Integrated Wireless RFID Temperature Sensor for Biological Aortic Valve Prostheses
Federica Naccarata, Gaetano Marrocco
Abstract
Body core temperature is one of the most reliable biometric indicators for monitoring the health status of a person. The gold standard in clinical settings is a highly invasive procedure involving the insertion of a catheter into the pulmonary artery, which receives blood directly from the core of the body. However, if a patient needs to host an Implanted Medical Device (IMD), a precise body core temperature measurement can be obtained without causing them additional discomfort, by adding communication and sensing capability to the IMD itself. This paper proposes a possible augmentation of a passive metal-free aortic valve prosthesis with a wrapped C-dipole provided by an RFID-based temperature sensor for batteryless and wireless temperature monitoring from the inside. A robust transcardiac link can be achieved with at least 24 dBm interrogation power by using a small on-skin reader antenna, which is also robust against moderate mutual misalignment among the two devices. The temperature sensing capability of a true sensorized valve, evaluated by means of a heated liquid phantom, demonstrated the possibility of sensing typical physiological temperature gradients with an average accuracy of less than 0.25∘C w.r.t. a reference thermocouple.