A programmable and self-adaptive ultrasonic wireless implant for personalized chronic pain management.

Chronic pain management typically involves opioids, which are associated with severe side effects such as addiction. Implantable percutaneous electrical stimulators are a promising alternative approach to pain management. However, they are expensive, can cause damage during surgery and often rely on a battery power supply that must be periodically replaced. Here we report an integrated flexible ultrasound-induced wireless implantable stimulator combined with a pain detection and management system for personalized chronic pain management. Power is supplied to the stimulator by a wearable ultrasound transmitter. We classify pain stimuli from brain recordings by developing a machine learning model and program the acoustic energy from the ultrasound transmitter and therefore the intensity of electrical stimulation. We show that the implant can generate targeted, self-adaptive and quantitative electrical stimulations to the spinal cord according to the classified pain levels for chronic pain management in free-moving animal models.