An ultra-low-noise electrical-potential probe for human-body scanning

In this paper we describe a new very-low-noise, high-input-impedance probe developed to make non-contact measurements of electrical potentials generated by currents flowing in the human body. With a noise level of 2 mu V Hz(-1/2) at 1 Hz, down to 0.1 mu V Hz(-1/2) at 1 kHz, and an operational bandwidth from 0.01 Hz to 100 KHz, this probe would seem well suited to the detection of a wide range of electrical activity in the body.