A dynamic electrode impedance matched acupuncture-type diagnosis system with concurrent feedback of physiological signals

A dynamic electrode impedance matched acupuncture-type diagnosis system is proposed for an active electro-acupuncture (EA) treatment with the concurrent feedback of physiological signals. The 4-channel ExG sensor front-end and the independent component analysis (ICA) processor, is used for the acquisition of pure ECG, EEG, and EMG signal when the EA stimulation is simultaneously applied to the human body. The EA stimulator front-end adopts both the large time constant (LTC) S/H current matching technique and the offset current regulation for the accurate charge balancing. As a result, it can achieve less than 10 nA DC offset current. There are 25 concentric circular electrodes in the bottom of the proposed system. The dynamic electrode impedance matching circuit monitors the stimulation voltage swing and optimizes the area of the stimulation electrodes and the sensing electrodes for the high CMRR. The proposed diagnosis IC of 5.0 mm × 5.0 mm is fabricated in 0.13 μm RF CMOS technology, and dissipates only 3.6 mW from 1.2 V.