bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Three-Dimensional Computer Simulation for Interactive Adjustment of Multiple Axes of Motion for the Upper Extremity
Authors: Pickard Julie M. , Buford William L. , Elder Karin W. , Patterson Rita M. 
Published: March 2022

Abstract
With the advent of high performance computer graphic workstations over the last decade, kinematic modeling of the human musculoskeletal system is developing rapidly. Previous kinematic models have been developed but their workstations and/or software have become outdated. Buford and Thompson (1987) developed an interactive kinematic simulation, but it is no longer utilizable because the software was developed on the outdated Evans and Sutherland (E&S) PS300 system. Lin, et. al. (1995) developed a three-dimensional kinematic simulation using PHIGS programming software. Since PHIGS is no longer the accepted standard for graphics software, this simulation has lost its portability.
Optimal Actuator Placement in Hyperthermia: A Reduced-Order Modeling Approach
Authors: Mattingly M. , Roemer R. B. , Devasia S. 
Published: March 2022

Abstract
Studies have shown a positive correlation between the effective temperature maintained inside a cancerous tumor during hyperthermia treatments and the response rate of that tumor to subsequent radiation therapy (see, for example, [1]). In addition, effective temperature control is crucial to avoid the premature abortion of hyperthermia treatments from patient discomfort due to overheating of the normal tissue surrounding these tumors. Hence, there is a need to optimally heat tumors and surrounding tissue — this is significantly affected by the choice of actuator placement and input powers. In this work, we show how the extended balanced realization model reduction approach [2] can be employed to efficiently determine the optimal scan path for a given hyperthermia treatment.
Preconditioning Does Not Reset the Strain History of Uniaxially Tested, Porcine Aortic Valve Tissues
Authors: Vesely Ivan , Brewer Amy R. 
Published: March 2022

Abstract
Heart valve leaflets are considered to be viscoelastic, much like most biological materials. When these materials are tested both uniaxially and biaxially, a so-called “preconditioning” effect is observed. Upon repetitive loading to a constant load, sucessive load/elongation plots migrate in the positive strain direction. After about 10 cycles, successive load/elongation plots are repeatable, both in terms of the energy dissipated as well as the exact elongation achieved at a given load. This type of preconditioning needs to be done prior to any data acquisition or analysis, since the initial curves are not reproducible from test to test. In other words, unless the tissue is preconditioned first, it will not generate the same load at the same strain.
Relationship of Flow Disturbances in Stented Vessels to Compliance Mismatch
Authors: Berry Joel L. , Moore James E. , Barnes Ralph W. 
Published: March 2022

Abstract
The mechanical conditions created by vascular stents may play a role in restenosis. Restenosis occurs due to the accumulation of blood-borne materials and the reaction of the wall to the presence of the stent. It has been previously demonstrated [1] that the flow patterns created by the placement of a rigid stent into a compliant blood vessel are highly complex, featuring large vortex formations. It was hypothesized that the abrupt changes in compliance at the proximal and distal stent/artery junctions created pressure wave reflections that led to the vortices. The purpose of this study was to test whether a smooth transition in compliance between stented and unstented vessel would minimize pressure wave reflections and reduce the complexity of fluid flow disturbances. For this purpose, a new stent design was conceived and tested that featured compliance transition zones at the proximal and distal ends. The design is called a compliance matching stent (CMS).
Flow Phenomena in the Human Aortic Root and Entrance Region of Coronary Arteries During Diastole
Authors: Ilegbusi Olusegun J. , Hu Zhenjun , Stone Peter H. , Feldman Charles L. 
Published: March 2022

Abstract
The potential role of hemodynamics on atherogenesis and lesion progression in coronary arteries has been widely studied both experimentally and numerically. Clinical and postmortem examinations have provided valuable insight on the location of these lesions and the impact of flow disturbance and wall shear stress on their development. The determination of the exact conditions at the entrance of the coronary arteries as required for accurate numerical simulation of intracoronary flow pattern is difficult due to the inherent flow unsteadiness and the complexity of the ostium geometry. Thus, most previous theoretical analyses have often assumed uniform or parabolic spatial distribution of the entrance velocity. Such assumption severely limits the scope of validity of these studies because the strong curvature of the ostium and the relatively short length of the epicardial coronary artery do not allow for adequate flow development upstream of the coronary branches or regions of curvature where lesions occur.
This problem is further exacerbated by the non-uniqueness of the location of the ostium. It has been shown that the rate of blood flow in the coronary artery depends on the ostium location which in turn affects the flow characteristics, wall shear stress distribution and lesion proliferation on the arterial wall.
The objective of this paper is to predict the entrance velocities in human coronary arteries through a numerical model of flow in the aortic root. Specifically, we perform a detailed investigation of the flow pattern in a model human aortic root with two adjoining arteries. At this initial phase of model development, we consider the flow behavior only at diastole, the period of maximum coronary artery flow. A range of ostium curvatures and locations and coronary flow Reynolds numbers are considered. Emphasis is placed on characterizing the flow separation and recirculation resulting from the complex geometry of the aortic root-ostium assembly. The conservation equations governing the transport of mass and momentum are written in curvilinear coordinate system and solved using a fully-implicit finite domain numerical scheme. The predictions are checked for numerical accuracy through systematic grid refinement. The predicted flow pattern at the entrance of the coronary artery is subsequently used as an input for calculation of flow and wall shear stress characteristics in stenosed coronary artery curvatures and bifurcations. The predictions are compared with the experimental data and existing numerical results where available.
Wrist Kinematics
Authors: Patterson R. M. , Nicodemus C. L. , Viegas S. F. , Elder K. W. 
Published: March 2022

Abstract
Much work has been done related to the qualitative osseous anatomy of the wrist yet there are still very few references for its quantitative geometric, biomechanic, or kinematic characteristics.1–3 Because of the structural complexity and morphological variations of the wrist, a reference database of normal anatomy and kinematics would provide valuable reference information which will facilitate diagnosis and treatment of various injuries and diseases.
Electrical Signal Transmission in a Bone Cell Network: The Influence of a Discrete Gap Junction
Authors: Zhang Dajun , Weinbaum Sheldon , Cowin Stephen C. 
Published: March 2022

Abstract
Live bone is a very dynamic tissue under constant remodeling in response to the mechanical loading it sustains. However, the exact load-sensing mechanism of bone tissue is not yet clear. Recent studies suggest that the electrical aspect of bone physiology, especially the streaming potential, may play an important role in relaying the mechanical signal to the effector bone cells in bone remodeling [1] [2] [3]. In this paper, we use cable theory to calculate the intracellular potential and current in the bone cell network induced by the extracellular strain generated streaming potentials (SGPs). As an extension to our earlier paper on this subject, Zhang et al. [5], we focus our attention on the following five aspects:
&lt;1&gt; influence of the axisymmetric, cylindrical geometry of the osteon on the SGP calculation;
&lt;2&gt; influence of one discrete gap junction in a cellular cable;
&lt;3&gt; influence of a range of the membrane resistance (hence the membrane time constant);
&lt;4&gt; influence of the extracellular glycocalyx (GAG) fiber matrix in the lacunae-canaliculi space on the SGP calculation;
&lt;5&gt; influence of a range of the membrane leakage area of a resting osteoblast as one end of the cellular cable.
Using a Fabric Flexible Composite Theory to Characterize the Soft Tissues
Authors: Taban Faruk , Luo Shen-Yi 
Published: March 2022

Abstract
The objective of this work is to propose an analytical model, which is based on a fabric flexible composite theory, to characterize soft tissues (such as heart muscle, skin, lung, blood vessel, etc.). The bi-axial mechanical behaviors of the soft tissues have been studied by many researchers. A common approach is to propose a set of constitutive equations, then use data regression method to obtain input values from both simple and bi-axial test results. This usually gives a good description of the stress-strain behavior for the particular material but gives no physical meaning of these input values obtained from the mathematical curve fittings. Pao et al. (1980) suggested that the mechanical properties of the fiber bundles must be predicted first to compute the stresses. In this proposed model, a soft tissue is considered as an orthogonal composite element containing wavy fibers in a soft incompressible matrix (Luo and Chou, 1990).
A Biomechanical Comparison Between Modern Anterior Versus Posterior Plate Fixation of Unstable Cervical Spine Injuries
Authors: Lim Tae-Hong , An Howard S. , Koh Young Do , McGrady Linda M. 
Published: March 2022

Abstract
Unstable cervical spine injuries include flexion-distraction injuries with unilateral or bilateral facet dislocations and burst fracture of the vertebral body. These unstable injuries have been treated in various ways. For instance, various posterior fixation methods have been available, and particularly plating with lateral mass screws was proved to provide a rigid fixation. However, most cervical decompressions need to be performed anteriorly because the majority of compression is caused by either vertebral body retro-pulsion or herniated disc material (anterior structure). Anterior plating technique was recently introduced and employed for the surgical treatment of unstable injuries. Anterior plating is thought to offer an acceptable stability through a single surgical approach, but additional posterior fixation is frequently recommend to achieve a sufficient stability. There is a paucity of data on a direct biomechanical comparison of the stiffness provided by modern anterior, posterior, or combined plate-screw fixation in a human cadaveric cervical spine model. The purpose of this study was to compare the biomechanical characteristics of anterior vs posterior plating constructs and to evaluate the stiffness of a combined anterior-posterior fixation construct in a clinically simulated flexion-distraction injury and burst fracture models of the cervical spine.
An EMG-Driven Model of Trunk During Complex Isometric Exertions in Upright Posture
Authors: Sheikhzadeh Ali , Parnianpour Mohamad , Nordin Margareta 
Published: March 2022

Abstract
The EMG-driven models of trunk have been used to predict force generated by the trunk muscles and thereby risk of injury by estimating the net joint reaction forces. These models are based on the assumption that tensile force generated in a muscle is related to the normalized EMG and adopted cross-sectional area of the muscle. The EMG-force relationship adopted by these models assumed a linear relationship with zero intercept. However, no experimental justification exists to explain the zero intercept in the EMG-driven models. The aim of this study was to test the hypothesis that the results of EMG-driven models will be affected significantly by the assumptions made with respect to the EMG-force relationship of the trunk muscles.
Response of the Lumbar Spine in Large Compression Loads: Effect of Load Distribution in Neutral Postures
Authors: Shirazi-Adl A. , Parnianpour M. 
Published: March 2022

Abstract
During various daily activities, the gravity as well as external compression loads are transmitted to the pelvis via the lumbar spine. A major portion of this load, accounting for the upper body, is applied on the L1 while the remaining portion is transferred directly through lower lumbar vertebrae L2 to L5. This latter accounts for the gravity and local muscle activities at the lumbar level. The more physiological application of the load distributed at all vertebral levels and not concentrated only at the most proximal one has been demonstrated to markedly stabilize the spine in axial compression [1,2]. This study aims to compute the detailed mechanics of the lumbar spine in neutral posture under 2800 N axial compression applied either at the L1 only or distributed at all levels with the proportion of 90% or 80% of the load at the L1 and the remaining part applied evenly among the other L2-L5 levels.
Carbon Based Prosthetic Devices
Authors: Devlin D. , Carroll D. , Barbero R. , Klawitter J. , Strzepa P. , Ogilive W. 
Published: March 2022

Abstract
The medical profession has a need for improved orthopedic devices and biomaterials. The replacement of knee and hip joints with metallic prosthetic devices has provided mobility to many elderly patients suffering from bone diseases. Unfortunately, metal prostheses, anchored with methyl methacrylate cement, have a useful life of 7 to 10 years. Bond failure and wear necessitates an entire replacement of the prosthesis. Bone resorption due to the presence of the implant limits the number of implant operations to two per patient. As a consequence joint replacement is restricted to patients over age 55. A definite need exists for a new material system for extending the expected life of these prosthetic devices for younger patients. The long term objective of this research is to greatly extend the service life of prosthetic devices, specifically artificial joints. A materials system approach is being employed to accomplish this objective. The two specific materials technologies being integrated in this proposed study are carbon/carbon composites and diamond-like carbon (DLC) coatings.
Tendon Force Estimates Following Hand Surgery
Authors: Peña Edward , Thompson David E. , Evans Roslyn B. 
Published: March 2022

Abstract
The need for quantitative methods for assessment of tendon forces following tendon reconstructive surgery arises because of the side effects of current post-operative therapy. The classical therapy over the past 50 years has been to insulate the hand from potential injury in a cradle of bandages. This method was originally introduced because movement of the hand following surgery was felt to result in failures of the repaired tendons which have a very limited strength. The subsequent stiffening of the joints, and reduction in the gliding action of tendons is exacerbated by the swelling and inflammatory processes resulting from the surgery. In recent years, a new post-surgical therapy has been introduced that dramatically improves the range of motion and reduces the time to clinical release of the patient. This procedure is similar to that used prior to the current conservative therapy, but better analytical methods have allowed restrictions to be imposed on the active motion of the hand following surgery.
The force analysis that has led to new guidelines for post-surgical hand therapy for flexor tendons is presented here. A graphical user interface is also presented which allows the user to study various external force loadings and obtain rapid feedback on the resulting tendon forces at user-defined joint angles. This is shown in Figure 1.
Framework Design for an Orofacial Implant-Supported Prosthesis
Authors: Kasra Mehran , Anderson James D. 
Published: March 2022

Abstract
Loss of the entire midface leaves few options available for support of the dentition. Total loss of the maxilla bilaterally means that none of the traditional support areas are even partially useful. Surgical reconstruction of the midface is aggressive, and yet problems of support and retention for a dental prosthesis, as well as the facial prosthesis, remain. Osseointegrated implants can provide support and retention utilizing the remaining bones, but the distribution of occlusal forces becomes a concern, given their unfavourable location relative to the opposing dentition. Considerable attention has been given to framework design for intraoral implant-supported prostheses (1) but designs for extraoral framework typically have not been engineered with a view to controlling forces on the individual implants. This work describes the design procedure of such an extraoral framework which was fabricated for an individual. To minimize the possibility of unintentional overloads, consideration of the forces on each of the implants was prominent in design planning.
Effects of Acetabular Component Lip Design on Dislocation Resistance in THA
Authors: Scifert Christopher F. , Brown Thomas D. , Pedersen Douglas R. , Callaghan John J. 
Published: March 2022

Abstract
Next to aseptic loosening, recurrent dislocation is the second leading cause of failure in total hip arthroplasty [1]. Impingement of the femoral component neck on the acetabular cup is a frequent mechanism. Dislocation rates range from 2–11% in primary THA surgeries, and up to 25% or more in revisions [2]. Despite this high incidence, little is known about contributory component design factors. A finite element (FE) model has therefore been developed to systematically study impingement and dislocation resistance.
The Effect of Femoral Component Rotation on the Stresses in an UHMWPE Patellar Prosthesis: A Finite Element Study
Authors: Petrella Anthony J. , Rubash Harry E. , Miller Mark C. 
Published: March 2022

Abstract
Complications associated with the patellofemoral joint remain among the most common causes for revision of total knee replacements [1]. Excessive patellar tilt and medial-lateral shift are signs of poor patellar tracking and are frequently associated with patellar subluxation. Experimental studies have shown that external rotation of the femoral component improves patellar tracking and the distribution of patellofemoral contact forces [2,3]. The objective of this study was to develop a finite element model to study the influence of femoral component external rotation on patellar kinematics and contact stresses under physiologic loading.
Alternative Bearing Surfaces for Arthroplasty
Authors: Graham Robin M. , LaBerge Martine 
Published: March 2022

Abstract
Elastomeric materials have been suggested for use in total joint arthroplasty as an alternative to ultra high molecular weight polyethylene (UHMWPE).1–2 As a bearing material operating under mixed lubrication regimes, UHMWPE is subject to wear. Wear particles cause an adverse tissue reaction eventually resulting in loosening of the prosthesis. The modulus of elasticity of the UHMWPE does not allow sufficient deformation of asperities which would increase the film thickness between the bearing surfaces and prevent wear. Elastomers, however, can deform under pressure and enhance lubrication by the formation of a fluid film through elastohydrodynamic and micro-elastohydrodynamic lubrication.3 However, elastomeric coatings are subject to fatigue and debonding from their rigid substrates. To promote fluid film lubrication and prevent failure associated with the use of soft elastomeric bearings, a “true cushion” bearing was designed consisting of a soft elastomer sandwiched between a thin rigid coating and a thick rigid substrate of similar chemistry. This study was aimed at characterizing the frictional behavior of this construct in a lubricated environment as compared to UHMWPE and a non-coated soft elastomeric bearing.
Relations Between Trabecular Bone Properties and MRI Relaxation Times
Authors: Hogan H. , Lin C. , Ambrose C. , Evans H. , Harrigan T. , Shackelford L. , LeBlanc A. 
Published: March 2022

Abstract
Increasing attention has been given in recent years to using magnetic resonance imaging (MRI) to assess skeletal condition. This method of imaging is sensitive to the marrow/bone interface and is therefore attractive for characterizing trabecular bone, which is the bone tissue most seriously affected by osteoporosis or bone loss due to disuse or weightlessness. With proper processing and analysis, the information gained from MRI scans has the potential to provide measures of trabecular bone architecture rather than just bulk density or mass, but the extent to which this is true has not been definitively documented to date. Recent studies by Chung et al. (1993) and Jergas et al. (1995) have examined the relationships among mechanical properties and MRI signals, with encouraging results. More specifically, the effective transverse relaxation time T2* and its reciprocal (transverse relaxation rate) have been the main parameters used in previous studies because T2* is believed to be an indicator to some degree of trabecular architectural features. The present study addressed these same questions but a different protocol for imaging and specimen preparation has been used, and a larger number of specimens were tested.
Degradation of Poly(L-Lactic Acid) Monofilaments for Experimental Intravascular Stent Designs
Authors: Nelson Kevin D. , Phansalkar Anagha R. , Romero Andres A. , Ye Yun-Wei , Eberhart Robert C. , Landau Charles , Meidell Robert S. 
Published: March 2022

Abstract
Metal stents are placed in coronary arteries as an adjunct to balloon angioplasty with increasing frequency. The long term follow up to these clinical stenting procedures in currently three years. There is no published experience for longer periods and many concerns have been raised, including metal fatigue, stress-enhanced corrosion and stress-enhanced damage to adjacent healthy tissue. As a potential improvement to current metal stent designs, we are developing more compliant polymeric stents, employing bioresorbable materials.
Effect of Chemical Fixation on the Fiber Kinematics of Bovine Pericardium
Authors: Billiar Kristen L. , Sacks Michael S. 
Published: March 2022

Abstract
Microstructural modeling of chemically treated bovine pericardium (BP), a popular material for cardiovascular bioprostheses, requires knowledge of the initial collagen fiber angular distribution and fiber kinematics.1 In a previous study, utilizing combined small angle light scattering (SALS) and biaxial stretch, we found that the collagen fibers in fresh BP reorient towards the direction of stretch to a greater extent than predicted by an affine transformation model.2
Haptic Perception of Simulated Surface Textures via Vibratory and Force Feedback Displays
Authors: Weisenberger Janet M. , Krier Michael J. 
Published: March 2022

Abstract
In human sensing of surface texture, both force feedback from surface features and vibratory feedback from repeated stimulation of tactile mechanoreceptors may be involved. The present study investigated the effectiveness of two haptic interfaces, one providing force feedback to the fingertip, and the other providing vibratory feedback to the fingertip, in conveying aspects of surface texture. Results for the vibratory display indicated that subjects could differentiate surfaces that differed in vibratory frequency, intensity, and spatial density. For the force display, we obtained minimum values for differences in spatial frequency and amplitude that permitted discrimination between pairs of surfaces. Implications for the simulation of real surfaces are discussed.