MODIFICATION OF INFANT RESPIRATORY OSCILLATION AND APNEA

早产儿呼吸暂停和婴儿猝死综合征都是 与呼吸暂停有关的重要临床问题。最好的办法可能是接近他们 通过基础研究探讨呼吸暂停的生理学基础。我们有 最近的研究表明，新生儿的呼吸暂停发生在 振荡的呼吸模式，而不是孤立或随机的 事件。在我们的新研究中，我们想知道 这些模式，以及呼吸暂停模式的局限性 两性关系。我们的研究还将提供有关 婴儿呼吸控制的动力学。该研究计划包括两个 调查的领域。 第一个领域涉及三项研究，即 早产儿的振荡呼吸模式。第一，振荡 图案将由灵感二氧化碳的正弦变化来突出。这个 与这些加重模式相关的最长呼吸暂停持续时间将 然后与我们观察到的内源性呼吸暂停极限进行比较，这就是呼吸暂停 持续时间小于或等于图案周期时间的一半。第二, 认为这些模式是由于呼吸不稳定造成的假说 控制系统，与驱动呼吸的神经振荡器相对 将通过控制潮气末PC02和P02独立于 通风，从而打开控制回路。控件时看到的模式 环路打开不可能是由于控制环路不稳定。第三，a 对婴儿呼吸控制系统进行严格的稳定性分析 使用呼气末PC02的正弦变化进行。 第二个领域涉及婴儿呼吸的数学模型 控制系统。尽管已经有许多模型可以解释周期性的 成人的呼吸现象，当他们被刻度成代表婴儿的时候 它们产生的图案与我们在 婴儿。我们的建模工作将基于我们自己的初步模型 以及邱线性化的微扰模型。

Apnea of prematurity and the Sudden Infant Death Syndrome are both important clinical problems related to apnea. They may be best approached through basic research into the physiological basis of apnea. We have recently shown that apnea in newborn infants occurs at the minimum phase of oscillatory breathing patterns rather than being an isolated or random event. In our new studies we want to know the physiological basis for these patterns, as well as the limits of the apnea - breathing pattern relationship. Our studies also will yield basic information about the dynamics of respiratory control in infants. The research plan includes two areas of investigation. The first area involves three studies into the causes and consequences of oscillatory breathing patterns in premature infants. First, oscillatory patterns will be accentuated by sinusoidal variation of inspired C02. The maximum duration of apnea associated with these accentuated patterns will then be compared to our observed endogenous apnea limit, which is apnea duration less than or equal to one-half of the pattern cycle time. Second, the hypothesis that the patterns are due to instability in the respiratory control system as opposed to a neurological oscillator driving respiration will be tested by controlling end tidal PC02 and P02 independently from ventilation, thus opening the control loop. Patterns seen when the control loop is open cannot be due to instability in that control loop. Third, a rigorous stability analysis of the infant's respiratory control system will be performed using sinusoidal variation of end tidal PC02. The second area involves mathematical modeling of the infant's respiratory control system. Although many models have been offered to explain periodic breathing phenomena in adults, when they are scaled to represent infants they do not produce patterns compatible with those we have seen in infants. Our modeling efforts will be based on our own preliminary model and on Khoo's linearized perturbation model.