Tissue ischemia measurement using induced-current impedance spectroscopy: interface and timing considerations

Impedance spectroscopy is a promising method for tissue ischemia measurement. Ischemia alters physiological and biochemical tissue properties, which change tissue impedance. Impedance spectroscopic measurement methods can detect and monitor these changes. We have previously developed a system for non-invasive ischemia measurements, based on injected-current impedance spectroscopy. The overall goal of the present research is to develop a non-invasive, non-contact, fully-automated, portable device for muscle tissue ischemia measurement, based on induced current impedance spectroscopy. In the course of this research, we are developing models and implement a device that will use eddy current impedance spectroscopic techniques to measure the impedance of small volume samples of tissue. In this paper, we present a system design to implement eddy current principles. Issues regarding interfacing the device modules and between the device and an external PC are addressed. Finally, the importance of precise communication timing between the modules is discussed