An Integrated Amplifier With Passive Neutralization of Myoelectric Interference from Neural Recording Tripoles

作者：Demosthenous Andreas^*; Pachnis Ioannis; Jiang Dai; Donaldson Nick

来源：IEEE Sensors Journal, 2013, 13(9): 3236-3248.

DOI：10.1109/JSEN.2013.2271477

• Implantable circuits
• instrumentation amplifier
• low noise
• myoelectric interference
• neural recording
• neural stimulation
• stimulator
• tripole

This paper describes an integrated amplifier for neural recording from tripolar electrode books connected in the quasi-tripole arrangement. The same tripole is used in the implant for neural stimulation. To remove myoelectric interference from neural recordings, a resistor-capacitor network is used to balance the electrode impedances in the tripole. The amplifier is programmable (recording mode, passband, gain, and trimming impedance) via a serial peripheral interface. Its front-end instrumentation amplifier employs current feedback to achieve high common-mode rejection ratio. The circuit was implemented in 0.35-mu m CMOS technology and occupies an area of similar to 1.2 mm(2). In the very-low noise mode, the analog front-end features a maximum of 0.68 mu V-rms input-referred noise in the passband and consumes similar to 310 mu A from a 3 V supply. The measured common-mode rejection ratio of the instrumentation amplifier (CMRRIA) approaches 100 dB. The effect of component mismatch on the CMRRIA and the noise performance of the instrumentation amplifier are examined. In addition, the recording tripole is analyzed to derive the overall common-mode rejection ratio that is shown to exceed 80 dB. The ability of the neural amplifier to reduce myoelectric interference is demonstrated. The amplifier is also tested with a tripole immersed in saline in the stimulate-record mode.

• 出版日期2013-9