Experimental WaveformsWaveform results for experimental modeling of CPAP, BiPAP, 1:1, 1:1.6, and 1:2 combinations
In order to minimize fluctuation in air flow on CPAP manifolds and between manifolds running asymmetrical inhale:exhale breathing algorithms, we modeled a number of common respiratory modes operating simultaneously on different patient flow manifolds. Below are illustrated the open/closed airflow waveforms for these combined modes. The horizontal axes are elapsed time (sec). The vertical axes are liters per minute flow rates from each patient port. Individual ports are color coded. If only three ports are visible, then two ports have identical flow settings. In this model, these fluctuations only apply when pump air is being mixed with oxygen and not when hospital air is used. From these models, we introduced the concept of “peak shifting” which is a way to synchronize the different manifolds so that each manifold is minimally impacted by the inhale/exhale patterns of the others. Note: due to system compliance and momentum principles, it is reasonable to assume that actual flow waveforms would behave as a smoothed version of these experimentally predicted waveforms.
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