An experimental and computational study of the inferior vena cava hemodynamics under respiratory-induced collapse of the infrarenal IVC
Pulmonary embolism (PE) is the third most common cause of death from cardiovascular disease, after heart attack and stroke [1]. Usually associated with deep vein thrombosis (DVT), pulmonary embolism occurs when a venous thrombus embolizes and passes through the inferior vena cava (IVC) to the pulmonary arteries. Emboli occluding blood flow to one or both lungs can lead to impaired oxygenation, heart strain, and death [2]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - February 24, 2018 Category: Biomedical Engineering Authors: Elisabetta Tedaldi, Chiara Montanari, Kenneth I. Aycock, Francesco Sturla, Alberto Redaelli, Keefe B. Manning Source Type: research
A flow-leak correction algorithm for pneumotachographic work-of-breathing measurement during high-flow nasal cannula oxygen therapy
High-flow oxygen therapy through a nasal cannula (HFNC) is increasingly used as a technique for treating respiratory failure [1]. Delivery of a heated and humidified oxygen/air mixture at high flow rates improves ventilatory efficiency and generates a positive pharyngeal pressure that reduces the work of breathing (WOB) [2]. In current practice, HFNC therapy is initiated at a flow rate of 1 L/kg/min + 1 and flow is then titrated according to respiratory distress [3]. Whether this procedure does so safely nevertheless remains uncertain, because subsequent variations in flow settings fail to take into account effectiv...
Source: Medical Engineering and Physics - February 24, 2018 Category: Biomedical Engineering Authors: Francesco Montecchia, Fabio Midulla, Paola Papoff Source Type: research
Dynamic properties of human incudostapedial joint —Experimental measurement and finite element modeling
The incudostapedial joint (ISJ) is a synovial joint connecting the incus and stapes in the middle ear. ISJ consists of the articular cartilage, meniscus, capsule, and synovial fluid [1 –3]. The function of the ISJ is to transmit mechanical vibration of the tympanic membrane (TM) to the stapes and cochlea, and provide flexibility to the middle ear ossicular chain [4]. The sound transmission function of the middle ear is closely related to the mechanical properties of the ISJ [4,5 ]. Abnormalities of the joint have been shown to impose severe conductive hearing loss, which usually requires surgical reconstruction of the os...
Source: Medical Engineering and Physics - February 22, 2018 Category: Biomedical Engineering Authors: Shangyuan Jiang, Rong Z. Gan Source Type: research
Design and experimental force analysis of a novel elliptical vibration assisted orthopedic oscillating saw
Orthopedic procedures such as osteotomies, and hip and knee joint replacements involve plane processing owing to the demand of implant assembly and fixation, for example, the surface to fixture interaction of the femoral component during total knee replacement. Orthopedic powered saws have been designed and widely used for plane processing since 1890s [1]. There are three main requirements for bone sawing: high efficiency, low temperature, and low cutting force. Considering the operation time of such a surgery, the high cutting efficiency is the most crucial factor for bone resection devices. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - February 20, 2018 Category: Biomedical Engineering Authors: Liming Shu, Naohiko Sugita, Masaya Oshima, Mamoru Mitsuishi Source Type: research
Post-operative ventricular flow dynamics following atrioventricular valve surgical and device therapies: A review
Recently, there has been a renewed interest in intra-ventricular flow, especially regarding vortex pattern. Vortex is one of the important coherent structures that is thought to be responsible for the active dynamics of turbulent flow. In the heart, a vortex typically arises due to the separation of boundary layers [1]. Due to the variation of velocity in the shear layer formed between the inflow and the solid (tissue) boundary, fluid elements in this layer develop tendency to swirl and may curl back when separating from the solid surface, spinning away from the central inflow jet and forming a vortex [1 –4]. (Source: Me...
Source: Medical Engineering and Physics - February 14, 2018 Category: Biomedical Engineering Authors: Yen Ngoc Nguyen, Munirah Ismail, Foad Kabinejadian, Edgar Lik Wui Tay, Hwa Liang Leo Source Type: research
Towards the enhancement of body standing balance recovery by means of a wireless audio-biofeedback system
The visual, the proprioception and the vestibular systems work to provide standing balance [1,2], so that when one or more of these systems are under sufferance (because of pathologies, diseases, or other reasons) balance capabilities can be reduce, even severely, in effectiveness. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - February 10, 2018 Category: Biomedical Engineering Authors: Giovanni Costantini, Daniele Casali, Fabio Paolizzo, Marco Alessandrini, Alessandro Micarelli, Andrea Viziano, Giovanni Saggio Tags: Technical note Source Type: research
A finite element modeling study of peripheral nerve recruitment by percutaneous tibial nerve stimulation in the human lower leg
Percutaneous tibial nerve stimulation (PTNS) is a minimally-invasive electrical neuromodulation therapy that has been shown to treat effectively symptoms of overactive bladder (OAB) [1 –3]. Although the therapeutic mechanism is unknown, the historical origins of PTNS suggest that electrical activation of tibial nerve (TN) fibers is a necessary requirement for treating OAB symptoms. This idea is supported by preclinical studies in anesthetized animals, which show that TN stimulat ion – using an implanted nerve cuff electrode, for example – can evoke bladder-inhibitory responses that persist after the stimulus has been...
Source: Medical Engineering and Physics - February 3, 2018 Category: Biomedical Engineering Authors: Christopher W. Elder, Paul B. Yoo Source Type: research
Mechanical properties of cancellous bone from the acetabulum in relation to acetabular shell fixation and compared with the corresponding femoral head
The use of uncemented fixation for total hip arthroplasty (THA) varies from country to country but registries report it is gaining in popularity. In the US in 2012, 93% of THA constructs were cementless, increasing from 46% in 2001, and the hybrid construct, comprising a cemented stem and cementless cup, accounted for just 5% [1]. This is higher than in most countries. In Australia, cementless components are used in 63.2% and hybrid fixation in 32.4% of primary THA [2], whereas in Sweden cemented fixation is still more popular with only 20.9% of procedures reported as being uncemented and 3% hybrid [3]. (Source: Medical En...
Source: Medical Engineering and Physics - February 3, 2018 Category: Biomedical Engineering Authors: Rianne van Ladesteijn, Holly Leslie, William A Manning, James P Holland, David J Deehan, Thomas Pandorf, Richard M Aspden Source Type: research
Numerical validation of a subject-specific parameter identification approach of a quadriceps femoris EMG-driven model
The estimation of individual muscle forces exerted during a motor task is a challenging problem in biomechanics, however with many potential applications [1,2]. For example, the assessment of imbalances in muscle synergies can be used to improve athletic performance and suggest rehabilitation strategies for neural or orthopedic patients. Mathematical muscle models can be used for this purpose since force measurements cannot be directly obtained in a non-invasive way. Muscle models are frequently part of a larger musculoskeletal dynamic model, which is analyzed through a forward or inverse dynamics formulation [3,4]. (Sourc...
Source: Medical Engineering and Physics - February 3, 2018 Category: Biomedical Engineering Authors: Cl áudio Bastos Heine, Luciano Luporini Menegaldo Source Type: research
Impact of isotropic constitutive descriptions on the predicted peak wall stress in abdominal aortic aneurysms
Peak Wall Stress (PWS) [1,2] and related biomechanical parameters [3 –5] receive increasing attention in assessing the rupture risk of Abdominal Aortic Aneurysms (AAA). Specifically, compared to the maximum diameter and its change in time, i.e. currently the most-used clinical risk assessment parameters, the biomechanics-based diagnostic parameters allow integratin g many patient-specific risk factors [6]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - February 2, 2018 Category: Biomedical Engineering Authors: V. Man, S. Polzer, T.C. Gasser, T. Novotny, J. Bursa Source Type: research
Constitutive modeling of compressible type-I collagen hydrogels
Collagen is a naturally occurring polymer that provides a low immunogenic and biologically compatible platform for cellular attachment [1,2]. Type-I collagen, the most abundant of the collagens, endows a diverse group of mammalian tissues with their mechanical properties [3,4]. This material can be processed from primary tissue sources into acidic solutions, molded into a variety of shapes, and reconstituted into gels using pH neutralization [5]. As such, its applications in biomedical engineering are vast. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - February 1, 2018 Category: Biomedical Engineering Authors: Brooks A. Lane, Katrina A. Harmon, Richard L. Goodwin, Michael J. Yost, Tarek Shazly, John F. Eberth Source Type: research
Spring assisted cranioplasty: A patient specific computational model
Craniosynostosis is a rare disease affecting 1 in 1700 live births consisting in premature fusion (ossification) of one or more cranial sutures during infancy [1]. The most common presentation is sagittal craniosynostosis, which occurs when the sagittal suture fuses, causing scaphocephaly – a craniofacial deformity described by long narrow heads (Fig. 1) – and in some cases, raised intracranial pressure with functional problems [2–4]. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - January 19, 2018 Category: Biomedical Engineering Authors: Alessandro Borghi, Naiara Rodriguez-Florez, Will Rodgers, Gregory James, Richard Hayward, David Dunaway, Owase Jeelani, Silvia Schievano Source Type: research
Design, optimisation and testing of a compact, inexpensive elastic element for series elastic actuators
Stroke is a common disease in modern society and considering the ageing of society a rise of cases is to be expected over the next years [1,2]. Stroke leads to temporary or permanent damage of parts of the patient ’s brain, often resulting in motor or cognitive deficits, depressions or hemiparesis [3]. It is possible to regain lost abilities with the help of intensive training with equally intensive therapeutic support. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - January 18, 2018 Category: Biomedical Engineering Authors: Cornelius Irmscher, Elmar Woschke, Erik May, Christian Daniel Tags: Technical note Source Type: research
Kinematic measures for upper limb robot-assisted therapy following stroke and correlations with clinical outcome measures: A review
Strokes are currently the second largest cause of disability-adjusted life years (DALYs) after ischemic heart disease in developing countries, and is the third largest cause of DALYs in developed countries (after ischemic heart disease and low back and neck pain) [1]. The functional activities of stroke survivors are significantly affected due to motor impairments, particularly in terms of upper limb disability. The impairment reduction and the recovery of upper limb are key objectives in stroke rehabilitation, which contribute to enhancing the quality of life of stroke survivors. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - January 18, 2018 Category: Biomedical Engineering Authors: Vi Do Tran, Paolo Dario, Stefano Mazzoleni Source Type: research
Automatic recognition of gait patterns in human motor disorders using machine learning: A review
Walking is one of the most common human physical activities that can be performed in a variety of conditions and environments [1]. Analysis of human gait patterns can provide significant information related to the physical and neurological functions, and it may contribute to the diagnosis of human motor disorders in pathological conditions [2,3]. For these purposes, the human gait patterns need to be recognized, i.e., categorized according to the situation or clinical status of the analysed locomotor function. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - January 18, 2018 Category: Biomedical Engineering Authors: Joana Figueiredo, Cristina P. Santos, Juan C. Moreno Source Type: research
