bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adhesions of the Patellar and Quadriceps Tendons: Mathematical Model Simulations
Authors: Roglic H. , Kwak S. D. , Henry J. H. , Ateshian G. A. , Rodkey W. G. , Steadman J. R. , Mow V. C. 
Published: March 2022

Abstract
Following knee surgery, especially after anterior cruciate ligament (ACL) reconstruction, a small percentage of patients complain about significantly decreased patellar mobility accompanied by anterior knee pain, sometimes severe. The limited mobility and knee pain usually do not disappear even with aggressive physical therapy. Arthroscopic exploration of these knees reveals a closure of the patellar tendon-tibial (PTT) interval, i.e., severe fibrous adhesion of the patellar tendon to the anterior aspect of the tibia, the formation of fibrous tissue between the quadriceps tendon and the femur, and a ‘closed-off’ suprapatellar pouch. Other investigators have also noted such adhesion (Paulos et al., 1987 & 1994; Jacobson et al., 1989), and Hughston (1985) attributed the tendon adhesion to the scarring of infrapatellar and suprapatellar fat pad caused by the surgery. While the adhesions are important clinical problems associated with knee surgery, no study to date, other than our experimental study on patellar tendon contracture, has quantitatively investigated the effect of these adhesions on knee kinematics and contact forces (Ahmad et al., 1997). In this study, we use a 3-D mathematical model of the knee joint to analyze the effects of the patellar tendon adhesion (PA) to the anterior tibia, and the quadriceps tendon adhesion (QA) to the anterior femur. Our objective, therefore, is to demonstrate the effects of these types of post-operative adhesions on patellofemoral joint mechanics.
Replacement of Biological Parts Using Solid Freeform Fabrication Technologies
Authors: Crawford R. H. , Barlow J. W. , Beaman J. J. , Bourell D. L. 
Published: March 2022

Abstract
The use of Solid Freeform Fabrication (SFF) for creating models and visual prototypes of products is gaining rapid acceptance in industry as an aid to decreasing time-to-market while increasing product quality. The strengths of these processes include rapid turnaround time and the ability to create parts of almost unlimited shape complexity. Research in these technologies has now turned to searching for new processes and material systems that will allow the creation of functional parts. One promising area of application is fabrication of replacement biological parts. SFF technologies are particularly suited to these applications because of the complex shapes involved. Research at The University of Texas at Austin is focused on the Selective Laser Sintering (SLS) process and the development of biocompatible material systems that can be processed with SLS. In this paper we describe the status of SLS processing of calcium powders to form artificial bones. We also present the results of animal implantation tests to prove biocompatibility of the materials.
Similarities Between Gait Adaptations in Preoperative and Postoperative Total Hip Replacement Patients
Authors: Hurwitz D. E. , Foucher K. C. , Andriacchi T. P. , Rosenberg A. G. , Galante J. O. 
Published: March 2022

Abstract
Gait adaptations among postoperative total hip replacement (THR) patients may be a response to the prosthesis and changes in the reconstructed joint mechanics or may be a learned response from an adaptation that was present preoperatively. Similarities have been reported between gait adaptations in preoperative and postoperative patients for THRs (1), but this was demonstrated in cross-sectional data and not longitudinal data. These gait adaptations may have implications on hip joint loading, rehabilitation protocols and can result in additional compensations at other joints. This longitudinal study tested the hypothesis that gait adaptations present preoperatively persist postoperatively.
Microdevices Made by the LIGA Technique for Applications in Minimally Invasive Therapy
Authors: Wallrabe Ulrike , Mohr Jürgen , Ruther Patrick , Ruzzu Antonio 
Published: March 2022

Abstract
For modern diagnostic and therapeutic methods new miniaturized analytical components and surgical tools are needed. This becomes obvious in the fields of endoscopic treatments or catheter based interventions. Since cleaning and sterilization of miniaturized devices is difficult or even impossible many of these tools are expected to be disposable. Therefore, they should be available at reasonable prices which can be achieved by batch fabrication of the devices. Using the LIGA technique diverse polymers and metals can be patterned which enables numerous applications. Turbines, pumps, valves, lenses, and spectrometers are developed for the use in minimally invasive therapy.
Analysis for Design of a Composite Hip Prosthesis
Authors: Joshi Makarand G. , Santare Michael H. , Advani Suresh G. , Miller Freeman 
Published: March 2022

Abstract
Total hip arthroplasty (THA) using metallic hip prostheses has been successfully performed since the early 1960’s and is now a routine procedure. The use of cement to fill the space between the bone and the prosthesis, and bony ingrowth, where the bone grows into a porous prosthesis, have been the two primary methods of fixation used. For the structure of the femur before THA, the load distribution can be essentially resolved into an axial component, two bending moments and a torsional moment which depend upon the leg stance. The distribution of these load components is changed after THA. The current methods of fixation allow for transfer of axial loads to the bone mainly through shear stresses at the bone-implant interface (The muscles attached to the femur transfer load and moments as before THA). The bending moment is effectively transferred to the bone, however, the great disparity in the stiffness of a metallic prosthesis and the surrounding bone reduces bending displacements changing the bending moment distribution in the surrounding bone. The current procedure although very successful in the older population has a relatively lower rate of success in the younger population.
Design and Evaluation of a Programmable Triaxial Joint Simulator
Authors: O’Connell Mary K. , James Susan P. 
Published: March 2022

Abstract
The goal of a joint simulator is to replicate the conditions experienced by an implanted prosthesis. The accuracy of in vivo joint modeling has become increasingly important as new materials, surface treatments, coatings, and implant designs are created. Force, motion, and environmental conditions are critical for modeling in vivo joints. True physiological joint articulations consist of three orthogonal force components coupled with triaxial motion.
Liner/Shell Load Transfer Mechanisms in a Modular Acetabular Component for Total Hip Replacement
Authors: Kurtz Steven M. , Ochoa Jorge A. , White Christopher V. 
Published: March 2022

Abstract
Modular acetabular components have seen widespread clinical use since the 1980’s (Collier et al., 1992). However, nonconformity between the polyethylene liner and the metal shell may exist in modular acetabular components by design, due to limitations on polyethylene liner manufacturing tolerances, or from the incorporation of locking mechanisms to attach the liner to the shell. Previous research has demonstrated that the stresses at the articulating surface are sensitive to nonconformity between the liner and the metal shell (Kurtz et al., 1994). Deleterious rim loading may also occur in a rimmed polyethylene liner with radial interference between the liner and the metal shell (Kurtz et al., 1993).
Osseocompatibility Tests: Do Biomechanical Factors Influence the Results?
Authors: Gharpuray Vasanti M. , Kerns Laura E. , Zyblewski Sean , Hiatt Mark J. , Zhuang Ming , Powers Dennis L. 
Published: March 2022

Abstract
The transcortical “plug” model has been used by numerous investigators for the evaluation of the response of bone to implanted biomaterials. It is generally assumed that this model represents a loaded or functional situation and thus is suitable for evaluation of bone ingrowth into porous surfaces. However, other investigators have suggested that this is an essentially unloaded situation. Further, different researchers have reported a wide range of results from experiments designed to measure the response to apparently similar implant materials (Black, 1989).
Improved Mechanical Properties of Bone Cement by Ultrasonic Vibration
Authors: Saha Subrata 
Published: March 2022

Abstract
Self-curing polymethylmethacrylate (PMMA) or acrylic bone cement is used extensively in total joint arthroplasty and in the repair of bone defects [1]–[3]. However, the hand mixing of the methylmethacrylate polymer and the liquid monomer entraps air bubbles making the cement porous. This adversely affects the mechanical properties of the bone cement [4]. This has prompted several investigators to improve the mechanical properties of bone cement by reducing the porosity due to air bubbles by the use of centrifugation or by vacuum mixing [5]–[8]. In this study we investigated if ultrasonic vibration during cement mixing could reduce the porosity and improve the mechanical properties of surgical grade polymethylmethacrylate.
A Dynamic Computed Tomography Technique for In Vitro Measurements of Local Aortic Elastic Modulus
Authors: Lee Mark , Drangova Maria , Holdsworth David 
Published: March 2022

Abstract
The ability to quantify the mechanical/material properties of the arterial system has been a highly sought after asset in the study of arterial atherosclerosis; however, conventional methods that take into account the dynamic viscoelastic nature of the artery are either destructive or lack high local spatial resolution[ 1,2]. A novel computed tomographic (CT) technique has been utilized to obtain the instantaneous measurement of the dynamic elastic modulus of intact excised porcine aortic vessels undergoing physiological pressure waveforms.
A Procedure to Determine Equilibrium Postural Configurations for Arbitrary Locations of the Feet
Authors: Gonzalez L. Javier , Sreenivasan S. V. 
Published: March 2022

Abstract
Existing rehabilitation devices for patients with balance problems are passive, and they do not distinguish between different levels of imbalance a patient might possess. The ideal rehabilitation machine would be a robotic device that would provide ‘barely adequate’ support to the patient without compromising its ability to prevent falls. It would also allow the patient to perform normal postural motions including nominal sway and typical responses to external disturbances.
Force Reflection for WIMPs: A Button Acquisition Experiment
Authors: Eberhardt Silvio , Neverov Misha , West Todd , Sanders Carl 
Published: March 2022

Abstract
The purpose of this study was to evaluate whether the common computer-interface task of button acquisition is performed more rapidly when buttons are surrounded by force attraction basins. Button acquisition time measures were obtained from five participants for each of five different pointer device configurations. A normal mouse served as control, and the remaining four configurations used a normal mouse mechanically linked to the end-effector of a PHANToM force-reflection mechanism (SensAble Devices, Cambridge, MA). Two configurations applied forces on the mouse in the direction of a (graphical) button whenever the cursor was in the vicinity of the button. Anchoring the PHANToM to the mouse also allowed comparing relative and absolute pointer positioning. Over all participants, mean button acquisition time improvements of at least 10% were obtained when using force reflection. Individual means were in every case better when force-reflection was used. Across participants, there was no difference between absolute and relative positioning, whether or not force-reflection was enabled.
Design and Analysis of Tunable Springs in Haptic Interface of Endoscopic Graspers
Authors: Faraz Ali , Payandeh Shahram 
Published: March 2022

Abstract
In endoscopy, tissue manipulation is performed by long graspers which do not reflect the grasping force to the surgeon hand properly, due to their mechanical limitations. In this study, other electro-mechanical designs are considered to enhance the force reflection. The type synthesis of such a haptic interface leads to the application of tunable springs. The design of tunable spring is optimized based on the haptic and surgical requirements. Moreover, by using suitable control laws, it was shown that the primary requirements can be met according to the simulation results. The limited bandwidth of such a system, along with possible improvements, and future works are also discussed.
Haptic Display for Replication of Rheological Behaviour of Surgical Tissues: Modelling, Control, and Experiments
Authors: Scilingo Enzo Pasquale , De Rossi Danilo , Bicchi Antonio , Iacconi Pietro 
Published: March 2022

Abstract
Current technology of minimally invasive surgery deprives the surgeon almost completely of the perception of rheological properties of manipulated tissues. As a first attempt to solve this problem, we realized a sensorized surgical tool, whose visual display was however not completely satisfactory. We present a preliminary realization of a tactile display returning the kinesthetic tactile sensation of the stiffness and damping of manipulated tissues. We also discuss identification algorithms of the model of the manipulated materials for detecting their properties and for replicating their dynamic behavior through the tactile display.
Intelligent Control for Electrical Power Generation Systems
Authors: Shoureshi Rahmat , Li Hanchu , Kramer Robert , Klaiman Henry 
Published: March 2022

Abstract
Deregulation of electric power, introduction of independent power producers and increase competition have introduce new challengers to the utility industry. The ability to project short term demands and be able to respond to highly varying loads with high power quality are essential elements of a reliable and secure power system. This paper presents a new approach to the automatic generation control that combines advanced in neural networks, control theory, and electric power systems.
Design of a Self-Organizing Fuzzy Logic Controller for Two Dimensional End Milling Operations
Authors: Chang Hsin-Chi , Gau Jenn-Terng , Lu Wen F. 
Published: March 2022

Abstract
In this study, a Self-Organizing Fuzzy Logic Controller (SOFLC) is designed for the control of two dimensional end milling operations. In order to achieve high quality product and high production rate in 2-D end milling operations, it is important to minimize the tracking error, and regulate the cutting force at (or below) a certain level with possible maximum cutting feedrate. SOFLC avoids the need of the prior knowledge of the system, and is able to generate and modify the control rules by learning based on a given performance criterion. With the learning capability, SOFLC is used to limit the tracking error, and to regulate the cutting force in 2-D end milling operations. Simulation results show that the SOFLC is able to minimize the tracking error through its learning and keep the cutting force at or below a reference level.
A Fuzzy Logic Controller for Orbital Rendezvous
Authors: Luo Jia , Kluever Craig A. 
Published: March 2022

Abstract
A new application of fuzzy logic is investigated. A control scheme based on fuzzy logic techniques is developed for the orbital rendezvous phase of a low-thrust spacecraft. The minimum-fuel trajectory between specified energy levels is utilized as a reference trajectory. The fuzzy logic controller responds effectively to a range of initial state perturbations and results in very precise terminal orbit conditions with good tracking performance. The fuzzy logic controller exhibits better tracking performance and in some cases substantial fuel savings compared to a Linear perturbation control method. Numerical results are presented for a range of rendezvous maneuvers.
Analysis, Design and Experimental Verification of Active Vibro-Acoustic Control
Authors: Shoureshi Rahmat A. , Vance James , Eberhard Günter , Karkosch Hans-Jürgen 
Published: March 2022

Abstract
Sound and vibration quality have become a major differentiating factor for general machinery and specifically the automotive vehicles and aircraft. This paper provides an overview of research and development results interms of analysis and design tools, as well as, a unique control approach to the problem of low frequency active vibration and undesirable noise. Implementation results on different vehicles and an aircraft are presented.
A Hybrid Bed/Chair System for Bedridden Patients: Elimination of Transfer Between a Bed and Wheelchair
Authors: Mascaro Stephen , Asada Haruhiko H. 
Published: March 2022

Abstract
A hybrid wheelchair/bed system for eliminating transfer between the bed and chair is developed and tested. A powered wheelchair can be docked to a bed portion and reconfigured to a flat stationary bed so that the bedridden person does not have to change seating when transferring between the chair and bed. Moreover the powered wheelchair can be docked to a toilet directly and automatically so that the bedridden can use the toilet without changing seating. A holonomic omnidirectional vehicle with a ball wheel mechanism is used for the wheelchair. The high maneuverability and holonomic nature of the vehicle allow the chair to be docked easily and precisely against a fixture. First, this paper describes the basic concept of the reconfigurable holonomic omnidirectional mobile bed with unified seating, or RHOMBUS for short. Issues on the mechanical design of the vehicle, chair, and bed are addressed, followed by control issues. A compliant bumper mechanism is used to assist in both bed and toilet docking control as well as to ensure rider comfort. A hybrid stiffness control docking method using force sensors embedded at optimal locations within the bumper is developed. A prototype system was designed and tested. The vehicle was successfully docked to the bed despite a small clearance ratio as well as large lateral and angular initial errors.
Control and Calibration of a 6-Axis Ultrasound Scanner for In Situ Measurement of Articular Cartilage Geometry and Thickness
Authors: O’Bryan J. , Murphy M. C. , Ito K. , Mann R. W. 
Published: March 2022

Abstract
The development of improved orthopedic implants, diagnostic tools and surgical procedures for clinicians requires a better understanding of the human musculoskeletal system and joint kinematics. Mathematical models continue to play an important role in advancing the understanding of musculoskeletal system performance. At the core of any useful mathematical model is a sound representation of the fundamental mechanics of the system and reliable, repeatable measurements of the necessary physical parameters. For joint models, essential data include the three dimensional geometry of the articulating surfaces and ligament insertion sites, the articulating cartilage thickness, and material properties of the different tissues.
Generating Pathological Gait Patterns via the Use of Robotic Locomotion Models
Authors: Ephanov Anton , Hurmuzlu Yildirim 
Published: March 2022

Abstract
In this article we explore a feasibility of modeling normal and pathological human gait using a relatively simple five-element model. We use a robust, nonlinear control scheme to regulate the gait pattern of the model. Simulated gait patterns are generated through the use of five constraint relationships that depend on four gait parameters. Two pathological conditions due to muscle weaknesses were simulated by modifying the control torques at the joints. We demonstrate that the model successfully approximates the qualitative and quantitative dynamic trends that were observed in normal and pathological human locomotion.
Motion Control of a Mobile Manipulator by Input-Output Linearization
Authors: Chung Jae H. , Velinsky Steven A. , Hess Ronald A. 
Published: March 2022

Abstract
This paper discusses the modeling and control of a spatial mobile manipulator which consists of a robotic manipulator mounted upon a wheeled mobile platform. By neglecting slip of the wheeled platform’s tires, nonholonomic constraints are introduced into the equations of motion which complicates the control problem. The dynamic equations of the mobile manipulator are derived using the Lagrange-d’Alembert formulation. In this formulation, the equations of motion are projected onto the subspace of allowable motions. Then, the solvability of tracking problems for the mobile manipulator is investigated by using input-output feedback linearization. The feasibility of the control approach is demonstrated through computer simulation.
Integrator Backstepping Control of a Pneumatic Actuator-Based Robot Manipulator
Authors: Rifal Osamah M. El , Bridges Michael M. 
Published: March 2022

Abstract
The tracking performance of a single link pneumatically actuated robot arm has been investigated. The actuator pressure dynamics were considered, and an exact model knowledge integrator backstepping-based, IB, controller was designed with flow rates as the system’s control inputs. A more realistic valve flow model was then developed with valve control currents as the system inputs. Exact model knowledge based plant inversion techniques were used to compute the required control current given the desired flow rate and chamber pressure. In order to avoid reverse flow in the valves and singularities in the flow function, the controller gains were adjusted to ensure that the chamber pressures were maintained above and below the exhaust and supply pressures, respectively, throughout the experiments. Furthermore, flow choking, i.e. valve saturation, imposed further limitation on the system’s bandwidth. The tracking performance of the IB controller, when compared to linear PD control, was found to provide superior tracking performance. Finally, it is hypothesized that the tracking speed for IB control can be increased, by varying the value of the computed (i.e. desired) control based on the desired direction of motion.
Multibody Dynamic Formulation Using Modified Velocity Transformation for Real-Time Simulation
Authors: Lee Kwang-Pyo , Choi Gyoo-Jae , Yoon Yong-San 
Published: March 2022

Abstract
It is known that the multibody dynamic formulations based on the velocity transformations are suited for the real-time dynamic simulation. However the conventional velocity transformations have many trivial calculations due to sparsity resulting in less efficient formulation. To avoid that inefficiency we are suggesting the modified velocity transformations that become more compact by bookkeeping which joint coordinates relate to which specific kinematical quantity. The modified velocity transformations and their related terms are calculated efficiently using the recursive algorithms. For the unconstrained open-chain multibody systems we improve the efficiency further by applying the Cholesky decomposition algorithm modified for the doubly bordered block diagonal matrices in solving the linear equations after making the mass matrices doubly bordered block diagonal with numbering the coordinates in proper order.
Robust Adaptive Compensation for a Class of Nonlinear Systems
Authors: Du Hongliu , Nair Satish S. 
Published: March 2022

Abstract
This paper proposes design details pertaining to a robust adaptive method for the compensation of uncertainties, for a class of nonlinear systems. The adaptive part of the control law uses a Gaussian network and robustness is provided by a sliding mode term. In the design, learning and control bounds are guaranteed by properly constructing the control architecture for which some methods are proposed. The robust adaptive control strategy, with the proposed design guidelines, has been validated using a hardware example case of a nonlinear electromechanical system. Experiments have shown that the inclusion of the proposed stable learning and robust terms into the control design, using the proposed constructive methods, results in improved system performance.