Hot off the presses - I was finally able to create a device medium capable of detecting artificial sources of EMI such that testing could take place in my vehicle. I wanted to do a P90D as well (as one kind TMCer offered) but the medium also served as an excellent petri dish. May repeat in the future with an antibiotic-impregnated solution. The following abstract has been submitted to the 2016 Heart Rhythm Society Scientific Sessions.
ABSTRACT TITLE: Shockingly safe: an in vitro evaluation of ICDs for potential electromagnetic interference within the Tesla Model S.
AUTHORS:
Matthew R. Evans, MD1; Brent Gattis1; Javier E. Banchs, MD, FACC, FHRS1; David L. Hayes, MD,FACC, FHRS2
1 Section of Clinical Cardiac Electrophysiology; Baylor Scott and White, Temple Memorial Hospital, 2401 South 31st Street, Temple, TX 76508
2 Division of Cardiovascular Diseases; Mayo Clinic, 200 First St. SW, Rochester, MN 55905
INTRODUCTION:
Electromagnetic interference (EMI) is a recognized cause of inappropriate implantable cardioverter-defibrillator (ICD) shocks. With the development of large-capacity, rapidly charging battery electric vehicles, concern has grown regarding its safety for patients with ICDs. Prior studies on hybrid vehicles have been negative for clinically-significant EMI. This study is the first to evaluate for evidence of EMI within the largest-capacity electric vehicle on the market, the Tesla Model S.
METHODS:
Three of the major device manufacturers, St. Jude Medical, Medtronic, and Boston Scientific, donated ICDs and leads (DF-1 and DF-2, single and dual coil, integrated and true bipolar) for the study. The devices were inserted between two layers of gelatin comprised of 0.8% saline in water (Figure) and sensing was performed in bipolar and unipolar configurations. A single chamber pacemaker and associated lead was also placed on the medium and set to pace at VOO during the study to serve as a background signal. All devices functioned appropriately within the medium. The medium was tested using DC and AC sources; corresponding EMI was successfully detected on the study devices (Figure 1). The devices were placed in the study vehicle, a 2013 Tesla Model S with a 60 kWh battery and single on-board charger. The vehicle was turned on, off and driven at speeds from 1 to 90 miles per hour for a period of at least 60 minutes, and battery of tests was performed with the devices placed in the front trunk, front passenger seat, rear passenger seat, and rear trunk (testing protocol available upon request). The devices were also placed within twelve inches of charging cables when charging at 40 Amps, 220 Volts and when supercharging at 300 Amps, 300 Volts. All devices were interrogated to evaluate for EMI detection during the period of testing.
RESULTS:
No EMI was detected in any of the test positions during any test protocols, including testing performed while charging using the on-board charger and supercharging.
CONCLUSION:
Data from this in vitro study suggest relative safety from EMI in patients with ICDs. Further testing should be performed in vivo and with different battery configurations to validate these results.
Figure 1.
Study devices submerged in conductive gelatin for testing within the test vehicle. The top portion of the figure represents pacing artifact from the VOO pacemaker (bottom right of the container) which served as a background signal source for the ICDs. The right of the strip shows artificial EMI, produced to ensure the devices’ ability to detect.