RFID Technology for Continuous Monitoring of Physiological Signals in Small Animals

Abstract

Telemetry systems enable researchers to continuously monitor physiological signals in unrestrained, freely moving small rodents. Drawbacks of common systems are limited operation time, the need to house the animals separately, and the necessity of a stable communication link. Furthermore, the costs of the typically proprietary telemetry systems reduce the acceptance. The aim of this paper is to introduce a low-cost telemetry system based on common radio frequency identification technology optimized for battery-independent operational time, good reusability, and flexibility. The presented implant is equipped with sensors to measure electrocardiogram, arterial blood pressure, and body temperature. The biological signals are transmitted as digital data streams. The device is able of monitoring several freely moving animals housed in groups with a single reader station. The modular concept of the system significantly reduces the costs to monitor multiple physiological functions and refining procedures in preclinical research.

Miniature implantable telemetry system for pressure-volume cardiac monitoring

“…A more recent implantable telemetry system was developed by Volk et al [22] that measured ECG, arterial pressure, and temperature, Fig. 2.16, in mice using custom flexible ECG and pressure sensors.…”

“…A low-power telemetry system [4] is capable of being implanted for longer periods of time while operating off of smaller capacity batteries. Active measurement cages have been used to provide wireless power to the implants enabling long-term data collection without the need for batteries [21,88] Current state-of-the-art wireless cardiac telemetry systems typically employ blood pressure (aortic), ECG, and temperature sensors [21,22,89]. Although small and advanced, these systems currently do not measure left ventricular blood volume, thus cannot be used to measure PV loops.…”

Design of a Programmable Passive SoC for Biomedical Applications Using RFID ISO 15693/NFC5 Interface

“…where K P is a process dependent constant for PMOS devices provided by the foundry, C ox is the oxide thickness, (W.L) 7,8 is the device dimension for M7-8 and f is the frequency. The process dependent factor K P is smaller for PMOS devices in compare to the NMOS devices (K N ) as the later uses buried channel to carry holes.…”

“…The typical operating frequency of RFID varies from a low frequency range 100 kHz, HF (high frequency) range of 13.56 MHz to ultra-high frequency range of 860-960 MHz and 2.45-5.8 GHz. Biotelemetry systems using RFID have persisted around for years where it is utilized for sensing and wireless identification [6][7][8].…”

Low-Frequency RFID Signal and Power Transfer Circuitry for Capacitive and Resistive Mixed Sensor Array

“…In these cases, the reader energizes the sensor unit with an on-board transponder and they exchange data, exploiting the wireless link. The transponder can harvest energy through the RF link and operate as a bus bridge towards other devices, such as microcontrollers or digital sensors [24][25][26][27][28]. When a microcontroller is available, the number of sensors can be larger, provided that the energy budget is adequate to power them.…”