Investigating the use of impedance plethysmography for detecting decreased blood flow in diabetic patient limbs

The amount of blood flow into a body tissue is very critical and can be evaluated by monitoring the distention of the blood vessel (artery) feeding that tissue. Several techniques for artery distention monitoring have been reported in the literature. In this study, the impedance plethysmography (IPG) technique has been used as a non-invasive method with multiple electrodes to find the impedance across a finger, and therefore, monitor the existence of blood flow. Simulations have been performed on COMSOL finite element analysis software, and experiments have been carried out to obtain the optimum parameters for this technique. The simulations use 4 electrodes in different positions with a current of 10mA applied throughout a variety of frequencies up to 100 GHz. The resultant data clearly show the advantage of using multiple electrodes to enhance the total information received from the signals, while also indicating that 100Hz can be the optimum frequency for applying IPG. This study demonstrates that IPG with multiple electrodes can be applied to detect the existence of blood flow into body limbs, which is vitally crucial specifically for diabetic patients.