Global Vagus Nerve Stimulation Market, Industry trends and forecast to 2029. Product Type (Implantable VNS Devices and External VNS Devices), Biomaterial (Ceramics, Metallic, and Polymeric), Application (Pain Management, Epileptic Seizures, Obesity Management, Depression and Anxiety, and Others), Patient Type (Adults, Pediatric, and Geriatric), End User (Hospitals, Ambulatory Surgery...