HCDE 451: Analog 3D Model Process Blog

Kenny Le
5 min readOct 19, 2020

The joint pressure sleeve is a wearable IOT device aimed at users who have injured muscles or joints through the overuse of them. Wearing the sleeve let users know when they are exerting too much pressure on their injured muscles so that they don’t re-aggravate their injury.


As I walked through Seward Park while talking to my swim coaches about possible ideas for a wearable IOT device, it felt like all of my ideas were not super feasible. Originally, I wanted to create an IOT device for swimmers (hence me talking to my swim coaches), but that idea was quickly scrapped once my coach asked if I was trying to recreate the Fitbit. My other coach was quick to say that no idea was an original idea, but rather just iterations on already existing designs (this might sound familiar to HCDE folks as he was a HCDE major who graduated in 2017). What my coach said really resonated with me and dispelled any notions that I had to come up with a revolutionary new idea.

Later that night, I was having a hard time understanding why my knee was still hurting when I injured it well over six months ago. It was then that the idea for my analog 3D model came to fruition. I wanted to design a device that could measure how much pressure a person was putting on an injured muscle/joint so that the device can let them know if what they are doing would cause them to re-injure their muscle/joint.

Sketching Designs

Before I could create a physical prototype of my idea, I wanted to sketch out some ideas of what the sleeve could look like. I tried not to spend too much time in the sketching phase as one thing that was emphasized early on in was to avoid perfection-ism.

A high level overview of my sleeve idea

Building the Prototype

After weeks of saving up cardboard boxes from Amazon and finding a pair of worn out jeans, I was ready to build my prototype. I decided to cut out one of the legs on the pair of jeans to use as the part because I realized that I didn’t necessarily need to build everything from scratch. If there was something that functionally already existed as a sleeve, I would avoid reinventing the wheel by utilizing one of jean’s legs in my prototype.

The sleeve prototype primarily consisted a pair of jeans, cardboard, and a lot of tape

The next part of the sleeve that I had to build was the support brackets on both sides of the sleeve since injury rehabilitation is a main component of injury prevention as well. Cardboard was the best choice for the low fidelity prototype because it was easy to form it into brackets but was also structurally sound enough to be physically used.

Pieces of cardboard and toothpicks were used to create bendable brackets

Part of the idea for my device was reading how much pressure each muscle was using. In order to integrate that functionality, sensors would have to be placed inside of the sleeve. Since I focused my prototype for the knee and its surrounding area, I used a placed pieces of green tape on the outside of the sleeve where the corresponding muscles would be. Using that as a guide, I then placed the appropriate sensors (brown tape) on the inside of the sleeve.

Green tape was used to mark key muscle locations for the knee and corresponding sensors (brown tape) was placed on the inside

Once everything was in place, I assembled all the pieces together with copious amounts of tape to make sure everything stayed in place.

The assembled joint pressure sleeve

User Testing Prototype

Living in quarantine meant that my ability to find people to test my prototype was very limited. Luckily, I’ve been quarantined with my brother so I would have someone to test my prototype.

At a first glance, my brother noted how intuitive it was to use; it was pretty clear to him that he had to slip it on one of his joint/muscle areas. Once it was on, he was surprised by how physically functional the prototype was — not having a restricted range of motion once it was on.

However, one area that he ran into trouble with the prototype was its fixed sizing. Because I used a pair of jeans and the pair of jeans happened to fit over my knee, I didn’t think of making the size adjustable to people with different body sizes.

Analysis and Reflection

After receiving feedback from user testing and an in-class critique section, I realized that while I had successfully created a physical manifestation of my design idea, my thought process and selection of some materials could be improved. Many people applauded my choice in using a pair of jeans for the main sleeve as it was comfortable and functional, yet a draw back of that would be its non-adjustable sizing.

Going forward, the next iteration of the joint pressure sleeve would most likely keep the same jean material for the main sleeve but would incorporate straps of some kind so that it could be used by a variety of people. In addition, I would look to replace the cardboard brackets with metal ones and use a different bonding material other than tape so that the overall structure would be more solid.

My testing procedures will be updated as well. I would ideally love to test the prototype on additional users, but in the current pandemic I realize that isn’t super feasible. However, I something I could change is to establish a more structured testing scenario where a user would have to conduct a series of tasks that emulate more everyday situations like picking up objects.