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Thomy is an insulin kit for children with type 1 diabetes (4+). The set contains temporary tattoos that allow children to remember where they have previously injected the insulin, and an insulin pen designed specifically for a child’s hand.

What it does

Thomy is an insulin kit for children with type 1 diabetes (4+). The set contains temporary tattoos that allow children to remember where they have previously injected the insulin, and an insulin pen designed specifically for a child’s hand.

Your inspiration

The idea for Thomy came from my six-year-old nephew, Thomás, who was diagnosed with Type 1 diabetes a year ago. Living with this condition involves altering daily habits, like monitoring glucose levels, injecting insulin, and supervising diet and exercise. After observing Thomás’s routine, I realized how tedious the process of injecting insulin into the body is. It’s hard for him to use a regular insulin pen because of his little hands, and it’s easy for him to forget where he last injected insulin. Thomy lets diabetic children have fun while managing their condition. My goal was to find the balance between a medical tool and a toy.

How it works

Thomy’s temporary tattoos visually indicate where the child has previously injected. These tattoos function by using an overall design language: the black ink stays on the body, and the colored dot is removed with an alcohol pad before each injection, ensuring that the patient disinfects the area. After a couple of days, the tattoo will no longer have color, indicating it’s time to choose another design and rotate to another injection site. Thomy’s second component is a non-disposable insulin pen that is easy to grasp and control by a child. The shape is fun and versatile, allowing users to grab it in different ways. It is compatible with standard 3ml insulin cartridges and pen needles. The pen’s release dial is covered in thermochromic plastic. This plastic changes color with temperature, hence changing color when you touch it. This adds a fun element to the pen, encouraging the child to keep it in longer until the full dose of insulin is administered.

Design process

First I identified the 3 main problems: rotating injection sites, ergonomic factors, and fully administering dose. Then I began doing ideation sketches, making complex illustrations for the tattoos. But I realized they wouldn't work after doing more medical research. I thought I had to follow a specific pattern (spiral, circle, etc) for the tattoo designs, but after interviewing doctors, I realized this wasn't necessary. I did user testing and realized the priority was simplicity and intuitiveness, to avoid errors. I chose the size of the dots specifically because it is the exact amount of ink that is easy to remove with an alcohol pad but not too small that it could get erased with the friction of clothes. As for the insulin pen, I started by exploring the form of a child’s hand, their grip, and their coordination. I wanted to find a form that felt natural for them. I also wanted to create a non-disposable pen to reduce waste and create an emotional attachment. After user testing, I refined the size and shape of the model; I explored the possibility of having the thermochromic pigment on the entire pen but decided this made it more of a toy than a medical tool.

How it is different

Despite the fact that early-age diabetes diagnoses are increasing, there are rarely any diabetic products designed specifically for children. Being diagnosed with diabetes forces a child to grow up; they have to learn to inject themselves, cope with a fear of needles, and add and subtract points to figure out what to eat. Not to mention they must forego candy. Thomy gives diabetic children something to look forward to when taking care of their condition, while solving the 3 main problems that diabetic children encounter on a daily basis. Thomy helps reduce anxiety associated with needles and gives children a sense of independence. The design of the insulin pen focuses on the ergonomic factors of a child’s hand and uses colorful elements to make it intuitive and fun to use. The tattoos help children remember to rotate the injection site and visually indicate prior injection spots, avoiding the need to memorize a specific shape or sequence.

Future plans

I would like to have the opportunity to test my prototypes with more diabetic children and get feedback from specialized doctors to refine and modify what’s necessary. I would work with graphic designers and illustrators to expand the selection of tattoo designs; mechanical engineers to refine the mechanism of the pen; and chemical engineers to develop a natural, harmless ink for the tattoos. I also want to create a webpage where the entire kit can be sold, either together or in parts, and where patients can view the different tattoo designs. Lastly, I would like to explore the possibility of other medical applications for the tattoos.


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