>> the manual for a powered wheelchair, and I was struck by their detailed explanation of RF interference and its effects on a powered wheelchair. I found their wording fascinating, in that they moved back and forth across the subject, alternately describing 20 V/M as a typically realistic immunity level. But then they didn't really claim compliance with this level, although they did make it sound like they had done immunity testing. I don't recall if the product was CE marked. <<
Having recently become involved in medical device EMC, it seemed to me that electric wheel-chair incidents were one factor in getting EMC on the FDA's "radar screen." However, it also seems to me that some medical device incidents had to have occurred at field strengths far higher than the Medical Directive's 10 and 20v/m limits. There's at least one extant report attributing a patient death to RF-induced defibrillator malfunction when a driver used the ambulance radio; one on-line article I saw said FS inside ambulances had been measured at 65 v/m.* *If I recall this report correctly, the vehicle shell had been changed from metal to fiberglass without considering where RF might go. It makes an impression on designers when one waves a handy-talkie over prototype board and the HT makes it turn on -- with every status LED lit, to boot. Back on topic, folks who might object to a SLA battery on a bus would *really* be horrified by the explosive potential of digital cameras' Lithium batteries! Cortland Richmond This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Scott Douglas [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
