Results are compared with the results of a simple two parameter mathematical model. These results suggest a method for non-invasive skin blood flow assessment to screen for peripheral artery disease and associated risk of cardiovascular events.

The aim of this research project is to test the feasibility of using low-power radio frequency (RF) radiation operating in the millimeter wave (MMW) range and non-contact infrared temperature acquisition to measure skin blood-flow rates. MMW is the band of the electromagnetic spectrum from 30 to 300 GHZ. It has been shown that millimeter waves will cause a local temperature rise in the skin, without the harmful effects of ionizing radiation [1]. Skin blood flow is a physiological variable that is essential in the assessment of many diseases, such as diabetes, and can also be the determining factor in many other heat-related body functions (i.e. hot flashes in menopausal women) and malfunctions (i.e. heat stroke) [2]. However, there is currently no non-invasive and non-contact means of measuring actual skin blood flow rates in a patient. During this research, millimeter waves at 35 GHz are being used to superficially heat the skin tissues of a rabbit ear. Simultaneous, non-contacting measurement of skin surface temperature could allow the inference of the rate of blood flow to the tissue, based on observed relationships between surface temperature and skin perfusion rates during MMW irradiation at 35 GHz [1, 3].