bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selectively Compliant Annuloplasty Ring to Enable Annular Dynamics in Mitral Valve Repair Evaluated by In-Vitro Stereovision
Authors: Frishman Samuel , Kight Ali , Pirozzi Ileana , Imbrie-Moore Annabel M. , Paulsen Michael J. , Woo Joseph Y. , Cutkosky Mark R. 
Published: August 2020

Abstract
Mitral valve (MV) annular dynamics are critical to the long term efficacy of MV repair. Today’s annuloplasty rings, used to restore MV function, impose significant constraints on the motion profile of the MV annulus. We present a selectively compliant ring that provides sufficient stiffness to stabilize a diseased annulus while allowing physiological annular dynamics. Ring design is informed by a finite element analysis and experimentally evaluated with in-vitro stereophotogrammetry. We compare the ring dynamics to commercially available semi-rigid rings as well as values found in literature for healthy annuli. The results demonstrate that motion of the selectively compliant ring is significantly closer to that of a healthy annulus based on standard metrics that define MV annular movement. Specifically, the metrics for the new ring compare to those in literature as follows: change in orifice area 12.5 ± 3% vs.10 ± 2%; change in anterior-posterior diam. 5.4 ± 0.3% vs. 7 ± 1%; change in inter-commissural diam. 6.6 ± 1.3% vs. 5 ± 1%.
Visualizing Telemetry Metrics From Upper-Airway Stimulation to Enhance Sleep Therapy Management
Authors: Araujo Matheus , Lee Kent , Ni Quan , Srivastava Jaideep 
Published: August 2020

Abstract
Upper-Airway Stimulation (UAS) therapy is an innovative alternative to Continuous Positive Airway Pressure (CPAP) treatment for patients with obstructive sleep apnea (OSA) and CPAP intolerance. Patients who have implanted a UAS device are responsible for activating and managing the therapy at home before sleep. Consistent nightly use is required for a reduced OSA burden, measured by the apnea-hypopnea index. Thus, understanding patient behavior and possible challenges to nightly use are crucial to therapy success. In this work, we present two novel visualizations to monitor telemetry data recorded by the UAS sleep remote. They provide doctors and sleep clinicians with detailed information to easily classify therapy use and sleep patterns. We also present how to show daily metrics such as hours of average usage, therapy intensity, and duration of therapy pauses, to identify optimal therapy settings and measure the long-term effectiveness of interventions.
A Hydraulic Bimodal Ankle to Improve Mobility and Stability for Prosthesis Users
Authors: Koehler-McNicholas Sara , Voss Gregory , Ficanha Evandro , Looft John , Walker Nicole , Colvin James , Hansen Andrew , Wernke Matthew 
Published: August 2020

Abstract
A bimodal prosthetic ankle-foot system has been developed to support the demands of both walking mobility and standing balance. Using a novel hydraulic locking mechanism, this system provides a curved effective rocker shape for walking and a flat effective rocker shape for standing and swaying on non-level surfaces. To date, the hydraulic cylinder sub-assembly has been cycle tested to 1.2 million cycles. Future testing with lower-limb prosthesis users is planned, which will reveal the extent to which this new hydraulic ankle-foot design improves standing balance on both level and non-level surfaces. The capacity for an automatic switching algorithm, designed to appropriately detect and switch between modes as users transition between walking and standing tasks, will also be evaluated.
Development of a Portable Blood Potassium Monitoring Device for Dialysis Patients
Authors: Vora Parth , Inserni Miguel , Lai Alan , Lapinski Maya M. , Wang Justin , Kim Min Jae , Lee Diane , Yu Rebecca , Manbachi Amir , Atta Mohamed G. 
Published: August 2020

Abstract
Approximately 500,000 dialysis patients in America are at a high risk of hyperkalemia, a condition where blood potassium becomes elevated above normal levels. Hyperkalemia is extremely dangerous, as it can result in severe cardiac complications if untreated. Hyperkalemia may be silent or present vague symptoms until those complications develop, at which point patients require emergency medical care. However, if patients have the ability to measure their potassium levels at home, they could detect hyperkalemia before it reaches a dangerous stage, and seek preventative medical care to avoid severe complications.
Therefore, we have designed a novel device allowing patients to measure their blood potassium levels at home. The workflow of our solution is as follows: (1) patients obtain a blood sample from a finger prick, (2) potassium concentration is measured with an ion specific electrode (ISE), and (3) the device displays their potassium levels and a recommended course of action based on their hyperkalemic risk.
We validate our solution with three major tests. First, our portable ISE technology must accurately measure potassium concentration in blood samples. Second, appropriate lancet parameters (gauge and depth) to minimize hemolysis in capillary blood samples must be found to minimize falsely elevated readings. Third, device portability and ease of use must be evaluated using patient input, as these factors will affect patient compliance. We have validated the use of portable ISE technology to feasibly measure potassium, and we continue to collect data for our second and third tests.
Deep Learning Algorithm for Image Classification of Waveforms Obtained From Electrically Stimulated Hypoxic Skeletal Muscle Bundles
Authors: Upchurch Weston , Deakyne Alex , Ramirez David A. , Iaizzo Paul A. 
Published: August 2020

Abstract
Acute compartment syndrome is a serious condition that requires urgent surgical treatment. While the current emergency treatment is straightforward — relieve intra-compartmental pressure via fasciotomy — the diagnosis is often a difficult one. A deep neural network is presented here that has been trained to detect whether isolated muscle bundles were exposed to hypoxic conditions and became ischemic.
A Flow Cytometry Method for Characterizing Platelet Activation
Authors: Alzua Brian , Smith Mark , Chen Yan 
Published: August 2020

Abstract
Hemocompatibility testing is critical for assessing the safety of blood-contacting medical devices. Comprehensive hemocompatibility testing requires examining a wide range of possible adverse effects cause by direct or indirect blood contact, such as hemolysis, complement activation, and thrombus formation [1]. Moreover, these domains each encompass complex intercellular processes with many potential targets for analysis. For example, the current testing paradigm of platelet function may involve exposing the device to human whole blood and performing simple blood counts and/or macroscopic evaluation to determine the extent of platelet activation and clot formation as described in ASTM F2888-19. However, this approach does not capture any observations for device-mediated initiation of any steps in the platelet activation pathway prior to aggregation. We have validated a method to evaluate platelet activation by quantifying surface p-selectin expression after exposure to various materials. This method will provide an additional level of detail about potential platelet activating properties of a medical device.
Flow cytometry has been used previously to measure platelet activation for clinical and research purposes. We sought to adapt this method to test for platelet activation induced by exposure of blood to medical devices or materials. We determined that processing fresh whole blood to platelet-rich plasma (PRP) by gentle centrifugation enhanced the signal compared to fresh blood itself. In each experiment, devices were exposed to PRP according to an extraction ratio of 6 cm2/mL for 1 hour. A blank control consisting of untreated PRP, and a positive control consisting of ADP, a potent agonist, were also used. After the exposure, excess plasma was removed from the articles and combined with anti-CD61 (to stain for platelets) and anti-CD62P (to stain for activated platelets) antibodies. Flow cytometry was then performed to quantify the percentage of CD62P+ over the total CD61+ cells to measure the percentage of activated platelets. In order to optimize the method, we investigated the effect of several experimental factors, including anticoagulant usage, donor variability, and selection of reference materials to serve as controls. Our results indicate that the flow cytometry-based method is consistent and reproducible, quick and easy to perform, and is well-correlated with results from the standard platelet and leukocyte count assay. The flow cytometry-based platelet activation method is a powerful supplement to the standard regimen of medical device hemocompatibility testing.
Thrombogenicity Testing Results for Control Legally Marketed Comparator Devices (LMCD): Comparison Between Traditional Non-Anticoagulated Venous Implant (NAVI) Assay and an In Vitro Ovine Blood Loop Test
Authors: Smith Mark E. , Chen Yan 
Published: August 2020

Abstract
Legally marketed comparator devices (LMCD) are required by many regulatory bodies in as a control for thrombogenicity testing when evaluating new devices. It is assumed by both the medical device manufacturing industry and regulatory bodies that these LMCD’s have good clinical history and should perform with no to minimal thrombus accumulation and thereby serve as valid negative controls for the assay. APS regularly performs these assays for many medical device manufacturers, all of whom select a predicate comparator device (required by FDA to be an LMCD), for both the in vivo Non-Anticoagulated Venous Implant (NAVI) assay as well as a custom in vitro blood loop AVI. In this retrospective analysis, we have compiled thrombogenicity scores of control/predicate devices (limited to assays which used LMCD’s), both the discrete score from the classification standard scoring scheme and the continuous values obtained from the percent surface area associated with thrombus. We have compared results from 37 NAVI studies and 22 in vitro blood loop studies. These compiled results show ∼25% of LMCDs score ≥ 3 (&gt; 50% of the surface covered in thrombus) in the NAVI model while &lt; 5% of LMCDs score ≥ 3 (&gt; 50% thrombus) in the Blood-Loop assay. In addition, the median score and mean % thrombus for LMCD in the blood loop assay is substantially lower than the median and mean scores for LMCD in the NAVI assay. This retrospective assessment highlights a high proportion of false-positive scores for LMCD in a large number of NAVI assays.
Design of a Wearable Health Monitoring System for In-Home and Emergency Use
Authors: Bertsch J. Michael , Gent Stephen P. 
Published: August 2020

Abstract
Recent advancements in wearable medical technologies have streamlined health monitoring with simple, non-invasive measurements. These devices, however, are rarely capable of monitoring all the necessary parameters for an accurate measure of health, such as blood pressure, and can cost the user hundreds to thousands of dollars. The objective of this project was to design an affordable, user-friendly, wearable device capable of monitoring multiple parameters: body temperature, blood pressure, heart rate, blood oxygen, and body positioning. By combining wearable sensors with Inter-Integrated Circuit (I2C) technology, the data from many sensors can be transmitted while maintaining a compact size for a wearable. In parallel with this device, a mobile application was designed as an interface to receive real-time comprehensive measurements. This device could be used to reduce monitor application time in emergency medical settings and monitor patients in rural communities who are often hours away from the nearest medical centers.
Surface Profile and Third-Body Layer Accumulation Measurement Using a 3D Laser Profiler
Authors: Radmehr Ahmad , Hosseinian Ahangarnejad Arash , Tajaddini Ali , Ahmadian Mehdi 
Published: August 2020

Abstract
The surface profile wear and the resulting third-body layer accumulation are investigated on the Virginia Tech-Federal Railroad Administration Roller Rig (VT-FRA Roller Rig), using a high-precision 3D laser profiler by Keyence. It is observed that the wheel surface gradually wears and the fine worn material accumulates on the running surfaces. It is further observed that with the progression of the wear and accumulation of a powder-like material at running surface, a preocular change in wheel-rail traction occurs. The first step in exploring the physics of the changes in traction is quantifying, precisely, the micron-sized surface finish changes and wear material accumulation. This paper provides the process of choosing a suitable surface profiler for the VT-FRA roller rig adaptation, and the results of a series of tests under various wheel load and contact configurations.
A baseline experiment is conducted to evaluate the wheel wear and the accumulation of the naturally-generated third body layer (the worn material) on the wheel’s running surface. Before each series of experiments, the wheel and roller running surfaces were polished and thoroughly cleaned to make sure that they are perfectly smooth (finished) and free of any debris or dust. The wheel surface profile is measured in the perfectly cleaned condition using the 3D laser scanner. Time controlled experiments are run with different wheel loads, % slippage, and angle of attack (AoA) for 500 seconds. For each run, the change with surface finish and accumulated third body layer build up is measured.
It is consistently observed that the traction forces increase gradually with time until they reach a stable level, presented by a plateau in the traction-slippage curves. The time to reach the plateau is directly related to wheel’s dynamic conditions including load, %slippage, and AOA. For some of the conditions, such as wheel load, the relationship is linear and for others (such as AOA) it is nonlinear. Concentrating on the analysis of the baseline results, it is observed that the change in surface finish and the third body layer that naturally accumulates at the running surface — hence, referred to as “natural third body layer” or “NTBL” — is directly correlated and somewhat linearly with NTBL and change in the running surface from smooth to rough. The correlation is most noticeable for the NTBL. With increasing NTBL, traction increases rapidly until the running surface is saturated with the accumulated wear material, presumably a ferrous oxide. There is far weaker correlation between the change in surface finish and traction variations. It is noticed that the surface finish continues to change beyond the time that the traction forces reach their plateau, and its effect remains far more gradual than NTBL.
Smart Bridge: Autonomous Structural Integrity Monitor for Railroad Bridges
Authors: Smith Frank J. 
Published: August 2020

Abstract
This paper provides an introduction to Smart Bridge; a railroad bridge structural integrity monitoring system based on Continuous Fiber Optic Strain Sensing (CFOSS) technology. This design concept allows for the real time observation of how a bridge responds to dynamic loading and provides for autonomous reporting of abnormal structural conditions.
The CFOSS technology can monitor the entire bridge and observe changes in the behavure of its structural elements. The structure is constantly monitored, both when the structure is at static load and when the bridge is supporting the load of a train. When significant changes are observed they can be defined by location and the degree of deviation from normal.
A Smart Bridge provides automatic notification of sudden changes to the structure in real time. These changes may be an indication of bridge impact damage. It also provides a graphical map of the changes in structural behavure over time. In both circumstances the technology will identify the specific structural element that is degrading.
Smart Bridge is based on Continuous Fiber Optic Strain Sensing technology. This technology manifests in the form of a cable that is bonded along the entire length of the structural elements of the bridge. The cable senses strain in both the axial and transverse directions. Unlike conventional strain gauge elements that are bonded to a single location, CFOSS cables run continuously along the beam, plate or tendon. The technology is able to observe the changes in the concentration of strain along a structure and identify the origin of the change.
CFOSS technology is currently under development as part of the Smart Rail project. The underlying fiber optic strain sensing cable technology is in commercial use in the oil well and petrochemical pipeline industry.
The adoption of Smart Bridge provides enhanced operational safety because it monitors the structural integrity of the bridge continuously and provides automatic status annunciations. This monitoring is active during times when the bridge is in dead load and when it is supporting the load of a passing train. Smart Bridge also improves the working safety of bridge inspectors by providing a map of structural changes that may indicate hazardous conditions. The use of Smart Bridge improves the inspection process by identifying potential structural problems that may require visual confirmation. And it provides autonomous warnings when sudden changes in the bridge structural integrity are detected.
A Literature Review on Rail Transport of Hazmat Release Risk Analysis
Authors: Bian Zheyong , Liu Xiang 
Published: August 2020

Abstract
Rail plays an important role in hazmat transportation, transporting over two million carloads of hazardous materials (hazmat) in the United States annually. Compared with a truck trailer carrying a single hazmat car, a train has much more severe consequence of hazmat release due to carrying multiple connected hazmat cars (e.g., 50 to 120 flammable liquid cars). It is of high priority for the government and railroad companies to enhance the railroad hazmat transportation safety since the train accidents can cause severe railroad hazmat release incidents. Based on the data provided by Federal Railroad Administration (FRA) of the U.S. Department of Transportation (U.S.DOT), there are over 300 accident causes, including infrastructure failure defects, rolling stock failures, human errors, weather conditions, etc. It is significant to understand the relationship between hazmat transportation risk and accident cause to provide guidance for developing, evaluating, and prioritizing accident prevention strategies, thereby mitigating hazmat transportation risk. Therefore, this paper reviews the literature on rail transport of hazmat release risk analysis in order to capture the event chain leading to hazmat release, possible risk factors, and the state of the art on existing risk analysis methodologies.
We reviewed the related references based on a five-step process: (1) train accident occurrence, (2) number of cars derailed, (3) number of hazardous material cars derailed, (4) number of hazmat cars releasing, and (5) release consequences. First, many severe hazmat release incidents are caused by train accidents, particularly train derailments. Prior research found that over 70% of freight train mainline derailments were caused by either infrastructure defects or rolling stock failures. Possible strategies for reducing the probability of train accidents include the prevention of track defects, equipment condition monitoring to reduce in-service failures, and the use of more advanced train control technologies to reduce human error. Second, number of cars derailed is an important factor causing hazmat releasing. Based on the reviewed literature, the total number of cars derailed depends on accident cause, speed, train length, and point of derailment. Third, the literature implied that the total number of hazmat cars derailed is related to train length, number of hazmat cars and non-hazmat cars in a train, and their placement. Fourth, the number of hazmat cars releasing contents is influenced by hazardous materials car safety design, accident speed, etc. Finally, the consequences of a release can be measured by different metrics, such as property damage, environmental impact, traffic delay, or the affected population. Geographical information systems (GIS) can be used for consequence analysis integrated with other databases such as census and rail network data.
CFD Verification and Validation Exercise: Turbulent Mixing of Stratified Layer
Authors: Thompson Jason , Boyd Christopher 
Published: August 2020

Abstract
The US Nuclear Regulatory Commission (NRC) participated in an Organization for Economic Cooperation and Development / Nuclear Energy Agency (OECD/NEA) benchmark activity based on testing in the PANDA facility located at the Paul Scherrer Institute in Switzerland. In this test, a stratified helium layer was eroded by a turbulent jet from below. NRC participated in this benchmark to develop expertise and modeling guidelines for computational fluid dynamics (CFD) in anticipation of utilizing these methods for future safety and confirmatory analyses. CFD predictions using ANSYS FLUENT V19.0 are benchmarked using the PANDA test data, and sensitivity studies are used to evaluate the significance of key phenomena, such as boundary conditions and modeling options, that impact the helium erosion rates and jet velocity distribution. The k-epsilon realizable approach with second order differencing resulted in the best prediction of the test data. The most significant phenomena are found to be the inlet mass flowrate and turbulent Schmidt number. CFD uncertainty for helium and velocity due to numerical error and input parameter uncertainty are predicted using a sensitivity coefficient approach. Numerical uncertainty resulting from the mesh design is estimated using a Grid Convergence Index (GCI) approach. Meshes of 0.5, 1.5 (base mesh), and 4.5 million cells are used for the GCI. Approximately second order grid convergence was observed but p (order of convergence) values from 1 to 5 were common. The final helium predictions with one-sigma uncertainty interval generally bounded the experimental data. The predicted jet centerline velocity was approximately 50% of the measured value at multiple measurement locations. This velocity benchmark is likely affected by the difference in the He content between the experiment and prediction. The predicted jet centerline velocity with the one-sigma uncertainty interval did not bound the experimental data.
On the Role of Discretization Errors in the Quantification of Parameter Uncertainties
Authors: Eça Luís , Pereira Filipe S. , Vaz Guilherme , Lopes Rui , Toxopeus Serge 
Published: August 2020

Abstract
The independence of numerical and parameter uncertainties is investigated for the flow around the KVLCC2 tanker at Re = 4.6 × 106 using the time-averaged RANS equations supplemented by the k–ω two-equation SST model. The uncertain input parameter is the inlet velocity that varies ±0.25% and ±0.50% for the determination of sensitivity coefficients using finite-difference approximations. The quantities of interest are the friction and pressure coefficients of the ship and the Cartesian velocity components and turbulence kinetic energy at the propeller plane.
A grid refinement study is performed for the nominal conditions to allow the estimation of the discretization error with power series expansions. However, for grids between 6 × 106 and 47.6 × 106 cells, not all the selected quantities of interest exhibit monotonic convergence. Therefore, the estimates of the sensitivity coefficients of the selected quantities of interest using the local sensitivity method and finite-differences performed for refinement levels that correspond to 0.764 × 106, 6 × 106 and 47.6 × 106 cells lead to significantly different values. Nonetheless, for a given grid, negligible differences are obtained for the sensitivity coefficients obtained with two different intervals in the finite-differences approximation.
Discrepancies between sensitivity coefficients are compared with the estimated numerical uncertainties. Results obtained in the study suggest that uncertainty quantification performed in coarse grids may be significantly affected by discretization errors.