bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stress Analysis of Soft Tissues as Nonhomogeneous Composites: Application to Disc Anulus, Knee Meniscus, and Articular Cartilage
Authors: Shirazi-Adl A. , Buschmann M. D. 
Published: January 2022

Abstract
Connective soft tissues such as intervertebral disc, knee meniscus and articular cartilage are primarily made of water, proteoglycans, and collagen fibrils. The structural organization and relative content of these components as well as the type of collagen and proteoglycan, however, vary from tissue to tissue resulting in substantial differences in mechanical response under applied loads/deformations in different tissues and in different directions. The collagen fibres primarily influence the behavior of the tissue in tension relegating the compression carrying task to remaining components, the solid portion of which is referred to as the tissue matrix. In doing so, each component plays a mechanical role for which it is best suited. A homogeneous anisotopic simulation can adequately account for the observed direction dependent material properties of soft tissues. It cannot, however, represent the distinction between the matrix and collagen fibres in that while they may be both undergoing the same strain in the same direction, the stresses could be quite different and even in opposite directions. Such a response becomes evident when considering, for example, the lateral expansion of a tissue specimen in response to an axial compression load generating tension in fibres and compression in matrix so that these two internal forces cancel each other out resulting in no net lateral force. Proper consideration of this phenomenon requires the simulation of the tissue as a nonhomogeneous composite of a fibre reinforced medium. In this work, we will present the finite element studies of such arrangements and compare the predictions with those based on equivalent homogeneous direction-dependent material properties. The emphasis in the presented results will be placed on our studies on the disc anulus fibrosus.
Strip Biaxial Experiments of Human Lung Parenchyma
Authors: Gao Jian , Huang Wei , Yen Michael R. T. 
Published: January 2022

Abstract
For the stress-strain relationships of human lung parenchyma, the present state of the art is that the form of the constitutive equations is known, but the material constants are unknown, and must be determined by new measurements. The objective of this study is to determine these constants by means of biaxial experiments on excised human lung parenchyma. Dynamic biaxial tests were done, and strain vs. Lagrangian stress curves were recorded. The experimental data were fitted with a pseudo-elastic constitutive equation and the physical constants could be identified.
Effects of Increasing Repetitive Strains on Tensile Failure Properties of the IGHL
Authors: Wang Vincent M. , Cohen Nathaniel P. , Bucchieri John S. , Huang Chun-Yuh , Flatow Evan L. , Bigliani Louis U. , Pollock Roger G. , Pawluk Robert J. , Mow Van C. 
Published: January 2022

Abstract
Considerable attention has been directed towards elucidating factors responsible for mechanical failure of ligaments and tendons [2,10,11]. Still, very few studies to date have examined the effects of repetitive loads on either the transient response or failure properties of ligaments. Panjabi et al. [3] simulated a subfailure injury during cyclic testing using a single cycle of high subfailure strain and found no statistical difference between the deformation to failure in these ligaments as compared to the controls. However, this study incorporated a relatively small number of preconditioning cycles as opposed to a prolonged duration of repetitive strains.
Effects of Fixed Charge Density on Stress-Relaxation Behavior of Hydrated Soft Tissues in Confined Compression
Authors: Mow V. C. , Ateshian G. A. , Lai W. M. , Sun D. N. , Wang C. B. , Gu W. Y. 
Published: January 2022

Abstract
Confined compression stress relaxation tests with porous platens (Fig 1) have been frequently used for investigating the flow-dependent viscoelastic behavior of biological hydrated soft tissues [Lai et al., 1981; Mow et al., 1980]. From experimental data, the one-dimensional (1D) compression modulus (i.e., the aggregate modulus) at equilibrium and the hydraulic permeability of the tissue can be calculated using the biphasic theory for cartilage developed by Mow et al. (1980). However, the swelling pressure effects associated with fixed charge density (FCD) can not be accounted for directly by the biphasic theory. Thus, in this abstract, we determine the effects of FCD, hence the osmotic pressure, on the confined compression stress-relaxation behavior of cartilage using our mechano-electrochemical theory [Lai et al., 1991]. The objectives of this study are to determine the confined compression stress-relaxation behavior of a charged, hydrated-soft tissue by: 1) delineating the contribution of the swelling pressure to the total stress when the tissue is compressed; 2) determining the deformation, flow, pressure and electric fields in the tissue for the understanding of mechano-electrochemical signal transduction within the tissue.
Fracture Toughness of Cortical Bone From the Femur Correlates With Radiogrammetrical Parameters in the Elderly
Authors: Yeni Yener N. , Brown Christopher U. , Norman Timothy L. 
Published: January 2022

Abstract
This investigation examined the relationship between fracture toughness, the ability of bone to prevent crack initiation, and the Cortical index and Singh index, clinical measures used to assess bone quality. Fracture toughness had significant relationships with both Cortical index and Singh index measurements supporting the use of fracture toughness as a clinically relevant research tool for studying bone fragility.
Convergence Characteristics of Voxel Based Finite Element Models of Trabecular Bone
Authors: Niebur Glen L. , Yuen Jonathan C. , Hsia Andy C. , Keaveny Tony M. 
Published: January 2022

Abstract
High resolution voxel based finite element models of trabecular bone have recently become popular as a method to investigate the properties of trabecular tissue (van Rietbergen et. al., 1995; Ladd et al., 1997; Huo and Fhyrie 1995) and the effects of microstructure on apparent properties (Hollister et al., 1994). In these models, high resolution (20–80 micron) images of the trabecular bone are converted to finite element models by assigning an 8-noded brick element to each image voxel (Fhyrie et al., 1992). As these models come into more widespread use, it is important to quantify their numerical convergence characteristics.
Does Lift-Off Occur in Unconstrained Non-Conforming Total Knee Arthroplasty?
Authors: Ed C. , Natarajan R. N. , Berzins A. , Harman M. K. , Banks S. A. , Andriacchi T. P. 
Published: January 2022

Abstract
Despite its widespread use in the orthopedic community, ultra-high molecular weight polyethylene (UHMWPE) remains the weak link in the prosthesis material chain. The vast majority of wear debris generated in total joint replacements originates from the UHMWPE component. These wear products lead to osteolysis, implant loosening and the eventual need for revision surgery. Therefore, the wear of UHMWPE is currently a significant concern in the orthopedic and material science communities. The current study focuses on the dimensional change wear in two types of unconstrained and non-conforming Miller-Galante retrieved tibial components. The hypothesis tested was: lift-off of the lateral side of the femoral component, which would produce large dimensional change near the outer medial compartment edges of the tibial components, does not occur in non-conforming tibial inserts.
Finite Element Analysis of Fiber Reinforced Composite Dental Bridges
Authors: Nowak Michael D. , Goldberg Jon 
Published: January 2022

Abstract
Recent advances in dental bridge construction have included the use of composite fiber resins. These composites are less expensive and easier to utilize in bridge fabrication than the common system of metal with porcelain cladding. The effects of varying the percentage of fiber-reinforced material and geometry of the internal bridge design are of great interest. Finite Element Analysis (FEA) methods show promise in the evaluation of fiber behavior within these bridges, along with bridge design.
State Estimation Theory in Human Movement Analysis
Authors: Alexander Eugene J. , Andriacchi Thomas P. 
Published: January 2022

Abstract
This work describes the application of state estimation theory to the analysis of skeletal movement based on markers placed on the skin. Skin-based retro-reflective markers contain error introduced by the non-rigidity of the limb segment. A technique for obtaining an optimal estimate of skeletal motion from skin-based marker data is presented.
The Development of a Force Platform: Numerical and Experimental Analysis
Authors: Bagesteiro Léia B. , Laranja Rafael A. C. , Tamagna Alberto 
Published: January 2022

Abstract
A design of a force platform for biomechanical use is presented here. The platform was built with four octagonal load cells, each one measuring two uncoupled forces, horizontal and vertical. The complete system can measure three orthogonal forces and moments. A comparison with numerical and experimental analysis of the force plate is discussed and the main advantages of particular constructional details singled out. The platform described here proves to be relatively simple, economical to build and with low crosstalk between channels.
An Evaluation of Muscle Force Predictions at the Hip Joint
Authors: Foucher Kharma C. , Hurwitz Debra E. , Andriacchi Thomas P. , Rosenberg Aaron G. , Sumner Dale R. 
Published: January 2022

Abstract
Understanding the loading of the hip joint and femur is a critical factor in understanding the progression of osteoarthritis (OA) and the mechanical factors influencing the outcome of total hip replacement surgery (THR). While in vivo transducers provide unique and valuable information about hip joint loading, they are limited to evaluating small numbers of postoperative THR patients. Musculoskeletal models, however, easily provide estimates of the hipjoint loads in larger patient populations with a variety of orthopedic conditions. Comparing the predicted forces with in vivo data is one approach to evaluating the results of such a model. The physiological phenomenon that bone changes in response to its loading environment presents an alternate method for evaluating modeled muscle forces. Validation of musculoskeletal models can be obtained by comparing femoral bone mineral density (BMD) patterns to the predicted forces. To evaluate muscle force predictions of a parametric three dimensional musculoskeletal model of the hip joint and femur, this study tested the hypothesis that the predicted abductor muscle force and greater trochanter BMD were significantly correlated and that the predicted contact force and proximal femur BMD were significantly correlated.
Effect of Precracking Method on the Static (J-Integral) Fracture Resistance of Ultrahigh Molecular Weight Polyethylene
Authors: Dapp Elizabeth K. , Rimnac Clare M. 
Published: January 2022

Abstract
The purpose of this study was to examine the effect of precracking preparation techniques on the J-integral static fracture resistance of ultrahigh molecular weight polyethylene (UHMWPE). One set of specimens was razor sharpened while the other set was cyclically precracked prior to testing. The results showed that the energy required for stable crack extension through UHMWPE was dependent on the precrack preparation method.
Comparison of the Fatigue Lifetimes of Simplex P and Osteobond Bone Cement
Authors: Jacobs Christopher R. , Davis Barclay R. , Naidu Sanjiv H. , Pellegrini Vincent D. , Case Kirt L. 
Published: January 2022

Abstract
Aseptic loosening is a primary mode of failure in cemented total joint surgery. Fatigue and eventual fracture of the cement mantle may be an important mechanism by which aseptic loosening occurs. Microcracking due to repetitive loading of the cement mantle has been implicated as a primary mechanism of failure in cemented femoral hip arthroplasties (1). This was the motivation behind the development of a new commercial bone cement formulation, known as Osteobond, designed to have an extended fatigue lifetime. Although the ultimate pre-clinical demonstration of enhanced in vivo performance remains the animal model, these studies are expensive and often inconclusive (2). Therefore, standard laboratory fatigue testing was employed (3). The fatigue performance of Osteobond was compared with that of Howmedica’s Simplex P using both open bowl mixing and vacuum mixing to prepare the samples.
Effect of Biochemical Composition on Cerebrospinal Fluid Viscosity
Authors: Bloomfield Isabelle G. S. , Johnston Ian H. , Bilston Lynne E. 
Published: January 2022

Abstract
The viscosity of the cerebrospinal fluid has long been assumed to be similar to water but only a handful of studies have measured the rheological properties of this fluid. In the present study the viscosity of cerebrospinal fluid was measured on a rotational rheometer at shear rates from 25 to 1460 sec−1, at 37°C. Each cerebrospinal fluid sample was biochemically analysed and comparisons of viscosity with protein, glucose and blood cell content in the sample were made. Despite the amount of proteins, glucose and blood cells, the viscosity of cerebrospinal fluid remained at a relatively constant level of 0.8mPa.s for the range of shear rate used, at 37°C. These findings were significant using linear regression analysis. It is concluded that cerebrospinal fluid is a newtonian fluid and that its viscosity does not significantly change with its composition.
Design and Evaluation of Microfabricated Acoustical Lenses for High Frequency Ultrasound Applications
Authors: Li Jinghong , Keynton Robert S. , Friedrich Craig R. 
Published: January 2022

Abstract
The purpose of this study was to employ new state-of-the-art micromachining techniques to fabricate acoustical lenses of identical geometric configuration for high frequency ultrasound applications. High frequency (20 MHz) piezoelectric crystals were placed in a holding jig and covered with one of two lens materials, PMMA or Epoxy. After curing, the holding jig was placed in a custom-made ultra-high precision micromilling machine. Each material was machined to yield lenses with focal lengths of 3 mm, 4 mm or 5 mm. A total of 18 lenses were machined and evaluated for compliance with the design specifications using a Roughness/Step Tester. In addition, performance characteristics of each lens were evaluated using a Schlieren Acoustic Visualization System. Overall, the radii of curvatures were within ± 14% and ± 8% of the design for PMMA and Epoxy, respectively. The focal lengths were found to be within ± 25% and ± 19% of the design, respectively. Finally, the lenses caused the acoustic beam to converge, which resulted in a reduction in the lateral dimension of the beam and an increase in the signal intensity within the near field.
In Situ Thermal Measurements for Estimaton of Relative Metabolic Utilization in Skeletal Muscle
Authors: Gustafson Kenneth J. , Reichenbach Steven H. 
Published: January 2022

Abstract
A variety of systems to drive cardiac assist devices with power from skeletal muscle have been proposed and are under development. The power available from a fixed mass of muscle is metabolically limited and maximizing sustained power is required for the successful application of such devices. The purpose of this study is to develop an approach that can yield relative metabolic utilization measures from single contractions of whole muscle used for cardiac assistance. Similar to classical muscle energetic studies, myothermic methods were employed in which muscle temperature was measured with a fast responding thermister and an infrared radiation thremopile transducer. In a series of tests on rabbit soleus muscle, the relative temperature increases during contractions were recorded. Relative muscle temperature increase was linearly related to the contraction duration. This relationship was incorporated into an existing muscle model to predict the optimum parameters for sustained skeletal muscle power generation.
Senior Design Projects to Aid the Disabled: The University of Toledo Experience
Authors: Hefzy Mohamed Samir , Kramer Steven , Naganathan Nagi , Nemunaitis Gregory 
Published: January 2022

Abstract
This paper describes the experience of the Department of Mechanical, Industrial and Manufacturing Engineering (MIME) at the University of Toledo (UT) during the past five years in supporting its senior students in developing custom designed devices for physically disabled individuals within the Toledo community. The goal of these projects is to assist disabled individuals to enjoy life and to reach toward their maximum potential. These projects significantly enhance the education of student engineers through the experience of designing and building devices to meet a real need with feedback on how well the device satisfies that need.
Model for Predicting Temperature Distribution During Medullary Reaming
Authors: Hekman Edsko E. G. , Nijenbanning Gert , Grootenboer Henk J. 
Published: January 2022

Abstract
Prior to placement of medullary nails the marrow cavity often needs to be reamed to a larger size. Measurements of the (potentially damaging) temperatures reported in literature show substantial variation. This paper describes a mathematical model which predicts a temperature profile throughout the bone cortex.
Doing Less for More: A New Mobile Arm Support
Authors: Landsberger Samuel , Shaperman Julie , Vargas Vicente , Meadows Ernest , Mitani Margaret , McNeal Donald R. 
Published: January 2022

Abstract
Mobile arm supports (MAS) are wheelchair-mounted mechanical linkages designed to support the weight of the arm and facilitate shoulder and arm motions. They enable individuals with flaccid paralysis or paresis of the shoulder and elbow muscles to function independently in many daily tasks. However, problems with commercially available designs have limited their use in spite of their low cost and functional benefits. This project aims to create a new MAS design to address these deficiencies.
A Novel Numerical Formulation for Modeling Tissue Compressibility
Authors: O’Dell W. G. , McCulloch A. D. 
Published: January 2022

Abstract
Nearly all mathematical and computational models of biological tissue impose the constraint that the material remain incompressible during deformation. The incompressibility assumption simplifies the determination of analytic solutions by removing a degree of freedom from the motion. However, many biological tissues, including myocardium, are sufficiently compressible to have enormous effects on the predicted stress equilibrium state[1]. Being able to model the compressibility of living tissue is a major step toward realistic modeling of intact, living tissue.
Comparison of Knee Flexion Angle Using Two Measurement Techniques
Authors: Patterson Rita M. , Buford William L. , Fay James M. , Nelson Carl J. , Ivey F. Marty 
Published: January 2022

Abstract
The motion across human joints is in general three-dimensional. Past researchers have1–4 studied the motion of the tibia with respect to the femur and discussed the application of several 2-D graphical methods to injury diagnosis and fixed axis prosthesis design. Others have studied the six degree of freedom motion of the knee.5,6 Though there are many reports of knee kinematics, most have reported large variations between measurements and conflicting results. The large variation makes it difficult to draw conclusions about normal knee kinematics.
A New Precision 3D Motion Analysis System
Authors: Wang Mei , Zhang Yong-M. , Abell Mike , D’Angelo Gregory L. , Voor Michael J. 
Published: January 2022

Abstract
A new in vitro technique for measuring three-dimensional six-degree-of-freedom motion was developed. The system consists of twenty-four nylon lines activating digital rotary encoders which are mounted on six panels of a rigid frame that surround the testing space. The system is capable of tracking motion of up to four independent bodies in a space of approximately 0.5 × 0.5 × 0.5 meter. By knowing the coordinates of three non-collinear points on the frame and the straight line distances from these points to any point on the moving body, the spatial location of that point can be determined based on simple geometry. The location and orientation of a rigid body can be further calculated from the spatial coordinates of three non-collinear points on the rigid body or its extension. The system has an accuracy of 1% in the vertical direction and 0.7% in the horizontal plane. The system can be used in biomechanical analysis of multi-segment spinal motion and motion of other joints.
Effects of Joint Loading on the Passive Moment at the Ankle
Authors: Amankwah Kofi , Triolo Ronald J. , Kirsch Robert , Zhao Weifeng 
Published: January 2022

Abstract
In this study, the aim was to measure the passive moment at the ankle under different loading conditions. During the experiment, the ankle was rotated at 20 deg/s and the load on the ankle was varied over a 60lb range. The results showed that increasing the joint load affects the amount of hysteresis seen in the moment vs. joint angle relationship. This result suggests that friction within the joint may be more significant than previously thought and therefore that joint loading may be a more important factor during dynamic activities such as gait and in disturbance rejection for static situations such as quiet standing.
Shaft/Shaft-Seal Interaction of a Multiple Disk Centrifugal Blood Pump: A Study of Thermal and Wear Characteristics
Authors: Manning Keefe B. , Miller Gerald E. 
Published: January 2022

Abstract
A multiple disk centrifugal pump (MDCP) is under investigation as a potential left ventricular assist device. As is the case with most shaft driven pumps, leakage problems around the shaft/shaft-seal interface are of major interest. If leakage were to occur during or after implantation, potential events such as blood loss, clotting, blood damage, and/or infections might result in adverse effects for the patient. Because these effects could be quite disastrous, potential shaft and shaft-seal materials have been investigated to determine the most appropriate course to limit these effects.
Teflon and Nylon were analyzed as potential shaft-seal candidates with both a stainless steel shaft and a Melonite® coated shaft, the latter provided by Houston Unlimited Inc. Metal Processing in Chappell Hill, Texas. The materials and shafts were evaluated under time, motor, and outer diameters. Motor speed and geometrical configurations were typical for the MDCP under normal physiologic conditions. The three parameters analyzed were the inner diameter (ID), the inner temperature, and the outer temperature. Statistical comparisons were computed for the shaft seal materials, the shafts, and the outer diameters along with the inner and outer temperatures.
The Application of Biot’s Consolidation Theory to Chromatography Column Gel Collapse
Authors: He Weiwei , Bruley Duane F. 
Published: January 2022

Abstract
Protein C is a vitamin K dependent glycoprotein which is synthesized by the liver [1]. It is the zymogen of a serine protease which acts as an anticoagulant by inhibiting activated factors V and VIII thus enhancing fibrinolysis. An increased risk for the development of venous thrombosis has been attributed to Protein C deficiency[2]. This work is to establish theoretical and experimental relationships for the scale up of Immobilized Metal Affinity Chromatography (IMAC) and Immuno Affinity Chromatography for the low cost production of large quantities of Protein C. Gel matrices for Protein C separation are being analyzed to determine the relationship between the materials properties of the gel and column collapse characteristics.