Dear Xing weibing, I can't give you a direct answer to your questions, but you may find the discussion in sub-clause 19.3 of the "General Guidance and Rationale" in IEC 60601-1 (Electrical Medical Equipment) of interest. There is information on the effect of electrical currents on the human body, as well as a list of references.
Regards, Jon Griver www.601help.com The Medical Device Developers Guide to IEC 60601-1 ------- Forwarded message follows ------- Dear colleagues I have a question regarding touch current limit of IEC 60950? We can read from table 5A of IEC60950:1999: Touch current limit for accessible parts and circuits not connected to protective earth: 0.25 mA question 1 : How does it (0.25mA) come from and what it is based on? based on IEC479? OR other source why it is not 0.5mA(based on IEC60479) question 2 :for hand-held equipment it is 0.75mA why ? Please shed some light for above questions Any comments are appreciated Best Regards Xing weibing 2002-06-24 ------- End of forwarded message ------- ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [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://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"

