Active alternating air cushions???

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Re: Active alternating air cushions???

Postby Irving » 22 Aug 2019, 16:16

Burgerman wrote:They do seem to be very good. No matter cheaply made and overpriced.

Personally I am trying to buy a https://www.ridedesigns.com/ride-custom ... heelchairs
That seems like it will prevent ALL pressure on the Ischael tuberosities and cocyx (cant spell that) completely. And put your weight only on the bits that are not sensitive to pressure.

But cannot find any way to get hold of one in the UK. Any ideas? eMAILED THe company. No reply.

Here's the problem :D :D :lol:
A fast, clean, intuitive and accurate process allows shapes to be rapidly scanned, then sent, along with photos and order information, through the secure, encrypted iOS app.


Seriously though, try the Ireland distributor by phone...
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Re: Active alternating air cushions???

Postby sacharlie » 22 Aug 2019, 16:16

flagman1776 wrote:The small but painful area on my bottom was nearly gone after alternating between the blue honeycomb cushion and the Apex alternating air cushion. With the desk chair I'm using at the computer, it takes more effort to keep my position with the Apex than the honeycomb. But the sore spot came back.
I switched to the Apex all of yesterday... pretty much pain free all day. I'll have to put up with the fatigue... I am back on the air cushion.

Why don'T you cut out the honeycomb center and use the apex bladder as an insert?
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Re: Active alternating air cushions???

Postby Burgerman » 22 Aug 2019, 16:28

I emailed them. The phone didnt work. No reply.
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Re: Active alternating air cushions???

Postby Irving » 22 Aug 2019, 17:03

Burgerman wrote:I emailed them. The phone didnt work. No reply.

Just spoke to Alison @ Ride in the US via Skype phone (for free). There's no current UK distribution and Momentum in Ireland have recently lost their authorised guy, he left the company, and they were aiming to recruit another but its been a while. Her best suggestion was to contact the guys in Germany. Although she doesn't know of any sales in UK the Germans cover many Scandinavian countries as well so may be OK coming to UK.
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Re: Active alternating air cushions???

Postby Swan T.W. » 22 Aug 2019, 18:14

Burgerman wrote:They do seem to be very good. No matter cheaply made and overpriced.

Personally I am trying to buy a https://www.ridedesigns.com/ride-custom ... heelchairs
That seems like it will prevent ALL pressure on the Ischael tuberosities and cocyx (cant spell that) completely. And put your weight only on the bits that are not sensitive to pressure.

But cannot find any way to get hold of one in the UK. Any ideas? eMAILED THe company. No reply.
Try the off the shelf Ride Foward cushion.I Know people that use them instead of the custom because the fittersare like chair mechanics, very hit and miss[more miss than hit].
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Re: Active alternating air cushions???

Postby flagman1776 » 22 Aug 2019, 18:39

sacharlie wrote:
flagman1776 wrote:The small but painful area on my bottom was nearly gone after alternating between the blue honeycomb cushion and the Apex alternating air cushion. With the desk chair I'm using at the computer, it takes more effort to keep my position with the Apex than the honeycomb. But the sore spot came back.
I switched to the Apex all of yesterday... pretty much pain free all day. I'll have to put up with the fatigue... I am back on the air cushion.

Why don't you cut out the honeycomb center and use the apex bladder as an insert?


The honeycomb cushion isn't enough bigger than the air cushions. I cut away all but 1" surround from the Apex foam in order to get it on my desk chair. I'm getting numbness on one leg from the chair. At times I shut the alternating air off and it still holds fine. It's still my best option. It's working. I'm using healing cream every time i get up.
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Re: Active alternating air cushions???

Postby flagman1776 » 22 Aug 2019, 19:03

I just switched to the honeycomb so I could examine the 1' foam surround of the Apex. After cutting away the big hunk of foam intended for the front of the Apex cushion... I turned it around so the air tubes exited from the front so I could place the control box beside me. The whole back (now front) of the Apex foam shell has torn so my wooden chair was exposed. I've removed the Apex foam for now. I'll try the bare air cushion but the plumbing exits the tubes through the bottom and it may need cushioning. If I need to, I can fabricate my own foam or something to recess the air tubes into. A flat plywood could have channels carved into it.
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Re: Active alternating air cushions???

Postby flagman1776 » 24 Aug 2019, 23:30

With the tearing on the foam square surround on the Apex cushion, I used my sharpest sissors to cut the rest of the square, leaving just the1/2" thick layer under the air cushion. I think something is necessary because the air tubes connect on the bottom of the air cushion. Maybe I'm wrong, since the air cushion should protect the user from the fittings... maybe... if there's enough air. I like it a bit soft to mold better.
I flopped it onto the chair. Sometimes on it's own. Other times on top of the honeycomb cushion. Whether I run the active air or not, it molds to my bottom better, relieving pressure points. It's nice to have the power inflation but many people might find the air cushion enough. It's better than any foam or the honeycomb.
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Re: Active alternating air cushions???

Postby Irving » 03 Sep 2019, 13:48

My Apex 500, ordered yesterday at 4pm from CLH Health Care, arrived 12pm today, excellent service and only £220 ex VAT which is pretty much the cheapest I've seen it anywhere that actually had stock.

Seems to work well enough. Mine is Li-Ion 7.2v 3400mAH pack, though power consumption is stated as 12v 1150mA (is that charging) and the charger is rated at 1250mA. The manual is confusing in that it implies you can't charge and run at the same time, though clearly you can, which helps explains the 4.5h charge time.
Some observations (in the hour or so I've been using it so far ;) )
  • Despite being billed as 4" thick its a good inch shallower than the Transair mains powered one, also supposedly 4" thick.
  • The foam at the front is fine for me, at 65kg it hardly compresses at all and is about the same thickness as my Jay3 cushion. This is good because the Transair, being air-filled throughout, pushed my knees up a good extra 1.5".
  • The pump is moderately noisy, running for about 25sec every 5min 30sec (on the 10min, comfort level 3 setting). I don't find it too obtrusive sitting here in my home office - it measures 20 - 25dBA on my sound meter (slightly below a whisper, TV at comfortable listening level is 50dBA) - but I'd probably think twice about going to the theatre with it.
  • Adjusting my seating position appears to cause the pump to run a short burst of 1-2sec as pressure changes.
  • At a comfort level below 3 there is a risk that the cushion could compress to the point that the pipe fittings might be an issue.
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Re: Active alternating air cushions???

Postby wheelie junkie » 03 Sep 2019, 15:51

How stable are they? I found high profile Roho's let me wobble about. The lower, shaped contour select I don't move at all. That cushion is working well so I am in 2 minds whether to give one of these a go. Working at the NEC next week and they will be much longer days in the chair than I do now.
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Re: Active alternating air cushions???

Postby Irving » 03 Sep 2019, 16:56

wheelie junkie wrote:How stable are they? I found high profile Roho's let me wobble about. The lower, shaped contour select I don't move at all. That cushion is working well so I am in 2 minds whether to give one of these a go. Working at the NEC next week and they will be much longer days in the chair than I do now.

As stable as my Jay3. Much better than the Transair or other 'all air' cushions. I'm finding I sit 'in' rather than 'on' at level 3; at level its starts getting a bit bouncy.
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Re: Active alternating air cushions???

Postby Irving » 03 Sep 2019, 17:25

Some more thoughts...

Took 3.5h to charge while in use (from battery low alarm) so that's about 52-ish Wh. I wonder about the accuracy of the charging regime as they quote a 6mo battery life which seems low for Li-Ion, but I'm guessing on a 12h run DoD is getting close to 80%. I read elsewhere that the best Panasonic 18650 3400mAh cells have a cycle life <150 @ 80% so maybe that's true. A new replacement pack is £48!

Answer is replace battery pack with 3D printed case containing a 24 -> 7.2v 50W buck converter and run it off the chair.
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Re: Active alternating air cushions???

Postby wheelie junkie » 03 Sep 2019, 17:37

Interesting to hear, my Roho is set very soft so I sit in it, don't seem to bottom out. For the price it might be worth a try.
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Re: Active alternating air cushions???

Postby sacharlie » 03 Sep 2019, 17:57

Irving I tested mine at the #1 comfort (softest level). Stacked 85lbs of weight in a 12" square pan. It measured a 1.125" sink. So that's 12x2x~1.25=30 square inches. I would think someone's but to be a bit more surface. There are some bike hand pumps with inline digital guage that I might rob the guage from just to see the PSI.
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Re: Active alternating air cushions???

Postby Irving » 03 Sep 2019, 18:18

sacharlie wrote:Irving I tested mine at the #1 comfort (softest level). Stacked 85lbs of weight in a 12" square pan. It measured a 1.125" sink. So that's 12x2x~1.25=30 square inches. I would think someone's but to be a bit more surface. There are some bike hand pumps with inline digital guage that I might rob the guage from just to see the PSI.

OK. My test was less scientific, at level 1 I put my full weight as best I could on my stretched out hands and I could feel the covering over the fittings on the 'relaxed' tube. I guess since you'd be supported on the stiffer tubes I'm maybe being a little pessimistic.
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Re: Active alternating air cushions???

Postby flagman1776 » 03 Sep 2019, 18:32

I like the softest setting for comfort. Yes, if I shift my weight I can get the pump to run. I dunno about battery life as I'm running in a fixed location off the adaptor.
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Re: Active alternating air cushions???

Postby wheelie junkie » 03 Sep 2019, 18:35

If the pressure needed is anything like a Roho a bike pump gauge won't measure it. Unloaded the pressure is tiny, even sat on it it is still low.
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Re: Active alternating air cushions???

Postby Burgerman » 03 Sep 2019, 18:48

Very low. And hard to measure. Remember this is not a roho that forms a floatation cushion. Its DESIGNED to lift you up over the deflated sections. So the higher the pressure the better the circulation in the previously loaded areas. So best set as high as comfort if you can feel it, and as high as stability allows.

It would not matter really if these were alternating wooden bars. As long as they alternate to bridge the opposite areas to allow oxygenation.
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Re: Active alternating air cushions???

Postby sacharlie » 03 Sep 2019, 19:28

Well 0.6psi/32mmhg is the maximum interface pressure that will not cause capillary blood flow impediment.
That is what all these immersion style cushions are shooting for.
I don't know the length of time your butt tissue will recover from when a small area of your butt is holding you up at greater than the above pressure.
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Re: Active alternating air cushions???

Postby Burgerman » 03 Sep 2019, 19:35

Well 0.6psi/32mmhg is the maximum interface pressure that will not cause capillary blood flow impediment.
That is what all these immersion style cushions are shooting for.
I don't know the length of time your butt tissue will recover from when a small area of your butt is holding you up at greater than the above pressure.


And no cushion is doing this, or you would not get the sores. At least not adequately. Even sitting on a wooden bench wont cause sores if you lift off it periodically. Its sitting for hours at a time with inadequate oxygenation that causes the problems.

So you dont need to aim for low pressures on the inflated bars. And you wont get it anyway as you are supporting your weight on half the area - so that doubles the average pressure.
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Re: Active alternating air cushions???

Postby stevelawiw » 03 Sep 2019, 19:40

Ok chaps, tell me to shut up if this has been considered and discarded as unworkable, but I've been using 240v alternating air cushions for over 5 years now without any problems on a 24 - 240v 300w inverter. No extra batteries needed, no danger of the battery not lasting all day, particularily if you have already gone lithium on your chairs main battery.
And you will never get a low voltage pump to work as silently as a 240v one IMO.
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Re: Active alternating air cushions???

Postby sacharlie » 03 Sep 2019, 19:44

Most of that is true.
But what is an acceptable time to alternate pressure points when the blood flow is cut off as these alternating systems do?
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Re: Active alternating air cushions???

Postby Burgerman » 03 Sep 2019, 19:46

I think they sound exactly the same? At least to my ears. So quiet as to not nother me at all

Also, my battery pump has no problem doing all day, then I forget to turn it off, and its going fine without me on it for another 8 hours till it gets put on charge again. I never saw it actually stop or go dead flat ever. Seems to last way longer than needed. Replacing the 4 cells (lithium ion dont last as long as the LiFePO4 cells) when needed it a trivial exersize. Just buy a couple of cells on eBay. And solder them in. 10 mins work.
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Re: Active alternating air cushions???

Postby Burgerman » 03 Sep 2019, 19:53

I suspect every 10 mins or every 15.
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Re: Active alternating air cushions???

Postby Irving » 04 Sep 2019, 17:22

sacharlie wrote:Most of that is true.
But what is an acceptable time to alternate pressure points when the blood flow is cut off as these alternating systems do?

Surprisingly, there is little research that points to any definitive figure. Bader (1990) showed that the 2 min every hour regime expounded by most hospitals was unlikely to be sufficient for most people and re-oxygenation times of 9 min or more could be necessary for some individuals. The 5 min on/5 min off cycle adopted by many cushion manufacturers appears to be empirical rather than backed by any specific research.
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Re: Active alternating air cushions???

Postby Irving » 05 Sep 2019, 09:04

So, after 2 days, my further thoughts about the Apex Sedens 500 cushion following on from posting.php?mode=reply&f=2&t=8081#pr144481

Battery ran for over 14h and was still going by bedtime yesterday, no low battery alarm yet, so easily betters it's 12h specification.

Used level 3 the day before yesterday. There was a red patch on right buttock on checking at night, it was blanching and was gone by the morning so yesterday tried level 2 instead. Can't really say that I could tell the difference. No marks at all yesterday evening after 14+ hours in the chair and no pressure relief done all day. I'd say that was a success.

I find the foam surround adequately supportive for my 65kg frame.
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Re: Active alternating air cushions???

Postby Burgerman » 05 Sep 2019, 10:11

Im twice your weight, but find everything the same as your report.ther than I need a much more supportive cushion surround that is 20 x 20 inches. The actual cells I have are 6 bars, but smaller. Not sure what difference that makes. Probably very little. And yes it will support you and run every 10 mins, easily for 14 hours. If you forget to turn it off, it keeps going all night too. And you can still get up, and just plug it into charge while you get breakfast or check mail.

If you want to do that on the fly, just get an xlr plug, and a cheap ebay buck inverter board - which are very small - and a plug that fits the pump charge socket. Then you can tuck that out of the way somewhere on the chair just in case. I must say that I never found the need.

Even a single 3 leg volt reg chip would do it. The current is low. So not much heat to waste. But buck inverter is a better way.

Theres even ready to go ones in a tiny box, 12V and up to 40V input. Just add an XLR plug and you have a charging lead. Up to 3A. https://www.ebay.co.uk/itm/Voltage-Conv ... 0005.m1851
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Re: Active alternating air cushions???

Postby jefferso » 05 Sep 2019, 15:11

Burgerman wrote:The actual cells I have are 6 bars, but smaller. Not sure what difference that makes. Probably very little.


Which one did you end up getting? I saw a few different links in the thread and couldn't work out which it was.

Was it:
BOS Combo 100 System Portable Alternating Pressure Relief Cushion
https://www.healthandcare.co.uk/alterna ... shion.html

or:
Alerta Mobile Alternating Air Cushion System
https://www.healthandcare.co.uk/alterna ... ystem.html
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Re: Active alternating air cushions???

Postby jefferso » 05 Sep 2019, 15:20

jefferso wrote:Alerta Mobile Alternating Air Cushion System
https://www.healthandcare.co.uk/alterna ... ystem.html


Just looked at those pages some more, judging from the photos, it must be the Alerta. Looks like it's the one with 6 cells instead of 4.
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Re: Active alternating air cushions???

Postby Burgerman » 05 Sep 2019, 15:21

The alerta one. But made my own cushion. Since they are all too small and just a lump of floppy foam.
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