help:volunteers devloping medical device need legal help

hi
my name is yaniv vilnai.
i'm the leader of an internet based volunteer group ,developing
a medical device for personal to be avaible at low cost .
our web site :[url]http://openeeg.sourceforge.net/index_old.html[/url]

are business program is at start sell this device , by the net ,
under some note who takes all responsibility from us .
(they can be sure it's safe , because were working with an open source design , so anybody can check the design , and it has
bein checked numerous times for being safe) .

so what laws we have to abide if were selling throught net ?
is it enough to post - were no responsible notice ?
can you think of other legal question we might need to ask ?

sincerly yaniv