RF-Induced Unintended Stimulation for Implantable Medical Devices in MRI

AbstractHistorically, patients with implantable medical devices have been denied access to magnetic resonance imaging (MRI) due to several potentially hazardous interactions. There has been significant interest in recent years to provide access to MRI to patients with implantable medical devices, as it is the preferred imaging modality for soft tissue imaging. Among the potential hazards of MRI for patients with an active implantable medical device is radio frequency (RF)-induced unintended stimulation. RF energy incident on the device may be rectified by internal active components. Any rectified waveform present at the lead electrodes may stimulate nearby tissue. In order to assess the risk to the patient, device manufacturers use computational human models (CHMs) to quantify the incident RF on the device and perform in vitro testing to determine the likelihood of unintended stimulation. The use of CHMs enables the investigation of millions of scenarios of scan parameters, patient sizes and anatomies, and MR system technologies.

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Ferromagnetic sand: A possible MRI hazard

The Neuroradiology Journal ◽

10.1177/1971400918795865 ◽

2018 ◽

Vol 31 (6) ◽

pp. 614-616 ◽

Cited By ~ 1

Author(s):

Emil Jernstedt Barkovich ◽

Matthew Jernstedt Barkovich ◽

Christopher Hess

Keyword(s):

San Francisco ◽

Medical Devices ◽

San Francisco Bay Area ◽

Resonance Imaging ◽

Geologic History ◽

Implantable Medical Devices ◽

Bay Area ◽

Geographic Regions ◽

Imaging Artifact ◽

Magnetic Resonance Imaging Mri

While the ferromagnetic properties of metallic objects, implantable medical devices, and cosmetics are well known, sand is not generally considered a consequential substance. Beaches in specific geographic regions, including the San Francisco Bay Area, have a propensity for ferromagnetic sand because of their geologic history. We describe a case in which ferromagnetic sand in a patient’s hair coated the magnetic resonance imaging (MRI) scanner bore and caused significant imaging artifact, fortunately with no harm to the patient. We recommend that MRI facilities in areas where ferromagnetic sand is found consider educating technologists and screening patients for recent black sand exposure prior to scanning.

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Ion Leaching from Implantable Medical Devices

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.754 ◽

2010 ◽

Vol 638-642 ◽

pp. 754-759

Author(s):

Lawrence E. Eiselstein ◽

Robert D. Caligiuri

Keyword(s):

Medical Devices ◽

Stainless Steels ◽

The Body ◽

Cobalt Chromium ◽

Implantable Medical Devices ◽

Device Development ◽

Soluble Ions ◽

Chromium Alloys

Implantable medical devices must be able to withstand the corrosive environment of the human body for 10 or more years without adverse consequences. Most reported research and development has been on developing materials and devices that are biocompatible and resistant to corrosion-fatigue, pitting, and crevice corrosion. However, little has been directly reported regarding implantable materials with respect to the rate at which they generate soluble ions in-vivo. Most of the biocompatibility studies have been done by examining animal implants and cell cultures rather than examining the rate at which these materials leach ions into the body. This paper will discuss what is currently known about the rate at which common implant materials (such as stainless steels, cobalt-chromium alloys, and nitinol) elute ions under in vitro conditions, what the limitations are of such data, and how this data can be used in medical device development.

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An Ultra-Low Power Implantable Medical Devices: An Engineering Perspective

Journal of University of Shanghai for Science and Technology ◽

10.51201/jusst/21/11920 ◽

2021 ◽

Vol 23 (12) ◽

pp. 46-59

Author(s):

B. Sathyabhama ◽

◽

B. Siva Shankari ◽

Keyword(s):

Low Power ◽

Medical Devices ◽

Neurological Disorders ◽

Heart Diseases ◽

Implantable Devices ◽

Implantable Medical Device ◽

Implantable Medical Devices ◽

Ultra Low Power ◽

Device Integration ◽

History Of

Implantable Medical Devices (IMDs) reside within human bodies either temporarily or permanently, for diagnostic, monitoring, or therapeutic purposes. IMDs have a history of outstanding success in the treatment of many diseases, including heart diseases, neurological disorders, and deafness etc.,With the ever-increasing clinical need for implantable devices comes along with the continuous flow of technical challenges. Comparing with the commercial portable products, implantable devices share the same need to reduce size, weight and power. Thus, the need for device integration becomes very much imperative. There are many challenges faced when creating an implantable medical device. While this paper focuses on various techniques adapted to design a reliable device and also focus on the key electronic features of designing an ultra-low power implantable medical circuits for devices and systems.

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In vitro Assessment of Electromagnetic Interference due to Low-Band RFID reader/writers on Active Implantable Medical Devices

Journal of Arrhythmia ◽

10.1016/s1880-4276(09)80013-6 ◽

2009 ◽

Vol 25 (3) ◽

pp. 142-152 ◽

Cited By ~ 6

Author(s):

Shunichi Futatsumori ◽

Yoshifumi Kawamura ◽

Takashi Hikage ◽

Toshio Nojima ◽

Ben Koike ◽

...

Keyword(s):

Medical Devices ◽

Electromagnetic Interference ◽

Implantable Medical Devices ◽

Rfid Reader ◽

In Vitro Assessment

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Legal and regulatory update

Journal of Commercial Biotechnology ◽

10.5912/jcb152 ◽

2005 ◽

Vol 12 (1) ◽

Author(s):

John Wilkinson

Keyword(s):

European Commission ◽

Medical Device ◽

Medical Devices ◽

Public Consultation ◽

Implantable Medical Devices ◽

Post Market Surveillance ◽

Post Market ◽

Definition Of ◽

Regulatory Update

The European Commission has launched a public consultation on its proposed amendments to the Medical Devices Directive (MDD) (Dir 93/42/EEC). The aim of the European Commission's proposals is to improve the coherence, transparency and effectiveness of the legislation governing medical devices in line with the recommendations of the report produced in 2002 by the European Commission's Medical Device Experts Group. This report recommended that the requirements for clinical evaluation of medical devices be clarified, transparency be increased by amending post-market surveillance requirements and that the decision making process be improved by empowering the European Commission to make binding decisions where individual national opinions differ on whether a product falls within the definition of 'medical device'. The report also recommended that the three directives governing medical devices (the MDD, the Active Implantable Medical Devices (AIMD) Directive 90/385/EEC and the In-vitro Medical Devices (IVDD) Directive 98/79/EC) should be made more consistent with each other.

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Iodinated poly(p-dioxanone) as a facile platform for X-ray imaging of resorbable implantable medical devices

Journal of Biomaterials Applications ◽

10.1177/0885328220912842 ◽

2020 ◽

Vol 35 (1) ◽

pp. 39-48

Author(s):

Fan Zhao ◽

Haiyan Xu ◽

Wen Xue ◽

Yan Li ◽

Jing Sun ◽

...

Keyword(s):

Medical Devices ◽

Melt Spinning ◽

Imaging Techniques ◽

Fibrous Materials ◽

Hybrid Fibers ◽

Implantable Medical Devices ◽

X Ray ◽

The Impact

Currently, implantable fibrous medical devices still suffer from invisibility under current clinical imaging techniques. To address this problem, 2, 3, 5-triiodobenzoic acid (TIBA) was recruited as a contrast agent, and then a set of iodinated poly( p-dioxanone) (PPDO) fibers was fabricated via melt-spinning hybrid blends of PPDO with TIBA (PPDO/TIBA). The impact of TIBA content on the rheological behavior of blends was evaluated firstly. The physical, chemical, and thermal properties of PPDO/TIBA fibers were investigated accordingly by SEM, FTIR, DSC, and TGA. Moreover, the radiopaque property of PPDO/TIBA hybrid fibers as a potential radio-opacifying platform for medical devices was verified in vitro and in vivo. Finally, the accumulated release results of the hybrid fibers during in vitro degradation indicate the continual X-ray visibility of the hybrid fibers maintains for 22 days. This intriguing iodinated platform may pave the way for constructing fibrous materials with in-situ X-ray tracking property.

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The Potential Role of Polymethyl Methacrylate as a New Packaging Material for the Implantable Medical Device in the Bladder

BioMed Research International ◽

10.1155/2015/852456 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Su Jin Kim ◽

Bumkyoo Choi ◽

Kang Sup Kim ◽

Woong Jin Bae ◽

Sung Hoo Hong ◽

...

Keyword(s):

Foreign Body ◽

Polymethyl Methacrylate ◽

Inflammatory Cytokines ◽

Medical Devices ◽

Foreign Body Reaction ◽

Early Period ◽

Implantable Medical Device ◽

Implantable Medical Devices ◽

Macrophage Activity ◽

Implanted Medical Devices

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-αwere 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.

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MRI-visible polymer based on poly(methyl methacrylate) for imaging applications

RSC Advances ◽

10.1039/c5ra23646k ◽

2016 ◽

Vol 6 (7) ◽

pp. 5754-5760 ◽

Cited By ~ 4

Author(s):

Mira Younis ◽

Vincent Darcos ◽

Cédric Paniagua ◽

Pauline Ronjat ◽

Laurent Lemaire ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Methyl Methacrylate ◽

Contrast Agents ◽

Medical Devices ◽

Resonance Imaging ◽

Implantable Medical Devices ◽

Poly Methyl Methacrylate ◽

Magnetic Resonance Imaging Mri

Macromolecular contrast agents are very attractive to afford efficient magnetic resonance imaging (MRI) visualization of implantable medical devices.

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In Vitro Models of Biological Responses to Implant Microbiological Models

Advances in Dental Research ◽

10.1177/08959374990130011701 ◽

1999 ◽

Vol 13 (1) ◽

pp. 67-72 ◽

Cited By ~ 15

Author(s):

Andrea Mombelli

Keyword(s):

Medical Devices ◽

Antimicrobial Agents ◽

In Vitro Models ◽

Implantable Medical Devices ◽

Oral Implants ◽

Common Features ◽

Biological Responses ◽

Implanted Medical Devices ◽

Micro Organisms

To study the etiology and explore possibilities for the therapy of implant-associated infections, investigators have developed and utilized various in vitro models. Major contributions have come from the non-oral medical field, where device-related infections can create life-threatening situations. Microbiological models may include (i) models to study the reaction of micro-organisms to the presence of implants, (ii) models to study the reaction of implant-associated micro-organisms to antimicrobial agents, and (iii) models to study the reaction of the host tissues to the presence of implants contaminated with micro-organisms. In evaluating the potential usefulness of these models for research in oral implantology, one must consider common features as well as important differences between implanted medical devices and oral implants. Although infections associated with implantable medical devices and oral peri-implant infections share a remarkable number of common features, there are also important differences that need attention when findings from in vitro experiments are extrapolated to clinical relevance.

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Workers with Active Implantable Medical Devices Exposed to EMF: In Vitro Test for the Risk Assessment

Environments ◽

10.3390/environments6110119 ◽

2019 ◽

Vol 6 (11) ◽

pp. 119

Author(s):

Eugenio Mattei ◽

Giovanni Calcagnini ◽

Federica Censi ◽

Iole Pinto ◽

Andrea Bogi ◽

...

Keyword(s):

Risk Assessment ◽

Scientific Evidence ◽

Health And Safety ◽

Implantable Defibrillator ◽

In Vitro Test ◽

Implantable Medical Device ◽

Implantable Medical Devices ◽

Electrosurgical Unit ◽

Magnetic Field Coupling

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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