Stress distribution in vertebral bone and pedicle screw and screw –bone load transfers among various fixation methods for lumbar spine surgical alignment: A finite element study
Pedicle-screw (PS)-based spine fusion is a standard treatment for degenerative spinal disorders which aims to consolidate the spine and restores the spinal stability [1,2]. Despite the continuous advances in PS designs and fixation techniques over the last two decades, failures of spinal implants, such as PS breakage [3], loosening and pullout, have not been fully eliminated in post-surgical spines [4 –6]. Excessive stress concentrations within the vertebral bone after the PS-fixation of the spine is one major cause for the PS loosening or pullout while the excessive stress in the implants could result in the structural ...
Source: Medical Engineering and Physics - October 18, 2018 Category: Biomedical Engineering Authors: Ming Xu, James Yang, Isador Lieberman, Ram Haddas Source Type: research
Rapid calculation of bespoke body segment parameters using 3D infra-red scanning
Musculoskeletal (MSK1) modelling of human movement requires body segment parameters (BSP) such as segment mass, centre of mass (CoM) and inertial properties, to calculate intersegmental muscle and joint forces. BSPs are typically calculated through the use of regression-based anthropometric tables derived from cadaver [1 –5] or imaging data [6–9], which feature both male and female subjects and a large range of ages. The segment mass and inertial properties predicted using these tables have been shown to vary by up to 40% [10]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - October 17, 2018 Category: Biomedical Engineering Authors: Samuel H.L. Smith, Anthony M.J. Bull Source Type: research
Clustering of Self-Organizing Maps as a means to support gait kinematics analysis and symmetry evaluation
Human gait is the typical walking pattern, corresponding to the highest level of functional independence, which can be compromised by several types of disabilities [1]. Antalgic gait, for instance, is a particular case in which limp is adopted to avoid pain on weight-bearing structures, characterized by a very short stance phase [2]. Gait analysis is necessary to confirm a functional diagnosis, which establishes a connection between dysfunction and movement pattern, providing a more holistic framework to design interventions [3]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - October 17, 2018 Category: Biomedical Engineering Authors: Rafael Caldas, Diego R átiva, Fernando Buarque de Lima Neto Tags: Technical note Source Type: research
Experimental and finite element analysis of surgical drill bits with and without irrigation channel – A case study approach
Drilling is a highly utilized procedure in bone and joint surgery interventions. During this process, an extensive amount of heat can be generated due to the friction between the drill bit and cortical bone. More friction results in higher cutting forces and bone temperatures which can potentially cause irreversible bone tissue damage or osteonecrosis. In order to avoid thermal osteonecrosis and to ensure fast and successful postoperative healing, a surgeon must maintain the bone temperature in the drilling zone below its upper limit. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - October 16, 2018 Category: Biomedical Engineering Authors: Zoran Domitran, Danko Brezak, Tomislav Staroveski, Miho Klaic, Tomislav Bruketa Source Type: research
Detection of ischemic changes in the vascular endothelial cell layer by using microelectrochemical impedance spectroscopy
Endothelial cells, constituting the endothelial layer, are located in the inner monolayer of the circulatory system, lymphatic system, and gastrointestinal system. The endothelial cells have important roles within each system. In particular, endothelial cells have important roles in the vascular system, including maintaining the vasomotor tone and hemostasis. In this context, dysfunction of endothelial cells is one of the critical factors in cardiovascular disease [1]. The endothelial cell dysfunction, which is caused by endothelial cell injury, leads to problems with hemostasis and the nitric oxide production mechanism. (...
Source: Medical Engineering and Physics - October 11, 2018 Category: Biomedical Engineering Authors: Jung-Joon Cha, Jinhwan Kim, Joho Yun, Yangkyu Park, Jong-Hyun Lee Tags: Short Communication Source Type: research
Reduced tibial strain-shielding with extraosseous total knee arthroplasty revision system
Revision total knee arthroplasty (RTKA) surgery is a growing socioeconomic burden [1,2], and is performed at a rate of 5 –11% of total primary TKA operations [3,4]. The major causes of implant revision include mechanical loosening, infection, osteolysis, instability, and misalignment [5]. The primary objectives of RTKA surgery are pain relief, joint stabilisation, re-establishment of the anatomical joint line, resto ration of bone stock, and ultimately a prompt return to full weight-bearing function [6,7]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - October 10, 2018 Category: Biomedical Engineering Authors: Tomas A. Correa, Bidyut Pal, Richard J. van Arkel, Felice Vanacore, Andrew A. Amis Source Type: research
Patella tracking calculation from patellofemoral positions at finite angles of knee flexion
Patellofemoral (PF) pain syndrome is a frequently diagnosed knee disorder. The incidence of this symptom is approximately 25% in the general population [1]. Anatomical features, such as patella alta, trochlear dysplasia, lateralized tibia tuberosity, abnormal Q angle, and imbalance of PF soft tissues, are predisposing factors of the PF pain and instability [2,3]. Previous studies reported that patella maltracking is highly correlated with the PF disorder, thereby could be crucial to diagnosis and pathological classification [4 –6]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - October 5, 2018 Category: Biomedical Engineering Authors: Jie Yao, Bin Yang, Yuxing Wang, Yubo Fan Source Type: research
Shoulder loading reliability in seated able-bodied subjects
Shoulder stability is ensured by a complex balance between mechanical constraints such as the articular geometry, capsule and ligaments [1,2] and the sensorimotor elements comprising of proprioception and neuromuscular control [3]. Proprioception acts as a feedback mechanism to the muscle groups to protect the shoulder against joint instability. After joint instability, surgery restores the mechanical functions of the shoulder lost by joint injury and restores in part the sensory deficits present after injury [3]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - October 5, 2018 Category: Biomedical Engineering Authors: Richard Ballas, Nicolas Peyrot, Paul Allard, Teddy Caderby, Pascal Edouard, Georges Dalleau Source Type: research
Evaluation of the accuracy of musculoskeletal simulation during squats by means of instrumented knee prostheses
Accurate knowledge of the internal loading conditions in the human musculoskeletal (MS) system, including muscle and joint contact forces (JCFs), can provide a strong evidence-based foundation for improving rehabilitation concepts and customising training programmes, as well as for optimising implant designs. Although direct, non-invasive access to muscle and JCFs is, in most cases, not possible, internal loading conditions have become widely available using MS simulation [1]. The accuracy of such simulations, especially if large ranges of motion (RoMs) are considered, is known to be sensitive to a wide variety of paramete...
Source: Medical Engineering and Physics - September 30, 2018 Category: Biomedical Engineering Authors: Florian Schellenberg, William R. Taylor, Adam Trepczynski, Renate List, Ines Kutzner, Pascal Sch ütz, Georg N. Duda, Silvio Lorenzetti Tags: Communication Source Type: research
Study of impaired cardiovascular and respiratory coupling during orthostatic stress based on joint symbolic dynamics
Beat-to-beat intervals (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - September 27, 2018 Category: Biomedical Engineering Authors: S. Reulecke, S. Charleston-Villalobos, J. Gonz ález-Hermosillo, R. González-Camarena, A. Voss, M. Gaitán-González, G. Hernández-Pacheco, R. Schroeder, T. Aljama-Corrales Source Type: research
A three-dimensional visco-hyperelastic FE model for simulating the mechanical dynamic response of preloaded phalanges
Long-term exposure to high levels of hand-transmitted vibration has been associated with disorders [1 –3] in the vascular, sensory–neural, and musculoskeletal structures of the finger–hand–arm system. These disorders are collectively termed hand–arm vibration syndrome (HAVS). To protect employees from such pathologies, daily hand-transmitted vibration exposure is regulated by the European Union [4]. Assessment of vibration doses must be conducted in accordance with the recommendations of ISO Standard 5349 [5,6] which requires the application of frequency weighting to accelerations measured on a machine handle. (S...
Source: Medical Engineering and Physics - September 24, 2018 Category: Biomedical Engineering Authors: Christophe No ël Source Type: research
Variability in strain distribution in the mice tibia loading model: A preliminary study using digital volume correlation
There is much experimental evidence of bone adapting its mass and structure to different loading conditions following mechanotransduction (net bone resorption occurring at low strains and net bone formation occurring at high strains or micro-damage theories [1 –9]). However, the mechanisms are still unclear, and a comprehensive understanding about how loads impact the bone remodelling process is required in order to improve diagnostic methods and treatments for bone pathologies. Mice models are used intensively for investigating the impact of mechanical stimuli on bone remodelling in the mouse tibia [10–14] by studying...
Source: Medical Engineering and Physics - September 19, 2018 Category: Biomedical Engineering Authors: M. Giorgi, E. Dall'Ara Source Type: research
Corrigendum to ‘A theoretical computerized study for the electrical conductivity of arterial pulsatile blood flow by an elastic tube model’ [Medical Engineering & Physics, 38 (2016) 1439 –1448]
The authors wish to make readers aware of the following errors in the above manuscript, which were not corrected during proof reading. On pages 1440 –1441, Equations (9), (10) and (23) should read as follows: (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - September 11, 2018 Category: Biomedical Engineering Authors: Hua Shen, Yong Zhu, Kai-Rong Qin Tags: Corrigendum Source Type: research
Rate and age-dependent damage elasticity formulation for efficient hip fracture simulations
Hip fractures are associated with significant morbidity and mortality, and constitute a substantial economic burden [1,2]. Most hip fractures are considered to originate from a fall to the side [1,3], although it has been suggested that some occur spontaneously [4,5], maybe as a result of uncoordinated muscle activity [6]. Prediction of bone failure is beneficial in a range of clinical situations from screening of osteoporotic patients with high fracture risk [7] to assessment of protective equipment against trauma [8], and improved design of implants and prosthetics [9]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - September 8, 2018 Category: Biomedical Engineering Authors: C.C. Villette, A.T.M. Phillips Source Type: research
Cardiac spiral wave drifting due to spatial temperature gradients – A numerical study
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting more than 10% of the elderly population [1]. AF is characterized by rapid and irregular activation of the atrium, and is often the result of fibrillatory conduction maintained by the existence of one or few organized "mother rotors", or alternatively by the existence of focal ectopic sources, [2,3]. Pharmacological treatment for AF includes antiarrhythmic drugs that are either rate or rhythm control. These effects are achieved by various ionic mechanisms altering the electrophysiological properties of the membrane voltage at either depolari...
Source: Medical Engineering and Physics - September 7, 2018 Category: Biomedical Engineering Authors: Guy Malki, Sharon Zlochiver Source Type: research
