A High Precision, Wide Dynamic Range Closed-Loop Neuromodulation IC With Rapid Stimulation Artifact Recovery

Area of Science:

• Biomedical Engineering
• Neuroscience
• Electrical Engineering

Background:

• Neuromodulation systems face challenges with stimulation artifacts (SA) and limited dynamic range (DR).
• Rapid SA recovery and high-fidelity neural signal acquisition are critical for effective closed-loop neuromodulation (CLNM).

Purpose of the Study:

• To develop a high-precision, wide dynamic range CLNM system with complete SA rejection and rapid SA recovery.
• To enhance neural signal acquisition during concurrent stimulation and recording.

Main Methods:

• A novel SA quick-blanking scheme for rail-to-rail SA rejection and minimized recovery time.
• An analog front-end (AFE) architecture with frequency-shaping (FS) for extended DR.
• A stimulation driver using redundant crossfire (RXF) technique for improved stimulation current resolution.

Main Results:

• The CLNM system demonstrated rail-to-rail (5 V) SA tolerance and reduced SA recovery time from 12 ms to 0.15 ms.
• The FS recorder achieved a DR of 17.5 bits at low frequencies, improving interference tolerance.
• The RXF stimulator enhanced effective resolution to 12.75 bits with minimal area and power overhead.

Conclusions:

• The developed CLNM system effectively rejects stimulation artifacts and recovers rapidly.
• The system enables high-fidelity neural signal acquisition immediately post-stimulation, supporting concurrent recording and stimulation.
• This technology advances the capabilities of neuromodulation devices for research and therapeutic applications.