光電池血量計による末梢血行障害の新しい診断法

Since 1934, Matthes has designed a recorder with two different filter-photocell systems using transmitted light. By these methods, he measured the ganeralized oxygen saturation change in order to study the hemodynamics in the cardio-pulmonary disorders. Since 1942, Millikan (1942), Hemingway (1984) and Wood (1949) have developed this method to the duble-scale ear oximeter method. While these investigators have attempted to measure the generalized oxygen saturation, we are trying to measure the local oxyhemoglobin concentration of the finger-tips. For this purpose we devised a new recording method using an ear oximeter, according to Wood's method.Our apparatus consists of following four parts : light source, filter-photocell system, control box, galvanometer and recorder.With this apparatus, we record the transmitted light volume of finger-tip under three conditions such as venous stagnation, arterial arrest and reactive hyperemia after releasing the arterial arrest.We can estimate the local oxyhemoglobin concentration from the extinction of both red and infrared systems, because the local oxyhemoglobin concentration is the function of the intensity of transmission factor in the red system (Ir) and the intensity of transmission factor in the infrared system (Iir), and these two variables can be measured from the record of transmission factors. As a matter of fact, we devised the following oxyhemoglobin index, from which we can estimate the local oxyhemoglobin concentration.Oxyhemoglobin index=(2-log₁₀Ir)/(2-log₁₀Iir) The change of oxyhemoglobin content is reverse to the one of index.With this method, we study the digital circulatory conditions. In a healthy subject, oxyhemoglobin index is about 1.0 and doesn't fluctuate by stagnation, arterial arrest or reactive hyperemia. In pale fingers of patients suffering from Buerger's or Raynaud's disease, the blood volume of the finger-tip is low and the oxyhemoglobin index is relatively high. Moreover, oxyhemoglobin index increases markedly after stagnation and arterial arrest, and is delayed in returning to its original value. In cyanotic fingers, the oxyhemoglobin index is relatively high, decreasing after stagnation, and increasing after arterial arrest. In red fingers, especially after local warming, the blood volume of the finger-tip is high, the oxyhemoglobin index approaches to 1.0, and the latter fluctuates little by stagnation, arterial arrest or reactive hyperemia.Thus by calculating the oxyhemoglobin index, we can express numerically the state of the color of the fingers, such as paleness, cyanosis or redness.