Non-invasive estimation method for lumbar spinal motion using flat belts and wires

This paper presents a novel method for estimating lumbar spinal motion using practical and simple measurements. Previous studies have investigated the measurement methods for the lumbar spine; however, none of the studies that use wearable measurement systems have calculated the exact velocity of each vertebra using a non-invasive method for measuring vertebral motion including translation. The purpose of this study is to establish and implement a method to estimate accurate vertebral motion using a non-invasive technique. In the proposed method, we estimate the motion of the vertebra by using a rigid body model of the spine. We observe the changes at the contact points between the two belts and the wearer's back. In this study, we show how to estimate the lumbar motion at each vertebra by using sensors to measure the shifting, bending, and contacting regions of the flat belt attached to the wearer's back. We also validate the estimation of the angular velocity of the vertebra by measuring the shift in the belt by using wires and potentiometers. This is an important part of estimating the accurate motion of the vertebra.