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Coping with motion artifacts by analog front-end ECG microchips under a low voltage supply, and variable digital resolution and gain.

The development of portable ECG has found growing markets, from wearable ECG sensor to ambulatory ECG recorder, encountering challenges of moderately complex to tightly regulated device. This study investigates how the different modalities of ECG are affected by motion artifact and their reduction techniques, when using analog front-end (AFE) integrated circuits such as the AD823X family. It is known that the typical range of current mobile health ECG devices ADC is 10-12 bits, and sometimes 16-bits, which might be insufficient to show up the small potential amplitudes useful in diagnosis; but the interest now is on the interplay of how a digital resolution choice and variable gain can cope with motion artifacts. With our methodology for a rapid prototyping of ECG device, and using the AFE AD8232 and Bluetooth communication, multiple ECG configurations are evaluated under two microcontroller systems of different resolution: a generic Arduino Nano board which features a 10-bit ADC and the 24-bit ADC converter of Silicon Labs C8051F350 board. From the ECG configuration applications (such as: cardiac monitor, fitness, HMR in chest, diagnostic, and Holter), analog filters characteristics and gain are explored under these two different microcontroller systems, in their capacity to solve the problems of motion artifacts alongside performance of the special parameters of each application.

Keywords: motion artifacts; portable ECG; analog front-end; AD8232; high-precision microcontroller;