Design of a Distributed Passive Micro-Magnetic Stimulator for Targeted Multi-Brain Region Neuromodulation

The multi-channel synchronous stimulator, aimed at achieving efficient and precise neural regulation, typically utilizes a monolithic microelectrode array structure. However, this structure limits the flexibility of electrode placement and the expansion to a large number of nodes, particularly in discontinuous locations. To address this, this paper designs a distributed passive micro-magnetic stimulation (DP-μMS) neuro-regulation device with multi-brain region collaborative stimulation functionality. It consists of an external Emission coil, Recognition coil, and multiple MEMS micro-coil (a collection unit of Stimulation coils and Addressing coils) distributed at different positions within the body. The DP-μMS utilizes magnetic coupling technology to achieve collaborative operation among the coils. In the downlink, the Stimulation coils couple with the energy transmitted by the Emission coil to achieve magnetic stimulation, and the rectifier circuit collects energy to power the Addressing coils. In the uplink, each Addressing coil returns a unique frequency signal using Frequency Division Multiple Access (FDMA), and the Recognition coil demodulates the frequency to identify the ID of the micro-coil, enabling the monitoring of the collaborative working status of each micro-coil. Based on this, biological experiments were conducted to verify the functionality of DP-μMS on the neural circuits in the hippocampal region. The results indicated that multi-point collaborative magnetic stimulation enhanced long-term potentiation (LTP) of the Schaffer-CA1 synapse more effectively than single-point stimulation. This study provides a solution for multi-brain region targeted therapy for neurological diseases.