Wireless Closed-loop System For Pain Inhibition Base On Neurostimulation

Chronic pain has been considered as a significant public health problem. However, most patients with chronic pain do not obtain adequate relief or experience unacceptable side effects from existing treatments with chemical means. An alternative option with high activity, low side effect and low cost is needed. Neurostimulation can be considered for this purpose. However, the current stimulator implants are operated in an open-loop mode which can not evaluate patient’s pain quantitatively in the the objective physiological signal monitoring level, or adjust the intensity of neural stimulation in real-time. Considering the safety and effectiveness, there is a great distance from clinical applications.A wireless closed-loop system for pain inhibition based on neural signal recording and stimulating modules has been developed. All the hardware of circuit and PC software for closed-loop feedback control has been designed, fabricated and tested. The wireless closed-loop system can acquire neural signals in real-time and generate synchronized stimulus pulses for chronic pain relief. The effectiveness of wireless closed-loop system to inhibit pain has been well verified through a series of animal experiments.Based on the wireless closed-loop system, an enhanced real-time feedback algorithm between the recorder and stimulator has been proposed and demonstrated. This algorithm incorporated both the rates of action potentials (APs) and the changes in AP rates as a gating factor to provide better accuracy in identifying the noxious threshold of the dorsal horn activities to increase the robustness in making real-time decisions for triggering stimulation with noisy input signals.In addition, we have also developed multi-channel neural signal acquisition systems, btteryless telemetric neuronal signal recording and stimulation system, and miniature implantable telemetric ECoG signal recording system. Wireless closed-loop system has not only provided a innovative experiment platform for pain processing research in freely moving animals, but also has provided a simplified and efficient method for further study of pain management and a potential application choice for patients in clinical.