Implantable optoelectronic platform with wearable physiological monitor for untethered, automated and shock-free termination of ventricular tachycardia in rodent
B L Den Ouden, S Deng, C I Bart, W H Bax, B J Boukens, R H Poelma, W D Van Driel, G Q Zhang, A A F De Vries, V Portero, D A PijnappelsAbstract
Implantable bioelectronic devices are essential for cardiac disease management, but conventional electrical defibrillation for ventricular tachycardia (VT) can cause pain and tissue damage due to non-selective high-voltage shocks. Optogenetics provides a shock-free, spatiotemporally precise alternative for rhythm modulation. Nevertheless, due to technical limitations, prior studies were limited to tethered, ex vivo, or sedated models, preventing ambulatory studies and translation.
We developed a novel, lightweight, fully wireless optogenetic system for rodents, integrating a modular implant with electrical stimulation for VT induction, ECG-based arrhythmia detection, and autonomous closed-loop optical restoration of sinus rhythm. The platform features a wearable ECG monitor that detects arrhythmic events and triggers programmable optical interventions via an embedded controller, restoring sinus rhythm without operator input or shocks.
Key engineering advancements include inductive wireless power transfer sustaining 1.28 W to four high-power LEDs for effective transmural optogenetic modulation of the myocardium. Electromagnetic simulations and benchtop testing validated efficient power delivery, low thermal rises (ΔTmax = 1.1°C), and specific absorption rates (SAR) below regulatory thresholds, ensuring safety for prolonged operations. The modular design accommodates additional sensors (e.g., pressure, oxygen) and actuators (e.g., electrical stimulators, drug delivery), enabling versatile chronic protocols.
In vivo demonstrations in anesthetized, optogenetically modified rats (green, see figure) confirmed functionality: the system induced VT electrically, detected VT episodes within seconds, and autonomously terminated arrhythmias via programable light pulses. Designed for awake, freely moving animals, this platform bridges gaps in experimental cardiology, facilitating mechanistic arrhythmia studies and preclinical development of shock-free bioelectronic therapies.