An embedded telemetry unit for bone strain monitoring is presented. The telemetry unit is designed using\r\ncommercially available components to lower design time and manufacturing costs. The unit can read up to eight\r\nstrain gauges and measures 2.4 cmÃ?â?? 1.3 cmÃ?â?? 0.7 cm. The unit is powered from a small Li-polymer battery that can be\r\nrecharged wirelessly through tissue, making it suitable for implanted applications. The average current consumption\r\nof the telemetry unit is 1.9 mA while transmitting at a rate of 75 kps and at a sampling rate of 20 Hz. The telemetry unit\r\nalso features a power-down mode to minimize its power consumption when it is not in use. The telemetry unit\r\noperates in the 915-MHz ISM radio band. The unit was tested in an ex vivo setting with an ulna bone from a mouse\r\nand in a simulated in vivo setting with a phantom tissue. Bone strain data collected ex vivo shows that the telemetry\r\nunit can measure strain with an accuracy comparable to a more expensive benchtop data acquisition system.
Loading....