Vagus nerve stimulation (VNS) is an established clinical therapy for drug-resistant epilepsy and certain inflammatory disorders, but therapeutic use can be limited by off-target stimulation that produces unwanted side effects. The authors set out to design, manufacture, and validate an implantable stimulation system that enables spatially selective VNS (sVNS) in order to deliver current to specific regions of the human vagus nerve and reduce activation of non-target organs.
The primary objective was to create a wirelessly powered, battery-free temporary implantable stimulator with a selectively addressable output stage compatible with a multichannel cuff electrode, and to evaluate its function in bench testing, accelerated ageing, an acute porcine model, and a pilot human study.
The system developed is a near-field communication (NFC)-controlled, wirelessly powered, battery-free implantable multichannel stimulator. It interfaces with a 15-channel sVNS cuff electrode consisting of 14 selective electrode pairs plus one circumferential whole-nerve channel. The output stage is selectively addressable to target discrete regions around the nerve circumference.
The device was designed for temporary implantation and was encapsulated accordingly for short-term use. Control is provided via NFC, enabling wireless power transfer and command signalling without an implanted battery.
Prior to in vivo use, the device underwent benchtop characterisation to confirm electrical performance, stimulation channel selectivity, and compatibility with the 15-channel cuff electrode. The implant was subjected to accelerated ageing protocols to evaluate short-term durability and encapsulation integrity for temporary implantation scenarios.
Details on specific benchtop metrics, stimulation parameters, electrical thresholds, or accelerated ageing durations were not reported in the source abstract and therefore are not included here.
The device was evaluated in an acute porcine study (n = 4). Using selective stimulation through the cuff electrode, the investigators observed a mean selective bradycardia of 23.28 ± 12.91% in pigs. These results demonstrate that the multichannel, geometrically selective approach can modulate cardiac function in a large-animal model.
The porcine validation served to confirm both functional activation of cardiac-related vagal fibres and the capability of the wireless battery-free stimulator to operate reliably in an in vivo setting.
A first-in-human pilot study was performed with a single participant (n = 1). Selective stimulation using the implanted, NFC-controlled device produced a bradycardic response of 7.5% in the human participant.
In this pilot, investigators reported clear separation of bradycardic and tachycardic effects and additional selectivity in laryngeal activity. The cardiac and laryngeal responses were separated circumferentially by 231° around the nerve, indicating geometrical selectivity of stimulation sites within the cuff electrode.
Key outcomes reported in the source include:
The human data additionally showed distinct bradycardic versus tachycardic effects depending on which electrode pairs were addressed, and demonstrated selectivity for laryngeal activation separate from cardiac responses.
The device was encapsulated for short-term implantation and evaluated under accelerated ageing; however, the abstract does not provide detailed safety metrics, adverse event reporting, or specific implantation durations beyond the designation of temporary/short-term use. The study reports acute porcine experiments and a single human pilot but does not present longer-term safety or chronic implant data in the abstract.
This work establishes feasibility of a wireless battery-free sVNS approach for cardiac applications using a temporary implantable device. The authors propose that geometrically selective stimulation may improve therapeutic efficacy while reducing stimulation-related side effects that arise from off-target organ activation.
Potential clinical applications highlighted include therapies for heart failure and other autonomic disorders where selective modulation of vagal fibres could be advantageous. The abstract notes that no previous implantable or portable devices were available to trial sVNS in a clinical setting prior to this work.
Limitations apparent from the abstract include the small-scale in vivo validation (acute porcine n = 4 and a single human pilot), and the absence of detailed long-term safety, functional durability, or comprehensive parameter sets in the reported summary. The abstract does not provide granular methodological details, stimulation waveforms, or adverse event data; these would be expected in the full text.
The study is published in Journal of Neural Engineering (J Neural Eng), 2026 Oct 8;23(5). PubMed PMID 42735697; DOI 10.1088/1741-2552/aea710. Authors are affiliated with multiple institutions, including University College London, Imperial College London, Royal Veterinary College London, University of California Los Angeles, and the National Hospital for Neurology and Neurosurgery, London.
Keywords listed by the authors include NFC, implantable, neuromodulation, selective stimulation, and vagus nerve.
Note: Specific methodological and numeric details beyond those reported in the abstract (such as benchtop performance metrics, exact stimulation parameters, implantation times, and safety/adverse event profiles) were not reported in the source abstract and are therefore not included here.