Challenge Throwdown
Invent-O-Doc
Posts: 768
I know there are some great people sitting on the sidelines, so I've got an idea for you. Hospitals and teaching centers everywhere routinely pay $80,000+ for a single manikin that does things like inflate lungs, produces a neck or wrist pulse that an examiner can feel and detect 'simulated' medications with RFID tags and place IVs, do airway stuff, etc. They will also make breath sounds and heart sounds.
Anyhow - Can somebody do all or even 1-2 of these things on the cheap to show it can be done inexpensively?
Manikin parts and skins are really cheap on ebay/amazon. We bough a head last month for nine bucks. I'm working with somebody on a book for how to build some of these things, but it wont be out until the contest closes. (Androids - Build your own lifelike robots (working title w/ B. Bergeron and I - McGraw Hill)
So, anybody up for the challenge?
Anyhow - Can somebody do all or even 1-2 of these things on the cheap to show it can be done inexpensively?
Manikin parts and skins are really cheap on ebay/amazon. We bough a head last month for nine bucks. I'm working with somebody on a book for how to build some of these things, but it wont be out until the contest closes. (Androids - Build your own lifelike robots (working title w/ B. Bergeron and I - McGraw Hill)
So, anybody up for the challenge?
Comments
By the way, were you thinking of a controller in each manikin, or an external controller that could be connected to different manikins, perhaps with different capabilities (EKG manikin, airway manikin, trauma manikin, etc)?
Also, let me know when I can buy a copy of your Android book!
Thanks!
Mike
As far as the book, I'm not really sure. It is Arduino focused but generalizable. I'm thinking of doing an LED book with prop1 and 2 next.
Two names come to mind immediately, Jonnymac and erco. Some their posts lead me to believe that would be right up their alley.
Frank.
This would be relatively simple to do actually.
Lungs, pulses and even the IV stuff should be somewhat simple to mechanically reproduce. The hardest thing would be trying to reproduce the skin.
Making breathing sounds would be easy to do as would heart sounds. (Linear actuators, fast acting solenoids and some creative stuff..)
I don't have the time to do it myself but this would be something simple to do with something like a prop driving it.
To do IV stuff you could use self sealing tubing of an appropriate size and hook that to the liquid pumper. This all could be controlled with a prop pretty easily since all you really want to do is control the speed and stroke length of these processes to represent simulations of the naturally occurring actions. The biggest problem as mentioned before would be the skin.. Which you could probably duplicate with some creative uses of Silicone.
http://www.smooth-on.com/Lifecasting/c1240/index.html
http://www.smooth-on.com/Special-Effects-an/c1241/index.html
So how much of this stuff would be needed to make an averaged sized torso with neck and head?
It would probably cost a bundle to make it solid, so you might want to learn how they do things with thinner layers of the realistic-looking stuff applied to cheaper materials. For proof of concept, you could always start with paper mache and then maybe overlay it with some rubber thingies you make for the externals. Down the road, you could make an entire army of rubber dummies that all look exactly like you, so you could end up becoming the model patient for the entire US Army. The possibilities are endless.
I am wondering if it would be possible to "mold" some lungs using this material and whether or not they would hold air if sealed using a valve type set up.
My personal experience with their products is limited to OOMOO, which is easy to make molds out of, but I don't think it would work to make fake lungs unless all you wanted was to make something rubbery look like lungs. Some of their other materials behave almost like skin but I don't know if they could be used as inflatables. I suppose much depends on what you want to do with it. Are you trying to simulate the actual volume and flow of air in lungs? the sound that lungs make when breathing? how lungs would appear on an X-ray? how lungs look to a surgeon when he or she opens up a patient? or what?
Edit: I think I am going to order some liquid latex and see how that works out. They make balloons from latex so I should be able to use enough so the "lungs" do not pop on me.
Okay, but why must the simulator have something that actually looks like lungs if they are going to be out of sight (or are they out of sight?)? What are the medical personnel experiencing from these lungs? Is it just the realistic rise and fall of the chest during breathing? Or are you trying to get actual air flow through the mouth, etc. that the medics can measure? Or is it to enhance the sound effects? The reason I'm asking is that I hate to see you go through all that trouble of making lungs if there's actually some other way to create the external effect you're looking for (of lungs). I'm guessing that getting this rubber material just right for your application is going to take a lot of trial and error, especially if you don't have previous experience with this sort of thing. I don't mean to discourage you - I'm just prodding you to think hard about what effect you're actually trying to achieve.
FF
As Frank Freedman noted, it would be useful to simulate a pleural effusion/hemothorax as one of the things I've noticed the current crop of medical students forget about is percussion of the chest. Pneumothorax simulations would also be a good thing to do. Simulating breath sounds might have to be done with with recorded sounds as I can't think of a simple way to emulate the fine basilar crepitations of CHF; another example of where med students make mistakes in assuming CHF when the problem might be interstitial lung disease. Having a realistic appearance of the jugular venous pulse (JVP) would be very helpful as this allows one to clinically diagnose CHF, volume overload/hypovolemia, tricuspid regurgitation, pericardial effusion as well as atrial fibrillation. Whether or not a lung/heart mechanical system would behave the same way as idealized human physiology is a good question. Whatever one does would have to be inexpensive as medical students/interns will be hard on whatever model one uses. It would have been nice to have a realistic simulator when I trained but all we had were live patients.
In the real world of medicine now, however, using physical signs to diagnose medical conditions is becoming a lost art. The medical students I see coming through the hospital now seem to think that the first thing one does is order a CT scan or an echocardiogram and are often lost when I tell them that they're supposed to do a physical examination of the patient and tell me what's going on. One useful aspect of a mannequin would be to have RF transmission of simulated EKG's from the mannequin to an EKG machine along with mechanical reproduction of the simulated electrical activity.
The other thing to remember, if one is using this mannequin in realistic simulations, is ABC for airway, breathing and circulation. The number 1 priority is to ensure patency of the airway, then deal with breathing and finally circulation. It would be easy to have inflatable balloons in the mannequin neck to compress the airway and the oropharyngeal anatomy should be that of the nightmarish patient for doing intubations. Of course, such difficult intubations are now done by use of fiber optic scopes to help guide one whereas we had to go blind during my internship when a larygoscope didn't help elucidate the anatomy. I don't know how well equipped the US army medics are but I'd be very surprised if they are working at the level of 23 years ago when I did my internship. OTOH, being out in the field one needs these basic skills.
Question, what are the devices called that are used in air mattresses and such that allow air in but not out?
Are you talking about check valves?
That's it!!! Thank you.
As far as lungs go in high end commercial manikins - it works two ways:
1) There is usually a plastic trachea tube and bifurcation going to two rubber balloons. The balloons work well with positive pressure ventilation like ambu-bags, mouth to mouth or ventilator machines. I'm sure there is a pressure sensor. Also, they are good because blowin them up raises the chest. There is also usually a stomach balloon in case a placed breathing tube is in the wrong hole you can see tummy rise instead of chest rise.
2) When the manikins appear to breathe on their own, they dont use the balloons, usually there is something motorized that lifts the chest at the center of the ribcage. Breath sounds are usually generated by speakers under the skin.
http://www.tascmet.ca/
Didn't realize how realistic one could get with silicone stick-ons (this is on live volunteers). The good quality training manequins that he's familiar with in Canada are in the $125 K range so there's a huge incentive to come up with something much cheaper.
One of the key points I got from him was that any device used in the field should be "soldier proof"; ie quite rugged. How much does the packaging of the device count in this contest? Is a proof of concept good enough, or does one get extra points for coming up with a "soldier proof" package?
American Science and surplus in Chicago has this respirator pumps I looked at them a million times but couldnt put a project to it
This would be perfect for filling simulated lungs.
I bet it cost 2 k to build this and u can have it all for $24.50 it has a 6 inch piston some type of servo or stepper motor and encoder.
http://www.sciplus.com/p/TAKEOUT-RESPIRATOR-PUMP-PARTS_50699