3次元骨格系モデルによる腰部支援用HALの動作支援評価

抄録

Low back pain (LBP) is one of severe diseases due to an overload onto lumbar area such as vertebrae, disks and nerves. The pathogenesis of LBP are caused by the physical load on the lumbar during the task of keeping a static posture, lifting a weight, spinning a lower back. To reduce the physical load, exoskeletal robots are researched and developed. However, it is difficult to verify non-invasively the load reduction of wearer's endoskeletal by motion assist. The load reduction of endoskeletal such as lumbar disks of area of injury can not be verified. The purpose of this paper is to propose and develop 3D skeletal model and the method that verify load reduction of wearer's endoskeletal, and to verify the effectiveness of HAL for lumbar support on lumbar load reduction. 3D skeletal model that consists of vertebrae and disks was developed based on anatomical insight and the radiograph of ordinary person. Finite element method (FEM) by using this model was proposed as the evaluation method of motion assist of exoskeletal robots. We simulated this model of wearer holding a weight, and analyzed the lumbar stress, without or with HAL support. The wearer held weights of 5-20kg in a flexed posture. The effectiveness of this model was confirmed, because the stress concentrates on lumbar disks in a flexed posture. The analysis results showed that motion assist by using HAL decreases lumbar stress when it is compared to without HAL support. We proposed and developed the method that verify load reduction of wearer's endoskeletal, and verified the effectiveness of HAL on lumbar load reduction. The evaluation method of motion assist of exoskeletal robots was developed by this study. The proposed method can be applied to upper and lower body. It is expected as new index of motion assist.