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In this paper we explore the mechanical behavior of the ankle in the progression stage of stance during normal walking. We show that the torque/angle behavior of the ankle during this stage can be approximated by an augmented linear torsional spring. The mechanical parameters completely specifying this spring are identified, including stiffness, amount of rotation, and angle of zero moment. The effect...
Taking inspiration from neurophysiological studies on synergies in the human grasping action, this paper tries to demonstrate that it is possible to find a general rule for performing a stable, human-like cylindrical grasp with a robotic hand. To this purpose, the theoretical formulation and the experimental validation of a reach-and-grasp algorithm for determining the optimal hand position and the...
Functional motor impairment due to Parkinson's disease and other movement disorders are currently assessed with visual rating scales such as the Unified Parkinson's Disease Rating Scale (UPDRS). These methods rely on the subjective judgment of a rater to assign scores representing the extent of impairment while subjects perform prescribed activities. We describe a new model-based framework that uses...
This paper investigates a quantization and clustering issue on human motion performance constrained by disabilities. In a longitudinal study of medical therapy on motion disorder, stages of patient disability condition change over time. We investigate four different stages of one arm constrained walking motions by restricting 0%, 10%, 16% and 22% of arm swing angles. For analysis we use One-way ANOVA...
In this paper, we propose a new joint watermarking/encryption algorithm for the purpose of verifying the reliability of medical images in both encrypted and spatial domains. It combines a substitutive watermarking algorithm, the quantization index modulation (QIM), with a block cipher algorithm, the Advanced Encryption Standard (AES), in CBC mode of operation. The proposed solution gives access to...
The knowledge of the poses and the positions of the knee bones and prostheses is of a great interest in the orthopedic and biomechanical applications. In this context, we use an ultra low dose bi-planar radiographic system called EOS to acquire two radiographs of the studied bones in each position. In this paper, we develop a new method for 2D 3D registration based on the frequency domain to determine...
Early recovery after stroke is significant for slow emergence of volitional movement. Initial movements are constrained by stereotypical co-activation of muscle groups such as shoulder abductors and distal limb flexors resulting in the loss of independent joint control. The objective of this study was to utilize new quantitative methods to evaluate the emergence and progression of the loss of independent...
Wearable inertial systems have recently been used to track human movement in and outside of the laboratory. Continuous monitoring of human movement can provide valuable information relevant to individual's level of physical activity and functional ability. Traditionally, orientation has been calculated by integrating the angular velocity from gyroscopes. However, a small drift in the measured velocity...
In order to provide natural, biomimetic control to recently developed powered ankle prostheses, we must characterize the impedance of the ankle during ambulation tasks. To this end, a platform robot was developed that can apply an angular perturbation to the ankle during ambulation and simultaneously acquire ground reaction force data. In this study, we detail the design of the platform robot and...
The natural non-spherical incongruent hip joint cartilage surface is normally assumed as spherical in shape, which has been extensively applied in orthopedic clinic, hip joint simulation studies and hip joint prosthesis design. The aim of the study was to investigate the contributions of non-spherical incongruent hip joint cartilage surface to the hip joint contact stress, and to assess the effect...
This paper presents an approach for measuring and monitoring human body joint angles using inertial measurement unit (IMU) sensors. This type of monitoring is beneficial for therapists and physicians because it facilitates remote assessment of patient activities. In our approach, two IMUs are mounted on the upper leg and the lower leg to measure the Euler angles of each segment. The Euler angles are...
For any image guided surgery, independently of the technique which is used (navigation, templates, robotics), it is necessary to get a 3D bone surface model from CT or MR images. Such model is used for planning, registration and visualization. We report that graphical representation of patient bony structure and the surgical tools, interconnectively with the tracking device and patient-to-image registration...
In this paper we describe a class of analog algorithms based on the concept of cellular neural networks (CNNs) for detecting osteoarthritis (OA) from x-ray images. The indicator of OA that we examine is the presence of bony spurs or osteophytes in the vicinity of the weight bearing joints of the fingers. Results on a series of hand x-ray images are shown to be promising.
In order to improve the quality of life of persons who lost their limb due to an accident or a sickness, many myoelectric artificial arms have been proposed. To control the motion of the elbow joint of the myoelectric arm, the EMG signals of the biceps brachii and the triceps brachii muscles are frequently used as input signals. However, since both muscles are the biarticular muscles between the shoulder...
A motorized upper extremity orthosis based on the passive WREX system is being developed. The orthosis is a 4 dof arm controlled by user residual force inputs. The arm is intended for people with neuromuscular weakness due to muscular dystrophy or spinal muscular atrophy. Previous work determined that actuation in parallel with gravity balancing springs required less torque than actuation in series...
Recent development methods for surgical robots have an inherent problem. The user-friendliness of operating robot cannot be revealed until completion of the robot. To assist the design of a surgical robot that is user-friendly in terms of surgeon's operation, we propose a system that considers the operation manner of surgeon during the design phase of the robot. This system includes the following...
This article compares two techniques for estimating the parameters describing the motion of a phantom designed to investigate shaking baby syndrome. Parameters of a simple computational model and an impulse response function for a linear second order system were both fitted using kinematic measurements of the motion of an inverted jointed pendulum. From the two methods respectively, the rotational...
In this paper, we explore the combined use of inertial sensors and the Kinect for applications on rehabilitation robotics and assistive devices. In view of the deficiencies of each individual system, a new method based on Kalman filtering was developed in order to perform online calibration of sensor errors automatically whenever measurements from Kinect are available. The method was evaluated on...
We propose a stochastic framework to analyze and compare differences in human motions for applications in injury prevention, rehabilitation, sports training and performance research. Human motions are modeled as Hidden Markov Models and the differences between the motions are measured using the Kullback-Leibler distance metric. The distance metric is recomputed with degrees of freedom excluded to...
The human arm including the shoulder, elbow, wrist joints and exclusion scapular motion has 7 Degrees of Freedom (DOF) while positioning of the wrist in space and orientating the palm is a task that requires 6 DOF. As such it includes one more DOF than is needed to complete the task. Given the redundant nature of the arm, multiple arm configurations can be used to complete a task, which is expressed...
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