Wheelchair Pressure-Mapping System
What is BioMap?
- A proof-of-concept prototype for Biomap.
- Seat cover for paraplegics that senses varying seated positions and pressures.
- An app that communicates with the cover and lets a user know when to offload pressure.
- The “Fitbit” for paraplegic users; health analytics and injury prevention.
Biomap helps paraplegic users prevent pressure ulcers by analyzing their seating habits, reminding them to move or shift weight from side to side periodically. Sitting in one position for too long can cause serious ulcer formations in the legs, and so keeping a user updated with time spent on either side of their posterior is essential in pressure ulcer prevention.
Biomap Consists of:
- A pressure-sensitive seat cover for wheel chairs.
- An Android application – processes the data from the seat.
- A Bluetooth processor sending data from the pressure mat to the application.
Who Were We?
I was one in a group of four who decided to take on this project during a Summer school projects course. It was an ambitious undertaking as we had to build a prototype in only a few months. None of us had any prior knowledge of circuitry and electronics – or Android for that matter. Even so, we wanted the challenge. We were successful in our endeavors and handed over a functional prototype to our client so that she may approach potential investors with her proof of concept.
What Did I Learn?
I learned more during this project than I have in the past year of school. I had to learn:
- Arduino/General Circuitry (how we would make a pressure sensitive device from scratch)
- Bluetooth technology (managing threads properly to collect 15 bytes of pressure-data from 15 different characteristics from our Nordic nRF chip)
- Android UI/UX design (making things cohesive and easy to navigate – and look damn good at the same time).
- Soldering/Sowing (during iteration 1, there was a LOT of soldering and a LOT of sowing to do – my curtain stitch is lit).
What Were Our Challenges?
We overcame a lot of issues that we feel are common to groups of programmers: organization and timing. Only two of us worked on the application and managed code so at times it felt like a daunting task to produce 2 different iterations of the Android application,
Bluetooth was extremely difficult and we were lucky enough to get into contact with a Bluetooth expert in Vancouver. He was extremely generous with his time and ended up putting together the firmware for the Bluetooth processor for free. Of course, we bought him a big ol’ bottle of brandy as a thank you.
Communication with the Bluetooth on the Android side was hard as well. Each “row” of sensor values from the pressure map was sent over as 15 bytes inside a characteristic (a characteristic is kind of like a package of broadcasted data from a Bluetooth device) and it was quite hard to design a UI that could process and display all that data. This is because, going into the project, I knew very little about threading and mobile development.
Our final presentation was touch-and-go. I’m usually very good with presentations and public speaking, but for some reason, I was nervous for this. The presentation was an accumulation of countless late nights and hardware nightmares, and we weren’t sure the Bluetooth was even going to work as we had just finished coding it 30-minutes prior. I loved the rush though, and in the end, everything worked out.
This project gave me a lot of confidence in my abilities to learn and overcome challenges. It taught me to say ‘yes’, even if I have no idea what I’m doing; I’ll learn. I’m proud of my team and what we did.