The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Steven M. Kurtz - One of the best experts on this subject based on the ideXlab platform.
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are ceramic Bearings becoming cost effective for all patients within a 90 day bundled payment period
Journal of Arthroplasty, 2019Co-Authors: Steven M. Kurtz, Edmund Lau, Doruk Baykal, Bryan D Springer, Susan M Odum, Thomas K FehringAbstract:BACKGROUND We analyzed whether the total hospital cost in a 90-day bundled payment period for ceramic-on-polyethylene (C-PE) and ceramic-on-ceramic (COC) total hip arthroplasty (THA) Bearings was changing over time, and whether the cost differential between ceramic Bearings and metal-on-polyethylene (M-PE) Bearings was approaching the previously published tipping point for cost-effectiveness of US$325. METHODS A total of 245,077 elderly Medicare patients (65+) who underwent primary THA between 2010 and 2015 were identified from the United States Medicare 100% national administrative hospital claims database. The total inpatient cost, calculated up to 90 days after index discharge, was computed using cost-to-charge ratios, and hospital payment was analyzed. The differential total inpatient cost of C-PE and COC Bearings, compared to metal-on-polyethylene (M-PE), was evaluated using parametric and nonparametric models. RESULTS After adjustment for patient and clinical factors, and the year of surgery, the mean hospital cost up to 90 days for primary THA with C-PE or COC was within ±1% of the cost for primary THA with M-PE Bearings (P < .001). From the nonparametric analysis, the median total hospital cost was US$296-US$353 more for C-PE and COC than M-PE. Cost differentials were found to decrease significantly over time (P < .001). CONCLUSION Patient and clinical factors had a far greater impact on the total cost of inpatient THA surgery than Bearing Selection, even when including readmission costs up to 90 days after discharge. Our findings indicate that the cost-effectiveness thresholds for ceramic Bearings relative to M-PE are changing over time and increasingly achievable for the Medicare population.
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ceramic on polyethylene Bearing usage in primary tha is associated with reduced readmission risk for the medicare population
Journal of wrist surgery, 2018Co-Authors: Steven M. Kurtz, Edmund Lau, Doruk Baykal, Bryan D SpringerAbstract:The authors hypothesized that unplanned readmissions, which are often caused by infections and dislocation, may be reduced with ceramic Bearing usage. They also sought to confirm that the readmission rates for ceramic Bearings were associated with the year of surgery. They identified 245,077 elderly patients (65+) who underwent primary total hip arthroplasty (THA) between 2010 and 2015 with known Bearing types (ceramic-on-polyethylene [C-PE] ceramic-on-ceramic [COC], and metal-on-polyethylene [M-PE]) from the Medicare 100% inpatient database. Outcomes included relative risk of 30- and 90-day readmission. Propensity scores were developed to adjust for Selection bias in the choice of Bearing type at index surgery. Cox regression incorporating propensity score stratification (10 levels) was used to evaluate the impact of Bearing Selection on outcomes, after adjusting for patient-, hospital-, surgeon-related factors, as well as the year of surgery. With C-PE Bearings, the unadjusted (crude) 90-day readmission rate decreased from 8.7% in 2010 to 8.3% in 2015. For COC Bearings, the crude 90-day readmission rate decreased from 10.5 to 9.1% from 2010 to 2015. After adjustment, year of surgery was associated with reduced readmission risk for both types of ceramic Bearings in 30-day readmissions (p
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The Latest Lessons Learned from Retrieval Analyses of Ultra-High Molecular Weight Polyethylene, Metal-on-Metal, and Alternative Bearing Total Disc Replacements
Seminars in spine surgery, 2012Co-Authors: Steven M. Kurtz, Jeffrey M. Toth, Ryan Siskey, Lauren Ciccarelli, Daniel W. Macdonald, Jorge Isaza, Todd H. Lanman, Ilona M. Punt, Marla Marla Steinbeck, Jan GoffinAbstract:Knowledge regarding the in vivo performance and periprosthetic tissue response of cervical and lumbar total disc replacements (TDRs) continues to expand. This review addresses the following 4 main questions: (1) What are the latest lessons learned from using polyethylene in large joints and how are they relevant to current TDRs? (2) What are the latest lessons learned regarding adverse local tissue reactions from metal-on-metal cobalt-chrome Bearings in large joints and how are they relevant to current TDRs? (3) What advancements have been made in understanding the in vivo performance of alternative biomaterials, such as stainless steel and polycarbonate urethane, for TDRs in the past 5 years? (4) How has retrieval analysis of all these various artificial disc Bearing technologies advanced the state-of-the-art in preclinical testing of TDRs? The study of explanted artificial discs and their associated tissues can help inform Bearing Selection as well as the design of future generations of disc arthroplasty. Analyzing retrieved artificial discs is also essential for validating preclinical test methods.
Jawren Lin - One of the best experts on this subject based on the ideXlab platform.
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Dynamic characteristics of exponential slider Bearings lubricated with a ferrofluid – Shliomis model
Industrial Lubrication and Tribology, 2018Co-Authors: Jawren Lin, Li-ming ChuAbstract:Purpose The purpose of this paper is to investigate the dynamic characteristics of exponential slider Bearings lubricated with a ferrofluid. Because of the development of modern engineering, the increasing use of ferrofluids in lubrication fields has shown great importance. Understanding the dynamic characteristics of exponential film Bearings is helpful for engineers in Bearing Selection. Design/methodology/approach Applying the Shliomis ferrohydrodynamic flow model and considering the squeezing action of Bearing pads, a dynamic Reynolds equation is obtained for an exponential film slider Bearing lubricated with a ferrofluid in the presence of a transverse magnetic field. Analytical solutions of dynamic characteristics are obtained. Findings According to the results, the ferrofluid-lubricated exponential film Bearing provides better dynamic stiffness and damping characteristics than the non-ferrofluid ones, especially the Bearing operating at higher values of the volume concentration parameter and the magnetic Langevin parameter. Originality/value Numerical tables of stiffness and damping coefficients for different values of the volume concentration parameter and the Langevin parameter are also included for engineering references.
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Lubrication Performance Analysis of Thrust Bearings with a Sine Film Profile
2017Co-Authors: Jawren LinAbstract:ABSTRACT Thrust Bearings are generally designed to support the axial thrust generated from a rotating shaft. In general, the performance analysis of thrust Bearings focuses on the Bearing with an inclined plane. In order to provide more messages in Bearing Selection and designing, further analyses on performance characteristics of Bearings with different film profiles is important. In the present study, the lubrication performances of thrust Bearings with a sine film profile are investigated. Comparing with the inclined plane Bearing, the lubrication performances of the sine film Bearing are discussed through the variation of the inlet-to-outlet ratio. In addition, the present results provide useful references for industrial engineering.
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Non‐Newtonian dynamic characteristics of wide composite slider Bearings lubricated with couple stress fluids
Industrial Lubrication and Tribology, 2013Co-Authors: Jawren Lin, Tsu‐liang ChouAbstract:Purpose – The purpose of this paper is to provide more information for fluid‐film Bearing Selection and designing. The present paper is mainly concerned with the dynamic characteristics of a wide composite slider Bearing lubricated with non‐Newtonian couple stress fluids.Design/methodology/approach – Taking into account the non‐Newtonian couple stress effects resulting from a Newtonian lubricant blended with additives, the non‐Newtonian dynamic coefficients are obtained for composite slider Bearings.Findings – Comparing with the non‐Newtonian inclined‐plane Bearing, the non‐Newtonian composite Bearing provides an improvement in the dynamic stiffness and damping coefficients; better Bearing characteristics are achieved for the non‐Newtonian composite Bearing under specific length‐ratio parameters.Originality/value – The paper includes a numerical example to provide guidance for non‐Newtonian composite slider Bearings.
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effects of magnetic fields on the dynamic characteristics of wide parallel step slider Bearings with electrically conducting fluids
Lubrication Science, 2012Co-Authors: Jawren Lin, Tzuchen Hung, Longjin LiangAbstract:By the use of electrically conducting fluids as lubricants together with the application of externally magnetic fields, the dynamic lubrication problems of parallel step slider Bearings lubricated with a nonconducting fluid are extended in this paper. A closed-form solution has been derived for the magneto-hydrodynamic characteristics of wide parallel step slider Bearings. Comparing with the Bearing lubricated with nonconducting fluids, the magneto-hydrodynamic parallel step slider Bearings signify an improvement in the load capacity, as well as the dynamic stiffness and damping coefficients. A numerical example and calculated values are also provided in tables for engineers in Bearing Selection and designing. Copyright © 2012 John Wiley & Sons, Ltd.
K I Ramachandran - One of the best experts on this subject based on the ideXlab platform.
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feature Selection using decision tree and classification through proximal support vector machine for fault diagnostics of roller Bearing
Mechanical Systems and Signal Processing, 2007Co-Authors: V Sugumaran, V Muralidharan, K I RamachandranAbstract:Abstract Roller Bearing is one of the most widely used rotary elements in a rotary machine. The roller Bearing's nature of vibration reveals its condition and the features that show the nature, are to be extracted through some indirect means. Statistical parameters like kurtosis, standard deviation, maximum value, etc. form a set of features, which are widely used in fault diagnostics. Often the problem is, finding out good features that discriminate the different fault conditions of the Bearing. Selection of good features is an important phase in pattern recognition and requires detailed domain knowledge. This paper illustrates the use of a Decision Tree that identifies the best features from a given set of samples for the purpose of classification. It uses Proximal Support Vector Machine (PSVM), which has the capability to efficiently classify the faults using statistical features. The vibration signal from a piezoelectric transducer is captured for the following conditions: good Bearing, Bearing with inner race fault, Bearing with outer race fault, and inner and outer race fault. The statistical features are extracted therefrom and classified successfully using PSVM and SVM. The results of PSVM and SVM are compared.
Zhang Jie - One of the best experts on this subject based on the ideXlab platform.
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Study on Rolling Bearing Selection System Based on Hybrid Algorithm
Machine Tool & Hydraulics, 2010Co-Authors: Zhang JieAbstract:A mixed calculation method combining rule process with fuzzy algorithm was presented,which solved the quantity problem of multiple factors and ensured the unique result of the Selection.Through MFC,Pro/Toolkit of Pro/E interface was called to generate three-dimensional drawing of Bearing automatically in VC++ platform.The drawing of Bearing could be used directly in the assembly design of product.The overall framework of the system and the functions of various modules were introduced.
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Development of Rolling Bearing Selection and Checking Systems Based on VBA
Journal of Sichuan University of Science & Engineering, 2009Co-Authors: Zhang JieAbstract:Rolling Bearing's design includes calculation of Selection and check.The method of traditional calculation needs frequent access to manuals,repeated calculation.This paper uses it's embedded VBA for secondary development in the AutoCAD environment.Design of the Selection and checking system is completed.And many affected factors of the Selection is talked fully into account about programmed algorithm and expression in system.At the same time,method is introduced about treatment of table data,the module's functions,etc.Though testing,it is stable operation and accurate calculation.improving the efficiency of the traditional system.
Mingzhi Feng - One of the best experts on this subject based on the ideXlab platform.
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Development and application of screw expander in natural gas pressure energy recovery at city gas station
Applied Thermal Engineering, 2018Co-Authors: Anna Diao, Yuli Wang, Yi Guo, Mingzhi FengAbstract:Abstract There is a tremendous energy loss in the process of natural gas delivery by pipes. The energy lost in the pressure reduction process can be first transformed into mechanical energy and then further converted into electricity by a generator. In this study, an oil free twin screw expander was designed and applied for the nature gas energy recovery at a city gas station for the first time. And the critical speed of the rotors, the seals and Bearings were discussed and presented in the design, which was proved that the system designed with the twin screw expander is much simpler without challenges of the sealing and Bearing Selection facing in the traditional turbine expander used in the CGS. Finally, the feasibility and simplicity of using the screw expander in natural gas energy recovery and power generation were proved through its stable running performance at site. The twin screw expander, therefore, could make up for the defects of the traditional turbine expander at a high rotation speed applied in the samilar area, and turned out to be an effective way to recover the pressure energy from the natural gas.