Electric potential probes - new directions in the remote sensing of the human body

In this paper we describe a new approach to the detection of human body electrical activity which has been made possible by recent advances in ultra-low-noise, ultra-high-input-impedance probes. As we demonstrate, these probes, which do not require a real current conducting path in order to operate, can be used non-invasively both on and off body. We present remarkable new data showing the application of these probes to the remote, off-body, sensing of the electrical activity of the heart at distances of up to I m from the body and to high-resolution electrocardiograms. We suggest that in the future such probes may form the basis of a radically new technology for measuring the dynamics of the human body as well as in non-contact, imaging systems for pre-emptive and diagnostic medicine.