Blower hours VS Therapy hours different numbers on M series

[Gerryk]

I have an M series and noticed that my machine shows one set of numbers for blower hours and one set for therapy hours. I don't run my machine when the mask isn't on my face, such as using it to dry the hose.

I have only seen people post about this with the M series. Is this something that only happens with the M series?

I wonder if it happens to everyone that has an M series?

What causes this?

Gerry

[Patrick A]

I have the same Bi-Pap Machine and I get the same readings?

[Hawthorne]

I think someone on the forum said that there was a difference in Blower hours and Therapy hours, because the machines were tested for several hours after they were manufactured so the Blower hours would show several hours more.

That's what I understood anyway.

[Gerryk]

The numbers seem to grow further apart the longer you have it and use it.

[falvesjr]

At the very beginning of my therapy I had a Respironics machine for about three weeks and remember reading somewhere about this. Think of it as the blower hours being like the odometer in your car. It starts at zero and is continuously incremented with each mile you drive. You cannot reset your car's odometer. The therapy hours is like the trip odometer in your car. It also starts at zero and increments as you drive, but it can be reset by the driver back to zero. The reason some machines have the two different hour counters is that they can be used for multiple patients and/or as rental units. You want to have a total counter that keeps track of the life of the machine, but you also want to be able to reset a counter for each individual patient. Hope this helps!

[cinco777]

One of my Respironics M-Series APAPs (I have two and alternate every 3+ months) currently shows 1010.5 Blower Hours and 1005.8 Therapy Hours on its LCD after 134 Sessions. This difference is 4.7 hours or 282 minutes which means that my Therapy Hours are less than my Blower Hours by an average of a little over 2 minutes per Session (one Noon-to-Noon 24-hour GMT day). I believe that this small elapsed time difference is occurring because my machine does not start accumulating Therapy Hours at the exact moment that it starts accumulating Blower Hours and accumulating Therapy Hours is often delayed for a small multiple of 30 seconds.

One of the EncorePro SQL tables that I query for my Excel Charting program shows Session Time. The start/end times for a Session are recorded/reported using two Record Types - type 4 and type 5. I was curious for a long time why Respironics and EncorePro used two Record types to record/report the start and end of a Session. Why wasn't one record type enough?? I have observed that these two record types often show slightly different start and end times (by multiples of 30 seconds, the minimum recording/reporting interval used my Respironics). Velbor suggested in a recent post that the small difference between Blower Hours and Therapy Hours may be due to our Respironics machines using a separate internal criteria for determining when Therapy starts and not starting its accumulation of Therapy Hours when we push the Blower-on button. Therapy Hours accumulation, he suggested, may be delayed until the machine determines a steady state condition on startup and this steady state is recorded/reported 0, 30 seconds, 60 seconds, or so after the Blower starts. I consider his theory as providing a plausible reason for Respironics / EncorePro using two Record Types for the start and end of a Session, as the small differences (0, 30, 60, ... seconds) that I have observed between the times recorded in the Type 4 and Type 5 records fit his theory.

Edited and added the following info on Monday, 12/14/09 at 8:30AM CA time:

My second APAP machine, which I just switched to and started using (for the next 3 months), shows the following: Sessions = 109, Blower Hours = 786.7, Therapy Hours = 784.0. The difference is 2.7 hours or 162 minutes or an average of 1.5 minutes per Session. For this Respironics M-Series APAP machine, Therapy Hours lags Blower Hours by an average of 1.5 minutes per Session (Noon-to-Noon 24-hour GMT day).