Ellis D G, Lampman R M
J Appl Physiol Respir Environ Exerc Physiol. 1980 Feb;48(2):386-8. doi: 10.1152/jappl.1980.48.2.386.
A new type of switching valve used in rebreathing studies for estimating cardiac output is described. This valve employs a unique deformable elastic element, actuated by low-pressure compressed air, to effect switching. The capability for remote operation (via a compressed air line) and the light weight of the valve (110 g) make the valve especially well suited to exercise stress testing studies. Two valves of this type have been satisfactorily used in graded exercise stress tests in a clinical setting for over 2 yr.
本文描述了一种用于重复呼吸研究以估算心输出量的新型切换阀。该阀采用由低压压缩空气驱动的独特可变形弹性元件来实现切换。其具备远程操作能力（通过压缩空气管路）以及较轻的重量（110克），使得该阀特别适用于运动压力测试研究。这种类型的两个阀已在临床环境中的分级运动压力测试中令人满意地使用了两年多。
