Implantable cardiac pacemaker electromagnetic compatibility testing in a novel security system Simulator

Abstract

This paper describes a novel simulator to perform electromagnetic compatibility (EMC) tests for active implantable medical devices (AIMDs) with electromagnetic fields emitted by security systems. The security system simulator was developed in response to over 100 incident reports over 17 years related to the interference of AIMD's with security systems and the lack of a standardized test method. The simulator was evaluated regarding field homogeneity, signal distortion, and maximum magnetic field strength levels. Small three-axis probes and a three-axis scanning system were designed to determine the spatial and temporal characteristics of the fields emitted by 12 different types of walk through metal detectors (WTMDs). Tests were performed on four implanted pacemakers with a saline phantom and correlated to a newly developed test method performed "in air" (without the phantom). Comparison of the simulator thresholds with tests performed in real WTMDs showed that the simulator is able to mimic the pacemaker interference. The interference thresholds found in the simulator indicate that pulsed magnetic fields are more likely to cause interference in pacemakers than sinusoidal fields. The security system simulator will help biomedical engineers, manufacturers of medical devices, and manufacturers of security systems to identify incompatible combinations of WTMDs and AIMDs early in the development stage.

Hand-held metal detectors and medical devices: measurements and testing for electromagnetic compatibility

“…Our previous study with walk-through metal detectors (WTMD) suggested that certain types of active medical devices may be more susceptible to emissions that are pulsed or have amplitude modulations within the pass-bands of the medical device. [4] The bulk of the sample HHMDs emit sinusoidal-type emissions that did not appear to affect the sample medical devices. However, the HHMD with unusually high emission field measurements appeared to affect some of the implanted medical devices, as was seen with the output of the pacemakers where errant output signals were observed.…”

“…[1][2][3] Our most recent paper reports in more detail about the emissions from walk-through metal detectors and medical device testing that found these emitters can cause disruptions in the functioning of implanted cardiac pacemakers. [4] EMISSIONS MEASUREMENTS For this study the emissions fields from each HHMD were measured and mapped and EMC testing was performed with 3 different types of ambulatory medical devices. Emissions measurements were performed using a three-dimensional probe positioning system with specially designed three axis magnetic field detector probes and readout.…”

Personal medical electronic devices and walk-through metal detector security systems: assessing electromagnetic interference effects

“…Among these EM sources, there have been specific concerns involving certain active medical devices such as implantable cardiac pacemakers and implantable neurostimulator (e.g., implanted spinal cord stimulators) being potentially vulnerable to EMI in proximity to security systems [1, 5, 6, 11]. There have been a few studies focus on metal detectors and active medical devices [5, 6, 12]. The Food and Drug Administration (FDA) recognized the issues associated with security systems and provided recommendations for patients with implantable medical devices [13].…”

“…Previous studies have evaluated possible interference between active medical devices and WTMD [5, 6, 12]. The studies done by Kainz et al [5] and Seidman et al [6] focus on implantable cardiac pacemaker and implantable neurostimulators using controlled in vitro testing for EMC and reveal potential EMI from exposure to WTMD.…”

EMC Characterization of Implantable Cardiac Medical Devices in an anechoic chamber

“…cell phones, safety systems, magnetic resonance, radiation, X-rays, etc.) [3]. In fact, not correctly interpreting the heartbeat signal, may due to EMI, can seriously jeopardize the health of the patient, even leading to drama.…”