Muffy wrote:since the Psearch patent suggests that hypoventilation... will elicit the same behavior as Variable Breathing:
The patent suggests hypoventilation is a sustained drop in flow signal. By contrast, Variable Breathing (or VB) is inherently erratic breathing, with criteria based largely in peak-flow standard deviation. So hypoventilation criteria is altogether separate from VB criteria.
But since those two conditions are not comprised of mutually exclusive criteria, that implies a breathing signal or flow condition can meet both criteria sets.
So what, in turn, does that mean regarding patients either meeting or failing to meet those separate criteria sets? It means that across the SDB patient population, some of those hypoventilation-positive detections will also be VB-positive while other hypoventilation-positive cases will not meet VB criteria. So let's follow both of those hopoventilation-positive cases through that flow chart:
Case One- Hypoventilation-Positve Criteria Combined With VB-Positive Criteria: Hypoventilation-positive cases or criteria always outrank VB-positive criteria regarding algorithmic priority. So in this case the flow signal is always sent back to the apnea-detection circuit for subsequent higher-priority reexamination---before dropping back down to that same hypoventilation-detection circuit for yet additional reexamination. That case never even has a chance to drop down to the lower-priority VB detection circuit until all higher-priority traces of apnea and/or hypoventilation are gone.
Case Two- Hypoventilation-Positve Criteria Lacking VB-Positive Criteria: Since no VB-positive criteria is present, but hypoventilation-positive criteria exists, the flow signal once again always gets sent back to the higher-priority apnea-detection circuit for subsequent reexamination. Once all traces of either apnea or hypoventilation are gone, then the algorithm is finally allowed to look for signs of lower-priority VB.
Above, we have hypoventilation-positive cases always being sent back to the higher-priority apnea-detection circuit for apnea reexamination---before dropping down for yet another pass at hypoventilation reexamination. The only flow-signal conditions that are allowed to be treated by the lower-priority VB circuit, are those VB flow signals lacking both higher-priority apnea and higher-priority hypoventilation criteria.
Muffy wrote:since the Psearch patent suggests that hypoventilation... will elicit the same behavior as Variable Breathing:
That control layer running Psearch happens to be lower priority than both the VB and hypoventilation detection circuits. So if criteria for either VB or hypoventilation surfaces during a Psearch, then algorithmic control reverts to the highest-priority control layer for which criteria matches.
Without data I would not have known I needed to significantly increase my pressure. But looking too closely at the numbers can be a hindrance. Even though I know the two machines score events differently, it seems to me we hear much more re data specifics from Respironics users than ResMed users.
