Devices to visualize swimming technique, such as cameras, can help swimmers notice areas to improve performance. As a swimmer for over ten years and member of the MIT swim team, Jack Bolte ‘28 recognized the limitations of current tools.

He explains, “I noticed some issues with the cameras that my club team had: they can only record from one angle, and they can only be either out of or in the water. With this [IMU-based] solution, you can view from any angle, and it records the same whether the swimmer is in or out of the pool.”

Beginning the summer before his first-year at MIT, Jack prototyped the first version of the system. He came up with a set of waterproofed, enclosed devices that would be strapped on to each joint of a swimmer. Each IMU would provide a measurement of the orientation of each joint which could then be transmitted through Bluetooth Low Energy (BLE) and represented in Blender, a 3D modeling software. The enclosure of each device was designed in Onshape and 3D-printed, and the circuit board containing a microcontroller and IMU was designed in Altium.

With support from an MIT MAD Mini Grant and resources in the Metropolis makerspace’s Electronic Mezzanine, Jack improved upon his initial version by spot-welding the batteries and potting the entire device in epoxy.

Jack found that his newest version was much improved on reliability but was less accurate than the first iteration. He plans to continue addressing the problem of analyzing swim technique with new techniques. “Based on the limitations of this project, I am going to try motion capture with a camera-based approach, which involves stitching together multiple camera angles to form a three-dimensional reconstruction of the swimmer.”