Wu V C, Nickell W T, Bhagat P K
Aviat Space Environ Med. 1982 Apr;53(4):375-8.
An ultrasonic plethysmograph, which gives improved performance over the standard Whitney Strain Gauge, is described. This instrument monitors dimension changes in human limbs by measuring the transit times of acoustic pulses across two chords of the limb. In the case of a small uniform expansion, the percentage change in limb volume is shown to be proportional to twice the percentage change in either of the measured chords. Measurement of two chords allows correction for possible non-uniform expansion. In addition, measurement of two chords allows an estimate of the absolute cross-sectional area of the limb. The developed instrument incorporates a microprocessor, which performs necessary calculation and control functions. Use of the microprocessor allows the instrument to be self-calibrating. In addition, the device can be easily reprogrammed to incorporate improvements in operating features or computational schemes.
本文描述了一种超声体积描记器，其性能优于标准的惠特尼应变仪。该仪器通过测量声脉冲在肢体两条弦上的传播时间来监测人体肢体的尺寸变化。在均匀小幅度扩张的情况下，肢体体积的百分比变化与所测两条弦中任一条弦的百分比变化的两倍成正比。测量两条弦可对可能的非均匀扩张进行校正。此外，测量两条弦还能估算肢体的绝对横截面积。所开发的仪器集成了一个微处理器，用于执行必要的计算和控制功能。使用微处理器使仪器能够进行自校准。此外，该设备可以很容易地重新编程，以纳入操作特性或计算方案方面的改进。
