Modal analysis for the assessment of cementless hip stem primary stability in preoperative THA planning
Over one million patients undergo Total Hip Arthroplasty (THA) worldwide per year. It is one of the most successful orthopedic surgical procedures with highly satisfactory outcomes, with an estimated survival rate of over 95% at 15 –20 years or more [1,2]. An increasing number of procedures are performed with cementless stems especially when treating young patients with high activity level [1,3]. Cementless total hip arthroplasty involves a press-fit condition between the stem and the femur. The primary stem stability is cru cial in order to achieve bone in-growth and good functional outcomes especially in the early post...
Source: Medical Engineering and Physics - September 7, 2017 Category: Biomedical Engineering Authors: Andres Rondon, Elhadi Sariali, Quentin Vallet, Quentin Grimal Source Type: research
Ulna-humerus contact mechanics: Finite element analysis and experimental measurements using a tactile pressure sensor
Articular cartilage endures high compressive and shearing forces while protecting the bone from excessive contact pressure. Articular cartilage within the elbow joint withstands repetitive mechanical forces that are about 50% body weight during activities of daily living [1]. Abnormal stress acting on cartilage is believed to be one of the leading causes for cartilage degeneration and osteoarthritis development [2]. A better understanding of elbow cartilage contact mechanics can provide insight into our understanding of cartilage degeneration mechanisms and assist in the development of elbow rehabilitation protocols. (Sour...
Source: Medical Engineering and Physics - September 7, 2017 Category: Biomedical Engineering Authors: Mohsen Sharifi Renani, Munsur Rahman, Akin Cil, Antonis P. Stylianou Source Type: research
Hemodynamic parameters that may predict false-lumen growth in type-B aortic dissection after endovascular repair: A preliminary study on long-term multiple follow-ups
Aortic dissection (AoD) is a severe cardiovascular disease, where a surge of blood flowing into the aortic wall via an initial tear or damage of the intima and splitting the single aortic lumen into a true and false lumen (TL and FL). Stanford type-B AoD indicates those with the dissection begins distal to the supraaortic branches. Interventional treatment of Stanford type-B AoD commonly involves thoracic endovascular aortic repair (TEVAR) [1]. In a number of patients, FL expansion is found post-TEVAR, especially in the infrarenal aorta. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - September 7, 2017 Category: Biomedical Engineering Authors: Huanming Xu, Zhenfeng Li, Huiwu Dong, Yilun Zhang, Jianyong Wei, Paul N. Watton, Wei Guo, Duanduan Chen, Jiang Xiong Source Type: research
Experimental and modelling characterisation of adjustable hollow Micro-needle delivery systems
Patch-based drug delivery offers certain appealing features, such as non-invasiveness and the ability to provide controlled release over time. However, it faces a significant challenge in increasing skin permeability, as most macromolecular drugs exhibit poor permeability owing to the existence of stratum corneum as a natural barrier [1,2]. Other approaches have been applied, such as chemical/lipid enhancers and physical means of assisting permeability to overcome the skin barrier. However, these methods are rarely used in clinical applications for various reasons, such as skin allergies, low effectiveness and inconvenienc...
Source: Medical Engineering and Physics - September 7, 2017 Category: Biomedical Engineering Authors: Ting-Ting Liu, Kai Chen, Min Pan Source Type: research
A simulation framework for humeral head translations
Several musculoskeletal models are available for the human shoulder that provide reliable predictions of both the muscle and joint reaction forces e.g. [1,2]. A vast majority of these models have been developed based on inverse dynamics, e.g. [2 –7]. In inverse dynamics, measured joints kinematics (rotations and translations) are required as inputs to calculate muscle and joint reaction forces. However, with the available measurement techniques, it is not straightforward to measure the translational DOF of the GH joint [8]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - September 7, 2017 Category: Biomedical Engineering Authors: Ehsan Sarshari, Alain Farron, Alexandre Terrier, Dominique Pioletti, Philippe Mullhaupt Source Type: research
Radiographic cup anteversion measurement corrected from pelvic tilt
Malpositioning of the cup in total hip arthroplasty (THA) can potentially cause impingement and dislocation [1 –3]. Radiographic assessment of cup orientation is critical to identify possible causes of postoperative instability. The cup orientation is determined by its circular cup rim, which is a three dimensional concept intra-operatively. However, its orientation in practice is measured by two planar pa rameters post-operatively, the cup inclination (IN) and the cup anteversion (AV) [2]. The cup IN and the cup AV are measurements of cup orientation in the coronal plane and the sagittal plane, which are determined by t...
Source: Medical Engineering and Physics - September 6, 2017 Category: Biomedical Engineering Authors: Liao Wang, Andrew R. Thoreson, Robert T. Trousdale, Bernard F. Morrey, Kerong Dai, Kai-Nan An Source Type: research
Characterization of an innovative intramedullary nail for diaphyseal fractures of long bones
In most cases, fractures are treated with a conservative approach that involves the immobilization of the limb by cast bandage. However, in some circumstances, it is necessary to stabilize the skeletal segments employing mechanical devices, applied by surgical interventions. Osteosynthesis is employed in the following cases: (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - September 1, 2017 Category: Biomedical Engineering Authors: V. Filardi Source Type: research
Vibration-based fixation assessment of tibial knee implants: A combined in vitro and in silico feasibility study
Total knee replacement (TKR) is a surgical procedure to replace the weight-bearing surfaces of the knee joint with a prosthesis. Although literature shows high survival rates, approximately 5 –10% of the prostheses still need to be replaced within 10–15 years [1]. Loosening of a component is one of the main indications for a revision. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - September 1, 2017 Category: Biomedical Engineering Authors: Steven Leuridan, Quentin Goossens, Tom Vander Sloten, Koen De Landsheer, Hendrik Delport, Leonard Pastrav, Kathleen Denis, Wim Desmet, Jos Vander Sloten Source Type: research
Microfludic platforms for the evaluation of anti-platelet agent efficacy under hyper-shear conditions associated with ventricular assist devices
Mechanical circulatory support devices, such as ventricular assist devices (VADs), continue to emerge as effective therapy for patients with advanced and end-stage heart failure [1,2]. Despite significant improvement of patient survival and quality of life associated with VADs versus medical treatment [3], VAD therapy remains plagued by post-implant adverse events including thrombosis, hemolysis, bleeding and infection [4]. Thrombus formation, in particular, is a frequent and serious complication [5] often occurring within the first year post-implant. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - August 28, 2017 Category: Biomedical Engineering Authors: Annalisa Dimasi, Marco Rasponi, Filippo Consolo, Gianfranco B. Fiore, Danny Bluestein, Marvin J. Slepian, Alberto Redaelli Source Type: research
Novel curved surface preparation technique for knee resurfacing
Articular cartilage damage is very common, affecting millions of people worldwide, especially the elderly [1,2]. The disease does not only cause pain and disability to the individuals [3], but it also brings a heavy burden to the medical insurance system [4,5]. Non-surgical treatment may work for the mild to medium conditions [6 –8], but in severe cases patients are usually treated with knee replacement [9]. However, these artificial components are not suitable for all cases [9], since they have limited life [10,11], so are unsuitable for younger, more active patients. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - August 22, 2017 Category: Biomedical Engineering Authors: Jianmo Li, Susannah Clarke, Justin P Cobb, Andrew A Amis Source Type: research
Thread-based microfluidics: Flow patterns in homogeneous and heterogeneous microfiber bundles
Thread-based microfluidics (TBM) is a relatively new concept of microfluidics which uses the wicking of fiber bundles and woven yarns to move fluids. This concept has recently seen important developments in the domain of portable diagnostic systems, smart bandages and tissue engineering. Usually, the threads consist of fibers of natural origin such as cotton or cellulose, or of artificial origin such as polymers, aligned or twisted together (Fig. 1). Wetting properties of the fibers are necessary to obtain wicking. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - August 22, 2017 Category: Biomedical Engineering Authors: J. Berthier, K.A. Brakke, D. Gosselin, E. Berthier, F. Navarro Source Type: research
Red blood cell (RBC) suspensions in confined microflows: Pressure-flow relationship
To quantify the properties of blood in the microcirculation, red blood cell (RBC) flows have been widely investigated in vitro as a proxy for the innate microvasculature [1 –3]. In this context, microfabrication techniques have facilitated the proliferation of in vitro studies on blood flows where the use of microfluidic models has helped address questions pertaining to the role of microvascular morphology [4,5], blood viscosity [6,7] and haematocrit [8], as well as RBC deformation [9–11]. In these experiments, blood is commonly resuspended to a desired haematocrit (Hct) level in a buffer solution (ranging from non-phy...
Source: Medical Engineering and Physics - August 22, 2017 Category: Biomedical Engineering Authors: Hagit Stauber, Dan Waisman, Netanel Korin, Josu é Sznitman Tags: Technical note Source Type: research
3D Reconstruction of human bones based on dictionary learning
Three-dimensional (3D) reconstruction from computed tomography (CT) medical images has gained much attention with the increasing application of CAD technology in the bio-medical field. Bio-CAD (the integration of CAD and bio-medical technology) [1 –3], combined with rapid prototyping technology, has been used in constructing anatomic models for diagnostic and therapeutic applications, thus improving the efficiency and accuracy of medical analysis and diagnosis. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - August 18, 2017 Category: Biomedical Engineering Authors: Binkai Zhang, Xiang Wang, Xiao Liang, Jinjin Zheng Tags: Technical note Source Type: research
Effect of longitudinal anatomical mismatch of stenting on the mechanical environment in human carotid artery with atherosclerotic plaques
Stent implantation is an effective and preferential treatment for atherosclerosis [1,2]. However, this treatment faces the challenge of late failure resulting from in-stent restenosis and late stent thrombosis. According to clinical data, 15% –30% of patients who have had stents for longer than 6–12 months suffer from restenosis [3,4]. Among various risk factors for those adverse results, LAM widely presents in clinical studies [5,31]. LAM was defined as the situation when the injured or stenotic segment of artery was not fully cover ed by the stent. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - August 17, 2017 Category: Biomedical Engineering Authors: Zhenmin Fan, Xiao Liu, Anqiang Sun, Nan Zhang, Zhanming Fan, Yubo Fan, Xiaoyan Deng Source Type: research
Second generation prototype of a variable stiffness transverse plane adapter for a lower limb prosthesis
The role of a prosthesis is to restore the abilities of the original intact limb and return the individual back to the highest activity level possible. Prosthesis innovations often focus on straight walking tasks, with little attention paid to activities such as turning and twisting that require transverse plane motion [1 –3]. Turning steps that include transverse plane motion comprise a significant portion of daily steps [4]. The inclusion of a transverse rotation adapter (TRA) has been associated with increases in amputee stability and activity level, as well as improved ability to negotiate turns [5–7]. (Source: Med...
Source: Medical Engineering and Physics - August 11, 2017 Category: Biomedical Engineering Authors: Corey Pew, Glenn K. Klute Source Type: research
