Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23148
Christopher T. Chen, P. Torzilli, K. Fishbein, R. Spencer, W. Horton
The objective of this study was to determine the biomechanical properties of cartilage grown in a hollow-fiber bioreactor and their correlation with biochemical properties and magnetic resonance images (MRT). Engineered/grown cartilage has been shown to be a useful resource for cartilage repair [5]. The integrity and functional strength of engineered tissues are reflected in their biomechanical properties. A better understanding of the biomechanical properties of engineered cartilage can benefit us when designing a system to grow cartilage.
{"title":"Biomechanical Properties of Grown Cartilage Are Decreased in the Presence of Retinoic Acid, Chondroitinase ABC and Ibuprofen","authors":"Christopher T. Chen, P. Torzilli, K. Fishbein, R. Spencer, W. Horton","doi":"10.1115/imece2001/bed-23148","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23148","url":null,"abstract":"\u0000 The objective of this study was to determine the biomechanical properties of cartilage grown in a hollow-fiber bioreactor and their correlation with biochemical properties and magnetic resonance images (MRT). Engineered/grown cartilage has been shown to be a useful resource for cartilage repair [5]. The integrity and functional strength of engineered tissues are reflected in their biomechanical properties. A better understanding of the biomechanical properties of engineered cartilage can benefit us when designing a system to grow cartilage.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72707196","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 : 2001-11-11DOI: 10.1115/imece2001/bed-23154
C. Nelson
The dynamic binding interactions between cell surface receptors and local bioactive ligands serves as the principal mechanism by which cells survey their microenvironment and accordingly modulate their behaviors, such as proliferation, differentiation, migration, and suicide. Using conventional and non-conventional microfabrication approaches to engineer well-defined cellular microenvironments, we are examining how cells recognize and respond to adhesive interactions with the insoluble extracellular matrix (ECM). We will discuss our approaches to control the architecture and geometry of the adhesive interactions, as well as our resulting progress in identifying and elucidating the mechanisms by which cells sense the physical, chemical, and structural information carried within the ECM. By developing these approaches to engineering cell-surface interactions, we hope to improve the interconnect between artificial surfaces and living cells.
{"title":"Building Cellular Microenvironments to Control Capillary Endothelial Cell Proliferation, Death, and Differentiation","authors":"C. Nelson","doi":"10.1115/imece2001/bed-23154","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23154","url":null,"abstract":"\u0000 The dynamic binding interactions between cell surface receptors and local bioactive ligands serves as the principal mechanism by which cells survey their microenvironment and accordingly modulate their behaviors, such as proliferation, differentiation, migration, and suicide. Using conventional and non-conventional microfabrication approaches to engineer well-defined cellular microenvironments, we are examining how cells recognize and respond to adhesive interactions with the insoluble extracellular matrix (ECM). We will discuss our approaches to control the architecture and geometry of the adhesive interactions, as well as our resulting progress in identifying and elucidating the mechanisms by which cells sense the physical, chemical, and structural information carried within the ECM. By developing these approaches to engineering cell-surface interactions, we hope to improve the interconnect between artificial surfaces and living cells.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72719994","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 : 2001-11-11DOI: 10.1115/imece2001/bed-23073
T. Andriacchi, David B. Camarillo, E. Alexander, C. Dyrby
The kinematics and kinetics of running to a stop and running and cutting were analyzed in the context of identifying mechanisms for non-contact injury to the anterior cruciate ligament of the knee. The study addressed the hypothesis that gender influences the mechanics of the way individuals perform running to a cut and running to a stop. The results demonstrate a difference during the early landing phase of the maneuver. Two patterns of limb loading were identified during the landing phase (foot strike to 200msec) of the run to cut maneuver. The results of this study suggest a potential injury mechanism associated with the biomechanics of landing in preparation for a run to stop or run to cut maneuver. Nine of ten male subjects in this population tended to land in a manner that produced a greater magnitude of the force component along the axis of the tibia. These findings provide new information that can be applied towards understanding gender difference patterns in non-contact ACL injuries.
{"title":"Mechanical Factors Can Influence the Gender Differences in the Incidence of Non-Contact Injuries","authors":"T. Andriacchi, David B. Camarillo, E. Alexander, C. Dyrby","doi":"10.1115/imece2001/bed-23073","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23073","url":null,"abstract":"\u0000 The kinematics and kinetics of running to a stop and running and cutting were analyzed in the context of identifying mechanisms for non-contact injury to the anterior cruciate ligament of the knee. The study addressed the hypothesis that gender influences the mechanics of the way individuals perform running to a cut and running to a stop. The results demonstrate a difference during the early landing phase of the maneuver. Two patterns of limb loading were identified during the landing phase (foot strike to 200msec) of the run to cut maneuver. The results of this study suggest a potential injury mechanism associated with the biomechanics of landing in preparation for a run to stop or run to cut maneuver. Nine of ten male subjects in this population tended to land in a manner that produced a greater magnitude of the force component along the axis of the tibia. These findings provide new information that can be applied towards understanding gender difference patterns in non-contact ACL injuries.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72891875","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 : 2001-11-11DOI: 10.1115/imece2001/bed-23140
R. Banerjee, L. Back, M. Back, Young I Cho
Lesion flow coefficients ( c ~ ) were determined from computational hemodynamics for the 32 patient group of Wilson et al. (1988) during coronary angioplasty in conjunction with quantitative angiography and measurements of the coronary flow reserve (CFR). The effect of the catheter insertion across lesions reduce blood flow during measurements, and also decrease ( c ~ ) due to larger viscous effects. The flow computations may be useful in interpretation of catheter measurements in the clinical setting for lesions of similar size, particularly for flow limiting hyperemic conditions.
{"title":"Effect of Endovascular Diagnostic Catheters on Human Coronary Artery Lesion Flow Coefficients","authors":"R. Banerjee, L. Back, M. Back, Young I Cho","doi":"10.1115/imece2001/bed-23140","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23140","url":null,"abstract":"\u0000 Lesion flow coefficients ( c ~ ) were determined from computational hemodynamics for the 32 patient group of Wilson et al. (1988) during coronary angioplasty in conjunction with quantitative angiography and measurements of the coronary flow reserve (CFR). The effect of the catheter insertion across lesions reduce blood flow during measurements, and also decrease ( c ~ ) due to larger viscous effects. The flow computations may be useful in interpretation of catheter measurements in the clinical setting for lesions of similar size, particularly for flow limiting hyperemic conditions.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78200727","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 : 2001-11-11DOI: 10.1115/imece2001/bed-23159
P. Leduc
The mechanical connection through the formation of focal adhesion complexes (FACs) is critical in cell growth and apoptosis. The FACs act between the cells and the extracellular matrix (ECM), which in turn influences angiogenesis, the growth of new capillary blood vessels [1]. These complexes form direct connections from ECM into the cell cytoskeleton through a series of protein binding events. This linkage is critical for mechanical force sensing and mechanotransduction signaling [2]. Here, the probabilistic modeling of this complex formation is undertaken to begin to uncover the effect of the spatial distribution and temporal effects on this dynamic process. In this, the rich dynamic process of the FACs formation through the binding events of integrin, paxillin, talin, and vinculin are examined. The FACs are mediated through the clustering of transmembrane integrins, which initiate the binding cascade. This interaction has been shown to be a critical event in the activation of the mechanochemical cascade and further mediates downstream signaling of protein tyrosine kinases including focal adhesion kinase [3].
{"title":"Dynamic Formation for the Mechanical Connection of Focal Adhesion Complexes to Study Localized Mechanisms of Angiogenesis Through Modeling With Cellular Automata","authors":"P. Leduc","doi":"10.1115/imece2001/bed-23159","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23159","url":null,"abstract":"\u0000 The mechanical connection through the formation of focal adhesion complexes (FACs) is critical in cell growth and apoptosis. The FACs act between the cells and the extracellular matrix (ECM), which in turn influences angiogenesis, the growth of new capillary blood vessels [1]. These complexes form direct connections from ECM into the cell cytoskeleton through a series of protein binding events. This linkage is critical for mechanical force sensing and mechanotransduction signaling [2]. Here, the probabilistic modeling of this complex formation is undertaken to begin to uncover the effect of the spatial distribution and temporal effects on this dynamic process. In this, the rich dynamic process of the FACs formation through the binding events of integrin, paxillin, talin, and vinculin are examined. The FACs are mediated through the clustering of transmembrane integrins, which initiate the binding cascade. This interaction has been shown to be a critical event in the activation of the mechanochemical cascade and further mediates downstream signaling of protein tyrosine kinases including focal adhesion kinase [3].","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74914796","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 : 2001-11-11DOI: 10.1115/imece2001/bed-23132
K. Kuribayashi, Z. You
Stents are flexible structures capable of being folded into small dimensions allowing their passage into the problematic locations in the body and then being expanded. Their prime usage is to treat patients with obstruction at several sites in the body. For example, they are used to open blocked coronary arteries and large veins, to treat obstructions to breathing in the trachea and bronchus, and those in the prostate to allow the passage of urine [1].
{"title":"Deployable Concepts for Oesophageal Stents","authors":"K. Kuribayashi, Z. You","doi":"10.1115/imece2001/bed-23132","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23132","url":null,"abstract":"\u0000 Stents are flexible structures capable of being folded into small dimensions allowing their passage into the problematic locations in the body and then being expanded. Their prime usage is to treat patients with obstruction at several sites in the body. For example, they are used to open blocked coronary arteries and large veins, to treat obstructions to breathing in the trachea and bronchus, and those in the prostate to allow the passage of urine [1].","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75507309","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 : 2001-11-11DOI: 10.1115/imece2001/bed-23164
S. Stott, Carrie A. Williams, G. Bao
Although many proteins in human cells have been identified, the structure-function relationships for most of them remain unknown. For example, protein motors such as kinesin and dynein were identified a long time ago but the exact mechanisms driving the motors are still elusive. Further, many protein molecules exhibit complex conformational dynamics which plays an important regulatory role in their functions. While it was common knowledge that DNA forms a double helix and that the helix is unwound by enzymes for transcription, the forces required to untwist the DNA was uncovered just recently. In carrying out nanomechanics studies of biomolecules such as DNA and proteins, we hope to answer some of the fundamental questions and more generally, to characterize the mechanical behavior of single molecules. The characteristics we wish to define include how a protein molecule deforms, unfolds, responds to a force and generates a force. Most proteins are small (1–100 nm) and the amplitudes of their deformation are even smaller, preventing them from being visible to a light microscope. Atomic force microscopy (AFM) can be used to measure the force-extension curves of proteins but the use of AFM is limited by the relatively high thermal noise. Thus, we elected to build an optical tweezers, a measurement system that can accurately measure forces in the range of 0.5–50 pN.
{"title":"Nanomechanics Studies of Biomolecules Using Optical Tweezers","authors":"S. Stott, Carrie A. Williams, G. Bao","doi":"10.1115/imece2001/bed-23164","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23164","url":null,"abstract":"\u0000 Although many proteins in human cells have been identified, the structure-function relationships for most of them remain unknown. For example, protein motors such as kinesin and dynein were identified a long time ago but the exact mechanisms driving the motors are still elusive. Further, many protein molecules exhibit complex conformational dynamics which plays an important regulatory role in their functions. While it was common knowledge that DNA forms a double helix and that the helix is unwound by enzymes for transcription, the forces required to untwist the DNA was uncovered just recently. In carrying out nanomechanics studies of biomolecules such as DNA and proteins, we hope to answer some of the fundamental questions and more generally, to characterize the mechanical behavior of single molecules. The characteristics we wish to define include how a protein molecule deforms, unfolds, responds to a force and generates a force. Most proteins are small (1–100 nm) and the amplitudes of their deformation are even smaller, preventing them from being visible to a light microscope. Atomic force microscopy (AFM) can be used to measure the force-extension curves of proteins but the use of AFM is limited by the relatively high thermal noise. Thus, we elected to build an optical tweezers, a measurement system that can accurately measure forces in the range of 0.5–50 pN.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75981876","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 : 2001-11-11DOI: 10.1115/imece2001/bed-23167
A. Subramanian, Lauren K. Yee, J. Kadambi, M. Wernet, H. Harasaki
Particle image velocimetry (PIV) processing techniques, Multi Pass Correlation (MPC) and Particle Tracking Velocimetry (PTV), are applied to images obtained from a bileaflet mechanical heart valve study to obtain velocity measurements with increased spatial resolution and accuracy. Using subregions of 32 pixels by 64 pixels, a spatial resolution of 0.23 mm in x and 0.46 mm in y is obtained, as compared to 0.46 mm in both directions for traditional PIV processing. When MPC and PTV are not utilized, spatial resolution can only be increased by decreasing the subregion size and time between images in an image pair, which sacrifices accuracy. High accuracy can only be obtained by increasing the subregion size and the time between pulses, which reduces spatial resolution. MPC and PTV allow both high spatial resolution and accuracy by altering the processing method as opposed to how the data is produced conventionally.
{"title":"Application of High Resolution PIV Processing in Flow Through Mechanical Heart Valve","authors":"A. Subramanian, Lauren K. Yee, J. Kadambi, M. Wernet, H. Harasaki","doi":"10.1115/imece2001/bed-23167","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23167","url":null,"abstract":"\u0000 Particle image velocimetry (PIV) processing techniques, Multi Pass Correlation (MPC) and Particle Tracking Velocimetry (PTV), are applied to images obtained from a bileaflet mechanical heart valve study to obtain velocity measurements with increased spatial resolution and accuracy. Using subregions of 32 pixels by 64 pixels, a spatial resolution of 0.23 mm in x and 0.46 mm in y is obtained, as compared to 0.46 mm in both directions for traditional PIV processing. When MPC and PTV are not utilized, spatial resolution can only be increased by decreasing the subregion size and time between images in an image pair, which sacrifices accuracy. High accuracy can only be obtained by increasing the subregion size and the time between pulses, which reduces spatial resolution. MPC and PTV allow both high spatial resolution and accuracy by altering the processing method as opposed to how the data is produced conventionally.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78793845","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 : 2001-11-11DOI: 10.1115/imece2001/bed-23092
D. Bartel, A. Edidin, T. Johnson, T. Sculco, T. Wright
Total knee replacement has become an accepted treatment for diseased and damaged joints with over 150,000 surgeries performed annually in the United States alone. The popularity of knee replacement stems from the excellent clinical results, which in some reported series exceeded ninety percent at twenty years follow-up [1]. The high level of clinical success in elderly populations has spurred surgeons to extend the indications to younger patients; today, about a third of total knee replacements are implanted in individuals under sixty-five years of age.
{"title":"Implant Technology: Knee Design for Improved Function and Wear","authors":"D. Bartel, A. Edidin, T. Johnson, T. Sculco, T. Wright","doi":"10.1115/imece2001/bed-23092","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23092","url":null,"abstract":"\u0000 Total knee replacement has become an accepted treatment for diseased and damaged joints with over 150,000 surgeries performed annually in the United States alone. The popularity of knee replacement stems from the excellent clinical results, which in some reported series exceeded ninety percent at twenty years follow-up [1]. The high level of clinical success in elderly populations has spurred surgeons to extend the indications to younger patients; today, about a third of total knee replacements are implanted in individuals under sixty-five years of age.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78983487","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 : 2001-11-11DOI: 10.1115/imece2001/bed-23134
K. Chandran, S. Ramaswamy, Yonggen Lai, A. Wahle, M. Sonka
Complete occlusion in any of the coronary vessels leads to a myocardial infarction. The role of fluid mechanical forces in atheroma development has been widely accepted because of preferential plaque growth at certain locations of the vessel geometry, such as a bifurcation or regions of high degrees of curvature. Areas of low and/or oscillatory shear stress have been correlated with atheroma development [1]. In order to determine the relationship between fluid mechanical stresses and development of lesions in the coronary vessels, it is important to analyze the fluid mechanics in actual three-dimensional geometries, incorporating the time-dependent translation and geometric alterations of these vessels [2,3].
{"title":"Effect of Position and Flow Waveform on the Fluid Mechanics of a Stenosed Human Right Coronary Artery","authors":"K. Chandran, S. Ramaswamy, Yonggen Lai, A. Wahle, M. Sonka","doi":"10.1115/imece2001/bed-23134","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23134","url":null,"abstract":"\u0000 Complete occlusion in any of the coronary vessels leads to a myocardial infarction. The role of fluid mechanical forces in atheroma development has been widely accepted because of preferential plaque growth at certain locations of the vessel geometry, such as a bifurcation or regions of high degrees of curvature. Areas of low and/or oscillatory shear stress have been correlated with atheroma development [1]. In order to determine the relationship between fluid mechanical stresses and development of lesions in the coronary vessels, it is important to analyze the fluid mechanics in actual three-dimensional geometries, incorporating the time-dependent translation and geometric alterations of these vessels [2,3].","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79431672","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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