Study to make an apparatus for measuring extremity skin and muscle blood flow noninvasively

The object of this study was to separately measure the skin and muscle blood flow of the extremities using near-infrared spectroscopy(NIRS)as an experimental procedure and mercury-in-rubber-strain-gauge plethysmography(RSGP)with the venous occlusion method as its golden standard.1)At first，the total blood flow of the finger，which is thought to equal to the skin blood flow of the fingerNIRS and RSGP showed a very good linear correlation(R I D 12 I D 1=0.90).2)Muscle blood flow of the forearm was then measured using the two methods under muscular exercise.Again，the muscle blood flow amount measured by the NIRS and the blood flow of the forearm measured by the RSGP showed a very good correlation(R I D12西耶D1=0.67).3)To measure the skin and muscle blood flow of the forearm separately，the total blood flow of the forearm was measured using RSGP，with separate and simultaneous measurement of the skin and muscle blood flow of the forearm by NIearm by。To decrease or increase only the skin blood flow，the opposite hand was immersed in icy water or the ipsilateral forearm was warmed using an electric fan，respectively。These two procedures，however，failed to produce a positive effect。Then，methyl nicotinate solution，a vasodilator，was sprayed over the forearm。This increased the skin blood flow of the forearm successfully in some selected cases.These data showed the possibility of separate measurement of the skin and muscle blood flow using NIRS and RSGP。

The object of this study was to separately measure the skin and muscle blood flow of the extremities using near-infrared spectroscopy (NIRS) as an experimental procedure and mercury-in-rubber-strain-gauge plethysmography (RSGP) with the venous occlusion method as its golden standard.1) At first, the total blood flow of the finger, which is thought to be equal to the skin blood flow of the finger, was measured by the two methods. NIRS and RSGP showed a very good linear correlation (RィイD12ィエD1=0.90).2) Muscle blood flow of the forearm was then measured using the two methods under muscular exercise. Again, the muscle blood flow amount measured by the NIRS and the blood flow of the forearm measured by the RSGP showed a very good correlation (RィイD12ィエD1=0.67).3) To measure the skin and muscle blood flow of the forearm separately, the total blood flow of the forearm was measured using RSGP, with separate and simultaneous measurement of the skin and muscle blood flow of the forearm by NIRS. To decrease or increase only the skin blood flow, the opposite hand was immersed in icy water or the ipsilateral forearm was warmed using an electric fan, respectively. These two procedures, however, failed to produce a positive effect. Then, methyl nicotinate solution, a vasodilator, was sprayed over the forearm. This increased the skin blood flow of the forearm successfully in some selected cases.These data showed the possibility of separate measurement of the skin and muscle blood flow using NIRS and RSGP.