by Engineering faculty, Universite Laval, Quebec, Canada.

http://www.gel.ulaval.ca/~busque00/elec/

An electric charge and field simulator allows viewers to place charges of selected signs and sizes on a map, and then to draw in electric field lines by clicking at various locations on the map. It is possible to create a plot of electric fields resulting from simple charge arrangements. We advise you read the brief explanation before using the applet.

from The Hippocrates Project at the New York University School of Medicine.

http://endeavor.med.nyu.edu/courses/
physiology/courseware/ekg_pt1/

A sophisticated shockwave tutorial describing how electrical depolarization and repolarization of heart tissue drives the heart and is recorded on a standard Electrocardiogram (ECG or EKG). Professor Sayegh, Physics Department, University of Michigan also has a site which explains some of the physics of an EKG.

The Hippocrates site contains other multimedia medical tutorials available to the public.