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.

Variation in viscoelastic properties of bovine articular cartilage below, up to and above healthy gait-relevant loading frequencies
In conclusion, viscoelastic properties of articular cartilage measured at frequencies below those of gait activities are poor predictors of its relevant dynamic mechanical behaviour. (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 - March 12, 2015 Category: Biomedical Engineering Authors: Sadeghi, H., Espino, D. M., Shepherd, D. E. Tags: Original Articles Source Type: research

Sliding of the load carrier in third-generation intramedullary nails for proximal femur fractures: An in vitro mechanical comparison study
Dynamic osteosynthesis of proximal femur fractures facilitates compression at the fracture site through distal glide of the femoral head load carrier in the intramedullary nail. Modern implants are currently designed according to diverse gliding principles. The aim of this study was to compare the sliding mechanisms of different types of nails. As in other similar mechanical studies the load patterns occurring around the femoral head load carrier and the intramedullary nail under full load were simulated for three different types of intramedullary nail - PFNA, Targon PFT and Trigen Intertan. The load necessary to trigger d...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - March 12, 2015 Category: Biomedical Engineering Authors: Konstantinidis, L., Grunewald, H., Hauschild, O., Schroter, S., Hirschmuller, A., Sudkamp, N. P., Helwig, P. Tags: Original Articles Source Type: research

A rapid infusion pump driven by micro electromagnetic linear actuation for pre-hospital intravenous fluid administration
A rapid infusion pump with a maximum flow rate of 6 L/h was designed experimentally using a micro electromagnetic linear actuator, and its effectiveness was evaluated by comparing with that of a commercial Power Infuser under preset flow rates of 0.2, 2, and 6 L/h. The flow rate, air detection sensitivity, occlusion response time, quantitative determination of hemolysis, and power consumption of the infusion devices were extensively investigated using statistical analysis methods (p < 0.05). The experimental results revealed that the flow rate of the designed infusion pump was more stable and accurate, and the hemolysis...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - March 12, 2015 Category: Biomedical Engineering Authors: Zhao, P., Chong, Y., Zhao, A., Lang, L., Wang, Q., Liu, J. Tags: Original Articles Source Type: research

Influence of stem type on material loss at the metal-on-metal pinnacle taper junction
The clinical importance of material loss at the head–stem junction is unknown. Comparison of retrievals with different stem types can provide the opportunity to understand the importance of the taper junction. This was a case–control study involving 20 retrieved 36 mm metal-on-metal Pinnacle (DePuy) hips that were paired with either a Corail (n = 10) or S-ROM (n = 10) stem. The median head taper material loss rate for the Corail group was 0.238 (0.0002–2.178) mm3/year and was significantly greater than the S-ROM group (p = 0.042), which had a median material loss rate of 0.132 (0.015–0.518) mm3/year...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - February 5, 2015 Category: Biomedical Engineering Authors: Hothi, H. S., Whittaker, R. K., Meswania, J. M., Blunn, G. W., Skinner, J. A., Hart, A. J. Tags: Original Articles Source Type: research

The biochemical characteristics of wear testing lubricants affect polyethylene wear in orthopaedic pin-on-disc testing
Lubricant protein concentration is known to affect crosslinked polyethylene wear in in vitro testing; however, the biochemical nature of these lubricants may also have a significant effect on wear and dictate its clinical relevance. A modified approach to pin-on-disc testing was implemented to explore the effect of four biochemically different lubricants on the wear of two types of crosslinked polyethylene materials (XLK™ and Marathon™; DePuy Synthes, Warsaw, IN, USA). XLK was associated with higher wear rates than Marathon. In comparison to lubricants containing deionized water, lubricants containing phosphate...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - February 5, 2015 Category: Biomedical Engineering Authors: Guenther, L. E., Turgeon, T. R., Bohm, E. R., Brandt, J.-M. Tags: Original Articles Source Type: research

Determining material loss from the femoral stem trunnion in hip arthroplasty using a coordinate measuring machine
In contrast to the articulating and taper surfaces of failed total hip replacements, volumetric wear analysis of trunnions is not routinely performed. Metal wear particles from the trunnion may contribute not only to the failures of metal-on-metal total hip replacements but also to all hip replacements utilising metal trunnions. A validation study was performed with the material removed in stages from the trunnions of an Exeter V40 stem, a Corail stem and an Accolade stem to simulate different magnitudes of wear. The material loss from the trunnions was measured both volumetrically with a coordinate measuring machine and g...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - February 5, 2015 Category: Biomedical Engineering Authors: Bone, M. C., Sidaginamale, R. P., Lord, J. K., Scholes, S. C., Joyce, T. J., Nargol, A. V., Langton, D. J. Tags: Original Articles Source Type: research

Exoskeleton control for lower-extremity assistance based on adaptive frequency oscillators: Adaptation of muscle activation and movement frequency
In this article, we analyze a novel strategy for assisting the lower extremities based on adaptive frequency oscillators. Our aim is to use the control algorithm presented here as a building block for the control of powered lower-limb exoskeletons. The algorithm assists cyclic movements of the human extremities by synchronizing actuator torques with the estimated net torque exerted by the muscles. Synchronization is produced by a nonlinear dynamical system combining an adaptive frequency oscillator with a form of adaptive Fourier analysis. The system extracts, in real time, the fundamental frequency component of the net mu...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - February 5, 2015 Category: Biomedical Engineering Authors: Aguirre-Ollinger, G. Tags: Original Articles Source Type: research

Determination of loads carried by polypropylene ankle-foot orthoses: A preliminary study
This study aimed to establish a method that would allow the quantification of the contribution of AFOs in the control of the ankle joint during gait. A possible way of achieving this aim would be to measure strain on the AFO during walking by the use of strain gauges. Following successful experimentation with the application of strain gauges to polypropylene tensile specimens, an AFO was instrumented by attaching strain gauges to it so as to allow the moment generated on the AFO in the sagittal plane about the ankle to be measured. Walking trials using this AFO on an able-bodied subject indicated good step-to-step repeatab...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - February 5, 2015 Category: Biomedical Engineering Authors: Papi, E., Maclean, J., Bowers, R. J., Solomonidis, S. E. Tags: Original Articles Source Type: research

Evaluation of the stiffnesses of the Achilles tendon and soleus from the apparent stiffness of the triceps surae
The objective of this work is therefore the estimation of the individual viscoelastic properties (stiffness and viscosity) of soleus and Achilles tendon from the apparent properties of the triceps surae obtained by free vibration techniques. Different procedures have been developed and discussed, showing a high degree of robustness in the predictions. The results obtained for a non-oriented set of subjects present a high level of variability, depending on the training conditions and anthropometric features, although the corresponding average values compare well with data previously reported in the literature, particularly ...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - February 5, 2015 Category: Biomedical Engineering Authors: Paris-Garcia, F., Barroso, A., Doblare, M., Canas, J., Paris, F. Tags: Original Articles Source Type: research

Metrology test object for dimensional verification in additive manufacturing of metals for biomedical applications
Additive manufacturing continues to increase in popularity and is being used in applications such as biomaterial ingrowth that requires sub-millimeter dimensional accuracy. The purpose of this study was to design a metrology test object for determining the capabilities of additive manufacturing systems to produce common objects, with a focus on those relevant to medical applications. The test object was designed with a variety of features of varying dimensions, including holes, cylinders, rectangles, gaps, and lattices. The object was built using selective laser melting, and the produced dimensions were compared to the tar...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - February 5, 2015 Category: Biomedical Engineering Authors: Teeter, M. G., Kopacz, A. J., Nikolov, H. N., Holdsworth, D. W. Tags: Original Articles Source Type: research

Sensitivity to model geometry in finite element analyses of reconstructed skeletal structures: Experience with a juvenile pelvis
This article analyses the application of a geometric morphometric technique, which facilitates the reconstruction of the articulated juvenile pelvis from cadaveric remains, in biomechanical modelling. The sensitivity of variation in reconstructed morphologies upon predicted stress/strain distributions is of particular interest. A series of finite element analyses of a 9-year-old hemi-pelvis were performed to examine differences in predicted strain distributions between a reconstructed model and the originally fully articulated specimen. Only minor differences in the minimum principal strain distributions were observed betw...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - February 5, 2015 Category: Biomedical Engineering Authors: Watson, P. J., Fagan, M. J., Dobson, C. A. Tags: Original Articles Source Type: research

Evaluation of acetabular cup initial fixation by using resonance frequency principle
The clinical practice shows that the loosening of acetabular cups is more frequent than stem loosening. With standard cups, the incidence of dislocation failure is highest in the first year after arthroplasty implantation. The aim of the study was to quantitatively evaluate the implant-bone stability of a cementless acetabular cup prosthesis by using a device based on resonance frequency analysis. The evaluation of this device was done by finite element analysis and in vitro experiments. It was shown that not all the resonance frequencies can be measured by our device. The resonance frequencies vary within the range of 500...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - February 5, 2015 Category: Biomedical Engineering Authors: Henys, P., Capek, L., Fencl, J., Prochazka, E. Tags: Original Articles Source Type: research

An in silico parametric model of vertebrae trabecular bone based on density and microstructural parameters to assess risk of fracture in osteoporosis
In this study, an in-silico parametric model of vertebral trabecular bone incorporating both material and microstructural parameters was developed towards the accurate assessment of osteoporosis and the consequent risk of bone fracture. The model confirms that the mechanical properties such as strength and stiffness of vertebral trabecular tissue are highly influenced by material properties as well as morphology characteristics such as connectivity, which reflects the quality of connected inter-trabecular parts. The FE cellular solid model presented here provides a holistic approach that incorporates both material and micr...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - December 16, 2014 Category: Biomedical Engineering Authors: Amjadi Kashani, M. R., Nikkhoo, M., Khalaf, K., Firoozbakhsh, K., Arjmand, N., Razmjoo, A., Parnianpour, M. Tags: Original Articles Source Type: research

The impact of proximal femoral morphology on failure strength with a mid-head resection short-stem hip arthroplasty
Mid-head resection short-stem hip arthroplasty is a conservative alternative to conventional total hip replacement and addresses proximal fixation challenges in patients not suitable for hip resurfacing. It is unclear whether proximal femoral morphology impacts the ultimate failure load of mid-head resection implanted femurs, thus the aim of this study was to investigate the effect of native neck-shaft angle (NSA) and coronal implant alignment on proximal femoral strength. In total, 36 synthetic femurs with two different proximal femoral morphologies were utilized in this study. Of them, 18 femurs with a varus NSA of 120&d...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - December 16, 2014 Category: Biomedical Engineering Authors: Olsen, M., Al Saied, M., Morison, Z., Sellan, M., Waddell, J. P., Schemitsch, E. H. Tags: Original Articles Source Type: research

Characterization of a pressure measuring system for the evaluation of medical devices
The purpose of this study is to evaluate the possible use of four "FSA" thin and flexible resistive pressure mapping systems, designed by Vista Medical (Winnipeg, Manitoba, Canada), for the measurement of interface pressure exerted by lumbar belts onto the trunk. These sensors were originally designed for the measurement of low pressure applied by medical devices on the skin. Two types of tests were performed: standard metrology tests such as linearity, hysteresis, repeatability, reproducibility and drift, and specific tests for this application such as curvature, surface condition and mapping system superposition. The lin...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - December 16, 2014 Category: Biomedical Engineering Authors: Bonnaire, R., Verhaeghe, M., Molimard, J., Calmels, P., Convert, R. Tags: Original Articles Source Type: research