Burgerman wrote:Its worse... Most cushions are 1024 sensors. Rohos one is 1380 sensors. And costs 10s of thousands of dollars.
ex-Gooserider wrote:Burgerman wrote:Its worse... Most cushions are 1024 sensors. Rohos one is 1380 sensors. And costs 10s of thousands of dollars.
I was guessing conservatively at the number of sensors... But not all that far off really...
Given your numbers, and assuming a square mat, that would be 32^2 sensors on most, and 37+^2 sensors on the Roho... In approximate numbers, if sticking with the assumption of a 20"^2 mat, then it would be about 1/2 to 3/4" between sensors (probably some metric equivalent...) or a bit wider if the mat was bigger....
Either way, my guess is that nearly all the cost is in the mat, as the electronics in the rest of the unit looked to be mostly off the shelf hardware and some relatively standard software.... I would also guess that the software is doing at least some level of interpolation between adjacent sensors in order to get more 'virtual' points on the pretty butt pictures.
ex-Gooserider
Burgerman wrote:
Also, Varilite Evolution maps for pressure on most users slightly worse than jay2 and considerably worse than roho for peak pressure on the ischeals. It might well be more comfortable. But its almost garanteed worse for ulcer prevention than a roho. I know that from looking at dozens of comparisons as above. So I never tried one.
One of the things I have heard about Roho's is that it is absolutely critical that the size of the cushion match the size of the butt that is sat upon it...
If the cushion is bigger than the butt, all the air moves to the un-sat-on cells and the sitter bottoms out unless very high pressures are used...
If the cushion is smaller than the butt there is no place for the air to go, so you end up w/ higher pressures in the cushion, while the excess butt droops over the edges...
The cushion needs a 'Goldilocks' style fit that is "just right"....
ex-Gooserider
This kept the sleeper from squishing the air out of the way and touching down
Burgerman wrote:I bought/made a cushion(s) very similar to that a year back. It worked quite well. Theres a thread here with pics somewhere. But still I think the roho works better IF configured correctly.
Burgerman wrote:I bought/made a cushion(s) very similar to that a year back. It worked quite well. Theres a thread here with pics somewhere. But still I think the roho works better IF configured correctly.
Burgerman wrote:This is what I use to determine pressure as I sit in the chair. I madeit from ebay parts. It allows me to increase or decrease the pressure and watch it change as I release air ir pump more in.
Because of extensive "plastic bag with hand in it" testing on multiple days with 3 different carers, and averaging the results I can say that when I have 10 to 12mm between me and the chairs base, at my ischeal tuberosity bones, the pressure is 36mmHg when my arms are on the armrests. (42 with then lifted.).
So that now I can check myself, get it exactly right, as often as I want. On my own. With no plastic bag/hand testing.
With a smaller gap, say 5mm I can't test. Fingers are thicker! But you wouldnt want to. With a bigger gap, say 20 to 25mm, the presure is a lot higher. Approx 44 to 46mmHg. So aiming for a 10 to 15mm gap makes a lot if difference. Remember these are MY figures for my backside on my cushion. You will need to determine your own from the hand tests.
You cannot do this without a quality pump. The one supplies isnt good enough. And you need a couple of adjustable valves, a T, and a quick release "fuel" connector so that it works as an airtight swivel to allow easy use of the cushions on/off valve. Test with the ISO valve on the cusion open. Lock it when finished and yourself in the correct position.
Burgerman wrote:Its plug and play. I can give you all the links...
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