By: Dipin Gyawali
Background:
While working on this project, there was no intention of documenting the work. That’s why the document may be short on photos of the process involved at some places. The sole purpose of documenting the work now is that this can be a motivation for somebody out there who wants to help a person in need and also this is the first prosthetic hand distributed from Design Lab, Kathmandu University. Although several hands were previously made in the lab, they were distributed by Enable Nepal. The prosthetic hand distributed here is called “The Opsrey Hand” by Alderhand and e-Nable. The Opsrey hand is a mechanical prosthetic powered by the wrist. All the parts are 3D printed and are joined with the help of screws. Then the mechanical motion is provided with the wrist which is transferred by the thin string used in the hand. The filament used to print the hand is ABS (Acrylonitrile Butadiene Styrene) and PLA (Polylactic Acid).
Motivation:
It was the month of September in Kathmandu University and a normal day in the Design lab where I was working as a student researcher. Students from third year were printing some parts in the 3D printer for their academic project and then suddenly I remembered that back in my home there was a guy who lost his hand in an accident while using a machine. At that particular time, all I know was I had resources to make a hand and a person who might need it. The person is a 35-year-old male who lost his left hand in a motor-powered hay mower about five years ago. He lost all his fingers in that accident. His name is Ram Naresh Kunwar and is a permanent resident of Tilottama Municipality, Rupandehi. He now works with the support of his remaining arm. He works on a small poultry farm owned by him. I didn’t even know his name then although everybody used to call him Kancha. I used to see him sometime in the market. At that time I discussed this situation with one of my friends, Niarajan Ghimire, and got all the information about the measurements that I have to take from the patient hand. Then, I went to my home for Dashain vacation where I saw him again.
Step 1:
So, I went to his house at almost dawn and then called one of my friends named, Smrit Dhimal and asked him what dimensions to take for the development of a Prosthetic Hand. After that, I called my Sir, Pratisthit Lal Shrestha. Pratisthit Lal Shrestha is an Assistant Professor at the Department of Mechanical Engineering, Kathmandu University, and also the founder of Design Lab. He is an inspiration for any students in the university. Then, I told him the situation of the Patient and explained everything that I saw in the house. I also send him a photograph of the patient. He told me to take the required measurement and said “Yes, we will make something for him.” After that, I visited the patient and explained to him about the work that we do in the lab. He was pretty much interested in hearing me and was ready to give the measurement. While explaining to him, I made sure that I was not giving him too much hope because too much hope can also lead to dissatisfaction while seeing the product in real life. I explained clearly to him that it will be a simple mechanical hand which can be a little support to his daily life.
Figure 1 Image that I sent to my Professor
Step 2:
Then, after completing my vacation and earning some money as Dashain, I returned back to my University where we started working on the design selection process. Here, we refer to me, Raman Silwal and Nirajan Ghimire. After just one day of working on the design, we realize that creating something is not as easy as we thought. There are like zillionth factors that should be considered while building something new. But still, with high hope and a cup of tea, we started working on the Prosthetic hand. Working on something can teach us so many new things rather than just studying it. After working on a design with the measurements available, we finally came up with a hand. Then we printed a 3D version of it in the Lab. During this development phase, we also build a prosthetic simulator. Here, a prosthetic simulator refers to a standard prosthetic arm that explains the technology for testing and research of body-powered prosthetic function to empathize and understand the user. It basically explains the principal to the user.
Figure 2 Prosthetic simulator in Design Lab, KU.
Step 3
Even after printing the parts of hand in the 3D printer, it was just a beginning. The parts were still to be assembled and final aesthetic touch was to be given. Here, aesthetic touch is also very important since it influences how people think and feel. The assembling process was pretty difficult due to the lack of mechanical screws, leathers, and threads in the market. But still, with a lot of surveys, we found screws to fit the pieces we had. Later, leather and threads were also managed from different places in the city. And then, we assembled the parts into a final product in the lab and gave the final aesthetic touch to the product. The aesthetic touch totally changed how the product looked. It was now actually looking like a real hand. We even got the call from the “evil dead” movie team, asking us to use the hand in their next franchise. Nah, It’s just a joke but what I am trying to say is that the hands were looking pretty real.
Figure 3 Top and bottom View of the Prosthetic Hand
Step 4
During the process of making this hand, I used to frequently go to my home for some personal reasons. There was one time, when I met the patient on the way to the market, he was looking at me with hope in his eyes. Even though I explained to him that the hand is still on its way to be completed, I was wishing in my mind that I should have completed and brought it this time only. After some weeks, I again went to my home with the final assembled working hand. But this time, he was nowhere to be seen in the market area. So, I went to his house in the evening hour. Then, I fitted the hand with the help of my brother and talked for some time with him. And Finally, I returned home with a happy heart and a lot of satisfaction.
Problems Encountered
There were many problems encountered on the way to build these prosthetics. Lack of experience was also a major problem. I have to reach the person 3-4 times just to take the measurement that I had missed in my last meeting. The market of Nepal is so small and certain materials are unavailable in this market. In our case, the screws smaller than 4 mm were unavailable for us. So we have to drill the hole to make it bigger. Also, sometimes the printer used to malfunction in the middle of the printing process. Powercut used to add more problems in our printing process.
Conclusion
In the end, I want to thank each and everyone who helped me to make this project see the light of the day or in this case the palm of the user. Thanks to Nirajan Ghimire and Raman Silwal for making me believe that this is possible in the first place. A huge thanks to our professor, Pratisthit Lal Shrestha for helping me in each step of the development. I used to turn to him whenever I encounter any problem and he always had some solution for us, his guidance was a major help for us. Raman was also the same as he was also full of the solution to the technical problem that used to arise in the making process. Design Lab was a major help for me and it would not have been possible if it was not for the lab. All the materials required for the development of the prosthetics were made available by the lab. Design Lab is a perfect place for those innovative students in the university who want to explore their idea and turn them into reality. Finally, I want to thank Smrit Dhimal, Abishek Kafle, Prakash Bhattarai, Asim Gyawali, and Hrithik Chapagain for their help in some stage of the development. Last but not the least, I want to thank Mr. Jhalak Raj Adhikari. Although he does not has any role in the development of the prosthetics, he was present every time in the room when we were making this hand which is a major help for us.
Figure 4 Installation of Prosthetic arm