Gait-pattern adaptation algorithms based on neural network for lower limbs active orthoses

Author(s):  
Marciel A. Gome ◽  
Guilherme L. M. Silveira ◽  
Adriano A. G. Siqueira
Author(s):  
Marciel A. Gomes ◽  
Adriano A. G. Siqueira ◽  
Guilherme L. M. Silveira

This work deals with neural network-based gait-pattern adaptation algorithm for an active orthosis. The proposed device is developed for lower limbs and based on a commercially available orthosis, Figure 1. Active orthoses can be designed for helping physically weak or injured people during rehabilitation procedures [1]. The robotic orthosis Lokomat is being recently used for rehabilitation of patients with stroke or spinal cord injury individuals [2]. Gait-pattern adaptation algorithms are proposed by Riener, et. al [3], considering the human-machine interaction. The algorithms in Riener, et. al [3] were developed for a fixed base robotic system; they can not be applied directly in the proposed orthosis, since no stability of the gait pattern is considered. A trajectory generator for biped robots taking into account the ZMP (Zero Moment Point) criterion is presented in Huang, et al. [4]. This method presents suitable results with smooth and second-order differentiable curves.


2020 ◽  
Vol 15 (3) ◽  
pp. 3-14
Author(s):  
Péter Müller ◽  
Ádám Schiffer

Examining a human movement can provide a wealth of information about a patient’s medical condition. The examination process can be used to diagnose abnormal changes (lesions), ability development and monitor the rehabilitation process of people with reduced mobility. There are several approaches to monitor people, among other things with sensors and various imaging and processing devices. In this case a Kinect V2 sensor and a self-developed LabView based application was used, to examine the movement of the lower limbs. The ideal gait pattern was recorded in the RoboGait training machine and the measured data was used to identify the phases of the human gait. During the evaluation, the position of the skeleton model, the associated body joints and angles can be calculated. The pre-recorded ideal and natural gait cycle can be compared.With the self-developed method the pre-recorded ideal and natural gait cycle can be compared and processed for further evaluation. The evaluated measurement data confirm that a reliable and mobile solution for gait analysis has been created.


2020 ◽  
Vol 10 (21) ◽  
pp. 7619
Author(s):  
Jucheol Moon ◽  
Nhat Anh Le ◽  
Nelson Hebert Minaya ◽  
Sang-Il Choi

A person’s gait is a behavioral trait that is uniquely associated with each individual and can be used to recognize the person. As information about the human gait can be captured by wearable devices, a few studies have led to the proposal of methods to process gait information for identification purposes. Despite recent advances in gait recognition, an open set gait recognition problem presents challenges to current approaches. To address the open set gait recognition problem, a system should be able to deal with unseen subjects who have not included in the training dataset. In this paper, we propose a system that learns a mapping from a multimodal time series collected using insole to a latent (embedding vector) space to address the open set gait recognition problem. The distance between two embedding vectors in the latent space corresponds to the similarity between two multimodal time series. Using the characteristics of the human gait pattern, multimodal time series are sliced into unit steps. The system maps unit steps to embedding vectors using an ensemble consisting of a convolutional neural network and a recurrent neural network. To recognize each individual, the system learns a decision function using a one-class support vector machine from a few embedding vectors of the person in the latent space, then the system determines whether an unknown unit step is recognized as belonging to a known individual. Our experiments demonstrate that the proposed framework recognizes individuals with high accuracy regardless they have been registered or not. If we could have an environment in which all people would be wearing the insole, the framework would be used for user verification widely.


Author(s):  
Gui-Liang CHEN ◽  
Xiao-Qiang FENG ◽  
Chen-Chen ZHENG ◽  
Geng-Qian LIU

2021 ◽  
Vol 69 (4) ◽  
Author(s):  
Jhon Fredy Ramírez-Villada ◽  
Carlos Mario Arango-Paternina ◽  
Annie Tibaduiza-Romero ◽  
Leonardo Rodríguez-Perdomo ◽  
Nery Cecilia Molina Restrepo ◽  
...  

Introduction: Some parameters used to diagnose sarcopenia, and functional autonomy disorders can lead to interpretation and classification errors. Objective: to analyze sarcopenia markers and their relationship with the strength and gait of physically active older women aged between 55 and 76 years. Materials & Methods: Analytical observational study conducted in 178 physically active Colombian women who were distributed in two age groups (Group 1: 55-66 years, n=98, and Group 2: 67-76 years, n=80). A multiple linear regression model was used to establish possible correlations between strength and gait indicators (dependent variables) and body composition (independent variables). Results: In group 1 (G1) the fat mass and the appendicular mass (appendicular lean/height2(kg/m2)) explained the variance of the power in the lower limbs (SJ: p= 0.001, R2 =0.56; CMJ: p =0.001, R2 =0.51; CMJAS: R2 =0.60, P= 0.001). Similar results were observed in group 2 (G2) (SJ: R2=0.32, DW=2.14; CMJ: R2 = 0.51, DW=2.38; CMJAS: R2=0.41, DW=2.56). Furthermore, fat mass explained differently the variance in G1 and G2 regarding the gait pattern (G1: p=-0.006; R2=20%; G2: p =-0.001; R2=29%).  Conclusion: The records of fat and appendicular mass allow studying negative changes in lower limb strength, and their effect on the gait pattern, as well as identifying the type of sarcopenia and functional autonomy disorders in Colombian physically active Colombian women aged 55 to 76 years.


2020 ◽  
Author(s):  
Fu-Cheng Wang ◽  
Chin-Hsien Lin ◽  
Wei Yuan ◽  
You-Chi Li ◽  
Tien-Yun Kuo ◽  
...  

Abstract Background: Stroke survivors usually experience partial disability, due to abnormal gaits, which vary widely and require tailored rehabilitation programs. However, most gait classifications are based mainly on clinical assessments, which can be influenced by the therapist’s experience. Inertial measurement units (IMUs) are devices that combine accelerometers and gyroscopes to detect movement. IMUs have been successfully used for assessing gait characteristics. Here, we aimed to develop a Deep Neural Network (DNN) model that incorporated information from a motion capture system and multi-labeling IMUs information. This DNN was developed to recognize individual gait patterns in patients affected by stroke to facilitate the design of suitable rehabilitation strategies and promote functional recovery.Methods: We recruited ten patients, aged 20–75 years, with a first-ever, unilateral, ischemic stroke, which caused mild to moderate leg paresis 4 weeks after stroke and ten neurologically normal healthy controls. We applied a motion capture system integrated with multi-label IMUs to acquire the gait information. The motion capture system measured gait information by detecting movement of LED markers attached to each participant. In addition, the IMUs were attached to each participant’s lower limbs to measure kinematic data. These measurements were then applied to the development of a DNN model that could recognize gait characteristics in patients after a stroke and in normal controls.Results: The DNN model achieved an average accuracy of 98.28% in differentiating the stroke gait from the normal gait. Among patients with stroke, the DNN model had an average accuracy of 96.86% in classifying the gait abnormality as either a drop-foot gait or a circumduction gait. We also applied a publicly available dataset, the Physical Activity Monitoring Data Set, which contained IMU information from another independent set of participants to validate our DNN model. We found an average accuracy of 98.60%.Conclusions: We developed a DNN model based on integrated information from a motion capture system and multi-label IMU inputs. This model might assist clinicians and therapists in identifying abnormal gaits more accurately and in applying suitable training programs within the “golden time window” of rehabilitation, after the onset of stroke.


2020 ◽  
Vol 120 ◽  
pp. 103732 ◽  
Author(s):  
Thong Phi Nguyen ◽  
Dong-Sik Chae ◽  
Sung-Jun Park ◽  
Kyung-Yil Kang ◽  
Woo-Suk Lee ◽  
...  

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