Journal articles: 'Artificial hip joints – Design'

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Yao, J. Q., T. V. Parry, A. Unsworth, and J. L. Cunningham. "Contact Mechanics of Soft Layer Artificial Hip Joints: Part 2: Application to Joint Design." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 208, no. 4 (December 1994): 206–15. http://dx.doi.org/10.1243/pime_proc_1994_208_290_02.

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In this paper, the general solutions previously obtained for the contact mechanics of a soft layer artificial hip joint have been applied to the design of such joints. In particular, simple power-law design formulae have been generated for the prediction of the contact radius and the maximum Tresca shear stress within the elastomeric layer, when the aspect ratio varied from 1 to 20 (which covered the entire range of the aspect ratio for soft layer artificial hip joints). The effects of the layer thickness, Young's modulus of the layer and the equivalent radius of the joint upon the contact area and the maximum Tresca shear stress have all been examined for physiological loading conditions which would be experienced by hip joint prostheses in the body. Furthermore, the shear strain field was calculated so that the level of strain expected for such joints under physiological loading conditions can be estimated. With these data, relevant fatigue tests can be devised to assess the long-term performance of any particular design of soft layer hip joint. Finally, the effect of the friction between articular surfaces upon the stress field within soft layers has been examined using a newly developed asymptotic analytical theory. It was shown that, for a low coefficient of friction, the maximum Tresca shear stress occurred at layer-substrate bonding interface. With an increase in the coefficient of friction, however, the maximum Tresca shear stress increased its magnitude and moved towards the centre of the contact area along the articular surface.

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Triyono, Joko, Aditya Rio Prabowo, and Jung Min Sohn. "Investigation of Meshing Strategy on Mechanical Behaviour of Hip Stem Implant Design Using FEA." Open Engineering 10, no. 1 (August 23, 2020): 769–75. http://dx.doi.org/10.1515/eng-2020-0087.

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AbstractHip joint is an important human joints system. The damaged hip joints need to be replaced with artificial hip joints. The Study of the hip joint is very costly therefore another calculation method is demanded to produce good result in acceptable time and cost. Considering this problem, a series of study to assess hip joint performance is conducted using numerical approach. Important parameter for example applied materials are used in the modelling by idealizing Ti-6Al-4V compared to SS 316 L, and stemlengthwas chosen to be 128 mm. ANSYS software was used to analyze models, and designed element size variations were set to be in range 1 to 2.5 mm. The magnitude of force was placed on the femoral head with an angle of 16∘C from the vertical axis. Results showed that SS 316 L material has smaller deformation than Ti material. Whereas Central Processing (CP) time decreases in increasing element size for both materials. In addition, more variations in mesh size are needed to get more accurate convergent results.

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Ilincic, S., N. Tungkunagorn, A. Vernes, G. Vorlaufer, P. A. Fotiu, and F. Franek. "Finite and boundary element method contact mechanics on rough, artificial hip joints." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 225, no. 11 (September 26, 2011): 1081–91. http://dx.doi.org/10.1177/1350650111406776.

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An extremely small roughness of constant height magnitude is considered on the femoral head of an artificial hip joint in order to determine the consequences of various regular shapes and clearances on the mechanical performance of this hip prosthesis via a properly coupled finite and boundary element method. In addition, different material combinations typical for widely used hard-on-hard and hard-on-soft hip joint replacements are also taken into account. By analysing the calculated pressure distribution and contact area between the femoral head and the acetabular cup in frictionless dry contact irrespective of material pairings in hip joints, it is shown that both the wavelength of roughness and the clearance significantly affect these mechanical quantities and accordingly too loose or too tight hip implants have to be avoided. Finally, in terms of all numerical findings a suitable optimal design of hip implants is also discussed.

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Dowson, D., J. Fisher, Z. M. Jin, D. D. Auger, and B. Jobbins. "Design Considerations for Cushion Form Bearings in Artificial Hip Joints." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 205, no. 2 (June 1991): 59–68. http://dx.doi.org/10.1243/pime_proc_1991_205_269_02.

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Tang, Gang, Hong Jiang Yang, Dao Fang Chang, Dong Mei Wang, and Gao Feng Wei. "Human Kinematic Characteristics during Stair Descent." Applied Mechanics and Materials 155-156 (February 2012): 545–49. http://dx.doi.org/10.4028/www.scientific.net/amm.155-156.545.

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To design and manufacture better artificial joints, it is necessary to obtain the motion range of lower limb statistically. General Staircase as an experimental device had been designed; motion capture system and plantar force measurement system were used to establish a systematic measurement method during stairs descent. The variation and range of hip, knee and ankle joints of 40 samples along different directions in a cycle have been calculated. During stair decent, motion range of hip, knee and ankle joints reach maximum in the sagittal plane and are larger comparing to joint motion range in walking and jogging.

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Scholes, S. C., A. Unsworth, J. M. Blamey, I. C. Burges, E. Jones, and N. Smith. "Design aspects of compliant, soft layer bearings for an experimental hip prosthesis." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 219, no. 2 (February 1, 2005): 79–87. http://dx.doi.org/10.1243/095441105x9318.

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Currently, an artificial hip joint can be expected to last, on average, in excess of 15 years with failure due, in the majority of cases, to late aseptic loosening of the acetabular component. A realistic alternative to the problem of wear in conventional joints is the introduction of bearing surfaces that exhibit low wear and operate in the full fluid-film lubrication regime. Contact analyses and friction tests were performed on compliant layer joints (metal-on-polyurethane) and the design of a prototype ovine arthroplasty model was investigated. When optimized, these components have been shown to achieve full fluid-film lubrication.

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Ishihara, Kazuhiko. "Highly lubricated polymer interfaces for advanced artificial hip joints through biomimetic design." Polymer Journal 47, no. 9 (June 10, 2015): 585–97. http://dx.doi.org/10.1038/pj.2015.45.

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Ren, Bin, Jianwei Liu, Xurong Luo, and Jiayu Chen. "On the kinematic design of anthropomorphic lower limb exoskeletons and their matching movement." International Journal of Advanced Robotic Systems 16, no. 5 (September 1, 2019): 172988141987590. http://dx.doi.org/10.1177/1729881419875908.

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The lower limb exoskeleton is a wearable device for assisting medical rehabilitation. A classical lower limb exoskeleton structures cannot precisely match the kinematics of the wearer’s limbs and joints in movement, so a novel anthropomorphic lower limb exoskeleton based on series–parallel mechanism is proposed in this article. Then, the human lower limb movements are measured by an optical gait capture system. Comparing the simulation results of the series–parallel mechanism with the measured human data, the kinematics matching model at the hip joint is established. The results show that the kinematic matching errors in the X, Y, and Z directions are less than 2 mm. So, the proposed kinematics matching model is effective and the anthropomorphic series–parallel mechanism has a significant improvement in tracing the human positions at the hip joint.

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Li, Gang, Qiying Su, Wenqiu Xi, Zhendong Song, Renren Bao, and Zhenjun Du. "Dynamic analysis and design of a multipurpose lower limb exoskeleton for rehabilitation." International Journal of Advanced Robotic Systems 19, no. 6 (November 1, 2022): 172988062211351. http://dx.doi.org/10.1177/17298806221135140.

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To solve some defects of exoskeleton robot at present, this article establishes the dynamic model of human lower limb. The torque curves for hip joint and knee joint are obtained. A dynamics simulation is conducted in ADAMS which will guide the selection of motors and reducers for exoskeleton joints. Three structural design projects for leg and an integrated joint with the function of force perception are proposed. Then a lightweight exoskeleton is put forward and a kinematics simulation of man–machine coupling system is carried out in ADAMS. This article sets up a 24-V low-voltage control electrical system and a rehabilitation training expert system. Some performance tests and clinical experiments are carried out by an experimental prototype. The results show that the joints have sufficient driving torque. Leg structure has large adjustment range and self-locking function. The exoskeleton has lightweight and does not interfere with human body during movement. The expert system has a friendly operation interface and abundant functions. Clinical experimental results show that lower limb exoskeleton has good rehabilitation effect for some diseases.

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Yao, J. Q. "Contact Mechanics of Soft Layer Artificial Hip Joints: Part 1: General Solutions." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 208, no. 4 (December 1994): 195–205. http://dx.doi.org/10.1243/pime_proc_1994_208_289_02.

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Unlike natural synovial joints, which are lubricated with a full fluid film lubrication mechanism, conventional artificial hip joints are lubricated with a mixed lubrication mechanism. Recently, however, a new generation of artificial hip joints employing compliant layers to mimic the compliance of articular cartilage in natural synovial joints have been developed to provide fluid film lubrication in these joints. While satisfactory lubrication can be achieved by employing soft layers, compliant thin layers are susceptible to the debonding between the soft layer and its stiffer substrate and long-term mechanical fatigue failure. Stress analyses for different designs of such joints are therefore important. In the present paper, the circular contact between a rigid sphere and an elastomeric layer bonded on to a rigid substrate has been analysed with a novel semi-analytical approach. The detailed contact parameters (the contact radius, the maximum surface deformation, the contact pressure and the contact stress inside the layer) have been examined for a wide range of aspect ratios (0 ≤ a/ht ≤ 100).

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Kim, Yun Hae, Sung Won Yoon, Min Kyo Jung, Jin Cheol Ha, and Ri Ichi Murakami. "Design of Artificial Hip Joint by Carbon/PEEK Composites." Advanced Materials Research 774-776 (September 2013): 1336–41. http://dx.doi.org/10.4028/www.scientific.net/amr.774-776.1336.

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The purpose of this study is to determine the correct estimation of the various designs for artificial hip joint of the Carbon/PEEK composites. Validity of the study has been tested with the alternative materials for the metal-based materials for artificial hip joint. Moreover, this work evaluated the FEA according to the fiber ply orientation and the condition of load. The stem shape of two kinds was designed through the normal shape of the femur. Three load cases of 1kN, 2.5kN and 5kN were used for each of FEA model. In the case of general shape, the results by ply configuration showed that the stress of ply configuration I was lower compared to ply configuration II and III. On the other hand, in the case of curved shape, ply configuration II were lower compared to ply configuration I and III. The result was checked that the stress of curved shape was higher than that of the general shape in the load of 2.5kN. It could be confirmed then that a similar phenomenon would occur in the condition of 5kN load. However, in the case of ply configuration II, the stress of the curved shape was lower than the stress of the general shape.

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Ishida, Toshimasa, Ikuya Nishimura, Hiromasa Tanino, Hiroshi Ito, Takeo Matsuno, and Yoshinori Mitamura. "1233 Multicriteria design optimization for an artificial hip joint." Proceedings of the JSME annual meeting 2005.5 (2005): 207–8. http://dx.doi.org/10.1299/jsmemecjo.2005.5.0_207.

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Fouly, Ahmed, Ibrahim A. Alnaser, Abdulaziz K. Assaifan, and Hany S. Abdo. "Evaluating the Performance of 3D-Printed PLA Reinforced with Date Pit Particles for Its Suitability as an Acetabular Liner in Artificial Hip Joints." Polymers 14, no. 16 (August 15, 2022): 3321. http://dx.doi.org/10.3390/polym14163321.

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Off-the-shelf hip joints are considered essential parts in rehabilitation medicine that can help the disabled. However, the failure of the materials used in such joints can cause individual discomfort. In support of the various motor conditions of the influenced individuals, the aim of the current research is to develop a new composite that can be used as an acetabular liner inside the hip joint. Polylactic acid (PLA) can provide the advantage of design flexibility owing to its well-known applicability as a 3D printed material. However, using PLA as an acetabular liner is subject to limitations concerning mechanical properties. We developed a complete production process of a natural filler, i.e., date pits. Then, the PLA and date pit particles were extruded for homogenous mixing, producing a composite filament that can be used in 3D printing. Date pit particles with loading fractions of 0, 2, 4, 6, 8, and 10 wt.% are dispersed in the PLA. The thermal, physical, and mechanical properties of the PLA–date pit composites were estimated experimentally. The incorporation of date pit particles into PLA enhanced the compressive strength and stiffness but resulted in a reduction in the elongation and toughness. A finite element model (FEM) for hip joints was constructed, and the contact stresses on the surface of the acetabular liner were evaluated. The FEM results showed an enhancement in the composite load carrying capacity, in agreement with the experimental results.

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Annanto, Gilar Pandu, Eko Saputra, J. Jamari, Athanasius Priharyoto Bayuseno, Rifky Ismail, Mohammad Tauviqirrahman, and Iwan Budiwan Anwar. "Numerical Analysis Of Stress Distribution On Artificial Hip Joint Due To Jump Activity." E3S Web of Conferences 73 (2018): 12005. http://dx.doi.org/10.1051/e3sconf/20187312005.

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Due to degenarative disorder of articular cartilage, hip joint need to be replaced with an artificial hip joint. Currently, the modular design of artificial hip joint become popular in the procedure because the modular type’s provide flexibility for the surgeon. But, there were several report about the failure of modular version, and the failure was likely to happen on the neck part. The main focus of this research was to ensure the design safety of present artificial hip joint using FEM (Finite Element Method). The present artificial hip joint was loaded with force that occurred due to jump activity, and there were 3 type of materials that used in this research (Titanium Alloy (Ti-6Al-4V), Cobalt - Chrome alloy, and stainless steel (SS) 316L). The result is maximum stress that occurred on Ti-6Al-4V, Co-Cr alloy, and SS316L were 296.13 MPa, 294.02 MPa, and 294.51 MPa, respectively. The Ti-6Al-4V perform the best among the others with the safety factor of 2.7.

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Bouziane, M. M., S. Benbarek, S. M. H. Tabeti, Bel Abbès Bachir Bouiadjra, B. Serier, and T. Achour. "Finite Element Analysis of the Mechanical Behaviour of the Different Cemented Hip Femoral Prostheses." Key Engineering Materials 577-578 (September 2013): 349–52. http://dx.doi.org/10.4028/www.scientific.net/kem.577-578.349.

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The designs of cemented hip femoral stems have an influence on both the quality of the metalbone cement contact and the failure rate of the cement mantle. Finite element stress technique has been used to optimize both design and material selection in load-bearing components in artificial hip joints based on the static load analysis, by selecting the peak load during the patient activity. In this study, two stem shapes (Ceraver Osteal and Charnley stems) for total hip arthoplasty (THA) were modelled. Static behaviour of these designed stem shapes were analyzed using commercial finite element analysis code ABAQUS. Linear elastic analysis is adapted; Von Mises stress and shear stress are the criterions that are of concern. Results show that, the stresses distribution in the femoral arthroplasty components depends on the material and design of the stem. In addition, the cement-bone and cement-stem interfaces seem to be crucial for the success of the hip replacement, hip prosthesis with Charnely stem induces the more stresses on the interfaces cement.

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Jin, Z. M., and D. Dowson. "A full numerical analysis of hydrodynamic lubrication in artificial hip joint replacements constructed from hard materials." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 213, no. 4 (April 1, 1999): 355–70. http://dx.doi.org/10.1243/0954406991522310.

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A full numerical analysis of the hydrodynamic lubrication problem of artificial hip joint replacements with surfaces of high elastic modulus materials, such as metal-on-metal or ceramic-on-ceramic, under cyclic walking conditions is reported in this paper. The Reynolds equation in spherical coordinates has been solved for both entraining and combined entraining and squeeze film motions under a three-dimensional variation in both the load and the speed experienced in hip joints during walking. It has been shown that a finite lubricating film thickness can be developed during the walking cycle owing to the combined action of the squeeze film and entraining motions under some conditions. It has been found that the design parameters for plain spherical bearings, such as the femoral head radius and the radial clearance between the femoral head and the acetabular cup, have a large effect on the magnitude of the predicted lubricating film thickness. Some interest has been shown in recent years in the performance of metal-on-metal bearings in which a dimple has been machined at the pole of the acetabular cup. It is shown that a dimple on the acetabular cup can significantly increase the film thickness throughout the walking cycle, particularly for relatively large depths and if the location of the dimple coincides with the direction of the resultant force acting on the joints. It is concluded that there is a good possibility that a full continuous hydrodynamic lubricating film can be developed in ceramic-on-ceramic hip joint replacements, and perhaps for some well-finished metal-on-metal implants with a relatively small radial clearance. For some metal-on-metal configurations, the effect of elastic deformation of the bearing surfaces must be taken into account in the lubrication analysis, particularly for a relatively large radial clearance.

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Saputra, Eko, Iwan Budiwan Anwar, J. Jamari, and Emile van der Heide. "A Bipolar Artificial Hip Joint Design for Contact Impingement Reduction." Advanced Materials Research 1123 (August 2015): 164–68. http://dx.doi.org/10.4028/www.scientific.net/amr.1123.164.

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The acetabular liner of an artificial hip joint (AHJ) is easily damaged locally in case of impingement, i.e. in case of contact of the liner wall with the stem neck, especially when it is made from relatively soft material such as ultra high molecular weight polyethylene (UHMWPE). Frequent impingement will severely damage the acetabular liner, requiring replacement of the AHJ. The aim of this study is to reduce AHJ impingement for specific combinations of flexion, internal rotation, and adduction of the thigh, by optimizing the design of the AHJ. The presented new design is based on modifying a conventional AHJ into a bipolar version with a higher free range of motion (RoM). Results show that the proposed design is able to prevent impingement for RoM. The latter range of motion corresponds well with the requirements of Shalat.

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Ismail, Rifky, Eko Saputra, Mohammad Tauviqirrahman, A. B. Legowo, Iwan Budiwan Anwar, and J. Jamari. "Numerical Study of Salat Movements for Total Hip Replacement Patient." Applied Mechanics and Materials 493 (January 2014): 426–31. http://dx.doi.org/10.4028/www.scientific.net/amm.493.426.

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Salat as a daily Muslim activitiy in praying contains several movements which are not suggested by orthopaedic doctor to be conducted by patient with total hip replacement (THR). Sujud and sitting are two movements in Salat which is recommended to be done above the chair for THR patients. There are lacks of scientific discussions about the consequences of the normal salat movement for Muslim THR patients. This paper observes the effect of these movements to the artificial hip joint in THR patient body. A three-dimensional finite element simulation is used to investigate the resisting moment, the contact pressure and the von Mises stress. An artificial hip joint model proposed by previous researcher is used in the simulations. The results show that sujud induces the impingement and plastic deformation whereas sitting is relatively safe to be conducted by THR patients. Some suggestions are also discussed with respect to the design of new artificial hip joint model which allows THR patients to conduct Salat in a normal way. The reduction of inset at the liner, the new profile at circumferential edge inner liner and the increase in the femoral head diameter can be considered as a guideline for new design of the artificial hip joint for Muslim.

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Qian, Zhi Hui, Jia Jia Wang, Lei Ren, Lu Quan Ren, and Tao Xu. "An Innovative Design and Structural Mechanics Analysis of Artificial Hip Joint." Advanced Materials Research 694-697 (May 2013): 3094–100. http://dx.doi.org/10.4028/www.scientific.net/amr.694-697.3094.

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Using finite element (FE) method, this work established and comparatively analyzed the basic femoral head model, and six innovative femoral head models with different micropore surface distribution, aiming to explore the most rational surface morphology to have better effect on artificial hip implant. The inboard and outboard femur, the metal handle, and the femoral head’ stress responses were concerned. As the results showed, compared with type A (original femur head, with “smoothed” surface), the other six shaped femur head design all have reduced the maximal stress with different degrees. However, femur model surface type C arranged with 1mm-diametre distributed in three rows of micropore caused the best effect. Within the scope of the study, both micropore size and arranging way influenced the stress distribution at key components of artificial hip joint, especially the effect of micropore size exceeded arranging way of them. Based on the simulation results, it is proposed the whole rigidity of the artificial femoral head with microporous morphology, was reduced to some degree and therefore reducing the stress shielding effect, decreasing the possibility of embedded part being deformed or flexible, which is beneficial to improving life span of the prosthesis.

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HIROSAKI, Kenichi, Kazuhiro SHINTANI, and Ayumi KANEUJI. "Development of Custom-made Design Method of Artificial Hip Joint Stem." Journal of the Japan Society for Precision Engineering 74, no. 3 (2008): 313–18. http://dx.doi.org/10.2493/jjspe.74.313.

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Xie, Hualong, Zhijie Li, and Fei Li. "Bionics Design of Artificial Leg and Experimental Modeling Research of Pneumatic Artificial Muscles." Journal of Robotics 2020 (February 28, 2020): 1–11. http://dx.doi.org/10.1155/2020/3481056.

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In the research and development of intelligent prosthesis, some of performance test experiments are required. In order to provide an ideal experimental platform for the performance test of intelligent prosthesis, a heterogeneous biped walking robot model is proposed. Artificial leg is an important part of heterogeneous biped walking robot, and its main function is to simulate the disabled a healthy normal gait, which provides intelligent bionic legs gait to follow the target trajectory. The pneumatic artificial muscles (PAM) have good application in the artificial leg. The bionic design of artificial leg mainly includes the structure of hip joint, knee joint, and ankle joint, adopting the four-bar mechanism as the mechanical structure of the knee joint, and PAM are used as the driving source of the knee joint. Secondly, the PAM performance test platform is built to establish the relationship among output force, shrinkage rate, and input pressure under the measured isobaric conditions, and the mathematical model of PAM is established. Finally, the virtual prototype technology is used to build a joint simulation platform, and PID control algorithm is used for verification simulation. The results show that the artificial leg can follow the target trajectory.

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Jamari, J., Rifky Ismail, Eko Saputra, S. Sugiyanto, and Iwan Budiwan Anwar. "The Effect of Repeated Impingement on UHMWPE Material in Artificial Hip Joint during Salat Activities." Advanced Materials Research 896 (February 2014): 272–75. http://dx.doi.org/10.4028/www.scientific.net/amr.896.272.

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In Indonesia, a country with largest Muslim population in the world, the necessity to study the artificial hip joint which allows Muslim patients with total hip replacement to have normal Salat becomes important issues. This paper discusses the effect of impingement which occurs during one of the Salat movements. i.e. last tashahhud sitting motion. An artificial hip joint model, proposed by previous researcher from developed country, is simulated using finite element analysis to perform last tashahhud sitting motion. The result shows that impingement occurs and causes the plastic deformations and plastic strains in the acetabular liner component which is manufactured from UHMWPE material. The repetition of Salat movement induces repeated impingements and higher plastic deformation. It experiences dimensional change in the liner lip and has a potency to cause clinical failure of total hip replacement. A new design of the artificial hip joint is required to be proposed to avoid the repeated impingement and deformations.

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Flanagan, S., E. Jones, and C. Birkinshaw. "In vitro friction and lubrication of large bearing hip prostheses." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 224, no. 7 (December 15, 2009): 853–64. http://dx.doi.org/10.1243/09544119jeim733.

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New material combinations and designs of artificial hip implants are being introduced in an effort to improve proprioception and functional longevity. Larger joints in particular are being developed to improve joint stability, and it is thought that these larger implants will be more satisfactory for younger and more physically active patients. The study detailed here used a hip friction simulator to assess the friction and lubrication properties of large-diameter hip bearings of metal-on-metal and ceramic-on-reinforced-polymer couplings. Joints of different diameters were evaluated to determine what effect, if any, bearing diameter had on lubrication. In addition, the effects of lubricant type are considered, using carboxymethyl cellulose and bovine calf serum, and the physiological lubricant is shown to be considerably more effective at reducing friction. The frictional studies showed that the metal-on-metal joints worked under a mixed lubrication regime, producing similar friction factor values to each other. The addition of bovine calf serum (BCS) reduced the friction. The ceramic-on-reinforced-polymer samples were shown to operate with high friction factors and mixed lubrication. When tested with BCS, the larger-diameter bearings showed a decrease in friction compared with the smaller-size bearings, and the addition of BCS resulted in an increase in friction, unlike the metal-on-metal system. The study demonstrated that the component's diameter had little or no influence on the lubrication and friction of the large bearing combinations tested.

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Gavrjushenko, N. S. "Recommendations with Respect to the Improvement of Lubricating Qualities of Synovial Fluid in Artificial Joints." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 207, no. 2 (June 1993): 111–14. http://dx.doi.org/10.1243/pime_proc_1993_207_278_02.

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This paper gives a short description of the lubricating properties of yellow and red bone marrow taken from a femur of a cadaver. The experiments have been conducted on a ‘ball-on-plate’ model. The balls were made from steel 100 CR6 (German) and the plates were made from the same steel and ultra-high molecular weight polyethylene (UHMWPE, German ‘Herulen’). The friction coefficients under loads of 50 and 300 N were determined with different combinations of friction components. It has been found that the lubricating properties of yellow and red marrow have advantages over synovial fluid. In the light of these results the author develops a new approach to the design of a new hip endoprosthesis.

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Ajayi, Michael Oluwatosin, Karim Djouani, and Yskandar Hamam. "Rhythmic Trajectory Design and Control for Rehabilitative Walking in Patients with Lower Limb Disorder." International Journal of Humanoid Robotics 13, no. 04 (November 29, 2016): 1650006. http://dx.doi.org/10.1142/s0219843616500067.

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Wearable robotic systems have been a mechanism which clearly drives the motive of bringing back paraplegics back on their feet as well as executing difficult task beyond human ability. The purpose of this research study is to design and investigate the efficacy of rehabilitative walking in patients with lower limb disorders using oscillators which may commonly be referred to as central pattern generators (CPGs). In order to achieve this, a rhythmic trajectory is designed using Van der Pol oscillators. This rhythmic trajectory commensurates with the movement pattern of the hips and knees for a normal walking gait of humans. The dynamical model of a five-link biped exoskeletal device having four actuated joints is computed with regard to the wearer using Lagrangian principles in the sagittal plane. A feedback linearization control technique is therefore utilized for tracking the rhythmic trajectory to achieve a proper following of the human walking gait. Matlab/Simulink is used to validate this proposed strategy in the presence of uncertainties with a view to implementing it practically in the laboratory with human in the loop. Results show that humans with the aid of the exoskeleton device will possess the ability to track this rhythmic trajectory representing the hip and knee joint movements. The controller proved robust enough against disturbance.

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UCHIDA, Takako, Akiko MORI, Koichi KURAMOTO, Noriyuki NAGAYAMA, and Takaaki SARAI. "Influence of Artificial Hip Joint Design on Stress Distribution in the Femur." Proceedings of the JSME annual meeting 2003.7 (2003): 145–46. http://dx.doi.org/10.1299/jsmemecjo.2003.7.0_145.

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KUNIMOTO, Hiromichi, Taiji ADACHI, and Yoshihiro TOMITA. "Stem Shape Design of Artificial Hip Joint Using the Voxel Based FEM." Proceedings of the 1992 Annual Meeting of JSME/MMD 2002 (2002): 441–42. http://dx.doi.org/10.1299/jsmezairiki.2002.0_441.

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Tijjani, Ibrahim, Shivesh Kumar, and Melya Boukheddimi. "A Survey on Design and Control of Lower Extremity Exoskeletons for Bipedal Walking." Applied Sciences 12, no. 5 (February 25, 2022): 2395. http://dx.doi.org/10.3390/app12052395.

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Exoskeleton robots are electrically, pneumatically, or hydraulically actuated devices that externally support the bones and cartilage of the human body while trying to mimic the human movement capabilities and augment muscle power. The lower extremity exoskeleton device may support specific human joints such as hip, knee, and ankle, or provide support to carry and balance the weight of the full upper body. Their assistive functionality for physically-abled and disabled humans is demanded in medical, industrial, military, safety applications, and other related fields. The vision of humans walking with an exoskeleton without external support is the prospect of the robotics and artificial intelligence working groups. This paper presents a survey on the design and control of lower extremity exoskeletons for bipedal walking. First, a historical view on the development of walking exoskeletons is presented and various lower body exoskeleton designs are categorized in different application areas. Then, these designs are studied from design, modeling, and control viewpoints. Finally, a discussion on future research directions is provided.

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Jin, Z. M. "A general axisymmetric contact mechanics model for layered surfaces, with particular reference to artificial hip joint replacements." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 214, no. 5 (May 1, 2000): 425–35. http://dx.doi.org/10.1243/0954411001535453.

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A general axisymmetric contact mechanics model for layered surfaces is considered in this study, with particular reference to artificial hip joint replacements. The indenting surface, which represents the femoral head, was modelled as an elastic solid with or without coating, while the other contacting surface, which represents the acetabular cup, was modelled as a two-layered solid. It is shown that this model is applicable to current total hip joint prostheses employing ultra-high molecular weight polyethylene (UHMWPE) acetabular cups against metallic, metallic with coating or ceramic femoral heads as well as metal-on-metal combinations. The effect of cement is also investigated for these prostheses using this model. The use of a metallic bearing surface bonded to a UHMWPE substrate for acetabular cups is particularly examined for metal-on-metal hip joint replacements. Both the contact radius and the contact pressure distribution are predicted for examples of these total hip joint replacements, under typical conditions. Application of contact mechanics to the design of artificial hip joint replacements employing various material combinations is discussed.

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Bader, Rainer, E. Steinhauser, Gerd Willmann, and R. Gradinger. "Limitations of Artificial Hip Joint Mobility Due to Wear and Ceramic Cup Design." Key Engineering Materials 192-195 (September 2000): 549–52. http://dx.doi.org/10.4028/www.scientific.net/kem.192-195.549.

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Wicaksono, Fabian Singgih, T. Towijaya, Eko Saputra, Rifky Ismail, Mohammad Tauviqirrahman, J. Jamari, and Athanasius P. Bayuseno. "Study of Sensor Deflection in Hip Simulator : Numerical and Experimental Method." E3S Web of Conferences 73 (2018): 01022. http://dx.doi.org/10.1051/e3sconf/20187301022.

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A lot of Hip Joint Simulator have been made nowadays, most of them use different structure and method. This research reports a pin-on-ring tribometer design that is used to became hip joint simulator based on the movement of the salat (salat gait). Modified femoral head and acetabular cup holder are performed, to design a reciprocating motion for simulation of artificial hip movement. An interesting finding from this study is a new linked-bar mechanism that leads to the ability to move femoral head against the acetabular cup and measure wear volume of an THR patients during normal salat gait. The designed motion angle is 121.5° in the flexion direction and 15.5° in the direction of abduction. Linked bar for sensor dial indicator have enough adjustment, but there is still a movement that is not rigid upon running hip joint process simulator. This research concentrates on the bar is already linked in accordance or not when compared with the data in the simulate on a computer. Estimation error and deviations that occur between numerical and experimental is going forward to improve hip joint simulator Undip to be more precise and relevant research to use THR Undip.

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Sunilkumar, Parvathi, Santhakumar Mohan, Jayant Kumar Mohanta, Philippe Wenger, and Larisa Rybak. "Design and motion control scheme of a new stationary trainer to perform lower limb rehabilitation therapies on hip and knee joints." International Journal of Advanced Robotic Systems 19, no. 1 (January 1, 2022): 172988142210751. http://dx.doi.org/10.1177/17298814221075184.

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Limb disability is one of the serious problems and rehabilitation of lower limb requires an assistive force to the patient. A new design for stationary trainer for performing rehabilitation therapies for lower limb at the knee as well as hip joints in the sitting/lying positions is presented in this article. A passive orthosis (similar to an exoskeleton) is suggested in this system to provide a support to lower limb of the patient. The suggested mechanism also comprises of an active Cartesian manipulator based upon a spatial three parallel prismatic–revolute–revolute–revolute kinematic arrangement to perform the required limb therapeutic motions in the transverse/horizontal/lateral and sagittal/longitudinal plane. Numerically, the usefulness of the designed stationary trainer is confirmed using computer-based simulations along with a motion control scheme by performing various clinically suggested therapeutic motion tracking (passive range of motions) tasks. The article demonstrates the accomplishment of the control scheme for various training procedures of the lower limb.

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Dragoni, E., and A. O. Andrisano. "Structural Evaluation of Ceramic Femoral Heads: Effect of Taper Friction, Support Conditions and Trunnion Compliance." Journal of Biomechanical Engineering 117, no. 3 (August 1, 1995): 293–99. http://dx.doi.org/10.1115/1.2794184.

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The outcome of a nonlinear finite element stress analysis of ceramic heads for artificial hip joints is presented. The analysis mainly covers the influence of taper friction, support conditions and trunnion modulus of elasticity on the hoop stress distribution at the surface of the head bore. The paper quantifies how much the maximum tensile stress decreases with increasing frictional coefficient, with stiffening of the support and with stiffening of the trunnion material. An appreciable rise of the maximum tensile upon unloading of the head is also shown for the case of cup support. The computational results are found in close correspondence with photoelastic measurements of taper pressures and encourage the use, for preliminary design purposes, of an approximate theoretical model retrieved from the literature.

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Asmaria, Talitha, Dita Ayu Mayasari, Alfensa Dinda Gestara Febrananda, Nadiya Nurul, Ahmad Jabir Rahyussalim, and Ika Kartika. "Computed tomography image analysis for Indonesian total hip arthroplasty designs." International Journal of Electrical and Computer Engineering (IJECE) 12, no. 6 (December 1, 2022): 6123. http://dx.doi.org/10.11591/ijece.v12i6.pp6123-6131.

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<span lang="EN-US">Total hip arthroplasty purposes to replace a hip joint damaged by an artificial hip joint. However, the developed products that already exist in the market lead to the mismatch between the hip implant equipment and the patient’s bone morphometric. Besides causing complications, the mismatch also continues to the dislocation effects, fracture, osteolysis, and thigh pain. This paper aims to design a customized hip implant based on real patient data, particularly for Indonesian patient, limited to the acetabular components and stem parts. The computed images were analyzed to estimate the patient proximal femur morphometric; those are the femoral head diameter, neck-shaft angle, mediolateral width, anteroposterior width, neck length and neck width. The experiment has succeeded in designing the acetabular shell with the thickness of 3 mm, the acetabular liner with the thickness of 6 mm, the femoral head between 22.4 to 24.8 mm, the short stem in both the right for 110.656 mm and left femur bone for 111.49 mm; that fit the patient's femur bone. Overall, the proposed steps in designing the customized hip implant in this work, based on image analysis on medical imaging data, can be a standard to be applied for other patient-needs hip arthroplasty implants.</span>

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Affatato, Saverio, and Alessandro Ruggiero. "A Perspective on Biotribology in Arthroplasty: From In Vitro toward the Accurate In Silico Wear Prediction." Applied Sciences 10, no. 18 (September 10, 2020): 6312. http://dx.doi.org/10.3390/app10186312.

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Nowadays hip arthroplasty is recognized as one of the most successful orthopedic surgical procedures, even if it involves challenges to overcome, such that lately, younger and more active patients are in need of total arthroplasty. Wear is still one of the main issues affecting joint prostheses endurance, and often causes loosening accompanied by implant failures. Actual in vitro wear tests executed by mechanical simulators have a long duration, are very expensive, and do not take into account all the possible daily activities of the patients; thus, the challenge to obtain a complete in silico tribological and dynamical model of (bio) tribo-systems could give the possibility to overcome the actual testing procedures and could contribute as a tool for a more accurate tribological design of human prostheses. This prospective paper is intended to underline actual research trends toward the challenge of having accurate numerical algorithms to be used both in preclinical testing and in the optimizations of the prostheses design. With this aim we depicted the possible in silico approach in artificial joints’ wear assessment over time, accounting for contact mechanics, numerical stress–strain analysis, musculoskeletal multibody, and synovial lubrication modelling (boundary/mixed, hydrodynamic, and elastohydrodynamic).

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Fouly, Ahmed, Abdulaziz K. Assaifan, Ibrahim A. Alnaser, Omar A. Hussein, and Hany S. Abdo. "Evaluating the Mechanical and Tribological Properties of 3D Printed Polylactic-Acid (PLA) Green-Composite for Artificial Implant: Hip Joint Case Study." Polymers 14, no. 23 (December 4, 2022): 5299. http://dx.doi.org/10.3390/polym14235299.

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Artificial implants are very essential for the disabled as they are utilized for bone and joint function in orthopedics. However, materials used in such implants suffer from restricted mechanical and tribological properties besides the difficulty of using such materials with complex structures. The current study works on developing a new polymer green composite that can be used for artificial implants and allow design flexibility through its usage with 3D printing technology. Therefore, a natural filler extracted from corn cob (CC) was prepared, mixed homogeneously with the Polylactic-acid (PLA), and passed through a complete process to produce a green composite filament suit 3D printer. The corn cob particles were incorporated with PLA with different weight fractions zero, 5%, 10%, 15%, and 20%. The physical, mechanical, and tribological properties of the PLA-CC composites were evaluated. 3D finite element models were constructed to evaluate the PLA-CC composites performance on a real condition implant, hip joints, and through the frictional process. Incorporating corn cob inside PLA revealed an enhancement in the hardness (10%), stiffness (6%), compression ultimate strength (12%), and wear resistance (150%) of the proposed PLA-CC composite. The finite element results of both models proved an enhancement in the load-carrying capacity of the composite. The finite element results came in line with the experimental results.

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Gao, Moyao, Zhanli Wang, Zaixiang Pang, Jianwei Sun, Jing Li, Shuang Li, and Hansi Zhang. "Electrically Driven Lower Limb Exoskeleton Rehabilitation Robot Based on Anthropomorphic Design." Machines 10, no. 4 (April 7, 2022): 266. http://dx.doi.org/10.3390/machines10040266.

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To help people with impairment of lower extremity movement regain the ability to stand and walk, and to enhance limb function, this study proposes an anthropomorphic design of an electrically driven, lower-limb exoskeleton rehabilitation robot. The angular range of the robot’s motion was determined according to the characteristics of the targeted lower-limb joints; the robot was given an active–passive anthropomorphic design with 12 degrees of freedom. The multi-degree-of-freedom hip exoskeleton, bionic artificial knee exoskeleton and passive rigid-flexible coupling ankle exoskeleton can assist patients in rehabilitation exercises with better wear comfort and exercise flexibility. A kinetic model of the seven-rod lower-limb exoskeleton rehabilitation robot was built, and data analysis of the dynamically captured motion trajectory was conducted. These provided a theoretical basis for gait planning and the control system of the lower-limb exoskeleton rehabilitation robot. The results show that the lower-limb exoskeleton rehabilitation robot system possesses sound wearing comfort and movement flexibility, and the degree of freedom of movement of the exoskeleton robot matches well with that of human movement. The robot can thus provide effective assistance to patients’ standing and walking rehabilitation training.

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38

KUNIMOTO, Hiromichi, Ken-ichi TSUBOTA, Taiji ADACHI, and Yoshihiro TOMITA. "1A42 Stem Design of Artificial Hip Joint Based on Stress Uniformity at Bone-Stem Interface." Proceedings of the JSME Bioengineering Conference and Seminar 2001.12 (2001): 27–28. http://dx.doi.org/10.1299/jsmebs.2001.12.0_27.

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MAEZAKI, Nobutaka, Tsutomu EZUMI, and Masashi HACHIYA. "1005 Study on Optimization of the Design Condition in Artificial Hip Joint using Photoelastic Method." Proceedings of Ibaraki District Conference 2010.18 (2010): 279–80. http://dx.doi.org/10.1299/jsmeibaraki.2010.18.279.

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40

NAKAMURA, Shohei, Mitsugu TODO, Toshihiko HARA, Masaaki MAWATARI, Takao HOTOKEBUCHI, and Youichi SUGIOKA. "1910 Effect of stem design of artificial hip joint on the mechanical condition of femur." Proceedings of The Computational Mechanics Conference 2009.22 (2009): 782–83. http://dx.doi.org/10.1299/jsmecmd.2009.22.782.

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41

Vinoth, A., and Shubhabrata Datta. "Design of the ultrahigh molecular weight polyethylene composites with multiple nanoparticles: An artificial intelligence approach." Journal of Composite Materials 54, no. 2 (July 2, 2019): 179–92. http://dx.doi.org/10.1177/0021998319859924.

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This study proposes a suitable composite material for acetabular cup replacements in hip joint that involves ultrahigh molecular weight polyethylene, a clinically proven material, as the matrix. To design new ultrahigh molecular weight polyethylene composites with multiple reinforcements for the improvement in mechanical and tribological performance, artificial neural network and genetic algorithm, the two artificial intelligence techniques, are employed. Published reports on the use of ultrahigh molecular weight polyethylene reinforced with multi-walled carbon nanotube and graphene are used as database to develop two artificial neural network models for Young's modulus and tensile strength. The optimum solutions are obtained using genetic algorithm, where the artificial neural network models are used as the objective functions. Two different composites, derived from the optimum solutions, are made reinforcing both multi-walled carbon nanotube and graphene. Tensile and wear tests show significant enhancement in the properties. The structures of the composites are also characterized, and wear mechanisms are discussed.

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Jiang, Hai-bo. "Static and dynamic mechanics analysis on artificial hip joints with different interface designs by the finite element method." Journal of Bionic Engineering 4, no. 2 (June 2007): 123–31. http://dx.doi.org/10.1016/s1672-6529(07)60024-9.

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43

Suslyaev, V. G., K. K. Scherbina, L. M. Smirnova, A. V. Sokurov, and T. V. Ermolenko. "Medical technology of early recovery of the ability to move independently after amputation of the lower limb." Bulletin of the Russian Military Medical Academy 21, no. 2 (December 15, 2019): 101–9. http://dx.doi.org/10.17816/brmma25928.

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Results of early restoration of the ability to independent movement after amputation of the lower extremities as possibilities of prevention of development of the complications connected with a hypodynamia for reduction of terms of medical rehabilitation and restoration of quality of life are presented. Preparation for prosthetics was carried out with the application of modern methods of medical physical culture according to four motor activity levels. For prevention of development of contractures of joints, decrease in the puffiness of tissues of a stump will be applied techniques of medical physical culture, orthopedic laying, elastic bandaging of a stump of a shin and hip, carrying compression elastic and polymeric (silicone) covers. For improvement of lympho-venous outflow, reduction of puffiness of soft fabrics and of a phantom pain syndrome elastic glue bandaging (a therapeutic adhesive tapes) of a stump is shown. Non-drug treatment of phantom pain syndrome is especially relevant at contraindications, intolerance the patient of medicines. Among non-drug techniques of simplification of a phantom pain, syndrome use various techniques of reflexotherapy (acupuncture, an akupressura, etc.), to an empatotekhnik, a mirror therapy, phantom-impulsive gymnastics. Holding sessions of a mirror-therapy was followed with phantom-impulsive gymnastics by the standard technique. For prevention of formation of a flexion contracture of a knee joint after below-knee amputation used universal adjustable elastic orthosis for the knee made of polyurethane foam in the form of the rolled design with the fixing tapes is offered. Besides of, the technique of training moving by artificial limb helps the truncated extremity with the regulated reception sleeve or the made reception sleeve which is put on a stump from the water hardened plastic bandage is improved. The value of the offered technique consists in the imitation of end-bearing on a stump in the adjustable socket with the put-on reception sleeve and to training in use before fitting and walking with an artificial limb. This medical technology of early restoration of moving ability after amputation of a shin or a hip with the application of new designs of adjustable reception sleeves from thermoplastic materials in the form of a adjustable socket row with modular connection for assembly of artificial limbs of the lower extremities by express methods provides essential positive social and economic effect. The technical documentation set on new designs of artificial limbs of a shin and hip is developed for early primary prosthetics. The offered medical technology of early primary prosthetics is introduced at 27 state and five non-state prosthetic and orthopedic enterprises of the Russian Federation and also the prosthetic and orthopedic enterprises of Dushanbe (Republic of Tajikistan), Tashkent (Republic of Uzbekistan).

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Basri, Hasan Basri, Tri Satya Ramadhoni Doni, Akbar Teguh Prakoso Prakoso, Muhammad Imam Ammarullah Imam, and J. Jamari Jamari. "Study of The Effect of Model Geometry and Body Mass Index on The Elastohydrodynamic Lubrication Performance of Metal-on-Metal Hip Joints." Journal of Medical Device Technology 1, no. 1 (October 8, 2022): 4–9. http://dx.doi.org/10.11113/jmeditec.v1n1.11.

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This study aims to provide benefits on the manufacturing side in considering design parameters for optimization of total hip arthroplasty based on body mass index (BMI) categories. The femoral and cup geometries in Total Hip Arthoplasty (THA) are modeled in a simple ball-on-plane form to analyze the pressure and thickness of the lubricant film in the elastohydrodynamic lubrication of artificial hip joints with vertical loads and parameters based on body mass index using the finite element method. The factor of being overweight is one of the causes of increasing the maximum load during activities. This study applies a maximum load based on BMI which is divided into two categories, namely normal and high BMI to obtain the distribution of contact pressure and fluid pressure on the bearing surfaces that are in contact with each other so that the thickness of the lubricating film formed can be determined. Validation of contact pressure and film thickness was carried out. The femoral head sizes applied were 24mm and 28mm with a radial clearance of 15μm, 30μm and 100μm using CoCrMo metal material. From the simulation the load at high BMI shows an increase by a large enough difference reaching 16.89MPa at contact pressure, 19.88MPa at fluid pressure and 0.004μm at the thickness of the lubricant film compared to normal BMI. This simple modeling provides the benefit of analyzing the effect of body mass index on tribological THA performance and can help reduce the growth rate of THA implantation failure revision surgery.

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Feller, David, and Christian Siemers. "Topological Analysis of a Novel Compact Omnidirectional Three-Legged Robot with Parallel Hip Structures Regarding Locomotion Capability and Load Distribution." Robotics 10, no. 4 (October 31, 2021): 117. http://dx.doi.org/10.3390/robotics10040117.

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In this study, a novel design for a compact, lightweight, agile, omnidirectional three-legged robot involving legs with four degrees of freedom, utilizing an spherical parallel mechanism with an additional non-redundant central support joint for the robot hip structure is proposed. The general design and conceptual ideas for the robot are presented, targeting a close match of the well-known SLIP-model. CAD models, 3d-printed prototypes, and proof-of-concept multi-body simulations are shown, investigating the feasibility to employ a geometrically dense spherical parallel manipulator with completely spherically shaped shell-type parts for the highly force-loaded application in the legged robot hip mechanism. Furthermore, in this study, an analytic expression is derived, yielding the calculation of stress forces acting inside the linkage structures, by directly constructing the manipulator hip Jacobian inside the force domain.

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WISSE, MARTIJN. "THREE ADDITIONS TO PASSIVE DYNAMIC WALKING: ACTUATION, AN UPPER BODY, AND 3D STABILITY." International Journal of Humanoid Robotics 02, no. 04 (December 2005): 459–78. http://dx.doi.org/10.1142/s0219843605000570.

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One of the main challenges in the design of human-like walking robots (useful for service or entertainment applications as well as the study of human locomotion) is to obtain dynamic locomotion, as opposed to the static form of locomotion demonstrated by most of the current prototypes. A promising concept is the idea of passive dynamic walking; even completely unactuated and uncontrolled mechanisms can perform a stable gait when walking down a shallow slope. This concept enables the construction of dynamically walking prototypes that are simpler yet more natural in their motions than the static bipeds. This paper presents three additions to the concept of passive dynamic walking. First, hip actuation is added to increase the fore-aft stability and to provide power to the system, removing the need for a downhill floor. Second, a bisecting hip mechanism is introduced to allow the addition of a passive upper body without compromising the simplicity, efficiency and naturalness of the concept of passive dynamic walking. Third, skateboard-like ankle joints are implemented to provide 3D stability. These ankles couple the unstable sideways lean motion to yaw (steering), a kinematic coupling which provides sideways stability when walking with sufficient forward velocity. The three additions are investigated both with elementary simulation models and with prototype experiments. All three prototypes demonstrate an uncannily natural and stable gait while requiring only two foot switches and three on/off actuators.

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KUNIMOTO, Hiromichi, Taiji ADACHI, and Yoshihiro TOMITA. "Application of traction method to design of artificial hip joint stem using the voxel based FEM." Proceedings of The Computational Mechanics Conference 2002.15 (2002): 37–38. http://dx.doi.org/10.1299/jsmecmd.2002.15.37.

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Wang, Hongbo, Yongfei Feng, Hongnian Yu, Zhenghui Wang, Victor Vladareanuv, and Yaxin Du. "Mechanical design and trajectory planning of a lower limb rehabilitation robot with a variable workspace." International Journal of Advanced Robotic Systems 15, no. 3 (May 1, 2018): 172988141877685. http://dx.doi.org/10.1177/1729881418776855.

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The early phase of extremity rehabilitation training has high potential impact for stroke patients. However, most of the lower limb rehabilitation robots in hospitals are proposed just suitable for patients at the middle or later recovery stage. This article investigates a new sitting/lying multi-joint lower limb rehabilitation robot. It can be used at all recovery stages, including the initial stage. Based on man–machine engineering and the innovative design for mechanism, the leg length of the lower limb rehabilitation robot is automatically adjusted to fit patients with different heights. The lower limb rehabilitation robot is a typical human–machine system, and the limb safety of the patient is the most important principle to be considered in its design. The hip joint rotation ranges are different in people’s sitting and lying postures. Different training postures cannot make the training workspace unique. Besides the leg lengths and joint rotation angles varied with different patients, the idea of variable workspace of the lower limb rehabilitation robot is first proposed. Based on the variable workspace, three trajectory planning methods are developed. In order to verify the trajectory planning methods, an experimental study has been conducted. Theoretical and actual curves of the hip rotation, knee rotation, and leg mechanism end point motion trajectories are obtained for three unimpaired subjects. Most importantly, a clinical trial demonstrated the safety and feasibility of the proposed lower limb rehabilitation robot.

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Haider, Saif M. J., Ayad M. Takhakh, and Muhannad Al-Waily. "Designing a 3D virtual test platform for evaluating prosthetic knee joint performance during the walking cycle." Open Engineering 12, no. 1 (January 1, 2022): 590–604. http://dx.doi.org/10.1515/eng-2022-0017.

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Abstract This article introduced a three-dimension CAD model of a prosthesis testing platform using SolidWorks software to conduct a kinematic and dynamic analysis of the transfemoral prosthesis of the virtual model. Concurrently, the event-based motion simulation (EBMS) procedure was carried out on the CAD model. The concept of the operational strategy of the test platform was clarified through the machine’s real-life experience before being constructed in vitro. The platform model is capable of reproducing two active movements to simulate the locomotion of the thigh angle and hip vertical displacement for assessing the artificial knee angle motion during the gait cycle. These motions were controlled by two rotary forces (motors) that are utilized to implement control actions in EBMS. The prosthetic knee joint was built with a single axis that performs flexion and extension via the axial force of the spring. The simulation results of the thigh angle motion ranged from 2 0 ° 2{0}^{^\circ } to − 1 5 ° -1{5}^{^\circ } , while the maximum flexion of the prosthetic knee joint was ( 4 6 ° 4{6}^{^\circ } ). The mean absolute error was ( 2.72 7 ° 2.72{7}^{^\circ } ) and ( 8.33 8 ° 8.33{8}^{^\circ } ) for the thigh and knee joints, respectively. In conclusion, the findings can be utilized to facilitate the design and development of prostheses.

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MAEZAKI, Nobutaka, Tsutomu EZUMI, and Masashi HACHIYA. "9B-01 Experiment Mechanics Evaluation on Optimization of the Design Condition in Artificial Hip Joint using Photoelastic Method." Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME 2010.23 (2011): 313–14. http://dx.doi.org/10.1299/jsmebio.2010.23.313.

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Journal articles on the topic 'Artificial hip joints – Design'

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