Foodmate: an assistive eating device for people with rheumatoid arthritis

Hi, we are Eva and Laure. We’re two Interaction Design students at Luca School of Arts in Genk, Belgium. For the master module Design for Health we needed to design a solution for people with a specific health problem. We decided to develop something for people with rheumatoid arthritis because Laure's father-in-law suffers from this condition. We went through a 2 weeks process that's explained shortly in the following steps. If you want to know more about this project ( and you speak Dutch) you can read our blog: https://designforrheumatism.wordpress.com/category/introductie/.

Step 1: Research Rheumatoid Arthritis and Inspiration

What is rheumatoid arthritis?

Rheumatoid arthritis (RA) is a chronic, progressive disease that causes inflammation in the joints. This results in painful deformity and immobility especially in the ankles, feet, wrists and fingers. Due to the decreased strength in their hands and fingers these people experience difficulties with holding objects. Eating with cutlery is very difficult for them. People with advanced RA therefore often need help from an assistant which can be very humiliating. That’s why we wanted to design an assistive tool that encourages independent eating.

We searched multiple existing design solutions for people with RA as inspiration. These are all tools that support the fingers, palm or hand with wrist included and are designed to offer support in different kinds of activities like writing, using cutlery, reading etc. All tools have proven their usefulness in the everyday life of RA patients.

Step 2: Brainstorm

After drawing sketches and trying out different shapes, forms and sizes, we decided to go for the cylindrical shaped handle with a gripper. We've chosen the cylinder because it has a shape that fits the palm of the hand and is comfortable to let your hand rest on. Handles to hold cutlery already exist but they can only hold one object that’s attached. We want to make a multifunctional one that can hold numerous thing.

Step 3: Defining Our Concept

After doing research and having numerous brainstorm sessions we came up with our final concept 'Foodmate' that can be defined as followed: foodmate is an assistive eating device for people with rheumatoid arthritis which allows them to feed themselves independently. The tool exists of a ready-to-use handle and a gripper that can hold a spoon or fork. It's multifunctional which means that it can also be used in other contexts.

Step 4: Concept Elaboration

Designing a 3D model

First we created a 3D model in Grasshopper (Rhino). Afterwards we had to design a tangible interface that can be connected to Grasshopper via Arduino. With the interface the user can personalize its own handle. By performing ‘real life’ actions like f.e. moving a slider, the 3D model can be adapted. The changes can be seen live on the computer screen.

Prototyping different interfaces

Interface with sliders

In this interface the user can measure his hand by using 4 sliders. In order to do this he has to put his hand in the opening and move the sliders. The measurement wasn’t very accurate and it wasn’t the easiest interface to use because 4 sliders had to be moved with just one hand.

We also used two sliders to measure the width of the cutlery. Because they represented the gripper perfectly we we decided to use them again in the second interface.

Interface with velcro

In the second interface we replaced the hand sliders by velcro that can be wrapped around the palm of the hand. We also draw a handprint on the interface so that it’s clear for the user where to put it.

The velcro seemed to be more accurate but still wasn't easy to use because the user only has one free hand. This means that someone’s help was still needed. You also need strength in your hand to adapt the velcro which as earlier mentioned is a problem for people with RA.

The handprint seemed to be efficient because the user knew what to do without telling him before.

Interface with sensors

In our third interface we used sensors to register the width and thickness of the palm. The only thing the user had to do was place his hand on the handprint so that it could be scanned automatically.

We decided to go for the last interface because it's very easy to use. The user doesn't need any help and can use the interface in a comfortable way without experiencing pain in his joints, fingers or hands.

Step 5: Final Interface

Our final interface is a portable box. We used 6mm MDF that was cutted and engraved by a lasercutter.

There are 2 distance sensors used in our interface. We used the Hc-sr05 ultrasonic sensor from Velleman (

https://www.gotron.be/hc-sr05-ultrasone-sensor.htm... The advantage of using these sensors is that their measurements are very fast and accurate and the only action the user has to do is placing his hand on the hand print.

Because of its proved efficiency during the tests we still used the two slide potentiometers as representation of the gripper.

How does the interface work?

As mentioned earlier the width of the gripper can be adjusted by using the sliders. In order to do this the spoon should be placed on the marked field between the sliders.

We implemented 2 distance sensors in the interface to ‘scan’ the user’s hand. Both its width and thickness are measured so that the handle matches the user’s hand and is comfortable to use. When the user is ready he can press the ‘OK’ button. If he wants to change something he can press ‘RESET’. When both the spoon and hand are measured the user can press the ‘PRINT’ button so that his own personalized Foodmate can be 3D printed.

Because an interface has to be easy to use and match the system image of the user, how the user thinks a system works, we devided the work flow into different steps. Every step is explained and printed on the interface so that the user almost automatically knows what to do and when to do it. We also engraved two fields where the cutlery and hand can be placed. As mentioned earlier the sliders and sensors are connected to the 3D Model in Grasshopper via Arduino. Do you want to see how the interface works in real life? Then our video is a must see!

Step 6: Additions

We succeeded in getting an accurate measurement of both the cutlery and hand and designed an easy-to-use interface for people with RA. Implement clay to 'copy' the hand grip could be an improvement so that the cylindrical handle is perfectly shaped to the user's grip. This could be more comfortable. In order to do this you'll probalby need a 3D scanner to be able to scan the grip print with precission.

Step 7: Your Turn

So..... Now it's your turn! We've uploaded every file (Grasshopper, Arduino and laser cut sketches) so that you can rebuild Foodmate on your own! All you need is your computer, Arduino and a laser cutter.

TIP: laser cutters can be used in Fablabs. We also worked at the Fablab in Genk.

Have fun!

Eva & Laure