Bill The obvious first step is to look at the various parts of IEC 60479 on the effects of current on the human body - especially the graphical curves and explanations in 60479-1 Tables 4 (AC) and 6 (DC) - but you should then take a look at Helmut Hintz's "Protection against electric shock" PSES presentation, which should be somewhere on the forum website and outlines some of the proposed changes. It might also be worthwhile putting together a little "demonstration" of the effects of leakage currents on the hospital administrators! [I will always remember a demo from Al Kanode of HP to various regulatory engineers within the company of the differences between the effect of 0.75mA and 3.5mA - that was enough to convince me that the former was as much as I ever want to take on a continuous basis, and the latter is almost unbearable! In addition, we recently did a project for a customer who wanted to demonstrate the effects of electricity to large numbers of people from all sorts of backgrounds without hurting them - that provides a pulsed PEAK current of around a 1mA for about 2.5mS on a 1-shot per second basis. Anything higher that that induced a "that's unacceptable" (or more "explicit") reaction >from a lot of people! As it is, the demonstration has now been running for nearly 4 months without any complaints. It also proved that 60479 recommendations are pretty close to the mark - although bear in mind that they are now under review and the new proposals will effectively tighten up on the design controls required.] Finally, does'nt the AMA have something to say about all this? Regards John Allen, Technical Consultant EMC and Safety Engineering ERA Technology Ltd. Cleeve Road Leatherhead Surrey KT22 7SA UK Tel: +44-1372-367025 (Direct) +44-1372-367000 (Switchboard) Fax: +44-1372-367102
Please take a minute to visit my recently updated (Sept 04) web pages at http://www.era.co.uk/services/rcm.asp and the main ERA Website at http://www.era.co.uk From: FastWave [mailto:[email protected]] Sent: 16 November 2004 17:23 To: '[email protected]' Subject: Hospital Leakage Current Research I am trying to assist some hospitals in our area who are working to assess the Leakage Current Hazards in their medical facilities. I believe a lot of this relates to the growing abundance of ITE products in medical facilities = in their words "flat screen monitors are showing up everywhere in patient areas" = the ITE certified products fail medical leakage current requirements. There are some people in the hospital (administrators) who do not believe they should be concerned at all with leakage current. The problem is proving that people are getting hurt/killed by leakage current = you can't see the problem and the cause is not obvious in an autopsy. I know I have seen at one time an article written in a medical journal questioning whether some patients are really being killed in surgery due to leakage current (rather than "complications of surgery" or "heart failure"). Can anybody direct me to any articles/research in this area? Thanks, Bill Bisenius, N.C.E. E.D.& D. [email protected] www.productsafeT.com <http://www.productsafet.com/> 919-469-9434 _____________________________________________________________________ This e-mail has been scanned for viruses by MCI's Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.mci.com ---------------------------------------------------------------- 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 ********************************************************************** Copyright ERA Technology Ltd. 2004. (www.era.co.uk). All rights reserved. The information supplied in this Commercial Communication should be treated in confidence. No liability whatsoever is accepted for any loss or damage suffered as a result of accessing this message or any attachments. ********************************************************************** _____________________________________________________________________ This e-mail has been scanned for viruses by MCI's Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.mci.com ---------------------------------------------------------------- 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
