Medical Interface: Q-Stim’s medical interface is a PC software application that makes it easy for healthcare providers to set stimulation parameters. From an intuitive graphical user interface, clinicians key in the dimensions of pulse amplitude, duration, and frequency. They can set these controls for all pacing channels at once, or for each independently. They can also set the sequence and timing among channels, establishing the optimal flow of electrical pulses across the four points of the Q-Stim pacing lead.

Telemetry Unit: Once a patient’s stimulation profile is complete, clinicians upload it to Q-Stim’s telemetry unit through a wired or wireless connection. The telemetry unit encodes all pacing parameters, and transmits them transcutaneously via low-frequency carrier signal to the stimulation generator.

Stimulation Generator: Based on the prescribed parameters, the stimulation generator calculates the charge needed at each channel of the pacing lead. It periodically tests the interface between this lead and the patient, obtaining a real-time electrical characterization, including measures of impedance and of the rate at which energy dissipates into the tissue. Based on these tests, and on the stimulation profile, the generator sends a precisely measured charge to a capacitor via low-power dissipation. The capacitor, in turn, passes that charge to the lead, out of circuit from the pulse generator. By adapting its electrical charge to conditions at the electrode-tissue interface – the connection between the pacing lead and the patient – Q-Stim intelligently compensates for aging of the system and changes in the patient’s tissue condition.

With this adaptive technology, and with capacitive coupling to separate pulse generation from delivery, Q-Stim ensures that only the charge needed for stimulation is sent to the patient. In this way, it promotes patient safety, guarding against over-stimulation. It also maximizes energy efficiency, revolutionizing the state of the art in pacemaker technology. Older pacemakers could not adapt their stimulation on the basis of frequent and complete electrical characterization of the tissue interface, and so generated excess charge to prepare for a worst-case scenario. This, however, wasted energy and shortened battery life. Q-Stim, by contrast, uses its proprietary adaptive technology to maximize energy efficiency, and to conserve the lives of both the system battery and the pacing lead. That, in turn, promotes patient safety by reducing the need to replace pacemakers over time.

Multi-Channel Pacing Lead: The final component of the Q-Stim system is a multi-point pacing lead, which delivers stimulation to the patient through any or all of four channels, in any sequence. By stimulating at multiple points, progressing from one to the next, Q-Stim can supplement or entrain the natural electrical flow that governs many functions of the body. In the stomach, for example, Q-Stim can progressively pace from proximal to distal regions, helping regulate the gastric slow wave and accelerate the flow of nutrients in patients who suffer gastroparesis, or delayed gastric emptying. By reversing this sequence – that is, by pacing from the distal to the proximal stomach – Q-Stim can promote feelings of fullness or satiety in patients who suffer obesity, and so help reduce caloric intake.

Virginia Technologies has developed reference designs and a prototype neurostimulator, demonstrating the Q-Stim technology. The company would be happy to review these with medical device developers who wish to license this technology for their own neurostimulation or pacemaker systems. To explore this opportunity, please click here.

back to top >