Development of three-dimensional motion measuring device for the human ankle joint by using parallel link mechanism

2014 ◽  
Author(s):  
Teru Yonezawa ◽  
Takayuki Onodera ◽  
Ming Ding ◽  
Hiroshi Mizoguchi ◽  
Hiroshi Takemura ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Three Dimensional ◽  
Measuring Device ◽  
Link Mechanism ◽  
Human Ankle ◽  
Parallel Link

Force, Stiffness and Viscous Damping Control of a Stewart-Platform-Type Ankle-Foot Rehabilitation Assist Device with Pneumatic Actuator

2013 ◽  
Vol 25 (6) ◽  
pp. 897-905 ◽  
Author(s):  
Takayuki Onodera ◽  
◽  
Eiji Suzuki ◽  
Ming Ding ◽  
Hiroshi Takemura ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Force Control ◽  
Physical Therapists ◽  
Viscous Damping ◽  
Mean Square ◽  
Assist Device ◽  
Link Mechanism ◽  
Parallel Link ◽  
And Control ◽  
Ankle And Foot

The number of physically disabled people in need of rehabilitation is increasing. Unfortunately, there is a shortage of physical therapists specializing in such rehabilitation. This has increased the demand for rehabilitation assist devices that can lessen the burden of physical therapists. In this study, the authors develop a device that can assist in the rehabilitation of the ankle joint by employing a Stewart-platform (SP)-type parallel-link mechanism. With the SP-type parallel-link mechanism, it is possible to measure and control six degrees-of-freedom (DOFs) of ankle-foot movement during rehabilitation. Because the device enables the measurements of the ankle and foot, it is possible to calculate the instantaneous center of the ankle joint. In previous studies, the authors proposed methods to calculate and control the posture of the ankle and foot by an SP-type parallel-link mechanism and verified their accuracy. In this paper, the authors propose a method for force control using the device and also verify its accuracy. Using this device, the force acting on the ankle-foot can be controlled by six air cylinders. The force produced by a single air cylinder is determined by controlling the pressures in the extension and retraction directions. The accuracy of the force control method is verified for a single air cylinder and for the assist device when all six air cylinders are engaged. Results show that the accuracy of the single air cylinder has a mean square error of 0.24 N or less, while those for force control of the entire device are 4.2 N or less for parallel translation and 3.2 Nm or less for rotation. This demonstrates a satisfactory accuracy. To incorporate rehabilitation assistance by means of stiffness or viscous damping in the future, the authors also propose methods to control the coefficients of stiffness and viscous damping of the air cylinder and verify their accuracy. The mean square errors for the accuracies in controlling the coefficients of stiffness and viscous damping are 3.4 N/m and 1.4 Ns/m, respectively, thus verifying the validity of the proposed methods.

The Three-Dimensional Kinematics and Flexibility Characteristics of the Human Ankle and Subtalar Joints—Part I: Kinematics

1988 ◽  
Vol 110 (4) ◽  
pp. 364-373 ◽  
Author(s):  
Sorin Siegler ◽  
Jie Chen ◽  
C. D. Schneck
Keyword(s):  
Range Of Motion ◽  
Internal Rotation ◽  
Ankle Joint ◽  
Subtalar Joint ◽  
External Rotation ◽  
Three Dimensional ◽  
Lower Limbs ◽  
Helical Axis ◽  
Kinematic Coupling ◽  
Human Ankle

The in-vitro, three dimensional kinematic characteristics of the human ankle and subtalar joint were investigated in this study. The main goals of this investigation were: 1) To determine the range of motion of the foot-shank complex and the associated range of motion of the ankle and subtalar joints; 2) To determine the kinematic coupling characteristics of the foot-shank complex, and 3) To identify the relationship between movements at the ankle and subtalar joints and the resulting motion produced between the foot and the shank. The tests were conducted on fifteen fresh amputated lower limbs and consisted of incrementally displacing the foot with respect to the shank while the motion of the articulating bones was measured through a three dimensional position data acquisition system. The kinematic analysis was based on the helical axis parameters describing the incremental displacements between any two of the three articulating bones and on a joint coordinate system used to describe the relative position between the bones. From the results of this investigation it was concluded that: 1) The range of motion of the foot-shank complex in any direction (dorsiflexion/plantarflexion, inversion/eversion and internal rotation/external rotation) is larger than that of either the ankle joint or the subtalar joint.; 2) Large kinematic coupling values are present at the foot-shank complex in inversion/eversion and in internal rotation/external rotation. However, only a slight amount of coupling was observed to occur in dorsiflexion/plantarflexion.; 3) Neither the ankle joint nor the subtalar joint are acting as ideal hinge joints with a fixed axis of rotation.; 4) Motion of the foot-shank complex in any direction is the result of rotations at both the ankle and the subtalar joints. However, the contribution of the ankle joint to dorsiflexion/plantarflexion of the foot-shank complex is larger than that of the subtalar joint and the contribution of the subtalar joint to inversion/eversion is larger than that of the ankle joint.; 5) The ankle and the subtalar joints have an approximately equal contribution to internal rotation/external rotation movements of the foot-shank complex.

The Three-Dimensional Kinematics and Flexibility Characteristics of the Human Ankle and Subtalar Joint—Part II: Flexibility Characteristics

1988 ◽  
Vol 110 (4) ◽  
pp. 374-385 ◽  
Author(s):  
Jie Chen ◽  
Sorin Siegler ◽  
Carson D. Schneck
Keyword(s):  
Ankle Joint ◽  
Angular Displacement ◽  
Three Dimensional ◽  
Anterior Talofibular Ligament ◽  
Neutral Position ◽  
Nonlinear Load ◽  
Highly Nonlinear ◽  
Human Ankle ◽  
Load Displacement

The objective of the present study was to investigate the in-vitro, coupled, three-dimensional load-displacement and flexibility characteristics of the human ankle joint complex consisting of the talocrural and the talocalcaneal joints and to determine the effects that sectioning of the anterior talofibular ligament has on these characteristics. Similar to other anatomical joints such as the knee and the intervertebral joint, the ankle joint complex was found to exhibit highly nonlinear load-displacement characteristics with the angular displacement approaching asymptotic values as the external load was increased. Therefore, a procedure of incremental linearization was used to derive the flexibility characteristics of this structure. According to this procedure, external loads were applied to the calcaneus in small increments and its resulting three dimensional displacements were recorded. The incremental flexibility coefficients were then derived by assuming linear load-displacement relationship for each increment. From the results obtained from fifteen human ankle specimens, it was evident that the ankle joint complex exhibit highly coupled flexibility and load-displacement characteristics. It was further concluded that the ankle joint complex is the most flexible in the neighborhood of the unloaded, neutral position and that all the flexibility coefficients of the structure decrease rapidly toward the extremes of the range of motion. Rupture of the anterior talofibular ligament was found to have a significant effect on the load-displacement and flexibility characteristics of the ankle joint complex. This effect was manifested as a change in the load-displacement characteristics and a large increase in the flexibility coefficients primarily in those corresponding to rotations in the transverse and the coronal plane. The results of the present study can provide the necessary data base for the development of quantitative diagnostic technique for identifying the site and the extent of injury to the collateral ligaments of the ankle.

Features of geometric design of planetary rotary hydraulic machines with satellite stands

2020 ◽  
pp. 472-478
Author(s):  
D.V. Fadyushin ◽  
G.Yu. Volkov
Keyword(s):  
Three Dimensional ◽  
Geometric Design ◽  
Design System ◽  
Link Mechanism ◽  
Hydraulic Machines ◽  
New Type ◽  
Geometric Calculation

А method of geometric calculation of a new type of planetary rotary hydraulic machines (PRGM) with satellite stands is developed. The method includes the steps of: 1) calculation of the initial round-link mechanism; 2) calculation of non-round links of the PRGM with outstretches; 3) construction and integration of three-dimensional design system COMPAS-3D fragments of crenellated crowns corresponding to the phases of abutments and lifting-lowering satellites; 4) correction of the toothed contours to eliminate the phenomenon of mismatch of satellite centers with the points of intersection of the trajectories of these centers in their movement relative to the rotor and stator. PRGM with satellite stands are designed to operate as vacuum pumps, compressors and pneumatic motors.

scholarly journals Determination of the Optimal Syndesmosis Fixation Angle Using Mortise View of The Ankle Joint

2021 ◽  
Author(s):  
Oğuzhan Tanoğlu ◽  
İzzet Özay Subaşı ◽  
Mehmet Burak Gökgöz
Keyword(s):  
Ankle Joint ◽  
Articular Surface ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Functional Results ◽  
Practical Method ◽  
Medial Malleolus ◽  
Significant Difference ◽  
Horizontal View ◽  
Mortise View

Background: Syndesmosis is an important soft tissue component supporting the ankle stability and commonly injured accompanying with ankle fractures. The accurate reduction and fixation of syndesmosis is essential to obtain better functional results. Therefore, we aimed to find a practical method using the mortise view of ankle to determine the optimal syndesmosis fixation angle intraoperatively. Methods: We randomly selected 200 adults (100 women and 100 men) between 18 - 60 years of age. Three-dimensional anatomical models of tibia and fibula were created using Materialise MIMICS 21. We created a best fit plane on articular surface of medial malleolus and a ninety degrees vertical plane to medial malleolus plane. We determined two splines on cortical borders of tibia and fibula distant from the most superior point of ankle joint in horizontal view. We created two spheres that fit to the predefined splines. The optimal syndesmosis fixation angle was determined measuring the angle between the line connecting the center points of spheres, and the ninety degrees vertical plane to medial malleolus plane. Results: We observed no statistically significant difference between gender groups in terms of optimal syndesmosis fixation angles. The mean age of our study population was 47.1 {plus minus} 10.5. The optimal syndesmosis fixation angle according to mortise view was found as 21 {plus minus} 4.3 degrees. Conclusions: We determined the optimal syndesmosis fixation angle as 21 {plus minus} 4.3 degrees in accordance with the mortise view of ankle. The surgeon could evaluate the whole articular surface of ankle joint with the medial and lateral syndesmotic space in mortise view accurately and at the same position syndesmosis fixation could be performed at 21 {plus minus} 4.3 degrees.

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