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Adam A Dalia - One of the best experts on this subject based on the ideXlab platform.
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continuous noninvasive arterial Pressure monitoring for transcatheter aortic valve replacement
Journal of Cardiothoracic and Vascular Anesthesia, 2021Co-Authors: Adam A DaliaAbstract:OBJECTIVES The objective of the present study, which was conducted in patients undergoing transcatheter aortic valve replacement, was to compare continuous noninvasive arterial Pressure measured with the ClearSight device (Edwards Lifesciences, Irvine, CA) with invasive radial artery Pressure used as the reference method. The authors hypothesized that the ClearSight device is an accurate, precise, safe, and efficient method for arterial blood Pressure measurement comparable with an invasive radial arterial Line. DESIGN The study included the retrospective review of 20 consecutive patients scheduled for elective transcatheter aortic valve replacement with the SAPIEN 3 transcatheter heart valve (Edwards Lifesciences) at a single tertiary academic hospital, who underwent monitoring with both the ClearSight device and an invasive radial arterial Pressure Line. The patients underwent transcatheter aortic valve replacement from October to December 2019. SETTING Single tertiary academic medical center. PARTICIPANTS The study comprised 20 patients, with 2,243 unique blood Pressure data points. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS A statistically significant correlation between the invasive radial arterial Pressure Line and the ClearSight device was observed for systolic blood Pressure (correlation coefficient 0.86; p < 0.001), diastolic blood Pressure (correlation coefficient 0.56; p < 0.001), and mean arterial Pressure (correlation coefficient 0.78; p < 0.001). Bland-Altman analysis was used to assess the agreement of systolic blood Pressure, diastolic blood Pressure, and mean arterial Pressure between the two methods. Results for systolic blood Pressure between the arterial Line and ClearSight device were as follows: bias = 9.8 ± 10.1, percentage bias = 7.6%, and mean error = 15.8%. Results for diastolic blood Pressure between the arterial Line and ClearSight device were as follows: bias = -5.9 ± 7.8, percentage bias = 10.7%, and mean error = 28.4%. Results for mean arterial Pressure between the arterial Line and ClearSight device were as follows: bias = 0.3 ± 7.4, percentage bias = 0.4%, and mean error = 18.3%. The concordance rates of systolic blood Pressure, diastolic blood Pressure, and mean arterial Pressure were 100%, 95.1%, and 98.8%, respectively. CONCLUSIONS The accuracy, agreement, and precision of the ClearSight device were convincing for mean arterial Pressure, systolic blood Pressure, and diastolic blood Pressure for patients with severe aortic stenosis undergoing elective transcatheter aortic valve replacement.
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continuous noninvasive arterial Pressure monitoring for transcatheter aortic valve replacement
Journal of Cardiothoracic and Vascular Anesthesia, 2021Co-Authors: Adam A DaliaAbstract:Objectives The objective of the present study, which was conducted in patients undergoing transcatheter aortic valve replacement, was to compare continuous noninvasive arterial Pressure measured with the ClearSight device (Edwards Lifesciences, Irvine, CA) with invasive radial artery Pressure used as the reference method. The authors hypothesized that the ClearSight device is an accurate, precise, safe, and efficient method for arterial blood Pressure measurement comparable with an invasive radial arterial Line. Design The study included the retrospective review of 20 consecutive patients scheduled for elective transcatheter aortic valve replacement with the SAPIEN 3 transcatheter heart valve (Edwards Lifesciences) at a single tertiary academic hospital, who underwent monitoring with both the ClearSight device and an invasive radial arterial Pressure Line. The patients underwent transcatheter aortic valve replacement from October to December 2019. Setting Single tertiary academic medical center. Participants The study comprised 20 patients, with 2,243 unique blood Pressure data points. Interventions None. Measurements and Main Results A statistically significant correlation between the invasive radial arterial Pressure Line and the ClearSight device was observed for systolic blood Pressure (correlation coefficient 0.86; p Conclusions The accuracy, agreement, and precision of the ClearSight device were convincing for mean arterial Pressure, systolic blood Pressure, and diastolic blood Pressure for patients with severe aortic stenosis undergoing elective transcatheter aortic valve replacement.
J T Hodges - One of the best experts on this subject based on the ideXlab platform.
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frequency stabilized cavity ring down spectroscopy measurements of Line mixing and collision induced absorption in the o2 a band
Journal of Chemical Physics, 2012Co-Authors: David A Long, D J Robichaud, J T HodgesAbstract:Frequency-stabilized cavity ring-down spectroscopy measurements were performed in the P-branch of the O2 A-band [b1Σg+ ← X 3Σg−(0,0)] near atmospheric Pressure. Line mixing parameters and collision-induced absorption were quantified and reported. These measurements show qualitative differences with those taken at relatively high Pressure (2 MPa–20 MPa). We also assess the implications of these measurements on atmospheric retrievals.
M Crialesiesposito - One of the best experts on this subject based on the ideXlab platform.
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fuel temperature influence on the performance of a last generation common rail diesel ballistic injector part i experimental mass flow rate measurements and discussion
Energy Conversion and Management, 2016Co-Authors: F J Salvador, J Gimeno, M Carreres, M CrialesiespositoAbstract:Abstract An experimental study is conducted in this paper in order to assess the influence of the fuel temperature on the performance of a last generation common-rail ballistic solenoid injector. Mass flow rate measurements are performed for a wide range of temperatures, extending from 253 to 373 K, representative of all the possible operating conditions of the injector in a real diesel engine, including cold start. The high Pressure Line and the injector holder were refrigerated, making it possible to carefully control the fuel temperature, whereas measurements at cold conditions were carried out with the help of a climatic chamber. Relevant features such as stationary mass flow, injection delay or the behaviour at the opening and closing stages are analysed together with parameters governing the flow, such as the injector discharge coefficient. Results show an important influence of the fuel temperature, especially at low injection Pressure. A low injection temperature results in a lower stationary mass flow rate, whereas injection duration is also reduced. These results will be explained mainly through the fuel properties variation induced by temperature, together with the ballistic nature of the injector used for the study. A second part of the paper introduces a one-dimensional model that makes it possible to reproduce these results and further explain them through the analysis of other relevant variables, such as the needle lift.
Vesga Hernandez, Jeison Leandro - One of the best experts on this subject based on the ideXlab platform.
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Feasibility Study of Application of Residual Curvature Method in Deepwater Free Hanging Risers
University of Stavanger Norway, 2019Co-Authors: Vesga Hernandez, Jeison LeandroAbstract:The Offshore Oil and Gas industry has been moving to deeper water and needs to manage production in more extreme conditions. Risers systems are essential components for the transportation of these hydrocarbons from producing subsea wells to topside facilities. To reduce costs and improve safety, it is vital to use the most proper and effective design for these conductor pipes. This thesis proposes a riser configuration to cope with high floater motions in deep water under extreme conditions such as hurricanes, producing from a typical subsea well. The idea was to modify the geometry of sections of free hanging steel catenary risers to improve its performance by partially decoupling the touch down point of this conductor pipe from floater motions. Residual Curvature Method (RCM) was applied to Steel Catenary Riser (SCR) to achieve this. This method has been applied to control thermal buckling during operation in subsea pipeLines. The mentioned technique involves the creation of un-straightened segments or sections with residual curvature in the riser during installation. For ease, any SCR with sections with residual curvature applied will be named as RCSCR. This project focuses on the Residual Curvature Method applied to a high-Pressure Line steel catenary riser for 1500m water depth. It was determined that the RCM is a self-limiting process, where the section with residual curvature is able to absorb compressive forces, improve utilization and fatigue in the touch down area of the riser; however, the un-straightened section itself brings more bending moment, utilization and fatigue where it is located, limiting its application. The most optimum configuration for the section, which is made up of 4 subsections, must be applied close to the touch down area and is limited to a curvature of 0.009 m-1 for a 10 inch-internal diameter and 39 mm of wall thickness SCR; with this, obtaining a residual strain of 0.15% in the section. Likewise, it was found that the un-straightened section length that perform best was 180 m which is 12% of the water depth. A screening of the downward velocities at the hang-off point up in the platform was considered and analyzed, identifying the maximum values for buckling utilization, bending moment and compression, which are main critical responses. SCR with RCM, RCSCR was investigated in terms of the capabilities needed to handle the floater motions. The riser configuration was examined concerning strength, as well as fatigue performances to determine its limitations and merits. The strength assessment was achieved by using load cases with different sea states, including a typical 3h-winter storm and a hurricane occurring in the Gulf of Mexico. In this study, the sea states were established following JONSWAP wave spectra. The screening approach was based on the downward velocity or heave velocity at the hang-off point, which has been validated to be the principal design criteria for riser integrity. All the checks were performed in accordance with DNV codes. According to the results for extreme analysis, the SCR studied is restricted to a maximum downward velocity of 2.64 m/s, while the Steel Catenary Riser with Residual Curvature method (RCSCR) can cope with downward velocities up to 2.94 m/s at the hang-off point. Similarly, it was validated that the selected Weight Distributed SCR (WDSCR) configuration for this study can cope with a downward velocity of 3.2 m/s, while the combination of the Residual Curvature Method and WDSCR configuration can improve the coping of downward velocity at the hang-off point up to 4.01 m/s. On the other hand, the fatigue analysis of the riser configurations was carried out taking into account wave-induced fatigue. In general, the application of the un-straightened section through the Residual Curvature Method extended the life in fatigue of the SCR, increasing its value from 243 years to 599 years in the RCSCR configuration. The application of the Residual Curvature Method was found to be a viable solution to improve the performance for strength and fatigue of SCR and WDSCR configurations to cope with high motion of floaters. Investigation needs to be done for stability in riser-rotation while in operation, durability and optimization of the un-straightened section. This thesis work showed that, although deep water free hanging risers (SCR and WDSCR) can be limited for coping with large floater motions, economic and innovative solutions can be proven to increase their feasibility to handle higher heave motions in extreme conditions. All in all, even though it is a self-limiting technique, the application of the Residual Curvature Method reduces stress and fatigue loads in SCR and WDSCR configurations
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Feasibility Study of Application of Residual Curvature Method in Deepwater Free Hanging Risers
University of Stavanger Norway, 2019Co-Authors: Vesga Hernandez, Jeison LeandroAbstract:Master's thesis in Offshore TechnologyThe Offshore Oil and Gas industry has been moving to deeper water and needs to manage production in more extreme conditions. Risers systems are essential components for the transportation of these hydrocarbons from producing subsea wells to topside facilities. To reduce costs and improve safety, it is vital to use the most proper and effective design for these conductor pipes. This thesis proposes a riser configuration to cope with high floater motions in deep water under extreme conditions such as hurricanes, producing from a typical subsea well. The idea was to modify the geometry of sections of free hanging steel catenary risers to improve its performance by partially decoupling the touch down point of this conductor pipe from floater motions. Residual Curvature Method (RCM) was applied to Steel Catenary Riser (SCR) to achieve this. This method has been applied to control thermal buckling during operation in subsea pipeLines. The mentioned technique involves the creation of un-straightened segments or sections with residual curvature in the riser during installation. For ease, any SCR with sections with residual curvature applied will be named as RCSCR. This project focuses on the Residual Curvature Method applied to a high-Pressure Line steel catenary riser for 1500m water depth. It was determined that the RCM is a self-limiting process, where the section with residual curvature is able to absorb compressive forces, improve utilization and fatigue in the touch down area of the riser; however, the un-straightened section itself brings more bending moment, utilization and fatigue where it is located, limiting its application. The most optimum configuration for the section, which is made up of 4 subsections, must be applied close to the touch down area and is limited to a curvature of 0.009 m-1 for a 10 inch-internal diameter and 39 mm of wall thickness SCR; with this, obtaining a residual strain of 0.15% in the section. Likewise, it was found that the un-straightened section length that perform best was 180 m which is 12% of the water depth. A screening of the downward velocities at the hang-off point up in the platform was considered and analyzed, identifying the maximum values for buckling utilization, bending moment and compression, which are main critical responses. SCR with RCM, RCSCR was investigated in terms of the capabilities needed to handle the floater motions. The riser configuration was examined concerning strength, as well as fatigue performances to determine its limitations and merits. The strength assessment was achieved by using load cases with different sea states, including a typical 3h-winter storm and a hurricane occurring in the Gulf of Mexico. In this study, the sea states were established following JONSWAP wave spectra. The screening approach was based on the downward velocity or heave velocity at the hang-off point, which has been validated to be the principal design criteria for riser integrity. All the checks were performed in accordance with DNV codes. According to the results for extreme analysis, the SCR studied is restricted to a maximum downward velocity of 2.64 m/s, while the Steel Catenary Riser with Residual Curvature method (RCSCR) can cope with downward velocities up to 2.94 m/s at the hang-off point. Similarly, it was validated that the selected Weight Distributed SCR (WDSCR) configuration for this study can cope with a downward velocity of 3.2 m/s, while the combination of the Residual Curvature Method and WDSCR configuration can improve the coping of downward velocity at the hang-off point up to 4.01 m/s. On the other hand, the fatigue analysis of the riser configurations was carried out taking into account wave-induced fatigue. In general, the application of the un-straightened section through the Residual Curvature Method extended the life in fatigue of the SCR, increasing its value from 243 years to 599 years in the RCSCR configuration. The application of the Residual Curvature Method was found to be a viable solution to improve the performance for strength and fatigue of SCR and WDSCR configurations to cope with high motion of floaters. Investigation needs to be done for stability in riser-rotation while in operation, durability and optimization of the un-straightened section. This thesis work showed that, although deep water free hanging risers (SCR and WDSCR) can be limited for coping with large floater motions, economic and innovative solutions can be proven to increase their feasibility to handle higher heave motions in extreme conditions. All in all, even though it is a self-limiting technique, the application of the Residual Curvature Method reduces stress and fatigue loads in SCR and WDSCR configurations
Roger Lyon - One of the best experts on this subject based on the ideXlab platform.
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dynamic plantar Pressure measurements in children with tarsal coalition
Pacific Conference on Computer Graphics and Applications, 2000Co-Authors: Roger LyonAbstract:Tarsal coalition is a congenital foot anomaly seen in childhood. It results in a rigid flatfoot deformity. Radiographic studies are needed to confirm the diagnosis. Characterization of this foot deformity during normal gait was done using the Emed plantar Pressure system (Novel Electronics Inc, St Paul, USA). The hindfoot demonstrated higher than normal peak Pressure and increased peak Pressure on the third metatarsal area with an increased plantar contact area on the midfoot. The center of Pressure Line had a normal trajectory.