A method for the noninvasive measurement of low-level ionically conducted electric currents flowing in electrolytes and tissue is investigated. Experiments show that the application of oscillating magnetic fields to current-carrying media will cause focal Lorentz forces which generate detectable vibrations. These vibrations can be sensitively and noninvasively detected by surface contact detectors and can be used to determine the magnitude of internal current flows. Microampere-level currents introduced in hamsters to simulate natural bioelectric currents have been sensitively detected by this approach. >