Journal articles: 'Active Implantable Device'

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Jensen, Maria Lund, and Jayme Coates. "Planning Human Factors Engineering for Development of Implantable Medical Devices." Proceedings of the International Symposium on Human Factors and Ergonomics in Health Care 7, no. 1 (June 2018): 156–60. http://dx.doi.org/10.1177/2327857918071037.

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Development of implantable medical devices is becoming increasingly interesting for manufacturers, but identifying the right Human Factors Engineering (HFE) approach to ensure safe use and effectiveness is challenging. Most active implantable devices are highly complex; they are built on extremely advanced, compact technology, often comprise systems of several device elements and accessories, and they span various types of user interfaces which must facilitate diverse interaction performed by several different user groups throughout the lifetime of the device. Furthermore, since treatment with implantable devices is often vital and by definition involves surgical procedures, potential risks related to use error can be severe. A systematic mapping of Product System Elements and Life Cycle Stages can help early identification of Use Cases, and for example user groups and high-level use risks, to be accounted for via HFE throughout development to optimize Human Factors processes and patient outcomes. This paper presents a concrete matrix tool which can facilitate an early systematic approach to planning and frontloading of Human Factors Engineering activities in complex medical device development.

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McEvedy, Samantha M., Jan Cameron, Eugene Lugg, Jennifer Miller, Chris Haedtke, Muna Hammash, Martha J. Biddle, et al. "Implantable cardioverter defibrillator knowledge and end-of-life device deactivation: A cross-sectional survey." Palliative Medicine 32, no. 1 (July 5, 2017): 156–63. http://dx.doi.org/10.1177/0269216317718438.

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Background: End-of-life implantable cardioverter defibrillator deactivation discussions should commence before device implantation and be ongoing, yet many implantable cardioverter defibrillators remain active in patients’ last days. Aim: To examine associations among implantable cardioverter defibrillator knowledge, patient characteristics and attitudes to implantable cardioverter defibrillator deactivation. Design: Cross-sectional survey using the Experiences, Attitudes and Knowledge of End-of-Life Issues in Implantable Cardioverter Defibrillator Patients Questionnaire. Participants were classified as insufficient or sufficient implantable cardioverter defibrillator knowledge and the two groups were compared. Setting/participants: Implantable cardioverter defibrillator recipients ( n = 270, mean age 61 ± 14 years; 73% male) were recruited from cardiology and implantable cardioverter defibrillator clinics attached to two tertiary hospitals in Melbourne, Australia, and two in Kentucky, the United States. Results: Participants with insufficient implantable cardioverter defibrillator knowledge ( n = 77, 29%) were significantly older (mean age 66 vs 60 years, p = 0.001), less likely to be Caucasian (77% vs 87%, p = 0.047), less likely to have received implantable cardioverter defibrillator shocks (26% vs 40%, p = 0.031), and more likely to have indications of mild cognitive impairment (Montreal Cognitive Assessment score <24: 44% vs 16%, p < 0.001). Insufficient implantable cardioverter defibrillator knowledge was associated with attitudes suggesting unwillingness to discuss implantable cardioverter defibrillator deactivation, even during the last days towards end of life ( p < 0.05). Conclusion: Implantable cardioverter defibrillator recipients, especially those who are older or have mild cognitive impairment, often have limited knowledge about implantable cardioverter defibrillator deactivation. This study identified several potential teachable moments throughout the patients’ treatment trajectory. An interdisciplinary approach is required to ensure that discussions about implantable cardioverter defibrillator deactivation issues are initiated at appropriate time points, with family members ideally also included.

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Fong, Jeffrey, Zhiming Xiao, and Kenichi Takahata. "Wireless implantable chip with integrated nitinol-based pump for radio-controlled local drug delivery." Lab on a Chip 15, no. 4 (2015): 1050–58. http://dx.doi.org/10.1039/c4lc01290a.

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Patil, B. P., Deepali Newaskar, Kunal Sharma, Tarun Baghmar, and Mahesh Ku Rajput. "EFFECT OF NUMBER OF TURNS AND MEDIUM BETWEEN COILS ON THE WIRELESS POWER TRANSFER EFFICIENCY OF AIMD’S." Biomedical Engineering: Applications, Basis and Communications 31, no. 02 (April 2019): 1950016. http://dx.doi.org/10.4015/s1016237219500169.

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Active implantable medical devices (AIMDs) like implantable cardiac pacemakers play very important role in extending lives of patients with some cardiovascular diseases. The life of implantable device depends on life of battery. If this device can be charged from outside with power transfer device, then the cost of surgical procedures for patient can be saved. One must ensure, while transferring this power there should not be any abnormal effect on human body tissues. Wireless recharging of such devices through magnetic resonant coupling is of concern and hence the topic of more research to have uninterrupted supply from battery. The technique of wireless power transfer, primary or transmitting coil is assumed to be on body and receiver coil is assumed to be inside the human body. Several critical aspects need to be studied while designing coil for wireless power transfer (WPT). One of which is choice of operational frequency. In this research experiment, designed circuit is tested for checking power transfer was studied. Effect of the distance between primary and secondary coil affects the efficiency of power transfer. Authors also tied to test this for using different medium like air, placing 80 GSM paper and cloth. It is found that the medium between the primary and secondary affects the transfer of power. Careful thought needs to be given while designing power transfer system.

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Stoevelaar, Rik, Arianne Stoppelenburg, Rozemarijn L. van Bruchem-Visser, Anne Geert van Driel, Dominic AMJ Theuns, Martine E. Lokker, Rohit E. Bhagwandien, Agnes van der Heide, and Judith AC Rietjens. "Advance care planning and end-of-life care in patients with an implantable cardioverter defibrillator: The perspective of relatives." Palliative Medicine 35, no. 5 (April 13, 2021): 904–15. http://dx.doi.org/10.1177/02692163211001288.

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Background: Little is known about the last phase of life of patients with implantable cardioverter defibrillators and the practice of advance care planning in this population. Aim: To describe the last phase of life and advance care planning process of patients with an implantable cardioverter defibrillator, and to assess relatives’ satisfaction with treatment and care. Design: Mixed-methods study, including a survey and focus group study. Setting/participants: A survey among 170 relatives (response rate 59%) reporting about 154 deceased patients, and 5 subsequent focus groups with 23 relatives. Results: Relatives reported that 38% of patients had a conversation with a healthcare professional about implantable cardioverter defibrillator deactivation. Patients’ and relatives’ lack of knowledge about device functioning and the perceived lack of time of healthcare professionals were frequently mentioned barriers to advance care planning. Twenty-four percent of patients experienced a shock in the last month of life, which were, according to relatives, distressing for 74% of patients and 73% of relatives. Forty-two to sixty-one percent of relatives reported to be satisfied with different aspects of end-of-life care, such as the way in which wishes of the patient were respected. Quality of death was scored higher for patients with a deactivated device than those with an active device (6.74 vs 5.67 on a 10-point scale, p = 0.012). Conclusions: Implantable cardioverter defibrillator deactivation was discussed with a minority of patients. Device shocks were reported to be distressing to patients and relatives. Relatives of patients with a deactivated device reported a higher quality of death compared to relatives of patients with an active device.

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YOSHINO, Yuuki, and Masao TAKI. "Induced Voltage to an Active Implantable Medical Device by a Near-Field Intra-Body Communication Device." IEICE Transactions on Communications E94-B, no. 9 (2011): 2473–79. http://dx.doi.org/10.1587/transcom.e94.b.2473.

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Yan, Bingxi. "Actuators for Implantable Devices: A Broad View." Micromachines 13, no. 10 (October 17, 2022): 1756. http://dx.doi.org/10.3390/mi13101756.

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The choice of actuators dictates how an implantable biomedical device moves. Specifically, the concept of implantable robots consists of the three pillars: actuators, sensors, and powering. Robotic devices that require active motion are driven by a biocompatible actuator. Depending on the actuating mechanism, different types of actuators vary remarkably in strain/stress output, frequency, power consumption, and durability. Most reviews to date focus on specific type of actuating mechanism (electric, photonic, electrothermal, etc.) for biomedical applications. With a rapidly expanding library of novel actuators, however, the granular boundaries between subcategories turns the selection of actuators a laborious task, which can be particularly time-consuming to those unfamiliar with actuation. To offer a broad view, this study (1) showcases the recent advances in various types of actuating technologies that can be potentially implemented in vivo, (2) outlines technical advantages and the limitations of each type, and (3) provides use-specific suggestions on actuator choice for applications such as drug delivery, cardiovascular, and endoscopy implants.

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Wang, Zhichao, Jianfeng Zheng, Yu Wang, Wolfgang Kainz, and Ji Chen. "On the Model Validation of Active Implantable Medical Device for MRI Safety Assessment." IEEE Transactions on Microwave Theory and Techniques 68, no. 6 (June 2020): 2234–42. http://dx.doi.org/10.1109/tmtt.2019.2957766.

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Wagner, Marcel Vila, and Thomas Schanze. "Challenges of Medical Device Regulation for Small and Medium sized Enterprises." Current Directions in Biomedical Engineering 4, no. 1 (September 1, 2018): 653–56. http://dx.doi.org/10.1515/cdbme-2018-0157.

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AbstractFor known reasons, the European Parliament was forced not only to revise the old Medical Device Directive (MDD) and the Active Implantable Medical Devices Directive (AIMDD), but to replace it with the extensive MDR. With the implementation of the Medical Device Regulation (MDR) in May 2017, manufacturers of medical devices will face new challenges for their products in the future, which also have to be implemented in a timely manner. Particularly small and medium-sized enterprises (SMEs) are concerned about whether a timely adaptation to the MDR and their requirements can be implemented. The conversion is associated with a huge effort for all producers of medical devices and certainly, produkt launchers. The purpose of this paper is to get an overview of the most relevant and emerging requirements that manufacturers need to adapt to sell their medical devices in compliance with the MDR regulations. It also explains the extent to which changes and innovations in the MDR are discusses and problems for SMEs.

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Paech, Christian, Victoria Ebel, Franziska Wagner, Stephanie Stadelmann, Annette M. Klein, Mirko Döhnert, Ingo Dähnert, and Roman Antonin Gebauer. "Quality of life and psychological co-morbidities in children and adolescents with cardiac pacemakers and implanted defibrillators: a cohort study in Eastern Germany." Cardiology in the Young 30, no. 4 (April 2020): 549–59. http://dx.doi.org/10.1017/s104795112000061x.

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AbstractIntroduction:The implantation of a pacemaker or an implantable cardioverter-defibrillator during childhood may reduce quality of life and lead to mental health problems. This study aimed to evaluate potential mental health problems (i.e., depressive and anxiety symptoms) and quality of life in children with cardiac active devices in comparison to healthy peers.Methods:We analysed data of children with pacemakers or implantable cardioverter-defibrillators aged 6–18 years. Quality of life, depressive and anxiety symptoms were assessed by standardised questionnaires. The results were compared to age-matched reference groups.Results:Children with implantable cardioverter-defibrillator showed significant lower quality of life in comparison to reference group (p = 0.03), but there was no difference in quality of life between children with pacemaker and reference group. There was no significant difference in depressive symptoms between children with a cardiac rhythm device compared to reference group (self-report: p = 0.67; proxy report: p = 0.49). There was no significant difference in anxiety (p = 0.53) and depressive symptoms (p = 0.86) between children with pacemaker and children with implantable cardioverter-defibrillator.Conclusions:Living with an implantable cardioverter-defibrillator in childhood seems to decrease the patients’ quality of life. Although children with pacemaker and implantable cardioverter-defibrillator don’t seem to show more depressive and anxiety symptoms in comparison to their healthy peers, there still can be an increased risk for those children to develop mental health problems. Therefore, treating physicians should be aware of potential mental health problems and provide the patients and their families with appropriate therapeutic offers.

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Chan, Yin, Stephanie Pranke, Farid Rashidi, Shravan Nosib, and Lawrence Worobetz. "Safety Profile of Liver FibroScan in Patients with Cardiac Pacemakers or Implantable Cardioverter-Defibrillators." Canadian Journal of Gastroenterology and Hepatology 2017 (2017): 1–6. http://dx.doi.org/10.1155/2017/7298032.

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Background. Emerging evidence suggests that nonalcoholic fatty liver disease (NAFLD) is associated with coronary artery diseases and arrhythmias. The FibroScan (Echosens, France), a widely available, noninvasive device, is able to detect liver fibrosis and steatosis within this patient population. However, the FibroScan is currently contraindicated in patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD).Objective. To determine the safety profile of FibroScan testing in patients with PM or ICD.Methods. Consecutive outpatients undergoing routine device interrogations at a tertiary level teaching hospital underwent simultaneous liver stiffness measurements. PM or ICD performance data, device types, patient demographics, medical history, and previous laboratory and conventional liver imaging results were collected.Results. Analysis of 107 subjects with 33 different types of implanted cardiac devices, from 5 different companies (Medtronic, Sorin, ELA Medical, Boston Scientific, and St. Jude), did not demonstrate any adverse events as defined by abnormal device sensing/pacing or ICD firing. This population included high risk subjects undergoing active pacing (n=53) and with right pectoral PM placement (n=1). None of the subjects had any clinical signs of decompensated congestive heart failure or cirrhosis during the exam.Conclusion. TE with FibroScan can be safely performed in patients with PM or ICD.

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Seidman, Seth J., Wolfgang Kainz, Jon Casamento, and Donald Witters. "Electromagnetic Compatibility Testing of Implantable Neurostimulators Exposed to Metal Detectors." Open Biomedical Engineering Journal 4, no. 1 (March 9, 2010): 63–70. http://dx.doi.org/10.2174/1874120701004010063.

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This paper presents results of electromagnetic compatibility (EMC) testing of three implantable neurostimulators exposed to the magnetic fields emitted from several walk-through and hand-held metal detectors. The motivation behind this testing comes from numerous adverse event reports involving active implantable medical devices (AIMDs) and security systems that have been received by the Food and Drug Administration (FDA). EMC testing was performed using three neurostimulators exposed to the emissions from 12 walk-through metal detectors (WTMDs) and 32 hand-held metal detectors (HHMDs). Emission measurements were performed on all HHMDs and WTMDs and summary data is presented. Results from the EMC testing indicate possible electromagnetic interference (EMI) between one of the neurostimulators and one WTMD and indicate that EMI between the three neurostimulators and HHMDs is unlikely. The results suggest that worst case situations for EMC testing are hard to predict and testing all major medical device modes and setting parameters are necessary to understand and characterize the EMC of AIMDs.

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Saha, Nandita, Jason M. Millward, Carl J. J. Herrmann, Faezeh Rahimi, Haopeng Han, Philipp Lacour, Florian Blaschke, and Thoralf Niendorf. "High-Fidelity 3D Stray Magnetic Field Mapping of Smartphones to Address Safety Considerations with Active Implantable Electronic Medical Devices." Sensors 23, no. 3 (January 20, 2023): 1209. http://dx.doi.org/10.3390/s23031209.

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Case reports indicate that magnets in smartphones could be a source of electromagnetic interference (EMI) for active implantable medical devices (AIMD), which could lead to device malfunction, compromising patient safety. Recognizing this challenge, we implemented a high-fidelity 3D magnetic field mapping (spatial resolution 1 mm) setup using a three-axis Hall probe and teslameter, controlled by a robot (COSI Measure). With this setup, we examined the stray magnetic field of an iPhone 13 Pro, iPhone 12, and MagSafe charger to identify sources of magnetic fields for the accurate risk assessment of potential interferences with AIMDs. Our measurements revealed that the stray fields of the annular array of magnets, the wide-angle camera, and the speaker of the smartphones exceeded the 1 mT limit defined by ISO 14117:2019. Our data-driven safety recommendation is that an iPhone 13 Pro should be kept at least 25 mm away from an AIMD to protect it from unwanted EMI interactions. Our study addresses safety concerns due to potential device–device interactions between smartphones and AIMDs and will help to define data-driven safety guidelines. We encourage vendors of electronic consumer products (ECP) to provide information on the magnetic fields of their products and advocate for the inclusion of smartphones in the risk assessment of EMI with AIMDs.

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Yang, Guang, Jie Wang, Yi Wang, Long Li, Xing Guo, and Shaobing Zhou. "An Implantable Active-Targeting Micelle-in-Nanofiber Device for Efficient and Safe Cancer Therapy." ACS Nano 9, no. 2 (January 23, 2015): 1161–74. http://dx.doi.org/10.1021/nn504573u.

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Buchko, Christopher J., Kenneth M. Kozloff, and David C. Martin. "Length-Scale-Dependent surface roughness measurements of bioactive polymer thin films using scanning probe microscopy." Proceedings, annual meeting, Electron Microscopy Society of America 54 (August 11, 1996): 198–99. http://dx.doi.org/10.1017/s0424820100163459.

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The development of implantable biomedical devices requires active biological interfaces that minimize the body’s immune response. We have identified candidate protein polymer coatings for biomedical applications and methods of processing these coatings that promote a favorable in vitro biological performance. However, the chronic implantation of biomedical devices, specifically the neural prosthetic devices developed at the University of Michigan, places additional requirements on the polymer coatings. Among these constraints are the efficient transport of neuronal signals from tissue to the device and the prevention of physical displacement of the device through tissue. To meet these potentially conflicting goals, we are developing discontinuous, porous polymer coatings that are rough at biologically-relevant length scales.In order to quantify the surface morphology of these thin polymer films, which are typically 0.02 μm to 5.0 μm thick, we employ a number of complementary techniques, including scanning probe microscopy (SPM), scanning electron microscopy (SEM), light optical microscopy (LOM), and transmission electron microscopy (TEM).

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Wang, Zhichao, Jianfeng Zheng, Yu Wang, Wolfgang Kainz, and Ji Chen. "Erratum to “On the Model Validation of Active Implantable Medical Device for MRI Safety Assessment”." IEEE Transactions on Microwave Theory and Techniques 68, no. 6 (June 2020): 2469. http://dx.doi.org/10.1109/tmtt.2020.2978595.

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McCarty Walsh, E., D. R. Morrison, and W. J. McFeely. "Totally implantable active middle-ear implants: a large, single-surgeon cohort." Journal of Laryngology & Otology 135, no. 4 (March 22, 2021): 304–9. http://dx.doi.org/10.1017/s0022215121000335.

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AbstractObjectivesThis study aimed to evaluate hearing outcomes and device safety in a large, single-surgeon experience with the totally implantable active middle-ear implants.MethodsThis was a retrospective case series review of 116 patients with moderate-to-severe sensorineural hearing loss undergoing implantation of active middle-ear implants.ResultsMean baseline unaided pure tone average improved from 57.6 dB before surgery to 34.1 dB post-operatively, signifying a mean gain in pure tone average of 23.5 dB (p = 0.0002). Phonetically balanced maximum word recognition score improved slightly from 70.5 per cent to 75.8 per cent (p = 0.416), and word recognition score at a hearing level of 50 dB values increased substantially from 14.4 per cent to 70.4 per cent (p < 0.0001). Both revision and explant rates were low and dropped with increasing surgeon experience over time.ConclusionThis study showed excellent post-operative hearing results with active middle-ear implants with regard to pure tone average and word recognition score at a hearing level of 50 db. Complication rates in this case series were significantly lower with increasing experience of the surgeon. Active middle-ear implants should be considered in appropriate patients with moderate-to-severe sensorineural hearing loss who have struggled with conventional amplification and are good surgical candidates.

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Tsang, W. S. S., J. K. Y. Yu, K. S. S. Bhatia, T. K. C. Wong, and M. C. F. Tong. "The Bonebridge semi-implantable bone conduction hearing device: experience in an Asian patient." Journal of Laryngology & Otology 127, no. 12 (October 29, 2013): 1214–21. http://dx.doi.org/10.1017/s0022215113002144.

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AbstractFor over three decades, bone conduction hearing aids have been changing the lives of patients with impaired hearing. The size, appearance and fitting discomfort of early generations of bone conduction hearing aids made them unpopular. The advent of bone-anchored hearing aids in the 1970s offered patients improved sound quality and fitting comfort, due to the application of osseointegration. However, the issue of post-operative peri-abutment pin tract wound infection persisted. The Bonebridge system incorporates the first active bone conduction device, and aims to resolve peri-abutment issues. Implantation of this system in an Asian patient is presented.

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Veselý, Miroslav, Břetislav Gál, Jiří Hložek, František Silný, and Jan Hanák. "Bonebridge – an active direct bone conduction hearing device in rehabilitation of single sided deafness Czech version." Otorinolaryngologie a foniatrie 70, no. 2 (May 20, 2021): 65–73. http://dx.doi.org/10.48095/ccorl202165.

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Overview Introduction: Bonebridge is a direct bone conduction hearing implantable system. The aim of the work is to present pilot results of rehabilitation of single sided deafness using this system. Material and methods: Analysis of three patients with single-sideded deafness, who underwent BB implantation in 2018 at the Department of Otorhinolaryngology and Head and Neck Surgery of St. Anna Hospital in Brno. Evaluation parameters: Bern Benefi t in Single-Sided Deafness Questionnaire, experimental examination of directional hearing and hearing in noise test. Results: Questionnaire: Within the visual analog scale in the range of –5 to +5 points, the average rating was + 2.4 points, so listening was rated as easier with Bonebridge than without hearing aids. The ability to locate the sound source was evaluated by 4 and 0–1 points in one and two respondents, respectively. Examination of spatial hearing: without hearing aid, the ability to locate the sound source was signifi cantly impaired in all the examined. With Bonebridge, with a tolerated deviation of 45°, the success rate of sound source localization was 75–100% in the range of 0–360° in the horizontal plane. Hearing in noise test: the greatest improvement in intelligibility (by 30–100%) was achieved with Bonebridge at SNR –5 dB. Conclusion: Bonebridge is not able to restore binaural hearing in patients with single sided deafness, it is a pseudo-binaural correction. Like other implantable bone conduction systems, Bonebridge is benefi tial for patients with single sided deafness in a variety of listening situations. Using experimental audiological tests, the contribution of Bonebridge to understanding sentences in acoustic noise and improving the ability to locate the sound source was found. However, validation of the results would require a larger number of probands. Keywords: single-sided deafness – BAHD – Bonebridge – bone conduction hearing implant – hearing in noise – directional hearing test

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Crisp, S. "The Medical Device Directives and Their Impact on the Development and Manufacturing of Medical Implants." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 210, no. 4 (December 1996): 233–39. http://dx.doi.org/10.1243/pime_proc_1996_210_419_02.

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The introduction of a legal framework for the supply of medical implants is discussed with reference to the Active Implantable Medical Device Directive and the Medical Device Directive. The definitions of medical device and manufacturer are discussed. The application of the Directives to device/drug combinations is considered. All implants must meet certain essential requirements to ensure that they do not harm the patient, clinician or any third party. For most implants this will be indicated on the product or its packaging by CE marking involving an independent organization called a Notified Body; the latter are appointed by the Competent Authority of the Member State. Devices are classified in proportion to the risk associated with them. The steps needed to be taken by manufacturers are outlined and the verification options discussed. The role of standards and the new approach to writing them in Europe is presented. After placing a product on the market, the manufacturer must set up a system of post-market surveillance, including a vigilance procedure, in order to monitor product performance. Individual Member States can exercise the safeguard clause when a product appears to have had the CE marking incorrectly applied.

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Jia, Yaoyao, Yan Gong, Arthur Weber, Wen Li, and Maysam Ghovanloo. "A mm-Sized Free-Floating Wireless Implantable Opto-Electro Stimulation Device." Micromachines 11, no. 6 (June 25, 2020): 621. http://dx.doi.org/10.3390/mi11060621.

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Towards a distributed neural interface, consisting of multiple miniaturized implants, for interfacing with large-scale neuronal ensembles over large brain areas, this paper presents a mm-sized free-floating wirelessly-powered implantable opto-electro stimulation (FF-WIOS2) device equipped with 16-ch optical and 4-ch electrical stimulation for reconfigurable neuromodulation. The FF-WIOS2 is wirelessly powered and controlled through a 3-coil inductive link at 60 MHz. The FF-WIOS2 receives stimulation parameters via on-off keying (OOK) while sending its rectified voltage information to an external headstage for closed-loop power control (CLPC) via load-shift-keying (LSK). The FF-WIOS2 system-on-chip (SoC), fabricated in a 0.35-µm standard CMOS process, employs switched-capacitor-based stimulation (SCS) architecture to provide large instantaneous current needed for surpassing the optical stimulation threshold. The SCS charger charges an off-chip capacitor up to 5 V at 37% efficiency. At the onset of stimulation, the capacitor delivers charge with peak current in 1.7–12 mA range to a micro-LED (µLED) array for optical stimulation or 100–700 μA range to a micro-electrode array (MEA) for biphasic electrical stimulation. Active and passive charge balancing circuits are activated in electrical stimulation mode to ensure stimulation safety. In vivo experiments conducted on three anesthetized rats verified the efficacy of the two stimulation mechanisms. The proposed FF-WIOS2 is potentially a reconfigurable tool for performing untethered neuromodulation.

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Mattei, Eugenio, Giovanni Calcagnini, Federica Censi, Iole Pinto, Andrea Bogi, and Rosaria Falsaperla. "Workers with Active Implantable Medical Devices Exposed to EMF: In Vitro Test for the Risk Assessment." Environments 6, no. 11 (November 15, 2019): 119. http://dx.doi.org/10.3390/environments6110119.

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The occupational health and safety framework identifies workers with an active implantable medical device (AIMD), such as a pacemaker (PM) or an implantable defibrillator (ICD), as a particularly sensitive risk group that must be protected against the dangers caused by the interference of electromagnetic field (EMF). In this paper, we describe the results of in vitro testing/measurements performed according to the EN50527-2-1:2016 standard, for the risk assessment of employees with a PM exposed to three EMF sources: (1) An electrosurgical unit (ESU); (2) a transcranial stimulator (TMS); and (3) an arc welder. The ESU did not affect the PM behavior in any of the configurations tested. For the TMS and the arc welder, interference phenomena were observed in limited experimental configurations, corresponding to the maximum magnetic field coupling between the EMF source and the implant. The in vitro measurements presented can be considered an example of how the specific risk assessment for a worker with a PM can be performed, according to one of the methodologies proposed in the EN50527-2-1:2016, and can be used as scientific evidence and literature data for future risk assessments on the same EMF sources.

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Hikage, Takashi, Toshio Nojima, and Hiroshi Fujimoto. "Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands." Physics in Medicine and Biology 61, no. 12 (May 25, 2016): 4522–36. http://dx.doi.org/10.1088/0031-9155/61/12/4522.

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Sokolovic, Sekib, and Samir Mehmedagic. "OS 11-06 The effect of vagus nerve stimulation on arterial hypertension using active implantable device." Journal of Hypertension 34, Supplement 1 (September 2016): e75. http://dx.doi.org/10.1097/01.hjh.0000500048.75087.92.

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Benkő, Ernő, Ilija German Ilič, Katalin Kristó, Géza Regdon, Ildikó Csóka, Klára Pintye-Hódi, Stane Srčič, and Tamás Sovány. "Predicting Drug Release Rate of Implantable Matrices and Better Understanding of the Underlying Mechanisms through Experimental Design and Artificial Neural Network-Based Modelling." Pharmaceutics 14, no. 2 (January 19, 2022): 228. http://dx.doi.org/10.3390/pharmaceutics14020228.

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There is a growing interest in implantable drug delivery systems (DDS) in pharmaceutical science. The aim of the present study is to investigate whether it is possible to customize drug release from implantable DDSs through drug–carrier interactions. Therefore, a series of chemically similar active ingredients (APIs) was mixed with different matrix-forming materials and was then compressed directly. Compression and dissolution interactions were examined by FT-IR spectroscopy. Regarding the effect of the interactions on drug release kinetics, a custom-made dissolution device designed for implantable systems was used. The data obtained were used to construct models based on artificial neural networks (ANNs) to predict drug dissolution. FT-IR studies confirmed the presence of H-bond-based solid-state interactions that intensified during dissolution. These results confirmed our hypothesis that interactions could significantly affect both the release rate and the amount of the released drug. The efficiencies of the kinetic parameter-based and point-to-point ANN models were also compared, where the results showed that the point-to-point models better handled predictive inaccuracies and provided better overall predictive efficiency.

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Stich, Manuel, Larissa Blümlein, Anne Slawig, Felix Schmidl, Karina Schuller, Richard Lösch, Matthias Hipp, Sabine Hentschel, Gregor Schaefers, and Ralf Ringler. "Development and validation of a tissue-equivalent test environment for detection of malfunctions in active medical implants caused by ionizing radiation." Current Directions in Biomedical Engineering 4, no. 1 (September 1, 2018): 153–56. http://dx.doi.org/10.1515/cdbme-2018-0038.

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AbstractMany patients in radiotherapy carry active implantable medical devices (AIMDs) such as pacemakers or cardioverter defibrillators (ICDs). The influence of the ionizing radiation can lead to failures in the device function. This study presents a tissue-equivalent test environment to investigate the influence of ionizing radiation on AIMDs. The in-vitro test environment is designed to simulate a human torso. Structures such as the heart, lungs, ribs, spinal column and soft tissue are replicated from tissue-equivalent materials to allow realistic treatment planning and to simulate the effect of ionizing radiation on active implants. CT measurements and Monte-Carlo validations have shown that Polytetrafluorethylen (bone), carrageenan (heart), Styrodur (lung) and Biresin® G27 (soft tissue) fulfill all requirements for suitable tissue surrogates. A plug-in unit integrated in the test environment has been designed specifically to allow the placement AIMDs in the phantom at typical positions for implant placement in humans. The dosimetry validation showed that the test environment is applicable in the full treatment planning process.

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Koo, Jahyun, Sung Bong Kim, Yeon Sik Choi, Zhaoqian Xie, Amay J. Bandodkar, Jawad Khalifeh, Ying Yan, et al. "Wirelessly controlled, bioresorbable drug delivery device with active valves that exploit electrochemically triggered crevice corrosion." Science Advances 6, no. 35 (August 2020): eabb1093. http://dx.doi.org/10.1126/sciadv.abb1093.

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Implantable drug release platforms that offer wirelessly programmable control over pharmacokinetics have potential in advanced treatment protocols for hormone imbalances, malignant cancers, diabetic conditions, and others. We present a system with this type of functionality in which the constituent materials undergo complete bioresorption to eliminate device load from the patient after completing the final stage of the release process. Here, bioresorbable polyanhydride reservoirs store drugs in defined reservoirs without leakage until wirelessly triggered valve structures open to allow release. These valves operate through an electrochemical mechanism of geometrically accelerated corrosion induced by passage of electrical current from a wireless, bioresorbable power-harvesting unit. Evaluations in cell cultures demonstrate the efficacy of this technology for the treatment of cancerous tissues by release of the drug doxorubicin. Complete in vivo studies of platforms with multiple, independently controlled release events in live-animal models illustrate capabilities for control of blood glucose levels by timed delivery of insulin.

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Oguri, Gaku, Toshiya Kojima, Katsuhito Fujiu, and Issei Komuro. "What is the mechanism of irregular pacing spikes? Pacing failure, sensing failure, or something else? A case report." European Heart Journal - Case Reports 4, no. 3 (April 4, 2020): 1–4. http://dx.doi.org/10.1093/ehjcr/ytaa065.

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Abstract Background In cardiac implantable electronic device management, confused electrocardiograms are sometimes encountered. Case summary We experienced a case of dizziness and presyncope, which was accompanied by irregular pacing spikes following QRS complexes, pacing failure, sensing failure, or something else. The patient’s second active pacemaker in her left chest was functioning normally. However, her old abdominal pacemaker had automatically changed from the OVO to VVI mode because of an elective replacement indicator. As a result, her old and second pacemakers had an interaction. Old invalid pacing spikes induced oversensing of the current pacemaker, which interfered with valid pacing. Discussion We experienced a rare case of dizziness and presyncope with confused pacing spikes. Physicians should be aware of the unexpected interactions that are possible with devices with automatic mode changes.

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Singh, Mandeep, Gerardo Palazzo, Giuseppe Romanazzi, Gian Paolo Suranna, Nicoletta Ditaranto, Cinzia Di Franco, Maria Vittoria Santacroce, et al. "Bio-sorbable, liquid electrolyte gated thin-film transistor based on a solution-processed zinc oxide layer." Faraday Discuss. 174 (2014): 383–98. http://dx.doi.org/10.1039/c4fd00081a.

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Among the metal oxide semiconductors, ZnO has been widely investigated as a channel material in thin-film transistors (TFTs) due to its excellent electrical properties, optical transparency and simple fabrication via solution-processed techniques. Herein, we report a solution-processable ZnO-based thin-film transistor gated through a liquid electrolyte with an ionic strength comparable to that of a physiological fluid. The surface morphology and chemical composition of the ZnO films upon exposure to water and phosphate-buffered saline (PBS) are discussed in terms of the operation stability and electrical performance of the ZnO TFT devices. The improved device characteristics upon exposure to PBS are associated with the enhancement of the oxygen vacancies in the ZnO lattice due to Na⁺ doping. Moreover, the dissolution kinetics of the ZnO thin film in a liquid electrolyte opens the possible applicability of these devices as an active element in “transient” implantable systems.

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Kim, Juho, Jimin Seo, Dongwuk Jung, Taeyeon Lee, Hunpyo Ju, Junkyu Han, Namyun Kim, et al. "Active photonic wireless power transfer into live tissues." Proceedings of the National Academy of Sciences 117, no. 29 (July 6, 2020): 16856–63. http://dx.doi.org/10.1073/pnas.2002201117.

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Recent advances in soft materials and mechanics activate development of many new types of electrical medical implants. Electronic implants that provide exceptional functions, however, usually require more electrical power, resulting in shorter period of usages although many approaches have been suggested to harvest electrical power in human bodies by resolving the issues related to power density, biocompatibility, tissue damage, and others. Here, we report an active photonic power transfer approach at the level of a full system to secure sustainable electrical power in human bodies. The active photonic power transfer system consists of a pair of the skin-attachable photon source patch and the photovoltaic device array integrated in a flexible medical implant. The skin-attachable patch actively emits photons that can penetrate through live tissues to be captured by the photovoltaic devices in a medical implant. The wireless power transfer system is very simple, e.g., active power transfer in direct current (DC) to DC without extra circuits, and can be used for implantable medical electronics regardless of weather, covering by clothes, in indoor or outdoor at day and night. We demonstrate feasibility of the approach by presenting thermal and mechanical compatibility with soft live tissues while generating enough electrical power in live bodies throughin vivoanimal experiments. We expect that the results enable long-term use of currently available implants in addition to accelerating emerging types of electrical implants that require higher power to provide diverse convenient diagnostic and therapeutic functions in human bodies.

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Green, James I. J. "Medical Device Regulation: Requirements for Dental Professionals Who Prescribe and Manufacture Custom-Made Devices." Primary Dental Journal 10, no. 1 (March 2021): 64–88. http://dx.doi.org/10.1177/2050168420980980.

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A custom-made device (CMD) is a medical device intended for the sole use of a particular patient. In a dental setting, CMDs include prosthodontic devices, orthodontic appliances, bruxism splints, speech prostheses and devices for the treatment of obstructive sleep apnoea, trauma prevention and orthognathic surgery facilitation (arch bars and interocclusal wafers). Since 1993, the production and provision of CMDs have been subject to European Union (EU) Directive 93/42/EEC (Medical Device Directive, MDD) given effect in the UK by The Medical Devices Regulations 2002 (Statutory Instrument 2002/618), and its subsequent amendments. Regulation (EU) 2017/745 (Medical Device Regulation, EU MDR) replaces the MDD and the other EU Directive pertaining to Medical Devices, Council Directive 90/385/EEC (Active Implantable Medical Device Directive, AIMDD). The EU MDR was published on 5 April 2017, came into force on 25 May 2017 and, following a three-year transition period was due to be fully implemented and repeal the MDD on 26 May 2020, but was deferred until 26 May 2021 due to the coronavirus disease 2019 (COVID-19) pandemic. In the UK, in preparation for the country’s planned departure from the EU, the EU MDR, with necessary amendments, was transposed into UK law (Medical Devices (Amendment etc.) (EU Exit) Regulations 2019, UK MDR). The UK left the Union on 31 January 2020 and entered a transition period that ended on 31 December 2020, meaning that, from 1 January 2021, dental professionals in Great Britain who prescribe and manufacture CMDs are mandated to do so in accordance with the new legislation while Northern Ireland remains in line with the EU legislation and implementation date. This paper sets out the requirements that relate to the production and provision of CMDs in a UK dental setting.

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Geis, Nicolas A., Anna Göbbel, Michael M. Kreusser, Tobias Täger, Hugo A. Katus, Norbert Frey, Philipp Schlegel, and Philip W. Raake. "Impact of Percutaneous Mitral Valve Repair Using the MitraClipTM System on Ventricular Arrhythmias and ICD Therapies." Life 12, no. 3 (February 25, 2022): 344. http://dx.doi.org/10.3390/life12030344.

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Transcatheter edge-to-edge repair (TEER) using the MitraClip™ device has been established as a suitable alternative to mitral valve surgery in patients with severe mitral regurgitation (MR) and high or prohibitive surgical risk. Only limited information regarding the impact of TEER on ventricular arrhythmias (VA) has been reported. The aim of the present study was to assess the impact of TEER using the MitraClipTM device on the burden of VA and ICD (Implantable Cardioverter Defibrillator) therapies. Among 600 MitraClipTM implantations performed in our clinic between September 2009 and October 2018, we identified 86 patients with successful TEER and an active implantable cardiac device (pacemaker, ICD, CRT-P/D (Cardiac Resynchronization Therapy-Pacemaker/Defibrillator)) eligible for retrospective VA analyses. These patients presented with mainly functional MR (81.4%) and severely reduced left ventricular ejection fraction (mean LVEF 22.1% ± 10.3%). The observation period comprised 456 ± 313 days before and 424 ± 287 days after TEER. The burden of ventricular arrhythmias (sustained ventricular tachycardia (sVT) and ventricular fibrillation (VF)) was significantly reduced after TEER (0.85 ± 3.47 vs. 0.43 ± 2.03 events per patient per month, p = 0.01). Furthermore, the rate of ICD therapies (anti-tachycardia pacing (ATP) and ICD shock) decreased significantly after MitraClipTM implantation (1.0 ± 3.87 vs. 0.32 ± 1.41, p = 0.014). However, reduction of VA burden did not result in improved two-year survival in this patient cohort with severely reduced LVEF. Mitral valve TEER using the MitraClip™ device was associated with a significant reduction of ventricular arrhythmias and ICD therapies.

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Abbasi, Wajahat, Hojong Choi, and Jungsuk Kim. "Hexagonal Stimulation Digital Controller Design and Verification for Wireless Subretinal Implant Device." Sensors 22, no. 8 (April 10, 2022): 2899. http://dx.doi.org/10.3390/s22082899.

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Significant progress has been made in the field of micro/nano-retinal implant technologies. However, the high pixel range, power leakage, reliability, and lifespan of retinal implants are still questionable. Active implantable devices are safe, cost-effective, and reliable. Although a device that can meet basic safety requirements set by the Food and Drug Administration and the European Union is reliable for long-term use and provides control on current and voltage parameters, it will be expensive and cannot be commercially successful. This study proposes an economical, fully controllable, and configurable wireless communication system based on field-programmable gated arrays (FPGAs) that were designed with the ability to cope with the issues that arise in retinal implantation. This system incorporates hexagonal biphasic stimulation pulses generated by a digital controller that can be fully controlled using an external transmitter. The integration of two separate domain analog systems and a digital controller based on FPGAs is proposed in this study. The system was also implemented on a microchip and verified using in vitro results.

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Egitto, Frank D., Rabindra N. Das, Glen E. Thomas, and Susan Bagen. "Miniaturization of Electronic Substrates for Medical Device Applications." International Symposium on Microelectronics 2012, no. 1 (January 1, 2012): 000186–91. http://dx.doi.org/10.4071/isom-2012-ta57.

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The medical industry is clearly and urgently in need of development of advanced packaging that can meet the growing demand for miniaturization, high-speed performance, and flexibility for handheld, portable, in vivo, and implantable devices. To accomplish this, new packaging structures need to be able to integrate more dies with greater function, higher I/O counts, smaller die pad pitches, and high reliability, while being pushed into smaller and smaller footprints. As a result, the microelectronics industry is moving toward alternative, innovative approaches as solutions for squeezing more function into smaller packages. In the present report, key enablers for achieving reduction in size, weight, and power (SWaP) in electronic packaging for a variety of medical applications are discussed. These enablers include materials selection, embedded passives and active devices, System-in-Package (SiP) designs, and flex circuits. Manufacturing methods and materials for producing advanced organic substrates and flex along with ultra fine pitch assemblies are discussed. A case study detailing the fabrication of a flexible substrate for use in an intravascular ultrasound (IVUS) catheter demonstrates how the challenges of miniaturization are met. These challenges include use of ultra-thin polymer films, extreme fine-feature circuitization, and assembly processes to accommodate die having reduced die pad pitch.

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Beneyto, Maxime, Matthieu Seguret, Marine Taranzano, Pierre Mondoly, Caroline Biendel, Anne Rollin, Fanny Bounes, Meyer Elbaz, Philippe Maury, and Clément Delmas. "Externalized Reusable Permanent Pacemaker for Prolonged Temporary Cardiac Pacing in Critical Cardiac Care Units: An Observational Monocentric Retrospective Study." Journal of Clinical Medicine 11, no. 23 (December 4, 2022): 7206. http://dx.doi.org/10.3390/jcm11237206.

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Introduction: The use of temporary cardiac pacing is frequent in critical care units for severe bradycardia or electrical storm, but may be associated with frequent and potentially severe complications, especially when indwelling for several days. In some cases, transient indication or ongoing contraindication for a permanent pacemaker justifies prolonged temporary pacing. In that case, the implantation of an active-fixation lead connected to an externalized pacemaker represents a valuable option to increase safety and patient comfort. Yet, evidence remains scarce. We aimed to describe the population receiving prolonged temporary cardiac pacing (PTCP) and their outcomes. Methods: We retrospectively included all consecutive patients, admitted to our hospital from 2016 to 2021, who underwent PTCP. We collected in-hospital and six-month outcomes. Results: Forty-six patients (median age of 73, 63% male) were included, and twenty-nine (63%) had prior heart disease. Indications for PTCP were found: seventeen (37%) potentially reversible high-grade conduction disorders, fourteen (30%) indications for permanent pacemaker but ongoing infection, seven (15%) cardiac implantable electronic device infections requiring extraction in pacing-dependent patients, seven (15%) severe vagal hyperreactivity in prolonged critical care hospitalizations, and one (2%) recurrent sustained ventricular tachycardia requiring overdrive pacing. The median PTCP duration was nine (5–13) days. Ten (22%) patients exhibited at least one complication during hospitalization. Twenty-six (56.5%) patients required definite device implantation (twenty-five pacemakers and one cardioverter-defibrillator) and twenty (43.5%) did not (fifteen PTCP device removal for recovery and five deaths under PTCP). At six months, two (5%) deaths and two (5%) new infections of a definite implanted device occurred, all in patients with initial active infection. Conclusion: The use of prolonged temporary cardiac pacing, with an active -fixation lead connected to an externalized pacemaker, is possible and reasonable; this would allow for the possible recovery or resolution of contraindication for definite device implantation.

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Feng, Chenyin, Christopher L. Frewin, Md Rubayat-E. Tanjil, Richard Everly, Jay Bieber, Ashok Kumar, Michael Cai Wang, and Stephen E. Saddow. "A Flexible a-SiC-Based Neural Interface Utilizing Pyrolyzed-Photoresist Film (C) Active Sites." Micromachines 12, no. 7 (July 13, 2021): 821. http://dx.doi.org/10.3390/mi12070821.

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Carbon containing materials, such as graphene, carbon-nanotubes (CNT), and graphene oxide, have gained prominence as possible electrodes in implantable neural interfaces due to their excellent conductive properties. While carbon is a promising electrochemical interface, many fabrication processes are difficult to perform, leading to issues with large scale device production and overall repeatability. Here we demonstrate that carbon electrodes and traces constructed from pyrolyzed-photoresist-film (PPF) when combined with amorphous silicon carbide (a-SiC) insulation could be fabricated with repeatable processes which use tools easily available in most semiconductor facilities. Directly forming PPF on a-SiC simplified the fabrication process which eliminates noble metal evaporation/sputtering and lift-off processes on small features. PPF electrodes in oxygenated phosphate buffered solution at pH 7.4 demonstrated excellent electrochemical charge storage capacity (CSC) of 14.16 C/cm2, an impedance of 24.8 ± 0.4 kΩ, and phase angle of −35.9 ± 0.6° at 1 kHz with a 1.9 kµm2 recording site area.

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Fonseca, Igor Yoshio Imagawa, Mariana Krutman, Kenji Nishinari, Guilherme Yazbek, Marcelo Passos Teivelis, Guilherme André Zottele Bomfim, Rafael Noronha Cavalcante, and Nelson Wolosker. "Brachial insertion of fully implantable venous catheters for chemotherapy: complications and quality of life assessment in 35 patients." Einstein (São Paulo) 14, no. 4 (December 2016): 473–79. http://dx.doi.org/10.1590/s1679-45082016ao3606.

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ABSTRACT Objective To prospectively evaluate the perioperative safety, early complications and satisfaction of patients who underwent the implantation of central catheters peripherally inserted via basilic vein. Methods Thirty-five consecutive patients with active oncologic disease requiring chemotherapy were prospectively followed up after undergoing peripheral implantation of indwelling venous catheters, between November 2013 and June 2014. The procedures were performed in the operating room by the same team of three vascular surgeons. The primary endpoints assessed were early postoperative complications, occurring within 30 days after implantation. The evaluation of patient satisfaction was based on a specific questionnaire used in previous studies. Results In all cases, ultrasound-guided puncture of the basilic vein was feasible and the procedure successfully completed. Early complications included one case of basilic vein thrombophlebitis and one case of pocket infection that did not require device removal. Out of 35 patients interviewed, 33 (94.3%) would recommend the device to other patients. Conclusion Implanting brachial ports is a feasible option, with low intraoperative risk and similar rates of early postoperative complications when compared to the existing data of the conventional technique. The patients studied were satisfied with the device and would recommend the procedure to others.

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Martin, Klaus Daniel, Witold Henryk Polanski, Anne-Kathrin Schulz, Michael Jöbges, Hansjoerg Hoff, Gabriele Schackert, Thomas Pinzer, and Stephan B. Sobottka. "Restoration of ankle movements with the ActiGait implantable drop foot stimulator: a safe and reliable treatment option for permanent central leg palsy." Journal of Neurosurgery 124, no. 1 (January 2016): 70–76. http://dx.doi.org/10.3171/2014.12.jns142110.

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OBJECT The ActiGait drop foot stimulator is a promising technique for restoration of lost ankle function by an implantable hybrid stimulation system. It allows ankle dorsiflexion by active peroneal nerve stimulation during the swing phase of gait. In this paper the authors report the outcome of the first prospective study on a large number of patients with stroke-related drop foot. METHODS Twenty-seven patients who experienced a stroke and with persisting spastic leg paresis received an implantable ActiGait drop foot stimulator for restoration of ankle movement after successful surface test stimulation. After 3 to 5 weeks, the stimulator was activated, and gait speed, gait endurance, and activation time of the system were evaluated and compared with preoperative gait tests. In addition, patient satisfaction was assessed using a questionnaire. RESULTS Postoperative gait speed significantly improved from 33.9 seconds per 20 meters to 17.9 seconds per 20 meters (p < 0.0001), gait endurance from 196 meters in 6 minutes to 401 meters in 6 minutes (p < 0.0001), and activation time from 20.5 seconds to 10.6 seconds on average (p < 0.0001). In 2 patients with nerve injury, surgical repositioning of the electrode cuff became necessary. One patient showed a delayed wound healing, and in another patient the system had to be removed because of a wound infection. Marked improvement in mobility, social participation, and quality of life was confirmed by 89% to 96% of patients. CONCLUSIONS The ActiGait implantable drop foot stimulator improves gait speed, endurance, and quality of life in patients with stroke-related drop foot. Regarding gait speed, the ActiGait system appears to be advantageous compared with foot orthosis or surface stimulation devices. Randomized trials with more patients and longer observation periods are needed to prove the long-term benefit of this device.

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Lefebvre, Philippe P., Javier Gisbert, Domenico Cuda, Stéphane Tringali, and Arnaud Deveze. "A Retrospective Multicentre Cohort Review of Patient Characteristics and Surgical Aspects versus the Long-Term Outcomes for Recipients of a Fully Implantable Active Middle Ear Implant." Audiology and Neurotology 21, no. 5 (2016): 333–45. http://dx.doi.org/10.1159/000454666.

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Objective: To summarise treatment outcomes compared to surgical and patient variables for a multicentre recipient cohort using a fully implantable active middle ear implant for hearing impairment. To describe the authors' preferred surgical technique to determine microphone placement. Study Design: Multicentre retrospective, observational survey. Setting: Five tertiary referral centres. Patients: Carina recipients (66 ears, 62 subjects) using the current Cochlear® Carina® System or the legacy device, the Otologics® Fully Implantable Middle Ear, with a T2 transducer. Methods: Patient file review and routine clinical review. Patient outcomes assessed were satisfaction, daily use and feedback reports at the first fitting and ≥12 months after implantation. Descriptive and statistical analysis of correlations of variables and their influence on outcomes was performed. Independently reported preferred methods for microphone placement are collectively summarised. Results: The average implant experience was 3.5 years. Satisfaction increased significantly over time (p < 0.05). No correlation with covariates examined was observed. Feedback significantly decreased over time, showing a significant correlation with microphone location, primary motivation, gender, age at implantation, and contralateral hearing aid use (p < 0.05). Patient satisfaction was inversely correlated with reports of system feedback (p < 0.05). The implantable microphone was most commonly on the posterior inferior mastoid line, in 42/66 (65%) cases, correlating with less likelihood for feedback and consistent with author surgical preference. Conclusion: Carina recipients in this study present as satisfied consistent daily users with very few reports of persistent feedback. As microphone location is an influencing factor, a careful surgical consideration of microphone placement is required. The authors prefer a posterior inferior mastoid line position whenever possible.

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Frausing, Maria Hee Jung Park, Jens Cosedis Nielsen, Jens Brock Johansen, Ole Dan Jørgensen, Thomas Olsen, Christian Gerdes, Jens Kristensen, and Mads Brix Kronborg. "Rate of permanent cardiac implantable electronic device infections after active fixation temporary transvenous pacing: A nationwide Danish cohort study." Heart Rhythm O2 3, no. 1 (February 2022): 50–56. http://dx.doi.org/10.1016/j.hroo.2021.11.008.

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Spiegel, Jennifer L., Bernhard G. Weiss, Mattis Bertlich, Ivelina Stoycheva, Martin Canis, and Friedrich Ihler. "Functional results with active middle ear implant or semi-implantable bone conduction device in patients with comparable hearing loss." International Journal of Audiology 61, no. 10 (September 1, 2021): 859–67. http://dx.doi.org/10.1080/14992027.2021.1966704.

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Fisher, Rebecca, David Jevotovsky, Jessica Raviv, and Barry Love. "Quantifying the Impact of COVID-19 “Lockdown” on Physical Activity in Children and Adults with Implanted Cardiac Rhythm Devices: A Single Center Experience Using Cardiac Rhythm Device Accelerometer Data." COVID 2, no. 9 (August 31, 2022): 1228–31. http://dx.doi.org/10.3390/covid2090089.

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Background: In response to the COVID-19 pandemic, the US states of New York and New Jersey instituted a “lockdown” that closed schools and most businesses except for essential services. The public was urged to remain at home. The 78-day lockdown period extended from 22 March 2020 to 6 June 2020. We sought to evaluate the impact of COVID-19 lockdown on continuously recorded physical activity in our patients with congenital heart disease with implanted cardiac rhythm management (CRM) devices—pacemakers (PPM), defibrillators (ICD) and implantable loop recorders (ILR) enabled with accelerometers that translate motion into a measure of active hours/day. Methods: All patients from our congenital CRM database with accelerometer-enabled devices who had stable cardiac status residing in NY and NJ were included. Forty-one patients met the inclusion criteria; the median age was 29.6 years (range 7–60); 54% female; 23 ICD, 15 PPM and 3 ILR. The patient activity was averaged for the 2 months prior to lockdown, during the lockdown, and the 2 months afterward. Paired t-tests were used to compare activity before and during lockdown, and before and after lockdown. Each patient served as his/her own control. Results: Active hours/day decreased by a mean of 32% (±27%) from baseline (p < 0.001). A total of 32 patients experienced a decline, 6 had no change and 3 had an increase. Active hours rebounded after lockdown and were unchanged compared to pre-lockdown levels. Conclusions: The COVID-19 lockdown in NY/NJ during the Spring of 2020 resulted in a significant drop in active hours/day in children and adults with congenital heart disease. Active hours/day rebounded to baseline after restrictions were lifted.

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Powell, Maria E., David L. Zealear, Yike Li, C. Gaelyn Garrett, Kate Von Wahlde, and James Netterville. "Unilateral and Bilateral Laryngeal Pacing for Bilateral Vocal Fold Paralysis." Current Otorhinolaryngology Reports 8, no. 4 (September 3, 2020): 395–401. http://dx.doi.org/10.1007/s40136-020-00313-7.

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Abstract Purpose of Review Present the state-of-the-art overview of laryngeal pacing for treatment of bilateral vocal fold paralysis. A minimally invasive unilateral pacing system and a fully implantable bilateral pacing system are currently in clinical trials. The relative advantages and disadvantages of each are discussed. Recent Findings Research in functional electrical stimulation for the reanimation of the posterior cricoarytenoid muscle has successfully translated from animal models to human clinical trials for unilateral pacing and bilateral pacing. Current findings suggest unilateral pacing in humans significantly improves ventilation but only marginally better than cordotomy. Bilateral pacing in canines increases glottal opening greater than 2-fold over unilateral pacing and restores exercise tolerance to normal. Summary Unilateral pacing can be considered a breathing assist device and may not be appropriate for active individuals. Bilateral pacing may be preferable for patients who wish to engage in strenuous exercise. Minimally invasive systems may be ideal for patients who prefer less invasive implantation and are not concerned with cosmesis. Fully implantable pacing systems offer greater electrode redundancy and stability, resulting in a system that is robust against electrode migration or damage.

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Bracke, Frank, Niels Verberkmoes, Marcel van 't Veer, and Berry van Gelder. "Lead extraction for cardiac implantable electronic device infection: comparable complication rates with or without abandoned leads." EP Europace 21, no. 9 (July 19, 2019): 1378–84. http://dx.doi.org/10.1093/europace/euz197.

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Abstract Aims Abandoned leads are often linked to complications during lead extraction, prompting pre-emptive extraction if leads become non-functional. We examined their influence on complications when extracted for device-related infection. Methods and results All patients undergoing lead extraction for device-related infection from 2006 to 2017 in our hospital were included. The primary endpoint was major complications. Out of 500 patients, 141 had abandoned leads, of whom 75% had only one abandoned lead. Median cumulative implant times were 24.2 (interquartile range 15.6–38.2) and 11.6 (5.6–17.4), respectively years with or without abandoned leads. All leads were extracted only with a femoral approach in 50.4% of patients. Mechanical rotational tools were introduced in 2014 and used in 22.2% of cases and replacing laser sheaths that were used in 5% of patients. Major complications occurred in 0.7% of patients with abandoned leads compared with 1.7% of patients with only active leads (P = 0.679). Failure to completely remove all leads was 14.9% and 6.4%, respectively with or without abandoned leads (P = 0.003), and clinical failure was 6.4% and 2.2% (P = 0.028), respectively. Procedural failure dropped to 9.2% and 5.7% (P = 0.37), respectively after the introduction of mechanical rotational tools. The only independent predictor of procedural and clinical failure in multivariate analysis was the cumulative implant duration. Conclusion Despite longer implant times, patients with abandoned leads did not have more major complications during lead extraction. Therefore, preventive extraction of non-functional leads to avoid complications at a later stage is not warranted.

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FRÍES, E. R., M. E. BERLI, S. UBAL, D. M. CAMPANA, and J. DI PAOLO. "COMPUTER SIMULATION OF PLATELET ACTIVATION IN A PULSATILE VENTRICULAR ASSIST DEVICE, THROUGH FINITE ELEMENTS AND A SIMPLIFIED GEOMETRY." Latin American Applied Research - An international journal 47, no. 3 (July 31, 2017): 83–88. http://dx.doi.org/10.52292/j.laar.2017.294.

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Ventricular assist devices are a technological solution for patients who suffer from cardiac insufficiency and await a transplant. In this work, a new design of an implantable pulsatile blood pump is analyzed in terms of blood damage, by means of finite elements on a simplified geometry. It is a double effect volumetric pump, which has a noncontact driven piston and four active valves. The analysis is done by means of blood flow simulation into the pump and the prediction of platelets activation. The last is a measure of the pump compatibility with human life. The platelet activation state is evaluated by an equivalent or representative shear stress and compared with bibliographic data corresponding to other VAD kinds and cardiac prosthetic valves. The results show that, for the complementary blood flow rate supplied by the simulated VAD, the predicted platelet damage is in the same levels of current cardiac devices, particularly other VADs.

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Oelze, Ilse-Barbara, Kurt Neeser, and Elvira Müller. "PP31 Medical Device Regulation: What Is New?" International Journal of Technology Assessment in Health Care 35, S1 (2019): 42–43. http://dx.doi.org/10.1017/s0266462319001958.

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IntroductionIn 2017, the European Union (EU) commission released the final versions of the Medical Device Regulation (MDR) and In-vitro Diagnostic Device Regulation. These regulations will replace the EU directives (Medical Device Directive [MDD], In-vitro Diagnostic Device [IVDD], and Active Implantable Medical Device [AIMD]). EU regulations are effective in all EU countries at date of publication. In contrast, the EU directives must be implemented in national law first.MethodsGuidelines and respective legislation, consultation results and methods/medical device (MD) evaluations were reviewed and analyzed. Decision criteria and reasoning, assessment outcomes and potential impact on price negotiations were the main aspects for comparison.ResultsManufacturers have to be aware of the importance of clinical data for demonstrating the compliance of their products. This applies both to the approval of the products and the “post-market activities” and particularly to the “post-market clinical follow-up” for which requirements for Class I and II products need to be further developed. The MDR requires manufacturers to collect clinical data before and after approval, which could lead to excessive documentation requirements. The term “sufficient clinical data” from the MDR is unclear. A functional Eudamed specification is necessary, which enables an automated processing of relevant data. A stronger involvement in the evaluation process is needed as well as more transparency in the Joint Federal Committee (G-BA) and faster evaluation processes.ConclusionsThe MDR increases the burden especially for small businesses, and it is doubtable that the ultimate goal – improving patient safety – will be achieved. The increased demands and rising costs of the new EU MDR and bottlenecks at Notified Bodies can be a risk for the MD industry. Due to the general reduction in the remuneration for services with a high proportion of technical services, it is feared that products will be withdrawn from the market for economic reasons or that they will not be marketed.

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Tippit, Danielle, Eric Siegel, Daniella Ochoa, Angela Pennisi, Erica Hill, Amelia Merrill, Mark Rowe, Ronda Henry-Tillman, Aneesha Ananthula, and Issam Makhoul. "Upper-Extremity Deep Vein Thrombosis in Patients With Breast Cancer With Chest Versus Arm Central Venous Port Catheters." Breast Cancer: Basic and Clinical Research 12 (January 1, 2018): 117822341877190. http://dx.doi.org/10.1177/1178223418771909.

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Most of the patients undergoing treatment for cancer require placement of a totally implantable venous access device to facilitate safe delivery of chemotherapy. However, implantable ports also increase the risk of deep vein thrombosis and related complications in this high-risk population. The objective of this study was to assess the incidence of upper-extremity deep vein thrombosis (UEDVT) in patients with breast cancer to determine whether the risk of UEDVT was higher with chest versus arm ports, as well as to determine the importance of previously reported risk factors predisposing to UEDVT in the setting of active cancer. We retrospectively reviewed the medical records of 297 women with breast cancer who had ports placed in our institution between the dates of December 1, 2010, and December 31, 2016. The primary outcome was the development of radiologically confirmed UEDVT ipsilateral to the implanted port. Overall, 17 of 297 study subjects (5.7%) were found to have UEDVT. There was 1 documented case of associated pulmonary embolism. Fourteen (9.5%) of 147 subjects with arm ports experienced UEDVT compared with only 3 (2.0%) of 150 subjects with chest ports ( P = .0056). Thus, implantation of arm ports as opposed to chest ports may be associated with a higher rate of UEDVT in patients with breast cancer.

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Ansó, Juan, Moaad Benjaber, Brandon Parks, Samuel Parker, Carina Renate Oehrn, Matthew Petrucci, Ro’ee Gilron, et al. "Concurrent stimulation and sensing in bi-directional brain interfaces: a multi-site translational experience." Journal of Neural Engineering 19, no. 2 (March 31, 2022): 026025. http://dx.doi.org/10.1088/1741-2552/ac59a3.

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Abstract Objective. To provide a design analysis and guidance framework for the implementation of concurrent stimulation and sensing during adaptive deep brain stimulation (aDBS) with particular emphasis on artifact mitigations. Approach. We defined a general architecture of feedback-enabled devices, identified key components in the signal chain which might result in unwanted artifacts and proposed methods that might ultimately enable improved aDBS therapies. We gathered data from research subjects chronically-implanted with an investigational aDBS system, Summit RC + S, to characterize and explore artifact mitigations arising from concurrent stimulation and sensing. We then used a prototype investigational implantable device, DyNeuMo, and a bench-setup that accounts for tissue–electrode properties, to confirm our observations and verify mitigations. The strategies to reduce transient stimulation artifacts and improve performance during aDBS were confirmed in a chronic implant using updated configuration settings. Main results. We derived and validated a ‘checklist’ of configuration settings to improve system performance and areas for future device improvement. Key considerations for the configuration include (a) active instead of passive recharge, (b) sense-channel blanking in the amplifier, (c) high-pass filter settings, (d) tissue–electrode impedance mismatch management, (e) time-frequency trade-offs in the classifier, (f) algorithm blanking and transition rate limits. Without proper channel configuration, the aDBS algorithm was susceptible to limit-cycles of oscillating stimulation independent of physiological state. By applying the checklist, we could optimize each block’s performance characteristics within the overall system. With system-level optimization, a ‘fast’ aDBS prototype algorithm was demonstrated to be feasible without reentrant loops, and with noise performance suitable for subcortical brain circuits. Significance. We present a framework to study sources and propose mitigations of artifacts in devices that provide chronic aDBS. This work highlights the trade-offs in performance as novel sensing devices translate to the clinic. Finding the appropriate balance of constraints is imperative for successful translation of aDBS therapies. Clinical trial: Institutional Review Board and Investigational Device Exemption numbers: NCT02649166/IRB201501021 (University of Florida), NCT04043403/IRB52548 (Stanford University), NCT03582891/IRB1824454 (University of California San Francisco). IDE #180 097.

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Allouche, Emna, Soumaya Chargui, Marwa Fathi, and Leila Bezdah. "Subacute right ventricle perforation: a pacemaker lead complication." BMJ Case Reports 14, no. 5 (May 2021): e242489. http://dx.doi.org/10.1136/bcr-2021-242489.

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Myocardial perforation is an uncommon but potentially life-threatening complication of pacemaker and implantable cardioverter-defibrillator. Myocardial perforation may be acute, subacute or chronic when it occurs within 24 hours of the device insertion; between 1 day and 30 days; and more than 30 days after implantation. This complication may occur in 1.7%–7% of patients. However, subacute myocardial perforation is rare and affects 0.5%–1.2% of patients. We report the case of an 85-year-old patient with a pacemaker failure 10 days after implantation due to a subacute myocardial perforation caused by an active fixation ventricular lead. Transthoracic echocardiography showed penetration of the ventricular lead through the right ventricular apex into the pericardium without any pericardial effusion. We confirmed myocardial perforation by a CT scan. We referred her to the surgery ward where she was successfully managed.

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Idbaih, A., A. Sonabend, R. Stupp, O. Chinot, H. Dufour, F. Ducray, P. Menei, J. de Groot, C. Desseaux, and A. Carpentier. "OS07.3.A Phase 1/2 clinical trial of blood-brain barrier opening with the SonoCloud-9 implantable ultrasound device in recurrent glioblastoma patients receiving IV carboplatin." Neuro-Oncology 24, Supplement_2 (September 1, 2022): ii16. http://dx.doi.org/10.1093/neuonc/noac174.048.

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Abstract Background Low intensity pulsed ultrasound (LIPU) in combination with microbubbles is a promising approach for brain drug delivery. A phase 1/2 clinical study (NCT03744026) was initiated to demonstrate the safety and efficacy of blood-brain barrier (BBB) disruption over a large volume using an implantable ultrasound system (SonoCloud-9) in patients with recurrent glioblastoma receiving carboplatin chemotherapy. Material and Methods The SonoCloud-9 device (Carthera, Paris, France) was placed at the end of tumor resection and replaced the bone flap. The device was activated 9-14 days after surgery for a duration of 270 seconds every 4 weeks until progression or treatment completion, concomitantly with IV DEFINITY microbubbles (10 μl/kg, Lantheus, Billerica, US). The Phase 1 cohort consisted of an escalation of BBB disruption volume by activation of 3 (n=3), 6 (n=3), then 9 (n=3) emitters of the device. Dose limiting toxicity (DLT) was assessed during the first 2 weeks after the 1st sonication. A subsequent expansion cohort consisted of patients treated with 9 emitters in which the primary endpoint was assessment of BBB opening on MRI using gadolinium (<1 hr after sonication). All patients received carboplatin either after (n=21) or before (n=12) device activation to disrupt the BBB. In addition, a sub-study was performed to investigate carboplatin concentration enhancement in the peritumoral region with sonication at time of device implantation. Results Study accrual is complete with 38 patients enrolled and 33 patients having been implanted and received at least one sonication+carboplatin. A total of 101 sonications were performed (range=1-10 sonication sessions/patient). No DLTs were observed. A total of 14 SAEs were observed including five events considered as possibly treatment related. BBB disruption was confirmed by gadolinium enhancement after sonication. In an analysis of 60 treatments in 27 patients that had all nine emitters active, 90% of activated emitters led to BBB opening in gray and/or white matter with good repeatability of BBB opening. In 3 patients who underwent intraoperative sonication and carboplatin administration, a 7.58-fold increase in brain/plasma drug levels was demonstrated. Updated and mature outcome results will be presented. Conclusion These results confirm the safety and feasibility of repeated BBB disruption using an implantable ultrasound system. LIPU substantially increases drug levels in the peritumoral brain.

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Journal articles on the topic 'Active Implantable Device'

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