Fay, L., Misra, V., & Sarpeshkar, R. (2009). A micropower electrocardiogram amplifier. IEEE transactions on biomedical circuits and systems, 3(5), 312-320.
We introduce an electrocardiogram (EKG) preamplifier with a power consumption of 2.8 muW, 8.1 muV rms input-referred noise, and a common-mode rejection ratio of 90 dB. Compared to previously reported work, this amplifier represents a significant reduction in power with little compromise in signal quality. The improvement in performance may be attributed to many optimizations throughout the design including the use of subthreshold transistor operation to improve noise efficiency, gain-setting capacitors versus resistors, half-rail operation wherever possible, optimal power allocations among amplifier blocks, and the sizing of devices to improve matching and reduce noise. We envision that the micropower amplifier can be used as part of a wireless EKG monitoring system powered by rectified radio-frequency energy or other forms of energy harvesting like body vibration and body heat.
Keywords: Power amplifiers, Noise reduction, Radiofrequency amplifiers, Preamplifiers, Energy consumption, Signal to noise ratio, Design optimization, Capacitors, Resistors, Operational amplifiers