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This paper presents the design of a direct driven under-actuated portable hand exoskeleton for rehabilitation. The design of the proposed Hand EXOskeleton SYStem (HEXOSYS) was driven by multi-objective optimisation strategy and inspiration from the human hand. The optimisation algorithm resulted in the choice of optimum link lengths of the device. The optimisation criteria are based on dexterity,...
This paper presents the design of an admittance-based assistive controller and preliminary experimental results for a high performance parallel robot used for ankle rehabilitation. The goal of this work was to design a suitable control algorithm for diagnosis, training and rehabilitation of the ankle in presence of musculoskeletal injuries. An admittance control technique is used to perform patient-active...
Atherosclerotic plaque complication is a major cause of vascular accidents. Although a variety of factors have been proposed as key factors in these process, the mechanism that contribute to this problem remain to be characterized. Previously we demonstrated that changes in arterial wall viscous and elastic properties and/or in the filtering function (FF) could be part of the arterial wall alterations...
Analysis of muscle activity by electrophysiological techniques is commonly used to analyze biomechanics. Although the simultaneous and intuitive understanding of both muscle activity and body motion is important in various fields, it is difficult to realize. This paper proposes a novel technique for visualizing physiological signals related to muscle activity by means of surface electromyography....
This work proposes an innovative textile sensor system to monitor dynamic body movement and human posture by attaching wearable digital sensors to analyze body motion. The proposed system can display and analyze signals when individuals are walking, running, veering around, walking up and down stairs, as well as falling down with a wearable monitoring system, which reacts to the coordination between...
We quantified the mechanical abnormalities of the spastic wrist in chronic stroke survivors, and determined whether these findings were representative of those recorded at the elbow and ankle joints. System identification techniques were used to characterize the mechanical abnormalities of these joints and to identify the contribution of intrinsic and reflex stiffness to these abnormalities. Modulation...
Although a variety of factors have been proposed as key factors of the atherosclerotic plaque vulnerability, the mechanisms that contribute to this problem are not yet fully characterized. In previous works we demonstrated that changes in arterial wall viscosity and elasticity and/or in the filtering function (FF) could be in the basis of arterial wall alterations. If these properties are altered...
In this paper, we present a method for extracting body sway parameters from a three-dimensional voxel reconstruction, which is built using silhouettes captured from two calibrated web camera views. The results were validated with a Vicon motion capture system. Experiments were conducted in which subjects stand and sway in the anterior-posterior direction and then in the lateral directions with two...
To enable compliant training modes with a rehabilitation robot, an important prerequisite is that any undesired human-robot interaction forces caused by robot dynamics must be avoided, either by an appropriate mechanical design or by compensating control strategies. Our recently proposed control scheme of “Generalized Elasticities” employs potential fields to compensate for robot dynamics, including...
The purpose of this project is to develop a method of providing a complete set of movement commands to an upper extremity neuroprosthesis when the number of command signals available is fewer than required by the mechanical system. The functional relevance of the developed command interface will be tested in a virtual reality environment, where users-able bodied and paralyzed-will use a limited number...
Dynamic joint stiffness defines the dynamic relationship between the position of the joint and the torque acting about it. Joint stiffness consists of two components: intrinsic and reflex stiffness. Previous work from our lab has shown that subjects can alter their reflex stiffness voluntarily and independently of intrinsic stiffness. Numerous studies have investigated whether reflex stiffness is...
This work aims at modeling, in the presence of simplifying physical and geometrical assumptions, acoustic wave propagation through human thoracic tissue. Presented here are preliminary modeling results that are indicative of dominant lung resonances at specific frequencies. These resonant modes strongly impact pressure distribution in the tissue as well as the pressure and acceleration at the tissue-air...
This paper introduces a morphological image segmentation method by applying watershed transform with markers to scale-space smoothed images and furthermore provides images for clinical monitoring and analysis of patients. The database comprises sagittal plane images taken from a digital camera of patients submitted to Global Postural Reeducation (GPR) physiotherapy treatment. Orthopaedic specialists...
Using an interactive, 3D, kinematic simulation of the human skeleton, the motion of the sacro-iliac (SI) joint is modeled based upon descriptions available in the literature. The major ligaments are added to the simulation data structure using deformable cubic B-spline curve paths. Ligament strains were generated and studied in response to the motion simulations. Results improve our understanding...
Background and aims: To establish gait analysis as part of routine clinical diagnoses, physicians demand accurate and flexible motion capture (Mocap). Currently, popular optical, mechanical and acoustic Mocap systems offer acceptable repeatability, but fall short of the spatial and economic benefits accompanying inertial motion capture (IMC). However, IMC is considered adolescent due to limited testing...
Fall-related injuries, disabilities, and fatalities are known to seriously affect the healthcare and industry sectors. Nevertheless, an abled individual, as well as a trained senior citizen, is believed to be capable of withstanding and overcoming unusual environmental variations in terms of postural stability and balance. Understanding the biomechanics of fall and fall recovery through quantitative...
In order to check validity of the porcine ligamentum flavum as a substitute of human tissue for evaluating the epidural needles, the thickness and the Young's modulus were measured, and a finite element analysis was carried out. Twenty-four specimens were stained by the Elastica-van Gieson method. The average value of the thickness was 1.2 mm. The tensile tester was employed for measuring the Young's...
For individuals with mobility limitations, powered wheelchair systems provide improved functionality, increased access to healthcare, education and social activities. Input devices such as joystick and switches can provide the necessary input required for efficient control of the powered wheelchair. For persons with limited dexterity, or fine control of the fingers, access to mechanical hardware such...
There is a strong need to measure the complex mechanical properties of soft tissues such as skin. An in vivo experiment characterizing the mechanical response of human skin is presented. A rich set of deformations were applied to several positions on the arm using a novel force-sensitive micro-robot. All sites studied exhibit highly non-linear, anisotropic, and viscoelastic behavior. The experiments...
The lack of reliable mechanical data on coronary arteries and, more specifically, on their wall strength hampers the application of numerical models and simulations to vascular problems, and precludes physicians from knowing in advance the response of coronary arteries to the different interventions. Studies of the mechanical properties of coronary arteries have been carried out almost exclusively...
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