A closed loop fully automated wireless vagus nerve stimulation system

Vagus nerve stimulation (VNS) has been explored as a treatment for a range of conditions, including epilepsy, cardiovascular disorders, drug-resistant depression, chronic pain, and obesity. Conventionally, VNS is administered using an open-loop approach, in which trained personnel adjust stimulation parameters. Medical supervision is necessary to minimize adverse effects, such as severe bradycardia, which can significantly interfere with daily activities. This requirement limits the feasibility of VNS in unsupervised settings and highlights the need for an automated control system. To address this limitation, we introduce the fully automated wireless VNS (FAW-VNS) system, which dynamically adjusts stimulation parameters to maintain steady-state operation while minimizing bradycardia. The FAW-VNS system operates in real-time and consists of a biocompatible, miniaturized, wirelessly powered implant equipped with cuff electrodes; a handheld device for power delivery and stimulation protocol communication; a sensing patch to collect and transmit heart rate (HR) data; and a central control unit (CCU) that updates stimulation protocols based on the acquired physiological signals. In-vivo studies were conducted on four anesthetized pigs to validate the system's ability to reach a steady-state response, achieving a controlled HR reduction within 2-4% of baseline during stimulation. This work lays the foundation for developing closed-loop, wireless implants for point-of-care applications.