Inclinometer Based Low-cost Biofeedback Balanceboard for Injury Rehabilitation

This paper details the design and development of a device that can, through the mechanism of biofeedback, assist individuals undergoing rehabilitation for leg injuries. The device consists of two plates, a base plate which is fixed and a top plate on which the user stands and can be tilted. The two plates are separated by an automotive ball joint and four springs which provide a damping force. A high resolution two axis inclinometer detects the angle of tilt of the platform, and thus implicitly the user's balance, then sends this information to a personal computer via a microcontroller unit. The tilt information is displayed on the computer monitor to provide immediate, real-time visual feedback to the user. The damping springs, all with a similar spring constant, provide a smooth and linear response over the operating range. Experiments confirm that the inclinometer was highly accurate and responsive. The graphical computer interface conveys feedback about the user's balance to them as they operate the device. The sensor output is also logged into a database for future retrieval and analysis to monitor the progress of a patient.