Infinite Input Impedance Biopotential Amplifier

Background

Existing contact-less biopotential sensor designs assume a large coupling capacitance, which assumes adequate mechanical force to press the sensing plate to the body. The relatively large input capacitance of commercially available amplifiers presents a significant design challenge for sensors that capacitively couple signals.

Technology Description

The amplifier design invented by UC San Diego researchers presents two major improvements: 1) a single amplifier with extremely high input resistance and low input capacitance (femto-farads) without the need for adjustment; and 2) self-biased with novel on-chip, low-leakage, low-noise structures.

Applications

This invention is useful as a high-performance impedance converter bridging an ultra-high source impedance sensor or transducer with subsequent amplification and signal processing circuits. Applications include cellular microelectrode amplifiers, contact-less biopotential sensors, and free-space electric field sensors.

State Of Development

A prototype circuit has been developed and demonstrated.

Related cases

See also SD2010-311 for a related technology.

Patent Status