bluuebunny/crossref_metadata_2025_split huggingface dataset:
Porohyperelastic Finite Element Models for Large Arteries Subjected to Cyclic Pressure
Authors: Simon B. R. , Liu J. , Kaufmann M. V. , Cordaro N. , Nichol J. , Baldwin A. L. 
Published: January 2022

Abstract
Recent research in vascular mechanics has addressed deformation and mobile fluid flux in the arterial wall using poroelastic finite element models (FEMs) of undrained and steady-state conditions. However, arteries are subjected to pulsatile pressures and axial tethering. Very little attention has been given to cyclic (pulsatile) arterial wall response. We will use our porohyperelastic (PHE) theory, material properties, and the ABAQUS FE program (Version 5.6) to simulate coupled structural-fluid transport in intact and de-endothelialized rabbit aortas subjected to “normal” as well as “hypertensive” idealized cardiac pressure cycles.
Finite Element Simulation of Stresses in Healing Cartilage Defects
Authors: Weiss Jeffrey A. , Moulis Patricia M. , Ayliffe H. Edward , Rosenberg Thomas D. , Cooley Vernon J. 
Published: January 2022

Abstract
Damage to the articular cartilage is an exceedingly common problem affecting the joints of millions of people. When the injury does not penetrate the subchondral bone, the outcome of biological healing is poor and eventually leads to the degeneration of the articular surface. In young patients, small focal defects are often treated using marrow-stimulation techniques, including subchondral drilling (Tippet, 1996), microfracture (Tippet, 1996) and abrasion arthroplasty (Johnson, 1996). In these procedures, the torn or compromised cartilage is removed to expose the underlying bone and a rim of healthy cartilage is defined surrounding the defect hole. This is followed by drilling, puncturing or abrading the underlying bone to stimulate an inflammatory response and/or generate a blood clot within the defect. Clinical results suggest that the relative success of these procedures (i.e. the extent and quality of defect fill-in) depends on the level of strain experienced by the healing tissue during the early period following the procedure. Although the state of compressive and shear strain within and around the chondral defect is presumed to depend on the size and location of the defect, the relationship between these factors is not well documented. A finite element model of the medial compartment of the knee was constructed to examine the effect of defect size and location on predicted strains within and around the defect.
Direct Measurements of Hydraulic Permeability Coefficients of Cartilaginous Tissues
Authors: Gu W. Y. , Mao X. G. , Rawlins B. A. 
Published: January 2022

Abstract
Fluid is a major component of cartilaginous tissues. Its transport is primarily governed by the hydraulic permeability coefficient of the tissue. The hydraulic permeability coefficient is important to the understanding of the transport processes of interstitial water and ions [e.g., Gu et al, 1993] and the viscoelastic behavior of the tissue [e.g., Mow et al, 1980; Setton et al, 1993]. However, the hydraulic permeability coefficients of these tissues are extremely low and difficult to quantify precisely. Studies in the literature report on the determination of the hydraulic permeability of these tissues directly by measuring fluid flux corresponding to the applied pressure difference in a permeation experiment [Edwards, 1967; Mansour and Mow, 1976; Mansour and Matsumoto, 1998; Maroudas and Bullough, 1968; McCutchen, 1962] or indirectly by curvefitting experimental data from confined compression or indentation tests using the biphasic theory[e.g., Athanasiou et al, 1991; Best et al, 1994; Drost et al, 1995; Houben et al, 1997, Iatridis et al, 1997; Mak et al, 1987; Mansour and Matsumoto, 1998; Mow et al, 1980; Setton et al, 1993]. Recently, Gu and co-workers (1998) reported that the permeability coefficient of human anulus fibrosus determined directly was one order of magnitude greater than that determined indirectly [e.g. Best et al, 1994, Drost et al, 1995, Houben et al, 1997, Iatridis et al, 1997]. To address this discrepancy, we investigated the hydraulic permeability coefficients of human lumbar anulus fibrosus and bovine articular cartilage using a new technique developed by Gu and co-workers (1998). The hydraulic permeability coefficient of human anulus fibrosus was compared to that of bovine articular cartilage measured under the same testing conditions.
Biomechanical Effects of Intra-Specimen Variations in Trabecular Thickness: A Three-Dimensional Finite Element Study
Authors: Yeh Oscar C. , Keaveny Tony M. 
Published: January 2022

Abstract
Underlying the importance of trabecular architecture on whole bone strength, osteoporosis has recently been defined as “a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk” [1]. Architectural measures, such as the fabric tensor and connectivity, can explain 20%–30% of the inter-specimen variance in modulus of trabecular bone [2–4]. It has also been observed that apparent density alone does not fully differentiate clinically between atraumatic fracture and non-fracture subjects [5] and that bone strength is not increased in response to fluoride treatments despite an increase in bone mass [6], both suggestive of the role of architecture on the mechanical properties of trabecular bone. Most previous studies on architecture have focused on inter-specimen variations in architecture, whereas intra-specimen variations have received little attention. Thus, the intra-specimen variation in trabecular thickness is considered in this study as an additional candidate parameter for assessing osteoporosis and the effectiveness of drug treatments.
Surgical Simulation of Tendon Transfers to Augment Lower Extremity Function With Functional Neuromuscular Stimulation
Authors: Zhao Weifeng , Triolo Ronald J. , Wibowo Michael , Bhadra Niloy 
Published: January 2022

Abstract
A musculoskeletal model was used to study tendon transfer surgery in order to decouple hip extension and knee flexion in lower extremity FNS applications. Effects of tendon transfer location and shortening length were quantitatively examined based on the resulting moment-generating capacity. Simulation results have shown that moment arm is not sensitive to the transfer locations. Appropriate shortening is the key to counteract the tendon slack caused by the transplantation and to achieve maximal hip extension strength.
Application of Nonlinear Stability Analyses to Study Human Standing/Balance
Authors: Wood Aaron J. , Reisinger Kim D. 
Published: January 2022

Abstract
Nonlinear dynamics analyses are utilized to explore some of the basic dynamics and stability of human standing/balance. Phase plane portraits, plots of angular velocity versus angular displacement, present kinematics of the system in a compact form and provide insight into the dynamics of the system. Poincaré maps depict the transient and steady-state motion, and provide information about the stability of the system. Five young adults with no known gait pathologies participated in this study. A motion analysis system and force plates were utilized to capture the displacements of each body segment and joint, and the shifting of body weight between feet. Participants were required to stand comfortably with one foot on each force plate. Phase plane portraits were constructed for each joint in each of the sagittal, frontal and transverse planes. Poincaré maps were constructed by identifying a shift in weight onto one foot and sampling the corresponding joint velocities at those times.
Accumulation of Microdamage With Increasing Strain in Bovine Trabecular Bone
Authors: Arthur Tara L. , Gibson Lorna J. 
Published: January 2022

Abstract
Microcracks are present in normal human bone, and microcracks are thought to be a stimulus for bone remodeling. When there is an imbalance between microcrack creation and repair, microdamage can accumulate and result in bone fracture.
Seventeen specimens were tested in monotonic compression to one of six total strain levels. Chelating fluorochromes were used to label cracks and distinguish between microdamage created before and during testing. Histology specimens were observed under epifluorescence for microdamage in the form of microcracks. The number of cracks, sum of the crack lengths, and frequency distribution were recorded for each specimen. Microdamage accumulated non-linearly with increasing total strain on the specimen, but the mean crack length remained the same with increasing damage.
Structure-Function Relationships for a Coralline Hydroxyapatite Bone Substitute
Authors: Haddock Sean M. , Debes Jack C. , Keaveny Tony M. 
Published: January 2022

Abstract
Coralline hydroxyapalite (Pro-Osteon 500, Interpore International, Irvine, CA) is an artificial bone substitute that has been approved by the FDA since 1993. Despite previous in vitro and animal studies on the mechanical behavior of coralline hydroxyapatite [1–3], its mechanical properties are not well understood. Further, the relationship between the microstructure and mechanical properties of coralline hydroxyapatite is unknown. Knowledge of this relationship is important in determining the optimal clinical use of this bone substitute.
Rheological Properties of Bovine Liver Tissue
Authors: Liu Zizhen , Bilston Lynne 
Published: January 2022

Abstract
Characterizing the rheological properties of liver tissue, especially within the linear viscoelastic region, is useful for investigating the behaviour of the tissue under mechanical loads. This paper reports three types of experiments of rheological properties of liver tissue that were carried out recently, including strain sweep oscillation, shear stress relaxation and strain controlled oscillation. These experiments were designed to investigate the following: a) the domain of linear viscoelasticity of liver tissue, b) the time dependent behavior of liver tissue, and c) the dynamic storage modulus and loss modulus. Fresh bovine liver tissues were used for the experiments. All the liver tissues were bathed in a 0.9% sodium chloride solution immediately after harvesting. The test samples were cut to a disk of diameter 20–30mm with 1.5–2.5mm thick. Several strain sweep oscillation tests were performed to measure the sample behavior at stepwise changing strain amplitude at 1 Hz frequency. The results showed that the linear viscoelastic limit of bovine liver tissue is of the order of 0.2% strain. The shear stress relaxation test indicated that there is no apparent long-term elastic modulus reached before 3000 seconds within the linear viscoelastic region. The dynamic storage modulus and loss modulus were obtained in the frequency range of 0.001–20 Hz.
Prediction of Postural Balance by Means of Zero Moment Point (ZMP)
Authors: Goswami Ambarish 
Published: January 2022

Abstract
Zero moment point (ZMP) is well-known in the robotics literature as an indicator of postural stability and has been successfully used to control anthropomorphic biped robots. In this paper we review the basics of ZMP, explain its behavior by means of planar point-mass models and full 3D extended rigid-body models, and show how it can be applied in the study of postural balance in the human.
ZMP is an easily understandable, intuitive, easy-to-use, and physically meaningful criterion for the prediction of balance in dynamic locomotion systems. ZMP may be defined as a point on the ground where the resultant rolling moment on the foot reduces to zero. In order for the foot not to roll, the point should be constrained within the footprint. We relate the foot moment with the dynamics of the body segments and derive the expression of ZMP. We demonstrate that the position of ZMP also indicates the magnitude of rolling moment and the direction of the impending roll. Being a dynamic criterion, ZMP is a function of the position, velocity and the acceleration of the body segments and is shown to be a general concept from which the center of pressure (CP) and the horizontal projection of center of mass (HCM) may be extracted as special cases.
A Method to Determine the Effect of the Individual Rotator Cuff Muscles to Dynamic Joint Stability of the Shoulder
Authors: Kim Kyu-Jung , Lee Seok-Beom , An Kai-Nan , Morrey Bernard F. 
Published: January 2022

Abstract
The prevalence of rotator cuff disease among the elderly population and the greatest incidence of acute dislocations will continue to provide challenging patient management decisions. Stability of the shoulder is critical to successful upper extremity function. The GH joint is stabilized by passive capsuloligamentous restraints as well as by active dynamic stabilizers through concavity compression. The compression of the convex humeral head (HH) into the concave glenoid fossa (GF) counteracts against translational shear forces (Matsen et. al 1994). The major compressive load across the joint is provided by the action of the surrounding musculature, especially the rotator cuff. The muscles may generate both compressive and shear force components as well as moments. The purpose of this study is to describe a new testing methodology of how to estimate the contribution of individual rotator cuff muscles to the dynamic stability of the GH joint at a given joint position.
Microcoaxial Electrode for Local Nitric Oxide Measurement in Biological Systems
Authors: Kitamura Yoshiichiro , Uzawa Tomoyuki , Oka Kotaro , Komai Yutaka , Ogawa Hiroto , Kobayashi Hirosuke , Takizawa Naosada , Tanishita Kazuo 
Published: January 2022

Abstract
A new nitric oxide (NO) selective electrode was developed. The tip diameter of the NO electrode is less than 10 μm. A working and a reference electrodes are located coaxially at the tip of the NO electrode. A stable NO donor SNAP (S-nitroso-N-acetyl-DL-penicillamine) and a putative NO scavenger hemoglobin (Hb) was used to examine the response of the electrode. Considering the instantaneous concentration of NO secretion previously reported in biological systems, 0.1, 1 μM NO solution was used to calibrate the electrode.
From the result of the test of the electrode with SNAP and Hb, we confirmed this microcoaxial NO electrode can detect NO released from SNAP directly and continuously. From the result of calibration of the electrode, good linearity was examined in sub-molar concentration range. It is expected to detect local NO concentration in biological systems with a high space resolution.
Circumferential Strain Around Femoral Cylinders due to Simulated Press-Fit Loading
Authors: Brown Christopher U. , Kish Vincent L. , Norman Timothy L. 
Published: January 2022

Abstract
An experimental model was developed to apply radial forces around a uniform cylinder of femoral bone to determine the short term strain response. Eight strain gages were applied at equal intervals around the circumference of the cylinder. No significant differences exist between the circumferential strain magnitudes of each cortical region, however, there is a trend for a difference between the posterior region and the other regions. Further analysis needs to be done to elucidate the relationship that may exist between the strain and the bone morphology and composition of the cortical regions.
Transient Discharge of Entrained Air From a Wound Roll
Authors: Keshavan M. B. , Wickert J. A. 
Published: January 2022

Abstract
As magnetic tape or other web-like material is wound onto a roll, air moving with the incoming stream and the roll becomes forced into the converging wedge at the stream’s point of tangency. The spiral-shaped air bearing so formed can extend many wraps into the roll’s interior. When the roll is subsequently brought to rest, the entrained air discharges from it, and the roll’s radius gradually decreases until all adjacent tape layers have come into direct contact. In the present paper, a model is developed for this transient discharge process, and for the rate at which the roll stabilizes following steady-state winding. Predictions of the model are compared with results from laboratory experiments in which the roll’s radius is measured through laser interferometry during the steady entrainment, and transient discharge, stages of winding. Parametric effects of the tape’s tension, speed, width, and surface roughness are specifically addressed with a view towards reducing the time required for the roll to stabilize.
Estimation of Distributions of Contact Stressess and Displacements Using Regularization Schemes
Authors: Kubo Shiro , Ohji Kiyotsugu 
Published: January 2022

Abstract
Estimation of tractions and displacements on inaccessible boundaries, such as contact areas of solids, can be regarded as an inverse boundary value problem. In this study finite-element based inverse analysis schemes with regularization were applied to the estimation of the distributions of tractions and displacements on contact areas. The finite element equation was rewritten in terms of unknown boundary values on the contact area using over-prescribed boundary values. This equation was solved for the boundary values on the contact area. Like many other inverse problems, this inverse problem was severely ill-conditioned and the estimated distributions were very sensitive to the over-prescribed boundary values used in the estimation. To overcome the ill-posedness of this boundary value inverse problem, the function expansion method and Tikhonov regularization were introduced in the finite element-based inverse analysis scheme. The number of terms in the function expansion and the smoothing parameter in Tikhonov regularization were regarded as regularization parameters in the inverse analysis. To determine the optimum value of these regularization parameters, the estimated error criterion and the AIC were introduced. The usefulness of the finite element-based inversion scheme was examined by numerical simulations. It was found that the distributions of tractions and displacements can be estimated reasonably even from noisy observations by using the finite-element based inverse analysis schemes with regularization. The optimum value of the regularization parameters can be estimated by the estimated error criterion or by the AIC.
Linear Buckle Analysis for Partially Buckled Webs
Authors: Loen Mark V. 
Published: January 2022

Abstract
Web processing requires that the web is stretched under tension between two processing rolls. When the processing rolls are misaligned or moved relative to each other, a web deflection is introduced which causes the web stress to change. Small roll misalignments or movements may cause large web stresses, yielding, and failure.
The web stress distribution and deflection can only be found if the buckled and unbuckled portions of the web are determined. This paper presents the assumptions and analytical method needed to find the boundary edge between the buckled and unbuckled portions of the web. Also, the method for analyzing the unbuckled portion of the web to determine the web end deflection, end rotation, and maximum stress is included.
Robust Damage-Mitigating Control of Mechanical Structures: Experimental Verification on a Test Apparatus
Authors: Zhang Hui , Ray Asok 
Published: January 2022

Abstract
The goal of damage-mitigating control is to achieve high performance of operating machinery without overstraining the mechanical structures and the potential benefit is an increase in the component service life with no significant loss of performance. This paper presents the design of a test apparatus, the synthesis of a damage-mitigating control system, and the results of experimentation where the objective is to demonstrate the concept of fatigue damage reduction as an extension of multivariable robust feedback control. The test apparatus is built upon a three-degree-of-freedom, two-input three-output mechanical structure. The methodology of the damage-mitigating control synthesis is built upon the principles of: (i) frequency-domain identification of the plant dynamics and modeling of uncertainties in the state-space setting; and (ii) robust control based on the H∞ approach by taking both plant dynamic performance and material degradation of structural components into consideration. Case studies on the test apparatus indicate that fatigue life of specimens can be substantially extended with no appreciable degradation in the dynamic performance of the mechanical system.
Enhancing Subjective Sensitivity to Vibrotactile Stimuli
Authors: Murray Anne M. , Klatzky Roberta L. , Khosla Pradeep K. 
Published: January 2022

Abstract
We demonstrate through a set of psychophysical experiments that the miniature voice coils we have selected for our vibrotactile glove design are capable of producing discriminablc vibrotactile information to a user. We examine three ways of modifying the vibration of the voice coil, by varying: 1) the amplitude of a sinusoidal signal at the optimal frequency (250–300Hz); 2) the frequency of a sinusoidal signal at the maximum (suprathreshold) amplitude; and 3) both the amplitude and the frequency of a sinusoidal signal. Through this work, we have found that a user’s sensitivity is significantly enhanced (at least 111%, p &lt; 0.001) by modulating both the amplitude and the frequency of a sinusoidal signal. The increase in sensitivity may result in better discrimination of less intense stimuli. If this vibrotactile glove were used to convey touch and grip force information, this sensitivity enhancement could enable a user to control smaller grip forces better.
Human Perception of Friction in Haptic Interfaces
Authors: Lawrence Dale A. , Pao Lucy Y. , Dougherty Anne M. , Pavlou Yiannis , Brown Shane W. , Wallace Stephen A. 
Published: January 2022

Abstract
Resistance to motion in haptic interfaces causes unwanted corruption of rendered data. Quantifying perceptual thresholds of this friction is important as a quality measure and design metric for these devices. Key difficulties in determining these perceptual thresholds are identified, and a strategy based on modeling activation in psychophysical channels is proposed to overcome these difficulties. An experiment is conducted to determine sensory thresholds for a particular haptic interface using pairs of friction-reducing force controllers to vary levels of residual friction presented to users. Results indicate the need for detailed channel-specific activation models of the type proposed.
Improved Uncertain Transfer Function Synthesis and Analysis Using Bond Graphs and Transmission Matrices
Authors: Wilson Bruce H. , Eryilmaz Bora 
Published: January 2022

Abstract
Various robust control applications require the value set of an uncertain transfer function, G(s, q), which is the complex-plane region {G(jω,q): q ∈ Q} where q is a vector of uncertain parameters. When the transfer function can be decomposed into a tree structure with disjoint sets of uncertain parameters, the value set synthesis process is simplified. A recently published bond-graph-based technique provides the means to synthesize a tree-structured transfer function (tstf). However, the method is difficult to use when the sensor-actuator pair is not collocated or nearly collocated. The present work overcomes this limitation by employing bond graph transmission operators to couple the input/output variables. Using the operators, we provide a method to synthesize a tstf, regardless of the separation of the sensor-actuator pair. A comprehensive example demonstrates transfer function synthesis using the operators. The technique provided here significantly augments the class of systems for which tstfs can be readily synthesized.