Design and analysis of novel sense amplifier for bio-medical applications

Abstract

This paper presents the realization of a novel sense amplifier for biomedical applications, with a primary focus on its application in cardiac pacemakers. The researchers focus on low-power biomedical devices, achieving this by advanced active devices like the Differential Voltage Current Conveyor (DVCC). In a pacemaker, both sensing and pacing functions are crucial. The sense amplifier consists of an instrumentation amplifier, a bandpass filter, and a comparator, enabling it to recognize the PQRST complex in the cardiac cycle. We introduce a novel model for the sense amplifier, employing a DVCC, and conduct analyses using the TSMC 130 nm technology. The gain of the current-mode instrumentation amplifier is 56.3, and the CMRR is 60.7. Moreover, the proposed design analysis addresses power dissipation, temperature, and noise. Furthermore, experiments performed with the analog IC AD844 have demonstrated the efficiency of the proposed sense amplifier design. Additionally, we analyzed the electrocardiogram (ECG) signal by identifying its patterns. We have used the Fast Fourier transform (FFT) to determine the power spectrum and frequency response of the signal. Studies that looked at signal analysis in the literature used radix-2, SRFFT, and other algorithms. These can save up to 5.066% of power compared to using an FFT ASIC. Hence, we proposed a modified radix-2 approach for the low power spectrum of an ECG cycle. The Radix-2 customized method drastically reduces the number of computations, resulting in a low power consumption of 3.339 mW, and a leakage power of 1.272 mW. Furthermore, it would promote real-time adaptability and increase accuracy in pattern recognition for ECG signals. The results demonstrate that the new sense amplifier model achieves substantial gain and a CMRR, making it more efficient than previous versions.