Monitoring Leg Lymphedema Over the Course of Therapy Using an Infrared System

There are many techniques of monitoring leg lymphedema during physical therapy. Taking volumetric measurements with a tape measure is among the most common clinically, and changes in volume are typically used to measure therapy efficacy. This study shows how the Kinect infrared (IR) sensor with custom algorithms can assess leg circumferences and volumes comparable with tape measurements taken by a trained therapist while exploring regional leg changes to determine uniformity of change. Leg volumes were measured in 38 lymphedema patients using the tape measure circumference method and the Kinect IR system. Changes in circumferences in various leg regions over the course of therapy were analyzed in 23 patients. The leg circumferences (R² = 0.9522) and volumes ( R² = 0.9847) strongly correlated between the two methods. The Bland-Altman analysis indicated a circumference percent different bias of 1.6 (6.2%), requiring a minor correction factor between the two methods. Over the course of therapy, patients with a reduction in leg volume, defined as a change >6.5% have greater reduction most distal to the body. The Kinect IR system explored can be used clinically for leg volume measurements to monitor leg lymphedema patients over the course of their therapy. Implementing analysis of regional leg changes can better inform physical therapy to improve efficacy of treatment.