lacks sensitivity, resulting in many false negatives. As a consequence, the applicability of this technique is limited to situations in which precise, exact knowledge of the needle's tip position is not mandatory. PMID:23853736

  1. Compensating for Torsion Windup in Steerable Needles

    PubMed Central

    Reed, Kyle B.

    2010-01-01

    Long, flexible, bevel-tip needles curve during insertion into tissue, and rotations of the needle base reorient the tip to steer subsequent insertions. Friction between the tissue and the needle shaft, however, can cause a severe discrepancy between the needle base and tip angles. In this paper, I demonstrate an algorithm to properly align the entire length of the needle using torque measured at the base. My algorithm uses several intermediate base rotations to align the orientation of points along the shaft with the desired angle, with minimal remaining torque exerted by the base. I performed an experimental validation with four angle sensors attached to the needle throughout the tissue. My compensation algorithm decreased the lag throughout the needle by up to 88%. PMID:20640198

  2. PERTINENT DRY NEEDLING CONSIDERATIONS FOR MINIMIZING ADVERSE EFFECTS – PART ONE

    PubMed Central

    Halle, Rob J.

    2016-01-01

    ABSTRACT Background Dry needling is an evidence-based treatment technique that is accepted and used by physical therapists in the United States. This treatment approach focuses on releasing or inactivating muscular trigger points to decrease pain, reduce muscle tension, and assist patients with an accelerated return to active rehabilitation. Issue While commonly used, the technique has some patient risk and value of the treatment should be based on benefit compared to the potential risk. Adverse effects (AEs) with dry needling can be mild or severe, with overall incidence rates varying from zero to rates of approximately 10 percent. While mild AEs are the rule, any procedure that involves a needle insertion has the potential for an AE, with select regions and the underlying anatomy increasing the risk. Known significant AEs from small diameter needle insertion include pneumothorax, cardiac tamponade, hematoma, infection, central nervous system injury, and other complications. Purpose/Objective Underlying anatomy across individuals has variability, requiring an in-depth knowledge of anatomy prior to any needle placement. This commentary is an overview of pertinent anatomy in the region of the thorax, with a ‘part two’ that addresses the abdomen, pelvis, back, vasovagal response, informed consent and other pertinent issues. The purpose of the commentary is to minimize the risk of a dry needling AE. Conclusions/Implications Dry needling is an effective adjunct treatment procedure that is within the recognized scope of physical therapy practice. Physical therapy education and training provides practitioners with the anatomy, basic sciences, and clinical foundation to use this intervention safely and effectively. A safe and evidenced-based implementation of the procedure is based on a thorough understanding of the underlying anatomy and the potential risks, with risks coordinated with patients via informed consent. Levels of Evidence Level 5 PMID:27525188

  3. Endoscopic ultrasound-fine needle injection for oncological therapy

    PubMed Central

    Kaplan, Jeremy; Khalid, Amaara; Cosgrove, Natalie; Soomro, Ayesha; Mazhar, Syed Mohsin; Siddiqui, Ali A

    2015-01-01

    The minimal invasiveness and precision of endoscopic ultrasound (EUS) has lead to both its widespread use as a diagnostic and staging modality for gastrointestinal and pancreaticobiliary malignancies, and to its expanding role as a therapeutic modality. EUS-guided celiac plexus neurolysis is now a well-accepted modality for palliation of pain in patients with pancreatic cancer. EUS-guided ablation, brachytherapy, fiducial marker placement, and antitumor agent injection have been described as methods of performing minimally invasive oncological therapy. EUS-fine needle injection may be performed as adjunctive, alternative, or palliative treatment. This review summarizes the studies to date that have described these methods. A literature search using the PubMed/MEDLINE databases was performed. While most published studies to date are limited with disappointing outcomes, the concept of a role of EUS in oncological therapy seems promising. PMID:26691224

  4. A biplanar fluoroscopic approach for the measurement, modeling, and simulation of needle and soft-tissue interaction.

    PubMed

    Hing, James T; Brooks, Ari D; Desai, Jaydev P

    2007-02-01

    A methodology for modeling the needle and soft-tissue interaction during needle insertion is presented. The approach consists of the measurement of needle and tissue motion using a dual C-arm fluoroscopy system. Our dual C-arm fluoroscopy setup allows real time 3-D extraction of the displacement of implanted fiducials in the soft tissue during needle insertion to obtain the necessary parameters for accurate modeling of needle and soft-tissue interactions. The needle and implanted markers in the tissue are tracked during the insertion and withdrawal of the needle at speeds of 1.016 mm/s, 12.7 mm/s and 25.4 mm/s. Both image and force data are utilized to determine important parameters such as the approximate cutting force, puncture force, the local effective modulus (LEM) during puncture, and the relaxation of tissue. We have also validated the LEM computed from our finite element model with arbitrary needle puncture tasks. Based on these measurements, we developed a model for needle insertion and withdrawal that can be used to generate a 1-DOF force versus position profile that can be experienced by a user operating a haptic device. This profile was implemented on a 7-DOf haptic device designed in our laboratory.

  5. Ultrasound guided spine needle insertion

    NASA Astrophysics Data System (ADS)

    Chen, Elvis C. S.; Mousavi, Parvin; Gill, Sean; Fichtinger, Gabor; Abolmaesumi, Purang

    2010-02-01

    An ultrasound (US) guided, CT augmented, spine needle insertion navigational system is introduced. The system consists of an electromagnetic (EM) sensor, an US machine, and a preoperative CT volume of the patient anatomy. Three-dimensional (3D) US volume is reconstructed intraoperatively from a set of two-dimensional (2D) freehand US slices, and is coregistered with the preoperative CT. This allows the preoperative CT volume to be used in the intraoperative clinical coordinate. The spatial relationship between the patient anatomy, surgical tools, and the US transducer are tracked using the EM sensor, and are displayed with respect to the CT volume. The pose of the US transducer is used to interpolate the CT volume, providing the physician with a 2D "x-ray vision" to guide the needle insertion. Many of the system software components are GPU-accelerated, allowing real-time performance of the guidance system in a clinical setting.

  6. Thermomechanical characterization of one-way shape memory Nitinol as an actuator for active surgical needle

    NASA Astrophysics Data System (ADS)

    Honarvar, Mohammad

    Needle-based intervention insertion is one of the common surgical techniques used in many diagnostic and therapeutic percutaneous procedures. The success of such procedures highly depends on the accuracy of needle placement at target locations. An active needle has the potential to enhance the accuracy of needle placement as well as to improve clinical outcome. Bending forces provided by the attached actuators can assist the maneuverability in order to reach the targets following a desired trajectory. There are three major research parts in the development of active needle project in the Composites Laboratory of Temple University. They are thermomechanical characterization of shape memory alloy (SMA) or Nitinol as an actuator for smart needle, mechanical modeling and design of smart needles, and study of tissue needle interaction. The characterization of SMA is the focus of this dissertation. Unique thermomechanical properties of Nitinol known as shape memory effect and superelasticity make it applicable for different fields such as biomedical, structural and aerospace engineering. These unique behaviors are due to the comparatively large amount of recoverable strain which is being produced in a martensitic phase transformation. However, under certain ranges of stresses and temperatures, Nitinol wires exhibit unrecovered strain (also known as residual strain); which limits their applicability. Therefore, for applications that rely on the strain response in repetitive loading and unloading cycles, it is important to understand the generation of the unrecovered strain in the Nitinol wires. In this study, the unrecovered strain of Nitinol wires with various diameters was investigated, using two experimental approaches: constant stress and uniaxial tensile tests. Moreover, a critical range of stress was found beyond which the unrecovered strain was negligible at temperatures of 70 to 80°C depending on the wire diameter. Wire diameters varied from 0.10 to 0.29 mm were

  7. Needle segmentation using 3D Hough transform in 3D TRUS guided prostate transperineal therapy

    SciTech Connect

    Qiu Wu; Yuchi Ming; Ding Mingyue; Tessier, David; Fenster, Aaron

    2013-04-15

    Purpose: Prostate adenocarcinoma is the most common noncutaneous malignancy in American men with over 200 000 new cases diagnosed each year. Prostate interventional therapy, such as cryotherapy and brachytherapy, is an effective treatment for prostate cancer. Its success relies on the correct needle implant position. This paper proposes a robust and efficient needle segmentation method, which acts as an aid to localize the needle in three-dimensional (3D) transrectal ultrasound (TRUS) guided prostate therapy. Methods: The procedure of locating the needle in a 3D TRUS image is a three-step process. First, the original 3D ultrasound image containing a needle is cropped; the cropped image is then converted to a binary format based on its histogram. Second, a 3D Hough transform based needle segmentation method is applied to the 3D binary image in order to locate the needle axis. The position of the needle endpoint is finally determined by an optimal threshold based analysis of the intensity probability distribution. The overall efficiency is improved through implementing a coarse-fine searching strategy. The proposed method was validated in tissue-mimicking agar phantoms, chicken breast phantoms, and 3D TRUS patient images from prostate brachytherapy and cryotherapy procedures by comparison to the manual segmentation. The robustness of the proposed approach was tested by means of varying parameters such as needle insertion angle, needle insertion length, binarization threshold level, and cropping size. Results: The validation results indicate that the proposed Hough transform based method is accurate and robust, with an achieved endpoint localization accuracy of 0.5 mm for agar phantom images, 0.7 mm for chicken breast phantom images, and 1 mm for in vivo patient cryotherapy and brachytherapy images. The mean execution time of needle segmentation algorithm was 2 s for a 3D TRUS image with size of 264 Multiplication-Sign 376 Multiplication-Sign 630 voxels. Conclusions

  8. Precision of a needle localization technic in the lumbosacral multifidus muscles for segmental specific needle electromyographic study: a cadaveric study.

    PubMed

    Chinsethagij, Kosum; Wongphaet, Parit; Su-archawaratana, Siripim; Dangprasert, Tanyarat

    2003-08-01

    The authors studied 14 cadavers to evaluate the claimed precision of needle placement into segment specific multifidus fascicles when using the "paraspinal mapping" electromyographic technic. Injection of acrylic dye was made according to landmarks proposed by Haig. The dissection showed 86.6 per cent of the injected dye in the correct fascicles. Only 1.4 per cent of the dye was lost. Spinous process level misidentification was the cause of the other 11.8 per cent incorrect injection. The authors expected that in living humans, in which the spinous processes are move identificable than embalmed cadavers, the precisions may be as high as 98.5 per cent. This remains to be studied in a further "in vivo" study.

  9. Learning Ultrasound-Guided Needle Insertion Skills through an Edutainment Game

    NASA Astrophysics Data System (ADS)

    Chan, Wing-Yin; Ni, Dong; Pang, Wai-Man; Qin, Jing; Chui, Yim-Pan; Yu, Simon Chun-Ho; Heng, Pheng-Ann

    Ultrasound-guided needle insertion is essential in many of minimally invasive surgeries or procedures, such as biopsy, drug delivery, spinal anaesthesia, etc. Accurate and safe needle insertion is a difficult task due to the high requirement of hand-eye coordination skills. Many proposed virtual reality (VR) based training systems put their emphasis on realistic simulation instead of pedagogical efficiency. The lack of schematic training scenario leads to boredom of repetitive operations. To solve this, we present our novel training system with the integration of game elements in order to retain the trainees' enthusiasm. Task-oriented scenarios, time attack scenarios and performance evaluation are introduced. Besides, some state-of-art technologies are also presented, including ultrasound simulation, needle haptic rendering as well as a mass-spring-based needle-tissue interaction simulation. These works are shown to be effective to keep the trainees up with learning.

  10. Real-time three-dimensional optical coherence tomography image-guided core-needle biopsy system

    PubMed Central

    Kuo, Wei-Cheng; Kim, Jongsik; Shemonski, Nathan D.; Chaney, Eric J.; Spillman, Darold R.; Boppart, Stephen A.

    2012-01-01

    Advances in optical imaging modalities, such as optical coherence tomography (OCT), enable us to observe tissue microstructure at high resolution and in real time. Currently, core-needle biopsies are guided by external imaging modalities such as ultrasound imaging and x-ray computed tomography (CT) for breast and lung masses, respectively. These image-guided procedures are frequently limited by spatial resolution when using ultrasound imaging, or by temporal resolution (rapid real-time feedback capabilities) when using x-ray CT. One feasible approach is to perform OCT within small gauge needles to optically image tissue microstructure. However, to date, no system or core-needle device has been developed that incorporates both three-dimensional OCT imaging and tissue biopsy within the same needle for true OCT-guided core-needle biopsy. We have developed and demonstrate an integrated core-needle biopsy system that utilizes catheter-based 3-D OCT for real-time image-guidance for target tissue localization, imaging of tissue immediately prior to physical biopsy, and subsequent OCT imaging of the biopsied specimen for immediate assessment at the point-of-care. OCT images of biopsied ex vivo tumor specimens acquired during core-needle placement are correlated with corresponding histology, and computational visualization of arbitrary planes within the 3-D OCT volumes enables feedback on specimen tissue type and biopsy quality. These results demonstrate the potential for using real-time 3-D OCT for needle biopsy guidance by imaging within the needle and tissue during biopsy procedures. PMID:22741064

  11. 34 CFR 300.327 - Educational placements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Educational placements. 300.327 Section 300.327... Educational Placements Development of Iep § 300.327 Educational placements. Consistent with § 300.501(c), each... makes decisions on the educational placement of their child. (Authority: 20 U.S.C. 1414(e))...

  12. 34 CFR 300.327 - Educational placements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 2 2011-07-01 2010-07-01 true Educational placements. 300.327 Section 300.327... Educational Placements Development of Iep § 300.327 Educational placements. Consistent with § 300.501(c), each... makes decisions on the educational placement of their child. (Authority: 20 U.S.C. 1414(e))...

  13. Estimation of Model Parameters for Steerable Needles

    PubMed Central

    Park, Wooram; Reed, Kyle B.; Okamura, Allison M.; Chirikjian, Gregory S.

    2010-01-01

    Flexible needles with bevel tips are being developed as useful tools for minimally invasive surgery and percutaneous therapy. When such a needle is inserted into soft tissue, it bends due to the asymmetric geometry of the bevel tip. This insertion with bending is not completely repeatable. We characterize the deviations in needle tip pose (position and orientation) by performing repeated needle insertions into artificial tissue. The base of the needle is pushed at a constant speed without rotating, and the covariance of the distribution of the needle tip pose is computed from experimental data. We develop the closed-form equations to describe how the covariance varies with different model parameters. We estimate the model parameters by matching the closed-form covariance and the experimentally obtained covariance. In this work, we use a needle model modified from a previously developed model with two noise parameters. The modified needle model uses three noise parameters to better capture the stochastic behavior of the needle insertion. The modified needle model provides an improvement of the covariance error from 26.1% to 6.55%. PMID:21643451

  14. Dry Ribbon for Heated Head Automated Fiber Placement

    NASA Technical Reports Server (NTRS)

    Hulcher, A. Bruce; Marchello, Joseph M.; Hinkley, Jeffrey A.; Johnston, Norman J.; Lamontia, Mark A.

    2000-01-01

    Ply-by-ply in situ processes involving automated heated head deposition are being developed for fabrication of high performance, high temperature composite structures from low volatile content polymer matrices. This technology requires (1) dry carbon fiber towpreg, (2) consolidation of towpreg to quality, placement-grade unidirectional ribbon or tape, and (3) rapid, in situ, accurate, ply-by-ply robotic placement and consolidation of this material to fabricate a composite structure. In this study, the physical properties of a candidate thermoplastic ribbon, PIXA/IM7, were evaluated and screened for suitability in robotic placement. Specifically, towpreg was prepared from PIXA powder. Various conditions (temperatures) were used to convert the powder-coated towpreg to ribbons with varying degrees of processability. Ribbon within preset specifications was fabricated at 3 temperatures: 390, 400 and 410 C. Ribbon was also produced out-of-spec by purposely overheating the material to a processing temperature of 450 C. Automated placement equipment at Cincinnati Milacron and NASA Langley was used to fabricate laminates from these experimental ribbons. Ribbons were placed at 405 and 450 C by both sets of equipment. Double cantilever beam and wedge peel tests were used to determine the quality of the laminates and, especially, the interlaminar bond formed during the placement process. Ribbon made under conditions expected to be non-optimal (overheated) resulted in poor placeability and composites with weak interlaminar bond strengths, regardless of placement conditions. Ribbon made under conditions expected to be ideal showed good processability and produced well-consolidated laminates. Results were consistent from machine to machine and demonstrated the importance of ribbon quality in heated-head placement of dry material forms. Preliminary screening criteria for the development and evaluation of ribbon from new matrix materials were validated.

  15. Dimensions of stabident intraosseous perforators and needles.

    PubMed

    Ramlee, R A; Whitworth, J

    2001-09-01

    Problems can be encountered inserting intraosseous injection needles through perforation sites. This in vitro study examined the variability and size compatibility of Stabident intraosseous injection components. The diameters of 40 needles and perforators from a single Stabident kit were measured in triplicate with a toolmakers microscope. One-way ANOVA revealed that mean needle diameter (0.411 mm) was significantly narrower than mean perforator diameter (0.427 mm) (p < 0.001). A frequency distribution plot revealed that needle diameter followed a normal distribution, indicating tight quality control during manufacture. The diameter of perforators was haphazardly distributed, with a clustering of 15% at the lower limit of the size range. However on no occasion was the diameter of a perforator smaller than that of an injection needle. We conclude that components of the Stabident intraosseous anaesthetic system are size-compatible, but there is greater and more haphazard variability in the diameter of perforators than injection needles.

  16. Observations of Needle-Tissue Interactions

    PubMed Central

    Misra, Sarthak; Reed, Kyle B.; Ramesh, K. T.; Okamura, Allison M.

    2010-01-01

    Needles with asymmetric bevel tips naturally bend when they are inserted into soft tissue. In this study, we present an analytical model for the loads developed at the bevel tip during needle-tissue interaction. The model calculates the loads based on the geometry of the bevel edge and gel material properties. The modeled transverse force developed at the tip is compared to forces measured experimentally. The analytical model explains the trends observed in the experiments. In addition to macroscopic studies, we also present microscopic observations of needle-tissue interactions. These results contribute to a mechanics-based model of robotic needle steering, extending previous work on kinematic models. PMID:19963709

  17. Metallurgically bonded needle holder jaws. A technique to enhance needle holding security without sutural damage.

    PubMed

    Abidin, M R; Dunlapp, J A; Towler, M A; Becker, D G; Thacker, J G; McGregor, W; Edlich, R F

    1990-10-01

    A new needle holder jaw face has been specifically designed and developed to increase needle holding security without sutural damage. Tungsten carbide particles have been metallurgically bonded into the stainless steel jaw to create a fine granular surface. This bonded jaw enhances needle holding security by limiting either twisting or rotation of the clamped needle. In addition, compression of the monofilament synthetic sutures by the bonded jaws does not reduce suture breaking strength.

  18. [Pulmonary needle biopsy in children].

    PubMed

    Gerbeaux, J

    1975-01-01

    Pulmonary biopsy done with a needle of circular bore, can be performed on very young children. A sample of tissue, big enough to establish a precise diagnosis in 2/3 of cases, can be obtained. The main complication is pneumothorax occuring about once in five. Hemoptysia or hemorrhage has never been observed. A proposed indication of premortem biopsy accelerated the death of a child with congenital pulmonary fibrosis. The search of a diagnosis in diffuse pulmonary diseases is the major indication for pulmonary biopsy in the child.

  19. Needle localization using a moving stylet/catheter in ultrasound-guided regional anesthesia: a feasibility study

    NASA Astrophysics Data System (ADS)

    Beigi, Parmida; Rohling, Robert

    2014-03-01

    Despite the wide range and long history of ultrasound guided needle insertions, an unresolved issue in many cases is clear needle visibility. A well-known ad hoc technique to detect the needle is to move the stylet and look for changes in the needle appearance. We present a new method to automatically locate a moving stylet/catheter within a stationary cannula using motion detection. We then use this information to detect the needle trajectory and the tip. The differences between the current frame and the previous frame are detected and localized, to minimize the influence of tissue global motions. A polynomial fit based on the detected needle axis determines the estimated stylet shaft trajectory, and the extent of the differences along the needle axis represents the tip. Over a few periodic movements of the stylet including its full insertion into the cannula to the tip, a combination of polynomial fits determines the needle trajectory and the last detected point represents the needle tip. Experiments are conducted in water bath and bovine muscle tissue for several stylet/catheter materials. Results show that a plastic stylet has the best needle shaft and tip localization accuracy in the water bath with RMSE = 0:16 mm and RMSE = 0:51 mm, respectively. In the bovine tissue, the needle tip was best localized with the plastic catheter with RMSE = 0:33 mm. The stylet tip localization was most accurate with the steel stylet, with RMSE = 2:81 mm and the shaft was best localized with the plastic catheter, with RMSE = 0:32 mm.

  20. Geographical and climatic limits of needle types of one- and two-needled pinyon pines

    PubMed Central

    Cole, Kenneth L; Fisher, Jessica; Arundel, Samantha T; Cannella, John; Swift, Sandra

    2008-01-01

    Aim The geographical extent and climatic tolerances of one- and two-needled pinyon pines (Pinus subsect. Cembroides) are the focus of questions in taxonomy, palaeoclimatology and modelling of future distributions. The identification of these pines, traditionally classified by one- versus two-needled fascicles, is complicated by populations with both one- and two-needled fascicles on the same tree, and the description of two more recently described one-needled varieties: the fallax-type and californiarum-type. Because previous studies have suggested correlations between needle anatomy and climate, including anatomical plasticity reflecting annual precipitation, we approached this study at the level of the anatomy of individual pine needles rather than species. Location Western North America. Methods We synthesized available and new data from field and herbarium collections of needles to compile maps of their current distributions across western North America. Annual frequencies of needle types were compared with local precipitation histories for some stands. Historical North American climates were modelled on a c. 1-km grid using monthly temperature and precipitation values. A geospatial model (ClimLim), which analyses the effect of climate-modulated physiological and ecosystem processes, was used to rank the importance of seasonal climate variables in limiting the distributions of anatomical needle types. Results The pinyon needles were classified into four distinct types based upon the number of needles per fascicle, needle thickness and the number of stomatal rows and resin canals. The individual needles fit well into four categories of needle types, whereas some trees exhibit a mixture of two needle types. Trees from central Arizona containing a mixture of Pinus edulis and fallax-type needles increased their percentage of fallax-type needles following dry years. All four needle types occupy broader geographical regions with distinctive precipitation regimes

  1. Geographical and climatic limits of needle types of one- and two-needled pinyon pines.

    PubMed

    Cole, Kenneth L; Fisher, Jessica; Arundel, Samantha T; Cannella, John; Swift, Sandra

    2008-02-01

    AIM: The geographical extent and climatic tolerances of one- and two-needled pinyon pines (Pinus subsect. Cembroides) are the focus of questions in taxonomy, palaeoclimatology and modelling of future distributions. The identification of these pines, traditionally classified by one- versus two-needled fascicles, is complicated by populations with both one- and two-needled fascicles on the same tree, and the description of two more recently described one-needled varieties: the fallax-type and californiarum-type. Because previous studies have suggested correlations between needle anatomy and climate, including anatomical plasticity reflecting annual precipitation, we approached this study at the level of the anatomy of individual pine needles rather than species. LOCATION: Western North America. METHODS: We synthesized available and new data from field and herbarium collections of needles to compile maps of their current distributions across western North America. Annual frequencies of needle types were compared with local precipitation histories for some stands. Historical North American climates were modelled on a c. 1-km grid using monthly temperature and precipitation values. A geospatial model (ClimLim), which analyses the effect of climate-modulated physiological and ecosystem processes, was used to rank the importance of seasonal climate variables in limiting the distributions of anatomical needle types. RESULTS: The pinyon needles were classified into four distinct types based upon the number of needles per fascicle, needle thickness and the number of stomatal rows and resin canals. The individual needles fit well into four categories of needle types, whereas some trees exhibit a mixture of two needle types. Trees from central Arizona containing a mixture of Pinus edulis and fallax-type needles increased their percentage of fallax-type needles following dry years. All four needle types occupy broader geographical regions with distinctive precipitation regimes

  2. Geographical and climatic limits of needle types of one- and two-needled pinyon pines

    USGS Publications Warehouse

    Cole, K.L.; Fisher, J.; Arundel, S.T.; Cannella, J.; Swift, S.

    2008-01-01

    Aim: The geographical extent and climatic tolerances of one- and two-needled pinyon pines (Pinus subsect. Cembroides) are the focus of questions in taxonomy, palaeoclimatology and modelling of future distributions. The identification of these pines, traditionally classified by one- versus two-needled fascicles, is complicated by populations with both one- and two-needled fascicles on the same tree, and the description of two more recently described one-needled varieties: the fallax-type and californiarum-type. Because previous studies have suggested correlations between needle anatomy and climate, including anatomical plasticity reflecting annual precipitation, we approached this study at the level of the anatomy of individual pine needles rather than species. Location: Western North America. Methods: We synthesized available and new data from field and herbarium collections of needles to compile maps of their current distributions across western North America. Annual frequencies of needle types were compared with local precipitation histories for some stands. Historical North American climates were modelled on a c. 1-km grid using monthly temperature and precipitation values. A geospatial model (ClimLim), which analyses the effect of climate-modulated physiological and ecosystem processes, was used to rank the importance of seasonal climate variables in limiting the distributions of anatomical needle types. Results: The pinyon needles were classified into four distinct types based upon the number of needles per fascicle, needle thickness and the number of stomatal rows and resin canals. The individual needles fit well into four categories of needle types, whereas some trees exhibit a mixture of two needle types. Trees from central Arizona containing a mixture of Pinus edulis and fallax-type needles increased their percentage of fallax-type needles following dry years. All four needle types occupy broader geographical regions with distinctive precipitation regimes

  3. Investigating the Possibility of Using TOEFL Scores for University ESL Decision-Making: Placement Trends and Effect of Time Lag

    ERIC Educational Resources Information Center

    Kokhan, Kateryna

    2012-01-01

    The English Placement Test (EPT) at the University of Illinois at Urbana-Champaign (UIUC) is designed to provide an accurate placement (or exemption) of international students into the ESL writing and pronunciation classes. Over the last five years, UIUC has experienced an increase in the number of international students taking the EPT. Because of…

  4. Sensor placement optimization in buildings

    NASA Astrophysics Data System (ADS)

    Bianco, Simone; Tisato, Francesco

    2012-01-01

    In this work we address the problem of optimal sensor placement for a given region and task. An important issue in designing sensor arrays is the appropriate placement of the sensors such that they achieve a predefined goal. There are many problems that could be considered in the placement of multiple sensors. In this work we focus on the four problems identified by Hörster and Lienhart. To solve these problems, we propose an algorithm based on Direct Search, which is able to approach the global optimal solution within reasonable time and memory consumption. The algorithm is experimentally evaluated and the results are presented on two real floorplans. The experimental results show that our DS algorithm is able to improve the results given by the most performing heuristic introduced in. The algorithm is then extended to work also on continuous solution spaces, and 3D problems.

  5. Halo Core Tracking for Galaxy Placement in Cosmological Simulations

    NASA Astrophysics Data System (ADS)

    Korytov, Danila

    2017-01-01

    Synthetic galaxy catalogs are an important product of cosmological simulations. Upcoming surveys, such as LSST, require high volume and high resolution simulations for generating large object catalogs. These catalogs have many uses including testing and improving analysis pipelines, predictions for different cosmologies and investigations of systematic errors. Dark matter (DM) only simulations are able to reach the required volume and resolution but need an accurate prescription for galaxy placement within DM halos. We present a method for galaxy placement. For halos above a characteristic mass, central DM simulation particles are taken as tracer particles for a galaxy. These halo ``cores'' are tracked through the simulation and may merge with other ``cores'' or be ripped apart by halo tidal forces. We examine how accurately we can reproduce galaxy cluster profiles, two point correlation functions and other galaxy statistics.

  6. Characterization of needle-assisted jet injections.

    PubMed

    Li, Xinxin; Ruddy, Bryan; Taberner, Andrew

    2016-12-10

    Hypodermic injections have been the standard for transcutaneous drug delivery for many years. However, needle phobia, pain, and risks of needle-stick injuries have manifested in poor patient compliance. Needle-free jet injections (NFJI) have been developed to address these drawbacks but the reliability of dose and depth of delivery have been limited by a lack of control over jet parameters, and by variability in the skin's mechanical properties among individuals. Moreover, the device size and cost have been restrained by the high pressure (>20MPa) required to penetrate the skin. Needle-assisted jet injections have been proposed to improve delivery reliability of conventional jet injectors by penetrating the skin with a short needle (<5mm) and thereby allowing jet delivery to a desired injection depth at a reduced pressure. This study characterized needle-assisted jet injections performed after first penetrating the skin with a 1.5mm needle, examining the effect of needle size on jet parameters, and evaluating injection performance in porcine skin. A voice-coil actuated jet injector was modified to incorporate needles of 30G, 31G and 32G. A series of pulse tests was performed to compare jet velocity and injection volume across the needle sizes, where it was found that the jet velocity and injection volume achieved with 32G needles were 13% and 16% lower, respectively, than with 30G. In contrast, there was no significant difference in jet velocity and injection volume between 30G and 31G needles, suggesting that a reduction of 10μm in the mean inner diameter of the 31G needle has minimal impact on jet velocity and injection volume. Injection studies performed in porcine skin revealed that injections driven by fluid pressures ranging between 0.8MPa and 1.4MPa were able to achieve substantial injectate penetration (~10mm) and delivery (~100μL) into subcutaneous fat regardless of needle size, in a period of 40ms. The required pressures are an order of magnitude lower

  7. Teleoperation System with Hybrid Pneumatic-Piezoelectric Actuation for MRI-Guided Needle Insertion with Haptic Feedback.

    PubMed

    Shang, Weijian; Su, Hao; Li, Gang; Fischer, Gregory S

    2013-01-01

    This paper presents a surgical master-slave tele-operation system for percutaneous interventional procedures under continuous magnetic resonance imaging (MRI) guidance. This system consists of a piezoelectrically actuated slave robot for needle placement with integrated fiber optic force sensor utilizing Fabry-Perot interferometry (FPI) sensing principle. The sensor flexure is optimized and embedded to the slave robot for measuring needle insertion force. A novel, compact opto-mechanical FPI sensor interface is integrated into an MRI robot control system. By leveraging the complementary features of pneumatic and piezoelectric actuation, a pneumatically actuated haptic master robot is also developed to render force associated with needle placement interventions to the clinician. An aluminum load cell is implemented and calibrated to close the impedance control loop of the master robot. A force-position control algorithm is developed to control the hybrid actuated system. Teleoperated needle insertion is demonstrated under live MR imaging, where the slave robot resides in the scanner bore and the user manipulates the master beside the patient outside the bore. Force and position tracking results of the master-slave robot are demonstrated to validate the tracking performance of the integrated system. It has a position tracking error of 0.318mm and sine wave force tracking error of 2.227N.

  8. Teleoperation System with Hybrid Pneumatic-Piezoelectric Actuation for MRI-Guided Needle Insertion with Haptic Feedback

    PubMed Central

    Shang, Weijian; Su, Hao; Li, Gang; Fischer, Gregory S.

    2014-01-01

    This paper presents a surgical master-slave tele-operation system for percutaneous interventional procedures under continuous magnetic resonance imaging (MRI) guidance. This system consists of a piezoelectrically actuated slave robot for needle placement with integrated fiber optic force sensor utilizing Fabry-Perot interferometry (FPI) sensing principle. The sensor flexure is optimized and embedded to the slave robot for measuring needle insertion force. A novel, compact opto-mechanical FPI sensor interface is integrated into an MRI robot control system. By leveraging the complementary features of pneumatic and piezoelectric actuation, a pneumatically actuated haptic master robot is also developed to render force associated with needle placement interventions to the clinician. An aluminum load cell is implemented and calibrated to close the impedance control loop of the master robot. A force-position control algorithm is developed to control the hybrid actuated system. Teleoperated needle insertion is demonstrated under live MR imaging, where the slave robot resides in the scanner bore and the user manipulates the master beside the patient outside the bore. Force and position tracking results of the master-slave robot are demonstrated to validate the tracking performance of the integrated system. It has a position tracking error of 0.318mm and sine wave force tracking error of 2.227N. PMID:25126446

  9. Epidural needle with embedded optical fibers for spectroscopic differentiation of tissue: ex vivo feasibility study

    PubMed Central

    Desjardins, Adrien E.; Hendriks, Benno H.W.; van der Voort, Marjolein; Nachabé, Rami; Bierhoff, Walter; Braun, Guus; Babic, Drazenko; Rathmell, James P.; Holmin, Staffan; Söderman, Michael; Holmström, Björn

    2011-01-01

    Epidural injection is commonly used to provide intraoperative anesthesia, postoperative and obstetric analgesia, and to treat acute radicular pain. Identification of the epidural space is typically carried out using the loss of resistance (LOR) technique, but the usefulness of this technique is limited by false LOR and the inability to reliably detect intravascular or subarachnoid needle placement. In this study, we present a novel epidural needle that allows for the acquisition of optical reflectance spectra from tissue close to the beveled surface. This needle has optical fibers embedded in the cannula that deliver and receive light. With two spectrometers, light received from tissue is resolved across the wavelength range of 500 to 1600 nm. To determine the feasibility of optical tissue differentiation, spectra were acquired from porcine tissues during a post mortem laminectomy. The spectra were processed with an algorithm that derives estimates of the hemoglobin and lipid concentrations. The results of this study suggest that the optical epidural needle has the potential to improve the accuracy of epidural space identification. PMID:21698009

  10. Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid

    MedlinePlus

    ... Index A-Z Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid An ultrasound-guided thyroid biopsy ... Thyroid? What is Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid? During a fine needle aspiration ...

  11. Optimizing prostate needle biopsy through 3D simulation

    NASA Astrophysics Data System (ADS)

    Zeng, Jianchao; Kaplan, Charles; Xuan, Jian Hua; Sesterhenn, Isabell A.; Lynch, John H.; Freedman, Matthew T.; Mun, Seong K.

    1998-06-01

    Prostate needle biopsy is used for the detection of prostate cancer. The protocol of needle biopsy that is currently routinely used in the clinical environment is the systematic sextant technique, which defines six symmetric locations on the prostate surface for needle insertion. However, this protocol has been developed based on the long-term observation and experience of urologists. Little quantitative or scientific evidence supports the use of this biopsy technique. In this research, we aim at developing a statistically optimized new prostate needle biopsy protocol to improve the quality of diagnosis of prostate cancer. This new protocol will be developed by using a three-dimensional (3-D) computer- based probability map of prostate cancer. For this purpose, we have developed a computer-based 3-D visualization and simulation system with prostate models constructed from the digitized prostate specimens, in which the process of prostate needle biopsy can be simulated automatically by the computer. In this paper, we first develop an interactive biopsy simulation mode in the system, and evaluate the performance of the automatic biopsy simulation with the sextant biopsy protocol by comparing the results by the urologist using the interactive simulation mode with respect to 53 prostate models. This is required to confirm that the automatic simulation is accurate and reliable enough for the simulation with respect to a large number of prostate models. Then we compare the performance of the existing protocols using the automatic biopsy simulation system with respect to 107 prostate models, which will statistically identify if one protocol is better than another. Since the estimation of tumor volume is extremely important in determining the significance of a tumor and in deciding appropriate treatment methods, we further investigate correlation between the tumor volume and the positive core volume with 89 prostate models. This is done in order to develop a method to

  12. Controllable design of super-oscillatory planar lenses for sub-diffraction-limit optical needles.

    PubMed

    Diao, Jinshuai; Yuan, Weizheng; Yu, Yiting; Zhu, Yechuan; Wu, Yan

    2016-02-08

    Sub-diffraction-limit optical needle can be created by a binary amplitude mask through tailoring the interference of diffraction beams. In this paper, a controllable design of super-oscillatory planar lenses to create sub-diffraction-limit optical needles with the tunable focal length and depth of focus (DOF) is presented. As a high-quality optical needle is influenced by various factors, we first propose a multi-objective and multi-constraint optimization model compromising all the main factors to achieve a needle with the prescribed characteristics. The optimizing procedure is self-designed using the Matlab programming language based on the genetic algorithm (GA) and fast Hankel transform algorithm. Numerical simulations show that the optical needles' properties can be controlled accurately. The optimized results are further validated by the theoretical calculation with the Rayleigh-Sommerfeld integral. The sub-diffraction-limit optical needles can be used in wide fields such as optical nanofabrication, super-resolution imaging, particle acceleration and high-density optical data storage.

  13. Biopsy needle localization using magnetic induction imaging principles: a feasibility study.

    PubMed

    Yusupov, B; Zlochiver, S

    2012-08-01

    The accurate navigation and location of a biopsy needle is of main clinical interest in cases of image-guided biopsies for patients with suspected cancerous lesions. Magnetic induction (MI) imaging is a relatively new simple and low-cost noninvasive imaging modality that can be used for measuring the changes of electrical conductivity distribution inside a biological tissue. The feasibility of using MI principles for measuring and imaging the location of a biopsy needle in a tissue with suspected lesion was studied in simulations and with an experimental system. A contactless excitation/sensing unit was designed, and raster scan was performed on a thin tissue slab with an inserted standard 22 gauge stainless steel biopsy needle. A 30-mA, 50-kHz excitation field was employed, and the secondary-induced electromotive force (emf(s)) was measured and plotted on a 2-D plane in order to yield an image of the needle location. The simulations demonstrated the significance of utilizing a ferrimagnetic core for the excitation coil in order to increase induced currents magnitude and scanning resolution. The experimental reconstructed images of the emf(s) spatial distribution revealed the needle position and orientation, with an accuracy of 0.1 mm and a signal-to-background ratio of ~30 dB. High correlation (R(2) = 0.89) between the experimental and simulation results was observed. We conclude that MI principles exhibit a potential alternative to existing imaging modalities for needle biopsy procedures.

  14. Localization of needle tip with color doppler during pericardiocentesis: In vitro validation and initial clinical application

    NASA Technical Reports Server (NTRS)

    Armstrong, G.; Cardon, L.; Vilkomerson, D.; Lipson, D.; Wong, J.; Rodriguez, L. L.; Thomas, J. D.; Griffin, B. P.

    2001-01-01

    This study evaluates a new device that uses color Doppler ultrasonography to enable real-time image guidance of the aspirating needle, which has not been possible until now. The ColorMark device (EchoCath Inc, Princeton, NJ) induces high-frequency, low-amplitude vibrations in the needle to enable localization with color Doppler. We studied this technique in 25 consecutive patients undergoing pericardiocentesis, and in vitro, in a urethane phantom with which the accuracy of color Doppler localization of the needle tip was compared with that obtained by direct measurement. Tip localization was excellent in vitro; errors axial to the ultrasound beam (velocity Doppler -0.13 +/- 0.90 mm, power Doppler -0.05 +/- 1.7 mm) were less than lateral errors (velocity -0.36 +/- 1.8 mm, power -0.02 +/- 2.8 mm). In 18 of 25 patients, the needle was identified and guided into the pericardial space with the ColorMark technique, and it allowed successful, uncomplicated drainage of fluid. Initial failures were the result of incorrect settings on the echocardiographic machine and inappropriate combinations of the needle puncture site and imaging window. This study demonstrates a novel color Doppler technique that is highly accurate at localizing a needle tip. The technique is feasible for guiding pericardiocentesis. Further clinical validation of this technique is required.

  15. Estimating needle-tissue interaction forces for hollow needles using fiber Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Kumar, Saurabh; Shrikanth, V.; Bharadwaj, Amrutur; Asokan, Sundarrajan; Bobji, M. S.

    2016-03-01

    Brachytherapy and neurological procedures can benefit from real-time estimation of needle-tissue interaction forces, specifically for robotic or robot-assisted procedures. Fiber Bragg Grating Sensors provide advantages of very small size and electromagnetic immunity for use in measurement of the forces directly at the needle tip. This has advantages compared to measurements at the needle shaft which require extensive models of the friction between needle and tissues with varying depth. This paper presents the measurement of tip forces for a hollow needle and compensation for bending when encountering regions of varying stiffness in phantoms with multiple layers prepared using Polydimethylsiloxane.

  16. Fine-needle aspiration biopsy: a historical overview.

    PubMed

    Rosa, Marilin

    2008-11-01

    Fine needle aspiration biopsy is a safe, inexpensive and accurate technique for the diagnosis of benign and malignant conditions. Its increase in popularity in the present days has made it a technique used on daily basis in the majority of medical centers in United States and around the world. However, the situation was not always like this. In its beginnings the procedure suffered from all kinds of criticism and attacks. The purpose of this manuscript is to provide an overview about the development of this technique from its birth to our days.

  17. Fine-Needle Aspiration in the Evaluation of Thyroid Neoplasms.

    PubMed

    Oertel, Yolanda C.

    1997-01-01

    Fine-needle aspiration (FNA) is a safe, rapid, and accurate diagnostic tool. Although it continues to gain acceptance, the pace is slow. Probably, if more pathologists master the basics (i.e., learn how to obtain a good sample), this simple technique could be utilized to its fullest advantage. If the sample is not adequate or representative of the lesion, the diagnosis will not be correct. Based on personal experience, we believe that suction should be minimal when obtaining thyroid aspirates. Cytologic diagnostic criteria for the most common neoplasms of the thyroid gland are provided.

  18. [Academic origin of round magnetic needle and standardization operation].

    PubMed

    Cheng, Yan-Ting; Zhang, Tian-Sheng; Meng, Li-Qiang; Shi, Rui-Qi; Ji, Lai-Xi

    2014-07-01

    The origin and development of round magnetic needle was explored, and the structure of round magnetic needle was introduced in detail, including the handle, the body and the tip of the needle. The clinical opera tion of round magnetic needle were standardized from the aspects of the methods of holding needle, manipulation skill, tapping position, strength of manipulation, application scope and matters needing attention, which laid foundation for the popularization and application of round magnetic needle.

  19. Short, multi-needle FDR sensor suitable for measuring soil water content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Time domain reflectometry (TDR) is a well-established electromagnetic technique used to measure soil water content. TDR sensors have been combined with heat pulse sensors to produce thermo-TDR sensors. Thermo-TDR sensors are restricted to having relatively short needles in order to accurately measur...

  20. 21 CFR 882.1350 - Needle electrode.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Needle electrode. 882.1350 Section 882.1350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Diagnostic Devices § 882.1350 Needle electrode....

  1. 21 CFR 882.1350 - Needle electrode.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Needle electrode. 882.1350 Section 882.1350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Diagnostic Devices § 882.1350 Needle electrode....

  2. 21 CFR 882.1350 - Needle electrode.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Needle electrode. 882.1350 Section 882.1350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Diagnostic Devices § 882.1350 Needle electrode....

  3. 21 CFR 882.1350 - Needle electrode.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Needle electrode. 882.1350 Section 882.1350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Diagnostic Devices § 882.1350 Needle electrode....

  4. 21 CFR 882.1350 - Needle electrode.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Needle electrode. 882.1350 Section 882.1350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Diagnostic Devices § 882.1350 Needle electrode....

  5. Needle Exchange Programs and Drug Injection Behavior

    ERIC Educational Resources Information Center

    DeSimone, Jeff

    2005-01-01

    This study examines how drug injection and needle sharing propensities respond when a needle exchange program (NEP) is introduced into a city. I analyze 1989-1995 Drug Use Forecasting data on adult male arrestees from 24 large U.S. cities, in nine of which NEPs opened during the sample period. After controlling for cocaine and heroin prices, AIDS…

  6. In-plane ultrasonic needle tracking using a fiber-optic hydrophone

    SciTech Connect

    Xia, Wenfeng Desjardins, Adrien E.; Mari, Jean Martial; West, Simeon J.; Ginsberg, Yuval; David, Anna L.; Ourselin, Sebastien

    2015-10-15

    Purpose: Accurate and efficient guidance of needles to procedural targets is critically important during percutaneous interventional procedures. Ultrasound imaging is widely used for real-time image guidance in a variety of clinical contexts, but with this modality, uncertainties about the location of the needle tip within the image plane lead to significant complications. Whilst several methods have been proposed to improve the visibility of the needle, achieving accuracy and compatibility with current clinical practice is an ongoing challenge. In this paper, the authors present a method for directly visualizing the needle tip using an integrated fiber-optic ultrasound receiver in conjunction with the imaging probe used to acquire B-mode ultrasound images. Methods: Needle visualization and ultrasound imaging were performed with a clinical ultrasound imaging system. A miniature fiber-optic ultrasound hydrophone was integrated into a 20 gauge injection needle tip to receive transmissions from individual transducer elements of the ultrasound imaging probe. The received signals were reconstructed to create an image of the needle tip. Ultrasound B-mode imaging was interleaved with needle tip imaging. A first set of measurements was acquired in water and tissue ex vivo with a wide range of insertion angles (15°–68°) to study the accuracy and sensitivity of the tracking method. A second set was acquired in an in vivo swine model, with needle insertions to the brachial plexus. A third set was acquired in an in vivo ovine model for fetal interventions, with insertions to different locations within the uterine cavity. Two linear ultrasound imaging probes were used: a 14–5 MHz probe for the first and second sets, and a 9–4 MHz probe for the third. Results: During insertions in tissue ex vivo and in vivo, the imaged needle tip had submillimeter axial and lateral dimensions. The signal-to-noise (SNR) of the needle tip was found to depend on the insertion angle. With

  7. A contrast and registration template for magnetic resonance image data guided dental implant placement

    NASA Astrophysics Data System (ADS)

    Eggers, Georg; Cosgarea, Raluca; Rieker, Marcus; Kress, Bodo; Dickhaus, Hartmut; Mühling, Joachim

    2009-02-01

    An oral imaging template was developed to address the shortcomings of MR image data for image guided dental implant planning and placement. The template was conctructed as a gadolinium filled plastic shell to give contrast to the dentition and also to be accurately re-attachable for use in image guided dental implant placement. The result of segmentation and modelling of the dentition from MR Image data with the template was compared to plaster casts of the dentition. In a phantom study dental implant placement was performed based on MR image data. MR imaging with the contrast template allowed complete representation of the existing dentition. In the phantom study, a commercially available system for image guided dental implant placement was used. Transformation of the imaging contrast template into a surgical drill guide based on the MR image data resulted in pilot burr hole placement with an accuracy of 2 mm. MRI based imaging of the existing dentition for proper image guided planning is possible with the proposed template. Using the image data and the template resulted in less accurate pilot burr hole placement in comparison to CT-based image guided implant placement.

  8. The Placement Professional as Marketeer.

    ERIC Educational Resources Information Center

    Walz, Garry R.

    1988-01-01

    Discusses resistance of helping professions to marketing. Defines human services marketing. Describes forces that are placing human services in an increasingly competitive position. Makes recommendations to enhance the image of career planning and placement services and increase their usage. Concludes that by adopting a marketeer orientation,…

  9. Placement Services: A Training Manual.

    ERIC Educational Resources Information Center

    National Advisory Council on Vocational Education, Washington, DC.

    This self-contained instructional package defines a comprehensive job placement program as a coordinated series of activities involving school-community interaction, staff training and curriculum development resulting in youth being able to obtain and retain satisfying employment. The author and contributors focus their efforts on presenting case…

  10. A Consideration of Placement Testing.

    ERIC Educational Resources Information Center

    Kilpatrick, Gordon

    This report consists of three sections, the first of which is a discussion of placement testing. It is maintained that the strengths and weaknesses of a tested population cannot be determined by a single composite test--yet, many institutions place students in beginning courses on the basis of such limited information. To assess basic capabilities…

  11. The Ironies of Mandatory Placement.

    ERIC Educational Resources Information Center

    Hadden, Craig

    2000-01-01

    Suggests that mandatory placement of underprepared students in developmental courses may actually provide the key to opening the door to true academic, vocational, or community success, despite criticism by some that it excludes students and restricts their freedoms. Discusses ethical balances between access, student success and academic…

  12. College Student Personnel Graduate Placement

    ERIC Educational Resources Information Center

    Packwood, William

    1976-01-01

    ACPA's Commission XII surveyed 103 college student personnel training institutions regarding their graduate placement. Graduates were identified according to degree, sex, and race. Percentages of graduates placed, areas within the college student personnel field, types of institutions, and areas of the country were computed. The discussion…

  13. Abdominal anatomy in the context of port placement and trocars

    PubMed Central

    Alkatout, Ibrahim; Mettler, Liselotte; Maass, Nicolai; Noé, Günter-Karl; Elessawy, Mohamed

    2015-01-01

    Although the anatomy of the human being has not changed, technical developments in operating materials and methods demand a simultaneous development in operative management. Developments in electronic and optical technologies permit many gynecological operations to be performed laparoscopically. One fundamental distinction between any other operating method and laparoscopy is the hurdle that the initial entry, whether with a needle, cannula, or trocar, is mostly performed blind. However, there is a risk that blind entry may result in vascular or organ damage. One of the difficulties associated with entry complications is that any damage may not be immediately recognized, leading to major abdominal reparative surgery, and at worst, a temporary colostomy. Therefore, the technical and operative quality of laparoscopic surgery begins with port placement and trocars. Visual access systems are available but are not yet widely used. The aim of this review was to introduce the different port placement and trocar systems as well as their correct and professional usage in correlation with the abdominal functional anatomy. PMID:26692776

  14. Mathematics Placement at the University of Illinois

    ERIC Educational Resources Information Center

    Ahlgren Reddy, Alison; Harper, Marc

    2013-01-01

    Data from the ALEKS-based placement program at the University of Illinois is presented visually in several ways. The placement exam (an ALEKS assessment) contains precise item-specific information and the data show many interesting properties of the student populations of the placement courses, which include Precalculus, Calculus, and Business…

  15. Can Placement Tests Inform Instructional Decisions?

    ERIC Educational Resources Information Center

    Green, Anthony B.; Weir, Cyril J.

    2004-01-01

    Studies of placement tests are typically narrowly concerned with their validation as instruments for the efficient grouping of students. They rarely explore the assumption that placement test content can be related to classroom tasks and so inform instructional decisions. This study focuses on a trial version of the Global Placement Test (GPT), a…

  16. 28 CFR 551.24 - Child placement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Child placement. 551.24 Section 551.24 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE INSTITUTIONAL MANAGEMENT MISCELLANEOUS Birth Control, Pregnancy, Child Placement, and Abortion § 551.24 Child placement. (a) The Warden may...

  17. 28 CFR 551.24 - Child placement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Child placement. 551.24 Section 551.24 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE INSTITUTIONAL MANAGEMENT MISCELLANEOUS Birth Control, Pregnancy, Child Placement, and Abortion § 551.24 Child placement. (a) The Warden may...

  18. 28 CFR 551.24 - Child placement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Child placement. 551.24 Section 551.24 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE INSTITUTIONAL MANAGEMENT MISCELLANEOUS Birth Control, Pregnancy, Child Placement, and Abortion § 551.24 Child placement. (a) The Warden may...

  19. 28 CFR 551.24 - Child placement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Child placement. 551.24 Section 551.24 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE INSTITUTIONAL MANAGEMENT MISCELLANEOUS Birth Control, Pregnancy, Child Placement, and Abortion § 551.24 Child placement. (a) The Warden may...

  20. 28 CFR 551.24 - Child placement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Child placement. 551.24 Section 551.24 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE INSTITUTIONAL MANAGEMENT MISCELLANEOUS Birth Control, Pregnancy, Child Placement, and Abortion § 551.24 Child placement. (a) The Warden may...

  1. 5 CFR 359.702 - Placement rights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Placement rights. 359.702 Section 359.702 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REMOVAL FROM THE SENIOR EXECUTIVE SERVICE; GUARANTEED PLACEMENT IN OTHER PERSONNEL SYSTEMS Guaranteed Placement § 359.702...

  2. 5 CFR 359.702 - Placement rights.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Placement rights. 359.702 Section 359.702 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS REMOVAL FROM THE SENIOR EXECUTIVE SERVICE; GUARANTEED PLACEMENT IN OTHER PERSONNEL SYSTEMS Guaranteed Placement § 359.702...

  3. [Comparative investigation of the discharge characteristics of a single needle jet and needle-plate jet].

    PubMed

    Li, Xue-Chen; Chang, Yuan-Yuan; Jia, Peng-Ying; Zhao, Huan-Huan; Liu, Run-Fu; Di, Cong

    2013-04-01

    In the present paper, discharge characteristics were studied in atmospheric pressure argon by a single needle jet and needle-plate jet through combination of optical measurement and electrical one. Results show that the length and cross-sectional area of the plasmas generated in the two jets increase with increasing the peak value of the applied voltage. The cross-sectional area generated by needle-plate jet is bigger than that of the single needle jet at the same voltage. A lower inception voltage is needed for the needle-plate jet compared with the single needle jet at the same U(p). Through the spectra emitted from the two jets, electron temperature and vibration temperature wee compared for the plasmas generated by the single needle jet and needle-plate jet, respectively. It can be found that the electron temperature and the vibrational temperature of the two jets increase with increasing U(p). The needle-plate jet has higher values of electron temperature and vibrational temperature than the single needle jet at the same U(p). These results have significant values for the industrial application of the atmospheric pressure plasma jet.

  4. The Biological Safety of Stainless Steel Needles Used in Warm-needling.

    PubMed

    Lim, Sabina; Lee, Seunghun; Yi, Seung-Ho; Son, Yang-Sun; Choi, Sung-Min; Kim, Young-Kon

    2010-06-01

    Warm-needling (also called thermo-acupuncture) is a combination of acupuncture and moxibustion. Due to the intense heat involved, there have been concerns over the biological safety of the acuneedles used in the treatment. This paper reports two phases of a safety test. For a preliminary test, we compared the temperature change patterns of stainless steel (SS304) needles and traditional gold alloy needles, which have been increasingly replaced by the former. To verify the effects of the presence of coating materials, the main test involved three different kinds of SS304: silicone-coated, salicylic acid-coated and non-coated needles. Each group of needles was tested for pH level, heavy metals and UV absorbance spectrum along with biological tests on the cytotoxicity and hemolysis of the needle. All the tests on the extractants from the needles were negative. In the biological tests, each test result showed a significant difference from the positive control samples, while no significant difference was observed compared with the negative control samples. In the hemolysis tests, all samples satisfied the Korean Government Standards. All the results suggest that SS304 needles are biologically safe to be used in warm-needling, though they can be improved to perform as well as the gold alloy needles in terms of temperature fluctuations.

  5. Efficacy of needle-placement technique in radiofrequency ablation for treatment of lumbar facet arthropathy

    PubMed Central

    Loh, Jeffrey T; Nicol, Andrea L; Elashoff, David; Ferrante, F Michael

    2015-01-01

    Background Many studies have assessed the efficacy of radiofrequency ablation to denervate the facet joint as an interventional means of treating axial low-back pain. In these studies, varying procedural techniques were utilized to ablate the nerves that innervate the facet joints. To date, no comparison studies have been performed to suggest superiority of one technique or even compare the prevalence of side effects and complications. Materials and methods A retrospective chart review was performed on patients who underwent a lumbar facet denervation procedure. Each patient’s chart was analyzed for treatment technique (early versus advanced Australian), preprocedural visual numeric scale (VNS) score, postprocedural VNS score, duration of pain relief, and complications. Results Pre- and postprocedural VNS scores and change in VNS score between the two groups showed no significant differences. Patient-reported benefit and duration of relief was greater in the advanced Australian technique group (P=0.012 and 0.022, respectively). The advanced Australian technique group demonstrated a significantly greater median duration of relief (4 months versus 1.5 months, P=0.022). Male sex and no pain-medication use at baseline were associated with decreased postablation VNS scores, while increasing age and higher preablation VNS scores were associated with increased postablation VNS scores. Despite increasing age being associated with increased postablation VNS scores, age and the advanced Australian technique were found to confer greater patient self-reported treatment benefit. Conclusion The advanced Australian technique provides a significant benefit over the early Australian technique for the treatment of lumbar facet pain, both in magnitude and duration of pain relief. PMID:26504407

  6. Needle guidance using handheld stereo vision and projection for ultrasound-based interventions.

    PubMed

    Stolka, Philipp J; Foroughi, Pezhman; Rendina, Matthew; Weiss, Clifford R; Hager, Gregory D; Boctor, Emad M

    2014-01-01

    With real-time instrument tracking and in-situ guidance projection directly integrated in a handheld ultrasound imaging probe, needle-based interventions such as biopsies become much simpler to perform than with conventionally-navigated systems. Stereo imaging with needle detection can be made sufficiently robust and accurate to serve as primary navigation input. We describe the low-cost, easy-to-use approach used in the Clear Guide ONE generic navigation accessory for ultrasound machines, outline different available guidance methods, and provide accuracy results from phantom trials.

  7. [Approach to teaching methods of the needling skill of filiform needle].

    PubMed

    Wang, Cai-Hong; Xu, Jian-Min; Wang, Yin-Ping; Li, Yi

    2008-08-01

    The present paper is armed at approach to a set of teaching method about the needling skill of filiform needle, so as to increase teaching quality. After review and analysis on present situation of teaching methods about the needling skill of filiform needle, it is raised that traditional teaching methods are unable to objectively and comprehensively reflect characteristics and requirement of manipulation, so try to adopt acupuncture manipulation detection instrument, on the basis of traditional teaching methods about the needling skill of filiform needle. And the parameters and figures of manipulation examine of real-time collection in 131 students and information of 120 copies of questionnaire are analyzed and summarized. It is indicated that combined teaching method of traditional model and the manipulation instrument is more reasonable, and basic manipulation training most he strengthened in manipulation skill training, particularly, pay attention to training of twirling manipulation.

  8. Needle-Tissue Interaction Forces for Bevel-Tip Steerable Needles

    PubMed Central

    Misra, Sarthak; Reed, Kyle B.; Douglas, Andrew S.; Ramesh, K. T.; Okamura, Allison M.

    2010-01-01

    The asymmetry of a bevel-tip needle results in the needle naturally bending when it is inserted into soft tissue. As a first step toward modeling the mechanics of deflection of the needle, we determine the forces at the bevel tip. In order to find the forces acting at the needle tip, we measure rupture toughness and nonlinear material elasticity parameters of several soft tissue simulant gels and chicken tissue. We incorporate these physical parameters into a finite element model that includes both contact and cohesive zone models to simulate tissue cleavage. We investigate the sensitivity of the tip forces to tissue rupture toughness, linear and nonlinear tissue elasticity, and needle tip bevel angle. The model shows that the tip forces are sensitive to the rupture toughness. The results from these studies contribute to a mechanics-based model of bevel-tip needle steering, extending previous work on kinematic models. PMID:22020139

  9. Needle-Tissue Interaction Forces for Bevel-Tip Steerable Needles.

    PubMed

    Misra, Sarthak; Reed, Kyle B; Douglas, Andrew S; Ramesh, K T; Okamura, Allison M

    2008-10-19

    The asymmetry of a bevel-tip needle results in the needle naturally bending when it is inserted into soft tissue. As a first step toward modeling the mechanics of deflection of the needle, we determine the forces at the bevel tip. In order to find the forces acting at the needle tip, we measure rupture toughness and nonlinear material elasticity parameters of several soft tissue simulant gels and chicken tissue. We incorporate these physical parameters into a finite element model that includes both contact and cohesive zone models to simulate tissue cleavage. We investigate the sensitivity of the tip forces to tissue rupture toughness, linear and nonlinear tissue elasticity, and needle tip bevel angle. The model shows that the tip forces are sensitive to the rupture toughness. The results from these studies contribute to a mechanics-based model of bevel-tip needle steering, extending previous work on kinematic models.

  10. Humanitarian engineering placements in our own communities

    NASA Astrophysics Data System (ADS)

    VanderSteen, J. D. J.; Hall, K. R.; Baillie, C. A.

    2010-05-01

    There is an increasing interest in the humanitarian engineering curriculum, and a service-learning placement could be an important component of such a curriculum. International placements offer some important pedagogical advantages, but also have some practical and ethical limitations. Local community-based placements have the potential to be transformative for both the student and the community, although this potential is not always seen. In order to investigate the role of local placements, qualitative research interviews were conducted. Thirty-two semi-structured research interviews were conducted and analysed, resulting in a distinct outcome space. It is concluded that local humanitarian engineering placements greatly complement international placements and are strongly recommended if international placements are conducted. More importantly it is seen that we are better suited to address the marginalised in our own community, although it is often easier to see the needs of an outside populace.

  11. Pine needle abortion biomarker detected in bovine fetal fluids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pine needle abortion is a naturally occurring condition in free-range cattle caused by the consumption of pine needles from select species of cypress, juniper, pine, and spruce trees. Confirmatory diagnosis of pine needle abortion has previously relied on a combined case history of pine needle cons...

  12. Needle optical coherence elastography for the measurement of microscale mechanical contrast deep within human breast tissues

    NASA Astrophysics Data System (ADS)

    Kennedy, Kelsey M.; McLaughlin, Robert A.; Kennedy, Brendan F.; Tien, Alan; Latham, Bruce; Saunders, Christobel M.; Sampson, David D.

    2013-12-01

    Optical coherence elastography (OCE) is an emerging imaging technique that probes microscale mechanical contrast in tissues with the potential to differentiate healthy and malignant tissues. However, conventional OCE techniques are limited to imaging the first 1 to 2 mm of tissue in depth. We demonstrate, for the first time, OCE measurements deep within human tissues using needle OCE, extending the potential of OCE as a surgical guidance tool. We use needle OCE to detect tissue interfaces based on mechanical contrast in both normal and malignant breast tissues in freshly excised human mastectomy samples, as validated against histopathology. Further, we demonstrate the feasibility of in situ measurements >4 cm from the tissue surface using ultrasound guidance of the OCE needle probe. With further refinement, our method may potentially aid in accurate detection of the boundary of the tumor to help ensure full removal of all malignant tissues, which is critical to the success of breast-conserving surgery.

  13. Science off the Sphere: Knitting Needles

    NASA Video Gallery

    International Space Station Expedition 30 astronaut Don Pettit uses knitting needles and water droplets to demonstrate physics in space for 'Science off the Sphere.' Through a partnership between N...

  14. Sliding Mode Control of Steerable Needles

    PubMed Central

    Rucker, D. Caleb; Das, Jadav; Gilbert, Hunter B.; Swaney, Philip J.; Miga, Michael I.; Sarkar, Nilanjan; Webster, Robert J.

    2014-01-01

    Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little computational resources. We show that if the standard nonholonomic model for tip-steered needles holds, then the control law will converge to desired targets in a reachable workspace, within a tolerance that can be defined by the control parameters. Experimental results validate the control law for target points and trajectory following in phantom tissue and ex vivo liver. Experiments with targets that move during insertion illustrate robustness to disturbances caused by tissue deformation. PMID:25400527

  15. Sliding Mode Control of Steerable Needles.

    PubMed

    Rucker, D Caleb; Das, Jadav; Gilbert, Hunter B; Swaney, Philip J; Miga, Michael I; Sarkar, Nilanjan; Webster, Robert J

    2013-10-01

    Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little computational resources. We show that if the standard nonholonomic model for tip-steered needles holds, then the control law will converge to desired targets in a reachable workspace, within a tolerance that can be defined by the control parameters. Experimental results validate the control law for target points and trajectory following in phantom tissue and ex vivo liver. Experiments with targets that move during insertion illustrate robustness to disturbances caused by tissue deformation.

  16. Inverse Kinematics of Concentric Tube Steerable Needles

    PubMed Central

    Sears, Patrick; Dupont, Pierre E.

    2013-01-01

    Prior papers have introduced steerable needles composed of precurved concentric tubes. The curvature and extent of these needles can be controlled by the relative rotation and translation of the individual tubes. Under certain assumptions on the geometry and design of these needles, the forward kinematics problem can be solved in closed form by means of algebraic equations. The inverse kinematics problem, however, is not as straightforward owing to the nonlinear map between relative tube displacements and needle tip configuration as well as to the multiplicity of solutions as the number of tubes increases. This paper presents a general approach to solving the inverse kinematics problem using a pseudoinverse solution together with gradients of nullspace potential functions to enforce geometric and mechanical constraints. PMID:23685532

  17. An illuminated flute needle for vitreoretinal surgery.

    PubMed

    Davison, C N; Rosen, P H

    1994-06-01

    We have developed a simple self-illuminated flute needle for internal drainage of subretinal fluid during three-port vitrectomy. This instrument facilitates visualization and drainage through peripheral retinal breaks.

  18. A Multi-Layered Needle Injection Simulator.

    PubMed

    Laufer, Shlomi; Kempton, Steve J; Maciolek, Kimberly; Terry, Aliyya; Ray, Rebeca D; Pugh, Carla M; Afifi, Ahmed M

    2016-01-01

    Insuring correct needle location is crucial in many medical procedures. This can be even more challenging for physicians injecting in a new location for the first time. Since they do not necessarily know how the tissue is supposed to feel, finding the correct location and correct depth can be difficult. In this study we designed a simulator for training needle injection. The simulator was fabricated to give a realistic feeling of injecting Botox® in the temporalis and the semispinalis muscles as part of migraine treatment. In addition the simulator provided real-time feedback of correct needle location. Nine residents and medical students evaluated the simulator. They made several errors that were corrected real time using the real time feedback provided. They found the simulator to be very useful and that the training significantly improved their confidence. The methods described in this study can easily be implemented for developing needle injection simulators for other anatomical locations.

  19. Imaging of implant needles for real-time HDR-brachytherapy prostate treatment using biplane ultrasound transducers.

    PubMed

    Siebert, Frank-André; Hirt, Markus; Niehoff, Peter; Kovács, György

    2009-08-01

    at positions (+/- standard deviation) -0.53 +/- 0.16, -0.16 +/- 0.14, and -0.30 +/- 0.16 mm using a gain of 15 dB. The minus sign indicates that the needle tips were detected more proximally than the actual position of the needle tip. When using a gain of -15 dB the mean values of two observers resulted in -0.62 +/- 0.08 and -0.51 +/- 0.12 mm. Additionally an alternative approach to the direct needle tip definition was investigated. Two observers detected the solid part of the needle tip in sagittal images. This solid part, often named as "dead space end," is the distance between the needle tip and the beginning of the hollow part of the implant needle. The dead space end is 6.2 mm for the investigated needle type. Two users found mean values of -6.70 +/- 0.16 and -7.00 +/- 0.06 mm, respectively, for 15 dB gain and -6.90 +/- 0.09 and -7.02 +/- 0.06 mm using the -15 dB gain setting. The results show that ultrasound-based needle tip definition in sagittal viewing mode is accurate. The inter- and intraobserver errors should, however, be taken into account. A lower gain setting of the ultrasound system reduces the intraobserver error.

  20. Extrapleural locating method in computed tomography-guided needle biopsies of 1,106 lung lesions

    PubMed Central

    WEI, YUE-HUA; ZHOU, FU-XIANG; LI, YAN; ZHOU, YUN-FENG; ANISH, KRISHNA; XU, LI-YING; LIAO, MEI-YAN

    2015-01-01

    Transthoracic needle biopsy is considered to be safe and effective for the diagnosis of focal lung lesions. The aim of the present study was to evaluate factors affecting the accuracy and safety of automated cutting needle lung biopsy (ACNB) using a new extrapleural locating (EPL) method. Computed tomography (CT)-guided needle biopsies were performed on 1,065 patients between March 2005 and May 2012 using the EPL method. The locating needle remained in the chest following extrapleural positioning, while the radiologist confirmed the puncture angle and distance between the locating needle and lesion. The biopsy instrument was advanced into the lung, and the core needle was subsequently fired into the lesion based on the direction indicated by the locating needle. Univariate and multivariate regression analyses were used to evaluate the diagnostic accuracy and safety of the procedure. The sensitivity, specificity, positive predictive value and negative predictive value of the extrapleural method were 91.9, 100, 100 and 82.9%, respectively, and the overall diagnostic accuracy was 94.2%. Significant risk factors affecting accuracy were younger age, atelectasis, hemoptysis and lesion depth (P<0.03). Multivariate logistic regression analysis revealed that the risk of malignant lesions receiving a false-negative diagnosis decreased for each additional year of subject age [odds ratio (OR), 0.97; P=0.027] and increased with each millimeter increase in lesion depth (OR, 1.03; P=0.008). Among the 1,106 lesions biopsied, 207 were associated with pneumothorax, 251 with hemorrhage and 58 with hemoptysis. Multivariate analysis revealed that lesion size and emphysema affected pneumothorax incidence, while age, lesion location and depth and emphysema significantly affected hemorrhage incidence (P<0.05). In conclusion, low-dose, CT-guided ACNB with the EPL method provides a safe and accurate diagnosis. PMID:26640541

  1. Dry needling versus acupuncture: the ongoing debate.

    PubMed

    Zhou, Kehua; Ma, Yan; Brogan, Michael S

    2015-12-01

    Although Western medical acupuncture (WMA) is commonly practised in the UK, a particular approach called dry needling (DN) is becoming increasingly popular in other countries. The legitimacy of the use of DN by conventional non-physician healthcare professionals is questioned by acupuncturists. This article describes the ongoing debate over the practice of DN between physical therapists and acupuncturists, with a particular emphasis on the USA. DN and acupuncture share many similarities but may differ in certain aspects. Currently, little information is available from the literature regarding the relationship between the two needling techniques. Through reviewing their origins, theory, and practice, we found that DN and acupuncture overlap in terms of needling technique with solid filiform needles as well as some fundamental theories. Both WMA and DN are based on modern biomedical understandings of the human body, although DN arguably represents only one subcategory of WMA. The increasing volume of research into needling therapy explains its growing popularity in the musculoskeletal field including sports medicine. To resolve the debate over DN practice, we call for the establishment of a regulatory body to accredit DN courses and a formal, comprehensive educational component and training for healthcare professionals who are not physicians or acupuncturists. Because of the close relationship between DN and acupuncture, collaboration rather than dispute between acupuncturists and other healthcare professionals should be encouraged with respect to education, research, and practice for the benefit of patients with musculoskeletal conditions who require needling therapy.

  2. Model-based assessment of probe placement criteria in cancer therapy using RF ablation

    NASA Astrophysics Data System (ADS)

    Tanotogono, E. W.; Akasum, G. F.; Suprijanto; Sudirham, J. J.

    2016-03-01

    Radiofrequency ablation has been developed as a minimally-invasive method for cancer therapy. Nevertheless, the unfeasibility of direct observation during ablation process sometimes becomes a challenge for practitioners, particularly those constrained by the absence of a proper monitoring system. Thus, aiming to develop a prudent cancer therapy planning, this research develops a 3D model that enable practitioners to predict the tissue damage resulted by a simulated ablation before a real ablation is executed. The model, developed using finite element method, is made to mimic real human liver tissue by simulating its physical properties as temperature-dependent functions. Three probe placement cases, representing three different approaches, are analysed to study the effect of probe placement configuration on tissue damage formed during a time-dependent ablation process. The three placement cases are surface-perpendicular placement, misaligned placement, and relatively accurate placement. It can be concluded that the accuracy of a probe placement configuration can be assessed by quantifying two major parameters: average tissue damage in the target domain and accumulated damage resulted in complementary tissue domain. Optimum ablation duration can also be determined by considering those parameters.

  3. Improved Screw Placement for Slipped Capital Femoral Epiphysis (SCFE) using Robotically-Assisted Drill Guidance

    PubMed Central

    Koutenaei, Bamshad Azizi; Guler, Ozgur; Wilson, Emmanuel; Thoranaghatte, Ramesh U.; Oetgen, Matthew; Navab, Nassir; Cleary, Kevin

    2014-01-01

    Slipped Capital Femoral Epiphysis (SCFE) is a common hip displacement condition in adolescents. In the standard treatment, the surgeon uses intra-operative fluoroscopic imaging to plan the screw placement and the drill trajectory. The accuracy, duration, and efficacy of this procedure are highly dependent on surgeon skill. Longer procedure times result in higher radiation dose, to both patient and surgeon. A robotic system to guide the drill trajectory might help to reduce screw placement errors and procedure time by reducing the number of passes and confirmatory fluoroscopic images needed to verify accurate positioning of the drill guide along a planned trajectory. Therefore, with the long-term goals of improving screw placement accuracy, reducing procedure time and intra-operative radiation dose, our group is developing an image-guided robotic surgical system to assist a surgeon with pre-operative path planning and intra-operative drill guide placement. PMID:25333154

  4. Combination of needle aspiration and core needle biopsy: A new technique of stereotactic biopsy

    PubMed Central

    Wani, Abrar Ahad; Wani, M. Afzal; Ramzan, Altaf U.; Nizami, Furqan A.; Malik, Nayil K.; Shafiq, S.; Ahmad, Rais; Kumar, Ashish; Lone, Iqbal; Makhdoomi, Rumana

    2016-01-01

    Aim: The study aims at describing the results of using a new technique to acquire the tissue sample in stereotactic biopsy of brain lesions. Materials and Methods: The study was performed in 19 patients over a period of 5 years in which we used the new technique, i.e., Abrar and Afzal technique (AT) of obtaining tissue biopsy. It is a combination of core tissue biopsy and needle aspiration techniques. The technique was devised to acquire greater amount of tissue for pathologic study. Results: While we could give pathologic diagnosis in 18 patients out of 19 (94.7%), in one patient, the tissue sample revealed only inflammatory cells and definitive diagnosis could not be reached. There was no significant morbidity or any mortality in the series. Conclusion: Abrar and Afzal technique is a reasonably accurate technique of acquiring larger tissue sample in stereotactic brain biopsy without any additional risks. It can be done with little modification of the conventional equipment available with the stereotactic system. PMID:27057212

  5. Accuracy evaluation of a 3D-printed individual template for needle guidance in head and neck brachytherapy.

    PubMed

    Huang, Ming-Wei; Zhang, Jian-Guo; Zheng, Lei; Liu, Shu-Ming; Yu, Guang-Yan

    2016-11-01

    To transfer the preplan for the head and neck brachytherapy to the clinical implantation procedure, a preplan-based 3D-printed individual template for needle insertion guidance had previously been designed and used. The accuracy of needle insertion using this kind template was assessed in vivo In the study, 25 patients with head and neck tumors were implanted with (125)I radioactive seeds under the guidance of the 3D-printed individual template. Patients were divided into four groups based on the site of needle insertion: the parotid and masseter region group (nine patients); the maxillary and paranasal region group (eight patients); the submandibular and upper neck area group (five patients); and the retromandibular region group (six patients). The distance and angular deviations between the preplanned and placed needles were compared, and the complications and time required for needle insertion were assessed. The mean entrance point distance deviation for all 619 needles was 1.18 ± 0.81 mm, varying from 0.857 ± 0.545 to 1.930 ± 0.843 mm at different sites. The mean angular deviation was 2.08 ± 1.07 degrees, varying from 1.85 ± 0.93 to 2.73 ± 1.18 degrees at different sites. All needles were manually inserted to their preplanned positions in a single attempt, and the mean time to insert one needle was 7.5 s. No anatomical complications related to inaccurately placed implants were observed. Using the 3D-printed individual template for the implantation of (125)I radioactive seeds in the head and neck region can accurately transfer a CT-based preplan to the brachytherapy needle insertion procedure. Moreover, the addition of individual template guidance can reduce the time required for implantation and minimize the damage to normal tissues.

  6. Accuracy evaluation of a 3D-printed individual template for needle guidance in head and neck brachytherapy

    PubMed Central

    Huang, Ming-Wei; Zhang, Jian-Guo; Zheng, Lei; Liu, Shu-Ming; Yu, Guang-Yan

    2016-01-01

    To transfer the preplan for the head and neck brachytherapy to the clinical implantation procedure, a preplan-based 3D-printed individual template for needle insertion guidance had previously been designed and used. The accuracy of needle insertion using this kind template was assessed in vivo. In the study, 25 patients with head and neck tumors were implanted with 125I radioactive seeds under the guidance of the 3D-printed individual template. Patients were divided into four groups based on the site of needle insertion: the parotid and masseter region group (nine patients); the maxillary and paranasal region group (eight patients); the submandibular and upper neck area group (five patients); and the retromandibular region group (six patients). The distance and angular deviations between the preplanned and placed needles were compared, and the complications and time required for needle insertion were assessed. The mean entrance point distance deviation for all 619 needles was 1.18 ± 0.81 mm, varying from 0.857 ± 0.545 to 1.930 ± 0.843 mm at different sites. The mean angular deviation was 2.08 ± 1.07 degrees, varying from 1.85 ± 0.93 to 2.73 ± 1.18 degrees at different sites. All needles were manually inserted to their preplanned positions in a single attempt, and the mean time to insert one needle was 7.5 s. No anatomical complications related to inaccurately placed implants were observed. Using the 3D-printed individual template for the implantation of 125I radioactive seeds in the head and neck region can accurately transfer a CT-based preplan to the brachytherapy needle insertion procedure. Moreover, the addition of individual template guidance can reduce the time required for implantation and minimize the damage to normal tissues. PMID:27422928

  7. Acadian flycatcher nest placement: Does placement influence reproductive success?

    USGS Publications Warehouse

    Wilson, R.R.; Cooper, R.J.

    1998-01-01

    We located 511 Acadian Flycatcher (Empidonax virescens) nests in bottomland hardwood forest of eastern Arkansas. Microhabitat characteristics were measured and their relationship with nest success evaluated. Fifty-two percent of all nesting attempts resulted in predation. Attributes of nest placement were similar between successful and unsuccessful nests, although successful nests were placed higher. Similarly, nonparasitized nests were typically higher than parasitized nests. Nests initiated late in the breeding season were placed in larger trees with higher canopy bases resulting in increased vegetation around the nest. Fifteen different tree species were used for nesting. Acadian Flycatchers chose nest trees in a nonrandom fashion, selecting Nuttall oak (Quercus nuttallii) and possumhaw (Ilex decidua) in greater proportions than their availability. However, there was no relationship between tree species used for nesting and nest success. Nest height was positively correlated with concealment at the nest site, supporting the predator-avoidance theory. No other attribute of nest placement differentiated successful nest sites, suggesting that nest predation is likely a function of random events in space and time.

  8. Two-dimensional optimal sensor placement

    SciTech Connect

    Zhang, H.

    1995-05-01

    A method for determining the optimal two-dimensional spatial placement of multiple sensors participating in a robot perception task is introduced in this paper. This work is motivated by the fact that sensor data fusion is an effective means of reducing uncertainties in sensor observations, and that the combined uncertainty varies with the relative placement of the sensors with respect to each other. The problem of optimal sensor placement is formulated and a solution is presented in the two dimensional space. The algebraic structure of the combined sensor uncertainty with respect to the placement of sensor is studied. A necessary condition for optimal placement is derived and this necessary condition is used to obtain an efficient closed-form solution for the global optimal placement. Numerical examples are provided to illustrate the effectiveness and efficiency of the solution. 11 refs.

  9. Peripheral Stent Placement in Hemodialysis Grafts

    SciTech Connect

    Kariya, Shuji Tanigawa, Noboru; Kojima, Hiroyuki; Komemushi, Atsushi; Shomura, Yuzo; Shiraishi, Tomokuni; Kawanaka, Toshiaki; Sawada, Satoshi

    2009-09-15

    The purpose of the present study was to evaluate the clinical outcome of peripheral stent placement after failed balloon angioplasty in patients with grafts who are on hemodialysis. We examined 30 Wallstents that were placed in 26 patients because balloon angioplasty failed or early restenosis (<3 months) occurred within 3 months. We retrospectively reviewed 267 consecutive balloon angioplasties performed in 71 patients with graft access between August 2000 and March 2007. Stent placements accounted for 30 (11.2%) of the 267 balloon angioplasties. The clinical success rate of stent placement was 93.3% (28 of 30 stent placements). The 3-, 6-, and 12-month primary patency rates were 73.3%, 39.3%, and 17.7%, respectively. The 1-, 2-, and 3-year secondary patency rates were 90.2%, 83.8%, and 83.8%, respectively. Primary patency was significantly prolonged by stent placement after early restenosis compared with previous balloon angioplasty alone (P = 0.0059). Primary patency after stent placement was significantly lower than after successful balloon angioplasty without indications for stent placement (P = 0.0279). Secondary patency rates did not significantly differ between stent placement and balloon angioplasty alone. The mean number of reinterventions required to maintain secondary patency after stent placement was significantly larger than that after balloon angioplasty alone (Mann-Whitney U test, P = 0.0419). We concluded that peripheral stent placement for graft access is effective for salvaging vascular access after failed balloon angioplasty and for prolonging patency in early restenosis after balloon angioplasty. However, reinterventions are required to maintain secondary patency after stent placement. Furthermore, peripheral stent placement for graft access cannot achieve the same primary patency as balloon angioplasty alone.

  10. Characterization of Pre-Curved Needles for Steering in Tissue

    PubMed Central

    Wedlick, Thomas R.; Okamura, Allison M.

    2010-01-01

    Needles with tip asymmetry deflect upon insertion into soft tissue, an effect that can be used to steer needles within the body. This paper presents a phenomenological characterization of the steering behavior of pre-curved needles, which have tip asymmetry due to curvature of the needle near the tip. We describe needle construction methods and a needle shaft triangulation algorithm to compute the shape of the needle based on images. Experimental results show that pre-curved needles possess greater dexterity than bevel-tipped needles and achieve radii of curvature similar to pre-bent needles. For long pre-curve arc lengths, the radius of curvature of the needle was found to approach the radius of curvature of the pre-curve. Pre-curved needles were found to display behaviors not seen with bevel-tipped needles, such as the insertion velocity influencing the path of the tip within the tissue and the ability to plastically deform the needle during steering. PMID:19963994

  11. Product placement of computer games in cyberspace.

    PubMed

    Yang, Heng-Li; Wang, Cheng-Shu

    2008-08-01

    Computer games are considered an emerging media and are even regarded as an advertising channel. By a three-phase experiment, this study investigated the advertising effectiveness of computer games for different product placement forms, product types, and their combinations. As the statistical results revealed, computer games are appropriate for placement advertising. Additionally, different product types and placement forms produced different advertising effectiveness. Optimum combinations of product types and placement forms existed. An advertisement design model is proposed for use in game design environments. Some suggestions are given for advertisers and game companies respectively.

  12. Adaptable Deployable Entry and Placement Technology (ADEPT)

    NASA Video Gallery

    The Adaptable, Deployable Entry Placement Technology (ADEPT) Project will test and demonstrate a deployable aeroshell concept as a viable thermal protection system for entry, descent, and landing o...

  13. Automated fiber placement: Evolution and current demonstrations

    NASA Technical Reports Server (NTRS)

    Grant, Carroll G.; Benson, Vernon M.

    1993-01-01

    The automated fiber placement process has been in development at Hercules since 1980. Fiber placement is being developed specifically for aircraft and other high performance structural applications. Several major milestones have been achieved during process development. These milestones are discussed in this paper. The automated fiber placement process is currently being demonstrated on the NASA ACT program. All demonstration projects to date have focused on fiber placement of transport aircraft fuselage structures. Hercules has worked closely with Boeing and Douglas on these demonstration projects. This paper gives a description of demonstration projects and results achieved.

  14. Medically relevant ElectroNeedle technology development.

    SciTech Connect

    Schmidt, Carrie Frances; Thomas, Michael Loren; McClain, Jaime L.; Harper, Jason C.; Achyuthan, Komandoor E.; Ten Eyck, Gregory A.

    2008-11-01

    ElectroNeedles technology was developed as part of an earlier Grand Challenge effort on Bio-Micro Fuel Cell project. During this earlier work, the fabrication of the ElectroNeedles was accomplished along with proof-of-concept work on several electrochemically active analytes such as glucose, quinone and ferricyanide. Additionally, earlier work demonstrated technology potential in the field of immunosensors by specifically detecting Troponin, a cardiac biomarker. The current work focused upon fabrication process reproducibility of the ElectroNeedles and then using the devices to sensitively detect p-cresol, a biomarker for kidney failure or nephrotoxicity. Valuable lessons were learned regarding fabrication assurance and quality. The detection of p-cresol was accomplished by electrochemistry as well as using fluorescence to benchmark ElectroNeedles performance. Results from these studies will serve as a guide for the future fabrication processes involving ElectroNeedles as well as provide the groundwork necessary to expand technology applications. One paper has been accepted for publication acknowledging LDRD funding (K. E. Achyuthan et al, Comb. Chem. & HTS, 2008). We are exploring the scope for a second paper describing the applications potential of this technology.

  15. Optical Coherence Tomography in a Needle Format

    NASA Astrophysics Data System (ADS)

    Lorenser, Dirk; McLaughlin, Robert A.; Sampson, David D.

    In this chapter, we review the technology and applications of needle probes for optical coherence tomography (OCT). Needle probes are miniaturized fiber-optic probes that can be mounted inside hypodermic needles, allowing them to be inserted deep into the body during OCT imaging. This overcomes the very limited imaging depth of OCT of only 2-3 mm in biological tissue, enabling access to deep-tissue locations that are beyond the reach of free-space optical scan heads or catheters. This chapter provides an in-depth review of the current state-of-the art in needle probe technology, including optical design and fabrication, scan mechanisms (including three-dimensional scanning), and integration into OCT systems. It also provides an overview of emerging applications of this fascinating new imaging tool in areas such as cancer diagnosis, pulmonary imaging, imaging of the eye and imaging of the brain. Finally, two case studies are presented, illustrating needle-based OCT imaging in breast cancer and lungs.

  16. Lumbar total disc arthroplasty: coronal midline definition and optimal TDA placement.

    PubMed

    Marshman, Laurence A G; Friesem, Tai; Rampersaud, Y Raja; Le Huec, Jean-Charles; Krishna, Manoj; Reddy, Guru R

    2008-01-01

    It is a general principle with arthroplasty insertion that precise implant centering is critical for long term function and outcome. Whilst some authors have proclaimed that lumbar total disc arthroplasty (TDA) may be different, and that off -centre placement may be functionally well tolerated, these claims are premature: significantly worse clinical results have already been reported with poorly placed TDA at 2 years. Accurate TDA placement requires a precise and consistent definition of the desired coronal midline target (which is currently lacking), as well as a procedural mechanism to optimize placement at that target. We summarize our experience, as well as others', in achieving these two requirements. Long-term outcomes after lumbar TDA insertion should only be compared with results from fusion where TDAs have been implanted accurately.

  17. Dynamics of Placement...How to Develop a Successful Career Planning & Placement Program.

    ERIC Educational Resources Information Center

    Shingleton, John D.; Fitzpatrick, Edwin B.

    This document presents college practitioners with a practical guide for establishing, maintaining, expanding, or revitalizing a contemporary career planning and placement center. The introduction to this guide contains a brief history of career planning and placement. Chapter 1, Career Planning and Placement in the Academic Setting, addresses the…

  18. Endovascular Placement of an Extraluminal Femoropopliteal Bypass Graft in Human Cadavers

    SciTech Connect

    Maynar, Manuel; Llorens, Rafael; Lopez-Sanchez, Carmen; Garcia-Martinez, Virginio; Qian Zhong; Lopera, Jorge; Castaneda, Wilfrido R.

    2005-04-15

    Purpose. A method to create an extraluminal femoropopliteal bypass graft using endovascular techniques was evaluated in situ on cadaver extremities in an attempt to develop a minimally invasive alternative technique for the management of infrainguinal occlusive arterial disease. Methods. The endovascular placement of an extraluminal femoropopliteal bypass graft was undertaken in 5 cadaver legs. Following percutaneous access to the popliteal artery (PA) or common femoral artery (CFA), a Rosch-Uchida needle was used to perforate the vascular wall, followed by the creation of an extraluminal tract using a looped wire and catheter. Once the desired level was reached the needle was again used to perforate the vascular wall of the proximal superficial femoral artery (SFA) or PA depending on the access used. Self-expanding expanded polytetrafluoroethylene (ePTFE) stent-grafts were then deployed to establish the extraluminal femoropopliteal bypass connecting the two arterial puncture sites. Following dilatation of the stent-graft, angiography was performed to assess the endoprostheses and to look for contrast leaks. Results. Technical success was achieved in all 5 legs. Procedure time varied from 15 to 30 min. The angiographic studies performed immediately after completion of the bypass procedure showed patency of the grafts with no evidence of kinking or leakage in any of the cases. Conclusion. This study has proved that the endovascular placement of an extraluminal femoropopliteal bypass graft in human cadaver legs using endovascular techniques under fluoroscopic control is technically feasible.

  19. Perception and Action in Teleoperated Needle Insertion

    PubMed Central

    Nisky, Ilana; Pressman, Assaf; Pugh, Carla M.; Mussa-Ivaldi, Ferdinando A.; Karniel, Amir

    2015-01-01

    We studied the effect of delay on perception and action in contact with a force field that emulates elastic soft tissue with a rigid nonlinear boundary. Such field is similar to forces exerted on a needle during teleoperated needle insertion. We found that delay causes motor underestimation of the stiffness of this nonlinear soft tissue, without perceptual change. These experimental results are supported by simulation of a simplified mechanical model of the arm and neural controller, and a model for perception of stiffness, which is based on regression in the force-position space. In addition, we show that changing the gain of the teleoperation channel cancels the motor effect of delay without adding perceptual distortion. We conclude that it is possible to achieve perceptual and motor transparency in virtual one-dimensional remote needle insertion task. PMID:26379813

  20. Accurate Finite Difference Algorithms

    NASA Technical Reports Server (NTRS)

    Goodrich, John W.

    1996-01-01

    Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

  1. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  2. Of Needles and Haystacks: Building an Accurate Statewide Dropout Early Warning System in Wisconsin

    ERIC Educational Resources Information Center

    Knowles, Jared E.

    2015-01-01

    The state of Wisconsin has one of the highest four year graduation rates in the nation, but deep disparities among student subgroups remain. To address this the state has created the Wisconsin Dropout Early Warning System (DEWS), a predictive model of student dropout risk for students in grades six through nine. The Wisconsin DEWS is in use…

  3. The Wiley Spinal Catheter-Over-Needle System for Continuous Spinal Anesthesia: A Case Series of 5 Cesarean Deliveries Complicated by Paresthesias and Headaches.

    PubMed

    McKenzie, Christine P; Carvalho, Brendan; Riley, Edward T

    2016-01-01

    Intrathecal catheter devices using a catheter-over-needle design and softer flexible material have been introduced to clinical practice with the aim of reducing some of the complications such as postdural puncture headaches and paresthesias seen with previous versions of intrathecal catheters. We present a case series of 5 cesarean deliveries using the Wiley Spinal intrathecal system (Epimed, Johnstown, New York), which was recently approved by the US Food and Drug Administration. The intrathecal catheter system consists of a flexible 23-gauge intrathecal cannula over a 27-gauge pencil-point spinal needle. The placement of the intrathecal catheter was successful in all 5 cases; however, paresthesias in 3 cases and postdural puncture headaches in 2 cases complicated the placement and use of the device. Although the unique catheter-over-needle design facilitates the use of smaller-gauge spinal needles for dural puncture and larger-gauge catheters for medication administration, this case series using the Wiley Spinal suggests that paresthesias and postdural puncture headaches may still limit its widespread utilization. Future studies are needed to determine the true incidence of complications and to determine the role of continuous spinal anesthesia in the obstetric population.

  4. Needle free injection technology: A complete insight

    PubMed Central

    Ravi, Ansh Dev; Sadhna, D; Nagpaal, D; Chawla, L

    2015-01-01

    Needle free injection technology (NFIT)is an extremely broad concept which include a wide range of drug delivery systems that drive drugs through the skin using any of the forces as Lorentz, Shock waves, pressure by gas or electrophoresis which propels the drug through the skin, virtually nullifying the use of hypodermic needle. This technology is not only touted to be beneficial for the pharma industry but developing world too find it highly useful in mass immunization programmes, bypassing the chances of needle stick injuries and avoiding other complications including those arising due to multiple use of single needle. The NFIT devices can be classified based on their working, type of load, mechanism of drug delivery and site of delivery. To administer a stable, safe and an effective dose through NFIT, the sterility, shelf life and viscosity of drug are the main components which should be taken care of. Technically superior needle-free injection systems are able to administer highly viscous drug products which cannot be administered by traditional needle and syringe systems, further adding to the usefulness of the technology. NFIT devices can be manufactured in a variety of ways; however the widely employed procedure to manufacture it is by injection molding technique. There are many variants of this technology which are being marketed, such as Bioject® ZetaJetTM, Vitajet 3, Tev-Tropin® and so on. Larger investment has been made in developing this technology with several devices already being available in the market post FDA clearance and a great market worldwide. PMID:26682189

  5. New needle-crystalline CR detector

    NASA Astrophysics Data System (ADS)

    Leblans, Paul J. R.; Struye, Luc; Willems, Peter

    2001-06-01

    The storage phosphor RbBr:Tl+ can be grown in needles via vacuum deposition. Thanks to reduced lateral light diffusion thick needle screens still offer acceptable resolution. Due to its low intrinsic X-ray absorption, however, a RbBr:Tl+ needle screen does not lead to a better absorption/resolution compromise than a BaFBr1-xIx:Eu2+ powder screen. CsBr:Eu2+ does combine high specific X-ray absorption and the possibility of needle growth. Its blue emission, peaking at 440 nm and near IR stimulation band, with maximum at 685 nm, make it well suited for use in CR systems. Sensitivity and sharpness of a 500 (mu) thick CsBr:Eu2+ needle screen were measured in a flying-spot scanner. The number of photostimulated light quanta per absorbed X-ray quantum is higher than for BaFBr1-xIx:Eu2+. At 70 kVp and 0.5 mm Cu filtration, equal sharpness is obtained for 85% vs. 46% X-ray absorption in BaFBr1-xIx:Eu2+ screens. DQE was measured at 2.5 (mu) Gy, 70 kVp, and 0.5 mm Cu filtration for a CsBr:Eu2+ needle screen in a flying-spot scanner. Up to 3 lp/mm, DQE was 2 times higher than for state-of-the-art CR systems and equal to the DQE claimed for flat panel DR systems, based on a-Si photodiodes combined with a CsI:Tl scintillator layer.

  6. Performance, Accuracy, and Web Server for Evolutionary Placement of Short Sequence Reads under Maximum Likelihood

    PubMed Central

    Berger, Simon A.; Krompass, Denis; Stamatakis, Alexandros

    2011-01-01

    We present an evolutionary placement algorithm (EPA) and a Web server for the rapid assignment of sequence fragments (short reads) to edges of a given phylogenetic tree under the maximum-likelihood model. The accuracy of the algorithm is evaluated on several real-world data sets and compared with placement by pair-wise sequence comparison, using edit distances and BLAST. We introduce a slow and accurate as well as a fast and less accurate placement algorithm. For the slow algorithm, we develop additional heuristic techniques that yield almost the same run times as the fast version with only a small loss of accuracy. When those additional heuristics are employed, the run time of the more accurate algorithm is comparable with that of a simple BLAST search for data sets with a high number of short query sequences. Moreover, the accuracy of the EPA is significantly higher, in particular when the sample of taxa in the reference topology is sparse or inadequate. Our algorithm, which has been integrated into RAxML, therefore provides an equally fast but more accurate alternative to BLAST for tree-based inference of the evolutionary origin and composition of short sequence reads. We are also actively developing a Web server that offers a freely available service for computing read placements on trees using the EPA. PMID:21436105

  7. Online parameter estimation for surgical needle steering model.

    PubMed

    Yan, Kai Guo; Podder, Tarun; Xiao, Di; Yu, Yan; Liu, Tien-I; Ling, Keck Voon; Ng, Wan Sing

    2006-01-01

    Estimation of the system parameters, given noisy input/output data, is a major field in control and signal processing. Many different estimation methods have been proposed in recent years. Among various methods, Extended Kalman Filtering (EKF) is very useful for estimating the parameters of a nonlinear and time-varying system. Moreover, it can remove the effects of noises to achieve significantly improved results. Our task here is to estimate the coefficients in a spring-beam-damper needle steering model. This kind of spring-damper model has been adopted by many researchers in studying the tissue deformation. One difficulty in using such model is to estimate the spring and damper coefficients. Here, we proposed an online parameter estimator using EKF to solve this problem. The detailed design is presented in this paper. Computer simulations and physical experiments have revealed that the simulator can estimate the parameters accurately with fast convergent speed and improve the model efficacy.

  8. Syringe and Needle Size, Syringe Type, Vacuum Generation, and Needle Control in Aspiration Procedures

    SciTech Connect

    Haseler, Luke J.; Sibbitt, Randy R.; Sibbitt, Wilmer L.; Michael, Adrian A.; Gasparovic, Charles M.; Bankhurst, Arthur D.

    2011-06-15

    Purpose: Syringes are used for diagnostic fluid aspiration and fine-needle aspiration biopsy in interventional procedures. We determined the benefits, disadvantages, and patient safety implications of syringe and needle size on vacuum generation, hand force requirements, biopsy/fluid yield, and needle control during aspiration procedures. Materials and Methods: Different sizes (1, 3, 5, 10, and 20 ml) of the conventional syringe and aspirating mechanical safety syringe, the reciprocating procedure device, were studied. Twenty operators performed aspiration procedures with the following outcomes measured: (1) vacuum (torr), (2) time to vacuum (s), (3) hand force to generate vacuum (torr-cm{sup 2}), (4) operator difficulty during aspiration, (5) biopsy yield (mg), and (6) operator control of the needle tip position (mm). Results: Vacuum increased tissue biopsy yield at all needle diameters (P < 0.002). Twenty-milliliter syringes achieved a vacuum of -517 torr but required far more strength to aspirate, and resulted in significant loss of needle control (P < 0.002). The 10-ml syringe generated only 15% less vacuum (-435 torr) than the 20-ml device and required much less hand strength. The mechanical syringe generated identical vacuum at all syringe sizes with less hand force (P < 0.002) and provided significantly enhanced needle control (P < 0.002). Conclusions: To optimize patient safety and control of the needle, and to maximize fluid and tissue yield during aspiration procedures, a two-handed technique and the smallest syringe size adequate for the procedure should be used. If precise needle control or one-handed operation is required, a mechanical safety syringe should be considered.

  9. Exploring Continuous Clinical Placement for Undergraduate Students

    ERIC Educational Resources Information Center

    McKenna, Lisa G.; Wray, Natalie; McCall, Louise

    2009-01-01

    Clinical placements are integral to health professional preparatory courses. These placements allow for the application of classroom-based learning into real patient care situations. In doing so, they provide opportunities for applying theoretical knowledge into practice contexts, skills development and socialisation into the chosen profession.…

  10. 32 CFR 1656.10 - Job placement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing ASWs in alternative service jobs. (b) An ASW who has identified his own job in accordance with §...

  11. 32 CFR 1656.10 - Job placement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing ASWs in alternative service jobs. (b) An ASW who has identified his own job in accordance with §...

  12. 32 CFR 1656.10 - Job placement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing ASWs in alternative service jobs. (b) An ASW who has identified his own job in accordance with §...

  13. 32 CFR 1656.10 - Job placement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing ASWs in alternative service jobs. (b) An ASW who has identified his own job in accordance with §...

  14. 32 CFR 1656.10 - Job placement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Job placement. 1656.10 Section 1656.10 National....10 Job placement. (a) Selective Service will maintain a job bank for the exclusive purpose of placing ASWs in alternative service jobs. (b) An ASW who has identified his own job in accordance with §...

  15. Private Placement Debt Financing for Public Entities

    ERIC Educational Resources Information Center

    Holman, Lance S.

    2010-01-01

    Private placement financing is a debt or capital lease obligation arranged between a municipality or a 501(c) (3) not-for-profit organization and a single sophisticated institutional investor. The investor can be a bank, insurance company, finance company, hedge fund, or high-net worth individual. Private placement financing is similar to…

  16. Developing Career Planning and Placement Strategies.

    ERIC Educational Resources Information Center

    Kolvitz, Marcia, Ed.

    These three conference papers from the Biennial Conference on Postsecondary Education for Persons who are Deaf or Hard of Hearing focus on career planning and placement strategies for students with deafness or hard of hearing. The first paper, "Successful Job Development and Placement Strategies with Deaf and Hard of Hearing College…

  17. Preparing ESP Learners for Workplace Placement

    ERIC Educational Resources Information Center

    Wood, David

    2009-01-01

    Engineering students in North American universities often participate in cooperative education placements in workplaces as part of the requirements for their degrees and professional certification. Students for whom English is an L2 often experience difficulties in these placements due to the fact that while their academic language ability may be…

  18. Advanced Placement Courses and American Indian Performance

    ERIC Educational Resources Information Center

    Moore, George; Slate, John R.

    2010-01-01

    Enrollment in Advanced Placement (AP) courses and performance on Advanced Placement examinations for American Indians in the U.S. for 2007 was analyzed. Scores on AP examinations, overall and then for five AP courses, were compared to the AP examination scores of White students. In every case, American Indians had AP examination scores that were…

  19. Implementation of Job Placement Services Guidelines.

    ERIC Educational Resources Information Center

    McGillicuddy (Shirley) & Associates, Sierra Madre, CA.

    The Implementation of Job Placement Services Guidelines Project was designed to strengthen placement programs and services for California community college vocational students, and for all students needing part-time employment to realize their educational goals. The project was designed to test the validity and relevance of quality indicators…

  20. New pole placement algorithm - Polynomial matrix approach

    NASA Technical Reports Server (NTRS)

    Shafai, B.; Keel, L. H.

    1990-01-01

    A simple and direct pole-placement algorithm is introduced for dynamical systems having a block companion matrix A. The algorithm utilizes well-established properties of matrix polynomials. Pole placement is achieved by appropriately assigning coefficient matrices of the corresponding matrix polynomial. This involves only matrix additions and multiplications without requiring matrix inversion. A numerical example is given for the purpose of illustration.

  1. Understanding Successful Sandwich Placements: A Bourdieusian Approach

    ERIC Educational Resources Information Center

    Clark, Martyn; Zukas, Miriam

    2016-01-01

    Sandwich placements and other integrated work and study schemes are increasingly advocated as a key means by which universities can promote students' employability. However, there is little understanding of how successful placements work in terms of facilitating learning and development. Drawing on three longitudinal case studies of students who…

  2. Math Placement in California's Public Schools

    ERIC Educational Resources Information Center

    Gao, Niu; Adan, Sara

    2016-01-01

    Last year, the California Legislature passed a new law--the California Mathematics Placement Act--to address widespread concern over equity in the math placement process. The law is aimed at improving the measurement of student performance in order to move more students successfully through the high school curriculum. In this context, researchers…

  3. Characteristics of Work Placements Valued by Employers.

    ERIC Educational Resources Information Center

    Chivers, Barbara; Flatten, Kay

    1996-01-01

    Group Feedback Strategy was used to evaluate data from 73 employers, 18 tutors, 156 students, and 45 graduates involved in work placements in a library and information science program. Respondents showed reasonably high satisfaction for the following characteristics of placements: teamwork experience, assessment of capabilities, training…

  4. Angioplasty and stent placement -- peripheral arteries

    MedlinePlus

    ... blood vessel in your groin. A tiny flexible wire will be inserted through this needle. Your surgeon ... area. Next, your surgeon will pass a guide wire through the catheter to the blockage. The surgeon ...

  5. Genetic Algorithm Approaches for Actuator Placement

    NASA Technical Reports Server (NTRS)

    Crossley, William A.

    2000-01-01

    This research investigated genetic algorithm approaches for smart actuator placement to provide aircraft maneuverability without requiring hinged flaps or other control surfaces. The effort supported goals of the Multidisciplinary Design Optimization focus efforts in NASA's Aircraft au program. This work helped to properly identify various aspects of the genetic algorithm operators and parameters that allow for placement of discrete control actuators/effectors. An improved problem definition, including better definition of the objective function and constraints, resulted from this research effort. The work conducted for this research used a geometrically simple wing model; however, an increasing number of potential actuator placement locations were incorporated to illustrate the ability of the GA to determine promising actuator placement arrangements. This effort's major result is a useful genetic algorithm-based approach to assist in the discrete actuator/effector placement problem.

  6. Changing attitudes toward needle biopsies of breast cancer in Shanghai: experience and current status over the past 8 years

    PubMed Central

    Hao, Shuang; Liu, Zhe-Bin; Ling, Hong; Chen, Jia-Jian; Shen, Ju-Ping; Yang, Wen-Tao; Shao, Zhi-Min

    2015-01-01

    Diagnostic patterns in breast cancer have greatly changed over the past few decades, and core needle biopsy (CNB) has become a reliable procedure for detecting breast cancer without invasive surgery. To estimate the changing diagnostic patterns of breast cancer in urban Shanghai, 11,947 women with breast lesions detected by preoperative needle biopsy between January 1995 and December 2012 were selected from the Shanghai Cancer Data base, which integrates information from approximately 50% of breast cancer patients in Shanghai. The CNB procedure uses an automated prone unit, biopsy gun, and 14-gauge needles under freehand or ultrasound guidance and was performed by experienced radiologists and surgeons specializing in needle biopsies. Diagnosis and classification for each patient were independently evaluated by pathologists. Over the indicated 8-year period, biopsy type consisted of 11,947 ultrasound-guided core needle biopsies (UCNBs), 2,015 ultrasound-guided vacuum-assisted biopsies (UVABs), and 654 stereotactic X-ray-guided vacuum-assisted biopsies (XVABs). For all the 11,947 women included in this study, image-guided needle biopsy was the initial diagnostic procedure. Approximately 81.0% of biopsied samples were histopathologically determined to be malignant lesions, 5.5% were determined to be high-risk lesions, and 13.5% were determined to be benign lesions. The number of patients choosing UCNB increased at the greatest rate, and UCNB has become a standard procedure for histodiagnosis because it is inexpensive, convenient, and accurate. The overall false-negative rate of CNB was 1.7%, and the specific false-negative rates for UCNB, UVAB, and XVAB, were 1.7%, 0%, and 0%, respectively. This study suggests that the use of preoperative needle biopsy as the initial breast cancer diagnostic procedure is acceptable in urban Shanghai. Preoperative needle biopsy is now a standard procedure in the Shanghai Cancer Center because it may reduce the number of surgeries

  7. Thoracic Pedicle Screw Placement Guide Plate Produced by Three-Dimensional (3-D) Laser Printing

    PubMed Central

    Chen, Hongliang; Guo, Kaijing; Yang, Huilin; Wu, Dongying; Yuan, Feng

    2016-01-01

    Background The aim of this study was to evaluate the accuracy and feasibility of an individualized thoracic pedicle screw placement guide plate produced by 3-D laser printing. Material/Methods Thoracic pedicle samples of 3 adult cadavers were randomly assigned for 3-D CT scans. The 3-D thoracic models were established by using medical Mimics software, and a screw path was designed with scanned data. Then the individualized thoracic pedicle screw placement guide plate models, matched to the backside of thoracic vertebral plates, were produced with a 3-D laser printer. Screws were placed with assistance of a guide plate. Then, the placement was assessed. Results With the data provided by CT scans, 27 individualized guide plates were produced by 3-D printing. There was no significant difference in sex and relevant parameters of left and right sides among individuals (P>0.05). Screws were placed with assistance of guide plates, and all screws were in the correct positions without penetration of pedicles, under direct observation and anatomic evaluation post-operatively. Conclusions A thoracic pedicle screw placement guide plate can be produced by 3-D printing. With a high accuracy in placement and convenient operation, it provides a new method for accurate placement of thoracic pedicle screws. PMID:27194139

  8. Feasibility Study: Comparison of Frontal Cortex Needle Core Versus Open Biopsy For Detection of Characteristic Proteinopathies of Neurodegenerative Diseases

    PubMed Central

    Serrano, Geidy E.; Intorcia, Anthony; Carew, Jeremiah; Chiarolanza, Glenn; Hidalgo, Jose A.; Sue, Lucia. I.; Dugger, Brittany N.; Saxon-LaBelle, Megan; Filon, Jessica; Scroggins, Alex; Pullen, Joel; Fornwalt, Brandon E.; Scott, Sarah; Sabbagh, Marwan M.; Adler, Charles H.; Akiyama, Haruhiko; Beach, Thomas G.

    2015-01-01

    The clinical diagnosis and classification of neurodegenerative diseases based on clinical examination or available biomarkers are currently insufficiently accurate. Although histological examination is considered the gold standard for diagnosis, brain biopsies have been avoided because of the high risk-benefit ratio. However, brain biopsies have previously been performed with a craniotomy and excision of approximately 1 cc of cerebral cortex tissue, and it is possible that needle core brain biopsies would have a lower morbidity and mortality risk. Here, we compared the ability of simulated needle core biopsy versus simulated open biopsy to detect the frontal cortex histopathology associated with common neurodegenerative diseases in the elderly using 144 autopsy-proven cases. Simulated needle core biopsy, as compared to simulated open biopsy, gave close to 90% sensitivity and specificity for identifying graded densities of β-amyloid and neuritic plaques, neurofibrillary tangles, phosphorylated α-synuclein, and phosphorylated TDP-43 pathology. This study shows that the presence and densities of the most common molecular pathologies may be histopathologically assessed in simulated frontal cortex needle biopsies with accuracy very close to that obtained by open cortical biopsy. An accurate estimation of the morbidity and mortality risk associated with cortical needle core biopsy will require specifically designed clinical trials in appropriate subjects. PMID:26230581

  9. Factors associated with external ventricular drain placement accuracy: data from an electronic health record repository

    PubMed Central

    Patil, Vaibhav; Lacson, Ronilda; Vosburgh, Kirby G.; Wong, Judith M.; Prevedello, Luciano; Andriole, Katherine; Mukundan, Srinivasan; Popp, A. John; Khorasani, Ramin

    2013-01-01

    Background We evaluated external ventricular drain placement for factors associated with placement accuracy. Data was acquired using an electronic health record data requisition tool. Method Medical records of all patients who underwent ventriculostomy from 2003–2010 were identified and evaluated. Patient demographics, diagnosis, type of guidance and number of catheter passes were searched for and recorded. Post-procedural hemorrhage and/or infection were identified. A grading scale was used to classify accuracy of catheter placements. A multiple logistic regression model was developed to assess features associated with accurate catheter placement. Results One hundred nine patients who underwent 111 ventriculostomies from 2003–2010 were identified. Patient diagnoses were classified into vascular (63%), tumor (21%), trauma (14%), and cyst (2%). Procedures were performed freehand in 90 (81%), with the Ghajar guide in 17 (15%), and with image guidance in 4 (4%) patients. Eighty-eight (79%) catheters were placed in the correct location. Trauma patients were more likely to have catheters misplaced (p=0.007) whereas patients in other diagnostic categories were not significantly associated with misplaced catheters. Post-procedural hemorrhage was noted in 2 (1.8%) patients on post-procedural imaging studies. Five (4.5%) definite and 6 (5.4%) suspected infections were identified. Conclusions External ventricular drain placement can be performed accurately in most patients. Patients with trauma are more likely to have catheters misplaced. Further development is required to identify and evaluate procedure outcomes using an electronic health record repository. PMID:23700258

  10. Improvements to the Processing and Characterization of Needled Composite Laminates

    DTIC Science & Technology

    2014-01-01

    that mode I fracture toughness improves up to 270% compared to non- needled baseline material. In-plane compressive strength of needled material... fracture toughness improves up to 270% compared to non-needled baseline material. In-plane compressive strength of needled material improves by up to 475...shear (DLS) tests are performed to assess improvements in mode-I fracture toughness and shear strength. Tension and compression tests are

  11. Needle Path Planning for Autonomous Robotic Surgical Suturing

    PubMed Central

    Jackson, Russell C.; Çavuşoğlu, M. Cenk

    2013-01-01

    This paper develops a path plan for suture needles used with solid tissue volumes in endoscopic surgery. The path trajectory is based on the best practices that are used by surgeons. The path attempts to minimize the interaction forces between the tissue and the needle. Using surgical guides as a basis, two different techniques for driving a suture needle are developed. The two techniques are compared in hardware experiments by robotically driving the suture needle using both of the motion plans. PMID:24683500

  12. Needle Path Planning for Autonomous Robotic Surgical Suturing.

    PubMed

    Jackson, Russell C; Cavuşoğlu, M Cenk

    2013-12-31

    This paper develops a path plan for suture needles used with solid tissue volumes in endoscopic surgery. The path trajectory is based on the best practices that are used by surgeons. The path attempts to minimize the interaction forces between the tissue and the needle. Using surgical guides as a basis, two different techniques for driving a suture needle are developed. The two techniques are compared in hardware experiments by robotically driving the suture needle using both of the motion plans.

  13. Evaluation of Robotic Needle Steering in ex vivo Tissue

    PubMed Central

    Majewicz, Ann; Wedlick, Thomas R.; Reed, Kyle B.; Okamura, Allison M.

    2010-01-01

    Insertion velocity, tip asymmetry, and shaft diameter may influence steerable needle insertion paths in soft tissue. In this paper we examine the effects of these variables on needle paths in ex vivo goat liver, and demonstrate practical applications of robotic needle steering for ablation, biopsy, and brachytherapy. All experiments were performed using a new portable needle steering robot that steers asymmetric-tip needles under fluoroscopic imaging. For bevel-tip needles, we found that larger diameter needles resulted in less curvature, i.e. less steerability, confirming previous experiments in artificial tissue. The needles steered with radii of curvature ranging from 3:4 cm (for the most steerable pre-bent needle) to 2:97m (for the least steerable bevel needle). Pre-bend angle significantly affected needle curvature, but bevel angle did not. We hypothesize that biological tissue characteristics such as inhomogeneity and viscoelasticity significantly increase path variability. These results underscore the need for closed-loop image guidance for needle steering in biological tissues with complex internal structure. PMID:21339851

  14. The Double-Needle Felling Machine. Module 17.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on the double-needle felling machine, one in a series dealing with industrial sewing machines, their attachments, and operation, covers two topics: performing special operations on the double-needle felling machine (straight seams) and performing special operations on the double-needle felling machine (curved flat-felled seams). For…

  15. 21 CFR 868.5150 - Anesthesia conduction needle.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient...

  16. 21 CFR 868.5150 - Anesthesia conduction needle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient...

  17. 21 CFR 884.6100 - Assisted reproduction needles.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Assisted reproduction needles. 884.6100 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6100 Assisted reproduction needles. (a) Identification. Assisted reproduction needles are devices used in...

  18. 21 CFR 884.6100 - Assisted reproduction needles.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Assisted reproduction needles. 884.6100 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6100 Assisted reproduction needles. (a) Identification. Assisted reproduction needles are devices used in...

  19. 21 CFR 884.6100 - Assisted reproduction needles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction needles. 884.6100 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6100 Assisted reproduction needles. (a) Identification. Assisted reproduction needles are devices used in...

  20. 21 CFR 884.6100 - Assisted reproduction needles.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Assisted reproduction needles. 884.6100 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6100 Assisted reproduction needles. (a) Identification. Assisted reproduction needles are devices used in...

  1. 21 CFR 884.6100 - Assisted reproduction needles.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Assisted reproduction needles. 884.6100 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6100 Assisted reproduction needles. (a) Identification. Assisted reproduction needles are devices used in...

  2. 21 CFR 868.5150 - Anesthesia conduction needle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient...

  3. 21 CFR 868.5150 - Anesthesia conduction needle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient...

  4. 21 CFR 868.5150 - Anesthesia conduction needle.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anesthesia conduction needle. 868.5150 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5150 Anesthesia conduction needle. (a) Identification. An anesthesia conduction needle is a device used to inject local anesthetics into a patient...

  5. Nasogastric tube placement and verification in children: review of the current literature.

    PubMed

    Irving, Sharon Y; Lyman, Beth; Northington, LaDonna; Bartlett, Jacqueline A; Kemper, Carol

    2014-06-01

    Placement of a nasogastric enteral access device (NG-EAD), often referred to as a nasogastric tube, is common practice and largely in the domain of nursing care. Most often an NG-EAD is placed at the bedside without radiographic assistance. Correct initial placement and ongoing location verification are the primary challenges surrounding NG-EAD use and have implications for patient safety. Although considered an innocuous procedure, placement of an NG-EAD carries risk of serious and potentially lethal complications. Despite acknowledgment that an abdominal radiograph is the gold standard, other methods of verifying placement location are widely used and have success rates from 80% to 85%. The long-standing challenges surrounding bedside placement of NG-EADs and a practice alert issued by the Child Health Patient Safety Organization on this issue were the stimuli for the conception of The New Opportunities for Verification of Enteral Tube Location Project sponsored by the American Society for Parenteral and Enteral Nutrition. Its mission is to identify and promote best practices with the potential of technology development that will enable accurate determination of NG-EAD placement for both the inpatient and outpatient pediatric populations. This article presents the challenges of bedside NG-EAD placement and ongoing location verification in children through an overview of the current state of the science. It is important for all health care professionals to be knowledgeable about the current literature, to be vigilant for possible complications, and to avoid complacency with NG-EAD placement and ongoing verification of tube location.

  6. Transthoracic needle aspiration in solitary pulmonary nodule

    PubMed Central

    Yang, Wen; Jiang, Hongli; Khan, Ali Nawaz; Allen, Carolyn; Bertolaccini, Luca

    2017-01-01

    With improved awareness of public health and the recent advances in various imaging technologies, the detection rate of solitary pulmonary nodules (SPN) is continuously increasing. Transthoracic needle aspiration (TTNA) has represented a major approach for the diagnosis and differential diagnosis of pulmonary masses, owing to its simplicity and minimal invasiveness. This paper demonstrates the role of TTNA in SPN. PMID:28331827

  7. A Modification to Maxwell's Needle Apparatus

    ERIC Educational Resources Information Center

    Soorya, Tribhuvan N.

    2015-01-01

    Maxwell's needle apparatus is used to determine the shear modulus (?) of the material of a wire of uniform cylindrical cross section. Conventionally, a single observation is taken for each observable, and the value of ? is calculated in a single shot. A modification to the above apparatus is made by varying one of the observables, namely the mass…

  8. The Single Needle Lockstitch Machine. Module 1.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on parts of the machine, one in a series on the single needle lockstitch sewing machine for student self-study, contains eight sections. Each section contains the following parts: an introduction, directions, an objective, learning activities, student information, student self-check, check-out activities, and an instructor's final…

  9. Transthoracic needle biopsy. What size syringe?

    PubMed

    Yankelevitz, D F; Hayt, D; Henschke, C I

    1995-01-01

    Using a vacuum gauge we demonstrated that with less effort, the identical vacuum can be obtained using a 10-cc syringe as opposed to a 50-cc syringe. We recommend using a 20 cc syringe during transthoracic needle aspiration since the syringe is easier to handle and still allows sufficient vacuum to be developed, even if a small amount of air enters the syringe.

  10. Bubble Growth and Detachment from a Needle

    NASA Astrophysics Data System (ADS)

    Shusser, Michael; Rambod, Edmond; Gharib, Morteza

    1999-11-01

    The release of bubbles from an underwater nozzle or orifice occurs in large number of applications, such as perforated plate columns, blood oxygenators and various methods of water treatment. It is also a widely used method in laboratory research on multiphase flow and acoustics for generating small bubbles in a controlled fashion. We studied experimentally the growth and pinch-off of air bubbles released from a submerged needle into a quiescent liquid or a liquid flowing parallel to the needle. Micron-sized bubbles were generated by an air-liquid dispenser. High-speed imaging was performed to study the formation and detachment of bubbles from the tip of the needle. The impact of the needle diameter was investigated and the size and number of produced bubbles were assessed for different flow rates of air and for different velocities of the imposed upward liquid flow. The results were compared with available theoretical models and numerical computations. The existence of a critical gas flow rate and two regimes of bubble growth were verified.

  11. Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age.

    PubMed

    Kuang, Yuan Wen; Wen, Da Zhi; Zhou, Guoyi; Liu, Shi Zhong

    2007-02-01

    Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd,) and Al concentrations as well as values of Ca/Al in the tip, middle and base sections, and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al.

  12. Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age.

    PubMed

    Kuang, Yuan Wen; Wen, Da Zhi; Zhou, Guo Yi; Liu, Shi Zhong

    2007-01-01

    Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd) and Al concentrations as well as values of Ca/Al in the tip, middle, base sections and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al.

  13. Nursing students' experience of practice placements.

    PubMed

    MacDonald, Kathleen; Paterson, Kirstie; Wallar, Jessica

    2016-11-02

    Clinical practice placements are an essential component of pre-registration nursing programmes. Integration into a new team in an unfamiliar setting, which has its own values, practices, culture and language, can be stressful for nursing students. This article presents and discusses students' reflections on preparing for, entering and leaving practice placements. Ten students who participated in fortnightly group reflective sessions, discussed and analysed their learning experiences while on practice placements in an acute hospital. The challenges the students encountered were deconstructed using a group narrative approach. The students experienced ethical dilemmas around patient dignity, consent and advocacy as well as factors external to the practice setting, such as navigating systems and processes to access information before starting practice placements, managing household duties and academic workloads while working long shifts, and managing fatigue and loneliness. The students devised recommendations for other students to enable them to navigate their practice placements effectively and enhance their learning experience. Raising awareness among academic and practice placement staff of the challenges students encounter before and during their practice placement is essential to assist students to succeed and maximise their learning potential.

  14. Relationship between levels of polycyclic aromatic hydrocarbons in pine needles and socio-geographic parameters.

    PubMed

    Fernández-Varela, Raquel; Ratola, Nuno; Alves, Arminda; Amigo, José Manuel

    2015-06-01

    The ability of pine needles to capture polycyclic aromatic hydrocarbons (PAHs) from the surrounding air is well known. In this work the current knowledge of this affinity will be enhanced, investigating the plausible links between the concentrations of PAHs found in pine needles collected in different sites in Portugal, and several socio-geographic variables with environmental relevance. Canonical correlation analysis (CCA) has proven to be a suitable and innovative technique to look for relationships within environmental datasets. In the current work, CCA will simultaneously include chemical information (concentration of PAHs found in pine needles) and socio-geographic information associated to the sampling areas. In order to be more robust in these conclusions, Pinus pinea and Pinus pinaster species were considered separately, allowing an accurate direct comparison between them. The information concerning the different seasons and land occupation was also taken into account. Our results demonstrate how CCA can be a useful tool in environmental impact assessment, and highlight the importance of pine needles as trustful biomonitors of the influence of socio-geographic parameters on the levels of PAHs in a given area.

  15. Accurate quantum chemical calculations

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1989-01-01

    An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.

  16. Hyaline globules in fine-needle aspiration smears of salivary gland neoplasms

    PubMed Central

    Gupta, Mayank; Bindra, Mandeep Singh

    2015-01-01

    Most salivary gland neoplasms can be accurately diagnosed on fine-needle aspiration cytology. Few cases present with overlapping cytomorphological features, so accurate distinction in these cases may be difficult. We describe a case of pleomorphic adenoma that had a close resemblance to adenoid cystic carcinoma on smears due to presence of numerous hyaline globules and bare nuclei. Careful analysis of cellular details along with corroborative clinical evidence clinched the correct diagnosis. This article discusses cytological features of salivary gland tumours in which hyaline globules can be seen on smears. PMID:25750224

  17. A comparison of needle tip localization accuracy using 2D and 3D trans-rectal ultrasound for high-dose-rate prostate cancer brachytherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Hrinivich, W. Thomas; Hoover, Douglas A.; Surry, Kathleen; Edirisinghe, Chandima; Montreuil, Jacques; D'Souza, David; Fenster, Aaron; Wong, Eugene

    2016-03-01

    Background: High-dose-rate brachytherapy (HDR-BT) is a prostate cancer treatment option involving the insertion of hollow needles into the gland through the perineum to deliver a radioactive source. Conventional needle imaging involves indexing a trans-rectal ultrasound (TRUS) probe in the superior/inferior (S/I) direction, using the axial transducer to produce an image set for organ segmentation. These images have limited resolution in the needle insertion direction (S/I), so the sagittal transducer is used to identify needle tips, requiring a manual registration with the axial view. This registration introduces a source of uncertainty in the final segmentations and subsequent treatment plan. Our lab has developed a device enabling 3D-TRUS guided insertions with high S/I spatial resolution, eliminating the need to align axial and sagittal views. Purpose: To compare HDR-BT needle tip localization accuracy between 2D and 3D-TRUS. Methods: 5 prostate cancer patients underwent conventional 2D TRUS guided HDR-BT, during which 3D images were also acquired for post-operative registration and segmentation. Needle end-length measurements were taken, providing a gold standard for insertion depths. Results: 73 needles were analyzed from all 5 patients. Needle tip position differences between imaging techniques was found to be largest in the S/I direction with mean+/-SD of -2.5+/-4.0 mm. End-length measurements indicated that 3D TRUS provided statistically significantly lower mean+/-SD insertion depth error of -0.2+/-3.4 mm versus 2.3+/-3.7 mm with 2D guidance (p < .001). Conclusions: 3D TRUS may provide more accurate HDR-BT needle localization than conventional 2D TRUS guidance for the majority of HDR-BT needles.

  18. Dual mode fuel injector with one piece needle valve member

    DOEpatents

    Lawrence, Keith E.; Hinrichsen, Michael H.; Buckman, Colby

    2005-01-18

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively by inner and outer needle value members. The homogenous charged nozzle outlet set is defined by an outer needle value member that is moveably positioned in an injector body, which defines the conventional nozzle outlet set. The inner needle valve member is positioned in the outer needle valve member. The outer needle valve member is a piece component that includes at least one external guide surface, an external value surface and an internal valve seat.

  19. Accurate Interpretation of the 12-Lead ECG Electrode Placement: A Systematic Review

    ERIC Educational Resources Information Center

    Khunti, Kirti

    2014-01-01

    Background: Coronary heart disease (CHD) patients require monitoring through ECGs; the 12-lead electrocardiogram (ECG) is considered to be the non-invasive gold standard. Examples of incorrect treatment because of inaccurate or poor ECG monitoring techniques have been reported in the literature. The findings that only 50% of nurses and less than…

  20. Needle insertion with duty-cycled rotation into multiple media.

    PubMed

    Lehocky, Craig A; Riviere, Cameron N

    2012-01-01

    Thin, flexible needles can be steered along nonlinear paths to reach deep anatomical structures within the human body. This study builds upon previous work involving steering of bevel-tipped needles by inserting while rotating in a duty-cycled fashion. Here we investigate how needle material and radius, duty cycle, and tissue stiffness affect needle curvature. Needles were inserted into media while rotated at a specified duty cycle and the curvature was measured. A linear relationship between duty cycle and curvature was observed across all needle materials and radii, and tissue stiffnesses. Following these observations, we developed a model that encapsulates needle and tissue parameters in order to predict the duty cycle needed to achieve a desired curvature.

  1. Tip-holed spinal needle: a new design concept.

    PubMed

    Jahangir, S M

    2000-01-01

    Dura-arachnoid puncture for spinal anesthesia is associated with several complications. Postdural puncture headache (PDPH) and needle bending are significant among these. The incidence of PDPH has been reduced significantly with the advent of pencil-point needles. However, these needles also have their limitations, such as obstruction of the delivery port by tissues affecting both cerebrospinal fluid flash back and drug delivery. Increasing the size of the lateral hole has led to mechanical complications, such as tip bending. A new spreading beveled spinal needle tip has been designed to overcome the disadvantages of all the currently used spinal needles. To assess the feasibility, a 26-gauge Quincke spinal needle (B. Braun, Melsungen, Germany) has been modified manually. The new tip-holed design seems to be sound both from theoretical and practical point of view. Searching Medline Plus through their Internet Web site (www.nlm.nih.com) did not reveal the existence of any such spinal needle.

  2. Mixed mode fuel injector with individually moveable needle valve members

    DOEpatents

    Stewart, Chris; Chockley, Scott A.; Ibrahim, Daniel R.; Lawrence, Keith; Tomaseki, Jay; Azam, Junru H.; Tian, Steven Ye; Shafer, Scott F.

    2004-08-03

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively, by first and second needle valve members. One of the needle valve members moves to an open position while the other needle valve member remains stationary for a homogeneous charge injection event. The former needle valve member stays stationary while the other needle valve member moves to an open position for a conventional injection event. One of the needle valve members is at least partially positioned in the other needle valve member. Thus, the injector can perform homogeneous charge injection events, conventional injection events, or even a mixed mode having both types of injection events in a single engine cycle.

  3. Torsional dynamics of steerable needles: modeling and fluoroscopic guidance.

    PubMed

    Swensen, John P; Lin, MingDe; Okamura, Allison M; Cowan, Noah J

    2014-11-01

    Needle insertions underlie a diversity of medical interventions. Steerable needles provide a means by which to enhance existing needle-based interventions and facilitate new ones. Tip-steerable needles follow a curved path and can be steered by twisting the needle base during insertion, but this twisting excites torsional dynamics that introduce a discrepancy between the base and tip twist angles. Here, we model the torsional dynamics of a flexible rod-such as a tip-steerable needle-during subsurface insertion and develop a new controller based on the model. The torsional model incorporates time-varying mode shapes to capture the changing boundary conditions inherent during insertion. Numerical simulations and physical experiments using two distinct setups-stereo camera feedback in semitransparent artificial tissue and feedback control with real-time X-ray imaging in optically opaque artificial tissue-demonstrate the need to account for torsional dynamics in control of the needle tip.

  4. MR-compatible biopsy needle with enhanced tip force sensing.

    PubMed

    Elayaperumal, Santhi; Bae, Jung Hwa; Christensen, David; Cutkosky, Mark R; Daniel, Bruce L; Costa, Joannes M; Black, Richard J; Faridian, Fereydoun; Moslehi, Behzad

    2013-04-01

    We describe an instrumented biopsy needle that provides physicians the capability to sense interaction forces directly at the tip of the needle's inner stylet. The sensors consist of optical fiber Bragg gratings (FBGs), and are unaffected by electromagnetic fields; hence the needle is suitable for MR-guided procedures. In comparison to previous instrumented needles that measure bending strains, the new design has additional sensors and a series of micro-machined holes at the tip. The holes increase strain sensitivity, especially to axial forces, without significantly reducing the stiffness or strength. A comparison of the dynamic forces measured with the new needle and those obtained using a force/torque sensor at the needle base shows that the enhanced tip sensitivity is particularly noticeable when there is significant friction along the needle sleeve.

  5. Needle Insertion with Duty-Cycled Rotation into Multiple Media

    PubMed Central

    Lehocky, Craig A.; Riviere, Cameron N.

    2012-01-01

    Thin, flexible needles can be steered along nonlinear paths to reach deep anatomical structures within the human body. This study builds upon previous work involving steering of bevel-tipped needles by inserting while rotating in a duty-cycled fashion. Here we investigate how needle material and radius, duty cycle, and tissue stiffness affect needle curvature. Needles were inserted into media while rotated at a specified duty cycle and the curvature was measured. A linear relationship between duty cycle and curvature was observed across all needle materials and radii, and tissue stiffnesses. Following these observations, we developed a model that encapsulates needle and tissue parameters in order to predict the duty cycle needed to achieve a desired curvature. PMID:23366042

  6. A standardized method for 4D ultrasound-guided peripheral nerve blockade and catheter placement.

    PubMed

    Clendenen, N J; Robards, C B; Clendenen, S R

    2014-01-01

    We present a standardized method for using four-dimensional ultrasound (4D US) guidance for peripheral nerve blocks. 4D US allows for needle tracking in multiple planes simultaneously and accurate measurement of the local anesthetic volume surrounding the nerve following injection. Additionally, the morphology and proximity of local anesthetic spread around the target nerve is clearly seen with the described technique. This method provides additional spatial information in real time compared to standard two-dimensional ultrasound.

  7. BIOACCESSIBILITY TESTS ACCURATELY ESTIMATE ...

    EPA Pesticide Factsheets

    Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, we measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from five Pb-contaminated Superfund sites had relative bioavailabilities from 33%-63%, with a mean of about 50%. Treatment of two of the soils with P significantly reduced the bioavailability of Pb. The bioaccessibility of the Pb in the test soils was then measured in six in vitro tests and regressed on bioavailability. They were: the “Relative Bioavailability Leaching Procedure” (RBALP) at pH 1.5, the same test conducted at pH 2.5, the “Ohio State University In vitro Gastrointestinal” method (OSU IVG), the “Urban Soil Bioaccessible Lead Test”, the modified “Physiologically Based Extraction Test” and the “Waterfowl Physiologically Based Extraction Test.” All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the RBALP pH 2.5 and OSU IVG tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter 24%, or present as Pb sulfate 18%. Ad

  8. SU-E-T-373: A Motorized Stage for Fast and Accurate QA of Machine Isocenter

    SciTech Connect

    Moore, J; Velarde, E; Wong, J

    2014-06-01

    Purpose: Precision delivery of radiation dose relies on accurate knowledge of the machine isocenter under a variety of machine motions. This is typically determined by performing a Winston-Lutz test consisting of imaging a known object at multiple gantry/collimator/table angles and ensuring that the maximum offset is within specified tolerance. The first step in the Winston-Lutz test is careful placement of a ball bearing at the machine isocenter as determined by repeated imaging and shifting until accurate placement has been determined. Conventionally this is performed by adjusting a stage manually using vernier scales which carry the limitation that each adjustment must be done inside the treatment room with the risks of inaccurate adjustment of the scale and physical bumping of the table. It is proposed to use a motorized system controlled outside of the room to improve the required time and accuracy of these tests. Methods: The three dimensional vernier scales are replaced by three motors with accuracy of 1 micron and a range of 25.4mm connected via USB to a computer in the control room. Software is designed which automatically detects the motors and assigns them to proper axes and allows for small shifts to be entered and performed. Input values match calculated offsets in magnitude and sign to reduce conversion errors. Speed of setup, number of iterations to setup, and accuracy of final placement are assessed. Results: Automatic BB placement required 2.25 iterations and 13 minutes on average while manual placement required 3.76 iterations and 37.5 minutes. The average final XYZ offsets is 0.02cm, 0.01cm, 0.04cm for automatic setup and 0.04cm, 0.02cm, 0.04cm for manual setup. Conclusion: Automatic placement decreased time and repeat iterations for setup while improving placement accuracy. Automatic placement greatly reduces the time required to perform QA.

  9. Educational Placement of Children with Spina Bifida.

    ERIC Educational Resources Information Center

    Lauder, Calvin E.; And Others

    1979-01-01

    Procedures of school placement for 38 children (ages 5 to 18 years) with spina bifida in 23 school districts in western New York State were studied 5 years after a mandated process was enacted. (Author)

  10. Basic technique in endoscopic ultrasound-guided fine needle aspiration for solid lesions: What needle is the best?

    PubMed Central

    Lachter, Jesse

    2014-01-01

    Basic technique for endoscopic ultrasound (EUS) of solid lesions has developed during 30 years of EUS, as endoscopes and accessory equipment, particularly needles, have been developed. Systematic high-quality examinations require understanding and planning. Needles used for EUS-guided fine needle aspiration (FNA) have gone through many improvements; some 18 characteristics of any needle are presented and these come under consideration whenever choosing the best needle for each procedure. The bright future of EUS and FNA for solid lesions currently still leaves much room for continued developments. PMID:24949410

  11. An Exploration of the Needling Depth in Acupuncture: The Safe Needling Depth and the Needling Depth of Clinical Efficacy

    PubMed Central

    Lin, Jaung-Geng; Chou, Pei-Chi; Chu, Heng-Yi

    2013-01-01

    Objective. To explore the existing scientific information regarding safe needling depth of acupuncture points and the needling depth of clinical efficacy. Methods. We searched the PubMed, EMBASE, Cochrane, Allied and Complementary Medicine (AMED), The National Center for Complementary and Alternative Medicine (NCCAM), and China National Knowledge Infrastructure (CNKI) databases to identify relevant monographs and related references from 1991 to 2013. Chinese journals and theses/dissertations were hand searched. Results. 47 studies were recruited and divided into 6 groups by measuring tools, that is, MRI, in vivo evaluation, CT, ultrasound, dissected specimen of cadavers, and another group with clinical efficacy. Each research was analyzed for study design, definition of safe depth, and factors that would affect the measured depths. Depths of clinical efficacy were discussed from the perspective of de-qi and other clinical observations. Conclusions. Great inconsistency in depth of each point measured from different subject groups and tools exists. The definition of safe depth should be established through standardization. There is also lack of researches to compare the clinical efficacy. A well-designed clinical trial selecting proper measuring tools to decide the actual and advisable needling depth for each point, to avoid adverse effects or complications and promote optimal clinical efficacy, is a top priority. PMID:23935678

  12. Computed tomography-guided endoscopic needle knife therapy for ileal pouch sinus.

    PubMed

    Nyabanga, Custon T; Veniero, Joseph; Shen, Bo

    2016-11-01

    Ileal pouch-anal anastomosis surgery can be complicated by anastomotic leaks, leading to the formation of abscess and chronic sinus that have been routinely managed by a surgical approach. We developed the endoscopic needle knife sinusotomy (NKSi) technique, which has become a valid alternative. The basic principle of endoscopic NKSi is dissection and drainage of the sinus through its orifice internally into the lumen of pouch body. The success of NKSi requires an access to the sinus from the pouch side. One of the most challenging situations for NKSi is a closed orifice of the sinus, which leaves an isolated chronic abscess cavity. Here we report a case of complicated presacral sinus with a closed orifice that was not amenable to NKSi, necessitating a CT-guided guide wire placement and subsequent NKSi.

  13. [Needling technique of Professor Li Yan-Fang].

    PubMed

    Li, Li-Jun

    2014-01-01

    Experiences of needling techniques of Professor LI Ya- fang is introduced in this article. Gentle and superficial insertion is adopted by Professor LI in clinic. Emphases are put on the qi regulation function, needling sensation to the affected region and insertion with both hands, especially the function of the left hand as pressing hand. The gentle and superficial insertion should be done as the follows: hold the needle with the right hand, press gently along the running course of meridians with the left hand to promote qi circulation, hard pressing should be applied at acupoints to disperse the local qi and blood, insert the needle gently and quickly into the subcutaneous region with the right hand, and stop the insertion when patient has the needling sensation. While the fast needling is characterized with shallow insertion and swift manipulation: the left hand of the manipulator should press first along the running course of the meridian, and fix the local skin, hold the needle with the right hand and insert the needle quickly into the acupoint. Withdrawal of the needle should be done immediately after the reinforcing and reducing manipulations. Professor LI is accomplished in qi regulation. It is held by him that regulating qi circulation is essence of acupuncture, letting the patient get the needling sensation is the most important task of needling. Lifting, thrusting and rotation manipulations should be applied to do reinforcing or reducing. The tissue around the tip of the needle should not be too contracted or too relaxed, and the resistance should not be too strong or too weak. The feeling of the insertion hand of the practitioner should not be too smooth or too hesitant. Needle should be inserted into the skin quickly at the moment of hard pressing by the left hand. And then, slow rotation and gentle lifting and thrusting can be applied to promote the needling sensation like electric current pass through and to reach the affected region along the

  14. PEG feeding tube placement and aftercare.

    PubMed

    Haywood, Sharlene

    Some adults and children are unable to swallow or eat and drink enough. Insertion of a percutaneous endoscopic gastrostomy (PEG) tube may enable long-term feeding, fluid and/or medication administration. The procedure involves gastroscopy under sedation to identify tube placement site, place the tube and check it has been placed correctly. Serious complications include peritonitis and perforation of the colon. Frequent observations immediately after placement are essential. With good nursing care, complications can be avoided or dealt with promptly.

  15. Coded excitation ultrasonic needle tracking: An in vivo study

    PubMed Central

    Xia, Wenfeng; Ginsberg, Yuval; West, Simeon J.; Nikitichev, Daniil I.; Ourselin, Sebastien; David, Anna L.; Desjardins, Adrien E.

    2016-01-01

    Purpose Accurate and efficient guidance of medical devices to procedural targets lies at the heart of interventional procedures. Ultrasound imaging is commonly used for device guidance, but determining the location of the device tip can be challenging. Various methods have been proposed to track medical devices during ultrasound-guided procedures, but widespread clinical adoption has remained elusive. With ultrasonic tracking, the location of a medical device is determined by ultrasonic communication between the ultrasound imaging probe and a transducer integrated into the medical device. The signal-to-noise ratio (SNR) of the transducer data is an important determinant of the depth in tissue at which tracking can be performed. In this paper, the authors present a new generation of ultrasonic tracking in which coded excitation is used to improve the SNR without spatial averaging. Methods A fiber optic hydrophone was integrated into the cannula of a 20 gauge insertion needle. This transducer received transmissions from the ultrasound imaging probe, and the data were processed to obtain a tracking image of the needle tip. Excitation using Barker or Golay codes was performed to improve the SNR, and conventional bipolar excitation was performed for comparison. The performance of the coded excitation ultrasonic tracking system was evaluated in an in vivo ovine model with insertions to the brachial plexus and the uterine cavity. Results Coded excitation significantly increased the SNRs of the tracking images, as compared with bipolar excitation. During an insertion to the brachial plexus, the SNR was increased by factors of 3.5 for Barker coding and 7.1 for Golay coding. During insertions into the uterine cavity, these factors ranged from 2.9 to 4.2 for Barker coding and 5.4 to 8.5 for Golay coding. The maximum SNR was 670, which was obtained with Golay coding during needle withdrawal from the brachial plexus. Range sidelobe artifacts were observed in tracking images

  16. Detecting stages of needle penetration into tissues through force estimation at needle tip using fiber Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Kumar, Saurabh; Shrikanth, Venkoba; Amrutur, Bharadwaj; Asokan, Sundarrajan; Bobji, Musuvathi S.

    2016-12-01

    Several medical procedures involve the use of needles. The advent of robotic and robot assisted procedures requires dynamic estimation of the needle tip location during insertion for use in both assistive systems as well as for automatic control. Most prior studies have focused on the maneuvering of solid flexible needles using external force measurements at the base of the needle holder. However, hollow needles are used in several procedures and measurements of forces in proximity of such needles can eliminate the need for estimating frictional forces that have high variations. These measurements are also significant for endoscopic procedures in which measurement of forces at the needle holder base is difficult. Fiber Bragg grating sensors, due to their small size, inert nature, and multiplexing capability, provide a good option for this purpose. Force measurements have been undertaken during needle insertion into tissue mimicking phantoms made of polydimethylsiloxane as well as chicken tissue using an 18-G needle instrumented with FBG sensors. The results obtained show that it is possible to estimate the different stages of needle penetration including partial rupture, which is significant for procedures in which precise estimation of needle tip position inside the organ or tissue is required.

  17. Accurate spectral color measurements

    NASA Astrophysics Data System (ADS)

    Hiltunen, Jouni; Jaeaeskelaeinen, Timo; Parkkinen, Jussi P. S.

    1999-08-01

    Surface color measurement is of importance in a very wide range of industrial applications including paint, paper, printing, photography, textiles, plastics and so on. For a demanding color measurements spectral approach is often needed. One can measure a color spectrum with a spectrophotometer using calibrated standard samples as a reference. Because it is impossible to define absolute color values of a sample, we always work with approximations. The human eye can perceive color difference as small as 0.5 CIELAB units and thus distinguish millions of colors. This 0.5 unit difference should be a goal for the precise color measurements. This limit is not a problem if we only want to measure the color difference of two samples, but if we want to know in a same time exact color coordinate values accuracy problems arise. The values of two instruments can be astonishingly different. The accuracy of the instrument used in color measurement may depend on various errors such as photometric non-linearity, wavelength error, integrating sphere dark level error, integrating sphere error in both specular included and specular excluded modes. Thus the correction formulas should be used to get more accurate results. Another question is how many channels i.e. wavelengths we are using to measure a spectrum. It is obvious that the sampling interval should be short to get more precise results. Furthermore, the result we get is always compromise of measuring time, conditions and cost. Sometimes we have to use portable syste or the shape and the size of samples makes it impossible to use sensitive equipment. In this study a small set of calibrated color tiles measured with the Perkin Elmer Lamda 18 and the Minolta CM-2002 spectrophotometers are compared. In the paper we explain the typical error sources of spectral color measurements, and show which are the accuracy demands a good colorimeter should have.

  18. 41 CFR 60-2.16 - Placement goals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... good faith effort to make all aspects of the entire affirmative action program work. Placement goals... placement goal for a particular job group, the contractor must establish a percentage annual placement goal... job group. (d) The placement goal-setting process described above contemplates that contractors...

  19. Semi-invasive and invasive procedures for the diagnosis and staging of lung cancer. I. Percutaneous transthoracic needle biopsy.

    PubMed

    Shaham, D

    2000-05-01

    PTNB is a well-established technique for the diagnosis of lung cancer. In recent years, CT guidance has become the primary imaging modality, replacing fluoroscopy guided biopsies in many institutions. CT fluoroscopy, which is currently not universally available, offers promising advantages and may permit accurate and rapid procedures. A recent innovation in biopsy needles has been the introduction of automatic core biopsy needle devices that yield large specimens and improve the diagnostic accuracy of needle biopsy, particularly in benign lesions. PTNB is one of several methods available for tissue diagnosis of suspected lung cancer. The decision as to which method to use should be tailored to each patient, and is preferably reached by a team consisting of pulmonary physicians, chest surgeons, oncologists, cytologists, and radiologists.

  20. A new placement optimization method for viscoelastic dampers: Energy dissipation method

    NASA Astrophysics Data System (ADS)

    Qu, Ji-Ting

    2012-09-01

    A new mathematic model of location optimization for viscoelastic dampers is established through energy analysis based on force analogy method. Three working conditions (three lower limits of the new location index) as well as four ground motions are considered in this study, using MATLAB and SAP2000 in programming and verifying. This paper deals with the optimal placement of viscoelastic dampers and step-by-step time history analyses are carried out. Numerical analysis is illustrated to verify the effectiveness and feasibility of the new mathematic model for structural control. In addition, not only the optimal placement method using force analogy method can confirm dampers' locations all at once and be accurate to each span, but also it is without circular calculating. At last, a few helpful conclusions on viscoelastic dampers' optimal placement are made.

  1. Maxillofacial Changes in Melnick-Needles Syndrome

    PubMed Central

    Albuquerque do Nascimento, Leilane Larissa; Salgueiro, Monica da Consolação Canuto; Quintela, Mariana; Mota, Ana Carolina Costa

    2016-01-01

    Background. Melnick-Needles Syndrome is rare congenital hereditary skeletal dysplasia caused by mutations in the FLNA gene, which codifies the protein filamin A. This condition leads to serious skeletal abnormalities, including the stomatognathic region. Case Presentation. This paper describes the case of a 13-year-old girl diagnosed with Melnick-Needles Syndrome presenting with different forms of skeletal dysplasia, such as cranial hyperostosis, short upper limbs, bowed long bones, metaphyseal thickening, genu valgum (knock-knee), shortened distal phalanges, narrow pelvis and shoulders, rib tapering and irregularities, elongation of the vertebrae, kyphoscoliosis, micrognathia, hypoplastic coronoid processes of the mandible, left stylohyoid ligament suggesting ossification, and dental development anomalies. Conclusion. Knowledge of this rare syndrome on the part of dentists is important due to the fact that this condition involves severe abnormalities of the stomatognathic system that cause an impact on the development of the entire face as well as functional and esthetic impairments. PMID:27478655

  2. Intraoperative Optical Coherence Tomography Guided Bleb Needling.

    PubMed

    Dada, Tanuj; Angmo, Dewang; Midha, Neha; Sidhu, Talvir

    2016-01-01

    Two patients with history of trabeculectomy presented with uncontrolled intraocular pressure (IOP) postoperatively. The first patient had a flat and vasularized bleb 10 weeks after the surgery, and the second subject developed encapsulated bleb 3 months postoperatively. Both patients were taken to the operating room and intraoperative optical coherence tomography (OCT) guided bleb needling was performed to restore aqueous egress into the subconjunctival space. Postoperatively, IOP of the operated eyes ranged 14-18 mmHg at week 6 and month 3. None of the eyes had any intraoperative or postoperative complications. This novel application of the intraoperative OCT for bleb needling facilitates precision surgery under direct visualization and reduces the risk of complications.

  3. Intraoperative Optical Coherence Tomography Guided Bleb Needling

    PubMed Central

    Dada, Tanuj; Angmo, Dewang; Midha, Neha; Sidhu, Talvir

    2016-01-01

    Two patients with history of trabeculectomy presented with uncontrolled intraocular pressure (IOP) postoperatively. The first patient had a flat and vasularized bleb 10 weeks after the surgery, and the second subject developed encapsulated bleb 3 months postoperatively. Both patients were taken to the operating room and intraoperative optical coherence tomography (OCT) guided bleb needling was performed to restore aqueous egress into the subconjunctival space. Postoperatively, IOP of the operated eyes ranged 14-18 mmHg at week 6 and month 3. None of the eyes had any intraoperative or postoperative complications. This novel application of the intraoperative OCT for bleb needling facilitates precision surgery under direct visualization and reduces the risk of complications. PMID:27994819

  4. Conductivity Probe after Trench-Bottom Placement

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Needles of the thermal and conductivity probe on NASA's Phoenix Mars Lander were positioned into the bottom of a trench called 'Upper Cupboard' during Sol 86 (Aug. 21, 2008), or 86th Martian day after landing. This image of the conductivity probe after it was raised back out of the trench was taken by Phoenix's Robotic Arm Camera. The conductivity probe is at the wrist of the robotic arm's scoop.

    The probe measures how fast heat and electricity move from one needle to an adjacent one through the soil or air between the needles. Conductivity readings can be indicators about water vapor, water ice and liquid water.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  5. Melnick- needles osteodysplasty presenting with quadriparesis.

    PubMed

    Bandyopadhyay, S K; Ghosal, J; Chakrabarti, Nandini; Dutta, Anita

    2006-03-01

    Melnick-Needles syndrome or osteodysplasty, a monogenic heritable bone dysplasia, is characterized by a typical facies and characteristic radiological findings. Less than 70 well-documented cases have been reported in literature; most of them were sporadic. We report the first case from Eastern India in an adolescent male, who had cranio-vertebral junction anomalies and presented with spastic quadriparesis at the age of 13 years.

  6. Electrical needle therapy of uremic pruritus.

    PubMed

    Duo, L J

    1987-01-01

    Six patients with intractable uremic pruritus were treated with a modified acupuncture technique, the electrical needle stimulation (ENS). Results were followed with a pruritic score scale based on severity, frequency and distribution of itching, together with sleeping hours and waking up at night. The results were encouraging: pruritus was drastically improved during or after ENS in several patients. A control treatment with superficial electrical stimulation was ineffective.

  7. Yield of new versus reused endobronchial ultrasound-guided transbronchial needle aspiration needles: A retrospective analysis of 500 patients

    PubMed Central

    Dhooria, Sahajal; Sehgal, Inderpaul Singh; Gupta, Nalini; Ram, Babu; Aggarwal, Ashutosh Nath; Behera, Digambar; Agarwal, Ritesh

    2016-01-01

    Background: Endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) requires a dedicated needle for aspiration of mediastinal lesions. There is no data on reuse of these needles. Methods: This is a retrospective study of patients who underwent EBUS-TBNA with either new or reused EBUS-TBNA needles. The needles were reused after thorough cleaning with filtered water and organic cleaning solution, disinfection with 2.4% glutaraldehyde solution followed by ethylene oxide sterilization. The yield of EBUS-TBNA was compared between the two groups. Results: A total of 500 EBUS-TBNA procedures (351 new, 149 reused needles) were performed. The baseline characteristics were different in the two groups with suspected granulomatous disorders (sarcoidosis or tuberculosis) being significantly more common in the new compared to the reused needle group. Similarly, the median, interquartile range number of lymph node stations sampled, and the total number of passes were significantly higher in the new versus the reused needle group. The diagnostic yield was significantly higher with new needle as compared to reused needle (65.2% vs. 53.7%, P = 0.02). On multivariate logistic regression analysis, clinical suspicion of granulomatous disorders (odds ratio 1.86 [95% confidence interval, 1.20-2.87], P = 0.005) was the only predictor of diagnostic yield, after adjusting for the type of needle (new or reused), total number of passes and the number of lymph node stations sampled. No case of mediastinitis was encountered in either group. Conclusions: The yield of EBUS-TBNA might be similar with single reuse of needles as compared to new needles. However, reuse of needle should be performed only when absolutely necessary. PMID:27578927

  8. Randomized Trial of Conventional Transseptal Needle Versus Radiofrequency Energy Needle Puncture for Left Atrial Access (the TRAVERSE‐LA Study)

    PubMed Central

    Hsu, Jonathan C.; Badhwar, Nitish; Gerstenfeld, Edward P.; Lee, Randall J.; Mandyam, Mala C.; Dewland, Thomas A.; Imburgia, Kourtney E.; Hoffmayer, Kurt S.; Vedantham, Vasanth; Lee, Byron K.; Tseng, Zian H.; Scheinman, Melvin M.; Olgin, Jeffrey E.; Marcus, Gregory M.

    2013-01-01

    Background Transseptal puncture is a critical step in achieving left atrial (LA) access for a variety of cardiac procedures. Although the mechanical Brockenbrough needle has historically been used for this procedure, a needle employing radiofrequency (RF) energy has more recently been approved for clinical use. We sought to investigate the comparative effectiveness of an RF versus conventional needle for transseptal LA access. Methods and Results In this prospective, single‐blinded, controlled trial, 72 patients were randomized in a 1:1 fashion to an RF versus conventional (BRK‐1) transseptal needle. In an intention‐to‐treat analysis, the primary outcome was time required for transseptal LA access. Secondary outcomes included failure of the assigned needle, visible plastic dilator shavings from needle introduction, and any procedural complication. The median transseptal puncture time was 68% shorter using the RF needle compared with the conventional needle (2.3 minutes [interquartile range {IQR}, 1.7 to 3.8 minutes] versus 7.3 minutes [IQR, 2.7 to 14.1 minutes], P=0.005). Failure to achieve transseptal LA access with the assigned needle was less common using the RF versus conventional needle (0/36 [0%] versus 10/36 [27.8%], P<0.001). Plastic shavings were grossly visible after needle advancement through the dilator and sheath in 0 (0%) RF needle cases and 12 (33.3%) conventional needle cases (P<0.001). There were no differences in procedural complications (1/36 [2.8%] versus 1/36 [2.8%]). Conclusions Use of an RF needle resulted in shorter time to transseptal LA access, less failure in achieving transseptal LA access, and fewer visible plastic shavings. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01209260. PMID:24045120

  9. Development of the force-feedback model for an epidural needle insertion simulator.

    PubMed

    Hiemenz, L; Stredney, D; Schmalbrock, P

    1998-01-01

    The Ohio Supercomputer Center and the Department of Anesthesiology at the OSU Medical Center have developed a computer-based simulation system for use in training anesthesiology residents in the technique of placing a needle for an epidural block. Although the simulator has been well regarded, the fidelity of the haptic feedback is limited because it is based on subjective expert-user evaluation and not on objective model-based or data-based empirical methods. Only a single degree of freedom for force-feedback is required. However, the simulation must be able to accurately portray the force required to puncture each layer of tissue in order to feel realistic. The purpose of the research described in this paper was to devise a methodology for creating empirically based realistic force-feedback models for the epidural needle insertion procedure using MRI data and biomechanical data from materials testing.

  10. [Design and application of silver needle-knife].

    PubMed

    Sun, Guodong; Shi, Bin; Zhang, Benwu; Xu, Haidong

    2015-04-01

    A silver needle-knife which has the dual function of silver needle and needle-knife is designed. The main components of this silver needle-knife are approximately 50% silver and approximately 50% nichrome. The silver needle-knife is composed of five parts, including needle-knife tail, spiral handle; steering handle, needle-knife body and needle-knife edge. It converges the advantages of needle-knife and silver needle, which can cut loose of diseased tissue and peel adhesion of lesions, but also be heated with moxa cone and thermal therapeutic instrument, and connect with electroacupuncture apparatus. It has the function of warming channel and removing coldness, dispelling wind and eliminating dampness, resolving spasm and relieving pain, dredging the channel and so on. Due to the spiral handle and the steering handle, the operation is easier, which reduces the blindness of cutting and increase the safety. It is mainly used for soft tissue injury, rheumatism and rheumatoid arthritis, as well as degenerative diseases of spine and joint, and it has obvious efficacy on some internal medical diseases.

  11. Electrotactile display using microfabricated micro-needle array

    NASA Astrophysics Data System (ADS)

    Kitamura, N.; Chim, J.; Miki, N.

    2015-02-01

    This paper describes an electrotactile display with micro-needle electrodes. The electrotactile display can produce tactile sensations by stimulating tactile receptors using an electric current. Micro-needle electrodes can drastically decrease the threshold voltage required to stimulate tactile receptors by penetrating the stratum corneum, which has a higher impedance than the dermis. In addition, the optimized length of the needle allows us to stimulate tactile receptors painlessly. In the present study, we developed a process for fabricating a micro-needle array in which the length and tip radius can be controlled using electrochemical etching. A micro-needle array was successfully fabricated to form an electrotactile display. In addition, we experimentally determined the suitable shape of the micro-needle electrodes for electrotactile display applications. When the tip radius of the needle is too small, the impedance between the finger and micro-needles becomes large due to the small contact area. On the other hand, when the tip radius is too large, the needle cannot penetrate the skin surface and the impedance is not sufficiently small. The experiments verified the superiority of needle electrode devices to flat electrode devices with respect to the threshold voltage at each frequency.

  12. Cytological diagnosis of metastatic malignant melanoma by fine-needle aspiration biopsy.

    PubMed

    Lindsey, Kathryn G; Ingram, Courtney; Bergeron, Joseph; Yang, Jack

    2016-07-01

    Despite increased surveillance and public awareness, the incidence of melanoma is increasing. Frequently, fine-needle aspiration is employed for the diagnosis of metastatic disease, and aspirated material is used for cytogenetic and molecular studies to guide treatment options. The pairing of a significant diagnosis with the numerous morphologic variants of melanoma can make the cytologic evaluation disquieting. We present selected examples of our experiences and a brief review of the literature to provide cytodiagnostic clues for this malignancy. The clinical history is foremost, although the fine-needle aspiration (FNA) of metastatic melanoma can provide a diagnosis before identification of the primary lesion in up to 20% of cases. If a history of melanoma is assured, negative results in sampling of pulmonary and subcutaneous nodules should be suspected as false negatives. The smearing pattern usually features poorly cohesive cells. Frankly malignant, spindled, and epithelioid cell shapes are most common, and cytoplasmic vacuoles, if sought on Romanowsky-stained specimens, can usually be found. The telltale feature of melanin production, although diagnostic, is only present in 50% of cases. Finally, eccentric placement of nuclei, nucleoli, and nuclear pseudoinclusions are accessory features for the cytologic interpretation of melanoma. Numerous morphologic patterns of melanoma are potentially seen, but a stepwise approach to diagnosis usually produces a successful result.

  13. Needle electrode-based electromechanical reshaping of rabbit septal cartilage: a systematic evaluation.

    PubMed

    Wu, Edward C; Protsenko, Dmitriy E; Khan, Adam Z; Dubin, Sterling; Karimi, Koohyar; Wong, Brian J F

    2011-08-01

    Electromechanical reshaping (EMR) provides a means of producing shape change in cartilage by initiating oxidation-reduction reactions in mechanically deformed specimens. This study evaluates the effect of voltage and application time on specimen shape change using needle electrodes. Rabbit septal cartilage specimens (20 x 8 x 1 mm, n = 200) were bent 90 degrees in a precision-machined plastic jig. Optimal electrode placement and the range of applied voltages were estimated using numerical modeling of the initial electric field within the cartilage sample. A geometric configuration of three platinum needle electrodes 2 mm apart from each other and inserted 6 mm from the bend axis on opposite ends was selected. One row of electrodes served as the anode and the other as the cathode. Constant voltage was applied at 1, 2, 4, 6, and 8 V for 1, 2, and 4 minutes, followed by rehydration in phosphate buffered saline. Samples were then removed from the jig and bend angle was measured. In accordance with previous studies, bend angle increased with increasing voltage and application time. Below a voltage threshold of 4 V, 4 minutes, no clinically significant reshaping was observed. The maximum bend angle obtained was 35.7 ± 1.7 º at 8 V, 4 minutes.

  14. Hybrid reflection type metasurface of nano-antennas designed for optical needle field generation

    NASA Astrophysics Data System (ADS)

    Wang, Shiyi; Zhan, Qiwen

    2015-03-01

    We propose a reflection type metal-insulator-metal (MIM) metasurface composed of hybrid optical antennas for comprehensive spatial engineering the properties of optical fields. Its capability is illustrated with an example to create a radially polarized vectorial beam for optical needle field generation. Functioning as local quarter-wave-plates (QWP), the MIM metasurface is designed to convert circularly polarized incident into local linear polarization to create an overall radial polarization with corresponding binary phases and desired normalized amplitude modulation ranged from 0.07 to 1. To obtain enough degrees of freedom, the optical-antenna layer comprises periodic arrangements of double metallic nano-bars with perpendicular placement and single nano-bars respectively for different amplitude modulation requirements. Both of the antennas enable to introduce π/2 retardation while reaching the desired modulation range both for phase and amplitude. Through adjusting the antennas' geometry and array carefully, we shift the gap-surface plasmon resonances facilitated by optical antennas to realize the manipulation of vectorial properties. Designed at 1064 nm wavelength, the particularly generated vectorial light output can be further tightly focused by a high numerical aperture objective to obtain longitudinally polarized flat-top focal field. The so-called optical needle field is a promising candidate for novel applications that transcend disciplinary boundaries. The proposed metasurface establishes a new class of compact optical components based on nano-scale structures, leading to compound functions for vectorial light generation.

  15. Needle-Electrode-Based Electromechanical Reshaping of Rabbit Septal Cartilage: A Systematic Evaluation

    PubMed Central

    Wu, Edward C.; Protsenko, Dmitriy E.; Khan, Adam Z.; Dubin, Sterling; Karimi, Koohyar

    2014-01-01

    Electromechanical reshaping (EMR) provides a means of producing shape change in the cartilage by initiating oxidation–reduction reactions in mechanically deformed specimens. This paper evaluates the effect of voltage and application time on specimen shape change using needle electrodes. Rabbit septal cartilage specimens (20 mm × 8 mm × 1 mm, n = 200) were bent 90° in a precision-machined plastic jig. Optimal electrode placement and the range of applied voltages were estimated using numerical modeling of the initial electric field within the cartilage sample. A geometric configuration of three platinum needle electrodes 2 mm apart from each other and inserted 6 mm from the bend axis on opposite ends was selected. One row of electrodes served as the anode and the other as the cathode. Constant voltage was applied at 1, 2, 4, 6, and 8 V for 1, 2, and 4 min, followed by rehydration in phosphate buffered saline. Samples were then removed from the jig and bend angle was measured. In accordance with previous studies, bend angle increased with increasing voltage and application time. Below a voltage threshold of 4 V, 4 min, no clinically significant reshaping was observed. The maximum bend angle obtained was 35.7 ± 1.7° at 8 V, 4 min. PMID:21606017

  16. Turbulent flow evaluation of the venous needle during hemodialysis.

    PubMed

    Unnikrishnan, Sunil; Huynh, Thanh N; Brott, B C; Ito, Y; Cheng, C H; Shih, A M; Allon, M; Anayiotos, Andreas S

    2005-12-01

    Arteriovenous (AV) grafts and fistulas used for hemodialysis frequently develop intimal hyperplasia (IH) at the venous anastomosis of the graft, leading to flow-limiting stenosis, and ultimately to graft failure due to thrombosis. Although the high AV access blood flow has been implicated in the pathogenesis of graft stenosis, the potential role of needle turbulence during hemodialysis is relatively unexplored. High turbulent stresses from the needle jet that reach the venous anastomosis may contribute to endothelial denudation and vessel wall injury. This may trigger the molecular and cellular cascade involving platelet activation and IH, leading to eventual graft failure. In an in-vitro graft/needle model dye injection flow visualization was used for qualitative study of flow patterns, whereas laser Doppler velocimetry was used to compare the levels of turbulence at the venous anastomosis in the presence and absence of a venous needle jet. Considerably higher turbulence was observed downstream of the venous needle, in comparison to graft flow alone without the needle. While turbulent RMS remained around 0.1 m/s for the graft flow alone, turbulent RMS fluctuations downstream of the needle soared to 0.4-0.7 m/s at 2 cm from the tip of the needle and maintained values higher than 0.1 m/s up to 7-8 cm downstream. Turbulent intensities were 5-6 times greater in the presence of the needle, in comparison with graft flow alone. Since hemodialysis patients are exposed to needle turbulence for four hours three times a week, the role of post-venous needle turbulence may be important in the pathogenesis of AV graft complications. A better understanding of the role of needle turbulence in the mechanisms of AV graft failure may lead to improved design of AV grafts and venous needles associated with reduced turbulence, and to pharmacological interventions that attenuate IH and graft failure resulting from turbulence.

  17. Modified algesimeter provides accurate depth measurements

    NASA Technical Reports Server (NTRS)

    Turner, D. P.

    1966-01-01

    Algesimeter which incorporates a standard sensory needle with a sensitive micrometer, measures needle point depth penetration in pain tolerance research. This algesimeter provides an inexpensive, precise instrument with assured validity of recordings in those biomedical areas with a requirement for repeated pain detection or ascertaining pain sensitivity.

  18. Organization, Operation, and Evaluation of Community College Placement Programs. Proceedings: Career Placement Workshop.

    ERIC Educational Resources Information Center

    Larsen, Howard B., Ed.; Karr, Susan, Ed.

    This publication seeks to examine the problems and practical concerns related to the organization and operation of an effective community college placement program. Using presentations given in workshops, basic information in four critical areas of placement activities in the community college is provided. First, a presentation by B. Keith Duffin…

  19. The Placement Process at Colorado Mountain College: Placement Testing and the Advising Matrix.

    ERIC Educational Resources Information Center

    Hadden, Craig

    At Colorado Mountain College (CMC), academic advising is based upon a comparison of students' basic skills with the skill requirements of individual courses. Students who enter CMC to obtain a degree must take placement tests in writing, reading, math, and study skills before they can enroll in classes. The placement test battery includes a…

  20. College Mathematics Placement Tests: Student Perceptions of Preparation and Appropriateness of Placement

    ERIC Educational Resources Information Center

    Magee, Pamela Ann

    2010-01-01

    An increasing number of recent high school graduates' college math placement test results indicate that they are not ready for college level math. This study examined the perceptions of recent high school graduates enrolled in developmental math classes to determine their level of satisfaction with their math placement, the relationship of…

  1. Registration of a needle-positioning robot to high-resolution 3D ultrasound and computed tomography for image-guided interventions in small animals

    NASA Astrophysics Data System (ADS)

    Waspe, Adam C.; Lacefield, James C.; Holdsworth, David W.; Fenster, Aaron

    2008-03-01

    Preclinical research often requires the delivery of biological substances to specific locations in small animals. Guiding a needle to targets in small animals with an error < 200 μm requires accurate registration. We are developing techniques to register a needle-positioning robot to high-resolution three-dimensional ultrasound and computed tomography small animal imaging systems. Both techniques involve moving the needle to predetermined robot coordinates and determining corresponding needle locations in image coordinates. Registration accuracy will therefore be affected by the robot positioning error and is assessed by measuring the target registration error (TRE). A point-based registration between robot and micro-ultrasound coordinates was accomplished by attaching a fiducial phantom onto the needle. A TRE of 145 μm was achieved when moving the needle to a set of robot coordinates and registering the coordinates to needle tip locations determined from ultrasound fiducial measurements. Registration between robot and micro-CT coordinates was accomplished by injecting barium sulfate into tracks created when the robot withdraws the needle from a phantom. Points along cross-sectional slices of the segmented needle tracks were determined using an intensity-weighted centroiding algorithm. A minimum distance TRE of 194 +/- 18 μm was achieved by registering centroid points to robot trajectories using the iterative closest point (ICP) algorithm. Simulations, incorporating both robot and ultrasound fiducial localization errors, verify that robot error is a significant component of the experimental registration. Simulations of micro-CT to robot ICP registration similarly agree with the experimental results. Both registration techniques produce a TRE < 200 μm, meeting design specification.

  2. Primary TEP placement in patients with laryngopharyngeal free tissue reconstruction and salivary bypass tube placement.

    PubMed

    Divi, Vasu; Lin, Derrick T; Emerick, Kevin; Rocco, James; Deschler, Daniel G

    2011-03-01

    The authors examined the feasibility and advantages of primary tracheoesophageal puncture (TEP) with intraoperative placement of the voice prosthesis for patients undergoing laryngopharyngectomy requiring free tissue reconstruction and salivary bypass tube placement. Six patients were identified; 4 underwent total laryngopharyngectomy, and 2 underwent total laryngectomy with partial pharyngectomy. All 6 required free tissue reconstruction, and a salivary bypass tube was placed in all cases. All patients had a 20F Indwelling Blom-Singer prosthesis (InHealth Technologies, Carpinteria, California) placed. No complications were noted with intraoperative prosthesis placement. No prostheses were dislodged in the postoperative period. At 6 months, 4 patients available for evaluation had successful voice outcomes, and 3 were disease free. This study demonstrates the effectiveness of voice prosthesis placement at the time of primary TEP associated with free tissue reconstruction of a laryngopharyngeal defect with salivary bypass tube placement.

  3. Ultrasound criteria and guided fine-needle aspiration diagnostic yields in small animal peritoneal, mesenteric and omental disease.

    PubMed

    Feeney, Daniel A; Ober, Christopher P; Snyder, Laura A; Hill, Sara A; Jessen, Carl R

    2013-01-01

    Peritoneal, mesenteric, and omental diseases are important causes of morbidity and mortality in humans and animals, although information in the veterinary literature is limited. The purposes of this retrospective study were to determine whether objectively applied ultrasound interpretive criteria are statistically useful in differentiating among cytologically defined normal, inflammatory, and neoplastic peritoneal conditions in dogs and cats. A second goal was to determine the cytologically interpretable yield on ultrasound-guided, fine-needle sampling of peritoneal, mesenteric, or omental structures. Sonographic criteria agreed upon by the authors were retrospectively and independently applied by two radiologists to the available ultrasound images without knowledge of the cytologic diagnosis and statistically compared to the ultrasound-guided, fine-needle aspiration cytologic interpretations. A total of 72 dogs and 49 cats with abdominal peritoneal, mesenteric, or omental (peritoneal) surface or effusive disease and 17 dogs and 3 cats with no cytologic evidence of inflammation or neoplasia were included. The optimized, ultrasound criteria-based statistical model created independently for each radiologist yielded an equation-based diagnostic category placement accuracy of 63.2-69.9% across the two involved radiologists. Regional organ-associated masses or nodules as well as aggregated bowel and peritoneal thickening were more associated with peritoneal neoplasia whereas localized, severely complex fluid collections were more associated with inflammatory peritoneal disease. The cytologically interpretable yield for ultrasound-guided fine-needle sampling was 72.3% with no difference between species, making this a worthwhile clinical procedure.

  4. Optimal Placement of Accelerometers for the Detection of Everyday Activities

    PubMed Central

    Cleland, Ian; Kikhia, Basel; Nugent, Chris; Boytsov, Andrey; Hallberg, Josef; Synnes, Kåre; McClean, Sally; Finlay, Dewar

    2013-01-01

    This article describes an investigation to determine the optimal placement of accelerometers for the purpose of detecting a range of everyday activities. The paper investigates the effect of combining data from accelerometers placed at various bodily locations on the accuracy of activity detection. Eight healthy males participated within the study. Data were collected from six wireless tri-axial accelerometers placed at the chest, wrist, lower back, hip, thigh and foot. Activities included walking, running on a motorized treadmill, sitting, lying, standing and walking up and down stairs. The Support Vector Machine provided the most accurate detection of activities of all the machine learning algorithms investigated. Although data from all locations provided similar levels of accuracy, the hip was the best single location to record data for activity detection using a Support Vector Machine, providing small but significantly better accuracy than the other investigated locations. Increasing the number of sensing locations from one to two or more statistically increased the accuracy of classification. There was no significant difference in accuracy when using two or more sensors. It was noted, however, that the difference in activity detection using single or multiple accelerometers may be more pronounced when trying to detect finer grain activities. Future work shall therefore investigate the effects of accelerometer placement on a larger range of these activities. PMID:23867744

  5. Drug injectors and the cleaning of needles and syringes.

    PubMed

    Hughes, R A

    2000-03-01

    When people share needles and syringes they risk transmitting human immunodeficiency virus (HIV) and other infections including hepatitis B virus (HBV) and hepatitis C virus (HCV). Cleaning needles and syringes can help to reduce, although not eliminate, these risks. This article begins by engaging with some of the literature on the cleaning of needles and syringes. Drawing on qualitative research conducted with drug injectors in England, the article then goes on to explore drug injectors' perceptions and experiences of cleaning needles and syringes inside and outside prison. The article concludes by highlighting the implications for future research and policy making. Ultimately there should be a stronger policy response to reduce the risks associated with sharing needles and syringes inside prison, which should include the piloting of prison needle and syringe exchange schemes.

  6. MR-compatible biopsy needle with enhanced tip force sensing

    PubMed Central

    Elayaperumal, Santhi; Bae, Jung Hwa; Christensen, David; Cutkosky, Mark R.; Daniel, Bruce L.; Costa, Joannes M.; Black, Richard J.; Faridian, Fereydoun; Moslehi, Behzad

    2015-01-01

    We describe an instrumented biopsy needle that provides physicians the capability to sense interaction forces directly at the tip of the needle’s inner stylet. The sensors consist of optical fiber Bragg gratings (FBGs), and are unaffected by electromagnetic fields; hence the needle is suitable for MR-guided procedures. In comparison to previous instrumented needles that measure bending strains, the new design has additional sensors and a series of micro-machined holes at the tip. The holes increase strain sensitivity, especially to axial forces, without significantly reducing the stiffness or strength. A comparison of the dynamic forces measured with the new needle and those obtained using a force/torque sensor at the needle base shows that the enhanced tip sensitivity is particularly noticeable when there is significant friction along the needle sleeve. PMID:26509189

  7. Evaluating the advances and use of hypodermic needles in dentistry.

    PubMed

    Boynes, Sean G

    2014-10-01

    Different injection techniques and patient management methodologies have been proposed to decrease the fear patients may have concerning dental needles. Dental providers should have an understanding of the technological advances, changes in techniques, and patient perceptions associated with the hypodermic needle. This article provides an overview of the pain perception process associated with dental injections. It reviews the two main sensory nerve fibers associated with injection pain and discusses needle properties as well as complications and adverse occurrences.

  8. [Pneumothorax following dry needling treatment: legal and ethical aspects].

    PubMed

    Ronconi, Gianpaolo; De Giorgio, Fabio; Ricci, Eleonora; Maggi, Loredana; Spagnolo, Antonio G; Ferrara, Paola Emilia

    2016-01-01

    Trigger point "dry needling" is a technique used to treat myofascial pain. It involves using filiform needles which are inserted into muscles to give local pain relief. Few cases of serious adverse events following this treatment have been reported in the literature. In this paper we describe the case of a professional swimmer who developed pneumothorax after dry needling treatment and discuss the medicolegal and ethical aspects related to competencies and responsibilities of medical doctors and physiotherapists performing the procedure.

  9. Chest Wall Dissemination of Nocardiosis after Percutaneous Transthoracic Needle Biopsy

    SciTech Connect

    Shimamoto, Hiroshi Inaba, Yoshitaka; Yamaura, Hidekazu; Sato, Yozo; Kamiya, Mika; Miyazaki, Masaya; Arai, Yasuaki; Horio, Yoshitsugu

    2007-07-15

    We described a case of chest wall dissemination after percutaneous transthoracic needle biopsy. A 65-year-old man had a lung nodule which was suspected to be lung carcinoma. He underwent percutaneous transthoracic needle biopsy using an 18G semiautomated biopsy needle and pathologic diagnosis showed organizing pneumonia. Two months after the biopsy, chest wall dissemination occurred. Implantation of carcinoma along the biopsy route was suspected, but the mass was actually due to pulmonary nocardiosis.

  10. The biopolitics of needle exchange in the United States

    PubMed Central

    McLean, Katherine

    2012-01-01

    Needle exchange began in the United States as a fragmented and illegal practice initiated by actors at the grassroots level; since the late 1980s, needle exchange has achieved increasing yet variable levels of institutional support across the country, receiving official sanction and funding from state and municipal governments. In turn, the practice(s) and discourse(s) of needle exchange have shifted significantly in many locales, becoming the purview of professional administration that advocates needle exchange as a necessary public health measure. This article is interested in the ways in which needle exchange has become implicated in and appropriated by networks of power seeking to discipline and regulate injection drug use. Drawing theoretically on Michel Foucault’s writings concerning biopower and governmentality, it will examine the proliferation of discourses, knowledges, and rules surrounding needle exchange in the United States. At the same time, this article will avoid a characterization of needle exchange that envisions the unilateral control of drug users by governmental power, illuminating instead both its negative and productive effects for drug users. Namely, it will explore how needle exchange creates both subjects of interest and subjects of resistance among drug users – that is to say, the governmentalization of needle exchange and its ‘clients’. PMID:22389572

  11. Lab in a needle for epidural space identification

    NASA Astrophysics Data System (ADS)

    Carotenuto, B.; Micco, A.; Ricciardi, A.; Amorizzo, E.; Mercieri, M.; Cutolo, A.; Cusano, A.

    2016-05-01

    This work relies on the development of a sensorized medical needle with an all-optical guidance (Lab in a Needle) system for epidural space identification. The device is based on the judicious integration of a Fiber Bragg grating sensor inside the lumen of an epidural needle to discriminate between different types of tissue and thus providing continuous and real time measurements of the pressure experienced by the needle tip during its advancement. Experiments carried out on an epidural training phantom demonstrate the validity of our approach for the correct and effective identification of the epidural space.

  12. Functional clinical placements: a driver for change.

    PubMed

    Goddard, L; Mackey, S; Davidson, P M

    2010-07-01

    The aim of the project was to create a supervised professional experience placement model involving undergraduate nursing students, families of children with intellectual disabilities and nursing lecturers. Action research provided the methodological framework for developing a new placement model. Five families with children with disabilities, nine nursing students and two nurse academics worked together through the cycles of the action research process to develop a family health promotion intervention to improve the health and wellness of the family members and reduce risk for illness. Awareness, valuing and understanding were key themes derived from the qualitative data. Findings of this project indicate that this model of university-initiated, community-focused professional experience placement is effective in achieving the competency-based learning outcomes required of undergraduate nursing students and is worthy of ongoing exploration.

  13. Macro cell placement with neural net algorithms

    NASA Astrophysics Data System (ADS)

    Storti-Gajani, Giancarlo

    Placement of VLSI (Very Large Scale Integration) macro cells is one of the hard problems encountered in the process of integrated circuits design. Since the problem is essentially NP-complete a solution must be searched for with the aid of heuristics using, maybe, non deterministic strategies. A new algorithm for cell preplacement based on neural nets that may be very well extended to find solution of the final placement problem is presented. Simulations for the part of the algorithm concerning preplacement are carried out on several different examples giving always a sharply decreasing cost function (where cost is evaluated essentially on total length of wires given a rectangular boundary). The direct mapping between neural units and VLSI blocks that is adopted in the algorithm makes the extension to the final placement problem quite simple. Simulation programs are implemented in a interpreted mathematical simulation language and a C language implementation is currently under way.

  14. Tools and Techniques for Placement Experiments

    NASA Astrophysics Data System (ADS)

    van der Vegt, Wim; Kalz, Marco; Giesbers, Bas; Wild, Fridolin; van Bruggen, Jan

    In Chap. 11 we presented placement in the context of Accreditation of Prior Learning and showed that in the scenario we address we do not assume the availability of controlled vocabulary with which the contents of the learner portfolio or the learning material in the learning network is described. Our placement service is based on the assumption that similarity between material produced or studied by the learner on the one hand and the learning material of the learning network on the other, can be used as a proxy to similarity in learning outcomes. The first task of any such placement service is therefore to establish whether these similarities are present for a given learner. The technology with which this is done, latent semantic analysis, is presented here. The emphasis here is on the technical and computational aspects of data preparation and analysis.

  15. Feedback and assessment for clinical placements: achieving the right balance

    PubMed Central

    Burgess, Annette; Mellis, Craig

    2015-01-01

    During clinical placements, the provision of feedback forms an integral part of the learning process and enriches students’ learning experiences. The purpose of feedback is to improve the learner’s knowledge, skills, or behavior. Receipt of accurate feedback can help to narrow the gap between actual and desired performance. Effective and regular feedback has the potential to reinforce good practice and motivate the learner toward the desired outcome. Despite the obvious role of feedback in effective teaching and learning, a common complaint from students is that they do not receive adequate feedback. Unfortunately, skills in giving and receiving feedback are rarely taught to students or clinicians. This study aims to provide an understanding of the role of feedback within the learning process, consider consequences of inadequate or poorly given feedback, consider the barriers to the feedback process, provide practical guidelines for providing feedback, and consider the need for student and faculty development in feedback skills. PMID:26056511

  16. EM-navigated catheter placement for gynecologic brachytherapy: an accuracy study

    NASA Astrophysics Data System (ADS)

    Mehrtash, Alireza; Damato, Antonio; Pernelle, Guillaume; Barber, Lauren; Farhat, Nabgha; Viswanathan, Akila; Cormack, Robert; Kapur, Tina

    2014-03-01

    Gynecologic malignancies, including cervical, endometrial, ovarian, vaginal and vulvar cancers, cause significant mortality in women worldwide. The standard care for many primary and recurrent gynecologic cancers consists of chemoradiation followed by brachytherapy. In high dose rate (HDR) brachytherapy, intracavitary applicators and /or interstitial needles are placed directly inside the cancerous tissue so as to provide catheters to deliver high doses of radiation. Although technology for the navigation of catheters and needles is well developed for procedures such as prostate biopsy, brain biopsy, and cardiac ablation, it is notably lacking for gynecologic HDR brachytherapy. Using a benchtop study that closely mimics the clinical interstitial gynecologic brachytherapy procedure, we developed a method for evaluating the accuracy of image-guided catheter placement. Future bedside translation of this technology offers the potential benefit of maximizing tumor coverage during catheter placement while avoiding damage to the adjacent organs, for example bladder, rectum and bowel. In the study, two independent experiments were performed on a phantom model to evaluate the targeting accuracy of an electromagnetic (EM) tracking system. The procedure was carried out using a laptop computer (2.1GHz Intel Core i7 computer, 8GB RAM, Windows 7 64-bit), an EM Aurora tracking system with a 1.3mm diameter 6 DOF sensor, and 6F (2 mm) brachytherapy catheters inserted through a Syed-Neblett applicator. The 3D Slicer and PLUS open source software were used to develop the system. The mean of the targeting error was less than 2.9mm, which is comparable to the targeting errors in commercial clinical navigation systems.

  17. EM-Navigated Catheter Placement for Gynecologic Brachytherapy: An Accuracy Study.

    PubMed

    Mehrtash, Alireza; Damato, Antonio; Pernelle, Guillaume; Barber, Lauren; Farhat, Nabgha; Viswanathan, Akila; Cormack, Robert; Kapur, Tina

    2014-03-12

    Gynecologic malignancies, including cervical, endometrial, ovarian, vaginal and vulvar cancers, cause significant mortality in women worldwide. The standard care for many primary and recurrent gynecologic cancers consists of chemoradiation followed by brachytherapy. In high dose rate (HDR) brachytherapy, intracavitary applicators and/or interstitial needles are placed directly inside the cancerous tissue so as to provide catheters to deliver high doses of radiation. Although technology for the navigation of catheters and needles is well developed for procedures such as prostate biopsy, brain biopsy, and cardiac ablation, it is notably lacking for gynecologic HDR brachytherapy. Using a benchtop study that closely mimics the clinical interstitial gynecologic brachytherapy procedure, we developed a method for evaluating the accuracy of image-guided catheter placement. Future bedside translation of this technology offers the potential benefit of maximizing tumor coverage during catheter placement while avoiding damage to the adjacent organs, for example bladder, rectum and bowel. In the study, two independent experiments were performed on a phantom model to evaluate the targeting accuracy of an electromagnetic (EM) tracking system. The procedure was carried out using a laptop computer (2.1GHz Intel Core i7 computer, 8GB RAM, Windows 7 64-bit), an EM Aurora tracking system with a 1.3mm diameter 6 DOF sensor, and 6F (2 mm) brachytherapy catheters inserted through a Syed-Neblett applicator. The 3D Slicer and PLUS open source software were used to develop the system. The mean of the targeting error was less than 2.9mm, which is comparable to the targeting errors in commercial clinical navigation systems.

  18. Endoscopic Gold Fiducial Marker Placement into the Bladder Wall to Optimize Radiotherapy Targeting for Bladder-Preserving Management of Muscle-Invasive Bladder Cancer: Feasibility and Initial Outcomes

    PubMed Central

    Garcia, Maurice M.; Gottschalk, Alexander R.; Brajtbord, Jonathan; Konety, Badrinath R.; Meng, Maxwell V.; Roach, Mack; Carroll, Peter R.

    2014-01-01

    Background and Purpose Bladder radiotherapy is a management option for carefully selected patients with muscle-invasive bladder cancer. However, the inability to visualize the tumor site during treatment and normal bladder movement limits targeting accuracy and increases collateral radiation. A means to accurately and reliably target the bladder during radiotherapy is needed. Materials and Methods Eighteen consecutive patients with muscle-invasive bladder cancer (T1–T4) elected bladder-preserving treatment with maximal transurethral resection (TUR), radiation and concurrent chemotherapy. All underwent endoscopic placement of 24-K gold fiducial markers modified with micro-tines (70 [2.9×0.9 mm.]; 19 [2.1×0.7 mm.) into healthy submucosa 5-10 mm. from the resection margin, using custom-made coaxial needles. Marker migration was assessed for with intra-op bladder-filling cystogram and measurement of distance between markers. Set-up error and marker retention through completion of radiotherapy was confirmed by on-table portal imaging. Results Between 1/2007 and 7/2012, a total of 89 markers (3–5 per tumor site) were placed into 18 patients of mean age 73.6 years. Two patients elected cystectomy before starting treatment; 16/18 completed chemo-radiotherapy. All (100%) markers were visible with all on-table (portal, cone-beam CT), fluoroscopy, plain-film, and CT-scan imaging. In two patients, 1 of 4 markers placed at the tumor site fell-out (voided) during the second half of radiotherapy. All other markers (80/82, 98%) were present through the end of radio-therapy. No intraoperative (e.g. uncontrolled bleeding, collateral injury) or post-operative complications (e.g. stone formation, urinary tract infection, post-TUR hematuria >48 hours) occurred. Use of micro-tined fiducial tumor-site markers afforded a 2 to 6-fold reduction in bladder-area targeted with high-dose radiation. Discussion Placement of the micro-tined fiducial markers into the bladder was feasible and

  19. Thinking ethically about needle and syringe programs.

    PubMed

    Kleinig, John

    2006-01-01

    Accepting-for the sake of argument-our current legal policies concerning heroin use and its users, what ethical questions are raised for needle and syringe program (NSPs)? Do they weaken drug laws, send the wrong message or obscure the right message, do little to eliminate the harm of drugs, detract from alternatives, and/or constitute a counsel of despair? I suggest that in the absence of established better alternatives, NSPs constitute a morally acceptable and in some cases even desirable option despite the continued criminalization of injecting drug use. Yet they must be conceived and administered in ways that do not reinforce prevailing social prejudices.

  20. Fully customized placement of orthodontic miniplates: a novel clinical technique

    PubMed Central

    2014-01-01

    Introduction The initial stability and survival rate of orthodontic mini-implants are highly dependent on the amount of cortical bone at their insertion site. In areas with limited bone availability, mini-plates are preferred to provide effective skeletal anchorage. The purpose of this paper was to present a new clinical technique for the insertion of mini-plates. Methods In order to apply this new technique, a cone-beam image of the insertion area is required. A software (Galaxy Sirona, Bensheim, Germany) is used to construct a three-dimensional image of the scanned area and to virtually determine the exact location of the mini-plate as well as the position of the fixation screws. A stereolithographic model (STL) is then created by means of a three-dimensional scanner. Prior to its surgical insertion, the bone plate is adapted to the stereo-lithographic model. Finally, a custom transfer jig is fabricated in order to assist with accurate placement of the mini-plate intra-operatively. Results The presented technique minimizes intra-operative decision making, because the final position of the bone plate is determined pre-surgically. This significantly reduces the duration of the surgical procedure and improves its outcome. Conclusions A novel method for surgical placement of orthodontic mini-plates is presented. The technique facilitates accurate adaptation of mini-plates and insertion of retaining surgical screws; thereby enabling clinicians to more confidently increase the use of bone plates, especially in anatomical areas where the success of non-osseointegrated mini-screws is less favorable. PMID:24886597

  1. Optimization Strategies for Sensor and Actuator Placement

    NASA Technical Reports Server (NTRS)

    Padula, Sharon L.; Kincaid, Rex K.

    1999-01-01

    This paper provides a survey of actuator and sensor placement problems from a wide range of engineering disciplines and a variety of applications. Combinatorial optimization methods are recommended as a means for identifying sets of actuators and sensors that maximize performance. Several sample applications from NASA Langley Research Center, such as active structural acoustic control, are covered in detail. Laboratory and flight tests of these applications indicate that actuator and sensor placement methods are effective and important. Lessons learned in solving these optimization problems can guide future research.

  2. Trajectory surgical guide stent for implant placement.

    PubMed

    Adrian, E D; Ivanhoe, J R; Krantz, W A

    1992-05-01

    This article describes a new implant placement surgical guide that gives both implant location and trajectory to the surgeon. Radiopaque markers are placed on diagnostic dentures and a lateral cephalometric radiograph is made that shows the osseous anatomy at the symphysis and the anterior tooth location. The ideal implant location and trajectory data are transferred to a surgical stent that programs the angle and location of the fixtures at time of surgery. The stent has the additional benefit of acting as an occlusion rim, a mouth prop, and tongue retractor. Use of this stent has resulted in consistently programming the placement of implant fixtures that are prosthodontically ideal.

  3. Performance consequences of parity placement in disk arrays

    NASA Technical Reports Server (NTRS)

    Lee, Edward K.; Katz, Randy H.

    1991-01-01

    The performance of a variety of parity placement schemes are defined and investigated to demonstrate that, at relatively large request sizes of hundreds of kilobytes, the choice of parity placement significantly affects performance (20 to 30 percent for the disk array configurations that are common today). It is shown that the left-symmetric, extended-left-symmetric and flat-left-symmetric are the best RAID level 5 parity placements. The placement with the highest read performance, flat-left-symmetric, has the lowest write performance, while the placement with the lowest read performance, left-symmetric, has the highest write performance. Suggestions for optimizing parity placements are included.

  4. JUGULAR CENTRAL VENOUS CATHETER PLACEMENT THROUGH A MODIFIED SELDINGER TECHNIQUE FOR LONG-TERM VENOUS ACCESS IN CHELONIANS.

    PubMed

    Pardo, Mariana A; Divers, Stephen

    2016-03-01

    Long-term or repeated venous access in chelonians is difficult to obtain and manage, but can be critically important for administration of medications and blood sampling in hospitalized patients. Jugular catheterization provides the most rapid and secure route for vascular access, but catheters can be difficult to place, and maintaining catheter patency may be challenging. Long multilumen polyurethane catheters provide flexibility and sampling access, and minimize difficulties, such as catheter displacement, that have been encountered with traditional over-the-needle catheters. We describe placement of 4 Fr. 13-cm polyurethane catheters in three chelonians with the use of a modified Seldinger technique. Venous access was obtained with the use of an over-the-needle catheter, which allowed placement of a 0.018-in.-diameter wire, over which the polyurethane catheter was placed. Indwelling time has ranged between 1 and 4 mo currently. All tortoises were sedated for this procedure. Polyurethane central catheters provide safe, long-term venous access that allows clinicians to perform serial blood sampling as well as intravenous administration of medications, anesthetic agents, and fluids. A jugular catheter can also allow central venous pressure measurement. Utilization of central line catheters was associated with improvements in diagnostic efficiency and therapeutic case management, with minimal risks and complications.

  5. Three-dimensional needle-tip localization by electric field potential and camera hybridization for needle electromyography exam robotic simulator

    PubMed Central

    He, Siyu; Gomez-Tames, Jose; Yu, Wenwei

    2016-01-01

    As one of neurological tests, needle electromygraphy exam (NEE) plays an important role to evaluate the conditions of nerves and muscles. Neurology interns and novice medical staff need repetitive training to improve their skills in performing the exam. However, no training systems are able to reproduce multiple pathological conditions to simulate real needle electromyogram exam. For the development of a robotic simulator, three components need to be realized: physical modeling of upper limb morphological features, position-dependent electromyogram generation, and needle localization; the latter is the focus of this study. Our idea is to couple two types of sensing mechanism in order to acquire the needle-tip position with high accuracy. One is to segment the needle from camera images and calculate its insertion point on the skin surface by a top-hat transform algorithm. The other is voltage-based depth measurement, in which a conductive tissue-like phantom was used to realize both needle-tip localization and physical sense of needle insertion. For that, a pair of electrodes was designed to generate a near-linear voltage distribution along the depth direction of the tissue-like phantom. The accuracy of the needle-tip position was investigated by the electric field potential and camera hybridization. The results showed that the needle tip could be detected with an accuracy of 1.05±0.57 mm. PMID:27382339

  6. Fat-Suppressed Gadolinium-Enhanced Three-Dimensional Magnetic Resonance Angiography Adequately Depicts the Status of Iliac Arteries Following Atherectomy and Stent Placement

    SciTech Connect

    Amano, Yasuo; Gemma, Kazuhito; Kawamata, Hiroshi; Kumazaki, Tatsuo

    1998-07-15

    Fat-suppressed, three-dimensional magnetic resonance angiography (3D MRA) was performed on nine patients with 11 iliac artery stenoses following atherectomy or stent placement. The MRA accurately depicted continued patency, restenosis, or aneurysm formation when compared with immediate posttreatment conventional arteriography. Therefore MRA is accurate and can be used independently for clinical decision making.

  7. A new needle on the block: EchoTip ProCore endobronchial ultrasound needle

    PubMed Central

    Dincer, H Erhan; Andrade, Rafael; Zamora, Felix; Podgaetz, Eitan

    2016-01-01

    Endobronchial ultrasound has become the first choice standard of care procedure to diagnose benign or malignant lesions involving mediastinum and lung parenchyma adjacent to the airways owing to its characteristics of being real-time and minimally invasive. Although the incidence of lung cancer has been decreasing, it is and will be the leading cause of cancer-related mortality in the next few decades. When compared to other cancers, lung cancer kills more females than breast and colon cancers combined and more males than colon and prostate cancers combined. The type of lung cancer has changed in recent decades and adenocarcinoma has become the most frequent cell type. Prognosis of lung cancer depends upon the cell type and the staging at the time of diagnosis. The cell type and molecular characteristics of adenocarcinoma may allow individualized targeted treatment. Other malignant conditions in the mediastinum and lung (eg, metastatic lung cancers and lymphoma) can be biopsied using endobronchial ultrasound needles. Endobronchial ultrasound needle biopsies provides mostly cytology specimens due to its small sizes of needles (22 gauge or larger) which may not give enough tissue to make a definitive diagnosis in malignant (eg, lymphoma) or benign conditions (eg, sarcoidosis). EchoTip ProCore endobronchial needle released in early 2014 provides histologic biopsy material. Larger tissue biopsies may potentially provide a higher diagnostic yield and it eliminates mediastinoscopy or other surgical interventions. Here we aim to review bronchoscopic approach in the diagnosis of mediastinal lesions with emphasis of EchoTip ProCore needles. PMID:27099535

  8. Development of a nanowire based titanium needle probe sensor for glucose monitoring

    NASA Astrophysics Data System (ADS)

    Deshpande, Devesh C.

    The need for continuous monitoring of various physiological functions such as blood glucose levels, neural functions and cholesterol levels has fostered the research and development of various schemes of biosensors to sense and help control the respective function. The needs of patients for sensors with minimal discomfort, longer life and better performance have necessitated the development towards smaller and more efficient sensors. In addition, the need for higher functionality from smaller sensors has led to the development of sensors with multiple electrodes, each electrode capable of sensing a different body function. Such multi-electrode sensors need to be fabricated using micro-fabrication processes in order to achieve precise control over the size, shape and placement of the electrodes. Multielectrode sensors fabricated using silicon and polymers have been demonstrated. One physiological function that attracts widespread interest is continuous glucose monitoring in our blood, since Diabetes affects millions of people all over the world. Significant deviations of blood glucose levels from the normal levels of 4-8 mM can cause fainting, coma and damage to the eyes, kidneys, nerves and blood vessels. For chronic patients, continuous monitoring of glucose levels is essential for accurate and timely treatment. A few continuous monitoring sensors are available in the market, but they have problems and cannot replace the strip type one-time glucose monitoring systems as yet. To address this need, large scale research efforts have been targeted towards continuous monitoring. The demand for higher accuracy and sensitivity has motivated researchers to evaluate the use of nanostructures in sensing. The large surface area-to-volume ratio of such structures could enable further miniaturization and push the detection limits, potentially enabling even single molecule detection. This research involved the development of a biocompatible titanium needle probe sensor for

  9. Noncontact Viscoelastic Measurement of Polymer Thin Films in a Liquid Medium Using Long-Needle Atomic Force Microscopy.

    PubMed

    Guan, Dongshi; Barraud, Chloé; Charlaix, Elisabeth; Tong, Penger

    2017-02-14

    We report the noncontact measurement of the viscoelastic property of polymer thin films in a liquid medium using frequency-modulation atomic force microscopy with a newly developed long-needle probe. The probe contains a long vertical glass fiber with one end adhered to a cantilever beam and the other end with a sharp tip placed near the liquid-film interface. The nanoscale flow generated by the resonant oscillation of the needle tip provides a precise hydrodynamic force acting on the soft surface of the thin film. By accurately measuring the mechanical response of the thin film, we obtain the elastic and loss moduli of the thin film using the linear response theory of elastohydrodynamics. The experiment verifies the theory and demonstrates its applications. The technique can be used to accurately measure the viscoelastic property of soft surfaces, such as those made of polymers, nanobubbles, live cells, and tissues.

  10. Predicting success on the Advanced Placement Biology Examination

    NASA Astrophysics Data System (ADS)

    Shepherd, Lesa Hanlin

    Four hundred sixty students in four public high schools were used as subjects to determine which of eleven academic and demographic factors studied were significant predictors of success for the Advanced Placement Biology Examination. Factors studied were attendance, class rank, gender, grade level at the time of the examination, grade point average, level of prerequisite biology course, number of Advanced Placement Examinations taken in the year prior to the Advanced Placement Biology Examination, number of Advanced Placement Examinations taken in the same year as the Advanced Placement Biology Examination, proposed major in college, race, and SAT mathematics, verbal, and combined score. Significant relationships were found to exist between the Advanced Placement Biology Examination score and attendance, class rank, gender, grade level at the time of the Advanced Placement Biology Examination, grade point average, number of Advanced Placement Examinations taken in the year prior to the Advanced Placement Biology Examination, number of Advanced Placement Examinations taken in the same year as the Advanced Placement Biology Examination, race, and SAT scores. Significant relationships were not found to exist between Advanced Placement Biology Examination score and level prerequisite biology course and Advanced Placement Biology Examination score and proposed major in college. A multiple regression showed the best combination of predictors to be attendance, SAT verbal score, and SAT mathematics score. Discriminant analysis showed the variables in this study to be good predictors of whether the student would pass the Advanced Placement Biology Examination (score a 3, 4, or 5) or fail the Advanced Placement Biology Examination (score a 1 or 2). These results demonstrated that significant predictors for the Advanced Placement Biology Examination do exist and can be used to assist in the prediction of scores, prediction of passing or failing, the identification of

  11. Estimating thermal diffusivity and specific heat from needle probe thermal conductivity data

    USGS Publications Warehouse

    Waite, W.F.; Gilbert, L.Y.; Winters, W.J.; Mason, D.H.

    2006-01-01

    Thermal diffusivity and specific heat can be estimated from thermal conductivity measurements made using a standard needle probe and a suitably high data acquisition rate. Thermal properties are calculated from the measured temperature change in a sample subjected to heating by a needle probe. Accurate thermal conductivity measurements are obtained from a linear fit to many tens or hundreds of temperature change data points. In contrast, thermal diffusivity calculations require a nonlinear fit to the measured temperature change occurring in the first few tenths of a second of the measurement, resulting in a lower accuracy than that obtained for thermal conductivity. Specific heat is calculated from the ratio of thermal conductivity to diffusivity, and thus can have an uncertainty no better than that of the diffusivity estimate. Our thermal conductivity measurements of ice Ih and of tetrahydrofuran (THF) hydrate, made using a 1.6 mm outer diameter needle probe and a data acquisition rate of 18.2 pointss, agree with published results. Our thermal diffusivity and specific heat results reproduce published results within 25% for ice Ih and 3% for THF hydrate. ?? 2006 American Institute of Physics.

  12. Needles: Toward Large-Scale Genomic Prediction with Marker-by-Environment Interaction.

    PubMed

    De Coninck, Arne; De Baets, Bernard; Kourounis, Drosos; Verbosio, Fabio; Schenk, Olaf; Maenhout, Steven; Fostier, Jan

    2016-05-01

    Genomic prediction relies on genotypic marker information to predict the agronomic performance of future hybrid breeds based on trial records. Because the effect of markers may vary substantially under the influence of different environmental conditions, marker-by-environment interaction effects have to be taken into account. However, this may lead to a dramatic increase in the computational resources needed for analyzing large-scale trial data. A high-performance computing solution, called Needles, is presented for handling such data sets. Needles is tailored to the particular properties of the underlying algebraic framework by exploiting a sparse matrix formalism where suited and by utilizing distributed computing techniques to enable the use of a dedicated computing cluster. It is demonstrated that large-scale analyses can be performed within reasonable time frames with this framework. Moreover, by analyzing simulated trial data, it is shown that the effects of markers with a high environmental interaction can be predicted more accurately when more records per environment are available in the training data. The availability of such data and their analysis with Needles also may lead to the discovery of highly contributing QTL in specific environmental conditions. Such a framework thus opens the path for plant breeders to select crops based on these QTL, resulting in hybrid lines with optimized agronomic performance in specific environmental conditions.

  13. Efficacy of Core Needle Biopsy Technique for Jawbone Diseases.

    PubMed

    Stolbizer, Federico; Cabrini, Romulo L; Keszler, Alicia

    2015-12-01

    Core needle biopsy (CNB) has been proven useful for diagnosing bone lesions, although it is not often used for jawbone lesions. The aim of this study was to evaluate the efficacy of the CNB method in a series of cases of intramaxillary lesions. CNB was performed on 85 patients with intraosseous lesions which were grouped according to radiographic appearance as: radiopaque lesions (RO, n=13), radiolucent lesions (RL, n=39) and mixed lesions with both radiolucent and radiopaque areas (RL-RO, n=33). The technique enabled us to obtain several tissue cylinders from each lesion (average 2.5 cylinders), which were processed following routine histopathological technique and H&E stain, plus special techniques when necessary. The histopathological analysis together with clinical data enabled accurate diagnosis (AD) in 81% of the cases and descriptive diagnosis (DD) in 14%. The material obtained in 5% of the cases was not appropriate for study (ND). The difference between successful (AD) and unsuccessful (DD+ND) CNB cases is statistically significant. The highest percentage of successful CBNs was for RO and RLRO lesions (85% and 100% respectively). RL lesions were more difficult because most of them were cystic lesions with fluid content.

  14. Toward improving fine needle aspiration cytology by applying Raman microspectroscopy

    NASA Astrophysics Data System (ADS)

    Becker-Putsche, Melanie; Bocklitz, Thomas; Clement, Joachim; Rösch, Petra; Popp, Jürgen

    2013-04-01

    Medical diagnosis of biopsies performed by fine needle aspiration has to be very reliable. Therefore, pathologists/cytologists need additional biochemical information on single cancer cells for an accurate diagnosis. Accordingly, we applied three different classification models for discriminating various features of six breast cancer cell lines by analyzing Raman microspectroscopic data. The statistical evaluations are implemented by linear discriminant analysis (LDA) and support vector machines (SVM). For the first model, a total of 61,580 Raman spectra from 110 single cells are discriminated at the cell-line level with an accuracy of 99.52% using an SVM. The LDA classification based on Raman data achieved an accuracy of 94.04% by discriminating cell lines by their origin (solid tumor versus pleural effusion). In the third model, Raman cell spectra are classified by their cancer subtypes. LDA results show an accuracy of 97.45% and specificities of 97.78%, 99.11%, and 98.97% for the subtypes basal-like, HER2+/ER-, and luminal, respectively. These subtypes are confirmed by gene expression patterns, which are important prognostic features in diagnosis. This work shows the applicability of Raman spectroscopy and statistical data handling in analyzing cancer-relevant biochemical information for advanced medical diagnosis on the single-cell level.

  15. Preschool Needle Pain Responding: Establishing 'Normal'.

    PubMed

    Waxman, Jordana A; DiLorenzo, Miranda G; Pillai Riddell, Rebecca R; Flora, David B; Greenberg, Saul; Garfield, Hartley

    2017-02-11

    The current study sets forth to provide both descriptive data for preschool vaccination pain responding and examine longitudinal relationships over early childhood. Growth mixture modeling (GMM) was first used to describe stable subgroups of preschoolers based on their pain response patterns over 2-minutes post-needle. Secondly, a parallel-process growth curve model was used to assess the stability of acute pain responding from 12-months of age to preschool age. Specifically, we examined whether preschool pain-related distress or regulation could be predicted from 12-month acute pain responding. Preschool participants were part of a Canadian longitudinal cohort (The OUCH Cohort; N = 302). GMM analyses discerned 3 distinct groups of preschoolers, with an important minority not regulating to low-no pain by 2 minutes post-needle. There were no significant associations between 12-month and preschool pain responding. These results highlight the steep trajectory of development between these different stages of early childhood and the variability of pain responding at the preschool vaccination.

  16. Cryosurgery and needle ablation of renal lesions.

    PubMed

    Johnson, D B; Nakada, S Y

    2001-05-01

    Laparoscopic renal cryoablation is a minimally invasive alternative for treating renal tumors utilizing narrow probes cooled with a compressed gas such as argon or carbon dioxide. At this time, cryotherapy has shown the most promise as an alternative to partial nephrectomy as a nephron-sparing treatment for renal tumors. Radiofrequency ablation employs needle electrodes placed percutaneously directly into renal lesions to deliver energy, creating high temperatures leading to cell death. High-intensity focused ultrasound is a noninvasive technique in which focused ultrasound energy is applied to cause cell death within the focal zone. Microwave thermotherapy uses small applicators to deliver microwave energy to tissues, resulting in the generation of heat. Although RF, HIFU, and microwave thermotherapy show promise as energy sources for tumor ablation, they are in the early stages of development. Little is known about their acute and chronic histologic effects and long-term efficacy as a treatment for malignant disease. Further work is needed to develop cryosurgery and needle ablation in order to delineate what role these techniques will ultimately play in the management of RCC.

  17. Feasibility of fine-needle aspiration biopsy and its applications in superficial cervical lesion biopsies

    PubMed Central

    Xu, Dong; Xu, Hai-Miao; Li, Ming-Kui; Chen, Li-Yu; Wang, Li-Jing

    2014-01-01

    The aim of the study was to investigate the feasibility and value of clinical application of fine-needle aspiration histological biopsy via ultrasound-guided thyroid nodule and enlarged cervical lymph node fine-needle aspiration histological biopsy. Fine-needle aspiration cytological and histological biopsies and surgical treatments were performed on 982 patients with thyroid nodule and 1435 patients with enlarged cervical lymph nodes. A comparative study of the histological and cytological examination results and post-surgical etiology results was subsequently conducted. Among the 982 thyroid nodule patients, the acquisition rates were 89.8% (882/982) for fine-needle aspiration histological biopsy and 96.2% (945/982) for cytological biopsy, while among the 1435 patients with enlarged cervical lymph nodes, the acquisition rate for fine-needle aspiration cytological biopsy was slightly higher than that for histological biopsy, with values of 95.7% (1374/1435) and 91.4% (1312/1435), respectively. For the thyroid nodule patients, when the acquired histological and cytological biopsy results were compared with the post-surgical etiology results, the sensitivity, specificity, and accuracy of the histological results were 98.5%, 100%, and 98.9%, respectively, whereas those of the cytological results were 86.8%, 82.9%, and 85.6%, respectively; the differences between the 2 biopsy methods were statistically significant (P < 0.05). For the patients with enlarged cervical lymph nodes, when the acquired histological and cytological biopsy results were compared with the post-surgical etiology results, the sensitivity, specificity, and accuracy of the histological results were 96.3%, 99.8%, and 97.6%, respectively, whereas the those of the cytological results were 76.8%, 92.1%, and 82.2%, respectively; again, the differences between the 2 methods were statistically significant (P < 0.05). In conclusion, Fine-needle aspiration histological biopsy is a reliable and highly

  18. Optimal sensor placement for spatial lattice structure based on genetic algorithms

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Gao, Wei-cheng; Sun, Yi; Xu, Min-jian

    2008-10-01

    Optimal sensor placement technique plays a key role in structural health monitoring of spatial lattice structures. This paper considers the problem of locating sensors on a spatial lattice structure with the aim of maximizing the data information so that structural dynamic behavior can be fully characterized. Based on the criterion of optimal sensor placement for modal test, an improved genetic algorithm is introduced to find the optimal placement of sensors. The modal strain energy (MSE) and the modal assurance criterion (MAC) have been taken as the fitness function, respectively, so that three placement designs were produced. The decimal two-dimension array coding method instead of binary coding method is proposed to code the solution. Forced mutation operator is introduced when the identical genes appear via the crossover procedure. A computational simulation of a 12-bay plain truss model has been implemented to demonstrate the feasibility of the three optimal algorithms above. The obtained optimal sensor placements using the improved genetic algorithm are compared with those gained by exiting genetic algorithm using the binary coding method. Further the comparison criterion based on the mean square error between the finite element method (FEM) mode shapes and the Guyan expansion mode shapes identified by data-driven stochastic subspace identification (SSI-DATA) method are employed to demonstrate the advantage of the different fitness function. The results showed that some innovations in genetic algorithm proposed in this paper can enlarge the genes storage and improve the convergence of the algorithm. More importantly, the three optimal sensor placement methods can all provide the reliable results and identify the vibration characteristics of the 12-bay plain truss model accurately.

  19. Accuracy of pedicle screw placement using intraoperative neurophysiological monitoring and computed tomography.

    PubMed

    Mavrogenis, Andreas F; Papagelopoulos, Panayiotis J; Korres, Demetrios S; Papadopoulos, Konstantinos; Sakas, Damianos E; Pneumaticos, Spiros

    2009-01-01

    cut-off value of 7 mA had a 98.73% (> 95%) positive predictive value for accurate pedicle screw placement.

  20. Analytic theory for the selection of 2-D needle crystal at arbitrary Peclet number

    NASA Technical Reports Server (NTRS)

    Tanveer, Saleh

    1989-01-01

    An accurate analytic theory is presented for the velocity selection of a two-dimensional needle crystal for arbitrary Peclet number for small values of the surface tension parameter. The velocity selection is caused by the effect of transcendentally small terms which are determined by analytic continuation to the complex plane and analysis of nonlinear equations. The work supports the general conclusion of previous small Peclet number analytical results of other investigators, though there are some discrepancies in details. It also addresses questions raised on the validity of selection theory owing to assumptions made on shape corrections at large distances from the tip.

  1. Analytic theory for the selection of a two-dimensional needle crystal at arbitrary Peclet number

    NASA Technical Reports Server (NTRS)

    Tanveer, S.

    1989-01-01

    An accurate analytic theory is presented for the velocity selection of a two-dimensional needle crystal for arbitrary Peclet number for small values of the surface tension parameter. The velocity selection is caused by the effect of transcendentally small terms which are determined by analytic continuation to the complex plane and analysis of nonlinear equations. The work supports the general conclusion of previous small Peclet number analytical results of other investigators, though there are some discrepancies in details. It also addresses questions raised on the validity of selection theory owing to assumptions made on shape corrections at large distances from the tip.

  2. Linking Services to Increased Productivity in Placement.

    ERIC Educational Resources Information Center

    Bostaph, Charles P.; Martoni, Charles J.

    1984-01-01

    Looks at the way Pennsylvania Job Search was brought to the Boyce Campus of Community College of Allegheny County. Discusses student and community participants in the job placement program, its unique services, benefits to the campus, and use of the model by other schools. (AYC)

  3. Placement of Engineering and Technology Graduates, 1980.

    ERIC Educational Resources Information Center

    Gilmore, Arthur W.

    Information on the placement status of 1980 engineering and technology graduates is presented. At the doctoral degree level, the percentage without job offers or other firm plans was lower than in 1979. The bachelor's degree level experienced a one percentage point reduction in the number of graduates employed as of graduation compared to 1979,…

  4. CAPS: Career Assistance & Placement Services. Resource Manual.

    ERIC Educational Resources Information Center

    Barrow, Connye M.; And Others

    This resource manual describes a model for planning and developing comprehensive career placement services integrated into the total career development efforts of secondary and postsecondary schools in Illinois. The manual is designed to be used by educational administrators at the local and regional level in developing specific program goals,…

  5. Modern Agriculture in Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Lanegran, David A.

    2000-01-01

    Discusses the four sections of the Advanced Placement (AP) human geography course focusing on agriculture: (1) development and diffusion of agriculture; (2) major agricultural production regions; (3) rural land use and change; and (4) impacts of modern agricultural change. Includes references and a resource list. (CMK)

  6. Health risks for students on overseas placements.

    PubMed

    Driver, Carolyn

    Health profession students are encouraged to take an elective during training and many do this overseas in tropical, low-income countries. Higher education institutions should offer advice and support on organising these placements but this varies and students may present for pre-travel health advice at their general practice or travel clinic. This article discusses how they should be advised.

  7. Advanced Placement Economics. Macroeconomics: Student Activities.

    ERIC Educational Resources Information Center

    Morton, John S.

    This book is designed to help advanced placement students better understand macroeconomic concepts through various activities. The book contains 6 units with 64 activities, sample multiple-choice questions, sample short essay questions, and sample long essay questions. The units are entitled: (1) "Basic Economic Concepts"; (2) "Measuring Economic…

  8. Advanced Placement Economics. Teacher Resource Manual.

    ERIC Educational Resources Information Center

    Morton, John S.

    This book, in conjunction with the student activities books for macroeconomics and microeconomics, is designed for teaching the Advanced Placement Economics course. The book contains five units for the microeconomic portion and six units for the macroeconomic portion of the text. Along with the many activities are sample multiple-choice questions,…

  9. Online Placement in First-Year Writing

    ERIC Educational Resources Information Center

    Peckham, Irvin

    2009-01-01

    This essay describes Louisiana State University's search for an alternative to available placement protocols. Under the leadership of Les Perelman at MIT, LSU collaborated with four universities to develop iMOAT, a program for administering online assessments of student writing. This essay focuses on LSU's On-line Challenge, which developed from…

  10. Academic Placement after Traumatic Brain Injury.

    ERIC Educational Resources Information Center

    Donders, Jacques

    The acadmic placement of 87 children (ages 6 to 16 years) who had sustained brain injuries was determined within 1 year after initial psychological assessment. Forty-five children had returned full time to regular academic programs, 21 children received special education support for less than half of their classes, and 21 children were enrolled in…

  11. BIBLIOGRAPHIC GUIDE FOR ADVANCED PLACEMENT, LATIN.

    ERIC Educational Resources Information Center

    BARRON, ROBERT; ROSELLE, LEONE

    LITERARY AND CRITICAL WORKS, REFERENCE BOOKS, PERIODICALS, RECORDS, FILMS, AND FILMSTRIPS DEALING WITH ROMAN LITERATURE, HISTORY, CIVILIZATION, MYTHOLOGY, AND LANGUAGE ARE INCLUDED IN THIS BIBLIOGRAPHY OF RECOMMENDED READING IN ENGLISH FOR ADVANCED PLACEMENT PROGRAMS IN LATIN. THE LIST IS DIVIDED INTO TWO $500 GROUPS, SO THAT FOR CONVENIENCE IN…

  12. Clitoral Pain Following Retropubic Midurethral Sling Placement

    PubMed Central

    Christofferson, Melanie; Barnard, Jami

    2015-01-01

    Abstract Introduction Although uncommon, postprocedural pain with associated sexual dysfunction may be seen in patients after retropubic midurethral sling placement for treatment of stress urinary incontinence. Aims To describe a report of a woman who developed localized severe, persistent periclitoral pain after placement of a retropubic midurethral sling. Methods A healthy 41‐year‐old underwent an uncomplicated retropubic midurethral sling procedure. She developed persistent postoperative clitoral pain with worsening associated with arousal, impairing sexual function. Symptoms resolved with time and a course of steroid medication. Main Outcome Measures To report a case of clitoral pain following midurethral sling surgery, and to provide a discussion about clitoral innervation, possible pain etiologies, and management options. Results We report a case of clitoral pain associated with sexual dysfunction and provide a review of clitoral innervation as well as potential mechanisms of nerve injury associated with a retropubic sling procedure. Conclusion Clitoral pain symptoms following placement of a retropubic midurethral sling should be evaluated and promptly addressed, given the potential negative impact on the patient's sexual function. Christofferson M, Barnard J, and Montoya TI. Clitoral pain following retropubic midurethral sling placement. Sex Med 2015;3:346–348. PMID:26797072

  13. Institutional Placement: Phases of the Transition.

    ERIC Educational Resources Information Center

    Zarit, Steven H.; Whitlatch, Carol J.

    1992-01-01

    Examined consequences of institutionalization for 555 caregivers of dementia patients. Consistent with stress process model, institutionalization was hypothesized to have large impact on primary effects of caregiving and lesser influence on secondary effects and well-being. Following placement, caregivers experienced relief from primary effects of…

  14. Expanding the Scope of Advanced Placement Classes

    ERIC Educational Resources Information Center

    Lim, Victoria

    2008-01-01

    Dr. Paul Dosal of the University of South Florida is not impressed with the way most high school students learn about Latin American history. Dosal believes an advanced placement course in the subject will change that. He's the executive director of ENLACE Florida, a statewide network funded by the W.K. Kellogg Foundation, designed to increase the…

  15. Introduction. Teaching Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Murphy, Alexander B.

    2000-01-01

    Introduces this special issue of "Journal of Geography" focusing on the teaching of Advanced Placement (AP) human geography. States that essays were developed by members of the AP Human Geography Development Committee focusing on areas in the human geography course outline which are included in the appendix. (CMK)

  16. Paired Field Placements: A Means for Collaboration

    ERIC Educational Resources Information Center

    Gardiner, Wendy; Robinson, Karen Shipley

    2009-01-01

    In this qualitative study, pairs of preservice teachers were placed with single cooperating teachers in a 100-hour urban field placement. The question guiding this research was would preservice teachers collaborate in ways that contributed to their professional development and if so why, how, and to what end? Results from field notes, multiple…

  17. In Job-Placement Rates, Fuzzy Data

    ERIC Educational Resources Information Center

    Sandoval, Timothy

    2012-01-01

    As colleges and lawmakers seek better data about the employment success of graduates, a lack of standardized tracking makes much of the information unreliable. Many colleges release placement rates based on scant information: More than a third of colleges' reported rates in 2010 were based on responses from half of their graduates or fewer,…

  18. Writing Strategies for Advanced Placement European History.

    ERIC Educational Resources Information Center

    Young, Jacqueline

    This guide to effective writing strategies is based on three ideas that provide motivation for writing skills development in an advanced placement history class: students learn to write by writing; problem essays are more effective in developing writing skills than topic essays; and writing is a learning tool. Stressing that writing practice is…

  19. Polytechnic Graduate Placement in Finnish Manufacturing

    ERIC Educational Resources Information Center

    Bockerman, Petri

    2007-01-01

    This paper analyses polytechnic graduate placement in Finnish manufacturing. The paper uses a register-based data source covering white-collar manufacturing workers over the period 1995-2004. Taken together, the results show that wages and job classification are higher for polytechnic graduates, once other covariates are controlled for. Despite…

  20. Literary Archetypes. Advanced Placement English Curriculum Guide.

    ERIC Educational Resources Information Center

    Anne Arundel County Public Schools, Annapolis, MD.

    Providing students with the opportunity to earn college credit while still in high school, the Advanced Placement English course described in this guide is designed to help students (1) want to choose from a wide range of literature for independent reading; (2) develop a critical awareness about literature; (3) recognize connections among works of…

  1. Advanced Placement: Model Policy Components. Policy Analysis

    ERIC Educational Resources Information Center

    Zinth, Jennifer

    2016-01-01

    Advanced Placement (AP), launched in 1955 by the College Board as a program to offer gifted high school students the opportunity to complete entry-level college coursework, has since expanded to encourage a broader array of students to tackle challenging content. This Education Commission of the State's Policy Analysis identifies key components of…

  2. A Collaborative Assessment of Students' Placement Learning

    ERIC Educational Resources Information Center

    Cooper, Susan

    2017-01-01

    The research informing this paper set out to investigate the qualitative experiences of students, supervisors and tutors involved in a summative collaborative assessment of placement learning on an undergraduate professional qualifying programme in the UK. Analysis of data gathered through semi-structured interviews provides valuable insights into…

  3. 34 CFR 300.116 - Placements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 2 2011-07-01 2010-07-01 true Placements. 300.116 Section 300.116 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN...

  4. 34 CFR 300.116 - Placements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false Placements. 300.116 Section 300.116 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN...

  5. 34 CFR 300.116 - Placements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 2 2014-07-01 2013-07-01 true Placements. 300.116 Section 300.116 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN...

  6. 34 CFR 300.116 - Placements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Placements. 300.116 Section 300.116 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN...

  7. Osseointegrated fixture placement with simultaneous tooth extraction.

    PubMed

    Schabes, G A; Sacks, H G; Kaufman, P S

    1992-03-01

    Three cases are presented that illustrate the potential for accelerating the healing phase with fixture-based treatment. Depending on the clinical circumstances, techniques may include radical alveolectomy, the use of fresh extraction sockets, and fixture placement in inter-radicular bone.

  8. 34 CFR 300.104 - Residential placement

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Residential placement 300.104 Section 300.104 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN...

  9. 34 CFR 300.116 - Placements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Placements. 300.116 Section 300.116 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN...

  10. Confessions of a Community Placement Optimist.

    ERIC Educational Resources Information Center

    Provencal, Gerald

    This paper offers reflections from the author's experience with community placement for developmentally disabled persons, specifically addressing practical and philosophical issues. Drawn from the author's personal involvement with the Macomb-Oakland Regional Center (MORE) in Michigan, this document notes nine illustrations of progress from…

  11. Layout Decision Making: The Placement of Illustrations.

    ERIC Educational Resources Information Center

    Johnsey, Ava L.; And Others

    This study investigated the position of illustrations and how they affect the sequential organization of text. The primary purpose was to describe learners' reading sequence and preference for page designs with variations of illustration placement. The 70 subjects were undergraduate and graduate students enrolled in education courses at Memphis…

  12. 21 CFR 1230.10 - Placement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Placement. 1230.10 Section 1230.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION REGULATIONS UNDER THE FEDERAL...

  13. 21 CFR 1230.10 - Placement.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Placement. 1230.10 Section 1230.10 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION REGULATIONS UNDER THE FEDERAL...

  14. 42 CFR 483.126 - Appropriate placement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Appropriate placement. 483.126 Section 483.126 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Screening and Annual Review of Mentally Ill and Mentally Retarded Individuals § 483.126...

  15. 42 CFR 483.126 - Appropriate placement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Appropriate placement. 483.126 Section 483.126 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Screening and Annual Review of Mentally Ill and Mentally Retarded Individuals § 483.126...

  16. Advanced Placement Courses Are Not for Everyone.

    ERIC Educational Resources Information Center

    Blagaich, Pete

    1999-01-01

    Demonstrates that Advanced Placement (AP) courses may not be appropriate for every student. Discusses the process of selecting students for AP U.S. history. Criteria include an application, summer sessions, and evidence of motivation to excel in the program. Considers the effects of this policy. (CMK)

  17. Grow Your Own: Online Placement Testing.

    ERIC Educational Resources Information Center

    Sokolik, Maggie; Duber, Jim

    2002-01-01

    Details the advantages and process of creating an online English-as-a-Second-Language placement test. Outlines the steps for constructing a good test and describes the piloting of an online exam over a 2-year period. (Author/VWL)

  18. How visual perceptual grouping influences foot placement

    PubMed Central

    Fennell, John; Goodwin, Charlotte; Burn, Jeremy F.; Leonards, Ute

    2015-01-01

    Everybody would agree that vision guides locomotion; but how does vision influence choice when there are different solutions for possible foot placement? We addressed this question by investigating the impact of perceptual grouping on foot placement in humans. Participants performed a stepping stone task in which pathways consisted of target stones in a spatially regular path of foot falls and visual distractor stones in their proximity. Target and distractor stones differed in shape and colour so that each subset of stones could be easily grouped perceptually. In half of the trials, one target stone swapped shape and colour with a distractor in its close proximity. We show that in these ‘swapped’ conditions, participants chose the perceptually groupable, instead of the spatially regular, stepping location in over 40% of trials, even if the distance between perceptually groupable steps was substantially larger than normal step width/length. This reveals that the existence of a pathway that could be traversed without spatial disruption to periodic stepping is not sufficient to guarantee participants will select it and suggests competition between different types of visual input when choosing foot placement. We propose that a bias in foot placement choice in favour of visual grouping exists as, in nature, sudden changes in visual characteristics of the ground increase the uncertainty for stability. PMID:26587273

  19. Photoelectron Spectroscopy in Advanced Placement Chemistry

    ERIC Educational Resources Information Center

    Benigna, James

    2014-01-01

    Photoelectron spectroscopy (PES) is a new addition to the Advanced Placement (AP) Chemistry curriculum. This article explains the rationale for its inclusion, an overview of how the PES instrument records data, how the data can be analyzed, and how to include PES data in the course. Sample assessment items and analysis are included, as well as…

  20. Honors and Advanced Placement Chemistry Courses.

    ERIC Educational Resources Information Center

    Journal of Chemical Education, 1983

    1983-01-01

    Summarizes papers and minipapers on honors and advanced placement (AP) chemistry courses presented at the Seventh Biennial Conference on Chemical Education (Stillwater, Oklahoma 1982). Advantages/disadvantages of AP chemistry, high school/college courses, and grouping all chemistry students in one class were among the topics discussed. (JN)

  1. The role of MRI in image-guided needle biopsy of focal bone and soft tissue neoplasms.

    PubMed

    Khoo, M M Y; Saifuddin, A

    2013-07-01

    Magnetic resonance imaging (MRI) plays a critical role in the management pathway of both soft tissue and bone neoplasms, from diagnosis through to post-treatment follow-up. There are a wide range of surgical, oncological, and combined treatment regimes but these rely on accurate histopathological diagnosis. This article reviews the role of MRI in the planning of image-guided needle biopsy for suspected soft tissue and bone tumors.

  2. Diagnosis of Langerhans cell histiocytosis on fine needle aspiration cytology: a case report and review of the cytology literature.

    PubMed

    Kumar, Neeta; Sayed, Shahin; Vinayak, Sudhir

    2011-01-20

    A case of multifocal Langerhans cell histiocytosis in a two-year-old child is presented where fine needle aspiration was helpful in achieving a rapid and accurate diagnosis in an appropriate clinical and radiological setting. This can avoid unnecessary biopsy and guide the management especially where access to histopathology is limited. The highly characteristic common and rare cytological features are highlighted with focus on differential diagnoses and causes of pitfalls.

  3. Synthesis of nano-crystalline multifibrous zirconia needle

    SciTech Connect

    Biswas, Mridula; Bandyopadhyay, Siddhartha

    2013-06-01

    Graphical abstract: - Highlights: • Zirconia needles have been successfully prepared by simple inorganic sol–gel route. • The shape of the needles was retained after firing with aspect ratio > 400. • Needles are composed of multiple fibres. • Fibres are composed of nano crystals. - Abstract: Zirconia needles have been successfully synthesized using a simple inorganic sol–gel process without using any template. The method employs mixture of zirconium oxychloride octahydrate and sulphuric acid in aqueous medium. This process requires heat treatment at 40 °C for 2 h in an oven for nucleus formation. Complete formation of needle occurs after 17 days. The green needle retained its original shape after calcination at 1200 °C. Fired needles were of 1–2 cm in length and 5–50 μm in diameter and possess monoclinic phase. Needles are composed of multiple fibres. Depending on the heat treatment temperature, crystallite size varies in the range of 8 to around 300 nm.

  4. Needle Steering in 3-D Via Rapid Replanning

    PubMed Central

    Patil, Sachin; Burgner, Jessica; Webster, Robert J.; Alterovitz, Ron

    2014-01-01

    Steerable needles have the potential to improve the effectiveness of needle-based clinical procedures such as biopsy and drug delivery by improving targeting accuracy and reaching previously inaccessible targets that are behind sensitive or impenetrable anatomical regions. We present a new needle steering system capable of automatically reaching targets in 3-D environments while avoiding obstacles and compensating for real-world uncertainties. Given a specification of anatomical obstacles and a clinical target (e.g., from preoperative medical images), our system plans and controls needle motion in a closed-loop fashion under sensory feedback to optimize a clinical metric. We unify planning and control using a new fast algorithm that continuously replans the needle motion. Our rapid replanning approach is enabled by an efficient sampling-based rapidly exploring random tree (RRT) planner that achieves orders-of-magnitude reduction in computation time compared with prior 3-D approaches by incorporating variable curvature kinematics and a novel distance metric for planning. Our system uses an electromagnetic tracking system to sense the state of the needle tip during the procedure. We experimentally evaluate our needle steering system using tissue phantoms and animal tissue ex vivo. We demonstrate that our rapid replanning strategy successfully guides the needle around obstacles to desired 3-D targets with an average error of less than 3 mm. PMID:25435829

  5. Needle and Syringe Cleaning Practices among Injection Drug Users.

    ERIC Educational Resources Information Center

    Fisher, Dennis G.; Harbke, Colin R.; Canty, John R.; Reynolds, Grace L.

    2002-01-01

    Evaluates the effect of needle exchange on the bleach-mediated disinfection (BMD) practices of 176 needle and syringe sharing injection drug users (IDUs). Results reveal that IDUs who traded sex for money or drugs were less likely to practice BMD, and IDUs who reported a reduced number of sex partners were more likely to practice BMD. (Contains 36…

  6. Design of a Slender Tuned Ultrasonic Needle for Bone Penetration

    NASA Astrophysics Data System (ADS)

    Cleary, Rebecca; Mathieson, Andrew; Wallace, Robert; Simpson, Hamish; Lucas, Margaret

    This paper reports on an ultrasonic bone biopsy needle, particularly focusing on design guidelines applicable for any slender tuned ultrasonic device component. Ultrasonic surgical devices are routinely used to cut a range of biological tissues, such as bone. However the realisation of an ultrasonic bone biopsy needle is particularly challenging. This is due to the requirement to generate sufficient vibrational amplitude capable of penetrating mineralised tissue, while avoiding flexural vibrational responses, which are known to reduce the performance and reliability of slender ultrasonic devices. This investigation uses finite element analysis (FEA) to predict the vibrational behaviour of a resonant needle which has dimensions that match closely to an 8Gx4inch bone marrow biopsy needle. Features of the needle, including changes in material and repeated changes in diameter, have been included and systematically altered to demonstrate that the location of and geometry of these features can significantly affect the resonant frequency of bending and torsional modes of vibration while having a limited effect on the frequency and shape of the tuned longitudinal mode. Experimental modal analysis was used to identify the modal parameters of the selected needle design, validating the FEA model predictions of the longitudinal mode and the close flexural modes. This verifies that modal coupling can be avoided by judicious small geometry modifications. Finally, the tuned needle assembly was driven under typical operational excitation conditions to demonstrate that an ultrasonic biopsy needle can be designed to operate in a purely longitudinal motion.

  7. Needle Steering in 3-D Via Rapid Replanning.

    PubMed

    Patil, Sachin; Burgner, Jessica; Webster, Robert J; Alterovitz, Ron

    2014-08-01

    Steerable needles have the potential to improve the effectiveness of needle-based clinical procedures such as biopsy and drug delivery by improving targeting accuracy and reaching previously inaccessible targets that are behind sensitive or impenetrable anatomical regions. We present a new needle steering system capable of automatically reaching targets in 3-D environments while avoiding obstacles and compensating for real-world uncertainties. Given a specification of anatomical obstacles and a clinical target (e.g., from preoperative medical images), our system plans and controls needle motion in a closed-loop fashion under sensory feedback to optimize a clinical metric. We unify planning and control using a new fast algorithm that continuously replans the needle motion. Our rapid replanning approach is enabled by an efficient sampling-based rapidly exploring random tree (RRT) planner that achieves orders-of-magnitude reduction in computation time compared with prior 3-D approaches by incorporating variable curvature kinematics and a novel distance metric for planning. Our system uses an electromagnetic tracking system to sense the state of the needle tip during the procedure. We experimentally evaluate our needle steering system using tissue phantoms and animal tissue ex vivo. We demonstrate that our rapid replanning strategy successfully guides the needle around obstacles to desired 3-D targets with an average error of less than 3 mm.

  8. Spain: government orders distribution of clean needles in prisons.

    PubMed

    2002-03-01

    In a previous issue of the Review we published an article about the positive results of the evaluation of the first needle exchange programs in Spanish prisons. Recently it was reported that Spain's Ministry of the Interior has ordered that sterile needles be distributed in prisons.

  9. Balloon needle for the atraumatic transcortical ventricular approach: technical note.

    PubMed

    Madrazo, I; Franco-Bourland, R; Aguilera, M; Reyes, P; Guízar-Sahagún, G

    1990-03-01

    We have designed a double-lumen inflatable needle for the atraumatic dissection of brain substance. This balloon needle has been successfully used for the ventricular approach in brain grafting procedures to obtain a rounded corticotomy with a diameter of 1.5-2 cm in the treatment of Parkinson's disease.

  10. Rehabilitation Manpower Specialist--A Job Description of Placement Personnel

    ERIC Educational Resources Information Center

    Hutchison, Jack; Cogan, Floyd

    1974-01-01

    The article responds to a national survey of State rehabilitation job placement personnel and synthesizes the materials received from 42 states pertaining to placement efforts, personnel, and duties. (EA)

  11. Suction-modified needle biopsy technique for the human soleus muscle

    PubMed Central

    Cotter, Joshua A.; Yu, Alvin; Kreitenberg, Arthur; Haddad, Fadia H.; Baker, Michael J.; Fox, John C.; Adams, Gregory R.

    2014-01-01

    INTRODUCTION The needle biopsy technique for the soleus muscle is of particular interest because of its unique fiber type distribution, contractile properties, and sensitivity to unloading. Unlike other commonly biopsied muscles, the soleus is not fully superficial and is in close proximity to neurovascular structures resulting in a more challenging biopsy. Because of this, a standardized protocol for performing needle biopsies on the human soleus muscle that is safe, reliable, and repeatable is presented. METHODS Ultrasonography was used on an initial set of 12 subjects to determine the optimal biopsy zone thereby guiding the location of the incision site. Forty-five subjects were recruited and attended two separate biopsy sessions. Each biopsy session incorporated 3 passes of the biopsy needle proximal, posterior, and distal using suction from a portable vacuum source producing 3 separate muscle specimens. RESULTS Eighty-four soleus muscle biopsy procedures were successfully conducted yielding 252 total samples without complication. Ultrasonography was used to confirm biopsy needle infiltration of the soleus muscle. Average sample weight obtained per pass was 61.5 ± 15.7 mg. Histochemistry and molecular analyses demonstrated a considerably higher amount of slow type I MHC in comparison to the vastus lateralis providing verification for the successful sampling of the soleus muscle. DISCUSSION The procedure presented consists of a detailed protocol to accurately and consistently obtain muscle biopsy samples from the human soleus muscle. We have demonstrated that the human soleus biopsy is a safe, reliable and repeatable procedure providing ample tissue for multiple types of analyses. PMID:24261060

  12. CT-Guided Fiducial Placement for CyberKnife Stereotactic Radiosurgery: An Initial Experience

    SciTech Connect

    Sotiropoulou, Evangelia; Stathochristopoulou, Irene; Stathopoulos, Konstantinos; Verigos, Kosmas; Salvaras, Nikolaos; Thanos, Loukas

    2010-06-15

    CyberKnife frameless image-guided radiosurgery has become a widely used system for parenchymal extracranial lesions. Gold fiducials are required for the planning and aiming of CyberKnife therapy. We report our initial experience and describe the technique of positioning tumor markers, under CT guidance. We conducted a retrospective review of 105 patients who were referred for CyberKnife stereotactic radiosurgery at Iatropolis CyberKnife Center in Athens. All patients underwent percutaneous fiducial placement via CT guidance. At the desired location, the 18-G needle was advanced into or near the tumor. Data collected included number and locations of fiducials placed and complications experienced to date. One hundred five patients underwent fiducial placement under CT guidance and a total number of 319 gold seeds were implanted. We experienced one episode of pneumothorax that required drainage, one mild pneumothorax, and three episodes of perifocal pulmonary hemorrhage. In conclusion, fiducial implantation under CT guidance appears to be a safe and efficient procedure, as long as it is performed by an experienced interventional radiologist.

  13. Modeling Electric Fields of Peripheral Nerve Block Needles.

    NASA Astrophysics Data System (ADS)

    Davis, James Ch.; Ramirez, Jason G.

    2005-11-01

    Peripheral nerve blocks present an alternative to general anesthesia in certain surgical procedures and a means of acute pain relief through continuous blockades. They have been shown to decrease the incidence of postoperative nausea and vomiting, reduce oral narcotic side effects, and improve sleep quality. Injecting needles, which carry small stimulating currents, are often used to aid in locating the target nerve bundle. With this technique, muscle responses indicate needle proximity to the corresponding nerve bundle. Failure rates in first injection attempts prompted our study of electric field distributions. Finite difference methods were used to solve for the electric fields generated by two widely used needles. Differences in geometry between needles are seen to effect changes in electric field and current distributions. Further investigations may suggest needle modifications that result in a reduction of initial probing failures.

  14. Modeling Electric Fields of Peripheral Nerve Block Needles.

    NASA Astrophysics Data System (ADS)

    Davis, James Ch.; Anderson, Norman E.; Meisel, Mark W.; Ramirez, Jason G.; Kayser Enneking, F.

    2006-03-01

    Peripheral nerve blocks present an alternative to general anesthesia in certain surgical procedures and a means of acute pain relief through continuous blockades. They have been shown to decrease the incidence of postoperative nausea and vomiting, reduce oral narcotic side effects, and improve sleep quality. Injecting needles, which carry small stimulating currents, are often used to aid in locating the target nerve bundle. With this technique, muscle responses indicate needle proximity to the corresponding nerve bundle. Failure rates in first injection attempts prompted our study of electric field distributions. Finite difference methods were used to solve for the electric fields generated by two widely used needles. Geometric differences in the needles effect variations in their electric field and current distributions. Further investigations may suggest needle modifications that result in a reduction of initial probing failures.

  15. [Brief introduction of acupuncture needling and teaching keypoint].

    PubMed

    Hou, Shu-wei; Guo, Li; Kong, Su-ping

    2014-09-01

    We summarized our accumulated clinical and teaching experiences and explored the regularity of acupuncture needling and teaching. It is of great importance in pressing hand during inserting needle. Stroking and pressing are two crucial parts which deserve more attention, and seldom useage of pressing hand should be abolished. Operating hand needs practice before inserting needle, while it should fully relaxed during inserting. Blending "touching", "stretch" "gathering" "erupting" and "advancing" in single moment, applying appropriate dynamic mode of inserting needle such as "join 3 forces as one" "3 points in a line" expertly and naturally. In addition, enough attention should be paid on "altering direction" and "shifting point". Inserting deftly and powerfully, no/slight sensation, deqi when inserting needle are the highest reflection as an acupuncturist.

  16. Design of an Optically Controlled MR-Compatible Active Needle

    PubMed Central

    Ryu, Seok Chang; Quek, Zhan Fan; Koh, Je-Sung; Renaud, Pierre; Black, Richard J.; Moslehi, Behzad; Daniel, Bruce L.; Cho, Kyu-Jin; Cutkosky, Mark R.

    2015-01-01

    An active needle is proposed for the development of magnetic resonance imaging (MRI)-guided percutaneous procedures. The needle uses a low-transition-temperature shape memory alloy (LT SMA) wire actuator to produce bending in the distal section of the needle. Actuation is achieved with internal optical heating using laser light transported via optical fibers and side coupled to the LT SMA. A prototype, with a size equivalent to a standard 16-gauge biopsy needle, exhibits significant bending, with a tip deflection of more than 14° in air and 5° in hard tissue. A single-ended optical sensor with a gold-coated tip is developed to measure the curvature independently of temperature. The experimental results in tissue phantoms show that human tissue causes fast heat dissipation from the wire actuator; however, the active needle can compensate for typical targeting errors during prostate biopsy. PMID:26512231

  17. SPOT-A SENSOR PLACEMENT OPTIMIZATION TOOL FOR ...

    EPA Pesticide Factsheets

    journal article This paper presents SPOT, a Sensor Placement Optimization Tool. SPOT provides a toolkit that facilitates research in sensor placement optimization and enables the practical application of sensor placement solvers to real-world CWS design applications. This paper provides an overview of SPOT’s key features, and then illustrates how this tool can be flexibly applied to solve a variety of different types of sensor placement problems.

  18. Placement techniques for the standard transistor array (Star)

    NASA Technical Reports Server (NTRS)

    Cox, G. W.; Carroll, B. D.

    1978-01-01

    Techniques for the placement of digital logic cells on STAR's (Standard Transistor Arrays) were developed. These techniques are designed to provide placement automation capabilities to low volume users with limited available processing power. A series of programs implementing the placement techniques was written and a number of test cases executed. Results of these test cases indicate that the methods achieve near optimum placements with respect to network routability.

  19. Prediction of Supported Employment Placements by Job Developers.

    ERIC Educational Resources Information Center

    Culver, Jill Blair; And Others

    1990-01-01

    The study attempted to identify activities performed by 47 job developers that positively or negatively influenced job placement. Variance in job placement was influenced by marketing activities, available job development time, use of specific client assessment procedures, frequency of use of trial job placements, and gender of the job developers.…

  20. 38 CFR 21.252 - Job development and placement services.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Job development and... 38 U.S.C. Chapter 31 Employment Services § 21.252 Job development and placement services. (a) General. Job development and placement services may include: (1) Direct placement assistance by VA;...

  1. 38 CFR 21.252 - Job development and placement services.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Job development and... 38 U.S.C. Chapter 31 Employment Services § 21.252 Job development and placement services. (a) General. Job development and placement services may include: (1) Direct placement assistance by VA;...

  2. 38 CFR 21.252 - Job development and placement services.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Job development and... 38 U.S.C. Chapter 31 Employment Services § 21.252 Job development and placement services. (a) General. Job development and placement services may include: (1) Direct placement assistance by VA;...

  3. 38 CFR 21.252 - Job development and placement services.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Job development and... 38 U.S.C. Chapter 31 Employment Services § 21.252 Job development and placement services. (a) General. Job development and placement services may include: (1) Direct placement assistance by VA;...

  4. Brand Placement and Consumer Choice: An in-Store Experiment

    ERIC Educational Resources Information Center

    Sigurdsson, Valdimar; Saevarsson, Hugi; Foxall, Gordon

    2009-01-01

    An in-store experiment was performed to investigate the effects of shelf placement (high, middle, low) on consumers' purchases of potato chips. Placement of potato chips on the middle shelf was associated with the highest percentage of purchases. The results confirm the importance of item placement as a factor in consumers' buying behavior.…

  5. BRAND PLACEMENT AND CONSUMER CHOICE: AN IN-STORE EXPERIMENT

    PubMed Central

    Sigurdsson, Valdimar; Saevarsson, Hugi; Foxall, Gordon

    2009-01-01

    An in-store experiment was performed to investigate the effects of shelf placement (high, middle, low) on consumers' purchases of potato chips. Placement of potato chips on the middle shelf was associated with the highest percentage of purchases. The results confirm the importance of item placement as a factor in consumers' buying behavior. PMID:20190939

  6. West Virginia Guidebook: Job Placement Services: What's Your Need?

    ERIC Educational Resources Information Center

    Allen, Thomas R., Jr.; And Others

    Opening with a discussion of the rationale of a school-based job placement program, the school's responsibilities, and student needs, the paper focuses on the organization of a placement service, the major functions of the job placement coordinator, and testing services. Organizational considerations include: labor laws, scope of service, the…

  7. Brand placement and consumer choice: an in-store experiment.

    PubMed

    Sigurdsson, Valdimar; Saevarsson, Hugi; Foxall, Gordon

    2009-01-01

    An in-store experiment was performed to investigate the effects of shelf placement (high, middle, low) on consumers' purchases of potato chips. Placement of potato chips on the middle shelf was associated with the highest percentage of purchases. The results confirm the importance of item placement as a factor in consumers' buying behavior.

  8. Parental Status Characteristics and Self-Placement of Young Adults.

    ERIC Educational Resources Information Center

    McBroom, William H.; Hammer, Gail

    1983-01-01

    Examines status self-placement literature. Tests Talcott Parsons's inferences that, in predicting young adults' self-placement, (1) father's occupation is more important than other status variables of the father, (2) mother's employment makes the process of self-placement less predictable, and (3) "emancipation" from family of…

  9. 41 CFR 60-2.16 - Placement goals.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of discrimination. (c) Where, pursuant to § 60-2.15, a contractor is required to establish a placement goal for a particular job group, the contractor must establish a percentage annual placement goal... job group. (d) The placement goal-setting process described above contemplates that contractors...

  10. 41 CFR 60-2.16 - Placement goals.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of discrimination. (c) Where, pursuant to § 60-2.15, a contractor is required to establish a placement goal for a particular job group, the contractor must establish a percentage annual placement goal... job group. (d) The placement goal-setting process described above contemplates that contractors...

  11. 41 CFR 60-2.16 - Placement goals.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of discrimination. (c) Where, pursuant to § 60-2.15, a contractor is required to establish a placement goal for a particular job group, the contractor must establish a percentage annual placement goal... job group. (d) The placement goal-setting process described above contemplates that contractors...

  12. 41 CFR 60-2.16 - Placement goals.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of discrimination. (c) Where, pursuant to § 60-2.15, a contractor is required to establish a placement goal for a particular job group, the contractor must establish a percentage annual placement goal... job group. (d) The placement goal-setting process described above contemplates that contractors...

  13. The Placement Director of the '80s: A Profile.

    ERIC Educational Resources Information Center

    Crouch, Larry R.; Tolle, Donald J.

    1982-01-01

    Conducted a national survey of career planning and placement directors (N=1,032) at colleges and universities to determine, describe, and analyze selected factors concerning the careers of placement directors. Results indicated the typical placement director in a four-year college is male, holds a masters degree, and reports to student affairs.…

  14. Better Prepared, Better Placement: An Online Resource for Health Students

    ERIC Educational Resources Information Center

    Grace, Sandra; O'Neil, Ross

    2014-01-01

    Despite calls for better preparation of students and supervisors for clinical placement, few dedicated pre-placement resources have been developed. The aim of this project was to design, pilot, and evaluate an online resource to prepare health students and supervisors for clinical placements. Development of an online resource was informed by the…

  15. [Acupuncture therapy for regaining consciousness in terms of acupoint location, needle insertion and needle manipulation].

    PubMed

    Meng, Xianggang; Gu, Wenlong; Ma, Fen; Du, Yuzheng; Zhao, Qi

    2015-03-01

    Acupuncture therapy for regaining consciousness activates soreness, numbness, distention, heaviness, radiating and moving, electric shock and ant climbing sensations at the specific acupoints in the stroke patients. Radiating and moving sensations are the summary of needling sensations such as soreness, numbness and twitching presenting during lifting and thrusting manipulation. These sensations are the essential factors of the therapeutic effect of regaining consciousness. Radiating sensation refers to the conduction along meridians and radiation of soreness and numbness. Moving sensation refers to the local muscular twitching at acupoints and the involuntary movement of limbs, joints and the distal. Acupuncture at the specific acupoints achieves radiating and moving sensations for promoting the circulation in meridians, regulating qi and mind and balancing yin and yang in stroke patients. This therapy was introduced in the paper in view of acupoint location, needle insertion and manipulation.

  16. Accuracy Assessment of Immediate and Delayed Implant Placements Using CAD/CAM Surgical Guides.

    PubMed

    Alzoubi, Fawaz; Massoomi, Nima; Nattestad, Anders

    2016-10-01

    The aim of this study is to assess the accuracy of immediately placed implants using Anatomage Invivo5 computer-assisted design/computer-assisted manufacturing (CAD/CAM) surgical guides and compare the accuracy to delayed implant placement protocol. Patients who had implants placed using Anatomage Invivo5 CAD/CAM surgical guides during the period of 2012-2015 were evaluated retrospectively. Patients who received immediate implant placements and/or delayed implant placements replacing 1-2 teeth were included in this study. Pre- and postsurgical images were superimposed to evaluate deviations at the crest, apex, and angle. A total of 40 implants placed in 29 patients were included in this study. The overall mean deviations measured at the crest, apex, and angle were 0.86 mm, 1.25 mm, and 3.79°, respectively. The means for the immediate group deviations were: crest = 0.85 mm, apex = 1.10, and angle = 3.49°. The means for the delayed group deviations were: crest = 0.88 mm, apex = 1.59, and angle = 4.29°. No statistically significant difference was found at the crest and angle; however, there was a statistically significant difference between the immediate and delayed group at the apex, with the immediate group presenting more accurate placements at the apical point than the delayed group. CAD/CAM surgical guides can be reliable tools to accurately place implants immediately and/or in a delayed fashion. No statistically significant differences were found between the delayed and the immediate group at the crest and angle, however apical position was more accurate in the immediate group.

  17. Accuracy and Learning Curve of Femoral Tunnel Placement in Medial Patellofemoral Ligament Reconstruction.

    PubMed

    Hiemstra, Laurie Anne; Kerslake, Sarah; O'Brien, Catherine L; Lafave, Mark R

    2017-02-13

    The purpose of this study was to assess the accuracy of femoral tunnel placement in a medial patellofemoral ligament reconstruction (MPFL-R) cohort. The secondary purpose was to establish the evidence of a learning curve to achieve acceptable femoral tunnel placement during MPFL-R. Two surgeons, using lateral radiographs, assessed 73 subjects post-MPFL-R. Femoral tunnel accuracy and direction of tunnel error were measured in relation to Schöttle's point (A-T distance). Interrater reliability (intraclass correlation coefficient 2,k) of these measures was calculated. Learning curve of accurate femoral tunnel placement was examined by dividing the patient cohort into quartiles. A one-way analysis of variance was used to assess the quartiles for accuracy of femoral tunnel position and surgical time. In relation to Schöttle's point, 66/73 (90.4%) femoral tunnels were categorized as being in a "good" or "excellent" position and 7/73 (9.6%) were categorized as being in a "poor" position. Evidence of an MPFL-R learning curve was established via a statistically significant difference in the mean A to T distance for the four quartiles (F [3, 69] = 6.41, p = 0.001). There was also a statistically significant difference in the surgical time for the four quartiles (F [3, 69] = 8.71, p = 0.001). In this series, accurate femoral tunnels were placed more than 90% of the time during MPFL-R. A clear learning curve for accurate femoral tunnel placement was demonstrated both with respect to distance of the tunnel from Schöttle point and with regard to surgical time. Level of evidence was IV.

  18. An accuracy study of computer-planned implant placement in the augmented maxilla using osteosynthesis screws.

    PubMed

    Verhamme, L M; Meijer, G J; Soehardi, A; Bergé, S J; Xi, T; Maal, T J J

    2017-04-01

    Previous research on the accuracy of flapless implant placement of virtually planned implants in the augmented maxilla revealed unfavourable discrepancies between implant planning and placement. By using the osteosynthesis screws placed during the augmentation procedure, the surgical template could be optimally stabilized. The purpose of this study was to validate this method by evaluating its clinically relevant accuracy. Twelve consecutive fully edentulous patients with extreme resorption of the maxilla were treated with a bone augmentation procedure. Virtual implant planning was performed and a surgical template was manufactured. Subsequently, six implants were installed using the surgical template, which was only supported by the osteosynthesis screws. Implant deviations between planning and placement were calculated. A total of 72 implants were installed. Mean deviations found in the mesiodistal direction were 0.817mm at the implant tip and 0.528mm at the implant shoulder. The angular deviation was 2.924°. In the buccolingual direction, a deviation of 1.038mm was registered at the implant tip and 0.633mm at the implant shoulder. The angular deviation was 3.440°. This study showed that implant placement in the augmented maxilla using a surgical template supported by osteosynthesis screws is accurate.

  19. Fine needle aspiration cytology in fibromatosis

    PubMed Central

    Tanwar, Pranay; Gupta, Nalini; Vasishta, Rakesh Kumar; Singh, Gurpreet

    2012-01-01

    Fibromatosis form a spectrum of clinicopathologic entities characterized by the infiltrative proliferation of fibroblasts that lack malignant cytologic features. The fibromatosis can be localized or infiltrative and multicentric and can involve internal tissues and organs as the mesentery, retroperitoneum, breast, and almost every organ and region of the body, including the bones, the meninges and the central nervous system. We report a case of 37-year-old male who presented with a right supraclavicular mass with superficial infiltrative type of fibromatosis and fine needle aspiration cytology (FNAC) was performed. We report this case because of limited literature of FNAC in fibromatosis and quick role of FNAC in the diagnosis of fibromatosis. PMID:22438623

  20. Multiple needle puncturing: balancing the varus knee.

    PubMed

    Bellemans, Johan

    2011-09-09

    The so-called "pie crusting" technique using multiple stab incisions is a well-established procedure for correcting tightness of the iliotibial band in the valgus knee. It is, however, not applicable for balancing the medial side in varus knees because of the risk for iatrogenic transsection of the medial collateral ligament (MCL). This article presents our experience with a safer alternative and minimally invasive technique for medial soft tissue balancing, where we make multiple punctures in the MCL using a 19-gauge needle to progressively stretch the MCL until a correct ligament balance is achieved. Our technique requires minimal to no additional soft tissue dissection and can even be performed percutaneously when necessary. This technique, therefore, does not impact the length of the skin or soft tissue incisions. We analyzed 61 cases with varus deformity that were intraoperatively treated using this technique. In 4 other cases, the technique was used as a percutaneous procedure to correct postoperative medial tightness that caused persistent pain on the medial side. The procedure was considered successful when a 2- to 4-mm mediolateral joint line opening was obtained in extension and 2 to 6 mm in flexion. In 62 cases (95%), a progressive correction of medial tightness was achieved according to the above-described criteria. Three cases were overreleased and required compensatory release of the lateral structures and use of a thicker insert. Based on these results, we consider needle puncturing an effective and safe technique for progressive correction of MCL tightness during minimally invasive total knee arthroplasty.

  1. Needle-based confocal laser endomicroscopy

    PubMed Central

    Giovannini, Marc

    2015-01-01

    New applications of confocal laser endomicroscopy were developed as pCLE in the bile duct and nCLE for pancreatic cystic tumors, pancreatic masses and lymph nodes. The aim of this paper would be to give you an update in this new technology and to try to define its place in the diagnosis of cystic and solid pancreatic masses. The material used was a 19G EUS-needle in which the stylet was replaced by the Confocal mini-probe. The mini-probe (0.632 mm of diameter) is pre-loaded and screwed by a locking device in the EUS-Needle and guided endosonographically in the target. Regarding pancreatic cystic lesion, the presence of epithelial villous structures based on nCLE was associated with pancreatic cystic neoplasm (IPMN) (P = 0.004) and provided a sensitivity of 59%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 50%. A superficial vascular network pattern visualized on nCLE was identified in serous cystadenomas. It corresponded on pathological specimen to a dense and subepithelial capillary vascularization. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of this sign for the diagnosis of SCA were 87%, 69%, 100%, 100%, and 82%, respectively. In pancreatic adenocarcinomas, nCLE found vascular leakage with irregular vessels with leakage of fluorescein into the tumor, large dark clumps which correspond to humps of malignant cells. These criteria correlate with the histological structure of those tumors which are characterized by tumoral glands, surrounded by fibrosis in case of fibrous stroma tumor. Neuroendocrine tumors showed a dense network of small vessels on a dark background, which fits with the histological structure based on cord of cells surrounded by vessels and by fibrosis. nCLE is feasible during a EUS examination; these preliminary results are very encouraging and may be used in the future in case of inconclusive EUS-FNA. PMID:26643694

  2. Remote Electromagnetic Vibration of Steerable Needles for Imaging in Power Doppler Ultrasound

    PubMed Central

    Cabreros, Sarah S.; Jimenez, Nina M.; Greer, Joseph D.; Adebar, Troy K.; Okamura, Allison M.

    2015-01-01

    Robotic needle steering systems for minimally invasive medical procedures require complementary medical imaging systems to track the needles in real time. Ultrasound is a promising imaging modality because it offers relatively low-cost, real-time imaging of the needle. Previous methods applied vibration to the base of the needle using a voice coil actuator, in order to make the needle visible in power Doppler ultrasound. We propose a new method for needle tip vibration, using electromagnetic actuation of small permanent magnets placed inside the needle to improve needle tip visibility in power Doppler imaging. Robotic needle insertion experiments using artificial tissue and ex vivo porcine liver showed that the electromagnetic tip vibration method can generate a stronger Doppler response compared to the previous base vibration method, resulting in better imaging at greater needle depth in tissue. It also eliminates previous issues with vibration damping along the shaft of the needle. PMID:26413379

  3. Remote Electromagnetic Vibration of Steerable Needles for Imaging in Power Doppler Ultrasound.

    PubMed

    Cabreros, Sarah S; Jimenez, Nina M; Greer, Joseph D; Adebar, Troy K; Okamura, Allison M

    2015-05-01

    Robotic needle steering systems for minimally invasive medical procedures require complementary medical imaging systems to track the needles in real time. Ultrasound is a promising imaging modality because it offers relatively low-cost, real-time imaging of the needle. Previous methods applied vibration to the base of the needle using a voice coil actuator, in order to make the needle visible in power Doppler ultrasound. We propose a new method for needle tip vibration, using electromagnetic actuation of small permanent magnets placed inside the needle to improve needle tip visibility in power Doppler imaging. Robotic needle insertion experiments using artificial tissue and ex vivo porcine liver showed that the electromagnetic tip vibration method can generate a stronger Doppler response compared to the previous base vibration method, resulting in better imaging at greater needle depth in tissue. It also eliminates previous issues with vibration damping along the shaft of the needle.

  4. Modeling Cryotherapy Ice Ball Dimensions and Isotherms in a Novel Gel-based Model to Determine Optimal Cryo-needle Configurations and Settings for Potential Use in Clinical Practice

    PubMed Central

    Shah, Taimur T.; Arbel, Uri; Foss, Sonja; Zachman, Andrew; Rodney, Simon; Ahmed, Hashim U.; Arya, Manit

    2016-01-01

    Objective To gain a better understanding of ice ball dimensions and temperature isotherms relevant for cell kill when using combinations of cryo-needles we set out to answer 4 questions: (1) what type of cryo-needle? (2) how many needles? (3) best spatial configuration? and (4) correct duty cycle percentage? Methods We conducted laboratory experiments to monitor ice ball dimensions and create multi-needle planar isotherm maps for 17G and 10G cryo-needles using a novel multi-needle thermocouple fixture within gel at body temperature. We tested configurations of 1-4 cryo-needles at duty cycles of 20%-100% with 1-2.5 cm spacing. Results Analysis of various combinations shows that a central core of ≤−40°C develops at a distance of ~1 cm around the cryo-needles. Temperature increases linearly from this point to the ice ball leading edge (0°C), which is a further ≈1 cm away. Thus, the −40°C isotherm is approximately 1 cm inside the leading edge of the ice ball. The optimum distance between cryo-needles was 1.5-2 cm, at duty cycle settings of 70%-100%. At distances further apart or with lower duty cycle settings, ice balls either had a central core >−40°C or had an hourglass shape. Conclusion In answer to questions 1-3, tumor length, diameter, and shape will ultimately determine the number of needles and their configuration. However, we propose a conservative distance for cryo-needle placement between 1 and 1.5 cm should be adopted for clinical practice. In answer to question 4, using low duty cycle settings runs the risk of incomplete −40°C isotherm coverage of the tumor, and thus in routine practice we suggest that settings of 70%-100% are most appropriate. PMID:26902833

  5. Accurate Evaluation of Quantum Integrals

    NASA Technical Reports Server (NTRS)

    Galant, D. C.; Goorvitch, D.; Witteborn, Fred C. (Technical Monitor)

    1995-01-01

    Combining an appropriate finite difference method with Richardson's extrapolation results in a simple, highly accurate numerical method for solving a Schrodinger's equation. Important results are that error estimates are provided, and that one can extrapolate expectation values rather than the wavefunctions to obtain highly accurate expectation values. We discuss the eigenvalues, the error growth in repeated Richardson's extrapolation, and show that the expectation values calculated on a crude mesh can be extrapolated to obtain expectation values of high accuracy.

  6. Needle steering for robot-assisted insertion into soft tissue: A survey

    NASA Astrophysics Data System (ADS)

    Gao, Dedong; Lei, Yong; Zheng, Haojun

    2012-07-01

    Needle insertion is a common surgical procedure used in diagnosis and treatment. The needle steering technologies make continuous developments in theoretical and practical aspects along with the in-depth research on needle insertion. It is necessary to summarize and analyze the existing results to promote the future development of theories and applications of needle insertion. Thus, a survey of the state of the art of research is presented on algorithms of needle steering techniques, the surgical robots and devices. Based on the analysis of the needle insertion procedure, the concept of needle steering is defined as a kinematics problem, which is to place the needle at the target and avoid the obstacles. The needle steering techniques, including the artificial potential field method and the nonholonomic model, are introduced to control the needles for improving the accuracy. Based on the quasi-static thinking, the virtual spring model and the cantilever-beam model are developed to calculate the amount of needle deflection and generate the needle path. The phantoms instead of the real tissue are used to verify the models mentioned in most of the experimentations. For the desired needle trajectories, the image-guided robotic devices and some novel needles are presented to achieve the needle steering. Finally, the challenges are provided involving the controllability of the long flexible needle and the properties of soft tissue. The results and investigations can be used for further study on the precision and accuracy of needle insertion.

  7. Comparison of a needle-free high-pressure injection system with needle-tipped injection of intracavernosal alprostadil for erectile dysfunction.

    PubMed

    Harding, L M; Adeniyi, A; Everson, R; Barker, S; Ralph, D J; Baranowski, A P

    2002-12-01

    Patients identified from hospital records as using alprostadil injections for erectile dysfunction were invited to take part in this open crossover study. On alternate weeks eight patients were given intracavernosal needle injections and transdermal needle-free injection of alprostadil in a randomized order. Efficacy of injection and associated pain were assessed and compared for the two methods. Pain produced during injection was significantly greater with the needle-free system than with the needle-tipped injection whilst efficacy was significantly less. Bruising was reported in all except one patient following needle-free injection only. Patient ratings of the needle-free injector were significantly lower than ratings for needle-tipped alprostadil delivery and when asked to express a preference, every patient chose the needle-tipped injection over the needle-free device.

  8. Image Guidance of Flexible Tip-Steerable Needles.

    PubMed

    Kallem, Vinutha; Cowan, Noah J

    2009-02-03

    Image guidance promises to improve targeting accuracy and broaden the scope of medical procedures performed with needles. This paper takes a step toward automating the guidance of a flexible tip-steerable needle as it is inserted into human tissue. We build upon a previously proposed nonholonomic model of needles that derive steering from asymmetric bevel forces at the tip. The bevel-tip needle is inserted and rotated at its base in order to steer it in six degrees of freedom. As a first step for control, we show that the needle tip can be automatically guided to a planar slice of tissue as it is inserted. Our approach keeps the physician in the loop to control insertion speed. The distance of the needle tip position from the plane of interest is used to drive an observer-based feedback controller which we prove is locally asymptotically stable. Numerical simulations demonstrate a large domain of attraction and robustness of the controller in the face of parametric uncertainty and measurement noise. Physical experiments with tip-steerable Nitinol needles inserted into a transparent plastisol tissue phantom under stereo image guidance validate the effectiveness of our approach.

  9. In vivo Monitoring of Serotonin by Nanomaterial Functionalized Acupuncture Needle

    NASA Astrophysics Data System (ADS)

    Li, Yu-Tao; Tang, Li-Na; Ning, Yong; Shu, Qing; Liang, Feng-Xia; Wang, Hua; Zhang, Guo-Jun

    2016-06-01

    Acupuncture treatment is amazing but controversial. Up to now, the mechanism of treating diseases by acupuncture and moxibustion is still unclear, especially the occurrence of the molecular events in local acupoints. Herein, we report an extremely stable microsensor by modifying carbon nanotube (CNT) to the tip surface of acupuncture needle and applying this CNT-modified acupuncture needle for real time monitoring of serotonin (5-HT) in vivo. To stabilize CNT modification on the needle tip surface, poly(3,4-ethylenedioxythiophene)(PEDOT) was employed as glue water to stick CNT on the needle. The detection limit of the CNT-modified needle was found to be approximately 50 nM and 78 nM in the PBS and the cell medium, respectively. In addition, the needle showed good selectivity to some inflammatory mediators and some electroactive molecules. For the first time, the CNT-modified needle could be directly probed into rat body for real time monitoring of 5-HT in vivo, showing a great potential for better understanding the mechanism of acupuncture treatment.

  10. Carbon Nanotube Micro-Needles for Rapid Transdermal Drug Delivery

    NASA Astrophysics Data System (ADS)

    Lyon, Bradley; Aria, Adrianus Indrat; Gat, Amir; Cosse, Julia; Montemayor, Lauren; Beizaie, Masoud; Gharib, Morteza

    2012-11-01

    By catalyst patterning, bundles of vertically-aligned carbon nanotubes (CNT) can be assembled to create 2D arrays of hollow micro-needles with feature size as small as a few microns. For transdermal drug delivery, the most challenging mechanical requirement is to make the CNT micro-needle small enough so that delivery is painless yet large enough so that the micro-needle can achieve skin penetration. By taking advantage of capillary action and the nanoporosity of CNT bundles, we can wick high strength polymer into the inter-spacing between nanotubes to augment the stiffness of our micro-needles. For low viscous polymers, the large ratio between the micron sized center hole of the micro-needle and the nanopores of the surrounding CNT allow us to wick polymer through the nanotubes while maintaining an open central hole for drug transport. For a transdermal patch prototype with a delivery area less than 1cm x 1cm square, we can fabricate 50 CNT micro-needles that produces a total flow rate up to 100 uL/s with actuation pressure provided by a mere finger tap. From in vitro experiments, we will demonstrate that CNT micro-needles provide a much faster convective delivery of drugs than conventional topical diffusion based patches. We acknowledge Zcube s.r.l for their support of this work.

  11. Image Guidance of Flexible Tip-Steerable Needles

    PubMed Central

    Kallem, Vinutha; Cowan, Noah J

    2010-01-01

    Image guidance promises to improve targeting accuracy and broaden the scope of medical procedures performed with needles. This paper takes a step toward automating the guidance of a flexible tip-steerable needle as it is inserted into human tissue. We build upon a previously proposed nonholonomic model of needles that derive steering from asymmetric bevel forces at the tip. The bevel-tip needle is inserted and rotated at its base in order to steer it in six degrees of freedom. As a first step for control, we show that the needle tip can be automatically guided to a planar slice of tissue as it is inserted. Our approach keeps the physician in the loop to control insertion speed. The distance of the needle tip position from the plane of interest is used to drive an observer-based feedback controller which we prove is locally asymptotically stable. Numerical simulations demonstrate a large domain of attraction and robustness of the controller in the face of parametric uncertainty and measurement noise. Physical experiments with tip-steerable Nitinol needles inserted into a transparent plastisol tissue phantom under stereo image guidance validate the effectiveness of our approach. PMID:20431694

  12. Development of plasma needle to be used for biomedical applications

    NASA Astrophysics Data System (ADS)

    Bora, B.; Jain, J.; Inestrosa-Izurieta, M. J.; Avaria, G.; Moreno, J.; Pavez, C.; Marcelain, K.; Armisen, R.; Soto, L.

    2016-05-01

    Plasma needle is a novel design of a plasma source at atmospheric pressure to achieve a non-thermal plasma jet. The advantage of the plasma needle is that it can be operated in open air, outside a vessel. The plasma that is generated with the plasma needle is small (about one millimetre) and non-thermal, the temperature of the neutral particles and ions is in about room temperature and suitably can interact with living biological cell without damaging the cell. In this work, we report the development of a plasma needle, which is operated by a dc power source and produced a stable plasma jet on water surface. Argon gas is used to operate the plasma needle. The preliminary electrical diagnostics of the plasma needle shows that the discharge is filamentary in nature. For diagnostic of the plasma jet produced by the developed plasma needle, the produced plasma jet is directed to water surface and characterization are carried out by means of electrical discharge characteristics and optical emission spectroscopy. In this work, preliminary results of the diagnostic will be presented.

  13. In vivo Monitoring of Serotonin by Nanomaterial Functionalized Acupuncture Needle

    PubMed Central

    Li, Yu-Tao; Tang, Li-Na; Ning, Yong; Shu, Qing; Liang, Feng-Xia; Wang, Hua; Zhang, Guo-Jun

    2016-01-01

    Acupuncture treatment is amazing but controversial. Up to now, the mechanism of treating diseases by acupuncture and moxibustion is still unclear, especially the occurrence of the molecular events in local acupoints. Herein, we report an extremely stable microsensor by modifying carbon nanotube (CNT) to the tip surface of acupuncture needle and applying this CNT-modified acupuncture needle for real time monitoring of serotonin (5-HT) in vivo. To stabilize CNT modification on the needle tip surface, poly(3,4-ethylenedioxythiophene)(PEDOT) was employed as glue water to stick CNT on the needle. The detection limit of the CNT-modified needle was found to be approximately 50 nM and 78 nM in the PBS and the cell medium, respectively. In addition, the needle showed good selectivity to some inflammatory mediators and some electroactive molecules. For the first time, the CNT-modified needle could be directly probed into rat body for real time monitoring of 5-HT in vivo, showing a great potential for better understanding the mechanism of acupuncture treatment. PMID:27301303

  14. Predicting the Insertion Length for Gastric Tube Placement in Neonates

    PubMed Central

    Ellett, Marsha L. Cirgin; Cohen, Mervyn D.; Perkins, Susan M.; Smith, Coral E.; Lane, Kathleen A.; Austin, Joan K.

    2011-01-01

    Objective To compare error rates of three existing methods of predicting the gastric tube insertion length in a group of neonates < one month corrected age: age-related, height-based (ARHB); direct distance nose-ear-xiphoid (NEX); and direct distance nose-ear-mid-umbilicus (NEMU). Design Randomized controlled trial. Setting Five neonatal care units in a large midwestern city. Participants One hundred seventy-three hospitalized neonates. Methods Neonates were randomly assigned to one of three groups: ARHB, NEX, or NEMU. For primary analysis, only tubes placed too high with the tube tip in the esophagus or at the gastroesophageal junction were considered to be misplaced. For secondary analysis, a stricter definition was used, and low placements (pylorus or duodenum) were also considered to be misplaced. All radiographs were blinded and read by a pediatric radiologist. Results For the primary analysis, the differences in percentages of correctly placed tubes among the three methods was statistically significant (chi-square = 34.45; p < 0.0001), with both NEMU and ARHB more accurate than NEX (NEMU chi-square = 18.59, p < 0.0001; ARHB chi-square = 21.34, p < 0.0001). Using the stricter definition for placement, ARHB was not significantly different from NEX (p = 0.0615). A new ARHB equation was developed specific for neonates < 1 month corrected age. Conclusions Direct distance nose-ear-xiphoid should no longer be used as an NG/OG tube insertion-length predictor in neonates. Either NEMU for nasogastric/orogastric (NG/OG) tubes or the new ARHB equation for NG tubes should be used. PMID:21639864

  15. Technological advances for PICC placement and management.

    PubMed

    Pettit, Janet

    2007-06-01

    Placement of a peripherally inserted central catheter (PICC) is often complicated by the infant's small size and previous use of the peripheral veins, making the traditional means of insertion inadequate. New techniques and technologies, previously reserved for pediatric and adult patients, are now available for use in neonates and can enhance the practice of neonatal PICC teams. The modified Seldinger technique allows insertion of the PICC via smaller peripheral veins while decreasing venous trauma and enhancing the rate of successful placement. A second useful technique, the catheter exchange procedure, allows insertion of a new catheter within the same vein when complications such as occlusion, breakage, or inappropriate position occur and require removal of the currently dwelling PICC. Clinicians caring for neonates and infants must continually update their knowledge and skill by incorporating new techniques into their practice.

  16. Customized ATP towpreg. [Automated Tow Placement

    NASA Technical Reports Server (NTRS)

    Sandusky, Donald A.; Marchello, Joseph M.; Baucom, Robert M.; Johnston, Norman J.

    1992-01-01

    Automated tow placement (ATP) utilizes robotic technology to lay down adjacent polymer-matrix-impregnated carbon fiber tows on a tool surface. Consolidation and cure during ATP requires that void elimination and polymer matrix adhesion be accomplished in the short period of heating and pressure rolling that follows towpreg ribbon placement from the robot head to the tool. This study examined the key towpreg ribbon properties and dimensions which play a significant role in ATP. Analysis of the heat transfer process window indicates that adequate heating can be achieved at lay down rates as high as 1 m/sec. While heat transfer did not appear to be the limiting factor, resin flow and fiber movement into tow lap gaps could be. Accordingly, consideration was given to towpreg ribbon having uniform yet non-rectangular cross sections. Dimensional integrity of the towpreg ribbon combined with customized ribbon architecture offer great promise for processing advances in ATP of high performance composites.

  17. Examining Waiting Placement in Hospital: Utilization and the Lived Experience

    PubMed Central

    Wilson, Donna M.; Vihos, Jill; Hewitt, Jessica A.; Barnes, Nancy; Peterson, Karen; Magnus, Ralph

    2014-01-01

    This mixed-methods study addressed the problem that although waiting placement is considered a major hospital utilization issue, minimal evidence exists to highlight the extent of it and the personal impact of waiting placement. An analysis of two years of complete hospital data for the Canadian province of Alberta was undertaken to examine waiting placement rates and describe waiting placement patients. Qualitative interviews and observations of elderly patients waiting in hospital for nursing home placement were also undertaken to gain an understanding of the lived experience of waiting for placement in hospital. Only 1.8% of all inpatients were waiting placement with an ALC (Alternative Level of Care) designation, 80% of ALC waits were less than 41 days (mean=29.85, median=14), and 2.2% of total hospital bed days in these two years were used by ALC patients. Three qualitative themes emerged: (a) coming to a realization of this significant move, (b) waiting is boring and distressing, and (c) hospitals are not designed for waiting placement. The findings of this study should raise awareness that although relatively few people wait placement in hospital, there are some major possible negative effects of waiting for placement in hospital for those who wait; with remedies to address waiting placement care deficits needed. PMID:24576361

  18. Social context of needle selling in Baltimore, Maryland.

    PubMed

    Latkin, Carl A; Davey, Melissa A; Hua, Wei

    2006-01-01

    Although much of the debate surrounding the distribution of sterile syringes to injection drug users (IDUs) has focused on needle exchange programs (NEPs), IDUs acquire their syringes from three major sources: NEPs, pharmacies, and secondary exchangers or needle sellers. The purpose of the present study is to examine types and frequencies of social interactions among drug injectors who sell needles, most of which come from NEPs, compared with individuals who do not sell needles. Specifically, we compared engagement in drug-related behaviors, roles in the drug economy, and social network membership. Data were collected as part of the SHIELD study, an HIV prevention intervention targeted at drug users and their social networks (n=910) from February 2001 through September 2003 in Baltimore, Maryland (USA). In this sample, 56 participants reported selling needles. Needle sellers had higher levels of engagement in drug-related social interactions, including using drugs with others, giving or receiving drugs from others, and buying drugs with other users. Participants who sold needles had a significantly higher number of roles in the drug economy. Also, they had more social network members who were injectors, with whom they talked about risky drug behaviors, gave needles to, and shared cookers and bleach with. Compared with nonselling injectors, needle sellers engage in HIV risk-related behaviors, such as injecting daily and sharing injection equipment, more frequently. The study's findings may be useful to determine whether secondary exchangers should be targeted for HIV prevention activities both to reduce their own risk and to diffuse risk reduction information throughout the drug using community.

  19. A novel curvature-controllable steerable needle for percutaneous intervention.

    PubMed

    Bui, Van Khuyen; Park, Sukho; Park, Jong-Oh; Ko, Seong Young

    2016-08-01

    Over the last few decades, flexible steerable robotic needles for percutaneous intervention have been the subject of significant interest. However, there still remain issues related to (a) steering the needle's direction with less damage to surrounding tissues and (b) increasing the needle's maximum curvature for better controllability. One widely used approach is to control the fixed-angled bevel-tip needle using a "duty-cycle" algorithm. While this algorithm has shown its applicability, it can potentially damage surrounding tissue, which has prevented the widespread adoption of this technology. This situation has motivated the development of a new steerable flexible needle that can change its curvature without axial rotation, while at the same time producing a larger curvature. In this article, we propose a novel curvature-controllable steerable needle. The proposed robotic needle consists of two parts: a cannula and a stylet with a bevel-tip. The curvature of the needle's path is controlled by a control offset, defined by the offset between the bevel-tip and the cannula. As a result, the necessity of rotating the whole needle's body is decreased. The duty-cycle algorithm is utilized to a limited degree to obtain a larger radius of curvature, which is similar to a straight path. The first prototype of 0.46 mm (outer diameter) was fabricated and tested with both in vitro gelatin phantom and ex vivo cow liver tissue. The maximum curvatures measured 0.008 mm(-1) in 6 wt% gelatin phantom, 0.0139 mm(-1) in 10 wt% gelatin phantom, and 0.0038 mm(-1) in cow liver. The experimental results show a linear relationship between the curvature and the control offset, which can be utilized for future implementation of this control algorithm.

  20. Multi-Target Single Cycle Instrument Placement

    NASA Technical Reports Server (NTRS)

    Pedersen, Liam; Smith, David E.; Deans, Matthew; Sargent, Randy; Kunz, Clay; Lees, David; Rajagopalan, Srikanth; Bualat, Maria

    2005-01-01

    This presentation is about the robotic exploration of Mars using multiple targets command cycle, safe instrument placements, safe operation, and K9 Rover which has a 6 wheel steer rocket-bogey chassis (FIDO, MER), 70% MER size, 1.2 GHz Pentium M laptop running Linux OS, Odometry and compass/inclinometer, CLARAty architecture, 5 DOF manipulator w/CHAMP microscopic camera, SciCams, NavCams and HazCams.