Week 6: The Foot Scanner!

Hello again! This week was a bit different than previous weeks in that I worked less with the prosthetics and orthotics and essentially set up a new scanning system that will send the foot scans directly to an outside fabrication center that will create the foot orthotic for us. The medical equipment that we acquired needed some adjustments for it to fit the scanner and hold it for storage. This was my job for the day. I ended up spending hours taking apart the stand and modifying it so that it fit the scanner and would hold the scanner safely in transport. For the image below I essentially had to take apart everything below the monitor, pulling apart the electrical system then moving it away from the storage compartments (locking mechanism). I removed some of the shelving and the keyboard stand as neither was necessary for what we were using it for. I also had a new problem of metal support that go in the way (also no longer necessary because the storage was removed). I ended up having to take the whole section out and saw off parts, finally laying a sticky fabric so the scanner does not slide and 2 sets up straps to hold it down.

When finished with all of the setup, all of the staff came together and had an informational seminar/call with the makers of the scanner and the system to explain exactly how to work the system properly. Of course as the intern, I was chosen as the initial test subject. The scanner itself looks somewhat similar to the one below. After having my feet scanned we went through the whole process of designating the specific type of orthotics to be made.

Earlier in the week, not too much happened as one of the clinicians was down in Mexico working at a clinic. These types of clinics rely heavily on the unpaid volunteering of American clinicians to fit over 40 patients in only a few days. Without such specialized service work it would be almost impossible for patients in the poorest parts of Mexico to receive such prosthetics. 

We have been having trouble with getting the software for the 3D scanner to work on the computers in the office. Next week we are going to try re-downloading the programs to finally get that scanner working. That will be exciting because I will most likely be tasked with getting that working. 

Week 5: This Week's Experience

Hello once again!

This week was very hectic as I got my first chance to actually work on some orthotics and prosthetics. I made my first pair of sports orthotics from hardened plastic. First, I used the cast of the foot taken from the prior consultation holstering it to a post. Using the oven, you first heat the plastic so that is pliable. The plastic heated to 400 F is then draped over the molded foot, you must quickly tighten the plastic before it re-hardens to make a tight hold. You then blow air through to both cool and keep the plastic off of the mold. Finally you must cut it off of the mold with a type of saw that vibrates at a very high frequency. This cut out is then ground down until it is smoothed out and comfortable to be used as an insole. This particular insole also had a hole in the heel to provide relief so it was a little bit more complicated than the average one.

I was also allowed to work on one of the prosthetic sockets filling the socket with alginate first which provides a highly detailed copy of the original socket. Alginate is a type of gelatinous fluid that hardens in air after being in contact with water. It is often used in Hollywood masks because of the highly detailed copy that it can make. Even as the alginate has cured it is not really too hard, and is easily used to make another cast which we then manipulated. The main reason we did this was to have a copy of the previous hard plastic socket so that we could make a carbon fiber more permanent version. Because the sockets change size constantly it is easier initially to use plastic as the socket material then shift to the carbon fiber after several plastic sockets.

Overall it was a very eventful week! I learned from my mistakes and although it took me two attempts to properly lay the plastic on the molds, I was successful in making a pair of sports orthotics! Despite that I have seen some of the same patients as they have come in for new adjustments because of pain which limits their movement and then leave able to walk again with such minor adjustments.

I will see you next week! 

Week 4: Where Can Prosthetics Go??

Hello again!

For this post I hope to discuss the direction prosthetics are moving towards in the future.

Let’s begin with lower limb amputees. At McCleve, I learned of a new innovative operation not currently available within the United States but offered elsewhere known as direct skeletal fixation. This operation fuses a metal rod into the remaining bone fixing it in place as an elongation to replace the missing bone. The procedure allows for more realistic control and feeling of the leg as the prosthetic does not require a suction device to hold it in place. This type of procedure is only in research settings currently in the United States but can be done elsewhere. One such patient flew from the United States to Australia to undergo this operation. While increasing the chances of infection with such a foreign body, the benefits of a successful operation are well beyond that of conventional prosthetics. Another recent innovation in prosthetics comes with the Power Knee which allows patients to use stairs, having a more functional knee. Such a device has its limitations as it is quite bulky but can have such a huge impact allowing users to ascend and descend stairs which normal prosthetics are unable to do. 

The above images show both the X-ray view and the view post operation of the direct skeletal fixation procedure.

I had the opportunity to meet with an Ossur representative, one of the leading companies in prosthetic parts from silicon sleeves to power knees, learning about this new device. In addition I was also shown a new type of prosthetic foot which has a split toe to provide more range of motion and increased balance. Such a small change can have a huge impact on the functionality of the limb. In general, the industry is slowly improving, year after year increasing strength and movement of the device while decreasing the overall weight. 

One very new research project has been able to create a prosthetic leg that is controlled by neural impulses communicating with the leg’s computer. Rather than the myoelectric signals that are currently used in the iLimb device (in upper extremities) this type of leg relies solely on the nerve signals. Another kind of similar cutting-edge form of prosthetic comes in the form of targeted muscle reinnervation (TMR) surgery. By redirecting the amputated nerves elsewhere in the body with functional nerves one can allow the user to control the prosthetic with the activity readings of the redirected nerve. Because the nerve is intact the use of the nerve will cause the movement. Although only research stages such operations and devices could revolutionize the capabilities of prosthetic devices.

Above is an image of prosthetic leg controlled by neural impulses and what nerves it focuses on.

Until next week! 

Sebastien Gilmour 

Images retrieved from: 

http://www.amputeeimplantdevices.com/wp-content/uploads/2014/12/Standing-xray1-e1418430132653.jpg

https://blesma.org/media/231277/IMG_5343.jpg

http://www.proklinik.com.tr/en/prosthetics/lower-extremity/microprocessor-knees/power-knee/

http://www.wired.com/2013/10/is-this-brain-controlled-bionic-leg-the-future-of-prosthetics/