Suspension design for medical stretcher

[Varadha]

Hello guys. I've planned to do my project on mechanising stretcher so as to minimise the injuries caused in handling casualties/traumatic patients on stretcher. My intuition was that if we could make a suspension/vibration damping mechanism along with special retractable compartments for holding the person's head, it would be better. Will it work better if I attach a kind of automobile suspension mechanisms on the vertical bars above the stretcher carrier wheels?

Please guide me friends.

 

[Mech_Engineer]

Are patients being injured by stretchers right now? What kind of terrain are we talking about? How will a suspension help, when balanced with the fact that it may make it more difficult for the doctors and nurses to provide care (especially CPR)?

 

[berkeman]

Hello guys. I've planned to do my project on mechanising stretcher so as to minimise the injuries caused in handling casualties/traumatic patients on stretcher. My intuition was that if we could make a suspension/vibration damping mechanism along with special retractable compartments for holding the person's head, it would be better. Will it work better if I attach a kind of automobile suspension mechanisms on the vertical bars above the stretcher carrier wheels?

Please guide me friends.

Are you referring to the gurney, or to a stretcher, or to a backboard? They are very different things. Can you post a link to the current design that you are wanting to modify?

And as M_E asked, do you have evidence of some type of injuries that currently occur that you want to mitigate with your design changes?

 

[etudiant]

Afaik, the riskiest part of using a stretcher for the patient is the getting on it in the first place.
If there are broken bones, shifting the patient can really exacerbate the problem. Paramedics learn to work together to minimize the displacement, but it is still a fraught procedure (just think of getting put on a stretcher with a broken vertebra).
Perhaps you could find a way to immobilize the patient in some sort of a protective cocoon instead?

 

[Varadha]

Are patients being injured by stretchers right now? What kind of terrain are we talking about? How will a suspension help, when balanced with the fact that it may make it more difficult for the doctors and nurses to provide care (especially CPR)?

Yes. I don't know much about what the westerners are up to, but here in India, most casualties(especially road accident victims) suffer very much in getting manhandled and transportation. And when I visited a few orthopaedic patients in a hospital, most of them told me that they couldn't bear the pain when they are shifted from bed to stretchers and transported to different blocks of the hospital, especially they found it really hard to cope up with setting up themselves for x-ray. So, I decided to work on it.


And yes, talking of CPR and other kind of stuff, we have planned for a ratchet mechanism to let the suspension system off the stretcher, or I have to think of any other means to lock the suspension off temporarily and releasing it while transportation. But I am still confused to take up the project, as you suggested it might worsen the patients unless we have proper damping and all that stuff.

 

[Varadha]

Thank you!

Are you referring to the gurney, or to a stretcher, or to a backboard? They are very different things. Can you post a link to the current design that you are wanting to modify?

And as M_E asked, do you have evidence of some type of injuries that currently occur that you want to mitigate with your design changes?

Yes. Cerebral bone injuries and spinal cord injuries go worse when the victim is shifted to the stretcher soon after the casualty. I want to work on the stretcher itself so that I could get the patient a little more cozy into the stretcher and also while transportation on ramps and inside the ambulance during transport.

In any developing country they still use a basic mechanical design on most hospitals and ambulance with average monitory funds. Kind of similar to this:

 

[berkeman]

The standard protocol here in the US is for all spine injury patients to be immobilized on a long backboard first, and then they are placed on the gurney for transport. They stay on the backboard until their spinal injuries are addressed (they go to x-ray on the backboard when they get to the hospital).

Are the protocols different in India?

 

[etudiant]

Question is how is it determined that spinal injuries are a concern.
In civil defense training, there was emphasis on only shifting the patient with care for possible spinal injuries.
I have no idea how emergency services in India are trained or how traffic accidents are treated, but manhandling the patient from stretcher to gurney seems worth avoiding.
Is there a simpler/cheaper way to achieve the same goal with procedural changes?

 

[Varadha]

The standard protocol here in the US is for all spine injury patients to be immobilized on a long backboard first, and then they are placed on the gurney for transport. They stay on the backboard until their spinal injuries are addressed (they go to x-ray on the backboard when they get to the hospital).

Are the protocols different in India?

Kind of. But I don't think getting them into backboard is cozy. Also I have to think of the possibilities of worsening the injuries inside the ambulance itself during travel; I suppose you know the road conditions of most of the places in India. A little comfortable gurneys are available only in certain sophisticated hospitals.

Recently one of my friend suffered multiple injuries on his legs and he felt really distressed when they transported him to the x-ray department which is in another block. The hospital had ramps and lifts but yet he said unbearable pain persisted for 2,3 days after such transportation. It was really worse than his physio and recovery treatment. This infact motivated me to do a research on the gurneys.

 

[Varadha]

Question is how is it determined that spinal injuries are a concern.
In civil defense training, there was emphasis on only shifting the patient with care for possible spinal injuries.
I have no idea how emergency services in India are trained or how traffic accidents are treated, but manhandling the patient from stretcher to gurney seems worth avoiding.
Is there a simpler/cheaper way to achieve the same goal with procedural changes?

I have to think of it. I had been thinking. And I would be happy if I could get some guidance from experienced persons.

 

[etudiant]

The civil defense training was rudimentary and the focus was on having at least 3 people help shift the patient, so that there was minimal flexing of the body, with the aim being to avoid possible spinal cord damage.
In traffic accidents, where the victim(s) may be pinned by the wreckage, that may not be possible. There are tools to cut out the interfering debris, but these may not be widely used in India. So there will be some manhandling involved.
The idea of making the ambulance trip less excruciating is an excellent one. Would something as simple as an air mattress under the stretcher be of any use?

 

[berkeman]

Kind of. But I don't think getting them into backboard is cozy. Also I have to think of the possibilities of worsening the injuries inside the ambulance itself during travel; I suppose you know the road conditions of most of the places in India. A little comfortable gurneys are available only in certain sophisticated hospitals.

Recently one of my friend suffered multiple injuries on his legs and he felt really distressed when they transported him to the x-ray department which is in another block. The hospital had ramps and lifts but yet he said unbearable pain persisted for 2,3 days after such transportation. It was really worse than his physio and recovery treatment. This infact motivated me to do a research on the gurneys.

The backboard is not meant to be cozy -- it is meant to immobilize the spine and prevent further injury due to movement of the patient. I can verify that it is definitely not comfortable -- I have been backboarded many times during EMT training.

For extremity fractures, splinting is key for preventing further injuries and for mitigating the pain the patient feels. Check out "inflatable splint", "air splint", and "mast device" for ideas for better field spliting protocols...

 

[Varadha]

Thanks etudiant and berkeman for all your support. Now I get a good idea of what I'm supposed to start with. I should think of a cheap and reliable backboard made from a reinforced fibre/flexible fabric material with air splints as the basic reconfiguration process with some focus on damping the gurney off unwanted vibrations which should be operable while transport.

Do tell me if you felt any further attachments could really mitigate the pain due to injury. Thank you both.

 

[etudiant]

Just to complicate your life a little, stretchers and backboards can get pretty gross when loaded with injured people. The design must allow for easy cleaning.
Also, there has to be a rigid strength member, so the patient does not get dropped because someone held the stretcher the wrong way and the device folds or twists.
In any case, your trinity of virtues is on the money: cheap, reliable and more comfortable/cushioned.
Good luck and please keep us posted on your progress.

 

[berkeman]

Just to complicate your life a little, stretchers and backboards can get pretty gross when loaded with injured people.

Roger that. The nurses usually leave them for us to clean up ourselves before we load them back up and head out.

 

[Varadha]

hmm.. Yeah. It's a good idea to make it fail proof and patient/handler-friendly.. I should work on it..

 

[etudiant]

One last point, please keep in mind that people are getting fatter.
US airlines used to use 170 pounds for the passenger weight, now they are at 200. Wheelchairs for 300 pound users are not uncommon. My guess is that you should factor in a 300 pound user in your design.