scholarly journals A Multi-Path Compensation Method for Ranging in Wearable Ultrasonic Sensor Networks for Human Gait Analysis

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1350
Author(s):  
Karalikkadan Ashhar ◽  
Mohammad Khyam ◽  
Cheong Soh
Keyword(s):  
Sensor Networks ◽  
Gait Analysis ◽  
Lower Limb ◽  
Mobile Node ◽  
Ultrasonic Sensor ◽  
Human Gait ◽  
Indoor Environments ◽  
Tracking Accuracy ◽  
Optical Motion ◽  
Analysis System

Gait analysis in unrestrained environments can be done with a single wearable ultrasonic sensor node on the lower limb and four fixed anchor nodes. The accuracy demanded by such systems is very high. Chirp signals can provide better ranging and localization performance in ultrasonic systems. However, we cannot neglect the multi-path effect in typical indoor environments for ultrasonic signals. The multi-path components closer to the line of sight component cannot be identified during correlation reception which leads to errors in the estimated range and which in turn affects the localization and tracking performance. We propose a novel method to reduce the multi-path effect in ultrasonic sensor networks in typical indoor environments. A gait analysis system with one mobile node attached to the lower limb was designed to test the performance of the proposed system during an indoor treadmill walking experiment. An optical motion capture system was used as a benchmark for the experiments. The proposed method gave better tracking accuracy compared to conventional coherent receivers. The static measurements gave 2.45 mm standard deviation compared to 10.45 mm using the classical approach. The RMSE between the ultrasonic gait analysis system and the reference system improved from 28.70 mm to 22.28 mm. The gait analysis system gave good performance for extraction of spatial and temporal parameters.

241 MARKERLESS VISION-BASED HUMAN GAIT ANALYSIS SYSTEM FOR GAIT REHABILITATION

2010 ◽  
Vol 16 ◽  
pp. S69 ◽  
Author(s):  
D. Ristić-Durrant ◽  
A. Leu ◽  
S. Slavnić ◽  
A. Gräser
Keyword(s):  
Gait Analysis ◽  
Human Gait ◽  
Gait Rehabilitation ◽  
Analysis System ◽  
Human Gait Analysis

scholarly journals A Mechanical Sensor Designed for Dynamic Joint Angle Measurement

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Congo Tak-Shing Ching ◽  
Su-Yu Liao ◽  
Teng-Yun Cheng ◽  
Chih-Hsiu Cheng ◽  
Tai-Ping Sun ◽  
...  
Keyword(s):  
Gait Analysis ◽  
Linear Correlation ◽  
Lower Limb ◽  
Joint Angle ◽  
Intraclass Correlation ◽  
Reliability And Validity ◽  
Angle Measurement ◽  
Joint Angles ◽  
Rehabilitation Programs ◽  
Analysis System

Background. The measurement of the functional range of motion (FROM) of lower limb joints is an essential parameter for gait analysis especially in evaluating rehabilitation programs.Aim. To develop a simple, reliable, and affordable mechanical goniometer (MGR) for gait analysis, with six-degree freedom to dynamically assess lower limb joint angles.Design. Randomized control trials, in which a new MGR was developed for the measurements of FROM of lower limb joints.Setting. Reliability of the designed MGR was evaluated and validated by a motion analysis system (MAS).Population. Thirty healthy subjects participated in this study.Methods. Reliability and validity of the new MGR were tested by intraclass correlation coefficient (ICC), Bland-Altman plots, and linear correlation analysis.Results. The MGR has good inter- and intrarater reliability and validity withICC≥0.93(for both). Moreover, measurements made by MGR and MAS were comparable and repeatable with each other, as confirmed by Bland-Altman plots. Furthermore, a very high degree of linear correlation (R≥0.92for all joint angle measurements) was found between the lower limb joint angles measured by MGR and MAS.Conclusion. A simple, reliable, and affordable MGR has been designed and developed to aid clinical assessment and treatment evaluation of gait disorders.

scholarly journals Design on electrohydraulic servo driving system with walking assisting control for lower limb exoskeleton robot

2021 ◽  
Vol 18 (1) ◽  
pp. 172988142199228
Author(s):  
Buyun Wang ◽  
Yi Liang ◽  
Dezhang Xu ◽  
Zhihong Wang ◽  
Jing Ji
Keyword(s):  
Pid Control ◽  
Lower Limb ◽  
Control Method ◽  
Human Gait ◽  
Tracking Accuracy ◽  
Driving System ◽  
Lower Limb Exoskeleton ◽  
Exoskeleton Robot ◽  
Pressure Compensation ◽  
Power Assistance

According to the characteristics of human gait and the requirements of power assistance, locomotive mechanisms and electrohydraulic servo driving are designed on a lower limb exoskeleton robot, in which the miniaturization and lightweight of driving system are realized. The kinematics of the robot is analyzed and verified via the typical movements of the exoskeleton. In this article, the simulation on the power of joints during level walking was analyzed in ADAMS 2016, which is a multibody simulation and motion analysis software. Motion ranges and driving strokes are then optimized. A proportional integral derivative (PID) control method with error estimation and pressure compensation is proposed to satisfy the requirements of joints power assistance and comply with the motion of human lower limb. The proposed method is implemented into the exoskeleton for assisted walking and is verified by experimental results. Finally, experiments show that the tracking accuracy and power-assisted performance of exoskeleton robot joints are improved.

Initial Results of Lower Limb Exoskeleton Therapy with Human Gait Analysis for a Paraplegic Patient

2021 ◽  
pp. 151-157
Author(s):  
Luca Toth ◽  
Adam Schiffer ◽  
Veronika Pinczker ◽  
Peter Muller ◽  
Andras Buki ◽  
...  
Keyword(s):  
Gait Analysis ◽  
Lower Limb ◽  
Human Gait ◽  
Lower Limb Exoskeleton ◽  
Human Gait Analysis ◽  
Paraplegic Patient ◽  
Initial Results

Mobile Gait Analysis System for Lower Limb Amputee High-Level Activity Rehabilitation

2013 ◽  
Author(s):  
III Evans ◽  
Farquhar Boyd M. ◽  
Nycz Ethan ◽  
Ericson Andrzej ◽  
Pusch Nance ◽  
...  
Keyword(s):  
Gait Analysis ◽  
Lower Limb ◽  
Lower Limb Amputee ◽  
Analysis System ◽  
High Level

scholarly journals A Doppler-Tolerant Ultrasonic Multiple Access Localization System for Human Gait Analysis

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2447 ◽  
Author(s):  
Karalikkadan Ashhar ◽  
Mohammad Khyam ◽  
Cheong Soh ◽  
Keng Kong
Keyword(s):  
Gait Analysis ◽  
Multiple Access ◽  
Human Movement ◽  
Lower Limbs ◽  
Human Gait ◽  
Tracking Accuracy ◽  
Ultrasonic Sensors ◽  
Access Methods ◽  
Localization System ◽  
Human Gait Analysis

Ranging based on ultrasonic sensors can be used for tracking wearable mobile nodes accurately for a long duration and can be a cost-effective method for human movement analysis in rehabilitation clinics. In this paper, we present a Doppler-tolerant ultrasonic multiple access localization system to analyze gait parameters in human subjects. We employ multiple access methods using linear chirp wave-forms and narrow-band piezoelectric transducers. A Doppler shift compensation Technique is also incorporated without compromising on the tracking accuracy. The system developed was used for tracking the trajectory of both lower limbs of five healthy adults during a treadmill walk. An optical motion capture system was used as the reference to compare the performance. The average Root Mean Square Error values between the 3D coordinates estimated from the proposed system and the reference system while tracking both lower limbs during treadmill walk experiment by 5 subjects were found to be 16.75, 14.68 and 20.20 mm respectively along X, Y and Z-directions. Errors in the estimation of spatial and temporal parameters from the proposed system were also quantified. These promising results show that narrowband ultrasonic sensors can be utilized to accurately track more than one mobile node for human gait analysis.

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