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Sample records for drug-loaded implantable devices

  1. Biological in situ Dose Painting for Image-Guided Radiation Therapy Using Drug-Loaded Implantable Devices

    SciTech Connect

    Cormack, Robert A.; Sridhar, Srinivas; Suh, W. Warren; D'Amico, Anthony V.; Makrigiorgos, G. Mike

    2010-02-01

    Purpose: Implantable devices routinely used for increasing spatial accuracy in modern image-guided radiation treatments (IGRT), such as fiducials or brachytherapy spacers, encompass the potential for in situ release of biologically active drugs, providing an opportunity to enhance the therapeutic ratio. We model this new approach for two types of treatment. Methods and Materials: Radiopaque fiducials used in IGRT, or prostate brachytherapy spacers ('eluters'), were assumed to be loaded with radiosensitizer for in situ drug slow release. An analytic function describing the concentration of radiosensitizer versus distance from eluters, depending on diffusion-elimination properties of the drug in tissue, was developed. Tumor coverage by the drug was modeled for tumors typical of lung stereotactic body radiation therapy treatments for various eluter dimensions and drug properties. Six prostate {sup 125}I brachytherapy cases were analyzed by assuming implantation of drug-loaded spacers. Radiosensitizer-induced subvolume boost was simulated from which biologically effective doses for typical radiosensitizers were calculated in one example. Results: Drug distributions from three-dimensional arrangements of drug eluters versus eluter size and drug properties were tabulated. Four radiosensitizer-loaded fiducials provide adequate radiosensitization for {approx}4-cm-diameter lung tumors, thus potentially boosting biologically equivalent doses in centrally located stereotactic body treated lesions. Similarly, multiple drug-loaded spacers provide prostate brachytherapy with flexible shaping of 'biologically equivalent doses' to fit requirements difficult to meet by using radiation alone, e.g., boosting a high-risk region juxtaposed to the urethra while respecting normal tissue tolerance of both the urethra and the rectum. Conclusions: Drug loading of implantable devices routinely used in IGRT provides new opportunities for therapy modulation via biological in situ dose painting.

  2. In vitro study of drug loading on polymer-free oxide films of metallic implants.

    PubMed

    Shih, Chun-Ming; Shih, Chun-Che; Su, Yea-Yang; Chang, Nen-Chung; Lin, Shing-Jong

    2005-12-01

    Traditionally, a drug that is loaded onto a metallic surface has to use various polymer bondings as its platform. Unfortunately, polymer coatings on a metallic surface cause numerous problems after implantation, such as late thrombosis, inflammation, and restenosis. This research was conducted to investigate whether an oxide layer can be used as a polymer-free platform for drug loading, especially for cardiovascular stents. The interaction and loading of heparin onto different oxide films on 316LVM stainless steel wire was confirmed in vitro by experimental studies using linear voltammetry, electrochemical impedance spectroscopy, and electron spectroscopy for chemical analysis. The eluting of heparin from heparinized surface was studied by using high-performance liquid chromatography, and activated clotting time in addition to linear voltammetry and electron spectroscopy for chemical analysis analyses. Experimental results show that amorphous oxide could be a potential substitute for the polymer coating of drug-loaded stents for minimizing metallic corrosion, inflammation, late thrombosis, and restenosis. PMID:16082699

  3. Near-infrared fluorescence imaging platform for quantifying in vivo nanoparticle diffusion from drug loaded implants.

    PubMed

    Markovic, Stacey; Belz, Jodi; Kumar, Rajiv; Cormack, Robert A; Sridhar, Srinivas; Niedre, Mark

    2016-01-01

    Drug loaded implants are a new, versatile technology platform to deliver a localized payload of drugs for various disease models. One example is the implantable nanoplatform for chemo-radiation therapy where inert brachytherapy spacers are replaced by spacers doped with nanoparticles (NPs) loaded with chemotherapeutics and placed directly at the disease site for long-term localized drug delivery. However, it is difficult to directly validate and optimize the diffusion of these doped NPs in in vivo systems. To better study this drug release and diffusion, we developed a custom macroscopic fluorescence imaging system to visualize and quantify fluorescent NP diffusion from spacers in vivo. To validate the platform, we studied the release of free fluorophores, and 30 nm and 200 nm NPs conjugated with the same fluorophores as a model drug, in agar gel phantoms in vitro and in mice in vivo. Our data verified that the diffusion volume was NP size-dependent in all cases. Our near-infrared imaging system provides a method by which NP diffusion from implantable nanoplatform for chemo-radiation therapy spacers can be systematically optimized (eg, particle size or charge) thereby improving treatment efficacy of the platform. PMID:27069363

  4. Near-infrared fluorescence imaging platform for quantifying in vivo nanoparticle diffusion from drug loaded implants

    PubMed Central

    Markovic, Stacey; Belz, Jodi; Kumar, Rajiv; Cormack, Robert A; Sridhar, Srinivas; Niedre, Mark

    2016-01-01

    Drug loaded implants are a new, versatile technology platform to deliver a localized payload of drugs for various disease models. One example is the implantable nanoplatform for chemo-radiation therapy where inert brachytherapy spacers are replaced by spacers doped with nanoparticles (NPs) loaded with chemotherapeutics and placed directly at the disease site for long-term localized drug delivery. However, it is difficult to directly validate and optimize the diffusion of these doped NPs in in vivo systems. To better study this drug release and diffusion, we developed a custom macroscopic fluorescence imaging system to visualize and quantify fluorescent NP diffusion from spacers in vivo. To validate the platform, we studied the release of free fluorophores, and 30 nm and 200 nm NPs conjugated with the same fluorophores as a model drug, in agar gel phantoms in vitro and in mice in vivo. Our data verified that the diffusion volume was NP size-dependent in all cases. Our near-infrared imaging system provides a method by which NP diffusion from implantable nanoplatform for chemo-radiation therapy spacers can be systematically optimized (eg, particle size or charge) thereby improving treatment efficacy of the platform. PMID:27069363

  5. Efficient antitumor effect of co-drug-loaded nanoparticles with gelatin hydrogel by local implantation.

    PubMed

    Zhang, Hao; Tian, Yong; Zhu, Zhenshu; Xu, Huae; Li, Xiaolin; Zheng, Donghui; Sun, Weihao

    2016-01-01

    Tetrandrine (Tet) could enhance the antitumor effect of Paclitaxel (Ptx) by increasing intracellular Reactive Oxygen Species (ROS) levels, which leads to the possibility of co-delivery of both drugs for synergistic antitumor effect. In the current study, we reported an efficient, local therapeutic strategy employing effective Tet and Ptx delivery with a nanoparticle-loaded gelatin system. Tet- and Ptx co-loaded mPEG-PCL nanoparticles (P/T-NPs) were encapsulated into the physically cross-linked gelatin hydrogel and then implanted on the tumor site for continuous drug release. The drug-loaded gelatin hydrogel underwent a phase change when the temperature slowly increased. In vitro study showed that Tet/Ptx-loaded PEG-b-PCL nanoparticles encapsulated within a gelatin hydrogel (P/T-NPs-Gelatin) inhibited the growth and invasive ability of BGC-823 cells more effectively than the combination of free drugs or P/T-NPs. In vivo study validated the therapeutic potential of P/T-NPs-Gelatin. P/T-NPs-Gelatin significantly inhibited the activation of p-Akt and the downstream anti-apoptotic Bcl-2 protein and also inducing the activation of pro-apoptotic Bax protein. Moreover, the molecular-modulating effect of P/T-NPs-Gelatin on related proteins varied slightly under the influence of NAC, which was supported by the observations of the tumor volumes and weights. Based on these findings, local implantation of P/T-NPs-Gelatin may be a promising therapeutic strategy for the treatment of gastric cancer. PMID:27226240

  6. Efficient antitumor effect of co-drug-loaded nanoparticles with gelatin hydrogel by local implantation

    PubMed Central

    Zhang, Hao; Tian, Yong; Zhu, Zhenshu; Xu, Huae; Li, Xiaolin; Zheng, Donghui; Sun, Weihao

    2016-01-01

    Tetrandrine (Tet) could enhance the antitumor effect of Paclitaxel (Ptx) by increasing intracellular Reactive Oxygen Species (ROS) levels, which leads to the possibility of co-delivery of both drugs for synergistic antitumor effect. In the current study, we reported an efficient, local therapeutic strategy employing effective Tet and Ptx delivery with a nanoparticle-loaded gelatin system. Tet- and Ptx co-loaded mPEG-PCL nanoparticles (P/T-NPs) were encapsulated into the physically cross-linked gelatin hydrogel and then implanted on the tumor site for continuous drug release. The drug-loaded gelatin hydrogel underwent a phase change when the temperature slowly increased. In vitro study showed that Tet/Ptx-loaded PEG-b-PCL nanoparticles encapsulated within a gelatin hydrogel (P/T-NPs-Gelatin) inhibited the growth and invasive ability of BGC-823 cells more effectively than the combination of free drugs or P/T-NPs. In vivo study validated the therapeutic potential of P/T-NPs-Gelatin. P/T-NPs-Gelatin significantly inhibited the activation of p-Akt and the downstream anti-apoptotic Bcl-2 protein and also inducing the activation of pro-apoptotic Bax protein. Moreover, the molecular-modulating effect of P/T-NPs-Gelatin on related proteins varied slightly under the influence of NAC, which was supported by the observations of the tumor volumes and weights. Based on these findings, local implantation of P/T-NPs-Gelatin may be a promising therapeutic strategy for the treatment of gastric cancer. PMID:27226240

  7. Implantable CMOS Biomedical Devices

    PubMed Central

    Ohta, Jun; Tokuda, Takashi; Sasagawa, Kiyotaka; Noda, Toshihiko

    2009-01-01

    The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented. PMID:22291554

  8. [Implantable medical devices].

    PubMed

    Crickx, B; Arrault, X

    2008-01-01

    Medical devices have been individualized to include a category of implantable medical devices, "designed to be totally implanted in the human body or to replace an epithelial surface or a surface of the eye, through surgery, and remain in place after the intervention" (directive 93/42/CEE and decree of 20 April 206). Each implantable medical device has a common name and a commercial name for precise identification of the model (type/references). The users' service and the implanting physician should be clearly identified. There are a number of rules concerning health traceability to rapidly identify patients exposed to risks in which the implantable medical devices of a particular batch or series were used and to monitor the consequences. The traceability data should be preserved 10 years and the patient's medical file for 20 years. PMID:18442666

  9. Implantable electrical device

    NASA Technical Reports Server (NTRS)

    Jhabvala, M. D. (Inventor)

    1982-01-01

    A fully implantable and self contained device is disclosed composed of a flexible electrode array for surrounding damaged nerves and a signal generator for driving the electrode array with periodic electrical impulses of nanoampere magnitude to induce regeneration of the damaged nerves.

  10. Sterilisation of implantable devices.

    PubMed

    Matthews, I P; Gibson, C; Samuel, A H

    1994-01-01

    The pathogenesis and rates of infection associated with the use of a wide variety of implantable devices are described. The multi-factorial nature of post-operative periprosthetic infection is outlined and the role of sterilisation of devices is explained. The resistance of bacterial spores is highlighted as a problem and a full description is given of the processes of sterilisation by heat, steam, ethylene oxide, low temperature steam and formaldehyde, ionising radiation and liquid glutaraldehyde. Sterility assurance and validation are discussed in the context of biological indicators and physical/chemical indicators. Adverse effects upon the material composition of devices and problems of process control are listed. Finally, possible optimisations of the ethylene oxide process and their potential significance to the field of sterilisation of implants is explored. PMID:10172076

  11. Implantable medical devices MRI safe.

    PubMed

    Dal Molin, Renzo; Hecker, Bertrand

    2013-01-01

    Pacemakers, ICDs, neurostimulators like deep brain stimulator electrodes, spiral cord stimulators, insulin pumps, cochlear implants, retinal implants, hearing aids, electro cardio gram (ECG) leads, or devices in interventional MRI such as vascular guide wires or catheters are affected by MRI magnetic and electromagnetic fields. Design of MRI Safe medical devices requires computer modeling, bench testing, phantom testing, and animal studies. Implanted medical devices can be MRI unsafe, MRI conditional or MRI safe (see glossary). In the following paragraphs we will investigate how to design implanted medical devices MRI safe. PMID:23739365

  12. Implantable biomedical devices on bioresorbable substrates

    DOEpatents

    Rogers, John A; Kim, Dae-Hyeong; Omenetto, Fiorenzo; Kaplan, David L; Litt, Brian; Viventi, Jonathan; Huang, Yonggang; Amsden, Jason

    2014-03-04

    Provided herein are implantable biomedical devices, methods of administering implantable biomedical devices, methods of making implantable biomedical devices, and methods of using implantable biomedical devices to actuate a target tissue or sense a parameter associated with the target tissue in a biological environment. Each implantable biomedical device comprises a bioresorbable substrate, an electronic device having a plurality of inorganic semiconductor components supported by the bioresorbable substrate, and a barrier layer encapsulating at least a portion of the inorganic semiconductor components. Upon contact with a biological environment the bioresorbable substrate is at least partially resorbed, thereby establishing conformal contact between the implantable biomedical device and the target tissue in the biological environment.

  13. Batteries used to Power Implantable Biomedical Devices

    PubMed Central

    Bock, David C.; Marschilok, Amy C.; Takeuchi, Kenneth J.; Takeuchi, Esther S.

    2012-01-01

    Battery systems have been developed that provide years of service for implantable medical devices. The primary systems utilize lithium metal anodes with cathode systems including iodine, manganese oxide, carbon monofluoride, silver vanadium oxide and hybrid cathodes. Secondary lithium ion batteries have also been developed for medical applications where the batteries are charged while remaining implanted. While the specific performance requirements of the devices vary, some general requirements are common. These include high safety, reliability and volumetric energy density, long service life, and state of discharge indication. Successful development and implementation of these battery types has helped enable implanted biomedical devices and their treatment of human disease. PMID:24179249

  14. [Remote monitoring of active implantable medical device].

    PubMed

    Zhang, Yujing

    2013-09-01

    Active implantable medical device develops rapidly in recent years. The clinical demands and current application are introduced, the technical trends are discussed, and the safety risks are analyzed in this paper. PMID:24409793

  15. Implantable drug therapy device: A concept

    NASA Technical Reports Server (NTRS)

    Feldstein, C.

    1972-01-01

    Design is described of small, rechargeable, implantable infusor which contains fluid medicament stored under pressure and which dispenses fluid continuously through catheter. Body of infusor is covered by pliable silicone rubber sheath attached to suture pad for securing device.

  16. Biofeedback With Implanted Blood-Pressure Device

    NASA Technical Reports Server (NTRS)

    Rischell, Robert E.

    1988-01-01

    Additional uses found for equipment described in "Implanted Blood-Pressure-Measuring Device" (GSC-13042). Implanted with device electronic circuitry that measures, interprets, and transmits data via inductive link through patient's skin to external receiver. Receiver includes audible alarm generator activated when patient's blood pressure exceeds predetermined threshold. Also included in receiver a blood-pressure display, recorder, or both, for use by patient or physician.

  17. Cochlear implantation: current and future device options.

    PubMed

    Carlson, Matthew L; Driscoll, Colin L W; Gifford, René H; McMenomey, Sean O

    2012-02-01

    Today most cochlear implant users achieve above 80% on standard speech recognition in quiet testing, and enjoy excellent device reliability. Despite such success, conventional designs often fail to provide the frequency resolution required for complex listening tasks. Furthermore, performance variability remains a vexing problem, with a select group of patients performing poorly despite using the most recent technologies and processing strategies. This article provides a brief history of the development of cochlear implant technologies, reviews current implant systems from all 3 major manufacturers, examines recently devised strategies aimed at improving device performance, and discusses potential future developments. PMID:22115692

  18. 21 CFR 876.5270 - Implanted electrical urinary continence device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Implanted electrical urinary continence device. (a) Identification. An implanted electrical urinary device is a device intended for treatment of urinary incontinence that consists of a receiver implanted in... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Implanted electrical urinary continence...

  19. 21 CFR 876.5270 - Implanted electrical urinary continence device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Implanted electrical urinary continence device. (a) Identification. An implanted electrical urinary device is a device intended for treatment of urinary incontinence that consists of a receiver implanted in... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Implanted electrical urinary continence...

  20. Do implantable devices improve mood? Comparisons of chronic pain patients with or without an implantable device.

    PubMed

    Jamison, Robert N; Washington, Tabitha A; Fanciullo, Gilbert J; Ross, Edgar L; McHugo, Gregory J; Baird, John C

    2008-10-01

    Objective.  This descriptive study compares outcome measures of a computerized assessment of pain, emotional distress, and quality of life between chronic noncancer pain patients who have received an implantable device (spinal cord stimulator or intrathecal pump; N = 143) and those who have not received a device (N = 130). Methods.  Each patient marked the location of their pain on a body diagram and rated pain intensity, emotional distress, and impact of their pain on mood, sleep, and quality of life using a computerized pain assessment program. An electronic version of the Hospital Anxiety and Depression Scale (HADS) also was administered. Results.  No significant differences were found on the pain variables between the two groups. Patients with an implantable device gave lower ratings (less impact) on emotional distress (p < 0.05) and rated their health quality of life as better compared with control patients (p < 0.05). The patients with implantable devices also scored lower on the HADS Depression Subscale. Conclusion.  The results suggest that although patients with an implantable device seem to have more pathology and greater disability, they report less emotional distress and improved quality of life compared with patients with chronic pain without an implantable device. Future controlled trials are needed to establish the role that an implantable device plays in improving mood and quality of life. PMID:22151138

  1. Implantable Devices for Sustained, Intravesical Drug Delivery

    PubMed Central

    2016-01-01

    In clinical settings, intravesical instillation of a drug bolus is often performed for the treatment of bladder diseases. However, it requires repeated instillations to extend drug efficacy, which may result in poor patient compliance. To alleviate this challenge, implantable devices have been developed for the purpose of sustained, intravesical drug delivery. In this review, we briefly summarize the current trend in the development of intravesical drug-delivery devices. We also introduce the most recently developed devices with strong potential for intravesical drug-delivery applications. PMID:27377941

  2. Three-Dimensional Printed PCL-Based Implantable Prototypes of Medical Devices for Controlled Drug Delivery.

    PubMed

    Holländer, Jenny; Genina, Natalja; Jukarainen, Harri; Khajeheian, Mohammad; Rosling, Ari; Mäkilä, Ermei; Sandler, Niklas

    2016-09-01

    The goal of the present study was to fabricate drug-containing T-shaped prototypes of intrauterine system (IUS) with the drug incorporated within the entire backbone of the medical device using 3-dimensional (3D) printing technique, based on fused deposition modeling (FDM™). Indomethacin was used as a model drug to prepare drug-loaded poly(ε-caprolactone)-based filaments with 3 different drug contents, namely 5%, 15%, and 30%, by hot-melt extrusion. The filaments were further used to 3D print IUS. The results showed that the morphology and drug solid-state properties of the filaments and 3D prototypes were dependent on the amount of drug loading. The drug release profiles from the printed devices were faster than from the corresponding filaments due to a lower degree of the drug crystallinity in IUS in addition to the differences in the external/internal structure and geometry between the products. Diffusion of the drug from the polymer was the predominant mechanism of drug release, whereas poly(ε-caprolactone) biodegradation had a minor effect. This study shows that 3D printing is an applicable method in the production of drug-containing IUS and can open new ways in the fabrication of controlled release implantable devices. PMID:26906174

  3. Power Approaches for Implantable Medical Devices

    PubMed Central

    Ben Amar, Achraf; Kouki, Ammar B.; Cao, Hung

    2015-01-01

    Implantable medical devices have been implemented to provide treatment and to assess in vivo physiological information in humans as well as animal models for medical diagnosis and prognosis, therapeutic applications and biological science studies. The advances of micro/nanotechnology dovetailed with novel biomaterials have further enhanced biocompatibility, sensitivity, longevity and reliability in newly-emerged low-cost and compact devices. Close-loop systems with both sensing and treatment functions have also been developed to provide point-of-care and personalized medicine. Nevertheless, one of the remaining challenges is whether power can be supplied sufficiently and continuously for the operation of the entire system. This issue is becoming more and more critical to the increasing need of power for wireless communication in implanted devices towards the future healthcare infrastructure, namely mobile health (m-Health). In this review paper, methodologies to transfer and harvest energy in implantable medical devices are introduced and discussed to highlight the uses and significances of various potential power sources. PMID:26580626

  4. Power Approaches for Implantable Medical Devices.

    PubMed

    Ben Amar, Achraf; Kouki, Ammar B; Cao, Hung

    2015-01-01

    Implantable medical devices have been implemented to provide treatment and to assess in vivo physiological information in humans as well as animal models for medical diagnosis and prognosis, therapeutic applications and biological science studies. The advances of micro/nanotechnology dovetailed with novel biomaterials have further enhanced biocompatibility, sensitivity, longevity and reliability in newly-emerged low-cost and compact devices. Close-loop systems with both sensing and treatment functions have also been developed to provide point-of-care and personalized medicine. Nevertheless, one of the remaining challenges is whether power can be supplied sufficiently and continuously for the operation of the entire system. This issue is becoming more and more critical to the increasing need of power for wireless communication in implanted devices towards the future healthcare infrastructure, namely mobile health (m-Health). In this review paper, methodologies to transfer and harvest energy in implantable medical devices are introduced and discussed to highlight the uses and significances of various potential power sources. PMID:26580626

  5. Treatment of Infected Cardiac Implantable Electronic Devices.

    PubMed

    Fakhro, Abdulla; Jalalabadi, Faryan; Brown, Rodger H; Izaddoost, Shayan A

    2016-05-01

    With their rising benefits, cardiac implantable electronic devices (CIEDs) such as pacemakers and left ventricular assist devices (LVADs) have witnessed a sharp rise in use over the past 50 years. As indications for use broaden, so too does their widespread employment with its attendant rise of CIED infections. Such large numbers of infections have inspired various algorithms mandating treatment. Early diagnosis of inciting organisms is crucial to tailoring appropriate antibiotic and or antifungal treatment. In addition, surgical debridement and explant of the device have been a longstanding modality of care. More novel therapies focus on salvage of the device by way of serial washouts and instilling drug-eluting antibiotic impregnated beads into the wound. The wound is then serially debrided until clean and closed. This technique is better suited to patients whose device cannot be removed, patients who are poor candidates for cardiac surgery, or patients who have failed conventional prior treatments. PMID:27152097

  6. 21 CFR 876.5270 - Implanted electrical urinary continence device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Implanted electrical urinary continence device. 876.5270 Section 876.5270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5270 Implanted electrical urinary continence device....

  7. Implantable photonic devices for improved medical treatments.

    PubMed

    Sheinman, Victor; Rudnitsky, Arkady; Toichuev, Rakhmanbek; Eshiev, Abdyrakhman; Abdullaeva, Svetlana; Egemkulov, Talantbek; Zalevsky, Zeev

    2014-01-01

    An evolving area of biomedical research is related to the creation of implantable units that provide various possibilities for imaging, measurement, and the monitoring of a wide range of diseases and intrabody phototherapy. The units can be autonomic or built-in in some kind of clinically applicable implants. Because of specific working conditions in the live body, such implants must have a number of features requiring further development. This topic can cause wide interest among developers of optical, mechanical, and electronic solutions in biomedicine. We introduce preliminary clinical trials obtained with an implantable pill and devices that we have developed. The pill and devices are capable of applying in-body phototherapy, low-level laser therapy, blue light (450 nm) for sterilization, and controlled injection of chemicals. The pill is also capable of communicating with an external control box, including the transmission of images from inside the patient’s body. In this work, our pill was utilized for illumination of the sinus-carotid zone in dog and red light influence on arterial pressure and heart rate was demonstrated. Intrabody liver tissue laser ablation and nanoparticle-assisted laser ablation was investigated. Sterilization effect of intrabody blue light illumination was applied during a maxillofacial phlegmon treatment. PMID:25279540

  8. Implantable photonic devices for improved medical treatments

    NASA Astrophysics Data System (ADS)

    Sheinman, Victor; Rudnitsky, Arkady; Toichuev, Rakhmanbek; Eshiev, Abdyrakhman; Abdullaeva, Svetlana; Egemkulov, Talantbek; Zalevsky, Zeev

    2014-10-01

    An evolving area of biomedical research is related to the creation of implantable units that provide various possibilities for imaging, measurement, and the monitoring of a wide range of diseases and intrabody phototherapy. The units can be autonomic or built-in in some kind of clinically applicable implants. Because of specific working conditions in the live body, such implants must have a number of features requiring further development. This topic can cause wide interest among developers of optical, mechanical, and electronic solutions in biomedicine. We introduce preliminary clinical trials obtained with an implantable pill and devices that we have developed. The pill and devices are capable of applying in-body phototherapy, low-level laser therapy, blue light (450 nm) for sterilization, and controlled injection of chemicals. The pill is also capable of communicating with an external control box, including the transmission of images from inside the patient's body. In this work, our pill was utilized for illumination of the sinus-carotid zone in dog and red light influence on arterial pressure and heart rate was demonstrated. Intrabody liver tissue laser ablation and nanoparticle-assisted laser ablation was investigated. Sterilization effect of intrabody blue light illumination was applied during a maxillofacial phlegmon treatment.

  9. Left Ventricular Assist Device Implantation After Intracardiac Parachute Device Removal.

    PubMed

    Abu Saleh, Walid K; Al Jabbari, Odeaa; Bruckner, Brian A; Suarez, Erik E; Estep, Jerry D; Loebe, Matthias

    2015-08-01

    Left ventricular assist device implantation is a proven and efficient modality for the treatment of end-stage heart failure. Left ventricular assist device versatility as a bridge to heart transplantation or destination therapy has led to improved patient outcomes with a concomitant rise in its overall use. Other less invasive treatment modalities are being developed to improve heart function and morbidity and mortality for the heart failure population. Percutaneous ventricular restoration is a new investigational therapy that deploys an intracardiac parachute to wall off damaged myocardium in patients with dilated left ventricles and ischemic heart failure. Clinical trials are under way to test the efficacy of percutaneous ventricular restoration using the parachute device. This review describes our encounter with the parachute device, its explantation due to refractory heart failure, and surgical replacement with a left ventricular assist device. PMID:26234850

  10. Right ventricular failure after left ventricular assist device implantation: the need for an implantable right ventricular assist device.

    PubMed

    Furukawa, Kojiro; Motomura, Tadashi; Nosé, Yukihiko

    2005-05-01

    Right ventricular failure after implantation of a left ventricular assist device is an unremitting problem. Consideration of portal circulation is important for reversing liver dysfunction and preventing multiple organ failure after left ventricular assist device implantation. To achieve these objectives, it is imperative to maintain the central venous pressure as low as possible. A more positive application of right ventricular assistance is recommended. Implantable pulsatile left ventricular assist devices cannot be used as a right ventricular assist device because of their structure and device size. To improve future prospects, it is necessary to develop an implantable right ventricular assist device based on a rotary blood pump. PMID:15854212

  11. Characterization of implantable microfabricated fluid delivery devices.

    PubMed

    Rathnasingham, Ruben; Kipke, Daryl R; Bledsoe, Sanford C; McLaren, John D

    2004-01-01

    The formal characterization of the performance of microfluidic delivery devices is crucial for reliable in vivo application. A comprehensive laboratory technique was developed and used to optimize, calibrate and validate microfabricated fluid delivery devices. In vivo experiments were carried out to verify the accuracy and reliability of the pressure driven devices. Acute guinea pig experiments were conducted to measure the response to alpha-amino-3-hydroxy-5-methyl-4-isoxalone propionic acid, an excitatory neurotransmitter, at multiple locations in the inferior colliculus. A nondimensional parameter, Q, was successfully used to classify devices in terms of geometry alone (i.e., independent of fluid properties). Functional devices exhibited long-term linearity and reliability in delivering single phase, Newtonian fluids, in discrete volumes with a resolution of 500 picoliters at less than 0.45 lbf/in2 (30 mbar) pressure drop. Results for non-Newtonian fluids are not presented here. The acute results showed a proportional increase in the firing rate for delivered volumes of 2 nL up to 10 nL (at rates of between 0.1 and 1 nL/s). Flow characteristics are maintained during acute experiments and post-implant. A control experiment conducted with Ringer solution produced negligible effects, suggesting the results to be truly pharmacological. The experimental techniques employed have proven to be reliable and will be used for future calibration and testing of next generation chronic microfluidic delivery devices. PMID:14723503

  12. Integrated Microbatteries for Implantable Medical Devices

    NASA Technical Reports Server (NTRS)

    Whitacre, Jay; West, William

    2008-01-01

    Integrated microbatteries have been proposed to satisfy an anticipated need for long-life, low-rate primary batteries, having volumes less than 1 mm3, to power electronic circuitry in implantable medical devices. In one contemplated application, such a battery would be incorporated into a tubular hearing-aid device to be installed against an eardrum. This device is based on existing tube structures that have already been approved by the FDA for use in human ears. As shown in the figure, the battery would comprise a single cell at one end of the implantable tube. A small volume of Li-based primary battery cathode material would be compacted and inserted in the tube near one end, followed by a thin porous separator, followed by a pressed powder of a Li-containing alloy. Current-collecting wires would be inserted, with suitably positioned insulators to prevent a short circuit. The battery would contain a liquid electrolyte consisting of a Li-based salt in an appropriate solvent. Hermetic seals would be created by plugging both ends with a waterproof polymer followed by deposition of parylene.

  13. [Future of implantable electrical cardiac devices].

    PubMed

    Daubert, Jean-Claude; Behaghel, Albin; Leclercq, Christophe; Mabo, Philippe

    2014-03-01

    Major improvements in implantable electrical cardiac devices have been made during the last two decades, notably with the advent of automatic internal defibrillation (ICD) to prevent sudden arrhythmic death, and cardiac resynchronisation (CRT) to treat the discoordinated failing heart. They now constitute a major therapeutic option and may eventually supersede drug therapy. The coming era will be marked by a technological revolution, with improvements in treatment delivery, safety and efficacy, and an expansion of clinical indications. Leadless technologyfor cardiac pacemakers and defibrillators is already in the pipeline, endovascular leads currently being responsible for most long-term complications (lead failure, infection, vein thrombosis, etc.). Miniaturized pacemakers based on nanotechnology can now be totally implanted inside the right ventricle through the transvenous route, thus eliminating leads, pockets and scarring In the same way, totally subcutaneous ICD systems are now available, although they are currently only capable of delivering shocks, without pacing (including antitachycardia pacing). In CRT optimised delivery is important to improve clinical responses and to reduce the non-response rate (around 30 % with current technology). Endocardial left ventricular pacing could be a solution if it can be achieved at an acceptable risk. Multisite ventricular pacing is an alternative. Besides CRT neuromodulation, especially by vagal stimulation, is another important field of device researchfor heart failure. Preliminary clinical results are encouraging. PMID:26427291

  14. Modulation Techniques for Biomedical Implanted Devices and Their Challenges

    PubMed Central

    Hannan, Mahammad A.; Abbas, Saad M.; Samad, Salina A.; Hussain, Aini

    2012-01-01

    Implanted medical devices are very important electronic devices because of their usefulness in monitoring and diagnosis, safety and comfort for patients. Since 1950s, remarkable efforts have been undertaken for the development of bio-medical implanted and wireless telemetry bio-devices. Issues such as design of suitable modulation methods, use of power and monitoring devices, transfer energy from external to internal parts with high efficiency and high data rates and low power consumption all play an important role in the development of implantable devices. This paper provides a comprehensive survey on various modulation and demodulation techniques such as amplitude shift keying (ASK), frequency shift keying (FSK) and phase shift keying (PSK) of the existing wireless implanted devices. The details of specifications, including carrier frequency, CMOS size, data rate, power consumption and supply, chip area and application of the various modulation schemes of the implanted devices are investigated and summarized in the tables along with the corresponding key references. Current challenges and problems of the typical modulation applications of these technologies are illustrated with a brief suggestions and discussion for the progress of implanted device research in the future. It is observed that the prime requisites for the good quality of the implanted devices and their reliability are the energy transformation, data rate, CMOS size, power consumption and operation frequency. This review will hopefully lead to increasing efforts towards the development of low powered, high efficient, high data rate and reliable implanted devices. PMID:22368470

  15. Degradability of Polymers for Implantable Biomedical Devices

    PubMed Central

    Lyu, SuPing; Untereker, Darrel

    2009-01-01

    Many key components of implantable medical devices are made from polymeric materials. The functions of these materials include structural support, electrical insulation, protection of other materials from the environment of the body, and biocompatibility, as well as other things such as delivery of a therapeutic drug. In such roles, the stability and integrity of the polymer, over what can be a very long period of time, is very important. For most of these functions, stability over time is desired, but in other cases, the opposite–the degradation and disappearance of the polymer over time is required. In either case, it is important to understand both the chemistry that can lead to the degradation of polymers as well as the kinetics that controls these reactions. Hydrolysis and oxidation are the two classes of reactions that lead to the breaking down of polymers. Both are discussed in detail in the context of the environmental factors that impact the utility of various polymers for medical device applications. Understanding the chemistry and kinetics allows prediction of stability as well as explanations for observations such as porosity and the unexpected behavior of polymeric composite materials in some situations. In the last part, physical degradation such interfacial delamination in composites is discussed. PMID:19865531

  16. Injury to the coronary arteries and related structures by implantation of cardiac implantable electronic devices.

    PubMed

    Pang, Benjamin J; Barold, S Serge; Mond, Harry G

    2015-04-01

    Damage to the coronary arteries and related structures from pacemaker and implantable cardioverter-defibrillator lead implantation is a rarely reported complication that can lead to myocardial infarction and pericardial tamponade that may occur acutely or even years later. We summarize the reported cases of injury to coronary arteries and related structures and review the causes of troponin elevation in the setting of cardiac implantable electronic device implantation. PMID:25564549

  17. Dealing with a left ventricular pseudoaneurysm during assist device implant.

    PubMed

    Ha, Richard V; Chiu, Peter; Banerjee, Dipanjan; Sheikh, Ahmad Y

    2016-06-01

    Despite increasing use of left ventricular devices for the surgical treatment of heart failure, there is limited experience with implantation of devices in the setting of challenging left apical anatomy. We report the case of a 68-year-old man with a chronic post-infarction calcified apical pseudoaneurysm, who underwent pseudoaneurysmectomy, ventricular myoplasty, and left ventricular assist device implantation. A review of the literature and operative strategies are presented. PMID:25834125

  18. 77 FR 36951 - Gastroenterology-Urology Devices; Reclassification of Implanted Blood Access Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-20

    ... requirement for premarket approval for implanted blood access devices (52 FR 17732 at 17738, May 11, 1987). In 2009, FDA published an order for the submission of information on implanted blood access devices (74 FR... the Device In the preamble to the proposed rule (46 FR 7616, January 23, 1981), the...

  19. Management of Cardiac Implantable Electronic Device Infection

    PubMed Central

    Podoleanu, Cristian

    2014-01-01

    Despite improved preventive measures, infection associated with the use of cardiac implantable electronic devices (CIEDs) to treat often life-threatening conditions is rising at an average annual rate of almost 5 %. This rise is being driven by the increasing complexity of CIED technology and by the advancing age and co-morbidities of the patients. Although CIED infection is usually suspected based on local signs at the generator pocket site, diagnosis can be challenging in patients presenting no local manifestations or symptoms. Diagnostic methods include microbiological testing and echocardiography, and may be completed by positron emission tomography (PET)/computed tomography (CT) scan in selected cases. CIED infection requires a multidisciplinary approach in view of hardware extraction, targeted antibiotic therapy and reimplantation on an as-needed basis. Antibiotic prophylaxis targeting staphylococcal flora is recommended but the relation of these infections to medical care exposes patients to multi-resistant bacteria. New preventive measures utilising an antibacterial sleeve look promising. Treatment can be started on an empirical basis using an antistaphylococcal agent but must be continued using targeted antibiotic therapy. Crucial questions remain as to the best prevention strategy, optimal duration and timing of antibiotic therapy, and the most effective reimplantation technique. PMID:26835089

  20. Energy harvesting for the implantable biomedical devices: issues and challenges

    PubMed Central

    2014-01-01

    The development of implanted devices is essential because of their direct effect on the lives and safety of humanity. This paper presents the current issues and challenges related to all methods used to harvest energy for implantable biomedical devices. The advantages, disadvantages, and future trends of each method are discussed. The concept of harvesting energy from environmental sources and human body motion for implantable devices has gained a new relevance. In this review, the harvesting kinetic, electromagnetic, thermal and infrared radiant energies are discussed. Current issues and challenges related to the typical applications of these methods for energy harvesting are illustrated. Suggestions and discussion of the progress of research on implantable devices are also provided. This review is expected to increase research efforts to develop the battery-less implantable devices with reduced over hole size, low power, high efficiency, high data rate, and improved reliability and feasibility. Based on current literature, we believe that the inductive coupling link is the suitable method to be used to power the battery-less devices. Therefore, in this study, the power efficiency of the inductive coupling method is validated by MATLAB based on suggested values. By further researching and improvements, in the future the implantable and portable medical devices are expected to be free of batteries. PMID:24950601

  1. 21 CFR 876.5270 - Implanted electrical urinary continence device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (premarket approval). (c) Date PMA or notice of completion of a PDP is required. A PMA or a notice of..., 1976. Any other implanted electrical urinary continence device shall have an approved PMA or a...

  2. 21 CFR 876.5270 - Implanted electrical urinary continence device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (premarket approval). (c) Date PMA or notice of completion of a PDP is required. A PMA or a notice of..., 1976. Any other implanted electrical urinary continence device shall have an approved PMA or a...

  3. Perioperative Management of Multiple Noncardiac Implantable Electronic Devices.

    PubMed

    Ramos, Juan A; Brull, Sorin J

    2015-12-01

    The number of patients with noncardiac implantable electronic devices is increasing, and the absence of perioperative management standards, guidelines, practice parameters, or expert consensus statements presents clinical challenges. A 69-year-old woman presented for latissimus dorsi breast reconstruction. The patient had previously undergone implantation of a spinal cord stimulator, a gastric pacemaker, a sacral nerve stimulator, and an intrathecal morphine pump. After consultation with device manufacturers, the devices with patient programmability were switched off. Bipolar cautery was used intraoperatively. Postoperatively, all devices were interrogated to ensure appropriate functioning before home discharge. Perioperative goals include complete preoperative radiologic documentation of device component location, minimizing electromagnetic interference, and avoiding mechanical damage to implanted device components. PMID:26588030

  4. Development of Implantable Medical Devices: From an Engineering Perspective

    PubMed Central

    2013-01-01

    From the first pacemaker implant in 1958, numerous engineering and medical activities for implantable medical device development have faced challenges in materials, battery power, functionality, electrical power consumption, size shrinkage, system delivery, and wireless communication. With explosive advances in scientific and engineering technology, many implantable medical devices such as the pacemaker, cochlear implant, and real-time blood pressure sensors have been developed and improved. This trend of progress in medical devices will continue because of the coming super-aged society, which will result in more consumers for the devices. The inner body is a special space filled with electrical, chemical, mechanical, and marine-salted reactions. Therefore, electrical connectivity and communication, corrosion, robustness, and hermeticity are key factors to be considered during the development stage. The main participants in the development stage are the user, the medical staff, and the engineer or technician. Thus, there are three different viewpoints in the development of implantable devices. In this review paper, considerations in the development of implantable medical devices will be presented from the viewpoint of an engineering mind. PMID:24143287

  5. Development of implantable medical devices: from an engineering perspective.

    PubMed

    Joung, Yeun-Ho

    2013-09-01

    From the first pacemaker implant in 1958, numerous engineering and medical activities for implantable medical device development have faced challenges in materials, battery power, functionality, electrical power consumption, size shrinkage, system delivery, and wireless communication. With explosive advances in scientific and engineering technology, many implantable medical devices such as the pacemaker, cochlear implant, and real-time blood pressure sensors have been developed and improved. This trend of progress in medical devices will continue because of the coming super-aged society, which will result in more consumers for the devices. The inner body is a special space filled with electrical, chemical, mechanical, and marine-salted reactions. Therefore, electrical connectivity and communication, corrosion, robustness, and hermeticity are key factors to be considered during the development stage. The main participants in the development stage are the user, the medical staff, and the engineer or technician. Thus, there are three different viewpoints in the development of implantable devices. In this review paper, considerations in the development of implantable medical devices will be presented from the viewpoint of an engineering mind. PMID:24143287

  6. 78 FR 17940 - Certain Computerized Orthopedic Surgical Devices, Software, Implants, and Components Thereof...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ... COMMISSION Certain Computerized Orthopedic Surgical Devices, Software, Implants, and Components Thereof..., Software, Implants, and Components Thereof, DN 2945; the Commission is soliciting comments on any public... devices, software, implants, and components thereof. The complaint names as respondents Stanmore...

  7. New horizon for infection prevention technology and implantable device.

    PubMed

    Kondo, Yusuke; Ueda, Marehiko; Kobayashi, Yoshio; Schwab, Joerg O

    2016-08-01

    There has been a significant increase in the number of patients receiving cardiovascular implantable electronic devices (CIED) over the last two decades. CIED infection represents a serious complication after CIED implantation and is associated with significant morbidity and mortality. Recently, newly advanced technologies have offered attractive and suitable therapeutic alternatives. Notably, the leadless pacemaker and anti-bacterial envelope decrease the potential risk of CIED infection and the resulting mortality, when it does occur. A completely subcutaneous implantable cardioverter defibrillator is also an alternative to the transvenous implantable cardioverter defibrillator (ICD), as it does not require implantation of any transvenous or epicardial leads. Among the patients who require ICD removal and subsequent antibiotics secondary to infection, the wearable cardioverter defibrillator represents an alternative approach to inpatient monitoring for the prevention of sudden cardiac death. In this review paper, we aimed to introduce the advanced technologies and devices for prevention of CIED infection. PMID:27588153

  8. Surgical implant techniques of left ventricular assist devices: an overview of acute and durable devices

    PubMed Central

    2015-01-01

    Left ventricular support for the failing heart has evolved to include short-term and long-term devices. These devices are implanted percutaneously and surgically. This manuscript provides a general overview of the contemporary, typically practiced, implant techniques with additional insight on minimally invasive approaches. PMID:26793329

  9. Orthopedic medical devices: ethical questions, implant recalls and responsibility.

    PubMed

    Racine, Jennifer

    2013-06-01

    The hip replacement is a surgical procedure to replace the femoral head and acetabulum with prosthetic implants to improve function, increase mobility, and relieve pain caused by damage from disorders such as osteoarthritis and fractures. In recent years, we have seen several recalls of poorly functioning implant systems, most recently, the Johnson and Johnson (J&J) Articular Surface Replacement device. Product recalls are often the results of premature failure of implants requiring additional surgery to exchange the failed device. This raises many questions - technical, medical, regulatory, ethical, and legal - that ultimately put patients at risk, compromise confidence in medicine and regulatory agencies, and important relationships including those between the physician-patient and physician-industry. Where do the responsibilities lie for the patients' suffering, morbidity, and costs of removing the failed device? This article discusses the current recall of the J&J implant, the responsibilities of the manufacturer, surgeons, and the regulatory agency. PMID:23741723

  10. Recharging the battery of implantable biomedical devices by light.

    PubMed

    Algora, Carlos; Peña, Rafael

    2009-10-01

    This article describes a new powering system for implantable medical devices that could significantly increase their lifetime. The idea is based on the substitution of the usual implantable device battery for an electric accumulator (rechargeable battery), which is fed by the electric power generated by a photovoltaic converter inside the implantable device. Light impinges on the photovoltaic device through an optical fiber going from the photovoltaic device to just beneath the patient's epidermis. Light can enter the optical fiber by passing through the skin. A complete power-by-light system has been developed and tested with a real implantable pulse generator for spinal cord stimulation. The feasibility of the proposed system has been evaluated theoretically. For example, after 13 h/week of laser exposure, the lifetime of the implantable device would increase by 50%. Other combinations resulting in lifetime increases of more than 100% are also possible. So, the proposed system is now ready to take a further step forward: in vivo animal testing. PMID:19624580

  11. Infected cardiac-implantable electronic devices: prevention, diagnosis, and treatment.

    PubMed

    Nielsen, Jens Cosedis; Gerdes, Jens Christian; Varma, Niraj

    2015-10-01

    Cardiac implantable electronic device (CIED) infection, according to current trends, appears to be an increasing problem. It can be indolent and its diagnosis challenging. Cardiac implantable electronic device infections are potentially lethal, and timely diagnosis and early initiation of correct treatment are of highest importance for patient prognosis. For reducing CIED infections, careful patient selection, preventative measures, and appropriate choice of device are key. The current review presents available data and consensus opinion within the field of CIED infection and identifies important current practice points and aspects for future development. Strategies for reducing CIED infection should be tested in sufficiently powered and well-designed multicentre randomized controlled trials. PMID:25749852

  12. Left ventricular assist device implantation strategies and outcomes

    PubMed Central

    Smith, LaVone A.; Yarboro, Leora T.

    2015-01-01

    Over the past 15 years, the field of mechanical circulatory support has developed significantly. Currently, there are a multitude of options for both short and long term cardiac support. Choosing the appropriate device for each patient depends on the amount of support needed and the goals of care. This article focuses on long term, implantable devices for both bridge to transplantation and destination therapy indications. Implantation strategies, including the appropriate concomitant surgeries are discussed as well as expected long term outcomes. As device technology continues to improve, long term mechanical circulatory support may become a viable alternative to transplantation. PMID:26793328

  13. Single glucose biofuel cells implanted in rats power electronic devices.

    PubMed

    Zebda, A; Cosnier, S; Alcaraz, J-P; Holzinger, M; Le Goff, A; Gondran, C; Boucher, F; Giroud, F; Gorgy, K; Lamraoui, H; Cinquin, P

    2013-01-01

    We describe the first implanted glucose biofuel cell (GBFC) that is capable of generating sufficient power from a mammal's body fluids to act as the sole power source for electronic devices. This GBFC is based on carbon nanotube/enzyme electrodes, which utilize glucose oxidase for glucose oxidation and laccase for dioxygen reduction. The GBFC, implanted in the abdominal cavity of a rat, produces an average open-circuit voltage of 0.57 V. This implanted GBFC delivered a power output of 38.7 μW, which corresponded to a power density of 193.5 μW cm(-2) and a volumetric power of 161 μW mL(-1). We demonstrate that one single implanted enzymatic GBFC can power a light-emitting diode (LED), or a digital thermometer. In addition, no signs of rejection or inflammation were observed after 110 days implantation in the rat. PMID:23519113

  14. Single Glucose Biofuel Cells Implanted in Rats Power Electronic Devices

    PubMed Central

    Zebda, A.; Cosnier, S.; Alcaraz, J.-P.; Holzinger, M.; Le Goff, A.; Gondran, C.; Boucher, F.; Giroud, F.; Gorgy, K.; Lamraoui, H.; Cinquin, P.

    2013-01-01

    We describe the first implanted glucose biofuel cell (GBFC) that is capable of generating sufficient power from a mammal's body fluids to act as the sole power source for electronic devices. This GBFC is based on carbon nanotube/enzyme electrodes, which utilize glucose oxidase for glucose oxidation and laccase for dioxygen reduction. The GBFC, implanted in the abdominal cavity of a rat, produces an average open-circuit voltage of 0.57 V. This implanted GBFC delivered a power output of 38.7 μW, which corresponded to a power density of 193.5 μW cm−2 and a volumetric power of 161 μW mL−1. We demonstrate that one single implanted enzymatic GBFC can power a light-emitting diode (LED), or a digital thermometer. In addition, no signs of rejection or inflammation were observed after 110 days implantation in the rat. PMID:23519113

  15. Why We Need Postmortem Analysis of Cardiac Implantable Electronic Devices.

    PubMed

    Mauf, Sabrina; Jentzsch, Thorsten; Laberke, Patrick J; Thali, Michael J; Bartsch, Christine

    2016-07-01

    The prevalence of cardiac implantable electronic devices (CIEDs), pacemakers and implantable cardioverter defibrillators (ICDs) is increasing. However, postmortem analysis of CIEDs is not performed routinely. Fourteen consecutive CIEDs were analyzed. The indication for and date of implantation, technical data, CIED reprogramming, heart rhythm disturbances, patient demographics and medical consultations were investigated. Death during the first year after implantation was seen in 54%, whereof 71% consulted a physician within 10 days before death. The time of death was attributed to a particular day in 29%. There was a relationship between CIEDs and cause/manner of death in 50%. Although limited by a small sample size, this study advocates the routine postmortem CIED analysis for forensic and clinical purposes in selected cases. Patients with CIEDs seem to show an increased risk of death during the first year after implantation. The analysis of CIEDs can be helpful in evaluating the time/cause/manner of death. PMID:27364278

  16. Tritium implantation in the accelerator production of tritium device

    SciTech Connect

    Kidman, R.B.

    1997-11-01

    We briefly describe the methods we have developed to compute the magnitude and spatial distribution of born and implanted tritons and protons in the Accelerator Production of Tritium (AFT) device. The methods are verified against experimental measurements and then used to predict that 16% of the tritium is implanted in the walls of the APT distribution tubes. The methods are also used to estimate the spatial distribution of implanted tritium, which will be required for determining the possible diffusion of tritium out of the walls and back into the gas stream.

  17. Cardiac Implantable Electronic Device Infection in Patients at Risk

    PubMed Central

    Tarakji, Khaldoun G; Ellis, Christopher R; Defaye, Pascal; Kennergren, Charles

    2016-01-01

    The incidence of infection following implantation of cardiac implantable electronic devices (CIEDs) is increasing at a faster rate than that of device implantation. Patients with a CIED infection usually require hospitalisation and complete device and lead removal. A significant proportion die from their infection. Transvenous lead extraction (TLE) is associated with rare but serious complications including major vascular injury or cardiac perforation. Operator experience and advances in lead extraction methods, including laser technology and rotational sheaths, have resulted in procedures having a low risk of complication and mortality. Strategies for preventing CIED infections include intravenous antibiotics and aseptic surgical techniques. An additional method to reduce CIED infection may be the use of antibacterial TYRX™ envelope. Data from non-randomised cohort studies have indicated that antibacterial envelope use can reduce the incidence of CIED infection by more than 80 % in high-risk patients and a randomised clinical trial is ongoing. PMID:27403296

  18. MRI compatibility and visibility assessment of implantable medical devices.

    PubMed

    Schueler, B A; Parrish, T B; Lin, J C; Hammer, B E; Pangrle, B J; Ritenour, E R; Kucharczyk, J; Truwit, C L

    1999-04-01

    We have developed a protocol to evaluate the magnetic resonance (MR) compatibility of implantable medical devices. The testing protocol consists of the evaluation of magnetic field-induced movement, electric current, heating, image distortion, and device operation. In addition, current induction is evaluated with a finite element analysis simulation technique that models the effect of radiofrequency fields on each device. The protocol has been applied to several implantable infusion pumps and neurostimulators with associated attachments. Experiments were performed using a 1.5-T whole-body MR system with parameters selected to approximate the intended clinical and worst case configuration. The devices exhibited moderate magnetic field-induced deflection and torque but had significant image artifacts. No heating was detected for any of the devices. Pump operation was halted in the magnetic field, but resumed after removed. Exposure to the magnetic field activated some of the neurostimulators. PMID:10232520

  19. Implantable rhythm devices and electromagnetic interference: myth or reality?

    PubMed

    Dyrda, Katia; Khairy, Paul

    2008-07-01

    Current medical guidelines have prompted implementation of increasing numbers of implantable rhythm devices, be they pacemakers, internal cardioverter-defibrillators or loop recorders. These devices rely on complex microcircuitry and use electromagnetic waves for communication. They are, therefore, susceptible to interference from surrounding electromagnetic radiation and magnetic energy. Hermetic shielding in metallic cases, filters, interference rejection circuits and bipolar sensing have contributed to their relative resistance to electromagnetic interference (EMI) in household and workplace environments. Device interactions have occurred in hospitals where EMI sources are ubiquitous, including radiation, electrocautery and MRI exposures. However, with rapidly evolving technology, devices and potential sources of EMI continue to change. This review provides a contemporary overview of the current state of knowledge regarding risks attributable to EMI; highlights current limitations of implantable rhythm devices; and attempts to distinguish myths from realities. PMID:18570620

  20. Critical appraisal of cardiac implantable electronic devices: complications and management

    PubMed Central

    Padeletti, Luigi; Mascioli, Giosuè; Perini, Alessandro Paoletti; Grifoni, Gino; Perrotta, Laura; Marchese, Procolo; Bontempi, Luca; Curnis, Antonio

    2011-01-01

    Population aging and broader indications for the implant of cardiac implantable electronic devices (CIEDs) are the main reasons for the continuous increase in the use of pacemakers (PMs), implantable cardioverter-defibrillators (ICDs) and devices for cardiac resynchronization therapy (CRT-P, CRT-D). The growing burden of comorbidities in CIED patients, the greater complexity of the devices, and the increased duration of procedures have led to an augmented risk of infections, which is out of proportion to the increase in implantation rate. CIED infections are an ominous condition, which often implies the necessity of hospitalization and carries an augmented risk of in-hospital death. Their clinical presentation may be either at pocket or at endocardial level, but they can also manifest themselves with lone bacteremia. The management of these infections requires the complete removal of the device and subsequent, specific, antibiotic therapy. CIED failures are monitored by competent public authorities, that require physicians to alert them to any failures, and that suggest the opportune strategies for their management. Although the replacement of all potentially affected devices is often suggested, common practice indicates the replacement of only a minority of devices, as close follow-up of the patients involved may be a safer strategy. Implantation of a PM or an ICD may cause problems in the patients’ psychosocial adaptation and quality of life, and may contribute to the development of affective disorders. Clinicians are usually unaware of the psychosocial impact of implanted PMs and ICDs. The main difference between PM and ICD patients is the latter’s dramatic experience of receiving a shock. Technological improvements and new clinical evidences may help reduce the total burden of shocks. A specific supporting team, providing psychosocial help, may contribute to improving patient quality of life. PMID:22915942

  1. [Perioperative management of patients equipped with cardiac implanted electronic devices].

    PubMed

    Booke, Michael; Casu, Sebastian

    2016-04-01

    Anaesthetists are in increasing frequency confronted with patients equipped with cardiac implantable electrical devices. A consensus conference standardized the handling of such patients for elective cases. However, this multidisciplinary approach is characterized by a complexity, which is hard to handle in emergency cases and even in nowadays clinical routine. However, risks associated with electrocautery or electromagnetic interference can be easily handled applying a significantly easier approach. Telemetric reprogramming and/or postoperative interrogation of the cardiac implanted eletronical device can be avoided in most cases. PMID:27070514

  2. Optimal operating frequency in wireless power transmission for implantable devices.

    PubMed

    Poon, Ada S Y; O'Driscoll, Stephen; Meng, Teresa H

    2007-01-01

    This paper examines short-range wireless powering for implantable devices and shows that existing analysis techniques are not adequate to conclude the characteristics of power transfer efficiency over a wide frequency range. It shows, theoretically and experimentally, that the optimal frequency for power transmission in biological media can be in the GHz-range while existing solutions exclusively focus on the MHz-range. This implies that the size of the receive coil can be reduced by 10(4) times which enables the realization of fully integrated implantable devices. PMID:18003300

  3. Wireless microsensor network solutions for neurological implantable devices

    NASA Astrophysics Data System (ADS)

    Abraham, Jose K.; Whitchurch, Ashwin; Varadan, Vijay K.

    2005-05-01

    The design and development of wireless mocrosensor network systems for the treatment of many degenerative as well as traumatic neurological disorders is presented in this paper. Due to the advances in micro and nano sensors and wireless systems, the biomedical sensors have the potential to revolutionize many areas in healthcare systems. The integration of nanodevices with neurons that are in communication with smart microsensor systems has great potential in the treatment of many neurodegenerative brain disorders. It is well established that patients suffering from either Parkinson"s disease (PD) or Epilepsy have benefited from the advantages of implantable devices in the neural pathways of the brain to alter the undesired signals thus restoring proper function. In addition, implantable devices have successfully blocked pain signals and controlled various pelvic muscles in patients with urinary and fecal incontinence. Even though the existing technology has made a tremendous impact on controlling the deleterious effects of disease, it is still in its infancy. This paper presents solutions of many problems of today's implantable and neural-electronic interface devices by combining nanowires and microelectronics with BioMEMS and applying them at cellular level for the development of a total wireless feedback control system. The only device that will actually be implanted in this research is the electrodes. All necessary controllers will be housed in accessories that are outside the body that communicate with the implanted electrodes through tiny inductively-coupled antennas. A Parkinson disease patient can just wear a hat-system close to the implantable neural probe so that the patient is free to move around, while the sensors continually monitor, record, transmit all vital information to health care specialist. In the event of a problem, the system provides an early warning to the patient while they are still mobile thus providing them the opportunity to react and

  4. Right heart failure post left ventricular assist device implantation

    PubMed Central

    Argiriou, Mihalis; Kolokotron, Styliani-Maria; Sakellaridis, Timothy; Argiriou, Orestis; Charitos, Christos; Katsikogiannis, Nikolaos; Kougioumtzi, Ioanna; Machairiotis, Nikolaos; Tsiouda, Theodora; Tsakiridis, Kosmas; Zarogoulidis, Konstantinos

    2014-01-01

    Right heart failure (RHF) is a frequent complication following left ventricular assist device (LVAD) implantation. The incidence of RHF complicates 20-50% (range, 9-44%) of cases and is a major factor of postoperative morbidity and mortality. Unfortunately, despite the fact that many risk factors contributing to the development of RHF after LVAD implantation have been identified, it seems to be extremely difficult to avoid them. Prevention of RHF consists of the management of the preload and the afterload of the right ventricle with optimum inotropic support. The administration of vasodilators designed to reduce pulmonary vascular resistance is standard practice in most centers. The surgical attempt of implantation of a right ventricular assist device does not always resolve the problem and is not available in all cardiac surgery centers. PMID:24672699

  5. Bulk Metallic Glasses for Implantable Medical Devices and Surgical Tools.

    PubMed

    Meagher, Philip; O'Cearbhaill, Eoin D; Byrne, James H; Browne, David J

    2016-07-01

    With increasing knowledge of the materials science of bulk metallic glasses (BMGs) and improvements in their properties and processing, they have started to become candidate materials for biomedical devices. A dichotomy in the types of medical applications has also emerged, in which some families of BMGs are being developed for permanent devices whilst another family - of Mg-based alloys - is showing promise in bioabsorbable implants. The current status of these metallurgical and technological developments is summarized. PMID:27031058

  6. Adhesive bonding of medical and implantable devices.

    PubMed

    Tavakoli, S M

    2002-09-01

    Although there are many commercially available medical-grade adhesives, their use for new applications requires detailed investigation. It is also important that as well as the initial joint strength, durability of the bonded components during intended use, including exposure to low and high temperatures, stress, fluids and sterilisation, are investigated. Design of accelerated ageing tests, which can simulate the service environments, is critical in providing realistic durability data. Interpretation of ageing data and lifetime prediction of the joint is essential in assessing the performance of medical devices. Emergence of new types of adhesives as well as further development of precision dispensing and rapid-curing technologies offer many exciting and commercially attractive opportunities for joining medical devices. PMID:12397833

  7. Biocompatibility tests of components of an implantable cardiac assist device.

    PubMed

    von Recum, A F; Imamura, H; Freed, P S; Kantrowitz, A; Chen, S T; Ekstrom, M E; Baechler, C A; Barnhart, M I

    1978-09-01

    A permanently implantable in-series left ventricular assist device, the dynamic aortic patch (DAP), has been tested in chronic animal experiments. The DAP replaces a section of the intrathoracic aortic wall. Hemothorax and hematocele at the implantation site have been complications in recent experiments. Primary postoperative hemorrhage was ruled out, and the biocompatibility of all components was therefore examined. Dacron velour, Teflon felt, conductive polyurethane, segmented polyether polyurethane, and Teflon-coated polyester fiber sutures were implanted in the pleural cavities of dogs and tested in vitro by culturing canine saphenous vein explants on them. In vivo experiments demonstrated that all components elicited mild to moderate inflammatory reactions, but hematocele occurred only when the components were implanted in the aorta with direct blood contact and exposed to arterial blood pressures. In vitro, cells were cultured on all components with no signs of toxic reactions. These results indicated that the host tolerated all implant components without major inflammatory responses. However, histological data indicated that chronic slow bleeding into or through the Dacron velour in contact with the arterial blood serum could account for hemothorax or hematocele formation. Therefore, a configuration of the assist device using materials impermeable to blood may obviate these difficulties. PMID:151687

  8. Surgical Management of the Patient with an Implanted Cardiac Device

    PubMed Central

    Madigan, John D.; Choudhri, Asim F.; Chen, Jonathan; Spotnitz, Henry M.; Oz, Mehmet C.; Edwards, Niloo

    1999-01-01

    Objective To identify the sources of electromagnetic interference (EMI) that may alter the performance of implanted cardiac devices and develop strategies to minimize their effects on patient hemodynamic status. Summary Background Data Since the development of the sensing demand pacemaker, EMI in the clinical setting has concerned physicians treating patients with such devices. Implanted cardiovertor defibrillators (ICDs) and ventricular assist devices (VADs) can also be affected by EMI. Methods All known sources of interference to pacemakers, ICDs, and VADs were evaluated and preventative strategies were devised. Results All devices should be thoroughly evaluated before and after surgery to make sure that its function has not been permanently damaged or changed. If electrocautery is to be used, pacemakers should be placed in a triggered or asynchronous mode; ICDs should have arrhythmia detection suspended before surgery. If defibrillation is to be used, the current flow between the paddles should be kept as far away from and perpendicular to the lead system as possible. Both pacemakers and ICDs should be properly shielded if magnetic resonance imaging, positron emission tomography, or radiation therapy is to be used. The effect of EMI on VADs depends on the model. Magnetic resonance imaging adversely affects all VADs except the Abiomed VAD, and therefore its use should be avoided in this population of patients. Conclusions The patient with an implanted cardiac device can safely undergo surgery as long as certain precautions are taken. PMID:10561087

  9. Hemolysis and Pulmonary Insufficiency following Right Ventricular Assist Device Implantation.

    PubMed

    Schubert, Sarah A; Soleimani, Behzad; Pae, Walter E

    2012-01-01

    We report a case of severe hemolysis and pulmonary valve insufficiency (PI) following right ventricular support using a paracorporeal pneumatic pump (Abiomed, Danvers, MA, USA). We speculate that the high velocity jet of blood emanating from the outflow cannula caused turbulence above the pulmonary valve, leading to PI and hemolysis. Despite the growing number of implanted ventricular assist devices, we could find no report in the literature describing pulmonary valve insufficiency secondary to right ventricular assist device (RVAD) placement. Fortunately, in this case, right ventricular function recovered sufficiently after seven days of support, allowing explantation of the device and resolution of PI and hemolysis. PMID:23213613

  10. Outcomes After Concomitant Procedures with Left Ventricular Assist Device Implantation: Implications by Device Type and Indication.

    PubMed

    Maltais, Simon; Haglund, Nicholas A; Davis, Mary E; Aaronson, Keith D; Pagani, Francis D; Dunlay, Shannon M; Stulak, John M

    2016-01-01

    Guidelines for performing concomitant procedures (CPs) in patients undergoing continuous flow-left ventricular assist device (CF-LVAD) implantation are unclear. The impact of an increased surgical complexity outside the constraint of landmark clinical trials has not been reported. From May 2004 to December 2013, 614 patients (499 males, 81%) underwent CF-LVAD implant at our institutions. Median age was 57 ± 13 years and 364 (59%) were bridge to transplantation (BTT). Survival and device-related complications were analyzed and stratified based on the surgical intervention. A total of 398 patients (65%) underwent CF-LVAD implantation without CPs. The remaining patients (35%, n = 216) were grouped according to various CPs. Survival was comparable between groups and not influenced by the CP, device type, or indication for implant. Time-to-first device-related adverse event was shorter in patients with CPs. Regression analysis revealed only increased age (p = 0.03), increase in baseline creatinine (p = 0.002), cardiopulmonary bypass time (p = 0.03), and decreased body mass index (p = 0.03) were predictors of mortality, whereas only age (p = 0.006) and prior sternotomy (p = 0.02) were related to adverse device-related events. Performing CPs leads to comparable survival and device-related outcomes after implant. The decision to perform CPs should be balanced with age, preoperative renal dysfunction, and projected complexity of surgery. PMID:27164038

  11. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted mechanical/hydraulic urinary continence....5280 Implanted mechanical/hydraulic urinary continence device. (a) Identification. An implanted mechanical/hydraulic urinary continence device is a device used to treat urinary incontinence by...

  12. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ....5280 Implanted mechanical/hydraulic urinary continence device. (a) Identification. An implanted mechanical/hydraulic urinary continence device is a device used to treat urinary incontinence by the... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Implanted mechanical/hydraulic urinary...

  13. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ....5280 Implanted mechanical/hydraulic urinary continence device. (a) Identification. An implanted mechanical/hydraulic urinary continence device is a device used to treat urinary incontinence by the... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Implanted mechanical/hydraulic urinary...

  14. A Review of the Biocompatibility of Implantable Devices: Current Challenges to Overcome Foreign Body Response

    PubMed Central

    Onuki, Yoshinori; Bhardwaj, Upkar; Papadimitrakopoulos, Fotios; Burgess, Diane J.

    2008-01-01

    In recent years, a variety of devices (drug-eluting stents, artificial organs, biosensors, catheters, scaffolds for tissue engineering, heart valves, etc.) have been developed for implantation into patients. However, when such devices are implanted into the body, the body can react to these in a number of different ways. These reactions can result in an unexpected risk for patients. Therefore, it is important to assess and optimize the biocompatibility of implantable devices. To date, numerous strategies have been investigated to overcome body reactions induced by the implantation of devices. This review focuses on the foreign body response and the approaches that have been taken to overcome this. The biological response following device implantation and the methods for biocompatibility evaluation are summarized. Then the risks of implantable devices and the challenges to overcome these problems are introduced. Specifically, the challenges used to overcome the functional loss of glucose sensors, restenosis after stent implantation, and calcification induced by implantable devices are discussed. PMID:19885290

  15. Cardiovascular implantable electronic devices: patient education, information and ethical issues.

    PubMed

    Manaouil, Cécile; Gignon, Maxime; Traulle, Sarah

    2012-09-01

    Cardiovascular implantable electronic devices (CIED) are implanted increasingly frequently. CIEDs are indicated for the treatment of bradycardia, tachycardia and heart failure and therefore improve quality of life and life expectancy. CIED can treat ventricular arrhythmias that would be fatal without immediate care. However, CIEDs raise several patient education, medico-legal, and ethical questions that will be addressed in this article. Information is a patient's right, and necessary for informed consent. When implanting a CIED, the patient must be educated about the need for the device, the function of the device, any restrictions that apply postimplant, and postimplant follow-up methods and schedules. This transfer of information to the patient makes the patient responsible. The occupational physician can determine whether a patient wearing a CIED is able to work. Under current French law, patients are not prohibited from working while wearing a CIED. However, access to certain job categories remains limited, such as jobs involving mechanical stress to the chest, exposure to electromagnetic fields, or jobs requiring permanent vigilance. Pacemakers and defibrillators are medical treatments and are subject to the same ethical and clinical considerations as any other treatment. However, stopping a pacemaker or a defibrillator raises different ethical issues. Implantable Cardioverter Defibrillator shocks can be considered to be equivalent to resuscitation efforts and can be interpreted as being unreasonable in an end-of-life patient. Pacing is painless and it is unlikely to unnecessarily prolong the life of a patient with a terminal disease. Patients with a CIED should live as normally as possible, but must also be informed about the constraints related to the device and must inform each caregiver about the presence of the device. The forensic and ethical implications must be assessed in relation to current legislation. PMID:23248837

  16. Integration of High Dose Boron Implants--Modification of Device Parametrics through Implant Temperature Control

    SciTech Connect

    Schmeide, Matthias; Ameen, M. S.; Kondratenko, Serguei; Krimbacher, Bernhard; Reece, Ronald N.

    2011-01-07

    In the present study, we have extended a previously reported 250 nm logic p-S/D implant (7 keV B 4.5x10{sup 15} cm{sup -2}) process matching exercise [5] to include wafer temperature, and demonstrate that matching can be obtained by increasing the temperature of the wafer during implant. We found that the high dose rate delivered by the single wafer implanter caused the formation of a clear amorphous layer, which upon subsequent annealing altered the diffusion, activation, and clustering properties of the boron. Furthermore, increasing the temperature of the wafer during the implant was sufficient to suppress amorphization, allowing profiles and device parameters to become matched. Figure 5 shows a representative set of curves indicating the cluster phenomena observed for the lower temperature, high flux single wafer implanter, and the influence of wafer temperature on the profiles. The results indicate the strong primary effect of dose rate in determining final electrical properties of devices, and successful implementation of damage engineering using wafer temperature control.

  17. Sexual Concerns of Patients With Implantable Left Ventricular Assist Devices.

    PubMed

    Merle, Pascal; Maxhera, Bujar; Albert, Alexander; Ortmann, Philipp; Günter, Mareile; Lichtenberg, Artur; Saeed, Diyar

    2015-08-01

    The growing field of implantable left ventricular assist devices (LVADs) lacks studies that evaluate the sexual and psychosocial concerns of LVAD patients. The aim of this prospective study was to determine the sexual and psychosocial behaviors of these patients. A sexual and psychosocial survey was conducted in patients who underwent the implantation of LVAD. Inclusion criteria were patients who were discharged home. The survey consisted of 17 questions with main focus on the sexual life and activities. The survey was sent to 38 patients. Twelve patients had either no partners or did not respond to the survey. Data of the remaining 26 patients with a mean age of 54 ± 13 years old were analyzed. The mean time between LVAD implantation and the first sexual activity was 16 ± 13 weeks (6-42 weeks). Following LVAD implantation, there was a steady improvement in the physical condition and quality of life. However, a remarkable decrease in the degree of satisfaction with sexual life following LVAD implantation (5.5 ± 2.2 vs. 4.1 ± 2.5) was observed (P = 0.05) (a scale of 1-7, with 7 being very satisfied and 1 not satisfied). Decreasing sexual activities after LVAD implantation was mainly to avoid partner disappointment, sudden cardiac arrest, and LVAD failure. There is a notable reduction in the degree of satisfaction with sexual life after LVAD implantation. The majority of the patients avoid discussing this issue with their physicians. Psychological and psychosocial support of LVAD patients is mandatory to improve their life quality. PMID:26148127

  18. III-Nitride ion implantation and device processing

    SciTech Connect

    Zolper, J.C.; Shul, R.J.; Baca, A.G.; Pearton, S.J.; Abernathy, C.R.; Wilson, R.G.; Stall, R.A.; Shur, M.

    1996-06-01

    Ion implantation doping and isolation has played a critical role in realizing high performance photonic and electronic devices in all mature semiconductor materials; this is also expected for binary III-Nitride materials (InN, GaN, AlN) and their alloys as epitaxy improves and more advanced device structures fabricated. This paper reports on recent progress in ion implantation doping of III-Nitride materials that has led to the first demonstration of a GaN JFET (junction field effect transistor). The JFET was fabricated with all ion implantation doping; in particular, p-type doping of GaN with Ca has been demonstrated with an estimated acceptor ionization energy of 169 meV. O-implantation has also been studied and shown to yield n-type conduction with an ionization energy of {similar_to}29 meV. Neither Ca or O display measurable redistribution during a 1125 C, 15 s activation anneal which sets an upper limit on their diffusivity at this temperature of 2.7{times}10{sup {minus}13}cm{sup 2}/s.

  19. Transvenous Lead Extraction for Cardiac Implantable Electronic Devices.

    PubMed

    Shea, Julie B

    2015-01-01

    This article illustrates the important role that lead extraction plays in the management of patients with cardiac implantable electronic devices. Individualized care of the patient is paramount when considering lead management strategies. The critical care nurse must have a comprehensive understanding of the indications, procedural considerations, and preprocedural and postprocedural care for patients undergoing lead extraction procedures, thereby improving patient safety and maximizing patient outcomes. PMID:26484992

  20. Ultra-thin layer packaging for implantable electronic devices

    NASA Astrophysics Data System (ADS)

    Hogg, A.; Aellen, T.; Uhl, S.; Graf, B.; Keppner, H.; Tardy, Y.; Burger, J.

    2013-07-01

    State of the art packaging for long-term implantable electronic devices generally uses reliable metal and glass housings; however, these are limited in the miniaturization potential and cost reduction. This paper focuses on the development of biocompatible hermetic thin-film packaging based on poly-para-xylylene (Parylene-C) and silicon oxide (SiOx) multilayers for smart implantable microelectromechanical systems (MEMS) devices. For the fabrication, a combined Parylene/SiOx single-chamber deposition system was developed. Topological aspects of multilayers were characterized by atomic force microscopy and scanning electron microscopy. Material compositions and layer interfaces were analyzed by Fourier transform infrared spectrometry and x-ray photoelectron spectroscopy. To evaluate the multilayer corrosion protection, water vapor permeation was investigated using a calcium mirror test. The calcium mirror test shows very low water permeation rates of 2 × 10-3 g m-2 day-1 (23 °C, 45% RH) for a 4.7 µm multilayer, which is equivalent to a 1.9 mm pure Parylene-C coating. According to the packaging standard MIL-STD-883, the helium gas tightness was investigated. These helium permeation measurements predict that a multilayer of 10 µm achieves the hermeticity acceptance criterion required for long-term implantable medical devices.

  1. Management of antithrombotic therapy during cardiac implantable device surgery.

    PubMed

    AlTurki, Ahmed; Proietti, Riccardo; Birnie, David H; Essebag, Vidal

    2016-06-01

    Anticoagulants are commonly used drugs that are frequently encountered during device placement. Deciding when to halt or continue the use of anticoagulants is a balance between the risks of thromboembolism versus bleeding. Patients taking warfarin with a high risk of thromboembolism should continue to take their warfarin without interruption during device placement while ensuring their international normalized ratio remains below 3. For patients who are taking warfarin and have low risk of thromboembolism, either interrupted or continued warfarin may be used, with no evidence to clearly support either strategy. There is little evidence to support continuing direct acting oral anticoagulants (DOACs) for device implantation. The timing of halting these medications depends largely on renal function. If bleeding occurs, warfarin׳s anticoagulation effect is reversible with vitamin K and activated prothrombin complex concentrate. There are no DOAC reversal agents currently available, but some are under development. Regarding antiplatelet agents, aspirin alone can be safely continued while clopidogrel alone may also be continued, but with a slightly higher bleeding risk. Dual antiplatelet therapy for bare-metal stent/drug-eluting stent implanted within 4 weeks/6 months, respectively, should be continued due to high risk of stent thrombosis; however, if they are implanted after this period, then clopidogrel can be halted 5 days before the procedure and resumed soon after, while aspirin is continued. If the patient is taking both aspirin and warfarin, aspirin should be halted 5 days prior to the procedure, while warfarin is continued. PMID:27354859

  2. In-vivo orthopedic implant diagnostic device for sensing load, wear, and infection

    DOEpatents

    Evans, III, Boyd McCutchen; Thundat, Thomas G.; Komistek, Richard D.; Dennis, Douglas A.; Mahfouz, Mohamed

    2006-08-29

    A device for providing in vivo diagnostics of loads, wear, and infection in orthopedic implants having at least one load sensor associated with the implant, at least one temperature sensor associated with the implant, at least one vibration sensor associated with the implant, and at least one signal processing device operatively coupled with the sensors. The signal processing device is operable to receive the output signal from the sensors and transmit a signal corresponding with the output signal.

  3. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Implanted mechanical/hydraulic urinary continence device. 876.5280 Section 876.5280 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5280 Implanted mechanical/hydraulic...

  4. Critical Assessment of Implantable Drug Delivery Devices in Glaucoma Management

    PubMed Central

    Manickavasagam, Dharani; Oyewumi, Moses O.

    2013-01-01

    Glaucoma is a group of heterogeneous disorders involving progressive optic neuropathy that can culminate into visual impairment and irreversible blindness. Effective therapeutic interventions must address underlying vulnerability of retinal ganglion cells (RGCs) to degeneration in conjunction with correcting other associated risk factors (such as elevated intraocular pressure). However, realization of therapeutic outcomes is heavily dependent on suitable delivery system that can overcome myriads of anatomical and physiological barriers to intraocular drug delivery. Development of clinically viable sustained release systems in glaucoma is a widely recognized unmet need. In this regard, implantable delivery systems may relieve the burden of chronic drug administration while potentially ensuring high intraocular drug bioavailability. Presently there are no FDA-approved implantable drug delivery devices for glaucoma even though there are several ongoing clinical studies. The paper critically assessed the prospects of polymeric implantable delivery systems in glaucoma while identifying factors that can dictate (a) patient tolerability and acceptance, (b) drug stability and drug release profiles, (c) therapeutic efficacy, and (d) toxicity and biocompatibility. The information gathered could be useful in future research and development efforts on implantable delivery systems in glaucoma. PMID:24066234

  5. The evolution of the cardiac implantable electronic device connector.

    PubMed

    Mond, Harry G; Helland, John R; Fischer, Avi

    2013-11-01

    Cardiac implantable electronic devices (CIEDs) play a vital role in the management of cardiac rhythm disturbances. The devices are comprised of two primary components: a generator and lead joined by a connector. Original pacemaker lead connectors were created de novo at the time of implantation or replacement and were very unreliable. With the development of new lead designs, creation of a standard connector configuration, the IS-1 connector became mandatory. Similar connector development also occurred with the advent of the implantable cardioverter defibrillator (ICD), resulting in creation of the high voltage standard: the DF-1 connector. Differing from a pacemaker lead, the ICD lead connector requires one IS-1 connector and one or two DF-1 connectors, resulting in a large cumbersome lead connector and generator header block. Recently, a revolutionary quad pole single plug connector standard has been approved for market release. These are the single-pin DF4 and IS4 lead connectors that carry low- and high-voltage poles or all low-voltage poles, respectively. These connectors, together with new labeling guidelines, have simplified operative procedures and reduced errors, when mating lead connectors into the generator's connector block. PMID:23808816

  6. Infection control in implantation of cardiac implantable electronic devices: current evidence, controversial points, and unresolved issues.

    PubMed

    Korantzopoulos, Panagiotis; Sideris, Skevos; Dilaveris, Polychronis; Gatzoulis, Konstantinos; Goudevenos, John A

    2016-04-01

    A significant increase in the implantation of cardiac implantable electronic devices (CIEDs) is evident over the past years, while there is evidence for a disproportionate increase in CIED-related infections. The cumulative probability of device infection seems to be higher in implantable cardioverter defibrillator and in cardiac resynchronization therapy patients compared with permanent pacemaker patients. Given that more than a half of CIED infections are possibly related to the operative procedure, there is a need for effective periprocedural infection control. However, many of the current recommendations are empirical and not evidence-based, while questions, unresolved issues, and conflicting evidence arise. The perioperative systemic use of antibiotics confers significant benefit in prevention of CIED infections. However, there are no conclusive data regarding the specific value of each agent in different clinical settings, the value of post-operative antibiotic treatment as well as the optimal duration of therapy. The merit of local pocket irrigation with antibiotic and/or antiseptic agents remains unproved. Of note, recent evidence indicates that the application of antibacterial envelopes into the device pocket markedly decreases the infection risk. In addition, limited reports on strict integrated infection control protocols show a dramatic reduction in infection rates in this setting and therefore deserve further attention. Finally, the relative impact of particular factors on the infection risk, including the type of the CIED, patients' individual characteristics and comorbidities, should be further examined since it may facilitate the development of tailored prophylactic interventions for each patient. PMID:26516219

  7. Feasibility study for future implantable neural-silicon interface devices.

    PubMed

    Al-Armaghany, Allann; Yu, Bo; Mak, Terrence; Tong, Kin-Fai; Sun, Yihe

    2011-01-01

    The emerging neural-silicon interface devices bridge nerve systems with artificial systems and play a key role in neuro-prostheses and neuro-rehabilitation applications. Integrating neural signal collection, processing and transmission on a single device will make clinical applications more practical and feasible. This paper focuses on the wireless antenna part and real-time neural signal analysis part of implantable brain-machine interface (BMI) devices. We propose to use millimeter-wave for wireless connections between different areas of a brain. Various antenna, including microstrip patch, monopole antenna and substrate integrated waveguide antenna are considered for the intra-cortical proximity communication. A Hebbian eigenfilter based method is proposed for multi-channel neuronal spike sorting. Folding and parallel design techniques are employed to explore various structures and make a trade-off between area and power consumption. Field programmable logic arrays (FPGAs) are used to evaluate various structures. PMID:22254974

  8. [The management of implantable medical device and the application of the internet of things in hospitals].

    PubMed

    Zhou, Li; Xu, Liang

    2011-11-01

    Implantable medical device is a special product which belongs to medical devices. It not only possesses product characteristics in common, but also has specificity for safety and effectiveness. Implantable medical device must be managed by the relevant laws and regulations of the State Food and Drug Administration. In this paper, we have used cardiac pacemakers as an example to describe the significance of the management of implantable medical device products and the application of the internet of things in hospitals. PMID:22379772

  9. 78 FR 38867 - Gastroenterology-Urology Devices; Reclassification of Implanted Blood Access Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-28

    ... section 513(e) proposing the reclassification of implanted blood access devices for hemodialysis (77 FR... reclassification for June 27, 2013 (78 FR 25747; May 2, 2013). The three comments submitted in response to the... discussed in the preamble to the proposed rule (46 FR 7616; January 23, 1981), the...

  10. The cardiac implantable electronic device power source: evolution and revolution.

    PubMed

    Mond, Harry G; Freitag, Gary

    2014-12-01

    Although the first power source for an implantable pacemaker was a rechargeable nickel-cadmium battery, it was rapidly replaced by an unreliable short-life zinc-mercury cell. This sustained the small pacemaker industry until the early 1970s, when the lithium-iodine cell became the dominant power source for low voltage, microampere current, single- and dual-chamber pacemakers. By the early 2000s, a number of significant advances were occurring with pacemaker technology which necessitated that the power source should now provide milliampere current for data logging, telemetric communication, and programming, as well as powering more complicated pacing devices such as biventricular pacemakers, treatment or prevention of atrial tachyarrhythmias, and the integration of innovative physiologic sensors. Because the current delivery of the lithium-iodine battery was inadequate for these functions, other lithium anode chemistries that can provide medium power were introduced. These include lithium-carbon monofluoride, lithium-manganese dioxide, and lithium-silver vanadium oxide/carbon mono-fluoride hybrids. In the early 1980s, the first implantable defibrillators for high voltage therapy used a lithium-vanadium pentoxide battery. With the introduction of the implantable cardioverter defibrillator, the reliable lithium-silver vanadium oxide became the power source. More recently, because of the demands of biventricular pacing, data logging, and telemetry, lithium-manganese dioxide and the hybrid lithium-silver vanadium oxide/carbon mono-fluoride laminate have also been used. Today all cardiac implantable electronic devices are powered by lithium anode batteries. PMID:25387600

  11. Successful left ventricular assist device re-implantation with omental covering for MDRP device infection.

    PubMed

    Inafuku, Hitoshi; Kuniyoshi, Yukio; Yamashiro, Satoshi; Totsuka, Yuichi; Ono, Minoru

    2016-06-01

    We present a case of paracorporeal left ventricular assist device (p-LVAD)-related infection, caused by multi-drug resistant Pseudomonas aeruginosae (MDRP), and successfully treated by p-LVAD re-implantation with omental covering. A 59-year-old man underwent p-LVAD implantation and coronary artery bypass grafting after percutaneous cardiopulmonary support and intra-aortic balloon pumping for cardiogenic shock due to acute myocardial infarction. Then, he was registered for heart transplantation. He suffered from blood stream infection causative organism of Pseudomonas aeruginosa, 2 months after that operation. He underwent re-median sternotomy and open drainage, 15 months after the p-LVAD implantation. However, he suffered from septic shock due to MDRP. He underwent p-LVAD re-implantation under hypothermic circulatory arrest and iodine gauze packing, followed by omental covering of the all artificial materials in his body 10 days after that operation. Soon after that, the infection was well controlled and the intravenous antibiotics could be discontinued 2 months after that operation. He successfully underwent heart transplantation, 17 months after that procedure. We concluded that p-LVAD re-implantation with omental covering is seemed to be useful in the treatment of massive device infection. This procedure might be a novel treatment for severe VAD-related infection until heart transplantation. PMID:26740211

  12. Direction or inertia: the future for regulation of surgical implant devices.

    PubMed

    Habal, M B; Karlan, M S; Leake, D

    1978-01-01

    The time has arrived when certain standards are to be introduced to control the introduction of and appropriate use of surgical implant devices. Now is the time for the professional groups involved in standards and medical device legislation to become active and develop surgical implant device standards to be applicable for the future. A commission could be established to work with FDA in respect to the requirements for surgical implant devices. It is time for the clinical organizations involved in writing consensus standards to cooperate in the introduction of surgical implant device standards. PMID:10316638

  13. New molecular strategies for reducing implantable medical devices associated infections.

    PubMed

    Holban, Alina Maria; Gestal, Monica Cartelle; Grumezescu, Alexandru Mihai

    2014-01-01

    Due to the great prevalence of persistent and recurrent implanted device associated-infections novel and alternative therapeutic approaches are intensely investigated. For reducing complications and antibiotic resistance development, one major strategy is using natural or synthetic modulators for targeting microbial molecular pathways which are not related with cell multiplication and death, as Quorum Sensing, virulence and biofilm formation. The purpose of this review paper is to discuss the most recent in vitro approaches, investigating the efficiency of some novel antimicrobial products and the nano-technologic progress performed in order to increase their effect and stability. PMID:24606502

  14. From hemodynamic towards cardiomechanic sensors in implantable devices

    NASA Astrophysics Data System (ADS)

    Ferek-Petric, Bozidar

    2013-06-01

    Sensor could significantly improve the cardiac electrotherapy. It has to provide long-term stabile signal not impeding the device longevity and lead reliability. It may not introduce special implantation and adjustment procedures. Hemodynamic sensors based on the blood flow velocity and cardiomechanic sensors based on the lead bending measurement are disclosed. These sensors have a broad clinical utility. Triboelectric and high-frequency lead bending sensors yield accurate and stable signals whereby functioning with every cardiac lead. Moreover, high frequency measurement avoids use of any kind of special hardware mounted on the cardiac lead.

  15. Management of Patients With Cardiovascular Implantable Electronic Devices in Dental, Oral, and Maxillofacial Surgery.

    PubMed

    Tom, James

    2016-01-01

    The prevalence of cardiovascular implantable electronic devices as life-prolonging and life-saving devices has evolved from a treatment of last resort to a first-line therapy for an increasing number of patients. As these devices become more and more popular in the general population, dental providers utilizing instruments and medications should be aware of dental equipment and medications that may affect these devices and understand the management of patients with these devices. This review article will discuss the various types and indications for pacemakers and implantable cardioverter-defibrillators, common drugs and instruments affecting these devices, and management of patients with these devices implanted for cardiac dysrhythmias. PMID:27269668

  16. Cardiac Implantable Electronic Device Infection: From an Infection Prevention Perspective

    PubMed Central

    Sastry, Sangeeta; Rahman, Riaz; Yassin, Mohamed H.

    2015-01-01

    A cardiac implantable electronic device (CIED) is indicated for patients with severely reduced ejection fraction or with life-threatening cardiac arrhythmias. Infection related to a CIED is one of the most feared complications of this life-saving device. The rate of CIED infection has been estimated to be between 2 and 25; though evidence shows that this rate continues to rise with increasing expenditure to the patient as well as healthcare systems. Multiple risk factors have been attributed to the increased rates of CIED infection and host comorbidities as well as procedure related risks. Infection prevention efforts are being developed as defined bundles in numerous hospitals around the country given the increased morbidity and mortality from CIED related infections. This paper aims at reviewing the various infection prevention measures employed at hospitals and also highlights the areas that have relatively less established evidence for efficacy. PMID:26550494

  17. Wireless energy transfer platform for medical sensors and implantable devices.

    PubMed

    Zhang, Fei; Hackworth, Steven A; Liu, Xiaoyu; Chen, Haiyan; Sclabassi, Robert J; Sun, Mingui

    2009-01-01

    Witricity is a newly developed technique for wireless energy transfer. This paper presents a frequency adjustable witricity system to power medical sensors and implantable devices. New witricity resonators are designed for both energy transmission and reception. A prototype platform is described, including an RF power source, two resonators with new structures, and inductively coupled input and output stages. In vitro experiments, both in open air and using a human head phantom consisting of simulated tissues, are employed to verify the feasibility of this platform. An animal model is utilized to evaluate in vivo energy transfer within the body of a laboratory pig. Our experiments indicate that witricity is an effective new tool for providing a variety of medical sensors and devices with power. PMID:19964948

  18. Ion Implantation Angle Variation to Device Performance and the Control in Production

    SciTech Connect

    Zhao, Z.Y.; Hendrix, D.; Wu, L.Y.; Cusson, B.K.

    2003-08-26

    As the device features get smaller and aspect ratios of photoresist openings get steeper, shadowing effect has more impact on the performance of devices. Many of the traditional 7 deg. tilt implants have progressed to 0 deg. implants. But shadowing may still occur if the tilt angle deviates from normal direction. Some implants, such as halo implants, demand even more stringent angle control to reduce device performance variation. The demand for implant angle control and monitoring thus becomes more obvious and important. However, statistical process control (SPC) cannot be done on shadowing effect without special test structures. Channeling, on the other hand, provides good sensitivity in regard to implant angle changes. It is the authors' intention to introduce channeling implant in different channels to monitor the implant angle variation. The incoming <100> silicon wafers have a cut-angle spec of +/- 1.0 deg. This poses a difficulty if one wants to control the implant angle's accuracy within +/- 0.5 deg. Other measures have to be taken to ensure the consistency of test wafers and to have prompt diagnosis feedback when needed. This paper will discuss the effect of implant tilt angle on device parameters and how to control the angle variation in production. Correlations of implant tilt angle variation to ThermaWave, sheet resistance (Rs), Secondary Ion Mass Spectrometry (SIMS) and device parameters will be covered with certain implant conditions.

  19. Ion Implantation Angle Variation to Device Performance and the Control in Production

    NASA Astrophysics Data System (ADS)

    Zhao, Z. Y.; Hendrix, D.; Wu, L. Y.; Cusson, B. K.

    2003-08-01

    As the device features get smaller and aspect ratios of photoresist openings get steeper, shadowing effect has more impact on the performance of devices. Many of the traditional 7° tilt implants have progressed to 0° implants. But shadowing may still occur if the tilt angle deviates from normal direction. Some implants, such as halo implants, demand even more stringent angle control to reduce device performance variation. The demand for implant angle control and monitoring thus becomes more obvious and important. However, statistical process control (SPC) cannot be done on shadowing effect without special test structures. Channeling, on the other hand, provides good sensitivity in regard to implant angle changes. It is the authors' intention to introduce channeling implant in different channels to monitor the implant angle variation. The incoming <100> silicon wafers have a cut-angle spec of +/- 1.0°. This poses a difficulty if one wants to control the implant angle's accuracy within +/- 0.5°. Other measures have to be taken to ensure the consistency of test wafers and to have prompt diagnosis feedback when needed. This paper will discuss the effect of implant tilt angle on device parameters and how to control the angle variation in production. Correlations of implant tilt angle variation to ThermaWave™, sheet resistance (Rs), Secondary Ion Mass Spectrometry (SIMS) and device parameters will be covered with certain implant conditions.

  20. Perioperative management of antithrombotic treatment during implantation or revision of cardiac implantable electronic devices: the European Snapshot Survey on Procedural Routines for Electronic Device Implantation (ESS-PREDI).

    PubMed

    Deharo, Jean-Claude; Sciaraffia, Elena; Leclercq, Christophe; Amara, Walid; Doering, Michael; Bongiorni, Maria G; Chen, Jian; Dagres, Nicolaus; Estner, Heidi; Larsen, Torben B; Johansen, Jens B; Potpara, Tatjana S; Proclemer, Alessandro; Pison, Laurent; Brunet, Caroline; Blomström-Lundqvist, Carina

    2016-05-01

    The European Snapshot Survey on Procedural Routines for Electronic Device Implantation (ESS-PREDI) was a prospective European survey of consecutive adults who had undergone implantation/surgical revision of a cardiac implantable electronic device (CIED) on chronic antithrombotic therapy (enrolment March-June 2015). The aim of the survey was to investigate perioperative treatment with oral anticoagulants and antiplatelets in CIED implantation or surgical revision and to determine the incidence of complications, including clinically significant pocket haematomas. Information on antithrombotic therapy before and after surgery and bleeding and thromboembolic complications occurring after the intervention was collected at first follow-up. The study population comprised 723 patients (66.7% men, 76.9% aged ≥66 years). Antithrombotic treatment was continued during surgery in 489 (67.6%) patients; 6 (0.8%) had their treatment definitively stopped; 46 (6.4%) were switched to another antithrombotic therapy. Heparin bridging was used in 55 out of 154 (35.8%) patients when interrupting vitamin K antagonist (VKA) treatment. Non-vitamin K oral anticoagulant (NOAC) treatment was interrupted in 88.7% of patients, with heparin bridging in 25.6%, but accounted for only 25.3% of the oral anticoagulants used. A total of 108 complications were observed in 98 patients. No intracranial haemorrhage or embolic events were observed. Chronic NOAC treatment before surgery was associated with lower rates of minor pocket haematoma (1.4%; P= 0.042) vs. dual antiplatelet therapy (13.0%), VKA (11.4%), VKA + antiplatelet (9.2%), or NOAC + antiplatelet (7.7%). Similar results were observed for bleeding complications (P= 0.028). Perioperative management of patients undergoing CIED implantation/surgical revision while on chronic antithrombotic therapy varies, with evidence of a disparity between guideline recommendations and practice patterns in Europe. Haemorrhagic complications were significantly

  1. 21 CFR 860.93 - Classification of implants, life-supporting or life-sustaining devices.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Classification of implants, life-supporting or... Classification § 860.93 Classification of implants, life-supporting or life-sustaining devices. (a) The classification panel will recommend classification into class III of any implant or life-supporting or...

  2. 21 CFR 860.93 - Classification of implants, life-supporting or life-sustaining devices.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Classification of implants, life-supporting or... Classification § 860.93 Classification of implants, life-supporting or life-sustaining devices. (a) The classification panel will recommend classification into class III of any implant or life-supporting or...

  3. 21 CFR 860.93 - Classification of implants, life-supporting or life-sustaining devices.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Classification of implants, life-supporting or... Classification § 860.93 Classification of implants, life-supporting or life-sustaining devices. (a) The classification panel will recommend classification into class III of any implant or life-supporting or...

  4. 21 CFR 860.93 - Classification of implants, life-supporting or life-sustaining devices.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Classification of implants, life-supporting or... Classification § 860.93 Classification of implants, life-supporting or life-sustaining devices. (a) The classification panel will recommend classification into class III of any implant or life-supporting or...

  5. Risk Factors Influencing Complications of Cardiac Implantable Electronic Device Implantation: Infection, Pneumothorax and Heart Perforation

    PubMed Central

    Lin, Yu-Sheng; Hung, Sheng-Ping; Chen, Pei-Rung; Yang, Chia-Hung; Wo, Hung-Ta; Chang, Po-Cheng; Wang, Chun-Chieh; Chou, Chung-Chuan; Wen, Ming-Shien; Chung, Chang-Ming; Chen, Tien-Hsing

    2014-01-01

    Abstract As the number of cardiac implantable electronic devices (CIEDs) is increasing annually, CIED-related complications are becoming increasingly important. The aim of the study was to assess the risks associated with CIEDs by a nationwide database. Patients were selected from the Taiwan National Health Insurance Database. Admissions for CIED implantation, replacement, and revision were evaluated and the evaluation period was 14 years. Endpoints included CIED-related infection, pneumothorax, and heart perforation. The study included 40,608 patients with a mean age of 71.8 ± 13.3 years. Regarding infection, the incidence rate was 2.45 per 1000 CIED-years. Male gender, younger age, device replacement, and previous infection were risks for infection while old age and high-volume centers (>200 per year) were protectors. The incidence of pneumothorax was 0.6%, with an increased risk in individuals who had chronic obstructive lung disease (COPD) and cardiac resynchronized therapy (CRT). The incidence of heart perforation was 0.09%, with an increased risk in individuals who had pre-operation temporal pacing and steroid use. High-volume center was found to decrease infection rate while male gender, young people, and individuals who underwent replacements were associated with an increased risk of infection. Additionally, pre-operation temporal pacing and steroid use should be avoided if possible. Furthermore, COPD patients or those who accept CRTs should be monitored closely. PMID:25501080

  6. Design of an implantable device for ocular drug delivery.

    PubMed

    Lee, Jae-Hwan; Pidaparti, Ramana M; Atkinson, Gary M; Moorthy, Ramana S

    2012-01-01

    Ocular diseases, such as, glaucoma, age-related macular degeneration (AMD), diabetic retinopathy, and retinitis pigmentosa require drug management in order to prevent blindness and affecting million of adults in USA and worldwide. There is an increasing need to develop devices for drug delivery to address ocular diseases. This study focuses on the design, simulation, and development of an implantable ocular drug delivery device consisting of micro-/nanochannels embedded between top and bottom covers with a drug reservoir made from polydimethylsiloxane (PDMS) which is silicon-based organic and biodegradable polymer. Several simulations were carried out with six different micro-channel configurations in order to see the feasibility for ocular drug delivery applications. Based on the results obtained, channel design of osmotic I and osmotic II satisfied the diffusion rates required for ocular drug delivery. Finally, a prototype illustrating the three components of the drug delivery design is presented. In the future, the device will be tested for its functionality and diffusion characteristics. PMID:22919500

  7. Endoscopic Electrosurgery in Patients with Cardiac Implantable Electronic Devices

    PubMed Central

    Baeg, Myong Ki; Kim, Sang-Woo; Ko, Sun-Hye; Lee, Yoon Bum; Hwang, Seawon; Lee, Bong-Woo; Choi, Hye Jin; Park, Jae Myung; Lee, In-Seok; Oh, Yong-Seog; Choi, Myung-Gyu

    2016-01-01

    Background/Aims: Patients with cardiac implantable electronic devices (CIEDs) undergoing endoscopic electrosurgery (EE) are at a risk of electromagnetic interference (EMI). We aimed to analyze the effects of EE in CIED patients. Methods: Patients with CIED who underwent EE procedures such as snare polypectomy, endoscopic submucosal dissection (ESD), and endoscopic retrograde cholangiopancreatography (ERCP) with endoscopic sphincterotomy (EST) were retrospectively analyzed. Postprocedural symptoms as well as demographic and outpatient follow-up data were reviewed through medical records. Electrical data, including preprocedural and postprocedural arrhythmia records, were reviewed through pacemaker interrogation, 24-hour Holter monitoring, or electrocardiogram. Results: Fifty-nine procedures in 49 patients were analyzed. Fifty procedures were performed in 43 patients with a pacemaker, and nine were performed in six patients with an implantable cardioverter-defibrillator. There were one gastric and 44 colon snare polypectomies, five gastric and one colon ESDs, and eight ERCPs with EST. Fifty-five cases of electrical follow-up were noted, with two postprocedural changes not caused by EE. Thirty-one pacemaker interrogations had procedure recordings, with two cases of asymptomatic tachycardia. All patients were asymptomatic with no adverse events. Conclusions: Our study reports no adverse events from EE in patients with CIED, suggesting that this procedure is safe. However, because of the possibility of EMI, recommendations on EE should be followed. PMID:26867552

  8. Psychosocial issues in ventricular assist device implantation and management

    PubMed Central

    Bauman, Lillian

    2015-01-01

    The primary goal of mechanical circulatory support (MCS) is to increase quantity and quality of life (QOL) in patients with systolic heart failure refractory to medical therapies. A key contributor to the success in MCS therapy is a comprehensive assessment of the candidate for device implantation. A crucial element of that assessment is an evaluation of the individual’s psychosocial status, recommended by most current MCS guidelines. By focusing on criteria including drug, alcohol and tobacco abuse, ability to learn and problem solve, history of adherence to medical regimens, and adequate psychosocial support following implant, the team has an opportunity to create an individualized post-discharge plan that addresses identified gaps and optimizes the patient’s likelihood for success. Information gathered also provides the team with a setting in which to discuss the patient’s personal goals for the therapy and advanced care planning. We explore all of these issues and offer recommendations for approaching psychosocial assessment for MCS patients. PMID:26793339

  9. Thin-film rechargeable lithium batteries for implantable devices

    SciTech Connect

    Bates, J.b.; Dudney, N.J.

    1997-05-01

    Thin films of LiCoO{sub 2} have been synthesized in which the strongest x-ray reflection is either weak or missing, indicating a high degree of preferred orientation. Thin-film solid state batteries with these textured cathode films can deliver practical capacities at high current densities. For example, for one of the cells 70% of the maximum capacity between 4.2 V and 3 V ({approximately}0.2 mAh/cm{sup 2}) was delivered at a current of 2 mA/cm{sup 2}. When cycled at rates of 0.1 mA/cm{sup 2}, the capacity loss was 0.001 %/cycle or less. The reliability and performance of Li-LiCoO{sub 2} thin-film batteries make them attractive for application in implantable devices such as neural stimulators, pacemakers, and defibrillators.

  10. Experimenting with microbial fuel cells for powering implanted biomedical devices.

    PubMed

    Roxby, Daniel N; Nham Tran; Pak-Lam Yu; Nguyen, Hung T

    2015-08-01

    Microbial Fuel Cell (MFC) technology has the ability to directly convert sugar into electricity by using bacteria. Such a technology could be useful for powering implanted biomedical devices that require a surgery to replace their batteries every couple of years. In steps towards this, parameters such as electrode configuration, inoculation size, stirring of the MFC and single versus dual chamber reactor configuration were tested for their effect on MFC power output. Results indicate that a Top-Bottom electrode configuration, stirring and larger amounts of bacteria in single chamber MFCs, and smaller amounts of bacteria in dual chamber MFCs give increased power outputs. Finally, overall dual chamber MFCs give several fold larger MFC power outputs. PMID:26736845

  11. Thin-film Rechargeable Lithium Batteries for Implantable Devices

    DOE R&D Accomplishments Database

    Bates, J. B.; Dudney, N. J.

    1997-05-01

    Thin films of LiCoO{sub 2} have been synthesized in which the strongest x ray reflection is either weak or missing, indicating a high degree of preferred orientation. Thin film solid state batteries with these textured cathode films can deliver practical capacities at high current densities. For example, for one of the cells 70% of the maximum capacity between 4.2 V and 3 V ({approximately}0.2 mAh/cm{sup 2}) was delivered at a current of 2 mA/cm{sup 2}. When cycled at rates of 0.1 mA/cm{sup 2}, the capacity loss was 0.001%/cycle or less. The reliability and performance of Li LiCoO{sub 2} thin film batteries make them attractive for application in implantable devices such as neural stimulators, pacemakers, and defibrillators.

  12. Development of implant loading device for animal study about various loading protocol: a pilot study

    PubMed Central

    Yoon, Joon-Ho; Park, Young-Bum; Cho, Yuna; Kim, Chang-Sung; Choi, Seong-Ho; Moon, Hong-Seok; Lee, Keun-Woo

    2012-01-01

    PURPOSE The aims of this pilot study were to introduce implant loading devices designed for animal study and to evaluate the validity of the load transmission ability of the loading devices. MATERIALS AND METHODS Implant loading devices were specially designed and fabricated with two implant abutments and cast metal bars, and orthodontic expansion screw. In six Beagles, all premolars were extracted and two implants were placed in each side of the mandibles. The loading device was inserted two weeks after the implant placement. According to the loading protocol, the load was applied to the implants with different time and method,simulating early, progressive, and delayed loading. The implants were clinically evaluated and the loading devices were removed and replaced to the master cast, followed by stress-strain analysis. Descriptive statistics of remained strain (µε) was evaluated after repeating three cycles of the loading device activation. Statistic analysis was performed using nonparametric, independent t-test with 5% significance level and Friedman's test was also used for verification. RESULTS The loading devices were in good action. However, four implants in three Beagles showed loss of osseointegration. In stress-strain analysis, loading devices showed similar amount of increase in the remained strain after applying 1-unit load for three times. CONCLUSION Specialized design of the implant loading device was introduced. The loading device applied similar amount of loads near the implant after each 1-unit loading. However, the direction of the loads was not parallel to the long axis of the implants as predicted before the study. PMID:23236575

  13. 21 CFR 860.93 - Classification of implants, life-supporting or life-sustaining devices.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Classification of implants, life-supporting or life-sustaining devices. 860.93 Section 860.93 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... Classification § 860.93 Classification of implants, life-supporting or life-sustaining devices. (a)...

  14. Ion implantation in compound semiconductors for high-performance electronic devices

    SciTech Connect

    Zolper, J.C.; Baca, A.G.; Sherwin, M.E.; Klem, J.F.

    1996-05-01

    Advanced electronic devices based on compound semiconductors often make use of selective area ion implantation doping or isolation. The implantation processing becomes more complex as the device dimensions are reduced and more complex material systems are employed. The authors review several applications of ion implantation to high performance junction field effect transistors (JFETs) and heterostructure field effect transistors (HFETs) that are based on compound semiconductors, including: GaAs, AlGaAs, InGaP, and AlGaSb.

  15. From micro- to nanostructured implantable device for local anesthetic delivery

    PubMed Central

    Zorzetto, Laura; Brambilla, Paola; Marcello, Elena; Bloise, Nora; De Gregori, Manuela; Cobianchi, Lorenzo; Peloso, Andrea; Allegri, Massimo; Visai, Livia; Petrini, Paola

    2016-01-01

    Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life) stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers) and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured to nanostructured systems, with the aim of reaching a scale comparable to the biological environment. Improved intracellular penetration compared to microstructured systems, indeed, provides specific drug absorption into the targeted tissue and can lead to an enhancement of its bioavailability and retention time. Nanostructured systems are realized by the modification of existing manufacturing processes (interfacial deposition and nanoprecipitation for degradable polyester particles and high- or low-temperature homogenization for liposomes) or development of novel strategies (electrospun matrices and nanogels). The high surface-to-volume ratio that characterizes nanostructured devices often leads to a burst drug release. This drawback needs to be addressed to fully exploit the advantage of the interaction between the target tissues and the drug: possible strategies

  16. From micro- to nanostructured implantable device for local anesthetic delivery.

    PubMed

    Zorzetto, Laura; Brambilla, Paola; Marcello, Elena; Bloise, Nora; De Gregori, Manuela; Cobianchi, Lorenzo; Peloso, Andrea; Allegri, Massimo; Visai, Livia; Petrini, Paola

    2016-01-01

    Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life) stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers) and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured to nanostructured systems, with the aim of reaching a scale comparable to the biological environment. Improved intracellular penetration compared to microstructured systems, indeed, provides specific drug absorption into the targeted tissue and can lead to an enhancement of its bioavailability and retention time. Nanostructured systems are realized by the modification of existing manufacturing processes (interfacial deposition and nanoprecipitation for degradable polyester particles and high- or low-temperature homogenization for liposomes) or development of novel strategies (electrospun matrices and nanogels). The high surface-to-volume ratio that characterizes nanostructured devices often leads to a burst drug release. This drawback needs to be addressed to fully exploit the advantage of the interaction between the target tissues and the drug: possible strategies

  17. Dental devices; reclassification of root-form endosseous dental implants and endosseous dental implant abutments. Final rule.

    PubMed

    2004-05-12

    The Food and Drug Administration (FDA) is reclassifying root-form endosseous dental implants and endosseous dental implant abutments from class III to class II (special controls). Root-form endosseous dental implants are intended to be surgically placed in the bone of the upper or lower jaw arches to provide support for prosthetic devices, such as artificial teeth, in order to restore the patient's chewing function. Endosseous dental implant abutments are separate components that are attached to the dental implant and intended to aid in prosthetic rehabilitation. FDA is reclassifying these devices on its own initiative on the basis of new information. Elsewhere in this issue of the Federal Register, FDA is announcing the availability of the guidance document that will serve as the special control for these devices. FDA is taking this action under the Federal Food, Drug, and Cosmetic Act (the act), as amended by the Medical Device Amendments of 1976 (the 1976 amendments), the Safe Medical Devices Act of 1990, the Food and Drug Administration Modernization Act of 1997, and the Medical Device User Fee and Modernization Act of 2002. PMID:15141676

  18. Remote monitoring of cardiac implantable electronic devices (CIED).

    PubMed

    Zeitler, Emily P; Piccini, Jonathan P

    2016-08-01

    With increasing indications and access to cardiac implantable electronic devices (CIEDs) worldwide, the number of patients needing CIED follow-up continues to rise. In parallel, the technology available for managing these devices has advanced considerably. In this setting, remote monitoring (RM) has emerged as a complement to routine in-office care. Rigorous studies, randomized and otherwise, have demonstrated advantages to patient with CIED management systems, which incorporates RM resulting in authoritative guidelines from relevant professional societies recommending RM for all eligible patients. In addition to clinical benefits, CIED management programs that include RM have been shown to be cost effective and associated with high patient satisfaction. Finally, RM programs hold promise for the future of CIED research in light of the massive data collected through RM databases converging with unprecedented computational capability. This review outlines the available data associated with clinical outcomes in patients managed with RM with an emphasis on randomized trials; the impact of RM on patient satisfaction, cost-effectiveness, and healthcare utilization; and possible future directions for the use of RM in clinical practice and research. PMID:27134007

  19. Changes in Spirometry After Left Ventricular Assist Device Implantation.

    PubMed

    Mohamedali, Burhan; Bhat, Geetha; Yost, Gardner; Tatooles, Antone

    2015-12-01

    Left ventricular assist devices (LVADs) are increasingly being used as life-saving therapy in patients with end-stage heart failure. The changes in spirometry following LVAD implantation and subsequent unloading of the left ventricle and pulmonary circulation are unknown. In this study, we explored long-term changes in spirometry after LVAD placement. In this retrospective study, we compared baseline preoperative pulmonary function test (PFT) results to post-LVAD spirometric measurements. Our results indicated that pulmonary function tests were significantly reduced after LVAD placement (forced expiratory volume in one second [FEV1 ]: 1.9 vs.1.7, P = 0.016; forced vital capacity [FVC]: 2.61 vs. 2.38, P = 0.03; diffusing capacity of the lungs for carbon monoxide [DLCO]: 14.75 vs. 11.01, P = 0.01). Subgroup analysis revealed greater impairment in lung function in patients receiving HeartMate II (Thoratec, Pleasanton, CA, USA) LVADs compared with those receiving HeartWare (HeartWare, Framingham, MA, USA) devices. These unexpected findings may result from restriction of left anterior hemi-diaphragm; however, further prospective studies to validate our findings are warranted. PMID:25994850

  20. Pyoderma gangrenosum after totally implanted central venous access device insertion

    PubMed Central

    Inan, Ihsan; Myers, Patrick O; Braun, Rolf; Hagen, Monica E; Morel, Philippe

    2008-01-01

    Background Pyoderma gangrenosum is an aseptic skin disease. The ulcerative form of pyoderma gangrenosum is characterized by a rapidly progressing painful irregular and undermined bordered necrotic ulcer. The aetiology of pyoderma gangrenosum remains unclear. In about 70% of cases, it is associated with a systemic disorder, most often inflammatory bowel disease, haematological disease or arthritis. In 25–50% of cases, a triggering factor such as recent surgery or trauma is identified. Treatment consists of local and systemic approaches. Systemic steroids are generally used first. If the lesions are refractory, steroids are combined with other immunosuppressive therapy or to antimicrobial agents. Case presentation A 90 years old patient with myelodysplastic syndrome, seeking regular transfusions required totally implanted central venous access device (Port-a-Cath®) insertion. Fever and inflammatory skin reaction at the site of insertion developed on the seventh post-operative day, requiring the device's explanation. A rapid progression of the skin lesions evolved into a circular skin necrosis. Intravenous steroid treatment stopped the necrosis' progression. Conclusion Early diagnosis remains the most important step to the successful treatment of pyoderma gangrenosum. PMID:18325095

  1. Percutaneous Endovascular Salvage Techniques for Implanted Venous Access Device Dysfunction

    SciTech Connect

    Breault, Stéphane; Glauser, Frédéric; Babaker, Malik Doenz, Francesco Qanadli, Salah Dine

    2015-06-15

    PurposeImplanted venous access devices (IVADs) are often used in patients who require long-term intravenous drug administration. The most common causes of device dysfunction include occlusion by fibrin sheath and/or catheter adherence to the vessel wall. We present percutaneous endovascular salvage techniques to restore function in occluded catheters. The aim of this study was to evaluate the feasibility, safety, and efficacy of these techniques.Methods and MaterialsThrough a femoral or brachial venous access, a snare is used to remove fibrin sheath around the IVAD catheter tip. If device dysfunction is caused by catheter adherences to the vessel wall, a new “mechanical adhesiolysis” maneuver was performed. IVAD salvage procedures performed between 2005 and 2013 were analyzed. Data included clinical background, catheter tip position, success rate, recurrence, and rate of complication.ResultsEighty-eight salvage procedures were performed in 80 patients, mostly women (52.5 %), with a mean age of 54 years. Only a minority (17.5 %) of evaluated catheters were located at an optimal position (i.e., cavoatrial junction ±1 cm). Mechanical adhesiolysis or other additional maneuvers were used in 21 cases (24 %). Overall technical success rate was 93.2 %. Malposition and/or vessel wall adherences were the main cause of technical failure. No complications were noted.ConclusionThese IVAD salvage techniques are safe and efficient. When a catheter is adherent to the vessel wall, mechanical adhesiolysis maneuvers allow catheter mobilization and a greater success rate with no additional risk. In patients who still require long-term use of their IVAD, these procedures can be performed safely to avoid catheter replacement.

  2. Dosimetric review of cardiac implantable electronic device patients receiving radiotherapy.

    PubMed

    Prisciandaro, Joann I; Makkar, Akash; Fox, Colleen J; Hayman, James A; Horwood, Laura; Pelosi, Frank; Moran, Jean M

    2015-01-01

    A formal communication process was established and evaluated for the management of patients with cardiac implantable electronic devices (CIEDs) receiving radiation therapy (RT). Methods to estimate dose to the CIED were evaluated for their appropriateness in the management of these patients. A retrospective, institutional review board (IRB) approved study of 69 patients with CIEDs treated with RT between 2005 and 2011 was performed. The treatment sites, techniques, and the estimated doses to the CIEDs were analyzed and compared to estimates from published peripheral dose (PD) data and three treatment planning systems(TPSs) - UMPlan, Eclipse's AAA and Acuros algorithms. When measurements were indicated, radiation doses to the CIEDs ranged from 0.01-5.06 Gy. Total peripheral dose estimates based on publications differed from TLD measurements by an average of 0.94 Gy (0.05-4.49 Gy) and 0.51 Gy (0-2.74 Gy) for CIEDs within 2.5 cm and between 2.5 and 10 cm of the treatment field edge, respectively. Total peripheral dose estimates based on three TPSs differed from measurements by an average of 0.69 Gy (0.02-3.72 Gy) for CIEDs within 2.5 cm of the field edge. Of the 69 patients evaluated in this study, only two with defibrillators experienced a partial reset of their device during treatment. Based on this study, few CIED-related events were observed during RT. The only noted correlation with treatment parameters for these two events was beam energy, as both patients were treated with high-energy photon beams (16 MV). Differences in estimated and measured CIED doses were observed when using published PD data and TPS calculations. As such, we continue to follow conservative guidelines and measure CIED doses when the device is within 10 cm of the field or the estimated dose is greater than 2 Gy for pacemakers or 1 Gy for defibrillators. PMID:25679176

  3. Safety of nerve conduction studies in patients with implanted cardiac devices.

    PubMed

    Schoeck, Andreas P; Mellion, Michelle L; Gilchrist, James M; Christian, Fredric V

    2007-04-01

    Patients with implanted cardiac devices and their physicians may defer important electrodiagnostic testing because of anxiety about potential negative effects on the device. To determine the safety of routine nerve conduction studies (NCS) in this population, 10 patients with permanent dual-chamber pacemakers of various types and five patients with implanted cardiac defibrillators (ICD) underwent nerve stimulation at sites commonly used during NCS. The implanted cardiac device was interrogated before and after the study and there was continuous monitoring of the surface electrocardiogram (ECG) and atrial and ventricular electrograms. Electrical impulses generated during routine NCS were never detected by the sensing amplifier and did not affect the programmed settings of the implanted cardiac device. We conclude that routine NCS is safe in patients with implanted cardiac pacemakers with bipolar sensing configurations and defibrillators. PMID:17094099

  4. Robotic Assisted Implantation of Ventricular Assist Device after Sternectomy & Pectoralis Muscle Flap

    PubMed Central

    Khalpey, Zain; Sydow, Nicole; Paidy, Samata; Slepian, Marvin J.; Friedman, Mark; Cooper, Anthony; Marsh, Katherine M.; Schmitto, Jan D; Poston, Robert

    2014-01-01

    Left ventricular assist devices are increasingly important in the management of advanced heart failure. Most patients who benefit from these devices have had some prior cardiac surgery, making implantation of higher risk. This is especially true in patients who have had prior pectoralis flap reconstruction after sternectomy for mediastinitis. We outline the course of such a patient, in whom the use of robotic assistance allowed for a less invasive device implantation approach with preservation of the flap for transplantation. PMID:25072555

  5. Minimally Invasive Right Ventricular Assist Device Implantation in a Patient with HeartWare left ventricular Assist Device.

    PubMed

    Maxhera, Bujar; Albert, Alexander; Westenfeld, Ralf; Boeken, Udo; Lichtenberg, Artur; Saeed, Diyar

    2015-01-01

    Many centers reported positive outcome after left ventricular assist devices (LVADs) implantation using a minimally invasive approach. The main drawback of this minimally invasive approach is the feasibility of right ventricular assist device (RVAD) implantation with direct cannulation of the pulmonary artery in cases of perioperative right ventricular failure (RVF). We report our experience with a 41-year-old male patient who was supported with a temporary RVAD using J-sternotomy approach for RVF after LVAD implantation. No technical issue was encountered, and the patient's condition stabilized immediately after RVAD implantation. However, several days later, the patient developed severe septic shock caused by pneumonia and died on the postoperative day 15 after RVAD implantation. PMID:25914955

  6. Capsule Endoscopy in Patients with Implantable Electromedical Devices is Safe

    PubMed Central

    Harris, Lucinda A.; Hansel, Stephanie L.; Rajan, Elizabeth; Srivathsan, Komandoor; Rea, Robert; Crowell, Michael D.; Fleischer, David E.; Pasha, Shabana F.; Gurudu, Suryakanth R.; Heigh, Russell I.; Shiff, Arthur D.; Post, Janice K.; Leighton, Jonathan A.

    2013-01-01

    Background and Study Aims. The presence of an implantable electromechanical cardiac device (IED) has long been considered a relative contraindication to the performance of video capsule endoscopy (CE). The primary aim of this study was to evaluate the safety of CE in patients with IEDs. A secondary purpose was to determine whether IEDs have any impact on images captured by CE. Patients and Methods. A retrospective chart review of all patients who had a capsule endoscopy at Mayo Clinic in Scottsdale, AZ, USA, or Rochester, MN, USA, (January 2002 to June 2010) was performed to identify CE studies done on patients with IEDs. One hundred and eighteen capsule studies performed in 108 patients with IEDs were identified and reviewed for demographic data, method of preparation, and study data. Results. The most common indications for CE were obscure gastrointestinal bleeding (77%), anemia (14%), abdominal pain (5%), celiac disease (2%), diarrhea (1%), and Crohn's disease (1%). Postprocedure assessments did not reveal any detectable alteration on the function of the IED. One patient with an ICD had a 25-minute loss of capsule imaging due to recorder defect. Two patients with LVADs had interference with capsule image acquisition. Conclusions. CE did not interfere with IED function, including PM, ICD, and/or LVAD and thus appears safe. Additionally, PM and ICD do not appear to interfere with image acquisition but LVAD may interfere with capsule images and require that capsule leads be positioned as far away as possible from the IED to assure reliable image acquisition. PMID:23710168

  7. Surgical management of infected cardiac implantable electronic devices.

    PubMed

    Chaudhry, Umar A R; Harling, Leanne; Ashrafian, Hutan; Athanasiou, Christina; Tsipas, Pantelis; Kokotsakis, John; Athanasiou, Thanos

    2016-01-15

    The growing use of cardiac implantable electronic devices (CIED) has led to infections requiring intervention. These are traditionally managed using a percutaneous transvenous approach to fully extract the culpable leads. Indications for such strategies are well-established and range from simple traction to the use of powered extraction tools including laser sheaths. Where such attempts fail, or if there are further complications, then there may be need for a cardiothoracic surgical approach. Limited evidence is currently available on the merits of individual strategies, and these are mainly drawn from case reports or series. Most utilise cardiopulmonary bypass, cardioplegic arrest and entry within the right atrium to allow direct visualisation of any vegetation and safely explant all CIED components whilst avoiding perforation, valvular and paravalvular damage. In this review, we describe a number of these and the unique challenges faced by surgeons when attempting to extract CIED. It is clear that future work should concentrate on creating clear consensus and guidelines on indications, risks and measures of efficacy outcomes for various surgical techniques. PMID:26590887

  8. Insertion of Totally Implantable Central Venous Access Devices by Surgeons

    PubMed Central

    An, Hyeonjun; Ryu, Chun-Geun; Jung, Eun-Joo; Kang, Hyun Jong; Paik, Jin Hee; Yang, Jung-Hyun

    2015-01-01

    Purpose The aim of this study is to evaluate the results for the insertion of totally implantable central venous access devices (TICVADs) by surgeons. Methods Total 397 patients, in whom TICVADs had been inserted for intravenous chemotherapy between September 2008 and June 2014, were pooled. This procedure was performed under local anesthesia in an operation room. The insertion site for the TICVAD was mainly in the right-side subclavian vein. In the case of breast cancer patients, the subclavian vein opposite the surgical site was used for insertion. Results The 397 patients included 73 males and 324 females. Primary malignant tumors were mainly colorectal and breast cancer. The mean operation time was 54 minutes (18-276 minutes). Operation-related complications occurred in 33 cases (8.3%). Early complications developed in 15 cases with catheter malposition and puncture failure. Late complications, which developed after 24 hours, included inflammation in 6 cases, skin necrosis in 6 cases, hematoma in 3 cases, port malfunction in 1 case, port migration in 1 case, and intractable pain at the port site in 1 case. Conclusion Insertion of a TICVAD under local anesthesia by a surgeon is a relatively safe procedure. Meticulous undermining of the skin and carefully managing the TICVAD could minimize complications. PMID:25960974

  9. Readmissions After Continuous Flow Left Ventricular Assist Device Implantation: Differences Observed Between Two Contemporary Device Types.

    PubMed

    Haglund, Nicholas A; Davis, Mary E; Tricarico, Nicole M; Keebler, Mary E; Maltais, Simon

    2015-01-01

    Readmissions after continuous flow left ventricular assist devices implantation are common. We compared the frequency and etiology of readmissions between two continuous flow left ventricular assist devices 6 months after implant. We retrospectively assessed readmissions in 81 patients who received a bridge to transplant HeartMate-II (HM-II) n = 35, 43% or HeartWare (HW) n = 46, 57%, from 2009 to 2014. Readmissions were divided into cardiac, infection, gastrointestinal bleeding, stroke, pump thrombosis, and miscellaneous profiles. Age, gender, creatinine, INTERMACS profiles were comparable between groups (p > 0.05). Sixty-one patients accounted for 141 readmissions. At 6 months, the overall readmission rate was higher among HM-II versus HW recipients (2.3 ± 1.7 vs. 1.4 ± 1.3; p = 0.024). Multiple readmissions (≥2) occurred more frequently in HM-II recipients (HM-II 23, 66% vs. HW 20, 44%; p = 0.047) which accounted for 87% of overall readmission frequency. Cardiac profile was the most common reason for readmission (HM-II = 15, HW = 17; p = 0.95). Readmission for arrhythmia (HM-II = 10, HW = 3; p = 0.021) and overall infection rate (0.49 ± 0.70 vs. 0.17 ± 0.68; p = 0.001) were more common among HM-II recipients; however, other readmission profiles were comparable between devices (p > 0.05). Readmission frequency, multiple readmissions, and clinical profile characteristics were different between HM-II and HW recipients. PMID:25806614

  10. Bizarre Paranoid Delusions Associated With an Implanted Surgical Device.

    PubMed

    Dodds, Peter R; Dodds, Tyler J; Jacoby, Teri L

    2016-03-01

    We describe a case involving bizarre paranoid delusions following implantation of a sacral nerve stimulator, and review the literature regarding psychotic symptoms related to surgical implants. A 64-year-old female developed bizarre paranoid delusions regarding a sacral nerve stimulator that had been implanted two years previously for dysfunctional voiding. The patient believed that the wires from the sacral nerve electrodes had grown up her spine and were affecting her vision as well as controlling her thoughts. The delusions developed in the setting of profound anxiety and feelings of loss after the death of her mother. The patient initially demanded that the implant be removed emergently. The delusions gradually abated as she adjusted to the loss of her mother. Fortunately the symptoms abated entirely with supportive care. We suspect that given the frequency of surgical implants that the association with delusional thoughts might be much higher than suggested by a literature review. PMID:27169299

  11. Subcutaneous Implantable Cardioverter-Defibrillator Implantation in a Patient with a Left Ventricular Assist Device Already in Place

    PubMed Central

    Subzposh, Faiz; Hankins, Shelley R.; Kutalek, Steven P.

    2015-01-01

    A 56-year-old man with ischemic cardiomyopathy, a biventricular implantable cardioverter-defibrillator (ICD), and a left ventricular assist device (LVAD) developed a pocket hematoma and infection after an ICD generator change. The biventricular ICD was extracted, and the patient was given a full course of antibiotics. Because he had no indications for bradycardia pacing or biventricular pacing, he was implanted with a subcutaneous ICD under full anticoagulation. There was no interference in sensing or shock delivery from the ICD. The LVAD readings were unchanged during and after the procedure. The patient had an uneventful postoperative course, and both devices were functioning normally. To our knowledge, this is the first reported case of the implantation of a subcutaneous ICD in the presence of an LVAD. This report illustrates that both devices can be implanted successfully in the same patient. In addition, the subcutaneous ICD minimizes the risk of bloodstream infections, which can be fatal in patients who have life-supporting devices such as an LVAD. PMID:25873825

  12. Kinetic and thermal energy harvesters for implantable medical devices and biomedical autonomous sensors

    NASA Astrophysics Data System (ADS)

    Cadei, Andrea; Dionisi, Alessandro; Sardini, Emilio; Serpelloni, Mauro

    2014-01-01

    Implantable medical devices usually require a battery to operate and this can represent a severe restriction. In most cases, the implantable medical devices must be surgically replaced because of the dead batteries; therefore, the longevity of the whole implantable medical device is determined by the battery lifespan. For this reason, researchers have been studying energy harvesting techniques from the human body in order to obtain batteryless implantable medical devices. The human body is a rich source of energy and this energy can be harvested from body heat, breathing, arm motion, leg motion or the motion of other body parts produced during walking or any other activity. In particular, the main human-body energy sources are kinetic energy and thermal energy. This paper reviews the state-of-art in kinetic and thermoelectric energy harvesters for powering implantable medical devices. Kinetic energy harvesters are based on electromagnetic, electrostatic and piezoelectric conversion. The different energy harvesters are analyzed highlighting their sizes, energy or power they produce and their relative applications. As they must be implanted, energy harvesting devices must be limited in size, typically about 1 cm3. The available energy depends on human-body positions; therefore, some positions are more advantageous than others. For example, favorable positions for piezoelectric harvesters are hip, knee and ankle where forces are significant. The energy harvesters here reported produce a power between 6 nW and 7.2 mW; these values are comparable with the supply requirements of the most common implantable medical devices; this demonstrates that energy harvesting techniques is a valid solution to design batteryless implantable medical devices.

  13. Improvement of device isolation using field implantation for GaN MOSFETs

    NASA Astrophysics Data System (ADS)

    Jiang, Ying; Wang, Qingpeng; Zhang, Fuzhe; Li, Liuan; Shinkai, Satoko; Wang, Dejun; Ao, Jin-Ping

    2016-03-01

    Gallium nitride (GaN) metal-oxide-semiconductor field-effect transistors (MOSFETs) with boron field implantation isolation and mesa isolation were fabricated and characterized. The process of boron field implantation was altered and subsequently conducted after performing high-temperature ohmic annealing and gate oxide thermal treatment. Implanted regions with high resistivity were achieved. The circular MOSFET fabricated in the implanted region showed an extremely low current of 6.5 × 10-12 A under a gate voltage value up to 10 V, thus demonstrating that the parasitic MOSFET in the isolation region was eliminated by boron field implantation. The off-state drain current of the rectangular MOSFET with boron field implantation was 5.5 × 10-11 A, which was only one order of magnitude higher than the 6.6 × 10-12 A of the circular device. By contrast, the rectangular MOSFET with mesa isolation presented an off-state drain current of 3.2 × 10-9 A. The field isolation for GaN MOSFETs was achieved by using boron field implantation. The implantation did not reduce the field-effect mobility. The isolation structure of both mesa and implantation did not influence the subthreshold swing, whereas the isolation structure of only the implantation increased the subthreshold swing. The breakdown voltage of the implanted region with 5 μm spacing was up to 901.5 V.

  14. Science and technology of biocompatible thin films for implantable biomedical devices.

    SciTech Connect

    Li, W.; Kabius, B.; Auciello, O.; Materials Science Division

    2010-01-01

    This presentation focuses on reviewing research to develop two critical biocompatible film technologies to enable implantable biomedical devices, namely: (1) development of bioinert/biocompatible coatings for encapsulation of Si chips implantable in the human body (e.g., retinal prosthesis implantable in the human eye) - the coating involves a novel ultrananocrystalline diamond (UNCD) film or hybrid biocompatible oxide/UNCD layered films; and (2) development of biocompatible films with high-dielectric constant and microfabrication process to produce energy storage super-capacitors embedded in the microchip to achieve full miniaturization for implantation into the human body.

  15. Implantable device for in-vivo intracranial and cerebrospinal fluid pressure monitoring

    DOEpatents

    Ericson, Milton N.; McKnight, Timothy E.; Smith, Stephen F.; Hylton, James O.

    2003-01-01

    The present invention relates to a completely implantable intracranial pressure monitor, which can couple to existing fluid shunting systems as well as other internal monitoring probes. The implant sensor produces an analog data signal which is then converted electronically to a digital pulse by generation of a spreading code signal and then transmitted to a location outside the patient by a radio-frequency transmitter to an external receiver. The implanted device can receive power from an internal source as well as an inductive external source. Remote control of the implant is also provided by a control receiver which passes commands from an external source to the implant system logic. Alarm parameters can be programmed into the device which are capable of producing an audible or visual alarm signal. The utility of the monitor can be greatly expanded by using multiple pressure sensors simultaneously or by combining sensors of various physiological types.

  16. Nanomaterials and synergistic low intensity direct current (LIDC) stimulation technology for orthopaedic implantable medical devices

    PubMed Central

    Samberg, Meghan E.; Cohen, Paul H.; Wysk, Richard A.; Monteiro-Riviere, Nancy A.

    2012-01-01

    Nanomaterials play a significant role in biomedical research and applications due to their unique biological, mechanical, and electrical properties. In recent years, they have been utilised to improve the functionality and reliability of a wide range of implantable medical devices ranging from well-established orthopaedic residual hardware devices (e.g. hip implants) that can repair defects in skeletal systems to emerging tissue engineering scaffolds that can repair or replace organ functions. This review summarizes the applications and efficacies of these nanomaterials that include synthetic or naturally occurring metals, polymers, ceramics, and composites in orthopaedic implants, the largest market segment of implantable medical devices. The importance of synergistic engineering techniques that can augment or enhance the performance of nanomaterial applications in orthopaedic implants is also discussed,, the focus being on a low intensity direct electric current (LIDC) stimulation technology to promote the long-term antibacterial efficacy of oligodynamic metal-based surfaces by ionization, while potentially accelerating tissue growth and osseointegration. While many nanomaterials have clearly demonstrated their ability to provide more effective implantable medical surfaces, further decisive investigations are necessary before they can translate into medically safe and commercially viable clinical applications. The paper concludes with a discussion about some of the critical impending issues with the application of nanomaterials-based technologies in implantable medical devices, and potential directions to address these. PMID:23335493

  17. High Curie temperature drive layer materials for ion-implanted magnetic bubble devices

    NASA Technical Reports Server (NTRS)

    Fratello, V. J.; Wolfe, R.; Blank, S. L.; Nelson, T. J.

    1984-01-01

    Ion implantation of bubble garnets can lower the Curie temperature by 70 C or more, thus limiting high temperature operation of devices with ion-implanted propagation patterns. Therefore, double-layer materials were made with a conventional 2-micron bubble storage layer capped by an ion-implantable drive layer of high Curie temperature, high magnetostriction material. Contiguous disk test patterns were implanted with varying doses of a typical triple implant. Quality of propagation was judged by quasistatic tests on 8-micron period major and minor loops. Variations of magnetization, uniaxial anisotropy, implant dose, and magnetostriction were investigated to ensure optimum flux matching, good charged wall coupling, and wide operating margins. The most successful drive layer compositions were in the systems (SmDyLuCa)3(FeSi)5O12 and (BiGdTmCa)3(FeSi)5O12 and had Curie temperatures 25-44 C higher than the storage layers.

  18. A novel implantable device for the treatment of obstructive sleep apnea: clinical safety and feasibility

    PubMed Central

    Pavelec, Vaclav; Rotenberg, Brian W; Maurer, Joachim T; Gillis, Edward; Verse, Thomas

    2016-01-01

    Objective Many cases of obstructive sleep apnea (OSA) involve collapse of the tongue base and soft palate during sleep, causing occlusion of the upper airway and leading to oxygen desaturation. Existing therapies can be effective, but they are plagued by patient adherence issues and the invasiveness of surgical approaches. A new, minimally invasive implant for OSA has been developed, which is elastic and contracts a few weeks after deployment, stabilizing the surrounding soft tissue. The device has had good outcomes in preclinical testing; this report describes the preliminary feasibility and safety of its implementation in humans. Patients and methods A prospective, multicenter, single-arm feasibility study was conducted. Subjects were adults with moderate-to-severe OSA who had previously failed or refused conventional continuous positive airway pressure treatment. Intraoperative feasibility data, postoperative pain, and safety information were collected for a 30-day postoperative period. Results Forty subjects participated (37 men, three women; average age of 46.1 years); each received two tongue-base implants and two soft-palate implants. Surgical procedure time averaged 43 minutes. Postsurgical pain resolved readily in most cases; at 30 days post implantation, <20% of subjects reported pain, which averaged less than two out of ten. Adverse events were generally the mild and expected sequelae of a surgical procedure with general anesthesia and intraoral manipulation. The device was well tolerated. Implant extrusions were reported with soft-palate implants (n=12), while tongue-base implants required few revisions (n=2). Quantitative and qualitative sleep effectiveness outcomes (including full-night polysomnographic and quality-of-life measures) will be presented in a subsequent report. Conclusion Implantation of the device was feasible. Although a relatively high rate of extrusions occurred in the now-discontinued palate implants, tongue-base implants were

  19. Cardiac Implantable Electronic Devices and End-of-Life Care: An Australian Perspective.

    PubMed

    Alhammad, Nasser J; O'Donnell, Mark; O'Donnell, David; Mariani, Justin A; Gould, Paul A; McGavigan, Andrew D

    2016-08-01

    Cardiac implantable electronic devices (pacemakers and defibrillators) are increasingly common in modern cardiology practice, and health professionals from a variety of specialties will encounter patients with such devices on a frequent basis. This article will focus on the subset of patients who may request, or be appropriate for, device deactivation and discuss the issues surrounding end-of-life decisions, along with the ethical and legal implications of device deactivation. PMID:27320854

  20. Animal Models for Evaluation of Bone Implants and Devices: Comparative Bone Structure and Common Model Uses.

    PubMed

    Wancket, L M

    2015-09-01

    Bone implants and devices are a rapidly growing field within biomedical research, and implants have the potential to significantly improve human and animal health. Animal models play a key role in initial product development and are important components of nonclinical data included in applications for regulatory approval. Pathologists are increasingly being asked to evaluate these models at the initial developmental and nonclinical biocompatibility testing stages, and it is important to understand the relative merits and deficiencies of various species when evaluating a new material or device. This article summarizes characteristics of the most commonly used species in studies of bone implant materials, including detailed information about the relevance of a particular model to human bone physiology and pathology. Species reviewed include mice, rats, rabbits, guinea pigs, dogs, sheep, goats, and nonhuman primates. Ultimately, a comprehensive understanding of the benefits and limitations of different model species will aid in rigorously evaluating a novel bone implant material or device. PMID:26163303

  1. Implantable Smart Technologies (IST): Defining the 'Sting' in Data and Device.

    PubMed

    Haddow, Gill; Harmon, Shawn H E; Gilman, Leah

    2016-09-01

    In a world surrounded by smart objects from sensors to automated medical devices, the ubiquity of 'smart' seems matched only by its lack of clarity. In this article, we use our discussions with expert stakeholders working in areas of implantable medical devices such as cochlear implants, implantable cardiac defibrillators, deep brain stimulators and in vivo biosensors to interrogate the difference facets of smart in 'implantable smart technologies', considering also whether regulation needs to respond to the autonomy that such artefacts carry within them. We discover that when smart technology is deconstructed it is a slippery and multi-layered concept. A device's ability to sense and transmit data and automate medicine can be associated with the 'sting' of autonomy being disassociated from human control as well as affecting individual, group, and social environments. PMID:26646672

  2. [A fully-implantable active hearing device in congenital auricular atresia].

    PubMed

    Siegert, R; Neumann, C

    2014-07-01

    Active implantable hearing devices were primarily developed for sensorineural hearing loss. The vibrator coupling mechanisms were oriented towards normal middle ear anatomy and function. The aim of this project was to modify the only fully implantable hearing device with an implantable microphone for application in congenital auricular atresia, Carina™, and to introduce the modified device into the clinic. A special prosthesis was developed for the transducer and its individual coupling achieved by a special cramping system. The system was implanted in 5 patients with congenital auricular atresia. Audiological results were good; with patients' hearing gain exceeding 30 dB HL. Anatomic limits to the system's indications and technical drawbacks are also discussed. PMID:25056646

  3. Patient Report and Review of Rapidly Growing Mycobacterial Infection after Cardiac Device Implantation

    PubMed Central

    Hirsh, David S.; Goswami, Neela D.

    2016-01-01

    Mycobacterial infections resulting from cardiac implantable electronic devices are rare, but as more devices are implanted, these organisms are increasingly emerging as causes of early-onset infections. We report a patient with an implantable cardioverter-defibrillator pocket and associated bloodstream infection caused by an organism of the Mycobacterium fortuitum group, and we review the literature regarding mycobacterial infections resulting from cardiac device implantations. Thirty-two such infections have been previously described; most (70%) were caused by rapidly growing species, of which M. fortuitum group species were predominant. When managing such infections, clinicians should consider the potential need for extended incubation of routine cultures or dedicated mycobacterial cultures for accurate diagnosis; combination antimicrobial drug therapy, even for isolates that appear to be macrolide susceptible, because of the potential for inducible resistance to this drug class; and the arrhythmogenicity of the antimicrobial drugs traditionally recommended for infections caused by these organisms. PMID:26890060

  4. Internet-Based Device-Assisted Remote Monitoring of Cardiovascular Implantable Electronic Devices

    PubMed Central

    Pron, G; Ieraci, L; Kaulback, K

    2012-01-01

    Executive Summary Objective The objective of this Medical Advisory Secretariat (MAS) report was to conduct a systematic review of the available published evidence on the safety, effectiveness, and cost-effectiveness of Internet-based device-assisted remote monitoring systems (RMSs) for therapeutic cardiac implantable electronic devices (CIEDs) such as pacemakers (PMs), implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices. The MAS evidence-based review was performed to support public financing decisions. Clinical Need: Condition and Target Population Sudden cardiac death (SCD) is a major cause of fatalities in developed countries. In the United States almost half a million people die of SCD annually, resulting in more deaths than stroke, lung cancer, breast cancer, and AIDS combined. In Canada each year more than 40,000 people die from a cardiovascular related cause; approximately half of these deaths are attributable to SCD. Most cases of SCD occur in the general population typically in those without a known history of heart disease. Most SCDs are caused by cardiac arrhythmia, an abnormal heart rhythm caused by malfunctions of the heart’s electrical system. Up to half of patients with significant heart failure (HF) also have advanced conduction abnormalities. Cardiac arrhythmias are managed by a variety of drugs, ablative procedures, and therapeutic CIEDs. The range of CIEDs includes pacemakers (PMs), implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices. Bradycardia is the main indication for PMs and individuals at high risk for SCD are often treated by ICDs. Heart failure (HF) is also a significant health problem and is the most frequent cause of hospitalization in those over 65 years of age. Patients with moderate to severe HF may also have cardiac arrhythmias, although the cause may be related more to heart pump or haemodynamic failure. The presence of HF, however

  5. Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review.

    PubMed

    Bocan, Kara N; Sejdić, Ervin

    2016-01-01

    Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters) and variability (changes over time). Current strategies in adaptive (or tunable) systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver. PMID:26999154

  6. Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review

    PubMed Central

    Bocan, Kara N.; Sejdić, Ervin

    2016-01-01

    Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters) and variability (changes over time). Current strategies in adaptive (or tunable) systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver. PMID:26999154

  7. Drug loading into porous calcium carbonate microparticles by solvent evaporation.

    PubMed

    Preisig, Daniel; Haid, David; Varum, Felipe J O; Bravo, Roberto; Alles, Rainer; Huwyler, Jörg; Puchkov, Maxim

    2014-08-01

    Drug loading into porous carriers may improve drug release of poorly water-soluble drugs. However, the widely used impregnation method based on adsorption lacks reproducibility and efficiency for certain compounds. The aim of this study was to evaluate a drug-loading method based on solvent evaporation and crystallization, and to investigate the underlying drug-loading mechanisms. Functionalized calcium carbonate (FCC) microparticles and four drugs with different solubility and permeability properties were selected as model substances to investigate drug loading. Ibuprofen, nifedipine, losartan potassium, and metronidazole benzoate were dissolved in acetone or methanol. After dispersion of FCC, the solvent was removed under reduced pressure. For each model drug, a series of drug loads were produced ranging from 25% to 50% (w/w) in steps of 5% (w/w). Loading efficiency was qualitatively analyzed by scanning electron microscopy (SEM) using the presence of agglomerates and drug crystals as indicators of poor loading efficiency. The particles were further characterized by mercury porosimetry, specific surface area measurements, differential scanning calorimetry, and USP2 dissolution. Drug concentration was determined by HPLC. FCC-drug mixtures containing equivalent drug fractions but without specific loading strategy served as reference samples. SEM analysis revealed high efficiency of pore filling up to a drug load of 40% (w/w). Above this, agglomerates and separate crystals were significantly increased, indicating that the maximum capacity of drug loading was reached. Intraparticle porosity and specific surface area were decreased after drug loading because of pore filling and crystallization on the pore surface. HPLC quantification of drugs taken up by FCC showed only minor drug loss. Dissolution rate of FCC loaded with metronidazole benzoate and nifedipine was faster than the corresponding FCC-drug mixtures, mainly due to surface enlargement, because only small

  8. The Esteem System: a totally implantable hearing device.

    PubMed

    Maurer, J; Savvas, E

    2010-01-01

    The Esteem totally implantable active middle ear implant is a new technology to augment hearing in patients suffering from moderate-to-severe and severe sensorineural hearing loss. In contrast to conventional (acoustic) hearing aids, the system uses two piezoelectric transducers (PZTs). PZTs are used as the sensor and driver to replace the function of the middle ear. Sound is received via a PZT sensor that picks up eardrum vibrations, following the piezoelectric principle, and transforms them into an electric signal. This signal is filtered, modified, amplified and transferred to a PZT driver, which mechanically drives the stapes and thereby the inner ear. The sound processor also contains a power source, which is an implantable lithium iodide battery. All components of the hearing restoration system are totally implantable to offer good sound fidelity and reduce hearing aid stigma caused by the visibility of conventional and semi-implantable hearing systems. Our experience shows that this system can provide considerable benefit to patients with sensorineural hearing loss. PMID:20610915

  9. Deuterium-incorporated gate oxide of MOS devices fabricated by using deuterium ion implantation

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Sung; Lear, Kevin L.

    2012-04-01

    In the aspect of metal-oxide-semiconductor (MOS) device reliability, deuterium-incorporated gate oxide could be utilized to suppress the wear-out that is combined with oxide trap generation. An alternative deuterium process for the passivation of oxide traps or defects in the gate oxide of MOS devices has been suggested in this study. The deuterium ion is delivered to the location where the gate oxide resides by using an implantation process and subsequent N2 annealing process at the back-end of metallization process. A conventional MOS field-effect transistor (MOSFET) with a 3-nm-thick gate oxide and poly-to-ploy capacitor sandwiched with 20-nm-thick SiO2 were fabricated in order to demonstrate the deuterium effect in our process. An optimum condition of ion implantation was necessary to account for the topography of the overlaying layers in the device structure and to minimize the physical damage due to the energy of the implanted ion. Device parameter variations, the gate leakage current, and the dielectric breakdown phenomenon were investigated in the deuterium-ion-implanted devices. We found the isotope effect between hydrogen- and deuterium-implanted devices and an improved electrical reliability in the deuterated gate oxide. This implies that deuterium bonds are generated effectively at the Si/SiO2 interface and in the SiO2 bulk.

  10. An unusual etiological agent of implantable cardioverter device endocarditis: Corynebacterium mucifaciens.

    PubMed

    Kaya, Adnan; Tekkesin, Ahmet Ilker; Kalenderoglu, Koray; Alper, Ahmet Taha

    2016-01-01

    Cardiac pacing devices and implantable cardioverter defibrillator (ICD) are becoming the mainstay of therapy in cardiology and infective endocarditis (IE) and pocket infection; however, these devices require careful monitoring. Here, we describe a case of a 68-year-old female with an ICD presenting with a previously unknown etiological agent of IE, Corynebacterium mucifaciens. PMID:27133333

  11. A Review of the Design Process for Implantable Orthopedic Medical Devices

    PubMed Central

    Aitchison, G.A; Hukins, D.W.L; Parry, J.J; Shepherd, D.E.T; Trotman, S.G

    2009-01-01

    The design process for medical devices is highly regulated to ensure the safety of patients. This paper will present a review of the design process for implantable orthopedic medical devices. It will cover the main stages of feasibility, design reviews, design, design verification, manufacture, design validation, design transfer and design changes. PMID:19662153

  12. Implantation of a defibrillator in a patient with an upper airway stimulation device.

    PubMed

    Ong, Adrian A; O'Brien, Terrence X; Nguyen, Shaun A; Gillespie, M Boyd

    2016-02-01

    The patient is a 62-year-old man with continuous positive airway pressure-intolerant obstructive sleep apnea who was enrolled in a study for a hypoglossal nerve upper airway stimulation device (UAS). Nearly 2.5 years later, he was admitted to the hospital for unstable angina. Diagnostic workup revealed a prior myocardial infarction, an ejection fraction of 30% on maximal medical therapy, and episodes of nonsustained ventricular tachycardia. During hospitalization, the patient received an implantable cardioverter defibrillator (ICD). This is the first reported case of simultaneous use of a UAS and an ICD, and we report no untoward device interference between the two implantable devices. PMID:26403681

  13. Telecardiology and Remote Monitoring of Implanted Electrical Devices: The Potential for Fresh Clinical Care Perspectives

    PubMed Central

    Diemberger, Igor; Martignani, Cristian; Biffi, Mauro; Valzania, Cinzia; Bertini, Matteo; Domenichini, Giulia; Saporito, Davide; Ziacchi, Matteo; Branzi, Angelo

    2007-01-01

    Telecardiology may help confront the growing burden of monitoring the reliability of implantable defibrillators/pacemakers. Herein, we suggest that the evolving capabilities of implanted devices to monitor patients’ status (heart rhythm, fluid overload, right ventricular pressure, oximetry, etc.) may imply a shift from strictly device-centered follow-up to perspectives centered on the patient (and patient-device interactions). Such approaches could provide improvements in health care delivery and clinical outcomes, especially in the field of heart failure. Major professional, policy, and ethical issues will have to be overcome to enable real-world implementation. This challenge may be relevant for the evolution of our health care systems. PMID:18095049

  14. Wireless communication with implanted medical devices using the conductive properties of the body

    PubMed Central

    Ferguson, John E; Redish, A David

    2013-01-01

    Many medical devices that are implanted in the body use wires or wireless radiofrequency telemetry to communicate with circuitry outside the body. However, the wires are a common source of surgical complications, including breakage, infection and electrical noise. In addition, radiofrequency telemetry requires large amounts of power and results in low-efficiency transmission through biological tissue. As an alternative, the conductive properties of the body can be used to enable wireless communication with implanted devices. In this article, several methods of intrabody communication are described and compared. In addition to reducing the complications that occur with current implantable medical devices, intrabody communication can enable novel types of miniature devices for research and clinical applications. PMID:21728728

  15. Biomedical Impact in Implantable Devices-The Transcatheter Aortic Valve as an example

    NASA Astrophysics Data System (ADS)

    Anastasiou, Alexandros; Saatsakis, George

    2015-09-01

    Objective: To update of the scientific community about the biomedical engineering involvement in the implantable devices chain. Moreover the transcatheter Aortic Valve (TAV) replacement, in the field of cardiac surgery, will be analyzed as an example of contemporary implantable technology. Methods: A detailed literature review regarding biomedical engineers participating in the implantable medical product chain, starting from the design of the product till the final implantation technique. Results: The scientific role of biomedical engineers has clearly been established. Certain parts of the product chain are implemented almost exclusively by experienced biomedical engineers such as the transcatheter aortic valve device. The successful professional should have a multidisciplinary knowledge, including medicine, in order to pursue the challenges for such intuitive technology. This clearly indicates that biomedical engineers are among the most appropriate scientists to accomplish such tasks. Conclusions: The biomedical engineering involvement in medical implantable devices has been widely accepted by the scientific community, worldwide. Its important contribution, starting from the design and extended to the development, clinical trials, scientific support, education of other scientists (surgeons, cardiologists, technicians etc.), and even to sales, makes biomedical engineers a valuable player in the scientific arena. Notably, the sector of implantable devices is constantly raising, as emerging technologies continuously set up new targets.

  16. Biofunctionalization of surfaces by energetic ion implantation: Review of progress on applications in implantable biomedical devices and antibody microarrays

    NASA Astrophysics Data System (ADS)

    Bilek, Marcela M. M.

    2014-08-01

    Despite major research efforts in the field of biomaterials, rejection, severe immune responses, scar tissue and poor integration continue to seriously limit the performance of today's implantable biomedical devices. Implantable biomaterials that interact with their host via an interfacial layer of active biomolecules to direct a desired cellular response to the implant would represent a major and much sought after improvement. Another, perhaps equally revolutionary, development that is on the biomedical horizon is the introduction of cost-effective microarrays for fast, highly multiplexed screening for biomarkers on cell membranes and in a variety of analyte solutions. Both of these advances will rely on effective methods of functionalizing surfaces with bioactive molecules. After a brief introduction to other methods currently available, this review will describe recently developed approaches that use energetic ions extracted from plasma to facilitate simple, one-step covalent surface immobilization of bioactive molecules. A kinetic theory model of the immobilization process by reactions with long-lived, mobile, surface-embedded radicals will be presented. The roles of surface chemistry and microstructure of the ion treated layer will be discussed. Early progress on applications of this technology to create diagnostic microarrays and to engineer bioactive surfaces for implantable biomedical devices will be reviewed.

  17. MEMS Based Broadband Piezoelectric Ultrasonic Energy Harvester (PUEH) for Enabling Self-Powered Implantable Biomedical Devices.

    PubMed

    Shi, Qiongfeng; Wang, Tao; Lee, Chengkuo

    2016-01-01

    Acoustic energy transfer is a promising energy harvesting technology candidate for implantable biomedical devices. However, it does not show competitive strength for enabling self-powered implantable biomedical devices due to two issues - large size of bulk piezoelectric ultrasound transducers and output power fluctuation with transferred distance due to standing wave. Here we report a microelectromechanical systems (MEMS) based broadband piezoelectric ultrasonic energy harvester (PUEH) to enable self-powered implantable biomedical devices. The PUEH is a microfabricated lead zirconate titanate (PZT) diaphragm array and has wide operation bandwidth. By adjusting frequency of the input ultrasound wave within the operation bandwidth, standing wave effect can be minimized for any given distances. For example, at 1 cm distance, power density can be increased from 0.59 μW/cm(2) to 3.75 μW/cm(2) at input ultrasound intensity of 1 mW/cm(2) when frequency changes from 250 to 240 kHz. Due to the difference of human body and manual surgical process, distance fluctuation for implantable biomedical devices is unavoidable and it strongly affects the coupling efficiency. This issue can be overcome by performing frequency adjustment of the PUEH. The proposed PUEH shows great potential to be integrated on an implanted biomedical device chip as power source for various applications. PMID:27112530

  18. MEMS Based Broadband Piezoelectric Ultrasonic Energy Harvester (PUEH) for Enabling Self-Powered Implantable Biomedical Devices

    PubMed Central

    Shi, Qiongfeng; Wang, Tao; Lee, Chengkuo

    2016-01-01

    Acoustic energy transfer is a promising energy harvesting technology candidate for implantable biomedical devices. However, it does not show competitive strength for enabling self-powered implantable biomedical devices due to two issues – large size of bulk piezoelectric ultrasound transducers and output power fluctuation with transferred distance due to standing wave. Here we report a microelectromechanical systems (MEMS) based broadband piezoelectric ultrasonic energy harvester (PUEH) to enable self-powered implantable biomedical devices. The PUEH is a microfabricated lead zirconate titanate (PZT) diaphragm array and has wide operation bandwidth. By adjusting frequency of the input ultrasound wave within the operation bandwidth, standing wave effect can be minimized for any given distances. For example, at 1 cm distance, power density can be increased from 0.59 μW/cm2 to 3.75 μW/cm2 at input ultrasound intensity of 1 mW/cm2 when frequency changes from 250 to 240 kHz. Due to the difference of human body and manual surgical process, distance fluctuation for implantable biomedical devices is unavoidable and it strongly affects the coupling efficiency. This issue can be overcome by performing frequency adjustment of the PUEH. The proposed PUEH shows great potential to be integrated on an implanted biomedical device chip as power source for various applications. PMID:27112530

  19. MEMS Based Broadband Piezoelectric Ultrasonic Energy Harvester (PUEH) for Enabling Self-Powered Implantable Biomedical Devices

    NASA Astrophysics Data System (ADS)

    Shi, Qiongfeng; Wang, Tao; Lee, Chengkuo

    2016-04-01

    Acoustic energy transfer is a promising energy harvesting technology candidate for implantable biomedical devices. However, it does not show competitive strength for enabling self-powered implantable biomedical devices due to two issues – large size of bulk piezoelectric ultrasound transducers and output power fluctuation with transferred distance due to standing wave. Here we report a microelectromechanical systems (MEMS) based broadband piezoelectric ultrasonic energy harvester (PUEH) to enable self-powered implantable biomedical devices. The PUEH is a microfabricated lead zirconate titanate (PZT) diaphragm array and has wide operation bandwidth. By adjusting frequency of the input ultrasound wave within the operation bandwidth, standing wave effect can be minimized for any given distances. For example, at 1 cm distance, power density can be increased from 0.59 μW/cm2 to 3.75 μW/cm2 at input ultrasound intensity of 1 mW/cm2 when frequency changes from 250 to 240 kHz. Due to the difference of human body and manual surgical process, distance fluctuation for implantable biomedical devices is unavoidable and it strongly affects the coupling efficiency. This issue can be overcome by performing frequency adjustment of the PUEH. The proposed PUEH shows great potential to be integrated on an implanted biomedical device chip as power source for various applications.

  20. Minimally invasive is the future of left ventricular assist device implantation

    PubMed Central

    Makdisi, George

    2015-01-01

    There have been many factors that have allowed for progressive improvement in outcomes and lower complication rates. These include the improvement in left ventricular assist device (LVAD) technologies, combined with better understanding of patient management, all these. Nowadays the numbers of LVAD implantations exceed the number of annual heart transplants worldwide. Minimally invasive procedures are shown to improve the surgical outcome in both LVAD insertion and replacement. These minimally invasive techniques can be grouped grossly into shifting from on-pump to off-pump implantation, alternative access for implantation other than sternotomy, and a combination of both, which should be the ultimate aim of minimally invasive LVAD implantation. Here we describe the alternative techniques and configurations of minimally invasive and sites of implantation. PMID:26543617

  1. Minimally invasive is the future of left ventricular assist device implantation.

    PubMed

    Makdisi, George; Wang, I-Wen

    2015-09-01

    There have been many factors that have allowed for progressive improvement in outcomes and lower complication rates. These include the improvement in left ventricular assist device (LVAD) technologies, combined with better understanding of patient management, all these. Nowadays the numbers of LVAD implantations exceed the number of annual heart transplants worldwide. Minimally invasive procedures are shown to improve the surgical outcome in both LVAD insertion and replacement. These minimally invasive techniques can be grouped grossly into shifting from on-pump to off-pump implantation, alternative access for implantation other than sternotomy, and a combination of both, which should be the ultimate aim of minimally invasive LVAD implantation. Here we describe the alternative techniques and configurations of minimally invasive and sites of implantation. PMID:26543617

  2. Security and privacy issues in implantable medical devices: A comprehensive survey.

    PubMed

    Camara, Carmen; Peris-Lopez, Pedro; Tapiador, Juan E

    2015-06-01

    Bioengineering is a field in expansion. New technologies are appearing to provide a more efficient treatment of diseases or human deficiencies. Implantable Medical Devices (IMDs) constitute one example, these being devices with more computing, decision making and communication capabilities. Several research works in the computer security field have identified serious security and privacy risks in IMDs that could compromise the implant and even the health of the patient who carries it. This article surveys the main security goals for the next generation of IMDs and analyzes the most relevant protection mechanisms proposed so far. On the one hand, the security proposals must have into consideration the inherent constraints of these small and implanted devices: energy, storage and computing power. On the other hand, proposed solutions must achieve an adequate balance between the safety of the patient and the security level offered, with the battery lifetime being another critical parameter in the design phase. PMID:25917056

  3. Utilization of YouTube as a Tool to Assess Patient Perception Regarding Implanted Cardiac Devices

    PubMed Central

    Hayes, Kevin; Mainali, Prajeena; Deshmukh, Abhishek; Pant, Sadip; Badheka, Apurva O; Paydak, Hakan

    2014-01-01

    Background: The outreach of YouTube may have a dramatic role in the widespread dissemination of knowledge on implantable cardioverter devices (ICD). Aims: This study was designed to review and analyze the information available on YouTube pertaining to implantable cardiac devices such as implantable cardioverter defibrillators (ICDs) and pacemakers. Materials and Methods: YouTube was queried for the terms “ICD”, “Implantable Cardioverter Defibrillator”, and “Pacemaker”. The videos were reviewed and categorized as according to content; number of views and “likes” or “dislikes” was recorded by two separate observers. Results: Of the 55 videos reviewed, 18 of the videos were categorized as patient education, 12 were advertisements, 8 were intraoperative videos documenting the device implantation procedures, 7 of the videos were produced to document personal patient experiences, and 4 were categorized as documentation of a public event. 3 were intended to educate health care workers. The remaining 3 were intended to raise public awareness about sudden cardiac death. The videos portraying intraoperative procedures generated the most “likes” or “dislikes” per view. Conclusion: While YouTube provides a logical platform for delivery of health information, the information on this platform is not regulated. Initiative by reputed authorities and posting accurate information in such platform can be a great aid in public education regarding device therapy. PMID:25077075

  4. Implantable devices for venous access: nurses' and patients' evaluation of three different port systems.

    PubMed

    Lilienberg, A; Bengtsson, M; Starkhammar, H

    1994-01-01

    Implantable injection port systems are safe and convenient for long-term venous access. The present investigation comprises nurses' and patients' evaluation of three different types of devices; Port-A-Cath (16.0 g), Cordis Miniport (3.8 g) for implantation in the chest wall and the PAS Port system (5.6 g) for implantation in the forearm. The devices were implanted for chemotherapy. Eighty patients and 17 nurses answered a questionnaire regarding their experience with the devices. Overall, the systems functioned well and were helpful for both patients and nurses. In the patient study few significant differences emerged. Nurses noted that the PAS Port system was more difficult to withdraw blood from (P < 0.001) and its infusion flow capacity was inferior to the two ports in the chest wall (P < 0.001). Port-A-Cath was judged to be the easiest system for needle insertion and the needle position was felt to be more secure (P < 0.001). Fourteen of the 17 nurses preferred Cordis Miniport for cosmetic reasons (P < 0.001). All devices functioned well. The differences in shape, size and site of implantation allow an optimum port selection for each patient. The replies in this study expressed the need for educational programmes in order to spread the injection port concept further. PMID:8138625

  5. Clinical use of antibacterial mesh envelopes in cardiovascular electronic device implantations

    PubMed Central

    Hirsh, David S; Bloom, Heather L

    2015-01-01

    Cardiovascular implantable electronic device system infection is a serious complication of cardiac device implantation and carries with it a risk of significant morbidity and mortality. In the last 15 years, expansions of indications for cardiac devices have resulted in much higher volumes of much sicker patients being implanted, carrying significant risk of infection. Coagulase (−) Staphylococcus and Staphylococcus aureus are responsible for the majority of these infections, and these organisms are increasingly resistant to methicillin. The Aigis™ envelop is a Food and Drug Administration–approved implantable mesh that is impregnated with antibiotics that can be placed in the surgical incision prior to closure. The antibiotics elute off the mesh for 7–10 days, providing in vivo surgical site coverage with rifampin and minocyclin. This paper reviews the three retrospective clinical trials published in peer-reviewed journals and the interim analysis of the two ongoing prospective trials that have been presented at international conferences. Overall consensus is that the Aigis™ offers significant risk reduction for cardiovascular implantable electronic device infection. We then give a comprehensive discussion of how to use the Aigis™ envelop in the clinical setting, comparing the manufacturer’s recommendations with our extensive clinical experience. PMID:25624774

  6. Shape-memory alloy overload protection device for osseointegrated transfemoral implant prosthetic limb attachment system

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Shao, Fei; Hughes, Steven

    2002-11-01

    The osseointegrated trans-femoral implant system provides a direct anchoring technique to attach prosthetic limb. This technique was first introduced PI Brenmark in Sweden. The UK had the first clinical trial in 1997 and currently has 6 active limb wearers. The success of this procedure has the potential for improved gait function and mobility, increased employability and significant long-term improvements in the quality of life for above knee amputees. However, the significant load involved in the trans-femoral implant system has caused permanent deformation and/or fractures of the implant abutment in several occasions. To protect the implant system, the implant abutment in particularly, an overloading protection device was introduced. The device uses mechanical mechanism to release torsion overload on the abutment. However, the bending overload protection remains unsolved. To solve the problem, a new overload protection device was developed. This device uses SMA component for bending overload protection. In this paper, the results of non-linear finite element modelling of the SMA and steel (AISI 1040) components were presented. Experiments were also carried out using steel components to assess the design which is based on the non-linear property of the materials.

  7. Implantable imaging device for brain functional imaging system using flavoprotein fluorescence

    NASA Astrophysics Data System (ADS)

    Sunaga, Yoshinori; Yamaura, Hiroshi; Haruta, Makito; Yamaguchi, Takahiro; Motoyama, Mayumi; Ohta, Yasumi; Takehara, Hiroaki; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Yoshimura, Yumiko; Ohta, Jun

    2016-03-01

    The autofluorescence of mitochondrial flavoprotein is very useful for functional brain imaging because the fluorescence intensity of flavoprotein changes as per neural activities. In this study, we developed an implantable imaging device for green fluorescence imaging and detected fluorescence changes of flavoprotein associated with visual stimulation using the device. We examined the device performance using anesthetized mice. We set the device on the visual cortex and measured fluorescence changes of flavoprotein in response to visual stimulation. A full-field sinusoidal grating with a vertical orientation was used for applying to activate the visual cortex. We successfully observed visually evoked fluorescence changes in the mouse visual cortex using our implantable device. This result suggests that we can observe the fluorescence changes of flavoprotein associated with visual stimulation in a freely moving mouse by using this technology.

  8. The role of industry in the implantation and follow-up of devices: a practitioner's perspective.

    PubMed

    Hayes, John J

    2003-01-01

    Implantable cardiac rhythm management devices continue to get more technologically complex at a pace that is difficult for most clinicians to keep up with. We have come to rely heavily on industry representatives to provide technical expertise during device implantation and follow-up. Concern has been raised about the involvement of medical device industry representatives in the clinical environment. Guidelines have been published that acknowledge the importance of device industry representatives in providing technical expertise and assistance, while also clarifying the role these representatives should play in patient care. The main principles from published policy statements are summarized, emphasizing that the physician remains responsible for the patient's overall care as well as device function and programming. PMID:12766520

  9. Stab injury and device implantation within the brain results in inversely multiphasic neuroinflammatory and neurodegenerative responses

    NASA Astrophysics Data System (ADS)

    Potter, Kelsey A.; Buck, Amy C.; Self, Wade K.; Capadona, Jeffrey R.

    2012-08-01

    An estimated 25 million people in the US alone rely on implanted medical devices, ˜2.5 million implanted within the nervous system. Even though many devices perform adequately for years, the host response to medical devices often severely limits tissue integration and long-term performance. This host response is believed to be particularly limiting in the case of intracortical microelectrodes, where it has been shown that glial cell encapsulation and localized neuronal cell loss accompany intracortical microelectrode implantation. Since neuronal ensembles must be within ˜50 µm of the electrode to obtain neuronal spikes and local field potentials, developing a better understanding of the molecular and cellular environment at the device-tissue interface has been the subject of significant research. Unfortunately, immunohistochemical studies of scar maturation in correlation to device function have been inconclusive. Therefore, here we present a detailed quantitative study of the cellular events and the stability of the blood-brain barrier (BBB) following intracortical microelectrode implantation and cortical stab injury in a chronic survival model. We found two distinctly inverse multiphasic profiles for neuronal survival in device-implanted tissue compared to stab-injured animals. For chronically implanted animals, we observed a biphasic paradigm between blood-derived/trauma-induced and CNS-derived inflammatory markers driving neurodegeneration at the interface. In contrast, stab injured animals demonstrated a CNS-mediated neurodegenerative environment. Collectively these data provide valuable insight to the possibility of multiple roles of chronic neuroinflammatory events on BBB disruption and localized neurodegeneration, while also suggesting the importance to consider multiphasic neuroinflammatory kinetics in the design of therapeutic strategies for stabilizing neural interfaces.

  10. Stab injury and device implantation within the brain results in inversely multiphasic neuroinflammatory and neurodegenerative responses.

    PubMed

    Potter, Kelsey A; Buck, Amy C; Self, Wade K; Capadona, Jeffrey R

    2012-08-01

    An estimated 25 million people in the US alone rely on implanted medical devices, ∼2.5 million implanted within the nervous system. Even though many devices perform adequately for years, the host response to medical devices often severely limits tissue integration and long-term performance. This host response is believed to be particularly limiting in the case of intracortical microelectrodes, where it has been shown that glial cell encapsulation and localized neuronal cell loss accompany intracortical microelectrode implantation. Since neuronal ensembles must be within ∼50 µm of the electrode to obtain neuronal spikes and local field potentials, developing a better understanding of the molecular and cellular environment at the device-tissue interface has been the subject of significant research. Unfortunately, immunohistochemical studies of scar maturation in correlation to device function have been inconclusive. Therefore, here we present a detailed quantitative study of the cellular events and the stability of the blood-brain barrier (BBB) following intracortical microelectrode implantation and cortical stab injury in a chronic survival model. We found two distinctly inverse multiphasic profiles for neuronal survival in device-implanted tissue compared to stab-injured animals. For chronically implanted animals, we observed a biphasic paradigm between blood-derived/trauma-induced and CNS-derived inflammatory markers driving neurodegeneration at the interface. In contrast, stab injured animals demonstrated a CNS-mediated neurodegenerative environment. Collectively these data provide valuable insight to the possibility of multiple roles of chronic neuroinflammatory events on BBB disruption and localized neurodegeneration, while also suggesting the importance to consider multiphasic neuroinflammatory kinetics in the design of therapeutic strategies for stabilizing neural interfaces. PMID:22832283

  11. Device-length changes and implant function following surgical implantation of the KineSpring in cadaver knees

    PubMed Central

    McNicholas, Michael J; Gabriel, Stefan M; Clifford, Anton G; Hasler, Evelyne M

    2015-01-01

    Introduction The KineSpring implant system has been shown to provide load reductions at the medial compartment of the knee, and has demonstrated clinical success in reducing pain and increasing function in patients with medial knee osteoarthritis. These results depend on the ability of the KineSpring to rotate, lengthen, and shorten to accommodate knee motions, and in response to knee position and loading. Purpose The present study was undertaken to determine length changes of the implanted KineSpring in response to a range of knee positions, external knee loads, and placements by different orthopedic surgeons. Materials and methods KineSpring system components were implanted in ten cadaver leg specimens by ten orthopedic surgeons, and absorber-length changes were measured under combined loading and in different positions of the knee. Results and conclusion Spring compression consistent with knee-load reduction, and device lengthening and shortening to accommodate knee loads and motions were seen. These confirm the functionality of the KineSpring when implanted medially to the knee. PMID:25610006

  12. Exercise Rehabilitation for Chronic Heart Failure Patients with Cardiac Device Implants

    PubMed Central

    Haennel, Robert G.

    2012-01-01

    In the past decade a significant development in the management and rehabilitation of people with chronic heart failure (CHF) has been the utilization of cardiac devices. The use of biventricular pacemakers, referred to as Cardiac Resynchronization Therapy (CRT) can yield improvements in functional abilities for a select group of CHF patients and the inclusion of implantable cardiac defibrillators (ICDs) may reduce the risk of sudden death. This review provides physical therapists with a basic understanding of how to prescribe exercise for people with CHF who have these device implants. PMID:22993499

  13. Which device is more accurate to determine the stability/mobility of dental implants? A human cadaver study.

    PubMed

    Tözüm, T F; Bal, B T; Turkyilmaz, I; Gülay, G; Tulunoglu, I

    2010-03-01

    Non-invasive devices including resonance frequency (RF) analysis and mobility measuring (MM) damping capacity assessment are used to measure implant stability/mobility. The aims of the study were to compare the primary stability of implant inserted into extraction sockets by using RF with cable, RF wireless and new wireless MM device, to clarify the relation between these devices and to understand the correlations between peri-implant bone levels and implant stability. A total of 30 screw-type implants (3.75 x 11 and 4.2 x 11 mm) were inserted into extraction sockets of eight mandibular pre-molar regions of human cadavers. The primary stability of implants was measured by three devices after insertion. Peri-implant vertical defects were created in millimetre increments ranging between 0 and 5 mm, and stability/mobility of implants were analysed. At placement, the mean implant stability quotient of RF with cable, RF wireless and MM device values was 46 +/- 1, 57.8 +/- 9 and -5.4 +/- 1, respectively. Statistical correlations were demonstrated between these devices (P = 0.001). Statistically significant differences were presented for all peri-implant detects ranging between 0 and 5 mm for RF with cable and RF wireless at all increments. However, only a significant decrease was found between 0 and 1 mm defects, and 4 and 5 mm defects in MM device. Although RF with cable and RF wireless seem to be suitable to detect peri-implant bone loss around implants in 1 mm increments, the new MM device may not be suitable to detect the 1 mm peri-implant bone changes in human dried cadaver mandibles. PMID:20002537

  14. Electromagnetic interference of implantable cardiac devices from a shoulder massage machine.

    PubMed

    Yoshida, Saeko; Fujiwara, Kousaku; Kohira, Satoshi; Hirose, Minoru

    2014-09-01

    Shoulder massage machines have two pads that are driven by solenoid coils to perform a per cussive massage on the shoulders. There have been concerns that such machines might create electromagnetic interference (EMI) in implantable cardiac devices because of the time-varying magnetic fields produced by the alternating current in the solenoid coils. The objective of this study was to investigate the potential EMI from one such shoulder massage machine on implantable cardiac devices. We measured the distribution profile of the magnetic field intensity around the massage machine. Furthermore, we performed an inhibition test and an asynchronous test on an implantable cardiac pacemaker using the standardized Irnich human body model. We examined the events on an implantable cardioverter-defibrillator (ICD) using a pacemaker programmer while the massage machine was in operation. The magnetic field distribution profile exhibited a peak intensity of 212 (A/m) in one of the solenoid coils. The maximal interference distance between the massage machine and the implantable cardiac pacemaker was 28 cm. Ventricular fibrillation was induced when the massage machine was brought near the electrode of the ICD and touched the Irnich human body model. It is necessary to provide a "don't use" warning on the box or the exterior of the massage machines or in the user manuals and to caution patients with implanted pacemakers about the dangers and appropriate usage of massage machines. PMID:24710851

  15. New cosurface capacitive stimulators for the development of active osseointegrative implantable devices.

    PubMed

    Soares Dos Santos, Marco P; Marote, Ana; Santos, T; Torrão, João; Ramos, A; Simões, José A O; da Cruz E Silva, Odete A B; Furlani, Edward P; Vieira, Sandra I; Ferreira, Jorge A F

    2016-01-01

    Non-drug strategies based on biophysical stimulation have been emphasized for the treatment and prevention of musculoskeletal conditions. However, to date, an effective stimulation system for intracorporeal therapies has not been proposed. This is particularly true for active intramedullary implants that aim to optimize osseointegration. The increasing demand for these implants, particularly for hip and knee replacements, has driven the design of innovative stimulation systems that are effective in bone-implant integration. In this paper, a new cosurface-based capacitive system concept is proposed for the design of implantable devices that deliver controllable and personalized electric field stimuli to target tissues. A prototype architecture of this system was constructed for in vitro tests, and its ability to deliver controllable stimuli was numerically analyzed. Successful results were obtained for osteoblastic proliferation and differentiation in the in vitro tests. This work provides, for the first time, a design of a stimulation system that can be embedded in active implantable devices for controllable bone-implant integration and regeneration. The proposed cosurface design holds potential for the implementation of novel and innovative personalized stimulatory therapies based on the delivery of electric fields to bone cells. PMID:27456818

  16. New cosurface capacitive stimulators for the development of active osseointegrative implantable devices

    PubMed Central

    Soares dos Santos, Marco P.; Marote, Ana; Santos, T.; Torrão, João; Ramos, A.; Simões, José A. O.; da Cruz e Silva, Odete A. B.; Furlani, Edward P.; Vieira, Sandra I.; Ferreira, Jorge A. F.

    2016-01-01

    Non-drug strategies based on biophysical stimulation have been emphasized for the treatment and prevention of musculoskeletal conditions. However, to date, an effective stimulation system for intracorporeal therapies has not been proposed. This is particularly true for active intramedullary implants that aim to optimize osseointegration. The increasing demand for these implants, particularly for hip and knee replacements, has driven the design of innovative stimulation systems that are effective in bone-implant integration. In this paper, a new cosurface-based capacitive system concept is proposed for the design of implantable devices that deliver controllable and personalized electric field stimuli to target tissues. A prototype architecture of this system was constructed for in vitro tests, and its ability to deliver controllable stimuli was numerically analyzed. Successful results were obtained for osteoblastic proliferation and differentiation in the in vitro tests. This work provides, for the first time, a design of a stimulation system that can be embedded in active implantable devices for controllable bone-implant integration and regeneration. The proposed cosurface design holds potential for the implementation of novel and innovative personalized stimulatory therapies based on the delivery of electric fields to bone cells. PMID:27456818

  17. An Adverse Electrophysiological Interaction Between an Implantable Cardioverter-Defibrillator and a Ventricular Assist Device.

    PubMed

    Chhabra, Lovely; Hiendlmayr, Brett; Kluger, Jeffrey

    2015-01-01

    Many patients with left ventricular assist devices (LVAD) have implantable cardioverter defibrillators (ICDs) as part of the management of advanced heart failure. With increasing use and coexistence of these devices in patients with advanced cardiomyopathy, adverse interactions between these devices have been recognized. We herewith describe a rare adverse interaction of electromagnetic interference (EMI) between a third-generation, continuous-flow device (The HeartWare HVAD) and an ICD which resulted in the delivery of inappropriate ICD therapies. A schematic approach for the prevention and treatment of electromagnetic interference has also been described. PMID:26263716

  18. How are arrhythmias detected by implanted cardiac devices managed in Europe? Results of the European Heart Rhythm Association Survey.

    PubMed

    Todd, Derick; Hernandez-Madrid, Antonio; Proclemer, Alessandro; Bongiorni, Maria Grazia; Estner, Heidi; Blomström-Lundqvist, Carina

    2015-09-01

    The management of arrhythmias detected by implantable cardiac devices can be challenging. There are no formal international guidelines to inform decision-making. The purpose of this European Heart Rhythm Association (EHRA) survey was to assess the management of various clinical scenarios among members of the EHRA electrophysiology research network. There were 49 responses to the questionnaire. The survey responses were mainly (81%) from medium-high volume device implanting centres, performing more than 200 total device implants per year. Clinical scenarios were described focusing on four key areas: the implantation of pacemakers for bradyarrhythmia detected on an implantable loop recorder (ILR), the management of patients with ventricular arrhythmia detected by an ILR or pacemaker, the management of atrial fibrillation in patients with pacemakers and cardiac resynchronization therapy devices and the management of ventricular tachycardia in patients with implantable cardioverter-defibrillators. PMID:26443791

  19. B-Type Natriuretic Peptide Levels Predict Ventricular Arrhythmia Post Left Ventricular Assist Device Implantation.

    PubMed

    Hellman, Yaron; Malik, Adnan S; Lin, Hongbo; Shen, Changyu; Wang, I-Wen; Wozniak, Thomas C; Hashmi, Zubair A; Pickrell, Jeanette; Jani, Milena; Caccamo, Marco A; Gradus-Pizlo, Irmina; Hadi, Azam

    2015-12-01

    B-type natriuretic peptide (BNP) levels have been shown to predict ventricular arrhythmia (VA) and sudden death in patients with heart failure. We sought to determine whether BNP levels before left ventricular assist device (LVAD) implantation can predict VA post LVAD implantation in advanced heart failure patients. We conducted a retrospective study consisting of patients who underwent LVAD implantation in our institution during the period of May 2009-March 2013. The study was limited to patients receiving a HeartMate II or HeartWare LVAD. Acute myocardial infarction patients were excluded. We compared between the patients who developed VA within 15 days post LVAD implantation to the patients without VA. A total of 85 patients underwent LVAD implantation during the study period. Eleven patients were excluded (five acute MI, four without BNP measurements, and two discharged earlier than 13 days post LVAD implantation). The incidence of VA was 31%, with 91% ventricular tachycardia (VT) and 9% ventricular fibrillation. BNP remained the single most powerful predictor of VA even after adjustment for other borderline significant factors in a multivariate logistic regression model (P < 0.05). BNP levels are a strong predictor of VA post LVAD implantation, surpassing previously described risk factors such as age and VT in the past. PMID:25864448

  20. A Study of Success Rate of Miniscrew Implants as Temporary Anchorage Devices in Singapore

    PubMed Central

    Yi Lin, Song; Mimi, Yow; Ming Tak, Chew; Kelvin Weng Chiong, Foong; Hung Chew, Wong

    2015-01-01

    Objective. To find out the success rate of miniscrew implants in the National Dental Centre of Singapore (NDCS) and the impact of patient-related, location-related, and miniscrew implant-related factors. Materials and Methods. Two hundred and eighty-five orthodontic miniscrew implants were examined from NDCS patient records. Eleven variables were analysed to see if there is any association with success. Outcome was measured twice, immediately after surgery prior to orthodontic loading (T1) and 12 months after surgery (T2). The outcome at T2 was assessed 12 months after the miniscrew's insertion date or after its use as a temporary anchorage device has ceased. Results. Overall success rate was 94.7% at T1 and 83.3% at T2. Multivariate analysis revealed only the length of miniscrew implant to be significantly associated with success at both T1 (P = 0.002) and T2 (P = 0.030). Miniscrew implants with lengths of 10–12 mm had the highest success rate (98.0%) compared to other lengths, and this is statistically significant (P = 0.035). At T2, lengths of 10–12 mm had significantly (P = 0.013) higher success rates (93.5%) compared to 6-7 mm (76.7%) and 8 mm (82.1%) miniscrew implants. Conclusion. Multivariate statistical analyses of 11 variables demonstrate that length of miniscrew implant is significant in determining success. PMID:25861272

  1. A study of success rate of miniscrew implants as temporary anchorage devices in singapore.

    PubMed

    Yi Lin, Song; Mimi, Yow; Ming Tak, Chew; Kelvin Weng Chiong, Foong; Hung Chew, Wong

    2015-01-01

    Objective. To find out the success rate of miniscrew implants in the National Dental Centre of Singapore (NDCS) and the impact of patient-related, location-related, and miniscrew implant-related factors. Materials and Methods. Two hundred and eighty-five orthodontic miniscrew implants were examined from NDCS patient records. Eleven variables were analysed to see if there is any association with success. Outcome was measured twice, immediately after surgery prior to orthodontic loading (T1) and 12 months after surgery (T2). The outcome at T2 was assessed 12 months after the miniscrew's insertion date or after its use as a temporary anchorage device has ceased. Results. Overall success rate was 94.7% at T1 and 83.3% at T2. Multivariate analysis revealed only the length of miniscrew implant to be significantly associated with success at both T1 (P = 0.002) and T2 (P = 0.030). Miniscrew implants with lengths of 10-12 mm had the highest success rate (98.0%) compared to other lengths, and this is statistically significant (P = 0.035). At T2, lengths of 10-12 mm had significantly (P = 0.013) higher success rates (93.5%) compared to 6-7 mm (76.7%) and 8 mm (82.1%) miniscrew implants. Conclusion. Multivariate statistical analyses of 11 variables demonstrate that length of miniscrew implant is significant in determining success. PMID:25861272

  2. Clinical Characteristics and Outcome of Cardiovascular Implantable Electronic Device Infections in Turkey.

    PubMed

    Aydin, Mesut; Yildiz, Abdulkadir; Kaya, Zeynettin; Kaya, Zekeriya; Basarir, Ahmet Ozgur; Cakmak, Nazmiye; Donmez, Ibrahim; Morrad, Baktash; Avci, Ahmet; Demir, Kenan; Cagliyan, Emre Caglar; Yuksel, Murat; Elbey, Mehmet Ali; Kayan, Fethullah; Ozaydogdu, Necdet; Islamoglu, Yahya; Cayli, Murat; Alan, Said; Ulgen, Mehmet Siddik; Ozhan, Hakan

    2016-07-01

    Infection is one of the most devastating outcomes of cardiovascular implantable electronic device (CIED) implantation and is related to significant morbidity and mortality. In our country, there is no evaluation about CIED infection. Therefore, our aim was to investigate clinical characteristics and outcome of patients who had infection related to CIED implantation or replacement. The study included 144 consecutive patients with CIED infection treated at 11 major hospitals in Turkey from 2005 to 2014 retrospectively. We analyzed the medical files of all patients hospitalized with the diagnosis of CIED infection. Inclusion criteria were definite infection related to CIED implantation, replacement, or revision. Generator pocket infection, with or without bacteremia, was the most common clinical presentation, followed by CIED-related endocarditis. Coagulase-negative staphylococci and Staphylococcus aureus were the leading causative agents of CIED infection. Multivariate analysis showed that infective endocarditis and ejection fraction were the strongest predictors of in-hospital mortality. PMID:25589093

  3. Cardiac implantable electronic device infections: the enemy that lurks beneath the skin.

    PubMed

    Margey, Ronan

    2010-01-01

    The use of cardiac implantable electronic devices has increased exponentially in recent years with expanding indications and the aging of the general population. Despite improvements in device design, infection control practices, and the administration of antibiotic prophylaxis, the rate of cardiac implantable electronic device (CIED) infection has increased at a faster rate. With CIED infection becoming an increasing management problem, the purpose of this paper is to review the epidemiology, causes, pathogenesis, management and outcomes of CIED infection, and to summarize the recent updated guidelines published by the American Heart Association. While an extensive retrospective literature exists, only a few prospective clinical studies exist to help guide our management of this important problem. Research continues into the diagnosis, treatment and prevention of CIED infection. CIED infection is a growing clinical problem with significant morbidity and mortality. Summarizing the currently available literature, CIED infection is best managed by a combined strategy of complete device and lead extraction plus appropriately tailored antimicrobial therapy. PMID:21395519

  4. Application of virtual reality force feedback haptic device for oral implant surgery.

    PubMed

    Kusumoto, Naoki; Sohmura, Taiji; Yamada, Shinichi; Wakabayashi, Kazumichi; Nakamura, Takashi; Yatani, Hirofumi

    2006-12-01

    A novel support system for implant surgery was tried out, which involves manipulating a three-dimensional (3-D) computed tomography (CT) image of a jawbone with a virtual reality force feedback haptic device. Through this virtual system, the haptic experience of bone drilling with vibration and the sound of the contra-angle handpiece could be realized. It is expected to be useful for training inexperienced dentists and educating dental students. The simulation of oral implant insertion was also focused on. A simple cylindrical implant model was inserted into a 3-D image of the jawbone by operating the haptic device, with consideration of bone condition. A rectangular solid object that served as a bone-supported surgical template was adopted, and the shapes of the bone and the implant were subtracted from the object. In this manner, the CAD of the surgical template with impressions of the bone and the implant guide holes for insertion was realized. The surgical template was milled with a computer-controlled milling machine (CAM). Surgical template accuracy was examined with an edentulous gypsum bone model having six holes for implant insertion. Simulation of the oral implant insertion and CAD/CAM of the surgical template were conducted. The milled surgical template was fitted on the gypsum bone model, and CT images were taken. Cross-sections of the guide holes in the surgical template were imaged, and misalignment between the guide holes of the surgical template and the drilled holes on the jawbone was measured. The average misalignment is less than 0.2 mm, and it indicates that the present system is potentially applicable to oral implant surgery. PMID:17092231

  5. Perioperative management for the prevention of bacterial infection in cardiac implantable electronic device placement.

    PubMed

    Imai, Katsuhiko

    2016-08-01

    Cardiac implantable electronic devices (CIEDs) have become important in the treatment of cardiac disease and placement rates increased significantly in the last decade. However, despite the use of appropriate antimicrobial prophylaxis, CIED infection rates are increasing disproportionately to the implantation rate. CIED infection often requires explantation of all hardware, and at times results in death. Surgical site infection (SSI) is the most common cause of CIED infection as a pocket infection. The best method of combating CIED infection is prevention. Prevention of CIED infections comprises three phases: before, during, and after device implantation. The most critical factors in the prevention of SSIs are detailed operative techniques including the practice of proper technique by the surgeon and surgical team. PMID:27588150

  6. Considerations in Patients With Cardiac Implantable Electronic Devices at End of Life.

    PubMed

    Gura, Melanie T

    2015-01-01

    Since the introduction of implantable cardiac pacemakers in 1958 and implantable cardioverter-defibrillators in 1980, these devices have been proven to save and prolong lives. Pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy are deemed life-sustaining therapies. Despite these life-saving technologies, all patients ultimately will reach the end of their lives from either their heart disease or development of a terminal illness. Clinicians may be faced with patient and family requests to withdraw these life-sustaining therapies. The purpose of this article is to educate clinicians about the legal and ethical principles that underlie withdrawal of life-sustaining therapies such as device deactivation and to highlight the importance of proactive communication with patients and families in these situations. PMID:26484996

  7. Security Risks, Low-tech User Interfaces, and Implantable Medical Devices: A Case Study with Insulin Pump Infusion Systems

    SciTech Connect

    Paul, Nathanael R; Kohno, Tadayoshi

    2012-01-01

    Portable implantable medical device systems are playing a larger role in modern health care. Increasing attention is now being given to the wireless control interface of these systems. Our position is that wireless security in portable implantable medical device systems is just a part of the overall system security, and increased attention is needed to address low-tech security issues.

  8. Electronic article surveillance systems and interactions with implantable cardiac devices: risk of adverse interactions in public and commercial spaces.

    PubMed

    Gimbel, J Rod; Cox, James W

    2007-03-01

    Electronic article surveillance (EAS) systems are widely implemented in public spaces and can adversely affect the performance of pacemakers and implantable cardioverter defibrillators. The interaction between implantable devices and EAS systems is a serious problem that can be minimized through appropriate facility design. Careful facility design and employee education along with patient vigilance remain imperative in avoiding potentially life-threatening EAS system-implantable device interactions. PMID:17352368

  9. Radiography of Cardiac Conduction Devices: A Pictorial Review of Pacemakers and Implantable Cardioverter Defibrillators

    PubMed Central

    Torres-Ayala, Stephanie C; Santacana-Laffitte, Guido; Maldonado, José

    2014-01-01

    Cardiac conduction devices (CCDs) depend on correct anatomic positioning to function properly. Chest radiography is the preferred imaging modality to evaluate CCD's anatomic location, lead wire integrity, and help in identifying several complications. In this pictorial review, our goal is to familiarize radiologists with CCD implantation techniques, appropriate positioning of the device, common causes of malfunction, methods to improve report accuracy, and assure maximal therapeutic benefit. PMID:25806132

  10. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... cuff to pass on the urethra. (b) Classification. Class III (premarket approval). (c) Date PMA or notice of completion of a PDP is required. A PMA or a notice of completion of a PDP is required to be filed... implanted mechanical/hydraulic urinary continence device shall have an approved PMA or a declared...

  11. The Challenges of Balancing Safety and Security in Implantable Medical Devices.

    PubMed

    Katzis, Konstantinos; Jones, Richard W; Despotou, George

    2016-01-01

    Modern Implantable Medical Devices (IMDs), implement capabilities that have contributed significantly to patient outcomes, as well as quality of life. The ever increasing connectivity of IMD's does raise security concerns though there are instances where implemented security measures might impact on patient safety. The paper discusses challenges of addressing both of these attributes in parallel. PMID:27350457

  12. Speech Intelligibility of Pediatric Cochlear Implant Recipients with 7 Years of Device Experience.

    ERIC Educational Resources Information Center

    Peng, Shu-Chen; Spencer, Linda J.; Tomblin, J. Bruce

    2004-01-01

    Speech intelligibility of 24 prelingually deaf pediatric cochlear implant (CI) recipients with 84 months of device experience was investigated. Each CI participant's speech samples were judged by a panel of 3 listeners. Intelligibility scores were calculated as the average of the 3 listeners' responses. The average write-down intelligibility score…

  13. Cardiac or Other Implantable Electronic Devices and Sleep-disordered Breathing – Implications for Diagnosis and Therapy

    PubMed Central

    Bitter, Thomas; Gutleben, Klaus-Jürgen; Horstkotte, Dieter; Oldenburg, Olaf

    2014-01-01

    Sleep-disordered breathing (SDB) is of growing interest in cardiology because SDB is a highly prevalent comorbidity in patients with a variety of cardiovascular diseases. The prevalence of SDB is particularly high in patients with cardiac dysrhythmias and/or heart failure. In this setting, many patients now have implantable cardiac devices, such as pacemakers, implantable cardioverter-defibrillators or implanted cardiac resynchronisation therapy devices (CRT). Treatment of SDB using implantable cardiac devices has been studied previously, with atrial pacing and CRT being shown not to bring about satisfactory results in SDB care. The latest generations of these devices have the capacity to determine transthoracic impedance, to detect and quantify breathing efforts and to identify SDB. The capability of implantable cardiac devices to detect SDB is of potential importance for patients with cardiovascular disease, allowing screening for SDB, monitoring of the course of SDB in relation to cardiac status, and documenting of the effects of treatment. PMID:26835077

  14. Legal, ethical, and procedural bases for the use of aseptic techniques to implant electronic devices

    USGS Publications Warehouse

    Mulcahy, Daniel M.

    2013-01-01

    The popularity of implanting electronic devices such as transmitters and data loggers into captive and free-ranging animals has increased greatly in the past two decades. The devices have become smaller, more reliable, and more capable (Printz 2004; Wilson and Gifford 2005; Metcalfe et al. 2012). Compared with externally mounted devices, implanted devices are largely invisible to external viewers such as tourists and predators; exist in a physically protected, thermally stable environment in mammals and birds; and greatly reduce drag and risk of entanglement. An implanted animal does not outgrow its device or attachment method as can happen with collars and harnesses, which allows young animals to be more safely equipped. However, compared with mounting external devices, implantation requires greater technical ability to perform the necessary anesthesia, analgesia, and surgery. More than 83% of publications in the 1990s that used radiotelemetry on animals assumed that there were no adverse effects on the animal (Godfrey and Bryant 2003). It is likely that some studies using implanted electronic devices have not been published due to a high level of unexpected mortality or to aberrant behavior or disappearance of the implanted animals, a phenomenon known as the “file drawer” problem (Rosenthal 1979; Scargle 2000). The near absence of such studies from the published record may be providing a false sense of security that procedures being used are more innocuous than they actually are. Similarly, authors sometimes state that it was unlikely that device implantation was problematic because study animals appeared to behave normally, or authors state that previous investigators used the same technique and saw no problems. Such statements are suppositions if no supporting data are provided or if the animals were equipped because there was no other way to follow their activity. Moreover, such suppositions ignore other adverse effects that affect behavior indirectly, and

  15. A high-efficiency power and data transmission system for biomedical implanted electronic devices

    NASA Astrophysics Data System (ADS)

    Hamici, Zoubir; Itti, Roland; Champier, Jacques

    1996-02-01

    In biomedical engineering, inductive transcutaneous links can be used for power and data transfer between external systems and implanted electronic devices. The development of a micro-telemeter having a significant implantation depth needs a high-efficiency magnetic transcutaneous link. This paper presents a new system, which uses a multi-frequency load network for transmitter coil based on the class E power amplifier. At the carrier frequency used, the resistive load is influenced by the coupling of the coils and by the variation of the implant equivalent resistance. Modulating this latter between two rails permits one to modulate the amplitude of the external transmitter current and then to transmit internal data without the use of the classical implanted emitter design. Furthermore, the fact that the modulation index depends on the coupling factor, allows one to find the external coil's correct position using a position feedback loop. A complete study of the concept of digital data transmission by impedance modulation associated with a class E power amplifier is presented. Internal data transmission using this system yields a decrease of the internal electronic circuitry bulk and constitutes a high-efficiency energizing device. A theoretical investigation shows that the efficiency of the power transfer varies between 44 and 75% within a wide range of implantation depths (20 - 40 mm).

  16. Compensating for Tissue Changes in an Ultrasonic Power Link for Implanted Medical Devices.

    PubMed

    Vihvelin, Hugo; Leadbetter, Jeff; Bance, Manohar; Brown, Jeremy A; Adamson, Robert B A

    2016-04-01

    Ultrasonic power transfer using piezoelectric devices is a promising wireless power transfer technology for biomedical implants. However, for sub-dermal implants where the separation between the transmitter and receiver is on the order of several acoustic wavelengths, the ultrasonic power transfer efficiency (PTE) is highly sensitive to the distance between the transmitter and receiver. This sensitivity can cause large swings in efficiency and presents a serious limitation on battery life and overall performance. A practical ultrasonic transcutaneous energy transfer (UTET) system design must accommodate different implant depths and unpredictable acoustic changes caused by tissue growth, hydration, ambient temperature, and movement. This paper describes a method used to compensate for acoustic separation distance by varying the transmit (Tx) frequency in a UTET system. In a benchtop UTET system we experimentally show that without compensation, power transfer efficiency can range from 9% to 25% as a 5 mm porcine tissue sample is manipulated to simulate in situ implant conditions. Using an active frequency compensation method, we show that the power transfer efficiency can be kept uniformly high, ranging from 20% to 27%. The frequency compensation strategy we propose is low-power, non-invasive, and uses only transmit-side measurements, making it suitable for active implanted medical device applications. PMID:26054073

  17. Predictors of right ventricular failure after left ventricular assist device implantation

    PubMed Central

    Koprivanac, Marijan; Kelava, Marta; Sirić, Franjo; Cruz, Vincent B.; Moazami, Nader; Mihaljević, Tomislav

    2014-01-01

    Number of left ventricular assist device (LVAD) implantations increases every year, particularly LVADs for destination therapy (DT). Right ventricular failure (RVF) has been recognized as a serious complication of LVAD implantation. Reported incidence of RVF after LVAD ranges from 6% to 44%, varying mostly due to differences in RVF definition, different types of LVADs, and differences in patient populations included in studies. RVF complicating LVAD implantation is associated with worse postoperative mortality and morbidity including worse end-organ function, longer hospital length of stay, and lower success of bridge to transplant (BTT) therapy. Importance of RVF and its predictors in a setting of LVAD implantation has been recognized early, as evidenced by abundant number of attempts to identify independent risk factors and develop RVF predictor scores with a common purpose to improve patient selection and outcomes by recognizing potential need for biventricular assist device (BiVAD) at the time of LVAD implantation. The aim of this article is to review and summarize current body of knowledge on risk factors and prediction scores of RVF after LVAD implantation. Despite abundance of studies and proposed risk scores for RVF following LVAD, certain common limitations make their implementation and clinical usefulness questionable. Regardless, value of these studies lies in providing information on potential key predictors for RVF that can be taken into account in clinical decision making. Further investigation of current predictors and existing scores as well as new studies involving larger patient populations and more sophisticated statistical prediction models are necessary. Additionally, a short description of our empirical institutional approach to management of RVF following LVAD implantation is provided. PMID:25559829

  18. Predictors of right ventricular failure after left ventricular assist device implantation.

    PubMed

    Koprivanac, Marijan; Kelava, Marta; Sirić, Franjo; Cruz, Vincent B; Moazami, Nader; Mihaljević, Tomislav

    2014-12-01

    Number of left ventricular assist device (LVAD) implantations increases every year, particularly LVADs for destination therapy (DT). Right ventricular failure (RVF) has been recognized as a serious complication of LVAD implantation. Reported incidence of RVF after LVAD ranges from 6% to 44%, varying mostly due to differences in RVF definition, different types of LVADs, and differences in patient populations included in studies. RVF complicating LVAD implantation is associated with worse postoperative mortality and morbidity including worse end-organ function, longer hospital length of stay, and lower success of bridge to transplant (BTT) therapy. Importance of RVF and its predictors in a setting of LVAD implantation has been recognized early, as evidenced by abundant number of attempts to identify independent risk factors and develop RVF predictor scores with a common purpose to improve patient selection and outcomes by recognizing potential need for biventricular assist device (BiVAD) at the time of LVAD implantation. The aim of this article is to review and summarize current body of knowledge on risk factors and prediction scores of RVF after LVAD implantation. Despite abundance of studies and proposed risk scores for RVF following LVAD, certain common limitations make their implementation and clinical usefulness questionable. Regardless, value of these studies lies in providing information on potential key predictors for RVF that can be taken into account in clinical decision making. Further investigation of current predictors and existing scores as well as new studies involving larger patient populations and more sophisticated statistical prediction models are necessary. Additionally, a short description of our empirical institutional approach to management of RVF following LVAD implantation is provided. PMID:25559829

  19. Fabrication and Characterization of Thin Film Ion Implanted Composite Materials for Integrated Nonlinear Optical Devices

    NASA Technical Reports Server (NTRS)

    Sarkisov, S.; Curley, M.; Williams, E. K.; Wilkosz, A.; Ila, D.; Poker, D. B.; Hensley, D. K.; Smith, C.; Banks, C.; Penn, B.; Clark, R.

    1998-01-01

    Ion implantation has been shown to produce a high density of metal colloids within the layer regions of glasses and crystalline materials. The high-precipitate volume fraction and small size of metal nanoclusters formed leads to values for the third-order susceptibility much greater than those for metal doped solids. This has stimulated interest in use of ion implantation to make nonlinear optical materials. On the other side, LiNbO3 has proved to be a good material for optical waveguides produced by MeV ion implantation. Light confinement in these waveguides is produced by refractive index step difference between the implanted region and the bulk material. Implantation of LiNbO3 with MeV metal ions can therefore result into nonlinear optical waveguide structures with great potential in a variety of device applications. We describe linear and nonlinear optical properties of a waveguide structure in LiNbO3-based composite material produced by silver ion implantation in connection with mechanisms of its formation.

  20. The Application of Virtual Planning and Navigation Devices for Mandible Reconstruction and Immediate Dental Implantation.

    PubMed

    Rahimov, Chingiz R; Farzaliyev, Ismayil M; Fathi, Hamid Reza; Davudov, Mahammad M; Aliyev, Anar; Hasanov, Emin

    2016-06-01

    Routine reconstruction of subtotal defects of the mandible and orthopedic rehabilitation supported by dental implants is achieved by means of detailed planning and lasts over a year. This article shows the outcomes of single-stage surgical treatment and immediate orthopedic rehabilitation performed with the help of preoperative virtual computer simulation. 3D investigation of pathological and donor sites, virtual simulation of tumor resection, positioning of the dental implants into fibula, virtual flap bending and transfer, virtual bending of fixing reconstruction plates, and fabrication of navigation templates and bridge prosthesis supported by dental implants were done preoperatively. The surgery included tumor resection, insertion of dental implants into fibula, elevation of fibula osteocutaneous free flap, rigid fixation within recipient site, and immediate loading by bridge orthopedic device. On 10-month follow-up, functional and esthetic results were asses as reasonable. Radiography showed dental implants to be integrated and positioned appropriately. We found that successful rehabilitation of the patients with extensive defects of the jaws could be achieved by ablative tumor resection, dental implants insertion prior to flap elevation guided by navigation templates, further osteotomy, modeling of the flap based on navigation template, flap transfer, and rigid fixation within recipient site by prebended plates, with application of prefabricated prosthesis. PMID:27162568

  1. RF communication with implantable wireless device: effects of beating heart on performance of miniature antenna

    PubMed Central

    Borghi, Alessandro; Bahmanyar, Mohammad Reza; McLeod, Christopher N.; Navaratnarajah, Manoraj; Yacoub, Magdi; Toumazou, Christofer

    2014-01-01

    The frequency response of an implantable antenna is key to the performance of a wireless implantable sensor. If the antenna detunes significantly, there are substantial power losses resulting in loss of accuracy. One reason for detuning is because of a change in the surrounding environment of an antenna. The pulsating anatomy of the human heart constitutes such a changing environment, so detuning is expected but this has not been quantified dynamically before. Four miniature implantable antennas are presented (two different geometries) along with which are placed within the heart of living swine the dynamic reflection coefficients. These antennas are designed to operate in the short range devices frequency band (863–870 MHz) and are compatible with a deeply implanted cardiovascular pressure sensor. The measurements recorded over 27 seconds capture the effects of the beating heart on the frequency tuning of the implantable antennas. When looked at in the time domain, these effects are clearly physiological and a combination of numerical study and posthumous autopsy proves this to be the case, while retrospective simulation confirms this hypothesis. The impact of pulsating anatomy on antenna design and the need for wideband implantable antennas is highlighted. PMID:26609377

  2. Safe use of MRI in people with cardiac implantable electronic devices.

    PubMed

    Lowe, Martin D; Plummer, Christopher J; Manisty, Charlotte H; Linker, Nicholas J

    2015-12-01

    MR scanning in patients with cardiac implantable electronic devices (CIEDs) was formerly felt to be contraindicated, but an increasing number of patients have an implanted MR conditional device, allowing them to safely undergo MR scanning, provided the manufacturer's guidance is adhered to. In addition, some patients with non-MR conditional devices may undergo MR scanning if no other imaging modality is deemed suitable and there is a clear clinical indication for scanning which outweighs the potential risk. The following guidance has been formulated by the British Heart Rhythm Society and endorsed by the British Cardiovascular Society and others. It describes protocols that should be followed for patients with CIEDs undergoing MR scanning. The recommendations, principles and conclusions are supported by the Royal College of Radiologists. PMID:26420818

  3. Development of a highly efficient implanted thermal ablation device: in vivo experiment in rat liver

    PubMed Central

    Matsui, H; Hamuro, M; Nakamura, K; Kayahara, H; Murano, K; Kotsuka, Y; Miki, Y

    2012-01-01

    Objectives To evaluate an implanted thermal ablation device that can be heated with high efficiency using a resonant circuit as the implant. Methods 16 rats were used. The implants, adjusted at a resonance frequency of 4 MHz, were fixed on the surface of the liver of rats under laparotomy. In 14 of 16 rats, an alternating magnetic field (AMF) was applied for 6 min with an output of 300 W from outside the body using a ferrite core applicator. The implant temperature during AMF exposure was measured. The 14 rats were divided into 5 groups, depending on time from AMF application until they were sacrificed (1 h, 1 day, 3 days, 7 days and 1 month after application). Two rats not exposed to AMF were used as controls. Livers were removed and evaluated; the cross-sectional area and width of the ablated region were measured. Results During AMF exposure, the implant temperature rose to 127.8±39.3 °C (mean±standard deviation). The cross-sectional area of the ablated region was largest after 1 day and tended to decrease with time. The widths of the ablated region were 4.87±0.22 mm, 4.15±0.36 mm, 3.67±0.58 mm and 3.24±0.16 mm in the 1 day, 3 day, 7 day and 1 month groups, respectively. No significant differences (p<0.05) were seen in either cross-sectional area or width of the ablated region. Conclusion Sufficient heat for ablation was obtained in vivo using a newly developed implanted thermal ablation device. This device may be a new option for thermal ablation therapy. PMID:22422380

  4. Ion implantation challenges in the drive towards 64 Mb and 256 Mb memory cell type devices

    NASA Astrophysics Data System (ADS)

    Giles, Alan D.; van der Steege, Anton

    1991-04-01

    Ion implantation techniques will be critical in the production of evermore complex devices, with major challenges for the device designer in utilising available techniques and those that are potentially available. Equally difficult challenges face the equipment designer in judging which technologies are required for future devices and welding these requirements into a reliable, productionworthy fabrication tool, capable of meeting or exceeding the automation and up-time expectations of the wafer fabrication managers. High yield and consistent performance on the wafer continue to be paramount. This paper will review these challenges from the equipment suppliers' viewpoint and in particular the new technology needs and cost of ownership issues.

  5. Preferred tools and techniques for implantation of cardiac electronic devices in Europe: results of the European Heart Rhythm Association survey.

    PubMed

    Bongiorni, Maria Grazia; Proclemer, Alessandro; Dobreanu, Dan; Marinskis, Germanas; Pison, Laurent; Blomstrom-Lundqvist, Carina

    2013-11-01

    The aim of this European Heart Rhythm Association (EHRA) survey was to assess clinical practice in relation to the tools and techniques used for cardiac implantable electronic devices procedures in the European countries. Responses to the questionnaire were received from 62 members of the EHRA research network. The survey involved high-, medium-, and low-volume implanting centres, performing, respectively, more than 200, 100-199 and under 100 implants per year. The following topics were explored: the side approach for implantation, surgical techniques for pocket incision, first venous access for lead implantation, preference of lead fixation, preferred coil number for implantable cardioverter-defibrillator (ICD) leads, right ventricular pacing site, generator placement site, subcutaneous ICD implantation, specific tools and techniques for cardiac resynchronization therapy (CRT), lead implantation sequence in CRT, coronary sinus cannulation technique, target site for left ventricular lead placement, strategy in left ventricular lead implant failure, mean CRT implantation time, optimization of the atrioventricular (AV) and ventriculo-ventricular intervals, CRT implants in patients with permanent atrial fibrillation, AV node ablation in patients with permanent AF. This panoramic view allows us to find out the operator preferences regarding the techniques and tools for device implantation in Europe. The results showed different practices in all the fields we investigated, nevertheless the survey also outlines a good adherence to the common standards and recommendations. PMID:24170423

  6. Solute diffusion through fibrotic tissue formed around protective cage system for implantable devices.

    PubMed

    Prihandana, Gunawan Setia; Ito, Hikaru; Tanimura, Kohei; Yagi, Hiroshi; Hori, Yuki; Soykan, Orhan; Sudo, Ryo; Miki, Norihisa

    2015-08-01

    This article presents the concept of an implantable cage system that can house and protect implanted biomedical sensing and therapeutic devices in the body. Cylinder-shaped cages made of porous polyvinyl alcohol (PVA) sheets with an 80-µm pore size and/or stainless steel meshes with 0.54-mm openings were implanted subcutaneously in the dorsal region of rats for 5 weeks. Analysis of the explanted cages showed the formation of fibrosis tissue around the cages. PVA cages had fibrotic tissue growing mostly along the outer surface of cages, while stainless steel cages had fibrotic tissue growing into the inside surface of the cage structure, due to the larger porosity of the stainless steel meshes. As the detection of target molecules with short time lags for biosensors and mass transport with low diffusion resistance into and out of certain therapeutic devices are critical for the success of such devices, we examined whether the fibrous tissue formed around the cages were permeable to molecules of our interest. For that purpose, bath diffusion and microfluidic chamber diffusion experiments using solutions containing the target molecules were performed. Diffusion of sodium, potassium and urea through the fibrosis tissue was confirmed, thus suggesting the potential of these cylindrical cages surrounded by fibrosis tissue to successfully encase implantable sensors and therapeutic apparatus. PMID:25303239

  7. A wireless power transmission system for implantable devices in freely moving rodents.

    PubMed

    Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Kim, Jinhyung; Kim, Junghoon; Lee, Sung Eun; Kim, Sung June

    2014-08-01

    Reliable wireless power delivery for implantable devices in animals is highly desired for safe and effective experimental use. Batteries require frequent replacement; wired connections are inconvenient and unsafe, and short-distance inductive coupling requires the attachment of an exterior transmitter to the animal's body. In this article, we propose a solution by which animals with implantable devices can move freely without attachments. Power is transmitted using coils attached to the animal's cage and is received by a receiver coil implanted in the animal. For a three-dimensionally uniform delivery of power, we designed a columnar dual-transmitter coil configuration. A resonator-based inductive link was adopted for efficient long-range power delivery, and we used a novel biocompatible liquid crystal polymer substrate as the implantable receiver device. Using this wireless power delivery system, we obtain an average power transfer efficiency of 15.2% (minimum efficiency of 10% and a standard deviation of 2.6) within a cage of 15×20×15 cm3. PMID:24946939

  8. The Jarvik-2000 ventricular assist device implantation: how we do it

    PubMed Central

    Tarzia, Vincenzo; Bottio, Tomaso; Gerosa, Gino

    2014-01-01

    The Jarvik-2000 is a non-pulsatile axial-flow left ventricular assist device (LVAD) that is largely used in patients who present in end-stage heart failure, as a bridge to transplant support or destination therapy. From its first utilization, several implantation techniques have been elaborated, starting from a median sternotomy with cardiopulmonary bypass (CPB) support and moving towards a minimally invasive access with an off-pump strategy. Here we present the favored surgical technique used in our department to implant the Jarvik-2000, in a step-by-step fashion. PMID:25452914

  9. Current Trends in Implantable Left Ventricular Assist Devices

    PubMed Central

    Garbade, Jens; Bittner, Hartmuth B.; Barten, Markus J.; Mohr, Friedrich-Wilhelm

    2011-01-01

    The shortage of appropriate donor organs and the expanding pool of patients waiting for heart transplantation have led to growing interest in alternative strategies, particularly in mechanical circulatory support. Improved results and the increased applicability and durability with left ventricular assist devices (LVADs) have enhanced this treatment option available for end-stage heart failure patients. Moreover, outcome with newer pumps have evolved to destination therapy for such patients. Currently, results using nonpulsatile continuous flow pumps document the evolution in outcomes following destination therapy achieved subsequent to the landmark Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure Trial (REMATCH), as well as the outcome of pulsatile designed second-generation LVADs. This review describes the currently available types of LVADs, their clinical use and outcomes, and focuses on the patient selection process. PMID:21822483

  10. Electromagnetic immunity of implantable pacemakers exposed to wi-fi devices.

    PubMed

    Mattei, Eugenio; Censi, Federica; Triventi, Michele; Calcagnini, Giovanni

    2014-10-01

    The purpose of this study is to evaluate the potential for electromagnetic interference (EMI) and to assess the immunity level of implantable pacemakers (PM) when exposed to the radiofrequency (RF) field generated by Wi-Fi devices. Ten PM from five manufacturers, representative of what today is implanted in patients, have been tested in vitro and exposed to the signal generated by a Wi-Fi transmitter. An exposure setup that reproduces the actual IEEE 802.11b/g protocol has been designed and used during the tests. The system is able to amplify the Wi-Fi signal and transmits at power levels higher than those allowed by current international regulation. Such approach allows one to obtain, in case of no EMI, a safety margin for PM exposed to Wi-Fi signals, which otherwise cannot be derived if using commercial Wi-Fi equipment. The results of this study mitigate concerns about using Wi-Fi devices close to PM: none of the PM tested exhibit any degradation of their performance, even when exposed to RF field levels five times higher than those allowed by current international regulation (20 W EIRP). In conclusion, Wi-Fi devices do not pose risks of EMI to implantable PM. The immunity level of modern PM is much higher than the transmitting power of RF devices operating at 2.4 GHz. PMID:25162422

  11. Management of Cardiovascular Implantable Electronic Devices Infections in High-Risk Patients

    PubMed Central

    Kennergren, Charles

    2015-01-01

    The incidence of infection following implantation of cardiovascular implantable electronic devices (CIEDs) is increasing, as is the number of pulse generator replacements and upgrades. The rate of infections is rising faster than the rate of device implantation, mainly due to the increasing age and number of comorbidities of patients receiving the devices. Patients with a CIED infection usually require hospitalisation, multiple consultations, prolonged intravenous antibiotics and, in the majority of cases, CIED explantation and replacement. A significant proportion die of their infection. CIED infection therefore represents a substantial health and economic burden, and management of infections is critical. Numerous risk factors have been identified including host, procedure and device-related factors. Established strategies for preventing CIED infections include intravenous antibiotics and aseptic techniques. The TYRX™ Absorbable Antibacterial Envelope offers potential as an effective method to reduce CIED infections. Several studies have found a statistically significant association between antibacterial envelope use and reduced incidence of CIED infection in high-risk patients. A prospective, randomised trial to further evaluate this potentially important strategy for CIED infection prophylaxis is underway. PMID:26835101

  12. In-situ photopolymerization and monitoring device for controlled shaping of tissue fillers, replacements, or implants

    NASA Astrophysics Data System (ADS)

    Schmocker, Andreas M.; Khoushabi, Azadeh; Bourban, Pierre-Etienne; Schizas, Constantin; Pioletti, Dominique; Moser, Christophe

    2015-03-01

    Photopolymerization is a common tool to harden materials initially in a liquid state. A surgeon can directly trigger the solidification of a dental implant or a bone or tissue filler simply by illumination. Traditionally, photopolymerization has been used mainly in dentistry. Over the last decade advances in material development including a wide range of biocompatible gel- and cement-systems open up a new avenue for in-situ photopolymerization. However, at the device level, surgical endoscopic probes are required. We present a miniaturized light probe where a photoactive material can be 1) mixed, pressurized and injected 2) photopolymerized or photoactivated and 3) monitored during the chemical reaction. The device enables surgeries to be conducted through a hole smaller than 1 mm in diameter. Beside basic injection mechanics, the tool consists of an optical fiber guiding the light required for photopolymerization and for chemical analysis. Combining photorheology and fluorescence spectroscopy, the current state of the photopolymerization is inferred and monitored in real time. Biocompatible and highly tuneable Poly-Ethylene-Glycol (PEG) hydrogels were used as the injection material. The device was tested on a model for intervertebral disc replacement. Gels were successfully implanted into a bovine caudal model and mechanically tested in-vitro during two weeks. The photopolymerized gel was evaluated at the tissue level (adherence and mechanical properties of the implant), at the cellular level (biocompatibility and cytotoxicity) and ergonomic level (sterilization procedure and feasibility study). This paper covers the monitoring aspect of the device.

  13. Robotic Left Ventricular Assist Device Implantation Using Left Thoracotomy Approach in Patients with Previous Sternotomies.

    PubMed

    Khalpey, Zain; Bin Riaz, Irbaz; Marsh, Katherine M; Ansari, Muhammad Zubair Ahmad; Bilal, Jawad; Cooper, Anthony; Paidy, Samata; Schmitto, Jan D; Smith, Richard; Friedman, Mark; Slepian, Marvin J; Poston, Robert

    2015-01-01

    Left ventricular assist devices (LVADs) are commonly used as either a bridge-to-transplant or a destination therapy. The traditional approach for LVAD implantation is via median sternotomy, but many candidates for this procedure have a history of failed cardiac surgeries and previous sternotomy. Redo sternotomy increases the risk of heart surgery, particularly in the setting of advanced heart failure. Robotics facilitates a less invasive approach to LVAD implantation that circumvents some of the morbidity associated with a redo sternotomy. We compared the outcomes of all patients at our institution who underwent LVAD implantation via either a traditional sternotomy or using robotic assistance. The robotic cohort showed reduced resource utilization including length of hospital stay and use of blood products. As the appropriate candidates become elucidated, robotic assistance may improve the safety and cost-effectiveness of reoperative LVAD surgery. PMID:25914953

  14. Miniscrew implants as temporary anchorage devices in orthodontics: a comprehensive review.

    PubMed

    Jasoria, Gaurav; Shamim, Wamiq; Rathore, Saurabh; Kalra, Amit; Manchanda, Mona; Jaggi, Nitin

    2013-01-01

    In recent times, the use of miniscrew implants to obtain absolute anchorage has gained momentum in clinical orthodontics as rigid anchorage modality. Miniscrew implants offers many advantages when used as temporary anchorage devices like, easy placement and removal, immediate loading, can be used in a variety of locations, provide absolute anchorage, economic and requires less patient cooperation. This makes them as a necessary treatment option in cases with critical anchorage that would have otherwise resulted in anchorage loss if treated with conventional means of anchorage. The aim of this comprehensive review is to highlight the gradual evolution, clinical use, advantages and disadvantages of the miniscrew implants when used to obtain a temporary but absolute skeletal anchorage for orthodontic applications. PMID:24685811

  15. Catalyst-dependent drug loading of LDI-glycerol polyurethane foams leads to differing controlled release profiles.

    PubMed

    Sivak, Wesley N; Pollack, Ian F; Petoud, Stéphane; Zamboni, William C; Zhang, Jianying; Beckman, Eric J

    2008-09-01

    The purpose of the present study was to develop biodegradable and biocompatible polyurethane foams based on lysine diisocyanate (LDI) and glycerol to be used as drug-delivery systems for the controlled release of 7-tert-butyldimethylsilyl-10-hydroxy-camptothecin (DB-67). The impact of urethane catalysts on cellular proliferation was assessed in an attempt to enhance the biocompatibility of our polyurethane materials. DB-67, a potent camptothecin analog, was then incorporated into LDI-glycerol polyurethane foams with two different amine urethane catalysts: 1,4-diazobicyclo[2.2.2]-octane (DABCO) and 4,4'-(oxydi-2,1-ethane-diyl)bismorpholine (DMDEE). The material morphologies of the polyurethane foams were analyzed via scanning electron microscopy, and DB-67 distribution was assessed by way of fluorescence microscopy. Both foam morphology and drug distribution were found to correlate to the amine catalyst used. Hydrolytic release rates of DB-67 from the polyurethane foams were catalyst dependent and also demonstrated greater drug loads being released at higher temperatures. The foams were capable of delivering therapeutic concentrations of DB-67 in vitro over an 11week test period. Cellular proliferation assays demonstrate that empty LDI-glycerol foams did not significantly alter the growth of malignant human glioma cell lines (P<0.05). DB-67 loaded LDI-glycerol polyurethane foams were found to inhibit cellular proliferation by at least 75% in all the malignant glioma cell lines tested (P<1.0x10(-8)). These results clearly demonstrate the long-term, catalyst-dependent release of DB-67 from LDI-glycerol polyurethane foams, indicating their potential for use in implantable drug-delivery devices. PMID:18440884

  16. Adhoc electromagnetic compatibility testing of non-implantable medical devices and radio frequency identification

    PubMed Central

    2013-01-01

    Background The use of radiofrequency identification (RFID) in healthcare is increasing and concerns for electromagnetic compatibility (EMC) pose one of the biggest obstacles for widespread adoption. Numerous studies have documented that RFID can interfere with medical devices. The majority of past studies have concentrated on implantable medical devices such as implantable pacemakers and implantable cardioverter defibrillators (ICDs). This study examined EMC between RFID systems and non-implantable medical devices. Methods Medical devices were exposed to 19 different RFID readers and one RFID active tag. The RFID systems used covered 5 different frequency bands: 125–134 kHz (low frequency (LF)); 13.56 MHz (high frequency (HF)); 433 MHz; 915 MHz (ultra high frequency (UHF])) and 2.4 GHz. We tested three syringe pumps, three infusion pumps, four automatic external defibrillators (AEDs), and one ventilator. The testing procedure is modified from American National Standards Institute (ANSI) C63.18, Recommended Practice for an On-Site, Ad Hoc Test Method for Estimating Radiated Electromagnetic Immunity of Medical Devices to Specific Radio-Frequency Transmitters. Results For syringe pumps, we observed electromagnetic interference (EMI) during 13 of 60 experiments (22%) at a maximum distance of 59 cm. For infusion pumps, we observed EMI during 10 of 60 experiments (17%) at a maximum distance of 136 cm. For AEDs, we observed EMI during 18 of 75 experiments (24%) at a maximum distance of 51 cm. The majority of the EMI observed was classified as probably clinically significant or left the device inoperable. No EMI was observed for all medical devices tested during exposure to 433 MHz (two readers, one active tag) or 2.4 GHz RFID (two readers). Conclusion Testing confirms that RFID has the ability to interfere with critical medical equipment. Hospital staff should be aware of the potential for medical device EMI caused by RFID systems and should be encouraged to

  17. Intrinsic signal imaging of brain function using a small implantable CMOS imaging device

    NASA Astrophysics Data System (ADS)

    Haruta, Makito; Sunaga, Yoshinori; Yamaguchi, Takahiro; Takehara, Hironari; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Ohta, Jun

    2015-04-01

    A brain functional imaging technique over a long period is important to understand brain functions related to animal behavior. We have developed a small implantable CMOS imaging device for measuring brain activity in freely moving animals. This device is composed of a CMOS image sensor chip and LEDs for illumination. In this study, we demonstrated intrinsic signal imaging of blood flow using the device with a green LED light source at a peak wavelength of 535 nm, which corresponds to one of the absorption spectral peaks of blood cells. Brain activity increases regional blood flow. The device light weight of about 0.02 g makes it possible to stably measure brain activity through blood flow over a long period. The device has successfully measured the intrinsic signal related to sensory stimulation on the primary somatosensory cortex.

  18. Home Monitoring for Cardiovascular Implantable Electronic Devices: Benefits to Patients and to Their Follow-up Clinic.

    PubMed

    Leahy, Robin A; Davenport, Elizabeth E

    2015-01-01

    Recent technological advances in the management of patients with cardiovascular implantable electronic devices (CIEDs) have expanded clinicians' ability to remotely monitor patients with CIEDs. Remote monitoring, in addition to periodic in-person device evaluation, provides many advantages to patients and clinicians. Aside from the therapeutic and diagnostic benefits of pacemakers, implantable cardioverter-defibrillators, cardiac resynchronization therapy devices, and implantable loop recorders, improvement in clinical outcomes, clinical efficiencies, and patient experience can be realized with the adoption of remote CIED monitoring. These advantages create significant value to both patients and CIED follow-up centers. PMID:26484995

  19. Effect of Continued Cardiac Resynchronization Therapy on Ventricular Arrhythmias After Left Ventricular Assist Device Implantation.

    PubMed

    Schleifer, John William; Mookadam, Farouk; Kransdorf, Evan P; Nanda, Udai; Adams, Jonathon C; Cha, Stephen; Pajaro, Octavio E; Steidley, David Eric; Scott, Robert L; Carvajal, Tomas; Saadiq, Rayya A; Srivathsan, Komandoor

    2016-08-15

    Cardiac resynchronization therapy (CRT) reduces ventricular arrhythmia (VA) burden in some patients with heart failure, but its effect after left ventricular assist device (LVAD) implantation is unknown. We compared VA burden in patients with CRT devices in situ who underwent LVAD implantation and continued CRT (n = 39) to those who had CRT turned off before discharge (n = 26). Implantable cardioverter-defibrillator (ICD) shocks were significantly reduced in patients with continued CRT (1.5 ± 2.7 shocks per patient vs 5.5 ± 9.3 with CRT off, p = 0.014). There was a nonsignificant reduction in cumulative VA episodes per patient with CRT continued at discharge (42 ± 105 VA per patient vs 82 ± 198 with CRT off, p = 0.29). On-treatment analysis by whether CRT was on or off identified a significantly lower burden of VA (17 ± 1 per patient-year CRT on vs 37 ± 1 per patient-year CRT off, p <0.0001) and ICD shocks (1.2 ± 0.3 per patient-year CRT on vs 1.7 ± 0.3 per patient-year CRT off, p = 0.018). In conclusion, continued CRT is associated with significantly reduced ICD shocks and VA burden after LVAD implantation. PMID:27328958

  20. Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands

    NASA Astrophysics Data System (ADS)

    Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

    2016-06-01

    The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz–460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich’s flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

  1. Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands.

    PubMed

    Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

    2016-06-21

    The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich's flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs. PMID:27224201

  2. Safety of anticoagulation with uninterrupted warfarin vs. interrupted dabigatran in patients requiring an implantable cardiac device

    PubMed Central

    Madan, Shivanshu; Muthusamy, Purushothaman; Mowers, Katie L.; Elmouchi, Darryl A.; Finta, Bohuslav; Gauri, Andre J.; Woelfel, Alan K.; Fritz, Timothy D.; Davis, Alan T.

    2016-01-01

    Background The optimal strategy of peri-procedural anticoagulation in patients undergoing permanent cardiac device implantation is controversial. Our objective was to compare the major bleeding and thromboembolic complications in patients managed with uninterrupted warfarin (UW) vs. interrupted dabigatran (ID) during permanent pacemaker (PPM) or implantable cardioverter defibrillators (ICD) implantation. Methods A retrospective cohort study of all eligible patients from July 2011 through January 2012 was performed. UW was defined as patients who had maintained a therapeutic international normalized ratio (INR) on the day of the procedure. ID was defined as stopping dabigatran ≥12 hours prior to the procedure and then resuming after implantation. Major bleeding events included hemothorax, hemopericardium, intracranial hemorrhage, gastrointestinal bleed, epistaxis, or pocket hematoma requiring surgical intervention. Thromboembolic complications included stroke, transient ischemic attack, deep venous thrombosis, pulmonary embolism, or arterial embolism. Results Of the 133 patients (73.4±11.0 years; 91 males) in the study, 86 received UW and 47 received ID. One (1.2%) patient in the UW group sustained hemopericardium perioperatively and died. In comparison, the ID patients had no complications. As compared to the ID group, the UW group had a higher median CHADS2 score (2 vs. 3, P=0.04) and incidence of Grade 1 pocket hematoma (0% vs. 7%, P=0.09). Neither group developed any thromboembolic complications. Conclusions Major bleeding rates were similar among UW and ID groups. Perioperative ID appears to be a safe anticoagulation strategy for patients undergoing PPM or ICD implantation. PMID:26885486

  3. A New Trans-Tympanic Microphone Approach for Fully Implantable Hearing Devices

    PubMed Central

    Woo, Seong Tak; Shin, Dong Ho; Lim, Hyung-Gyu; Seong, Ki-Woong; Gottlieb, Peter; Puria, Sunil; Lee, Kyu-Yup; Cho, Jin-Ho

    2015-01-01

    Fully implantable hearing devices (FIHDs) have been developed as a new technology to overcome the disadvantages of conventional acoustic hearing aids. The implantable microphones currently used in FIHDs, however, have difficulty achieving high sensitivity to environmental sounds, low sensitivity to body noise, and ease of implantation. In general, implantable microphones may be placed under the skin in the temporal bone region of the skull. In this situation, body noise picked up during mastication and touching can be significant, and the layer of skin and hair can both attenuate and distort sounds. The new approach presently proposed is a microphone implanted at the tympanic membrane. This method increases the microphone’s sensitivity by utilizing the pinna’s directionally dependent sound collection capabilities and the natural resonances of the ear canal. The sensitivity and insertion loss of this microphone were measured in human cadaveric specimens in the 0.1 to 16 kHz frequency range. In addition, the maximum stable gain due to feedback between the trans-tympanic microphone and a round-window-drive transducer, was measured. The results confirmed in situ high-performance capabilities of the proposed trans-tympanic microphone. PMID:26371007

  4. Revision total hip and knee arthroplasty implant identification: implications for use of Unique Device Identification 2012 AAHKS member survey results.

    PubMed

    Wilson, Natalia A; Jehn, Megan; York, Sally; Davis, Charles M

    2014-02-01

    FDA's Unique Device Identification (UDI) Rule will mandate manufacturers to assign unique identifiers to their marketed devices. UDI use is expected to improve implant documentation and identification. A 2012 American Association of Hip and Knee Surgeons membership survey explored revision total hip and knee arthroplasty implant identification processes. 87% of surgeons reported regularly using at least 3 methods to identify failed implants pre-operatively. Median surgeon identification time was 20 min; median staff time was 30 min. 10% of implants could not be identified pre-operatively. 2% could not be identified intra-operatively. UDI in TJA registry and UDI in EMR were indicated practices to best support implant identification and save time. FDA's UDI rule sets the foundation for UDI use in patient care settings as standard practice for implant documentation. PMID:23890830

  5. Performance Enhancement of PFET Planar Devices by Plasma Immersion Ion Implantation (P3I)

    SciTech Connect

    Ortolland, Claude; Horiguchi, Naoto; Kerner, Christoph; Chiarella, Thomas; Eyben, Pierre; Everaert, Jean-Luc; Hoffmann, Thomas; Del Agua Borniquel, Jose Ignacio; Poon, Tze; Santhanam, Kartik; Porshnev, Peter; Foad, Majeed; Schreutelkamp, Robert; Absil, Philippe; Vandervorst, Wilfried; Felch, Susan

    2008-11-03

    A study of doping the pMOS Lightly Doped Drain (LDD) by Plasma Immersion Ion Implantation (P3i) with BF3 is presented which demonstrates a better transistor performance compared to standard beam line Ion Implantation (I/I). The benefit of P3i comes from the broad angular distribution of the impinging ions thereby doping the poly-silicon gate sidewall as well. Gate capacitance of short channel devices has been measured and clearly shows this improvement. This model is clearly supported by high resolution 2D-carrier profiles using Scanning Spreading Resistance Microscopy (SSRM) which shows this gate sidewall doping. The broad angular distribution also implies a smaller directional sensitivity (to for instance the detailed gate edge shape) and leads to devices which are perfectly balanced, when Source and Drain electrode are switched.

  6. Columnar transmitter based wireless power delivery system for implantable device in freely moving animals.

    PubMed

    Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Lee, Sung Eun; Jun, Sang Bum; Kim, Sung June

    2013-01-01

    A wireless power delivery system is developed to deliver electrical power to the neuroprosthetic devices that are implanted into animals freely moving inside the cage. The wireless powering cage is designed for long-term animal experiments without cumbersome wires for power supply or the replacement of batteries. In the present study, we propose a novel wireless power transmission system using resonator-based inductive links to increase power efficiency and to minimize the efficiency variations. A columnar transmitter coil is proposed to provide lateral uniformity of power efficiency. Using this columnar transmitter coil, only 7.2% efficiency fluctuation occurs from the maximum transmission efficiency of 25.9%. A flexible polymer-based planar type receiver coil is fabricated and assembled with a neural stimulator and an electrode. Using the designed columnar transmitter coil, the implantable device successfully operates while it moves freely inside the cage. PMID:24110073

  7. Processing of Silver-Implanted Aluminum Nitride for Energy Harvesting Devices

    NASA Astrophysics Data System (ADS)

    Alleyne, Fatima Sierre

    One of the more attractive sources of green energy has roots in the popular recycling theme of other green technologies, now known by the term "energy scavenging." In its most promising conformation, energy scavenging converts cyclic mechanical vibrations in the environment or random mechanical pressure pulses, caused by sources ranging from operating machinery to human footfalls, into electrical energy via piezoelectric transducers. While commercial piezoelectrics have evolved to favor lead zirconate titanate (PZT) for its combination of superior properties, the presence of lead in these ceramic compounds raises resistance to their application in anything "green" due to potential health implications during their manufacturing, recycling, or in-service application, if leaching occurs. Therefore in this study we have pursued the application of aluminum nitride (AlN) as a non-toxic alternative to PZT, seeking processing pathways to augment the modest piezoelectric performance of AlN and exploit its compatibility with complementary-metal-oxide semiconductor (CMOS) manufacturing. Such piezoelectric transducers have been categorized as microelectromechanical systems (MEMS), which despite more than a decade of research in this field, is plagued by delamination at the electrode/piezoelectric interface. Consequently the electric field essential to generate and sustain the piezoelectric response of these devices is lost, resulting in device failure. Working on the hypothesis that buried conducting layers can both mitigate the delamination problem and generate sufficient electric field to engage the operation of resonator devices, we have undertaken a study of silver ion implantation to experimentally assess its feasibility. As with most ion implantation procedures employed in semiconductor fabrication, the implanted sample is subjected to a thermal treatment, encouraging diffusion-assisted precipitation of the implanted species at high enough concentrations. The objective

  8. Processing of Silver-Implanted Aluminum Nitride for Energy Harvesting Devices

    NASA Astrophysics Data System (ADS)

    Alleyne, Fatima Sierre

    One of the more attractive sources of green energy has roots in the popular recycling theme of other green technologies, now known by the term "energy scavenging." In its most promising conformation, energy scavenging converts cyclic mechanical vibrations in the environment or random mechanical pressure pulses, caused by sources ranging from operating machinery to human footfalls, into electrical energy via piezoelectric transducers. While commercial piezoelectrics have evolved to favor lead zirconate titanate (PZT) for its combination of superior properties, the presence of lead in these ceramic compounds raises resistance to their application in anything "green" due to potential health implications during their manufacturing, recycling, or in-service application, if leaching occurs. Therefore in this study we have pursued the application of aluminum nitride (AlN) as a non-toxic alternative to PZT, seeking processing pathways to augment the modest piezoelectric performance of AlN and exploit its compatibility with complementary-metal-oxide semiconductor (CMOS) manufacturing. Such piezoelectric transducers have been categorized as microelectromechanical systems (MEMS), which despite more than a decade of research in this field, is plagued by delamination at the electrode/piezoelectric interface. Consequently the electric field essential to generate and sustain the piezoelectric response of these devices is lost, resulting in device failure. Working on the hypothesis that buried conducting layers can both mitigate the delamination problem and generate sufficient electric field to engage the operation of resonator devices, we have undertaken a study of silver ion implantation to experimentally assess its feasibility. As with most ion implantation procedures employed in semiconductor fabrication, the implanted sample is subjected to a thermal treatment, encouraging diffusion-assisted precipitation of the implanted species at high enough concentrations. The objective

  9. A practical approach to perioperative management of cardiac implantable electronic devices

    PubMed Central

    Chia, Pow-Li; Foo, David

    2015-01-01

    With the increased use of cardiac implantable electronic devices (CIEDs), it is increasingly important to recognise the unique challenges involved in the management of patients with CIEDs who are undergoing surgery. Practice advisories and consensus statements have been issued by the American Society of Anesthesiologists and the Heart Rhythm Society, advocating a multidisciplinary approach. This review discusses and presents a practical approach to perioperative CIED management in the Singapore context. PMID:26512144

  10. A practical approach to perioperative management of cardiac implantable electronic devices.

    PubMed

    Chia, Pow-Li; Foo, David

    2015-10-01

    With the increased use of cardiac implantable electronic devices (CIEDs), it is increasingly important to recognise the unique challenges involved in the management of patients with CIEDs who are undergoing surgery. Practice advisories and consensus statements have been issued by the American Society of Anesthesiologists and the Heart Rhythm Society, advocating a multidisciplinary approach. This review discusses and presents a practical approach to perioperative CIED management in the Singapore context. PMID:26512144

  11. Detection of deeply implanted impedance-switching devices using ultrasound doppler.

    PubMed

    Mari, Jean Martial; Lafon, Cyril; Chapelon, Jean Yves

    2013-06-01

    Communication with and transmission of energy to remote devices, such as deeply-implanted physiological recorders, using ultrasound presents several technical problems. In particular, device detection and piezoelectric sensor targeting remains difficult. Both tasks require differentiating the device from the surrounding fully passive tissues. Like radiofrequency identification devices, ultrasonic transponders have the capacity to rapidly change the impedance of their piezoelectric elements, which modulates their backscattering coefficient and allows the device to "flash" periodically at a very low energy cost, and, in particular situations, to communicate with an external device. A method for localizing the device by interpreting this flashing as movement is presented here. An ultrasound Doppler scan sequence is implemented using a programmable scanner, and radio-frequency data are collected and processed. The data are then analyzed for different excitation lengths and flashing frequencies to determine the optimum detection parameters. Measurements show that 1) detection can be achieved and is maximal when the excitation length reaches that of the Doppler processing window, and 2) when the flashing frequency is in a specific range. A study of the incidence angle also showed that 3) the sensor of the device can be detected over a given angular window. The conclusion is that by using ultrasound color Doppler sequences, impedance-switching piezoelectric devices can be detected under the conditions provided in the present study, and can be distinguished from fully passive structures. PMID:25004471

  12. Surgical Considerations and Challenges for Bilateral Continuous-Flow Durable Device Implantation.

    PubMed

    Maltais, Simon; Womack, Sara; Davis, Mary E; Danter, Matthew R; Kushwaha, Sudhir S; Stulak, John M; Haglund, Nicholas

    2016-01-01

    The concept of biventricular support with durable centrifugal pumps is evolving, and the surgical strategy and best practice guidelines for implantation of right-sided devices are still unknown. We present optimal strategy for bilateral HeartWare continuous-flow ventricular assist device (HVAD) implantation in a series of four patients. Patients were implanted with the HVAD pumps simultaneously or sequentially. This report offers a perspective on surgical considerations such as right ventricular positioning, implications related to potential risks of obstruction from the tricuspid apparatus, the role if any of downsizing the outflow anastomosis, and considerations for speed adjustments. In this series, one patient died on support and three patients experienced pump thrombosis requiring device revision. All other patients survived until orthotopic heart transplantation, although one of these patients died from perioperative complications, 2 days posttransplantation. Surgical management of patients with medically refractory biventricular heart failure remains challenging and associated with a high incidence of pump thrombosis. Best practice guidelines from experts' consensus are still needed to address this challenging population. PMID:26479465

  13. A flexible super-capacitive solid-state power supply for miniature implantable medical devices.

    PubMed

    Meng, Chuizhou; Gall, Oren Z; Irazoqui, Pedro P

    2013-12-01

    We present a high-energy local power supply based on a flexible and solid-state supercapacitor for miniature wireless implantable medical devices. Wireless radio-frequency (RF) powering recharges the supercapacitor through an antenna with an RF rectifier. A power management circuit for the super-capacitive system includes a boost converter to increase the breakdown voltage required for powering device circuits, and a parallel conventional capacitor as an intermediate power source to deliver current spikes during high current transients (e.g., wireless data transmission). The supercapacitor has an extremely high area capacitance of ~1.3 mF/mm(2), and is in the novel form of a 100 μm-thick thin film with the merit of mechanical flexibility and a tailorable size down to 1 mm(2) to meet various clinical dimension requirements. We experimentally demonstrate that after fully recharging the capacitor with an external RF powering source, the supercapacitor-based local power supply runs a full system for electromyogram (EMG) recording that consumes ~670 μW with wireless-data-transmission functionality for a period of ~1 s in the absence of additional RF powering. Since the quality of wireless powering for implantable devices is sensitive to the position of those devices within the RF electromagnetic field, this high-energy local power supply plays a crucial role in providing continuous and reliable power for medical device operations. PMID:23832644

  14. Current Approaches to Device Implantation in Pediatric and Congenital Heart Disease Patients

    PubMed Central

    Miller, Jacob R; Lancaster, Timothy S; Eghtesady, Pirooz

    2015-01-01

    Summary The pediatric ventricular assist device (VAD) has recently shown substantial improvements in survival as a bridge to heart transplant for patients with end-stage heart failure. Since that time, its use has become much more frequent. With increasing utilization, additional questions have arisen including patient selection, timing of VAD implantation and device selection. These challenges are amplified by the uniqueness of each patient, the recent abundance of literature surrounding VAD use, as well as the technological advancements in the devices themselves. Ideal strategies for device placement must be sought, for not only improved patient care, but for optimal resource utilization. Here, we review the most relevant literature to highlight some of the challenges facing the heart failure specialist, and any physician, who will care for a child with a VAD. PMID:25732410

  15. A cranial window imaging method for monitoring vascular growth around chronically implanted micro-ECoG devices.

    PubMed

    Schendel, Amelia A; Thongpang, Sanitta; Brodnick, Sarah K; Richner, Thomas J; Lindevig, Bradley D B; Krugner-Higby, Lisa; Williams, Justin C

    2013-08-15

    Implantable neural micro-electrode arrays have the potential to restore lost sensory or motor function to many different areas of the body. However, the invasiveness of these implants often results in scar tissue formation, which can have detrimental effects on recorded signal quality and longevity. Traditional histological techniques can be employed to study the tissue reaction to implanted micro-electrode arrays, but these techniques require removal of the brain from the skull, often causing damage to the meninges and cortical surface. This is especially unfavorable when studying the tissue response to electrode arrays such as the micro-electrocorticography (micro-ECoG) device, which sits on the surface of the cerebral cortex. In order to better understand the biological changes occurring around these types of devices, a cranial window implantation scheme has been developed, through which the tissue response can be studied in vivo over the entire implantation period. Rats were implanted with epidural micro-ECoG arrays, over which glass coverslips were placed and sealed to the skull, creating cranial windows. Vascular growth around the devices was monitored for one month after implantation. It was found that blood vessels grew through holes in the micro-ECoG substrate, spreading over the top of the device. Micro-hematomas were observed at varying time points after device implantation in every animal, and tissue growth between the micro-ECoG array and the window occurred in several cases. Use of the cranial window imaging technique with these devices enabled the observation of tissue changes that would normally go unnoticed with a standard device implantation scheme. PMID:23769960

  16. Mechanical Reliability of Devices Subdermally Implanted into the Young of Long-Lived and Endangered Wildlife

    NASA Astrophysics Data System (ADS)

    Hori, Bryan; Petrell, Royann J.; Fernlund, Goran; Trites, Andrew

    2012-09-01

    Service data does not exist for the strength of enclosures for subdermally implanted biotelemetry devices intended for young wild animals. Developing adequate tests especially for implants intended for endangered species is difficult due to the very limited availability of live animals and cadaverous tissue, ethical concerns about using them, and high enclosure costs. In this research, these limitations were overcome by taking a conservative approach to design and testing. Reliability tests were developed and performed to establish the likelihood that a thin subdermally and cranially implanted alumina enclosure would fail due to typical external forces related to diving, fights, and falls over the expected 30-year life time of sea lions. Cyclic fatigue tests indicative of deep dives performed out of tissue and at the 90% reliability level indicated no failure after 70,000 stress cycles at stresses of approximately 15 MPa; dynamic fatigue tests indicated a 5% probability of failure at 250 MPa; and puncture tests indicative of fight bites showed a 5% probability of failure at 1500 N. These values were far outside of what the animals might expect to encounter in real life. On the other hand, the response of the enclosure to impact outside of the tissue was failure at a mean energy level of 6.7 J. Modeling results predict that head impacts due to trampling by fighting sea lion males and falls over 1 m onto a rocky ledge typical of haul out environments would likely fracture an infant's head as well as the implant. The device can be implanted under an impact absorbing 1 cm blubber layer for extra protection. More service data for enclosures can be made more available despite limited availability of test animals if a conservative approach to testing is taken.

  17. Usefulness of Sonication of Cardiovascular Implantable Electronic Devices to Enhance Microbial Detection

    PubMed Central

    Nagpal, Avish; Patel, Robin; Greenwood-Quaintance, Kerryl E.; Baddour, Larry M.; Lynch, David T.; Lahr, Brian D.; Maleszewski, Joseph J.; Friedman, Paul A.; Hayes, David L.; Sohail, M. Rizwan

    2015-01-01

    The cardiovascular implantable electronic device (CIED) infection rate is rising disproportionately to the rate of device implantation. Identification of microorganisms that cause CIED infections is not always achieved using present laboratory techniques. We conducted a prospective study to determine whether device vortexing-sonication followed by culture of the resulting sonicate fluid would enhance microbial detection compared with traditional swab or pocket tissue cultures. Forty-two subjects with noninfected and 35 with infected CIEDs were prospectively enrolled over 12 months. One swab each from the device pocket and device surface, pocket tissue, and the CIED were collected from each patient. Swabs and tissues were cultured using routine methods. The CIED was processed in Ringer’s solution using vortexing-sonication and the resultant fluid semiquantitatively cultured. Tissue and swab growth was considered significant when colonies grew on ≥2 quadrants of the culture plate and device was considered significant when ≥20 colonies were isolated from 10 ml of sonicate fluid. In noninfected group, 5% of sonicate fluids yielded significant bacterial growth, compared with 5% of tissue cultures (p = 1.00) and 2% of both pocket and device swab cultures (p = 0.317 each). In infected group, significant bacterial growth was observed in 54% of sonicate fluids, significantly greater than the sensitivities of pocket swab (20%, p = 0.001), device swab (9%, p <0.001), or tissue (9%, p <0.001) culture. In conclusion, vortexing-sonication of CIEDs with semiquantitative culture of the resultant sonicate fluid results in a significant increase in the sensitivity of culture results, compared with swab or tissue cultures. PMID:25779615

  18. [Comparative test on puncture coring of two different needles used with the implantable drug-supplying device].

    PubMed

    Wan, Min; Wu, Ping; Song, Jinzi; Yu, Xin; Mou, Pengtao

    2010-11-01

    A comparison test on the number of puncture coring is conducted using the normal needle and the Huber needle in the injection area of the implantable drug-supplying device separately. The result indicates that the number of coring using the Huber needle is much less than that using the normal needle during the puncturing. So it is suggested to popularize the Huber needle in the drug transfusion of the implantable drug-supplying device. PMID:21360986

  19. Constraining OCT with Knowledge of Device Design Enables High Accuracy Hemodynamic Assessment of Endovascular Implants

    PubMed Central

    Brown, Jonathan; Lopes, Augusto C.; Kunio, Mie; Kolachalama, Vijaya B.; Edelman, Elazer R.

    2016-01-01

    Background Stacking cross-sectional intravascular images permits three-dimensional rendering of endovascular implants, yet introduces between-frame uncertainties that limit characterization of device placement and the hemodynamic microenvironment. In a porcine coronary stent model, we demonstrate enhanced OCT reconstruction with preservation of between-frame features through fusion with angiography and a priori knowledge of stent design. Methods and Results Strut positions were extracted from sequential OCT frames. Reconstruction with standard interpolation generated discontinuous stent structures. By computationally constraining interpolation to known stent skeletons fitted to 3D ‘clouds’ of OCT-Angio-derived struts, implant anatomy was resolved, accurately rendering features from implant diameter and curvature (n = 1 vessels, r2 = 0.91, 0.90, respectively) to individual strut-wall configurations (average displacement error ~15 μm). This framework facilitated hemodynamic simulation (n = 1 vessel), showing the critical importance of accurate anatomic rendering in characterizing both quantitative and basic qualitative flow patterns. Discontinuities with standard approaches systematically introduced noise and bias, poorly capturing regional flow effects. In contrast, the enhanced method preserved multi-scale (local strut to regional stent) flow interactions, demonstrating the impact of regional contexts in defining the hemodynamic consequence of local deployment errors. Conclusion Fusion of planar angiography and knowledge of device design permits enhanced OCT image analysis of in situ tissue-device interactions. Given emerging interests in simulation-derived hemodynamic assessment as surrogate measures of biological risk, such fused modalities offer a new window into patient-specific implant environments. PMID:26906566

  20. Implantation of venous access devices under local anesthesia: patients’ satisfaction with oral lorazepam

    PubMed Central

    Chang, De-Hua; Hiss, Sonja; Herich, Lena; Becker, Ingrid; Mammadov, Kamal; Franke, Mareike; Mpotsaris, Anastasios; Kleinert, Robert; Persigehl, Thorsten; Maintz, David; Bangard, Christopher

    2015-01-01

    Objective The aim of the study reported here was to evaluate patients’ satisfaction with implantation of venous access devices under local anesthesia (LA) with and without additional oral sedation. Materials and methods A total of 77 patients were enrolled in the prospective descriptive study over a period of 6 months. Subcutaneous implantable venous access devices through the subclavian vein were routinely implanted under LA. Patients were offered an additional oral sedative (lorazepam) before each procedure. The level of anxiety/tension, the intensity of pain, and patients’ satisfaction were evaluated before and immediately after the procedure using a visual analog scale (ranging from 0 to 10) with a standardized questionnaire. Results Patients’ satisfaction with the procedure was high (mean: 1.3±2.0) with no significant difference between the group with premedication and the group with LA alone (P=0.54). However, seven out of 30 patients (23.3%) in the group that received premedication would not undergo the same procedure without general anesthesia. There was no significant influence of lorazepam on the intensity of pain (P=0.88). In 12 out of 30 patients (40%) in the premedication group, the level of tension was higher than 5 on the visual analog scale during the procedure. In 21 out of 77 patients (27.3%), the estimate of the level of tension differed between the interventionist and the patient by 3 or more points in 21 out of 77 patients (27.3%). Conclusion Overall patient satisfaction is high for implantation of venous access devices under LA. A combination of LA with lorazepam administered orally might not be adequate for patients with a high level of anxiety and tension. The level of tension is often underestimated by the interventionist. Pre-procedural standardized questionnaires could be used to identify patients for whom a gradual approach of individualized sedation may be more effective. PMID:26185424

  1. Inductive coupling links for lowest misalignment effects in transcutaneous implanted devices.

    PubMed

    Abbas, Saad Mutashar; Hannan, Mahammad A; Samad, Salina A; Hussain, Aini

    2014-06-01

    Use of transcutaneous inductive links is a widely known method for the wireless powering of bio-implanted devices such as implanted microsystems. The design of the coil for inductive links is generally not optimal. In this study, inductive links were used on the basis of the small loop antenna theory to reduce the effects of lateral coil misalignments on the biological human tissue model at 13.56 MHz. The tissue, which measures 60 mm×70 mm×5 mm, separates the reader and the implanted coils. The aligned coils and the lateral misalignment coils were investigated in different parametric x-distance misalignments. The optimal coil layout was developed on the basis of the layout rules presented in previous studies. Results show that the gain around the coils, which were separated by wet and dry skin, was constant and confirmed the omnidirectional radiation pattern even though the lateral misalignment between coils was smaller or greater than the implanted coil radius. This misalignment can be <4 mm or >6 mm up to 8 mm. Moreover, coil misalignments and skin condition do not affect the efficient performance of the coil. PMID:24445231

  2. A phone-assistive device based on Bluetooth technology for cochlear implant users.

    PubMed

    Qian, Haifeng; Loizou, Philipos C; Dorman, Michael F

    2003-09-01

    Hearing-impaired people, and particularly hearing-aid and cochlear-implant users, often have difficulty communicating over the telephone. The intelligibility of telephone speech is considerably lower than the intelligibility of face-to-face speech. This is partly because of lack of visual cues, limited telephone bandwidth, and background noise. In addition, cellphones may cause interference with the hearing aid or cochlear implant. To address these problems that hearing-impaired people experience with telephones, this paper proposes a wireless phone adapter that can be used to route the audio signal directly to the hearing aid or cochlear implant processor. This adapter is based on Bluetooth technology. The favorable features of this new wireless technology make the adapter superior to traditional assistive listening devices. A hardware prototype was built and software programs were written to implement the headset profile in the Bluetooth specification. Three cochlear implant users were tested with the proposed phone-adapter and reported good speech quality. PMID:14518792

  3. Dental management of a patient fitted with subcutaneous Implantable Cardioverter Defibrillator device and concomitant warfarin treatment

    PubMed Central

    Shah, Altaf Hussain; Khalil, Hesham Saleh; Kola, Mohammed Zaheer

    2015-01-01

    Automated Implantable Cardioverter Defibrillators (AICD), simply known as an Implantable Cardioverter Defibrillator (ICD), has been used in patients for more than 30 years. An Implantable Cardioverter Defibrillator (ICD) is a small battery-powered electrical impulse generator that is implanted in patients who are at a risk of sudden cardiac death due to ventricular fibrillation, ventricular tachycardia or any such related event. Typically, patients with these types of occurrences are on anticoagulant therapy. The desired International Normalized Ratio (INR) for these patients is in the range of 2–3 to prevent any subsequent cardiac event. These patients possess a challenge to the dentist in many ways, especially during oral surgical procedures, and these challenges include risk of sudden death, control of post-operative bleeding and pain. This article presents the dental management of a 60 year-old person with an ICD and concomitant anticoagulant therapy. The patient was on multiple medications and was treated for a grossly neglected mouth with multiple carious root stumps. This case report outlines the important issues in managing patients fitted with an ICD device and at a risk of sudden cardiac death. PMID:26236132

  4. Implantable Port Devices, Complications and outcome in Pediatric Cancer, a Retrospective Study

    PubMed Central

    Esfahani, H; Ghorbanpor, M; Tanasan, A

    2016-01-01

    Background Peripheral blood vessels, due to availability are used for many years in cancer patients, however in patients with potentially harmful drugs to skin (vesicant drugs) or difficult accessibility to vessels, the use of implantable port (totally implantable venous access port-TIVAP) devices with central vascular access are important. Materials and Methods In this retrospective study, 85 pediatric cancer patients younger than 16 years, with TIVAP implantation, were followed for their complications and outcome. In addition to demographic data, patients’ port complications were assessed and compared with published articles. Results Mean days of implanted port usage were 531 ± 358 days in all patients. This period was 287 ±194 days in complicated patients. Complications included as infection (tunnel infection and catheter related blood-stream infection), malfunction and thrombosis, skin erosion, tube avulsion, and tube adhesion to the adjacent vessels were seen in 30.6% of patients. Conclusion According to the published data and this experience, the most common complications in TIVAP are infection and catheter malfunction. It is important to notice that in order to prolong its efficacious life, effective sterilization methods, prevention of clot formation and trauma, are the most useful measures. PMID:27222696

  5. Relationship of Tricuspid Repair at the time of Left Ventricular Assist Device Implantation and Survival

    PubMed Central

    Brewer, Robert J.; Cabrera, Rafael; El-Atrache, Mazen; Zafar, Amna; Hrobowski, Tara N.; Nemeh, Hassan M.; Selektor, Yelena; Paone, Gaetano; Williams, Celeste T.; Velez, Mauricio; Tita, Cristina; Morgan, Jeffrey A.; Lanfear, David E.

    2015-01-01

    Purpose Tricuspid regurgitation contributes to right ventricular failure (RVF) and is associated with worse clinical outcomes in patients undergoing Left Ventricular Assist Device (LVAD). However, whether tricuspid valve repair (TVR) at the time of LVAD implantation improves outcomes is not clear. Methods We identified all patients undergoing initial implantation of a long-term continuous flow LVAD at our institution from 3/2006 to 8/2011. We assessed the impact of TVR on survival and incidence of RVF using Kaplan-Meier curves and proportional hazards regression adjusted for age, gender, baseline tricuspid regurgitation, RV function, MELD score, albumin, and indication (bridge vs. destination). Results A total of 101 patients were included in the analysis, of which 14 patients underwent TVR concomitant LVAD. All TVR patients had moderate or severe baseline regurgitation. Crude survival was not different between groups. In multivariable models adjusted for confounding factors, TVR showed a significant association with improved survival (HR=0.1, p=0.049). Adjusted models showed no difference in RVF. Conclusions In this cohort of patients TVR at the time of LVAD implantation appears associated with better survival. Additional larger studies are needed to verify the effect of TVR at the time of LVAD implantation, and whether it should be utilized more frequently. PMID:25450319

  6. Blood Product Utilization with Left Ventricular Assist Device Implantation: A Decade of Statewide Data.

    PubMed

    Quader, Mohammed; LaPar, Damien J; Wolfe, Luke; Ailawadi, Gorav; Rich, Jeffrey; Speir, Alan; Fonner, Clifford; Kasirajan, Vigneshwar

    2016-01-01

    Blood transfusion rates with cardiac surgery over time have decreased, this trend has not been examined for patients undergoing left ventricular assist device (LVAD) implantation. We investigated blood transfusion trends with LVAD implantation in a statewide database. Between July 2004 and June 2014, 666 LVADs were implanted (age 54.5 ± 12.6 years. 77% men). Reoperation for bleeding was required in 22% of cases. Postoperative mortality was 13.2%. Over the decade, use of any blood products with LVAD surgery by year ranged from 83% to 100% (92 ± 5.3%). Intraoperative and postoperative blood products use was 71.8% and 73%, respectively. Only 7.4% of patients did not receive any blood products. Blood transfusion during surgery consisted of plasma (60%), platelets (56%), red blood cells (RBCs) (44.3%), and cryoprecipitate (32%), whereas after surgery RBC use was more frequent (68%). Compared with the initial 5 years (2005-2009), the units of blood transfused in the second 5 years (2010-2014) were significantly less, 21 ± 23 units vs. 16.6 ± 20.5 units, p = 0.0038. By multivariable analysis, preoperative factors predictive of blood transfusion are lower hematocrit, lower BMI, reoperative surgery, requirement for intraaortic balloon pump (IABP), and nonelective surgery. Blood transfusion with LVAD implantation remains very high. However, the amount of blood product transfused has decreased in the last 5 years. PMID:26809087

  7. Corrosion of silicon integrated circuits and lifetime predictions in implantable electronic devices.

    PubMed

    Vanhoestenberghe, A; Donaldson, N

    2013-06-01

    Corrosion is a prime concern for active implantable devices. In this paper we review the principles underlying the concepts of hermetic packages and encapsulation, used to protect implanted electronics, some of which remain widely overlooked. We discuss how technological advances have created a need to update the way we evaluate the suitability of both protection methods. We demonstrate how lifetime predictability is lost for very small hermetic packages and introduce a single parameter to compare different packages, with an equation to calculate the minimum sensitivity required from a test method to guarantee a given lifetime. In the second part of this paper, we review the literature on the corrosion of encapsulated integrated circuits (ICs) and, following a new analysis of published data, we propose an equation for the pre-corrosion lifetime of implanted ICs, and discuss the influence of the temperature, relative humidity, encapsulation and field-strength. As any new protection will be tested under accelerated conditions, we demonstrate the sensitivity of acceleration factors to some inaccurately known parameters. These results are relevant for any application of electronics working in a moist environment. Our comparison of encapsulation and hermetic packages suggests that both concepts may be suitable for future implants. PMID:23685410

  8. Speech Intelligibility of Pediatric Cochlear Implant Recipients With 7 Years of Device Experience

    PubMed Central

    Peng, Shu-Chen; Spencer, Linda J.; Tomblin, J. Bruce

    2011-01-01

    Speech intelligibility of 24 prelingually deaf pediatric cochlear implant (CI) recipients with 84 months of device experience was investigated. Each CI participant's speech samples were judged by a panel of 3 listeners. Intelligibility scores were calculated as the average of the 3 listeners' responses. The average write-down intelligibility score was 71.54% (SD = 29.89), and the average rating-scale intelligibility score was 3.03 points (SD = 1.01). Write-down and rating-scale intelligibility scores were highly correlated (r = .91, p < .001). Linear regression analyses revealed that both age at implantation and different speech-coding strategies contribute to the variability of CI participants' speech intelligibility. Implantation at a younger age and the use of the spectral-peak speech-coding strategy yielded higher intelligibility scores than implantation at an older age and the use of the multipeak speech-coding strategy. These results serve as indices for clinical applications when long-term advancements in spoken-language development are considered for pediatric CI recipients. PMID:15842006

  9. [Remote monitoring for follow-up of patients with implantable cardiac devices].

    PubMed

    Oliveira, Mário; Silva Cunha, Pedro; da Silva, Nogueira

    2013-03-01

    With a widening of indications for cardiac devices, especially in view of the clinical benefits of implantable cardioverter-defibrillators and cardiac resynchronization therapy, the number of patients with such devices is growing steadily. However, the resources required, and the need for long-term regular interrogation in dedicated clinics, represent a significant burden for already overstretched electrophysiology teams and hospital services. Remote telemonitoring is increasingly used for such follow-up, as it is a safe and effective alternative to conventional follow-up programs in outpatient clinics. This technology has been shown to be technically reliable, enabling early identification of device malfunction, arrhythmic events and heart failure decompensation, while reducing the risk of under-reporting, the number of outpatient clinic visits and hospitalizations due to cardiac events, and healthcare costs. Further studies are needed to determine how best to implement this new technology in a cost-effective manner, and what new legislation governing the use of remote monitoring in clinical practice may be required. In this article, we describe current systems, review the technical and clinical evidence in the literature regarding remote monitoring of implantable cardiac devices, and expand on outstanding questions. PMID:23415739

  10. An implantable active-targeting micelle-in-nanofiber device for efficient and safe cancer therapy.

    PubMed

    Yang, Guang; Wang, Jie; Wang, Yi; Li, Long; Guo, Xing; Zhou, Shaobing

    2015-02-24

    Nanocarriers have attracted broad attention in cancer therapy because of their ability to carry drugs preferentially into cancer tissue, but their application is still limited due to the systemic toxicity and low delivery efficacy of intravenously delivered chemotherapeutics. In this study, we develop a localized drug delivery device with combination of an active-targeting micellar system and implantable polymeric nanofibers. This device is achieved first by the formation of hydrophobic doxorubicin (Dox)-encapsulated active-targeting micelles assembled from a folate-conjugated PCL-PEG copolymer. Then, fabrication of the core-shell polymeric nanofibers is achieved with coaxial electrospinning in which the core region consists of a mixture of poly(vinyl alcohol) and the micelles and the outer shell layer consists of cross-linked gelatin. In contrast to the systematic administration of therapeutics via repeatedly intravenous injections of micelles, this implantable device has these capacities of greatly reducing the drug dose, the frequency of administration and side effect of chemotherapeutic agents while maintaining highly therapeutic efficacy against artificial solid tumors. This micelle-based nanofiber device can be developed toward the next generation of nanomedicine for efficient and safe cancer therapy. PMID:25602381