Low Cost Inertial Sensors for the Motion Tracking and Orientation Estimation of Human Upper Limbs in Neurological Rehabilitation

Lu Bai,Mohamed Sakel,Malcolm Phillips,Matthew G Pepper,Yong Yan

doi:10.1109/access.2020.2981014

Abstract

This paper presents the feasibility of utilizing low cost inertial sensors such as those found in Sony Move, Nintendo Wii (Wii Remote with Wii MotionPlus) and smartphones for upper limb motion monitoring in neurorehabilitation. Kalman and complementary filters based on data fusion are used to estimate sensor 3D orientation. Furthermore, a two-segment kinematic model was developed to estimate limb segment position tracking. Performance has been compared with a high-accuracy measurement system using the Xsens MTx. The experimental results show that Sony Move, Wii and smartphones can be used for measuring upper limb orientation, while Sony Move and smartphones can also be used for specific applications of upper limb segment joint orientation and position tracking during neurorehabilitation. Sony Move’s accuracy is within 1.5° for Roll and Pitch and 2.5° for Yaw and position tracking to within 0.5 cm over a 10 cm movement. This accuracy in measurement is thought to be adequate for upper limb orientation and position tracking. Low cost inertial sensors can be used for the accurate assessment/measurement of upper limb movement of patients with neurological disorders and also makes it a low cost replacement for upper limb motion measurements. The low cost inertial sensing systems were shown to be able to accurately measure upper limb joint orientation and position during neurorehabilitation.

Highlights

Human motion analysis is commonly used for diagnosis and monitoring the efficacy of treatment in rehabilitation of the lower and upper limbs
Of special interest has been the development of MicroElectro Mechanical Systems (MEMS) which has resulted in high quality miniature inertial sensing units whose size and
In consideration of the patient’s privacy and object of reducing system complexity, in this paper we focus on assessing the upper limb motion solely based on an Inertial Measurement Unit (IMU) system

Summary

Introduction

Human motion analysis is commonly used for diagnosis and monitoring the efficacy of treatment in rehabilitation of the lower and upper limbs. Camera based systems are still the gold standard for motion tracking within the laboratory and clinic [1]. The required measurement space, the cost of equipment and the complexity of set up limits the use of the camera tracking system to specialized clinics and laboratories. Because of these restrictions, alternative technologies using magnetic and mechanical sensing [1] have been developed. Of special interest has been the development of MicroElectro Mechanical Systems (MEMS) which has resulted in high quality miniature inertial sensing units whose size and. One example of a commercial inertial sensor is the Xsens MTx [4] which incorporates a tri-axial accelerometer, rate gyro and magnetometer to enable sensor orientation tracking and, when combined with a kinematic model, limb segment position tracking

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Discussion

Conclusion