Modeling of EXG (ECG, EMG and EEG) non-idealities using MATLAB
Mahesh Kumar Adimulam, Mandalika B. Srinivas · 2016
EXG [Electrocardiography (ECG), Electromyography (EMG) and Electroencephalogram (EEG)] signals are of very low amplitude and frequency with immense diagnostic value. These signals acquire noise while travelling through electrodes, printed circuit board (PCB), integrated circuits (ICs), etc. and thus their detection and interpretation is a challenge in biomedical engineering. This paper presents MATLAB Simulink environment for an integrated EXG electronic measuring system that allows designers to analyze the time/frequency domain behavior of sensing electrodes, programmable instrumentation amplifiers (PIA), programmable band pass filter (BPF) and second order sigma delta analog to digital converter (SD-ADC). The Simulink model provides non-idealities such as sensing electrodes noise, programmable gain amplifier parameters (thermal noise, flicker noise, resistor mismatch, settling time (slew rate), dc gain, bandwidth, and voltage dynamic ranges), band pass filter parameters (noise and bandwidth), and sigma delta ADC parameters (clock jitter, capacitor mismatch, noise, settling time (slew rate), dc gain, bandwidth, and voltage dynamic ranges). A detailed simulation and implementation (Using CMOS, 180nm technology) results of the complete system is presented for both the ideal and actual performance parameters.