Technology for Ankle Instability Assessment

Ankle injury is one of the most common mishaps in the US, with military personnel at greater risks. First injury may be just the tip of a big iceberg for a significant fraction of the patients who experience neuro-muscular changes that prevent healing. This condition, known as chronic ankle instability (CAI), has tremendous socio-economic cost because of the lingering pain and recurrent injury. CAI must be managed with routine assessment of ankle laxity, but such tests are currently administered only at a clinic, which is a roadblock for military personnel. An even bigger challenge is the lack of objectivity in the test results, whether the test is manual or instrumented. Therefore, a portable CAI assessment tool that can be used without any clinical knowledge or environment is badly needed for both military and civilian applications.​ Impulse Technology proposes a novel CAI assessment technology after performing a bio-mechanical engineering analysis of why even the most experienced doctor, let alone an instrument, cannot objectively measure ankle laxity. Our technology not only addresses the deficiencies in the state of the art, but also provides simplest user-interface (the user only needs to mimic a ‘rowing’ exercise) and ultra-portability so that accurate and repeatable results are obtained with the highest resolution. It performs the gold standard tests (anterior drawer and talar tilt). The technology has an ‘auto-alignment’ feature that can target specific ankle ligaments to extract their laxity without any influence from the patient’s foot-size, weight, and ankle strength. It delivers the true displacement of the ligament by subtracting any relative motion in the ankle complex. The resolution of measurement is unprecedented as we mechanically amplify the signal (unlike electronic amplification where noise is amplified as well). The most distinctive feature of our technology is that a patient can administer it at home. The product design borrows from Origami to achieve ultra-portability (weight: 2 lbs; stowaway volume: 12x24x4 in3) with only an AA battery needed for a display console. The team includes Dr. Gregory Lewis (Penn State University’s Hershey Medical School) as a consultant and Dr. Sara Peterson (Dept. of Veterans Affairs at the University of Pittsburgh) as a military/veteran advisor. The objectives of this Phase I project are to develop a detailed engineering design, build functional prototypes, and perform benchtop tests on 3D printed articulated ankle-foot models with various shapes and sizes. The over-arching goal is to demonstrate that the proposed technology is able to eliminate subjectivity by addressing the challenges in human variability and measurement error. We envision our final product to disrupt the current market by transforming the current perception of ankle assessment from ‘performed by a doctor in a clinic’ to ‘self-administered by a patient at home’.