Background

A tremor is a non-intentional rhythmic movement of a body part (Alvarez 2019). It is estimated that nearly 7 million people in the United States suffer from some kind of Essential Tremor (ET), which creates a population of approximately 7 million people with a condition that disturbs them from common function (Louis 2014). One such person suffers from an elbow tremor, so during meal times, a specialized utensil called a Liftware spoon is necessary for food intake without spilling when a tremor arises. The problem with the spoon is its short handle, stopping the user from utilizing the spoon to its full potential because of limited gyro usage. The user is holding onto the gyro portion of the spoon, stopping the gyro from working. The short handle of the spoon causes discomfort for the user when trying to use the spoon, so the user holds the spoon farther down and nearer to the gyro, causing the problems that are seen here. This project will require a lot of interaction between the team and the client, as this is a highly personalized device that is meant to principally help one person. This device would allow the client to comfortably use their Liftware spoon without coming into contact with the gyro.

Engineering Goal

The aim of this project is to engineer and deliver an adaptive device that will allow a woman with tremors to eat independently. The adaptive device will be an add-on to the already existing Liftware spoon, which is a spoon designed for people with tremors. The add-on should prevent the user from grabbing onto the gyro of the Liftware spoon and should also extend the handle of the spoon without affecting the usability of the spoon.

Competitor Analysis

The existing products on the market in order to enable people suffering from tremors to eat normally without the help of another person are mostly Liftware products. The Liftware spoons allow for up to 70% less movement when a user suffers from a tremor, which greatly decreases the amount of food that can be spilled. This device works by charging during the time a user is not eating, then electronically balancing the spoon with a gyro.

The first spoon to note is the Liftware Steady spoon. The handle is quite small, meaning people with bigger hands may have trouble holding the spoon without limiting its range of motion, such as the client in question. This is the spoon the client uses, so it will be important to continue examining this device later. The entire kit for this spoon costs $195, which translates to 17¢ per meal for a whole year, then the kit is completely paid off (Liftware 2019). This pricing seems reasonable for a product that is used two to three times a day. The problems with this device are the size of the handle and the inability to add more features to it, which can limit to what extent a client can use it. The biggest problem is most likely handle size, as seen through the client for this project, who touches the gyro due to the short grip. The introduction of the handle lengthening and gyro protecting device will allow for a more customizable spoon as well as a more comfortable grip on the spoon.

The next device is the BUNMO Adaptive Utensil, which takes the form of knives, spoons, and forks. This utensil is a lot more adaptable than the Liftware spoon because of its possibility to come in different style of utensil. These can be washed in the dishwasher, which is a nice addition to include in the product. This product isn’t packaged as well as the Liftware spoon, but it does give a more complete set. The downsides of this set are that they may be too light for users, so easier to drop because of tremors (BunMo 2007). The handle is much longer on these than on the Liftware spoons, so client feedback does not include problems with holding the utensil. The introduction of our device on this would be less meaningful than on the Liftware spoon because of the presence of an already functional and usable handle. One big advantage with this set is the price, as the whole set costs $25, which is much less than the Liftware spoons.

The third researched market product is the Liftware Level Starter Kit, which is similar to the first Liftware product but instead has a very long grip. This spoon is meant to accommodate for people that may suffer from movement deficiencies, such as cerebral palsy (Liftware 2020). This spoon’s goal is not only to deal with tremors, so having a person who suffers from only tremors use this can cause a decrease in confidence. The advantages of this spoon are that it does offer an extended grip with the same balancing effect as the Liftware Steady kit, but it can give the impression that a user suffers from a disability they do not have. This can cause a blow to confidence for the client, so using the Liftware Steady kit would be a better option. This also costs $195, just like the first Liftware spoon, so it an investment. The prototype being designed would not make sense to use on this because of the already elongated handle, and the client wants a product specifically made for a Liftware Steady kit. The device being designed will take this idea and merge it with the ability to come on and off, as well as protect the gyro.

STEM2_J1_Final_Reqs.pdf
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Supplies

3D-printed Liftware Spoon substitute (for testing)
3D-printed Adaptation device with attachment screws
Sand (for testing)

Cost Estimates

The target cost for the production and testing of the adaptation product was no more than $50. The cost of the final device was estimated to be up to $20 in total, which is much more cost-efficient than the Liftware spoon and attachments.

Step 1: Build Process

Design Objective

Although the customer had a preference for a device that did not require CAD or 3D-printing, due to the circumstances of COVID-19 and given the resources available it made more sense to pursue a design that relied on CAD files that could be shared remotely and later 3D-printed. A Liftware spoon was also not available to be used during testing, so a benefit of the computer design was the ability to create a spoon using CAD to be substituted for the Liftware.

Procedure

The prototype that was decided upon was created with CAD using SolidWorks, according to initial design sketches based on the criteria indicated by the customer.
A substitute had to also be designed using CAD, due to the lack of access to a Liftware spoon.
The prototype and provisional spoon were then 3D-printed for physical evaluation and testing.
During the first evaluation, it was determined that the size of the initial prototype needed to be reduced, so there was a final reprint of a 70%-sized adaptation device and an original-sized Liftware substitute.

Step 2: Usage

Test Purpose

The test was designed to determine the functionality of the device and ensure that the requirements were meant. The testing was completed in two rounds. One round determined the usability of the device with both left and right hands. The second determined the effectiveness of the spoon while the device was attached. Because we were unable to have test subjects with arm tremors due to the current circumstances, our test subject was to simulate hand and arm tremors consistently and to the best of his ability.

Methodology

Because a Liftware device was not accessible at the time of testing, an alternative spoon had to be designed using CAD and was 3D-printed to simulate the shape and size of the Liftware Spoon.
The printed device was given to a test subject who did not know the weight of each criterion, to ensure impartial testing. The user then attached the adaptation device to the provisional spoon as they would with a Liftware.
To test the criteria, the user filled the spoon with 5g of sand and simulated both left- and right-handed eating with tremors by shaking their hand and arm while carrying food. The amount of sand that fell from the spoon during each trial was recorded. The average amount of sand lost was used to determine the effectiveness of the device.

Usage Results and Conclusion

The handle prototype was able to successfully allow full usage of the Liftware spoon without compromising its assistive capabilities. It was able to be as comfortable to use as the normal Liftware handle because of the finger holes on the grip and was able to successfully tighten around the Liftware spoon when the attachment screws were used and prevented the user from touching the gyro. It could be predicted that the amount of food spilled during a tremor with the provisional spoon would be greater than when used with a real Liftware device. The sand spilled while using the adaptation device was essentially the same as when the device was not used, so the adaptation was shown to not negatively affect the integrity of the Liftware device.

Step 3: Improvements and Extensions

Prototype #1 - Evaluated 05/09/20

The grip was comfortable and the print as a whole was large enough to fully envelop the spoon. However, there was too much room for the spoon to move around when it was in the device, so the size was reduced by 30% in Fusion 360. The attachment screws had to be smaller, as a result, so the correct size was identified.

Prototype #2 - Evaluated 05/17/20

With the reduced size, the grip size of the handle remained appropriate, while the spoon fit more snugly within the device, without being too small. The Liftware substitute was able to be held in the device in a way that prevented the user from touching the area where the gyro would be on an actual Liftware spoon.

Extensions

In the future, it would be beneficial to test the device with a real Liftware spoon, rather than the substitute that was used due to issues with accessibility. It would also be helpful to receive input from the client after the device was created and printed, rather than solely during the design process, in order to better refine it to suit their particular needs.

Step 4: Resources and References

Alvarez, N. (2019, June 28). Familial and Essential Tremors: Causes of Hand, Muscle & Body Tremors. Retrieved from https://www.emedicinehealth.com/tremors/article_e...

BunMo Adaptive Utensils. (2007). Retrieved from https://bunmo.com/product/bunmo-adaptive- utensils/

Liftware. (2019). Liftware Steady Starter Kit. Retrieved from https://bunmo.com/product/bunmo-adaptive- kit?variant=34761630471¤cy&gclid=Cj0KCQiA4sjyBRC5ARIsAEHsELGzoZCsZ4NnAvK9e8jx7dN3EA Rlca34fKY1oQrQUvLJJFnzEF5uso4aAuT3EALw_wcB

Louis, E. D., & Ottman, R. (2014, August 14). How many people in the USA have essential tremor? Deriving a population estimate based on epidemiological data. Retrieved from https://bunmo.com/product/bunmo-adaptive-