Study on Effects of Shoch-Type Vibration on Peripheral Circulation in the Hand-Arm

虽然冲击型振动对手臂的恶化效应已被指出，但国际手臂振动暴露标准并未提供有关冲击型振动的有效信息。记录和分析了工作场所正常使用链锯、气动锤子、气动铆钉锤和气动钉子时所产生的波动。在频率加权均方根值恒定的x向加速度为6.3m/S^2的情况下，冲击峰值因子(Cf)的大小顺序为：链锯、气动锤、气动铆钉锤、气动钉钉器。通过监测恒定频率加权均方根加速度(a&lt；xhw&gt；)为6.3m/S^2的冲击型振动引起的手指皮肤血流量，观察休克对周围循环的影响。结果表明，CF值为9.5的气动钉子在暴露后4分钟和5分钟的血流量显著减少。这一结果表明，应该评估振动的影响，包括冲动的大小。检测手抓握效果的实验表明，与抓握相关的外周血流量显著减少。随着抓持力的增大，具有防止振动容易传递到手臂的措施的工具应该在未来得到开发。

Altough deteriorating effects of shock-type vibration on hand-arm have been pointed out, the international standard for hand-arm vibration exposure have not provided available information on shock-type vibration. Waves produced by the normal use of chain-saw, pneumatic hammer, pneumatic riveting hammer, and pneumatic nailer at workplaces was recorded and analyzed. The order of the size in the impulsiveness, crest factor (CF) was chain-saw, pneumatic hammer, pneumatic riveting hammer, and pneumatic nailer at a constant frequency-weighted rms acceleration at x direction (a_<xhw>) of 6.3 m/s^2. No statistically significant effects of shock was recognized in comparisons of subjective response to shock-type vibration with that to shockless vibration of shain-saw. Effects of shock on peripheral circulation was examined by monitoring finger skin blood flow induced by the shock-type vibration at a constant frequency-weighted rms acceleration at x direction (a_<xhw>) of 6.3 m/s^2. In a result, pneumatic nailer with the CF of 9.5 produced significant decreases in the blood flow at 4 and 5 min after the exposure. This result suggests that effects of vibration should be assessed including the size of the impulsiveness. Experiments examining effects of hand-grasping showed significant reduction in peripheral blood flow associated with the grasping. Tools with measures which protect vibration from transmitting into hand-arm easily with the growth of grasping force should be developed in future.