The Vagal Interrupt Clamp is a precision neuroelectrical field instrument designed to apply targeted, calibrated electrical stimulation to the vagus nerve, enabling emergency management of life-threatening cardiac arrhythmias, neurogenic shock, and severe autonomic storms — particularly those triggered by cyberware cascade failures or electrostimulant overdose. The device resembles a modified clamp or forceps approximately 20cm in length, with two paddle-contact ends lined with conductive polymer. It is applied externally to the neck at the carotid triangle, where the vagus nerve runs closest to the skin surface, and delivers a precise sub-threshold electrical signal that modulates nerve activity without causing tissue damage.

Zheng-Dao's engineering philosophy is evident in the device's control interface: a single dial with five positions (Suppress / Moderate Suppress / Neutral Monitor / Moderate Stimulate / Stimulate) and a numerical readout showing real-time heart rate and estimated vagal tone. There are no automated modes. Zheng-Dao's bioelectrical division believes that in the critical moments of a cardiac or autonomic emergency, a trained operator making active decisions produces better outcomes than an automated protocol that cannot account for the full clinical picture. The clamp's signal generator is powered by a rechargeable cell good for approximately four hours of continuous use, and the conductive polymer contacts are replaced per-use via a simple swap cartridge.

It is called 'The Undertaker's Thumb' in field medicine circles — a reference to the ancient practice of pressing the carotid to check for life, and a sardonic acknowledgment that the device occupies the boundary between intervention and acceptance.