5 ms·

Prosthetic Limb Restores a Sense of Body Position

46 points by oblib 8y ago

whymauri 8y ago
Very excited to see this posted here. I was an undergraduate research assistant at this lab working on related projects on this team. It's amazing what the AMI (regenerative antagonist-agonist myoneural interface) can do and I assisted with a follow-up project to expand the use-cases of this surgical architecture (currently under review). Solving the proprioception problem is big news as even people like our PI, Hugh, who have had prosthetics for decades have to mentally calculate movements that are natural for un-injured people. It's incredibly tiring and I think we will be seeing a drastic improvement in the quality-of-life of people with prosthetic devices. A year ago, I even met someone who had a foot but due to chronic pain wanted it amputated and was exploring the AMI. That is, they would prefer a bionic solution with the sort of neuro-integration the AMI can offer over an actual foot! I think that hits the core of our group's vision, which is not just rehabilitation but recovery beyond standard human capacities. This is inspired by how Hugh was able to rock-climb better post-amputation than before, a concept he often calls 'Human 2.0'
kevinmchugh 8y ago
This is fascinating. I recently read up on phantom limb syndrome and found one of the most horrifying ideas I've ever seen. Wikipedia summarizes: > Until recently, the dominant hypothesis for the cause of phantom limbs was irritation in the severed nerve endings [...] These nerve endings can become inflamed, and were thought to send anomalous signals to the brain [...] Treatments based on this hypothesis were generally failures. In extreme cases, surgeons would perform a second amputation, shortening the stump, with the hope of removing the inflamed nerve endings and causing temporary relief from the phantom pain. But instead, the patients' phantom pains increased, and many were left with the sensation of both the original phantom limb, as well as a new phantom stump, with a pain all its own.[0] It will be interesting to see if this treatment can stop phantom limb pain. One hypothesis is that pain is the result of the brain modifying to accomodate a lack of signals from the severed limb. If this treatment prevents pain, that would be a good indicator for that hypothesis. [0] https://en.wikipedia.org/wiki/Phantom_limb#Mechanism https://en.wikipedia.org/wiki/Phantom_limb#Mechanism
- oblib 8y ago
  I worked with amputees for around 14 years back in the 70-80s and was kind of shocked when I first heard about phantom limb syndrome. I'd just never imagined such a thing before then. It's not just "pain", but really annoying "itches" and other sensations too. People with above the knee amputations would tell me their "foot was itching". One of the biggest issues back that was weight gain/loss. Just a few pounds would change how the the limb fit and since they were held in place in large part via suction (vacuum) when it didn't fit right it could be somewhat painful and at the least very annoying when they got loose or too tight. I spent many hours helping amputees apply and sand "bondo" inside their "leg" where it attached to their "stump" to get them to fit comfortably. It's been close to 30 years now since I've worked on those and I've not kept up on what's changed. I imagine there have been improvements. I sure hope so.
skybrian 8y ago
It looks like this might be the paper: https://www.media.mit.edu/publications/proprioception-from-a-neurally-controlled-lower-extremity-prosthesis/ https://www.media.mit.edu/publications/proprioception-from-a...

46 points by oblib 8y ago

Very excited to see this posted here. I was an undergraduate research assistant at this lab working on related projects on this team. It's amazing what the AMI (regenerative antagonist-agonist myoneural interface) can do and I assisted with a follow-up project to expand the use-cases of this surgical architecture (currently under review). Solving the proprioception problem is big news as even people like our PI, Hugh, who have had prosthetics for decades have to mentally calculate movements that are natural for un-injured people. It's incredibly tiring and I think we will be seeing a drastic improvement in the quality-of-life of people with prosthetic devices. A year ago, I even met someone who had a foot but due to chronic pain wanted it amputated and was exploring the AMI. That is, they would prefer a bionic solution with the sort of neuro-integration the AMI can offer over an actual foot! I think that hits the core of our group's vision, which is not just rehabilitation but recovery beyond standard human capacities. This is inspired by how Hugh was able to rock-climb better post-amputation than before, a concept he often calls 'Human 2.0'

kevinmchugh 8y ago

This is fascinating. I recently read up on phantom limb syndrome and found one of the most horrifying ideas I've ever seen. Wikipedia summarizes: > Until recently, the dominant hypothesis for the cause of phantom limbs was irritation in the severed nerve endings [...] These nerve endings can become inflamed, and were thought to send anomalous signals to the brain [...] Treatments based on this hypothesis were generally failures. In extreme cases, surgeons would perform a second amputation, shortening the stump, with the hope of removing the inflamed nerve endings and causing temporary relief from the phantom pain. But instead, the patients' phantom pains increased, and many were left with the sensation of both the original phantom limb, as well as a new phantom stump, with a pain all its own.[0] It will be interesting to see if this treatment can stop phantom limb pain. One hypothesis is that pain is the result of the brain modifying to accomodate a lack of signals from the severed limb. If this treatment prevents pain, that would be a good indicator for that hypothesis. [0] https://en.wikipedia.org/wiki/Phantom_limb#Mechanism https://en.wikipedia.org/wiki/Phantom_limb#Mechanism

oblib 8y ago
I worked with amputees for around 14 years back in the 70-80s and was kind of shocked when I first heard about phantom limb syndrome. I'd just never imagined such a thing before then. It's not just "pain", but really annoying "itches" and other sensations too. People with above the knee amputations would tell me their "foot was itching". One of the biggest issues back that was weight gain/loss. Just a few pounds would change how the the limb fit and since they were held in place in large part via suction (vacuum) when it didn't fit right it could be somewhat painful and at the least very annoying when they got loose or too tight. I spent many hours helping amputees apply and sand "bondo" inside their "leg" where it attached to their "stump" to get them to fit comfortably. It's been close to 30 years now since I've worked on those and I've not kept up on what's changed. I imagine there have been improvements. I sure hope so.

skybrian 8y ago

It looks like this might be the paper: https://www.media.mit.edu/publications/proprioception-from-a-neurally-controlled-lower-extremity-prosthesis/ https://www.media.mit.edu/publications/proprioception-from-a...