Knee Injury Diagnostic Device

Abstract

Knee injuries are difficult to accurately diagnose. The manual evaluation relies on many subjective factors such as physician experience, swelling, patient guarding, and the severity of the injury. These factors can lead to an inaccurate or incomplete diagnosis, resulting in less than optimal treatment and recovery. Knee injuries are very common among athletes and can occur during the day to day activities, with many resulting in tears to one or more of the four ligaments. For evaluation, a physician manually manipulates the knee with a series of standard tests. Even though these standard manual tests are considered best practice, they are known to lead to some inaccuracies with upwards of 1 in 8 patients being misdiagnosed due to testing deficiencies. Imaging by MRI is used to support the diagnosis if available, though not available to all patients due to cost and time requirements. This purpose of this project was to develop and test a wearable diagnostic system contained within a sleeve over the knee. Incorporated sensors were used to monitor movement and electromyographic activity to determine quantitative measurements toward a diagnosis. The movement and displacement monitoring subsystems were tested on a constructed model of the lower leg and knee. Preliminary results have shown accurate readings with an average percent error of 1% for range of motion testing and 3% (0.1 to 0.2 mm) for laxity testing. This measurement determined by this system could be reported to a physician who could use when making a diagnosis. Improved diagnosis would guide appropriate treatment and contribute to improved recovery.