Abstract: A device and method for detecting the potential level of the electromagnetic field present between a reference point and a test point of a living organism is disclosed. A reference electrode provides a first signal indicative of the potential level of the electromagnetic field at the reference point. A test electrode provides a second signal indicative of the potential level of the electromagnetic field at the test point. More than one test electrode and corresponding second signals can be employed. An analog-to-digital converter responsive to the first and second signals generates a digital signal as a function of the potential difference between the first and second signals. A processor provides an output signal indicative of a parameter or parameters of the living organism as a function of the digital signal. In addition, a low pass filter can be provided ahead of the analog-to-digital converter for filtering out undesired charges and alternating current signals from the first and second signals.