Pub Date : 2018-06-14DOI: 10.1504/IJECB.2018.10013555
M. Raoufi, H. Niazmand, M. Pourramezan
In contrast to straight blood vessels, more complicated flow patterns in tortuous vessels lead to a disruption of a regular distribution of oxygen on the vessel walls. This disturbance correspondingly plays a significant role in the origin and worsening of clogged arteries. In this study, using a rescaled Newtonian model for non-Newtonian behaviour of blood flow, oxygen mass transporting a 180° curved artery is computationally investigated. The model used considers the oxygen carried by hemoglobin along with oxygen absorbed in the avascular wall of the artery. Our results indicate that there is a substantial reduction of oxygen mass transport to the inner bend of the vessel wall, while the outer bend wall locally exhibits a minimum PO2 distribution, around the curved inlet. These regions are more susceptible to atherosclerosis disease, a risk that is heightened by increases in vessel wall thickness, curvature ratio, and reduction of the Reynolds number.
{"title":"Non-Newtonian blood flow and coupled blood-wall oxygen mass transport in a 180° curved artery","authors":"M. Raoufi, H. Niazmand, M. Pourramezan","doi":"10.1504/IJECB.2018.10013555","DOIUrl":"https://doi.org/10.1504/IJECB.2018.10013555","url":null,"abstract":"In contrast to straight blood vessels, more complicated flow patterns in tortuous vessels lead to a disruption of a regular distribution of oxygen on the vessel walls. This disturbance correspondingly plays a significant role in the origin and worsening of clogged arteries. In this study, using a rescaled Newtonian model for non-Newtonian behaviour of blood flow, oxygen mass transporting a 180° curved artery is computationally investigated. The model used considers the oxygen carried by hemoglobin along with oxygen absorbed in the avascular wall of the artery. Our results indicate that there is a substantial reduction of oxygen mass transport to the inner bend of the vessel wall, while the outer bend wall locally exhibits a minimum PO2 distribution, around the curved inlet. These regions are more susceptible to atherosclerosis disease, a risk that is heightened by increases in vessel wall thickness, curvature ratio, and reduction of the Reynolds number.","PeriodicalId":90184,"journal":{"name":"International journal of experimental and computational biomechanics","volume":"4 1","pages":"79"},"PeriodicalIF":0.0,"publicationDate":"2018-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43327726","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}
Pub Date : 2016-02-17DOI: 10.1504/ijecb.2015.074733
H. Stauber, Rami Fishler, Philipp Hofemeier, D. Waisman, J. Sznitman
With growing evidence of the ability of inhaled nanoparticles (NP) to translocate from the lungs into the pulmonary circulation, increased concerns regarding the fate of such particles reaching body organs have risen. Until present, there is still a limited understanding on the transport dynamics of NPs following translocation into the pulmonary microcirculation. To gain initial insight into such processes, simulations of the transport and dispersion of various particle sizes are conducted in anatomically-inspired alveolar capillary networks (ACN). Our models, based on the seminal 'sheet flow' model, investigate quantitatively the influence of network porosity on particle dynamics. For fixed flow conditions, we find that the effective dispersion coefficient is sensibly enhanced with decreasing porosity levels and decreasing particle sizes. Furthermore, particle size significantly influences the characteristics of particle spreading and tortuosity. Overall, our findings represent a tangible first step in further understanding inhaled NP transport in networks representative of the alveolar capillaries.
{"title":"Particle dispersion in morphologically-inspired computational models of alveolar capillary networks","authors":"H. Stauber, Rami Fishler, Philipp Hofemeier, D. Waisman, J. Sznitman","doi":"10.1504/ijecb.2015.074733","DOIUrl":"https://doi.org/10.1504/ijecb.2015.074733","url":null,"abstract":"With growing evidence of the ability of inhaled nanoparticles (NP) to translocate from the lungs into the pulmonary circulation, increased concerns regarding the fate of such particles reaching body organs have risen. Until present, there is still a limited understanding on the transport dynamics of NPs following translocation into the pulmonary microcirculation. To gain initial insight into such processes, simulations of the transport and dispersion of various particle sizes are conducted in anatomically-inspired alveolar capillary networks (ACN). Our models, based on the seminal 'sheet flow' model, investigate quantitatively the influence of network porosity on particle dynamics. For fixed flow conditions, we find that the effective dispersion coefficient is sensibly enhanced with decreasing porosity levels and decreasing particle sizes. Furthermore, particle size significantly influences the characteristics of particle spreading and tortuosity. Overall, our findings represent a tangible first step in further understanding inhaled NP transport in networks representative of the alveolar capillaries.","PeriodicalId":90184,"journal":{"name":"International journal of experimental and computational biomechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1504/ijecb.2015.074733","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745454","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}
Pub Date : 2016-02-17DOI: 10.1504/ijecb.2015.074740
Junfeng Liang, B. Fu, Huiyang Luo, Don U. Nakmali, R. Gan, Hongbing Lu
Mechanical properties of tympanic membrane (TM) are crucial inputs for modelling acoustic transmission through the ear. In this paper a combined experimental and numerical approach was used to determine the mechanical properties of guinea pig TM under quasi-static condition based on the response of the TM to static pressure. A guinea pig bulla was prepared and the intact TM was subjected to both positive and negative pressures while its topography was measured using the micro-fringe projection technique. Images of the deformed TM were acquired and processed with a phase-shift method to reconstruct the surface profile and determine the volume deformation of the TM under pressures. Finite element method with the implementation of a hyperelastic model was established. The simulated TM deformations under applied pressures demonstrated a good agreement with the measured curves of the pressure-volume displacement relationship. The Young's modulus of guinea pig TM from seven bullas was determined as 15.2-28.3 MP...
{"title":"Characterisation of the nonlinear elastic behaviour of guinea pig tympanic membrane using micro-fringe projection","authors":"Junfeng Liang, B. Fu, Huiyang Luo, Don U. Nakmali, R. Gan, Hongbing Lu","doi":"10.1504/ijecb.2015.074740","DOIUrl":"https://doi.org/10.1504/ijecb.2015.074740","url":null,"abstract":"Mechanical properties of tympanic membrane (TM) are crucial inputs for modelling acoustic transmission through the ear. In this paper a combined experimental and numerical approach was used to determine the mechanical properties of guinea pig TM under quasi-static condition based on the response of the TM to static pressure. A guinea pig bulla was prepared and the intact TM was subjected to both positive and negative pressures while its topography was measured using the micro-fringe projection technique. Images of the deformed TM were acquired and processed with a phase-shift method to reconstruct the surface profile and determine the volume deformation of the TM under pressures. Finite element method with the implementation of a hyperelastic model was established. The simulated TM deformations under applied pressures demonstrated a good agreement with the measured curves of the pressure-volume displacement relationship. The Young's modulus of guinea pig TM from seven bullas was determined as 15.2-28.3 MP...","PeriodicalId":90184,"journal":{"name":"International journal of experimental and computational biomechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1504/ijecb.2015.074740","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745473","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}
Pub Date : 2016-02-17DOI: 10.1504/ijecb.2015.074732
Peyman Honarmandi, A. Sadegh, P. Cavallaro
In recent years, increasing concussions among American football players have drawn attention and concerns regarding safety of today's football helmets. This study investigates the effects of concussive impact forces on the brain of football players and the shock absorbing performance of actual football helmets. Initially, the mechanical properties of typical helmet materials were obtained through compression tests and hysteresis loop experiments. Next, a lumped-mass model was developed to physically describe both the head and helmet together against an impact load, and the brain response was obtained from the semi-analytical analysis. To extract more information such as strains and wave propagations within the brain, a detailed continuum model was constructed and the response of the brain was analysed by using the finite element method. A realistic impact load was obtained from a case study of actual football play. Our experimental data along with biomechanical data of the head and brain from the available literature were incorporated into our modelling and analyses. The results indicated that the accelerations and strains in the brain were both above the concussion thresholds and that current football helmet designs may not protect players against concussion.
{"title":"Modelling and impact analysis of football player head with helmet toward mitigating brain concussion","authors":"Peyman Honarmandi, A. Sadegh, P. Cavallaro","doi":"10.1504/ijecb.2015.074732","DOIUrl":"https://doi.org/10.1504/ijecb.2015.074732","url":null,"abstract":"In recent years, increasing concussions among American football players have drawn attention and concerns regarding safety of today's football helmets. This study investigates the effects of concussive impact forces on the brain of football players and the shock absorbing performance of actual football helmets. Initially, the mechanical properties of typical helmet materials were obtained through compression tests and hysteresis loop experiments. Next, a lumped-mass model was developed to physically describe both the head and helmet together against an impact load, and the brain response was obtained from the semi-analytical analysis. To extract more information such as strains and wave propagations within the brain, a detailed continuum model was constructed and the response of the brain was analysed by using the finite element method. A realistic impact load was obtained from a case study of actual football play. Our experimental data along with biomechanical data of the head and brain from the available literature were incorporated into our modelling and analyses. The results indicated that the accelerations and strains in the brain were both above the concussion thresholds and that current football helmet designs may not protect players against concussion.","PeriodicalId":90184,"journal":{"name":"International journal of experimental and computational biomechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1504/ijecb.2015.074732","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745405","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}
Pub Date : 2016-01-01DOI: 10.1504/IJECB.2016.10002676
Hongyi Zhao, Shudong Li, Lisa Li, G. Rothwell, James Ren
In this work, the indention process with a standard Shore OO indenter is investigated with both numerical modelling and analytical approaches. For thick samples, both Johnson's (1985) model for elastic half space and the Hayes' (1972) model based on finite thickness are evaluated. For thinner samples, the Hayes' (1972) model and FE models are comparatively used to investigate Shore OO hardness testing of finite thickness samples. In both cases, FE models of Shore OO hardness test with bonded sample conditions are developed to simulate the effect of sample thickness. A re-meshing program is developed to incorporate large deformation of soft materials to reach the required level of load for the Shore OO hardness. The data from numerical modelling and analytical solution is systematically compared for cases of thick and finite thickness samples. A chart correlating the stiffness and the Shore OO hardness is presented and its potential use and influencing factors are discussed.
{"title":"Numerical modelling and analytical analysis of Shore OO hardness tests on soft materials","authors":"Hongyi Zhao, Shudong Li, Lisa Li, G. Rothwell, James Ren","doi":"10.1504/IJECB.2016.10002676","DOIUrl":"https://doi.org/10.1504/IJECB.2016.10002676","url":null,"abstract":"In this work, the indention process with a standard Shore OO indenter is investigated with both numerical modelling and analytical approaches. For thick samples, both Johnson's (1985) model for elastic half space and the Hayes' (1972) model based on finite thickness are evaluated. For thinner samples, the Hayes' (1972) model and FE models are comparatively used to investigate Shore OO hardness testing of finite thickness samples. In both cases, FE models of Shore OO hardness test with bonded sample conditions are developed to simulate the effect of sample thickness. A re-meshing program is developed to incorporate large deformation of soft materials to reach the required level of load for the Shore OO hardness. The data from numerical modelling and analytical solution is systematically compared for cases of thick and finite thickness samples. A chart correlating the stiffness and the Shore OO hardness is presented and its potential use and influencing factors are discussed.","PeriodicalId":90184,"journal":{"name":"International journal of experimental and computational biomechanics","volume":"4 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745518","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}
Pub Date : 2016-01-01DOI: 10.1504/IJECB.2016.10002680
S. Ganpule, R. Salzar, B. Perry, N. Chandra
Blast induced traumatic brain injury (bTBI) has emerged as the most significant injury to war fighters in recent conflicts. Interaction of the blast wave with the head and helmet are not well understood. In this work, the effects of blast were investigated on the post-mortem human subject (PMHS) head using a compression driven shock tube. The results suggest that the evolution of intracranial pressure profiles is strongly governed by the wave propagation through skin-skull-brain parenchyma. It is also observed that the sinus cavities naturally attenuate the blast overpressure. Performance of two helmet configurations (padded and suspension) in mitigating the blast is also evaluated. The results suggest that the amount of mitigation offered by each helmet varies with the helmet configuration. For helmets with the suspension system, the blast wave is intensified beneath the helmet. Further, the degree of blast wave mitigation is affected by the morphology of the PMHS itself. Overall, these results suggest that the blast wave interacts with the head and the helmet in a complex manner and these interaction effects must be taken into account while designing strategies for protection of the head against the blast.
{"title":"Role of helmets in blast mitigation: insights from experiments on PMHS surrogate","authors":"S. Ganpule, R. Salzar, B. Perry, N. Chandra","doi":"10.1504/IJECB.2016.10002680","DOIUrl":"https://doi.org/10.1504/IJECB.2016.10002680","url":null,"abstract":"Blast induced traumatic brain injury (bTBI) has emerged as the most significant injury to war fighters in recent conflicts. Interaction of the blast wave with the head and helmet are not well understood. In this work, the effects of blast were investigated on the post-mortem human subject (PMHS) head using a compression driven shock tube. The results suggest that the evolution of intracranial pressure profiles is strongly governed by the wave propagation through skin-skull-brain parenchyma. It is also observed that the sinus cavities naturally attenuate the blast overpressure. Performance of two helmet configurations (padded and suspension) in mitigating the blast is also evaluated. The results suggest that the amount of mitigation offered by each helmet varies with the helmet configuration. For helmets with the suspension system, the blast wave is intensified beneath the helmet. Further, the degree of blast wave mitigation is affected by the morphology of the PMHS itself. Overall, these results suggest that the blast wave interacts with the head and the helmet in a complex manner and these interaction effects must be taken into account while designing strategies for protection of the head against the blast.","PeriodicalId":90184,"journal":{"name":"International journal of experimental and computational biomechanics","volume":"4 1","pages":"13"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745530","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}
Pub Date : 2016-01-01DOI: 10.1504/IJECB.2016.10002682
Talip Çelik, İ. Mutlu, A. Özkan, Y. Kişioğlu
The material selection of dynamic hip screw (DHS) is not usually considered from the point of mechanical effects. In this study, the effects of the titanium alloy and stainless steel DHS was investigated in the cut-out risk of femur using finite element analysis (FEA). Intertrochanteric femur fracture (IFF) (31-A2 type according to AO classification) was created in the 3D femur model obtained from computer tomography images. The DHS model was inserted to the fractured femur model in two different positions (inferior and middle). The material properties of DHS were defined for the FEA. The force applied to the femoral head was determined according to the maximum value that is observed during walking. The results show that the safest model was obtained in the middle placement of titanium alloy DHS according to the safety factor. Consequently, the use of stainless steel DHS for IFF could cause higher failure risk of DHS than the use of titanium alloy DHS.
{"title":"How does the material variation of dynamic hip screw affect the cut-out risk in the treatment of intertrochanteric femoral fractures?","authors":"Talip Çelik, İ. Mutlu, A. Özkan, Y. Kişioğlu","doi":"10.1504/IJECB.2016.10002682","DOIUrl":"https://doi.org/10.1504/IJECB.2016.10002682","url":null,"abstract":"The material selection of dynamic hip screw (DHS) is not usually considered from the point of mechanical effects. In this study, the effects of the titanium alloy and stainless steel DHS was investigated in the cut-out risk of femur using finite element analysis (FEA). Intertrochanteric femur fracture (IFF) (31-A2 type according to AO classification) was created in the 3D femur model obtained from computer tomography images. The DHS model was inserted to the fractured femur model in two different positions (inferior and middle). The material properties of DHS were defined for the FEA. The force applied to the femoral head was determined according to the maximum value that is observed during walking. The results show that the safest model was obtained in the middle placement of titanium alloy DHS according to the safety factor. Consequently, the use of stainless steel DHS for IFF could cause higher failure risk of DHS than the use of titanium alloy DHS.","PeriodicalId":90184,"journal":{"name":"International journal of experimental and computational biomechanics","volume":"4 1","pages":"49"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745580","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}
Pub Date : 2016-01-01DOI: 10.1504/IJECB.2016.10002687
S. Hashemi, Douglas Jahnke, A. Sadegh, Y. Andreopoulos
In this paper, the induced pressure in blood vessels of the brain due to a blast has been investigated. An idealised experiment was designed, consisting of a ballistic rectangular gel block with a built-in conduit filled with water, representing the brain with a blood vessel, was placed in front of a shock tube. The experimental setup was simulated by a local 3D FE model which was validated with the experimental data. Results demonstrated that the skull, brain and meningeal layers reduce the intensity of a primary blast wave by a factor of 86 until it reaches the brain vessels. Furthermore, it was concluded that the striking shock waves with BOP greater than 5 MPa would increase the blood pressure to the critical level of 57 kPa which could onset failure and cause hematoma.
{"title":"The effect of shock waves on brain blood pressure; experimental and computational studies","authors":"S. Hashemi, Douglas Jahnke, A. Sadegh, Y. Andreopoulos","doi":"10.1504/IJECB.2016.10002687","DOIUrl":"https://doi.org/10.1504/IJECB.2016.10002687","url":null,"abstract":"In this paper, the induced pressure in blood vessels of the brain due to a blast has been investigated. An idealised experiment was designed, consisting of a ballistic rectangular gel block with a built-in conduit filled with water, representing the brain with a blood vessel, was placed in front of a shock tube. The experimental setup was simulated by a local 3D FE model which was validated with the experimental data. Results demonstrated that the skull, brain and meningeal layers reduce the intensity of a primary blast wave by a factor of 86 until it reaches the brain vessels. Furthermore, it was concluded that the striking shock waves with BOP greater than 5 MPa would increase the blood pressure to the critical level of 57 kPa which could onset failure and cause hematoma.","PeriodicalId":90184,"journal":{"name":"International journal of experimental and computational biomechanics","volume":"4 1","pages":"59"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745627","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}
Pub Date : 2016-01-01DOI: 10.1504/IJECB.2016.10002681
Rajesh Surapureddy, A. Schonning, S. Stagon, A. Kassab
A static implicit nonlinear finite element model (FEM) was created and analysed to determine the pressure distribution between the residual limb and the prosthetic socket of a transfemoral amputee. This analysis was performed in an attempt to develop a process allowing healthcare providers and engineers to simulate the fit and comfort of transfemoral prosthetics to reduce the number of re-fittings. The FEM considered the effects of donning and body weight and included geometric nonlinearity due to large deflections, nonlinear contacts due to friction, and nonlinear hyper-elastic material properties for the residual limb's soft tissue. The results attained can provide prosthetic fitting clinicians customised information on where the prosthetic fits too tight, and how stress concentrations would change as a result of geometric modifications to the prosthetic. This knowledge can improve patients' comfort levels by providing well targeted and more accurate modifications to the prosthetic, minimising the need for numerous refittings.
{"title":"Predicting pressure distribution between transfemoral prosthetic socket and residual limb using finite element analysis","authors":"Rajesh Surapureddy, A. Schonning, S. Stagon, A. Kassab","doi":"10.1504/IJECB.2016.10002681","DOIUrl":"https://doi.org/10.1504/IJECB.2016.10002681","url":null,"abstract":"A static implicit nonlinear finite element model (FEM) was created and analysed to determine the pressure distribution between the residual limb and the prosthetic socket of a transfemoral amputee. This analysis was performed in an attempt to develop a process allowing healthcare providers and engineers to simulate the fit and comfort of transfemoral prosthetics to reduce the number of re-fittings. The FEM considered the effects of donning and body weight and included geometric nonlinearity due to large deflections, nonlinear contacts due to friction, and nonlinear hyper-elastic material properties for the residual limb's soft tissue. The results attained can provide prosthetic fitting clinicians customised information on where the prosthetic fits too tight, and how stress concentrations would change as a result of geometric modifications to the prosthetic. This knowledge can improve patients' comfort levels by providing well targeted and more accurate modifications to the prosthetic, minimising the need for numerous refittings.","PeriodicalId":90184,"journal":{"name":"International journal of experimental and computational biomechanics","volume":"4 1","pages":"32"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745571","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}
Pub Date : 2015-12-31DOI: 10.1504/ijecb.2015.073929
Kyrin Liong, A. Lahiri, Shujin Lee, D. Chia, A. Biswas, H. Lee
Carpal tunnel syndrome (CTS) is a common neuropathy, yet its etiology is unknown. While repetitive finger flexion and interstitial subsynovial connective tissue (SSCT) thickening are commonly associated with idiopathic CTS development, the stress that the nerve experiences remain unexamined. In this study, a patient-specific computational model of the carpal tunnel was developed. Tendon displacements corresponding to thumb, index finger (IF) and middle finger (MF) flexion were prescribed. To replicate a CTS candidate, the most common physiological finding - fibrosis of the SSCT - was modelled. Heightened nerve coefficients were also prescribed to simulate nerve stiffening. This revealed that volarly-moving tendons, as in IF and thumb flexion, elicit greater nerve stresses than those dorsally-moving tendons, as in MF flexion. The stress encountered in CTS candidates significantly exceeded those in normal candidates, demonstrating that tendon path, and the in-vivo conditions of an individual's SSCT and median nerve stiffness predominantly affect nerve stress.
{"title":"Finite element simulation of intra-carpal tunnel pressure: the effects of individual finger flexion and histological changes","authors":"Kyrin Liong, A. Lahiri, Shujin Lee, D. Chia, A. Biswas, H. Lee","doi":"10.1504/ijecb.2015.073929","DOIUrl":"https://doi.org/10.1504/ijecb.2015.073929","url":null,"abstract":"Carpal tunnel syndrome (CTS) is a common neuropathy, yet its etiology is unknown. While repetitive finger flexion and interstitial subsynovial connective tissue (SSCT) thickening are commonly associated with idiopathic CTS development, the stress that the nerve experiences remain unexamined. In this study, a patient-specific computational model of the carpal tunnel was developed. Tendon displacements corresponding to thumb, index finger (IF) and middle finger (MF) flexion were prescribed. To replicate a CTS candidate, the most common physiological finding - fibrosis of the SSCT - was modelled. Heightened nerve coefficients were also prescribed to simulate nerve stiffening. This revealed that volarly-moving tendons, as in IF and thumb flexion, elicit greater nerve stresses than those dorsally-moving tendons, as in MF flexion. The stress encountered in CTS candidates significantly exceeded those in normal candidates, demonstrating that tendon path, and the in-vivo conditions of an individual's SSCT and median nerve stiffness predominantly affect nerve stress.","PeriodicalId":90184,"journal":{"name":"International journal of experimental and computational biomechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1504/ijecb.2015.073929","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66745338","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}
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