Use Your Head

Preventing cycling injury one smart helmet at a time

As part of my Industrial Engineering coursework (Design for Human Factors), I developed an incentive-based app and integrated hardware solution to encourage college students to wear helmets while cycling. In addition, the app utilized IMU sensors to extrapolate the rider’s posture and provide biofeedback to prevent injuries due to repetitive strain and poor posture.

This project was completed as a team in my IEOR 170 - “Design for Human Factors” class with Carson Trinh, Lee Chow Liang, Jason Tang, and Tony Li. My primary responsibilities were as team lead and hardware designer (including sensors and communications systems).

Multi-SENSOR NETWORK

While the system was functional with a single sensor designed to fit neatly into the Giro Savant helmet, it could reliably extrapolate body position when paired with a secondary sensor module placed in an ankle strap. Using the IMU’s on board magnetometer and gyroscope, relative leg and neck angles could be determined, allowing us to determine a REBA score for the cyclist, an empirical score typically used to quantify the risk of strain injuries in the workplace.

PHYSICAL PROTOTYPE

Using 3D printing and reference models of the Giro Savant helmet, we developed a snug-fitting combined module (top right) that remained firmly in place even when riding over rough terrain.

The helmet module went through several iterations attempting to find a design that fit inside the helmet, could accommodate (mockups) of all the electronic components, and stayed firmly in place. Eventually, I resorted to using clay and calipers - pressing the clay firmly into the gap, letting it harden slightly, and then removing it and measuring it with calipers to find appropriate sizing. Crude, but effective.

The ankle module (bottom left) was a bit more bare-bones, but since we weren’t shape-constrained as severely, we were able to fit a mockup of a significantly larger battery.

Unfortunately, the IEOR department did not provide funding to assist in course projects, so the sensor system never made it past the SolidWorks/Block Diagram/Physical Mockup phase of development.

Still, this project equipped me with the tools to approach the later endeavor (Athletic Performance Tracking) with some degree of confidence. Knowledge of what sensors existed commercially, how they worked, and how they could interface with each other and smart devices was an invaluable learning experience in and of itself.

UI/UX Design for FUnctional Clarity

Utilizing lessons learned on human cognition and attention, we designed a UI/UX that served a dual purpose - communicating valuable information and suggestions on rider posture and incentivizing helmet use and proper posture through a “points” system redeemable for discounts at local restaurants and shops.

Going into this project, I saw UI/UX as a very “soft” discipline, more like art and “design” than actual engineering or science.

However, I quickly realized how wrong that was. Human beings respond in specific ways to stimuli and incentives, and by structuring our app in a pleasing way that conveyed information easily and had a good flow between elements, we could accomplish our design goal of increasing safety much more effectively.