Sample records for implantable devices current

  1. Implantable electronic medical devices

    CERN Document Server

    Fitzpatrick, Dennis


    Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

  2. Current Trends in Implantable Left Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Jens Garbade


    Full Text Available 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.

  3. Nanomaterials and synergistic low-intensity direct current (LIDC) stimulation technology for orthopedic implantable medical devices. (United States)

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


    Nanomaterials play a significant role in biomedical research and applications because of their unique biological, mechanical, and electrical properties. In recent years, they have been utilized to improve the functionality and reliability of a wide range of implantable medical devices ranging from well-established orthopedic 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 orthopedic 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 orthopedic 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 article 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.

  4. Implantable Medical Devices (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Implantable Medical Devices Updated:Sep 16,2016 For Rhythm Control ... a Heart Attack Introduction Medications Surgical Procedures Implantable Medical Devices • Life After a Heart Attack • Heart Attack ...

  5. Statistical design of unicompartmental tibial implants and comparison with current devices. (United States)

    Fitzpatrick, Clare; FitzPatrick, David; Lee, Jordan; Auger, Daniel


    This study defines, in the context of unicompartmental tibial replacement, the medial and lateral resection surfaces of 34 tibiae at a depth of 5 mm below the articular surface. Using statistical techniques, three optimal theoretical size and shape unicompartmental tibial designs, (i) implants of consistent shape in varying size (ii) implants symmetric about their ML axis; (iii) implants of varying size and shape, were constructed to best fit the population. Two currently available commercial implants, the Preservation Uni System (DePuy Orthopaedics Inc., Warsaw, IN) and the LCS Uni System (DePuy Orthopaedics Inc., Warsaw, IN), which were similar to types (i) and (ii) respectively, of the theoretical designs, were also included in the analysis. All implants, commercial and theoretical, were compared with one another to determine which implant designs gave the best cortical bone coverage on both the medial and lateral compartments. Of the commercial implants, the type (i) design fitted best, with an average of 67% of the implant edge lying on cortical bone, compared with 57% for the type (ii) implants. Of the theoretical implants, 72%, 67% and 76% of the implant edge lay on cortical bone for types (i), (ii) and (iii) designs, respectively, indicating that there is room for improvement in current implant designs to achieve better coverage in both the medial and lateral compartments combined.

  6. Osseointegration of metallic devices: current trends based on implant hardware design. (United States)

    Coelho, Paulo G; Jimbo, Ryo


    Osseointegration of metallic devices has been one of the most successful treatments in rehabilitative dentistry and medicine over the past five decades. While highly successful, the quest for designing surgical instrumentation and associated implantable devices that hastens osseointegration has been perpetual and has often been approached as single variable preclinical investigations. The present manuscript presents how the interplay between surgical instrumentation and device macrogeometry not only plays a key role on both early and delayed stages of osseointegration, but may also be key in how efficient smaller length scale designing (at the micrometer and nanometer scale levels) may be in hastening early stages of osseointegration. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Complications after cardiac implantable electronic device implantations

    DEFF Research Database (Denmark)

    Kirkfeldt, Rikke Esberg; Johansen, Jens Brock; Nohr, Ellen Aagaard;


    Complications after cardiac implantable electronic device (CIED) treatment, including permanent pacemakers (PMs), cardiac resynchronization therapy devices with defibrillators (CRT-Ds) or without (CRT-Ps), and implantable cardioverter defibrillators (ICDs), are associated with increased patient...

  8. The mismatch between patient life expectancy and the service life of implantable devices in current cardioverter-defibrillator therapy: a call for larger device batteries. (United States)

    Neuzner, Jörg


    In 2005, Bob Hauser published a paper in the Journal of the American College of Cardiology entitled "The growing mismatch between patient longevity and the service life of Implantable Cardioverter-Defibrillators". Now, nearly a decade later, I would like to perform a second look on the problem of a mismatching between ICD device service life and the survival of ICD recipients. Since 2005, the demographics of the ICD population has changed significantly. Primary prevention has become the dominant indication in defibrillator therapy and device implantation is indicated more and more in earlier stages of cardiac diseases. In former larger scale ICD trials, the patient average 5-year survival probability was in a range of 68-71%; in newer CRT-D trials in a range of 72-88%. Due to a progressively widened ICD indication and implantation preferentially performed in patients with better life expectancy, the problem of inadequate device service life is of growing importance. The early days of defibrillator therapy started with a generator volume of 145 ccm and a device service life life were similar challenges for the technicians. Today, we have reached a formerly unexpected extent of device miniaturization. However, technologic improvements were often preferentially translated in further device miniaturization and not in prolonging device service life. In his analysis, Bob Hauser reported a prolonged device service life of 2.3 years in ICD models with a larger battery capacity of 0.54 up to 0.69 Ah. Between 2008 and 2014, several studies had been published on the problem of ICD longevity in clinical scenarios. These analyses included "older" and currently used single chamber, dual chamber and CRT devices. The reported average 5-year device service life ranged from 0 to 75%. Assuming today technology, larger battery capacities will only result in minimal increase in device volume. Selected ICD patients may further benefit from device miniaturization-but the vast majority

  9. Implantable biomedical devices on bioresorbable substrates (United States)

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


    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.

  10. Longevity of implantable cardioverter-defibrillators for cardiac resynchronization therapy in current clinical practice: an analysis according to influencing factors, device generation, and manufacturer. (United States)

    Landolina, Maurizio; Curnis, Antonio; Morani, Giovanni; Vado, Antonello; Ammendola, Ernesto; D'onofrio, Antonio; Stabile, Giuseppe; Crosato, Martino; Petracci, Barbara; Ceriotti, Carlo; Bontempi, Luca; Morosato, Martina; Ballari, Gian Paolo; Gasparini, Maurizio


    Device replacement at the time of battery depletion of implantable cardioverter-defibrillators (ICDs) may carry a considerable risk of complications and engenders costs for healthcare systems. Therefore, ICD device longevity is extremely important both from a clinical and economic standpoint. Cardiac resynchronization therapy defibrillators (CRT-D) battery longevity is shorter than ICDs. We determined the rate of replacements for battery depletion and we identified possible determinants of early depletion in a series of patients who had undergone implantation of CRT-D devices. We retrieved data on 1726 consecutive CRT-D systems implanted from January 2008 to March 2010 in nine centres. Five years after a successful CRT-D implantation procedure, 46% of devices were replaced due to battery depletion. The time to device replacement for battery depletion differed considerably among currently available CRT-D systems from different manufacturers, with rates of batteries still in service at 5 years ranging from 52 to 88% (log-rank test, P < 0.001). Left ventricular lead output and unipolar pacing configuration were independent determinants of early depletion [hazard ratio (HR): 1.96; 95% 95% confidence interval (CI): 1.57-2.46; P < 0.001 and HR: 1.58, 95% CI: 1.25-2.01; P < 0.001, respectively]. The implantation of a recent-generation device (HR: 0.57; 95% CI: 0.45-0.72; P < 0.001), the battery chemistry and the CRT-D manufacturer (HR: 0.64; 95% CI: 0.47-0.89; P = 0.008) were additional factors associated with replacement for battery depletion. The device longevity at 5 years was 54%. High left ventricular lead output and unipolar pacing configuration were associated with early battery depletion, while recent-generation CRT-Ds displayed better longevity. Significant differences emerged among currently available CRT-D systems from different manufacturers. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

  11. Contraceptive implants: current perspectives

    Directory of Open Access Journals (Sweden)

    Rowlands S


    Full Text Available Sam Rowlands,1,2 Stephen Searle3 1Centre of Postgraduate Medical Research and Education, School of Health and Social Care, Bournemouth University, Bournemouth, United Kingdom; 2Dorset HealthCare, Bournemouth, United Kingdom; 3Sexual Health Services, Chesterfield, United KingdomAbstract: Progestin-only contraceptive implants are a highly cost-effective form of long-acting reversible contraception. They are the most effective reversible contraceptives and are of a similar effectiveness to sterilization. Pregnancies are rare in women using this method of contraception, and those that do occur must be fully investigated, with an ultrasound scan of the arm and serum etonogestrel level if the implant cannot be located. There are very few contraindications to use of implants, and they have an excellent safety profile. Both acceptability and continuation with the method are high. Noncontraceptive benefits include improvements in dysmenorrhea, ovulatory pain, and endometriosis. Problematic bleeding is a relatively common adverse effect that must be covered in preinsertion information-giving and supported adequately if it occurs. Recognized training for both insertion and removal should be undertaken. Care needs to be taken at both insertion and removal to avoid neurovascular injury. Implants should always be palpable; if they are not, noninsertion should be assumed until disproven. Etonogestrel implants are now radiopaque, which aids localization. Anticipated difficult removals should be performed by specially trained experts. Keywords: contraceptive, subdermal implant, etonogestrel, levonorgestrel, progestin-only, long-acting reversible contraception

  12. Modulation Techniques for Biomedical Implanted Devices and Their Challenges

    Directory of Open Access Journals (Sweden)

    Salina A. Samad


    Full Text Available 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.

  13. Current status of the gyro centrifugal blood pump--development of the permanently implantable centrifugal blood pump as a biventricular assist device (NEDO project). (United States)

    Nosé, Yukihiko; Furukawa, Kojiro


    The New Energy and Industrial Technology Development Organization (NEDO) project was started in 1995. The goal is the development of a multipurpose, totally implantable biventricular assist device (BVAD) that can be used for any patient who suffers from severe heart failure. Our C1E3 (two-week pump) centrifugal pump, called the Gyro pump, has three design characteristics: a magnetic coupling and double pivot bearing system, an eccentric inlet port, and secondary vanes on the bottom of the impeller. The pump was miniaturized. The C1E3 evolved into the NEDO PI-601, a totally implantable centrifugal pump for BVAD. The current NEDO PI-710 pump (five-year pump) system includes a centrifugal pump with pivot bearings, a hydraulically-levitated impeller, an rpm-controlled miniaturized actuator (all-in-one actuator plus controller), an emergency clamp on the left outflow, and a Frank-Starling-type flow control. The final mass production model is now finalized, and the final animal study and two-year endurance studies are ongoing.

  14. Left ventricular assist device implantation strategies and outcomes


    Smith, LaVone A.; Yarboro, Leora T; Kennedy, Jamie L. W.


    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 surgerie...

  15. Titania nanotube arrays: Interfaces for implantable devices (United States)

    Smith, Barbara Symie

    For the 8--10% of Americans (20--25 million people) that have implanted biomedical devices, biomaterial failure and the need for revision surgery are critical concerns. The major causes for failure in implantable biomedical devices promoting a need for re-implantation and revision surgery include thrombosis, post-operative infection, immune driven fibrosis and biomechanical failure. The successful integration of long-term implantable devices is highly dependent on the early events of tissue/biomaterial interaction, promoting either implant rejection or a wound healing response (extracellular matrix production and vasculature). Favorable interactions between the implant surface and the respective tissue are critical for the long-term success of any implantable device. Recent studies have shown that material surfaces which mimic the natural physiological hierarchy of in vivo tissue may provide a possible solution for enhancing biomaterial integration, thus preventing infection and biomaterial rejection. Titania nanotube arrays, fabricated using a simple anodization technique, provide a template capable of promoting altered cellular functionality at a hierarchy similar to that of natural tissue. This work focuses on the fabrication of immobilized, vertically oriented and highly uniform titania nanotube arrays to determine how this specific nano-architecture affects skin cell functionality, hemocompatibility, thrombogenicity and the immune response. The results in this work identify enhanced dermal matrix production, altered hemocompatibility, reduced thrombogenicity and a deterred immune response on titania nanotube arrays. This evidences promising implications with respect to the use of titania nanotube arrays as beneficial interfaces for the successful implantation of biomedical devices.

  16. Batteries used to Power Implantable Biomedical Devices (United States)

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


    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

  17. Batteries used to Power Implantable Biomedical Devices. (United States)

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


    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.

  18. 21 CFR 876.5270 - Implanted electrical urinary continence device. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted electrical urinary continence device... 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...

  19. Implantable rhythm devices and electromagnetic interference: myth or reality? (United States)

    Dyrda, Katia; Khairy, Paul


    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.

  20. Toward biomaterial-based implantable photonic devices (United States)

    Humar, Matjaž; Kwok, Sheldon J. J.; Choi, Myunghwan; Yetisen, Ali K.; Cho, Sangyeon; Yun, Seok-Hyun


    Optical technologies are essential for the rapid and efficient delivery of health care to patients. Efforts have begun to implement these technologies in miniature devices that are implantable in patients for continuous or chronic uses. In this review, we discuss guidelines for biomaterials suitable for use in vivo. Basic optical functions such as focusing, reflection, and diffraction have been realized with biopolymers. Biocompatible optical fibers can deliver sensing or therapeutic-inducing light into tissues and enable optical communications with implanted photonic devices. Wirelessly powered, light-emitting diodes (LEDs) and miniature lasers made of biocompatible materials may offer new approaches in optical sensing and therapy. Advances in biotechnologies, such as optogenetics, enable more sophisticated photonic devices with a high level of integration with neurological or physiological circuits. With further innovations and translational development, implantable photonic devices offer a pathway to improve health monitoring, diagnostics, and light-activated therapies.

  1. Advances in Microelectronics for Implantable Medical Devices

    Directory of Open Access Journals (Sweden)

    Andreas Demosthenous


    Full Text Available Implantable medical devices provide therapy to treat numerous health conditions as well as monitoring and diagnosis. Over the years, the development of these devices has seen remarkable progress thanks to tremendous advances in microelectronics, electrode technology, packaging and signal processing techniques. Many of today’s implantable devices use wireless technology to supply power and provide communication. There are many challenges when creating an implantable device. Issues such as reliable and fast bidirectional data communication, efficient power delivery to the implantable circuits, low noise and low power for the recording part of the system, and delivery of safe stimulation to avoid tissue and electrode damage are some of the challenges faced by the microelectronics circuit designer. This paper provides a review of advances in microelectronics over the last decade or so for implantable medical devices and systems. The focus is on neural recording and stimulation circuits suitable for fabrication in modern silicon process technologies and biotelemetry methods for power and data transfer, with particular emphasis on methods employing radio frequency inductive coupling. The paper concludes by highlighting some of the issues that will drive future research in the field.

  2. Current trends in dental implants


    Gaviria, Laura; Salcido, John Paul; Guda, Teja; Ong, Joo L.


    Tooth loss is very a very common problem; therefore, the use of dental implants is also a common practice. Although research on dental implant designs, materials and techniques has increased in the past few years and is expected to expand in the future, there is still a lot of work involved in the use of better biomaterials, implant design, surface modification and functionalization of surfaces to improve the long-term outcomes of the treatment. This paper provides a brief history and evoluti...

  3. Implantable Medical Devices; Networking Security Survey

    Directory of Open Access Journals (Sweden)

    Siamak Aram


    Full Text Available The industry of implantable medical devices (IMDs is constantly evolving, which is dictated by the pressing need to comprehensively address new challenges in the healthcare field. Accordingly, IMDs are becoming more and more sophisticated. Not long ago, the range of IMDs’ technical capacities was expanded, making it possible to establish Internet connection in case of necessity and/or emergency situation for the patient. At the same time, while the web connectivity of today’s implantable devices is rather advanced, the issue of equipping the IMDs with sufficiently strong security system remains unresolved. In fact, IMDs have relatively weak security mechanisms which render them vulnerable to cyber-attacks that compromise the quality of IMDs’ functionalities. This study revolves around the security deficiencies inherent to three types of sensor-based medical devices; biosensors, insulin pump systems and implantable cardioverter defibrillators. Manufacturers of these devices should take into consideration that security and effectiveness of the functionality of implants is highly dependent on the design. In this paper, we present a comprehensive study of IMDs’ architecture and specifically investigate their vulnerabilities at networking interface.

  4. [Design and application of implantable medical device information management system]. (United States)

    Cao, Shaoping; Yin, Chunguang; Zhao, Zhenying


    Through the establishment of implantable medical device information management system, with the aid of the regional joint sharing of resources, we further enhance the implantable medical device traceability management level, strengthen quality management, control of medical risk.

  5. Implantable photonic devices for improved medical treatments. (United States)

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


    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.

  6. Implantable photonic devices for improved medical treatments (United States)

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


    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.

  7. Cardiac device implantation in Fabry disease (United States)

    Sené, Thomas; Lidove, Olivier; Sebbah, Joel; Darondel, Jean-Marc; Picard, Hervé; Aaron, Laurent; Fain, Olivier; Zenone, Thierry; Joly, Dominique; Charron, Philippe; Ziza, Jean-Marc


    Abstract The incidence and predictive factors of arrhythmias and/or conduction abnormalities (ACAs) requiring cardiac device (CD) implantation are poorly characterized in Fabry disease (FD). The aim of our retrospective study was to determine the prevalence, incidence, and factors associated with ACA requiring CD implantation in a monocentric cohort of patients with confirmed FD who were followed up in a department of internal medicine and reference center for FD. Forty-nine patients (20M, 29F) were included. Nine patients (4M, 5F; 18%) had at least one episode of ACA leading to device therapy. Six patients (4M/2F) required a pacemaker (PM) for sinus node dysfunction (n = 4) or atrioventricular disease (n = 2). One female patient required an internal cardioverter-defibrillator (ICD) to prevent sudden cardiac death because of nonsustained ventricular tachycardia (nSVT). One female patient required PM-ICD for sinus node dysfunction and nSVT. One patient underwent CD implantation before the diagnosis of FD. The annual rate of CD implantation was estimated at 1.90 per 100 person years. On univariate analysis at the end of the follow-up period, the factors associated with ACAs requiring CD implantation were as follows: delayed diagnosis of FD, delayed initiation of enzyme replacement therapy, age at the last follow-up visit, and severe multiorgan phenotype (hypertrophic cardiomyopathy, chronic kidney disease, and/or sensorineural hearing loss). On multivariate analysis, age at diagnosis of FD and age at the last follow-up visit were independently associated with an increased risk of ACAs requiring CD (P sudden death in patients with FD, regular monitoring is mandatory, especially in patients with a late diagnosis of FD and/or with a severe phenotype. Regular Holter ECGs, therapeutic education of patients, and deliverance of an emergency card including a phenotype summary are crucial in the care of FD patients. Available guidelines for device therapy and the

  8. Cardiovascular implantable electronic devices: patient education, information and ethical issues. (United States)

    Manaouil, Cécile; Gignon, Maxime; Traulle, Sarah


    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.

  9. Current trends to measure implant stability. (United States)

    Swami, Vasanthi; Vijayaraghavan, Vasantha; Swami, Vinit


    Implant stability plays a critical role for successful osseointegration. Successful osseointegration is a prerequisite for functional dental implants. Continuous monitoring in an objective and qualitative manner is important to determine the status of implant stability. Implant stability is measured at two different stages: Primary and secondary. Primary stability comes from mechanical engagement with cortical bone. Secondary stability is developed from regeneration and remodeling of the bone and tissue around the implant after insertion and affected by the primary stability, bone formation and remodelling. The time of functional loading is dependent upon the implant stability. Historically the gold standard method to evaluate stability were microscopic or histologic analysis, radiographs, however due to invasiveness of these methods and related ethical issues various other methods have been proposed like cutting torque resistance, reverse torque analysis, model analysis etc. It is, therefore, of an utmost importance to be able to access implant stability at various time points and to project a long term prognosis for successful therapy. Therefore this review focuses on the currently available methods for evaluation of implant stability.

  10. Security for wireless implantable medical devices

    CERN Document Server

    Hei, Xiali


    In the treatment of chronic diseases, wireless Implantable Medical Devices (IMDs) are commonly used to communicate with an outside programmer (reader). Such communication raises serious security concerns, such as the ability for hackers to gain access to a patient's medical records. This brief provides an overview of such attacks and the new security challenges, defenses, design issues, modeling and performance evaluation in wireless IMDs.  While studying the vulnerabilities of IMDs and corresponding security defenses, the reader will also learn the methodologies and tools for designing securi

  11. Critical factors in the translation of improved antimicrobial strategies for medical implants and devices

    NARCIS (Netherlands)

    Grainger, David W.; van der Mei, Henny C.; Jutte, Paul C.; van den Dungen, Jan J. A. M.; Schultz, Marcus J.; van der Laan, Bernard F. A. M.; Zaat, Sebastian A. J.; Busscher, Henk J.


    Biomaterials-associated infection incidence represents an increasing clinical challenge as more people gain access to medical device technologies worldwide and microbial resistance to current approaches mounts. Few reported antimicrobial approaches to implanted biomaterials ever get commercialized f

  12. Security and privacy for implantable medical devices

    CERN Document Server

    Carrara, Sandro


     This book presents a systematic approach to analyzing the challenging engineering problems posed by the need for security and privacy in implantable medical devices (IMD).  It describes in detail new issues termed as lightweight security, due to the associated constraints on metrics such as available power, energy, computing ability, area, execution time, and memory requirements. Coverage includes vulnerabilities and defense across multiple levels, with basic abstractions of cryptographic services and primitives such as public key cryptography, block ciphers and digital signatures. Experts from engineering introduce to some IMD systems that have  recently been proposed and developed. Experts from Computer Security and Cryptography present new research, which shows vulnerabilities in existing IMDs and proposes solutions. Experts from Privacy Technology and Policy will discuss the societal, legal and ethical challenges surrounding IMD security as well as technological solutions that build on the latest in C...

  13. Transcutaneous optical power converter for implantable devices (United States)

    Tamura, Toshiyo; Shamsuddin, A. K. M.; Kawarada, Atsushi; Togawa, Tatsuo; Oberg, P. Ake


    An optical transcutaneous power converter has been developed for the power supply of implanted devices. It consists of a light source, optical fiber system and a photo detector. The light source is either a halogen lamp or continuous high-power laser diode which illuminated skin surface. The light penetrates through the skin to the solar cells. The preliminary experiments with a slice of tissue in between the light source and the solar cells showed that the power transfer efficiency was 40% in comparison to direct illumination of the solar cells. The maximum electric power obtained with a slice of tissue simulating the skin was about 8 mW at a laser diode run at a power of 100 mW. The electric power transferred is enough to supply low power consuming CMOS circuits.

  14. The cardiac implantable electronic device power source: evolution and revolution. (United States)

    Mond, Harry G; Freitag, Gary


    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. ©2014 Wiley Periodicals, Inc.

  15. Low Power Design for Future Wearable and Implantable Devices

    DEFF Research Database (Denmark)

    Lundager, Katrine; Zeinali, Behzad; Tohidi, Mohammad


    power provider for such devices. However, batteries have a fixed energy density, limited lifetime and chemical side effect plus the fact that the total size of the WID is dominated by the battery size. These issues make the design very challenging or even impossible. A promising solution is to design...... limit, which is a critical limit for further miniaturization to develop smaller and smarter wearable/implantable devices (WIDs), especially for multi-task continuous computing purposes. Developing smaller and smarter devices with more functionality requires larger batteries, which are currently the main......, the energy provided by each of these harvesting mechanisms is very limited and thus cannot be used for complex tasks. Therefore, a more comprehensive solution is the use of different harvesting mechanisms on a single platform providing enough energy for more complex tasks without the need of batteries...

  16. Low Power Design for Future Wearable and Implantable Devices

    Directory of Open Access Journals (Sweden)

    Katrine Lundager


    Full Text Available With the fast progress in miniaturization of sensors and advances in micromachinery systems, a gate has been opened to the researchers to develop extremely small wearable/implantable microsystems for different applications. However, these devices are reaching not to a physical limit but a power limit, which is a critical limit for further miniaturization to develop smaller and smarter wearable/implantable devices (WIDs, especially for multi-task continuous computing purposes. Developing smaller and smarter devices with more functionality requires larger batteries, which are currently the main power provider for such devices. However, batteries have a fixed energy density, limited lifetime and chemical side effect plus the fact that the total size of the WID is dominated by the battery size. These issues make the design very challenging or even impossible. A promising solution is to design batteryless WIDs scavenging energy from human or environment including but not limited to temperature variations through thermoelectric generator (TEG devices, body movement through Piezoelectric devices, solar energy through miniature solar cells, radio-frequency (RF harvesting through antenna etc. However, the energy provided by each of these harvesting mechanisms is very limited and thus cannot be used for complex tasks. Therefore, a more comprehensive solution is the use of different harvesting mechanisms on a single platform providing enough energy for more complex tasks without the need of batteries. In addition to this, complex tasks can be done by designing Integrated Circuits (ICs, as the main core and the most power consuming component of any WID, in an extremely low power mode by lowering the supply voltage utilizing low-voltage design techniques. Having the ICs operational at very low voltages, will enable designing battery-less WIDs for complex tasks, which will be discussed in details throughout this paper. In this paper, a path towards battery

  17. An implantable thermoresponsive drug delivery system based on Peltier device. (United States)

    Yang, Rongbing; Gorelov, Alexander V; Aldabbagh, Fawaz; Carroll, William M; Rochev, Yury


    Locally dropping the temperature in vivo is the main obstacle to the clinical use of a thermoresponsive drug delivery system. In this paper, a Peltier electronic element is incorporated with a thermoresponsive thin film based drug delivery system to form a new drug delivery device which can regulate the release of rhodamine B in a water environment at 37 °C. Various current signals are used to control the temperature of the cold side of the Peltier device and the volume of water on top of the Peltier device affects the change in temperature. The pulsatile on-demand release profile of the model drug is obtained by turning the current signal on and off. The work has shown that the 2600 mAh power source is enough to power this device for 1.3 h. Furthermore, the excessive heat will not cause thermal damage in the body as it will be dissipated by the thermoregulation of the human body. Therefore, this simple novel device can be implanted and should work well in vivo.

  18. Interference Between Cellular Telephones and Implantable Rhythm Devices: A Review on Recent Papers

    Directory of Open Access Journals (Sweden)

    Johnson Francis


    Full Text Available Background: Cardiac pacemakers and implantable defibrillators are potentially susceptible to electromagnetic interferences as they have complex circuitry for sensing and communication purposes. Cellular telephones being an important source of electromagnetic waves are likely to cause interference in the function of these devices. Methods: A systematic analysis of studies on interaction between cellular telephones and implantable devices was done using professional databases for literature. Related articles and references of relevant articles were also searched for suitable studies. Results: Fourteen studies on pacemakers and eight studies on implantable defibrillators were identified. No dangerous malfunction was found in any of the analyzed studies, but most of the studies noted interference with device function when the phone was operated very close to the device. Interference was minimally in those devices with built in feed-through filters for eliminating electromagnetic interference. Device programming and interrogation were the most susceptible phases of operation. Summary: Cellular phones are likely to interfere with implantable rhythm devices if operated in close proximity or during programming of the device. Patients with implanted devices can safely use cellular phones if they are not carried close to the implanted devices or operated near them. Carrying the cellular phones in the belt position, receiving calls in the ear opposite to the side of the implanted device and keeping the phone as far away as possible while dialing can be considered a safe practice. Interrogation of the devices should take place exclusively in areas where utilization of cellular phones is strictly prohibited. Studies on pacemakers published in the current decade have shown much lesser rates of interference, possibly due to improvement in device technology.

  19. Percutaneous Implantation of A Parachute Device For Treatment of Ischemic Heart Failure

    Energy Technology Data Exchange (ETDEWEB)

    Cilingiroglu, Mehmet, E-mail:; Rollefson, William A.; Mego, David


    Congestive heart failure (CHF) secondary to ischemic cardiomyopathy is associated with significant morbidity and mortality despite currently available medical therapy. The Parachute{sup TM} device is a novel left ventricular partitioning device that is delivered percutaneously in the left ventricle (LV) in patients with anteroapical regional wall motion abnormalities, dilated LV and systolic dysfunction after anterior myocardial infarction with favorable clinical and LV hemodynamic improvements post-implantation. Here, we do review the current literature and present a case of the Parachute device implantation.

  20. Surgical Templates for Dental Implant Positioning; Current ...

    African Journals Online (AJOL)

    applied scientifically based research techniques to develop an endosseous implant that forms ... KEYWORDS: Dental implants, surgical templates, surgical procedure, stent .... during the surgical stage for single implant therapy.[24] Afterward,.

  1. Anaesthesia for patients undergoing ventricular assist-device implantation. (United States)

    Feussner, Markus; Mukherjee, Chirojit; Garbade, Jens; Ender, Joerg


    In the last 10 years, implantation of ventricular-assist devices has become an interesting option as either bridge-to-transplantation or destination procedure for patients with end-stage congestive heart failure. In the future, the number of ventricular assist device implantations is expected to increase furthermore. In general, this patient cohort is associated with significant co-morbidities, for example, pulmonary hypertension, peripheral vascular disease and renal insufficiency. Anaesthetic management for implantation of ventricular assist devices can be challenging for cardiac anaesthesiologists. Even minor changes in their haemodynamics and physiological parameters can cause significant morbidity and mortality. Experience in haemodynamic monitoring including echocardiography and pharmacological management (use of inotropes, phosphodiesterase inhibitors and vasopressors) is a requirement. Particularly, the diagnosis and therapy of right-sided heart failure after implantation of left-ventricular assist devices should be addressed.

  2. [Radiotherapy and implantable medical device: example of infusion pumps]. (United States)

    Abrous-Anane, S; Benhassine, S; Lopez, S; Cristina, K; Mazeron, J-J


    Indication for radiotherapy is often questioned for patients equipped with implantable medical devices like infusion pumps as the radiation tolerance is poor or not known. We report here on the case of a patient who we treated with pelvic radiotherapy for cervical cancer and who had an infusion pump in iliac fossa. We conducted a series of tests on five identical pumps that insured that the treatment protocol is harmless to the implanted device.

  3. Radiographic appearances of uncommon paediatric implants and devices

    Energy Technology Data Exchange (ETDEWEB)

    Urquia, Arlen; Watson, Tom A.; Arthurs, Owen J. [Great Ormond Street Hospital NHS Foundation Trust, Department of Radiology, London (United Kingdom)


    As childhood survival of chronic illness improves, long-term implanted devices will be encountered more frequently in routine radiology. In our paediatric tertiary referral hospital, we have come across several types of implanted devices that were not confidently recognised or identified by front-line staff and were often only identified by discussion with the patient, family or clinical team. This pictorial review highlights the appearance of nonvascular devices on paediatric radiographs in order to help clinicians identify the most frequent complications and to improve awareness of these important devices. (orig.)

  4. Thin-film Rechargeable Lithium Batteries for Implantable Devices (United States)

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


    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.

  5. Thin-film rechargeable lithium batteries for implantable devices

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  6. Problems associated with direct-to-consumer advertising (DTCA) of restricted, implantable medical devices: should the current regulatory approach be changed? (United States)

    Patsner, Bruce


    Advertising and promotion of Food and Drug Administration (FDA)-approved medical products has been one of the most controversial and bitterly litigated areas in food and drug law in the U.S. for more than a decade. Hundreds of newspaper articles and dozens of law review articles have been written on the subject of the risks and benefits of direct to consumer advertising (DTCA) of medical products, but until very recently virtually all of this literature and commentary has focused exclusively on prescription and over-the-counter drugs. Even when FDA has sponsored public hearings to address the issue of DTCA of all medical products, as it did in 2005, review of the content of the speakers' presentations reveals that almost all of the subject matter, nearly all of the data, and the majority of comments concerned DTCA of drugs. Not a single law review article has ever been devoted exclusively to the subject of advertising and promotion of medical devices to consumers--until now.

  7. Occlusion on oral implants: current clinical guidelines. (United States)

    Koyano, K; Esaki, D


    Proper implant occlusion is essential for adequate oral function and the prevention of adverse consequences, such as implant overloading. Dental implants are thought to be more prone to occlusal overloading than natural teeth because of the loss of the periodontal ligament, which provides shock absorption and periodontal mechanoreceptors, which provide tactile sensitivity and proprioceptive motion feedback. Although many guidelines and theories on implant occlusion have been proposed, few have provided strong supportive evidence. Thus, we performed a narrative literature review to ascertain the influence of implant occlusion on the occurrence of complications of implant treatment and discuss the clinical considerations focused on the overloading factors at present. The search terms were 'dental implant', 'dental implantation', 'dental occlusion' and 'dental prosthesis'. The inclusion criteria were literature published in English up to September 2013. Randomised controlled trials (RCTs), prospective cohort studies and case-control studies with at least 20 cases and 12 months follow-up interval were included. Based on the selected literature, this review explores factors related to the implant prosthesis (cantilever, crown/implant ratio, premature contact, occlusal scheme, implant-abutment connection, splinting implants and tooth-implant connection) and other considerations, such as the number, diameter, length and angulation of implants. Over 700 abstracts were reviewed, from which more than 30 manuscripts were included. We found insufficient evidence to establish firm clinical guidelines for implant occlusion. To discuss the ideal occlusion for implants, further well-designed RCTs are required in the future.

  8. 78 FR 17940 - Certain Computerized Orthopedic Surgical Devices, Software, Implants, and Components Thereof... (United States)


    ... 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...

  9. New horizon for infection prevention technology and implantable device

    Directory of Open Access Journals (Sweden)

    Yusuke Kondo, MD, PhD


    Full Text Available 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.

  10. Complete removal of infected devices and simultaneous implantation of new devices for infective endocarditis after pacemaker implantation. (United States)

    Miura, Takuya; Inoue, Kazushige; Yokota, Takenori; Iwata, Takashi; Yoshitatsu, Masao


    Two cases of infective endocarditis after pacemaker implantation were reported. Complete removal of infected devices was performed under cardiopulmonary bypass, and simultaneous implantation of new devices was performed using epicardial leads and generator on the abdominal wall. The postoperative course was uneventful and recurrence was not recognized. These procedures may be suitable for the patients who depend on the pacemaker or who have repeat bacteremia with other infectious disease or conditions.

  11. Implantation of left ventricular assist device complicated by undiagnosed thrombophilia. (United States)

    Szarszoi, Ondrej; Maly, Jiri; Turek, Daniel; Urban, Marian; Skalsky, Ivo; Riha, Hynek; Maluskova, Jana; Pirk, Jan; Netuka, Ivan


    A patient with dilated cardiomyopathy and no history of thromboembolic events received a surgically implanted axial-flow left ventricular assist device. After implantation, transesophageal echocardiography revealed a giant thrombus on the lateral and anterior aspects of the left ventricle. The inflow cannula inserted through the apex of the left ventricle was not obstructed, and the device generated satisfactory blood flow. Laboratory screening for thrombophilia showed protein S deficiency, heterozygous factor V Leiden mutation, and heterozygous MTHFR C667T mutation. During the entire duration of circulatory support, no significant suction events were detected, and the patient was listed for heart transplantation. Ventricular assist device implantation can unmask previously undiagnosed thrombophilia; therefore, it should be necessary to identify thrombophilic patients before cardiac support implantation.

  12. Perioperative management of patients with cardiac implantable electronic devices. (United States)

    Poveda-Jaramillo, R; Castro-Arias, H D; Vallejo-Zarate, C; Ramos-Hurtado, L F


    The use of implantable cardiac devices in people of all ages is increasing, especially in the elderly population: patients with pacemakers, cardioverter-defibrillators or cardiac resynchronization therapy devices regularly present for surgery for non-cardiac causes. This review was made in order to collect and analyze the latest evidence for the proper management of implantable cardiac devices in the perioperative period. Through a detailed exploration of PubMed, Academic Search Complete (EBSCO), ClinicalKey, Cochrane (Ovid), the search software UpToDate, textbooks and patents freely available to the public on Google, we selected 33 monographs, which matched the objectives of this publication.

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

    Directory of Open Access Journals (Sweden)

    Kara N. Bocan


    Full Text Available 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.

  14. Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review. (United States)

    Bocan, Kara N; Sejdić, Ervin


    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.

  15. Infective endocarditis and risk of death after cardiac implantable electronic device implantation

    DEFF Research Database (Denmark)

    Özcan, Cengiz; Raunsø, Jakob; Lamberts, Morten;


    AIMS: To determine the incidence, risk factors, and mortality of infective endocarditis (IE) following implantation of a first-time, permanent, cardiac implantable electronic device (CIED). METHODS AND RESULTS: From Danish nationwide administrative registers (beginning in 1996), we identified all...... de-novo permanent pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) together with the occurrence of post-implantation IE-events in the period from 2000-2012. Included were 43 048 first-time PM/ICD recipients. Total follow-up time was 168 343 person-years (PYs). The incidence rate...

  16. Wireless communication with implanted medical devices using the conductive properties of the body. (United States)

    Ferguson, John E; Redish, A David


    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.

  17. Current Concepts in Restorative Implant Dentistry

    Institute of Scientific and Technical Information of China (English)



    Patients today are incteasingly aware of dental implants.and their expectations are for esthetically and functionally pleasingimplant restorations that mimic natural teeth.This presentation will give both the experienced and novice practitioner a better understand-ing of how restorative implant dentistry has evolved.Treatment planning and restorative options for single implants.multiple implants andfully edentulons arches will be discussed,and the use of modern materials and CADCAM technology in fabricating the most contemporaryfixed implant supported prostheses will be demonstrated.

  18. New implantable therapeutic device for the control of an atrial fibrillation attack using the Peltier element. (United States)

    Yambe, Tomoyuki; Sumiyoshi, Taketada; Koga, Chihiro; Shiraishi, Yasuyuki; Miura, Hidekazu; Sugita, Norihiro; Tanaka, Akira; Yoshizawa, Makoto


    For the development of the new therapeutic device for the atrial fibrillation, implantable cooling device using Peltier element was developed in this study. An implantable cooling device had been consisted from Peltier element with transcutaneous energy transmission system (TETS). 1st coil can be contacted from outside of the body, when the patients will feel palpitation. Electrical current will be induced to the implanted 2nd coil. Peltier element will able to cool the surface of the atrium. For the confirmation of the effect of the cooling device, trial manufacture model was developed. Animal experiments using six healthy adult goats after animal ethical committee allowance was carried out. Fourth intercostals space had been opened after anesthesia inhalation, and various sensors had been inserted. AF was induced by the electrical current with battery. As the results, AF had been recovered to the normal sinus rhythm after cooling in all six goats. So, this cooling system for the control of AF showed evident effect in these experiments. Smaller size cooling device has been under development aiming at totally implantable type. Catheter type cooling device for the insertion by the use of fiber-scope type is now under planning for the clinical application. This new type device may be able to become good news for the patients with uncontrollable AF.

  19. Current status and correlated issues on cochlear implantation

    Institute of Scientific and Technical Information of China (English)

    CAO Ke-li; WANG Lin-e


    @@ Cochlear implant is a biomedical device, which can directly stimulate the auditory nerve pass-by the damaged hair cell to recover and rebuild the hearing of deaf people. The implant can also stimulate the auditory brainstem and cortex in patients whose auditory nerve is not accessible because of acoustic tumors. Cochlear implantation can make the patients generate electrical hearing (artificial hearing).The artificial hearing can recover,improve or rebuild the hearing of deaf people through electrical stimulus.

  20. Implantable optical-electrode device for stimulation of spinal motoneurons (United States)

    Matveev, M. V.; Erofeev, A. I.; Zakharova, O. A.; Pyatyshev, E. N.; Kazakin, A. N.; Vlasova, O. L.


    Recent years, optogenetic method of scientific research has proved its effectiveness in the nerve cell stimulation tasks. In our article we demonstrate an implanted device for the spinal optogenetic motoneurons activation. This work is carried out in the Laboratory of Molecular Neurodegeneration of the Peter the Great St. Petersburg Polytechnic University, together with Nano and Microsystem Technology Laboratory. The work of the developed device is based on the principle of combining fiber optic light stimulation of genetically modified cells with the microelectrode multichannel recording of neurons biopotentials. The paper presents a part of the electrode implant manufacturing technique, combined with the optical waveguide of ThorLabs (USA).

  1. Wireless microsensor network solutions for neurological implantable devices (United States)

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


    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

  2. Development of an auditory implant manipulator for minimally invasive surgical insertion of implantable hearing devices. (United States)

    Stieger, C; Caversaccio, M; Arnold, A; Zheng, G; Salzmann, J; Widmer, D; Gerber, N; Thurner, M; Nauer, C; Mussard, Y; Kompis, M; Nolte, L P; Häusler, R; Weber, S


    To present the auditory implant manipulator, a navigation-controlled mechanical and electronic system which enables minimally invasive ('keyhole') transmastoid access to the tympanic cavity. The auditory implant manipulator is a miniaturised robotic system with five axes of movement and an integrated drill. It can be mounted on the operating table. We evaluated the surgical work field provided by the system, and the work sequence involved, using an anatomical whole head specimen. The work field provided by the auditory implant manipulator is considerably greater than required for conventional mastoidectomy. The work sequence for a keyhole procedure included pre-operative planning, arrangement of equipment, the procedure itself and post-operative analysis. Although system improvements are necessary, our preliminary results indicate that the auditory implant manipulator has the potential to perform keyhole insertion of implantable hearing devices.

  3. Ultrasound appearances of Implanon implanted contraceptive devices.

    LENUS (Irish Health Repository)

    McNeill, G


    Subdermal contraceptive devices represent a popular choice of contraception. Whilst often removed without the use of imaging, circumstances exist where imaging is required. Ultrasound is the modality of choice. The optimal technique and typical sonographic appearances are detailed in this article.

  4. Ultrasound appearances of Implanon implanted contraceptive devices. (United States)

    McNeill, G; Ward, E; Halpenny, D; Snow, A; Torreggiani, W


    Subdermal contraceptive devices represent a popular choice of contraception. Whilst often removed without the use of imaging, circumstances exist where imaging is required. Ultrasound is the modality of choice. The optimal technique and typical sonographic appearances are detailed in this article.

  5. Patient perspective on remote monitoring of cardiovascular implantable electronic devices

    DEFF Research Database (Denmark)

    Versteeg, H; Pedersen, Susanne S.; Mastenbroek, M H;


    BACKGROUND: Remote patient monitoring is a safe and effective alternative for the in-clinic follow-up of patients with cardiovascular implantable electronic devices (CIEDs). However, evidence on the patient perspective on remote monitoring is scarce and inconsistent. OBJECTIVES: The primary...

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

    Directory of Open Access Journals (Sweden)

    Padeletti L


    Full Text Available Luigi Padeletti1, Giosuè Mascioli2, Alessandro Paoletti Perini1, Gino Grifoni1, Laura Perrotta1, Procolo Marchese3, Luca Bontempi3, Antonio Curnis31Istituto di Clinica Medica e Cardiologia, Università degli Studi di Firenze, Italia; 2Elettrofisiologia, Istituto Humanitas Gavazzeni, Bergamo, Italia; 3Elettrofisiologia, Spedali Civili, Brescia, ItaliaAbstract: 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

  7. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device. (United States)


    ... 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... application of continuous or intermittent pressure to occlude the urethra. The totally implanted device...

  8. A quick guide to safety and compatibility of passive implants and devices in an MR environment

    Directory of Open Access Journals (Sweden)

    D.J. Kotze


    Full Text Available An increasing number of patients with metal implants are being referred for magnetic resonance imaging (MRI investigations. Implants and devices may be divided into two groups, namely active and passive. This article will focus on passive devices. A device is MR-safe when it is used in the MR environment, but presents no additional risk to the patient or other individuals, although the quality of diagnostic information may be affected. MR procedures may be contraindicated due to various interactions between the MR environment and medical devices, which include torque, translational force, heating, induced electrical currents, magnetic field interactions, artefacts, and misrepresentation. Therefore, before deciding whether any object is MRsafe/ compatible, the intended use and the possible retaining mechanisms must be considered.

  9. Personalized Remote Monitoring of the Atrial Fibrillation Patients with Electronic Implant Devices

    Directory of Open Access Journals (Sweden)

    Gokce B. Laleci


    Full Text Available Cardiovascular Implantable Electronic Devices (CIED are gaining popularity in treating patients with heart disease. Remote monitoring through care management systems enables continuous surveillance of such patients by checking device functions and clinical events. These care management systems include decision support capabilities based on clinical guidelines. Data input to such systems are from different information sources including medical devices and Electronic Health Records (EHRs. Although evidence-based clinical guidelines provides numerous benefits such as standardized care, reduced costs, efficient and effective care management, they are currently underutilized in clinical practice due to interoperability problems among different healthcare data sources. In this paper, we introduce the iCARDEA care management system for atrial fibrillation patients with implant devices and describe how the iCARDEA care plan engine executes the clinical guidelines by seamlessly accessing the EHR systems and the CIED data through standard interfaces.

  10. The value and limitations of a wound inspection clinic after cardiac device implantation

    NARCIS (Netherlands)

    Deuling, J. Han H.; Smit, Marcelle D.; Maass, Alexander H.; Van den Heuvel, Ad F. M.; Nieuwland, Wybe; Zijlstra, Felix; Van Gelder, Isabelle C.


    Background: Due to the growing number of cardiac device implantations it is important to develop methods to reduce device-implantation related complications. Aims: To determine whether a wound inspection clinic can play a role in the detection of device-implantation related complications. Methods:

  11. Forensic identification using multiple lot numbers of an implanted device. (United States)

    Takeshita, H; Nagai, T; Sagi, M; Chiba, S; Kanno, S; Takada, M; Mukai, T


    We report a case in which identification of a deceased individual was established using multiple lot numbers printed on a body implantable device. Autopsy of an unknown woman revealed an intramedullary nail inserted within her right femur. The device manufacturer was identified from the configuration of the intramedullary nail, and the "use history" was traced from lot numbers printed on the device's multiple parts. The deceased individual was thus identified as a woman who had attempted suicide by jumping from a height about a year previously and had been transported to a hospital and undergone surgery that included implantation of the intramedullary nail. The main factor contributing to the rapid identification was the manufacturer's and distributor's record of the use history (traceability) of the product, because of their accountability for purposes of quality control. A second contributing factor was multiple lot numbers, resulting in extremely low probability of the same combination of lot numbers being present in multiple individuals. This case confirmed the utility of multiple lot numbers of body implantable devices in forensic identification.

  12. Characterization of piezoelectric device for implanted pacemaker energy harvesting (United States)

    Jay, Sunny; Caballero, Manuel; Quinn, William; Barrett, John; Hill, Martin


    Novel implanted cardiac pacemakers that are powered by energy harvesters driven by the cardiac motion and have a 40 year lifetime are currently under development. To satisfy space constraints and energy requirements of the device, silicon-based MEMS energy harvesters are being developed in the EU project (MANpower1). Such MEMS harvesters for vibration frequencies below 50 Hz have not been widely reported. In this paper, an analytical model and a 3D finite element model (FEM) to predict displacement and open circuit voltage, validated through experimental analysis using an off-the-shelf low frequency energy harvester, are presented. The harvester was excited through constant amplitude sinusoidal base displacement over a range of 20 to 70 Hz passing through its first mode natural frequency at 47 Hz. At resonance both models predict displacements with an error of less than 2% when compared to the experimental result. Comparing the two models, the application of the experimentally measured damping ratio differs for accurate displacement prediction and the differences in symmetry in the measured and modelled displacement and voltage data around the resonance frequency indicate the two piezoelectric voltage models use different fundamental equations.

  13. Electromagnetic interference of implantable cardiac devices from a shoulder massage machine. (United States)

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


    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.

  14. Catheter embolization from implanted venous access devices: case reports. (United States)

    Carr, M E


    Two cases of catheter embolization from implanted venous access devices are reported and the available literature is reviewed. The catheter from an implanted venous access device migrated into the right heart after slippage of the O-ring, which attaches the catheter to the infusion port. The distal 6 cm of an infusion port catheter embolized to the right heart after spontaneous fracture of the catheter at the point where it passed between the clavicle and first rib. Both catheters were removed percutaneously without complication. Risk factors for embolization were apparent on x-ray films with evidence of O-ring slippage in 1 case an obvious kinking of the catheter in the other. Symptoms of embolization included chest discomfort, right upper quadrant pain, and nausea. In 1 case, an extra heart sound, initially thought to be an S3, disappeared when the catheter was removed.

  15. Tunable Ultrasonic Energy Harvesting for Implantable Biosensors and Medical Devices (United States)

    Pellegrino, M.; Eovino, B. E.; Beker, L.; Bourouina, T.; Lin, L.


    This work reports a tunable ultrasonic energy harvesting (UEH) device capable of high power output and/or large bandwidth based on concentric piezoelectric ring-shaped structures. Two different designs are presented: (1) the single ring-shaped UEH (r-UEH), and (2) concentric r-UEHs. Concentric r-UEHs can save space and therefore can provide benefits in powering low-power implantable biosensors and medical devices. This paper presents results of simulation studies and initial experiments of a single r-UEH.

  16. Intrapulmonal dislocation of a totally implantable venous access device

    Directory of Open Access Journals (Sweden)

    Sido Bernd


    Full Text Available Abstract Background Totally implantable venous access devices are widely used for infusion of chemotherapy or parenteral nutrition. Device associated complications include technical operative problems, infections, paravasal infusions and catheter or punction chamber dislocation. Case presentation We present the case of a 49-year-old patient with the rare complication of a intrapulmonal catheter dislocation of a totally implantable venous access system. Treosulfane for chemotherapy of metastatic breast cancer was infused via the catheter causing instant coughing and dyspnoea which lead to the diagnosis of catheter dislocation. The intrapulmonal part of the catheter was removed under thoracoscopic control without further complications. Conclusion Intrapulmonal catheter dislocation is a rare complication of a totally implantable venous access device which can not be avoided by any prophylactic measures. Therefore, the infusion system should be tested before each use and each new symptom, even when not obviously related to the catheter should be carefully documented and evaluated by expert physicians to avoid severe catheter-associated complications.

  17. Postoperative care and complications after ventricular assist device implantation. (United States)

    Allen, Sara Jane; Sidebotham, David


    In this article, the routine postoperative care and complications of patients with ventricular assist devices are reviewed. Routine postoperative care encompasses patients who have undergone emergency ventricular assist device (VAD) implantation for acute cardiogenic shock, as a bridge to decision making, and semi-elective patients who have undergone VAD implantation for end-stage heart failure, either as destination therapy or as a bridge to heart transplantation. Early postoperative management should focus on haemodynamic optimisation, including fluid and inotrope therapy, VAD settings and support of right ventricular function. Echocardiography is an essential tool in optimising haemodynamics and identifying complications. Early postoperative complications include bleeding, arrhythmias, right ventricular failure and infection. Late postoperative problems include bleeding, thrombosis and thrombo-embolism, device failure and psychological problems. In a small percentage of patients, weaning and explantation of the VAD are possible. For patients undergoing VAD implantation for destination therapy, end-of-life care planning should form part of the multidisciplinary care of the patient.

  18. Power sources and electrical recharging strategies for implantable medical devices

    Institute of Scientific and Technical Information of China (English)

    Xiaojuan WEI; Jing LIU


    Implantable medical devices (IMDs) are crit-ically requested for the survival of patients subject to certain serious diseases such as bradycardia, fibrillation, diabetes, and disability, etc. Appropriate working of an active implantable medical device (IMD) heavily relies on the continuous supply of electricity. In this sense, long-term powering and recharging of an IMD via a highly safe, efficient and convenient way is, therefore, extremely important in clinics. Several conventional batteries, such as lithium cell, nuclear cell and bio-fuel cell, etc., have been developed to power IMDs. Meanwhile, the recharge of IMD from outside of the human body is also under investigation. In this paper, some of the most typical IMD batteries are reviewed. Their advantages and disadvantages are compared. In addition, several emer-ging innovations to recharge or directly drive the implanted batteries, including electromagnetic energy transmission, piezoelectric power generation, thermoelec-tric devices, ultrasonic power motors, radio frequency recharging and optical recharging methods, etc., are also discussed. Some fundamental and practical issues thus involved are summarized, and future prospects in this area are made.

  19. Safety of magnetic resonance imaging in patients with implanted cardiac prostheses and metallic cardiovascular electronic devices. (United States)

    Baikoussis, Nikolaos G; Apostolakis, Efstratios; Papakonstantinou, Nikolaos A; Sarantitis, Ioannis; Dougenis, Dimitrios


    Magnetic resonance imaging (MRI) in patients with implanted cardiac prostheses and metallic cardiovascular electronic devices is sometimes a risky procedure. Thus MRI in these patients should be performed when it is the only examination able to help with the diagnosis. Moreover the diagnostic benefit must outweigh the risks. Coronary artery stents, prosthetic cardiac valves, metal sternal sutures, mediastinal vascular clips, and epicardial pacing wires are not contraindications for MRI, in contrast to pacemakers and implantable cardioverter-defibrillators. Appropriate patient selection and precautions ensure MRI safety. However it is commonly accepted that although hundreds of patients with pacemakers or implantable cardioverter-defibrillators have undergone safe MRI scanning, it is not a safe procedure. Currently, heating of the pacemaker lead is the major problem undermining MRI safety. According to the US Food and Drug Administration (FDA), there are currently neither "MRI-safe" nor "MRI-compatible" pacemakers and implantable cardioverter-defibrillators. In this article we review the international literature in regard to safety during MRI of patients with implanted cardiac prostheses and metallic cardiovascular electronic devices.

  20. Constant pressure fluid infusion into rat neocortex from implantable microfluidic devices (United States)

    Retterer, S. T.; Smith, K. L.; Bjornsson, C. S.; Turner, J. N.; Isaacson, M. S.; Shain, W.


    Implantable electrode arrays capable of recording and stimulating neural activity with high spatial and temporal resolution will provide a foundation for future brain computer interface technology. Currently, their clinical impact has been curtailed by a general lack of functional stability, which can be attributed to the acute and chronic reactive tissue responses to devices implanted in the brain. Control of the tissue environment surrounding implanted devices through local drug delivery could significantly alter both the acute and chronic reactive responses, and thus enhance device stability. Here, we characterize pressure-mediated release of test compounds into rat cortex using an implantable microfluidic platform. A fixed volume of fluorescent cell marker cocktail was delivered using constant pressure infusion at reservoir backpressures of 0, 5 and 10 psi. Affected tissue volumes were imaged and analyzed using epifluorescence and confocal microscropies and quantitative image analysis techniques. The addressable tissue volume for the 5 and 10 psi infusions, defined by fluorescent staining with Hoescht 33342 dye, was significantly larger than the tissue volume addressed by simple diffusion (0 psi) and the tissue volume exhibiting insertion-related cell damage (stained by propidium iodide). The results demonstrate the potential for using constant pressure infusion to address relevant tissue volumes with appropriate pharmacologies to alleviate reactive biological responses around inserted neuroprosthetic devices.

  1. In-vivo orthopedic implant diagnostic device for sensing load, wear, and infection (United States)

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


    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.

  2. First Case of Trichoderma longibrachiatum CIED (Cardiac Implantable Electronic Device)-Associated Endocarditis in a Non-immunocompromised Host: Biofilm Removal and Diagnostic Problems in the Light of the Current Literature. (United States)

    Tascini, Carlo; Cardinali, Gianluigi; Barletta, Valentina; Di Paolo, Antonello; Leonildi, Alessandro; Zucchelli, Giulio; Corte, Laura; Colabella, Claudia; Roscini, Luca; Consorte, Augusta; Pasticci, Maria Bruna; Menichetti, Francesco; Bongiorni, Maria Grazia


    Trichoderma species are saprophytic filamentous fungi producing localized and invasive infections that are cause of morbidity and mortality, especially in immunocompromised patients, causing up to 53% mortality. Non-immunocompromised patients, undergoing continuous ambulatory peritoneal dialysis, are other targets of this fungus. Current molecular diagnostic tools, based on the barcode marker ITS, fail to discriminate these fungi at the species level, further increasing the difficulty associated with these infections and their generally poor prognosis. We report on the first case of endocarditis infection caused by Trichoderma longibrachiatum in a 30-year-old man. This patient underwent the implantation of an implantable cardioverter defibrillator in 2006, replaced in 2012. Two years later, the patient developed fever, treated successfully with amoxicillin followed by ciprofloxacin, but an echocardiogram showed large vegetation onto the ventricular lead. After CIED extraction, the patient had high-grade fever. The culturing of the catheter tip was positive only in samples deriving from sonication according to the 2014 ESCMID guidelines, whereas the simple washing failed to remove the biofilm cells from the plastic surface. Subsequent molecular (ITS sequencing) and microbiological (macromorphology) analyses showed that the vegetation was due to T. longibrachiatum. This report showed that T. longibrachiatum is an effective threat and that sonication is necessary for the culturing of vegetations from plastic surfaces. Limitations of the current barcode marker ITS, and the long procedures required by a multistep approach, call for the development of rapid monophasic tests.

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

    Directory of Open Access Journals (Sweden)

    Dharani Manickavasagam


    Full Text Available 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.

  4. 78 FR 2647 - Dental Devices; Reclassification of Blade-Form Endosseous Dental Implant (United States)


    ...-Form Endosseous Dental Implant AGENCY: Food and Drug Administration, HHS. ACTION: Proposed order... dental implant, a preamendments class III device, into class II (special controls). On its own initiative... published a proposed rule for classification of endosseous dental implants (without distinguishing implants...

  5. Feasibility study for future implantable neural-silicon interface devices. (United States)

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


    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.

  6. Electromagnetic immunity of implantable pacemakers exposed to wi-fi devices. (United States)

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


    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.

  7. [The management of implantable medical device and the application of the internet of things in hospitals]. (United States)

    Zhou, Li; Xu, Liang


    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.

  8. Electromagnetic semi-implantable hearing device: phase I. Clinical trials. (United States)

    McGee, T M; Kartush, J M; Heide, J C; Bojrab, D I; Clemis, J D; Kulick, K C


    Conventional hearing aids have improved significantly in recent years; however, amplification of sound within the external auditory canal creates a number of intrinsic problems, including acoustic feedback and the need for a tight ear mold to increase usable gain. Nonacoustic alternatives which could obviate these encumbrances have not become practical due to inefficient coupling (piezoelectric techniques) or unfeasible power requirements (electromagnetic techniques). Recent technical advances, however, prompted a major clinical investigation of a new electromagnetic, semi-implantable hearing device. This study presents the details of clinical phase I, in which an electromagnetic driver was coupled with a target magnet temporarily affixed onto the lateral surface of the malleus of six hearing aid users with sensorineural losses. The results indicate that the electromagnetic hearing device provides sufficient gain and output characteristics to benefit individuals with sensorineural hearing loss. Significant improvements compared to conventional hearing aids were noted in pure-tone testing and, to a lesser degree, in speech discrimination. Subjective responses were quite favorable, indicating that the electromagnetic hearing device 1. produces no acoustic feedback; 2. works well in noisy environments; and 3. provides a more quiet, natural sound than patients' conventional hearing aids. These favorable results led to phase II of the project, in which patients with surgically amendable mixed hearing losses were implanted with the target magnet incorporated within a hydroxyapatite ossicular prosthesis. The results of this second-stage investigation were also encouraging and will be reported separately.

  9. From hemodynamic towards cardiomechanic sensors in implantable devices (United States)

    Ferek-Petric, Bozidar


    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.

  10. Galvanic disruption of vestibulospinal postural control by cochlear implant devices. (United States)

    Black, F O; Wall, C; O'Leary, D P; Bilger, R C; Wolf, R V


    All subjects with implanted cochlear stimulators demonstrated evidence of abnormal postural stability without their stimulators activated. Instability increased when they were tested with cochlear stimulation units turned on, and additional instability was demonstrated in four of these subjects when tested in noise. These findings suggest that the electrical stimulation delivered by the cochlear prosthesis is not limited to the auditory system. The precise characteristics of electrical stimulation devices designed for stimulations limited to the cochlea and their spurious effects upon motor performance should be investigated. The design of future intralabyrinthine auditory electrical prostheses must include hardware designs and stimulus paradigms that avoid undesirable vestibular system stimulation.

  11. Current status of noncemented hip implants. (United States)

    Harris, W H


    Recently the operative techniques, instrumentation, design, and material properties of bony ingrowth total hip replacement have been greatly improved. I prefer a hemispherical acetabular component fixed with screws going through the metal shell. The titanium mesh allows microinterlock with new bone, and macrointerlock is obtained by adding bone graft into the unused screw holes. The femoral component, made of Tivanium with titanium mesh attached to it by a new process called diffusion bonding, retains superalloy fatigue strength characteristics. An intimate press fit is assured by the specific operative technique, and both the fiber mesh and the collar provide proximal stress transfer. The design affords a nondestructive method for removal if necessary. The short-term clinical results are promising; most patients function as well as with cemented total hip replacement. The incidence of thigh pain has been significantly reduced since prior reports of cementless total hip replacement; however, a few patients still have thigh pain. The results in revision surgery are also promising, but as in cemented total hip replacement, the functional capacity of revision cases is usually lower than primary cases. There is an increased capacity to correct complex and difficult acetabular problems with this acetabular component. Obviously, long-term data are needed to establish the behavior of these implants over the immediate and long term.

  12. An implantable device for neuropsychiatric rehabilitation by chronic deep brain stimulation in freely moving rats (United States)

    Wang, Chenguang; Zhang, Fuqiang; Jia, Hong


    Successful practice of clinical deep brain stimulation (DBS) calls for basic research on the mechanisms and explorations of new indications in animals. In the article, a new implantable, single-channel, low-power miniature device is proposed, which may transmit pulses chronically into the brain nucleus of freely moving rats. The DBS system consists of an implantable pulse generator (IPG), a bipolar electrode, and an external programmer. The IPG circuit module is assembled as a 20-mm diameter circular board and fixed on a rat’s skull together with an electrode and battery. The rigid electrode may make its fabrication and implantation more easy. The external programmer is designed for bidirectional communication with the IPG by a telecontrol transceiver and adjusts stimulation parameters. A biological validation was performed in which the effects of electrical stimulation in brain nucleus accumbens were detected. The programmed parameters were accurate, implant steady, and power sufficient to allow stimulation for more than 3 months. The larger area of the electrode tip provided a moderate current or charge density and minimized the damage from electrochemistry and pyroelectricity. The rats implanted with the device showed a reduction in morphine-induced conditioned place preference after high-frequency stimulation. In conclusion, the DBS device is based on the criteria of simple technology, minimal invasion, low cost, small in size, light-weight, and wireless controlled. This shows that our DBS device is appropriate and can be used for preclinical studies, indicating its potential utility in the therapy and rehabilitation of neuropsychiatric disorders. PMID:28121810

  13. To ventricular assist devices or not: When is implantation of a ventricular assist device appropriate in advanced ambulatory heart failure? (United States)

    Cerier, Emily; Lampert, Brent C; Kilic, Arman; McDavid, Asia; Deo, Salil V; Kilic, Ahmet


    Advanced heart failure has been traditionally treated via either heart transplantation, continuous inotropes, consideration for hospice and more recently via left ventricular assist devices (LVAD). Heart transplantation has been limited by organ availability and the futility of other options has thrust LVAD therapy into the mainstream of therapy for end stage heart failure. Improvements in technology and survival combined with improvements in the quality of life have made LVADs a viable option for many patients suffering from heart failure. The question of when to implant these devices in those patients with advanced, yet still ambulatory heart failure remains a controversial topic. We discuss the current state of LVAD therapy and the risk vs benefit of these devices in the treatment of heart failure.

  14. In-situ photopolymerization and monitoring device for controlled shaping of tissue fillers, replacements, or implants (United States)

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


    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.

  15. Cardiac Implantable Electronic Device Infection: From an Infection Prevention Perspective (United States)

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


    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

  16. Wireless energy transfer platform for medical sensors and implantable devices. (United States)

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


    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.

  17. A flexible super-capacitive solid-state power supply for miniature implantable medical devices. (United States)

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


    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.

  18. Safety of active implantable devices during MRI examinations: a finite element analysis of an implantable pump. (United States)

    Büchler, Philippe; Simon, Anne; Burger, Jürgen; Ginggen, Alec; Crivelli, Rocco; Tardy, Yanik; Luechinger, Roger; Olsen, Sigbjørn


    The goal of this study was to propose a general numerical analysis methodology to evaluate the magnetic resonance imaging (MRI)-safety of active implants. Numerical models based on the finite element (FE) technique were used to estimate if the normal operation of an active device was altered during MRI imaging. An active implanted pump was chosen to illustrate the method. A set of controlled experiments were proposed and performed to validate the numerical model. The calculated induced voltages in the important electronic components of the device showed dependence with the MRI field strength. For the MRI radiofrequency fields, significant induced voltages of up to 20 V were calculated for a 0.3T field-strength MRI. For the 1.5 and 3.0OT MRIs, the calculated voltages were insignificant. On the other hand, induced voltages up to 11 V were calculated in the critical electronic components for the 3.0T MRI due to the gradient fields. Values obtained in this work reflect to the worst case situation which is virtually impossible to achieve in normal scanning situations. Since the calculated voltages may be removed by appropriate protection circuits, no critical problems affecting the normal operation of the pump were identified. This study showed that the proposed methodology helps the identification of the possible incompatibilities between active implants and MR imaging, and can be used to aid the design of critical electronic systems to ensure MRI-safety.

  19. A Novel Transdermal Power Transfer Device for the Application of Implantable Microsystems

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    Jing-Quan Liu


    Full Text Available This paper presents a transdermal power transfer device for the application of implantable devices or systems. The device mainly consists of plug and socket. The power transfer process can be started after inserting the plug into the socket with an applied potential on the plug. In order to improve the maneuverability and reliability of device during power transfer process, the metal net with mesh structure were added as a part of the socket to serve as intermediate electrical connection layer. The socket was encapsulated by polydimethylsiloxane (PDMS with good biocompatibility and flexibility. Two stainless steel hollow needles placed in the same plane acted as the insertion part of the needle plug, and Parylene C thin films were deposited on needles to serve as insulation layers. At last, the properties of the transdermal power transfer device were tested. The average contact resistance between needle and metal mesh was 0.454 Ω after 50 random insertions, which showed good electrical connection. After NiMH (nickel-metal hydride batteries were recharged for 10 min with current up to 200 mA, the caused resistive heat was less than 0.6 °C, which also demonstrated the low charging temperature and was suitable for charging implantable devices.

  20. Analysis of induced electrical currents from magnetic field coupling inside implantable neurostimulator leads

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    Seidman Seth J


    Full Text Available Abstract Background Over the last decade, the number of neurostimulator systems implanted in patients has been rapidly growing. Nearly 50, 000 neurostimulators are implanted worldwide annually. The most common type of implantable neurostimulators is indicated for pain relief. At the same time, commercial use of other electromagnetic technologies is expanding, making electromagnetic interference (EMI of neurostimulator function an issue of concern. Typically reported sources of neurostimulator EMI include security systems, metal detectors and wireless equipment. When near such sources, patients with implanted neurostimulators have reported adverse events such as shock, pain, and increased stimulation. In recent in vitro studies, radio frequency identification (RFID technology has been shown to inhibit the stimulation pulse of an implantable neurostimulator system during low frequency exposure at close distances. This could potentially be due to induced electrical currents inside the implantable neurostimulator leads that are caused by magnetic field coupling from the low frequency identification system. Methods To systematically address the concerns posed by EMI, we developed a test platform to assess the interference from coupled magnetic fields on implantable neurostimulator systems. To measure interference, we recorded the output of one implantable neurostimulator, programmed for best therapy threshold settings, when in close proximity to an operating low frequency RFID emitter. The output contained electrical potentials from the neurostimulator system and those induced by EMI from the RFID emitter. We also recorded the output of the same neurostimulator system programmed for best therapy threshold settings without RFID interference. Using the Spatially Extended Nonlinear Node (SENN model, we compared threshold factors of spinal cord fiber excitation for both recorded outputs. Results The electric current induced by low frequency RFID emitter

  1. Electronic Voltage and Current Transformers Testing Device

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    Yong Xiao


    Full Text Available A method for testing electronic instrument transformers is described, including electronic voltage and current transformers (EVTs, ECTs with both analog and digital outputs. A testing device prototype is developed. It is based on digital signal processing of the signals that are measured at the secondary outputs of the tested transformer and the reference transformer when the same excitation signal is fed to their primaries. The test that estimates the performance of the prototype has been carried out at the National Centre for High Voltage Measurement and the prototype is approved for testing transformers with precision class up to 0.2 at the industrial frequency (50 Hz or 60 Hz. The device is suitable for on-site testing due to its high accuracy, simple structure and low-cost hardware.

  2. Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands (United States)

    Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi


    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.

  3. Survey of currently selected dental implants and restorations by prosthodontists. (United States)

    Cardoso, Richard C; Gerngross, Peter J; Dominici, John T; Kiat-amnuay, Sudarat


    The purpose of this study was to survey the prosthodontists of the American College of Prosthodontists (ACP) and the American Academy of Maxillofacial Prosthetics (AAMP) to identify the most commonly used implant both during their training and currently in practice, and to evaluate overall restorative preference. Participants were asked to rank criteria that make an implant company desirable and important features when selecting an implant. An electronic survey was emailed to 1,739 members of the ACP and AAMP. The majority of respondents (79%) were trained using Nobel Biocare brand implants, which was also the brand most often selected by participants for use in all regions of the oral cavity (34% to 39%, location dependent). Abutment preferences varied by area: incisors and canines (29%) and highly esthetic areas (53%) were more likely to be restored with custom milled zirconia abutments, while prefabricated titanium abutments were preferred for premolars and molar areas. Conventional loading was most often applied, ranging from 95% in medically compromised patients to 55% in esthetic areas. The majority of participants (86%) used Locator attachments for complete overdenture restorations. Also, respondents selected an implant company based on features and literature support versus cost and customer service. The implant features deemed most important were the design of the internal connection and ease of finding replacement parts; thread design and variety of abutments were deemed least important. Respondents reported that while implant planning software was used, they rarely/never order the concurrent surgical guide. Within the study's limitations, the majority of prosthodontists select implants based on training, features, and literature support.

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

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    Seong Tak Woo


    Full Text Available 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.

  5. Design of an Implantable Device for Ocular Drug Delivery

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    Jae-Hwan Lee


    Full Text Available 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.

  6. Wireless platform for controlled nitric oxide releasing optical fibers for mediating biological response to implanted devices. (United States)

    Starrett, Michael A; Nielsen, Matthew; Smeenge, David M; Romanowicz, Genevieve E; Frost, Megan C


    Despite the documented potential to leverage nitric oxide generation to improve in vivo performance of implanted devices, a key limitation to current NO releasing materials tested thus far is that there has not been a means to modulate the level of NO release after it has been initiated. We report the fabrication of a wireless platform that uses light to release NO from a polymethylmethacrylate (PMMA) optical fiber coated with an S-nitroso-N-acetylpenicillamine derivatized polydimethylsiloxane (SNAP-PDMS). We demonstrate that a VAOL-5GSBY4 LED (λ(dominant)=460 nm) can be used as a dynamic trigger to vary the level of NO released from 500 μm diameter coated PMMA. The ability to generate programmable sequences of NO flux from the surface of these coated fibers offers precise spatial and temporal control over NO release and provides a platform to begin the systematic study of in vivo physiological response to implanted devices. NO surface fluxes up to 3.88 ± 0.57 × 10(-10)mol cm(-2)min(-1) were achieved with -100 μm thick coatings on the fibers and NO flux was pulsed, ramped and held steady using the wireless platform developed. We demonstrate the NO release is linearly proportional to the drive current applied to the LED (and therefore level of light produced from the LED). This system allow the surface flux of NO from the fibers to be continuously changed, providing a means to determine the level and duration of NO needed to mediate physiological response to blood contacting and subcutaneous implants and will ultimately lead to the intelligent design of NO releasing materials tailored to specific patterns of NO release needed to achieve reliable in vivo performance for intravascular and subcutaneous sensors and potentially for a wide variety of other implanted biomedical devices.

  7. Simulation study of a high power density rectenna array for biomedical implantable devices (United States)

    Day, John; Yoon, Hargsoon; Kim, Jaehwan; Choi, Sang H.; Song, Kyo D.


    The integration of wireless power transmission devices using microwaves into the biomedical field is close to a practical reality. Implanted biomedical devices need a long lasting power source or continuous power supply. Recent development of high efficiency rectenna technology enables continuous power supply to these implanted devices. Due to the size limit of most of medical devices, it is imperative to minimize the rectenna as well. The research reported in this paper reviews the effects of close packing the rectenna elements which show the potential of directly empowering the implanted devices, especially within a confined area. The rectenna array is tested in the X band frequency range.

  8. Achieving more frequent and longer dialysis for the majority: wearable dialysis and implantable artificial kidney devices. (United States)

    Fissell, William H; Roy, Shuvo; Davenport, Andrew


    The long-term survival for many chronic kidney failure patients who remain treated by dialysis in economically advanced countries remains similar to that of those with solid-organ malignancy, despite a disproportionate amount of health-care expenditure. As such, the current paradigm of three times weekly in-center hemodialysis for 4 h or shorter sessions needs to change to improve patient outcomes. Although more frequent and longer dialysis sessions have been reported to improve cardiovascular risk surrogates and short-term outcomes, these options are only practically available to a very small fraction of the total dialysis population. As such, radically new approaches are required to improve patient outcomes and quality of life for the majority of dialysis patients. Currently, two different approaches are being developed, wearable devices based on current dialysis techniques and more futuristic implantable devices modeled on the natural nephron.

  9. Hydroimplantation: foldable intraocular lens implantation without an ophthalmic viscosurgical device. (United States)

    Tak, Harshul


    I describe a technique for implantation of a 1-piece acrylic foldable intraocular lens (IOL) using an irrigation cannula of the phaco machine without using an ophthalmic viscosurgical device (OVD). The irrigating cannula introduced through a side port provides excellent stability and positioning to the eye; if required, the cannula tip is used to guide the leading haptic of the IOL into the capsular bag. The fluid coming from the side port via a bimanual irrigation cannula maintains adequate formation of the capsular bag and anterior chamber while the foldable IOL is inserted. The hydroimplantation technique has the advantage of increased efficiency, reduced surgical time and cost, no need for OVD removal from behind the IOL or for additional instrumentation, no OVD-induced intraocular pressure elevation postoperatively, and no risk of early capsular bag distension syndrome. Copyright 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  10. Sequential bilateral cochlear implantation in children: parents' perspective and device use. (United States)

    Sparreboom, Marloes; Leeuw, A Rens; Snik, Ad F M; Mylanus, Emmanuel A M


    The purpose of this study was (1) to measure parental expectations before surgery of a sequentially placed second cochlear implant and compare these results with parental observations postoperatively and (2) to measure device use of the second cochlear implant and compare to unilateral implant use. Thirty prelingually deaf children with a unilateral cochlear implant (mean age at first implant 1.8 years) received a second implant at a mean age of 5.3 years. To measure parental expectations and observations, parents completed the Parents' Perspective before surgery of the second implant and after 12 and 24 months. The questionnaire included 1 additional question on sound localization. Device use of both the first and second implants was assessed retrospectively after 6, 12 and 24 months of implant use. Device use of the study group was also compared to a reference group of 30 unilateral implant users matched for age at second implantation. Parental expectations with regard to sound localization were significantly higher than the observed changes within the first year of bilateral implant use. The observed changes in communication, listening to speech without lipreading, and speech and language skills met or surpassed parental expectations. Irrespective of age at second implantation, the second implant was significantly less worn than the first implant. No significant difference was observed between the use of the second implant of the study group and device use of the reference group. Second implant use was significantly correlated with the difference in speech recognition between the 2 implants alone. Preoperative parental expectations were too high with regard to the observed localization skills within the first year of bilateral implant use. The study showed that several of these sequentially implanted children had more difficulties in wearing the second implant than in wearing the first implant during the rehabilitation period. The present results suggest that

  11. From micro- to nanostructured implantable device for local anesthetic delivery. (United States)

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


    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

  12. Do we need to establish guidelines for patients with neuromodulation implantable devices, including spinal cord stimulators undergoing nonspinal surgeries?

    Directory of Open Access Journals (Sweden)

    Ramsis F Ghaly


    Full Text Available Background: Spinal cord stimulation is currently approved to treat chronic intractable pain of the trunk and limbs. However, such implantable electronic devices are vulnerable to external electrical currents and magnetic fields. Within the hospitals and modern operating rooms (ORs, there is an abundance of electrical devices and other types of equipment that could interfere with such devices. Despite the increasing number of patients with neuromodulation implantable devices, there are no written guidelines available or consensus of cautions for such patients undergoing unrelated surgery. Case Descriptions: A 60-year-old female with a permanent St. Jude′s spinal cord stimulator (SCS presented for open total abdominal hysterectomy. Both the anesthesia and gynecology staffs were aware of the device presence, but were unaware of any precautions regarding intraoperative management. The device was found to be nonmagnetic resonance imaging compatible, and bipolar cautery was used instead of monopolar cautery. A 59-year-old female with a 9-year-old permanent Medtronic SCS, presented for right total hip arthroplasty. The device was switched off prior to entering the OR, bipolar cautery was used, and grounding pads were placed away from her battery site. In each case, the manufacturer′s representative was contacted preoperative. Both surgeries proceeded uneventfully. Conclusions: The Food and Drug Administration safety information manual warns about the use of diathermy, concomitant implanted stimulation devices, lithotripsy, external defibrillation, radiation therapy, ultrasonic scanning, and high-output ultrasound, all of which can lead to permanent implant damage if not turned off prior to undertaking procedures. Lack of uniform guidelines makes intraoperative management, as well as remote anesthesia care of patients with previously implanted SCSs unsafe.

  13. Implantation of a left ventricular assist device in patients with a complex apical anatomy. (United States)

    Palmen, Meindert; Verwey, Harriette F; Haeck, Marlieke L A; Holman, Eduard R; Schalij, Martin J; Klautz, Robert J M


    Implantation of a left ventricular assist device can be challenging in patients with an altered apical anatomy after cardiac surgery or as the result of the presence of a calcified apical aneurysm. In this paper we present 2 cases with a challenging apical anatomy and introduce a new surgical technique facilitating left ventricular assist device implantation in these patients.

  14. Vibrant semi-implantable hearing device with digital sound processing: effective gain and speech perception.

    NARCIS (Netherlands)

    Snik, A.F.M.; Cremers, C.W.R.J.


    BACKGROUND: The Vibrant Soundbridge (Symphonix Devices, San Jose, Calif) is a semi-implantable hearing device. The transducer is attached directly to the incus and is linked by telemetry to the externally worn audioprocessor. A major advantage of this semi-implantable setup, especially during its ex

  15. A breakdown voltage model for implanted resurf p-LDMOS device on n+ buried layer

    NARCIS (Netherlands)

    Zhou, Ming-Jiang; Van Calster, A.


    This paper presents an analytical expression of the breakdown voltage of a high voltage implanted RESURF p-LDMOS device which uses the n+ buried layer as an effective device substrate. In this model, the doping profile of the buried layer is considered and discussed. The implant dose for the drift r

  16. Signal Processing Strategies for Cochlear Implants Using Current Steering

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    Waldo Nogueira


    Full Text Available In contemporary cochlear implant systems, the audio signal is decomposed into different frequency bands, each assigned to one electrode. Thus, pitch perception is limited by the number of physical electrodes implanted into the cochlea and by the wide bandwidth assigned to each electrode. The Harmony HiResolution bionic ear (Advanced Bionics LLC, Valencia, CA, USA has the capability of creating virtual spectral channels through simultaneous delivery of current to pairs of adjacent electrodes. By steering the locus of stimulation to sites between the electrodes, additional pitch percepts can be generated. Two new sound processing strategies based on current steering have been designed, SpecRes and SineEx. In a chronic trial, speech intelligibility, pitch perception, and subjective appreciation of sound were compared between the two current steering strategies and standard HiRes strategy in 9 adult Harmony users. There was considerable variability in benefit, and the mean results show similar performance with all three strategies.

  17. Implantation reduces the negative effects of bio-logging devices on birds. (United States)

    White, Craig R; Cassey, Phillip; Schimpf, Natalie G; Halsey, Lewis G; Green, Jonathan A; Portugal, Steven J


    Animal-borne logging or telemetry devices are widely used for measurements of physiological and movement data from free-living animals. For such measurements to be relevant, however, it is essential that the devices themselves do not affect the data of interest. A recent meta-analysis reported an overall negative effect of these devices on the birds that bear them, i.e. on nesting productivity, clutch size, nest initiation date, offspring quality, body condition, flying ability, foraging behaviours, energy expenditure and survival rate. Method of attachment (harness, collar, glue, anchor, implant, breast-mounted or tailmount) had no influence on the strength of these effects but anchored and implanted transmitters had the highest reported rates of device-induced mortality. Furthermore, external devices, but not internal devices, caused an increase in 'device-induced behaviour' (comfort behaviours such as preening, fluffing and stretching, and unrest activities including unquantifiable 'active' behaviours). These findings suggest that, with the exception of device-induced behaviour, external attachment is preferable to implantation. In the present study we undertake a meta-analysis of 183 estimates of device impact from 39 studies of 36 species of bird designed to explicitly compare the effects of externally attached and surgically implanted devices on a range of traits, including condition, energy expenditure and reproduction. In contrast to a previous study, we demonstrate that externally attached devices have a consistent detrimental effect (i.e. negative influences on body condition, reproduction, metabolism and survival), whereas implanted devices have no consistent effect. We also show that the magnitude of the negative effect of externally attached devices decreases with time. We therefore conclude that device implantation is preferable to external attachment, providing that the risk of mortality associated with the anaesthesia and surgery required for

  18. Energetic neutral contamination in modern high-current implanters (United States)

    Cherekdjian, S.; Weisenberger, W.


    The presence of energetic neutrals in a high-current, high-energy implant can result in nonuniformities on a silicon wafer. A larger concern is when the energetic neutrals are not of the desired energy. This is a major consideration when designing ion implanters with pre- and post-acceleration stages. This paper investigates the levels of pre-accelerated boron neutrals present in a 180 kV boron implant. The machines investigated were a Nova 20A and an Applied Materials PI9000. A comparison of their vacuum systems and their ability to cope with photoresist batches and argon backfill are presented. Silicon wafers were mapped by four-point probe resistivity measurements and the levels of pre-accelerated neutrals were quantified by spreading resistance profiles (SRPs). It is clearly demonstrated that good uniformity on a bare silicon wafer is not an indicator of a clean ion beam. Even though it is well understood that this problem is vacuum-related, modern high-current implanters are still being built and marketed with improper vacuum isolation and insufficient pumping capability.

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

    Directory of Open Access Journals (Sweden)

    Hagen Monica E


    Full Text Available Abstract 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.

  20. Changes in Spirometry After Left Ventricular Assist Device Implantation. (United States)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Breault, Stéphane, E-mail: [Lausanne University Hospital, Diagnostic and Interventional Radiology Department (Switzerland); Glauser, Frédéric, E-mail: [Lausanne University Hospital, Angiology and Diagnostic and Interventional Radiology Departments (Switzerland); Babaker, Malik, E-mail:; Doenz, Francesco, E-mail:; Qanadli, Salah Dine, E-mail: [Lausanne University Hospital, Diagnostic and Interventional Radiology Department (Switzerland)


    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. Post-operative orbital imaging: a focus on implants and prosthetic devices

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    Adams, Ashok [Royal London Hospital, Diagnostic Neuroradiology, Barts Health NHS Trust, London (United Kingdom); Mankad, Kshitij [Great Ormond Street Hospital, Diagnostic Neuroradiology, London (United Kingdom); Poitelea, Cornelia; Verity, David H. [Moorfields Eye Hospital, London (United Kingdom); Davagnanam, Indran [National Hospital for Neurology and Neurosurgery, London (United Kingdom)


    Accurate interpretation of orbital imaging in the presence of either orbital implants requires a sound knowledge of both the surgical approach used and the imaging characteristics of the implanted devices themselves. In this article, the radiological appearance of the various devices used in ophthalmology, and their relationship to other orbital structures, is reviewed. In addition, the intended anatomical location, function of these devices, and clinical indications for their use are provided. (orig.)

  3. Assessment of more than 1,000 implanted percutaneous bone conduction devices: skin reactions and implant survival. (United States)

    Dun, Catharina A J; Faber, Hubert T; de Wolf, Maarten J F; Mylanus, Emmanuel A M; Cremers, Cor W R J; Hol, Myrthe K S


    This study assesses soft tissue reactions and implant stability of 1,132 percutaneous titanium implants (970 patients) for bone conduction devices (BCDs). In addition, it examines BCD usage and comparisons between different patient groups. Retrospective survey. Mean follow-up time of 4.6 years. Tertiary care referral center. The surveyed cohort was divided into 3 different age groups (children, adults, and the elderly). In addition, 4 groups with variable loading times (i.e., the time between placement of the implant and loading the BCD sound processor) were identified as well as a subgroup of patients with mental retardation. Soft tissue reactions around the percutaneous implants as classified by the Holgers grading system, implant failure, and revision surgery rates. In 95.5% of the 7,415 observations of 1,132 implants, there were no adverse soft tissue reactions. Implant loss was 8.3%. Significantly more soft tissue reactions and implant failures were observed in children compared with adults and the elderly (p < 0.05). Implant survival was lower in patients with mental retardation compared with patients without mental retardation (p = 0.001). The loading time did not influence the occurrence of soft tissue reactions and implant survival rates. Children and patients with mental retardation are the most vulnerable to soft tissue reactions and implant losses. Additional and more frequent care needs to be given during outpatient consultations. Because loading as early as 3 to 5 weeks did not negatively affect skin reactions or implant survival, full BCD installation can occur earlier without risk.

  4. 34 CFR 300.113 - Routine checking of hearing aids and external components of surgically implanted medical devices. (United States)


    ... components of surgically implanted medical devices. 300.113 Section 300.113 Education Regulations of the... surgically implanted medical devices. (a) Hearing aids. Each public agency must ensure that hearing aids worn...) External components of surgically implanted medical devices. (1) Subject to paragraph (b)(2) of...

  5. Mass spectrometry improvement on an high current ion implanter

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, J.G., E-mail: [Instituto Superior de Engenharia de Lisboa and Centro de Fisica Nuclear of the University of Lisbon, Rua Conselheiro Emidio Navarro, 1, 1959-007 Lisbon (Portugal); Alegria, F.C., E-mail: [Instituto Superior Tecnico/Technical University of Lisbon and Instituto de Telecomunicacoes, Av. Rovisco Pais, 1, 1049-001 Lisbon (Portugal); Redondo, L.M., E-mail: [Instituto Superior de Engenharia de Lisboa and Centro de Fisica Nuclear of the University of Lisbon, Rua Conselheiro Emidio Navarro, 1, 1959-007 Lisbon (Portugal); Rocha, J., E-mail: [Instituto Tecnologico Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Alves, E., E-mail: [Instituto Tecnologico Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal)


    The development of accurate mass spectrometry, enabling the identification of all the ions extracted from the ion source in a high current implanter is described. The spectrometry system uses two signals (x-y graphic), one proportional to the magnetic field (x-axes), taken from the high-voltage potential with an optic fiber system, and the other proportional to the beam current intensity (y-axes), taken from a beam-stop. The ion beam mass register in a mass spectrum of all the elements magnetically analyzed with the same radius and defined by a pair of analyzing slits as a function of their beam intensity is presented. The developed system uses a PC to control the displaying of the extracted beam mass spectrum, and also recording of all data acquired for posterior analysis. The operator uses a LabVIEW code that enables the interfacing between an I/O board and the ion implanter. The experimental results from an ion implantation experiment are shown.

  6. Overcoming the current issues surrounding device leads: reducing the complications during extraction. (United States)

    Bongiorni, Maria Grazia; Segreti, Luca; Di Cori, Andrea; Zucchelli, Giulio; Paperini, Luca; Viani, Stefano; Soldati, Ezio


    The implantation rate of cardiac implantable electronic devices has consistently increased in the last 20 years, as have the related complication rates. The most relevant issue is the removal of pacing and implantable cardioverter defibrillator (ICD) leads, which a few months after implantation tend to develop intravascular fibrosis, often making extraction a challenging and risky procedure. Areas covered: The transvenous lead extraction (TLE) scenario is constantly evolving. TLE is a key procedure in lead management strategies. Many efforts have been made to develop new TLE approaches and techniques allowing a safe and effective procedure for patients. The increasing rate of cardiac implantable electronic device (CIED) implantations and of CIED related complications highlight the importance of TLE. Lead related- and patient-related factors may change the future of extractions. We review the current status of TLE, focusing on the strategies available to perform the optimal procedure in the right patient and reducing procedure related complications. Expert commentary: Understanding the importance of an accurate TLE risk stratification is mandatory to optimize the procedural risk-to-benefits ratio. The use of adequate tools, techniques and approaches, and appropriate training are cornerstones for the achievement of safer procedures.

  7. A device for vacuum drying, inert gas backfilling and solder sealing of hermetic implant packages. (United States)

    Schuettler, Martin; Huegle, Matthias; Ordonez, Juan S; Wilde, Juergen; Stieglitz, Thomas


    Modern implanted devices utilize microelectronics that have to be protected from the body fluids in order to maintain their functionality over decades. Moisture protection of implants is addressed by enclosing the electronic circuits into gas-tight packages. In this paper we describe a device that allows custom-built hermetic implant packages to be vacuum-dried (removing residual moisture from inside the package), backfilled with an inert gas at adjustable pressure and hermetically sealed employing a solder seal. A typical operation procedure of the device is presented.

  8. Update on Renal Replacement Therapy: Implantable Artificial Devices and Bioengineered Organs. (United States)

    Attanasio, Chiara; Latancia, Marcela T; Otterbein, Leo E; Netti, Paolo A


    Recent advances in the fields of artificial organs and regenerative medicine are now joining forces in the areas of organ transplantation and bioengineering to solve continued challenges for patients with end-stage renal disease. The waiting lists for those needing a transplant continue to exceed demand. Dialysis, while effective, brings different challenges, including quality of life and susceptibility to infection. Unfortunately, the majority of research outputs are far from delivering satisfactory solutions. Current efforts are focused on providing a self-standing device able to recapitulate kidney function. In this review, we focus on two remarkable innovations that may offer significant clinical impact in the field of renal replacement therapy: the implantable artificial renal assist device (RAD) and the transplantable bioengineered kidney. The artificial RAD strategy utilizes micromachining techniques to fabricate a biohybrid system able to mimic renal morphology and function. The current trend in kidney bioengineering exploits the structure of the native organ to produce a kidney that is ready to be transplanted. Although these two systems stem from different technological approaches, they are both designed to be implantable, long lasting, and free standing to allow patients with kidney failure to be autonomous. However, for both of them, there are relevant issues that must be addressed before translation into clinical use and these are discussed in this review.

  9. 21 CFR 860.93 - Classification of implants, life-supporting or life-sustaining devices. (United States)


    ... 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 OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES MEDICAL DEVICE CLASSIFICATION...

  10. Radiofrequency identification and medical devices: the regulatory framework on electromagnetic compatibility. Part II: active implantable medical devices. (United States)

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


    The number and the types of electromagnetic emitters to which patients with active implantable medical devices (AIMD) are exposed to in their daily activities have proliferated over the last decade. Radiofrequency identification (RFID) is an example of wireless technology applied in many fields. The interaction between RFID emitters and AIMD is an important issue for patients, industry and regulators, because of the risks associated with such interactions. The different AIMDs refer to different standards that address the electromagnetic immunity issue in different ways. Indeed, different test setups, immunity levels and rationales are used to guarantee that AIMDs are immune to electromagnetic nonionizing radiation. In this article, the regulatory framework concerning electromagnetic compatibility between RFID systems and AIMDs is analyzed to understand whether and how the application of the current AIMD standards allows for the effective control of the possible risks associated with RFID technology.

  11. Psychophysical Map Stability in Bilateral Sequential Cochlear Implantation: Comparing Current Audiology Methods to a New Statistical Definition. (United States)

    Domville-Lewis, Chloe; Santa Maria, Peter L; Upson, Gemma; Chester-Browne, Ronel; Atlas, Marcus D


    The purpose of this study was to establish a statistical definition for stability in cochlear implant maps. Once defined, this study aimed to compare the duration taken to achieve a stable map in first and second implants in patients who underwent sequential bilateral cochlear implantation. This article also sought to evaluate a number of factors that potentially affect map stability. A retrospective cohort study of 33 patients with sensorineural hearing loss who received sequential bilateral cochlear implantation (Cochlear, Sydney, Australia), performed by the senior author. Psychophysical parameters of hearing threshold scores, comfort scores, and the dynamic range were measured for the apical, medial, and basal portions of the cochlear implant electrode at a range of intervals postimplantation. Stability was defined statistically as a less than 10% difference in threshold, comfort, and dynamic range scores over three consecutive mapping sessions. A senior cochlear implant audiologist, blinded to implant order and the statistical results, separately analyzed these psychophysical map parameters using current assessment methods. First and second implants were compared for duration to achieve stability, age, gender, the duration of deafness, etiology of deafness, time between the insertion of the first and second implant, and the presence or absence of preoperative hearing aids were evaluated and its relationship to stability. Statistical analysis included performing a two-tailed Student's t tests and least squares regression analysis, with a statistical significance set at p ≤ 0.05. There was a significant positive correlation between the devised statistical definition and the current audiology methods for assessing stability, with a Pearson correlation coefficient r = 0.36 and a least squares regression slope (b) of 0.41, df(58), 95% confidence interval 0.07 to 0.55 (p = 0.004). The average duration from device switch on to stability in the first implant was 87

  12. Enhanced light extraction efficiency of GaN-based light-emittng diodes by nitrogen implanted current blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Deok; Oh, Seung Kyu; Park, Min Joo; Kwak, Joon Seop, E-mail:


    Highlights: • A nitrogen implanted current-blocking layer was successfully demonstrated. • Light-extraction efficiency and radiant intensity was increased by more than 20%. • Ion implantation was successfully implemented in GaN based light-emitting diodes. - Abstract: GaN-based light emitting diodes (LEDs) with a nitrogen implanted current-blocking layer (CBL) were successfully demonstrated for improving the light extraction efficiency (LEE) and radiant intensity. The LEE and radiant intensity of the LEDs with a shallow implanted CBL with nitrogen was greatly increased by more than 20% compared to that of a conventional LED without the CBL due to an increase in the effective current path, which reduces light absorption at the thick p-pad electrode. Meanwhile, deep implanted CBL with a nitrogen resulted in deterioration of the LEE and radiant intensity because of formation of crystal damage, followed by absorption of the light generated at the multi-quantum well(MQW). These results clearly suggest that ion implantation method, which is widely applied in the fabrication of Si based devices, can be successfully implemented in the fabrication of GaN based LEDs by optimization of implanted depth.

  13. Right ventricular failure after implantation of a continuous-flow left ventricular assist device

    DEFF Research Database (Denmark)

    Cordtz, Johan Joakim; Nilsson, Jens C; Hansen, Peter B;


    Right ventricular failure (RVF) is a significant complication after implantation of a left ventricular assist device. We aimed to identify haemodynamic changes in the early postoperative phase that predicted subsequent development of RVF in a cohort of HeartMate II (HMII) implanted patients....

  14. Monitoring device acceptance in implantable cardioverter defibrillator patients using the Florida Patient Acceptance Survey

    DEFF Research Database (Denmark)

    Versteeg, Henneke; Starrenburg, Annemieke; Denollet, Johan


    Patient device acceptance might be essential in identifying patients at risk for adverse patient-reported outcomes following implantation of an implantable cardioverter defibrillator (ICD). We examined the validity and reliability of the Florida Patient Acceptance Scale (FPAS) and identified corr...

  15. Sequential bilateral cochlear implantation in children: parents' perspective and device use.

    NARCIS (Netherlands)

    Sparreboom, M.; Leeuw, A.R.; Snik, A.F.M.; Mylanus, E.A.M.


    OBJECTIVE: The purpose of this study was (1) to measure parental expectations before surgery of a sequentially placed second cochlear implant and compare these results with parental observations postoperatively and (2) to measure device use of the second cochlear implant and compare to unilateral im

  16. Sequential bilateral cochlear implantation in children: parents' perspective and device use.

    NARCIS (Netherlands)

    Sparreboom, M.; Leeuw, A.R.; Snik, A.F.M.; Mylanus, E.A.M.


    OBJECTIVE: The purpose of this study was (1) to measure parental expectations before surgery of a sequentially placed second cochlear implant and compare these results with parental observations postoperatively and (2) to measure device use of the second cochlear implant and compare to unilateral im

  17. Identification of causative organism in cardiac implantable electronic device infections. (United States)

    Fukunaga, Masato; Goya, Masahiko; Nagashima, Michio; Hiroshima, Kenichi; Yamada, Takashi; An, Yoshimori; Hayashi, Kentaro; Makihara, Yu; Ohe, Masatsugu; Ichihashi, Kei; Ohtsuka, Morimasa; Miyazaki, Hiroaki; Ando, Kenji


    The causative organism in cardiovascular implantable electronic device (CIED) infection is usually diagnosed with the cultures from blood, removed leads, and/or infected pocket material. The cultured organism, however, is sometimes different among these samples. Two hundred sixty patients with CIED infection, who underwent lead extraction between April 2005 and December 2014, were analyzed. More than two blood culture sets, all the extracted leads, and swab culture of the pocket were sent to the laboratory for culture. Among the patients all of whose microbiological examinations were available, we analyzed the causative organism defined as the species detected in at least two different sites. All the culture results were available in the 208 patients, showing 69 systemic infections (including 30 cases of infectious endocarditis) and 139 local infections. Blood culture, lead culture, and swab culture were positive in 57 (27%), 169 (81%), and 152 (73%), respectively. Staphylococcus aureus [37% including methicillin-resistant S. aureus (MRSA) (12%)] and coagulase-negative staphylococci (CoNS, 36%) were the most common causative organism, followed by non-staphylococci (23%), and poly-microbial infection (4%). The detection of S. aureus from pocket or removed leads rendered higher predictive value of a causative organism than that of CoNS. The detection of Gram-negative bacteria, fungi, and mycobacteria indicated that it was most likely a causative organism. Gram-positive bacteria excluding Staphylococcus, such as Corynebacterium spp., tended to coexist as a benign organism. The causative organism is mostly S. aureus and CoNS. Detection of S. aureus or Gram-negative bacteria means that it is more likely a causative organism. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.


    NARCIS (Netherlands)



    Various totally implantable drug delivery systems from single access ports to micropumps are now available for administration of repeated boluses, and continuous or programmable infusions. In this respect, emphasis is given to a relatively cheap, totally implantable system for self-administering int

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

    Directory of Open Access Journals (Sweden)

    Zorzetto L


    Full Text Available Laura Zorzetto,1 Paola Brambilla,1 Elena Marcello,1 Nora Bloise,2 Manuela De Gregori,3 Lorenzo Cobianchi,4,5 Andrea Peloso,4,5 Massimo Allegri,6 Livia Visai,2,7 Paola Petrini1 1Department of Chemistry, Materials and Chemical Engineering ‘G. Natta’, Politecnico di Milano, Milan, 2Department of Molecular Medicine, Centre for Health Technologies (CHT, INSTM UdR of Pavia, University of Pavia, 3Pain Therapy Service, IRCCS Foundation Policlinico San Matteo Pavia, Pavia, 4General Surgery Department, IRCCS Foundation Policlinico San Matteo, Pavia, 5Departments of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, 6Department of Surgical Sciences, University of Parma, Parma, 7Department of Occupational Medicine, Toxicology and Environmental Risks, S. Maugeri Foundation, IRCCS, Lab of Nanotechnology, Pavia, Italy Abstract: 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

  20. Implanting inequality: empirical evidence of social and ethical risks of implantable radio-frequency identification (RFID) devices. (United States)

    Monahan, Torin; Fisher, Jill A


    The aim of this study was to assess empirically the social and ethical risks associated with implantable radio-frequency identification (RFID) devices. Qualitative research included observational studies in twenty-three U.S. hospitals that have implemented new patient identification systems and eighty semi-structured interviews about the social and ethical implications of new patient identification systems, including RFID implants. The study identified three primary social and ethical risks associated with RFID implants: (i) unfair prioritization of patients based on their participation in the system, (ii) diminished trust of patients by care providers, and (iii) endangerment of patients who misunderstand the capabilities of the systems. RFID implants may aggravate inequalities in access to care without any clear health benefits. This research underscores the importance of critically evaluating new healthcare technologies from the perspective of both normative ethics and empirical ethics.

  1. Pectoral nerves (PECS) and intercostal nerve block for cardiac resynchronization therapy device implantation


    Fujiwara, Atsushi; Komasawa, Nobuyasu; Minami, Toshiaki


    A 71-year-old man was scheduled to undergo cardiac resynchronization therapy device (CRTD) implantation. He was combined with severe chronic heart failure due to ischemic heart disease. NYHA class was 3 to 4 and electrocardiogram showed non-sustained ventricular. Ejection fraction was about 20% revealed by transthoracic echocardiogram. He was also on several anticoagulation medications. We planned to implant the device under the greater pectoral muscle. As general anesthesia was considered ri...

  2. Additively manufactured custom load-bearing implantable devices: grounds for caution

    Directory of Open Access Journals (Sweden)

    Elisabetta M Zanetti


    Full Text Available Background Additive manufacturing technologies are being enthusiastically adopted by the orthopaedic community since they are providing new perspectives and new possibilities. First applications were finalised for educational purposes, pre-operative planning, and design of surgical guides; recent applications also encompass the production of implantable devices where 3D printing can bring substantial benefits such as customization, optimization, and manufacturing of very complex geometries. The conceptual smoothness of the whole process may lead to the idea that any medical practitioner can use a 3D printer and her/his imagination to design and produce novel products for personal or commercial use. Aims Outlining how the whole process presents more than one critical aspects, still demanding further research in order to allow a safe application of this technology for fully-custom design, in particular confining attention to orthopaedic/orthodontic prostheses defined as components responding mainly to a structural function. Methods Current knowledge of mechanical properties of additively manufactured components has been examined along with reasons why the behaviour of these components might differ from traditionally manufactured components. The structural information still missing for mechanical design is outlined. Results Mechanical properties of additively manufactured components are not completely known, and especially fatigue limit needs to be examined further. Conclusion At the present stage, with reference to load-bearing implants subjected to many loading cycles, the indication of custom-made additively manufactured medical devices should be restricted to the cases with no viable alternative.

  3. Nanomaterial-Based Approaches for Prevention of Biofilm-Associated Infections on Medical Devices and Implants. (United States)

    Naik, Kshipra; Srivastava, Pallavee; Deshmukh, Ketaki; Monsoor, M S; Kowshik, Meenal


    Biofilm formation is a major problem in medical device-related infections leading to failure of implant-based therapies. Though various conventional approaches to counter biofilm formation like physical and/or mechanical removal, chemical removal, and the use of antimicrobials exist, they fail due to increased resistance of biofilms. This review discusses various nanomaterial-based approaches such as the use of metallic and metal oxide nanoparticles- and polymer-based nanocomposites, which are currently being developed for prevention and treatment of biofilms. Nanoparticles of transition metals and their oxides are toxic to microorganisms and exhibit their toxicity through the generation of reactive oxygen species at concentrations that are non-toxic to eukaryotic cells. Other approaches include the entrapment of bioactive agents in polymer/ceramic nanoparticles, for enhanced anti-biofilm activity due to the synergistic effect between them. These nanomaterial-based approaches could play an important role in control and eradication of biofilm related infections and complications associated with medical devices and implants.

  4. Medical devices for the anesthetist: current perspectives

    Directory of Open Access Journals (Sweden)

    Ingrande J


    Full Text Available Jerry Ingrande, Hendrikus JM LemmensDepartment of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USAAbstract: Anesthesiologists are unique among most physicians in that they routinely use technology and medical devices to carry out their daily activities. Recently, there have been significant advances in medical technology. These advances have increased the number and utility of medical devices available to the anesthesiologist. There is little doubt that these new tools have improved the practice of anesthesia. Monitoring has become more comprehensive and less invasive, airway management has become easier, and placement of central venous catheters and regional nerve blockade has become faster and safer. This review focuses on key medical devices such as cardiovascular monitors, airway equipment, neuromonitoring tools, ultrasound, and target controlled drug delivery software and hardware. This review demonstrates how advances in these areas have improved the safety and efficacy of anesthesia and facilitate its administration. When applicable, indications and contraindications to the use of these novel devices will be explored as well as the controversies surrounding their use.Keywords: catheters, echocardiography, ultrasound, fiberoptic bronchoscope, laryngeal mask airway, closed-loop anesthesia

  5. National projections of time, cost and failure in implantable device identification: Consideration of unique device identification use. (United States)

    Wilson, Natalia; Broatch, Jennifer; Jehn, Megan; Davis, Charles


    U.S. health care is responding to significant regulation and meaningful incentives for higher quality care, patient safety, electronic documentation and data exchange. FDA's Unique Device Identification (UDI) Rule, a relatively new regulation aligned with these goals, requires standard labeling of medical devices by manufacturers. This lays the foundation for UDI scanning and documentation in the electronic health record, expected to change the landscape of medical device identification and postmarket surveillance. We developed national projections for time, cost and failure in implant identification prior to revision total hip and knee arthroplasty (THA/TKA) using American Association of Hip and Knee Surgeons 2012 membership survey data, Nationwide Inpatient Sample 2011 data and THA/TKA demand projection data. Our projections suggest that cumulative surgeon time spent identifying failed implants could reach 133,000 h in 2030, representing opportunity to perform over 500,000 15 min established patient office visits. Staff time could reach 220,000 h with a cost of $3.3m. Failed implants that cannot be identified may be greater than 50,000 preoperatively and 25,000 intraoperatively in 2030. Study projections indicate significant time, cost and inability to identify failed implants, supporting need for improvement of implant documentation. FDA's UDI Rule sets the foundation for UDI scanning and documentation in the electronic health record, a process poised to serve as the standard system for device documentation. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Atrioverter : An implantable device for the treatment of atrial fibrillation

    NARCIS (Netherlands)

    Wellens, HJJ; Lau, CP; Luderitz, B; Akhtar, M; Waldo, AL; Camm, AJ; Timmermans, C; Tse, HF; Jung, W; Jordaens, L; Ayers, G


    Background-During atrial fibrillation, electrophysiological changes occur in atrial tissue that favor the maintenance of the arrhythmia and facilitate recurrence after conversion to sinus rhythm. An implantable defibrillator connected to right atrial and coronary sinus defibrillation leads allows pr

  7. Scientists Design Heat-Activated Penis Implant (United States)

    ... news/fullstory_162815.html Scientists Design Heat-Activated Penis Implant Device an improvement on current implants, researchers ... News) -- Doctors report that they have crafted a penis implant that becomes erect when heated. Dubbed by ...

  8. The effect of steam sterilization on the accuracy of spring-style mechanical torque devices for dental implants

    Directory of Open Access Journals (Sweden)

    Mahshid M


    Full Text Available Minoo Mahshid,1 Aboulfazl Saboury,1 Ali Fayaz,1 Seyed Jalil Sadr,1 Friedrich Lampert,2 Maziar Mir2,31Department of Prosthodontics, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2Department of Conservative Dentistry, Aachen RWTH Hospital, Aachen, Germany; 3Beckman Laser Institute, UCI, Irvine, CA, USABackground: Mechanical torque devices (MTDs are one of the most commonly recommended devices used to deliver optimal torque to the screw of dental implants. Recently, high variability has been reported about the accuracy of spring-style mechanical torque devices (S-S MTDs. Joint stability and survival rate of fixed implant supported prosthesis depends on the accuracy of these devices. Currently, there is limited information on the steam sterilization influence on the accuracy of MTDs. The purpose of this study was to assess the effect of steam sterilization on the accuracy (±10% of the target torque of spring-style mechanical torque devices for dental implants.Materials and methods: Fifteen new S-S MTDs and their appropriate drivers from three different manufacturers (Nobel Biocare, Straumann [ITI], and Biomet 3i [3i] were selected. Peak torque of devices (5 in each subgroup was measured before and after autoclaving using a Tohnichi torque gauge. Descriptive statistical analysis was used and a repeated-measures ANOVA with type of device as a between-subject comparison was performed to assess the difference in accuracy among the three groups of spring-style mechanical torque devices after sterilization. A Bonferroni post hoc test was used to assess pairwise comparisons.Results: Before steam sterilization, all the tested devices stayed within 10% of their target values. After 100 sterilization cycles, results didn't show any significant difference between raw and absolute error values in the Nobel Biocare and ITI devices; however the results demonstrated an increase of error values in the 3i group (P < 0.05. Raw error

  9. Single-Ion Implantation for the Development of Si-Based MOSFET Devices with Quantum Functionalities

    Directory of Open Access Journals (Sweden)

    Jeffrey C. McCallum


    Full Text Available Interest in single-ion implantation is driven in part by research into development of solid-state devices that exhibit quantum behaviour in their electronic or optical characteristics. Here, we provide an overview of international research work on single ion implantation and single ion detection for development of electronic devices for quantum computing. The scope of international research into single ion implantation is presented in the context of our own research in the Centre for Quantum Computation and Communication Technology in Australia. Various single ion detection schemes are presented, and limitations on dopant placement accuracy due to ion straggling are discussed together with pathways for scale-up to multiple quantum devices on the one chip. Possible future directions for ion implantation in quantum computing and communications are also discussed.

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

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


    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.

  11. Finite volume analysis of temperature effects induced by active MRI implants with cylindrical symmetry: 1. Properly working devices

    Directory of Open Access Journals (Sweden)

    Schnorr Jörg


    Full Text Available Abstract Background Active Magnetic Resonance Imaging implants are constructed as resonators tuned to the Larmor frequency of a magnetic resonance system with a specific field strength. The resonating circuit may be embedded into or added to the normal metallic implant structure. The resonators build inductively coupled wireless transmit and receive coils and can amplify the signal, normally decreased by eddy currents, inside metallic structures without affecting the rest of the spin ensemble. During magnetic resonance imaging the resonators generate heat, which is additional to the usual one described by the specific absorption rate. This induces temperature increases of the tissue around the circuit paths and inside the lumen of an active implant and may negatively influence patient safety. Methods This investigation provides an overview of the supplementary power absorbed by active implants with a cylindrical geometry, corresponding to vessel implants such as stents, stent grafts or vena cava filters. The knowledge of the overall absorbed power is used in a finite volume analysis to estimate temperature maps around different implant structures inside homogeneous tissue under worst-case assumptions. The "worst-case scenario" assumes thermal heat conduction without blood perfusion inside the tissue around the implant and mostly without any cooling due to blood flow inside vessels. Results The additional power loss of a resonator is proportional to the volume and the quality factor, as well as the field strength of the MRI system and the specific absorption rate of the applied sequence. For properly working devices the finite volume analysis showed only tolerable heating during MRI investigations in most cases. Only resonators transforming a few hundred mW into heat may reach temperature increases over 5 K. This requires resonators with volumes of several ten cubic centimeters, short inductor circuit paths with only a few 10 cm and a quality

  12. Feasibility of Home-Use Animal-Assisted Activities in Patients With Implanted Cardiac Electronic Devices

    Directory of Open Access Journals (Sweden)

    Peter Jirak


    Full Text Available Animal-assisted activities (AAAs are mainly carried out in institutions. The aim of this prospective pilot study was to assess the willingness of patients with cardiac implanted electronic devices (IEDs to participate in AAA. The sample included 75 ambulatory patients (18 females, M age = 69 years, who attended an outpatient clinic for control of antibradycardic pacemakers (n = 15 or implanted cardioverter defibrillators (n = 60. Twenty-three percent were current and 48% were previous pet-owners. Current pet-owners were younger than non-pet-owners (63.5 vs. 72.0 years, p = .0003. Twelve patients (16% showed interest in AAA visits. However, only two patients agreed to an AAA visit. Both patients were visited once, but declined further visits. Hence, AAA sessions at home were poorly accepted, mainly because the patients considered themselves too busy or healthy, or due to a general disinterest in AAA. Potential health benefits associated with AAA may not be feasible to investigate during home visits of AAA-teams in patients with IEDs who are healthy enough to leave their homes. For further studies concerning AAA in patients with cardiovascular diseases, we suggest focusing on institutions like rehabilitation centers or day care centers and on more severely sick, homebound patients.

  13. Bilateral cochlear implantation: current concepts, indications, and results. (United States)

    Basura, Gregory J; Eapen, Rose; Buchman, Craig A


    The optimal treatment for bilateral hearing loss continues to evolve as cochlear implant (CI) and hearing aid technologies advance, as does our understanding of the central auditory system. Ongoing discussions continue on the validity and feasibility of bilateral CI in terms of performance, justification of need, medical/surgical safety concerns, and economics. The purpose of this review article is to provide an update on the advantages and disadvantages of bilateral CI and to provide a discussion on timing (simultaneous vs. sequential), technology (bimodal vs. binaural) and feasibility. Binaural advantages are found in both adult and pediatric bilateral CI recipients, the greatest being the head shadow effect and improvements in localization and loudness summation. This theoretically offers an advantage over their unilateral implanted counterparts in terms of improved sound localization and enhanced speech perception under noisy conditions. Most investigators agree that bilateral stimulation during critical periods of development is paramount for optimizing auditory functioning in children. Currently, bilateral CI is widely accepted as a safe and effective means of bilateral auditory stimulation.

  14. Anesthesia management for MitraClip device implantation

    Directory of Open Access Journals (Sweden)

    Harikrishnan Kothandan


    Full Text Available Aims and Objectives: Percutaneous MitraClip implantation has been demonstrated as an alternative procedure in high-risk patients with symptomatic severe mitral regurgitation (MR who are not suitable (or denied mitral valve repair/replacement due to excessive co morbidity. The MitraClip implantation was performed under general anesthesia and with 3-dimensional transesophageal echocardiography (TEE and fluoroscopic guidance. Materials and Methods: Peri-operative patient data were extracted from the electronic and paper medical records of 21 patients who underwent MitraClip implantations. Results: Four MitraClip implantation were performed in the catheterization laboratory; remaining 17 were performed in the hybrid operating theatre. In 2 patients, procedure was aborted, in one due to migration of the Chiari network into the left atrium and in second one, the leaflets and chords of the mitral valve torn during clipping resulting in consideration for open surgery. In the remaining 19 patients, MitraClip was implanted and the patients showed acute reduction of severe MR to mild-moderate MR. All the patients had invasive blood pressure monitoring and the initial six patients had central venous catheterization prior to the procedure. Intravenous heparin was administered after the guiding catheter was introduced through the inter-atrial septum and activated clotting time was maintained beyond 250 s throughout the procedure. Protamine was administered at the end of the procedure. All the patients were monitored in the intensive care unit after the procedure. Conclusions: Percutaneous MitraClip implantation is a feasible alternative in high-risk patients with symptomatic severe MR. Anesthesia management requirements are similar to open surgical mitral valve repair or replacement. TEE plays a vital role during the MitraClip implantation.

  15. Evaluating the Safety Profile of Non-Active Implantable Medical Devices Compared with Medicines

    NARCIS (Netherlands)

    Pane, J. (Josep); P.M. Coloma (Preciosa); K.M.C. Verhamme (Katia); M.C.J.M. Sturkenboom (Miriam); Rebollo, I. (Irene)


    textabstractRecent safety issues involving non-active implantable medical devices (NAIMDs) have highlighted the need for better pre-market and post-market evaluation. Some stakeholders have argued that certain features of medicine safety evaluation should also be applied to medical devices. Our obje

  16. Capsule endoscopy in patients with cardiac pacemakers, implantable cardioverter defibrillators and left heart assist devices. (United States)

    Bandorski, Dirk; Höltgen, Reinhard; Stunder, Dominik; Keuchel, Martin


    According to the recommendations of the US Food and Drug Administration and manufacturers, capsule endoscopy should not be used in patients carrying implanted cardiac devices. For this review we considered studies indexed (until 30.06.2013) in Medline [keywords: capsule endoscopy, small bowel endoscopy, cardiac pacemaker, implantable cardioverter defibrillator, interference, left heart assist device], technical information from Given Imaging and one own publication (not listed in Medline). Several in vitro and in vivo studies included patients with implanted cardiac devices who underwent capsule endoscopy. No clinically relevant interference was noticed. Initial reports on interference with a simulating device were not reproduced. Furthermore technical data of PillCam (Given Imaging) demonstrate that the maximum transmission power is below the permitted limits for cardiac devices. Hence, impairment of cardiac pacemaker, defibrillator or left ventricular heart assist device function by capsule endoscopy is not expected. However, wireless telemetry can cause dysfunction of capsule endoscopy recording. Application of capsule endoscopy is feasible and safe in patients with implanted cardiac devices such as pacemakers, cardioverter defibrillators, and left heart assist devices. Development of new technologies warrants future re-evaluation.

  17. Identification of Bodies by Unique Serial Numbers on Implanted Medical Devices. (United States)

    Blessing, Melissa M; Lin, Peter T


    Visual identification is the most common identification method used by medical examiners but is not always possible. Alternative methods include X-ray, fingerprint, or DNA comparison, but these methods require additional resources. Comparison of serial numbers on implanted medical devices is a rapid and definitive method of identification. To assess the practicality of using this method, we reviewed 608 consecutive forensic autopsies performed at a regional medical examiner office. Of these, 56 cases required an alternative method of identification due to decomposition (n = 35), gunshot wound (n = 9), blunt trauma (n = 6), or charring (n = 6). Of these 56 cases, eight (14.3%) were known to have an implanted medical device. Of these eight cases, five (63%) could be positively identified by comparing serial numbers. If an implanted medical device is known to be present, and medical records are available, identification by medical device serial number should be a first-line method. © 2017 American Academy of Forensic Sciences.

  18. Optimal position of the transmitter coil for wireless power transfer to the implantable device. (United States)

    Jinghui Jian; Stanaćević, Milutin


    The maximum deliverable power through inductive link to the implantable device is limited by the tissue exposure to the electromagnetic field radiation. By moving away the transmitter coil from the body, the maximum deliverable power is increased as the magnitude of the electrical field at the interface with the body is kept constant. We demonstrate that the optimal distance between the transmitter coil and the body is on the order of 1 cm when the current of the transmitter coil is limited to 1 A. We also confirm that the conditions on the optimal frequency of the power transmission and the topology of the transmission coil remain the same as if the coil was directly adjacent to the body.

  19. Breast Implants (United States)

    ... Medical Procedures Implants and Prosthetics Breast Implants Breast Implants Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Breast implants are medical devices that are implanted under the ...

  20. Comparison of in vivo biocompatibilities between parylene-C and polydimethylsiloxane for implantable microelectronic devices

    Indian Academy of Sciences (India)

    Dong Sup Lee; Su Jin Kim; Eun Bi Kwon; Cheol Whee Park; Su Min Jun; Bumkyoo Choi; Sae Woong Kim


    Implantable devices are often composed of or coated with different biologically compatible materials based on their requirements. Selecting a surface material for an implantable device is not an easy task, and it is necessary to compare the biocompatibilities of the available surface materials. In this study, we perform a comparison of the in vivo biocompatibilities of polydimethylsiloxane (PDMS) and para-xylyene polymer (parylene-C) as they are considered to be candidates for a coating material for implantable microelectronic devices. For in vivo biocompatibility testing, fifty four male Sprague-Dawley rats were used for testing, and they were divided into three groups (PDMS, parylene-C and a positive control). At one, four and twelve weeks after implantation of the test object, the density of inflammatory cells and the granulation layer thickness were recorded for each group and compared with other groups using visible light and fluorescence microscopy. The thickness of the granulation layer tended to decrease over time for all of the experimental groups, whereas the granulation layer thickness remained constant in the positive control group. The thinnest capsular layer was observed for the parylene-C group and fewest inflammatory cells were observed in this group during the entire experimental period. Macrophage infiltration was minimal, even at one week, and was not observed thereafter. The parylene-C group showed better biocompatibility than the PDMS groups, both for acute and chronic implantation. Thus, parylene-C is the best candidate of the tested materials for applications involving permanent implantable micro-devices.

  1. A zero-voltage switching technique for minimizing the current-source power of implanted stimulators. (United States)

    Çilingiroğlu, Uğur; İpek, Sercan


    The current-source power of an implanted stimulator is reduced almost to the theoretical minimum by driving the electrodes directly from the secondary port of the inductive link with a dedicated zero-voltage switching power supply. A feedback loop confined to the secondary of the inductive link adjusts the timing and conduction angle of switching to provide just the right amount of supply voltage needed for keeping the current-source voltage constant at or slightly above the compliance limit. Since drive is based on current rather than voltage, and supply-voltage update is near real-time, the quality of the current pulses is high regardless of how the electrode impedance evolves during stimulation. By scaling the switching frequency according to power demand, the technique further improves overall power consumption of the stimulator. The technique is implemented with a very simple control circuitry comprising a comparator, a Schmitt trigger and a logic gate of seven devices in addition to an on-chip switch and an off-chip capacitor. The power consumed by the proposed supply circuit itself is no larger than what the linear regulator of a conventional supply typically consumes for the same stimulation current. Still, the sum of supply and current-source power is typically between 20% and 75% of the conventional source power alone. Functionality of the proposed driver is verified experimentally on a proof-of-concept prototype built with 3.3 V devices in a 0.18 μm CMOS technology.

  2. Assessing infection risk in implanted tissue-engineered devices

    NARCIS (Netherlands)

    Kuijer, Roel; Jansen, Edwin J. P.; Emans, Pieter J.; Bulstra, Sjoerd K.; Riesle, Jens; Pieper, Jeroen; Grainger, David W.; Busscher, Henk J.


    Peri-operative contamination is the major cause of biomaterial-associated infections, highly complicating surgical patient outcomes. While this risk in traditional implanted biomaterials is well-recognised, newer cell-seeded, biologically conducive tissue-engineered (TE) constructs now targeted for

  3. Assessing infection risk in implanted tissue-engineered devices

    NARCIS (Netherlands)

    Kuijer, Roel; Jansen, Edwin J. P.; Emans, Pieter J.; Bulstra, Sjoerd K.; Riesle, Jens; Pieper, Jeroen; Grainger, David W.; Busscher, Henk J.


    Peri-operative contamination is the major cause of biomaterial-associated infections, highly complicating surgical patient outcomes. While this risk in traditional implanted biomaterials is well-recognised, newer cell-seeded, biologically conducive tissue-engineered (TE) constructs now targeted for

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

    Shi, Qiongfeng; Wang, Tao; Lee, Chengkuo


    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.

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

    Shi, Qiongfeng; Wang, Tao; Lee, Chengkuo


    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.

  6. Accuracy and Reproducibility of Radiographic Images for Assessing Crestal Bone Height of Implants Using the Precision Implant X-ray Locator (PIXRL) Device. (United States)

    Malloy, Kyle A; Wadhwani, Chandur; McAllister, Bradley; Wang, Mansen; Katancik, James A

    Assessment of crestal bone levels around implants is essential to monitor success and health. This is best accomplished with intraoral radiographs exposed at 90 degrees to the long axis of the implant, but this can be challenging to achieve clinically. Radiographic paralleling devices produce orthogonal radiographs but traditionally have required access to the implant body for each exposure. This study was conducted to determine if use of the Precision Implant X-ray Locator (PIXRL), a radiographic paralleling device that indexes the implant at the time of surgical placement, can produce orthogonal radiographs of dental implants more accurately than traditional radiologic techniques for assessing crestal bone levels. Three dental implants were inserted in dry human skulls in supracrestal positions to simulate crestal bone loss (maxillary right first premolar [site 14], maxillary right central incisor [site 11], and mandibular left second premolar [site 35]). The implants were masked with a soft tissue moulage and restored with provisional restorations. Four dental assistants exposed six radiographs using their usual and customary technique and six using the PIXRL device for each implant. A single examiner measured crestal bone levels on the radiographs relative to the implant platform shoulder on the mesial and distal of each implant. Recorded measurements were compared to the known values. Statistical analysis was completed using a generalized linear regression model to analyze the differences, and post-hoc comparisons with pairwise adjustment were applied. The images produced using the PIXRL device were more accurate overall compared to traditional techniques and were also more consistent. The greater degree of accuracy was statistically significant for all sites with the exception of the mesial measurements of the implant at site 11. This study demonstrates that the use of the PIXRL device can assist clinicians in obtaining more accurate orthogonal radiographs

  7. Evaluating the Safety Profile of Non-Active Implantable Medical Devices Compared with Medicines. (United States)

    Pane, Josep; Coloma, Preciosa M; Verhamme, Katia M C; Sturkenboom, Miriam C J M; Rebollo, Irene


    Recent safety issues involving non-active implantable medical devices (NAIMDs) have highlighted the need for better pre-market and post-market evaluation. Some stakeholders have argued that certain features of medicine safety evaluation should also be applied to medical devices. Our objectives were to compare the current processes and methodologies for the assessment of NAIMD safety profiles with those for medicines, identify potential gaps, and make recommendations for the adoption of new methodologies for the ongoing benefit-risk monitoring of these devices throughout their entire life cycle. A literature review served to examine the current tools for the safety evaluation of NAIMDs and those for medicines. We searched MEDLINE using these two categories. We supplemented this search with Google searches using the same key terms used in the MEDLINE search. Using a comparative approach, we summarized the new product design, development cycle (preclinical and clinical phases), and post-market phases for NAIMDs and drugs. We also evaluated and compared the respective processes to integrate and assess safety data during the life cycle of the products, including signal detection, signal management, and subsequent potential regulatory actions. The search identified a gap in NAIMD safety signal generation: no global program exists that collects and analyzes adverse events and product quality issues. Data sources in real-world settings, such as electronic health records, need to be effectively identified and explored as additional sources of safety information, particularly in some areas such as the EU and USA where there are plans to implement the unique device identifier (UDI). The UDI and other initiatives will enable more robust follow-up and assessment of long-term patient outcomes. The safety evaluation system for NAIMDs differs in many ways from those for drugs, but both systems face analogous challenges with respect to monitoring real-world usage. Certain features

  8. Development of an auditory implant manipulator for minimally invasive surgical insertion of implantable hearing devices


    Stieger, C.; Caversaccio, M; Arnold, A.; Zheng, G.; Salzmann, J; Widmer, D.; Gerber, N.; Thurner, M; Nauer, C.; Mussard, Y; Kompis, M.; Nolte, L P.; Häusler, R.; S. Weber


    Abstract Objective: To present the auditory implant manipulator, a navigation-controlled mechanical and electronic system which enables minimally invasive (‘keyhole') transmastoid access to the tympanic cavity. Materials and methods: The auditory implant manipulator is a miniaturised robotic system with five axes of movement and an integrated drill. It can be mounted on the operating table. We evaluated the surgical work field provided by the system, and the work sequence involved, using an a...

  9. Rechargeable membraneless glucose biobattery: Towards solid-state cathodes for implantable enzymatic devices (United States)

    Yazdi, Alireza Ahmadian; Preite, Roberto; Milton, Ross D.; Hickey, David P.; Minteer, Shelley D.; Xu, Jie


    Enzymatic biobatteries can be implanted in living organisms to exploit the chemical energy stored in physiological fluids. Generally, commonly-used electron donors (such as sugars) are ubiquitous in physiological environments, while electron acceptors such as oxygen are limited due to many factors including solubility, temperature, and pressure. The wide range of solid-state cathodes, however, may replace the need for oxygen breathing electrodes and serve in enzymatic biobatteries for implantable devices. Here, we have fabricated a glucose biobattery suitable for in vivo applications employing a glucose oxidase (GOx) anode coupled to a solid-state Prussian Blue (PB) thin-film cathode. PB is a non-toxic material and its electrochemistry enables fast regeneration if used in a secondary cell. This novel biobattery can effectively operate in a membraneless architecture as PB can reduce the peroxide produced by some oxidase enzymes. The resulting biobattery delivers a maximum power and current density of 44 μW cm-2 and 0.9 mA cm-2 , respectively, which is ca. 37% and 180% higher than an equivalent enzymatic fuel cell equipped with a bilirubin oxidase cathode. Moreover, the biobattery demonstrated a stable performance over 20 cycles of charging and discharging periods with only ca. 3% loss of operating voltage.

  10. Radiographic implications of procedures involving cardiac implantable electronic devices (CIEDs – Selected aspects

    Directory of Open Access Journals (Sweden)

    Roman Steckiewicz


    Full Text Available Background: Some cardiac implantable electronic device (CIED implantation procedures require the use of X-rays, which is reflected by such parameters as total fluoroscopy time (TFT and dose-area product (DAP – defined as the absorbed dose multiplied by the area irradiated. Material and Methods: This retrospective study evaluated 522 CIED implantation (424 de novo and 98 device upgrade and new lead placement procedures in 176 women and 346 men (mean age 75±11 years over the period 2012–2015. The recorded procedure-related parameters TFT and DAP were evaluated in the subgroups specified below. The group of 424 de novo procedures included 203 pacemaker (PM and 171 implantable cardioverter-defibrillator (ICD implantation procedures, separately stratified by single-chamber and dual-chamber systems. Another subgroup of de novo procedures involved 50 cardiac resynchronization therapy (CRT devices. The evaluated parameters in the group of 98 upgrade procedures were compared between 2 subgroups: CRT only and combined PM and ICD implantation procedures. Results: We observed differences in TFT and DAP values between procedure types, with PM-related procedures showing the lowest, ICD – intermediate (with values for single-chamber considerably lower than those for dual-chamber systems and CRT implantation procedures – highest X-ray exposure. Upgrades to CRT were associated with 4 times higher TFT and DAP values in comparison to those during other upgrade procedures. Cardiac resynchronization therapy de novo implantation procedures and upgrades to CRT showed similar mean values of these evaluated parameters. Conclusions: Total fluoroscopy time and DAP values correlated progressively with CIED implantation procedure complexity, with CRT-related procedures showing the highest values of both parameters. Med Pr 2017;68(3:363–374

  11. Current concepts of regenerative biomaterials in implant dentistry

    Directory of Open Access Journals (Sweden)

    Annapurna Ahuja


    Full Text Available The primary objective of any implant system is to achieve firm fixation to the bone and this could be influenced by biomechanical as well as biomaterial selection. An array of materials is used in the replacement of missing teeth through implantation. The appropriate selection of biomaterials directly influences the clinical success and longevity of implants. Thus the clinician needs to have adequate knowledge of the various biomaterials and their properties for their judicious selection and application in his/her clinical practice. The recent materials such as bioceramics and composite biomaterials that are under consideration and investigation have a promising future. For optimal performance, implant biomaterials should have suitable mechanical strength, biocompatibility, and structural biostability in the physiological environment. This article reviews the various implant biomaterials and their ease of use in implant dentistry.

  12. [Biodegradable synthetic polymers for the design of implantable medical devices: the ligamentoplasty case]. (United States)

    Garric, Xavier; Nottelet, Benjamin; Pinese, Coline; Leroy, Adrien; Coudane, Jean


    The sector of implantable medical devices is a growing sector of health products especially dynamic in the field of research. To improve the management of patients and to meet clinical requirements, researchers are developing new types of medical devices. They use different families of biomaterials presenting various chemical and physical characteristics in order for providing clinicians with health products optimized for biomedical applications. In this article, we aim to show how, starting from a family of biomaterials (degradable polymers), it is possible to design an implantable medical device for the therapeutic management of the failure of anterior cruciate ligament. The main steps leading to the design of a total ligament reinforcement are detailed. They range from the synthesis and characterization of degradable polymer to the shaping of the knitted implant, through the assessment of the study of the impact of sterilization on mechanical properties and checking cytocompatibility. © 2017 médecine/sciences – Inserm.


    Directory of Open Access Journals (Sweden)

    J. Ahmadi


    Full Text Available Totally implantable venous access devices (TIVAD or implantable catheter ports are devices which can be implanted subcutaneously. They enable prolonged and repeated access to the vascular system, into the peritoneal cavity or intravertebral space. This device is particularly useful for repeated medical injection, for blood sampling or transfusion of blood and blood derivatives and for total parenteral nutrition (TPN. Although many patients benefit from the insertion of TIVAD without any secondary effects, any surgical implantation can nevertheless lead to complications. ‎In this study, we investigated the advantages and disadvantages of TIVAD catheter in pediatric age group. A total of 94 cases, 2 to 14 years old, were included in our study. We implanted TIVAD in these patients for chemotherapy in 83 cases (88.29%, for prolonged TPN in 6 cases (6.38%, for corticosteroid and antibiotic therapy after ‎Kasai operation in 2 cases (2.12%, for intermittent IV therapy in 2 cases (2.12% and for need to partial parenteral nutrition in 1 case (1.06%. Out of 94 cases, 14 cases (15% had some kind of complications and 80 cases (85% had no complication. There was no mortality. Most patients and their parents (82 cases, 87.23% were satisfied from TIVAD. ‎It seems that TIVAD can be a useful device for many chronic patients who need an IV access for multiple injections.

  14. Stab injury and device implantation within the brain results in inversely multiphasic neuroinflammatory and neurodegenerative responses (United States)

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


    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.

  15. Committee Opinion No. 642: Increasing Access to Contraceptive Implants and Intrauterine Devices to Reduce Unintended Pregnancy. (United States)


    Unintended pregnancy persists as a major public health problem in the United States. Although lowering unintended pregnancy rates requires multiple approaches, individual obstetrician-gynecologists may contribute by increasing access to contraceptive implants and intrauterine devices. Obstetrician-gynecologists should encourage consideration of implants and intrauterine devices for all appropriate candidates, including nulliparous women and adolescents. Obstetrician-gynecologists should adopt best practices for long-acting reversible contraception insertion. Obstetrician-gynecologists are encouraged to advocate for coverage and appropriate payment and reimbursement for every contraceptive method by all payers in all clinically appropriate circumstances.

  16. Heat generation by electric current in mesoscopic devices


    Sun, Qing-Feng; Xie, X. C.


    We study the heat generation in a nano-device with an electric current passing through the device. For the first time, a general formula for the heat generation is derived by using the nonequilibrium Keldysh Green functions. This formula can be applied in both the linear and nonlinear transport regions, for time-dependent systems, and with multi-terminal devices. The formula is also valid when the nano-device contains various interactions. As an application of the formula, the heat generation...

  17. Management of antithrombotic therapy during cardiac implantable device surgery


    AlTurki, Ahmed; PROIETTI, RICCARDO; Birnie, David H.; Essebag, Vidal


    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 th...

  18. A remote monitoring system for patients with implantable ventricular assist devices with a personal handy phone system. (United States)

    Okamoto, E; Shimanaka, M; Suzuki, S; Baba, K; Mitamura, Y


    The usefulness of a remote monitoring system that uses a personal handy phone for artificial heart implanted patients was investigated. The type of handy phone used in this study was a personal handy phone system (PHS), which is a system developed in Japan that uses the NTT (Nippon Telephone and Telegraph, Inc.) telephone network service. The PHS has several advantages: high-speed data transmission, low power output, little electromagnetic interference with medical devices, and easy locating of patients. In our system, patients have a mobile computer (Toshiba, Libretto 50, Kawasaki, Japan) for data transmission control between an implanted controller and a host computer (NEC, PC-9821V16) in the hospital. Information on the motor rotational angle (8 bits) and motor current (8 bits) of the implanted motor driven heart is fed into the mobile computer from the implanted controller (Hitachi, H8/532, Yokohama, Japan) according to 32-bit command codes from the host computer. Motor current and motor rotational angle data from inside the body are framed together by a control code (frame number and parity) for data error checking and correcting at the receiving site, and the data are sent through the PHS connection to the mobile computer. The host computer calculates pump outflow and arterial pressure from the motor rotational angle and motor current values and displays the data in real-time waveforms. The results of this study showed that accurate data on motor rotational angle and current could be transmitted from the subjects while they were walking or driving a car to the host computer at a data transmission rate of 9600 bps. This system is useful for remote monitoring of patients with an implanted artificial heart.

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

    Directory of Open Access Journals (Sweden)

    McNicholas MJ


    Full Text Available Michael J McNicholas,1 Stefan M Gabriel,2 Anton G Clifford,2 Evelyne M Hasler2 1Aintree University Hospital, Teaching Hospital, Major Trauma Centre, NHS Foundation Trust, Liverpool, UK; 2Moximed, Hayward, CA, USA 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. Keywords: KineSpring, knee, function, preservation, offloading, osteoarthritis

  20. Device related complications of the Coflex interspinous process implant for the lumbar spine

    Institute of Scientific and Technical Information of China (English)

    ZANG Lei; DU Peng; HAI Yong; SU Qing-jun; LU Shi-bao; LIU Tie


    Background Coflex,a type of interspinous process implant,can provide intervertebral dynamic stability for surgical segments and effectively relieve lumbocrural pain.However,few studies have described therapeutic strategies and the avoidance of Coflex implant complications.Methods Coflex implant complications in this study included intraoperative or postoperative spinous process fracture,aggravated postoperative lumbocrural pain,dislodgment and malposition.The complications were analyzed,and therapeutic strategies were applied according to the specific complication.The Visual Analogue Scale and Oswestry Disability Index scores were evaluated by using the paired-samples test from SPSS 12.0.Results Conservative treatment was provided to seven patients who experienced aggravated lumbocrural pain even though their devices remained in the correct position,and pedicle screw treatment was used as an alternative in four cases.The Visual Analogue Scale and Oswestry Disability Index scores showed evident improvement in these patients.The Visual Analogue Scale and Oswestry Disability Index scores of two patients who underwent revision were also improved.Conclusions Coflex implants should be avoided in patients with osteoporosis,a narrow interspinous space and intervertebral coronal spondylolysis,or sagittal instability.Furthermore the device choice,depth of implantation,and clamping intensity should be appropriate.Conservative treatment can be provided to patients with symptoms if the device remains in the correct position; however,revisions and salvages should be undertaken with internal fixation of pedicle screws for patients with device malposition,intraoperative implantation failure,or device intolerance.

  1. Placement of an implantable central venous access device

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Hoon; Lee, Young Suk [Dan Kook Univ., Seoul (Korea, Republic of). Hospital


    To evaluate the efficacy and safety of placement of a central venous catheter with infusion port into the superior vena cava. Central venous catheters with a infusion port were implanted in 21 patients (M:F=4:17, age range:15-63, mean age: 41) diagnosed as suffering from breast cancer (n=9), lymphoma (n=7), thymoma (n=2) rhabdomyosarcoma(n=2) and rectal cancer (n=1). The per(n=9), lymphoma(n=7), thymoma (n=2) rhabdomyosarcoma (n=2) and rectal cancer (n=1). The peripheral portion of the subclavian vein was punctured under fluoroscopic guidance during injection of contrast media at the site of the ipsilateral peripheral vein (20 cases) and under ultrasonographic guidance (1 case). 9.6F central venous catheters placed in the superior vena cava via the subclavian vein and the connected infusion ports were implanted in the subcutaneous pocket near the puncture site of the right anterosuperior chest wall. Radiologic placement under fluoroscopic guidance of a central venous catheter with a infusion port is easy, safe and useful for patients requiring long-term venous access. (author). 21 refs., 2 figs.

  2. Auditory midbrain implant: a combined approach for vestibular schwannoma surgery and device implantation. (United States)

    Samii, Amir; Lenarz, Minoo; Majdani, Omid; Lim, Hubert H; Samii, Madjid; Lenarz, Thomas


    The lateral suboccipital approach is a well-established route for safe removal of vestibular schwannomas in neurofibromatosis Type 2 (NF2) patients. The goal of this study was to assess if this approach can be extended to a lateral supracerebellar infratentorial approach to enable insertion of an auditory midbrain implant (AMI) penetrating array along the tonotopic gradient of the inferior colliculus central nucleus (ICC). The AMI is a new auditory prosthesis designed for penetrating stimulation of the ICC in patients with neural deafness. The initial candidates are NF2 patients who, because of the growth and/or surgical removal of bilateral acoustic neuromas, develop neural deafness and are unable to benefit from cochlear implants. The ideal surgical approach in NF2 patients must first enable safe removal of vestibular schwannomas and then provide sufficient exposure of the midbrain for AMI implantation. This study was performed on formalin-fixed and fresh cadaver specimens. Computed tomography scan and magnetic resonance imaging were used to study the heads of the specimens and for surgical navigation. The lateral suboccipital craniotomy enabled sufficient exposure of the cerebellopontine angle and internal auditory canal for tumor removal. It could then be extended to a lateral supracerebellar infratentorial approach that provided good exposure of the dorsolateral aspect of the tentorial hiatus and mesencephalon for implantation of the AMI along the tonotopic gradient of the ICC. This approach did not endanger the trochlear nerve or any major midline venous structures in the quadrigeminal cistern. This modified lateral suboccipital approach ensures safe removal of large vestibular schwannomas and provides sufficient exposure of the inferior colliculus for ideal AMI implantation.

  3. Additive manufacturing of polymer melts for implantable medical devices and scaffolds. (United States)

    Youssef, Almoatazbellah; Hollister, Scott J; Dalton, Paul D


    Melt processing is routinely used to fabricate medical polymeric devices/implants for clinical reconstruction and can be incorporated into quality systems procedures for medical device manufacture. As additive manufacturing (AM) becomes increasingly used for biomaterials and biofabrication, the translation of new, customizable, medical devices to the clinic becomes paramount. Melt processing is therefore a distinguishable group within AM that provides an avenue to manufacture scaffolds/implants with a clinical end-point. Three key melt processing AM technologies are highlighted in this review: melt micro-extrusion, selective laser sintering and melt electrospinning writing. The in vivo (including clinical) outcomes of medical devices and scaffolds made with these processes are reviewed. Together, they encompass the melt AM of scaffold architectures with feature sizes and resolutions ranging from 800 nm up to 700 μm.

  4. Implantable optogenetic device with CMOS IC technology for simultaneous optical measurement and stimulation (United States)

    Haruta, Makito; Kamiyama, Naoya; Nakajima, Shun; Motoyama, Mayumi; Kawahara, Mamiko; Ohta, Yasumi; Yamasaki, Atsushi; Takehara, Hiroaki; Noda, Toshihiko; Sasagawa, Kiyotaka; Ishikawa, Yasuyuki; Tokuda, Takashi; Hashimoto, Hitoshi; Ohta, Jun


    In this study, we have developed an implantable optogenetic device that can measure and stimulate neurons by an optical method based on CMOS IC technology. The device consist of a blue LED array for optically patterned stimulation, a CMOS image sensor for acquiring brain surface image, and eight green LEDs surrounding the CMOS image sensor for illumination. The blue LED array is placed on the CMOS image sensor. We implanted the device in the brain of a genetically modified mouse and successfully demonstrated the stimulation of neurons optically and simultaneously acquire intrinsic optical images of the brain surface using the image sensor. The integrated device can be used for simultaneously measuring and controlling neuronal activities in a living animal, which is important for the artificial control of brain functions.

  5. Preventing bacterial growth on implanted device with an interfacial metallic film and penetrating X-rays. (United States)

    An, Jincui; Sun, An; Qiao, Yong; Zhang, Peipei; Su, Ming


    Device-related infections have been a big problem for a long time. This paper describes a new method to inhibit bacterial growth on implanted device with tissue-penetrating X-ray radiation, where a thin metallic film deposited on the device is used as a radio-sensitizing film for bacterial inhibition. At a given dose of X-ray, the bacterial viability decreases as the thickness of metal film (bismuth) increases. The bacterial viability decreases with X-ray dose increases. At X-ray dose of 2.5 Gy, 98% of bacteria on 10 nm thick bismuth film are killed; while it is only 25% of bacteria are killed on the bare petri dish. The same dose of X-ray kills 8% fibroblast cells that are within a short distance from bismuth film (4 mm). These results suggest that penetrating X-rays can kill bacteria on bismuth thin film deposited on surface of implant device efficiently.

  6. Persistent spin current in nano-devices and definition of the spin current


    Sun, Qing-feng; Xie, X. C.; WANG Jian


    We investigate two closely related subjects: (i) existence of a pure persistent spin current in semiconducting mesoscopic device with a spin-orbit interaction's (SOI), and (ii) the definition of the spin current in the presence of SOI. Through physical argument from four physical pictures in different aspects, we provide strong evidences that the persistent spin current does exist in a device with SOI in the absence of any magnetic materials. This persistent spin current is an analog of the p...

  7. Surgical templates for dental implant positioning; current knowledge and clinical perspectives

    Directory of Open Access Journals (Sweden)

    Mohammed Zaheer Kola


    Full Text Available Dental implants have been used in a variety of different forms for many years. Since the mid-20 th century, there has been an increase in interest in the implant process for the replacement of missing teeth. Branemark was one of the initial pioneers who applied scientifically based research techniques to develop an endosseous implant that forms an immobile connection with bone. The need for a dental implant to completely address multiple physical and biological factors imposes tremendous constraints on the surgical and handling protocol. Metallic dental implants have been successfully used for decades, but they have serious shortcomings related to their bony union and the fact that their mechanical properties do not match those of bone. However, anatomic limitation and restorative demands encourage the surgeon to gain precision in planning and surgical positioning of dental implants. Ideal placement of the implant facilitates the establishment of favorable forces on the implants and the prosthetic component as well as ensures an aesthetic outcome. Therefore, it is advisable to establish a logical continuity between the planned restoration and the surgical phases, it is essential to use a transfer device that for sure increases the predictability of success. The surgical guide template is fabricated by a dental technician after the presurgical restorative appointments that primarily include determination of occlusal scheme and implant angulations. Here, authors genuinely attempted to review the evolution and clinical applicability of surgical templates used in the placement of dental implants.

  8. Report of an external basal annuloplasty device for mitral regurgitation (basal annuloplasty of the cardia externally device implantation

    Directory of Open Access Journals (Sweden)

    Milind Hote


    Full Text Available We report the successful implant of an external basal annuloplasty device (basal annuloplasty of the cardia externally, which is a dimethyl silicone band, slipped around the base of the heart at the atrioventricular groove and the sub-annular myocardium to provide external myocardial support and mitral annuloplasty. The patient had ischemic heart disease with moderate functional mitral regurgitation which was reduced to mild regurgitation. The patient underwent coronary artery bypass during the same surgery.

  9. Clinical Characteristics and Outcome of Cardiovascular Implantable Electronic Device Infections in Turkey. (United States)

    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


    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.

  10. A phone-assistive device based on Bluetooth technology for cochlear implant users. (United States)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Nathanael R [ORNL; Kohno, Tadayoshi [University of Washington, Seattle


    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.

  12. Ultra Low-Power Algorithm Design for Implantable Devices: Application to Epilepsy Prostheses

    Directory of Open Access Journals (Sweden)

    Shriram Raghunathan


    Full Text Available Low-power circuit design techniques have enabled the possibility of integrating signal processing and feature extraction algorithms on-board implantable medical devices, eliminating the need for wireless transfer of data outside the patient. Feature extraction algorithms also serve as valuable tools for modern-day artificial prostheses, made possible by implantable brain-computer-interface systems. This paper intends to review the challenges in designing feature extraction blocks for implantable devices, with specific focus on developing efficacious but computationally efficient algorithms to detect seizures. Common seizure detection features used to construct algorithms are evaluated and algorithmic, mathematical as well as circuit-level design techniques are suggested to effectively translate the algorithms into hardware implementations on low-power platforms.

  13. A new device for impression transfer for non-parallel endosseus implants. (United States)

    Danza, Matteo; Zollino, Ilaria; Guidi, Riccardo; Carinci, Francesco


    The three-dimensional orientation of dental implant is transferred to a model by means of transfer device and impression material. If more than one implant is inserted and fixtures are not perfectly parallel, the impression may become distorted when removed from the mouth. In this case, a transfer that can be disengaged from the internal implant-abutment connection and removed together with the tray could be useful. An impression transfer device composed of a proper transfer, an inner hexagon and a central screw is described. When the central screw and the hexagon are removed, the proper transfer is free to move horizontally and the tray can be removed from the mouth without distortion of the impression material.

  14. Update on bariatric surgical procedures and an introduction to the implantable weight loss device: the Maestro Rechargeable System

    Directory of Open Access Journals (Sweden)

    Hwang SS


    Full Text Available Stephanie S Hwang,1 Mark C Takata,1 Ken Fujioka,2 William Fuller1 1Division of General/Bariatric Surgery, Scripps Clinic Weight Management, 2Division of Diabetes and Endocrinology, Scripps Clinic, La Jolla, CA, USA Abstract: There are many different methods of treating obesity, ranging from various medical options to several surgical therapies. This paper briefly summarizes current surgical options for weight loss with a focus on one of the newest US Food and Drug Administration-approved devices for surgical weight loss therapy, the Maestro Rechargeable System. Also known as the vagal blocking for obesity control implantable device, this tool blocks vagal nerve activity to induce weight loss. Keywords: VBLOC device, vagal, vagus, obesity

  15. X-ray exposure hazards for physicians performing ablation procedures and device implantation

    DEFF Research Database (Denmark)

    Marinskis, Germanas; Bongiorni, Maria Grazia; Dagres, Nikolaos


    The purpose of the survey was to evaluate physician's and authorities policies and clinical practices when using occupational X-ray during ablation procedures and device implantation. This survey shows infrequent use of lead gloves, radiation absorbing pads, and lead glass cabins, but increasing ...

  16. Densities in the left innominate vein after removal of an implantable venous device: a case report.

    NARCIS (Netherlands)

    Bastelaar, J. van; Janssen, C.H.; Bont, E. de; Blijlevens, N.M.A.; Baren, R. van


    ABSTRACT: INTRODUCTION: Pericatheter calcifications are unusual and rare after removal of indwelling central venous catheters with few reports in the literature. We present a case of a woman with calcifications in her left innominate vein after removal of an implantable venous device. CASE PRESENTAT

  17. Method to pattern <10 micrometer conducting and passivating features on 3D substrates for implantable devices

    Energy Technology Data Exchange (ETDEWEB)

    Tolosa, Vanessa; Pannu, Satinderpall S.; Sheth, Heeral; Tooker, Angela C.; Shah, Kedar G.


    An implantable device has a cylindrical base, at least one electrode on the cylindrical base, at least one electrically conducting lead on the cylindrical base connected to the electrode wherein the electrically conducting lead has a feature size of <10 micrometers. A protective coating on the cylindrical base covers the at least one electrically conducting lead.

  18. Audiological application criteria for implantable hearing aid devices: a clinical experience at the Nijmegen ORL clinic.

    NARCIS (Netherlands)

    Verhaegen, V.J.O.; Mylanus, E.A.M.; Cremers, C.W.R.J.; Snik, A.F.M.


    OBJECTIVES/HYPOTHESIS: To define audiological application criteria for different implantable hearing aid devices. STUDY DESIGN: Retrospective study. METHODS: Comparisons were made between aided speech recognition scores obtained at conversational level (65 dB) in patients with the Vibrant Soundbridg

  19. Iliac branched device implantation in tortuous iliac anatomy after previous open ruptured aortic aneurysm repair

    NARCIS (Netherlands)

    Vourliotakis, G.; Bracale, U. M.; Sondakh, A.; Tielliu, I. F. J.; Prins, T. R.; Verhoeven, E. L. G.


    The aim of this paper was to present iliac branched device (IBD) implantation in a fit 67-year-old man with tortuous iliac anatomy after previous emergent open abdominal aortic aneurysm (AAA) repair. The patient underwent open treatment for a ruptured abdominal aortic aneurysm in another hospital. T

  20. Holter monitoring for syncope: diagnostic yield in different patient groups and impact on device implantation. (United States)

    Kühne, M; Schaer, B; Moulay, N; Sticherling, C; Osswald, S


    Holter monitoring is routinely used in patients referred for the evaluation of syncope, but its diagnostic value in different patient groups is unclear, as is its impact on device implantation (pacemaker or cardioverter-defibrillator). To determine the diagnostic yield of Holter monitoring in the routine evaluation of syncope, and its impact on subsequent device implantation. Retrospective record review. We reviewed all Holter studies in patients referred with syncope between 2000 and 2005. Strict criteria were applied to determine whether a study was diagnostic. The diagnostic value of Holter monitoring (overall and in five subgroups: age, gender, structural heart disease, ejection fraction, medication) and its impact on the implantation of devices, were determined. Of 4877 Holter studies, 826 were performed in patients with syncope (age 72 +/- 15 years): 71 (8.6%) were considered to explain the syncope. Structural heart disease, ejection fraction and age were significant predictors of a diagnostic study (all p Holter did not explain their syncope, after mean 7 months, whereas 45 patients (5.4%) received a pacemaker based on the Holter results (p = 0.32). The overall diagnostic yield of Holter monitoring in the evaluation of syncope was 8.6%, with dramatic differences between subgroups. Our data suggest that the impact of Holter monitoring on device implantation is generally overestimated.

  1. Osteogenic protein 1 device increases bone formation and bone graft resorption around cementless implants

    DEFF Research Database (Denmark)

    Jensen, Thomas B; Overgaard, Søren; Lind, Martin;


    In each femoral condyle of 8 Labrador dogs, a non weight-bearing hydroxyapatite-coated implant was inserted surrounded by a 3 mm gap. Each gap was filled with bone allograft or ProOsteon with or without OP-1 delivered in a bovine collagen type I carrier (OP-1 device). 300 microg OP-1 was used in ...

  2. Is the daily use of vacuum erection device for a month before penile prosthesis implantation beneficial? a randomized controlled trial. (United States)

    Canguven, O; Talib, R A; Campbell, J; De Young, L; El Ansari, W; Al-Ansari, A


    Patient concerns about penile length after penile prosthesis (PP) implantation for erectile dysfunction (ED) have significant impact on patients and their partners. In addition, corporal fibrosis is associated with difficult PP implantation. The preoperative use of vacuum erectile devices (VED) is an uncommon physical treatment for such concerns. Therefore, the current randomized controlled study assessed two outcomes: whether pre-operative VED use for a month before surgery would significantly increase flaccid stretched penile length (SPL) on the day of surgery, and facilitate easier corporal dilatation intraoperatively. Fifty-one patients scheduled for PP implantation for ED were randomized to either intervention group (pre-operative VED use; 10-15 min/day for ≥30 days; Group A; n = 25), or control group (no intervention; Group B; n = 26). A research assistant (blinded to the treatment assignments) recorded SPL at baseline (initial consultation) and on day of surgery. The surgeons performing the PP implantation (also blinded to the treatment assignments) provided subjective assessments of the ease of corporal dilatation. Baseline patient characteristics, demographics, and comorbidities were the same in both groups. Baseline measurements (SPL-1) were 10.71 ± 1.28 and 10.87 ± 1.26 cm in Group A and Group B, respectively; and the day of surgery measurements (SPL-2) were 11.50 ± 1.33 and 11.06 ± 1.34 cm in Group A and Group B, respectively. In terms of outcomes: mean SPL increase in Group A was significantly more by a mean of 0.80 ± 0.38 cm (p outcomes of penile prosthesis implantation after pre-operative use of vacuum erectile devices.

  3. Legal, ethical, and procedural bases for the use of aseptic techniques to implant electronic devices (United States)

    Mulcahy, Daniel M.


    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

  4. Transaxillary Subpectoral Placement of Cardiac Implantable Electronic Devices in Young Female Patients (United States)

    Oh, Joo Hyun; Kim, Chae Min; Song, Seung Yong; Uhm, Jae Sun; Lew, Dae Hyun


    Background The current indications of cardiac implantable electronic devices (CIEDs) have expanded to include young patients with serious cardiac risk factors, but CIED placement has the disadvantage of involving unsightly scarring and bulging of the chest wall. A collaborative team of cardiologists and plastic surgeons developed a technique for the subpectoral placement of CIEDs in young female patients via a transaxillary approach. Methods From July 2012 to December 2015, subpectoral CIED placement via an axillary incision was performed in 10 young female patients, with a mean age of 25.9 years and mean body mass index of 20.1 kg/m2. In the supine position, with the patient's shoulder abducted, an approximately 5-cm linear incision was made along one of the deepest axillary creases. The submuscular plane was identified at the lateral border of the pectoralis major, and the dissection continued over the clavipectoral fascia until the subpectoral pocket could securely receive a pulse generator. Slight upward dissection also exposed an entrance to the subclavian vein, allowing the cardiology team to gain access to the vein. One patient with dilated cardiomyopathy underwent augmentation mammoplasty and CIED insertion simultaneously. Results One case of late-onset device infection occurred. All patients were highly satisfied with the results and reported that they would recommend the procedure to others. Conclusions With superior aesthetic outcomes compared to conventional methods, the subpectoral placement of CIEDs via a transaxillary approach is an effective, single-incision method to hide operative scarring and minimize bulging of the device, and is particularly beneficial for young female or lean patients. PMID:28194345

  5. An Implantable Intravascular Pressure Sensor for a Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Luigi Brancato


    Full Text Available The aim of this study is to investigate the intravascular application of a micro-electro-mechanical system (MEMS pressure sensor to directly measure the hemodynamic characteristics of a ventricular assist device (VAD. A bio- and hemo-compatible packaging strategy is implemented, based on a ceramic thick film process. A commercial sub-millimeter piezoresistive sensor is attached to an alumina substrate, and a double coating of polydimethylsiloxane (PDMS and parylene-C is applied. The final size of the packaged device is 2.6 mm by 3.6 mm by 1.8 mm. A prototype electronic circuit for conditioning and read-out of the pressure signal is developed, satisfying the VAD-specific requirements of low power consumption (less than 14.5 mW in continuous mode and small form factor. The packaged sensor has been submitted to extensive in vitro tests. The device displayed a temperature-independent sensitivity (12 μ V/V/mmHg and good in vitro stability when exposed to the continuous flow of saline solution (less than 0.05 mmHg/day drift after 50 h. During in vivo validation, the transducer has been successfully used to record the arterial pressure waveform of a female sheep. A small, intravascular sensor to continuously register the blood pressure at the inflow and the outflow of a VAD is developed and successfully validated in vivo.

  6. The Analog Blanking Period of Implantable Cardiac Rhythm Devices. (United States)

    Barold, S Serge; Kucher, Andreas


    Analog blanking periods (BPs) that hold down the display of electrograms (EGMs) in cardiac rhythm devices have received much less attention than the well-known digital BPs which do not influence the EGM display. In Biotronik devices (Biotronik GmbH, Berlin, Germany), when a paced event initiates an analog BP in one chamber (right atrium, right ventricle [RV], or left ventricle [LV]), an identical cross-chamber analog BP starts in the other two chambers. All clinical observations were recorded from patients with Biotronik devices. The effect of the atrial cross-chamber analog BP initiated by a ventricular paced event on the atrial EGM was studied in the records of seven patients with frequent paroxysmal atrial flutter to determine the effect of critically timed RV paced event (RVp) or LV paced event (LVp) upon the atrial EGM. The effect of atrial pacing triggering cross-chamber analog BPs in the RV and LV channels on the RV and LV EGMs was also investigated in cases of conducted supraventricular beats and ventricular premature complexes. The effect of a triggered LVp initiating a cross-chamber analog BP in the RV channel on the EGM of a sensed RV sensed event was evaluated in 10 cases. Simulation studies were also performed to verify the clinical observations. Patients with atrial flutter showed intermittent truncation or deformity and even disappearance of the atrial signals due to an atrial cross-chamber analog BP initiated by RVp and/or LVp. Three patients demonstrated deformity of the signal shape of ventricular premature beats falling within a ventricular cross-chamber analog BP initiated by right atrial paced event (RAp). We found only one case of a supraventricular QRS complex trapped in a ventricular cross-chamber analog BP initiated by RAp. All the recordings of LVp triggering upon RVs revealed a variety of RV signal deformities occasionally with preservation of the terminal part of the RV signal. Simulation studies confirmed the effect of the analog BP on

  7. Compensating for Tissue Changes in an Ultrasonic Power Link for Implanted Medical Devices. (United States)

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


    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.

  8. Nanomedicine Design of Particles, Sensors, Motors, Implants, Robots, and Devices

    CERN Document Server

    Schulz, Mark J


    This forward-looking resource outlines the extraordinary new tools that are becoming available in nanomedicine. The book presents an integrated set of perspectives that describe where we are now and where we should be headed to put nanomedicine devices in to applications as quickly as possible, including consideration of the possible dangers of nanomedicine. Written by some of the most innovative minds in medicine and engineering, this unique volume helps you understand cutting-edge and futuristic areas of research that can have tremendous payoff in terms of improving human health. You find in

  9. Current challenges in successful rehabilitation with oral implants. (United States)

    Wennerberg, A; Albrektsson, T


    Very high survival/success rates have been reported for implant treatment, irrespective of the prosthetic type of reconstruction, be those full arcs, partial dentures, combined tooth implants or single crowns. However, survival/success is commonly reported in simple Cumulative Survival/Success Rate (CSR) tables only that may overestimate the true clinical outcome; furthermore, future challenges to clinical success may originate from too rapid launching of untested novelties or recommendations to apply too bold clinical procedures, potential problems that are summarised in the present paper.

  10. A wireless power transmission system for implantable devices in freely moving rodents. (United States)

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


    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.

  11. Remote monitoring of cardiac implantable devices in the Asia-Pacific. (United States)

    Lau, Chu-Pak; Zhang, Shu


    Remote monitoring of pacemakers and implantable cardioverter defibrillators (ICDs) has emerged as a tool to replace regular follow-up of such devices, and to detect hardware failure, arrhythmias, and heart failure decompensation. The Asia-Pacific region is a geographically diverse area, with widely different cardiac device implant rates and expertise. However, common to all countries, distance and logistic for patients to reach an expert monitoring centre for routine follow up are significant, and in some countries, this will likely be replaced by remote monitoring. Unscheduled visits such as for the treatment of atrial fibrillation and ICD shocks will be expedited. There has been an increase in both pacemaker and ICD implant rates in Asia-Pacific, due to an ageing population and improvement in economic condition. Among the countries, Australia and Japan are the major users of remote monitoring. According to the statistics of the suppliers, in Australia, up to 15% of pacemakers, 40% ICD, and 30% cardiac resynchronization therapy (CRT)/cardiac resynchronization therapy defibrillator (CTRD) are remotely monitored. The corresponding numbers for Japan are 5, 50, and 50% respectively. The monitoring personnel include nurses, technicians, and doctors, either from local centre or from device companies. Cost, lack of reimbursement, and logistic support are major issues in widespread application of remote monitoring technology. In conclusion, remote monitoring is increasing in Asia-Pacific region despite the increase in cost. Implantable cardioverter defibrillators and CRT/CRTDs are more likely than pacemakers to be enabled with remote monitoring.

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

    Directory of Open Access Journals (Sweden)

    Caroline C O'Brien

    Full Text Available 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.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.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.

  13. Nanobionics: the impact of nanotechnology on implantable medical bionic devices. (United States)

    Wallace, G G; Higgins, M J; Moulton, S E; Wang, C


    The nexus of any bionic device can be found at the electrode-cellular interface. Overall efficiency is determined by our ability to transfer electronic information across that interface. The nanostructure imparted to electrodes plays a critical role in controlling the cascade of events that determines the composition and structure of that interface. With commonly used conductors: metals, carbon and organic conducting polymers, a number of approaches that promote control over structure in the nanodomain have emerged in recent years with subsequent studies revealing a critical dependency between nanostructure and cellular behaviour. As we continue to develop our understanding of how to create and characterise electromaterials in the nanodomain, this is expected to have a profound effect on the development of next generation bionic devices. In this review, we focus on advances in fabricating nanostructured electrodes that present new opportunities in the field of medical bionics. We also briefly evaluate the interactions of living cells with the nanostructured electromaterials, in addition to highlighting emerging tools used for nanofabrication and nanocharacterisation of the electrode-cellular interface.

  14. RF communication with implantable wireless device: effects of beating heart on performance of miniature antenna. (United States)

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


    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.

  15. [Ultrasound-guided percutaneous insertion of implantable venous devices: a review of 102 patients]. (United States)

    Nguyen, V; Jarry, J; Farthouat, P; Bourilhon, N; Milou, F; Michel, P


    Techniques of insertion of implantable venous devices have been widely described. The use of ultrasound guidance is part of the good practice recommendations of the SOR 2008 but there are few data in the literature and recommendations are based only on expert agreement. To this end we conducted a prospective, single-center study from January 2008 to August 2009 on percutaneous ultrasound-guided insertion of implantable devices. In addition to age, sex, the therapeutic indication and the site of implantation, we identified the operative time and number of venipunctures performed for each procedure. We then identified the infectious complications at three months and thromboembolic complications at 1 year and a half. Our study examined 102 consecutive patients. The mean age was 61.8 years (28-90); 71% of patients were men. For 101 patients, the internal jugular vein was punctured, the subclavian vein in one patient. In 86% of cases, the implantable venous device was inserted into the right vein. The average length of procedure was 30 minutes (18-60) for a single-vein puncture. Among the 102 patients, the overall morbidity was 7.8% with four infections (3.9%) and four thromboses (3.9%). There were no immediate perioperative complications (arterial puncture, hematoma, pneumothorax). In conclusion, percutaneous ultrasound-guided insertion of implantable venous devices in the internal jugular vein is a safe, minimally invasive technique which complies with the 2008 SOR recommendations by preventing the risk of venous thrombosis and avoiding repeated venous puncture. Less invasive than the open surgical approach, ultrasound-guided insertion is safer than puncture based solely on anatomical landmarks. In summary, this is a reliable, simple and easily reproducible technique which limits iatrogenic risks and improves patient comfort.

  16. Preferred tools and techniques for implantation of cardiac electronic devices in Europe: results of the European Heart Rhythm Association survey. (United States)

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


    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.

  17. Perioperative management of antithrombotic treatment during implantation or revision of cardiac implantable electronic devices

    DEFF Research Database (Denmark)

    Deharo, Jean-Claude; Sciaraffia, Elena; Leclercq, Christophe;


    (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...

  18. Compatibility of Radiofrequency Surgical Sponge Detection Technology with Cardiac Implantable Electronic Devices and Temporary Pacemakers. (United States)

    Salcedo, Jonathan D; Pretorius, Victor G; Hsu, Jonathan C; Lalani, Gautam G; Schricker, Amir A; Hebsur, Shrinivas M; McGARRY, Thomas J; Hunter, Jessica A; Lewis, Kathryn E; Krummen, David E; Feld, Gregory K; Birgersdotter-Green, Ulrika


    Radiofrequency (RF) technology has improved detection of retained surgical sponges with a reported 100% sensitivity and specificity. However, the potential for interactions of the RF signals emitted by the detection system with cardiac implantable electronic devices (CIEDs) or temporary pacemakers may limit its use in those patients with these devices. This study investigated whether RF detection technology causes interference or clinically significant changes in the programmed settings of implanted pacemakers and defibrillators or temporary epicardial pacemakers. Fifty patients who were scheduled either for CIED removal or placement of a temporary epicardial pacemaker (at the time of open heart surgery) were recruited for this study. Device settings and measurements from separate interrogations before and after scanning with the RF detection system were compared. For the temporary pacemakers, we observed for any changes in hemodynamics or signs of pacing interference. Twenty (40%) pacemakers, 20 (40%) implantable cardioverter defibrillators, and 10 (20%) temporary pacemakers were analyzed in this study. During scanning, no signal interference was detected in any permanent device, and there were no significant changes in programmed settings after scanning with the RF detection system. However, pacing inhibition was detected with temporary pacing systems when programmed to a synchronous mode (DDD). RF detection technology can be safely used to scan for retained surgical sponges in patients with permanent CIEDs and temporary pacemakers set to asynchronous mode. © 2016 Wiley Periodicals, Inc.

  19. CT pre-operative planning of a new semi-implantable bone conduction hearing device

    Energy Technology Data Exchange (ETDEWEB)

    Law, Eric K.C.; Bhatia, Kunwar S.S. [Prince of Wales Hospital, The Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Hong Kong, SAR (China); Tsang, Willis S.S.; Tong, Michael C.F. [Prince of Wales Hospital, The Chinese University of Hong Kong, Department of Otorhinolaryngology, Head and Neck Surgery, Hong Kong, SAR (China); Shi, Lin [The Chinese University of Hong Kong, Department of Medicine and Therapeutics, Hong Kong, SAR (China); The Chinese University of Hong Kong, Chow Yuk Ho Technology Center for Innovative Medicine, Hong Kong, SAR (China)


    Accommodating a novel semi-implantable bone conduction hearing device within the temporal bone presents challenges for surgical planning. This study describes the utility of CT in pre-operative assessment of such an implant. Retrospective review of pre-operative CT, clinical and surgical records of 16 adults considered for device implantation. Radiological suitability was assessed on CT using 3D simulation software. Antero-posterior (AP) dimensions of the mastoid bone and minimum skull thickness were measured. CT planning results were correlated with operative records. Eight and five candidates were suitable for device placement in the transmastoid and retrosigmoid positions, respectively, and three were radiologically unsuitable. The mean AP diameter of the mastoid cavity was 14.6 mm for the transmastoid group and 4.6 mm for the retrosigmoid group (p < 0.05). Contracted mastoid and/or prior surgery were predisposing factors for unsuitability. Four transmastoid and five retrosigmoid positions required sigmoid sinus/dural depression and/or use of lifts due to insufficient bone capacity. A high proportion of patients being considered have contracted or operated mastoids, which reduces the feasibility of the transmastoid approach. This finding combined with the complex temporal bone geometry illustrates the importance of careful CT evaluation using 3D software for precise device simulation. (orig.)

  20. New Analysis and Design of a RF Rectifier for RFID and Implantable Devices

    Directory of Open Access Journals (Sweden)

    Xiong-Fei Tao


    Full Text Available New design and optimization of charge pump rectifiers using diode-connected MOS transistors is presented in this paper. An analysis of the output voltage and Power Conversion Efficiency (PCE is given to guide and evaluate the new design. A novel diode-connected MOS transistor for UHF rectifiers is presented and optimized, and a high efficiency N-stage charge pump rectifier based on this new diode-connected MOS transistor is designed and fabricated in a SMIC 0.18-μm 2P3M CMOS embedded EEPROM process. The new diode achieves 315 mV turn-on voltage and 415 nA reverse saturation leakage current. Compared with the traditional rectifier, the one based on the proposed diode-connected MOS has higher PCE, higher output voltage and smaller ripple coefficient. When the RF input is a 900-MHz sinusoid signal with the power ranging from −15 dBm to −4 dBm, PCEs of the charge pump rectifier with only 3-stage are more than 30%, and the maximum output voltage is 5.5 V, and its ripple coefficients are less than 1%. Therefore, the rectifier is especially suitableto passive UHF RFID tag IC and implantable devices.

  1. Evaluation of biofouling in stainless microfluidic channels for implantable multilayered dialysis device (United States)

    Ota, Takashi; To, Naoya; Kanno, Yoshihiko; Miki, Norihisa


    An implantable artificial kidney can markedly improve the quality of life of renal disease patients. Our group has developed an implantable multilayered dialysis system consisting of microfluidic channels and dialysis membranes. Long-term evaluation is necessary for implant devices where biofouling is a critical factor, culminating in the deterioration of dialysis performance. Our previous work revealed that surface conditions, which depend on the manufacturing process, determine the amount of biofouling, and that electrolytic etching is the most suitable technique for forming a channel wall free of biofouling. In this study, we investigated the electrolytic etching conditions in detail. We conducted in vitro experiments for 7 d and evaluated the adhesion of biomaterials by scanning electron microscopy. The experiments revealed that a surface mirror-finished by electrolytic etching effectively prevents biofouling.

  2. Implantable batteryless device for on-demand and pulsatile insulin administration (United States)

    Lee, Seung Ho; Lee, Young Bin; Kim, Byung Hwi; Lee, Cheol; Cho, Young Min; Kim, Se-Na; Park, Chun Gwon; Cho, Yong-Chan; Choy, Young Bin


    Many implantable systems have been designed for long-term, pulsatile delivery of insulin, but the lifetime of these devices is limited by the need for battery replacement and consequent replacement surgery. Here we propose a batteryless, fully implantable insulin pump that can be actuated by a magnetic field. The pump is prepared by simple-assembly of magnets and constituent units and comprises a drug reservoir and actuator equipped with a plunger and barrel, each assembled with a magnet. The plunger moves to noninvasively infuse insulin only when a magnetic field is applied on the exterior surface of the body. Here we show that the dose is easily controlled by varying the number of magnet applications. Also, pump implantation in diabetic rats results in profiles of insulin concentration and decreased blood glucose levels similar to those observed in rats treated with conventional subcutaneous insulin injections.

  3. Effect of high energy proton implantation on the device characteristics of InAlGaAs-capped InGaAs/GaAs quantum dot based infrared photodetectors (United States)

    Upadhyay, S.; Mandal, A.; Ghadi, H.; Pal, D.; Subrahmanyam, N. B. V.; Singh, P.; Chakrabarti, S.


    Self-assembled In(Ga)As/GaAs quantum dot infrared photodetectors (QDIPs) have promising applications in the midwavelength infrared and long-wavelength infrared regions for various defense and space application purposes. It has been demonstrated that the performance of QDIPs has improved significantly by using architectures such as dots-in-awell, different combinational capping or post growth treatment with high energy hydrogen ions. In this work, we enhanced the electrical properties InGaAs/GaAs using high energy proton implantation. Irradiation with proton resulted suppression in field assisted tunnelling of dark current by three orders for implanted devices. Photoluminescence (PL) enhancement was observed up to certain dose of protons due to eradication of as-grown defects and non radiative recombination centers. In addition, peak detectivity (D*) increased up to two orders of magnitude from 6.1 x108 to 1.0 × 1010 cm-Hz1/2/W for all implanted devices.

  4. Simulation of leakage current measurement on medical devices using helmholtz coil configuration with different current flow (United States)

    Sutanto, E.; Chandra, F.; Dinata, R.


    Leakage current measurement which can follow IEC standard for medical device is one of many challenges to be answered. The IEC 60601-1 has defined that the limit for a leakage current for Medical Device can be as low as 10 µA and as high as 500 µA, depending on which type of contact (applied part) connected to the patient. Most people are using ELCB (Earth-leakage circuit breaker) for safety purpose as this is the most common and available safety device in market. One type of ELCB devices is RCD (Residual Current Device) and this RCD type can measure the leakage current directly. This work will show the possibility on how Helmholtz Coil Configuration can be made to be like the RCD. The possibility is explored by comparing the magnetic field formula from each device, then it proceeds with a simulation using software EJS (Easy Java Simulation). The simulation will make sure the concept of magnetic field current cancellation follows the RCD concept. Finally, the possibility of increasing the measurement’s sensitivity is also analyzed. The sensitivity is needed to see the possibility on reaching the minimum leakage current limit defined by IEC, 0.01mA.

  5. Method and device for current driven electric energy conversion

    DEFF Research Database (Denmark)


    configurations such as half bridge buck, full bridge buck, half bridge boost, or full bridge boost. A current driven conversion is advantageous for high efficient energy conversion from current sources such as solar cells or where a voltage source is connected through long cables, e.g. powerline cables for long......Device comprising an electric power converter circuit for converting electric energy. The converter circuit comprises a switch arrangement with two or more controllable electric switches connected in a switching configuration and controlled so as to provide a current drive of electric energy from...... the output from the switch arrangement and designed such that a high impedance at a frequency range below the switching frequency is obtained, seen from the output terminals. Switches implemented by normally-on-devices are preferred, e.g. in the form of a JFET. The converter circuit may be in different...

  6. Mapping the ion current distribution in nanopore/electrode devices. (United States)

    Rutkowska, Agnieszka; Edel, Joshua B; Albrecht, Tim


    Solid-state nanopores with integrated electrodes have interesting prospects in next-generation single-molecule biosensing and sequencing. These include "gated" nanopores with a single electrode integrated into the membrane, as well as two-electrode designs, such as a transversal tunneling junction. Here we report the first comprehensive analysis of current flow in a three-electrode device as a model for this class of sensors. As a new feature, we observe apparent rectification in the pore current that is rooted in the current distribution of the cell, rather than the geometry or electrostatics of the pore. We benchmark our results against a recently developed theoretical model and define operational parameters for nanopore/electrode structures. Our findings thus facilitate the rational design of such sensor devices.

  7. Evaluating the osseointegration of nanostructured titanium implants in animal models: Current experimental methods and perspectives (Review). (United States)

    Babuska, Vaclav; Moztarzadeh, Omid; Kubikova, Tereza; Moztarzadeh, Amin; Hrusak, Daniel; Tonar, Zbynek


    The aim of this paper is to review the experimental methods currently being used to evaluate the osseointegration of nanostructured titanium implants using animal models. The material modifications are linked to the biocompatibility of various types of oral implants, such as laser-treated, acid-etched, plasma-coated, and sand-blasted surface modifications. The types of implants are reviewed according to their implantation site (endoosseous, subperiosteal, and transosseous implants). The animal species and target bones used in experimental implantology are carefully compared in terms of the ratio of compact to spongy bone. The surgical technique in animal experiments is briefly described, and all phases of the histological evaluation of osseointegration are described in detail, including harvesting tissue samples, processing undemineralized ground sections, and qualitative and quantitative histological assessment of the bone-implant interface. The results of histological staining methods used in implantology are illustrated and compared. A standardized and reproducible technique for stereological quantification of bone-implant contact is proposed and demonstrated. In conclusion, histological evaluation of the experimental osseointegration of dental implants requires careful selection of the experimental animals, bones, and implantation sites. It is also advisable to use larger animal models and older animals with a slower growth rate rather than small or growing experimental animals. Bones with a similar ratio of compact to spongy bone, such as the human maxilla and mandible, are preferred. A number of practical recommendations for the experimental procedures, harvesting of samples, tissue processing, and quantitative histological evaluations are provided.

  8. Secondary electron current loss in electron cooling devices (United States)

    Sharapa, A. N.; Shemyakin, A. V.


    The efficiency of secondary electron capture in a recuperator with a longitudinal magnetic field is evaluated. To characterize this efficiency, the value of the collector secondary emission coefficient is introduced, for the calculation of which a simple formula is proposed. The effects determining the difference between the current losses in straight systems and devices with bending magnets are analyzed. It is experimentally shown that there is no unambiguous relation between the efficiency of the secondary electron capture by the collector and the current loss. The mechanism which determines the current loss in straight systems is suggested.

  9. Revision total hip and knee arthroplasty implant identification: implications for use of Unique Device Identification 2012 AAHKS member survey results. (United States)

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


    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. © 2013.

  10. Inappropriate implantable cardioverter defibrillator shock from a transcutaneous muscle stimulation device therapy. (United States)

    Siu, Chung-Wah; Tse, Hung-Fat; Lau, Chu-Pak


    Inappropriate shock from implantable cardioverter defibrillator (ICD) may result from external electromagnetic interference (EMI), especially for unipolar ventricle sensing. Previous case reports and small in-vitro safety study suggested that endocardial bipolar lead system may be immune from EMI resulting from transcutaneous electrical neuromuscle stimulation (TENS) therapy. This report presents an unusual case of inappropriate discharge in a patient with ICD of endocardial bipolar lead system, receiving TENS from a commercially available device.

  11. Implanted cardiac devices are reliably detected by commercially available metal detectors

    DEFF Research Database (Denmark)

    Holm, Katja Fiedler; Hjortshøj, Søren; Pehrson, Steen;


    Explosions of Cardiovascular Implantable Electronic Devices (CIEDs) (pacemakers, defibrillators, and loop recorders) are a well-recognized problem during cremation, due to lithium-iodine batteries. In addition, burial of the deceased with a CIED can present a potential risk for environmental cont...... contamination. Therefore, detection of CIEDs in the deceased would be of value. This study evaluated a commercially available metal detector for detecting CIEDs....

  12. Processing of Silver-Implanted Aluminum Nitride for Energy Harvesting Devices (United States)

    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

  13. Occlusion in implant dentistry. A review of the literature of prosthetic determinants and current concepts. (United States)

    Gross, M D


    Today the clinician is faced with widely varying concepts regarding the number, location, distribution and inclination of implants required to support the functional and parafunctional demands of occlusal loading. Primary clinical dilemmas of planning for maximal or minimal numbers of implants, their axial inclination, lengths and required volume and quality of supporting bone remain largely unanswered by adequate clinical outcome research. Planning and executing optimal occlusion schemes is an integral part of implant supported restorations. In its wider sense this includes considerations of multiple inter-relating factors of ensuring adequate bone support, implant location number, length, distribution and inclination, splinting, vertical dimension aesthetics, static and dynamic occlusal schemes and more. Current concepts and research on occlusal loading and overloading are reviewed together with clinical outcome and biomechanical studies and their clinical relevance discussed. A comparison between teeth and implants regarding their proprioceptive properties and mechanisms of supporting functional and parafunctional loading is made and clinical applications made regarding current concepts in restoring the partially edentulous dentition. The relevance of occlusal traumatism and fatigue microdamage alone or in combination with periodontal or peri-implant inflammation is reviewed and applied to clinical considerations regarding splinting of adjacent implants and teeth, posterior support and eccentric guidance schemes. Occlusal restoration of the natural dentition has classically been divided into considerations of planning for sufficient posterior support, occlusal vertical dimension and eccentric guidance to provide comfort and aesthetics. Mutual protection and anterior disclusion have come to be considered as acceptable therapeutic modalities. These concepts have been transferred to the restoration of implant-supported restoration largely by default. However, in

  14. Bailout transcatheter closure of patent foramen ovale for refractory hypoxaemia after left ventricular assist device implantation. (United States)

    Fischer, Quentin; Kirsch, Matthias; Brochet, Eric; Juliard, Jean-Michel


    We describe the interdisciplinary management of a 59-year old man with ischaemic cardiomyopathy on a HeartMate II left ventricular assist device (LVAD) and temporary right extracorporeal membrane oxygenation (ECMO) as a bridge-to-heart transplantation. He suffered refractory hypoxaemia due to massive right-to-left shunting by a patent foramen ovale (PFO), diagnosed after weaning off of temporary right ECMO. Percutaneous closure of the PFO was successfully achieved with an Amplatzer septal occluder device, which allowed the patient's extubation and departure from hospital. The patient received heart transplantation 7 weeks after LVAD implantation and was discharged from the intensive care unit 2 weeks after transplantation.

  15. Shrinking the Supply Chain for Implantable Coronary Stent Devices. (United States)

    Moore, Sean S; O'Sullivan, Kevin J; Verdecchia, Francesco


    Stenting treatments for the management of disease in the heart, arterial and venous systems, biliary ducts, urethras, ureters, oesophageal tract and prostate have made enormous technical advances since their introduction into clinical use. The progression from metallic to polymer based bio-absorbable stents, coupled with the advances in additive manufacturing techniques, present a unique opportunity to completely re-envision the design, manufacture, and supply chain of stents. This paper looks at current stenting trends and proposes a future where the stent supply chain is condensed from ~150 days to ~20 min. The Cardiologist therefore has the opportunity to become a designer, manufacturer and user with patients receiving custom stents specific to their unique pathology that will be generated, delivered and deployed in the Cath-lab. The paper will outline this potentially revolutionary development and consider the technical challenges that will need to be overcome in order to achieve these ambitious goals. A high level overview of the generating eluting stents in situ program-GENESIS-is outlined including some early experimental work.

  16. A power-efficient communication system between brain-implantable devices and external computers. (United States)

    Yao, Ning; Lee, Heung-No; Chang, Cheng-Chun; Sclabassi, Robert J; Sun, Mingui


    In this paper, we propose a power efficient communication system for linking a brain-implantable device to an external system. For battery powered implantable devices, the processor and the transmitter power should be reduced in order to both conserve battery power and reduce the health risks associated with transmission. To accomplish this, a joint source-channel coding/decoding system is devised. Low-density generator matrix (LDGM) codes are used in our system due to their low encoding complexity. The power cost for signal processing within the implantable device is greatly reduced by avoiding explicit source encoding. Raw data which is highly correlated is transmitted. At the receiver, a Markov chain source correlation model is utilized to approximate and capture the correlation of raw data. A turbo iterative receiver algorithm is designed which connects the Markov chain source model to the LDGM decoder in a turbo-iterative way. Simulation results show that the proposed system can save up to 1 to 2.5 dB on transmission power.

  17. [An implantable micro-device using wireless power transmission for measuring aortic aneurysm sac pressure]. (United States)

    Guo, Xudong; Ge, Bin; Wang, Wenxing


    In order to detect endoleaks after endovascular aneurysm repair (EVAR), we developed an implantable micro-device based on wireless power transmission to measure aortic aneurysm sac pressure. The implantable micro-device is composed of a miniature wireless pressure sensor, an energy transmitting coil, a data recorder and a data processing platform. Power transmission without interconnecting wires is performed by a transmitting coil and a receiving coil. The coupling efficiency of wireless power transmission depends on the coupling coefficient between the transmitting coil and the receiving coil. With theoretical analysis and experimental study, we optimized the geometry of the receiving coil to increase the coupling coefficient. In order to keep efficiency balance and satisfy the maximizing conditions, we designed a closed loop power transmission circuit, including a receiving voltage feedback module based on wireless communication. The closed loop improved the stability and reliability of transmission energy. The prototype of the micro-device has been developed and the experiment has been performed. The experiments showed that the micro-device was feasible and valid. For normal operation, the distance between the transmitting coil and the receiving coil is smaller than 8cm. Besides, the distance between the micro-device and the data recorder is within 50cm.

  18. Direct metal laser sintering titanium dental implants: a review of the current literature. (United States)

    Mangano, F; Chambrone, L; van Noort, R; Miller, C; Hatton, P; Mangano, C


    Statement of Problem. Direct metal laser sintering (DMLS) is a technology that allows fabrication of complex-shaped objects from powder-based materials, according to a three-dimensional (3D) computer model. With DMLS, it is possible to fabricate titanium dental implants with an inherently porous surface, a key property required of implantation devices. Objective. The aim of this review was to evaluate the evidence for the reliability of DMLS titanium dental implants and their clinical and histologic/histomorphometric outcomes, as well as their mechanical properties. Materials and Methods. Electronic database searches were performed. Inclusion criteria were clinical and radiographic studies, histologic/histomorphometric studies in humans and animals, mechanical evaluations, and in vitro cell culture studies on DMLS titanium implants. Meta-analysis could be performed only for randomized controlled trials (RCTs); to evaluate the methodological quality of observational human studies, the Newcastle-Ottawa scale (NOS) was used. Results. Twenty-seven studies were included in this review. No RCTs were found, and meta-analysis could not be performed. The outcomes of observational human studies were assessed using the NOS: these studies showed medium methodological quality. Conclusions. Several studies have demonstrated the potential for the use of DMLS titanium implants. However, further studies that demonstrate the benefits of DMLS implants over conventional implants are needed.

  19. Direct Metal Laser Sintering Titanium Dental Implants: A Review of the Current Literature

    Directory of Open Access Journals (Sweden)

    F. Mangano


    Full Text Available Statement of Problem. Direct metal laser sintering (DMLS is a technology that allows fabrication of complex-shaped objects from powder-based materials, according to a three-dimensional (3D computer model. With DMLS, it is possible to fabricate titanium dental implants with an inherently porous surface, a key property required of implantation devices. Objective. The aim of this review was to evaluate the evidence for the reliability of DMLS titanium dental implants and their clinical and histologic/histomorphometric outcomes, as well as their mechanical properties. Materials and Methods. Electronic database searches were performed. Inclusion criteria were clinical and radiographic studies, histologic/histomorphometric studies in humans and animals, mechanical evaluations, and in vitro cell culture studies on DMLS titanium implants. Meta-analysis could be performed only for randomized controlled trials (RCTs; to evaluate the methodological quality of observational human studies, the Newcastle-Ottawa scale (NOS was used. Results. Twenty-seven studies were included in this review. No RCTs were found, and meta-analysis could not be performed. The outcomes of observational human studies were assessed using the NOS: these studies showed medium methodological quality. Conclusions. Several studies have demonstrated the potential for the use of DMLS titanium implants. However, further studies that demonstrate the benefits of DMLS implants over conventional implants are needed.

  20. Experiencia en implante de dispositivos de estimulación cardiaca Experience in implant of cardiac stimulation devices

    Directory of Open Access Journals (Sweden)

    Alejandro Orjuela

    appropriate parameters regarding the more frequent diagnosis, type of stimulation and implant techniques. Methods: 1.004 patients were followed during an average of 41 months. All electro-physiologists used a standardized technique. In the last years, the position of the ventricular electrode varied, using the right ventricle out-going tract and the interventricular septum. The implant’s reports and the clinical histories of almost all patients were reviewed. Results: the most frequent diagnosis was sinus node disease in 43% of patients, followed by complete atrio-ventricular block in 40%. 60% received bicameral stimulation, including patients with sinus node disease for its probability of progression to complete atrio-ventricular block. 33% of the patients received a monocameral stimulation device. Total complications were 3.8%, being the most common the displacement of the ventricular electrode. Conclusions: in the results published by a Colombian group of electrophysiology, similar data to those published in the world literature in regard to indications of pace-makers’ implant, stimulation types and incidence of complications were found. Prospective studies are required in order to evaluate the long- term impact of septal stimulation and stimulation of the right ventricle out-going tract, as well as of the progression to complete AV block in patients with sinus node disease.

  1. Implantation of a new access device for hemodialysis (Dialock): initial experience in 5 patients

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz-Rode, T.; Buecker, A.; Tacke, J.; Wingen, M.; Guenther, R.W. [Dept. of Diagnostic Radiology, Universitaetsklinikum der RWTH Aachen (Germany); Noah, M. [Dept. of Plastic Surgery, Universitaetsklinikum der RWTH Aachen (Germany); Ketteler, M. [Dept. of Nephrology, Universitaetsklinikum der RWTH Aachen (Germany)


    A new hemodialysis access port system was implanted. Methods: The Dialock{sup TM} consists of a port-like double-valve, implanted subcutaneously below the clavicle, which is attached to two catheters, placed in the right atrium via the jugular vein. The device has been implanted in 5 patients (4 female, 1 male). Results: In all 5 patients the implantation of the catheters and the port was technically successful. Total average duration of dialysis was 3.6 months. Two patients developed a port pocket hematoma 10-14 days post implantation, one of them required surgical revision. One port was explanted due to septicemia, whereas a port infection was not confirmed. One patient showed a thrombotic occlusion of both catheter tips 8 days after implantation, fixed by catheter exchange. Another patient presented with slight migration of the port catheters, which was managed by refixation of the port within the pocket. Beside these complications, the devices were working well. Conclusion: The Dialock system offers an interesting alternative to external catheters for hemodialysis. With respect to the complications it deserves further studies to determine its future role in the field of vascular access. (orig.) [German] Ein neues Haemodialyse-Portsystem wurde klinisch erprobt. Methoden: Das Dialock{sup TM}-System besteht aus einem Doppelventil-Port, der subkutan unterhalb der Klavikel implantiert wird. An den Port sind zwei Katheter angeschlossen, die subkutan getunnelt transjugulaer im rechten Vorhof platziert werden. Das System wurde in 5 Patienten implantiert (4 Frauen, 1 Mann). Ergebnisse: Bei allen 5 Patienten war die Katheter- und Portimplantation technisch erfolgreich. Die bisherige mittlere Dialyse-Dauer betraegt 3,6 Monate. Bei zwei Patienten bildete sich ein Haematom der Porttasche 10-14 Tage nach der Implantation. In einem Fall war eine operative Ausraeumung erforderlich. Ein Patient entwickelte eine Sepsis, worauf das Portsystem explantiert wurde. Eine Portinfektion

  2. Improvised explosive devices: pathophysiology, injury profiles and current medical management. (United States)

    Ramasamy, A; Hill, A M; Clasper, J C


    The improvised explosive device (IED), in all its forms, has become the most significant threat to troops operating in Afghanistan and Iraq. These devices range from rudimentary home made explosives to sophisticated weapon systems containing high-grade explosives. Within this broad definition they may be classified as roadside explosives and blast mines, explosive formed pojectile (EFP) devices and suicide bombings. Each of these groups causeinjury through a number of different mechanisms and can result in vastly different injury profiles. The "Global War on Terror" has meant that incidents which were previously exclusively seen in conflict areas, can occur anywhere, and clinicians who are involved in emergency trauma care may be required to manage casualties from similar terrorist attacks. An understanding of the types of devices and their pathophysiological effects is necessary to allow proper planning of mass casualty events and to allow appropriate management of the complex poly-trauma casualties they invariably cause. The aim of this review article is to firstly describe the physics and injury profile from these different devices and secondly to present the current clinical evidence that underpins their medical management.

  3. Design of a computer program for the registration of implantable medical device, field safety corrective action and advers events, as a tool for medical device surveillance

    Directory of Open Access Journals (Sweden)

    Juan Francisco Márquez-Peiró


    Full Text Available Objective: To describe the features of computer program to support the activity of the responsible for surveillance of medical devices. To evaluate their use after one year of implementation in a hospital. Method: The stages of the process were: description of the activities of medical devices surveillance and implant registration, definition of functionality and data processing, creation of databases, implementation in a private hospital which manages PS, validation of the program and analysis of their usefulness. Results: SIVIPS was developed using Acces®. Main variables were described for all the activities of the responsible for medical device surveillance (implants, alert, medical device incidents, including for in vitro diagnostics and all the functionalities of the computer program. SIVIPS was introduced in a pharmacy service with one pharmacist for the management of medical devices. One year after its implementation we had registered 564 implants with a description by type of implant, 31 alerts and 6 incidents. SIVIPS allow monitoring of the actions taken in these cases. Conclusions: SIVIPS® is the first tool to support the activity of medical device surveillance. It is an easy tool that allows the registration of alerts and medical device related incidents, and registration of implants performed in the center, which will improve the traceability of the PS.

  4. Multicenter audiometric results with the Vibrant Soundbridge, a semi-implantable hearing device for sensorineural hearing impairment.

    NARCIS (Netherlands)

    Snik, A.F.M.; Mylanus, E.A.M.; Cremers, C.W.R.J.; Dillier, N.; Fisch, U.; Gnadeberg, D.; Lenarz, T.; Mazolli, M.; Babighian, G.; Uziel, A.; Cooper, H.R.; Connor, A.F. O'; Fraysse, B.; Charachon, R.; Shehata-Dieler, W.E.


    The Vibrant Soundbridge, a semi-implantable hearing device for subjects with moderate to severe sensorineural hearing impairment was introduced commercially. First audiologic results are presented on 63 patients from 10 European implant centers. Hearing loss was at 0.5, 1, 2, and 4 kHz varying betwe

  5. 78 FR 38994 - Implanted Blood Access Devices for Hemodialysis; Draft Guidance for Industry and Food and Drug... (United States)


    ... HUMAN SERVICES Food and Drug Administration Implanted Blood Access Devices for Hemodialysis; Draft Guidance for Industry and Food and Drug Administration Staff; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA) is announcing...

  6. Mechanical Reliability of Devices Subdermally Implanted into the Young of Long-Lived and Endangered Wildlife (United States)

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


    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.

  7. Choice of the levonorgestrel intrauterine device, etonogestrel implant or depot medroxyprogesterone acetate for contraception after aspiration abortion. (United States)

    Steinauer, Jody E; Upadhyay, Ushma D; Sokoloff, Abby; Harper, Cynthia C; Diedrich, Justin T; Drey, Eleanor A


    Women who have abortions are at high risk of contraception discontinuation and subsequent unintended pregnancy. The objective of this analysis was to identify factors associated with choice of highly effective, long-acting, progestin-only contraceptive methods after abortion. Women presenting for surgical abortion who selected the levonorgestrel intrauterine device (IUD), the progestin implant or the progestin injection (depot medroxyprogesterone acetate or DMPA) as their postabortion contraceptives were recruited to participate in a 1-year prospective cohort study. We used multivariable multinomial logistic regression to identify factors associated with choosing long-acting reversible contraceptives (IUD or implant) compared to DMPA. A total of 260 women, aged 18-45 years, enrolled in the study, 100 of whom chose the IUD, 63 the implant and 97 the DMPA. The women were 24.9 years old on average; 36% were black, and 29% were Latina. Fifty-nine percent had had a previous abortion, 66% a prior birth, and 55% were undergoing a second-trimester abortion. In multivariable analyses, compared with DMPA users, women who chose the IUD or the implant were less likely to be currently experiencing intimate partner violence (IPV); reported higher stress levels; weighed more; and were more likely to have finished high school, to have used the pill before and to report that counselors or doctors were helpful in making the decision (all significant at p<.05, see text for relative risk ratios and confidence intervals.) In addition, women who chose the IUD were less likely to be black (p<.01), and women who chose the implant were more likely to report that they would be unhappy to become pregnant within 6 months (p<.05) than DMPA users. A variety of factors including race/ethnicity, past contraceptive use, feelings towards pregnancy, stress and weight were different between LARC and DMPA users. Notably, current IPV was associated with choice of DMPA over the IUD or implant, implying

  8. Constraining OCT with Knowledge of Device Design Enables High Accuracy Hemodynamic Assessment of Endovascular Implants (United States)

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


    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

  9. DEGRO/DGK guideline for radiotherapy in patients with cardiac implantable electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Gauter-Fleckenstein, Benjamin; Steil, Volker; Wenz, Frederik [Ruprecht-Karls-Universitaet Heidelberg, Klinik fuer Strahlentherapie und Radioonkologie, Universitaetsmedizin Mannheim, Mannheim (Germany); Israel, Carsten W. [Klinik fuer Innere Medizin - Kardiologie, Diabetologie und Nephrologie, Ev. Krankenhaus Bielefeld, Bielefeld (Germany); Dorenkamp, Marc [Charite - Universitaetsmedizin Berlin, Campus Virchow-Klinikum, Medizinische Klinik mit Schwerpunkt Kardiologie, Berlin (Germany); Dunst, Juergen [Universitaetsklinik Schleswig-Holstein, Campus Luebeck, Klinik fuer Strahlentherapie, Luebeck (Germany); Roser, Mattias [Charite - Universitaetsmedizin Berlin, Campus Benjamin Franklin, Medizinische Klinik fuer Kardiologie und Pulmologie, Berlin (Germany); Schimpf, Rainer [Ruprecht-Karls-Universitaet Heidelberg, I. Medizinische Klinik - Kardiologie, Universitaetsmedizin Mannheim, Heidelberg (Germany); Schaefer, Joerg [Strahlentherapie Speyer, Speyer (Germany); Hoeller, Ulrike [Charite Universitaetsmedizin Berlin, Campus Charite Mitte, Klinik fuer Radioonkologie und Strahlentherapie, Berlin (Germany)


    An increasing number of patients undergoing radiotherapy (RT) have cardiac implantable electronic devices [CIEDs, cardiac pacemakers (PMs) and implanted cardioverters/defibrillators (ICDs)]. Ionizing radiation can cause latent and permanent damage to CIEDs, which may result in loss of function in patients with asystole or ventricular fibrillation. Reviewing the current literature, the interdisciplinary German guideline (DEGRO/DGK) was developed reflecting patient risk according to type of CIED, cardiac condition, and estimated radiation dose to the CIED. Planning for RT should consider the CIED specifications as well as patient-related characteristics (pacing-dependent, previous ventricular tachycardia/fibrillation). Antitachyarrhythmia therapy should be suspended in patients with ICDs, who should be under electrocardiographic monitoring with an external defibrillator on stand-by. The beam energy should be limited to 6 (to 10) MV CIEDs should never be located in the beam, and the cumulative scatter radiation dose should be limited to 2 Gy. Personnel must be able to respond adequately in the case of a cardiac emergency and initiate basic life support, while an emergency team capable of advanced life support should be available within 5 min. CIEDs need to be interrogated 1, 3, and 6 months after the last RT due to the risk of latent damage. (orig.) [German] Strahlentherapie (RT) ist zunehmend haeufig bei Patienten mit kardialen implantierten elektronischen Geraeten (CIED; Herzschrittmacher [SM] und Kardioverter-Defibrillatoren [ICD]) indiziert. Durch ionisierende Strahlen koennen Schaeden und Fehlfunktionen des CIED auftreten, die einen permanenten Funktionsverlust beim Geraet und eine Asystolie oder Kammerflimmern beim Patienten ausloesen. Deshalb wurde vor dem Hintergrund der bisher verfuegbaren Daten eine interdisziplinaere Leitlinie (DEGRO/DGK) erarbeitet, die sich an der zu erwartenden Strahlendosis am CIED sowie dem kardialen Risiko des Patienten orientiert. In

  10. Health Care Utilization and Expenditures Associated With Remote Monitoring in Patients With Implantable Cardiac Devices. (United States)

    Ladapo, Joseph A; Turakhia, Mintu P; Ryan, Michael P; Mollenkopf, Sarah A; Reynolds, Matthew R


    Several randomized trials and decision analysis models have found that remote monitoring may reduce health care utilization and expenditures in patients with cardiac implantable electronic devices (CIEDs), compared with in-office monitoring. However, little is known about the generalizability of these findings to unselected populations in clinical practice. To compare health care utilization and expenditures associated with remote monitoring and in-office monitoring in patients with CIEDs, we used Truven Health MarketScan Commercial Claims and Medicare Supplemental Databases. We selected patients newly implanted with an implantable cardioverter defibrillators (ICD), cardiac resynchronization therapy defibrillator (CRT-D), or permanent pacemaker (PPM), in 2009, who had continuous health plan enrollment 2 years after implantation. Generalized linear models and propensity score matching were used to adjust for confounders and estimate differences in health care utilization and expenditures in patients with remote or in-office monitoring. We identified 1,127; 427; and 1,295 pairs of patients with a similar propensity for receiving an ICD, CRT-D, or PPM, respectively. Remotely monitored patients with ICDs experienced fewer emergency department visits resulting in discharge (p = 0.050). Remote monitoring was associated with lower health care expenditures in office visits among patients with PPMs (p = 0.025) and CRT-Ds (p = 0.006) and lower total inpatient and outpatient expenditures in patients with ICDs (p monitoring of patients with CIEDs may be associated with reductions in health care utilization and expenditures compared with exclusive in-office care.

  11. Dental management of a patient fitted with subcutaneous Implantable Cardioverter Defibrillator device and concomitant warfarin treatment. (United States)

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


    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.

  12. [Proposal for updated listing criteria for heart transplantation and indications to implant of left ventricular assist devices]. (United States)

    Ammirati, Enrico; Oliva, Fabrizio; Colombo, Tiziano; Botta, Luca; Cipriani, Manlio; Cannata, Aldo; Verde, Alessandro; Turazza, Fabio M; Russo, Claudio F; Paino, Roberto; Martinelli, Luigi; Frigerio, Maria


    Heart transplantation (HTx) is considered to be the gold standard treatment for advanced heart failure (HF) but it is available only for a minority of patients, due to paucity of donor hearts (278 HTx were performed in 2011 in Italy). Patients listed for HTx have a prolonged waiting time (that is about 2.3 years in the 2006-2010 time period in Italy) that is superior compared with patients who receive HTx (median time around 6 months), to underline the presence of an allocation system that prioritizes candidates in critical conditions. Patients listed for HTx have a poor quality of life and their annual mortality is around 8-10%. Another 10-15% of HTx candidates are removed from the waiting list each year because they are no longer suitable for transplantation. On the other hand, continuous-flow left ventricular assist devices (LVADs) have been demonstrated to improve survival and quality of life of patients with advanced/refractory HF. LVAD therapy can represent a valid alternative to HTx, and it is recommended for patients with advanced HF in the recent edition of the European Society of Cardiology guidelines on HF management. In the United States, a larger number of centers compared with European ones started to apply a strategy of LVAD implant for many patients who meet clinical criteria for listing for HTx. Data from our center concerning the last 6 years of LVAD implant (51 implants since 2006) reported a 75.5% survival rate at 1 year. In Italian series, as in our center, current HTx survival is only slightly superior (83% survival rate at 1 year), based on data from the Italian National Transplant Center. We report a proposal for updated listing criteria for HTx and indications for LVAD implant in patients with advanced acute and chronic HF. Criteria for identifying suitable patients for HTx and/or LVAD considering the shortage of donors are discussed.

  13. Generation of electrical power under human skin by subdermal solar cell arrays for implantable bioelectronic devices. (United States)

    Song, Kwangsun; Han, Jung Hyun; Yang, Hyung Chae; Nam, Kwang Il; Lee, Jongho


    Medical electronic implants can significantly improve people's health and quality of life. These implants are typically powered by batteries, which usually have a finite lifetime and therefore must be replaced periodically using surgical procedures. Recently, subdermal solar cells that can generate electricity by absorbing light transmitted through skin have been proposed as a sustainable electricity source to power medical electronic implants in bodies. However, the results to date have been obtained with animal models. To apply the technology to human beings, electrical performance should be characterized using human skin covering the subdermal solar cells. In this paper, we present electrical performance results (up to 9.05mW/cm(2)) of the implantable solar cell array under 59 human skin samples isolated from 10 cadavers. The results indicate that the power densities depend on the thickness and tone of the human skin, e.g., higher power was generated under thinner and brighter skin. The generated power density is high enough to operate currently available medical electronic implants such as pacemakers that require tens of microwatt.

  14. A Semiconductor Device Noise Model: A Deterministic Approach to Semiconductor Device Current Noise for Semiclassical Transport (United States)

    Noaman, B. A.; Korman, C. E.


    In this paper, we present a deterministic approach to calculate terminal current noise characteristics in semiconductor devices in the framework of semiclassical transport based on the spherical harmonics of the Boltzmann Transport Equation. The model relies on the solution of the Boltzmann equation in the frequency domain with special initial and boundary conditions. The terminal current fluctuation is directly related to scattering without the additional Langevin noise term added to the calculation. Simulation results are presented for the terminal current spectral density for a 1-D n+nn+ structure due to elastic-acoustic and intervally scattering.

  15. The potential role of polymethyl methacrylate as a new packaging material for the implantable medical device in the bladder. (United States)

    Kim, Su Jin; Choi, Bumkyoo; Kim, Kang Sup; Bae, Woong Jin; Hong, Sung Hoo; Lee, Ji Youl; Hwang, Tae-Kon; Kim, Sae Woong


    Polydimethylsiloxane (PDMS) is used in implantable medical devices; however, PDMS is not a completely biocompatible material for electronic medical devices in the bladder. To identify novel biocompatible materials for intravesical implanted medical devices, we evaluated the biocompatibility of polymethyl methacrylate (PMMA) by analyzing changes in the levels of macrophages, macrophage migratory inhibitory factor (MIF), and inflammatory cytokines in the bladder. A ball-shaped metal coated with PMMA or PDMS was implanted into the bladders of rats, and after intravesical implantation, the inflammatory changes induced by the foreign body reaction were evaluated. In the early period after implantation, increased macrophage activity and MIF in the urothelium of the bladder were observed. However, significantly decreased macrophage activity and MIF in the bladder were observed after implantation with PMMA- or PDMS-coated metal in the later period. In addition, significantly decreased inflammatory cytokines such as IL-1β, IL-6, and TNF-α were observed with time. Based on these results, we suggest that MIF plays a role in the foreign body reaction and in the biocompatible packaging with PMMA for the implanted medical devices in the bladder.

  16. Polymeric salt bridges for conducting electric current in microfluidic devices (United States)

    Shepodd, Timothy J.; Tichenor, Mark S.; Artau, Alexander


    A "cast-in-place" monolithic microporous polymer salt bridge for conducting electrical current in microfluidic devices, and methods for manufacture thereof is disclosed. Polymeric salt bridges are formed in place in capillaries or microchannels. Formulations are prepared with monomer, suitable cross-linkers, solvent, and a thermal or radiation responsive initiator. The formulation is placed in a desired location and then suitable radiation such as UV light is used to polymerize the salt bridge within a desired structural location. Embodiments are provided wherein the polymeric salt bridges have sufficient porosity to allow ionic migration without bulk flow of solvents therethrough. The salt bridges form barriers that seal against fluid pressures in excess of 5000 pounds per square inch. The salt bridges can be formulated for carriage of suitable amperage at a desired voltage, and thus microfluidic devices using such salt bridges can be specifically constructed to meet selected analytical requirements.

  17. A microfabricated low cost enzyme-free glucose fuel cell for powering low-power implantable devices (United States)

    Oncescu, Vlad; Erickson, David

    In the past decade the scientific community has showed considerable interest in the development of implantable medical devices such as muscle stimulators, neuroprosthetic devices, and biosensors. Those devices have low power requirements and can potentially be operated through fuel cells using reactants present in the body such as glucose and oxygen instead of non-rechargeable lithium batteries. In this paper, we present a thin, enzyme-free fuel cell with high current density and good stability at a current density of 10 μA cm -2. A non-enzymatic approach is preferred because of higher long term stability. The fuel cell uses a stacked electrode design in order to achieve glucose and oxygen separation. An important characteristic of the fuel cell is that it has no membrane separating the electrodes, which results in low ohmic losses and small fuel cell volume. In addition, it uses a porous carbon paper support for the anodic catalyst layer which reduces the amount of platinum or other noble metal catalysts required for fabricating high surface area electrodes with good reactivity. The peak power output of the fuel cell is approximately 2 μW cm -2 and has a sustainable power density of 1.5 μW cm -2 at 10 μA cm -2. An analysis on the effects of electrode thickness and inter electrode gap on the maximum power output of the fuel cell is also performed.

  18. Patch Testing for Evaluation of Hypersensitivity to Implanted Metal Devices: A Perspective From the American Contact Dermatitis Society. (United States)

    Schalock, Peter C; Crawford, Glen; Nedorost, Susan; Scheinman, Pamela L; Atwater, Amber Reck; Mowad, Christen; Brod, Bruce; Ehrlich, Alison; Watsky, Kalman L; Sasseville, Denis; Silvestri, Dianne; Worobec, Sophie M; Elliott, John F; Honari, Golara; Powell, Douglas L; Taylor, James; DeKoven, Joel


    The American Contact Dermatitis Society recognizes the interest in the evaluation and management of metal hypersensitivity reactions. Given the paucity of robust evidence with which to guide our practices, we provide reasonable evidence and expert opinion-based guidelines for clinicians with regard to metal hypersensitivity reaction testing and patient management. Routine preoperative evaluation in individuals with no history of adverse cutaneous reactions to metals or history of previous implant-related adverse events is not necessary. Patients with a clear self-reported history of metal reactions should be evaluated by patch testing before device implant. Patch testing is only 1 element in the assessment of causation in those with postimplantation morbidity. Metal exposure from the implanted device can cause sensitization, but a positive metal test does not prove symptom causality. The decision to replace an implanted device must include an assessment of all clinical factors and a thorough risk-benefit analysis by the treating physician(s) and patient.

  19. Optimized Axillary Vein Technique versus Subclavian Vein Technique in Cardiovascular Implantable Electronic Device Implantation: A Randomized Controlled Study

    Institute of Scientific and Technical Information of China (English)

    Peng Liu; Yi-Feng Zhou; Peng Yang; Yan-Sha Gao; Gui-Ru Zhao; Shi-Yan Ren; Xian-Lun Li


    Background:The conventional venous access for cardiovascular implantable electronic device (CIED) is the subclavian vein,which is often accompanied by high complication rate.The aim of this study was to assess the efficacy and safety of optimized axillary vein technique.Methods:A total of 247 patients undergoing CIED implantation were included and assigned to the axillary vein group or the subclavian vein group randomly.Success rate of puncture and complications in the perioperative period and follow-ups were recorded.Results:The overall success rate (95.7% vs.96.0%) and one-time success rate (68.4% vs.66.1%) of punctures were similar between the two groups.In the subclavian vein group,pneumothorax occurred in three patients.The subclavian gaps of three patients were too tight to allow operation of the electrode lead.In contrast,there were no puncture-associated complications in the axillary vein group.In the patient follow-ups,two patients in the subclavian vein group had subclavian crush syndrome and both of them received lead replacement.The incidence of complications during the perioperative period and follow-ups of the axillary vein group and the subclavian vein group was 1.6% (2/125) and 8.2% (10/122),respectively (x2=5.813,P =0.016).Conclusion:Optimized axillary vein technique may be superior to the conventional subclavian vein technique for CIED lead placement.

  20. A 100-channel hermetically sealed implantable device for chronic wireless neurosensing applications. (United States)

    Yin, Ming; Borton, David A; Aceros, Juan; Patterson, William R; Nurmikko, Arto V


    A 100-channel fully implantable wireless broadband neural recording system was developed. It features 100 parallel broadband (0.1 Hz-7.8 kHz) neural recording channels, a medical grade 200 mAh Li-ion battery recharged inductively at 150 kHz , and data telemetry using 3.2 GHz to 3.8 GHz FSK modulated wireless link for 48 Mbps Manchester encoded data. All active electronics are hermetically sealed in a titanium enclosure with a sapphire window for electromagnetic transparency. A custom, high-density configuration of 100 individual hermetic feedthrough pins enable connection to an intracortical neural recording microelectrode array. A 100 MHz bandwidth custom receiver was built to remotely receive the FSK signal and achieved -77.7 dBm sensitivity with 10(-8) BER at 48 Mbps data rate. ESD testing on all the electronic inputs and outputs has proven that the implantable device satisfies the HBM Class-1B ESD Standard. In addition, the evaluation of the worst-case charge density delivered to the tissue from each I/O pin verifies the patient safety of the device in the event of failure. Finally, the functionality and reliability of the complete device has been tested on-bench and further validated chronically in ongoing freely moving swine and monkey animal trials for more than one year to date.

  1. Current-Voltage Characteristics of Molecular Devices at Low Bias

    Institute of Scientific and Technical Information of China (English)

    LIAO Yun-Xing; CHEN Hao; R.Note; H.Mizuseki; Y.Kawazoe


    We use density functional theory and the Green function formalism with charge energy effect included in the self-consistent calculation of the Ⅰ- Ⅴ characteristics of a single benzene ring with an appendage of cf3, and identify some interesting properties of the Ⅰ-Ⅴ characteristics at low bias. The molecule picks up a fractional charge at zero bias, then the additional fractional charge produces a barrier on the junction of the molecule and contacts to perturb current flow on the molecule. This phenomenon may be useful for the design of future molecular devices.

  2. Prodigiosin release from an implantable biomedical device: kinetics of localized cancer drug release

    Energy Technology Data Exchange (ETDEWEB)

    Danyuo, Y.; Obayemi, J.D.; Dozie-Nwachukwu, S. [Department of Materials Science and Engineering, African University of Science and Technology (AUST), Abuja, Federal Capital Territory (Nigeria); Ani, C.J. [Department of Theoretical Physics, African University of Science and Technology (AUST), Abuja, Federal Capital Territory (Nigeria); Odusanya, O.S. [Biotechnology and Genetic Engineering Advanced Laboratory, Sheda Science and Technology Complex (SHESTCO), Abuja, Federal Capital Territory (Nigeria); Oni, Y. [Department of Chemistry, Bronx Community College, New York, NY (United States); Anuku, N. [Department of Chemistry, Bronx Community College, New York, NY (United States); Princeton Institute for the Science and Technology of Materials (PRISM), 70 Prospect Street, Princeton, NJ 08544 (United States); Malatesta, K. [Department of Chemistry, Bronx Community College, New York, NY (United States); Soboyejo, W.O., E-mail: [Department of Materials Science and Engineering, African University of Science and Technology (AUST), Abuja, Federal Capital Territory (Nigeria); Princeton Institute for the Science and Technology of Materials (PRISM), 70 Prospect Street, Princeton, NJ 08544 (United States); Department of Mechanical and Aerospace Engineering 1 Olden Street, Princeton, NJ 08544 (United States)


    This paper presents an implantable encapsulated structure that can deliver localized heating (hyperthermia) and controlled concentrations of prodigiosin (a cancer drug) synthesized by bacteria (Serratia marcesce (subsp. marcescens)). Prototypical Poly-di-methyl-siloxane (PDMS) packages, containing well-controlled micro-channels and drug storage compartments, were fabricated along with a drug-storing polymer produced by free radical polymerization of Poly(N-isopropylacrylamide)(PNIPA) co-monomers of Acrylamide (AM) and Butyl-methacrylate (BMA). The mechanisms of drug diffusion of PNIPA-base gels were elucidated. Scanning Electron Microscopy (SEM) was also used to study the heterogeneous porous structure of the PNIPA-based gels. The release exponents, n, of the gels were found to between 0.5 and 0.7. This is in the range expected for Fickian (n = 0.5). Deviation from Fickian diffusion was also observed (n > 0.5) diffusion. The gel diffusion coefficients were shown to vary between 2.1 × 10{sup −12} m{sup 2}/s and 4.8 × 10{sup −6} m{sup 2}/s. The implications of the results are then discussed for the localized treatment of cancer via hyperthermia and the controlled delivery of prodigiosin from encapsulated PNIPA-based devices. - Highlights: • Fabricated thermo-sensitive hydrogels for localized drug release from an implantable biomedical device. • Determined the cancer drug diffusion mechanisms of PNIPA-co-AM copolymer hydrogel. • Encapsulated PNIPA-based hydrogels in PDMS capsules for controlled drug delivery. • Established the kinetics of drug release from gels and channels in an implantable biomedical device. • Demonstrated the potential for the controlled release of prodigiosin (PG) as an anticancer drug.

  3. Prolonged use of the etonogestrel implant and levonorgestrel intrauterine device: 2 years beyond Food and Drug Administration-approved duration. (United States)

    McNicholas, Colleen; Swor, Erin; Wan, Leping; Peipert, Jeffrey F


    The subdermal contraceptive implant and the 52-mg levonorgestrel intrauterine device are currently Food and Drug Administration approved for 3 and 5 years of use, respectively. Limited available data suggested both of these methods are effective beyond that time. Demonstration of prolonged effectiveness will improve the cost-effectiveness of the device, and potentially patient continuation and satisfaction. We sought to evaluate the effectiveness of the contraceptive implant and the 52-mg hormonal intrauterine device in women using the method for 2 years beyond the current Food and Drug Administration-approved duration. We initiated this ongoing prospective cohort study in January 2012. We are enrolling women using the contraceptive implant or 52-mg levonorgestrel intrauterine device for a minimum of 3 and 5 years, respectively (started intrauterine device in ≥2007 or implant in ≥2009). Demographic and reproductive health histories, as well as objective body mass index, were collected. Implant users were offered periodic venipuncture for analysis of serum etonogestrel levels. The primary outcome, unintended pregnancy rate, was calculated per 100 woman-years. We analyzed baseline demographic characteristics using χ(2) test and Fisher exact test, and compared serum etonogestrel levels stratified by body mass index using the Kruskal-Wallis test. Implant users (n = 291) have contributed 444.0 woman-years of follow-up. There have been no documented pregnancies in implant users during the 2 years of postexpiration follow-up. Calculated failure rates in the fourth and fifth years for the implant are calculated as 0 (1-sided 97.5% confidence interval, 0-1.48) per 100 woman-years at 4 years and 0 (1-sided 97.5% confidence interval, 0-2.65) per 100 woman-years at 5 years. Among 496 levonorgestrel intrauterine device users, 696.9 woman-years of follow-up have been completed. Two pregnancies have been reported. The failure rate in the sixth year of use of the

  4. Characterization of current transport in ferroelectric polymer devices

    KAUST Repository

    Hanna, Amir


    We report the charge injection characteristics in poly(vinylidene fluoride-trifluoroethylene), P(VDF-TrFE), as a function of electrode material in metal/ferroelectric/metal device structures. Symmetric and asymmetric devices with Al, Ag, Au and Pt electrodes were fabricated to determine the dominant carrier type, injection current density, and to propose transport mechanisms in the ferroelectric polymer. Higher work function metals such as Pt are found to inject less charges compared to lower work function metals, implying n-type conduction behavior for P(VDF-TrFE) with electrons as the dominant injected carrier. Two distinct charge transport regimes were identified in the P(VDF-TrFE) devices; a Schottky-limited conduction regime for low to intermediate fields (E < 20 MV/m), and a space-charge limited conduction (SCLC) regime for high fields (20 < E < 120 MV/m). Implication of these results for degradation in P(VDF-TrFE) memory performance are discussed. © 2013 Elsevier B.V. All rights reserved.

  5. Hemodynamic Sensor in Cardiac Implantable Electric Devices: The Endocardial Accelaration Technology

    Directory of Open Access Journals (Sweden)

    Stefania Sacchi


    Full Text Available There have been substantial progresses in the technology of cardiac implantable electric devices (CIEDs during the past decades. One of the progresses is represented by the development of a hemodynamic sensor embedded at the tip of a pacing lead that measures myocardial contractility by the analysis of myocardial mechanical vibrations occurring during the cardiac cycle. This sensor, providing continuous hemodynamic monitoring, could play an important role in clinical practice because of several clinical applications in CIEDs recipients. The objectives of this work are to report how this sensor operates and to review the main findings about its clinical applications.

  6. Laser fabrication of electrical feedthroughs in polymer encapsulations for active implantable medical devices. (United States)

    Gough, Zara; Chaminade, Cedric; Barclay-Monteith, Philip; Kallinen, Annukka; Lei, Wenwen; Ganesan, Rajesh; Grace, John; McKenzie, David R


    Hermetic electrical feedthroughs are essential for safe and functional active implantable biomedical devices and for a wide range of other applications such as batteries, supercapacitors, OLEDs and solar cells. Ceramics and metals have previously been the materials of choice for encapsulations, while polymers have advantages of ease of mass production and end user compatibility. We demonstrate a laser sealing technology that gives hermetic, mechanically strong feedthroughs with low electrical resistance in a polyetheretherketone (PEEK) encapsulation. The conductive pathways are wires and sputtered thin films. The water vapor transmission rate through the fabricated encapsulations is comparable to that of PEEK itself.

  7. [Magnetic urethral closure device. Negative outcome after implantation for the treatment of female urinary incontinence]. (United States)

    Anding, R; van Ahlen, H; Müller, S C; Latz, S


    We report on a negative outcome after implantation of a magnetic urethral closure device, consisting of one part screwed into the pubic bone and one part as a vaginal cone, for the treatment of urinary stress incontinence grade III. Continence was never achieved for the patient. The urethra narrowed over time due to erosion and scarring and the patient started intermittent catheterization, because spontaneous micturition was not possible. The magnet was broken, the bladder neck was eroded, several fragments were found in the bladder, and numerous fragments were scattered throughout the small pelvis. Surgery consisted of removing most of the fragments, followed by bladder neck closure and suprapubic diversion.

  8. Weak Values from Displacement Currents in Multiterminal Electron Devices (United States)

    Marian, D.; Zanghı, N.; Oriols, X.


    Weak values allow the measurement of observables associated with noncommuting operators. Up to now, position-momentum weak values have been mainly developed for (relativistic) photons. In this Letter, a proposal for the measurement of such weak values in typical electronic devices is presented. Inspired by the Ramo-Shockley-Pellegrini theorem that provides a relation between current and electron velocity, it is shown that the displacement current measured in multiterminal configurations can provide either a weak measurement of the momentum or strong measurement of position. This proposal opens new opportunities for fundamental and applied physics with state-of-the-art electronic technology. As an example, a setup for the measurement of the Bohmian velocity of (nonrelativistic) electrons is presented and tested with numerical experiments.

  9. Current and Perspective Applications of Dense Plasma Focus Devices (United States)

    Gribkov, V. A.


    Dense Plasma Focus (DPF) devices' applications, which are intended to support the main-stream large-scale nuclear fusion programs (NFP) from one side (both in fundamental problems of Dense Magnetized Plasma physics and in its engineering issues) as well as elaborated for an immediate use in a number of fields from the other one, are described. In the first direction such problems as self-generated magnetic fields, implosion stability of plasma shells having a high aspect ratio, etc. are important for the Inertial Confinement Fusion (ICF) programs (e.g. as NIF), whereas different problems of current disruption phenomenon, plasma turbulence, mechanisms of generation of fast particles and neutrons in magnetized plasmas are of great interest for the large devices of the Magnetic Plasma Confinement—MPC (e.g. as ITER). In a sphere of the engineering problems of NFP it is shown that in particular the radiation material sciences have DPF as a very efficient tool for radiation tests of prospect materials and for improvement of their characteristics. In the field of broad-band current applications some results obtained in the fields of radiation material sciences, radiobiology, nuclear medicine, express Neutron Activation Analysis (including a single-shot interrogation of hidden illegal objects), dynamic non-destructive quality control, X-Ray microlithography and micromachining, and micro-radiography are presented. As the examples of the potential future applications it is proposed to use DPF as a powerful high-flux neutron source to generate very powerful pulses of neutrons in the nanosecond (ns) range of its duration for innovative experiments in nuclear physics, for the goals of radiation treatment of malignant tumors, for neutron tests of materials of the first wall, blankets and NFP device's constructions (with fluences up to 1 dpa per a year term), and ns pulses of fast electrons, neutrons and hard X-Rays for brachytherapy.

  10. Contraceptive implants. (United States)

    McDonald-Mosley, Raegan; Burke, Anne E


    Implantable contraception has been extensively used worldwide. Implants are one of the most effective and reversible methods of contraception available. These devices may be particularly appropriate for certain populations of women, including women who cannot use estrogen-containing contraception. Implants are safe for use by women with many chronic medical problems. The newest implant, Implanon (Organon International, Oss, The Netherlands), is the only device currently available in the United States and was approved in 2006. It is registered for 3 years of pregnancy prevention. Contraceptive implants have failure rates similar to tubal ligation, and yet they are readily reversible with a return to fertility within days of removal. Moreover, these contraceptive devices can be safely placed in the immediate postpartum period, ensuring good contraceptive coverage for women who may be at risk for an unintended pregnancy. Irregular bleeding is a common side effect for all progestin-only contraceptive implants. Preinsertion counseling should address possible side effects, and treatment may be offered to women who experience prolonged or frequent bleeding. Thieme Medical Publishers.

  11. Reimplantation and Repeat Infection After Cardiac-Implantable Electronic Device Infections: Experience From the MEDIC (Multicenter Electrophysiologic Device Infection Cohort) Database. (United States)

    Boyle, Thomas A; Uslan, Daniel Z; Prutkin, Jordan M; Greenspon, Arnold J; Baddour, Larry M; Danik, Stephan B; Tolosana, Jose M; Le, Katherine; Miro, Jose M; Peacock, James; Sohail, Muhammad R; Vikram, Holenarasipur R; Carrillo, Roger G


    Infection is a serious complication of cardiovascular-implantable electronic device implantation and necessitates removal of all hardware for optimal treatment. Strategies for reimplanting hardware after infection vary widely and have not previously been analyzed using a large, multicenter study. The MEDIC (Multicenter Electrophysiologic Device Infection Cohort) prospectively enrolled subjects with cardiovascular-implantable electronic device infections at multiple institutions in the United States and abroad between 2009 and 2012. Reimplantation strategies were evaluated overall, and every patient who relapsed within 6 months was individually examined for clinical information that could help explain the negative outcome. Overall, 434 patients with cardiovascular-implantable electronic device infections were prospectively enrolled at participating centers. During the initial course of therapy, complete device removal was done in 381 patients (87.8%), and 220 of them (57.7%) were ultimately reimplanted with new devices. Overall, the median time between removal and reimplantation was 10 days, with an interquartile range of 6 to 19 days. Eleven of the 434 patients had another infection within 6 months, but only 4 of them were managed with cardiovascular-implantable electronic device removal and reimplantation during the initial infection. Thus, the repeat infection rate was low (1.8%) in those who were reimplanted. Patients who retained original hardware had a 11.3% repeat infection rate. Our study findings confirm that a broad range of reimplant strategies are used in clinical practice. They suggest that it is safe to reimplant cardiac devices after extraction of previously infected hardware and that the risk of a second infection is low, regardless of reimplant timing. © 2017 American Heart Association, Inc.

  12. Ultrahigh-current-density metal-ion implantation and diamondlike-hydrocarbon films for tribological applications (United States)

    Wilbur, P. J.


    The metal-ion-implantation system used to implant metals into substrates are described. The metal vapor required for operation is supplied by drawing sufficient electron current from the plasma discharge to an anode-potential crucible so a solid, pure metal placed in the crucible will be heated to the point of vaporization. The ion-producing, plasma discharge is initiated within a graphite-ion-source body, which operates at high temperature, by using an argon flow that is turned off once the metal vapor is present. Extraction of ion beams several cm in diameter at current densities ranging to several hundred micro-A/sq cm on a target 50 cm downstream of the ion source were demonstrated using Mg, Ag, Cr, Cu, Si, Ti, V, B, and Zr. These metals were implanted into over 100 substrates (discs, pins, flats, wires). A model describing thermal stresses induced in materials (e.g. ceramic plates) during high-current-density implantation is presented. Tribological and microstructural characteristics of iron and 304-stainless-steel samples implanted with Ti or B are examined. Diamondlike-hydrocarbon coatings were applied to steel surfaces and found to exhibit good tribological performance.

  13. Intractable Hematuria After Left Ventricular Assist Device Implantation: Can Lessons Learned from Gastrointestinal Bleeding Be Applied? (United States)

    Son, Andre Y; Zhao, Lee; Reyentovich, Alex; Deanda, Abe; Balsam, Leora B


    Patients with continuous-flow left ventricular assist devices (CF-LVADs) are at increased risk of bleeding. We reviewed our institutional experience with bleeding in the urinary tract after CF-LVAD implantation and quantified the impact on hospital resource utilization in comparison with bleeding in the gastrointestinal (GI) tract, the most commonly reported mucosal site of bleeding after LVAD implantation. Records were retrospectively reviewed for patients undergoing CF-LVAD implantation at our institution between October 2011 and April 2015. Major adverse events of gross hematuria and GI bleeding were identified, and patient demographics and hospital course were reviewed. Gross hematuria occurred in 3 of the 35 patients (8.6%) and in 5.1% of all hospitalizations for CF-LVAD patients. Severe hematuria occurred after traumatic urethral catheterization, urinary retention, or urologic surgery. Hospitalization for hematuria was six times less likely than hospitalization for GI bleeding; however, hematuria hospitalizations lasted 3.2 times longer than GI bleeding hospitalizations (17.0 vs. 5.3 days). Late recurrent gross hematuria occurred in all cases, with rehospitalization occurring after 109 ± 53 days. In conclusion, gross hematuria is an infrequent but morbid bleeding complication in CF-LVAD patients. Strategies to avoid this complication include strict avoidance of traumatic urethral catheterization and urinary retention in high-risk patients.

  14. Splenic abcesses as infectious complication following implantation of left ventricular asssist device - case report. (United States)

    Gajda, Sławomir; Szczepanik, Anna M; Religa, Grzegorz; Misiak, Andrzej; Szczepanik, Andrzej B


    Left ventricular assist device (LVAD) is one of the modern management therapies in patients with advanced heart failure, and it serves as a bridge to heart transplantation or even as destination therapy. However, it is burdened with a high risk of thromboembolic, hemorrhagic, and infectious complications despite prophylactic management. Splenic abscesses, as septic complications following implantation of mechanical ventricular support, have not yet been described in the literature. We report of a patient with severe left ventricular insufficiency (NYHA II/III), pulmonary hypertension, and arrhythmia who underwent implantation of the Heart Ware® pump for left ventricular support with simultaneous tricuspidvalvoplasty, as a bridge therapy to heart transplantation. During two years after LVAD implantation, the patient had three MRSA skin infections, localized at the exit site of the drive-line connecting the artificial ventricle with external unit, that were complicated by sepsis and treated with broad-spectrum antibiotics. A few months later, abdominal CT revealed two abscesses in the spleen, and the patient was qualified for splenectomy. Open splenectomy was performed under full-dose anticoagulant therapy with continuous intravenous infusions of unfractionated heparin (UFH). The intra- and postoperative course was uneventful. UFH therapy was continued for 6 days, and oral anticoagulation was re-administered on day 4 after surgery. The patient was discharged on day 7 after surgery with primary healed wound. Open splenectomy, performed with full-dose anticoagulant therapy, proved to be an effective and definitive method of treatment without any complications.

  15. Intra-operative evaluation of cementless hip implant stability: a prototype device based on vibration analysis. (United States)

    Lannocca, Maurizio; Varini, Elena; Cappello, Angelo; Cristofolini, Luca; Bialoblocka, Ewa


    Cementless implants are mechanically stabilized during surgery by a press-fitting procedure. Good initial stability is crucial to avoid stem loosening and bone cracking, therefore, the surgeon must achieve optimal press-fitting. A possible approach to solve this problem and assist the surgeon in achieving the optimal compromise, involves the use of vibration analysis. The present study aimed to design and test a prototype device able to evaluate the primary mechanical stability of a cementless prosthesis, based on vibration analysis. In particular, the goal was to discriminate between stable and quasi-stable implants; thus the stem-bone system was assumed to be linear in both cases. For that reason, it was decided to study the frequency responses of the system, instead of the harmonic distortion. The prototype developed consists of a piezoelectric exciter connected to the stem and an accelerometer attached to the femur. Preliminary tests were performed on four composite femurs implanted with a conventional stem. The results showed that the input signal was repeatable and the output could be recorded accurately. The most sensitive parameter to stability was the shift in resonance frequency of the stem-bone system, which was highly correlated with residual micromotion on all four specimens.

  16. Our experience with implantation of VentrAssist left ventricular assist device

    Directory of Open Access Journals (Sweden)

    Hiriyur Shivalingappa Jayanthkumar


    Full Text Available Perioperative anaesthetic management of the VentrAssist TM left ventricular assist device (LVAD is a challenge for anaesthesiologists because patients presenting for this operation have long-standing cardiac failure and often have associated hepatic and renal impairment, which may significantly alter the pharmacokinetics of administered drugs and render the patients coagulopathic. The VentrAssist is implanted by midline sternotomy. A brief period of cardiopulmonary bypass (CPB for apical cannulation of left ventricle is needed. The centrifugal pump, which produces non-pulsatile, continuous flow, is positioned in the left sub-diaphragmatic pocket. This LVAD is preload dependent and afterload sensitive. Transoesophageal echocardiography is an essential tool to rule out contraindications and to ensure proper inflow cannula position, and following the implantation of LVAD, to ensure right ventricular (RV function. The anaesthesiologist should be prepared to manage cardiac decompensation and acute desaturation before initiation of CPB, as well as RV failure and severe coagulopathic bleeding after CPB. Three patients had undergone implantation of VentrAssist in our hospital. This pump provides flow of 5 l/min depending on preload, afterload and pump speed. All the patients were discharged after an average of 30 days. There was no perioperative mortality.

  17. Elevation of procalcitonin after implantation of an interventional lung assist device in critically ill patients. (United States)

    Kott, Matthias; Bewig, Burkhard; Zick, Günther; Schaedler, Dirk; Becher, Tobias; Frerichs, Inéz; Weiler, Norbert


    A pumpless interventional arteriovenous lung assist device (iLA) facilitates the removal of carbon dioxide from the blood and is used as part of the lung-protective ventilation strategy in patients with acute respiratory distress syndrome (ARDS). In case of bacterial infection, delayed antimicrobial therapy increases the mortality in this group of high-risk critically ill patients, whereas overtreatment promotes bacterial resistance and leads to increased drug toxicity and costs. Besides clinical signs and symptoms, antimicrobial treatment is based on the kinetics of biomarkers such as procalcitonin (PCT). We hereby report an up to 10-fold increase in PCT serum concentrations in four mechanically ventilated patients with ARDS detected within 12-20 hours after iLA implantation in the absence of any infection. Procalcitonin concentrations returned to nearly baseline values in all patients on the fourth day after iLA implantation. We discuss the possible mechanisms of PCT induction in this specific patient population and recommend the onset of antibiotics administration after iLA implantation to be carefully considered in the context of other clinical findings and not solely based on the PCT kinetics. Repeated PCT measurements in short time intervals should be performed in these patients.

  18. Surface implantation treatments to prevent infection complications in short term devices. (United States)

    Davenas, J; Thévenard, P; Philippe, F; Arnaud, M N


    Surface treatments of short term devices are actually evaluated to reduce the risk of infections, which in particular are one of the main causes of complications following catheter insertion. We have investigated the efficacy of ion beam techniques to reduce bacterial adhesion-or to induce bactericidal activity of different polymer materials: PVC, silicone rubber, poly(urethane) and poly(ethylene). Two routes have been evaluated, based on the production of non fouling surfaces, through the production of diamond-like surfaces upon irradiation with rare gases, or the implantation of silver, known for its bactericidal action. In this contribution we discuss more specifically the treatment of poly(ethylene), where a broad range of surface characterisation techniques could show that the biological activity resulted from the formation of metallic colloidal silver near the surface of the polymer, associated to the formation of a dense surface acting as a diffusion barrier. Reduction of the implantation energy to 10 keV, led to activity enhancement resulting from the easier accessibility of surface colloids evidenced by AFM microscopy. This study emphasises the specific processes induced by the formation of silver nano-particles at low energy implantation, which differs basically from Ion Beam Assisted Deposition (IBAD technique) leading to the formation of a continuous silver coating (Artif. Organs 18 (1994) 266; International Patent (PCT) WO 95/18637 (1995)).

  19. Improvement of wireless power transmission efficiency of implantable subcutaneous devices by closed magnetic circuit mechanism. (United States)

    Jo, Sung-Eun; Joung, Sanghoon; Suh, Jun-Kyo Francis; Kim, Yong-Jun


    Induction coils were fabricated based on flexible printed circuit board for inductive transcutaneous power transmission. The coil had closed magnetic circuit (CMC) structure consisting of inner and outer magnetic core. The power transmission efficiency of the fabricated device was measured in the air and in vivo condition. It was confirmed that the CMC coil had higher transmission efficiency than typical air-core coil. The power transmission efficiency during a misalignment between primary coil and implanted secondary coil was also evaluated. The decrease of mutual inductance between the two coils caused by the misalignment led to a low efficiency of the inductive link. Therefore, it is important to properly align the primary coil and implanted secondary coil for effective power transmission. To align the coils, a feedback coil was proposed. This was integrated on the backside of the primary coil and enabled the detection of a misalignment of the primary and secondary coils. As a result of using the feedback coil, the primary and secondary coils could be aligned without knowledge of the position of the implanted secondary coil.

  20. Cryogenic ion implantation near amorphization threshold dose for halo/extension junction improvement in sub-30 nm device technologies

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hugh; Todorov, Stan; Colombeau, Benjamin; Rodier, Dennis; Kouzminov, Dimitry; Zou Wei; Guo Baonian; Khasgiwale, Niranjan; Decker-Lucke, Kurt [Applied Materials, Varian Semiconductor Equipment, 35 Dory Road, Gloucester, Massachusetts 01930 (United States)


    We report on junction advantages of cryogenic ion implantation with medium current implanters. We propose a methodical approach on maximizing cryogenic effects on junction characteristics near the amorphization threshold doses that are typically used for halo implants for sub-30 nm technologies. BF{sub 2}{sup +} implant at a dose of 8 Multiplication-Sign 10{sup 13}cm{sup -2} does not amorphize silicon at room temperature. When implanted at -100 Degree-Sign C, it forms a 30 - 35 nm thick amorphous layer. The cryogenic BF{sub 2}{sup +} implant significantly reduces the depth of the boron distribution, both as-implanted and after anneals, which improves short channel rolloff characteristics. It also creates a shallower n{sup +}-p junction by steepening profiles of arsenic that is subsequently implanted in the surface region. We demonstrate effects of implant sequences, germanium preamorphization, indium and carbon co-implants for extension/halo process integration. When applied to sequences such as Ge+As+C+In+BF{sub 2}{sup +}, the cryogenic implants at -100 Degree-Sign C enable removal of Ge preamorphization, and form more active n{sup +}-p junctions and steeper B and In halo profiles than sequences at room temperature.

  1. Malfunctions of Implantable Cardiac Devices in Patients Receiving Proton Beam Therapy: Incidence and Predictors

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Daniel R., E-mail: [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Poenisch, Falk [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Pinnix, Chelsea C. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Sheu, Tommy [Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chang, Joe Y. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Memon, Nada [Department of Cardiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mohan, Radhe [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rozner, Marc A. [Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Dougherty, Anne H. [Department of Cardiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)


    Purpose: Photon therapy has been reported to induce resets of implanted cardiac devices, but the clinical sequelae of treating patients with such devices with proton beam therapy (PBT) are not well known. We reviewed the incidence of device malfunctions among patients undergoing PBT. Methods and Materials: From March 2009 through July 2012, 42 patients with implanted cardiac implantable electronic devices (CIED; 28 pacemakers and 14 cardioverter-defibrillators) underwent 42 courses of PBT for thoracic (23, 55%), prostate (15, 36%), liver (3, 7%), or base of skull (1, 2%) tumors at a single institution. The median prescribed dose was 74 Gy (relative biological effectiveness; range 46.8-87.5 Gy), and the median distance from the treatment field to the CIED was 10 cm (range 0.8-40 cm). Maximum proton and neutron doses were estimated for each treatment course. All CIEDs were checked before radiation delivery and monitored throughout treatment. Results: Median estimated peak proton and neutron doses to the CIED in all patients were 0.8 Gy (range 0.13-21 Gy) and 346 Sv (range 11-1100 mSv). Six CIED malfunctions occurred in 5 patients (2 pacemakers and 3 defibrillators). Five of these malfunctions were CIED resets, and 1 patient with a defibrillator (in a patient with a liver tumor) had an elective replacement indicator after therapy that was not influenced by radiation. The mean distance from the proton beam to the CIED among devices that reset was 7.0 cm (range 0.9-8 cm), and the mean maximum neutron dose was 655 mSv (range 330-1100 mSv). All resets occurred in patients receiving thoracic PBT and were corrected without clinical incident. The generator for the defibrillator with the elective replacement indicator message was replaced uneventfully after treatment. Conclusions: The incidence of CIED resets was about 20% among patients receiving PBT to the thorax. We recommend that PBT be avoided in pacing-dependent patients and that patients with any type of CIED receiving

  2. A comparison of the health status and psychological distress of partners of patients with a left ventricular assist device versus an implantable cardioverter defibrillator

    DEFF Research Database (Denmark)

    Brouwers, Corline; Caliskan, Kadir; de Jonge, Nicolaas;


    OBJECTIVE: To examine if the caregiving for patients with a left ventricular assist device (LVAD) is related to a poorer health status and more distress compared to patients with an implantable cardioverter defibrillator (ICD). BACKGROUND: Partners distress may influence patient outcomes and is t......OBJECTIVE: To examine if the caregiving for patients with a left ventricular assist device (LVAD) is related to a poorer health status and more distress compared to patients with an implantable cardioverter defibrillator (ICD). BACKGROUND: Partners distress may influence patient outcomes...... (F = 10.71, p = .001) but poorer mental health status (F = 14.82, p compared to ICD partners (F = 3.68, p = .05) at 6 months follow-up, also in adjusted analyses. There was no significant difference between groups on anxiety. CONCLUSION: Caregivers of LVAD...... patients show higher distress levels compared to caregivers of ICD patients. LVAD partners may have a need for support beyond what is offered currently in clinical practice....

  3. Long-acting reversible contraceptives: intrauterine devices and the contraceptive implant. (United States)

    Espey, Eve; Ogburn, Tony


    The provision of effective contraception is fundamental to the practice of women's health care. The most effective methods of reversible contraception are the so-called long-acting reversible contraceptives, intrauterine devices and implants. These methods have multiple advantages over other reversible methods. Most importantly, once in place, they do not require maintenance and their duration of action is long, ranging from 3 to 10 years. Despite the advantages of long-acting reversible contraceptive methods, they are infrequently used in the United States. Short-acting methods, specifically oral contraceptives and condoms, are by far the most commonly used reversible methods. A shift from the use of short-acting methods to long-acting reversible contraceptive methods could help reduce the high rate of unintended pregnancy in the United States. In this review of long-acting reversible contraceptive methods, we discuss the intrauterine devices and the contraceptive implant available in the United States, and we describe candidates for each method, noncontraceptive benefits, and management of complications.

  4. Carina® and Esteem®: a systematic review of fully implantable hearing devices.

    Directory of Open Access Journals (Sweden)

    Janaina Oliveira Bentivi Pulcherio

    Full Text Available To review the outcomes of the fully implantable middle ear devices Carina and Esteem regarding the treatment of hearing loss.PubMed, Embase, Scielo, and Cochrane Library databases were searched.Abstracts of 77 citations were screened, and 43 articles were selected for full review. From those, 22 studies and two literature reviews in English directly demonstrating the results of Carina and Esteem were included.There were a total of 244 patients ranging from 18 to 88 years. One hundred and 10 patients were implanted with Carina and with 134 Esteem. There were registered 92 males and 67 females. Five studies provided no information about patients' age or gender. From the data available, the follow-up ranged from 2 to 29.4 months.The comparison of the results about word recognition is difficult as there was no standardization of measurement. The results were obtained from various sound intensities and different frequencies. The outcomes comparing to conventional HAs were conflicting. Nevertheless, all results comparing to unaided condition showed improvement and showed a subjective improvement of quality of life.There are still some problems to be solved, mainly related to device functioning and price. Due to the relatively few publications available and small sample sizes, we must be careful in extrapolating these results to a broader population. Additionally, none of all these studies represented level high levels of evidence (i.e. randomized controlled trials.

  5. Cost-effectiveness of early detection of atrial fibrillation via remote control of implanted devices. (United States)

    Lorenzoni, Giulia; Folino, Franco; Soriani, Nicola; Iliceto, Sabino; Gregori, Dario


    Atrial fibrillation (AF) is an independent risk factor for stroke, and its incidence is high in patients implanted with pacemakers (PMs) and implantable cardioverter defibrillators (ICDs). The aim of our study is to evaluate the potential benefit of remote control (RC) on the incidence of stroke related to AF in patients with new-onset AF implanted with PMs and ICDs and to evaluate the impact of RC on the consumption of medical resources. The study consisted of two cohorts of patients: group AMB (patients attending ambulatory care clinics from August to October 2013) and group RC (patients followed remotely). All detected cases of new-onset AF were confirmed by the electrogram stored in the device's memory or by standard electrocardiogram recording. Monte Carlo simulations were performed in order to evaluate the potential risk reduction of stroke related to AF. The costs were estimated from the perspectives of the hospital, the patients and the National Health Service. We enrolled 223 patients in group RC and 359 in group AMB. We detected 20 new-onset cases of AF, and the median time to AF detection was 2 days in the RC and 78 days in the ambulatory care clinic control. Management of patients was more efficient with RC, with an average savings in direct costs of €40.88 per year per patient. Through the use of Monte Carlo simulations, we showed that the early detection of new-onset AF may provide a relative risk reduction of 94.3% for stroke in PM-implanted patients older than 55 years. RC potentially provides a risk reduction for stroke because it allows an early detection of new-onset AF. Moreover, it is also a cost-saving means of follow-up. © 2014 John Wiley & Sons, Ltd.

  6. Design of Floating Mass Type Piezoelectric Actuator for Implantable Middle Ear Hearing Devices

    Institute of Scientific and Technical Information of China (English)

    LIU Houguang; TA Na; MING Xiaofeng; RAO Zhushi


    To overcome some of the problems inherent in conventional hearing aids such as low gain at high frequencies due to acoustic feedback, discomfort in occlusion of the external ear canal and so on, implantable middle ear hearing devices (IMEHDs) have been developed over the past two decades. For such kinds of IMEHDS, this paper presents the design of a floating mass piezoelectric actuator using a PMN-30%PT stack as a new type of vibrator. The proposed piezoelectric actuator consists of only three components of a piezoelectric stack, a metal case and a clamp. For the purpose of aiding the design of this actuator, a coupling biomechanics model of human middle ear and the piezoelectric actuator was constructed. This model was built based on a complete set of computerized tomography section images of a healthy volunteer's left ear by reverse engineering technology. The validity of this model was confirmed by comparing the motion of the tympanic membrane and stapes footplate obtained by this model with published experimental measurements on human temporal bones. It is shown that the designed actuator can be implanted on the incus long process by a simple surgical operation, and the stapes footplate displacement by its excitation at 10.5 V root-mean-square(RMS) voltage was equivalent to that from acoustic stimulation at 100 dB sound pressure level(SPL), which is adequate stimulation to the nssicular chain. The corresponding power consumption is 0.04 mW per volt of excitation at 1 kHz, which is low enough for the transducer to be used in an implantable middle ear device.

  7. Institutional Cost Comparison Between Heart Transplants and Left Ventricular Assist Device Implantations. (United States)

    Chimanji, Neeraj; Kilic, Arman; Hasan, Ayesha; Higgins, Robert S D; Whitson, Bryan A; Kilic, Ahmet


    Increased numbers of end-stage heart failure patients and improved technology have led to increased use of left ventricular assist devices as a viable alternative to heart transplants. Given the current economic climate, we compared costs of heart transplant versus device placement. Medical records of patients who received heart transplants or left ventricular assist devices were cross-referenced with institutional financial data. The device cohort was limited to those receiving durable (not temporary) devices. Index admission, 1-year readmission, and overall 1-year charges were compared using standard statistical methods. Of 184 identified patients with end-stage heart failure surgical therapy, 121 received left ventricular assist devices, 43 had heart transplants, and 20 received left ventricular assist devices as bridge to heart transplant; these latter patients were excluded from our analyses. At index admission, mean charges were $863 433 ± $398 427 for device patients and $725 877 ± $488 685 for transplant patients (P = .05). One-year mean readmission rates were similar (4.65/transplant patient and 4.53/device patient; P = .94), with corresponding 1-year survival rates of 87.8% and 78.0% (P = .04). Total readmission charges during year 1 were $169 732 ± $242 366 for device patients and $201 682 ± $297 565 for transplant patients (P = .08), with corresponding overall charges at 1 year of $1 029 732 ± $450 498 and $927 559 ± $562 404 (P = .49). During the first year, heart transplant and left ventricular assist device placement have similar costs. Initial index admission costs seem to favor heart transplant, with device pump costs accounting for some of the difference. From a 1-year survival perspective, heart transplant may be more effective; however, with lack of suitable donors, left ventricular assist devices are valuable in the armamentarium of advanced heart failure surgical options.

  8. Metallurgical Behavior of Ti-6Al-4V Alloy Mini-Implants as a Temporary Anchorage Device in Orthodontics Applications

    Directory of Open Access Journals (Sweden)

    Mendoza-Bravo Ivan


    Full Text Available The application of mini implants as a temporary anchorage device in orthodontics is a new technique that allows the movement of teeth in an efficient and predictable way. Although they have started to be used in Germany, Japan and South Korea, there is still the need to analyze and diffuse the advantages this procedure can offer over the traditional techniques. The objective of this research work was to analyze the integrity of Ti-6Al-4V mini implants temporary employed for 4 months on three patients as an anchorage device. The mini implants were analyzed by means of electron scanning microscopy in order to determine superficial and microstructural changes as well as the interaction with human tissue. Results showed the presence of wear on the thread zone caused during the insertion into the maxilar bone. The adherence of organic tissue was also observed on two mini-implants.

  9. Enhanced current noise correlations in a Coulomb-Majorana device (United States)

    Lü, Hai-Feng; Lu, Hai-Zhou; Shen, Shun-Qing


    Majorana bound states (MBSs) nested in a topological nanowire are predicted to manifest nonlocal correlations in the presence of a finite energy splitting between the MBSs. However, the signal of the nonlocal correlations has not yet been detected in experiments. A possible reason is that the energy splitting is too weak and seriously affected by many system parameters. Here we investigate the charging energy induced nonlocal correlations in a hybrid device of MBSs and quantum dots. The nanowire that hosts the MBSs is assumed in proximity to a mesoscopic superconducting island with a finite charging energy. Each end of the nanowire is coupled to one lead via a quantum dot with resonant levels. With a floating superconducting island, the devices show a negative differential conductance and giant super-Poissonian shot noise, due to the interplay between the nonlocality of the MBSs and dynamical Coulomb blockade effect. When the island is strongly coupled to a bulk superconductor, the current cross correlations at small lead chemical potentials are negative by tuning the dot energy levels. In contrast, the cross correlation is always positive in a non-Majorana setup. This difference may provide a signature for the existence of the MBSs.

  10. Phantom-based evaluation method for surgical assistance devices in minimally invasive cochlear implantation (United States)

    Lexow, G. Jakob; Kluge, Marcel; Majdani, Omid; Lenarz, Thomas; Rau, Thomas S.


    Several research groups have proposed individual solutions for surgical assistance devices to perform minimally invasive cochlear implantation. The main challenge is the drilling of a small bore hole from the surface of the skull to the inner ear at submillimetric accuracy. Each group tested the accuracy of their device in their respective test bench or in a small number of temporal bone specimens. This complicates the comparison of the different approaches. Thus, a simple and inexpensive phantom based evaluation method is proposed which resembles clinical conditions. The method is based on half-skull phantoms made of bone-substitute material - optionally equipped with an artificial skin replica to include skin incision within the evaluation procedure. Anatomical structures of the temporal bone derived from segmentations using clinical imaging data are registered into a computer tomographic scan of the skull phantom and used for the planning of the drill trajectory. Drilling is performed with the respective device under conditions close to the intraoperative setting. Evaluation of accuracy can either be performed through postoperative imaging or by means of added targets on the inside of the skull model. Two different targets are proposed: simple reference marks only for measuring the accuracy of the device and a target containing a scala tympani model for evaluation of the complete workflow including the insertion of the electrode carrier. Experiments using the presented method take place under reproducible conditions thus allowing the comparison of the different approaches. In addition, artificial phantoms are easier to obtain and handle than human specimens.

  11. Radiofrequency and microwave tumor ablation in patients with implanted cardiac devices: Is it safe?

    Energy Technology Data Exchange (ETDEWEB)

    Skonieczki, Brendan D., E-mail: [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States); Wells, Catherine, E-mail: [Department of Radiology, Harvard Medical School/Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215 (United States); Wasser, Elliot J., E-mail: [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States); Dupuy, Damian E., E-mail: [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States)


    Purpose: To identify malfunction of implanted cardiac devices during or after thermal ablation of tumors in lung, kidney, liver or bone, using radiofrequency (RF) or microwave (MW) energy. Materials and methods: After providing written consent, 19 patients (15 men and 4 women; mean age 78 years) with pacemakers or pacemaker/defibrillators underwent 22 CT image-guided percutaneous RF or MW ablation of a variety of tumors. Before and after each procedure, cardiac devices were interrogated and reprogrammed by a trained cardiac electrophysiology fellow. Possible pacer malfunctions included abnormalities on electrocardiographic (EKG) monitoring and alterations in device settings. Our institutional review board approved this Health Insurance Portability and Accountability Act-compliant study. Informed consent for participation in this retrospective study was deemed unnecessary by our review board. Results: During 20 of 22 sessions, no abnormalities were identified in continuous, EKG tracings or pacemaker functions. However, in two sessions significant changes, occurred in pacemaker parameters: inhibition of pacing during RF application in one, session and resetting of mode by RF energy in another session. These changes did not, result in hemodynamic instability of either patient. MW ablation was not associated with, any malfunction. In all 22 sessions, pacemakers were undamaged and successfully reset to original parameters. Conclusion: RF or MW ablation of tumors in liver, kidney, bone and lung can be performed safely in patients with permanent intra-cardiac devices, but careful planning between radiology and cardiology is essential to avoid adverse outcomes.

  12. In vivo biostability of polymeric spine implants: retrieval analyses from a United States investigational device exemption study


    Shen, Ming; Zhang, Kai; Koettig, Petra; Welch, William C.; Dawson, John M.


    The Dynesys System for stabilizing the lumbar spine was first surgically implanted in Europe in 1994. In 2003, a prospective, randomized, investigational device exemption clinical trial of the system for non-fusion dynamic stabilization began. Polycarbonate urethane (PCU) and polyethylene terephthalate (PET) components explanted from four patients who had participated in the study were analyzed for biostability. Components had been implanted 9–19 months. The explanted components were visually...

  13. The channeling effect of Al and N ion implantation in 4H–SiC during JFET integrated device processing

    Energy Technology Data Exchange (ETDEWEB)

    Lazar, M.; Laariedh, F. [Université de Lyon, Laboratoire AMPERE, INSA Lyon, UMR CNRS 5005, 21 Avenue Jean Capelle, 69621 Villeurbanne (France); Cremillieu, P. [Université de Lyon, Institut des Nanotechnologies de Lyon, Ecole Centrale de Lyon, UMR CNRS 5270, 36 Avenue Guy de Collongue, 69134 Ecully (France); Planson, D. [Université de Lyon, Laboratoire AMPERE, INSA Lyon, UMR CNRS 5005, 21 Avenue Jean Capelle, 69621 Villeurbanne (France); Leclercq, J.-L. [Université de Lyon, Institut des Nanotechnologies de Lyon, Ecole Centrale de Lyon, UMR CNRS 5270, 36 Avenue Guy de Collongue, 69134 Ecully (France)


    A strong channeling effect is observed for the ions of Al and N implanted in 4H–SiC due to its crystalline structure. This effect causes difficulties in subsequent accurate estimation of the depth of junctions formed by multiple ion implantation steps. A variety of lateral JFET transistors integrated on the same 4H–SiC wafer have been fabricated. Secondary Ion Mass Spectrometry measurements and Monte-Carlo simulations were performed in order to quantify and control the channeling effect of the implanted ions. A technological process was established enabling to obtain devices working with the presence of the channeling effect.

  14. A novel implantable device for a minimally invasive surgical treatment of obstructive sleep apnea: design and preclinical safety assessment

    Directory of Open Access Journals (Sweden)

    Gillis E


    Full Text Available Edward Gillis, Charles Rampersaud, Emmanuelle Pease, Paul Buscemi ReVENT Medical, Inc., Newark, CA, USA Background: In obstructive sleep apnea (OSA, occlusion of the upper airway by soft tissue causes intermittent hypoxemia and can have serious sequelae. A novel implantable medical device for OSA is composed of a linear silicone elastic element held in an extended state by a bioabsorbable external sheath. The implant is delivered to the tongue base or soft palate via a minimally invasive approach. Normal tissue healing anchors the device at the attachment points before the bioabsorbable material dissolves and the elastic element contracts to stabilize the surrounding tissue.Methods: Device prototypes were evaluated in multiple investigations: 1 a finite elements analysis model simulated the movement of the tongue base during sleep with and without the implant; 2 dynamic mechanical testing simulated 10 years’ normal use; 3 cadaveric implantations were conducted; 4 an ovine study in which implants of varying design were evaluated via gross pathology and histological assessment; and 5 a canine study in which implants of varying design in the tongue base and soft palate were evaluated via gross pathology and histological assessment.Results: 1 The implant was capable of reducing ~95% of tongue base movement during simulated sleep; 2 implants remained intact throughout the testing with no evidence of creep fatigue or change in dynamic modulus; 3 the device could be reliably deployed in the desired placement locations and was appropriate for various anatomies; and 4 all implants were well tolerated through 1 year, with minimal inflammatory responses.Conclusion: This new minimally invasive device for OSA has been demonstrated, through various bench and animal testing, to be safe, well tolerated, suitable for long-term use, and to function as intended. No adverse health consequences were observed in the animals, and histological evaluation

  15. Radiotherapy-Induced Malfunction in Contemporary Cardiovascular Implantable Electronic Devices: Clinical Incidence and Predictors. (United States)

    Grant, Jonathan D; Jensen, Garrett L; Tang, Chad; Pollard, Julianne M; Kry, Stephen F; Krishnan, Sunil; Dougherty, Anne H; Gomez, Daniel R; Rozner, Marc A


    Risk stratification and management paradigms for patients with cardiovascular implantable electronic devices (CIEDs) requiring radiotherapy (RT) vary widely and are based on limited clinical data. To identify the incidence and predictors of CIED malfunction and describe associated clinical consequences in a large cohort of patients treated with photon- and electron-based RT. Retrospective analysis of all patients with a functioning CIED who underwent RT between August 2005 and January 2014 with CIED interrogation data following RT at an academic cancer center. We identified 249 courses of photon- and electron-based RT in 215 patients (123 pacemakers [57%]; 92 implantable cardioverter-defibrillators [43%]). Substantial neutron production was generated in 71 courses (29%). Implantation of CIED with subsequent therapeutic radiation treatment (neutron producing with 15- or 18-MV photons and non-neutron producing with electrons, GammaKnife, or 6-MV photons). Malfunction of CIED, characterized as single-event upset (data loss, parameter resets, unrecoverable resets), and delayed effects including signal interference, pacing threshold changes, and premature battery depletion. Malfunction of CIED attributable to RT occurred during 18 courses (7%), with 15 CIEDs experiencing single-event upsets, and 3, transient signal interference. All single-event upsets occurred during neutron-producing RT, at a rate of 21%, 10%, and 34% per neutron-producing course for CIEDs, pacemakers, and implantable cardioverter-defibrillators, respectively. No single-event upsets were found among 178 courses of non-neutron-producing RT. Incident CIED dose did not correlate with device malfunction. Patients treated to the abdomen and pelvis region were more likely to undergo a single-event upset (hazard ratio, 5.2 [95% CI, 1.2-22.6]; P = .03). Six patients with a CIED parameter reset developed clinical symptoms: 3 experienced hypotension and/or bradycardia, 2 experienced abnormal chest ticking

  16. Characterization of Heat Treated Titanium-Based Implants by Nondestructive Eddy Current and Ultrasonic Tests (United States)

    Mutlu, Ilven; Ekinci, Sinasi; Oktay, Enver


    This study presents nondestructive characterization of microstructure and mechanical properties of heat treated Ti, Ti-Cu, and Ti-6Al-4V titanium-based alloys and 17-4 PH stainless steel alloy for biomedical implant applications. Ti, Ti-Cu, and 17-4 PH stainless steel based implants were produced by powder metallurgy. Ti-6Al-4V alloy was investigated as bulk wrought specimens. Effects of sintering temperature, aging, and grain size on mechanical properties were investigated by nondestructive and destructive tests comparatively. Ultrasonic velocity in specimens was measured by using pulse-echo and transmission methods. Electrical conductivity of specimens was determined by eddy current tests. Determination of Young's modulus and strength is important in biomedical implants. Young's modulus of specimens was calculated by using ultrasonic velocities. Calculated Young's modulus values were compared and correlated with experimental values.

  17. Design and evaluation of wide-range and low-power analog front-end enabling body-implanted devices to monitor charge injection properties (United States)

    Ito, Keita; Uno, Shoma; Goto, Tatsuya; Takezawa, Yoshiki; Harashima, Takuya; Morikawa, Takumi; Nishino, Satoru; Kino, Hisashi; Kiyoyama, Koji; Tanaka, Tetsu


    For safe electrical stimulation with body-implanted devices, the degradation of stimulus electrodes must be considered because it causes the unexpected electrolysis of water and the destruction of tissues. To monitor the charge injection property (CIP) of stimulus electrodes while these devices are implanted, we have proposed a charge injection monitoring system (CIMS). CIMS can safely read out voltages produced by a biphasic current pulse to a stimulus electrode and CIP is calculated from waveforms of the acquired voltages. In this paper, we describe a wide-range and low-power analog front-end (AFE) for CIMS that has variable gain-frequency characteristics and low-power analog-to-digital (A/D) conversion to adjust to the degradation of stimulus electrodes. The designed AFE was fabricated with 0.18 µm CMOS technology and achieved a valuable gain of 20-60 dB, an upper cutoff frequency of 0.2-10 kHz, and low-power interleaving A/D conversion. In addition, we successfully measured the CIP of stimulus electrodes for body-implanted devices using CIMS.

  18. Temperature rise during removal of fractured components out of the implant body: an in vitro study comparing two ultrasonic devices and five implant types. (United States)

    Meisberger, Eric W; Bakker, Sjoerd J G; Cune, Marco S


    Ultrasonic instrumentation under magnification may facilitate mobilization of screw remnants but may induce heat trauma to surrounding bone. An increase of 5°C is considered detrimental to osseointegration. The objective of this investigation was to examine the rise in temperature of the outer implant body after 30 s of ultrasonic instrumentation to the inner part, in relation to implant type, type of ultrasonic equipment, and the use of coolants in vitro. Two ultrasonic devices (Satelec Suprasson T Max and Electro Medical Systems (EMS) miniMaster) were used on five different implant types that were provided with a thermo couple (Astra 3.5 mm, bone level Regular CrossFit (RC) 4.1 mm, bone level Narrow CrossFit (NC) 3.3 mm, Straumann tissue level regular body regular neck 3.3 mm, and Straumann tissue level wide body regular neck 4.8 mm), either with or without cooling during 30 s. Temperature rise at this point in time is the primary outcome measure. In addition, the mean maximum rise in temperature (all implants combined) was assessed and statistically compared among devices, implant systems, and cooling mode (independent t-tests, ANOVA, and post hoc analysis). The Satelec device without cooling induces the highest temperature change of up to 13°C, particularly in both bone level implants (p < 0.05) but appears safe for approximately 10 s of continuous instrumentation, after which a cooling down period is rational. Cooling is effective for both devices. However, when the Satelec device is used with coolant for a longer period of time, a rise in temperature must be anticipated after cessation of instrumentation, and post-operational cooling is advised. The in vitro setup used in this experiment implies that care should be taken when translating the observations to clinical recommendations, but it is carefully suggested that the EMS device causes limited rise in temperature, even without coolant.

  19. Pirfenidone inhibits fibrosis in foreign body reaction after glaucoma drainage device implantation

    Directory of Open Access Journals (Sweden)

    Jung KI


    Full Text Available Kyoung In Jung, Chan Kee ParkDepartment of Ophthalmology and Visual Science, Seoul St Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, South KoreaBackground: The aim of this study was to investigate the antiscarring effects of pirfenidone on foreign body reaction in a rabbit model of glaucoma drainage implant surgery.Methods: Adult New Zealand White rabbits had glaucoma drainage device implantation using Model FP8 Ahmed glaucoma valves. One eye was randomly assigned to receive postoperative intrableb injection of pirfenidone followed by topical treatment. The other eye underwent the same procedure but without the addition of pirfenidone. Histochemical staining and immunohistochemistry for blebs were performed.Results: The degree of cellularity was smaller in the pirfenidone group than in the control group at 2 weeks post operation (P=0.005. A few foreign body giant cells were detected in the inner border of the capsule, and their numbers were similar in the control and pirfenidone groups (P>0.05. Using Masson’s trichrome stain, the inner collagen-rich layer was found to be thinner in the pirfenidone group than the control group at 4 weeks (P=0.031 and 8 weeks (P=0.022 post operation. The percentage of proliferating cell nuclear antigen-positive cells was lower in the pirfenidone group than in the control group at 2 weeks post operation (total bleb, P=0.022; inner bleb, P=0.036. Pirfenidone treatment decreased the immunoreactivity of connective tissue growth factor at 2 weeks post operation (total bleb, P=0.029; inner bleb, P=0.018. The height and area of α-smooth muscle actin expression were lower in the pirfenidone group than the control group at 2 weeks, 4 weeks, and 8 weeks post operation (all P<0.05.Conclusion: Postoperative intrableb injection of pirfenidone followed by topical administration reduced fibrosis following glaucoma drainage device implantation. These findings suggest that pirfenidone

  20. Minimally Invasive Cochlear Implantation Assisted by Bi-planar Device: An Exploratory Feasibility Study in vitro

    Institute of Scientific and Technical Information of China (English)

    Jia Ke; Shao-Xing Zhang; Lei Hu; Chang-Sheng Li; Yun-Feng Zhu; Shi-Long Sun; Li-Feng Wang


    Background:A single drilled tunnel from the lateral mastoid cortex to the cochlea via the facial recess is essential for minimally invasive cochlear implant surgery.This study aimed to explore the safety profile of this kind of new image-guided and bi-planar device-assisted surgery procedure in vitro.Methods:Image-guided minimally invasive cochlear implantations were performed on eight cadaveric temporal bone specimens.The main procedures were:(1) temporal bone specimens were prepared for surgery and fiducial markers were registered.(2) computed tomography (CT) scans were performed for future reference.(3) CT scan images were processed and drill path was planned to minimize cochlear damage.(4) bi-planar device-assisted drilling was performed on the specimens using the registration.(5) surgical safety was evaluated by calculating the deviation between the drill and the planned paths,and by measuring the closest distance between the drilled path and critical anatomic structures.Results:Eight cases were operated successfully to the basal turn of the cochlear with intact facial nerves (FNs).The deviations from target points and entrance points were 0.86 mm (0.68-1.00 mm) and 0.44 mm (0.30-0.96 mm),respectively.The angular error between the planned and the drilled trajectory was 1.74° (1.26-2.41°).The mean distance from the edge of the drilled path to the FN and to the external canal was 0.60 mm (0.35-0.83 mm) and 1.60 mm (1.30-2.05 mm),respectively.In five specimens,the chorda tympani nerves were well preserved.In all cases,no injury happened to auditory ossicles.Conclusions:This exploratory study demonstrated the safety of the newly developed image-guided minimally invasive cochlear implantation assisted by the bi-planar device and established the operational procedures.Further,more in vitro experiments are needed to improve the system operation and its safety.

  1. Minimally Invasive Cochlear Implantation Assisted by Bi-planar Device: An Exploratory Feasibility Study in vitro (United States)

    Ke, Jia; Zhang, Shao-Xing; Hu, Lei; Li, Chang-Sheng; Zhu, Yun-Feng; Sun, Shi-Long; Wang, Li-Feng; Ma, Fu-Rong


    Background: A single drilled tunnel from the lateral mastoid cortex to the cochlea via the facial recess is essential for minimally invasive cochlear implant surgery. This study aimed to explore the safety profile of this kind of new image-guided and bi-planar device-assisted surgery procedure in vitro. Methods: Image-guided minimally invasive cochlear implantations were performed on eight cadaveric temporal bone specimens. The main procedures were: (1) temporal bone specimens were prepared for surgery and fiducial markers were registered. (2) computed tomography (CT) scans were performed for future reference. (3) CT scan images were processed and drill path was planned to minimize cochlear damage. (4) bi-planar device-assisted drilling was performed on the specimens using the registration. (5) surgical safety was evaluated by calculating the deviation between the drill and the planned paths, and by measuring the closest distance between the drilled path and critical anatomic structures. Results: Eight cases were operated successfully to the basal turn of the cochlear with intact facial nerves (FNs). The deviations from target points and entrance points were 0.86 mm (0.68–1.00 mm) and 0.44 mm (0.30–0.96 mm), respectively. The angular error between the planned and the drilled trajectory was 1.74° (1.26–2.41°). The mean distance from the edge of the drilled path to the FN and to the external canal was 0.60 mm (0.35–0.83 mm) and 1.60 mm (1.30–2.05 mm), respectively. In five specimens, the chorda tympani nerves were well preserved. In all cases, no injury happened to auditory ossicles. Conclusions: This exploratory study demonstrated the safety of the newly developed image-guided minimally invasive cochlear implantation assisted by the bi-planar device and established the operational procedures. Further, more in vitro experiments are needed to improve the system operation and its safety. PMID:27748341

  2. Differences of Mortality Rates between Pocket and Nonpocket Cardiovascular Implantable Electronic Device Infections. (United States)

    Lee, Dong Heun; Gracely, Edward J; Aleem, Sarah Y; Kutalek, Steven P; Vielemeyer, Ole


    A steady rise in the use of cardiovascular implantable electronic devices (CIEDs), particularly in the elderly, has led to an increase in device-related infections. Although often studied and reported as a single entity, these complications in fact comprise a heterogeneous group. Specific subgroups may be associated with distinct mortality risks. Medical records of all patients who underwent device extraction for CIED-related infection at a single tertiary referral center between 1991 and 2007 were reviewed. Infections were divided into four subgroups: primary pocket site infection (PPSI), pocket site infection with bacteremia, primary/isolated bacteremia (PIB), and device-related infective endocarditis (DRIE). Clinical presentation, laboratory data, and mortality rates were obtained by chart review and by querying the Social Security Death Index. A total of 387 cases were analyzed. The overall in-hospital and 1-year all-cause mortality rates were 7.2% and 25.3%, respectively. Patients with PIB or DRIE had significantly higher mortality rates (hazard ratio [HR] 2.3; 95% confidence interval [CI] 1.2-4.6 and HR 2.5; 95% CI 1.6-4.1, respectively) when compared with patients in the PPSI group. Patients who did not receive a new device during the initial admission also had a higher 1-year mortality rate compared to those who did (HR 2.7; 95% CI 1.8-4.1). Our patients with CIED-related infections requiring extraction/hospitalization had a significant mortality risk. Presence of pocket site infection carried a more favorable prognosis, regardless of the presence of bacteremia. Early detection and prevention of CIED-related infections with PIB (i.e., no pocket site involvement), especially for high-risk populations, is needed. ©2015 Wiley Periodicals, Inc.

  3. Interference of cardiac pacemaker and implantable cardioverter-defibrillator activity during electronic dental device use. (United States)

    Roedig, Jason J; Shah, Jignesh; Elayi, Claude Samy; Miller, Craig S


    The authors conducted a study to determine if electromagnetic interference of cardiac pacemaker and implantable cardioverter-defibrillator (ICD) activity occurs during the operation of electronic dental devices. The authors tested nine electronic dental devices in vitro to assess their ability to interfere with the function of two pacemakers and two ICDs as determined by electrocardiographic telemetry. The pacing activity of both pacemakers and the dual-chamber ICD were inhibited during operation of the battery-operated composite curing light at between 2 and 10 centimeters from the generator or leads. The use of the ultrasonic scaler interfered with the pacing activity of the dual-chamber pacemaker at between 17 and 23 cm from the generator or leads, the single-chamber pacemaker at 15 cm from the generator or leads and both ICDs at 7 cm from the leads. The operation of the ultrasonic cleaning system interfered with the activity of the dual-chamber pacemaker at between 15 and 23 cm from the generator or leads, and of the single-chamber pacemaker at 12 cm. Operation of the electric toothbrush, electrosurgical unit, electric pulp tester, high- and low-speed handpieces, and an amalgamator did not alter pacing function. Select electronic dental devices interfere with pacemakers' and ICDs' sensing and pacing activity in vitro. Use of the ultrasonic scaler, ultrasonic cleaning system and battery-operated composite curing light may produce deleterious effects in patients who have pacemakers or ICDs.

  4. Antibacterial Peptide-Based Gel for Prevention of Medical Implanted-Device Infection.

    Directory of Open Access Journals (Sweden)

    Mihaela Mateescu

    Full Text Available Implanted medical devices are prone to infection. Designing new strategies to reduce infection and implant rejection are an important challenge for modern medicine. To this end, in the last few years many hydrogels have been designed as matrices for antimicrobial molecules destined to fight frequent infection found in moist environments like the oral cavity. In this study, two types of original hydrogels containing the antimicrobial peptide Cateslytin have been designed. The first hydrogel is based on alginate modified with catechol moieties (AC gel. The choice of these catechol functional groups which derive from mussel's catechol originates from their strong adhesion properties on various surfaces. The second type of gel we tested is a mixture of alginate catechol and thiol-terminated Pluronic (AC/PlubisSH, a polymer derived from Pluronic, a well-known biocompatible polymer. This PlubisSH polymer has been chosen for its capacity to enhance the cohesion of the composition. These two gels offer new clinical uses, as they can be injected and jellify in a few minutes. Moreover, we show these gels strongly adhere to implant surfaces and gingiva. Once gelled, they demonstrate a high level of rheological properties and stability. In particular, the dissipative energy of the (AC/PlubisSH gel detachment reaches a high value on gingiva (10 J.m-2 and on titanium alloys (4 J.m-2, conferring a strong mechanical barrier. Moreover, the Cateslytin peptide in hydrogels exhibited potent antimicrobial activities against P. gingivalis, where a strong inhibition of bacterial metabolic activity and viability was observed, indicating reduced virulence. Gel biocompatibility tests indicate no signs of toxicity. In conclusion, these new hydrogels could be ideal candidates in the prevention and/or management of periimplant diseases.

  5. Complications after Surgical Procedures in Patients with Cardiac Implantable Electronic Devices: Results of a Prospective Registry (United States)

    da Silva, Katia Regina; Albertini, Caio Marcos de Moraes; Crevelari, Elizabeth Sartori; de Carvalho, Eduardo Infante Januzzi; Fiorelli, Alfredo Inácio; Martinelli Filho, Martino; Costa, Roberto


    Background: Complications after surgical procedures in patients with cardiac implantable electronic devices (CIED) are an emerging problem due to an increasing number of such procedures and aging of the population, which consequently increases the frequency of comorbidities. Objective: To identify the rates of postoperative complications, mortality, and hospital readmissions, and evaluate the risk factors for the occurrence of these events. Methods: Prospective and unicentric study that included all individuals undergoing CIED surgical procedures from February to August 2011. The patients were distributed by type of procedure into the following groups: initial implantations (cohort 1), generator exchange (cohort 2), and lead-related procedures (cohort 3). The outcomes were evaluated by an independent committee. Univariate and multivariate analyses assessed the risk factors, and the Kaplan-Meier method was used for survival analysis. Results: A total of 713 patients were included in the study and distributed as follows: 333 in cohort 1, 304 in cohort 2, and 76 in cohort 3. Postoperative complications were detected in 7.5%, 1.6%, and 11.8% of the patients in cohorts 1, 2, and 3, respectively (p = 0.014). During a 6-month follow-up, there were 58 (8.1%) deaths and 75 (10.5%) hospital readmissions. Predictors of hospital readmission included the use of implantable cardioverter-defibrillators (odds ratio [OR] = 4.2), functional class III­-IV (OR = 1.8), and warfarin administration (OR = 1.9). Predictors of mortality included age over 80 years (OR = 2.4), ventricular dysfunction (OR = 2.2), functional class III-IV (OR = 3.3), and warfarin administration (OR = 2.3). Conclusions: Postoperative complications, hospital readmissions, and deaths occurred frequently and were strongly related to the type of procedure performed, type of CIED, and severity of the patient's underlying heart disease. PMID:27579544

  6. Antibacterial Peptide-Based Gel for Prevention of Medical Implanted-Device Infection (United States)

    Mateescu, Mihaela; Baixe, Sébastien; Garnier, Tony; Jierry, Loic; Ball, Vincent; Haikel, Youssef; Metz-Boutigue, Marie Hélène; Nardin, Michel; Schaaf, Pierre; Etienne, Olivier; Lavalle, Philippe


    Implanted medical devices are prone to infection. Designing new strategies to reduce infection and implant rejection are an important challenge for modern medicine. To this end, in the last few years many hydrogels have been designed as matrices for antimicrobial molecules destined to fight frequent infection found in moist environments like the oral cavity. In this study, two types of original hydrogels containing the antimicrobial peptide Cateslytin have been designed. The first hydrogel is based on alginate modified with catechol moieties (AC gel). The choice of these catechol functional groups which derive from mussel’s catechol originates from their strong adhesion properties on various surfaces. The second type of gel we tested is a mixture of alginate catechol and thiol-terminated Pluronic (AC/PlubisSH), a polymer derived from Pluronic, a well-known biocompatible polymer. This PlubisSH polymer has been chosen for its capacity to enhance the cohesion of the composition. These two gels offer new clinical uses, as they can be injected and jellify in a few minutes. Moreover, we show these gels strongly adhere to implant surfaces and gingiva. Once gelled, they demonstrate a high level of rheological properties and stability. In particular, the dissipative energy of the (AC/PlubisSH) gel detachment reaches a high value on gingiva (10 J.m-2) and on titanium alloys (4 J.m-2), conferring a strong mechanical barrier. Moreover, the Cateslytin peptide in hydrogels exhibited potent antimicrobial activities against P. gingivalis, where a strong inhibition of bacterial metabolic activity and viability was observed, indicating reduced virulence. Gel biocompatibility tests indicate no signs of toxicity. In conclusion, these new hydrogels could be ideal candidates in the prevention and/or management of periimplant diseases. PMID:26659616

  7. Can Direct Current Electrotherapy Be Used for Patients With Orthopedic Implants? (United States)

    Thaler, Evangeline; Toledo, Felippe; Korte, Holger


    Although electrotherapy appears to have particularly interesting applications in the field of postoperative orthopedic rehabilitation, relatively little scientifically based research has been conducted in the area of electrotherapy with regard to safety involving patients with orthopedic implants. Three electrotherapy forms were tested, such as high-volt stimulation (HVS), transcutaneous electric nerve stimulation (TENS), and galvanic current (GAL), using a model system containing a metal implant plate to evaluate whether heating in excess of 3°C would occur. All changes in temperature for HVS, GAL, and TENS therapeutic electrical currents observed in our model system fall below the predefined 3°C. To the best of our knowledge, this is the first experimental based observation that prolonged exposure to a direct electrical current at therapeutic strength does not result in heating of metal titanium plates.

  8. Power loss measurement of implantable wireless power transfer components using a Peltier device balance calorimeter (United States)

    Leung, Ho Yan; Budgett, David M.; Taberner, Andrew; Hu, Patrick


    Determining heat losses in power transfer components operating at high frequencies for implantable inductive power transfer systems is important for assessing whether the heat dissipated by the component is acceptable for implantation and medical use. However, this is a challenge at high frequencies and voltages due to limitations in electronic instrumentation. Calorimetric methods of power measurement are immune to the effects of high frequencies and voltages; hence, the measurement is independent of the electrical characteristics of the system. Calorimeters have been widely used to measure the losses of high power electrical components (>50 W), however it is more difficult to perform on low power components. This paper presents a novel power measurement method for components dissipating anywhere between 0.2 W and 1 W of power based on a heat balance calorimeter that uses a Peltier device as a balance sensor. The proposed balance calorimeter has a single test accuracy of ±0.042 W. The experimental results revealed that there was up to 35% difference between the power measurements obtained with electrical methods and the proposed calorimeter.

  9. A micropower miniature piezoelectric actuator for implantable middle ear hearing device. (United States)

    Wang, Zhigang; Mills, Robert; Luo, Hongyan; Zheng, Xiaolin; Hou, Wensheng; Wang, Lijun; Brown, Stuart I; Cuschieri, Alfred


    This paper describes the design and development of a small actuator using a miniature piezoelectric stack and a flextensional mechanical amplification structure for an implantable middle ear hearing device (IMEHD). A finite-element method was used in the actuator design. Actuator vibration displacement was measured using a laser vibrometer. Preliminary evaluation of the actuator for an IMEHD was conducted using a temporal bone model. Initial results from one temporal bone study indicated that the actuator was small enough to be implanted within the middle ear cavity, and sufficient stapes displacement can be generated for patients with mild to moderate hearing losses, especially at higher frequency range, by the actuator suspended onto the stapes. There was an insignificant mass-loading effect on normal sound transmission (actuator was attached to the stapes and switched off. Improved vibration performance is predicted by more firm attachment. The actuator power consumption and its generated equivalent sound pressure level are also discussed. In conclusion, the actuator has advantages of small size, lightweight, and micropower consumption for potential use as IMHEDs.

  10. Impact of implantation on the properties of N 2O-nitrided oxides of p +- and n +-gate MOS devices (United States)

    Naumova, O. V.; Fomin, B. I.; Sakharova, N. V.; Ilnitsky, M. A.; Popov, V. P.


    The impact of the gate implantation on properties of N2O-nitrided thermal oxides MOS dielectric layers were evaluated in this study via current-voltage, j-ramp and current-temperature techniques. The data obtained show that implantation with boron of poly-Si gates can result in generation of border traps in oxides. The energy position of traps generated in the oxides after Fowler-Nordheim voltage stress and after hard breakdown treatments were evaluated.

  11. The Quest for Nonthrombotic Surface Modifications to Achieve Hemocompatibility of Implantable Devices. (United States)

    Tchouta, Lise Nadine; Bonde, Pramod Narayan


    The use of blood-contacting implantable devices is limited by surface-induced thrombosis, which has led to the development of thromboresistant surfaces. Multidisciplinary efforts have promoted the development of surface modifications to minimize thrombosis by targeting surface-induced coagulation. To this date, no material has been identified that remains irrevocably hemocompatible with time but many options are now available with their own limitations. Essential to this review is the understanding of some of the challenges in this field and newer opportunities for hemocompatibility research. This report will also briefly review many of the achievements in the development of hemocompatible biomaterial coating, including surface modifications against protein adsorption and platelet adhesion, biomimetism, and endothelialization.

  12. Low-Power Implantable Device for Onset Detection and Subsequent Treatment of Epileptic Seizures: A Review

    Directory of Open Access Journals (Sweden)

    Muhammad Tariqus Salam


    Full Text Available Over the past few years, there has been growing interest in neuro-responsive intracerebral local treatments of seizures, such as focal drug delivery, focal cooling, or electrical stimulation. This mode of treatment requires an effective intracerebral electroencephalographic acquisition system, seizure detector, brain stimulator, and wireless system that consume ultra-low power. This review focuses on alternative brain stimulation treatments for medically intractable epilepsy patients. We mainly discuss clinical studies of long-term responsive stimulation and suggest safer optimized therapeutic options for epilepsy. Finally, we conclude our study with the proposed low-power, implantable fully integrated device that automatically detects low-voltage fast activity ictal onsets and triggers focal treatment to disrupt seizure progression. The detection performance was verified using intracerebral electroencephalographic recordings from two patients with epilepsy. Further experimental validation of this prototype is underway.

  13. A novel prosthetic device and method for guided tissue preservation of immediate postextraction socket implants. (United States)

    Chu, Stephen J; Hochman, Mark N; Tan-Chu, Jocelyn Hui-Ping; Mieleszko, Adam J; Tarnow, Dennis P


    Preservation of the surrounding hard and soft tissues associated with an immediate postextraction socket implant to replace a nonrestorable tooth in the esthetic zone is one of the greatest challenges facing the dental team. Several studies have documented the biologic and esthetic benefits of bone graft containment with either a custom healing abutment or provisional restoration. Use of a prefabricated shell that replicates the extracted tooth at the cervical region can help achieve guided tissue preservation and sustainable esthetic outcomes in an easy, simple, consistent, and less time consuming way. The following case report of a hopeless maxillary right central incisor in a female patient possessing adjacent teeth with a thin periodontal phenotype illustrates this new treatment device, method, and concept.

  14. Long-term outcome of complete cardiovascular implantable electronic device removal with cardiopulmonary bypass. (United States)

    Okada, Masaho; Narita, Yuji; Araki, Yoshimori; Oshima, Hideki; Usui, Akihiko; Ueda, Yuichi


    Definitive endovascular techniques have been developed for pacemaker lead extraction; however, a few patients require immediate secondary open heart surgery because of incomplete transvenous lead extraction. This study examined the safety, effectiveness, and long-term outcome of the removal of cardiovascular implantable electronic device (CIED) via median sternotomy under cardiopulmonary bypass. The removal of CIED was performed in 6 patients (mean age 57 ± 16 years, 5 males and 1 female), from September 2000 to April 2011. The reasons for removal included eradication of an infection in 5 patients and elimination of pacemaker component allergy in 1. Positive culture results, including methicillin-sensitive Staphylococcus aureus (MSSA, n = 2), methicillin-resistant S. aureus (MRSA, n = 1), coagulase-negative staphylococci (CNS, n = 1), and methicillin-resistant S. epidermidis (MRSE, n = 1) were observed in all 5 infected patients. Mitral annuloplasty (n = 1), mitral valvuloplasty (n = 1), tricuspid annuloplasty (n = 3). Implantation of myocardial pacing leads (n = 5) were performed concomitantly (n = 4), or secondarily (n = 1). All 6 patients were alive in good condition at 72 ± 55 months following CIED removal. New device infection occurred in 1 patient during long-term follow up. Complete surgical removal of pacing systems via median sternotomy with cardiopulmonary bypass is, therefore, considered to be safe and feasible with acceptable long term results.

  15. Cardiovascular implantable electronic device replacement infections and prevention: results from the REPLACE Registry. (United States)

    Uslan, Daniel Z; Gleva, Marye J; Warren, David K; Mela, Theofanie; Chung, Mina K; Gottipaty, Venkateshwar; Borge, Richard; Dan, Dan; Shinn, Timothy; Mitchell, Kevin; Holcomb, Richard G; Poole, Jeanne E


    Infection following cardiovascular implantable electronic device (CIED) replacement is a serious complication, and rates of infection have increased. Analysis of procedural and clinical data from device replacement procedures collected by the REPLACE Registry may provide insights into infection prevention strategies and outcomes. We prospectively evaluated procedural complications in patients undergoing CIED replacement over 6 months from 72 U.S. sites. Major and minor infections were predefined and adjudicated by an independent blinded clinical events committee. Data regarding infection prevention strategies and infectious outcomes were analyzed for their potential relationships. A total of 1,744 patients were included in REPLACE. All patients received preoperative intravenous antibiotics and 68.7% received postoperative systemic antibiotic therapy. CIED infection developed in 22 patients (1.3%), of which 14 cases were major (0.8%, 95% confidence interval [CI] 0.4%-1.3%) and eight were minor (0.5%, 95% CI 0.2%-0.9%). Patients with infections were more likely to have had postoperative hematomas (five of 22 [22.7%] vs 17 of 1,722 [0.98%], P = 0.002). Participating sites experiencing infection rates >5% were more likely to use povidone-iodine for topical antisepsis, had lower implantation volume, and had patients with higher Charlson Comorbidity Index (2.79 vs 2.32, 95% CI for difference 0.08-0.86, P = 0.019). In this multicenter prospective study with 6 months of follow-up, infections associated with CIED replacements were surprisingly infrequent, possibly due to the use of preoperative antibiotics. Patients with infections were more likely to have had a postoperative hematoma, and sites with higher infection rates had sicker patients and lower overall procedural volume. ©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.

  16. Thalamic DBS with a constant-current device in essential tremor: A controlled clinical trial. (United States)

    Wharen, Robert E; Okun, Michael S; Guthrie, Barton L; Uitti, Ryan J; Larson, Paul; Foote, Kelly; Walker, Harrison; Marshall, Frederick J; Schwalb, Jason; Ford, Blair; Jankovic, Joseph; Simpson, Richard; Dashtipour, Khashayar; Phibbs, Fenna; Neimat, Joseph S; Stewart, R Malcolm; Peichel, DeLea; Pahwa, Rajesh; Ostrem, Jill L


    This study of thalamic deep brain stimulation (DBS) investigated whether a novel constant-current device improves tremor and activities of daily living (ADL) in patients with essential tremor (ET). A prospective, controlled, multicenter study was conducted at 12 academic centers. We investigated the safety and efficacy of unilateral and bilateral constant-current DBS of the ventralis intermedius (VIM) nucleus of the thalamus in patients with essential tremor whose tremor was inadequately controlled by medications. The primary outcome measure was a rater-blinded assessment of the change in the target limb tremor score in the stimulation-on versus stimulation-off state six months following surgery. Multiple secondary outcomes were assessed at one-year follow-up, including motor, mood, and quality-of-life measures. 127 patients were implanted with VIM DBS. The blinded, primary outcome variable (n = 76) revealed a mean improvement of 1.25 ± 1.26 points in the target limb tremor rating scale (TRS) score in the arm contralateral to DBS (p < 0.001). Secondary outcome variables at one year revealed significant improvements (p ≤ 0.001) in quality of life, depression symptoms, and ADL scores. Forty-seven patients had a second contralateral VIM-DBS, and this group demonstrated reduction in second-sided tremor at 180 days (p < 0.001). Serious adverse events related to the surgery included infection (n = 3), intracranial hemorrhage (n = 3), and device explantation (n = 3). Unilateral and bilateral constant-current VIM DBS significantly improves upper extremity tremor, ADL, quality of life, and depression in patients with severe ET. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Fundus fluorescein angiographic findings in patients who underwent ventricular assist device implantation. (United States)

    Ozturk, Taylan; Nalcaci, Serhad; Ozturk, Pelin; Engin, Cagatay; Yagdi, Tahir; Akkin, Cezmi; Ozbaran, Mustafa


    Disruption of microcirculation in various tissues as a result of deformed blood rheology due to ventricular assist device (VAD) implantation causes novel arteriovenous malformations. Capillary disturbances and related vascular leakage in the retina and choroidea may also be seen in patients supported by VADs. We aimed to evaluate retinal vasculature deteriorations after VAD implantation. The charts of 17 patients who underwent VAD implantation surgery for the treatment of end-stage heart failure were retrospectively reviewed. Eight cases (47.1%) underwent pulsatile pump implantation (Berlin Heart EXCOR, Berlin Heart Mediprodukt GmbH, Berlin, Germany); however, nine cases (52.9%) had continuous-flow pump using centrifugal design (HeartWare, HeartWare Inc., Miramar, FL, USA). Study participants were selected among the patients who had survived with a VAD for at least 6 months, and results of detailed ophthalmologic examinations including optic coherence tomography (OCT) and fundus fluorescein angiography (FA) were documented. All of the 17 patients were male, with a mean age of 48.5 ± 14.8 years (15-67 years). Detailed ophthalmologic examinations including the evaluation of retinal vascular deteriorations via FA were performed at a mean of 11.8 ± 3.7 months of follow-up (6-18 months). Mean best-corrected visual acuity and intraocular pressure were found as logMAR 0.02 ± 0.08 and 14.6 ± 1.9 mm Hg, respectively in the study population. Dilated fundoscopy revealed severe focal arteriolar narrowing in two patients (11.8%), and arteriovenous crossing changes in four patients (23.5%); however, no pathological alteration was present in macular OCT scans. In patients with continuous-flow blood pumps, mean arm-retina circulation time (ARCT) and arteriovenous transit time (AVTT) were found to be 16.8 ± 3.0 and 12.4 ± 6.2 s, respectively; whereas those with pulsatile-flow blood pumps were found to be 17.4 ± 3.6 and 14.0 ± 2.1 s in patients (P=0.526 and P=0

  18. Divergent endometrial inflammatory cytokine expression at peri-implantation period and after the stimulation by copper intrauterine device. (United States)

    Chou, Chia-Hung; Chen, Shee-Uan; Shun, Chia-Tung; Tsao, Po-Nien; Yang, Yu-Shih; Yang, Jehn-Hsiahn


    Endometrial inflammation has contradictory effects. The one occurring at peri-implantation period is favourable for embryo implantation, whereas the other occurring after the stimulation by copper intrauterine device (Cu-IUD) prevents from embryo implantation. In this study, 8 week female ICR mice were used to investigate the endometrial inflammation, in which they were at proestrus stage (Group 1), at peri-implantation period (Group 2), and had a copper wire implanted into right uterine horn (Group 3). Cytokine array revealed that two cytokines were highly expressed in Group 2 and Group 3 as compared with Group 1, and seven cytokines, including tumour necrosis factor α (TNF-α), had selectively strong expression in Group 3. Immunohistochemistry demonstrated prominent TNF-α staining on the endometrium after Cu-IUD stimulation, and in vitro culture of human endometrial glandular cells with Cu induced TNF-α secretion. The increased TNF-α concentration enhanced in vitro THP-1 cells chemotaxis, and reduced embryo implantation rates. These results suggest that inflammatory cytokine profiles of endometrium are different between those at peri-implantation period and after Cu-IUD stimulation, and TNF-α is the one with selectively strong expression in the latter. It might account for the contradictory biological effects of endometrial inflammation.

  19. Noninvasive control of the power transferred to an implanted device by an ultrasonic transcutaneous energy transfer link. (United States)

    Shmilovitz, Doron; Ozeri, Shaul; Wang, Chua-Chin; Spivak, Boaz


    Ultrasonic transcutaneous energy transfer is an effective method for powering implanted devices noninvasively. Nevertheless, the amount of power harvested by the implanted receiver is sensitive to the distance and orientation of the external transmitting transducer attached to the skin with respect to the implanted receiving transducer. This paper describes an ultrasonic power transfer link whose harvested power is controlled by an inductive link. A small (5 μF) storage capacitor voltage, which is part of the implanted unit, is allowed to swing between 3.8 and 3.5 V using hysteretic control. The two control states are indicated by excitation (while the implanted storage capacitor voltage decreases) or the absence of excitation of an implanted coil that is magnetically coupled to an external coil attached to the skin surface. A 35 mW Ultrasonic Transcutaneous Energy Transfer link was fabricated using two piezoelectric transducers of equal size (Fuji Ceramics C-2 PZT disc 15 mm × 3 mm) operated at a vibration frequency of 720 kHz. By applying the proposed hysteretic control, the captured power was effectively regulated for implantation depths of up to 85 mm.

  20. In-vitro diagnostic devices introduction to current point-of-care diagnostic devices

    CERN Document Server

    Cheng, Chao-Min; Chen, Chien-Fu


    Addressing the origin, current status, and future development of point-of-care diagnostics, and serving to integrate knowledge and tools from Analytical Chemistry, Bioengineering, Biomaterials, and Nanotechnology, this book focusses on addressing the collective and combined needs of industry and academia (including medical schools) to effectively conduct interdisciplinary research. In addition to summarizing and detailing developed diagnostic devices, this book will attempt to point out the possible future trends of development for point-of-care diagnostics using both scientifically based research and practical engineering needs with the aim to help novices comprehensively understand the development of point-of-care diagnostics. This includes demonstrating several common but critical principles and mechanisms used in point-of-care diagnostics that address practical needs (e.g., disease or healthcare monitoring) using two well-developed examples so far: 1) blood glucose meters (via electrochemistry); and, 2) p...

  1. Early Healing Events around Titanium Implant Devices with Different Surface Microtopography: A Pilot Study in an In Vivo Rabbit Model

    Directory of Open Access Journals (Sweden)

    Ester Orsini


    Full Text Available In the present pilot study, the authors morphologically investigated sandblasted, acid-etched surfaces (SLA at very early experimental times. The tested devices were titanium plate-like implants with flattened wide lateral sides and jagged narrow sides. Because of these implant shape and placement site, the device gained a firm mechanical stability but the largest portion of the implant surface lacked direct contact with host bone and faced a wide peri-implant space rich in marrow tissue, intentionally created in order to study the interfacial interaction between metal surface and biological microenvironment. The insertion of titanium devices into the proximal tibia elicited a sequence of healing events. Newly formed bone proceeded through an early distance osteogenesis, common to both surfaces, and a delayed contact osteogenesis which seemed to follow different patterns at the two surfaces. In fact, SLA devices showed a more osteoconductive behavior retaining a less dense blood clot, which might be earlier and more easily replaced, and leading to a surface-conditioning layer which promotes osteogenic cell differentiation and appositional new bone deposition at the titanium surface. This model system is expected to provide a starting point for further investigations which clarify the early cellular and biomolecular events occurring at the metal surface.

  2. Use of plasma "reconstitution" during cardio pulmonary bypass for a heart transplant after previous left ventricular assist device implant surgery. (United States)

    Babaev, A; Saczkowski, R; Hynes, M; Boodhwani, M; Hudson, C C C


    The case report describes a novel technique of pre-emptive plasma "reconstitution" prior to disengagement from cardiopulmonary bypass (CPB) to minimize RV volume overload. The concomitant use of hemoconcentration facilitates volume and blood product management in cardiac transplant after previous left ventricular assist device implant surgery.

  3. Analysis of sub-1 keV implants in silicon using SIMS, SRP, MEISS and DLTS: The xRLEAP low energy, high current implanter evaluated

    Energy Technology Data Exchange (ETDEWEB)

    Foad, M.A.; England, J.G.; Moffatt, S. [Applied Materials Implant Division, West Sussex (United Kingdom); Armour, D.G. [Univ. of Salford (United Kingdom)


    Ultra shallow junctions can be formed, amongst other techniques, by very low energy ion implantation. The Implant Division of Applied Materials have recently developed a low energy, high current ion implanter, the xRLEAP (xR family, Low Energy Advance Process). This implanter is capable of delivering product worthy beam currents, in the milli-ampere regime down to energies of few hundred electron volts. A series of B and BF{sub 2} implants were carried out onto non-amorphised, 200mm Si wafers using beam energies in the range 0.2keV < E < 1keV. As-implanted and annealed samples were profiled using Secondary Ion Mass Spectrometry (SIMS). Surface damage due to implantation was evaluated using Medium Energy Ion Scattering Spectroscopy (MEISS). The carrier concentration profiles and junction depths of the annealed samples were investigated using Spreading Resistance Probe (SRP). Samples with ultra shallow junctions, < 0.07{mu}m, were examined using Deep Level Transient Spectroscopy (DLTS) for the first time.

  4. Twelve-month contraceptive continuation and repeat pregnancy among young mothers choosing postdelivery contraceptive implants or postplacental intrauterine devices. (United States)

    Cohen, Rebecca; Sheeder, Jeanelle; Arango, Natalia; Teal, Stephanie B; Tocce, Kristina


    To compare discontinuation rates and incidence of repeat pregnancy within 1 year among young mothers choosing postplacental intrauterine devices (IUDs) versus postpartum contraceptive implants. We enrolled a prospective cohort of postpartum adolescents and young women who chose either postplacental IUDs or postpartum contraceptive implants prior to hospital discharge. We used chart review and phone interviews to assess device discontinuation (by request or expulsion) and pregnancy within 12 months. Of the 244 13-22 year-old participants, 82 chose IUDs (74 levonorgestrel IUDs and 8 copper IUDs), and 162 chose implants. Both groups had participant-requested discontinuation rates of 14% (9/67 IUD; 19/135 implant) within 1 year. Participants choosing IUDs had a 25% (17/67) expulsion rate. Median time to expulsion was 4.1 weeks (range: 0.4-29.3 weeks, 16/17 within 12 weeks), and participants recognized 15/17 expulsions. IUD initiators had significantly higher pregnancy rates by 12 months (7.6% vs. 1.5%, p=0.04). Most pregnancies occurred when women discontinued their initial device and did not start alternative contraception. Participant-requested discontinuation was similar in both groups. Differences in overall device discontinuation rates were due to IUD expulsions. Pregnancy rates by 12 months postpartum were lower than previously reported in this age group in both implant initiators and IUD initiators. Young mothers who choose postplacental IUDs or postpartum contraceptive implants are unlikely to request removal within the first year. Clinicians should counsel postplacental IUD users that early expulsion is common (25%) and may be unrecognized (11% of expulsions). Patients should have a plan for contraceptive management should expulsion occur. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Current perspectives in percutaneous atrial septal defect closure devices

    Directory of Open Access Journals (Sweden)

    Bissessor N


    Full Text Available N Bissessor1–4 1Department of Cardiology, The Epworth Hospital, Melbourne, VIC, Australia; 2Division of Interventional Cardiology, The Alfred Hospital, Melbourne, VIC, Australia; 3Department of Clinical Science, Charles Sturt University Albury Campus, NSW, Australia; 4Heart Foundation, Griffith University, QLD, Australia Abstract: In the last decade, percutaneous atrial septal defect (ASD closure has become the treatment of choice in most clinical presentations of ASD. Percutaneous ASD closure has established procedural safety through operator experience and improved device structure and deliverability. There have also been advances in diagnostic capabilities. Devices have evolved from large bulky meshes to repositionable, minimal residual mesh content that easily endothelializes and conforms well to surrounding structures. Biodegradable technology has been introduced and will be closely watched as a future option. The evolution of ASD closure device usage in the last four decades incorporates development that minimizes a wide range of serious side effects that have been reported over the years. Complications reported in the literature include thrombus formation, air embolization, device embolization, erosions, residual shunts, and nickel hypersensitivity. Modern devices have intermediate to long term data with outcomes that have been favorable. Devices are available in multiple sizes with improved delivery mechanisms to recapture, reposition, and safely close simple and complex ASDs amenable to percutaneous closure. In this review, commonly used devices and deployment procedures are discussed together with a look at devices that show promise for the future. Keywords: ASD, congenital, Amplatzer, Gore Helex, Biostar, Figulla

  6. Remote monitoring of implantable devices: Should we continue to ignore it? (United States)

    Bertini, Matteo; Marcantoni, Lina; Toselli, Tiziano; Ferrari, Roberto


    The number of patients with implantable cardioverter defibrillators (ICDs) is increasing. In addition to improve survival, ICD can collect data related to device function and physiological parameters. Remote monitoring (RM) of these data allows early detection of technical or clinical problems and a prompt intervention (reprogramming device or therapy adjustment) before the patient require hospitalization. RM is not a substitute for emergency service and its consultation is now limited during working hours. Thus, a consent form is required to inform patients about benefits and limitations. The available studies indicate that remote monitoring is more effective than traditional calendar face to face based encounters. RM is safe, highly reliable, cost efficient, allows quick reply to failures, and reduces the number of scheduled visits and the incidence of inappropriate shocks with a positive impact on survival. It follows that RM has the credentials to be the standard of care for ICD management; however, unfortunately, there is a delay in physician acceptance and implementation. The recent observations from randomized IN-TIME study that showed a clear survival benefit with RM in heart failure patients have encouraged us to review both the negative and positive aspects of RM collected in a little more than a decade.

  7. Intracochlear drug delivery in combination with cochlear implants : Current aspects. (United States)

    Plontke, S K; Götze, G; Rahne, T; Liebau, A


    Local drug application to the inner ear offers a number of advantages over systemic delivery. Local drug therapy currently encompasses extracochlear administration (i. e., through intratympanic injection), intracochlear administration (particularly for gene and stem cell therapy), as well as various combinations with auditory neurosensory prostheses, either evaluated in preclinical or clinical studies, or off-label. To improve rehabilitation with cochlear implants (CI), one focus is the development of drug-releasing electrode carriers, e. g., for delivery of glucocorticosteroids, antiapoptotic substances, or neurotrophins to the inner ear. The performance of cochlear implants may thus be improved by protecting neuronal structures from insertion trauma, reducing fibrosis in the inner ear, and by stimulating growth of neuronal structures in the direction of the electrodes. Controlled drug release after extracochlear or intracochlear application in conjunction with a CI can also be achieved by use of a biocompatible, resorbable controlled-release drug-delivery system. Two case reports for intracochlear controlled release drug delivery in combination with cochlear implants are presented. In order to treat progressive reduction in speech discrimination and increased impedance, two cochlear implant patients successfully underwent intracochlear placement of a biocompatible, resorbable drug-delivery system for controlled release of dexamethasone. The drug levels reached in inner ear fluids after different types of local drug application strategies can be calculated using a computer model. The intracochlear drug concentrations calculated in this way were compared for different dexamethasone application strategies.

  8. Submammary device implantation. Good long-term performance and better patients' satisfaction. A single-center experience. (United States)

    Savastano, Simone; Rordorf, Roberto; Scotti Foglieni, Andrea; Klersy, Catherine; Vicentini, Alessandro; Petracci, Barbara; Sanzo, Antonio; Marino, Rossella; Taravelli, Erika; De Regibus, Valentina; Landolina, Maurizio; De Servi, Stefano


    Device related distress negatively affects the quality of life of cardiac device recipients mostly of women. A submammary approach has been proposed to reduce the physical impact of the implantation. Our aim was to assess the safety of this approach and to evaluate the patients' acceptance of the device. We enrolled 42 patients who underwent a submammary device. The primary endpoint was the need for implant revision that was assessed in the study group compared with the overall control group of 72 standard cardiac device recipients (29 females and 43 males)and with the female group (29 females of controls). In the female population (42 women of the submammary group and 29 of controls) patients' acceptance was calculated with the Florida Patient Acceptance Survey (FPAS). The rate of implant revision was similar in the two groups and the revision-free survival was comparable with a median follow-up of about six years (Log rank test p=0.949). Similar results were found when considering only the female population. Patients' acceptance was greater in the submammary group [total FPAS 85 (95%CI 83-86) vs 74.5 (95%CI 70.2-77.3) p<0,001] and a strongly significant superiority of the submammary group was found regarding body image concerns [10 (95%CI 10-10) vs 8 (95%CI 8-8) p<0.001) and device related distress [23 (95%CI 22-23) vs 1 (95%CI 1-1) p<0.001]. Submammary device implantation is safe and more accepted than standard approach. Our results should encourage cardiologists to suggest this approach to their patients for a better acceptance of the therapy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Finite volume analysis of temperature effects induced by active MRI implants with cylindrical symmetry: 1. Properly working devices


    Schnorr Jörg; Vollmann Wolfgang; Busch Martin HJ; Grönemeyer Dietrich HW


    Abstract Background Active Magnetic Resonance Imaging implants are constructed as resonators tuned to the Larmor frequency of a magnetic resonance system with a specific field strength. The resonating circuit may be embedded into or added to the normal metallic implant structure. The resonators build inductively coupled wireless transmit and receive coils and can amplify the signal, normally decreased by eddy currents, inside metallic structures without affecting the rest of the spin ensemble...

  10. Personal view: current role of artificial liver support devices. (United States)

    O'Grady, J


    Enthusiasm for liver support devices, particularly cell-based biological systems and albumin dialysis, increased over the last decade and there has been considerable clinical activity both within and without the construct of clinical trials. Most data have been generated on patients with acute liver failure or in patients with decompensation of chronic liver disease, often referred to as acute-on-chronic liver failure. In acute liver failure liver, liver support devices are more realistically being used as a 'bridge' to liver transplantation rather than to transplant-free survival. In acute-on-chronic liver failure the clinical objective of attaining clinical stability with treatment appears more achievable. The so-called bioartificial liver device, based on porcine hepatocytes, is the most extensively evaluated biological device. A sizeable clinical trial failed to demonstrate efficacy, but secondary analyses suggest it would be unwise to assume futility had been established with this device. Molecular adsorbent recirculating system leads the way in the non-biological category in terms of the number of patients treated, but data from large clinical trials are not yet available. One of the strongest conclusions of this review is that the amount of high-quality data available on liver support devices dramatically understates the effort and money that have been expended in their assessment. It is very clear that randomized controlled trials are mandatory to establish clinical efficacy, but it is less clear how the ideal trial should be constructed.

  11. Pacemaker Use in New Zealand - Data From the New Zealand Implanted Cardiac Device Registry (ANZACS-QI 15). (United States)

    Larsen, P D; Kerr, A J; Hood, M; Harding, S A; Hooks, D; Heaven, D; Lever, N A; Sinclair, S; Boddington, D; Tang, E W; Swampillai, J; Stiles, M K


    The New Zealand Cardiac Implanted Device Registry (Device) has recently been developed under the auspices of the New Zealand Branch of the Cardiac Society of Australia and New Zealand. This study describes the initial Device registry cohort of patients receiving a new pacemaker, their indications for pacing and their perioperative complications. The Device Registry was used to audit patients receiving a first pacemaker between 1(st) January 2014 and 1(st) June 2015. We examined 1611 patients undergoing first pacemaker implantation. Patients were predominantly male (59%), and had a median age of 70 years. The most common symptom for pacemaker implantation was syncope (39%), followed by dizziness (30%) and dyspnoea (12%). The most common aetiology for a pacemaker was a conduction tissue disorder (35%), followed by sinus node dysfunction (22%). Atrioventricular (AV) block was the most common ECG abnormality, present in 44%. Dual chamber pacemakers were most common (62%), followed by single chamber ventricular pacemakers (34%), and cardiac resynchronisation therapy - pacemakers (CRT-P) (2%). Complications within 24hours of the implant procedure were reported in 64 patients (3.9%), none of which were fatal. The most common complication was the need for reoperation to manipulate a lead, occurring in 23 patients (1.4%). This is the first description of data entered into the Device registry. Patients receiving a pacemaker were younger than in European registries, and there was a low use of CRT-P devices compared to international rates. Complications rates were low and compare favourably to available international data. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  12. Morphometrical measurements of resected surface of femurs in Chinese knees: correlation to the sizing of current femoral implants. (United States)

    Ho, Wei-Pin; Cheng, Cheng-Kung; Liau, Jiann-Jong


    Morphometrical data were measured in the resected femurs of seventy Chinese patients who underwent total knee arthroplasties. Two measured parameters, the anterior-posterior length of the lateral condyle and the total width of the distal condyle, were compared to the anterior-posterior length and the medial-lateral width of five femoral implants currently used in Taiwan. Three implants (Duracon, NexGen and UKnee) have a larger medial-lateral width than the total width of the resected distal condyle for a given femoral implant anterior-posterior length. These implants tend to overhang the medial-lateral width of resected femurs from Chinese patients. In addition, one femoral implant (Duracon), which has previously been shown to be suitable for use in Caucasian patients, is not suitable in Chinese patients. Our results will allow manufacturers to design femoral implants better suited to Chinese patients.

  13. An Implantable Device for Manipulation of the in vivo Tumor Microenvironment (United States)

    Williams, James K.

    In the past decade, it has become increasingly recognized that interactions between cancer cells and the tumor microenvironment (TME) regulate metastasis. One such interaction is the paracrine loop between macrophages and cancer cells which drives metastatic invasion in mammary tumors. Tumor associated macrophages release epidermal growth factor (EGF), a chemoattractant which induces the migration of cancer cells toward the blood vessels. The cancer cells reciprocate by releasing a macrophage chemoattractant, colony-stimulating factor 1 (CSF-1), resulting in the co-migration of both cell types and subsequent intravasation. In this work, a new technology has been developed for studying the mechanisms by which invasive tumor cells migrate in vivo toward gradients of EGF. Conventional in vitro methods used for studying tumor cell migration lack the complexity found in the TME and are therefore of limited relevance to in vivo metastasis. The Nano Intravital Device (NANIVID) has been designed as an implantable tool to manipulate the TME through the generation of soluble factor gradients. The NANIVID consists of two etched glass substrates, loaded with a hydrogel containing EGF, and sealed together using a polymer membrane. When implanted in vivo, the hydrogel will swell and release the entrapped EGF, forming a diffusion gradient in the tumor over many hours. The NANIVID design has been optimized for use with multiphoton-based intravital imaging, to monitor migration toward the device at single-cell resolution. Stabilization techniques have been developed to minimize imaging artifacts caused by breathing and specimen movement over the course of the experiment. The NANIVID has been validated in vivo using a mouse model of metastasis. When implanted in MDA-MB-231 xenograft tumors grown in SCID mice, chemotaxis of tumor cells was induced by the EGF gradient generated by the device. Cell motility parameters including velocity, directionality, and chemotactic index were

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


    Altaf Hussain Shah; Hesham Saleh Khalil; Mohammed Zaheer Kola


    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 antic...

  15. Ionic current devices-Recent progress in the merging of electronic, microfluidic, and biomimetic structures. (United States)

    Koo, Hyung-Jun; Velev, Orlin D


    We review the recent progress in the emerging area of devices and circuits operating on the basis of ionic currents. These devices operate at the intersection of electrochemistry, electronics, and microfluidics, and their potential applications are inspired by essential biological processes such as neural transmission. Ionic current rectification has been demonstrated in diode-like devices containing electrolyte solutions, hydrogel, or hydrated nanofilms. More complex functions have been realized in ionic current based transistors, solar cells, and switching memory devices. Microfluidic channels and networks-an intrinsic component of the ionic devices-could play the role of wires and circuits in conventional electronics.

  16. Current Reversal and Negative Conductance for a Super-Conducting Junctions Device

    Institute of Scientific and Technical Information of China (English)

    LI Jing-Hui


    In the paper, we study a super-conducting junctions device subject to an input periodic signal and a constant force. It is shown that, for this device, we can get current reversals for the current of the electron pairs versus the frequency of the periodic signal and negative conductance for the current of the electron pairs as a function of the constant force.

  17. Vision implants: An electrical device will bring light to the blind

    Institute of Scientific and Technical Information of China (English)


    Cochlear implant has been successfully applied in clinic. Recent research indicates vision implants may be the potential way to restore sight for the blind. Here, principle and common structure of vision implants are introduced. Main vision approaches of retinal, optic nerve, and cortical prosthesis are reviewed. In our progress, electrical response at visual cortex is recorded, when penetrating electrodes stimulate rabbit optic nerve, vision implants based on optic nerve stimulator chip (ONSC) and Chipcon radio frequency (RF) chip are under developing. Despite several obstacles to overcome, promising results in animal and human experiments give scientists confidence that artificial vision implants will bring light to the blind in the near future.

  18. Cochlear Implants (United States)

    A cochlear implant is a small, complex electronic device that can help to provide a sense of sound. People who are ... of-hearing can get help from them. The implant consists of two parts. One part sits on ...

  19. Surgical implantation of a cardiac resynchronization therapy device in a western lowland gorilla (Gorilla gorilla gorilla) with fibrosing cardiomyopathy. (United States)

    Rush, Elizabeth Marie; Ogburn, Anna L; Hall, Jeffrey; Rush, Dwain; Lau, Yung; Dillon, A R; Garmon, Linda; Tillson, D M; Kay, G Neal


    A 24-yr-old, male western lowland gorilla (Gorilla gorilla gorilla) was diagnosed in March of 2003 with congestive heart failure (CHF). Transesophageal and transthoracic echocardiography demonstrated global left and right ventricular hypokinesia with a left ventricular ejection fraction of 0.20. At the time of diagnosis, the animal exhibited symptoms and signs of CHF with minimal exertion (New York Heart Association class III). Over a 16-mo period, the severity of CHF progressed to class IV (resting signs and symptoms) despite angiotensin-converting enzyme inhibition, beta-blockers, and diuretics. Because of intractable CHF and a QRS duration that was markedly prolonged compared with the normal range for this species, a cardiac resynchronization therapy (CRT) device was implanted using implantation techniques based on human surgical procedures. Placement of the right ventricular, right atrial, and left ventricular leads and pulse generator were accomplished in 5.5 hr. Telemetry of the device postoperatively via wand or remote radio frequency has allowed for noninvasive programming and interrogation. The clinical improvement in CHF with this therapy was immediate and dramatic for this animal. Six months after CRT device implantation, the device leads became dislodged during an altercation with another gorilla, with the rapid development of CHF upon cessation of biventricular pacing. A second procedure to replace the leads returned the gorilla to his previous level of activity. In 2007, the pulse generator was electively replaced for battery depletion with a device capable of remote radiofrequency programming and interrogation. CRT implantation, although requiring specialized equipment and surgical skill, appears to be a viable option for treatment of dilated cardiomyopathy in gorillas.

  20. Scientific collaboration: a social network analysis based on literature of animal-derived regenerative implantable medical devices. (United States)

    Yu, Shu-Yang; Wang, Hong-Man


    The collaboration network of English publications on animal-derived regenerative implantable medical devices based on tissue engineering technology and its evolving processes and current states were mapped in this paper. A total of 10 159 English papers published before 1 January 2015 were obtained in eight databases. Social network analysis was conducted on these papers by utilizing UCINET software and Statistical Analysis Software for Informatics researched and developed by Peking University. The collaboration network has evolved from scattered formation to single-core dominated, and then to a core-edge one; collaboration has become more frequent and wider; network density and centrality have decreased; USA, UK and China are the top three countries with Wake Forest University, Harvard University and Tufts University being the top three contributing institutions cooperated mostly during the period between 2010 and 2014; plenty of edge institutes exist. In conclusion, more collaboration among different institutions and countries is needed; Edge institutions and developing countries should expand their scope of collaboration.

  1. Influence of time between last myocardial infarction and prophylactic implantable defibrillator implant on device detections and therapies. “Routine Practice” data from the SEARCH MI registry

    Directory of Open Access Journals (Sweden)

    Boriani Giuseppe


    Full Text Available Abstract Background A multicenter European Registry, SEARCH-MI, was instituted in the year 2002 in order to assess patients’ outcomes and ICD interventions in patients with a previous MI and depressed LV function, treated with an ICD according to MADIT II results. In this analysis, we evaluate the influence of the time elapsed between last myocardial infarction (MI and prophylactic cardioverter defibrillator (ICD implant on device activations. Methods 643 patients with left ventricular dysfunction (mean LVEF 26 ± 5% and NYHA class I-III were prospectively followed for 1.8 ± 1.2 years in a multicenter registry. The population was divided into 3 groups according to the time between last MI and ICD implant: [1] from 40 days to less than 1.5 years; [2] from 1.5 to less than 7 years and [3] at least 7 years. Results The cumulative incidence of ventricular tachyarrhymias and appropriate device therapy (ATP or shock were higher in patients implanted longer time from last MI (Gray’s Test p = 0.002 and p = 0.013 respectively. No significant differences were seen in all cause mortality (Gray’s Test p = 0.618 or sudden cardiac death across the MI stratification groups (Gray’s Test p = 0.663. Conclusions Patients implanted with an ICD longer after the MI have a higher chance of presenting ventricular tachyarrhythmias and appropriate ICD therapy, while no differences were seen in overall mortality. These observations may be important for improving patient targeting in sudden death prevention.

  2. Wireless miniature implantable devices and ASICs for monitoring, treatment, and study of glaucoma and cardiac disease (United States)

    Chow, Eric Y.

    Glaucoma affects about 65 million people and is the second leading cause of blindness in the world. Although the condition is irreversible and incurable, early detection is vital to slowing and even stopping the progression of the disease. Our work focuses on the design, fabrication, and assembly of a continuous active glaucoma intraocular pressure (IOP) monitor that provides clinicians with the necessary data to more accurately diagnose and treat patients. Major benefits of an active monitoring device include the potential to develop a closed-loop treatment system and to operate independently for extended periods of time. The fully wireless operation uses gigahertzfrequency electromagnetic wave propagation, which allows for an orientation independent transfer of power and data over reasonable distances. Our system is comprised of a MEMS capacitive sensor, capacitive power storage array, ASIC, and monopole antenna assembled into a biocompatible liquid crystal polymer (LCP) package. We have performed in vivo trials on rabbits, both chronic and acute, to validate system functionality, fully wireless feasibility, and biocompatibility. Heart failure (HF) affects approximately 2% of the adult population in developed countries and 6-10% of people over the age of 65. Continuous monitoring of blood pressure, flow, and chemistry from a minimally invasive device can serve as a diagnostic and early-warning system for cardiac health. We developed a miniaturized system attached to the outer surface of an FDA approved stent, used as both the antenna for wireless telemetry/powering and structural support. The system comprises of a MEMS pressure sensor, ASIC for the sensor interface and wireless capabilities, LCP substrate, and FDA approved stent. In vivo studies on pigs validated functionality and fully wireless operation and demonstrate the feasibility of a stent-based wireless implant for continuous monitoring of blood pressure as well as other parameters including oxygen, flow

  3. Educational Behavior Apps and Wearable Devices: Current Research and Prospects (United States)

    Lowe, Heather


    Dartmouth and MIT have developed educational behavior apps and wearable devices that collect contiguous streams of data from student users. Given the consent of the user, the app collects information about a student's physical activity, sleep patterns, and location to form conjectures about social and academic behavior. These apps have the…

  4. First principle leakage current reduction technique for CMOS devices

    CSIR Research Space (South Africa)

    Tsague, HD


    Full Text Available that the device is suitable for low power applications. Physical models used for simulation included SI(sub3)N(sub4) and HfO(sub2) as gate dielectric with TiSix as metal gate. From the simulation result, it was shown that HfO2 was the best dielectric material when...

  5. "Optical communication with brain cells by means of an implanted duplex micro-device with optogenetics and Ca(2+) fluoroimaging". (United States)

    Kobayashi, Takuma; Haruta, Makito; Sasagawa, Kiyotaka; Matsumata, Miho; Eizumi, Kawori; Kitsumoto, Chikara; Motoyama, Mayumi; Maezawa, Yasuyo; Ohta, Yasumi; Noda, Toshihiko; Tokuda, Takashi; Ishikawa, Yasuyuki; Ohta, Jun


    To better understand the brain function based on neural activity, a minimally invasive analysis technology in a freely moving animal is necessary. Such technology would provide new knowledge in neuroscience and contribute to regenerative medical techniques and prosthetics care. An application that combines optogenetics for voluntarily stimulating nerves, imaging to visualize neural activity, and a wearable micro-instrument for implantation into the brain could meet the abovementioned demand. To this end, a micro-device that can be applied to the brain less invasively and a system for controlling the device has been newly developed in this study. Since the novel implantable device has dual LEDs and a CMOS image sensor, photostimulation and fluorescence imaging can be performed simultaneously. The device enables bidirectional communication with the brain by means of light. In the present study, the device was evaluated in an in vitro experiment using a new on-chip 3D neuroculture with an extracellular matrix gel and an in vivo experiment involving regenerative medical transplantation and gene delivery to the brain by using both photosensitive channel and fluorescent Ca(2+) indicator. The device succeeded in activating cells locally by selective photostimulation, and the physiological Ca(2+) dynamics of neural cells were visualized simultaneously by fluorescence imaging.

  6. Isopropyl Myristate-Modified Polyether-Urethane Coatings as Protective Barriers for Implantable Medical Devices

    Directory of Open Access Journals (Sweden)

    Pankaj Vadgama


    Full Text Available Polyurethane films have potential applications in medicine, especially for packaging implantable medical devices. Although polyether-urethanes have superior mechanical properties and are biocompatible, achieving water resistance is still a challenge. Polyether based polyurethanes with two different molecular weights (PTMO1000, PTMO2000 were prepared from 4,4’-diphenylmethane diisocyanate and poly(tetra-methylene oxide. Polymer films were introduced using different concentrations (0.5-10 wt % of isopropyl myristate lipid (IPM as a non-toxic modifying agent. The physical and mechanical properties of these polymers were characterised using physical and spectroscopy techniques (FTIR, Raman, DSC, DMA, tensile testing. Water contact angle and water uptake of the membranes as a function of IPM concentration was also determined accordingly. The FTIR and Raman data indicate that IPM is dispersed in polyurethane at ≤ 2wt% and thermal analysis confirmed this miscibility to be dependent on soft segment length. Modified polymers showed increased tensile strength and failure strain as well as reduced water uptake by up to 24% at 1-2 wt% IPM.

  7. Vibrant Soundbridge implantable hearing device: critical review and single-surgeon short- and long-term results. (United States)

    Luetje, Charles M; Brown, Sandra A; Cullen, Robert D


    We conducted a retrospective descriptive study of a series of 31 consecutively presenting patients who had been implanted with the Vibrant Soundbridge middle ear hearing device. All implantations had been performed by the senior author. Three of these patients had undergone bilateral implantation, and 4 others had undergone subsequent explantation and reimplantation in response to known or suspected device failure, giving us a total of 34 ears and 38 implants. Our goal was to ascertain short- and long-term outcomes as measured by conventional audiometry (pure-tone average at 1 to 6 kHz) and long-term benefit as defined by the use or nonuse of the device. We found that at the initial activation session 2 months postoperatively, the average hearing thresholds were within 3 dB of the preoperative thresholds in all 34 ears and all 38 implants. The mean short-term gain at activation in the 38 implants was 28.1 dB. Nineteen patients (20 ears) were available for long-term evaluation, with the length of follow-up ranging from less than 1 year to 11 years (mean: 7.3). Of these 20 ears, 9 demonstrated further gain (mean: 10.8 dB) despite any natural hearing deterioration; of the remaining 11 ears, gain was unchanged in 2, diminished in 7 (mean: -3.6 dB), and gain data were unavailable in 2. In the final analysis, there were 20 user ears and 10 nonuser ears; 4 ears were lost to all follow-up. We conclude that direct-drive hearing with the Vibrant Soundbridge middle ear hearing device is beneficial and provides sustained audiometric gain. Factors that have a significant impact on patient use or nonuse include difficulty in obtaining audiologic support and the direct and indirect costs of the device. Without audiologic or financial support, some patients may choose to become nonusers and to either switch to conventional hearing aid amplification or become apathetic about hearing improvement.

  8. Autologous Cell Delivery to the Skin-Implant Interface via the Lumen of Percutaneous Devices in vitro

    Directory of Open Access Journals (Sweden)

    Antonio Peramo


    Full Text Available Induced tissue regeneration around percutaneous medical implants could be a useful method to prevent the failure of the medical device, especially when the epidermal seal around the implant is disrupted and the implant must be maintained over a long period of time. In this manuscript, a novel concept and technique is introduced in which autologous keratinocytes were delivered to the interfacial area of a skin-implant using the hollow interior of a fixator pin as a conduit. Full thickness human skin explants discarded from surgeries were cultured at the air-liquid interface and were punctured to fit at the bottom of hollow cylindrical stainless steel fixator pins. Autologous keratinocytes, previously extracted from the same piece of skin and cultured separately, were delivered to the specimens thorough the interior of the hollow pins. The delivered cells survived the process and resembled undifferentiated epithelium, with variations in size and shape. Viability was demonstrated by the lack of morphologic evidence of necrosis or apoptosis. Although the cells did not form organized epithelial structures, differentiation toward a keratinocyte phenotype was evident immunohistochemically. These results suggest that an adaptation of this technique could be useful for the treatment of complications arising from the contact between skin and percutaneous devices in vivo.



    Girling, A; Lilford, R; Cole, A; Young, T


    OBJECTIVES: The headroom approach to medical device development relies on the estimation of a value-based price ceiling at different stages of the development cycle. Such price-ceilings delineate the commercial opportunities for new products in many healthcare systems. We apply a simple model to obtain critical business information as the product proceeds along a development pathway, and indicate some future directions for the development of the approach. METHODS: Health economic modelling in...

  10. Breast reconstruction with anatomical implants: A review of indications and techniques based on current literature

    Directory of Open Access Journals (Sweden)

    Marco Gardani


    Full Text Available One important modality of breast cancer therapy is surgical treatment, which has become increasingly less mutilating over the last century. Breast reconstruction has become an integrated part of breast cancer treatment due to long-term psychosexual health factors and its importance for breast cancer survivors. Both autogenous tissue-based and implant-based reconstruction provides satisfactory reconstructive options due to better surgeon awareness of “the ideal breast size”, although each has its own advantages and disadvantages. An overview of the current options in breast reconstruction is presented in this article.

  11. ACOG Committee Opinion no. 450: Increasing use of contraceptive implants and intrauterine devices to reduce unintended pregnancy. (United States)


    High unintended pregnancy rates in the United States may in part be the result of relatively low use of long-acting reversible contraceptive (LARC) methods, specifically the contraceptive implant and intrauterine devices. Top-tier reversible methods share the characteristic of requiring a single act of motivation for long-term use, eliminating adherence and user-dependence from the effectiveness equation. According to the World Health Organization's evidence-based Medical Eligibility Criteria for contraceptive use, LARC methods have few contraindications, and almost all women are eligible for implants and intrauterine devices. Because of these advantages and the potential to reduce unintended pregnancy rates, LARC methods should be offered as first-line contraceptive methods and encouraged as options for most women. To increase use of LARC methods, barriers such as lack of health care provider knowledge or skills, low patient awareness, and high upfront costs must be addressed.

  12. Crossing the bends: Support-catheter based left ventricular lead placement in challenging cardiac resynchronization therapy device implantation

    Directory of Open Access Journals (Sweden)

    Amit Kumar Malik, MBBS, MD


    Full Text Available The combined use of an Amplatz guiding catheter and support catheter creates a progressively supportive rail to implant the left ventricular (LV lead in difficult cardiac resynchronization therapy device implantation. We describe the case of a 32-year-old male with non-ischaemic cardiomyopathy, left bundle-branch block, and an LV ejection fraction of 30%, who was referred to our centre for a repeat attempt at an LV lead implant. Previously, the implanter had been unable to advance different guide catheters over the wire to the desired tributary of the coronary sinus (CS. At our centre, the CS was cannulated with a 6-Fr AL2 coronary guiding catheter. A 135-cm support catheter (Spectranetics Quick-Cross was advanced via AL2 guiding over the 0.035 in. guide wire to the distal CS. The proximal luer fitting of the support catheter was cut and an inner sheath (Medtronic ATTAIN SELECT II advanced over the support catheter into the CS. A 4-Fr over-the-wire LV lead was advanced through the inner sheath over a 0.014 in. percutaneous transluminal coronary angioplasty wire after removal of the support catheter. The use of a support catheter serves as rail for the placement of the inner sheath deep in the CS and facilitates implantation of the LV pacing lead. This technique is safe and easily applied.

  13. In vivo demonstration of ultrasound power delivery to charge implanted medical devices via acute and survival porcine studies. (United States)

    Radziemski, Leon; Makin, Inder Raj S


    Animal studies are an important step in proving the utility and safety of an ultrasound based implanted battery recharging system. To this end an Ultrasound Electrical Recharging System (USER™) was developed and tested. Experiments in vitro demonstrated power deliveries at the battery of up to 600 mW through 10-15 mm of tissue, 50 mW of power available at tissue depths of up to 50 mm, and the feasibility of using transducers bonded to titanium as used in medical implants. Acute in vivo studies in a porcine model were used to test reliability of power delivery, temperature excursions, and cooling techniques. The culminating five-week survival study involved repeated battery charging, a total of 10.5h of ultrasound exposure of the intervening living tissue, with an average RF input to electrical charging efficiency of 20%. This study was potentially the first long term cumulative living-tissue exposure using transcutaneous ultrasound power transmission to an implanted receiver in situ. Histology of the exposed tissue showed changes attributable primarily due to surgical implantation of the prototype device, and no damage due to the ultrasound exposure. The in vivo results are indicative of the potential safe delivery of ultrasound energy for a defined set of source conditions for charging batteries within implants.

  14. Complications after Surgical Procedures in Patients with Cardiac Implantable Electronic Devices: Results of a Prospective Registry. (United States)

    Silva, Katia Regina da; Albertini, Caio Marcos de Moraes; Crevelari, Elizabeth Sartori; Carvalho, Eduardo Infante Januzzi de; Fiorelli, Alfredo Inácio; Martinelli, Martino; Costa, Roberto


    Complications after surgical procedures in patients with cardiac implantable electronic devices (CIED) are an emerging problem due to an increasing number of such procedures and aging of the population, which consequently increases the frequency of comorbidities. To identify the rates of postoperative complications, mortality, and hospital readmissions, and evaluate the risk factors for the occurrence of these events. Prospective and unicentric study that included all individuals undergoing CIED surgical procedures from February to August 2011. The patients were distributed by type of procedure into the following groups: initial implantations (cohort 1), generator exchange (cohort 2), and lead-related procedures (cohort 3). The outcomes were evaluated by an independent committee. Univariate and multivariate analyses assessed the risk factors, and the Kaplan-Meier method was used for survival analysis. A total of 713 patients were included in the study and distributed as follows: 333 in cohort 1, 304 in cohort 2, and 76 in cohort 3. Postoperative complications were detected in 7.5%, 1.6%, and 11.8% of the patients in cohorts 1, 2, and 3, respectively (p = 0.014). During a 6-month follow-up, there were 58 (8.1%) deaths and 75 (10.5%) hospital readmissions. Predictors of hospital readmission included the use of implantable cardioverter-defibrillators (odds ratio [OR] = 4.2), functional class III--IV (OR = 1.8), and warfarin administration (OR = 1.9). Predictors of mortality included age over 80 years (OR = 2.4), ventricular dysfunction (OR = 2.2), functional class III-IV (OR = 3.3), and warfarin administration (OR = 2.3). Postoperative complications, hospital readmissions, and deaths occurred frequently and were strongly related to the type of procedure performed, type of CIED, and severity of the patient's underlying heart disease. Complicações após procedimentos cirúrgicos em portadores de dispositivos cardíacos eletrônicos implantáveis (DCEI) são um

  15. Bibliometric analysis of the literature from the mainland of China on animal-derived regenerative implantable medical devices (United States)

    Wang, Hong-Man; Li, Fu-Yao


    Choosing animal-derived regenerative implantable medical devices based on tissue engineering technology as a research theme, this paper presents bibliometric analysis of relative literature from the mainland of China to understand such data as publication year and journal preference, authors' geographic location, research topics and core expertise to predict the research trends and provide an informed basis of decision making for researchers and clinicians.

  16. Characterization of device isolation in GaAs MESFET circuits by boron implantation

    Energy Technology Data Exchange (ETDEWEB)

    Clauwaert, F.; Van Daele, P.; Lagasse, P.


    The use of boron implantation for the electrical isolation of MESFET's and other electronic components in GaAs high speed digital IC's has been investigated. The sheet isolation resistance was measured as a function of the implantation energy and dose and of the anneal temperature and time. Topics considered include fabrication, integrated circuits, electric conductivity, annealing, transistors, ion implantation, and digital systems.

  17. Device Architecture and Materials for Organic Light-Emitting Devices Targeting High Current Densities and Control of the Triplet Concentration

    CERN Document Server

    Schols, Sarah


    Device Architecture and Materials for Organic Light-Emitting Devices focuses on the design of new device and material concepts for organic light-emitting devices, thereby targeting high current densities and an improved control of the triplet concentration. A new light-emitting device architecture, the OLED with field-effect electron transport, is demonstrated. This device is a hybrid between a diode and a field-effect transistor. Compared to conventional OLEDs, the metallic cathode is displaced by one to several micrometers from the light-emitting zone, reducing optical absorption losses. The electrons injected by the cathode accumulate at an organic heterojunction and are transported to the light-emission zone by field-effect. High mobilities for charge carriers are achieved in this way, enabling a high current density and a reduced number of charge carriers in the device. Pulsed excitation experiments show that pulses down to 1 µs can be applied to this structure without affecting the light intensity, sug...

  18. Towards real-time cardiovascular magnetic resonance-guided transarterial aortic valve implantation: In vitro evaluation and modification of existing devices

    Directory of Open Access Journals (Sweden)

    Ladd Mark E


    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR is considered an attractive alternative for guiding transarterial aortic valve implantation (TAVI featuring unlimited scan plane orientation and unsurpassed soft-tissue contrast with simultaneous device visualization. We sought to evaluate the CMR characteristics of both currently commercially available transcatheter heart valves (Edwards SAPIEN™, Medtronic CoreValve® including their dedicated delivery devices and of a custom-built, CMR-compatible delivery device for the Medtronic CoreValve® prosthesis as an initial step towards real-time CMR-guided TAVI. Methods The devices were systematically examined in phantom models on a 1.5-Tesla scanner using high-resolution T1-weighted 3D FLASH, real-time TrueFISP and flow-sensitive phase-contrast sequences. Images were analyzed for device visualization quality, device-related susceptibility artifacts, and radiofrequency signal shielding. Results CMR revealed major susceptibility artifacts for the two commercial delivery devices caused by considerable metal braiding and precluding in vivo application. The stainless steel-based Edwards SAPIEN™ prosthesis was also regarded not suitable for CMR-guided TAVI due to susceptibility artifacts exceeding the valve's dimensions and hindering an exact placement. In contrast, the nitinol-based Medtronic CoreValve® prosthesis was excellently visualized with delineation even of small details and, thus, regarded suitable for CMR-guided TAVI, particularly since reengineering of its delivery device toward CMR-compatibility resulted in artifact elimination and excellent visualization during catheter movement and valve deployment on real-time TrueFISP imaging. Reliable flow measurements could be performed for both stent-valves after deployment using phase-contrast sequences. Conclusions The present study shows that the Medtronic CoreValve® prosthesis is potentially suited for real-time CMR-guided placement

  19. Current status of epibulbar anti-glaucoma drainage devices in glaucoma surgery. (United States)

    Thieme, Hagen


    The term "glaucoma" covers a heterogeneous group of progressive optic neuropathies that are accompanied by characteristic visual-field defects. Primary open-angle glaucoma, the most common type, progresses insidiously and causes blindness if untreated. All current forms of treatment aim at lowering the intraocular pressure (IOP) in patients whose IOP is elevated. The implantation of anti-glaucoma drainage systems is one of the available options for surgical treatment. This review is based on pertinent literature retrieved by a selective search, including glaucoma treatment guidelines from Germany and abroad. A paradigm shift is currently underway regarding the indications for the implantation of anti-glaucoma drainage systems. Trabeculectomy (a "fistulating" operation in which the aqueous humor is led out of the eye under the conjunctiva) is still considered the surgical gold standard, but drainage systems have been implanted with increasing frequency in recent years. Studies have shown that these systems are more likely to be beneficial the earlier they are implanted in the course of the patient's disease. Five-year follow-up data from the randomized, multicenter Tube Versus Trabeculectomy (TVT) study have now revealed that anti-glaucoma drainage systems are equivalent to trabeculectomy with respect to long-term IOP reduction, complication rates, and absolute and relative clinical success rates. Glaucoma is a major clinical and socio-economic problem whose surgical treatment increasingly involves the implantation of anti-glaucoma drainage systems.

  20. Science and Technology of Bio-Inert Thin Films as Hermetic-Encapsulating Coatings for Implantable Biomedical Devices: Application to Implantable Microchip in the Eye for the Artificial Retina (United States)

    Auciello, Orlando; Shi, Bing

    Extensive research has been devoted to the development of neuron prostheses and hybrid bionic systems to establish links between the nervous system and electronic or robotic prostheses with the main focus of restoring motor and sensory functions in blind patients. Artificial retinas, one type of neural prostheses we are currently working on, aim to restore some vision in blind patients caused by retinitis picmentosa or macular degeneration, and in the future to restore vision at the level of face recognition, if not more. Currently there is no hermetic microchip-size coating that provides a reliable, long-term (years) performance as encapsulating coating for the artificial retina Si microchip to be implanted inside the eye. This chapter focuses on the critical topics relevant to the development of a robust, long-term artificial retina device, namely the science and technology of hermetic bio-inert encapsulating coatings to protect a Si microchip implanted in the human eye from being attacked by chemicals existing in the eye's saline environment. The work discussed in this chapter is related to the development of a novel ultrananocrystalline diamond (UNCD) hermetic coating, which exhibited no degradation in rabbit eyes. The material synthesis, characterization, and electrochemical properties of these hermetic coatings are reviewed for application as encapsulating coating for the artificial retinal microchips implantable inside the human eye. Our work has shown that UNCD coatings may provide a reliable hermetic bio-inert coating technology for encapsulation of Si microchips implantable in the eye specifically and in the human body in general. Electrochemical tests of the UNCD films grown under CH4/Ar/H2 (1%) plasma exhibit the lowest leakage currents (˜7 × 10-7 A/cm2) in a saline solution simulating the eye environment. This leakage is incompatible with the functionality of the first-generation artificial retinal microchip. However, the growth of UNCD on top of the

  1. Hybrid approach of ventricular assist device and autologous bone marrow stem cells implantation in end-stage ischemic heart failure enhances myocardial reperfusion

    Directory of Open Access Journals (Sweden)

    Khayat Andre


    Full Text Available Abstract We challenge the hypothesis of enhanced myocardial reperfusion after implanting a left ventricular assist device together with bone marrow mononuclear stem cells in patients with end-stage ischemic cardiomyopathy. Irreversible myocardial loss observed in ischemic cardiomyopathy leads to progressive cardiac remodelling and dysfunction through a complex neurohormonal cascade. New generation assist devices promote myocardial recovery only in patients with dilated or peripartum cardiomyopathy. In the setting of diffuse myocardial ischemia not amenable to revascularization, native myocardial recovery has not been observed after implantation of an assist device as destination therapy. The hybrid approach of implanting autologous bone marrow stem cells during assist device implantation may eventually improve native cardiac function, which may be associated with a better prognosis eventually ameliorating the need for subsequent heart transplantation. The aforementioned hypothesis has to be tested with well-designed prospective multicentre studies.

  2. Nutrition Assessment With Indirect Calorimetry in Patients Evaluated for Left Ventricular Assist Device Implantation. (United States)

    Yost, Gardner; Gregory, Mary; Bhat, Geetha


    Malnutrition is known to negatively impact the clinical course of advanced heart failure and is associated with increased mortality following left ventricular assist device (LVAD) implantation. Appropriate assessment of nutrition requirements in these patients is critical in their clinical care, yet there has been little discussion on how to best determine resting energy expenditure (REE) in the hospital setting. We investigated the use of indirect calorimetry in a group of patients with advanced heart failure. Results from preoperative indirect calorimetry testing in 98 patients undergoing evaluation for LVAD candidacy were collected. REE was compared with 10 predictive equations that estimated caloric need based on a range of patient-specific demographic and clinical variables. This study enrolled 22 female and 76 male patients with a mean age of 59.4 ± 12.5 years, body mass index of 29.6 ± 6.0 kg/m(2), and ejection fraction of 19.4 ± 6.6%. The average REE by indirect calorimetry in this group was 1610.0 ± 612.7 kcal/d. All predictive equations significantly overestimated REE. However, those equations intended for use in the critically ill demonstrated the greatest accuracy, with the Brandi equation achieving both the highest correlation (r = 0.605, P calorimetry may be reliably and safely used to determine caloric requirements in patients with advanced heart failure. The use of predictive equations based on demographic and clinical parameters appears to generate inaccurate estimations of REE in these patients. However, equations designed for use in critically ill patients better estimate nutrition requirements than those designed for healthy individuals. © 2015 American Society for Parenteral and Enteral Nutrition.

  3. Electronic health records and cardiac implantable electronic devices: new paradigms and efficiencies. (United States)

    Slotwiner, David J


    The anticipated advantages of electronic health records (EHRs)-improved efficiency and the ability to share information across the healthcare enterprise-have so far failed to materialize. There is growing recognition that interoperability holds the key to unlocking the greatest value of EHRs. Health information technology (HIT) systems including EHRs must be able to share data and be able to interpret the shared data. This requires a controlled vocabulary with explicit definitions (data elements) as well as protocols to communicate the context in which each data element is being used (syntactic structure). Cardiac implantable electronic devices (CIEDs) provide a clear example of the challenges faced by clinicians when data is not interoperable. The proprietary data formats created by each CIED manufacturer, as well as the multiple sources of data generated by CIEDs (hospital, office, remote monitoring, acute care setting), make it challenging to aggregate even a single patient's data into an EHR. The Heart Rhythm Society and CIED manufacturers have collaborated to develop and implement international standard-based specifications for interoperability that provide an end-to-end solution, enabling structured data to be communicated from CIED to a report generation system, EHR, research database, referring physician, registry, patient portal, and beyond. EHR and other health information technology vendors have been slow to implement these tools, in large part, because there have been no financial incentives for them to do so. It is incumbent upon us, as clinicians, to insist that the tools of interoperability be a prerequisite for the purchase of any and all health information technology systems.

  4. Influence of electromagnetic interference on implanted cardiac arrhythmia devices in and around a magnetically levitated linear motor car. (United States)

    Fukuta, Motoyuki; Mizutani, Noboru; Waseda, Katsuhisa


    This study was designed to determine the susceptibility of implanted cardiac arrhythmia devices to electromagnetic interference in and around a magnetically levitated linear motor car [High-Speed Surface Transport (HSST)]. During the study, cardiac devices were connected to a phantom model that had similar characteristics to the human body. Three pacemakers from three manufacturers and one implantable cardioverter-defibrillator (ICD) were evaluated in and around the magnetically levitated vehicle. The system is based on a normal conductive system levitated by the attractive force of magnets and propelled by a linear induction motor without wheels. The magnetic field strength at 40 cm from the vehicle in the nonlevitating state was 0.12 mT and that during levitation was 0.20 mT. The magnetic and electric field strengths on a seat close to the variable voltage/variable frequency inverter while the vehicle was moving and at rest were 0.13 mT, 2.95 V/m and 0.04 mT, 0.36 V/m, respectively. Data recorded on a seat close to the reactor while the vehicle was moving and at rest were 0.09 mT, 2.45 V/m and 0.05 mT, 1.46 V/m, respectively. Measured magnetic and electric field strengths both inside and outside the linear motor car were too low to result in device inactivation. No sensing, pacing, or arrhythmic interactions were noted with any pacemaker or ICD programmed in either bipolar and unipolar configurations. In conclusion, our data suggest that a permanent programming change or a device failure is unlikely to occur and that the linear motor car system is probably safe for patients with one of the four implanted cardiac arrhythmia devices used in this study under the conditions tested.

  5. Radiotherapy-Induced Cardiac Implantable Electronic Device Dysfunction in Patients With Cancer. (United States)

    Bagur, Rodrigo; Chamula, Mathilde; Brouillard, Émilie; Lavoie, Caroline; Nombela-Franco, Luis; Julien, Anne-Sophie; Archambault, Louis; Varfalvy, Nicolas; Gaudreault, Valérie; Joncas, Sébastien X; Israeli, Zeev; Parviz, Yasir; Mamas, Mamas A; Lavi, Shahar


    Radiotherapy can affect the electronic components of a cardiac implantable electronic device (CIED) resulting in malfunction and/or damage. We sought to assess the incidence, predictors, and clinical impact of CIED dysfunction (CIED-D) after radiotherapy for cancer treatment. Clinical characteristics, cancer, different types of CIEDs, and radiation dose were evaluated. The investigation identified 230 patients, mean age 78 ± 8 years and 70% were men. A total of 199 patients had pacemakers (59% dual chamber), 21 (9%) cardioverter-defibrillators, and 10 (4%) resynchronizators or defibrillators. The left pectoral (n = 192, 83%) was the most common CIED location. Sixteen patients (7%) experienced 18 events of CIED-D after radiotherapy. Reset to backup pacing mode was the most common encountered dysfunction, and only 1 (6%) patient of those with CIED-D experienced symptoms of atrioventricular dyssynchrony. Those who had CIED-D tended to have a shorter device age at the time of radiotherapy compared to those who did not (2.5 ± 1.5 vs 3.8 ± 3.4 years, p = 0.09). The total dose prescribed to the tumor was significantly greater among those who had CIED-D (66 ± 30 vs 42 ± 23 Gy, p <0.0001). Multivariate logistic regression analysis identified the total dose prescribed to the tumor as the only independent predictor for CIED-D (odds ratio 1.19 for each increase in 5 Gy, 95% confidence interval 1.08 to 1.31, p = 0.0005). In conclusion, in this large population of patients with CIEDs undergoing radiotherapy for cancer treatment, the occurrence of newly diagnosed CIED-D was 7%, and the reset to backup pacing mode was the most common encountered dysfunction. The total dose prescribed to the tumor was a predictor of CIED-D. Importantly, although the unpredictability of CIEDs under radiotherapy is still an issue, none of our patients experienced significant symptoms, life-threatening arrhythmias, or conduction disorders.

  6. Strain shielding in distal radius after wrist arthroplasty with a current generation implant: An in vitro analysis. (United States)

    Completo, A; Pereira, J; Nascimento, A; Almeida, F


    A systematic review of peer reviewed articles has shown that the main cause for wrist arthroplasty revision is carpal and radial prosthetic loosening and instability. To improve arthroplasty outcomes, successive generations of implants have been developed over time. The problem with the current generation of implants is the lack of long-term outcomes data. The aim of the present work was to test the hypothesis that the current generation Maestro WRS implant has a stress, strain and stability behaviour which may be associated with a reduced risk of long-term radial component loosening. This study was performed using synthetic radii to experimentally predict the cortex strain behaviour and implant stability considering different load conditions for both intact and implanted conditions. Finite element models were developed to assess the structural behaviour of cancellous-bone and bone-cement, these models were validated against experimentally measured cortex strains. Measured cortex strains showed a significant reduction between intact and implanted states. Cancellous bone adjacent to the radial body component suffers a two to threefold strain reduction, comparing with the intact condition, while along the radial stem, in the axial direction, a strain increase was observed. It is concluded that the use of contemporary Maestro WRS implant changes the biomechanical behaviour of the radius and is associated with a potential risk of bone resorption by stress-shielding in the distal radius region for wrist loads in the range of daily activities.

  7. Electronic heat current rectification in hybrid superconducting devices

    Energy Technology Data Exchange (ETDEWEB)

    Fornieri, Antonio, E-mail:; Giazotto, Francesco, E-mail: [NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa (Italy); Martínez-Pérez, María José [Physikalisches Institut - Experimentalphysik II Universität Tübingen, D-72076 Tübingen (Germany)


    In this work, we review and expand recent theoretical proposals for the realization of electronic thermal diodes based on tunnel-junctions of normal metal and superconducting thin films. Starting from the basic rectifying properties of a single hybrid tunnel junction, we will show how the rectification efficiency can be largely increased by combining multiple junctions in an asymmetric chain of tunnel-coupled islands. We propose three different designs, analyzing their performance and their potential advantages. Besides being relevant from a fundamental physics point of view, this kind of devices might find important technological application as fundamental building blocks in solid-state thermal nanocircuits and in general-purpose cryogenic electronic applications requiring energy management.

  8. Biological effects of an impulse current according to laboratory researches of electroshock devices

    Directory of Open Access Journals (Sweden)

    Grigoryev О.A.


    Full Text Available The federal law "About Weapons" permits the use of electroshock devices if they are safe for people. We developed requirements for the procedure medical-biological testing on the safety of electroshock devices. We did an experimental study assessing medical-biological safety of electroshock devices. The assessment is based on a point system, which use ranges of biological effects. The experiments were performed in rabbits. We used 13 electroshock devices with different characteristics. Electroshock devices were made in Russia. We found that the response of a biological object to inrush current included convulsions, respiratory and cardiac activity. We analyzed the biological effects of pulsed current electroshock device obtained in experimental conditions. It is concluded that the characteristic clinical and physiological response to the action of electric current is pulsepolyparametric and depending on a combination of characteristics and condition of the electric impulse influence object.

  9. Left atrial appendage closure device implantation and pulmonary vein isolation as a comprehensive treatment for atrial fibrillation

    Directory of Open Access Journals (Sweden)

    А. А. Якубов


    Full Text Available Objective. This randomized clinical trial was designed to assess the impact of pulmonary vein isolation (PVI combined with LAA occlusion on patients with high-risk AF. Methods. Patients with a history of symptomatic paroxysmal (P AF and/or persistent (Pers AF and CHA2DS2-VASc score ≥2 and HAS-BLED score ≥3 were randomized in groups with PVI only (n = 44 and PVI combined with LAA occlusion (n = 45. All patients were followed during 24 months in order to evaluate the safety of thromboembolic complications and to monitor the heart rhythm conducted by means of an implantable cardiac monitor. Results. 6 patients from the PVI with LAA occlusion group were transferred to the PVI only group because of a failure to implant a LAA closure device. Based on ILR data, by the end of the follow-up 33 (66% out of 50 patients in the PVI only group and 23 (59% out of 39 patients in the PVI with LAA closure device implantation group were free from atrial fibrillation and flutter without antiarrhythmic drugs (p = 0.34. In the blanking period, AF% was significantly higher in the PVI with LAA closure group than that in the PVI-only group, 9.7±10.8 and 4.2±4.1% respectively (p = 0.004. After the blanking period, the AF% was similar in both groups. During the entire follow-up, no AF/intervention-related complications were observed. Conclusion. The combination of LAA closure device implantation with PVI seems to be a safe procedure. However, it does not improve the efficacy of PVI in patients with symptomatic refractory AF. But in the blanking period LAA occlusion increases AF %.

  10. Implantable Microimagers

    Directory of Open Access Journals (Sweden)

    Jun Ohta


    Full Text Available Implantable devices such as cardiac pacemakers, drug-delivery systems, and defibrillators have had a tremendous impact on the quality of live for many disabled people. To date, many devices have been developed for implantation into various parts of the human body. In this paper, we focus on devices implanted in the head. In particular, we describe the technologies necessary to create implantable microimagers. Design, fabrication, and implementation issues are discussed vis-à-vis two examples of implantable microimagers; the retinal prosthesis and in vivo neuro-microimager. Testing of these devices in animals verify the use of the microimagers in the implanted state. We believe that further advancement of these devices will lead to the development of a new method for medical and scientific applications.

  11. First audiometric results with the Vibrant soundbridge, a semi-implantable hearing device for sensorineural hearing loss. (United States)

    Snik, A F; Cremers, C W


    The Vibrant soundbridge is a semi-implantable hearing device. The implanted electromagnetic transducer is attached to the incus and it is linked by telemetry to the externally worn audio processor. In Nijmegen, this device has been applied to seven patients with moderate or severe sensorineural hearing loss (PTA between 43 and 71 dB HL) who could not tolerate ear moulds. As the amplification of the device depends on the input level (amplifier with wide dynamic range compression), loudness scaling measurements were performed. The gain as a function of input level was determined from aided and unaided loudness growth curves. The mean gain was 21 dB at an input level of 40 dB SPL. The mean gain decreased to 5 dB at an input level of 90 dB SPL. Measured gain values were lower than target values prescribed by the FIG6 method, mainly however for the low-frequency range and for low-level sounds. It was concluded that this device is very promising for patients who cannot tolerate an ear mould.

  12. Mastoid cavity dimensions and shape: method of measurement and virtual fitting of implantable devices. (United States)

    Handzel, Ophir; Wang, Haobing; Fiering, Jason; Borenstein, Jeffrey T; Mescher, Mark J; Swan, Erin E Leary; Murphy, Brian A; Chen, Zhiqiang; Peppi, Marcello; Sewell, William F; Kujawa, Sharon G; McKenna, Michael J


    Temporal bone implants can be used to electrically stimulate the auditory nerve, to amplify sound, to deliver drugs to the inner ear and potentially for other future applications. The implants require storage space and access to the middle or inner ears. The most acceptable space is the cavity created by a canal wall up mastoidectomy. Detailed knowledge of the available space for implantation and pathways to access the middle and inner ears is necessary for the design of implants and successful implantation. Based on temporal bone CT scans a method for three-dimensional reconstruction of a virtual canal wall up mastoidectomy space is described. Using Amira software the area to be removed during such surgery is marked on axial CT slices, and a three-dimensional model of that space is created. The average volume of 31 reconstructed models is 12.6 cm(3) with standard deviation of 3.69 cm(3), ranging from 7.97 to 23.25 cm(3). Critical distances were measured directly from the model and their averages were calculated: height 3.69 cm, depth 2.43 cm, length above the external auditory canal (EAC) 4.45 cm and length posterior to EAC 3.16 cm. These linear measurements did not correlate well with volume measurements. The shape of the models was variable to a significant extent making the prediction of successful implantation for a given design based on linear and volumetric measurement unreliable. Hence, to assure successful implantation, preoperative assessment should include a virtual fitting of an implant into the intended storage space. The above-mentioned three-dimensional models were exported from Amira to a Solidworks application where virtual fitting was performed. Our results are compared to other temporal bone implant virtual fitting studies. Virtual fitting has been suggested for other human applications.

  13. Autonomous Method and System for Minimizing the Magnitude of Plasma Discharge Current Oscillations in a Hall Effect Plasma Device (United States)

    Hruby, Vladimir (Inventor); Demmons, Nathaniel (Inventor); Ehrbar, Eric (Inventor); Pote, Bruce (Inventor); Rosenblad, Nathan (Inventor)


    An autonomous method for minimizing the magnitude of plasma discharge current oscillations in a Hall effect plasma device includes iteratively measuring plasma discharge current oscillations of the plasma device and iteratively adjusting the magnet current delivered to the plasma device in response to measured plasma discharge current oscillations to reduce the magnitude of the plasma discharge current oscillations.

  14. A Rat Model of Thrombosis in Common Carotid Artery Induced by Implantable Wireless Light-Emitting Diode Device

    Directory of Open Access Journals (Sweden)

    Jih-Chao Yeh


    Full Text Available This work has developed a novel approach to form common carotid artery (CCA thrombus in rats with a wireless implantable light-emitting diode (LED device. The device mainly consists of an external controller and an internal LED assembly. The controller was responsible for wirelessly transmitting electrical power. The internal LED assembly served as an implant to receive the power and irradiate light on CCA. The thrombus formation was identified with animal sonography, 7T magnetic resonance imaging, and histopathologic examination. The present study showed that a LED assembly implanted on the outer surface of CCA could induce acute occlusion with single irradiation with 6 mW/cm2 LED for 4 h. If intermittent irradiation with 4.3–4.5 mW/cm2 LED for 2 h was shut off for 30 min, then irradiation for another 2 h was applied; the thrombus was observed to grow gradually and was totally occluded at 7 days. Compared with the contralateral CCA without LED irradiation, the arterial endothelium in the LED-irradiated artery was discontinued. Our study has shown that, by adjusting the duration of irradiation and the power intensity of LED, it is possible to produce acute occlusion and progressive thrombosis, which can be used as an animal model for antithrombotic drug development.

  15. Numerical evaluation of implantable hearing devices using a finite element model of human ear considering viscoelastic properties. (United States)

    Zhang, Jing; Tian, Jiabin; Ta, Na; Huang, Xinsheng; Rao, Zhushi


    Finite element method was employed in this study to analyze the change in performance of implantable hearing devices due to the consideration of soft tissues' viscoelasticity. An integrated finite element model of human ear including the external ear, middle ear and inner ear was first developed via reverse engineering and analyzed by acoustic-structure-fluid coupling. Viscoelastic properties of soft tissues in the middle ear were taken into consideration in this model. The model-derived dynamic responses including middle ear and cochlea functions showed a better agreement with experimental data at high frequencies above 3000 Hz than the Rayleigh-type damping. On this basis, a coupled finite element model consisting of the human ear and a piezoelectric actuator attached to the long process of incus was further constructed. Based on the electromechanical coupling analysis, equivalent sound pressure and power consumption of the actuator corresponding to viscoelasticity and Rayleigh damping were calculated using this model. The analytical results showed that the implant performance of the actuator evaluated using a finite element model considering viscoelastic properties gives a lower output above about 3 kHz than does Rayleigh damping model. Finite element model considering viscoelastic properties was more accurate to numerically evaluate implantable hearing devices.

  16. Comparison of the Edwards SAPIEN S3 Versus Medtronic Evolut-R Devices for Transcatheter Aortic Valve Implantation. (United States)

    Ben-Shoshan, Jeremy; Konigstein, Maayan; Zahler, David; Margolis, Gilad; Chorin, Ehud; Steinvil, Arie; Arbel, Yaron; Aviram, Galit; Granot, Yoav; Barkagan, Michael; Keren, Gad; Halkin, Amir; Banai, Shmuel; Finkelstein, Ariel


    New generation of the most widely used devices for transcatheter aortic valve implantation have been recently introduced into practice. We compare the short-term outcomes of transcatheter aortic valve implantation with the Edwards SAPIEN S3 and the Medtronic Evolut-R. We performed a retrospective analysis from a single high-volume tertiary center. Valve Academic Research Consortium-2 criteria were used to define composite end points of device success and safety at 30 days. Study population included 232 patients implanted with the SAPIEN S3 (n = 124) and Evolut-R (n = 108). Device success reached 91.9% and 95.4% in the SAPIEN S3 and Evolut-R groups, respectively (p = 0.289). Postprocedural echocardiography showed greater aortic valve gradients (22.8 ± 7 vs 16 ± 9 mm Hg, p <0.001) among SAPIEN S3 group. Paravalvular leak of ≥ moderate severity was observed in 2.4% and 0% in the SAPIEN S3 and Evolut-R groups, respectively (p = 0.251). Similar rates of in-hospital complications, including major bleedings, vascular complications, and pacemaker implantations were recorded in both groups. At 30-day follow-up, the combined safety end point was reached in 5.6% and in 6.5% of patients in the SAPIEN S3 and Evolut-R groups, respectively (p = 0.790). During follow-up of 237 ± 138 days, all-cause mortality was higher in patients implanted with Evolut-R compared with SAPIEN S3 (7 vs 1 cases, respectively, p = 0.006), however, cardiovascular mortality was not significantly different between groups. In conclusions, in a single-center comparative analysis, comparable rate of device success as well as safety profile and long-term cardiovascular mortality were observed with the SAPIEN S3 and Evolut-R valves. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Albumin coatings by alternating current electrophoretic deposition for improving corrosion resistance and bioactivity of titanium implants. (United States)

    Höhn, Sarah; Braem, Annabel; Neirinck, Bram; Virtanen, Sannakaisa


    Although Ti alloys are generally regarded to be highly corrosion resistant, inflammatory conditions following surgery can instigate breakdown of the TiO2 passivation layer leading to an increased metal ion release. Furthermore proteins present in the surrounding tissue will readily adsorb on a titanium surface after implantation. In this paper alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin (BSA) on Ti6Al4V was investigated in order to increase the corrosion resistance and control the protein adsorption capability of the implant surface. The Ti6Al4V surface was characterized with SEM, XPS and ToF-SIMS after long-term immersion tests under physiological conditions and simulated inflammatory conditions either in Dulbecco's Modified Eagle Medium (DMEM) or DMEM supplemented with fetal calf serum (FCS). The analysis showed an increased adsorption of amino acids and proteins from the different immersion solutions. The BSA coating was shown to prevent selective dissolution of the vanadium (V) rich β-phase, thus effectively limiting metal ion release to the environment. Electrochemical impedance spectroscopy measurements confirmed an increase of the corrosion resistance for BSA coated surfaces as a function of immersion time due to the time-dependent adsorption of the different amino acids (from DMEM) and proteins (from FCS) as observed by ToF-SIMS analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Role of {sup 18}F-FDG PET/CT in the diagnosis of infective endocarditis in patients with an implanted cardiac device: a prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Graziosi, Maddalena; Lorenzini, Massimiliano; Diemberger, Igor; Pasquale, Ferdinando; Ziacchi, Matteo; Biffi, Mauro; Martignani, Cristian; Boriani, Giuseppe; Rapezzi, Claudio [Alma Mater-University of Bologna, and S. Orsola-Malpighi Hospital, Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, Bologna (Italy); Nanni, Cristina; Bonfiglioli, Rachele; Fanti, Stefano [Alma Mater-University of Bologna, and S. Orsola-Malpighi Hospital, Nuclear Medicine Unit, Department of Experimental, Diagnostic and Specialty Medicine, Bologna (Italy); Bartoletti, Michele; Tumietto, Fabio; Viale, Pier Luigi [Alma Mater-University of Bologna, and S. Orsola-Malpighi Hospital, Infectious Diseases Unit, Department of Medical and Surgical Sciences, Bologna (Italy)


    Infective endocarditis (IE) is widely underdiagnosed or diagnosed after a major delay. The diagnosis is currently based on the modified DUKE criteria, where the only validated imaging technique is echocardiography, and remains challenging especially in patients with an implantable cardiac device. The aim of this study was to assess the incremental diagnostic role of {sup 18}F-FDG PET/CT in patients with an implanted cardiac device and suspected IE. We prospectively analysed 27 consecutive patients with an implantable device evaluated for suspected device-related IE between January 2011 and June 2013. The diagnostic probability of IE was defined at presentation according to the modified DUKE criteria. PET/CT was performed as soon as possible following the clinical suspicion of IE. Patients then underwent medical or surgical treatment based on the overall clinical evaluation. During follow-up, we considered: lead cultures in patients who underwent extraction, direct inspection and lead cultures in those who underwent surgery, and a clinical/instrumental reevaluation after at least 6 months in patients who received antimicrobial treatment or had an alternative diagnosis and were not treated for IE. After the follow-up period, the diagnosis was systematically reviewed by the multidisciplinary team using the modified DUKE criteria and considering the new findings. Among the ten patients with a positive PET/CT scan, seven received a final diagnosis of ''definite IE'', one of ''possible IE'' and two of ''IE rejected''. Among the 17 patients with a negative PET/CT scan, four were false-negative and received a final diagnosis of definite IE. These patients underwent PET/CT after having started antibiotic therapy (≥48 h) or had a technically suboptimal examination. In patients with a cardiac device, PET/CT increases the diagnostic accuracy of the modified Duke criteria for IE, particularly in the subset of

  19. Totally implantable artificial hearts and left ventricular assist devices: selecting impermeable polycarbonate urethane to manufacture ventricles. (United States)

    Yang, M; Zhang, Z; Hahn, C; Laroche, G; King, M W; Guidoin, R


    In the development of a new generation of totally implantable artificial hearts and left ventricular assist devices (VADs) for long-term use, the selection of an acceptable material for the fabrication of the ventricles probably represents one of the greatest challenges. Segmented polyether urethanes used to be the material of choice due to their superior flexural performance, acceptable blood compatibility, and ease of processing. However, because they are known to degrade and to be readily permeable to water, they cannot meet the rigorous requirements needed for a new generation of implantable artificial hearts and VADs. Therefore, the objective of the present study was to identify alternative polymeric materials that would be satisfactory for fabricating the ventricles, and in particular, to determine the water permeability through membranes made from four commercial polycarbonate urethanes (Carbothane PC3570A, Chronoflex AR, Corethane 80A, and Corethane 55D) in comparison to those made from two traditional polyether urethanes (Tecoflex EG80A and Tecothane TT-1074A). In addition to determining the rate of water transmission through the six membranes by exposing them to deionized water, saline, and albumin-Krebs solution under pressure and measuring the displacement of liquid by means of a recently developed capillary method, the inherent surface and chemical properties of the six membranes were characterized by SEM, contact angle measurements, FTIR, DSC, and GPC techniques. The results of the study demonstrated that the rate of water transmission through the four polycarbonate urethane membranes was significantly lower than through the two polyether urethanes. In fact the lowest values were recorded with the two Corethane membranes, and the harder type 55D polymer had a lower value (2.7 x 10(-7) g/s cm2) than the softer 80A version (3.3 x 10(-7) g/s cm2). This level of water vapor permeability, which appears to be controlled primarily by a Fickian diffusion

  20. SU-E-T-570: Management of Radiation Oncology Patients with Cochlear Implant and Other Bionic Devices in the Brain and Head and Neck Regions

    Energy Technology Data Exchange (ETDEWEB)

    Guo, F.Q; Chen, Z; Nath, R [Yale New Haven Hospital, New Haven, CT (United States); Yale UniversitySchool of Medicine, New Haven, CT (United States)


    Purpose: To investigate the current status of clinical usage of cochlear implant (CI) and other bionic devices (BD) in the brain and head and neck regions (BH and N) and their management in patients during radiotherapy to ensure patient health and safety as well as optimum radiation delivery. Methods: Literature review was performed with both CIs and radiotherapy and their variants as keywords in PubMed, INSPEC and other sources. The focus was on CIs during radiotherapy, but it also included other BDs in BHȦN, such as auditory brainstem implant, bionic retinal implant, and hearing aids, among others. Results: Interactions between CIs and radiation may cause CIs malfunction. The presence of CIs may also cause suboptimum dose distribution if a treatment plan was not well designed. A few studies were performed for the hearing functions of CIs under irradiations of 4 MV and 6 MV x-rays. However, x-rays with higher energies (10 to 18 MV) broadly used in radiotherapy have not been explored. These higher energetic beams are more damaging to electronics due to strong penetrating power and also due to neutrons generated in the treatment process. Modern CIs are designed with more and more complicated integrated circuits, which may be more susceptible to radiation damage and malfunction. Therefore, careful management is important for safety and treatment outcomes. Conclusion: Although AAPM TG-34, TG-63, and TG-203 (update of TG-34, not published yet) reports may be referenced for management of CIs and other BDs in the brain and H and N regions, a site- and device-specified guideline should be developed for CIs and other BDs. Additional evaluation of CI functions under clinically relevant set-ups should also be performed to provide clinicians with better knowledge in clinical decision making.

  1. Mathematical Modeling of Eddy-Current Loss for a New Induction Heating Device

    Directory of Open Access Journals (Sweden)

    Hai Du


    Full Text Available A new induction heating device is presented in this paper. This device can convert mechanical energy into heat energy by utilizing eddy currents, which are induced by rotating permanent magnets. A mathematical model is established for estimating eddy-current loss of the device. The distribution of induced currents and the resultant magnetic field intensity are considered in the process of modeling the eddy-current loss and so is the mutual influence of the electric field between neighborhood pole projection areas. Particularly, the skin effect is considered by correcting the numerical integral domain of eddy current density, which has great effect on the calculating results. Based on specific examples, the effectiveness and correctness of proposed model are proved by finite element analysis. The results show that the mathematical model can provide important reference for design and structure optimization of the device.

  2. Multimodality Imaging of the Long-term Vascular Responses Following Implantation of Metallic and Bioresorbable Devices

    NARCIS (Netherlands)

    V.D. Gkogkas (Vasileios)


    markdownabstract__Abstract__ The pattern of vascular responses following stent/scaffold implantation in conventional interventional practice has been assessed by coronary angiography, intravascular ultrasound or optical coherence tomography and manifests as in-stent vascular response (focal or dif

  3. Energy-efficient adaptive modulation in wireless communication for implanted medical devices. (United States)

    Qiu, Yinyue; Haley, David; Chen, Ying


    In contrast to conventional wireless communication which takes place over the air, Radio Frequency (RF) communication through the human body poses unique challenges. Studies on RF propagation through human body indicate that the heterogeneous body tissues with different dielectric properties constitute a complicated and lossy environment for signal propagation. This environment also varies with different implant positions, individuals, body shapes and postures. As a result, there is a large variation in the path loss value of the in-body communication channel. In this paper, we first examine the energy efficiency of different digital modulation schemes in a basic wireless implant system. We point out that using a fixed type of modulation does not help to achieve the best energy efficiency in the implant system that has varying channel conditions. We then propose an adaptive communication system model which is suitable for wireless medical implant. Simulations results show that adopting adaptive modulation can provide a considerable amount of energy saving.

  4. Study of damage formation and annealing of implanted III-nitride semiconductors for optoelectronic devices (United States)

    Faye, D. Nd.; Fialho, M.; Magalhães, S.; Alves, E.; Ben Sedrine, N.; Rodrigues, J.; Correia, M. R.; Monteiro, T.; Boćkowski, M.; Hoffmann, V.; Weyers, M.; Lorenz, K.


    An n-GaN/n-AlGaN/p-GaN light emitting diode (LED) structure was implanted with Eu ions. High temperature high pressure annealing at 1400 °C efficiently decreases implantation damage and optically activates the Eu ions. However, the electrical properties of the p-n junction deteriorate possibly due to the formation of conducting paths along dislocations during the extreme annealing conditions.

  5. Where Does It Lead? Imaging Features of Cardiovascular Implantable Electronic Devices on Chest Radiograph and CT

    Energy Technology Data Exchange (ETDEWEB)

    Lanzman, Rotem S.; Blondin, Dirk; Furst, Gunter; Scherer, Axel; R Miese, Falk; Kroepil, Patric [University of Duesseldorf, Medical Faculty, 40225 Duesseldorf (Germany); Winter, Joachim [University Hospital Duesseldorf, 40225 Duesseldorf (Germany); Abbara, Suhny [Massachusetts General Hospital, Boston, MA (US)


    Pacemakers and implantable cardioverter defibrillators (ICDs) are being increasingly employed in patients suffering from cardiac rhythm disturbances. The principal objective of this article is to familiarize radiologists with pacemakers and ICDs on chest radiographs and CT scans. Therefore, the preferred lead positions according to pacemaker types and anatomic variants are introduced in this study. Additionally, the imaging features of incorrect lead positions and defects, as well as complications subsequent to pacemaker implantation are demonstrated herein.

  6. Study of damage formation and annealing of implanted III-nitride semiconductors for optoelectronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Faye, D. Nd.; Fialho, M.; Magalhães, S.; Alves, E. [IPFN, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 2695-066 Bobadela LRS (Portugal); Ben Sedrine, N.; Rodrigues, J.; Correia, M.R.; Monteiro, T. [Departamento de Física e I3N, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Boćkowski, M. [Institute of High Pressure Physics, Polish Academy of Sciences, 01-142 Warsaw (Poland); Hoffmann, V.; Weyers, M. [Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin (Germany); Lorenz, K., E-mail: [IPFN, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 2695-066 Bobadela LRS (Portugal)


    An n-GaN/n-AlGaN/p-GaN light emitting diode (LED) structure was implanted with Eu ions. High temperature high pressure annealing at 1400 °C efficiently decreases implantation damage and optically activates the Eu ions. However, the electrical properties of the p–n junction deteriorate possibly due to the formation of conducting paths along dislocations during the extreme annealing conditions.

  7. Telemetry and Telestimulation via Implanted Devices Necessary in Long-Term Experiments Using Conscious Untethered Animals for the Development of New Medical Treatments (United States)

    Sugimachi, Masaru; Kawada, Toru; Uemura, Kazunori

    Effective countermeasures against explosive increase in healthcare expenditures are urgently needed. A paradigm shift in healthcare is called for, and academics and governments worldwide are working hard on the application of information and communication technologies (ICT) as a feasible and effective measure for reducing medical cost. The more prevalent the disease and the easier disease outcome can be improved, the more efficient is medical ICT in reducing healthcare cost. Hypertension and diabetes mellitus are such examples. Chronic heart failure is another disease in which patients may benefit from ICT-based medical practice. It is conceivable that daily monitoring of hemodynamics together with appropriate treatments may obviate the expensive hospitalization. ICT potentially permit continuous monitoring with wearable or implantable medical devices. ICT may also help accelerate the development of new therapeutic devices. Traditionally effectiveness of treatments is sequentially examined by sacrificing a number of animals at a given time point. These inefficient and inaccurate methods can be replaced by applying ICT to the devices used in chronic animal experiments. These devices allow researchers to obtain biosignals and images from live animals without killing them. They include implantable telemetric devices, implantable telestimulation devices, and imaging devices. Implanted rather than wired monitoring and stimulation devices permit experiments to be conducted under even more physiological conditions, i.e., untethered, free-moving states. Wireless communication and ICT are indispensible technologies for the development of such telemetric and telestimulation devices.

  8. Predictors of changes in health status between and within patients 12 months post left ventricular assist device implantation

    DEFF Research Database (Denmark)

    Brouwers, Corline; de Jonge, Nicolaas; Caliskan, Kadir;


    LVAD implantation. METHODS: Health status [Kansas City Cardiomyopathy Questionnaire (KCCQ); Short-Form 12 (SF-12)] were assessed at 3-4 weeks after implantation, and at 3, 6 and 12 months follow up in 54 LVAD patients (74% men; mean age 54 ± 9 years). RESULTS: Patients experienced significant......BACKGROUND: Improving patient-reported outcomes (e.g. health status) has become an important goal in left ventricular assist device (LVAD) therapy, in addition to reducing mortality and morbidity. We examined predictors of changes in health status scores between and within patients 12 months post...... improvements in health status between baseline and 3 months follow-up as assessed by the KCCQ (clinical summary score: F = 33.49, P 12 (physical component score: F = 31.59, P 

  9. Microwave annealing, a low-thermal-budget process for dopant activation in phosphorus-implanted MOSFET devices (United States)

    Lim, Cheol-Min; Cho, Won-Ju


    In this work, we investigated a low-thermal-budget dopant activation process based on microwave annealing (MWA) of phosphorus ions implanted by plasma doping and compared the proposed technique with the conventional furnace annealing and the rapid thermal annealing processes. We fabricated p-n junction diodes and metal-oxide-semiconductor field-effect transistors (MOSFETs) on silicon and silicon-on-insulator substrates, respectively, in order to examine the dopant activation resulting from MWA. The investigated low-thermal-budget MWA technique proved effective for implanted dopant atom activation and diffusion suppression. In addition, a good interface property between the gate oxide and the silicon channel was achieved. Thus, low-thermal-budget MWA is a promising and effective method for the fabrication of highly-integrated semiconductor devices.

  10. Candida and cardiovascular implantable electronic devices: a case of lead and native aortic valve endocarditis and literature review. (United States)

    Glavis-Bloom, Justin; Vasher, Scott; Marmor, Meghan; Fine, Antonella B; Chan, Philip A; Tashima, Karen T; Lonks, John R; Kojic, Erna M


    Use of cardiovascular implantable electronic devices (CIED), including permanent pacemakers (PPM) and implantable cardioverter defibrillators (ICD), has increased dramatically over the past two decades. Most CIED infections are caused by staphylococci. Fungal causes are rare and their prognosis is poor. To our knowledge, there has not been a previously reported case of multifocal Candida endocarditis involving both a native left-sided heart valve and a CIED lead. Here, we report the case of a 70-year-old patient who presented with nausea, vomiting, and generalised fatigue, and was found to have Candida glabrata endocarditis involving both a native aortic valve and right atrial ICD lead. We review the literature and summarise four additional cases of CIED-associated Candida endocarditis published from 2009 to 2014, updating a previously published review of cases prior to 2009. We additionally review treatment guidelines and discuss management of CIED-associated Candida endocarditis.

  11. A multi-faceted treatment approach for anterior reconstructions using current ceramics, implants, and adhesive systems. (United States)

    Hajtó, Jan; Gehringer, Uwe; Ozcan, Mutlu


    Of all developments in dental technology, fulfilling the esthetic and functional demands of the patient, especially regarding anterior reconstructions, is still a challenge for both dentists and dental technicians. This becomes more difficult for patients with a previous treatment history that is not ideal. This case presentation demonstrates reconstruction of an anterior zirconia resin-bonded fixed dental prosthesis (RBFDP) for the mandible with a combined approach utilizing veneers for harmonized space distribution on the abutment teeth and an implant-supported zirconia fixed dental prosthesis in the anterior segment of the maxilla. Adhesive cementation of the restorations is also presented in a step-by-step approach based on the current state of the art.

  12. A High Voltage High Frequency Resonant Inverter for Supplying DBD Devices with Short Discharge Current Pulses


    Bonnin, Xavier; Brandelero, Julio; Videau, Nicolas; Piquet, Hubert; Meynard, Thierry


    International audience; In this paper, the merits of a high-frequency resonant converter for supplying dielectric barrier discharges (DBD) devices are established. It is shown that, thanks to its high-frequency operating condition, such a converter allows to supply DBD devices with short discharge current pulses, a high repetition rate, and to control the injected power. In addition, such a topology eliminates the matter of connecting a high-voltage transformer directly across the DBD device ...

  13. Challenges facing academic research in commercializing event-detector implantable devices for an in-vivo biomedical subcutaneous device for biomedical analysis (United States)

    Juanola-Feliu, E.; Colomer-Farrarons, J.; Miribel-Català, P.; Samitier, J.; Valls-Pasola, J.


    It is widely recognized that the welfare of the most advanced economies is at risk, and that the only way to tackle this situation is by controlling the knowledge economies and dealing with. To achieve this ambitious goal, we need to improve the performance of each dimension in the "knowledge triangle": education, research and innovation. Indeed, recent findings point to the importance of strategies of adding-value and marketing during R+D processes so as to bridge the gap between the laboratory and the market and so ensure the successful commercialization of new technology-based products. Moreover, in a global economy in which conventional manufacturing is dominated by developing economies, the future of industry in the most advanced economies must rely on its ability to innovate in those high-tech activities that can offer a differential added-value, rather than on improving existing technologies and products. It seems quite clear, therefore, that the combination of health (medicine) and nanotechnology in a new biomedical device is very capable of meeting these requisites. This work propose a generic CMOS Front-End Self-Powered In-Vivo Implantable Biomedical Device, based on a threeelectrode amperometric biosensor approach, capable of detecting threshold values for targeted concentrations of pathogens, ions, oxygen concentration, etc. Given the speed with which diabetes can spread, as diabetes is the fastest growing disease in the world, the nano-enabled implantable device for in-vivo biomedical analysis needs to be introduced into the global diabetes care devices market. In the case of glucose monitoring, the detection of a threshold decrease in the glucose level it is mandatory to avoid critic situations like the hypoglycemia. Although the case study reported in this paper is complex because it involves multiple organizations and sources of data, it contributes to extend experience to the best practices and models on nanotechnology applications and

  14. Current Indications for Implantable Cardioverter Defibrillators in Non-Ischemic Cardiomyopathies and Channelopathies. (United States)

    González-Torrecilla, Esteban; Arenal, Angel; Atienza, Felipe; Datino, Tomás; Bravo, Loreto; Ruiz, Pablo; Ávila, Pablo; Fernández-Avilés, Francisco


    Current indications for implantable cardioverter defibrillators (ICDs) in patients with channelopathies and cardiomyopathies of non-ischemic origin are mainly based on non-randomized evidence. In patients with nonischemic dilated cardiomyopathy (NIDCM), there is a tendency towards a beneficial effect on total mortality of ICD therapy in patients with significant left ventricular (LV) dysfunction. Although an important reduction in sudden cardiac death (SCD) seems to be clearly demonstrated in these patients, a net beneficial effect on total mortality is unclear mostly in cases with good functional status. Risk stratification has been changing over the last two decades in patients with hypertrophic cardiomyopathy (HCM). Its risk profile has been delineated in parallel with the beneficial effect of ICD in high risk patients. Observational results based on "appropriate" ICD interventions do support its usefulness both in primary and secondary SCD prevention in these patients. Novel risk models quantify the rate of sudden cardiac death in these patients on individual basis. Less clear risk stratification is available for cases of arrhythmogenic right ventricular cardiomyopathy (ARVC) and in other uncommon familiar cardiomyopathies. Main features of risk stratification vary among the different channelopathies (long QT syndrome -LQTS-, Brugada syndrome, etc) with great debate on the management of asymptomatic patients. For most familiar cardiomyopathies, ICD therapy is the only accepted strategy in the prevention of SCD. So far, genetic testing has a limited role in risk evaluation and management of the individual patient. This review aims to summarize these criticisms and to refine the current indications of ICD implantation in patients with cardiomyopathies and major channelopathies.

  15. Identifying atrial arrhythmias versus pacing-induced rhythm disorders with state-of-the-art cardiac implanted devices

    Directory of Open Access Journals (Sweden)

    Ritsuko Kohno, MD, PhD


    Full Text Available Repetitive non-reentrant ventriculo-atrial synchrony (RNRVAS is a pacemaker-induced arrhythmia that must be distinguished from atrial fibrillation (AF. Pacemaker-induced arrhythmias are commonly detected as atrial high rate episodes (AHRE by implanted cardiac devices. Two main types of atrial oversensing are recognized: far-field R-wave (FFRW oversensing and pacemaker-induced arrhythmias, which include pacemaker-mediated tachycardia and RNRVAS. The presence of ventriculo-atrial conduction is required for both types of pacemaker-induced arrhythmias. The incidence of RNRVAS can increase with the use of various device settings and functions, such as long atrioventricular (AV interval programming, the rate-adaptive mode, and the atrial overdrive pacing algorithm. The negative aspects of pacemaker-induced arrhythmias, especially RNRVAS, include (1 loss of optimal AV delay, (2 inappropriate increase in ventricular pacing, (3 induction of atrial arrhythmias, and (4 inaccurate diagnosis of AHRE. We review the incidence of arrhythmias, electrophysiological mechanisms, and the clinical diagnosis of RNRVAS identified by using dual-chamber implantable cardiac devices.

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

    Directory of Open Access Journals (Sweden)

    Chang DH


    Full Text Available De-Hua Chang,1 Sonja Hiss,1 Lena Herich,2 Ingrid Becker,2 Kamal Mammadov,1 Mareike Franke,1 Anastasios Mpotsaris,1 Robert Kleinert,3 Thorsten Persigehl,1 David Maintz,1 Christopher Bangard1 1Department of Radiology, 2Institute of Medical Statistics, Informatics and Epidemiology, 3Department of Surgery, University Hospital of Cologne, Cologne, Germany 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

  17. Titanium coated with functionalized carbon nanotubes — A promising novel material for biomedical application as an implantable orthopaedic electronic device

    Energy Technology Data Exchange (ETDEWEB)

    Przekora, Agata, E-mail: [Department of Biochemistry and Biotechnology, Medical University of Lublin, Faculty of Pharmacy with Medical Analytics Division, Chodzki 1, 20-093 Lublin (Poland); Benko, Aleksandra; Nocun, Marek; Wyrwa, Jan; Blazewicz, Marta [Faculty of Materials Science and Ceramics, AGH-Univ. of Science and Technology, A. Mickiewicz 30 Ave., 30-059 Cracow (Poland); Ginalska, Grazyna [Department of Biochemistry and Biotechnology, Medical University of Lublin, Faculty of Pharmacy with Medical Analytics Division, Chodzki 1, 20-093 Lublin (Poland)


    The aim of the study was to fabricate titanium (Ti) material coated with functionalized carbon nanotubes (f-CNTs) that would have potential medical application in orthopaedics as an implantable electronic device. The novel biomedical material (Ti-CNTs-H{sub 2}O) would possess specific set of properties, such as: electrical conductivity, non-toxicity, and ability to inhibit connective tissue cell growth and proliferation protecting the Ti-CNTs-H{sub 2}O surface against covering by cells. The novel material was obtained via an electrophoretic deposition of CNTs-H{sub 2}O on the Ti surface. Then, physicochemical, electrical, and biological properties were evaluated. Electrical property evaluation revealed that a Ti-CNTs-H{sub 2}O material is highly conductive and X-ray photoelectron spectroscopy analysis demonstrated that there are mainly COOH groups on the Ti-CNTs-H{sub 2}O surface that are found to inhibit cell growth. Biological properties were assessed using normal human foetal osteoblast cell line (hFOB 1.19). Conducted cytotoxicity tests and live/dead fluorescent staining demonstrated that Ti-CNTs-H{sub 2}O does not exert toxic effect on hFOB cells. Moreover, fluorescence laser scanning microscope observation demonstrated that Ti-CNTs-H{sub 2}O surface retards to a great extent cell proliferation. The study resulted in successful fabrication of highly conductive, non-toxic Ti-CNTs-H{sub 2}O material that possesses ability to inhibit osteoblast proliferation and thus has a great potential as an orthopaedic implantable electronic device. - Highlights: • Functionalized carbon nanotubes were electrophoretically deposited on Ti surface. • Physicochemical, electrical, and biological properties were evaluated. • Ti-CNTs-H{sub 2}O is highly conductive and there are mainly COOH groups on its surface. • Novel material is non-toxic and retards to a great extent osteoblast proliferation. • Ti-CNTs-H{sub 2}O has a promising potential as implantable orthopaedic

  18. The current situation and development of medical device testing institutes in China. (United States)

    Yang, Xiaofang; Mu, Ruihong; Fan, Yubo; Wang, Chunren; Li, Deyu


    This article analyses the current situation and development of Chinese medical device testing institutes from the perspectives of the two most important functions - testing functions and medical device standardization functions. Areas Covered: The objective of the Chinese government regulations for medical device industry is to ensure the safety and effectiveness of medical devices for Chinese patients. To support the regulation system, the Chinese government has established medical device testing institutes at different levels for example, the national, provincial, and municipal levels. These testing institutes also play an important role in technical support during medical device premarket registration and post market surveillance, they are also the vital practitioners of Chinese medical device standardization. Expert Commentary: Chinese medical device testing institutes are technical departments established by government, and serve the regulatory functions of government agency. In recent years, with the rapid development of medical device industry as well as constantly increasing international and domestic medical device market, the importance of medical device testing institute is more prominent, However, there are still some problems unsolved, such as their overall capacity remains to be improved, construction of standardization is to be strengthened, etc.

  19. Perioperative Anticoagulation of Cardiovascular Implantable Electronic Devices Implantation in Patients Receiving Long-term Anticoagulant Therapy%长期抗凝者植入心脏植入装置围手术期抗凝策略

    Institute of Scientific and Technical Information of China (English)

    姜运秋(综述); 田颖(审校)


    大量需要植入心脏植入装置的患者正在接受长期抗凝治疗,围手术期面临出血和血栓栓塞事件的双重风险,多数指南推荐根据患者血栓栓塞危险度决定抗凝方案。围手术期进行肝素桥接或双联抗血小板治疗可显著增加囊袋血肿发生的风险,而不间断华法林可能是平衡利弊的优秀策略。现对长期抗凝者心脏植入型电子装置植入围手术期抗凝策略的现状和进展进行综述。%A large proportion of patients who require cardiovascular implantable electronic devices ( CIED ) implantation surgery are receiving long-term anticoagulant therapy , undertaking risks of both hemorrhagic and thromboembolic events during perioperative period . Most guidelines recommend altering anticoagulant regimens according to thromboembolism risks .The use of perioperative heparin bridging or dual antiplatelet therapy significantly increases the risk of pocket-hematoma .Warfarin continuation appears promising in terms of balancing the pros and cons .This article aims at reviewing the current status and potential development of CIED perioperative management of anticoag -ulant therapy .

  20. Classification of methods for measuring current-voltage characteristics of semiconductor devices

    Directory of Open Access Journals (Sweden)

    Iermolenko Ia. O.


    Full Text Available It is shown that computer systems for measuring current-voltage characteristics are very important for semiconductor devices production. The main criteria of efficiency of such systems are defined. It is shown that efficiency of such systems significantly depends on the methods for measuring current-voltage characteristics of semiconductor devices. The aim of this work is to analyze existing methods for measuring current-voltage characteristics of semiconductor devices and to create the classification of these methods in order to specify the most effective solutions in terms of defined criteria. To achieve this aim, the most common classifications of methods for measuring current-voltage characteristics of semiconductor devices and their main disadvantages are considered. Automated and manual, continuous, pulse, mixed, isothermal and isodynamic methods for measuring current-voltage characteristics are analyzed. As a result of the analysis and generalization of existing methods the next classification criteria are defined: the level of automation, the form of measurement signals, the condition of semiconductor device during the measurements, and the use of mathematical processing of the measurement results. With the use of these criteria the classification scheme of methods for measuring current-voltage characteristics of semiconductor devices is composed and the most effective methods are specified.

  1. Two-year continuation of intrauterine devices and contraceptive implants in a mixed-payer setting: a retrospective review. (United States)

    Sanders, Jessica N; Turok, David K; Gawron, Lori M; Law, Amy; Wen, Lonnie; Lynen, Richard


    As the popularity of long-acting reversible contraception increases, so does the need for accurate data on method continuation in diverse clinical settings. We determined 2-year continuation rates for the levonorgestrel 52-mg intrauterine device, the copper T380A intrauterine device, and the 68-mg etonogestrel contraceptive implant in an academic healthcare system with mixed-payer reimbursement. The purpose of this study was to examine the proportion and characteristics of women who continue intrauterine device and implant use to 2 years and to relate continuation to device type when controlling for patient characteristics. This retrospective chart review assessed University of Utah Healthcare System patients who had an intrauterine device or contraceptive implant inserted between January 1, 2004, and December 31, 2012. We identified users and dates of insertions and removals by querying billing, medication, and procedural data in the Electronic Data Warehouse. Multivariable Poisson regression was conducted to estimate incidence risk ratios and to relate the probability of 2-year continuous use to device type. Data on 8603 device insertions were obtained with the following distribution: levonorgestrel 52-mg intrauterine devices (6459; 75.1%), copper T380A intrauterine devices (1136; 13.2%), and 68-mg etonogestrel implant (1008; 11.7%). Two-year continuation rates were 77.8%, 73.1%, and 75.9%, respectively. There was no statistical difference in 2-year continuation between levonorgestrel 52-mg intrauterine device users (adjusted risk ratio, 1.1; 95% confidence interval, 1.0-1.1) and 68-mg etonogestrel implant users (adjusted risk ratio, 1.1; 95% confidence interval, 1.0-1.1) compared with copper device users, after we controlled for age, Hispanic ethnicity, payer type, and year of insertion. Older-age, self-pay, or public payer insurance (reference commercial payer) and Hispanic ethnicity were associated with 2-year continuation. Three-quarters of women with an

  2. Atomic layer deposited TiO{sub 2} for implantable brain-chip interfacing devices

    Energy Technology Data Exchange (ETDEWEB)

    Cianci, E., E-mail: [Laboratorio MDM, IMM-CNR, 20864 Agrate Brianza (MB) (Italy); Lattanzio, S. [Istituto di Fisiologia, Dipartimento di Anatomia Umana e Fisiologia, Universita di Padova, 35131 Padova (Italy); Dipartimento di Ingegneria dell' Informazione, Universita di Padova, 35131 Padova (Italy); Seguini, G. [Laboratorio MDM, IMM-CNR, 20864 Agrate Brianza (Italy); Vassanelli, S. [Istituto di Fisiologia, Dipartimento di Anatomia Umana e Fisiologia, Universita di Padova, 35131 Padova (Italy); Fanciulli, M. [Laboratorio MDM, IMM-CNR, 20864 Agrate Brianza (Italy); Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano-Bicocca, 20126 Milano (Italy)


    In this paper we investigated atomic layer deposition (ALD) TiO{sub 2} thin films deposited on implantable neuro-chips based on electrolyte-oxide-semiconductor (EOS) junctions, implementing both efficient capacitive neuron-silicon coupling and biocompatibility for long-term implantable functionality. The ALD process was performed at 295 Degree-Sign C using titanium tetraisopropoxide and ozone as precursors on needle-shaped silicon substrates. Engineering of the capacitance of the EOS junctions introducing a thin Al{sub 2}O{sub 3} buffer layer between TiO{sub 2} and silicon resulted in a further increase of the specific capacitance. Biocompatibility for long-term implantable neuroprosthetic systems was checked upon in-vitro treatment.

  3. SEMICONDUCTOR DEVICES: Reducing the influence of STI on SONOS memory through optimizing added boron implantation technology (United States)

    Yue, Xu; Feng, Yan; Zhiguo, Li; Fan, Yang; Yonggang, Wang; Jianguang, Chang


    The influence of shallow trench isolation (STI) on a 90 nm polysilicon-oxide-nitride-oxide-silicon structure non-volatile memory has been studied based on experiments. It has been found that the performance of edge memory cells adjacent to STI deteriorates remarkably. The compressive stress and boron segregation induced by STI are thought to be the main causes of this problem. In order to mitigate the STI impact, an added boron implantation in the STI region is developed as a new solution. Four kinds of boron implantation experiments have been implemented to evaluate the impact of STI on edge cells, respectively. The experimental results show that the performance of edge cells can be greatly improved through optimizing added boron implantation technology.

  4. Development of an implantable wireless ECoG 128ch recording device for clinical brain machine interface. (United States)

    Matsushita, Kojiro; Hirata, Masayuki; Suzuki, Takafumi; Ando, Hiroshi; Ota, Yuki; Sato, Fumihiro; Morris, Shyne; Yoshida, Takeshi; Matsuki, Hidetoshi; Yoshimine, Toshiki


    Brain Machine Interface (BMI) is a system that assumes user's intention by analyzing user's brain activities and control devices with the assumed intention. It is considered as one of prospective tools to enhance paralyzed patients' quality of life. In our group, we especially focus on ECoG (electro-corti-gram)-BMI, which requires surgery to place electrodes on the cortex. We try to implant all the devices within the patient's head and abdomen and to transmit the data and power wirelessly. Our device consists of 5 parts: (1) High-density multi-electrodes with a 3D shaped sheet fitting to the individual brain surface to effectively record the ECoG signals; (2) A small circuit board with two integrated circuit chips functioning 128 [ch] analogue amplifiers and A/D converters for ECoG signals; (3) A Wifi data communication & control circuit with the target PC; (4) A non-contact power supply transmitting electrical power minimum 400[mW] to the device 20[mm] away. We developed those devices, integrated them, and, investigated the performance.

  5. Ventricular assist device (United States)

    VAD; RVAD; LVAD; BVAD; Right ventricular assist device; Left ventricular assist device; Biventricular assist device; Heart pump; Left ventricular assist system; LVAS; Implantable ventricular assist device

  6. Use of SIG device to accurately place permanent miniature dental implants to retain mandibular overdenture. A case report. (United States)

    Sussman, Harold I; Goodridge, Opal F


    A case of mini-dental implant insertion for retention of a mandibular overdenture in a hospitalized patient has been documented. The additional use of the SIG (drill guide) directional device in the implant placement protocol gave the practitioner more confidence and resulted in the proper alignment of the three ball-top, one-piece fixtures. The three implants were inserted exactly 1 cm apart and parallel to each other. The distal fixtures were approximately 1 cm away from the mental foramina, thereby eliminating the risk of lip paresthesia. Keeper caps were placed in the denture's intaglio after one month. The keeper caps allowed for proper retention of the overdenture. The caps also enabled the patient to easily insert and withdraw his denture, even though he displayed limited manual dexterity. The tissue response was excellent, and oral hygiene was made easier with adequate spacing of the exposed ball-tops. The overall experience for both the operator and the patient was very positive. General dentists should be able to readily master this technique and add it to their armamentarium for the benefit of all their patients.

  7. In vivo biostability of polymeric spine implants: retrieval analyses from a United States investigational device exemption study. (United States)

    Shen, Ming; Zhang, Kai; Koettig, Petra; Welch, William C; Dawson, John M


    The Dynesys System for stabilizing the lumbar spine was first surgically implanted in Europe in 1994. In 2003, a prospective, randomized, investigational device exemption clinical trial of the system for non-fusion dynamic stabilization began. Polycarbonate urethane (PCU) and polyethylene terephthalate (PET) components explanted from four patients who had participated in the study were analyzed for biostability. Components had been implanted 9-19 months. The explanted components were visually inspected and digitally photographed. Scanning electron microscopy was used to analyze the surface of the spacers. The chemical and molecular properties of the retrieved spacers and cords were quantitatively compared with lot-matched, shelf-aged, components that had not been implanted using attenuated total reflection Fourier transform infrared (FTIR) and gel permeation chromatography (GPC). FTIR analyses suggested that the explanted spacers exhibited slight surface chemical changes but were chemically unchanged below the surface and in the center. New peaks that could be attributed to biodegradation of PCU were not observed. The spectral analyses for the cords revealed that the PET cords were chemically unchanged at both the surface and the interior. Peaks associated with the PET biodegradation were not detected. GPC results did not identify changes to the distributions of molecular weights that might be attributed to biodegradation of either PCU spacers or PET cords. The explanted condition of the retrieved components demonstrated the biostability of both PCU spacers and PET cords that had been in vivo for up to 19 months.

  8. Combined percutaneous balloon mitral valvuloplasty and left atrial appendage occlusion device implantation for rheumatic mitral stenosis and atrial fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Murdoch, Dale, E-mail: [The Prince Charles Hospital, Brisbane (Australia); The University of Queensland, Brisbane (Australia); McAulay, Laura [The Prince Charles Hospital, Brisbane (Australia); Walters, Darren L. [The Prince Charles Hospital, Brisbane (Australia); The University of Queensland, Brisbane (Australia)


    Rheumatic heart disease is a common cause of cardiovascular morbidity and mortality worldwide, mostly in developing countries. Mitral stenosis and atrial fibrillation often coexist, related to both structural and inflammatory changes of the mitral valve and left atrium. Both predispose to left atrial thrombus formation, commonly involving the left atrial appendage. Thromboembolism can occur, with devastating consequences. We report the case of a 62 year old woman with rheumatic heart disease resulting in mitral stenosis and atrial fibrillation. Previous treatment with warfarin resulted in life-threatening gastrointestinal bleeding and she refused further anticoagulant therapy. A combined procedure was performed, including percutaneous balloon mitral valvuloplasty and left atrial appendage occlusion device implantation with the Atritech® Watchman® device. No thromboembolic or bleeding complications were encountered at one year follow-up. Long-term follow-up in a cohort of patients will be required to evaluate the safety and efficacy of this strategy.

  9. Lab-on-a-brain: Implantable micro-optical fluidic devices for neural cell analysis in vivo (United States)

    Takehara, Hiroaki; Nagaoka, Akira; Noguchi, Jun; Akagi, Takanori; Kasai, Haruo; Ichiki, Takanori


    The high-resolution imaging of neural cells in vivo has brought about great progress in neuroscience research. Here, we report a novel experimental platform, where the intact brain of a living mouse can be studied with the aid of a surgically implanted micro-optical fluidic device; acting as an interface between neurons and the outer world. The newly developed device provides the functions required for the long-term and high-resolution observation of the fine structures of neurons by two-photon laser scanning microscopy and the microfluidic delivery of chemicals or drugs directly into the brain. A proof-of-concept experiment of single-synapse stimulation by two-photon uncaging of caged glutamate and observation of dendritic spine shrinkage over subsequent days demonstrated a promising use for the present technology.

  10. Use of cone beam computed tomography in implant dentistry: current concepts, indications and limitations for clinical practice and research. (United States)

    Bornstein, Michael M; Horner, Keith; Jacobs, Reinhilde


    Diagnostic radiology is an essential component of treatment planning in the field of implant dentistry. This narrative review will present current concepts for the use of cone beam computed tomography imaging, before and after implant placement, in daily clinical practice and research. Guidelines for the selection of three-dimensional imaging will be discussed, and limitations will be highlighted. Current concepts of radiation dose optimization, including novel imaging modalities using low-dose protocols, will be presented. For preoperative cross-sectional imaging, data are still not available which demonstrate that cone beam computed tomography results in fewer intraoperative complications such as nerve damage or bleeding incidents, or that implants inserted using preoperative cone beam computed tomography data sets for planning purposes will exhibit higher survival or success rates. The use of cone beam computed tomography following the insertion of dental implants should be restricted to specific postoperative complications, such as damage of neurovascular structures or postoperative infections in relation to the maxillary sinus. Regarding peri-implantitis, the diagnosis and severity of the disease should be evaluated primarily based on clinical parameters and on radiological findings based on periapical radiographs (two dimensional). The use of cone beam computed tomography scans in clinical research might not yield any evident beneficial effect for the patient included. As many of the cone beam computed tomography scans performed for research have no direct therapeutic consequence, dose optimization measures should be implemented by using appropriate exposure parameters and by reducing the field of view to the actual region of interest.

  11. Physical Activity Measured With Implanted Devices Predicts Patient Outcome in Chronic Heart Failure

    NARCIS (Netherlands)

    Conraads, Viviane M.; Spruit, Martijn A.; Braunschweig, Frieder; Cowie, Martin R.; Tavazzi, Luigi; Borggrefe, Martin; Hill, Michael R. S.; Jacobs, Sandra; Gerritse, Bart; van Veldhuisen, Dirk J.


    Background- Physical activity (PA) predicts cardiovascular mortality in the population at large. Less is known about its prognostic value in patients with chronic heart failure (HF). Methods and Results- Data from 836 patients with implantable cardioverter defibrillator without or with cardiac resyn

  12. Matching Automatic Gain Control Across Devices in Bimodal Cochlear Implant Users

    NARCIS (Netherlands)

    Veugen, L.C.E.; Chalupper, J.; Snik, A.F.M.; Opstal, A.J. van; Mens, L.H.M.


    OBJECTIVES: The purpose of this study was to improve bimodal benefit in listeners using a cochlear implant (CI) and a hearing aid (HA) in contralateral ears, by matching the time constants and the number of compression channels of the automatic gain control (AGC) of the HA to the CI. Equivalent AGC

  13. Interacciones entre dispositivos cardíacos implantables y modalidades fisioterapéuticas: ¿Mito o realidad? Cardiac implantable devices and physiotherapy practices interaction: Myth or real?

    Directory of Open Access Journals (Sweden)

    Genevieve C. Digby


    Full Text Available La fisioterapia se ha transformado en una especialidad que claramente incide en la calidad de vida de nuestros pacientes. En poblaciones añosas, el uso de fisioterapia incluye múltiples modalidades para un alto número de distintas enfermedades. Varios informes sobre posibles interacciones negativas entre las distintas modalidades de fisioterapia y los dispositivos cardíacos implantables (marcapasos y cardiodesfibriladores han sido publicados en los últimos aňos. A pesar de ello, existe muy poca evidencia y guías precisas para identificar cuáles son las modalidades de fisioterapia seguras a utilizar en esta población de pacientes. En la siguiente revisión, nos propusimos resumir las interacciones documentadas entre fisioterapia y dispositivos cardíacos implantables (DCI, discutir el estándar actual de estas prácticas e identificar las principales consideraciones que existen desde la perspectiva de un servicio de electrofisiología cardíaca, para el tratamiento adecuado en estos pacientes. Finalmente, abogamos por fortalecer la colaboración entre fisioterapeutas y electrofisiólogos, con el fin de asegurar una óptima y segura atención de este grupo de pacientes.Several reports of negative interactions between physiotherapy practices and cardiac rhythm devices (CRDs have been described in the literature. In spite of this, there is very little evidence to suggest the extent to which it is safe to use physiotherapy practices in this patient population. Here we summarize the documented interactions between physiotherapy and CRDs, discuss the current standard of practice for treating CRD patients, and outline the main considerations that exist from the arrhythmia service perspective in terms of patient and device factors. Finally, we advocate for a stronger cooperation between physiotherapists and the electrophysiology service team in order to safely and effectively deliver optimal physiotherapy care to CRD patients.

  14. Improved anticoagulation management after Palmaz Schatz coronary stent implantation by sealing the arterial puncture site with a vascular hemostasis device. (United States)

    Kiemeneij, F; Laarman, G J


    Sealing the arterial puncture site with a vascular hemostasis device has the potential to maintain optimal anticoagulation after stent implantation. The level of heparinization during the first 3 days after successful stent implantation was retrospectively compared between 2 groups of medically treated patients with (group A; n = 18) and without (group B; n = 17) a Vasoseal after sheath removal. The number of APTTs sampled in group A and B was 233 and 168, respectively. Respective mean values of APTT (seconds) in group A and B were 180 +/- 79 and 172 +/- 91 at day 1 (p = NS), 132 +/- 43 and 125 +/- 61 at day 2 (p = NS) and 123 +/- 36 and 116 +/- 48 at day 3 (p = NS). More APTTs were suboptimal (< 80 secs) in group B (34/168; 20%) compared to group A (17/233; 7%) [p < 0.001]. More patients in group B compared to group A had 1 or more (14/17; 82% vs. 8/18; 44%; p = 0.04), 2 or more (10/17; 59% versus 3/18; 17%; p = 0.02) and 3 or more (8/17; 47% vs. 2/18; 11%; p = 0.03) suboptimal APTTs. Bleeding complications were seen in 4 patients without and in 3 patients with a Vasoseal. Thus application of a vascular hemostasis device results in a less variable anticoagulation after coronary stenting, but it does not abolish entry site-related bleeding complications.

  15. The CentriMag centrifugal blood pump as a benchmark for in vitro testing of hemocompatibility in implantable ventricular assist devices. (United States)

    Chan, Chris H H; Pieper, Ina Laura; Hambly, Rebecca; Radley, Gemma; Jones, Alyssa; Friedmann, Yasmin; Hawkins, Karl M; Westaby, Stephen; Foster, Graham; Thornton, Catherine A


    Implantable ventricular assist devices (VADs) have proven efficient in advanced heart failure patients as a bridge-to-transplant or destination therapy. However, VAD usage often leads to infection, bleeding, and thrombosis, side effects attributable to the damage to blood cells and plasma proteins. Measuring hemolysis alone does not provide sufficient information to understand total blood damage, and research exploring the impact of currently available pumps on a wider range of blood cell types and plasma proteins such as von Willebrand factor (vWF) is required to further our understanding of safer pump design. The extracorporeal CentriMag (Thoratec Corporation, Pleasanton, CA, USA) has a hemolysis profile within published standards of normalized index of hemolysis levels of less than 0.01 g/100 L at 100 mm Hg but the effect on leukocytes, vWF multimers, and platelets is unknown. Here, the CentriMag was tested using bovine blood (n = 15) under constant hemodynamic conditions in comparison with a static control for total blood cell counts, hemolysis, leukocyte death, vWF multimers, microparticles, platelet activation, and apoptosis. The CentriMag decreased the levels of healthy leukocytes (P pump which could be used as a standard in blood damage assays to inform the design of new implantable blood pumps.

  16. Thermal and Electrodynamic Risk of Residual Current Devices in the Case of Back-Up Protection by Overcurrent Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Stanisław Czapp


    Full Text Available Residual current operated circuit breakers without integral overcurrent protection should be back-up protected. As back-up protection devices, overcurrent circuit breakers are used. The maximum let-through energy and let-through current of the overcurrent devices were evaluated under laboratory conditions. The thermal and electrodynamic risk of residual current devices was analyzed.

  17. Energy transmission and power sources for mechanical circulatory support devices to achieve total implantability. (United States)

    Wang, Jake X; Smith, Joshua R; Bonde, Pramod


    Left ventricular assist device therapy has radically improved congestive heart failure survival with smaller rotary pumps. The driveline used to power today's left ventricular assist devices, however, continues to be a source of infection, traumatic damage, and rehospitalization. Previous attempts to wirelessly power left ventricular assist devices using transcutaneous energy transfer systems have been limited by restrictions on separation distance and alignment between the transmit and receive coils. Resonant electrical energy transfer allows power delivery at larger distances without compromising safety and efficiency. This review covers the efforts to wirelessly power mechanical circulatory assist devices and the progress made in enhancing their energy sources.

  18. Bruxism: overview of current knowledge and suggestions for dental implants planning

    NARCIS (Netherlands)

    Manfredini, D.; Bucci, M.B.; Sabattini, V.B.; Lobbezoo, F.


    Bruxism is commonly considered a detrimental motor activity, potentially causing overload of the stomatognathic structures and representing a risk factor for dental implant survival. The available literature does not provide evidence-based guidelines for the management of bruxers undergoing implant-

  19. The increased risk of stroke/transient ischemic attack in women with a cardiac implantable electronic device is not associated with a higher atrial fibrillation burden

    DEFF Research Database (Denmark)

    Boriani, Giuseppe; Lip, Gregory Y H; Ricci, Renato Pietro;


    AIMS: To evaluate if the increased thromboembolic risk in female patients may be related to a higher burden of atrial fibrillation (AF). METHODS AND RESULTS: Data collected in a prospective observational research of patients implanted with a cardiac implantable electrical device (CIED) were...... predictor of stroke/TIA. CONCLUSIONS: Among patients implanted with a CIED, an AF burden of at least 5 min is a common finding, (44% of patients). Female patients have a risk of stroke and TIAs that is around two-fold that of male patients, but this increased risk cannot be ascribed to a higher burden of AF...

  20. Canadian Registry of ICD Implant Testing procedures (CREDIT): current practice, risks, and costs of intraoperative defibrillation testing. (United States)

    Healey, Jeff S; Dorian, Paul; Mitchell, L Brent; Talajic, Mario; Philippon, Francois; Simpson, Chris; Yee, Raymond; Morillo, Carlos A; Lamy, Andre; Basta, Magdy; Birnie, David H; Wang, Xiaoyin; Nair, Girish M; Crystal, Eugene; Kerr, Charles R; Connolly, Stuart J


    There is uncertainty about the proper role of defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion. A prospective registry was conducted at 13 sites in Canada between January 2006 and October 2007. To document the details of DT, the reasons for not conducting DT, and the costs and complications associated with DT. DT was conducted at implantation in 230 of 361 patients (64%). DT was more likely to be conducted for new implants compared with impulse generator replacements (71% vs 32%, P = 0.0001), but was similar for primary and secondary prevention indications (64% vs 63%, P = NS). Among patients not having DT, the reason(s) given were: considered unnecessary (44%); considered unsafe, mainly due to persistent atrial fibrillation (37%); lack of an anesthetist (20%); and, patient or physician preference (6%). When performed, DT consisted of a single successful shock > or = 10J below maximum device output in 65% of cases. A 10J safety-margin was met by 97% of patients, requiring system modification in 2.3%. Major perioperative complications occurred in 4.4% of patients having DT versus 6.6% of patients not having DT (P = NS). ICD insertion was $844 more expensive for patients having DT (P = 0.16), largely due to increased costs ($28,017 vs $24,545) among patients having impulse generator replacement (P = 0.02). DT was not performed in a third of ICD implants, usually due to a perceived lack of need or relative contraindication.

  1. A novel implantable electromechanical ventricular assist device - First acute animal testing

    NARCIS (Netherlands)

    Kaufmann, R; Rakhorst, G; Mihaylov, D; Elstrodt, J; Nix, C; Reul, H; Rau, G


    A novel ventricular assist device (HIA-EMLVAD-AT1, Helmholtz Institute Aachen-electromechanical Left Ventricular Assist Device-Animal Test Version 1), driven by a uniformly and unidirectionally rotating actuator and a patented hypocycloidic pusherplate displacement gear unit, was developed and teste

  2. Titanium-Based Biomaterials for Preventing Stress Shielding between Implant Devices and Bone

    Directory of Open Access Journals (Sweden)

    M. Niinomi


    Full Text Available β-type titanium alloys with low Young's modulus are required to inhibit bone atrophy and enhance bone remodeling for implants used to substitute failed hard tissue. At the same time, these titanium alloys are required to have high static and dynamic strength. On the other hand, metallic biomaterials with variable Young's modulus are required to satisfy the needs of both patients and surgeons, namely, low and high Young's moduli, respectively. In this paper, we have discussed effective methods to improve the static and dynamic strength while maintaining low Young's modulus for β-type titanium alloys used in biomedical applications. Then, the advantage of low Young's modulus of β-type titanium alloys in biomedical applications has been discussed from the perspective of inhibiting bone atrophy and enhancing bone remodeling. Further, we have discussed the development of β-type titanium alloys with a self-adjusting Young's modulus for use in removable implants.

  3. Safe inductive power transmission to millimeter-sized implantable microelectronics devices. (United States)

    Ibrahim, Ahmed; Kiani, Mehdi


    Power transfer efficiency (PTE) and power delivered to the load (PDL) are key inductive link design parameters for powering millimeter-sized implants. While several groups have suggested increasing the power carrier frequency (fp) of inductive links to 100s of MHz to maximize PTE, we have demonstrated that operating at 10s of MHz offers higher allowable PDL under the safety absorption rate (SAR) constraints. We have proposed a closed-form power function that relates maximum power levels that can safely be transferred at different frequencies under the SAR constraints. Three sets of inductive links at different frequencies of 50 MHz, 200 MHz, and 400 MHz have been optimized for powering a 1 mm(3)-sized implant. We have shown in simulations that reducing fp from 200 MHz to 50 MHz along with shrinking the size of the transmitter coil results in ~7.8 times higher PDL under SAR constraints, at the cost of only 52% drop in PTE.

  4. Cardiac Resynchronization Therapy Device Implantation in a Patient with Congenitally Corrected Transposition of Great Vessels

    Directory of Open Access Journals (Sweden)

    Reza Mollazadeh


    Full Text Available A 29-year-old woman was referred to our hospital due to exacerbation in dyspnea on exertion and easy fatigability. A known case of congenitally corrected transposition of the great vessels and congenital complete heart block, she had already received a permanent single-chamber pacemaker. Decision was made to implant a biventricular pacemaker for the treatment of the failing heart. Excellent coronary sinus lead implantation was done, conferring amelioration of symptoms, QRS narrowing in the electrocardiogram, and improvement of systemic ventricular systolic function in echocardiography. Over a 15-month follow-up period, she had no dyspnea on exertion. This case highlights the significance of upgrading pacemakers in patients with heart failure.

  5. Multimodality Imaging of the Long-term Vascular Responses Following Implantation of Metallic and Bioresorbable Devices


    Gkogkas, Vasileios


    markdownabstract__Abstract__ The pattern of vascular responses following stent/scaffold implantation in conventional interventional practice has been assessed by coronary angiography, intravascular ultrasound or optical coherence tomography and manifests as in-stent vascular response (focal or diffuse) or as edge vascular response (EVR) at the transition zones (focal). The utilization of bioresorbable scaffolds made of biodegradable polymers or biocorrodible metals for coronary revacularizati...

  6. Implantable devices having ceramic coating applied via an atomic layer deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Xinhua; Weimer, Alan W.; Bryant, Stephanie J.


    Substrates coated with films of a ceramic material such as aluminum oxides and titanium oxides are biocompatible, and can be used in a variety of applications in which they are implanted in a living body. The substrate is preferably a porous polymer, and may be biodegradable. An important application for the ceramic-coated substrates is as a tissue engineering scaffold for forming artificial tissue.

  7. Single-phase Multilevel Current Source Inverter with Reduced Device Count and Current Balancing Capability

    Directory of Open Access Journals (Sweden)



    Full Text Available Nowadays power converters play an important role in power system and industrial centers. One of the most important and widely used types of conversion is DC to AC conversion that is also called inverters. Generally inverters are divided to voltage source inverter (VSI and current source inverter (CSI. From another view the inverters are divided to two-level and multilevel types. The multilevel inverters are attractive because of their good output waveform quality. However, there has been less attention to multilevel current source inverter (MLCSI when compared with multilevel VSI. In this paper, a new topology for MLCSI is proposed. The proposed topology employs reduced number of switches to generate desired multilevel output current. The proposed MLCSI is capable of balancing the currents of the inductors that are used in the MLCSI structure. A multicarrier PWM based switching strategy is also proposed for the MLCSI. The simulation results using PSCAD/EMTDC as well as the experimental results from a single-phase 5-level CSI laboratory prototype demonstrate its validity.

  8. Feedback Direct Injection Current Readout For Infrared Charge-Coupled Devices (United States)

    Kubo, Kazuya; Wakayama, Hiroyuki; Kajihara, Nobuyuki; Awamoto, Kenji; Miyamoto, Yoshihiro


    We are proposing current readout for infrared charge coupled devices (IRCCDs) which can operate at higher temperatures. Feedback direct injection (FDI) consists of a simple amplifier of gain, AFDI was used in a medium-wavelength IRCCD operating at a high temperature. We made a 64-element HgCdTe linear IRCCD using FDI. The device operates at 195 K with an NETD of 0.5 K.

  9. Synthesis of Co-silicides and fabrication of microwavepower device using MEVVA source implantation

    Institute of Scientific and Technical Information of China (English)

    张通和; 吴瑜光; 钱卫东; 刘要东; 张旭


    Co synthesis silicides with good properties were prepared using MEVVA ion implantation with flux of 25-125 mA/cm2 to does of 5×1017/cm2. The structure of the silicides was investigated using X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM analysis shows that if the ion dose is greater than 2×1017/cm2, a continuous silicide layer will be formed. The sheet resistance of Co silicide decreases with an increase in ion flux and ion dose. The formation of silicides with CoSi and CoSi2 are identified by XRD analysis. After annealing, the sheet resistance decreases further. A continuous silicide layer with a width of 90-133 nm is formed. The optimal implantation condition is that the ion flux and dose are 50 mA/cm2 and 5×1017/cm2, respectively. The optimal annealing temperature and time are 900℃ and 10 s, respectively. The ohmic contact for power microwave transistors is fabricated using Co ion implantation technique for the first time. The emitter contact resistance and noise of the transistors decrease markedly; the microwave property has been improved obviously.

  10. Design of a radio-linked implantable cochlear prosthesis using surface acoustic wave devices. (United States)

    Jeutter, D C; Josse, F


    Cochlear prosthesis systems for postlingually deaf individuals (those who have become deaf due to disease or injury after having developed mature speech capability) are considered. These systems require the surgical implantation of an array of electrodes within the cochlea and are driven by processed sound signals from outside the body. A system that uses an analog signal approach for transcutaneous transfer of six processed speech data channels using frequency multiplexing is described. The system utilizes a filterbank of six narrowband surface acoustic wave (SAW) filters in the range 72-78 MHz with a 1.2-MHz channel spacing to multiplex the six carrier signals, frequency modulated, by the processed speech signals, onto a composite signal. The same SAW filters are used in the receiver filterbank for signal separation, but are housed in a miniaturized package. The system includes a portable transmitter and a receiver package which is to be implanted in the patient. The implanted circuits are supplied exclusively from power transferred from outside the body via a separate 10-MHz transcutaneous link.

  11. Biological aspects of dental implant; Current knowledge and perspectives in oral implantology

    Directory of Open Access Journals (Sweden)

    Sukant Sahoo


    Full Text Available The utilization of dental implants became a scientifically accepted treatment modality for the rehabilitation of fully and partially edentulous patients. The evolution of dental implants has completely changed dentistry. Implants can offer a number of benefits, from improved esthetics, to reducing bone loss, to improving denture retention for edentulous patients. Branemark et al., was the first person to examined submerged titanium implants with a machined surface in dogs and later called this procedure as osseointegration, which is now defined as "A direct structural and functional connection between ordered, living bone and the surface of a load-bearing implant." Commercially pure titanium is recognized today as a material of choice, since it is characterized by excellent biological and also good mechanical properties. In this comprehensive review, authors have sought to explore various biological aspects of dental implant as pertinent to clinical procedure so as to provide research foundation for the establishment of suitable strategies that can assist in successful implant therapy.

  12. Release of Intracoronary Microparticles during Stent Implantation into Stable Atherosclerotic Lesions under Protection with an Aspiration Device.

    Directory of Open Access Journals (Sweden)

    Patrick Horn

    Full Text Available Stent implantation into atherosclerotic coronary vessels impacts on downstream microvascular function and induces the release of particulate debris and soluble substances, which differs qualitatively and quantitatively between native right coronary arteries (RCAs and saphenous vein grafts on right coronary arteries (SVG-RCAs. We have now quantified the release of microparticles (MPs during stent implantation into stable atherosclerotic lesions and compared the release between RCAs and SVG-RCAs.In symptomatic, male patients with stable angina and a stenosis in their RCA or SVG-RCA, respectively (n = 14/14, plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Coronary aspirate was retrieved during stent implantation with a distal occlusion/aspiration device and divided into particulate debris and plasma. Particulate debris was weighed. Platelet-derived MPs (PMPs were distinguished by flow cytometry as CD41+, endothelium-derived MPs (EMPs as CD144+, CD62E+ and CD31+/CD41-, leukocyte-derived MPs as CD45+, and erythrocyte-derived MPs as CD235+.In patients with comparable plaque volume and composition in RCAs and SVG-RCAs, intracoronary PMPs and EMPs were increased after stent implantation into their RCAs and SVG-RCAs (CD41+: 2729.6 ± 645.6 vs. 4208.7 ± 679.4 and 2355.9 ± 503.9 vs. 3285.8 ± 733.2 nr/µL; CD144+: 451.5 ± 87.9 vs. 861.7 ± 147.0 and 444.6 ± 74.8 vs. 726.5 ± 136.4 nr/µL; CD62E+: 1404.1 ± 247.7 vs. 1844.3 ± 378.6 and 1084.6 ± 211.0 vs. 1783.8 ± 384.3 nr/µL, P < 0.05, but not different between RCAs and SVG-RCAs.Stenting in stable atherosclerotic lesions is associated with a substantial release not only of PMPs, but also of EMPs in RCAs and SVG-RCAs. Their release does not differ between RCAs and NCT01430884.

  13. Post market surveillance in the german medical device sector - current state and future perspectives. (United States)

    Zippel, Claus; Bohnet-Joschko, Sabine


    Medical devices play a central role in the diagnosis and treatment of diseases but also bring the potential for adverse events, hazards or malfunction with serious consequences for patients and users. Medical device manufacturers are therefore required by law to monitor the performance of medical devices that have been approved by the competent authorities (post market surveillance). Conducting a nationwide online-survey in the German medical device sector in Q2/2014 in order to explore the current status of the use of post market instruments we obtained a total of 118 complete data sets, for a return rate of 36%. The survey included manufacturers of different sizes, producing medical devices of all risk classes. The post market instruments most frequently reported covered the fields of production monitoring and quality management as well as literature observation, regulatory vigilance systems, customer knowledge management and market observation while Post Market Clinical Follow-up and health services research were being used less for product monitoring. We found significant differences between the different risk classes of medical devices produced and the intensity of use of post market instruments. Differences between company size and the intensity of instruments used were hardly detected. Results may well contribute to the development of device monitoring which is a crucial element of the policy and regulatory system to identify device-related safety issues. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Analysis of Current Source PWM Inverter for Different Levels with No-Insulating Switching Device


    Kumar Abhishek; K.Parkavi Kathirvelu; Balasubramanian, R.


    This paper gives the new set-up of inverter having DC current source (CSI) having no insulated switching device. In the proposed new CSI topology every switching device are connected across a common-source level, thus a single power supply gate drive circuit is required and no insulated power supply and the customary bootstrap circuit is applied. This CSI topology is even legitimate for utmost level of current waveform output, where the power switches number increases. As a turn up, gate driv...

  15. An Implantable MEMS Drug Delivery Device for Rapid Delivery in Ambulatory Emergency Care (United States)


    even engaged 2 telemetrically, as opposed to passive devices that depend on the degradation chemistry of the specific device materials in the...cardioverter-defibrillator," American Journal of Cardiology , vol. 85, pp. 981-985, 2000. A. C. R. Grayson, I. S. Choi, B. M. Tyler, P. P. Wang...cardioverter defibrillator patients," Journal of Interventional Cardiology , vol. 11, pp. 205-211, 1998. M. Staples, K. Daniel, M. J. Cima, and R

  16. Guideline-driven telemonitoring and follow-up of cardiovascular implantable electronic devices using IEEE 11073, HL7 & IHE profiles. (United States)

    Yang, Maohua; Chronaki, Catherine E; Lüpkes, Christian; Thiel, Andreas; Plössnig, Manuela; Hinterbuchner, Lynne; Arbelo, Elena; Laleci, Gokce Banu; Kabak, Yildiray; Duarte, Fernandez; Guillén, Alejandra; Navarro, Xavier; Dogac, Asuman; Eichelberg, Marco; Hein, Andreas


    For patients with Cardiovascular Implantable Electronic Devices (CIEDs), telemonitoring promises improved quality of life and safety, since events recorded by the device or observed by the patient can alert a health professional. Taking into account the latest clinical guidelines when responding to such alerts, is a topic of active research addressed by the iCARDEA project. A key technical challenge is correlating telemonitoring CIED report data in a vendor-independent format with Electronic Health Record (EHR) data collected in the hospital and Personal Health Record (PHR) data entered by the patient, in guideline-driven care processes. The iCARDEA CIED exposure service component presented in this paper employs standards specifications from ISO/IEEE 11073 (Health Informatics, Point-of-care Medical Device Communication) and HL7v2.x in the context of Integrating the Healthcare Enterprise (IHE) profiles to deliver telemonitoring CIED report data from two different CIED vendors to the adaptive care planner that implements guideline-driven care plans. Experience gained with implementation and initial component testing is discussed, while challenges and expectations for future health information standards to effectively support EHR-integrated guide-line-driven telemonitoring services are highlighted.

  17. Current Status of Implant-based Breast Reconstruction in Patients Receiving Postmastectomy Radiation Therapy (United States)

    Kronowitz, Steven J.


    Background Increasing numbers of patients with breast cancer are being treated with postmastectomy radiation therapy (PMRT). The author reviewed the literature to determine the clinical impact of this increasing use of PMRT in patients with breast cancer who desire implant-based breast reconstruction. Methods The author searched the MEDLINE database for articles on breast reconstruction and radiation therapy published between January 2008 and June 2011, and reviewed the abstracts of those articles to identify articles with information about the impact of radiation on implant-based breast reconstruction. This subgroup of articles was reviewed in detail. Results Two-hundred eighty-five articles were identified. 19 papers were reviewed in detail. 8 papers provided level III evidence; one provided level I or II (n = 8) evidence from high-quality multicenter or single-center randomized controlled trials or prospective cohort studies. Two papers provided level IV evidence from case series and were included in the review because they offered a novel approach or perspective. The most recent studies find a significant need for unplanned or major corrective surgery in irradiated breasts reconstructed with implants. Although breast implant reconstruction in irradiated breasts is associated with high rates of complications; only a minority of patients require conversion to an autologous tissue flap. Conclusions Although the majority of patients who undergo implant-based reconstruction and receive radiation ultimately keep the implant reconstruction, patient surveys show that radiation has a significantly negative effect on patient satisfaction. PMID:23018711

  18. The AC (Alternating Current) Electrical Behavior of Multi-layered Thermoelectric Devices (United States)

    Alim, Mohammad A.; Budak, Satilmis; Bhattacharjee, Sudip


    In this study the ac (alternating current) small-signal electrical data in the frequency range 5 Hz ≤ f ≤ 13 MHz are obtained for the multi-layered thermoelectric (TE) devices to extract underlying operative mechanisms via an equivalent circuit model. This model is developed from the complex plane plots in conjunction with the Bode plot. It is observed that the inductive behavior is prevalent for both unbombarded and bombarded TE devices regardless of the doses as both types are observed as somewhat weak in thermoelectric properties. The bombarded multi-layered devices followed a systematic pattern in ac behavior via semicircular relaxation both in the impedance and admittance planes for the same measured data. This pattern is attributed to the transition from one lumped behavior to two distinct mechanisms. It is observed that the conductive nature of the equivalent circuit model via non-blocking (non-capacitive) elements, attributed to the underlying operative electrical paths between the two opposite electrodes across the multi-layered device exists, satisfying direct current conditions of the equivalent circuit model. The inductive behavior at high frequencies originates from the conductive aspect of the lumped response of the device in addition to the contribution of the electrode leads. Thus, the proposed equivalent circuit model contains external inductance that verifies a meaningful representation of the multi-layered TE device, though weak in thermoelectric properties.

  19. A Web-based searchable system to confirm magnetic resonance compatibility of implantable medical devices in Japan: a preliminary study. (United States)

    Fujiwara, Yasuhiro; Fujioka, Hitoshi; Watanabe, Tomoko; Sekiguchi, Maiko; Murakami, Ryuji


    Confirmation of the magnetic resonance (MR) compatibility of implanted medical devices (IMDs) is mandatory before conducting magnetic resonance imaging (MRI) examinations. In Japan, few such confirmation methods are in use, and they are time-consuming. This study aimed to develop a Web-based searchable MR safety information system to confirm IMD compatibility and to evaluate the usefulness of the system. First, MR safety information for intravascular stents and stent grafts sold in Japan was gathered by interviewing 20 manufacturers. These IMDs were categorized based on the descriptions available on medical package inserts as: "MR Safe," "MR Conditional," "MR Unsafe," "Unknown," and "No Medical Package Insert Available". An MR safety information database for implants was created based on previously proposed item lists. Finally, a Web-based searchable system was developed using this database. A questionnaire was given to health-care personnel in Japan to evaluate the usefulness of this system. Seventy-nine datasets were collected using information provided by 12 manufacturers and by investigating the medical packaging of the IMDs. Although the datasets must be updated by collecting data from other manufacturers, this system facilitates the easy and rapid acquisition of MR safety information for IMDs, thereby improving the safety of MRI examinations.

  20. Listening to Brain Microcircuits for Interfacing With External World—Progress in Wireless Implantable Microelectronic Neuroengineering Devices (United States)

    Nurmikko, Arto V.; Donoghue, John P.; Hochberg, Leigh R.; Patterson, William R.; Song, Yoon-Kyu; Bull, Christopher W.; Borton, David A.; Laiwalla, Farah; Park, Sunmee; Ming, Yin; Aceros, Juan


    Acquiring neural signals at high spatial and temporal resolution directly from brain microcircuits and decoding their activity to interpret commands and/or prior planning activity, such as motion of an arm or a leg, is a prime goal of modern neurotechnology. Its practical aims include assistive devices for subjects whose normal neural information pathways are not functioning due to physical damage or disease. On the fundamental side, researchers are striving to decipher the code of multiple neural microcircuits which collectively make up nature’s amazing computing machine, the brain. By implanting biocompatible neural sensor probes directly into the brain, in the form of microelectrode arrays, it is now possible to extract information from interacting populations of neural cells with spatial and temporal resolution at the single cell level. With parallel advances in application of statistical and mathematical techniques tools for deciphering the neural code, extracted populations or correlated neurons, significant understanding has been achieved of those brain commands that control, e.g., the motion of an arm in a primate (monkey or a human subject). These developments are accelerating the work on neural prosthetics where brain derived signals may be employed to bypass, e.g., an injured spinal cord. One key element in achieving the goals for practical and versatile neural prostheses is the development of fully implantable wireless microelectronic “brain-interfaces” within the body, a point of special emphasis of this paper. PMID:21654935

  1. A new cable-tie based sternal closure system: description of the device, technique of implantation and first clinical evaluation

    Directory of Open Access Journals (Sweden)

    Grapow Martin TR


    Full Text Available Abstract Background Wire closure still remains the preferred technique despite reasonable disadvantages. Associated complications, such as infection and sternal instability, cause time- and cost-consuming therapies. We present a new tool for sternal closure with its first clinical experience and results. Methods The sternal ZipFixTM System is based on the cable-tie principle. It primarily consists of biocompatible Poly-Ether-Ether-Ketone implants and is predominantly used peristernally through the intercostal space. The system provides a large implant-to-bone contact for better force distribution and for avoiding bone cut through. Results 50 patients were closed with the ZipFixTM system. No sternal instability was observed at 30 days. Two patients developed a mediastinitis that necessitated the removal of the device; however, the ZipFixTM were intact and the sternum remained stable. Conclusions In our initial evaluation, the short-term results have shown that the sternal ZipFixTM can be used safely and effectively. It is fast, easy to use and serves as a potential alternative for traditional wire closure.

  2. Few-Layer MoS₂ p-Type Devices Enabled by Selective Doping Using Low Energy Phosphorus Implantation. (United States)

    Nipane, Ankur; Karmakar, Debjani; Kaushik, Naveen; Karande, Shruti; Lodha, Saurabh


    P-type doping of MoS2 has proved to be a significant bottleneck in the realization of fundamental devices such as p-n junction diodes and p-type transistors due to its intrinsic n-type behavior. We report a CMOS compatible, controllable and area selective phosphorus plasma immersion ion implantation (PIII) process for p-type doping of MoS2. Physical characterization using SIMS, AFM, XRD and Raman techniques was used to identify process conditions with reduced lattice defects as well as low surface damage and etching, 4X lower than previous plasma based doping reports for MoS2. A wide range of nondegenerate to degenerate p-type doping is demonstrated in MoS2 field effect transistors exhibiting dominant hole transport. Nearly ideal and air stable, lateral homogeneous p-n junction diodes with a gate-tunable rectification ratio as high as 2 × 10(4) are demonstrated using area selective doping. Comparison of XPS data from unimplanted and implanted MoS2 layers shows a shift of 0.67 eV toward lower binding energies for Mo and S peaks indicating p-type doping. First-principles calculations using density functional theory techniques confirm p-type doping due to charge transfer originating from substitutional as well as physisorbed phosphorus in top few layers of MoS2. Pre-existing sulfur vacancies are shown to enhance the doping level significantly.

  3. Benefit of the Vibrant Soundbridge device in patients implanted for 5 to 8 years. (United States)

    Mosnier, Isabelle; Sterkers, Olivier; Bouccara, Didier; Labassi, Samia; Bebear, Jean-Pierre; Bordure, Philippe; Dubreuil, Christian; Dumon, Thibaud; Frachet, Bruno; Fraysse, Bernard; Lavieille, Jean-Pierre; Magnan, Jacques; Martin, Christian; Meyer, Bernard; Mondain, Michel; Portmann, Didier; Robier, Alain; Schmerber, Sébastien; Thomassin, Jean-Marc; Truy, Eric; Uziel, Alain; Vanecloo, François-Michel; Vincent, Christophe; Ferrary, Evelyne


    To assess audiological performance, satisfaction rate, and side effects of 100 patients who have been using the middle ear implant Vibrant Soundbridge (VSB) for 5 to 8 yr when compared with data collected from 3 to 18 mo postsurgery. Audiological testing and subjective evaluation using self-assessment scales were performed in 77 out of the 100 patients using the VSB for 5 to 8 years. The results were compared to data collected 3 months (audiological testing) and 18 months (self-assessment scales) after surgery. Twenty-three patients have not been evaluated for different reported reasons. Pure-tone hearing thresholds decreased similarly in both implanted and contralateral ears. The satisfaction ratings and the functional gain provided by the VSB remained stable. Speech comprehension in quiet conditions without the VSB decreased from 56 to 37% in 5 to 8 yr, but an 81% score was achieved with the VSB. This study demonstrates that the performance of the VSB does not deteriorate for more than 5 yr, without adverse effect. These results confirm the safety and the effectiveness of the VSB with a long-term follow-up.

  4. Low profile, highly configurable, current sharing paralleled wide band gap power device power module (United States)

    McPherson, Brice; Killeen, Peter D.; Lostetter, Alex; Shaw, Robert; Passmore, Brandon; Hornberger, Jared; Berry, Tony M


    A power module with multiple equalized parallel power paths supporting multiple parallel bare die power devices constructed with low inductance equalized current paths for even current sharing and clean switching events. Wide low profile power contacts provide low inductance, short current paths, and large conductor cross section area provides for massive current carrying. An internal gate & source kelvin interconnection substrate is provided with individual ballast resistors and simple bolted construction. Gate drive connectors are provided on either left or right size of the module. The module is configurable as half bridge, full bridge, common source, and common drain topologies.

  5. TOPICAL REVIEW: Current-driven dynamics in molecular-scale devices (United States)

    Seideman, Tamar


    We review recent theoretical work on current-triggered processes in molecular-scale devices - a field at the interface between solid state physics and chemical dynamics with potential applications in diverse areas, including artificial molecular machines, unimolecular transport, surface nanochemistry and nanolithography. The qualitative physics underlying current-triggered dynamics is first discussed and placed in context with several well-studied phenomena with which it shares aspects. A theory for modelling these dynamics is next formulated within a time-dependent scattering approach. Our end result provides useful insight into the system properties that determine the reaction outcome as well as a computationally convenient framework for numerical realization. The theory is applied to study single-molecule surface reactions induced by a scanning tunnelling microscope and current-triggered dynamics in single-molecule transistors. We close with a discussion of several potential applications of current-induced dynamics in molecular devices and several opportunities for future research.

  6. Titanium coated with functionalized carbon nanotubes--a promising novel material for biomedical application as an implantable orthopaedic electronic device. (United States)

    Przekora, Agata; Benko, Aleksandra; Nocun, Marek; Wyrwa, Jan; Blazewicz, Marta; Ginalska, Grazyna


    The aim of the study was to fabricate titanium (Ti) material coated with functionalized carbon nanotubes (f-CNTs) that would have potential medical application in orthopaedics as an implantable electronic device. The novel biomedical material (Ti-CNTs-H2O) would possess specific set of properties, such as: electrical conductivity, non-toxicity, and ability to inhibit connective tissue cell growth and proliferation protecting the Ti-CNTs-H2O surface against covering by cells. The novel material was obtained via an electrophoretic deposition of CNTs-H2O on the Ti surface. Then, physicochemical, electrical, and biological properties were evaluated. Electrical property evaluation revealed that a Ti-CNTs-H2O material is highly conductive and X-ray photoelectron spectroscopy analysis demonstrated that there are mainly COOH groups on the Ti-CNTs-H2O surface that are found to inhibit cell growth. Biological properties were assessed using normal human foetal osteoblast cell line (hFOB 1.19). Conducted cytotoxicity tests and live/dead fluorescent staining demonstrated that Ti-CNTs-H2O does not exert toxic effect on hFOB cells. Moreover, fluorescence laser scanning microscope observation demonstrated that Ti-CNTs-H2O surface retards to a great extent cell proliferation. The study resulted in successful fabrication of highly conductive, non-toxic Ti-CNTs-H2O material that possesses ability to inhibit osteoblast proliferation and thus has a great potential as an orthopaedic implantable electronic device. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Simulation of ion beam induced current in radiation detectors and microelectronic devices.

    Energy Technology Data Exchange (ETDEWEB)

    Vizkelethy, Gyorgy


    Ionizing radiation is known to cause Single Event Effects (SEE) in a variety of electronic devices. The mechanism that leads to these SEEs is current induced by the radiation in these devices. While this phenomenon is detrimental in ICs, this is the basic mechanism behind the operation of semiconductor radiation detectors. To be able to predict SEEs in ICs and detector responses we need to be able to simulate the radiation induced current as the function of time. There are analytical models, which work for very simple detector configurations, but fail for anything more complex. On the other end, TCAD programs can simulate this process in microelectronic devices, but these TCAD codes costs hundreds of thousands of dollars and they require huge computing resources. In addition, in certain cases they fail to predict the correct behavior. A simulation model based on the Gunn theorem was developed and used with the COMSOL Multiphysics framework.

  8. Biomechanical study of dynamic changes in L4-L5 foramen surface area in flexion and extension after implantation of four interspinous process devices. (United States)

    Hirsch, C; Breque, C; Ragot, S; Pascal-Mousselard, H; Richer, J-P; Scepi, M; Khiami, F


    Lumbar spinal stenosis is a major public health issue. Interspinous devices implanted using minimally invasive techniques may constitute an alternative to the reference standard of bony decompression with or without intervertebral fusion. However, their indications remain unclear, due to a paucity of clinical and biomechanical data. Our objective was to evaluate the effects of four interspinous process devices implanted at L4-L5 on the intervertebral foramen surface areas at the treated and adjacent levels, in flexion and in extension. Six fresh frozen human cadaver lumbar spines (L2-sacrum) were tested on a dedicated spinal loading frame, in flexion and extension, from 0 to 10 N·m, after preparation and marking of the L3-L4, L4-L5, and L5-S1 foramina. Stereoscopic 3D images were acquired at baseline then after implantation at L4-L5 of each of the four devices (Inspace(®), Synthes; X-Stop(®), Medtronic; Wallis(®), Zimmer; and Diam(®), Medtronic). The surface areas of the three foramina of interest were computed. All four devices significantly opened the L4-L5 foramen in extension. The effects in flexion separated the devices into two categories. With the two devices characterized by fixation in the spinous processes (Wallis(®) and Diam(®)), the L4-L5 foramen opened only in extension; whereas with the other two devices (X-Stop(®) and Inspace(®)), the L4-L5 foramen opened not only in extension, but also in flexion and in the neutral position. None of the devices implanted at L4-L5 modified the size of the L3-L4 foramen. X-Stop(®) and Diam(®) closed the L5-S1 foramen in extension, whereas the other two devices had no effect at this level. Our results demonstrate that interspinous process devices modify the surface area of the interspinous foramina in vitro. Clinical studies are needed to clarify patient selection criteria for interspinous process device implantation. Level IV. Investigating an orthopaedic device. Copyright © 2015 Elsevier Masson SAS. All

  9. Assessment of Current Practice for Tank Testing of Small Marine Energy Devices

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Frigaard, Peter

    Discussion Report. Equitable Testing and Evaluation of Marine Energy Extraction Devices in terms of Performance, Cost and Environmental Impact. The report is a contribution by Aalborg University (AAU) to the deliverable on Assessment of current practice for tank testing of small marine energy...


    Directory of Open Access Journals (Sweden)

    S. V. Gautier


    Full Text Available The paper describes the first clinical experience in RF of successful application of domestic circulatory support device based on implantable axial pump for two stage heart transplantation. This case demonstrate the effec- tiveness and safety of our device (АВК-Н for a longtime (270 days left ventricular bypass and the ability to perform a successful transplantation of donor,s heart after application of this system. 



    S. V. Gautier; G. P. Itkin; S. Yu. Shemakin; R. Sh. Saitgareev; V. N. Poptsov; V. M. Zakharevich; G. A. Akopov; A. Ya. Kormer; T. A. Khalilulin; O. P. Shevchenko; А. М. Nevzorov; I. А. Filatov; S. V. Selishev


    The paper describes the first clinical experience in RF of successful application of domestic circulatory support device based on implantable axial pump for two stage heart transplantation. This case demonstrate the effec- tiveness and safety of our device (АВК-Н) for a longtime (270 days) left ventricular bypass and the ability to perform a successful transplantation of donor,s heart after application of this system. 

  12. Superhydrophobic SAM Modified Electrodes for Enhanced Current Limiting Properties in Intrinsic Conducting Polymer Surge Protection Devices. (United States)

    Jabarullah, Noor H; Verrelli, Emanuele; Mauldin, Clayton; Navarro, Luis A; Golden, Josh H; Madianos, Leonidas M; Kemp, Neil T


    Surface interface engineering using superhydrophobic gold electrodes made with 1-dodecanethiol self-assembled monolayer (SAM) has been used to enhance the current limiting properties of novel surge protection devices based on the intrinsic conducting polymer, polyaniline doped with methanesulfonic acid. The resulting devices show significantly enhanced current limiting characteristics, including current saturation, foldback, and negative differential effects. We show how SAM modification changes the morphology of the polymer film directly adjacent to the electrodes, leading to the formation of an interfacial compact thin film that lowers the contact resistance at the Au-polymer interface. We attribute the enhanced current limiting properties of the devices to a combination of lower contact resistance and increased Joule heating within this interface region which during a current surge produces a current blocking resistive barrier due to a thermally induced dedoping effect caused by the rapid diffusion of moisture away from this region. The effect is exacerbated at higher applied voltages as the higher temperature leads to stronger depletion of charge carriers in this region, resulting in a negative differential resistance effect.

  13. Effect of Left Ventricular Assist Device Implantation and Heart Transplantation on Habitual Physical Activity and Quality of Life☆ (United States)

    Jakovljevic, Djordje G.; McDiarmid, Adam; Hallsworth, Kate; Seferovic, Petar M.; Ninkovic, Vladan M.; Parry, Gareth; Schueler, Stephan; Trenell, Michael I.; MacGowan, Guy A.


    The present study defined the short- and long-term effects of left ventricular assist device (LVAD) implantation and heart transplantation (HT) on physical activity and quality of life (QoL). Forty patients (LVAD, n = 14; HT, n = 12; and heart failure [HF], n = 14) and 14 matched healthy subjects were assessed for physical activity, energy expenditure, and QoL. The LVAD and HT groups were assessed postoperatively at 4 to 6 weeks (baseline) and 3, 6, and 12 months. At baseline, LVAD, HT, and HF patients demonstrated low physical activity, reaching only 15%, 28%, and 51% of that of healthy subjects (1,603 ± 302 vs 3,036 ± 439 vs 5,490 ± 1,058 vs 10,756 ± 568 steps/day, respectively, p <0.01). This was associated with reduced energy expenditure and increased sedentary time (p <0.01). Baseline QoL was not different among LVAD, HT, and HF groups (p = 0.44). LVAD implantation and HT significantly increased daily physical activity by 60% and 52%, respectively, from baseline to 3 months (p <0.05), but the level of activity remained unchanged at 3, 6, and 12 months. The QoL improved from baseline to 3 months in LVAD implantation and HT groups (p <0.01) but remained unchanged afterward. At any time point, HT demonstrated higher activity level than LVAD implantation (p <0.05), and this was associated with better QoL. In contrast, physical activity and QoL decreased at 12 months in patients with HF (p <0.05). In conclusion, patients in LVAD and HT patients demonstrate improved physical activity and QoL within the first 3 months after surgery, but physical activity and QoL remain unchanged afterward and well below that of healthy subjects. Strategies targeting low levels of physical activity should now be explored to improve recovery of these patients. PMID:24925802

  14. Prediction of right ventricular failure after ventricular assist device implant: systematic review and meta-analysis of observational studies. (United States)

    Bellavia, Diego; Iacovoni, Attilio; Scardulla, Cesare; Moja, Lorenzo; Pilato, Michele; Kushwaha, Sudhir S; Senni, Michele; Clemenza, Francesco; Agnese, Valentina; Falletta, Calogero; Romano, Giuseppe; Maalouf, Joseph; Dandel, Michael


    Right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation is associated with increased morbidity and mortality, but the identification of LVAD candidates at risk for RVF remains challenging. We undertook a systematic review and meta-analysis of observational studies of risk factors associated with RVF after LVAD implant. Thirty-six studies published between 1 January 1995 and 30 April 2015, comprising 995 RVF patients out of a pooled final population of 4428 patients, were identified. Meta-analysed prevalence of post-LVAD RVF was 35%. A need for mechanical ventilation [odds ratio (OR) 2.99], or continuous renal replacement therapy (CRRT; OR 4.61, area under the curve 0.78, specificity 0.91) were the clinical variables with the highest effect size (ES) in predicting RVF. International normalized ratio [INR; standardized mean difference (SMD) 0.49] and N-terminal pro-brain natriuretic peptide (NT-proBNP) (SMD 0.52) were the biochemical markers that best discriminated between RVF and No-RVF populations, though NT-proBNP was highly heterogeneous. Right ventricular stroke work index (RVSWI) and central venous pressure (CVP) (SMD -0.58 and 0.47, respectively) were the haemodynamic measures with the highest ES in identifying patients at risk of post-LVAD RVF; CVP was particularly useful in risk stratifying patients undergoing continuous-flow LVAD implant (SMD 0.59, P implant moderate to severe right ventricular (RV) dysfunction, as assessed qualitatively (OR 2.82), or a greater RV/LV diameter ratio (SMD 0.51) were the standard echocardiographic measurements with the highest ES in comparing RVF with No-RVF patients. Longitudinal systolic strain of the RV free wall had the highest ES (SMD 0.73) but also the greatest heterogeneity (I(2) = 74%) and was thus only marginally significant (P = 0.05). Patients on ventilatory support or CRRT are at high risk for post-LVAD RVF, similarly to patients with slightly increased INR, high NT-proBNP or

  15. Left ventricular assist device implantation via left thoracotomy: alternative to repeat sternotomy. (United States)

    Pierson, Richard N; Howser, Renee; Donaldson, Terri; Merrill, Walter H; Dignan, Rebecca J; Drinkwater, Davis C; Christian, Karla G; Butler, Javed; Chomsky, Don; Wilson, John R; Clark, Rick; Davis, Stacy F


    Repeat sternotomy for left ventricular assist device insertion may result in injury to the right heart or patent coronary grafts, complicating intraoperative and postoperative management. In 4 critically ill patients, left thoracotomy was used as an alternative to repeat sternotomy. Anastomosis of the outflow conduit to the descending thoracic aorta provided satisfactory hemodynamic support.

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

    Directory of Open Access Journals (Sweden)

    Altaf Hussain Shah


    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.

  17. Implants as drug delivery devices for the treatment of eye diseases

    Directory of Open Access Journals (Sweden)

    Gisele Rodrigues da Silva


    Full Text Available The treatment of diseases affecting the posterior segment of the eye is limited by the difficulty in transporting effective doses of drugs to the vitreous, retina, and choroid. Topically applied drugs are poorly absorbed due to the low permeability of the external ocular tissues and tearing. The blood-retina barrier limits drug diffusion from the systemic blood to the posterior segment, thus high doses of drug are needed to maintain therapeutic levels. In addition, systemic side effects are common. Intraocular injections could be an alternative, but the fast flowing blood supply in this region, associated with rapid clearance rates, causes drug concentration to quickly fall below therapeutic levels. To obtain therapeutic levels over longer time periods, polymeric sustained-drug release systems implanted within the vitreous are being studied for the treatment of vitreoretinal disorders. These systems are prepared using different kinds of biodegradable or non-biodegradable polymers. This review aims to demonstrate the main characteristics of these drug delivery implants and their potential for clinical application.O tratamento de doenças do segmento posterior do olho é limitado pela dificuldade no transporte de doses efetivas de fármacos para o vítreo, retina e coróide. Os fármacos aplicados topicamente são pouco absorvidos por causa da baixa permeabilidade dos tecidos oculares externos e ao lacrimejamento. Embora a administração sistêmica seja capaz de transportar fármacos para o segmento posterior do olho, as barreiras hemato-aquosa e hematorretiniana dificultam a absorção e, normalmente, são necessárias doses elevadas, as quais estão geralmente associadas a potenciais efeitos adversos. Injeções intravitreais são capazes de transportar fármacos para o segmento posterior do olho, mas é uma técnica invasiva, pouco tolerada pelos pacientes e apresenta riscos de infecções oculares e danos aos tecidos. Visando a obtenção de

  18. An orthodontic device for retaining implanted radioactive sources during brachytherapy for cancer of the oral cavity

    Energy Technology Data Exchange (ETDEWEB)

    Masuko, Noriko; Katsura, Kouji [Niigata Univ. (Japan). School of Dentistry; Sugita, Tadashi; Sakai, Kunio; Sato, Katsurou; Kawana, Masahiro; Nonomura, Naobumi


    An orthodontic retainer was devised to keeping implanted radioactive sources in position and improve the quality of life during brachytherapy for cancer of the oral cavity. The retainer was used in 3 patients with oral cancer, one with cancer of the hard palate, one with cancer of the soft palate, and one with cancer of the floor of mouth, during brachytherapy using {sup 198}Au grains and {sup 137}Cs needles. These patients could speak freely. One with cancer of the hard palate could drink water and ingest semi-liquid food during treatment instead of nasal tube feeding. The plaster dental model obtained while making the retainer proved to be useful for training radiation oncologists. (author)

  19. Chronic cortical and electromyographic recordings from a fully implantable device: preclinical experience in a nonhuman primate (United States)

    Ryapolova-Webb, Elena; Afshar, Pedram; Stanslaski, Scott; Denison, Tim; de Hemptinne, Coralie; Bankiewicz, Krystof; Starr, Philip A.


    Objective. Analysis of intra- and perioperatively recorded cortical and basal ganglia local field potentials in human movement disorders has provided great insight into the pathophysiology of diseases such as Parkinson's, dystonia, and essential tremor. However, in order to better understand the network abnormalities and effects of chronic therapeutic stimulation in these disorders, long-term recording from a fully implantable data collection system is needed. Approach. A fully implantable investigational data collection system, the Activa® PC + S neurostimulator (Medtronic, Inc., Minneapolis, MN), has been developed for human use. Here, we tested its utility for extended intracranial recording in the motor system of a nonhuman primate. The system was attached to two quadripolar paddle arrays: one covering sensorimotor cortex, and one covering a proximal forelimb muscle, to study simultaneous cortical field potentials and electromyography during spontaneous transitions from rest to movement. Main results. Over 24 months of recording, movement-related changes in physiologically relevant frequency bands were readily detected, including beta and gamma signals at approximately 2.5 μV/\\sqrtHz and 0.7 μV/\\sqrt{Hz}, respectively. The system architecture allowed for flexible recording configurations and algorithm triggered data recording. In the course of physiological analyses, sensing artifacts were observed (˜1 μVrms stationary tones at fixed frequency), which were mitigated either with post-processing or algorithm design and did not impact the scientific conclusions. Histological examination revealed no underlying tissue damage; however, a fibrous capsule had developed around the paddles, demonstrating a potential mechanism for the observed signal amplitude reduction. Significance. This study establishes the usefulness of this system in measuring chronic brain and muscle signals. Use of this system may potentially be valuable in human trials of chronic brain

  20. Protocol updated for the treatment of patients in radiotherapy with implanted cardiac devices; Protocolo actualizado para el tratamiento de pacientes en radioterapia con dispositivos cardiacos implantados

    Energy Technology Data Exchange (ETDEWEB)

    Martin Martin, G.; Bermudez Luna, R.; Rodriguez Rodriguez, C.; Lopez Fernandez, A.; Rodriguez Perez, A.; Sotoca Ruiz, A.


    Radiotherapy treatment can be safely performed in patients with pacemakers or implanted defibrillators, however, it is very important to ensure that the patient receives the minimum dose possible in your heart device. Is considered essential good coordination with the cardiology service before, during and after radiotherapy treatment for the patient safety. Finally we present a protocol updated to treat these patients in radiotherapy. (Author)

  1. A summary of the update on cardiovascular implantable electronic device infections and their management A scientific statement from the American Heart Association

    NARCIS (Netherlands)

    Baddour, Larry M.; Epstein, Andrew E.; Erickson, Christopher C.; Knight, Bradley P.; Levison, Matthew E.; Lockhart, Peter B.; Masoudi, Frederick A.; Okum, Eric J.; Wilson, Walter R.; Beerman, Lee B.; Bolger, Ann F.; Estes, N. A. Mark; Gewitz, Michael; Newburger, Jane W.; Schron, Eleanor B.; Taubert, Kathryn A.


    Background. The purpose of this statement is to update the recommendations by the American Heart Association (AHA) for cardiovascular implantable electronic device (CIED) infections and their management, which were last published in 2003. Methods and Results. The AHA commissioned this scientific sta

  2. A summary of the update on cardiovascular implantable electronic device infections and their management A scientific statement from the American Heart Association

    NARCIS (Netherlands)

    Baddour, Larry M.; Epstein, Andrew E.; Erickson, Christopher C.; Knight, Bradley P.; Levison, Matthew E.; Lockhart, Peter B.; Masoudi, Frederick A.; Okum, Eric J.; Wilson, Walter R.; Beerman, Lee B.; Bolger, Ann F.; Estes, N. A. Mark; Gewitz, Michael; Newburger, Jane W.; Schron, Eleanor B.; Taubert, Kathryn A.

    Background. The purpose of this statement is to update the recommendations by the American Heart Association (AHA) for cardiovascular implantable electronic device (CIED) infections and their management, which were last published in 2003. Methods and Results. The AHA commissioned this scientific

  3. [The clinical practice guidelines of the Sociedad Española de Cardiología on the automatic implantable defibrillator]. (United States)

    Pérez-Villacastín, J; Carmona Salinas, J R; Hernández Madrid, A; Marín Huerta, E; Merino Llorens, J L; Ormaetxe Merodio, J; Moya i Mitjans, A


    Since the first implantation in man in 1980 implantable cardioverter defibrillator technology has greatly improved and the number of devices implanted has increased considerably every year. Non thoracotomy lead systems and biphasic shocks are now the approach of choice, offering an almost 100% success rate. This document reviews the recommendations for qualification of personnel and for the centres implanting and carrying out follow-ups on defibrillators. The current indications for the implantation of implantable cardioverter defibrillator are also addressed.

  4. Principle and experimental investigation of current-driven negative-inductance superconducting quantum interference device (United States)

    Li, Hao; Liu, Jianshe; Zhang, Yingshan; Cai, Han; Li, Gang; Liu, Qichun; Han, Siyuan; Chen, Wei


    A negative-inductance superconducting quantum interference device (nSQUID) is an adiabatic superconducting logic device with high energy efficiency, and therefore a promising building block for large-scale low-power superconducting computing. However, the principle of the nSQUID is not that straightforward and an nSQUID driven by voltage is vulnerable to common mode noise. We investigate a single nSQUID driven by current instead of voltage, and clarify the principle of the adiabatic transition of the current-driven nSQUID between different states. The basic logic operations of the current-driven nSQUID with proper parameters are simulated by WRspice. The corresponding circuit is fabricated with a 100 A cm‑2 Nb-based lift-off process, and the experimental results at low temperature confirm the basic logic operations as a gated buffer.

  5. Modeling and Simulation of the Current Quenching Behavior of a Line Lightning Protection Device

    CERN Document Server

    Mürmann, Mario; Fuchs, Roman; Nefedov, Alexander; Nordborg, Henrik


    We develop a consistent model for a Line Lightning Protection Device and demonstrate that this model can explain the two modes of current quenching -- impulse quenching and current zero quenching -- observed in such devices. A dimensional analysis shows that impulse quenching can always be obtained if the power loss from the electric arcs is large enough as compared to $U_0 I_f$, where $U_0$ is the grid voltage and $I_f$ is the maximum follow current after a lightning strike. We further show that the two modes of quenching can be reproduced in a full 3D arc simulations coupled to the appropriate circuit model. This means the arc simulations can be used for optimization and development of future LLPDs.

  6. Modeling the current-voltage characteristics of bilayer polymer photovoltaic devices (United States)

    Barker, J. A.; Ramsdale, C. M.; Greenham, N. C.


    We have developed a numerical model to predict the current-voltage curves of bilayer conjugated polymer photovoltaic devices. The model accounts for charge photogeneration, injection, drift, diffusion, and recombination, and includes the effect of space charge on the electric field within the device. Charge separation at the polymer-polymer interface leads to the formation of bound polaron pairs which may either recombine monomolecularly or be dissociated into free charges, and we develop expressions for the field dependence of the dissociation rate. We find that the short-circuit quantum efficiency is determined by the competition between polaron pair dissociation and recombination. The model shows a logarithmic dependence of the open-circuit voltage on the incident intensity, as seen experimentally. This additional intensity-dependent voltage arises from the field required to produce a drift current that balances the current due to diffusion of carriers away from the interface.

  7. Rupture of totally implantable central venous access devices (Intraports in patients with cancer: report of four cases

    Directory of Open Access Journals (Sweden)

    Filippou Georgios K


    Full Text Available Abstract Background Totally implantable central venous access devices (intraports are commonly used in cancer patients to administer chemotherapy or parenteral nutrition. Rupture of intraport is a rare complication. Patients and methods During 3 years period, a total of 245 intraports were placed in cancer patients for chemotherapy. Four of these cases (two colon cancer and one each of pancreas and breast cancer had rupture of the intraport catheter, these forms the basis of present report. Results Mean time insitu for intraports was 164∀35 days. Median follow-up time was 290 days and total port time in situ was 40180 days. The incidence of port rupture was 1 per 10,000 port days. Three of the 4 cases were managed by successful removal of catheters. In two of these the catheter was removed under fluoroscopic control using femoral route, while in the third patient the catheter (partial rupture was removed surgically. One of the catheters could not be removed and migrated to right ventricle on manipulations. Conclusion Port catheter rupture is a rare but dreaded complication associated with subcutaneous port catheter device placement for chemotherapy. In case of such an event the patient should be managed by an experienced vascular surgeon and interventional radiologist, as in most cases the ruptured catheter can be retrieved by non operative interventional measures.

  8. Recanalization of Chronic Total Occlusion Lesions: A Critical Appraisal of Current Devices and Techniques (United States)


    Chronic Total Occlusion (CTO) has been considered as one of the “final frontier” in interventional cardiology. Until recently, the patients with CTO are often managed surgically or medically due to lack of published evidence of clinical benefits and lower success rate of percutaneous recanalization of CTO. However, the introduction of enhanced guidewires, microcatheters combined with novel specialized devices and techniques reduce the number of unapproachable CTO. In this review article, current techniques and devices of percutaneous recanalization of CTO have been systematically summarized, which may help budding interventional cardiologists to theoretically understand these complex procedures and to deliver safe and effective percutaneous management of CTO to the patients. PMID:27790503

  9. Retinal implants: a systematic review. (United States)

    Chuang, Alice T; Margo, Curtis E; Greenberg, Paul B


    Retinal implants present an innovative way of restoring sight in degenerative retinal diseases. Previous reviews of research progress were written by groups developing their own devices. This systematic review objectively compares selected models by examining publications describing five representative retinal prostheses: Argus II, Boston Retinal Implant Project, Epi-Ret 3, Intelligent Medical Implants (IMI) and Alpha-IMS (Retina Implant AG). Publications were analysed using three criteria for interim success: clinical availability, vision restoration potential and long-term biocompatibility. Clinical availability: Argus II is the only device with FDA approval. Argus II and Alpha-IMS have both received the European CE Marking. All others are in clinical trials, except the Boston Retinal Implant, which is in animal studies. Vision restoration: resolution theoretically correlates with electrode number. Among devices with external cameras, the Boston Retinal Implant leads with 100 electrodes, followed by Argus II with 60 electrodes and visual acuity of 20/1262. Instead of an external camera, Alpha-IMS uses a photodiode system dependent on natural eye movements and can deliver visual acuity up to 20/546. Long-term compatibility: IMI offers iterative learning; Epi-Ret 3 is a fully intraocular device; Alpha-IMS uses intraocular photosensitive elements. Merging the results of these three criteria, Alpha-IMS is the most likely to achieve long-term success decades later, beyond current clinical availability.

  10. Ventricular Assist Device implant (AB 5000 prototype cannula: In vitro assessment of MRI issues at 3-Tesla

    Directory of Open Access Journals (Sweden)

    Valencerina Samuel


    Full Text Available Abstract Purpose To evaluate MRI issues at 3-Tesla for a ventricular assist device (VAD. Methods The AB5000 Ventricle with a prototype Nitinol wire-reinforced In-Flow Cannula and Out-Flow Cannula attached (Abiomed, Inc., Danvers, MA was evaluated for magnetic field interactions, heating, and artifacts at 3-Tesla. MRI-related heating was assessed with the device in a gelled-saline-filled, head/torso phantom using a transmit/received RF body coil while performing MRI at a whole body averaged SAR of 3-W/kg for 15-min. Artifacts were assessed for the main metallic component of this VAD (atrial cannula using T1-weighted, spin echo and gradient echo pulse sequences. Results The AB5000 Ventricle with the prototype In-Flow Cannula and Out-Flow Cannula attached showed relatively minor magnetic field interactions that will not cause movement in situ. Heating was not excessive (highest temperature change, +0.8°C. Artifacts may create issues for diagnostic imaging if the area of interest is in the same area or close to the implanted metallic component of this VAD (i.e., the venous cannula. Conclusion The results of this investigation demonstrated that it would be acceptable for a patient with this VAD (AB5000 Ventricle with a prototype Nitinol wire-reinforced In-Flow Cannula and Out-Flow Cannula attached to undergo MRI at 3-Tesla or less. Notably, it is likely that the operation console for this device requires positioning a suitable distance (beyond the 100 Gauss line or in the MR control room from the 3-Tesla MR system to ensure proper function of the VAD.

  11. Performance of an implantable automatic atrial fibrillation detection device: impact of software adjustments and relevance of manual episode analysis. (United States)

    Eitel, Charlotte; Husser, Daniela; Hindricks, Gerhard; Frühauf, Manuela; Hilbert, Sebastian; Arya, Arash; Gaspar, Thomas; Wetzel, Ulrike; Bollmann, Andreas; Piorkowski, Christopher


    Implantable loop recorders (ILRs) with specific atrial fibrillation (AF) detection algorithms (ILR-AF) have been developed for continuous AF monitoring. We sought to analyse the clinical value of a new AF monitoring device and to compare it to serial 7-day Holter. Sixty-four consecutive patients suffering from paroxysmal AF were included in this prospective analysis and received an ILR-AF. Manual electrogram analysis was performed for each automatically detected episode and each was categorized into one of three possible diagnoses: 'no AF', 'definite AF', and 'possible AF' (non-diagnostic). Analysis was performed separately before and after a software upgrade that was introduced during the course of the study. A subgroup of patients (51 of 64) underwent AF catheter ablation with subsequent serial 7-day Holter in comparison with the ILR-AF. A total of 333 interrogations were performed (203 before and 130 after software upgrade). The number of patients with AF misdetection was significantly reduced from 72 to 44% following the software upgrade (P = 0.001). The number of patients with non-diagnostic interrogations went from 38 to 16% (P = 0.001). Compared with serial 7-day Holter, the ILR-AF had a tendency to detect a higher number of patients with AF recurrences (31 vs. 24%; P = 0.125). The rate of AF detection on ILR-AF may be higher compared with standard AF monitoring. However, false-positive AF recordings hamper the clinical value. Developments in device technology and device handling are necessary to minimize non-diagnostic interrogations.

  12. Pericarditis-induced hyponatremia after cardiac electronic implantable device (CEID) procedures. (United States)

    Rakhshan, Elnaz; Mirabbasi, Seyed Abbas; Khalighi, Bahar; Khalighi, Koroush


    Pericardial effusion along with pleural effusion is one of the rare complications of permanent pacemaker placement. Although extremely uncommon, it is more prevalent in elderly patients and may be complicated with hyponatremia. We observed development of hyponatremia in association with pericardial effusion and pleural effusion, within one month after pacemaker placement in two women with BMI of heart block. Three weeks later, she complained of progressive left-sided rib cage pain and poor oral intake. Her echocardiography showed a moderately large amount of pericardial effusion, but no evidence of tamponade. She also had hyponatremia (Na=119 mEq/dl). Extensive work-up suggested hyponatremia presumably due to SIADH, caused by pericardial/pleural effusion. Case 2: An 83-year-old woman with history of severe sick sinus syndrome required a transvenous Av sequential pacemaker 3 weeks before. She then presented with generalized weakness, fatigue, and poor oral intake of over one week. There was a small-moderate pericardial effusion echocardiographically, and her serum sodium was 116 mEq/dl. Although extremely uncommon, pericarditis can develop following transvenous pacemaker insertion, which may result in hyponatremia, likely due to SIADH. The most common scenario is an elderly, petite woman with low BMI (<20), usually after using a helical screw/active fixation pacing leads, several weeks post-implant. Early recognition and therapy can significantly improve outcome and morbidity.

  13. A Low-Power Asynchronous Step-Down DC-DC Converter for Implantable Devices. (United States)

    Al-Terkawi Hasib, Omar; Sawan, M; Savaria, Y


    In this paper, we present a fully integrated asynchronous step-down switched capacitor dc-dc conversion structure suitable for supporting ultra-low-power circuits commonly found in biomedical implants. The proposed converter uses a fully digital asynchronous state machine as the heart of the control circuitry to generate the drive signals. To minimize the switching losses, the asynchronous controller scales the switching frequency of the drive signals according to the loading conditions. It also turns on additional parallel switches when needed and has a backup synchronous drive mode. This circuit regulates load voltages from 300 mV to 1.1 V derived from a 1.2-V input voltage. A total of 350 pF on-chip capacitance was implemented to support a maximum of 230-μ W load power, while providing efficiency up to 80%. The circuit validating the proposed concepts was fabricated in 0.13- μm complementary metal-oxide semiconductor technology. Experimental test results confirm the expected functionality and performance of the proposed circuit.

  14. Management of three cardiogenic pulmonary edemas occurring in a patient scheduled for left ventricular assist device implantation: indicators for determining left ventricular assist device pump speed. (United States)

    Toyama, Hiroaki; Takei, Yusuke; Saito, Kazutomo; Ota, Takahisa; Kurotaki, Kenji; Ejima, Yutaka; Matsuura, Takeshi; Akiyama, Masatoshi; Saiki, Yoshikatsu; Yamauchi, Masanori


    A male patient with Marfan syndrome underwent aortic root replacement and developed left ventricular (LV) failure. Four years later, he underwent aortic arch and aortic valve replacement. Thereafter, his LV failure progressed, and cardiogenic pulmonary edema (CPE) appeared, which we treated with extracorporeal LV assist device (LVAD) placement. Three months later, the patient developed aspiration pneumonia, which caused hyperdynamic right ventricle (RV) and CPE. We treated by changing his pneumatic LVAD to a high-flow centrifugal pump. A month later, he underwent thoracoabdominal aortic replacement. After four weeks, he developed septic thrombosis and LVAD failure, which caused CPE. We treated with LVAD circuit replacement and an additional membrane oxygenator. Four months later, he underwent DuraHeart(®) implantation. During this course, pulmonary artery wedge pressure (PAWP) varied markedly. Additionally, systolic pulmonary artery pressure (sPAP), left atrial diameter (LAD), RV end-diastolic diameter (RVEDD) and estimated RV systolic pressure (esRVP) changed with PAWP changes. In this patient, LV failure and hyperdynamic RV caused the CPEs, which we treated by adjusting the LVAD output to the RV output. Determining LVAD output, RV function and LV end-diastolic diameter are typically referred, and PAWP, LAD, RVEDD, and sPAP could be also referred.

  15. A Review of Additive Mixed-Electric Discharge Machining: Current Status and Future Perspectives for Surface Modification of Biomedical Implants

    Directory of Open Access Journals (Sweden)

    Abdul’Azeez Abdu Aliyu


    Full Text Available Surface treatment remained a key solution to numerous problems of synthetic hard tissues. The basic methods of implant surface modification include various physical and chemical deposition techniques. However, most of these techniques have several drawbacks such as excessive cost and surface cracks and require very high sintering temperature. Additive mixed-electric discharge machining (AM-EDM is an emerging technology which simultaneously acts as a machining and surface modification technique. Aside from the mere molds, dies, and tool fabrication, AM-EDM is materializing to finishing of automobiles and aerospace, nuclear, and biomedical components, through the concept of material migrations. The mechanism of material transfer by AM-EDM resembles electrophoretic deposition, whereby the additives in the AM-EDM dielectric fluids are melted and migrate to the machined surface, forming a mirror-like finishing characterized by extremely hard, nanostructured, and nanoporous layers. These layers promote the bone in-growth and strengthen the cell adhesion. Implant shaping and surface treatment through AM-EDM are becoming a key research focus in recent years. This paper reports and summarizes the current advancement of AM-EDM as a potential tool for orthopedic and dental implant fabrication. Towards the end of this paper, the current challenges and future research trends are highlighted.

  16. Biasing, operation and parasitic current limitation in single device equivalent to CMOS, and other semiconductor systems (United States)

    Welch, James D.


    Disclosed are semiconductor devices including at least one junction which is rectifying whether the semiconductor is caused to be N or P-type, by the presence of applied gate voltage field induced carriers in essentially intrinsic, essentially homogeneously simultaneously containing both N and P-type metallurgical dopants at substantially equal doping levels, essentially homogeneously simultaneously containing both N and P-type metallurgical dopants at different doping levels, and containing a single metallurgical doping type, and functional combinations thereof. In particular, inverting and non-inverting gate voltage channel induced semiconductor single devices with operating characteristics similar to conventional multiple device CMOS systems, which can be operated as modulators, are disclosed as are a non-latching SCR and an approach to blocking parasitic currents utilizing material(s) which form rectifying junctions with both N and P-type semiconductor whether metallurigically or field induced.

  17. Novel Alternating Current Electroluminescent Devices with an Asymmetric Structure Based on a Polymer Heterojunction

    Institute of Scientific and Technical Information of China (English)

    谭海曙; 姚建铨; 王昕; 王鹏; 谢洪泉


    Novel alternating current electroluminescent devices with an asymmetric structure are successfully fabricated by using a hole-type polymer, poly(2,5-bis (dodecyloxy)-phenylenevinylene) (PDDOPV), and an electron-type polymer, poly(phenyl quinoxaline) (PPQ). The performance of the polymer devices with heteto junctions under ac operation is insensitive to the thickness of the two polymer layers, compared to that under dc operation. This new advantage means easy and cheap production facility on a large scale in the near future. Different emission spectra are obtained when our ac devices are operated in an ac mode, forward or reverse bias. The emission spectrum at reverse bias includes two parts: one from PDDOPV and the other from PPQ.

  18. Thermal analytic model of current gain for bipolar junction transistor-bipolar static induction transistor compound device

    Institute of Scientific and Technical Information of China (English)

    Zhang You-Run; Zhang Bo; Li Ze-Hong; Lai Chang-Jin; Li Zhao-Ji


    This paper proposes a thermal analytical model of current gain for bipolar junction transistor-bipolar static induction transistor (BJT-BSIT) compound device in the low current operation. It also proposes a best thermal compensating factor to the compound device that indicates the relationship between the thermal variation rate of current gain and device structure. This is important for the design of compound device to be optimized. Finally, the analytical model is found to be in good agreement with numerical simulation and experimental results. The test results demonstrate that thermal variation rate of current gain is below 10% in 25℃C-85℃ and 20% in -55℃-25℃.

  19. Sleep-disordered breathing in heart failure patients after ventricular assist device implantation and heart transplantation. (United States)

    Chowdhury, Anindita; Mathew, Reeba; Castriotta, Richard J


    Chronic heart failure (CHF) represents a major health and economic burden and is associated with high rates of hospital admission, morbidity, mortality and decreased quality-adjusted life years. New advances in the treatment of CHF such as ventricular assist devices (VADs) and heart transplantation have helped improve outcomes. Sleep-disordered breathing (SDB) is highly prevalent in CHF patients and the associated morbidity makes it essential for physicians to be more cognizant about its existence, interaction and need for treatment. This is a review of what is known to date about SDB in CHF patients who have undergone advanced treatments with VADs and/or heart transplantation.

  20. Performances of low-dose dual-energy CT in reducing artifacts from implanted metallic orthopedic devices

    Energy Technology Data Exchange (ETDEWEB)

    Filograna, Laura [Catholic University of Rome, School of Medicine, University Hospital ' ' A. Gemelli' ' , Department of Radiological Sciences, Institute of Radiology, Rome (Italy); University of Zurich, Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, Zurich (Switzerland); Magarelli, Nicola; Leone, Antonio; Bonomo, Lorenzo [Catholic University of Rome, School of Medicine, University Hospital ' ' A. Gemelli' ' , Department of Radiological Sciences, Institute of Radiology, Rome (Italy); De Waure, Chiara; Calabro, Giovanna Elisa [Catholic University of Rome, School of Medicine, University Hospital ' ' A. Gemelli' ' , Research Centre for Health Technology Assessment, Department of Public Health, Section of Hygiene, Rome (Italy); Finkenstaedt, Tim [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Thali, Michael John [University of Zurich, Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, Zurich (Switzerland)


    The objective was to evaluate the performances of dose-reduced dual-energy computed tomography (DECT) in decreasing metallic artifacts from orthopedic devices compared with dose-neutral DECT, dose-neutral single-energy computed tomography (SECT), and dose-reduced SECT. Thirty implants in 20 consecutive cadavers underwent both SECT and DECT at three fixed CT dose indexes (CTDI): 20.0, 10.0, and 5.0 mGy. Extrapolated monoenergetic DECT images at 64, 69, 88, 105, 120, and 130 keV, and individually adjusted monoenergy for optimized image quality (OPTkeV) were generated. In each group, the image quality of the seven monoenergetic images and of the SECT image was assessed qualitatively and quantitatively by visually rating and by measuring the maximum streak artifact respectively. The comparison between SECT and OPTkeV evaluated overall within all groups showed a significant difference (p <0.001), with OPTkeV images providing better images. Comparing OPTkeV with the other DECT images, a significant difference was shown (p <0.001), with OPTkeV and 130-keV images providing the qualitatively best results. The OPTkeV images of 5.0-mGy acquisitions provided percentages of images with scores 1 and 2 of 36 % and 30 % respectively, compared with 0 % and 33.3 % of the corresponding SECT images of 10- and 20-mGy acquisitions. Moreover, DECT reconstructions at the OPTkeV of the low-dose group showed higher CT numbers than the SECT images of dose groups 1 and 2. This study demonstrates that low-dose DECT permits a reduction of artifacts due to metallic implants to be obtained in a similar manner to neutral-dose DECT and better than reduced or neutral-dose SECT. (orig.)

  1. Review of Mechanical Testing and Modelling of Thrombus Material for Vascular Implant and Device Design. (United States)

    Johnson, S; Duffy, S; Gunning, G; Gilvarry, M; McGarry, J P; McHugh, P E


    A thrombus or blood clot is a solid mass, made up of a network of fibrin, platelets and other blood components. Blood clots can form through various pathways, for example as a result of exposed tissue factor from vascular injury, as a result of low flow/stasis, or in very high shear flow conditions. Embolization of cardiac or vascular originating blood clots, causing an occlusion of the neurovasculature, is the major cause of stroke and accounts for 85% of all stroke. With mechanical thrombectomy emerging as the new standard of care in the treatment of acute ischemic stroke (AIS), the need to generate a better understanding of the biomechanical properties and material behaviour of thrombus material has never been greater, as it could have many potential benefits for the analysis and performance of these treatment devices. Defining the material properties of a thrombus has obvious implications for the development of these treatment devices. However, to-date this definition has not been adequately established. While some experimentation has been performed, model development has been extremely limited. This paper reviews the previous literature on mechanical testing of thrombus material. It also explores the use of various constitutive and computational models to model thrombus formation and material behaviour.

  2. Cardiac Sarcoidosis: The Impact of Age and Implanted Devices on Survival. (United States)

    Zhou, Ying; Lower, Elyse E; Li, Hui-Ping; Costea, Alexandru; Attari, Mehran; Baughman, Robert P


    To assess the clinical characteristics, diagnosis, and outcome of cardiac sarcoidosis in a single institution sarcoidosis clinic. Patients with cardiac sarcoidosis were identified using refined World Association of Sarcoidosis and Other Granulomatous Diseases (WASOG) criteria of highly probable and probable. Patient demographics, local and systemic treatments, and clinical outcome were collected. Of the 1,815 patients evaluated over a 6-year period, 73 patients met the WASOG criteria for cardiac sarcoidosis. The median age at diagnosis was 46 years, with a median follow-up of 8.8 years. Reduced left ventricular ejection fraction (LVEF) was the most common manifestation (54.8%). Patients with arrhythmias experienced ventricular tachycardia or severe heart block, (35.6% and 19.2%, respectively) with or without reduced LVEF. A total of 45 (61.6%) patients underwent cardiac PET scan and/or MRI, with 41 (91.1%) having a positive study. During follow-up, 10 patients (13.7%) either underwent transplant (n = 3) or died (n = 7) from sarcoidosis. Kaplan-Meier survival curves revealed 5- and 10-year survival rates of 95.5% and 93.4%, respectively. Univariate factors of age at diagnosis  40% were associated with improved survival. Cox regression analysis demonstrated that age ≥ 46 years and lack of an implanted pacemaker or defibrillator were the only independent predictors of mortality. The new WASOG criteria were able to characterize cardiac involvement in our sarcoidosis clinic. Age and lack of pacemaker or defibrillator were the significant predictors of mortality for cardiac sarcoidosis, and reduced LVEF < 40% was associated with worse prognosis.; No.: NCT02356445; URL: Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  3. Redundant drive current imbalance problem of the Automatic Radiator Inspection Device (ARID) (United States)

    Latino, Carl D.


    The Automatic Radiator Inspection Device (ARID) is a 4 Degree of Freedom (DOF) robot with redundant drive motors at each joint. The device is intended to automate the labor intensive task of space shuttle radiator inspection. For safety and redundancy, each joint is driven by two independent motor systems. Motors driving the same joint, however, draw vastly different currents. The concern was that the robot joints could be subjected to undue stress. It was the objective of this summer's project to determine the cause of this current imbalance. In addition it was to determine, in a quantitative manner, what was the cause, how serious the problem was in terms of damage or undue wear to the robot and find solutions if possible. It was concluded that most problems could be resolved with a better motor control design. This document discusses problems encountered and possible solutions.

  4. A system architecture, processor, and communication protocol for secure implants

    NARCIS (Netherlands)

    C. Strydis (Christos); R.M. Seepers (Robert); P. Peris-Lopez (Pedro); D. Siskos (Dimitrios); I. Sourdis (Ioannis)


    textabstractSecure and energy-efficient communication between Implantable Medical Devices (IMDs) and authorized external users is attracting increasing attention these days. However, there currently exists no systematic approach to the problem, while solutions from neighboring fields, such as

  5. Eddy current nondestructive testing device for measuring variable characteristics of a sample utilizing Walsh functions (United States)

    Libby, Hugo L.; Hildebrand, Bernard P.


    An eddy current testing device for measuring variable characteristics of a sample generates a signal which varies with variations in such characteristics. A signal expander samples at least a portion of this generated signal and expands the sampled signal on a selected basis of square waves or Walsh functions to produce a plurality of signal components representative of the sampled signal. A network combines these components to provide a display of at least one of the characteristics of the sample.

  6. Enhanced Ion Current Rectification in 2D Graphene‐Based Nanofluidic Devices


    MIANSARI, Morteza; Friend, James R.; Yeo, Leslie Y.


    Furthering the promise of graphene‐based planar nanofluidic devices as flexible, robust, low cost, and facile large‐scale alternatives to conventional nanochannels for ion transport, we show how the nonlinear current–voltage (I–V) characteristics and ion current rectification in these platforms can be enhanced by increasing the system asymmetry. Asymmetric cuts made to the 2D multilayered graphene oxide film, for example, introduces further asymmetry to that natively inherent in the structura...

  7. Analysis of Current Source PWM Inverter for Different Levels with No-Insulating Switching Device

    Directory of Open Access Journals (Sweden)

    Kumar Abhishek


    Full Text Available This paper gives the new set-up of inverter having DC current source (CSI having no insulated switching device. In the proposed new CSI topology every switching device are connected across a common-source level, thus a single power supply gate drive circuit is required and no insulated power supply and the customary bootstrap circuit is applied. This CSI topology is even legitimate for utmost level of current waveform output, where the power switches number increases. As a turn up, gate drive complexity is reduced, and it also eliminates the cost of capacitors and transformers in switching devices, driver circuits. In addition, this new topology of current-source PWM inverter (CSI can operate even at utmost switching frequency, as every switches will be connected across a common source level. In this paper the different level of proposed CSI operation principle, its design using computer simulation (MATLAB with its total harmonic distortion (THD is analyzed. The computer simulation using MATLAB determines the feasibility of this topology with the analysis of different level which results in reduction of its complexity and the physical size.

  8. Current and Planned Cochlear Implant Research at New York University Laboratory for Translational Auditory Research (United States)

    Svirsky, Mario A.; Fitzgerald, Matthew B.; Neuman, Arlene; Sagi, Elad; Tan, Chin-Tuan; Ketten, Darlene; Martin, Brett


    The Laboratory of Translational Auditory Research (LTAR/NYUSM) is part of the Department of Otolaryngology at the New York University School of Medicine and has close ties to the New York University Cochlear Implant Center. LTAR investigators have expertise in multiple related disciplines including speech and hearing science, audiology, engineering, and physiology. The lines of research in the laboratory deal mostly with speech perception by hearing impaired listeners, and particularly those who use cochlear implants (CIs) or hearing aids (HAs). Although the laboratory's research interests are diverse, there are common threads that permeate and tie all of its work. In particular, a strong interest in translational research underlies even the most basic studies carried out in the laboratory. Another important element is the development of engineering and computational tools, which range from mathematical models of speech perception to software and hardware that bypass clinical speech processors and stimulate cochlear implants directly, to novel ways of analyzing clinical outcomes data. If the appropriate tool to conduct an important experiment does not exist, we may work to develop it, either in house or in collaboration with academic or industrial partners. Another notable characteristic of the laboratory is its interdisciplinary nature where, for example, an audiologistandan engineer might work closely to develop an approach that would not have been feasible if each had worked singly on the project. Similarly, investigators with expertise in hearing aids and cochlear implants might join forces to study how human listeners integrate information provided by a CI and a HA. The following pages provide a flavor of the diversity and the commonalities of our research interests. PMID:22668763

  9. Numerical Analysis on Current Transport Characteristics in Single Layer Organic Electroluminescent Devices

    Institute of Scientific and Technical Information of China (English)


    A new model to describe I-V characteristics of organic light-emitting devices (OLEDs) is developed based on experimental results. The dependence of I-V characteristics on energy barrier, trap density and carrier mobility is analyzed. The result shows that this model combin