A Novel Front-End Design for Bioelectrical Signal Wearable Acquisition

Mismatch of front-end branches introduced by the numerical error of the peripheral components will limit the matching level of the front end and lead to the difficulty for obtaining high common mode rejection ratio. In this paper, a novel front-end design is proposed for high-quality bioelectrical signal wearable acquisition. Through partial public dc bias circuit and virtual right leg drive circuit, the common-mode rejection ration of the proposed design can be improved effectively without accurate matching the peripheral components, which is valuable for engineering simplification and wearable device development. Both theoretical analysis and experiment results are given to show the advantages of the proposed design compared with the traditional design. Based on the proposed front-end design, an ECG system with common precision configuration of peripheral components is developed, and its common-mode rejection ratio can reach 100 dB. Three wearable ECG applications, portable finger ECG measurement, palm ECG acquisition for cycling, and chest ECG test under different motion states, are carried out and the experimental results of the proposed design are compared with those of traditional design with the same parameter error, which show that the developed ECG system with the proposed design can effectively suppress power line interference and motion artifact and has the superiority for bioelectrical signal wearable acquisition.