VPAP Adapt SV reliability issues?

JohnBFisher wrote:. . . For example, this unit has a very odd 30V DC power input for the DC voltage. They've moved their current units back toward more standard voltages.

I see nothing inherently wrong with a 30VDC internal power set-up. ResMed’s 30VDC converter, however, is a prime example of shoddy engineering.

DC operation is important to us because we camp a lot in a travel trailer. We bought the expensive ResMed 30VDC converter. It will not work in the camper. (My REMstar Auto works fine with no issues at all.)

Sent the unit back to ResMed and they say it works just like it is supposed to. After a couple of long discussions with the ResMed technician, I find that they were testing it in a warm lab and not with a 12-volt battery but rather with an electronic power supply. I also learned that the DC converter was engineered to shut down if the input power dropped below 12.0 VDC. This may be fine in a lab environment, but it is worse than useless in the real world.

A fully-charged 12-volt battery will put out about 12.65 volts at 70*F. Factor in 1) colder weather with batteries outside on the trailer tongue, 2) a moderately long cable run, 3) deep-cycle batteries that are not constantly 100% charged, and 4) other loads on the line and there is not a prayer of never falling below 12.0 VDC. Our experience was that the machine would “boot-up” okay, but the moment my wife tried to use it for therapy (i.e., she put the mask on her face) the power converter would shut down and the VPAP would start alarming.

The VPAP is engineered so that if it alarms when on DC power there is NO WAY to get it to stop alarming if DC power is reapplied! The ResMed technician confirmed this to me. The only way to get it to stop alarming is to plug it in the 120VAC and work from there. Brilliant!

FWIW, the DC converter (12 volts) for the S-8 is engineered to power off when the input power drops to 10.5 VDC or some such. Virtually all 12-volt appliances are engineered this way and will work fine in a camper.

Our solution was to install a pure-sine-wave inverter to have 120VAC from our 12-volt batteries in the camper.

I understand that the logic behind the unit coming on to therapeutic power after it has been switched off in back (without first having been turned off with the button on top) and the resultant alarm, is to allow for the machine coming back on if the power goes off in the middle of the night. However, this is totally unnecessary as the machine is oversensitive to ANY disturbance of the mask. If someone is wearing the mask there is zero chance that the machine will not turn on. Having the machine turn on to full therapeutic power after a power outage, without sensing someone at the end of the mask, and immediately beginning the painful alarm, if also terribly stupid engineering, IMO.

The humidifier is another example of terrible engineering. First, to fill it you have to remove the tank and turn it vertically.

There is a “full” line when held vertically but it is not possible to have the tank sit level on a counter in this position. As a result, you add water to the tank, then lay it flat to check the water level against the “full” line for the horizontal position. There seems to be no agreement between the two “full” marks. Go with the horizontal mark.

When you return the tank to the humidifier, you must again run the “Learn Circuit” because the machine is too stupid to remember the settings before and after water was added. (Or so we were told.) What a pain!

With my REMstar Auto (and the REMstar Auto SV?) all that is necessary to fill the tank is to pull off the hose, stick on a funnel, and fill to the line. Done!

I’m glad this unit provides good therapy for you. It does the same for my wife. But I can’t help but wonder if with only a little thought and effort they couldn’t have made it without all the warts. And I wonder if the Respironics equivalent might not work as well and be more user friendly.

Wayne

I just received an email from my wife’s DME confirming that her replacement machine is warranted by ResMed for two years from the date she received it. Wow!

I may have misgivings about ResMed’s design/engineering, but their warranty policy is outstanding!

Wayne

Wayne,

Re the engineering of the machine, you have raised some interesting issues. I was never ever impressed with the design of the power boards in any Resmed model when compared to similar era Puritan Bennett (pre 42x models) or the pre-M series Respironics. The old Respironics tank machines stand out as top quality design & quality manufacture.

The motor/blower in the Vpap Adapt SV does stand out as one of the revolutionary designs in cpap. They justifiably won some prestigious awards for it. Three of the factors that made it stand out were: 1) the use of a fan at each end of the motor shaft (more efficient, better balanced, reduced harmonic whine, superior flow control), 2) whisper quite in use, 3) low cost of manufacture.

One other intent of the design that was innovative too, was the level of automation of the flow in that there are really only 2 settings to adjust vs many on nearly all other brands. If the algorithm works for someone, they have so few settings to worry about. The machine does though, get messed up if the mask leaks & is considered to be one of the most leak intolerant machines on the market. Am having my own bout of frustrations in that dept right now. When it all works it is great when the mask plays up it becomes vexatious.

DSM

just received an email from my wife’s DME confirming that her replacement machine is warranted by ResMed for two years from the date she received it. Wow!

I may have misgivings about ResMed’s design/engineering, but their warranty policy is outstanding!


WOOO HOO!!!

My husband has complex sleep apnea and a ResMed Adapt SV which he got 13 months ago - it was just converted from a rental to purchase so he now owns it although the Medical Supply Co continues to provide service, supplies etc. This machine has had alarm issues from the beginning. Our RT managed to silence the alarm once for a few weeks but the alarm turns itself back on. Last night my husband put on his mask as usual and started the machine - ALARM!! Our RT told us to run the learn circuit but when the display showed learn circuit and we selected "yes" nothing happened. We unplugged it from the wall - disassembled the humidifier and hose, put it all back together again. Same problem - low pressure ALARM. How can this be possible? Nothing had changed from the night before. At the moment we are waiting for a home visit from the RT who is bringing another machine. So no one slept last night. Any suggestions? Thanks very much.