Artifact-Tolerant Electrophysiological Sensor Interface With 3.6V/1.8V DM/CM Input Range and 52.3mV_pp/${\mu}$s...

Area of Science:

• Biomedical Engineering
• Integrated Circuit Design
• Wearable Sensor Technology

Background:

• Wearable sensors face signal integrity issues due to large-amplitude motion and stimulation artifacts, leading to signal chain saturation.
• Closed-loop brain stimulation therapy generates rapid stimulation artifacts, complicating real-time biopotential signal acquisition.
• Existing sensor interfaces struggle to handle high-amplitude artifacts without compromising signal quality and data loss.

Purpose of the Study:

• To develop a sensor interface capable of handling large artifacts (hundreds of mV) without saturation.
• To minimize information loss during artifact events in wearable biopotential recordings.
• To enhance the real-time signal acquisition capabilities for applications like closed-loop brain stimulation.

Main Methods:

• Introduction of a continuous-time track-and-zoom (CT-TAZ) technique for artifact management.
• Design and fabrication of a prototype chip in a 180nm CMOS process.
• Characterization of the system's input range, power consumption, and artifact recovery performance.

Main Results:

• The CT-TAZ system achieves a 3.6V/1.8V differential-mode/common-mode full-scale input range.
• The prototype chip exhibits low power consumption (12/32.6/51.6μW) under various artifact conditions.
• Demonstrated an average artifact recovery time of 65.3 μs for 3.6V stimulation artifacts, with a recovery speed of 52.3mVpp/μs.

Conclusions:

• The proposed CT-TAZ technique effectively handles large motion and stimulation artifacts in wearable sensor applications.
• The system offers a significantly larger input range (2.25x) and faster recovery (3x) compared to state-of-the-art solutions.
• This advancement is crucial for improving the reliability and performance of biopotential signal acquisition in demanding environments.