Method and apparatus for non-invasive cardiovascular diagnosis

Abstract

A non-invasive method and apparatus for sensing relative blood flow to extremities, such as using photoelectric dermachromography to measure differential blood flow between extremities, for the purpose of diagnosing cardiovascular conditions, employs reflective colorimeters for performing comparative light reflection rheology (LRR) on blood flow to the extremities. The resting, steady-state LRR for both the left and right palms are simultaneously measured when both arms are in a raised, steady-state condition, and again when both arms are in a lowered, steady-state condition, thereby providing a repeatable measurement of overall vasomotor tone, the tone of the smooth muscles of the arterial walls. Two portable light gauges are used, each including a plurality of light sources such as light-emitting diodes (LEDs) arranged around at least one light detector. Each gauge is removably attachable to the palms of the hands of the patient whose vasomotor tone is to be determined. The gauges are removably attached to the palms so that the hands are movable, and measurements are taken while the left and/or right hands are in a raised, substantially steady-state UP condition, and then again while the left and/or right hands are in a lowered, substantially steady-state DOWN condition. After a series of these UP and DOWN measurements are taken, the gauges are switched and another series of UP and DOWN measurements with the reversed gauges are taken. Each gauge is independently calibrated by using standardizing reference scales.