A Novel Low Power, Electronically Tunable DVCCTA-based Sense Amplifier for Pulse Generators in Cardiac Pacemakers

This research paper presents the design and implementation of a unique Sense Amplifier design utilizing a Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA). Cardiac pacemakers are crucial in the emerging medical field for monitoring cardiac activity, especially for individuals suffering from arrhythmia. A pacemaker’s main functions are sensing and pacing, carried out by its core component, the pulse generator. This unit includes a sensing amplifier, a timing unit, and a logic circuit. The sense amplifier, consisting of an Instrumentation Amplifier (INA), a Band Pass Filter (BPF), and a Comparator, works together to identify the QRS complex or R wave within the heart’s electrical signals. The output of the sense amplifier informs the timing and logic control unit, which determines whether pacing is necessary, thus fulfilling the requirements of demand pacing. The functionality of the designs is examined using 180 nm technology parameters in OrCAD PSPICE. All circuits within the sense amplifier design feature the ability to be electronically tuned through IB (bias current) via the transconductance parameter (gm) of the DVCCTA. A significant power reduction, approximately 20 times less, is observed in the DVCCTA-based Sense Amplifier relative to the op-amp-based sense amplifier. The performance of the suggested topologies is assessed through Monte Carlo simulations, non-ideal analysis, and temperature analysis with the simulated responses closely aligning with theoretical predictions.