Real Project — a 3-lead ECG instrumentation amplifier design for a bedside patient monitor, with worked gain and CMRR calculations.
This project designs a 3-lead ECG front end for a bedside patient monitor, acquiring a surface ECG signal in the 0.5-4 mV amplitude range and feeding a 12-bit ADC with a 3.3V full-scale input, targeting the AAMI EC13/IEC 60601-2-27 monitoring-mode bandwidth of 0.5-40 Hz rather than the wider diagnostic-mode bandwidth a 12-lead cart requires.
It works through a worked instrumentation amplifier gain calculation and CMRR requirement, high-pass filter design for baseline wander rejection, low-pass filter design for anti-aliasing and EMG noise rejection, and a right-leg-drive circuit that improves common-mode rejection while limiting patient safety current — assembling the complete front end and directly applying the instrumentation amplifier principles built in Module 6 and the leakage current limits built in Module 18.