A computational fluid –structure interaction analysis of coronary Y-grafts
Coronary artery bypass graft (CABG) surgery, the standard procedure to treat advanced coronary artery disease, consists in bypassing a blocked portion of a coronary artery in order to restore the proper blood flow to the heart. The incidence of CABG operation is significant in the Western countries. For example, in the USA the number of CABG operations was about 250,000 in 2006 (0.09% of the population) and it is expected to increase by over 50% between 2006 and 2025 [1]. The bypass used for the procedure is typically autologous, i.e., harvested from the patient ’s own body. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 19, 2017 Category: Biomedical Engineering Authors: Bruno Guerciotti, Christian Vergara, Sonia Ippolito, Alfio Quarteroni, Carlo Antona, Roberto Scrofani Source Type: research
Modeling the cleavage of von Willebrand factor by ADAMTS13 protease in shear flow
In case of a vascular injury, a complex hemostatic process is initiated, where various blood components form a plug (or clot) at the injury site in order to stop bleeding. Von Willebrand factor (VWF) is a key player in the primary hemostatic process and acts as a ‘glue’, mediating adhesion of blood platelets to the areas of damaged endothelial cells with exposed collagen [1–3]. In fact, at high enough shear rates VWF function is indispensable, because platelets are not able to bind efficiently to an injury site by themselves [4,5]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 19, 2017 Category: Biomedical Engineering Authors: Brooke Huisman, Masoud Hoore, Gerhard Gompper, Dmitry A. Fedosov Source Type: research
Development of a multi-DoF transhumeral robotic arm prosthesis
Development of Upper Limb (UL) prostheses is a research topic that is garnering high interest because loss of UL owing to varied levels of amputation extensively limits the activities of daily living (ADL) of an individual [1]. Prostheses are expected to replace the lost functions of its biological counterpart, while also providing aesthetic appearance for enhanced social interaction. Until the present, several UL prostheses have been developed [2 –16]; these are reasonably capable of providing the amputees satisfactory functionality to assist them in their ADL. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 17, 2017 Category: Biomedical Engineering Authors: D.S.V. Bandara, R.A.R.C. Gopura, K.T.M.U. Hemapala, Kazuo Kiguchi Source Type: research
Deformability- and size-based microcapsule sorting
The shape and mechanical properties of blood cells govern many important phenomena, such as margination [1], adhesion [2], and extravasation [3]. Pathologies such as cancer [4] or infections [5] may alter cell size and stiffness. Abnormal stiffness can be used as a sorting parameter in the detection and isolation of pathological cells [6]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 17, 2017 Category: Biomedical Engineering Authors: Doriane Vesperini, Oriane Chaput, Nad ège Munier, Pauline Maire, Florence Edwards-Lévy, Anne-Virginie Salsac, Anne Le Goff Source Type: research
A mechanistic force model for simulating haptics of hand-held bone burring operations
Virtual reality (VR) interfaces integrated with haptic devices are increasingly being used in medical training to simulate surgeries [1 –3]. Haptic devices use algorithms based on a force rendering model to calculate forces experienced during the manipulation of soft and hard tissues. However, creating realistic haptic feedback is challenging for operations involving biological material removal because of the varying position and orientation of the cutting tool and the highly dynamic and non-linear material responses, as opposed to simple elastic contact and deformation of the object. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 17, 2017 Category: Biomedical Engineering Authors: Avinash Danda, Mathew A. Kuttolamadom, Bruce L. Tai Source Type: research
Finite element analysis of TAVI: Impact of native aortic root computational modeling strategies on simulation outcomes
Aortic Stenosis (AS) is the most common form of valvular heart disease in developed countries, occurring in 3% of people older than 65 [1]. It is a degenerative disease of the aortic valve, compromising its function of regulating blood flow from the left ventricle to the aorta, with significant consequences on morbidity and mortality of patients, thus representing a current relevant clinical problem. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 17, 2017 Category: Biomedical Engineering Authors: Alice Finotello, Simone Morganti, Ferdinando Auricchio Source Type: research
Mass-spring models for the simulation of mitral valve function: Looking for a trade-off between reliability and time-efficiency
The mitral valve (MV) is located between the left atrium and the left ventricle. In physiological conditions, it allows for diastolic blood flow from the former to the latter with minimal energy dissipation, and it prevents from systolic backflow [1]. MV physiologic function requires the correct interplay of its components: annulus, leaflets, papillary muscles (PMs), which originate from the ventricular myocardium, and chordae tendineae, which connect the leaflets to the PMs [1]. In particular, in systole the annulus shrinks, the leaflets coapt and occlude the MV orifice, the PMs contract and together with chordae tendinea...
Source: Medical Engineering and Physics - July 17, 2017 Category: Biomedical Engineering Authors: O.A. Pappalardo, F. Sturla, F. Onorati, G. Puppini, M. Selmi, G.B. Luciani, G. Faggian, A. Redaelli, E. Votta Source Type: research
Three-dimensional computational model of a blood oxygenator reconstructed from micro-CT scans
According to the National Health Service (NHS [19]) and Health and Safety Executive (HSE [10]), up to 25,000 people die of Chronic Obstructive Pulmonary Disease (COPD) every year and the disorder affects over a million individuals in Great Britain. In addition up to 400 people develop Acute Respiratory Distress Syndrome (ARDS) with a mortality rate of over 50%. Improving treatment techniques have a direct social and individual impact in saving lives, increasing life expectancy and reducing cost to the public health services. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 14, 2017 Category: Biomedical Engineering Authors: C. D ’Onofrio, R. van Loon, S. Rolland, R. Johnston, L. North, S. Brown, R. Phillips, J. Sienz Source Type: research
Dynamic simulation of knee-joint loading during gait using force-feedback control and surrogate contact modelling
Accurate knowledge of muscle and joint loading during human locomotion is critical for improving the diagnosis of musculoskeletal conditions such as knee osteoarthritis and for evaluating the effects of implant design and surgical technique on the functional performance of total joint replacements. Direct measurement of muscle and articular joint contact forces is infeasible thus computational modelling is used in conjunction with gait analysis techniques to evaluate these quantities non-invasively. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 13, 2017 Category: Biomedical Engineering Authors: Jonathan P. Walter, Marcus G. Pandy Source Type: research
A framework for computational fluid dynamic analyses of patient-specific stented coronary arteries from optical coherence tomography images
Coronary heart diseases (CHDs) are the major causes of death in the Western Countries [1,2]. The principal source of CHD is the narrowing of vessel lumen because of atherosclerotic plaque development. The most widely performed CHD surgical treatment is percutaneous coronary intervention (PCI), due to the reduced hospitalization, recovery time and costs [2]. The influence of coronary anatomy on PCI outcomes is largely confirmed [3]. Consequently, the significant anatomic variability observed among individuals has led to an increasing application of intravascular imaging techniques for the characterization of each specific c...
Source: Medical Engineering and Physics - July 12, 2017 Category: Biomedical Engineering Authors: Susanna Migliori, Claudio Chiastra, Marco Bologna, Eros Montin, Gabriele Dubini, Cristina Aurigemma, Roberto Fedele, Francesco Burzotta, Luca Mainardi, Francesco Migliavacca Source Type: research
Particle image velocimetry study of the celiac trunk hemodynamic induced by continuous-flow left ventricular assist device
Left ventricular assist device (LVAD) is the gold-standard treatment for end-stage heart failure in patients, who are not eligible for heart transplantation [1,2]. In patients with refractory heart failure, LVAD has evolved into a permanent or destination therapy [3,4]. Although outcomes after LVAD implantation have significantly improved in the last year [5], the understanding of hemodynamic alterations induced by the LVAD into the aorta, especially if support is provided by a continuous flow pump system, has to be elucidated. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 12, 2017 Category: Biomedical Engineering Authors: Francesco Scardulla, Diego Bellavia, Leonardo D'Acquisto, Giuseppe M Raffa, Salvatore Pasta Source Type: research
Large eddy simulations of blood dynamics in abdominal aortic aneurysms
Dynamics of blood plays a major role in the development of abdominal aortic aneurysms (AAA), an enlargement of the abdominal aorta whose rupture could lead to fatal events [1]. In particular, specific wall shear stress (WSS) conditions regulate the production of nitric oxide [2], which is known to cause the loss of elastin which is at the root of aneurysm formation and growth; cause the activation of blood platelets [3], playing a central role in thrombus formation; and are responsible for anisotropic displacements of the aneurysmatic sac [4]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 12, 2017 Category: Biomedical Engineering Authors: Christian Vergara, Davide Le Van, Maurizio Quadrio, Luca Formaggia, Maurizio Domanin Source Type: research
Improving the detection of evoked responses to periodic stimulation by using bivariate local spectral F-test – Application to EEG during photic stimulation
The spectral F-test has been widely used for automatic detection of periodic signals in noisy environments [1,2], and its definition dates back to seminal works such as those by Rayleigh [3], Schuster [4], Fisher, [5], and Siegel, [6]. Basically, the spectral F-test compares the energy at a given frequency (called signal frequency) with that of the neighbouring frequencies (called noise frequencies). This kind of comparison is often used in clinical practice for detecting, for example, auditory responses in the brain [1,2]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 12, 2017 Category: Biomedical Engineering Authors: Leonardo Bonato Felix, Paulo F ábio Rocha, Eduardo Mazoni Andrade Marçal Mendes, Antonio Mauricio Ferreira Leite Miranda de Sá Source Type: research
Fixation strength of a polyetheretherketone femoral component in total knee arthroplasty
The initial fixation of the femoral component after total knee arthroplasty (TKA) is an important outcome measure for the success of the procedure. The research and development in cementless TKA is focused on primary stability through mechanical fixation (e.g. press-fit or pin/screw fixation) to allow the biological process of bone ingrowth to provide long-term fixation [1 –5]. In cemented fixation there are two interfaces at which failure can occur; the cement–bone and cement–implant interface. Studies that focused on the integrity of the cement–bone interface concluded that of the two this one was the most vulner...
Source: Medical Engineering and Physics - July 12, 2017 Category: Biomedical Engineering Authors: Lennert de Ruiter, Dennis Janssen, Adam Briscoe, Nico Verdonschot Tags: Technical note Source Type: research
A review of bioregulatory and coupled mechanobioregulatory mathematical models for secondary fracture healing
Bone is a unique tissue that can renew itself and maintain skeletal integrity through resorption [1]. Unlike other tissues, bone tissue is a unique and the only tissue that can heal without scaring [2]. Despite bone ’s unique self-regeneration capacity and continuing research efforts, delayed healing and non-unions resulting from bone fractures often occur. Fractures not only bring pains to patients, but also cost societies large amounts of money. It is reported that the cost of treating non-unions is between £7 000 and £79 000 per person [3–6]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - July 11, 2017 Category: Biomedical Engineering Authors: Monan Wang, Ning Yang Source Type: research
