Modular Robot Wear for Walking Rehabilitation Assistance According to Physical Functionality

As people age, walking can become difficult. This difficulty in walking can lead to further physical decline and eventually result in the need for caregiving. To prevent this, wearable robots supporting walking rehabilitation have been developed. In this study, we aim to develop a modular robot wear that can be customized according to the user’s needs. The modular robot wear consists of motor modules, sensor modules, and a processor. Motor modules can be attached to any part of the body that requires assistance, enabling support not only in the sagittal plane but also in the frontal plane. By calculating the relative movement of the center of gravity based on the information from the acceleration sensors in the sensor modules, commands to the motor modules are generated. This allows for assistance tailored to the user’s walking pattern. Through verification experiments of the robot wear’s operation, we confirmed its ability to provide support according to changes in walking patterns. However, while the robot wear can induce changes in walking patterns, there are challenges regarding the output it provides to the wearer. I. INTRODUCITON Walking is important for independent daily living, but with aging, there can be a decline in physical function that makes walking difficult. In particular, conditions such as knee osteoarthritis (KOA) and osteoporosis can lead to difficulty walking due to decreased function of the musculoskeletal system, including joints and bones. This is referred to as locomotive syndrome, which is commonly observed in adults aged 40 and older [1]. Li et al. reported that falls mostly occur during walking [2]. Elderly individuals are at a higher risk of fracturing their pelvis by falling. Such fractures can lead to further immobilization, accelerating dependency and ultimately requiring care. Therefore, to reduce the increase in the care level required for the elderly, assistance with walking becomes crucial. Canes and walkers are major assistive devices for walking among the elderly. In particular, the RT.2 developed by RT.WORKS enables assistance on inclines and not only enhances the safety of walking but also extends the range of mobility [3]. However, it’s worth noting that canes and walkers may limit hand movements, potentially increasing the risk of falls [4]. Therefore, there is increasing attention on walking assis- tance through wearable devices [5][6]. As a wearable robot aimed at rehabilitation, CyberDyne’s HAL is notable [6]. 1Human Augmentation Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 6-2-3 Kashiwa-no-ha, Kashiwa-shi, Chiba, Japan ogata.kunihiro, futawatari-toshiki1002, masahiro-fujimoto, yumeko.imamura, yoshio.matsumoto@aist.go.jp 2 Department of Human and Engineered Environmental Studies, GSFS, The University of Tokyo, 6-2-3 Kashiwa-no-ha, Kashiwa-shi, Chiba, Japan 3 Tokyo University of Science Fig. 1. Overview of modular robot wear. Additionally, devices like Hocoma’s Lokomat [7] and Toy- ota’s Welwalk [8], which combine treadmills and displays to enhance rehabilitation effects, are gaining prominence. These robots consist of rigid hardware and are referred to as exoskeleton robots. Many conventional exoskeleton robots are limited to sagittal plane support. Kuo et al. argue that while sagittal plane movement is passively stabilized, stability in the frontal plane is maintained actively through control [9]. Consequently, exoskeleton robots capable of supporting both the sagittal and frontal planes are also being developed. However, many patients may only have partial dysfunction in their lower limbs, such as stroke patient, making exoskele- ton robots like those mentioned above functionally redun- dant. There are few examples of wearable robots that can provide tailored support according to each user’s individual physical function. II. PROPOSAL AND PURPOSE In this study, we aim to develop wearable robots capable of providing support tailored to the user’s conditions and challenges. To achieve this, it is necessary to decompose the functions of the robot and reconfigure them for each user. Therefore, we propose a modular wearable robot. A. Proposed Robot The concept of modular robot wear is illustrated in Fig. 1. This robot wear modularizes functions such as actuators, sensors, processors, etc., allowing these modules to be at- tached in the required numbers to the necessary areas. For example, if support is needed in the sagittal plane of both legs, actuators would be attached to the anterior surface of 2024 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) October 14-18, 2024. Abu Dhabi, UAE 979-8-3503-7769-9/24/$31.00 ©2024 IEEE 4651