Experimental verification of causal relationships between measurements of near-infrared spectroscopy and mechanisms of oxygen transport to skeletal muscles

这一研究项目的目的是通过实验验证近红外光谱测量与氧向骨骼肌运输机制之间的因果关系。这些关系对于理解近红外光谱测量的时间响应是必不可少的。通过对志愿者的测量、组织代谢的计算机模拟和动物的显微光谱研究，获得了以下结果：(1)基于肌肉氧合成像的肌肉代谢的时空分析：新开发了一种基于空间分辨光谱的肌肉氧饱和度成像系统。运动和恢复过程中的肌肉氧饱和度根据运动方式和氧债的大小表现出不同的特征(2)运动过程中肌肉耗氧量的瞬时测量：利用由于强烈收缩而导致的血流停止，我们开发了一种测量局部耗氧率Mu…的技术更多的骨痂是根据组织氧浓度下降的速度确定的。利用最新研制的高速采样率为0.1%的S装置，在不阻断动脉的情况下，对肌肉收缩过程中的耗氧率进行了瞬时测量。(3)近红外光谱测量分析中的肌肉代谢计算机模拟：建立了由有氧和无氧系统、磷原能量系统和氧运输系统组成的肌肉代谢模型，并将模拟结果与实际测量结果进行了比较。有人强烈建议，Hb和Mb对近红外光谱测量的贡献率取决于肌肉的氧合水平，反映了Hb和Mb的解离曲线之间的巨大差异。(4)利用显微光谱测量组织氧饱和度：为研究氧向组织的运输，构建了一个6波长显微光谱系统。用多元回归方法剔除散射成分。小血管的血氧饱和度能够在小鼠和大鼠的肠系膜和提睾肌中成像。较少

The purpose of this research project was to experimentally verify the causal relationships between measurements of near-infrared spectroscopy and the mechanisms of oxygen transport to the skeletal muscles. These relationships are essential for understanding temporal responses of NIRS measurements. The following results were obtained from measurements in volunteers, computer simulation of tissue metabolism and microspectroscopic studies in animals.(1) Spatio-temporal analyses of muscle metabolism based on muscle oxygenation imaging : An imaging system of muscle oxygen saturation using spatially resolved spectroscopy was newly developed. Muscle oxygen saturation during exercise and recovery showed distinct features depending on a pattern of exercise and an amount of oxygen debt(2) Instantaneous measurement of muscle oxygen consumption during exercise : Utilizing the cease of blood flow due to strong contraction, we developed a technique for measuring a local oxygen consumption rate of mu … More scles that was determined from a decreasing rate of tissue oxygen concentration. Oxygen consumption rates during contraction were instantaneously measured without arterial occlusion using a newly developed device that had a high-speed sampling rate of 0.1 s(3) Computer simulation of muscle metabolism for analyses of NIRS measurements : A model of muscle metabolism consisting of aerobic and anaerobic systems, phosphagen energy system and oxygen transport system was constructed, and results of simulation were compared with those of the actual measurements. It was strongly suggested that contribution rates of hemoglobin (Hb) and myoglobin (Mb) to NIRS measurements depend on a muscle oxygenation level, reflecting the great difference between the dissociation curves of Hb and Mb.(4) Measurement of tissue oxygen saturation using microspectroscopy : A 6-wavelength microspectroscopic system was constructed for studying oxygen transport to tissues. Scattering component was eliminated by a multiple regression method. Oxygen saturation of small vessels was able to be imaged in the mesenteries and cremaster muscles of mice and rats. Less