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A novel high input impedance front-end for capacitive biopotential measurement
Rongrong Wu1, Yue Tang1, Zhiyu Li2
1School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu Province, China.
Medical & Biological Engineering & Computing
|January 9, 2018
Summary
A novel high input impedance front-end achieves over 100 GΩ for capacitive biopotential measurement. This design enhances input impedance significantly for electrocardiogram signal sensing, offering improved performance.
Area of Science:
- Biomedical Engineering
- Electronics Engineering
Background:
- Capacitive biopotential measurement requires high input impedance front-ends.
- Existing non-inverting amplifier circuits have limitations in achieving ultra-high input impedance.
Purpose of the Study:
- To propose a novel high input impedance front-end circuit for capacitive biopotential measurements.
- To analyze and optimize the noise performance of the proposed front-end.
- To demonstrate the feasibility of the front-end for electrocardiogram (ECG) signal sensing.
Main Methods:
- Design and simulation of a novel front-end circuit with peripheral parameter matching.
- Development of a noise model for the front-end.
- Experimental verification of the front-end's input impedance and ECG sensing capabilities.
Main Results:
- Achieved an input impedance exceeding 100 GΩ.
- The proposed front-end offers two orders of magnitude higher input impedance compared to non-inverting amplifiers.
- Input-referred noise increased by a factor of two, which is acceptable for the impedance gain.
Conclusions:
- The novel high input impedance front-end is feasible for capacitive biopotential measurements.
- The design significantly improves input impedance for applications like electrocardiogram sensing.
- The trade-off between impedance and noise is well-defined and acceptable.
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