RESPIRATORY ACTION OF THE INTERCOSTAL MUSCLES

肋间肌肉驱动肋骨的扩张和收缩 在呼吸过程中。 肋间肌的作用已经被研究过了 主要是通过研究它们对肋骨位移的影响， 对肺容量的扩大仍然知之甚少。 在以前的工作中，我们 结合建模，理论和实验，建立一种方法， 评估肋间肌的机械优势。 机械 优势被定义为每单位力的气道压力变化 由活跃的肌肉施加，机械优势被证明等于 被动胸部每单位体积扩张的肌肉缩短分数 墙 我们计算了肋间肌的机械优势 并测试了我们对狗的最大呼吸效应的预测， 整个吸气肌群 计算结果显示， 关于吸气肋间的呼吸动作的信息 肌肉. 计算出的内肋间肌的机械效益 在胸骨旁区域（PA）中，每个间隙内显示梯度 机械效益随着离胸骨的距离而减小， 在第三层中具有更大机械效益的间隙之间的梯度 比第六层空间更大。 在机械效益方面， 外部肋间也预测与机械优势 最大的在背侧区域和逐渐减少向腹侧 地区 我们假设肌肉活动的分布 在自主呼吸过程中可能遵循机械性 优势 在拟议的研究中，我们将测试的计算值 通过测量PA和EI的缩短作为机械效益， 空间内和空间间的位置函数。 我们将 测量激活的分布，作为最大值的分数， 激活，PA和EI测试的假设，肌肉与最大 机械优势在呼吸期间更活跃。

The intercostal muscles drive expansion and contraction of the rib cage during respiration. The action of the intercostal muscles has been studied primarily by studying their effect on rib displacement, but their effect on lung volume expansion is still poorly understood. In our previous work, we combined modeling, theory, and experiment to establish a method for evaluating the mechanical advantage of the intercostal muscles. Mechanical advantage was defined as the change in airway pressure per unit force exerted by an active muscle, and mechanical advantage was shown to equal fractional muscle shortening per unit volume expansion of the passive chest wall. We calculated the mechanical advantages of the intercostal muscles of the dog and tested our prediction of the maximum respiratory effect of entire inspiratory muscle groups. The calculations revealed new information about the respiratory action of the inspiratory intercostal muscles. The calculated mechanical advantage of the internal intercostals in the parasternal region (PA) showed a gradient within each interspace with mechanical advantage decreasing with distance from the sternum and a gradient between interspaces with mechanical advantage greater in the third than in the sixth interspace. Gradients in mechanical advantage of the external intercostals were also predicted with mechanical advantage greatest in the dorsal region and decreasing gradually toward the ventral region. We hypothesized that the distribution of the muscle activation during spontaneous breathing might follow the distribution of mechanical advantage. In the proposed research, we will test the calculated values of mechanical advantage by measuring the shortening of the PA and EI as a function of position within interspaces and across interspaces. We will measure the distribution of activation, as a fraction of maximal activation, of PA and EI to test the hypothesis that muscles with greatest mechanical advantage are more active during breathing.