Weytjens J L, Viberg D A, Caputi A A, Kallesøe K, Hoffer J A
Department of Clinical Neurosciences, University of Calgary, Faculty of Medicine, Alberta, Canada.
J Neurosci Methods. 1992 Dec;45(3):217-25. doi: 10.1016/0165-0270(92)90079-s.
Muscle length in unrestrained, chronically implanted animals is conventionally measured with gauges consisting of a compliant silicone rubber tube filled with either hypertonic saline or mercury, the measurement principle being a continuous change in the electrical resistance of the fluid column inside the tubing with stretch. These gauges have two major disadvantages: (1) changes in resistance that are not related to changes in length, such as those produced by changes in temperature or osmotic dilution of the hypertonic saline, cause the measurements to drift, and (2) there is no direct and accurate way to calibrate the measurements. In this communication two new types of muscle length gauge are described that eliminate both problems. Both types make use of the principle of sonomicrometry, i.e., the measurement of distances with pulsed ultrasound. Both types have been successfully used to measure the length of the medial gastrocnemius muscle in chronically implanted cats during treadmill locomotion.
在未受约束的慢性植入动物中，肌肉长度通常使用由填充有高渗盐水或汞的顺应性硅橡胶管组成的应变仪进行测量，测量原理是随着拉伸，管内液柱的电阻会持续变化。这些应变仪有两个主要缺点：（1）与长度变化无关的电阻变化，例如由温度变化或高渗盐水的渗透稀释产生的电阻变化，会导致测量值漂移；（2）没有直接且准确的方法来校准测量值。在本通讯中，描述了两种新型肌肉长度应变仪，它们消除了这两个问题。这两种类型都利用了超声测量法的原理，即使用脉冲超声测量距离。这两种类型都已成功用于测量慢性植入猫在跑步机运动期间腓肠肌内侧的长度。
