Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Evaluation of total knee mechanics using a crouching simulator with a synthetic knee substitute
Mechanical evaluation of total knees is frequently required for aspects such as wear, strength, kinematics, contact areas, and force transmission. In order to carry out such tests, we developed a crouching simulator, based on the Oxford-type machine, with novel features including a synthetic knee including ligaments. The instrumentation and data processing methods enabled the determination of contact area locations and interface forces and moments, for a full flexion–extension cycle. To demonstrate the use of the simulator, we carried out a comparison of two different total knee designs, cruciate retaining and substi...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - May 8, 2016 Category: Biomedical Engineering Authors: Lowry, M., Rosenbaum, H., Walker, P. S. Tags: Special Issue Articles Source Type: research

Incorporating corrosion measurement in hip wear simulators: An added complication or a necessity?
This article evaluates how, by incorporating real-time corrosion measurements in total hip replacement simulations, pre-clinical evaluations and research studies can both yield much more information and accelerate the process towards improved implants. (Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine)
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - May 8, 2016 Category: Biomedical Engineering Authors: Neville, A., Hesketh, J., Beadling, A. R., Bryant, M. G., Dowson, D. Tags: Special Issue Articles Source Type: research

Measurement outcomes from hip simulators
In this study, hard-on-hard (CoCr alloy, AgCrN coating) and hard-on-soft (CoCr alloy and CrN coating on vitamin E blended highly cross-linked polyethylene) bearing combinations were tested in an orbital hip simulator under standard and some adverse conditions. Gravimetric wear rates were determined for all bearings, with cobalt and where applicable, silver release determined throughout testing. Isolation of wear particles from the lubricating fluid was used to determine the influence of different bearing combinations and wear conditions on particle morphology. It was found that cobalt and silver could be measured in the lu...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - May 8, 2016 Category: Biomedical Engineering Authors: de Villiers, D., Shelton, J. C. Tags: Special Issue Articles Source Type: research

Influence of hip joint simulator design and mechanics on the wear and creep of metal-on-polyethylene bearings
This study confirmed the influence of hip simulator design and loading conditions on the wear of polyethylene, and therefore direct comparisons of absolute wear rates between different hip joint simulators should be avoided. This study also confirmed that the resulting wear path was the governing factor in obtaining clinically relevant wear rates, and this can be achieved with either two axes or three axes of rotations. However, three axes of rotation (with the inclusion of adduction/abduction) more closely replicate clinical conditions and should therefore be the design approach for newly developed hip joint simulators us...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - May 8, 2016 Category: Biomedical Engineering Authors: Ali, M., Al-Hajjar, M., Partridge, S., Williams, S., Fisher, J., Jennings, L. M. Tags: Special Issue Articles Source Type: research

Simultaneous measurement of friction and wear in hip simulators
We propose and have evaluated a method to measure hip friction during wear testing on a popular multi-station hip simulator. A 6-degree-of-freedom load cell underneath the specimen sensed forces and torques during implant wear testing of simulated walking. This included internal–external and adduction–abduction rotations which are often neglected during friction testing on pendulum-type machines. Robust mathematical analysis and data processing provided friction estimates in three simultaneous orthogonal rotations, over extended multi-million cycle wear tests. We tested various bearing couples including metal-o...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - May 8, 2016 Category: Biomedical Engineering Authors: Haider, H., Weisenburger, J. N., Garvin, K. L. Tags: Special Issue Articles Source Type: research

Friction measurement in a hip wear simulator
A torque measurement system was added to a widely used hip wear simulator, the biaxial rocking motion device. With the rotary transducer, the frictional torque about the drive axis of the biaxial rocking motion mechanism was measured. The principle of measuring the torque about the vertical axis above the prosthetic joint, used earlier in commercial biaxial rocking motion simulators, was shown to sense only a minor part of the total frictional torque. With the present method, the total frictional torque of the prosthetic hip was measured. This was shown to consist of the torques about the vertical axis above the joint and ...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - May 8, 2016 Category: Biomedical Engineering Authors: Saikko, V. Tags: Special Issue Articles Source Type: research

Some aspects of frictional measurements in hip joint simulators
This article attempts to share the thoughts behind over 40 years of measuring friction in artificial joints using the Durham Friction Simulators. This has led to accrued consistency of measurement and a robust scientific design rationale to understand the nature of friction in these spherical contacts. It also impacts on how to obtain accurate measurements as well as on the understanding of where the difficult issues lie and how to overcome them. (Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine)
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - May 8, 2016 Category: Biomedical Engineering Authors: Unsworth, A. Tags: Special Issue Articles Source Type: research

Can physical joint simulators be used to anticipate clinical wear problems of new joint replacement implants prior to market release?
This study gives four steps to follow in conducting such wear simulator testing. Two major examples involving hip wear simulators are discussed in which attempts had been made to predict clinical wear performance prior to market release. The second one, involving the DePuy ASR implant systems, is chosen for more extensive treatment by making it an illustrative example to explore whether wear simulator testing can anticipate clinical wear problems. It is concluded that hip wear simulator testing did provide data in the academic literature that indicated some risk of clinical wear problems prior to market release of the ASR ...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - May 8, 2016 Category: Biomedical Engineering Authors: Medley, J. B. Tags: Special Issue Articles Source Type: research

Physical Joint Simulators
(Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine)
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - May 8, 2016 Category: Biomedical Engineering Authors: Dowson, D., Unsworth, A. Tags: Special Issue Editorial Source Type: research

Prediction of knee joint moment changes during walking in response to wedged insole interventions
Wedged insoles are prescribed for medial knee osteoarthritis to reduce the knee adduction moment; however, it is currently not possible to predict which patients will in fact experience reduced moments. The purpose of this study was to identify a simple method using two-dimensional data for predicting the expected change in knee adduction moments with wedged insoles. Knee adduction moments during walking were determined for healthy individuals (n = 15) and individuals with medial knee osteoarthritis (n = 19) while wearing their own shoe without an insole (control), with a 6-mm medial wedge and with a 6-mm lateral wedge. Th...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - March 18, 2016 Category: Biomedical Engineering Authors: Lewinson, R. T., Stefanyshyn, D. J. Tags: Original Articles Source Type: research

A biomechanical model of the wrist joint for patient-specific model guided surgical therapy: Part 2
In this study, the simulation model of the wrist joint was used for investigating deeper the biomechanical function of the wrist joint. In representative physiological scenarios, the joint behavior and muscle forces were computed. Furthermore, the load transmission of the proximal wrist joint was investigated. The model was able to calculate the parameters of interest that are not easily obtainable experimentally, such as muscle forces and proximal wrist joint forces. In the case of muscle force investigation, the computational model was able to accurately predict the computational outcome for flexion and extension motion....
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - March 18, 2016 Category: Biomedical Engineering Authors: Eschweiler, J., Stromps, J.-P., Fischer, M., Schick, F., Rath, B., Pallua, N., Radermacher, K. Tags: Original Articles Source Type: research

Development of a biomechanical model of the wrist joint for patient-specific model guided surgical therapy planning: Part 1
An enhanced musculoskeletal biomechanical model of the wrist joint is presented in this article. The developed computational model features the two forearm bones radius and ulna, the eight wrist bones, the five metacarpal bones, and a soft tissue apparatus. Validation of the model was based on information taken from the literature as well as own experimental passive in vitro motion analysis of eight cadaver specimens. The computational model is based on the multi-body simulation software AnyBody. A comprehensive ligamentous apparatus was implemented allowing the investigation of ligament function. The model can easily pati...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - March 18, 2016 Category: Biomedical Engineering Authors: Eschweiler, J., Stromps, J.-P., Fischer, M., Schick, F., Rath, B., Pallua, N., Radermacher, K. Tags: Original Articles Source Type: research

Establishing the biomechanical properties of the pelvic soft tissues through an inverse finite element analysis using magnetic resonance imaging
The mechanical characteristics of the female pelvic floor are relevant when explaining pelvic dysfunction. The decreased elasticity of the tissue often causes inability to maintain urethral position, also leading to vaginal and rectal descend when coughing or defecating as a response to an increase in the internal abdominal pressure. These conditions can be associated with changes in the mechanical properties of the supportive structures—namely, the pelvic floor muscles—including impairment. In this work, we used an inverse finite element analysis to calculate the material constants for the passive mechanical b...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - March 18, 2016 Category: Biomedical Engineering Authors: Silva, M., Brandao, S., Parente, M., Mascarenhas, T., Natal Jorge, R. Tags: Original Articles Source Type: research

Prediction of medial and lateral contact force of the knee joint during normal and turning gait after total knee replacement
The objective of this study was to extend previous modeling technique and to improve the validity of the model prediction using publicly available data set of the fifth "Grand Challenge Competition to Predict In Vivo Knee Loads." A two-stage modeling approach, which combines conventional inverse dynamic analysis (the first stage) with a multi-body subject-specific lower limb model (the second stage), was used to calculate medial and lateral compartment contact forces. The validation was performed by direct comparison of model predictions and experimental measurement of medial and lateral compartment contact forces during n...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - March 18, 2016 Category: Biomedical Engineering Authors: Purevsuren, T., Dorj, A., Kim, K., Kim, Y. H. Tags: Original Articles Source Type: research

A reduced-order model-based study on the effect of intermittent pneumatic compression of limbs on the cardiovascular system
This study presents a reduced-order numerical model of the interaction between the cardiovascular system and the intermittent pneumatic compression device. The effect that different intermittent pneumatic compression operating conditions have on the overall circulation is investigated. Our findings confirm (1) that an overall positive effect on hemodynamics can be obtained by properly applying the intermittent pneumatic compression device and (2) that using intermittent pneumatic compression for cardiocirculatory recovery is feasible in subjects affected by lower limb disease. (Source: Proceedings of the Institution of Mec...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - March 18, 2016 Category: Biomedical Engineering Authors: Maffiodo, D., De Nisco, G., Gallo, D., Audenino, A., Morbiducci, U., Ferraresi, C. Tags: Original Articles Source Type: research