In a pilot study of 11 healthy adults (24 to 39 years, all male), we characterize the influence of external probe pressure on optical diffuse correlation spectroscopy (DCS) measurements of pulsatile blood flow obtained on the forearm and forehead. For external probe pressure control, a hand inflatable air balloon is inserted between the tissue and an elastic strap. The air balloon is sequentially inflated to achieve a wide range of external probe pressures between 20 and 250 mmHg on the forearm and forehead, which are measured with a flexible pressure sensor underneath the probe. At each probe pressure, the pulsatility index (PI) of arteriole blood flow on the forehead and forearm is measured with DCS (2.1-cm source-detector separation). We observe a strong correlation between probe pressure and PI on the forearm ( R = 0.66 , p < 0.001 ), but not on the forehead ( R = - 0.11 , p = 0.4 ). The forearm measurements demonstrate the sensitivity of the DCS PI to skeletal muscle tissue pressure, whereas the forehead measurements indicate that DCS PI measurements are not sensitive to scalp tissue pressure. Note, in contrast to pulsatility, the time-averaged DCS blood flow index on the forehead was significantly correlated with probe pressure ( R = - 0.55 , p < 0.001 ). This pilot data appears to support the initiation of more comprehensive clinical studies on DCS to detect trends in internal pressure in brain and skeletal muscle.

中文翻译：

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探头压力对前臂和前额区域脉动扩散相关光谱血流信号的影响。

在一项针对11位健康成年人（24至39岁，均为男性）的初步研究中，我们表征了外部探头压力对前臂和前额获得的脉动血流的光学扩散相关光谱（DCS）测量的影响。对于外部探头压力控制，将手动充气气球插入组织和弹性带之间。依次对气球充气，以在前臂和前额上获得20至250 mmHg的较大外部探头压力，该压力可通过探头下方的柔性压力传感器进行测量。在每个探针压力下，用DCS（2.1厘米源-探测器间距）测量前额和前臂上小动脉血流的搏动指数（PI）。我们观察到前臂上的探针压力与PI之间有很强的相关性（R = 0.66，p <0.001），但不在额头上（R =-0.11，p = 0.4）。前臂测量表明DCS PI对骨骼肌组织压力的敏感性，而前额测量表明DCS PI测量对头皮组织压力不敏感。注意，与搏动性相反，额头上的平均时间DCS血流指数与探头压力显着相关（R =-0.55，p <0.001）。该初步数据似乎支持对DCS进行更全面的临床研究，以检测大脑和骨骼肌内压的趋势。注意，与搏动性相反，额头上的平均时间DCS血流指数与探头压力显着相关（R =-0.55，p <0.001）。该初步数据似乎支持对DCS进行更全面的临床研究，以检测大脑和骨骼肌内压的趋势。注意，与搏动性相反，额头上的平均时间DCS血流指数与探头压力显着相关（R =-0.55，p <0.001）。该初步数据似乎支持对DCS进行更全面的临床研究，以检测大脑和骨骼肌内压的趋势。