Assessment of Peripheral Circulatory Function among Workers Exposed to Hand-Arm Vibration using Laser Doppler Perfusion Imager

激光多普勒血流成像（LDPI）是一种新的皮肤血流成像技术。该方法采用二维水平扫描的流动在一个特定的组织，并使其可视化的空间变化在感兴趣的区域。本研究的目的是阐明LDPI技术在评估暴露于手臂振动的工人的外周循环功能方面的实用性。在初步研究中，我们使用LDPI测量了8名年轻健康男性志愿者（34.1±2.9岁）在不同测试条件下的手指皮肤血液灌注。与室温23℃和25℃相比，室温21℃下皮肤血液灌注明显减少。在三个室温水平下，灌注值有显著差异。此外，无论水温如何，手浸泡在水中时，手指皮肤血液灌注都趋于较低。然而，在浸水过程中，灌注量的下降幅度较小，且与水深无关。因此，我们认为LDPI技术可以监测浸入冷水中的手的皮肤血液灌注，并且皮肤血液灌注的评估需要严格控制环境温度的条件。实验研究了47名27 ~ 63岁（42.5±8.4岁）男性志愿者手指皮肤血液灌注在冷水浸泡（10℃，10min）后的变化。所有受试者均无手部周围循环系统损伤并发症。由于手浸在冷水中，手指的血液灌注急剧减少。但灌注值逐渐升高，直至浸泡结束。将手从冷水中取出后，手指血液灌注恢复迅速，接近基线值。血流灌注值与年龄有显著相关性，50岁组明显低于30岁组。这些结果表明，不同年龄组的工人在冷水浸泡后手指皮肤血液灌注的变化是不同的，因此在评估手臂振动工人的外周循环功能时应考虑年龄相关的变化。此外，我们还研究了16名年龄在46 ~ 59岁（52.9±3.4岁）的被试，他们都是在私营林业企业中操作链锯和灌木清扫器等振动工具的工人。与年龄相仿的对照组相比，振动暴露组的食指皮肤血灌注基线值。暴露组的血液灌注在冷水浸泡期间保持在最低水平不变，而对照组的血液灌注逐渐增加。在浸泡后的恢复阶段，暴露受试者的血流灌注随着时间的增加没有恢复的趋势。两组受试者在基线、冷水浸泡后期和整个恢复期的灌注值经年龄和室温的影响进行统计学调整后，差异均有统计学意义。总之，本研究结果表明，LDPI技术能够可视化和量化冷水浸泡对手指皮肤血液灌注的外周血管影响，因此有可能提供更详细和准确的信息，有助于检测暴露于振动的工人手指的外周循环损伤。少

Laser Doppler perfusion imaging(LDPI) is a new technique for mapping cutaneous blood flow. The method employs a two-dimensional horizontal scanning of the flow in a specific tissue, and makes it possible to visualize the spatial variation over the region of interest. The aim of this study was to clarify the usefulness of the LDPI technique in the assessment of peripheral circulatory functions among workers exposed to hand-arm vibration.In the preliminary study, we measured the finger skin blood perfusion of 8 young healthy male volunteers (34.1±2.9 years) using LDPI in various testing conditions. The skin blood perfusion decreased markedly under the room temperature of 21℃ compared to 23℃ and 25℃ conditions. Significant differences in the perfusion values were observed between the three levels of room temperature. In addition, the finger skin blood perfusion tended to be low during the hand was immersed in water, irrespective of the water temperature. However, the decrease of perfusion … More during the immersion was slight and showed similar values independent of the depths under the water. It is, therefore, suggested that the LDPI technique enables a monitoring of skin blood perfusion of the hand being immersed in cold water and that the assessment of skin blood perfusion requires a strictly controlled condition of ambient temperature.In the experimental study, the changes in the finger skin blood perfusion in response to cold water immersion test (10℃, 10min) were evaluated in 47 male volunteers aged 27 to 63 years (42.5±8.4 years). None of the subjects had complications relating to peripheral circulatory impairments of the hands. The finger blood perfusion reduced sharply as a result of immersion of the hand in cold water. However, the perfusion value increased gradually until the end of the immersion. After removal of the hand from the cold water, the finger blood perfusion recovered rapidly and nearly reached the baseline value. The blood perfusion values were significantly correlated with age, and subjects in the 50 years group had significantly lower values than the 30 years group. These results indicate that the changes in finger skin blood perfusion in response to cold water immersion are different by age group and thus the age-related variation should be considered in the assessment of peripheral circulatory function of workers exposed to hand-arm vibration.In addition, we examined 16 subjects, aged 46 to 59 years (52.9±3.4 years), who were selected from workers operating vibrating tools such as chainsaws and bush cleaners in private forestry enterprises. When compared to the control subjects of similar age, the vibration-exposed subjects had lower finger skin blood perfusion at baseline. The blood perfusion of the exposed subjects remained unchanged at the lowest level over the period of cold water immersion, while that of the control subjects showed a gradual increase. At the recovery phase following the immersion, the blood perfusion of exposed subjects had no tendency to recover as the time span increased. There were significant differences in the perfusion values of the two groups of subjects at baseline, the latter phase of the cold water immersion, and throughout the recovery period after statistical adjustments for the effects of age and room temperature.In conclusion, the findings of this study suggest that the LDPI technique enables visualizing and quantifying the peripheral vascular effects of cold water immersion on the finger skin blood perfusion and thus has the potential of providing more detailed and accurate information that may help detect the peripheral circulatory impairment in the fingers of vibration-exposed workers. Less