SnapCut, A Cutting Tool to Assist Users Who Have Limited Function of One of Their Hands (Georgia Institute of Technology)

Olivia Davis

ABSTRACT

Sometimes we take advantage of the ease and accessibility that comes with having two arms and two hands. We tend to design with the assumption that our users have complete function as well, but with research and I have found that we should start designing more with empathy and consideration of the 15% of the population that is living with disabilities.  I simplified the current task analysis that was associated with scissors to try and minimize the number of steps and eliminating the need for two hands. The goal in designing this project was to create something to help people who have lost control in one of their hands to be more efficient, productive, and have more control over their daily tasks. The SNAPCUT is a small device that aids the user in the process of opening small packaging, as in: sugar packets, ketchup packets, small chip bags, etc. using only one hand.

 

INTRODUCTION/BACKGROUND

I met a user that halted her search in new technologies because of all the advancements she was seeing in this field that dealt with people who had lost a leg. She felt that she was being left out and her interest in finding solutions that may be out there plummeted. After her accident, she acquired multiple tools throughout the years that

were helping her complete daily tasks. One that popped out to me was a cutting board that her husband had altered to help her have more control in the kitchen. It was a normal wood cutting board and he had flipped it over and drilled nails in it. He did it in two places of the board and when the board was right side up the nails were sticking out. The goal was for her to be able to stick fruits and vegetables on the cutting board and hold them in place while she cut. Another thing she mentioned to me was the portability of these tools. She yearned for tools that could be thrown in her purse that she could use outside of the comfort of her home. These basic tasks that come so easily for people with two arms can hold another persons’ life back. I feel that it is necessary to not only design innovatively, but to also consider the audiences we may be leaving out.

PROBLEM STATEMENT

When someone needs to open or cut something, what is the first thing that comes to their mind? Scissors? A knife? Now think about how they use these tools.One hand holds

the scissors or knife and the other holds the object. Now, consider how they would open this object using only one hand. Would they hold it with their feet, or hold one end with their teeth? My design goals included: designing a tool that would only need one hand while allowing the users to feel more confident and self-sufficient while eating out, simplify the amount of steps to complete the process, make the device easy to carry around, and universally designing this to meet different types of users likes, wants, and needs.

 

 

DESIGN AND DEVELOPMENT

Simulation was used heavily during the design process. I simulated only using one arm and trying to complete the tasks of going through a school dining hall. Carrying my tray, balancing food and drink items, getting my money out to pay, these were all made much more complicated. Then after making my way through a crowd, finding an empty table, and setting down my tray without spilling my food; my next challenge was opening my silverware package, the premade food container, and putting my straw in my drink. By the time I had finished setting up my meal to eat I was exhausted, frustrated, and had lost my appetite. It highlighted the challenges posed by tasks that are considered simple by those with both arms. I became inspired to design something that people who suffer from this disability could use and would improve their lifestyle.

My design started with “out of the box” ideas while I was brainstorming. Everything from add-on basket trays for prosthetics to portable, foldable rolling trays. Then I began to narrow the ideas and started developing a package opener. The opener resembled a scorpion in the fact that a sharp part would push down on the package to puncture it, but I wanted more than a punctured hole. I wanted it to slice also so that the components of the package would empty out easier. I also began thinking about how I really want to minimize the steps in the process of opening a package, and with this design it would require finding the device in a bag, putting it on the table, putting the package in the device’s mouth, pushing down and puncturing a hole, removing the package and emptying it, and then putting the device pack in its place. I began to think of the main tool that a one-armed person has, which is their one hand. If I could design to universally work with that one, very important hand and incorporate the other functions I may minimize steps and reach my goals.

 

Two common actions performed by the hand are pinching motions between the pointer finger and thumb, and the snapping motion of the middle finger and thumb. The human factors and ergonomic advantages of these natural motions were taken advantage of in the evolving concepts.

 

Figure 1. The Alligator Chomp

The first concept, the alligator chomp (Figure 1), consisted of a model constructed out of two thimbles connected by a piece of elastic. Covered in felt just to act as a cover material and a push pin that had been cut down. The goal was to use your pointer finger and thumb in the pinching motion to puncture the sugar packet.

 

Figure 2. The Snapping Turtle

The second concept, the snapping turtle (Figure 2), used the same materials except the push pin. Instead of the push pin a sharpened tracing wheel was used. The goal of this concept was to use the snapping motion with your pointer or middle finger and thumb to complete a slicing action. The slicing action required you to pick up the sugar packet, hold it between the wheel and the opposite thimble and with a snap, the edge of the packet would be cut off.

After testing these two concepts and receiving feedback, I decided that if I combined the two motions (snapping and chomping) that I would get the puncture I needed to break the packaging and the slice I wanted to make it a big enough hole for the package to be emptied completely.

 

Figure 3. Steps

Figure 3 outlines the steps of using the device. One put their thumb and finger into the device (the placement depends on the user), then the user picks up the sugar package, pushes the blade into the corner of the package, then with a snapping motion slices the corner of the packing off. This leaves a cut sugar packet ready to pour.

Materials

The final materials for the device were rubber, steel, magnets, and elastic. The prototype of the key chain holder was made out of high density foam and steel inserts to attract the magnets.
Since the wheel blade is sharp I needed a case for the device to be able to be carried around without accidentally injuring or cutting yourself. I designed a key chain case that holds the SNAPCUT  by magnetic force into the case and can be hooked on wherever. The magnets are strong enough to hold the light-weight device and allow a user to not have to open a lid or latch to get the device out.

 

 

 

 

 

 

USER PERFORMANCE

One of the people who tested the SNAPCUT was in her late 60’s and had lost her dominate arm only 12 years ago. She was still learning how to write again and completing tasks that used to come so easy for her. The device was introduced to her along with a cup of coffee and a few packets of sweetener. She then progressed with completing a list of tasks that had been assigned.

Figure 5. User Testing

After performing the outlined tasks, she answered a series of related questions and discussed how she felt about using the device. She enjoyed the keychain, as carrying her tools out of the house was an issue. She felt that it made her more productive, gave her more control, and required very few steps and energy. She also agreed that she could use it without written instructions and by looking at it the first time she expected it to do everything that it looked like it would do. Where we ran into trouble was grasping the packaging.

–Question: Do you feel that this device would take time to learn, meaning that you are more successful the longer you use it?

–Answer: Yes. This would take some learning, but as you see I’ve already figured out a way to pick it up and now I’m working on cutting it and pouring it into my cup. I’ve only been playing with it for 5 minutes.

After the questionnaire she continued to play with the SNAPCUT and ended up finding a comfortable way to pick up and use the device different from how I did. I continued to show her how I use it and did talk about how I have been playing with it for weeks. I did master picking up the device out of its case, then picking up the sugar packet, slicing and pouring into my cup, and then returning it to its case, but it took time.

Every user uses it a different way and that’s not a bad thing. The fact that I personally found it more successful using my middle finger and thumb was interesting when my user in this specific interview found it more comfortable to use her pointer finger and thumb. The SNAPCUT gives the user that flexibility to play with the product, find what works for them, and then adjust and learn the new tool.

COST

The SNAPCUT is inexpensive and was easily made. Two thimbles at the cost of $1.19 each. The rubber used for the cover was about $1.99 and the elastic used was $0.20. The magnetic ended to keep it in the case totaled less than $0.25. The total price of the final prototype came to about $4.82. The casing was cheap as well. The casing totaled less than $2.00.

MOVING FORWARD

The SNAPCUT has potential to reach a broad audience and enhance the daily lives of users with disabilities. I believe with improved materials and structure finalization this device would be very successful to long term and short term users of all ages. I am currently working towards a design that has a retractable blade. This would eliminate the case and help with safety concerns. To keep up with this product development and to see more about how I came to this design visit oliviagracedavis.com.

 

CONCLUSION

In conclusion, the SNAPCUT could potentially enhance the lives of users with this disability by allowing them to feel more confident and self-sufficient throughout their day.

ACKNOWLEDGEMENTS

I would like to thank my professor, Young Mi Choi for guidance and direction for this project and helping me think out of the box. I would also like to thank Judy Maddox who was excited to test the product and provided great, helpful feedback.

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