bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biomechanics of the Total Knee Replacement: Theoretical and Computational Modeling of Biomechanical Response to the Tibial Insert
Authors: Sathyamoorthy Mohan 
Published: March 2022

Abstract
Degenerative bone disease is a condition that often affects the articulating joints in the body by compromising the normal range of movement in those areas. As the condition progresses, the patient experiences a more painful and reduced level of mobility, often requiring joint replacement therapy. As the use of orthopaedic implants has become commonplace, the need to adequately understand and characterize the body’s biomechanical response to such implants is necessary to assist patients in achieving a more complete recovery, and more importantly, to optimize the design of biocompatible implants. The total knee replacement (TKR), a modular assembly comprising of femoral, tibial, and patellar components, has demonstrated great benefit to patients in terms of pain management and restoration of mobility. However, with reported disadvantages including stem loosening and bone fracture [1], correlating three dimensional stress concentrations to bone resorption may be an effective predictor of potential bone fracture site in TKR patients. The relationship between stress adaptive theories, stress concentrations predicted by computational modeling, and bone resorption has previously not been studied in great detail. This paper develops a continuum relationship that relates stress adaptive bone remodeling in response to stress concentrations, and presents a basic finite element model to quantify stress concentrations to help verify the proposed relationship. Results could eventually be used recursively to optimize TKR implant design and performance.
Modelling of Oxygen Diffusion in Pulmonary Capillaries
Authors: Frank Andreas O. , Chuong C. J. Charles 
Published: March 2022

Abstract
Oxygen (O2) uptake by the lungs occurs from the alveolar air space to hemoglobin (Hb) in the red blood cell (RBC), which can conceptually be separated into membrane and red cell segments (Roughton and Forster Equation) [8]. The objective of this study was to determine O2 uptake using the finite element method (FEM) and assess the effects of geometry. We developed a modified 2D model representing the sheet flow characteristics of the pulmonary capillaries [2]. Analysis of an axisymmetric model of comparable hematocrit (Hct) was also carried out. The Nusselt number was used to assess the efficiency in oxygen transport of these two geometric configurations.
Gel Compression Considerations for Chromatography Scale-Up for Protein C Purification
Authors: He Weiwei , Bruley Duane F. , Drohan William N. 
Published: March 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.
An Analysis of Hemodialysis Catheter Fluid Mechanics
Authors: Siegel John M. , Makhijani Vinod B. 
Published: March 2022

Abstract
Hemodialysis catheters are primarily used in instances of acute renal failure and poisonings, although there is increasing use of these catheters for long-term access, particularly in the elderly population. The typical hemodialysis catheter consists of a polymer tube with either a single or double lumen. This tube is inserted into one of three preferred catheter access sites: the femoral vein, subclavian vein, or internal jugular vein (the femoral vein is typically used for acute access only). Once in place, the catheter is available for vascular access during hemodialysis.
Altered Swelling-Induced Strain Fields in Articular Cartilage Following Periods of Immobilization
Authors: Narmoneva D. A. , Wang J. Y. , Patel S. S. , Howell D. S. , Setton L. A. 
Published: March 2022

Abstract
Swelling effects in cartilage arise from a high density of negatively-charged proteoglycans which generate a large swelling pressure. Swelling effects in cartilage are regulated by a balance between this swelling pressure and elastic forces generated within the cartilage solid matrix (1,2). Increased swelling is a characteristic of osteoarthritic cartilage and reflects a pathological alteration in the balance between swelling pressure and elastic restraining forces (3). Recently, we have developed a new technique to measure the nonuniform swelling-induced strain fields in samples of articular cartilage in situ, i.e., while attached to the subchondral bone (4). We observed variations in swelling behavior of cartilage with depth from the articular surface, reflecting the nonhomogeneous composition and structure of the material. In this study, we apply our newly-developed experimental technique to measure the swelling-induced strain fields in cartilage following removal of weight-bearing forces with cast immobilization. Periods of joint immobilization have been shown to produce compositional changes characteristic of osteoarthritis including a decreased proteoglycan content and changes in proteoglycan conformation (5, 6). We hypothesize that the changes associated with joint immobilization will alter the swelling behavior of articular cartilage, which will be detected as a change in swelling-induced strain fields in cartilage in situ.
Confined and Unconfined Stress Relaxation of Cartilage: A Transversely Isotropic Analysis
Authors: Bursać Predrag M. , Obitz Toby W. , Eisenberg Solomon R. , Stamenović Dimitrije 
Published: March 2022

Abstract
It has been shown that the stress relaxation response of articular cartilage in unconfined compression is not adequately described by an isotropic biphasic model [1,2]. Two possible explanations have been advanced to account for this observed disagreement between theory and experiment:
(i) friction at the indenter/tissue interface that the model assumes to be negligible [3];
(ii) cartilage behaves as a transversely isotropic material [4,5].
In the present study, stress-relaxation experiments were performed in both confined and unconfined compression on immature bovine knee cartilage. High aspect ratio (height/diameter) specimens were used to minimize the effect of friction at the indenter/tissue interface [3]. The data obtained from these tests were used with a transversely isotropic biphasic model to estimate material parameters.
Effects of Varying Strain Amplitudes and Cyclic Loads on the Tensile Behavior of the IGHL
Authors: Wang Vincent M. , Huang Chun-Yuh , Cohen Nathaniel P. , Pawluk Robert J. , Bucchieri John S. , Flatow Evan L. , Bigliani Louis U. , Pollock Roger G. , Mow Van C. 
Published: March 2022

Abstract
Cyclic tensile testing of soft collagenous tissues is a useful tool for studying their mechanical response in situ as well as for simulating repetitive joint motion [2,5]. It has been hypothesized that the cumulative effects of repetitive microtrauma may contribute to acquired instability in the glenohumeral joint [3]. Many investigations have focused on the inferior glenohumeral ligament (IGHL) which is the primary restraint of the joint in the most common position of shoulder dislocation [4,8]. Not until recently, however, has an experimental protocol addressed repetitive loading of the capsular ligaments at subfailure levels of strain [6,9], The objectives of this study are to examine the effects of increasing: 1) the number of repetitive loading cycles, and 2) strain magnitudes, on the tensile load response and induced laxity in the IGHL.
In Situ Mechanical Behavior of a Repaired Articular Surface
Authors: Wayne Jennifer S. , Mukherjee Nilay 
Published: March 2022

Abstract
Once damaged, articular cartilage in diarthrodial joints is difficult to repair. Altered mechanical conditions around the repair site and inferior material properties of the repair tissue may be possible reasons for its ultimate degeneration (1). Understanding and quantifying this mechanical environment would provide valuable information to help improve protocols in the management of damaged articular surfaces. In this study, the in situ mechanical conditions on a repaired articular surface were examined.
Effect of Strain Rate on Failure Behaviour of the Annulus Fibrosus in Tension
Authors: Kasra M. , Parnianpour M. , Wang J. L. , Shirazi-Adl A. , Grynpas M. D. 
Published: March 2022

Abstract
A large proportion of overexertion injuries in sport and work related activities occur during high strain rate loading. The disc is known to have time dependent material properties (1). The joint load and stiffness may increase and the mode of failure may change from a location to another when higher loading rates are sustained (2). In order to quantify the response of the spine to dynamic loads, we need to account for the rate dependencies of the intervertebral disc in tension as well as other loading conditions. Bending tasks stretch the annulus fibrosus in the vertical direction and render the disc vulnerable to prolapse if the hydrostatic pressure in the nucleus pulposus is raised at the same time. Thus, the ability of the annulus to resist repeated vertical stretching may have a decisive influence on a disc’s susceptibility to prolapse. Tensile properties of the annulus fibrosus have been reported in the literature (3). However, to what extent loading rate can affect annulus tensile properties still needs to be clarified. The objective of this study was to investigate the loading rate sensitivity and regional variations in tensile mechanical properties of the annulus fibrosus, using disc annulus specimens from sheep.
A Cervical Spine Model to Predict Vertebral Stresses in High Acceleration
Authors: Sadegh Ali M. , Tchako Abraham 
Published: March 2022

Abstract
A cervical spine model was developed to investigate the stresses in each vertebra when subjected to high G-z and G-y accelerations. The experimental data used were collected from the biodynamic responses of human volunteers. The model accounts for the biodynamic viscoelastic characteristics of the neck. The results indicated that high stress occurred in C2 and C4 for G-z acceleration cases, while for G-y the high stresses were at C1 and C7.
Intervertebral Disc Pressure Changes During a Chiropractic Procedure
Authors: Gudavalli Maruti R. , Cox James M. , Baker James A. , Cramer Gregory D. , Patwardhan Avinash G. 
Published: March 2022

Abstract
Some of the treatments for low back pain use traction as the loading mechanism to the spine. One such treatment protocol used by chiropractic physicians in the treatment of low back pain is the Cox flexion-distraction procedure (1). The Cox procedure consists of placing the patient in a prone position on a flexion-distraction table and then creating traction and flexion motions at the joint of interest. The treatment is based on the hypothesis that the intradiscal pressure decreases during the procedure and may provide an opportunity for the disc bulge to reduce. However, no data exist to support this hypothesis. The purpose of the present study was to measure the changes in the intradiscal pressures in the lumbar spine on unembalmed cadavers during the flexion-distraction procedure.
Evaluation of a Modular Polyaxial Spinal Component With Interlocking Tapers
Authors: Needham Dusty A. , Rouleau Jeffrey P. , Buchanan Dennis J. , Conta Robert L. , Parr Jack E. 
Published: March 2022

Abstract
The use of tapers in orthopaedic applications for the fixation of one implant component to another is well documented, such as in femoral head fixation to a hip stem. By providing sufficient interference between the two components, hoop stresses and friction forces are generated which hold the assembly together. Under normal physiological conditions, the spine is subjected to a variety of loading regimes, including tension, compression, torsion, bending, and combinations of all four. With the addition of instrumentation, these spinal loads are shared with the fixation device. The resulting construct must be strong enough to maintain correction of the spinal deformity during healing. To examine the strength of a spinal instrumentation system which includes the new locking mechanism of tapers, several tests were utilized, including flexion-extension, axial rod gripping capacity, torsional rod gripping capacity, anterior-posterior pull, and fatigue flexion-extension tests.
Biofidelity of the Hybrid III Neck for Spinal Trauma Assessment
Authors: Sances Anthony , Voo Liming 
Published: March 2022

Abstract
The objective of this study was to delineate the dynamic axial compressive responses of the Hybrid head-neck system and compare with the intact human cadaver head-neck complex responses. The Hybrid III head-neck preparation was tested under dynamic loading at rates to 8.0 m/sec. Inertially compensated forces, axial deformations, and distal generalized six-axis load cell histories were gathered at dynamic sampling rates. The localized axial compressions of the neck were obtained using retroreflective target information and high-speed photography. The Hybrid III dummy responded with non-linear and rate stiffening characteristics with minimal initial softening. This was in contrast to the human cadaver tissues wherein initial softening characteristics were present in the force-deformation curves. The Hybrid III neck was found to be at least two times stiffer compared to the human under dynamic axial compressive loading. Furthermore, the shape of the Hybrid III force-deformation response was different from the human cadaver tissues. These differences must be included to properly extrapolate the results from the Hybrid III to predict injury in real-world vehicular crash environments.
Design Optimization of a Composite Splint Material for Strength and Thermoformability
Authors: Ainsworth Stephen D. , Latour Robert A. 
Published: March 2022

Abstract
The development of a short fiber reinforced, low temperature thermoplastic splint material has potential to improve the ease, cost and efficiency of splinting and casting musculoskeletal problems. Design optimization of the fiber/matrix system is a key step in the development process of this new material. The tensile strength, flexural strength, and elastic moduli were found for 2-D randomly oriented short E-glass fiber reinforced polycaprolactone at both room temperature and at 170°F. The effect of fiber length and fiber volume fraction on the previously mentioned properties were studied by testing a range of fiber volume fractions (0.0 to 0.10) with fiber lengths of 3 mm and 7 mm. The results of this study show potential for increasing strength and rigidity of the low temperature thermoplastic through fiber reinforcement, while maintaining some degree of thermoformability.
A Surgeon’s Perspective on MEMS for Surgery
Authors: Treat M. R. 
Published: March 2022

Abstract
Surgery has changed a great deal in the past decade. The change is denoted by the term “minimally invasive surgery”. The essence of minimally invasive surgery is the use of technology to enable the surgeon to perform his therapeutic tasks in ways which are less physically and physiologically harmful to the patient. At present, the technologies principally in use are imaging technologies (chiefly video and x-ray) coupled with some very basic mechanical devices which allow the surgeon to manipulate organs in various body cavities without opening the body cavity. There is still a long way to go in achieving the full potential of minimally invasive surgery. MEMS technologies can definitely play a role here. I envision the main use for MEMS technology to be in allowing us to design surgical instruments which incorporate various kinds of sensors. Placing micro sensors on the instruments will restore for the surgeon the tactile immediacy of operating with his hands directly on the tissue, instead of through the intermediary of an insensitive and awkward mechanical device. The sensor types which will probably be useful for surgical instruments fall into two overall categories: the first category is sensors which give the surgeon some force feedback as he goes about the job of placing various types of tissue fasteners (staples or sutures). Many surgical complications arise because there is insufficient or inaccurate force feedback to regulate the closing pressure of staples or sutures. Excessive closing pressures can result in tissue necrosis while insufficient pressures may result in leakage through the staple/suture line. The other category of sensors would be various chemo sensors, which can detect the pH, oxygen and carbon dioxide levels in tissue, as well as other chemical entities of clinical importance such as lactic acid.
A New Linear Stepper Motor Within a Hand Held Surgical Device
Authors: Rizq Raed N. , Wulfman David R. , Peichel David , Erdman Arthur G. , Polla Dennis L. 
Published: March 2022

Abstract
A new hand held surgical device intended to aid physicians in microsurgery is reported. This device provides a means for delivering small implants through the use of a precision motion linear stepper motor fabricated from silicon and piezoelectric components. Test instruments have delivered over fifty implants with consistent performance. Typically the test instruments have attained 1.2 mm/s advancement speeds against 3 Newton resistance loads, a maximum output force of 4.6 Newtons, and maximum total displacement of 38 mm.
Hip Implant With Metal-on-Metal Articulation: Some Design Aspects
Authors: Shareef Nazeer H. , Levine Danny L. , Laurent Michel , Hamman Gary 
Published: March 2022

Abstract
One of the main concerns in the orthopaedic community today is the generation of UHMWPE wear debris causing aseptic loosening and osteolysis in total hip arthroplasties. Consequently, there is a growing interest among researchers in this area to explore the use of alternate bearing surfaces in hip implants (1). The performance of total hip replacements can possibly be improved by using metal-on-metal articulating surfaces as is supported by the clinical findings (2). Proper characterization of the prosthetic implants with metal-on-metal bearing surfaces necessitates appropriate material screening and examination of the wear properties of the material in use (3,4).
Maneuverable NURBS Models Within a Haptic Virtual Environment
Authors: Thompson Thomas V. , Nelson Donald D. , Cohen Elaine , Hollerbach John 
Published: March 2022

Abstract
Haptic rendering should not be limited to immobile polygonal models. This paper presents a system that performs Direct Parametric Tracing (DPT) on maneuverable Non-Uniform Rational B-Splines (NURBS) models without the use of an intermediate representation. The system distributes computation between an advanced CAD modeling system and a microprocessor controller for a Sarcos force-reflecting exo-skeleton arm. Methods ranging from model manipulation to simulation of the dynamics of simple assemblies are discussed. Solutions to synchronicity issues that arise in such a distributed system are also described.
A Ray-Based Haptic Rendering Technique for Displaying Shape and Texture of 3D Objects in Virtual Environments
Authors: Basdogan Cagatay , Ho Chih-Hao , Srinivasan Mandayam A. 
Published: March 2022

Abstract
In this paper, we propose a new ray-based haptic rendering method for displaying 3D objects in virtual environments. We have developed a set of software algorithms that work with a force reflecting haptic interface and enable the user to touch and feel arbitrary 3D polyhedral virtual objects. Using the interface device and the suggested model, the user feels as if exploring the shape and surface details of objects such as textures. The components of the model include a hierarchical database for storing geometrical and material properties of objects, collision detection algorithms, a simple mechanistic model for computing the forces of interaction between the 3D virtual objects and the force-reflecting device, and a haptic filtering technique for simulating surface details of objects such as smoothness and texture. The developed algorithms together with a haptic interface device have several applications in areas such as medicine, education, computer animation, teleoperation, entertainment, and rehabilitation.
Direct Integration of Haptic User Interface in CAD Systems
Authors: Stewart Paul , Chen Yifan , Buttolo Pietro 
Published: March 2022

Abstract
The potential of haptic interfaces applied to product design is of growing interest to the automotive industry. However, the full potential of any technology is best realized when it is integrated effectively into the product development environment and process. For most every large manufacturing company this means integration into a commercial CAD system. This paper addresses the fundamental concerns arising from an industrial CAD environment, and highlights the benefits of direct haptic interaction with the CAD model. Design fidelity, a concern of most product development applications, and its relationship to haptics is discussed. The advantages of interacting directly with mathematical CAD models, such as NURBS, are explained. Subsequently, numerical methods and procedures to haptically render NURBS surfaces are discussed. And finally a description of the fully immersive prototype CAD system recently developed at Ford which allows a designer to both see and touch CAD surfaces during product development is provided.
Cooperative Object Manipulation in Virtual Space Using Virtual Physics
Authors: Noma Haruo , Miyasato Tsutomu 
Published: March 2022

Abstract
This study focuses on precise and natural cooperative object manipulation by multi-users in a virtual space. We first considered the advantages of direct virtual object manipulation by multi-users’ hands and the necessity of mechanical restriction between them. Here, we applied an illusion between the visual and haptic sensations to create realistic cooperative manipulation when using VR devices that cannot simulate entire physics. We introduce two virtually-expanded physical laws: “virtual mechanical equilibrium on a rigid object” and “exclusive object arrangement”. We have built a trial system with two hands according to our proposed design, and the experimental results demonstrate the effectiveness of our proposed method for both-hands manipulation. This method’s aim is to allow users to exchange intentions of manipulation through haptic and visual channels by using limited VR devices.
Getting a Feel for Dynamics: Using Haptic Interface Kits for Teaching Dynamics and Controls
Authors: Richard Christopher , Okamura Allison M. , Cutkosky Mark R. 
Published: March 2022

Abstract
Low cost, single-axis force reflecting joysticks were used to teach students about electromechanical systems, dynamics and controls. The students assembled the devices from kits, tested and analyzed them, and used them to interact with computer models of dynamic systems. The devices helped students to appreciate such phenomena as equivalent inertia, friction and the effects of changing control system parameters. They also generated high enthusiasm among the students, particularly when used in cooperative “haptic video games” at the end of the course.