Description:

INSTRUMENTATION AMPLIFIER WITH BUILT-IN DIGITALLY PROGRAMMABLE INPUT CAPACITANCE CANCELLATION

INV-14068

INVENTORS: Chun-hsiang Chang, Marvin Onabajo

Description       

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.

 

 

Value Proposition

The mechanism:

•Doesn’t consume any extra power as compared to prior art mechanisms

•Avoids use of additional amplifier(s) for generating negative capacitance

•Significantly improves the input impedance from few mega-ohms to above 500 mega-ohms

•Effectively uses dry electrodes that are better suited for long-term monitoring as compared to wet electrodes used        conventionally

•Doesn’t affect the important performance parameters such as common-mode rejection ratio, power supply rejection        ratio, etc., unlike prior art techniques

•Would be commercially useful for various applications such as:

oLong-term brain signal monitoring such as EEG

oDry contact measurements with Ag/AgCl electrodes

 

Intellectual Property status

Provisional Application 61/946,022

License status

Available for license

 

Patent Information:
For Information, Contact:
Mark Saulich
Associate Director of Commercialization
Northeastern University
m.saulich@northeastern.edu
Inventors:
Chun-Hsiang Chang
Marvin Onabajo
Keywords:
Diagnostics
Health
Medical Device