Bootstrapped Non-Inverting Front-End Amplifier for Capacitive Electrocardiogram Measurement

Front-end amplifier for capacitive electrocardiogram (cECG) measurement requires high input impedance only in the corresponding frequency band. To achieve high input impedance around the ECG band, a bootstrapping technique was applied to a non-inverting amplifier (NiA), then combined with a stray capacitance canceller (SCC). Theoretical formulas were derived to design the band and skirt unfavorable resonances. Validities of the formulas were confirmed respectively in the experiments using a physical model. Bootstrapped NiA with SCC suppressed attenuation the most in the cECG measurement.