Goldman M D, Grassino A, Mead J, Sears T A
J Appl Physiol Respir Environ Exerc Physiol. 1978 Jun;44(6):840-8. doi: 10.1152/jappl.1978.44.6.840.
We determined the static, isometric relationship between diaphragmatic EMG (Edi) and transdiaphragmatic pressure (Pdi) in man at specified abdominothoracic configurations, assessed with magnetometers. During inspiratory airflow, measurements of Edi and Pdi were taken as the respiratory system passed through the same configuration as obtained during the static isometric contractions, allowing a comparison of static and dynamic contractions of the diaphragm at a given length and curvature. When voluntary inspiratory maneuvers are performed with no associated outward displacement of the abdominal wall, or with slight inward displacement, the Pdi developed dynamically is the same as that developed statically at a given Edi. When outward movement of the abdominal wall occurs during inspiratory airflow, the Pdi developed dynamically depends on the rate of abdominal displacement, not on overall inspiratory airflow rate. We conclude that the velocity of shortening of the diaphragm increases directly as the rate of abdominal displacement. We construct a pressure-flow analogue of the force-velocity relationship for the diaphragm and discuss the functional implications of these observations in relation to spontaneous breathing.
我们使用磁力计，在人体特定的腹胸配置下，确定了膈肌肌电图（Edi）与跨膈压（Pdi）之间的静态、等长关系。在吸气气流期间，当呼吸系统经过与静态等长收缩时相同的配置时，测量Edi和Pdi，从而能够在给定的长度和曲率下比较膈肌的静态和动态收缩。当进行自主吸气动作且腹壁无相关向外移位或有轻微向内移位时，动态产生的Pdi与在给定Edi下静态产生的Pdi相同。当吸气气流期间腹壁出现向外运动时，动态产生的Pdi取决于腹部移位的速率，而不是整体吸气气流速率。我们得出结论，膈肌缩短的速度直接随着腹部移位的速率增加。我们构建了膈肌力-速度关系的压力-流量模拟，并讨论了这些观察结果与自主呼吸相关的功能意义。
