Grumpy48 wrote: ↑Mon Jun 21, 2021 10:48 am
Many years ago when I worked in an electronic manufacturing company we had an engineering department whose function was to come up with some numbers related to reliability and lifespan of our products. These were known as MTBF amd MTTF and explained in the link below. I would suspect somewhere in course of product design and manufacture Philips has done a reliability study (probably easier with computers now as we had to rely on HP programmable calculators back in the day) and have determined 5 years to be an optimum time for replacement. Some devices may last longer than 5 years, some less. The MTBF for a Philips CPAP might be published somewhere, but I couldn't find it readily.
https://en.wikipedia.org/wiki/Mean_time ... n_failures
https://resources.pcb.cadence.com/blog/ ... lectronics
Perhaps at one point replacement time was derived on a MTBF or MTTF, but I doubt it now.
Like all things CPAP, replacement time frames are based on when Insurance will replace them.
Then DME's and manufacturers then push to replace machines and consumables on the insurance schedules.
Had replacement schedules for machines been based on an actual mean time, then not all machines by all manufacturers be 5 years. The same is true for supplies, all full face masks regardless of manufacturer has the identical replacement schedule, the same is true for hoses, headstraps, pillows.
As much as I hate unnecessary replacement of supplies, the same is not true fr devices. One can cheaply keep spare supplies for unanticipated failure, the same is not true for machines.
HairyReasoner wrote: ↑Mon Jun 21, 2021 11:41 am
ChicagoGranny wrote: ↑Mon Jun 21, 2021 10:23 am
HairyReasoner wrote: ↑Mon Jun 21, 2021 10:13 am
I don't know why they are assigning what seems to me an arbitrary 5 year life.
What would you propose?
When the machine no longer functions as needed. Just like how we decide when to replace other things.
Sure, let's start treating our essential medical equipment like toasters.