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Instrumentation amplifier with built-in digitally-programmable input capacitance cancellation

Technology Benefits

The mechanism:ΓÇóDoesnΓÇÖt consume any extra power as compared to prior art mechanismsΓÇóAvoids use of additional amplifier(s) for generating negative capacitanceΓÇóSignificantly improves the input impedance from few mega-ohms to above 500 mega-ohmsΓÇóEffectively uses dry electrodes that are better suited for long-term monitoring as compared to wet electrodes used conventionallyΓÇóDoesnΓÇÖt affect the important performance parameters such as common-mode rejection ratio, power supply rejection ratio, etc., unlike prior art techniquesΓÇóWould be commercially useful for various applications such as:oLong-term brain signal monitoring such as EEGoDry contact measurements with Ag/AgCl electrodes

Detailed Technology Description

None

*Abstract

Bio-potential measurement devices are becoming increasingly widespread in the medical diagnostics field. In prior art, bio-potentials such as electroencephalography (EEG) and electrocardiography (ECG) are measured using wet electrodes (covered with gels or solutions); however, such electrodes cause discomfort and dry out in long-term monitoring applications. As a result, for long-term applications, use of dry electrodes is more suitable; however, even these electrodes are associated with limitations such as increased contact resistances. This invention relates to a novel input capacitance cancellation mechanism that comprises an instrumentation amplifier to digitally tune its input impedance for more accurate applications, overcoming most prior art limitations and/or unmet needs.

*Principal Investigator

Name: Chun-hsiang Chang

Department:

Name: Marvin Onabajo

Department:

Country/Region

USA