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I was curious so looked at a few power wheelchairs...It's wild how expensive they are, especially considering the advancements in electric mobility tech elsewhe

I was curious so looked at a few power wheelchairs...It's wild how expensive they are, especially considering the advancements in electric mobility tech elsewhere. You'd think they'd share some components with e-scooters, e-bikes, or even electric cars – motors, batteries, controllers. Are the powertrains and control systems in power wheelchairs really that specialised? Or is it another case of the medical device markup and regulatory hurdles driving up costs?

amiga 2y ago
I'm a guy who has disassembled and reverse engineered a standard Jazzy power chair, and what I noticed was the attention to detail regarding failures. The chair is thoroughly designed to shut down at the slightest bit of trouble. There's some redundancy in things like the controller, where it used redundant hall effect sensors that were identical to the others, but ran in an inverted power profile, to detect any weirdness in the sensor outputs. I ended up adding a long range remote control to it. A remote control power chair is fun to drive around. People do get a little concerned when they see a chair rolling around without a driver
- orlehuxwell 2y ago
  My mum recently had a curbside crash while she was riding an e-bike. This resulted in her breaking bones in both her hands, which resulted in a surgery in her left hand and various problems (tcl fracture related) with her right hand. This makes me actually appreciate reliability in e-vehicles motor cutoffs etc. I keep thinking if this could have been avoided with a better quality e-bike or if actually it would be even worst with a cheaper one. Which makes one think, how often a wheelchair with cheap e-scooter parts would crash people into staris, cars etc
  - TeMPOraL 2y ago
    I know public use devices have their own problems with reliability, but I did almost cause a traffic accident a couple times over the years. Every time, the scooter's accelerator lever got "sticky" due to repetitive (mis)use, and would sometimes not go all the way to 0 when released. Stuck at ~10%, the scooter would brake normally and remain at halt under my weight, but the moment I stepped off it, it would suddenly launch itself at the cross traffic. It's these little things that get you. The scooters all have some kind of debounce logic, disabling the accelerator until you're moving sufficiently fast - but the logic doesn't kick in when you stop without releasing the lever. A little bit of redundancy would've helped here.
  - _flux 2y ago
    A friend has an e-unicycle (I think the category devices has some other name as well..) and he wanted to try out how it behaves in a track. He sort of knew, but didn't expect it, that when the roll of the device exceeds a certain threshold, the device will shutdown. Even if you're on a curve going with some speed. Broke his wrist. Since then he's also wearing wrist protectors that keep the hand straight. Actually it was a bit unexpected that it would have known to do that; it must have used its complete IMU data to even know it was rolled, as plain accelerometer would have been pointing "down" as usual.
    - snatchpiesinger 2y ago
      > Actually it was a bit unexpected that it would have known to do that; it must have used its complete IMU data to even know it was rolled, as plain accelerometer would have been pointing "down" as usual. That actually feels like overengineering based on well-intentioned, but wrong specs. You probably want to just use sideways acceleration for "falling over" detection, instead of roll.
    - leoedin 2y ago
      I'm an embedded software engineer with past experience developing robotics and motor control drivers. Those e-unicycles terrify me. No way I'd trust my life to one. Once you're at speed, every failure mode results in instant passenger ejection. I see people flying through traffic on those things - they're just one sensor glitch or integer overflow away from serious injury.
  - tim333 2y ago
    The safety with ebikes does vary a bit although I'm not sure it's down to price. My one is quite a cheap one but has quite a lot of safety features - will only go if you pedal it, motor cut if you touch the breaks, 14 mph speed limiter etc. But I guess you can come off any two wheeled vehicle.
- crooked-v 2y ago
  > People do get a little concerned when they see a chair rolling around without a driver Add a hat and a scarf on a wire and you've got a Halloween prop.
lynx23 2y ago
Assistive technology costs are high because consumers barely have an alternative. I am blind. In Europe, a 40-cell braille display starts a 6k. 6k, just for a monitor which displays 40 characters. Prices are largely unchanged since 20 years. Technological advancements are irrelevant. Resellers will squeeze the cow, thats plain capitalism man.
- zestyping 2y ago
  If you don't mind educating a curious person — why are Braille displays still worth making when text-to-speech is free, everywhere, and communicates information much more quickly than Braille? I can understand that there might be special situations where you really need a device to be silent, but it's hard for me to see how the cost-benefit tradeoff would weigh in favour of a Braille display except in the rarest of circumstances.
- mistercheph 2y ago
  Just from googling -- an orbit reader 40-cell appears to cost $1,700 USD, is there a reason this doesn't actually solve the same problem as the 6,000 euro display, or are these not available in your market for that cost? Sorry if my question is off the mark, I don't know a lot about this and your comment piqued my curiosity.
  - lynx23 2y ago
    Orbit reader is the most low-quality device you can find on the market. This is like suggesting a bicycle to someone complaining about car prices.
    - krisoft 2y ago
      I’m sure the commenter meant well. You said “In Europe, a 40-cell braille display starts a 6k.” Which to me means that the most low quality, cheapest device starts at 6k. Now i learn from you that that low quality device is so bad that you consider it a separate product class in itself. Can you tell us more what does it lack? In other words what features are you looking for when you are looking for a 40-cell brail display? (What is the minimum quality for it to be a “car” in your analogy?)
Cthulhu_ 2y ago
I suspect a major difference is that those e-scooters, bikes, cars, etc are produced and sold by the millions, whereas wheelchairs are small volume by comparison. Another commenter mentioned the legal requirements, which complicates things. That said, a quick google says there's 65-132 million wheelchair users worldwide so it's not a small market either.
- space_oddity 2y ago
  ...but the production and distribution of wheelchairs
- nothercastle 2y ago
  Most of them are probably in countries where 1000 is a years wages.
tim333 2y ago
It's impressive and a little sad how cheap you can get them second hand.
space_oddity 2y ago
I think a significant portion of the cost is related to the "medical device" label.

amiga 2y ago

I'm a guy who has disassembled and reverse engineered a standard Jazzy power chair, and what I noticed was the attention to detail regarding failures. The chair is thoroughly designed to shut down at the slightest bit of trouble. There's some redundancy in things like the controller, where it used redundant hall effect sensors that were identical to the others, but ran in an inverted power profile, to detect any weirdness in the sensor outputs. I ended up adding a long range remote control to it. A remote control power chair is fun to drive around. People do get a little concerned when they see a chair rolling around without a driver

orlehuxwell 2y ago
My mum recently had a curbside crash while she was riding an e-bike. This resulted in her breaking bones in both her hands, which resulted in a surgery in her left hand and various problems (tcl fracture related) with her right hand. This makes me actually appreciate reliability in e-vehicles motor cutoffs etc. I keep thinking if this could have been avoided with a better quality e-bike or if actually it would be even worst with a cheaper one. Which makes one think, how often a wheelchair with cheap e-scooter parts would crash people into staris, cars etc
- TeMPOraL 2y ago
  I know public use devices have their own problems with reliability, but I did almost cause a traffic accident a couple times over the years. Every time, the scooter's accelerator lever got "sticky" due to repetitive (mis)use, and would sometimes not go all the way to 0 when released. Stuck at ~10%, the scooter would brake normally and remain at halt under my weight, but the moment I stepped off it, it would suddenly launch itself at the cross traffic. It's these little things that get you. The scooters all have some kind of debounce logic, disabling the accelerator until you're moving sufficiently fast - but the logic doesn't kick in when you stop without releasing the lever. A little bit of redundancy would've helped here.
- _flux 2y ago
  A friend has an e-unicycle (I think the category devices has some other name as well..) and he wanted to try out how it behaves in a track. He sort of knew, but didn't expect it, that when the roll of the device exceeds a certain threshold, the device will shutdown. Even if you're on a curve going with some speed. Broke his wrist. Since then he's also wearing wrist protectors that keep the hand straight. Actually it was a bit unexpected that it would have known to do that; it must have used its complete IMU data to even know it was rolled, as plain accelerometer would have been pointing "down" as usual.
  - snatchpiesinger 2y ago
    > Actually it was a bit unexpected that it would have known to do that; it must have used its complete IMU data to even know it was rolled, as plain accelerometer would have been pointing "down" as usual. That actually feels like overengineering based on well-intentioned, but wrong specs. You probably want to just use sideways acceleration for "falling over" detection, instead of roll.
  - leoedin 2y ago
    I'm an embedded software engineer with past experience developing robotics and motor control drivers. Those e-unicycles terrify me. No way I'd trust my life to one. Once you're at speed, every failure mode results in instant passenger ejection. I see people flying through traffic on those things - they're just one sensor glitch or integer overflow away from serious injury.
- tim333 2y ago
  The safety with ebikes does vary a bit although I'm not sure it's down to price. My one is quite a cheap one but has quite a lot of safety features - will only go if you pedal it, motor cut if you touch the breaks, 14 mph speed limiter etc. But I guess you can come off any two wheeled vehicle.
crooked-v 2y ago
> People do get a little concerned when they see a chair rolling around without a driver Add a hat and a scarf on a wire and you've got a Halloween prop.

lynx23 2y ago

Assistive technology costs are high because consumers barely have an alternative. I am blind. In Europe, a 40-cell braille display starts a 6k. 6k, just for a monitor which displays 40 characters. Prices are largely unchanged since 20 years. Technological advancements are irrelevant. Resellers will squeeze the cow, thats plain capitalism man.

zestyping 2y ago
If you don't mind educating a curious person — why are Braille displays still worth making when text-to-speech is free, everywhere, and communicates information much more quickly than Braille? I can understand that there might be special situations where you really need a device to be silent, but it's hard for me to see how the cost-benefit tradeoff would weigh in favour of a Braille display except in the rarest of circumstances.
mistercheph 2y ago
Just from googling -- an orbit reader 40-cell appears to cost $1,700 USD, is there a reason this doesn't actually solve the same problem as the 6,000 euro display, or are these not available in your market for that cost? Sorry if my question is off the mark, I don't know a lot about this and your comment piqued my curiosity.
- lynx23 2y ago
  Orbit reader is the most low-quality device you can find on the market. This is like suggesting a bicycle to someone complaining about car prices.
  - krisoft 2y ago
    I’m sure the commenter meant well. You said “In Europe, a 40-cell braille display starts a 6k.” Which to me means that the most low quality, cheapest device starts at 6k. Now i learn from you that that low quality device is so bad that you consider it a separate product class in itself. Can you tell us more what does it lack? In other words what features are you looking for when you are looking for a 40-cell brail display? (What is the minimum quality for it to be a “car” in your analogy?)

Cthulhu_ 2y ago

I suspect a major difference is that those e-scooters, bikes, cars, etc are produced and sold by the millions, whereas wheelchairs are small volume by comparison. Another commenter mentioned the legal requirements, which complicates things. That said, a quick google says there's 65-132 million wheelchair users worldwide so it's not a small market either.

space_oddity 2y ago
...but the production and distribution of wheelchairs
nothercastle 2y ago
Most of them are probably in countries where 1000 is a years wages.

tim333 2y ago

It's impressive and a little sad how cheap you can get them second hand.

space_oddity 2y ago

I think a significant portion of the cost is related to the "medical device" label.