Wireless power source for implantable telemetry devices

Abstract

Recent advancements in biotelemetry systems allow measurements of blood flow, blood pressure, ECG and temperature in small animals such as rats (EG3‐Vx‐Sx‐Mx, Transonic EndoGear Inc) with minimal intrusion into their environment. However, these implants cannot be used continuously for extended periods of time, because they use finite capacity batteries. Different size batteries maybe used for different size animals, which also dictates the maximum duration of measurements. To provide telemetry monitoring over extended periods of time, we developed Wireless Power Supply (WPS) that uses inductive power technology to send power to an implanted 3‐dimentional Wireless Power Receiver (WPR) that is used instead of the battery. This WPR can provide continuous power to a telemetry system used in small animals such as rats. The WPS uses a self‐tuning design that adjusts for maximum power delivery even when multiple animals are present in the same cage. This is also possible due to the self‐regulation of the WPR that does not depend on back‐telemetry and regulation of the WPS. These advancements make it possible to have two, or more instrumented animals in the same cage. The WPR receives a maximum of 20mA at 3.5V up to a distance of 15cm, in all 3 dimensions, in a standard size rat cage. This is more than enough to power a telemetry system with the capability to measure advanced cardiovascular parameters such as blood flow, blood pressure, ECG and temperature.