Assessment of Workspace Attributes Under Simulated Index Finger Proximal Interphalangeal Arthrodesis

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Paul G. Arauz ◽  
Sue A. Sisto ◽  
Imin Kao
Keyword(s):  
Index Finger ◽  
Model Parameters ◽  
System Parameters ◽  
System A ◽  
Flexion Extension ◽  
Pip Joint ◽  
Interphalangeal Arthrodesis ◽  
Analysis System ◽  
The Impact ◽  
Proximal Interphalangeal Arthrodesis

This article presented an assessment of quantitative measures of workspace (WS) attributes under simulated proximal interphalangeal (PIP) joint arthrodesis of the index finger. Seven healthy subjects were tested with the PIP joint unconstrained (UC) and constrained to selected angles using a motion analysis system. A model of the constrained finger was developed in order to address the impact of the inclusion of prescribed joint arthrodesis angles on WS attributes. Model parameters were obtained from system identification experiments involving flexion–extension (FE) movements of the UC and constrained finger. The data of experimental FE movements of the constrained finger were used to generate the two-dimensional (2D) WS boundaries and to validate the model. A weighted criterion was formulated to define an optimal constraint angle among several system parameters. Results indicated that a PIP joint immobilization angle of 40–50 deg of flexion maximized the 2D WS. The analysis of the aspect ratio of the 2D WS indicated that the WS was more evenly distributed as the imposed PIP joint constraint angle increased. With the imposed PIP joint constraint angles of 30 deg, 40 deg, 50 deg, and 60 deg of flexion, the normalized maximum distance of fingertip reach was reduced by approximately 3%, 4%, 7%, and 9%, respectively.

scholarly journals Modelling rheumatoid arthritis: A hybrid modelling framework to describe pannus formation in a small joint

2021 ◽  
Author(s):  
Fiona R Macfarlane ◽  
Mark AJ Chaplain ◽  
Raluca Eftimie
Keyword(s):  
Rheumatoid Arthritis ◽  
Numerical Simulations ◽  
Model Parameters ◽  
Inflammatory Disorder ◽  
Pannus Formation ◽  
Chronic Inflammatory Disorder ◽  
Modelling Framework ◽  
Small Joint ◽  
Pip Joint ◽  
The Impact

AbstractRheumatoid arthritis (RA) is a chronic inflammatory disorder that causes pain, swelling and stiffness in the joints, and negatively impacts the life of affected patients. The disease does not have a cure yet, as there are still many aspects of this complex disorder that are not fully understood. While mathematical models can shed light on some of these aspects, to date there are not many such models that can be used to better understand the disease. As a first step in the mechanistic understanding of RA, in this study we introduce a new hybrid mathematical modelling framework that describes pannus formation in a small proximal interphalangeal (PIP) joint. We perform numerical simulations with this new model, to investigate the impact of different levels of immune cells (macrophages and fibroblasts) on the degradation of bone and cartilage. Since many model parameters are unknown and cannot be estimated due to a lack of experiments, we also perform a sensitivity analysis of model outputs to various model parameters (single parameters or combinations of parameters). Finally, we connect our numerical results with current treatments for RA, by discussing our numerical simulations in the context of various drug therapies using, for example, methotrexate, TNF-inhibitors or tocilizumab, which can impact different model parameters.

Biomechanics and Pinch Force of the Index Finger Under Simulated Proximal Interphalangeal Arthrodesis

2017 ◽  
Vol 42 (8) ◽  
pp. 658.e1-658.e7 ◽  
Author(s):  
Paul Arauz ◽  
Karen DeChello ◽  
Alexander Dagum ◽  
Sue Ann Sisto ◽  
Imin Kao
Keyword(s):  
Index Finger ◽  
Pinch Force ◽  
Interphalangeal Arthrodesis ◽  
Proximal Interphalangeal Arthrodesis

Perturbation Analysis and Parametric Study of Planetary Gear Vibration

2012 ◽  
Author(s):  
Cheon-Jae Bahk ◽  
Robert G. Parker
Keyword(s):  
Dynamic Response ◽  
Perturbation Analysis ◽  
Parametric Instability ◽  
Planetary Gear ◽  
Vibration Modes ◽  
Contact Ratio ◽  
System Parameters ◽  
Analysis System ◽  
The Impact ◽  
Perturbation Solutions

This study analytically investigates the impact of system parameters on planetary gear vibration by using perturbation solutions. Closed-form expressions, which explicitly includes the system parameters such as contact ratio, mesh stiffness, damping, and number of planets, of the peak resonant response amplitude and parametric instability width of subharmonic resonance are obtained from perturbation analysis. System parameters related with sun-planet and ring-planet meshes show different influence on dynamic response. The effects of the system parameters are found to be sensitive to vibration modes. With use of the well-defined planetary gear modal properties, mathematical expressions of the weighting factors are derived to quantify the different sensitivity of dynamic response to the sun-planet and ring-planet meshes and to the vibration modes. The perturbation solutions are effective to examine the dependence of dynamic response on the system parameters and help one seek optimal parameters to reduce planetary gear vibration.

Kinematic Perturbation in the Flexion-Extension Axis for Two Lumbar Rigs During a High Impact Jump Task

2011 ◽  
Vol 27 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Marc R. Portus ◽  
David G. Lloyd ◽  
Bruce C. Elliott ◽  
Neil L. Trama
Keyword(s):  
High Impact ◽  
Fast Fourier Transformation ◽  
Signal Power ◽  
Motion Data ◽  
Flexion Extension ◽  
Spine Motion ◽  
Analysis System ◽  
Impact Phase ◽  
Base Of Support ◽  
The Impact

The measurement of lumbar spine motion is an important step for injury prevention research during complex and high impact activities, such as cricket fast bowling or javelin throwing. This study examined the performance of two designs of a lumbar rig, previously used in gait research, during a controlled high impact bench jump task. An 8-camera retro-reflective motion analysis system was used to track the lumbar rig. Eleven athletes completed the task wearing the two different lumbar rig designs. Flexion extension data were analyzed using a fast Fourier transformation to assess the signal power of these data during the impact phase of the jump. The lumbar rig featuring an increased and pliable base of support recorded moderately less signal power through the 0–60 Hz spectrum, with statistically less magnitudes at the 0–5 Hz (p= .039), 5–10 Hz (p= .005) and 10–20 Hz (p= .006) frequency bins. A lumbar rig of this design would seem likely to provide less noisy lumbar motion data during high impact tasks.

Modelling and Parameter Identification for a Flexible Rotor With Periodic Impacts

2021 ◽  
Author(s):  
Stefan Holzinger ◽  
Manuel Schieferle ◽  
Johannes Gerstmayr ◽  
Manfred Hofer ◽  
Christoph Gutmann
Keyword(s):  
Measurement Data ◽  
Rotor System ◽  
Real System ◽  
Model Parameters ◽  
Genetic Optimization ◽  
Flexible Rotor ◽  
Unknown Parameters ◽  
System Parameters ◽  
Unknown System ◽  
The Impact

Abstract The ability of a multibody dynamics model to accurately predict the behavior of a real system depends heavily on the correct choice of model parameters. The identification of unknown system parameters, which cannot be directly computed or measured is usually time consuming and costly. If experimental measurement data of the real system is available, the parameters in the mathematical model can be determined by minimizing the error between the model response and the measurement data. The latter task can be solved by means of optimization. While many optimization methods are available, optimization with a genetic algorithm is a promising approach for searching optimal solutions for complex engineering problems, as reported in a paper of one of the authors. So far, however, there is no general approach how to apply genetic optimization algorithms for complex multibody system dynamics models in order to obtain unknown parameters automatically — which is however of great importance when dealing with real flexible multibody systems. In the present paper we present a methodology to determine several unknown system parameters applied to a flexible rotor system which is excited with periodic impacts. Experiments were performed on the physical system to obtain measurement data which is used to identify the impact force as well as the support stiffnesses of the rotor system using genetic optimization.

Proximal Interphalangeal Arthrodesis of Lesser Toes Utilizing K-Wires Versus Expanding Implants: Comparative Biomechanical Cadaveric Study

2018 ◽  
Vol 40 (2) ◽  
pp. 231-236 ◽  
Author(s):  
Shane D. Rothermel ◽  
Umur Aydogan ◽  
Evan P. Roush ◽  
Gregory S. Lewis
Keyword(s):  
Cortical Bone ◽  
Cadaver Study ◽  
Initial Stiffness ◽  
Fixation Devices ◽  
Fusion Site ◽  
Load To Failure ◽  
Pip Joint ◽  
Interphalangeal Arthrodesis ◽  
K Wires ◽  
Proximal Interphalangeal Arthrodesis

Background: Lesser toe proximal interphalangeal (PIP) joint arthrodesis is one of the most common foot and ankle elective procedures often using K-wires for fixation. K-wire associated complications led to development of intramedullary fixation devices. We hypothesized that X Fuse (Stryker) and Smart Toe (Stryker) would provide stronger and stiffer fixation than K-wire fixation. Methods: 12 cadaveric second toe pairs were used. In one group, K-wires stabilized 6 PIP joints, and 6 contralateral PIP joints were fixed with X Fuse. A second group used K-wires to stabilize 6 PIP joints, and 6 contralateral PIP joints were fixed with Smart Toe. Specimens were loaded cyclically with extension bending using 2-N step increases (10 cycles per step). Load to failure and initial stiffness were assessed. Statistical analysis used paired t tests. Results: K-wire average failure force, 91.0 N (SD 28.3), was significantly greater than X Fuse, 63.3 N (SD 12.9) ( P < .01). K-wire average failure force, 102.3 N (SD 17.7), was also significantly greater than Smart Toe, 53.3 N (SD 18.7) ( P < .01). K-wire initial stiffness 21.3 N/mm (SD 5.7) was greater than Smart Toe 14.4 N/mm (SD 9.3) ( P = .02). K-wire failure resulted from bending of K-wire or breaching cortical bone. X Fuse typically failed by implant pullout. Smart Toe failure resulted from breaching cortical bone. Conclusion: K-wires may provide stiffer and stronger constructs in extension bending than the X Fuse or Smart Toe system. This cadaver study assessed stability of the fusion site at time zero after surgery. Clinical Relevance: Our findings provide new data supporting biomechanical stability of K-wires for lesser toe PIP arthrodesis, at least in this clinically relevant mode of cyclic loading.

scholarly journals Impact Evaluation of Assimilating Surface Sensitive Infrared Radiance Observations over Land and Sea Ice from Observing System Simulation Experiments

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
S. K. Dutta ◽  
L. Garand ◽  
S. Heilliette
Keyword(s):  
Sea Ice ◽  
System Simulation ◽  
Polar Regions ◽  
Simulation Experiments ◽  
Weather Forecasts ◽  
Infrared Radiance ◽  
System A ◽  
Analysis System ◽  
The Tropics ◽  
The Impact

In this study, Observing System Simulation Experiments (OSSEs) are conducted to analyze the impact of assimilating surface sensitive infrared radiance observations over land and sea ice. This type of assimilation has not yet been successfully implemented at operational weather centers. Infrared radiance from AIRS (Atmospheric Infrared Sounder) and IASI (Infrared Atmospheric Sounding Interferometer) is simulated from the Nature Run (NR) provided by European Centre for Medium-Range Weather Forecasts and assimilated in a 3D-Var. analysis system. A control simulation was generated excluding the new data source, but including all data assimilated operationally at the Canadian Meteorological Center. Experiments were conducted allowing surface sensitive channels to be assimilated over all surfaces or excluding Polar Regions. Resulting forecasts were intercompared and validated against NR fields. Results indicate significant positive impacts in the tropics and Southern Hemisphere extratropics and more modest impacts in the Northern Hemisphere extratropics. Some limitations of the OSSE approach are identified, linked to the different forecast systems used for the NR and the assimilation and higher cloud contamination in Polar Regions. This analysis provides useful insight in preparation for the assimilation of real radiance observations.

Technology and Hospital Information System: A Case of Implementation of Electronic Clinical Records in Hospital Maternity Irene Neto in Lubango, Angola

2019 ◽  
Vol 10 (11) ◽  
pp. 1131-1135
Author(s):  
Tomas Hambili Paulo Sanjuluca ◽  
◽  
Ricardo Correia ◽  
Anabela Antunes de Almeida ◽  
Ana Gloria Diaz Martinez ◽  
...  
Keyword(s):  
Maternity Hospital ◽  
Management Support ◽  
Retrospective Case ◽  
System A ◽  
Clinical Records ◽  
Retrospective Case Study ◽  
The Impact ◽  
And Child Health

Introduction: In order to have a good assessment of the quality of maternal and child health care, it is essential that there is up-to-date and reliable information. Objective: To evaluate the impact of the implementation of a computerized database of clinical processes in the admission, archive and medical statistics section, of Maternity hospital Irene Neto/Lubango-Angola. Methodology: A descriptive study with a quantitative and qualitative approach to carry out a retrospective case study deliveries and newborns, records from 2014 to 2017. Final considerations: The implementation of this project may contribute to the improvement of clinical management support management of the hospital as well as facilitating access to information for research and scientific production.

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