WIT Transactions on Biomedicine and Health最新文献

{"title":"Numerical simulation of electromechanical activity of the gastric smooth muscle","authors":"O. Al-Qabandi, R. Miftahof","doi":"10.2495/BIO130061","DOIUrl":"https://doi.org/10.2495/BIO130061","url":null,"abstract":"A null-dimensional mathematical model of the myoelectrical activity of the gastric smooth muscle (myofiber) is studied numerically. Based on real morphological and electrophysiological data, the model assumes that: the kinetics of L- and T-type Ca 2+ , Ca 2+ -activated K + , voltage dependent K + and Cl","PeriodicalId":370021,"journal":{"name":"WIT Transactions on Biomedicine and Health","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114183456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of image segmentation methods for intracranial aneurysm haemodynamic research","authors":"Y. Sen, Y. Zhang, Y. Qian, M. Morgan","doi":"10.2495/BIO130231","DOIUrl":"https://doi.org/10.2495/BIO130231","url":null,"abstract":"Patient-specific haemodynamic technology has been applied in clinical applications. Computational haemodynamic simulation is performed by utilization of geometric results obtained via medical image segmentation. However, the geometry and volume of intracranial aneurysm models are highly dependent upon different segmentation methods, even when employed upon the same medical imaging data. Moreover, methods of vascular segmentation have been insufficiently validated. In this study, we compared three segmentation methods; the Region Growing Threshold (RGT), Chan-Vese model (CV) and Threshold-Based Level Set (TLS), to segment the aneurysm geometry through the use of CTA image data. The results were evaluated via measurement of arterial volume differences (VD), local geometric shapes, and haemodynamic simulation results. We found that the maximum VD of three segmentation methods sat at around ±15%. Local artery anatomical shapes of aneurysms were likewise found to significantly influence segmentation results. The computational haemodynamic simulation was performed modelling three types of geometries, with typical haemodynamic characteristics; i.e. energy loss and shear stress. We found that there was a maximum of 58% difference between segmentation methods. The results indicated that it is essential to validate segmentation methods in order to confirm the quality of segmentation processes in the application of patient-specific cerebrovascular haemodynamic analysis.","PeriodicalId":370021,"journal":{"name":"WIT Transactions on Biomedicine and Health","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125847936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dermis Mechanical Behaviour:Influence Of Cell Removal Treatment","authors":"A. Audenino, C. Bignardi, E. Businaro, C. Castagnoli, M. Terzini, E. Zanetti","doi":"10.2495/BIO130161","DOIUrl":"https://doi.org/10.2495/BIO130161","url":null,"abstract":"The mechanical behaviour of skin is very important as regards dermatology, surgery and impact trauma. Engineered skin substitutes can bring significant medical benefit, in particular to patients with extensive burn wounds, even if current skin substitutes do not restore normal skin anatomy and its natural mechanical properties. This work considers the mechanical characterization of a particular layer of skin: dermis. Dermis can be used as a filling material and as support in different areas of reconstructive plastic surgery such as post mastectomy reconstructive surgery and abdominal surgery. The aim was to verify the influence of the decellularization treatment on its properties. The specimens were subjected to uniaxial static tests performed with Bose Electroforce ® 3200 and experimental data were represented with engineering and real time stress-strain curves. To begin, descriptive parameters were identified for stress vs. strain curves, such as ultimate tensile strength and maximum Young’s modulus, and they were subsequently compared through multivariate analysis of variance to determine the influence of specimen cut orientation and decellularization treatment duration. Dermis, that had been decellularized over 5 or 6 weeks, exhibited mechanical properties comparable with natural ones and ultimate tensile strength and maximum Young’s modulus were shown to be considerably higher in real time curves than in engineering ones.","PeriodicalId":370021,"journal":{"name":"WIT Transactions on Biomedicine and Health","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131203030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of fractured clavicles and reconstruction plates using CAD, finite element analysis and real musculoskeletal forces input","authors":"Marie Cronskär, M. Bäckström","doi":"10.2495/BIO130211","DOIUrl":"https://doi.org/10.2495/BIO130211","url":null,"abstract":"This doctoral thesis is devoted to studying the possibilities of using additive manufacturing (AM) and design based on computed tomography (CT), for the production of patient-specific implants within orthopedic surgery, initially in a broad perspective and, in the second part of the thesis focusing on customized clavicle osteosynthesis plates. The main AM method used in the studies is the Electron Beam Melting (EBM) technology. Using AM, the parts are built up directly from 3D computer models, by melting or in other ways joining thin layers of material, layer by layer, to build up the part. Over the last 20 years, this fundamentally new way of manufacturing and the rapid development of software for digital 3D reconstruction of anatomical models from medical imaging, have opened up entirely new opportunities for the design and manufacturing of patient-specific implants. Based on the information in a computed tomography (CT) scan, both digital and physical models of the anatomy can be created and of implants that are customized based on the anatomical models. The main method used is a number of case studies performed, focusing on different parts of the production chain, from CT-scan to final implant, and with several aims: learning about the details of the different steps in the procedure, finding suitable applications, developing the method and trying it out. The first study was on customized hip stems, focusing on the EBM method and its special preconditions and possibilities. It was followed by a study of bone plates, designed to follow the patient-specific bone contour, in this case a tibia fracture including the whole production chain. Further, four cases of patient-specific plates for clavicle fracture fixation were performed in order to develop and evaluate the method. The plates fit towards the patient’s bone were tested in cooperation with an orthopedic surgeon at Ostersund hospital. In parallel with the case studies, a method for finite element (FE) analysis of fixation plates placed on a clavicle bone was developed and used for the comparative strength analysis of different plates and plating methods. The loading on the clavicle bone in the FE model was defined on a muscle and ligament level using multibody musculoskeletal simulation for more realistic loading than in earlier similar studies. The initial studies (papers I and II) showed that the EBM method has great potential, both for the application of customized hip stems and bone plates; in certain conditions EBM manufacturing can contribute to significant cost reductions compared to conventional manufacturing methods due to material savings and savings in file preparation time. However, further work was needed in both of the application areas before implementation. The studies on the fracture fixation using patient-specific clavicle plates indicated that the method can facilitate the work for the surgeon both in the planning and in the operating room, with the potential of a smoothe","PeriodicalId":370021,"journal":{"name":"WIT Transactions on Biomedicine and Health","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134087581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particle Motion In Coronary Serial Stenoses","authors":"S. Bernad, A. Totorean, E. Bernad, R. Susan-Resiga","doi":"10.2495/BIO130151","DOIUrl":"https://doi.org/10.2495/BIO130151","url":null,"abstract":"Atherosclerosis creating a constriction can significantly alter the local blood flow dynamics. From a biological aspect, the changes that take place in the flow have a profound effect on the structure and function of the arterial wall and the development of the disease. The purpose of this paper was to non-invasively assess hemodynamic parameters such as wall shear stress, wall pressure and particle depositions with computational fluid dynamics (CFD) in coronary artery serial stenoses. A 3-D model of a serial stenosed RCA was reconstructed based on multislice computerized tomography images. Energy loss associated with such flow expansion after each constriction will be large and consequently the pressure drop will be higher. Pressure drop across the stenoses ST1 and ST3 is lower (4.62 mmHg and 4.81 mmHg respectively) during the time T2 = 0.79s, but is significant during the peak systole T1 = 0.26s. The maximum WSS in the proximal stenosis ST1 is about 254 Pa, and in the distal stenosis ST3 are 232 Pa. One diameter downstream of the each stenosis, the WSS is low because of the formation of the recirculation zone.","PeriodicalId":370021,"journal":{"name":"WIT Transactions on Biomedicine and Health","volume":"107 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133833403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling of blood coagulation in cerebral aneurysms","authors":"Y. Aida, K. Shimano","doi":"10.2495/BIO130051","DOIUrl":"https://doi.org/10.2495/BIO130051","url":null,"abstract":"A fatal subarachnoid haemorrhage occurs when an intracranial aneurysm ruptures and there are no guidelines for rupture risk assessment with perfect reliability. Thrombus formation in stagnant flow condition has been said to play an important role in rupture. However, there are, at present, no mathematical models that allow us to simulate the whole process of thrombus formation in aneurysms. In this study, the authors proposed a mathematical model of intraaneurysmal coagulation so that the amount of fibrin generated in the aneurysm can be calculated. It is known that coagulation is initiated by erythroelastase-IX (EE-IX) in stagnant flow condition. This process is different from contact and tissue factor pathways. In the present coagulation model, the reaction rate constant of factor IX activation by EE-IX was determined. A group of reactions in which anticoagulants are involved are treated as a whole so as to reduce computational cost, and a quantity for the combined reaction rate constant is also determined. It is demonstrated that the present coagulation model can reproduce the rate of fibrin generation in a reference experiment at a reasonable computational cost.","PeriodicalId":370021,"journal":{"name":"WIT Transactions on Biomedicine and Health","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129255724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating implantable glucose biosensors pitfalls: a fault tree analysis approach","authors":"C. Siontorou, F. Batzias","doi":"10.2495/BIO130091","DOIUrl":"https://doi.org/10.2495/BIO130091","url":null,"abstract":"Implantable sensors for glucose monitoring are the first step towards the development of an implantable closed-loop diabetes control system. Although significant advances in the designs and chemistries employed to prepare intravascular and subcutaneous devices have been achieved, the biological responses can have a dramatic impact on the analytical accuracy of such probes. With a view to assisting the effective design of such devices for assuring clinical performance, the causes of implantable glucose sensor failure have been investigated by means of Fault Tree Analysis (FTA) relying on fuzzy reasoning to account for uncertainty. The approach suggested may contribute significantly to the self-optimisation of the measuring equipment from one generation to the next as it supports the flexible, ad hoc, and tailor made sensor development, thus potentiating the progress of epidemics from statistics to individualisation.","PeriodicalId":370021,"journal":{"name":"WIT Transactions on Biomedicine and Health","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124973509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Psychophysiological determinants of drivers' condition","authors":"K. Rózanowski, Z. Piotrowski, M. Bernat","doi":"10.2495/BIO130081","DOIUrl":"https://doi.org/10.2495/BIO130081","url":null,"abstract":"The psychophysiological state of vehicle drivers is of key importance for road safety and for the life and health of other users of the transport infrastructure. A number of external factors may contribute to gradual deterioration of the driver’s condition and undiagnosed illness may result in abrupt health disorders. The objective of this paper is to establish, on the basis of tests, surveys, and measurements, an index reflecting the psychophysiological state of a vehicle driver. The research was based on a database of results for a group of 15 rested volunteer drivers. The results were classified into two subgroups corresponding to two components of the index: physiological and psychological. On the basis of arranged data, a method was proposed to calculate the FIZ and PSY indices. As a result of the research, we have obtained determinants of the psychophysiological condition of the subject drivers and a group of correlated indices. They are candidate items (inter alia) of a short survey aimed to verify the short-term condition of a driver.","PeriodicalId":370021,"journal":{"name":"WIT Transactions on Biomedicine and Health","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123586280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational technologies in tissue engineering","authors":"H. Almeida, P. Bártolo","doi":"10.2495/BIO130111","DOIUrl":"https://doi.org/10.2495/BIO130111","url":null,"abstract":"In last decades, many advances have been made in order to aid the medical community. Numerous computational technologies have been developed and improved the efficiency in diagnostic and treatment of many diseases. Many of the technologies were developed with the main goal of aiding in the research of genetic and viral diseases. Tissue engineering is a multidisciplinary field that requires the combined effort of cell biologists, engineers, material scientists, mathematicians, geneticists, and clinicians toward the development of biological substitutes that restore, maintain, or improve tissue function. The success of this emerging medical domain relies on the current technological advances. This paper presents an overview of the existing computational technologies that have been implemented in tissue engineering and the design of scaffolds for tissue engineering applications. These computational technologies contemplate medical imaging processing, numerical calculations (structural, vascular and topological) and biofabrication techniques necessary for the scaffolds optimum design and production.","PeriodicalId":370021,"journal":{"name":"WIT Transactions on Biomedicine and Health","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116504320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arterial pulse waves measured with EMFi and PPG sensors and comparison of the pulse waveform spectral and decomposition analysis in healthy young and elderly subjects","authors":"M. Huotari, A. Vehkaoja, Kari Määttä, J. Kostamovaara, J. Röning","doi":"10.2495/BIO130011","DOIUrl":"https://doi.org/10.2495/BIO130011","url":null,"abstract":"The purpose of this study is to show the time domain and frequency domain analysis of signals recorded with electromechanical film (EMFi) and photoplethysmographic (PPG) sensors in arterial elasticity estimation via pulse wave decomposition and spectral components obtained from left forefinger, left wrist, and left second toe arteries. ECG and pulse waves from the subjects were recorded firstly from 20 voluntaries by PPG sensors and from 7 persons (30– 60 y) by parallel EMFi and PPG sensors in supine position. Decomposition of the pulse waves produces five components: percussion wave, tidal wave, dicrotic wave, and 1st and 2nd presystolic waves. Pulse wave decomposition parameters between EMFi and PPG are compared to find out information on a person’s arterial elasticity. Results show that elastic information in the form of pulse wave decomposition from PPG waves is obtainable and shows clear shortening between percussion wave and tidal wave time with age. The spectral information obtained with frequency domain analysis could also be valuable in assessing the arterial elasticity.","PeriodicalId":370021,"journal":{"name":"WIT Transactions on Biomedicine and Health","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129863958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}