1978 Volume 16 Issue 2 Pages 55-71
Pulse amplitude of blood flow in the middle finger phalanx of the right hand was investigated by photo-plethysmograph on five male subjects, who were given transient vibration of three types on a vertical whole body vibration table. The vibration types were: single shock motion (SSM), one period sinusoidal vibration at an ultra-low frequency (OPV), and single burst random vibration (SBR). Blood flow decreased abruptly, due to vasoconstriction, shortly after the onset of vibration and recovered gradually to approximately the pre-test level observed under the usual rest conditions. Similar plethysmogram patterns were obtained regardless of the type of transient vibration.
Blood flow was inversely related to the amplitude of the transient vibration, and in addition, was influenced by the characteristics of the vibration such as duration of the SSM, fundamental frequency of the OPV, or build-up time of the SBR. Relations between blood flow and these factors were quantified by variance analysis in the experimental design. From the results, blood flow response could be used to evaluate the nature of the whole body vertical transient vibration.