Colleen Miller

contriving a purpose . graphic + interaction design

Tackling Weight Loss with Physical Computing

Posted March 6th by Colleen in MFA Interaction Design

Mindfull is a small electronic device that reminds you to slow down when eating. It takes at least twenty minutes after eating for your stomach to tell your brain that it is full. But most of us finish a meal in ten minutes or less. You can give your stomach time to catch up to your brain by slowing down your consumption rate.

A quicker pace of eating is associated with higher body mass. Eating slower allows time for your body to product a hormone that’s responsible to signal your brain that you are full. Eating is supposed to be a mindful event. This device offers a way for fast eaters to be mindful of their speed, allowing the brain time to process when the stomach is becoming full.

How it Works:

After putting food in your mouth, put your fork on the Mindfull rest and let go. Do not touch the fork until your mouth is empty. If Mindfull lights up, you are eating too fast! Repeat through the entire meal.

Ideation:

We brainstormed with questions—What if the sensors were built into a placemat or rest, detecting the weight of the fork when it is placed down? Could the sensors be built into the rim of a plate, allowing the user to rest his/her fork on the edge of the vessel while eating? Should the device be build right into the utensil itself? An accelerometer or motion detector could detect movement, and light, sound or vibration would provide output.

Mindfull sketches

Ideation sketches for incorporating a sensor to detect eating speed

Prototyping:

This project implements electronic prototyping with Arduino, an open-source electronics prototyping platform. We decided that a fork rest would be the most effective way to test our concept with fast eaters. In our first prototype, our input was a lever switch that detected whether or not a utensil was placed onto the stand. Outputs (feedback) included a) a light turning on when the lever was not pressed and b) the light blinking after ten seconds of the switch being unpressed. This second output served as a signal to users to put their fork down.

In the second prototype, we experimented with a bi-colored LED that changed from green to orange in a ten-second interval while the lever was unpressed. This replaced the blinking output from round one. We also started experimenting with the form of the fork rest, considering the style of chopstick rests in Asian food restaurants. After uploading the new program to the board and switching out the LED, most users found the feedback to be a little too subtle.

In later prototypes, we were looking to minimize the size of the device in order to perform user testing outside of the studio, e.g. in a restaurant. Our goal was to be able to place the electronics into a small hidden box, with the ultimate goal of incorporating all of the pieces into the fork rest container itself. Using a smaller breadboard, we were able to compact the device immensely. Standard hookup wire was also replaced with thinner ribbon cable, which allowed the fork rest to flex in all directions with respect to the Arduino board.

Other additions included a straw, which was placed into the stand and around the LED. This helped to create a more distributed, diffuse glow from the LED throughout the form. Getting to this point allowed us to do a more user testing in social environments—the wires were hidden, and the device could be tested for usability.

Compacting the electronics helped with testing and adding a straw helped diffuse the output light throughout the case.

In our final presentation prototype, we listened closely to the advice of our testers and implemented a few changes, including:

  • Adding a knob which allows the user to control the blinking intensity of the LED
  • Adjustment of the code to make the blinking more of a soft pulse when set to slow speed.
  • Determining the average time taken between bites to be thirteen seconds, code was adjusted to reflect this.
  • The cover of the device was made in an opaque black plastic, while the bottom remains translucent in order to view the output light.

Testing Video and Conclusions

As our user testing shows, there are more rounds of testing we would like to do to make Mindfull Better! Of course, getting the components as small as possible will be a strong factor in future usability, which we believe can be accomplished with better parts in manufacturing process.

CREDITS: Group project with Stephanie Aaron, Gene Lu and Beatriz Vizcaino




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