Changes

If we look closely at the bi-level algorithm in use by Lowenstein, we notice that following the release of IPAP pressure down to EPAP pressure, the machine immediately begins to ramp back up to IPAP pressure. Peak During a period known as EEPAP (end expiratory positive airway pressure is set ), the pressure already well on the way to peak pressure and will arrive closely aligned with the beginning of at IPAP pressure early during inspiration. This is how Lowenstein achieves Apnea control at lower main pressures. By returning gently ramping back to max pressure near the end of throughout exhalation (when Apneas develop)and stenting the airway during late exhale and into the pause between exhale and inhale at zero on the flow chart.

In contrast, the Resmed example below shows the very different implementation of its a Bi-Level mode. The lower pressure of EPAP is maintained throughout exhalation, it does not provide a movement toward IPAP pressure until the beginning of inspiration. Peak IPAP pressure is not reached until mid to late inspiration.