Development of Shape Measurement System for Edema

Abstract

Lymphatic edema is the disease which is caused by the difficulty of lymphkinesis. By lymphokinetic disorder, lymph gradually accumulates in intracellular space, with continuous pain and fever. Accurate data acquisition needs high costs and large equipment, but a tape measure by doctors' hands provides less accurate results, because of tension variation. In order to overcome such problems, we developed a measurement system that can measure the shape of the limbs without contact by the light-section method.At first, we developed a shape of cross-section measurement system, which can measure the limbs smaller than 250mm in diameter, or 750mm in circumference. It consists of two line-lasers, two USB cameras, and several mirrors. Since a patient lies on bed, we cannot observe the part of the circumference, which contact the bed. The area was assumed to be flat. For other unobservable parts, the cubic spline interpolation was performed. In order to ensure the accuracy and the feasibility of usage, we prepared the models of 300, 500, 750mm in circumference. The result of the measurement showed that circumference error was smaller than 5mm, and it was usable. Hereafter we can move the device along a limb axis continuously and observe the shape of the limbs. It will give useful information for clinicians.