Cystic Fibrosis is a recessive genetic disorder that affects the lungs, as well as pancreas, liver, and intestine. The CF gene produces a mutant protein that interferes with cells’ ability to manage chloride. This causes secretions throughout the body to thicken, and turn dry/gluey. In the ducts of the pancreas, the flow of digestive enzymes becomes blocked, making a child less able to absorb food, which leads to poor growth. However, the effects on the lungs are what make CF lethal. Thickened mucus will slowly fill the small airways of the lungs and harden, thus shrinking the lung capacity.Typically, a child with CF has to be monitored daily for energy levels, appetite, and cough frequency. This data is useful in determining treatments.
The Little Devices Lab at MIT focuses on the design, intervention, and policy spaces for DIY health technologies. By developing a series of medical technology prototyping kits, the Lab has provided new materials and “plug-and-play” components to help nurses and doctors expand their ideas and solutions for better patient care.
The Lab was approached by a parent/nurse to develop a wearable sensor to measure and record her child’s cough frequency. Ultimately, the wearable sensor would be able to transfer the data to a smart phone (or some other means for storing data) enabling physicians and parents to keep track of a child’s health.
Through the opportunities of the MSSD program, I was able to prototype the wearable cystic fibrosis cough monitor for the Little Devices Lab using open-source electronics and software.
My initial tests were to determine cough occurrences based on movement and sound. I began the project using an Arduino, as well as two breakout boards for accelerometer and microphone data. However, these components are bulky. When it comes to wearable electronics, size and power matter. Since the CF monitor is intended to be a wearable device, I researched other microcontrollers. The relatively small Flora and can be sewn into fabric and washed. It also makes use of rechargeable micro-lipo batteries. With the onboard 3.3v 150mA regulator, the Flora can power most common modules and sensors. I then migrated my tests from the Arduino version to the Flora.
For this prototype, I used a velcro strip as an armband to hold the components.