This post is written by Najma Dawood and Shuang Liang, the winners of the December MakerSpace Mini Grant.
Team members Najma Dawood and Shuang Liang set out to prototype a device that detects levels of physiological response to stimuli. We began the project with lofty goals of creating a beautiful device that would detect the heart rate, breath, sweat, temperature, movement, and changes in voice of the person wearing it.
Once we began planning the project, we realized that it would be better to create something that fulfilled a few of those requirements and then iterate over time, as we were not very familiar with the capabilities of microcontrollers at this time. We decided to proceed with detecting only heart rate, breath, and sweat. We applied for the MakerSpace grant and were able to purchase a pulse sensor to detect heart rate, conductive fabric for the breath sensor, a battery pack, and LED lights.
Galvanic Skin Response Sensor
We began by trying to create a GSR sensor, which seemed simple enough based upon the tutorials. Though we were able to get some feedback in the arduino serial monitor, the data was reading inconsistently and didn’t make it into the final prototype. We decided to move forward with creating the other sensors.
Breath Sensor
Initially, we attempted to create a breath sensor out of the conductive fabric that the MakerSpace ordered for us. We began by sewing it to a piece of spandex fabric in order to make it stretchy. Unfortunately, the fabric that we ordered did not have enough stretch to it and couldn’t be used for a breath sensor. We turned to conductive yarn for a solution. In order to create the breath sensor, we wove together conductive yarn with regular cotton yarn with some stretch to it. When attached to the FLORA by alligator clips, the knitted yarn is triggered when stretched. This could be placed around the body and used to sense the rhythm of the wearers breath.
Pulse Sensor
For the pulse sensor we used the plug-and-play heart-rate sensor that the MakerSpace ordered for us with the built in Arduino code.
3D Printing
We used the MakerSpace 3D printers to print a necklace and set of earrings to place the sensors in. We placed the heart rate monitor in a clip on earring and hooked the breath sensor into the necklace. We placed two LED’s in the necklace, one to represent heart rate and one to represent breath rhythm.
Results
After much trial and error, we were able to create a working prototype that successfully detected both breath and heart rate, and met our aesthetic goals. We hope to continue iterating on this project in the MakerSpace to include a galvanic skin response and improve upon the breath sensor.
