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Sample records for hancock ii valve

  1. Exercise Hemodynamics and Quality of Life after Aortic Valve Replacement for Aortic Stenosis in the Elderly Using the Hancock II Bioprosthesis

    PubMed Central

    Long, Theodore; Lopez, Becky M.; Berberian, Christopher; Cunningham, Mark J.; Starnes, Vaughn A.; Cohen, Robbin G.

    2014-01-01

    Background and Aim. While aortic valve replacement for aortic stenosis can be performed safely in elderly patients, there is a need for hemodynamic and quality of life evaluation to determine the value of aortic valve replacement in older patients who may have age-related activity limitation. Materials and Methods. We conducted a prospective evaluation of patients who underwent aortic valve replacement for aortic stenosis with the Hancock II porcine bioprosthesis. All patients underwent transthoracic echocardiography (TTE) and completed the RAND 36-Item Health Survey (SF-36) preoperatively and six months postoperatively. Results. From 2004 to 2007, 33 patients were enrolled with an average age of 75.3 ± 5.3 years (24 men and 9 women). Preoperatively, 27/33 (82%) were New York Heart Association (NYHA) Functional Classification 3, and postoperatively 27/33 (82%) were NYHA Functional Classification 1. Patients had a mean predicted maximum VO2 (mL/kg/min) of 19.5 ± 4.3 and an actual max VO2 of 15.5 ± 3.9, which was 80% of the predicted VO2. Patients were found to have significant improvements (P ≤ 0.01) in six of the nine SF-36 health parameters. Conclusions. In our sample of elderly patients with aortic stenosis, replacing the aortic valve with a Hancock II bioprosthesis resulted in improved hemodynamics and quality of life. PMID:25544931

  2. Mid- to long-term outcome comparison of the Medtronic Hancock II and bi-leaflet mechanical aortic valve replacement in patients younger than 60 years of age: a propensity-matched analysis.

    PubMed

    Wang, Yin; Chen, Si; Shi, Jiawei; Li, Geng; Dong, Nianguo

    2016-03-01

    This study aims to compare mid-long-term clinical outcomes between patients younger than 60 years of age undergoing bioprosthetic and mechanical aortic valve replacement. From January 2002 to December 2009, patients younger than 60 years of age who received Medtronic Hancock II porcine bioprostheses were selected and compared with those who received mechanical bi-leaflet valves in the aortic position. A stepwise logistic regression propensity score identified a subset of 112 evenly matched patient-pairs. Mid-long-term outcomes of survival, valve-related reoperations, thromboembolic events and bleeding events were assessed. The follow-up was only 95.1% complete. Fourteen measurable variables were statistically similar for the matched cohort. Postoperative in-hospital mortality was 3.6% (bioprosthetic valves) and 2.7% (mechanical valves) (P = 0.700). Survival at 5 and 10 years was 96.3 and 88.7% for patients receiving bioprosthetic valve replacement versus 96.3 and 87.9% for patients receiving mechanical valve replacement (P = 0.860), respectively. At 5 and 10 years after operations, freedom from valve-related reoperation was 97.2 and 94.8% for patients receiving mechanical valve replacement, and 96.3 and 90.2% for patients receiving bioprosthetic valve replacement (P = 0.296), respectively. There was no difference between freedom from thromboembolic events (P = 0.528) and bleeding events (P = 0.128) between the matched groups during the postoperative 10 years. In patients younger than 60 years of age undergoing aortic valve replacement, mid-long-term survival rate was similar for patients receiving bioprosthetic versus mechanical valve replacement. Bioprosthetic valves were associated with a trend for a lower risk of anticoagulation treatment and did not have significantly greater likelihood of a reoperation. These findings suggest that a bioprosthetic valve may be a reasonable choice for AVR in patients younger than 60 years of age. © The Author 2015. Published by

  3. Unusual 30-year durability of Hancock II porcine bioprosthesis in tricuspid position.

    PubMed

    Oumeiri, Bachar El; Eynden, Frédéric Vanden; Nooten, Guido Van

    2015-01-01

    We describe an unusual durability of a Hancock II porcine bioprosthesis in tricuspid position. Sustainability of bioprostheses is known to be limited especially in young patients. A 52-year old Caucasian woman with a history of multiple valve interventions. Her clinical presentation of dyspnoea and lower limb oedema led to the diagnosis of severe tricuspid valve stenosis and right heart failure, and was managed by the replacement of the tricuspid bioprosthesis by another bioprosthesis 30-years after the initial implantation. Calcification is the leading cause of bioprosthesis structural deterioration. This immune-induced phenomenon is more pronounced in young patients. Although several patient-related and valve-related factors influence the durability of a xenograft, unknown factors may be of some importance. To our knowledge, this is the first report of a 30-year durability of tricuspid bioprosthesis in a young recipient. In the absence of extensive calcifications, pannus formation covering the whole prosthesis, peculiar hemodynamics and other unknown factors might have contributed to an extended durability in this young patient. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Comprehensive echocardiographic assessment of normal mitral Medtronic Hancock II, Medtronic Mosaic, and Carpentier-Edwards Perimount bioprostheses early after implantation.

    PubMed

    Blauwet, Lori A; Malouf, Joseph F; Connolly, Heidi M; Hodge, David O; Evans, Katie N; Herges, Regina M; Sundt, Thoralf M; Miller, Fletcher A

    2010-06-01

    Normal Doppler-derived hemodynamic data for mitral valve bioprostheses are limited. To establish parameters for identifying normal function for each of the 3 types of bioprostheses examined, we conducted a comprehensive, retrospective, two-dimensional, and Doppler echocardiographic assessment of 179 patients who underwent implantation of the Medtronic Hancock II or the Medtronic Mosaic (Medtronic, Inc, Minneapolis, MN) porcine mitral valve bioprosthesis or the Carpentier-Edwards Perimount (Edwards Lifesciences LLC, Irvine, CA) bovine pericardial mitral valve bioprosthesis. All bioprostheses were normal by clinical examination, intraoperative transesophageal echocardiography, and postoperative transthoracic echocardiography. Regardless of valve type and body surface area, the pressure half-time was < 124 ms in all patients. Mean gradient < 9.5 mm Hg, mitral E velocity < 2.6 m/s, mitral valve prosthesis time-velocity integral < 69 cm, and ratio of the mitral valve prosthesis time-velocity integral to the left ventricular outflow tract time-velocity integral < 3.4 were recorded in nearly all patients. These cutoff values (mean + 2 standard deviation) are specific, but not sensitive, for identifying mitral valve prosthesis dysfunction. Prostheses with hemodynamic values that are higher than these cutoff values are likely dysfunctional, but in select cases, mitral valve prosthesis dysfunction may be present even when hemodynamic values are lower than these thresholds. Copyright 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

  5. Twenty-year durability of the aortic Hancock II bioprosthesis in young patients: is it durable enough?.

    PubMed

    Une, Dai; Ruel, Marc; David, Tirone E

    2014-11-01

    There is a current trend towards the use of bioprosthetic aortic valves in the aortic position in young patients, but there is limited information on durability beyond the first decade. The Hancock II bioprosthesis has been reported to have excellent durability in patients ≥ 60 years of age. This study examines the long-term durability of the Hancock II bioprosthesis in the aortic position in patients <60 years of age. From 1982 to 2008, 304 patients aged 59 years or less underwent aortic valve replacement (AVR) with a Hancock II bioprosthesis at two centres. The mean age was 49.2 ± 9.0 years, and 79% of the patients were male. Valve function was serially assessed by echocardiography. The median follow-up was 14.6 years (maximum 27.5 years). Survival and freedom from adverse events were calculated by using a Kaplan-Meier method. Independent predictors of those events were assessed by using Cox proportional hazards analyses. Survival and freedom from repeat AVR (re-AVR) at 20 years were 57.0 ± 6.1 and 25.4 ± 4.7%, respectively. During the follow-up, 100 patients (33%) underwent re-AVR: 78 for structural valve deterioration (SVD), 11 for endocarditis, 4 for non-structural valve dysfunction and 7 for other reasons. The overall 10-, 15- and 20-year freedom from re-AVR due to SVD were 91.4 ± 2.1, 64.7 ± 4.3 and 29.1 ± 5.3%, respectively. By age group, the 20-year freedom from re-AVR due to SVD amounted to 14.1 ± 8.7% in patients younger than 40 years of age, 21.5 ± 8.5% in patients aged 40-49 and 41.4 ± 8.2% in patients between 50 and 59 (P = 0.04). The independent predictors of re-AVR due to SVD were age [odds ratio (OR): 0.72 per 10 years; 95% confidence interval (CI): 0.58, 0.90; P < 0.01] and prosthesis-patient mismatch (PPM) (effective orifice area index <0.80 cm(2)/m(2)) (OR: 1.63; 95% CI: 1.01, 2.63; P = 0.045). The Hancock II bioprosthesis for AVR in patients <60 years of age is associated with excellent durability during the first decade. However

  6. Installation Restoration Program. Phase II. Confirmation/Quantification. Stage 1 for Hancock Field, New York and HQTAC, Langley AFB, Virginia.

    DTIC Science & Technology

    1984-10-01

    TEST CHART Installation Restoration Program Phase II - Confirmation/Quantification Stage 1 in! 0 Lfl Final Report for Hancock Field, New York and HQTAC...Hancock Field, New York . 2-2 2-2 Topography of Hancock Field, 1978 ........... ... 2-3 2-3 Topography of Area Prior to Base Construction . . . . 2-4...Portion of the Eastern Oswego River Basin, New York ....... ... 2-8 2-6 Location of Sites D-1 and D-3 in Zone 2 ....... . 2-12 2-7 Location of Sites D-5

  7. Modified level II streambed-scour analysis for structure I-70-104-5128 crossing Brandywine Creek in Hancock County, Indiana

    USGS Publications Warehouse

    Miller, R.L.; Robinson, B.A.; Voelker, D.C.

    1997-01-01

    Level II scour evaluations follow a process in which hydrologic, hydraulic, and sedient-transport data are evaluated to calculate the depth of scour that may result when given discharge is routed through a bridge opening. the results of the modified Levell II analysis for structure I-70-104-5128 on Interstate 70 crossing Brandywine Creek in Hancock County, Indiana, are presented. The site is near the town of Greenfield in the central part of Hancock County. Scour depths were computed with the Water Surface PROfile model, version V050196, which incorporates the scour-calculation procedures outlined in Hydraulic Engineering Circular No. 18. Total scour depths at the piers were approximately 6.5 feet for the modeled discharge of 6,900 cubic feet per second and approximately 8.0 feet for the modeled discharge of 9,140 cubic feet per second.

  8. Hancock County Awards Gala

    NASA Image and Video Library

    2008-08-26

    Gene Goldman (left), deputy director of NASA's John C. Stennis Space Center, accepts an Award of Excellence from Jack Zink, executive director of the Hancock County Port and Harbor Commission, during the 2008 Annual Hancock County Awards Gala. The Award of Excellence was presented to recognize Stennis Space Center's contribution to NASA's 50 years of excellence in space exploration.

  9. Hancock County Awards Gala

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Gene Goldman (left), deputy director of NASA's John C. Stennis Space Center, accepts an Award of Excellence from Jack Zink, executive director of the Hancock County Port and Harbor Commission, during the 2008 Annual Hancock County Awards Gala. The Award of Excellence was presented to recognize Stennis Space Center's contribution to NASA's 50 years of excellence in space exploration.

  10. Level II scour analysis for Bridge 10 (HANCTH00010010) on Town Highway 1, crossing the White River, Hancock, Vermont

    USGS Publications Warehouse

    Olson, Scott A.; Ivanoff, Michael A.

    1996-01-01

    This report provides the results of a detailed Level II analysis of scour potential at structure HANCTH00010010 on town highway 1 crossing the White River, Hancock, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province of central Vermont. The 59.8-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is primarily grass with trees and brush on the immediate channel banks. In the study area, the White River has a sinuous channel with a slope of approximately 0.005 ft/ft, an average channel top width of 104 ft and an average channel depth of 6 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 98.9 mm (0.325 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 15, 1994, indicated that the reach was stable. The town highway 1 crossing of the White River is a 91-ft-long, two-lane bridge consisting of one 89-foot steel-beam span (Vermont Agency of Transportation, written communication, August 26, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees to the opening while the opening-skew-to-roadway is 0 degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed

  11. Bioprosthetic Valve Fracture to Facilitate Transcatheter Valve-in-Valve Implantation.

    PubMed

    Allen, Keith B; Chhatriwalla, Adnan K; Cohen, David J; Saxon, John T; Aggarwal, Sanjeev; Hart, Anthony; Baron, Suzanne; Davis, J Russell; Pak, Alex F; Dvir, Danny; Borkon, A Michael

    2017-06-29

    Valve-in-valve transcatheter aortic valve replacement is less effective in small surgical bioprostheses. We evaluated the feasibility of bioprosthetic valve fracture with a high-pressure balloon to facilitate valve-in-valve transcatheter aortic valve replacement. In vitro bench testing on aortic tissue valves was performed on 19-mm and 21-mm Mitroflow (Sorin, Milan, Italy), Magna and Magna Ease (Edwards Lifesciences, Irvine, CA), Trifecta and Biocor Epic (St. Jude Medical, Minneapolis, MN), and Hancock II and Mosaic (Medtronic, Minneapolis, MN). High-pressure balloons Tru Dilation, Atlas Gold, and Dorado (C.R. Bard, Murray Hill, NJ) were used to determine which valves could be fractured and at what pressure fracture occurred. Mitroflow, Magna, Magna Ease, Mosaic, and Biocor Epic surgical valves were successfully fractured using high-pressures balloon 1 mm larger than the labeled valve size whereas Trifecta and Hancock II surgical valves could not be fractured. Only the internal valve frame was fractured, and the sewing cuff was never disrupted. Manufacturer's rated burst pressures for balloons were exceeded, with fracture pressures ranging from 8 to 24 atmospheres depending on the surgical valve. Testing further demonstrated that fracture facilitated the expansion of previously constrained, underexpanded transcatheter valves (both balloon and self-expanding) to the manufacturer's recommended size. Bench testing demonstrates that the frame of most, but not all, bioprosthetic surgical aortic valves can be fractured using high-pressure balloons. The safety of bioprosthetic valve fracture to optimize valve-in-valve transcatheter aortic valve replacement in small surgical valves requires further clinical investigation. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  12. Minimally Invasive Mitral Valve Surgery II

    PubMed Central

    Wolfe, J. Alan; Malaisrie, S. Chris; Farivar, R. Saeid; Khan, Junaid H.; Hargrove, W. Clark; Moront, Michael G.; Ryan, William H.; Ailawadi, Gorav; Agnihotri, Arvind K.; Hummel, Brian W.; Fayers, Trevor M.; Grossi, Eugene A.; Guy, T. Sloane; Lehr, Eric J.; Mehall, John R.; Murphy, Douglas A.; Rodriguez, Evelio; Salemi, Arash; Segurola, Romualdo J.; Shemin, Richard J.; Smith, J. Michael; Smith, Robert L.; Weldner, Paul W.; Lewis, Clifton T. P.; Barnhart, Glenn R.; Goldman, Scott M.

    2016-01-01

    Abstract Techniques for minimally invasive mitral valve repair and replacement continue to evolve. This expert opinion, the second of a 3-part series, outlines current best practices for nonrobotic, minimally invasive mitral valve procedures, and for postoperative care after minimally invasive mitral valve surgery. PMID:27654406

  13. Comparison of dysfunction with mechanical and porcine mitral valve prostheses.

    PubMed

    Magilligan, D J; Oyama, C; Alam, M

    1985-09-01

    We reviewed the incidence of dysfunction of the Smeloff-Cutter mechanical prosthetic valve and the Hancock porcine prosthetic valve in the mitral position. The Smeloff-Cutter valve was implanted from 1966 to 1972; 107 patients were discharged from the hospital and were at risk for dysfunction. Follow-up averaged 10 +/- 0.7 years SD. The Hancock valve was implanted from 1971 through 1984; 473 patients were at risk and follow-up averaged 4.7 +/- 3.4 years SD. Dysfunction of the Smeloff-Cutter valve occurred as thrombosis with incomplete poppet opening in 13 patients. Dysfunction of the Hancock valve occurred as primary tissue failure in 47 patients. At 10 years the freedom from dysfunction of the Smeloff-Cutter valve was 84 +/- 5% SE and that for the Hancock valve was 71 +/- 4% SE (p greater than .06). The mortality associated with dysfunction of the Smeloff-Cutter valve was 46%; mortality associated with dysfunction of the Hancock valve was 15% (p less than .02). At 10 years the Hancock valve had a greater incidence of dysfunction than the Smeloff-Cutter valve but this difference was not statistically significant. The mortality associated with dysfunction of the Smeloff-Cutter valve, however, was three times that associated with dysfunction of the Hancock valve.

  14. Masoneilan Camflex II valve, METC SOA Test Valve No. A-15 and Test Valve No. A-15R. State-of-the-Art: Lockhopper Valve-Testing and Development Project. Summary test report

    SciTech Connect

    Gardner, J. F.; Gayheart, T. R.; Griffith, R. A.; Hall, R. C.; Hornbeck, R. G.; Maxfield, D. A.; Nutter, T. M.; Sgamma, R. B.

    1981-04-01

    The 8-inch ANSI Class 600 Masoneilan Camflex II Valve (METC SOA Test Valve No. A-15) accumulated 306 cycles in the Valve Static Test Unit (VSTU) and 901 cycles in the Valve Dynamic Test Unit (VDTU). METC SOA Test Valve No. A-15R accumulated 848 cycles in the VSTU and 5070 cycles in the VDTU. The test valve satisfactorily completed the ambient, 300/sup 0/F, and 600/sup 0/F static tests. The valve leakage rates exceeded the maximum allowable leakage rates during dynamic testing using limestone as the test medium. Excessive leakage occurred due to improper clearances between the valve parts and degradation of the valve sealant. The sealing surfaces showed minimal degradation as a result of exposure to solids. This - plus the design's similarity to other valves that have performed well in lockhopper testing - suggests that with appropriate modifications the Camflex II could have potential for use in solids-feeding lockhopper service.

  15. 209. Photocopied July 1978. (QMC) 'QUINCY SMELTING WORKS, HANCOCK, MICH., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    209. Photocopied July 1978. (QMC) 'QUINCY SMELTING WORKS, HANCOCK, MICH., SCALE BUILDING FOR TWO 6-TON SCALES. OCT. 22, 1907.' SECTIONS, ELEVATIONS AND DETAILS. - Quincy Mining Company, Hancock, Houghton County, MI

  16. 206. Photocopied July 1978. (QMC) 'QUINCY SMELTING WORKS, HANCOCK, MICH., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    206. Photocopied July 1978. (QMC) 'QUINCY SMELTING WORKS, HANCOCK, MICH., PROPOSED MECHANICAL CASTING PLANT, MAY 17, 1914.' PLAN, SECTIONS, AND MACHINERY ELEVATIONS. - Quincy Mining Company, Hancock, Houghton County, MI

  17. 50 CFR 665.209 - Fishing moratorium at Hancock Seamounts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Fishing moratorium at Hancock Seamounts... Hawaii Fisheries § 665.209 Fishing moratorium at Hancock Seamounts. Fishing for, and possession of, Hawaii bottomfish and seamount groundfish MUS in the Hancock Seamounts Ecosystem Management Area is...

  18. 50 CFR 665.209 - Fishing moratorium at Hancock Seamounts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Fishing moratorium at Hancock Seamounts... Hawaii Fisheries § 665.209 Fishing moratorium at Hancock Seamounts. Fishing for, and possession of, Hawaii bottomfish and seamount groundfish MUS in the Hancock Seamounts Ecosystem Management Area is...

  19. 50 CFR 665.209 - Fishing moratorium at Hancock Seamounts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Fishing moratorium at Hancock Seamounts... Hawaii Fisheries § 665.209 Fishing moratorium at Hancock Seamounts. Fishing for, and possession of, Hawaii bottomfish and seamount groundfish MUS in the Hancock Seamounts Ecosystem Management Area is...

  20. 50 CFR 665.209 - Fishing moratorium at Hancock Seamounts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Fishing moratorium at Hancock Seamounts... Hawaii Fisheries § 665.209 Fishing moratorium at Hancock Seamounts. Fishing for, and possession of, Hawaii bottomfish and seamount groundfish MUS in the Hancock Seamounts Ecosystem Management Area is...

  1. 50 CFR 665.209 - Fishing moratorium on Hancock Seamount.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Fishing moratorium on Hancock Seamount... Hawaii Fisheries § 665.209 Fishing moratorium on Hancock Seamount. Fishing for Hawaii bottomfish and seamount groundfish MUS on the Hancock Seamount is prohibited through August 31, 2010. ...

  2. Massachusetts' "Hancock" Case and the Adequacy Doctrine

    ERIC Educational Resources Information Center

    Costrell, Robert

    2006-01-01

    The Hancock school finance case put the adequacy doctrine to its strictest test yet, to see if even a national educational leader such as Massachusetts could be found in constitutional violation. The doctrine failed this test, as the court found in favor of the defendants due to the vigorous reform program since 1993. The court credited the…

  3. A New School for Hancock County.

    ERIC Educational Resources Information Center

    McDaniel, Lynda

    2001-01-01

    Describes the new elementary school in rural Hancock County, Tennessee, financed as a result of efforts to equalize funding throughout the state. Compares conditions in the new and old schools. Discusses the greatly expanded space, new technology features, the school clinic, after-school activities, and various special student services. (SV)

  4. Aortic sutureless bioprosthesis implantation following degeneration of a SOLO stentless valve.

    PubMed

    Vola, Marco; Gerbay, Antoine; Campisi, Salvatore; Thulane, Claire; Fuzellier, François

    2015-03-01

    A case is presented of the early degeneration of a 21 mm SOLO stentless valve concomitant with severe mitral regurgitation (MR). Transcatheter valve-in-valve implantation was considered in this high-risk case (logistic EuroSCORE 29.3%), but was dismissed because of the risk of coronary occlusion, an absence of visual landmarks, and the impossibility to treat the MR. Following the implantation of a 27 mm Medtronic Hancock II mitral bioprosthesis, the leaflets of the SOLO valve were removed, and a 19 mm 3f Enable sutureless bioprosthesis delivered into the remaining sewing belt of the stentless valve. The total cross-clamp time was 64 min. No aortic paravalvular leakage was detected at discharge and early follow up (four months); the mean and peak transvalvular aortic gradients were 13 and 23 mmHg, respectively, and the left ventricular ejection fraction 60%. A sutureless strategy simplified the management of this high-risk case.

  5. The use of MAVIS II to integrate the modeling and analysis of explosive valve interactions

    SciTech Connect

    Ng, R.; Kwon, D.M.

    1998-12-31

    The MAVIS II computer program provides for the modeling and analysis of explosive valve interactions. This report describes the individual components of the program and how MAVIS II is used with other available tools to integrate the design and understanding of explosive valves. The rationale and model used for each valve interaction is described. Comparisons of the calculated results with available data have demonstrated the feasibility and accuracy of using MAVIS II for analytical studies of explosive valve interactions. The model used for the explosive or pyrotechnic used as the driving force in explosive valves is the most critical to be understood and modeled. MAVIS II is an advanced version that incorporates a plastic, as well as elastic, modeling of the deformations experienced when plungers are forced into a bore. The inclusion of a plastic model has greatly expanded the use of MAVIS for all categories (opening, closure, or combined) of valves, especially for the closure valves in which the sealing operation requires the plastic deformation of either a plunger or bore over a relatively large area. In order to increase its effectiveness, the use of MAVIS II should be integrated with the results from available experimental hardware. Test hardware such as the Velocity Interferometer System for Any Reflector (VISAR) and Velocity Generator test provide experimental data for accurate comparison of the actual valve functions. Variable Explosive Chamber (VEC) and Constant Explosive Volume (CEV) tests are used to provide the proper explosive equation-of-state for the MAVIS calculations of the explosive driving forces. The rationale and logistics of this integration is demonstrated through an example. A recent valve design is used to demonstrate how MAVIS II can be integrated with experimental tools to provide an understanding of the interactions in this valve.

  6. Design and development of a leak tight helium II valve with low thermal impact

    NASA Technical Reports Server (NTRS)

    Mills, G. L.

    1991-01-01

    The Lambda Point Experiment is a precision measurement of the specific heat of liquid helium near the lambda point phase transition, in the low gravity of the space shuttle. It requires a valve for the helium sample chamber that operates at helium II temperature, has minimal thermal disturbance to the rest of the instrument, and is leak tight to helium II. A valve meeting these and all of the other science and engineering requirements of the mission has been developed by Ball. Initially, both torque and pressure actuated valve concepts were considered; the final flight design is pressure actuated. The rational for this decision as well as the rest of the valve design are given. The paper also discusses the manufacturing and testing of the prototype and flight valves. Test data is presented and discussed.

  7. Double valve Implantation

    PubMed Central

    Stassano, Paolo; Mannacio, Vito; Musumeci, Antonino; Golino, Alessandro; Maida, Piero; Ferrigno, Vincenzo; Buonocore, Gaetano; Spampinato, Nicola

    1991-01-01

    From January 1976 through December 1987, 194 patients with a mean age of 43.3 ± 13.7 years (range, 11 to 74 years) underwent double (mitral and aortic) replacement of native valves with 8 types of bioprostheses: Carpentier-Edwards, 127 valves; Hancock, 76 valves; Liotta-Bioimplant, 57 valves; Ionescu-Shiley, 53 valves; Vascor, 27 valves; Carpentier-Edwards Pericardial, 22 valves; Angell-Shiley, 20 valves; and Implamedic, 6 valves. Concomitant cardiac procedures were performed in 25 patients (12.8%). There were 18 operative deaths (9.27%). Our retrospective analysis was restricted to 352 bioprostheses implanted in the 176 patients who survived surgery and were considered at risk for valve tissue failure. The overall cumulative duration of follow-up was 1,174.1 patient-years (range, 1 to 13 years). The durations of follow-up for specific valves were: Carpentier-Edwards, 920.2 valve-years; Hancock, 383.8 valve-years; Liotta-Bioimplant, 310.2 valve-years; Ionescu-Shiley, 357.7 valve-years; Vascor, 131.2 valve-years; Carpentier-Edwards Pericardial, 52.0 valve-years; Angell-Shiley, 167.0 valve-years; and Implamedic, 31.0 valve-years. Thirty patients had thromboembolic accidents, for a linearized incidence of 2.5% per patient-year. At 13 years, the actuarial freedom from thromboembolic accidents was 85.8% ± 10.7%. Nine patients had endocarditis, for a linearized incidence of 0.7% per patient-year. At 13 years, the actuarial freedom from endocarditis was 92.0% ± 1.5%. Twenty-four patients had valve tissue failure, for a cumulative linearized incidence of 1.87% per valve-year. The cumulative actuarial probability of freedom from valve tissue failure was 78.6% ± 3.7% at 10 years and 51.2% ± 10.7% at 13 years. The 24 patients with valve tissue failure all underwent reoperation: 20 of these had double valve replacement, 3 had aortic valve replacement alone, and 1 had mitral valve replacement alone. The mean interval between initial valve implantation and reoperation was

  8. Cyclic pressure and angiotensin II influence the biomechanical properties of aortic valves.

    PubMed

    Myles, Valtresa; Liao, Jun; Warnock, James N

    2014-01-01

    Hypertension is a known risk factor for aortic stenosis. The elevated blood pressure increases the transvalvular load and can elicit inflammation and extracellular matrix (ECM) remodeling. Elevated cyclic pressure and the vasoactive agent angiotensin II (Ang II) both promote collagen synthesis, an early hallmark of aortic sclerosis. In the current study, it was hypothesized that elevated cyclic pressure and/or angiotensin II decreases extensibility of aortic valve leaflets due to an increase in collagen content and/or interstitial cell stiffness. Porcine aortic valve leaflets were exposed to pressure conditions of increasing magnitude (static atmospheric pressure, 80, and 120 mmHg) with and without 10−6 M Ang II. Biaxial mechanical testing was performed to determine extensibility in the circumferential and radial directions and collagen content was determined using a quantitative dye-binding method at 24 and 48 h. Isolated aortic valve interstitial cells exposed to the same experimental conditions were subjected to atomic force microscopy to assess cellular stiffness at 24 h. Leaflet tissue incubated with Ang II decreased tissue extensibility in the radial direction, but not in the circumferential direction. Elevated cyclic pressure decreased extensibility in both the radial and circumferential directions. Ang II and elevated cyclic pressure both increased the collagen content in leaflet tissue. Interstitial cells incubated with Ang II were stiffer than those incubated without Ang II while elevated cyclic pressure caused a decrease in cell stiffness. The results of the current study demonstrated that both pressure and Ang II play a role in altering the biomechanical properties of aortic valve leaflets. Ang II and elevated cyclic pressure decreased the extensibility of aortic valve leaflet tissue. Ang II induced direction specific changes in extensibility, demonstrating different response mechanisms. These findings help to provide a better understanding of

  9. VALVE

    DOEpatents

    Arkelyan, A.M.; Rickard, C.L.

    1962-04-17

    A gate valve for controlling the flow of fluid in separate concentric ducts or channels by means of a single valve is described. In one position, the valve sealing discs engage opposed sets of concentric ducts leading to the concentric pipes defining the flow channels to block flow therethrough. In another position, the discs are withdrawn from engagement with the opposed ducts and at the same time a bridging section is interposed therebetween to define concentric paths coextensive with and connecting the opposed ducts to facilitate flow therebetween. A wedge block arrangement is employed with each sealing disc to enable it to engage the ducts. The wedge block arrangement also facilitates unobstructcd withdrawal of the discs out of the intervening space between the sets of ducts. (AEC)

  10. Valve

    DOEpatents

    Cho, Nakwon

    1980-01-01

    A positive acting valve suitable for operation in a corrosive environment is provided. The valve includes a hollow valve body defining an open-ended bore for receiving two, axially aligned, spaced-apart, cylindrical inserts. One insert, designated the seat insert, terminates inside the valve body in an annular face which lies within plane normal to the axis of the two inserts. An elastomeric O-ring seal is disposed in a groove extending about the annular face. The other insert, designated the wedge insert, terminates inside the valve body in at least two surfaces oppositely inclined with respect to each other and with respect to a plane normal to the axis of the two inserts. An elongated reciprocable gate, movable between the two inserts along a path normal to the axis of the two inserts, has a first flat face portion disposed adjacent and parallel to the annular face of the seat insert. The gate has a second face portion opposite to the first face portion provided with at least two oppositely inclined surfaces for mating with respective inclined surfaces of the wedge insert. An opening is provided through the gate which registers with a flow passage through the two inserts when the valve is open. Interaction of the respective inclined surfaces of the gate and wedge insert act to force the first flat face portion of the gate against the O-ring seal in the seat insert at the limits of gate displacement where it reaches its respective fully open and fully closed positions.

  11. Transcatheter aortic valve replacement for severe symptomatic aortic stenosis using a repositionable valve system: 30-day primary endpoint results from the REPRISE II study.

    PubMed

    Meredith Am, Ian T; Walters, Darren L; Dumonteil, Nicolas; Worthley, Stephen G; Tchétché, Didier; Manoharan, Ganesh; Blackman, Daniel J; Rioufol, Gilles; Hildick-Smith, David; Whitbourn, Robert J; Lefèvre, Thierry; Lange, Rüdiger; Müller, Ralf; Redwood, Simon; Allocco, Dominic J; Dawkins, Keith D

    2014-09-30

    Transcatheter aortic valve replacement provides results comparable to those of surgery in patients at high surgical risk, but complications can impact long-term outcomes. The Lotus valve, designed to improve upon earlier devices, is fully repositionable and retrievable, with a unique seal to minimize paravalvular regurgitation (PVR). The prospective, single-arm, multicenter REPRISE II study (REpositionable Percutaneous Replacement of Stenotic Aortic Valve Through Implantation of Lotus Valve System: Evaluation of Safety and Performance) evaluated the transcatheter valve system for treatment of severe symptomatic calcific aortic valve stenosis. Patients (n = 120; aortic annulus 19 to 27 mm) considered by a multidisciplinary heart team to be at high surgical risk received the valve transfemorally. The primary device performance endpoint, 30-day mean pressure gradient, was assessed by an independent echocardiographic core laboratory and compared with a pre-specified performance goal. The primary safety endpoint was 30-day mortality. Secondary endpoints included safety/effectiveness metrics per Valve Academic Research Consortium criteria. Mean age was 84.4 years, 57% of the patients were female, and 76% were New York Heart Association functional class III/IV. Mean aortic valve area was 0.7 ± 0.2 cm(2). The valve was successfully implanted in all patients, with no cases of valve embolization, ectopic valve deployment, or additional valve implantation. All repositioning (n = 26) and retrieval (n = 6) attempts were successful; 34 patients (28.6%) received a permanent pacemaker. The primary device performance endpoint was met, because the mean gradient improved from 46.4 ± 15.0 mm Hg to 11.5 ± 5.2 mm Hg. At 30 days, the mortality rate was 4.2%, and the rate of disabling stroke was 1.7%; 1 (1.0%) patient had moderate PVR, whereas none had severe PVR. REPRISE II demonstrates the safety and effectiveness of the Lotus valve in patients with severe aortic stenosis who are at

  12. Type II collagen is transiently expressed during avian cardiac valve morphogenesis.

    PubMed

    Swiderski, R E; Daniels, K J; Jensen, K L; Solursh, M

    1994-08-01

    We present new evidence of the temporal and spatial expression of type II collagen in the embryonic chick heart during the very early stages of its development. In particular, we emphasize the distribution of its mRNA and protein during valve formation. Type II collagen as well as several other fibrillar collagens (types I, III, and V) are present in stage 18 endocardial cushion mesenchymal cells. At stage 23, alpha 1 (II) collagen transcripts and the cognate polypeptide colocalize in the atrioventricular valves. As development proceeds, the relative abundance of alpha 1 (II) collagen transcripts decreases during the stages studied (stages 22 to 45; day 3.5 to day 19) as assayed by RNA blotting of extracts of whole hearts. Type II collagen protein was immunologically undetectable in stage 38 (day 12) hearts, although collagens I, III, and V persisted and localize in the valve regions, in the endothelial lining of the heart, and in the epicardium. In keeping with other observations of type II collagen expression in non-chondrogenic regions of a variety of vertebrate embryos, the avian heart also exhibits transient type II collagen expression.

  13. 5. VIEW EAST NORTHEAST OF BUILDING 21, INTERSECTION OF HANCOCK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW EAST NORTHEAST OF BUILDING 21, INTERSECTION OF HANCOCK AND RAILROAD AVENUES; BUILDING 18 IS AT EXTREME RIGHT OF PHOTOGRAPH - Bryant Electric Company, 1421 State Street, Bridgeport, Fairfield County, CT

  14. TRUPACT-II Hydrogen G-Valve Program Test Plan

    SciTech Connect

    Mroz, Eugene J.

    1999-01-01

    This test plan describes the objectives, scope, participants, and components of the Transuranic Package Transporter-II (TRUPACT-II) Hydrogen G-Value Program (GH2P). The GH2P builds on the experience, results, and experimental setup of the TRUPACT-II Matrix Depletion Program (MDP) to establish effective hydrogen G-values (G-values) for additional waste matrices. This plan details the experimental design and test matrices for experiments to measure the G-value for additional waste matrices, including first- and second-stage sludges at the Idaho National Engineering and Environmental Laboratory, and molten salt extraction residues with varying amounts of residual moisture (i.e., unbound water). Data collected from the GH2P will be used to support an application to the US Nuclear Regulatory Commission for G-values and corresponding wattage limits for the TRUPACT-II payloads containing these waste matrices. The testing will also evaluate the ability to determine G-values on a waste stream basis.

  15. [Experience of Mitral Valve Replacement Using a Pulmonary Autograft (Ross II Operation) in an Infant;Report of a Case].

    PubMed

    Kawahito, Tomohisa; Egawa, Yoshiyasu; Yoshida, Homare; Shimoe, Yasushi; Onishi, Tatsuya; Miyagi, Yuhichi; Terada, Kazuya; Ohta, Akira

    2015-07-01

    A 24-day-old boy suddenly developed progressive heart failure and was transported to our hospital. Echocardiography showed massive mitral regurgitation due to chordal rupture. Mitral valve repair was performed at 28 days of life, but postoperative valvular function was not satisfactory. A mechanical valve was implanted in the supra-annular position at 37 days of life. Two months after valve replacement, the mechanical valve was suddenly stuck. Emergent redo valve replacement was performed, but the prosthetic valve became stuck again 2 months after the 3rd operation, despite sufficient anti-coagulation therapy. At the 4th operation (6 months after birth), we implanted a pulmonary autograft in the mitral position instead of another mechanical valve in an emergent operation. The right ventricular outflow tract was reconstructed with a valved conduit. A postoperative catheter examination, which was performed 1 year after the Ross II operation, showed mild mitral stenosis with no regurgitation. Previous reports of Ross II operations in infants are rare and long-term results are unknown. However, we advocate that this procedure should be a rescue operation for mitral valve dysfunction in the early period of infants.

  16. Stent valve implantation in conventional redo aortic valve surgery to prevent patient-prosthesis mismatch.

    PubMed

    Ferrari, Enrico; Franciosi, Giorgio; Clivio, Sara; Faletra, Francesco; Moccetti, Marco; Moccetti, Tiziano; Pedrazzini, Giovanni; Demertzis, Stefanos

    2017-03-01

    The goal was to show the technical details, feasibility and clinical results of balloon-expandable stent valve implantation in the aortic position during conventional redo open-heart surgery in selected obese patients with a small aortic prosthesis and severe patient-prosthesis mismatch. Two symptomatic overweight patients (body mass index of 31 and 38), each with a small aortic prosthesis (a 4-year-old, 21-mm Hancock II biological valve and a 29-year-old, 23-mm Duromedic mechanical valve), increased transvalvular gradients (59/31 and 74/44 mmHg) and a reduced indexed effective orifice area (0.50 and 0.43 cm 2 /m 2 ) underwent implantation of two 26-mm balloon-expandable Sapien 3 valves during standard on-pump redo valve surgery. Using full re-sternotomy, cardiopulmonary bypass and cardioplegic arrest, the two balloon-expandable stent valves were implanted under direct view using a standard aortotomy, after prosthesis removal and without annulus enlargement. Aortic cross-clamp times were 162 and 126 min; cardiopulmonary bypass times were 178 and 180 min; total surgical times were 360 and 318 min. At discharge, echocardiograms showed transvalvular peak and mean gradients of 13/9 and 23/13 mmHg and indexed effective orifice areas of 0.64 and 1.08 cm 2 /m 2 . The 3-month echocardiographic follow-up showed transvalvular peak and mean gradients of 18/9 and 19/11 mmHg and indexed effective orifice areas of 0.78 cm 2 /m 2 and 0.84 cm 2 /m 2 , with improved symptoms (New York Heart Association class 1). Implantation of a balloon-expandable stent valve during redo aortic valve surgery is feasible in selected cases and prevents patient-prosthesis mismatch in obese patients without need for aortic annulus enlargement. Moreover, in the case of stent valve degeneration, this approach permits additional valve-in-valve procedures with large stent valves and prevents re-redo surgery.

  17. 76 FR 72731 - John Hancock Variable Insurance Trust, et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-25

    ... that the purpose of section 17(d) is to avoid overreaching by and unfair advantage to insiders... any John Hancock Fund obtaining an undue advantage over any other John Hancock Fund. 4. Section 17(a...

  18. Fairchild Stratos Division's Type II prototype lockhopper valve: METC Prototype Test Valve No. F-1 prototype lockhopper valve-testing and development project. Static test report

    SciTech Connect

    Goff, D. R.; Cutright, R. L.; Griffith, R. A.; Loomis, R. B.; Maxfield, D. A.; Moritz, R. S.

    1981-10-01

    METC Prototype Test Valve No. F-1 is a hybrid design, based on a segmented ball termed a visor valve, developed and manufactured by Fairchild Stratos Division under contract to the Department of Energy. The valve uses a visor arm that rotates into position and then translates to seal. This valve conditionally completed static testing at METC with clean gas to pressures of 1600 psig and internal valve temperatures to 600/sup 0/F. External leakage was excessive due to leakage through the stuffing box, purge fittings, external bolts, and other assemblies. The stuffing box was repacked several times and redesigned midway through the testing, but external leakage was still excessive. Internal leakage through the seats, except for a few anomalies, was very low throughout the 2409 cycles of testing. As shown by the low internal leakage, the visor valve concept appears to have potential for lock-hopper valve applications. The problems that are present with METC Prototype Test Valve No. F-1 are in the seals, which are equivalent to the shaft and bonnet seals in standard valve designs. The operating conditions at these seals are well within the capabilities of available seal designs and materials. Further engineering and minor modifications should be able to resolve the problems identified during static testing.

  19. Pawpaw-Hancock folio, Maryland-West Virginia-Pennsylvania

    USGS Publications Warehouse

    Stose, G.W.; Swartz, C. K.

    1912-01-01

    The Pawpaw and Hancock quadrangles embrace parts of eastern West Virginia, western Maryland, and southern Pennsylvania between parallels 39° 30' abd 39° 45' and meridians 78° and 78° 30', and contain 460 square miles.  (See fig. 1.)  Parts of eight counties are included in the area, Morgan, Berkeley, and Hampshire in West Virginia, Washington and Allegany in Maryland, and Bedford, Fulton, and Franklin in Pennsylvania.  Hancock, Md., the the largest town in the area, Pawpaw, Great Cacapon, and Berkeley Springs, W. Va., being next in importance.

  20. 78 FR 29648 - Regulated Navigation Area; Waldo-Hancock Bridge Demolition, Penobscot River, Between Prospect and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA11 Regulated Navigation Area; Waldo-Hancock Bridge... Waldo- Hancock Bridge in order to facilitate the removal of the trusses, cables, and towers of the Waldo-Hancock Bridge. This temporary final rule (TFR) is necessary to provide for the safety of life on the...

  1. 76 FR 53531 - Environmental Impact Statement: Hancock County, MS

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ... Federal Highway Administration Environmental Impact Statement: Hancock County, MS AGENCY: Federal Highway... this notice to advise the public that an environmental impact statement will be prepared for a proposed... Transportation (MDOT), will prepare an Environmental Impact Statement (EIS) for the proposed widening and/or...

  2. 5. HANCOCK AVENUE NEAR HIGH WATER MARK LOOKING SOUTH TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. HANCOCK AVENUE NEAR HIGH WATER MARK LOOKING SOUTH TO PENNSYLVANIA MONUMENT. NOTE LINE OF MONUMENTS AND CONTEMPORARY ADAPTATION OF GUTTER, (PAVED WITH YELLOW CAUTION MARKINGS) NOT STONE LINED. VIEW S. - Gettysburg National Military Park Tour Roads, Gettysburg, Adams County, PA

  3. Hydrologic description of Lake Hancock, Polk County, Florida

    USGS Publications Warehouse

    Hammett, K.M.; Snell, L.J.; Joyner, Boyd F.

    1981-01-01

    Available data were evaluated to document hydrologic conditions in the Lake Hancock basin. Bathymetric data indicate that Lake Hancock is very shallow, having a maximum depth of about 3 feet. The lake bottom is covered by a layer of organic material that may be more than 5 feet thick near the center of the lake. Lake Hancock 's stage fluctuates within 0.5 foot of average stage about 40 percent of the time. Lake outflow is through an operable control. There are many days with no outflow in some years. A water-budget analysis of the lake indicates that substantial lake stage declines in 1968 and 1975 followed successive years of deficient precipitation and were primarily the result of a net loss of water from the lake to the ground-water system. During a period in 1971-72 when lake stage remained relatively stable, the ground-water system contributed a significant volume of water to the lake. Water-quality data indicate that Lake Hancock is in a eutrophic state. The eutrophication process appears to have been accelerated through the addition of nutrients from inflow of wastewater effluent from secondary treatment plants. (USGS)

  4. Pressure drop and temperature rise in He II flow in round tubes, Venturi flowmeters and valves

    NASA Technical Reports Server (NTRS)

    Walstrom, P. L.; Maddocks, J. R.

    1988-01-01

    Pressure drops in highly turbulent He II flow were measured in round tubes, valves, and Venturi flowmeters. Results are in good agreement with single-phase flow correlations for classical fluids. The temperature rise in flow in a round tube was measured, and found to agree well with predictions for isenthalpic expansion. Cavitation was observed in the venturis under conditions of low back pressure and high flow rate. Metastable superheating of the helium at the venturi throat was observed before the helium made a transition to saturation pressure.

  5. Optimal Implantation Depth and Adherence to Guidelines on Permanent Pacing to Improve the Results of Transcatheter Aortic Valve Replacement With the Medtronic CoreValve System: The CoreValve Prospective, International, Post-Market ADVANCE-II Study.

    PubMed

    Petronio, Anna S; Sinning, Jan-Malte; Van Mieghem, Nicolas; Zucchelli, Giulio; Nickenig, Georg; Bekeredjian, Raffi; Bosmans, Johan; Bedogni, Francesco; Branny, Marian; Stangl, Karl; Kovac, Jan; Schiltgen, Molly; Kraus, Stacia; de Jaegere, Peter

    2015-05-01

    The aim of the CoreValve prospective, international, post-market ADVANCE-II study was to define the rates of conduction disturbances and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement with the Medtronic CoreValve System (Minneapolis, Minnesota) using optimized implantation techniques and application of international guidelines on cardiac pacing. Conduction disturbances are a frequent complication of transcatheter aortic valve replacement. The rates of PPI in the published reports vary according to bioprosthesis type and the indications for PPI. The primary endpoint was the 30-day incidence of PPI with Class I/II indications when the Medtronic CoreValve System was implanted at an optimal depth (≤6 mm below the aortic annulus). The timing and resolution of all new-onset conduction disturbances were analyzed. A total of 194 patients were treated. The overall rate of PPI for Class I/II indications was 18.2%. An optimal depth was reached in 43.2% of patients, with a nonsignificantly lower incidence of PPI in patients with depths ≤6 mm, compared with those with deeper implants (13.3% vs. 21.1%; p = 0.14). In a paired analysis, new-onset left bundle branch block and first-degree atrioventricular block occurred in 45.4% and 39.0% of patients, respectively, and resolved spontaneously within 30 days in 43.2% and 73.9%, respectively. In patients with new PPI, the rate of intrinsic sinus rhythm increased from 25.9% at 7 days to 59.3% at 30 days (p = 0.004). Optimal Medtronic CoreValve System deployment and adherence to international guidelines on cardiac pacing are associated with a lower rate of new PPI after transcatheter aortic valve replacement, compared with results reported in previous studies. (CoreValve Advance-II Study: Prospective International Post-Market Study [ADVANCE II]; NCT01624870). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  6. Scoping of Flood Hazard Mapping Needs for Hancock County, Maine

    USGS Publications Warehouse

    Schalk, Charles W.; Dudley, Robert W.

    2007-01-01

    Background The Federal Emergency Management Agency (FEMA) developed a plan in 1997 to modernize the FEMA flood mapping program. FEMA flood maps delineate flood hazard areas in support of the National Flood Insurance Program (NFIP). FEMA's plan outlined the steps necessary to update FEMA's flood maps for the nation to a seamless digital format and streamline FEMA's operations in raising public awareness of the importance of the maps and responding to requests to revise them. The modernization of flood maps involves conversion of existing information to digital format and integration of improved flood hazard data as needed. To determine flood mapping modernization needs, FEMA has established specific scoping activities to be done on a county-by-county basis for identifying and prioritizing requisite flood-mapping activities for map modernization. The U.S. Geological Survey (USGS), in cooperation with FEMA and the Maine Floodplain Management Program (MFMP) State Planning Office, began scoping work in 2006 for Hancock County. Scoping activities included assembling existing data and map needs information for communities in Hancock County, documentation of data, contacts, community meetings, and prioritized mapping needs in a final scoping report (this document), and updating the Mapping Needs Update Support System (MNUSS) database with information gathered during the scoping process. The average age of the FEMA floodplain maps (all types) in Hancock County, Maine, is at least 19 years. Most of these studies were published in the late 1980s and early 1990s, and no study is more recent than 1992. Some towns have partial maps that are more recent than their study, indicating that the true average age of the data is probably more than 19 years. Since the studies were done, development has occurred in some of the watersheds and the characteristics of the watersheds have changed. Therefore, many of the older studies may not depict current conditions or accurately estimate

  7. Elevated Serotonin Interacts with Angiotensin-II to Result in Altered Valve Interstitial Cell Contractility and Remodeling.

    PubMed

    Perez, Jessica; Diaz, Nancy; Tandon, Ishita; Plate, Rachel; Martindale, Christopher; Balachandran, Kartik

    2017-02-28

    While the valvulopathic effects of serotonin (5HT) and angiotensin-II (Ang-II) individually are known, it was not clear how 5HT and Ang-II might interact, specifically in the context of the mechanobiological responses due to altered valve mechanics potentiated by these molecules. In this context, the hypothesis of this study was that increased serotonin levels would result in accelerated progression toward disease in the presence of angiotensin-II-induced hypertension. C57/BL6 J mice were divided into four groups and subcutaneously implanted with osmotic pumps containing: PBS (control), 5HT (2.5 ng/kg/min), Ang-II (400 ng/kg/min), and 5HT + Ang-II (combination). Blood pressure was monitored using the tail cuff method. Echocardiography was performed on the mice before surgery and every week thereafter to assess ejection fraction. After three weeks, the mice were sacrificed and their hearts excised, embedded and sectioned for analysis of the aortic valves via histology and immunohistochemistry. In separate experiments, porcine valve interstitial cells (VICs) were directly stimulated with 5HT (10(-7) M), Ang-II (100 nM) or both and assayed for cellular contractility, cytoskeletal organization and collagen remodeling. After three weeks, average systolic blood pressure was significantly increased in the 5HT, Ang-II and combination groups compared to control. Echocardiographic analysis demonstrated significantly reduced ejection fraction in Ang-II and the combination groups. H&E staining demonstrated thicker leaflets in the combination groups, suggesting a more aggressive remodeling process. Picrosirius red staining and image analysis suggested that the Ang-II and combination groups had the largest proportion of thicker collagen fibers. VIC orientation, cellular contractility and collagen gene expression was highest for the 5HT + Ang-II combination treatment compared to all other groups. Overall, our results suggest that 5HT and Ang-II interact to result in

  8. 76 FR 53531 - Rescinding the Notice of Intent for an Environmental Impact Statement (EIS): Hancock and Pearl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ...): Hancock and Pearl River Counties, MS AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Rescind... Interstate 10 south of Kiln and Interstate 59 in the City of Picayune, Hancock and Pearl River Counties...

  9. 77 FR 41717 - Regulated Navigation Area; Original Waldo-Hancock Bridge Removal, Penobscot River, Bucksport, ME

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-16

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA11 Regulated Navigation Area; Original Waldo-Hancock Bridge... of the Penobscot River near Bucksport, ME, under and surrounding the original Waldo-Hancock Bridge in... life on the navigable waters during bridge deconstruction operations that could pose an imminent hazard...

  10. Proceedings: EPRI (Electric Power Research Institute) Power Plant valves symposium II

    SciTech Connect

    Brooks, B.; McCloskey, T.H.

    1989-07-01

    On October 11-12, 1988, an EPRI Power Plant Valves Symposium was conducted in Charlotte, North Carolina, to address significant current issues relating to valves in both nuclear and fossil fueled power plants. This was the second such meeting on this subject. The proceedings of the first meeting are published in EPRI Report CS/NP 5878-SR. Approximately 250 attendees, consisting of representatives from the utility industry, valve manufacturers and service organizations, and government, university and other organizations, participated in the symposium. A total of 14 technical papers was presented in the following three major categories: Check Valve Performance, Motor Operated Valve Performance, and Valve Improvement Programs. Separate from the formal presentations of the symposium, discussion groups were organized for each of these categories to provide a format for further discussion, description of experience, and exchange of ideas. 46 refs., 76 figs., 17 tabs.

  11. Technology Reinvestment Program/Advanced ``Zero Emission'' Control Valve (Phase II)

    SciTech Connect

    J. Napoleon

    1998-12-01

    The objectives of this effort are to determine, develop and demonstrate the feasibility of significantly reducing the cost and expanding the applications for a family of Advanced Zero Emissions Control Valves that meets the fugitive emissions requirements of the 1990 Amendments to the Clean Air Act. This program is a direct technology spin-off from the valve technology that is critical to the US Navy's Nuclear Powered Fleet. These zero emissions valves will allow the Hydrocarbon and Chemical Processing Industries, etc., to maintain their competitiveness and still meet environmental and safety requirements. Phase 2 is directed at refining the basic technologies developed during Phase 1 so that they can be more readily selected and utilized by the target market. In addition to various necessary certifications, the project will develop a full featured digital controller with ``smart valve'' growth capability, expanding valve sizes/applications and identifying valve materials to permit applications in severe operational environments.

  12. 77 FR 20046 - Establishment of the Gateway National Recreation Area Fort Hancock 21st Century Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... Establishment of the Gateway National Recreation Area Fort Hancock 21st Century Advisory Committee AGENCY... Interior (Secretary) is announcing the establishment of the Gateway National Recreation Area Fort Hancock... relating to future uses of the Fort Hancock Historic Landmark District of Gateway National Recreation area...

  13. Hancocked: Manulife and the Limits of Private Health Insurance

    PubMed Central

    Evans, Robert G.

    2011-01-01

    Long-term care (LTC) insurance is a salesman's dream. Millions of well-heeled boomers, anxious to protect their estates from the random expropriation of institutional dependency — what a market! But for Manulife, bleeding $1.5 million a day in LTC claims through subsidiary John Hancock, LTC is a nightmare. Company spokesmen blame unexpected increases in life expectancy. But management's fundamental error was insuring correlated risks. Risk pooling works only when individual risks are uncorrelated. Increases in life expectancy affect all contracts together. Manulife made the same mistake selling equity-linked annuities with guaranteed floors — essentially insuring against stock market declines. Results for shareholders have been catastrophic. Top management, meanwhile, have been honoured and richly rewarded. PMID:22851982

  14. Hancocked: manulife and the limits of private health insurance.

    PubMed

    Evans, Robert G

    2011-08-01

    Long-term care (LTC) insurance is a salesman's dream. Millions of well-heeled boomers, anxious to protect their estates from the random expropriation of institutional dependency - what a market! But for Manulife, bleeding $1.5 million a day in LTC claims through subsidiary John Hancock, LTC is a nightmare. Company spokesmen blame unexpected increases in life expectancy. But management's fundamental error was insuring correlated risks. Risk pooling works only when individual risks are uncorrelated. Increases in life expectancy affect all contracts together. Manulife made the same mistake selling equity-linked annuities with guaranteed floors - essentially insuring against stock market declines. Results for shareholders have been catastrophic. Top management, meanwhile, have been honoured and richly rewarded.

  15. Installation Restoration Program. Phase I. Records Search, Hancock Field, New York.

    DTIC Science & Technology

    1982-07-01

    ADCOM Region was created. Hancock Field now serves as headquarters for the 21st NORAD Region, the 21st ADCOM Region and the 21st Air Division. Hancock...The newest realignment, occurred in mid 1979, placed the 21st Air Division under Tactical Air Command. Earlier in the year, the 21st ADCOM Region was...created. Hancock Field will now serve as headquarters for the 21st NORAD Region, the 21st ADCOM Region and the 21st Air Division. TENANT MISSIONS

  16. Tricuspid valve endocarditis complicated by Mobitz type II heart block – a case report and literature review

    PubMed Central

    Agu, Chidozie Charles; Salhan, Divya; Bakhit, Ahmed; Basheer, Hiba; Basunia, Md; Bhattarai, Bikash; Oke, Vikram; Schmidt, Marie Frances; Dufresne, Alix

    2015-01-01

    We present a case of a middle-aged male who manifested with low-grade fever and lower back pain. MRI and bone scan of the spine were suggestive of vertebral osteomyelitis. Blood cultures were persistently positive for Enterococcus faecalis and echocardiogram revealed tricuspid valve endocarditis. There was no history of IV drug use and urine toxicology was negative. EKG showed Mobitz type II AV block and a transesophageal echocardiogram revealed no valve ring or septal abscesses. The heart block persisted despite antibiotic therapy and an epicardial pacemaker was placed. This is a rare presentation of high-grade AV block with tricuspid endocarditis in the absence of echocardiographic evidence of perivalvular extension of infection. Also, unique in this case is the finding of E. faecalis hematogenous vertebral osteomyelitis. PMID:26653699

  17. Acute and 12-month results with catheter-based mitral valve leaflet repair: the EVEREST II (Endovascular Valve Edge-to-Edge Repair) High Risk Study.

    PubMed

    Whitlow, Patrick L; Feldman, Ted; Pedersen, Wes R; Lim, D Scott; Kipperman, Robert; Smalling, Richard; Bajwa, Tanvir; Herrmann, Howard C; Lasala, John; Maddux, James T; Tuzcu, Murat; Kapadia, Samir; Trento, Alfredo; Siegel, Robert J; Foster, Elyse; Glower, Donald; Mauri, Laura; Kar, Saibal

    2012-01-10

    The EVEREST II (Endovascular Valve Edge-to-Edge Repair) High Risk Study (HRS) assessed the safety and effectiveness of the MitraClip device (Abbott Vascular, Santa Clara, California) in patients with significant mitral regurgitation (MR) at high risk of surgical mortality rate. Patients with severe MR (3 to 4+) at high risk of surgery may benefit from percutaneous mitral leaflet repair, a potentially safer approach to reduce MR. Patients with severe symptomatic MR and an estimated surgical mortality rate of ≥12% were enrolled. A comparator group of patients screened concurrently but not enrolled were identified retrospectively and consented to compare survival in patients treated by standard care. Seventy-eight patients underwent the MitraClip procedure. Their mean age was 77 years, >50% had previous cardiac surgery, and 46 had functional MR and 32 degenerative MR. MitraClip devices were successfully placed in 96% of patients. Protocol-predicted surgical mortality rate in the HRS and concurrent comparator group was 18.2% and 17.4%, respectively, and Society of Thoracic Surgeons calculator estimated mortality rate was 14.2% and 14.9%, respectively. The 30-day procedure-related mortality rate was 7.7% in the HRS and 8.3% in the comparator group (p = NS). The 12-month survival rate was 76% in the HRS and 55% in the concurrent comparator group (p = 0.047). In surviving patients with matched baseline and 12-month data, 78% had an MR grade of ≤2+. Left ventricular end-diastolic volume improved from 172 ml to 140 ml and end-systolic volume improved from 82 ml to 73 ml (both p = 0.001). New York Heart Association functional class improved from III/IV at baseline in 89% to class I/II in 74% (p < 0.0001). Quality of life was improved (Short Form-36 physical component score increased from 32.1 to 36.1 [p = 0.014] and the mental component score from 45.5 to 48.7 [p = 0.065]) at 12 months. The annual rate of hospitalization for congestive heart failure in surviving patients

  18. Update: Cardiac Imaging (II). Transcatheter Aortic Valve Replacement: Advantages and Limitations of Different Cardiac Imaging Techniques.

    PubMed

    Podlesnikar, Tomaz; Delgado, Victoria

    2016-03-01

    Transcatheter aortic valve replacement is an established therapy for patients with symptomatic severe aortic stenosis and contraindications or high risk for surgery. Advances in prostheses and delivery system designs and continuous advances in multimodality imaging, particularly the 3-dimensional techniques, have led to improved outcomes with significant reductions in the incidence of frequent complications such as paravalvular aortic regurgitation. In addition, data on prosthesis durability are accumulating. Multimodality imaging plays a central role in the selection of patients who are candidates for transcatheter aortic valve replacement, procedure planning and guidance, and follow-up of prosthesis function. The strengths and limitations of each imaging technique for transcatheter aortic valve replacement will be discussed in this update article. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  19. Percutaneous mitral valve repair for mitral regurgitation in high-risk patients: results of the EVEREST II study.

    PubMed

    Glower, Donald D; Kar, Saibal; Trento, Alfredo; Lim, D Scott; Bajwa, Tanvir; Quesada, Ramon; Whitlow, Patrick L; Rinaldi, Michael J; Grayburn, Paul; Mack, Michael J; Mauri, Laura; McCarthy, Patrick M; Feldman, Ted

    2014-07-15

    The EVEREST II (Endovascular Valve Edge-to-Edge REpair STudy) High-Risk registry and REALISM Continued Access Study High-Risk Arm are prospective registries of patients who received the MitraClip device (Abbott Vascular, Santa Clara, California) for mitral regurgitation (MR) in the United States. The purpose of this study was to report 12-month outcomes in high-risk patients treated with the percutaneous mitral valve edge-to-edge repair. Patients with grades 3 to 4+ MR and a surgical mortality risk of ≥12%, based on the Society of Thoracic Surgeons risk calculator or the estimate of a surgeon coinvestigator following pre-specified protocol criteria, were enrolled. In the studies, 327 of 351 patients completed 12 months of follow-up. Patients were elderly (76 ± 11 years of age), with 70% having functional MR and 60% having prior cardiac surgery. The mitral valve device reduced MR to ≤2+ in 86% of patients at discharge (n = 325; p < 0.0001). Major adverse events at 30 days included death in 4.8%, myocardial infarction in 1.1%, and stroke in 2.6%. At 12 months, MR was ≤2+ in 84% of patients (n = 225; p < 0.0001). From baseline to 12 months, left ventricular (LV) end-diastolic volume improved from 161 ± 56 ml to 143 ± 53 ml (n = 203; p < 0.0001) and LV end-systolic volume improved from 87 ± 47 ml to 79 ± 44 ml (n = 202; p < 0.0001). New York Heart Association functional class improved from 82% in class III/IV at baseline to 83% in class I/II at 12 months (n = 234; p < 0.0001). The 36-item Short Form Health Survey physical and mental quality-of-life scores improved from baseline to 12 months (n = 191; p < 0.0001). Annual hospitalization rate for heart failure fell from 0.79% pre-procedure to 0.41% post-procedure (n = 338; p < 0.0001). Kaplan-Meier survival estimate at 12 months was 77.2%. The percutaneous mitral valve device significantly reduced MR, improved clinical symptoms, and decreased LV dimensions at 12 months in this high-surgical-risk cohort

  20. Level II scour analysis for Bridge 8 (HANCTH00020008) on Town Highway 2, crossing Hancock Branch White River, Hancock, Vermont

    USGS Publications Warehouse

    Boehmler, Erick M.

    1996-01-01

    Contraction scour for all modelled flows ranged from 0.6 ft to 1.3 ft and the worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 9.4 ft to 15.2 ft and the worst-case abutment scour occurred at the 500-year discharge. Scour depths and depths to armoring are summarized on p. 14 in the section titled “Scour Results”. Scour elevations, based on the calculated depths are presented in tables 1 and 2; a graph of the scour elevations is presented in figure 8 Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. For all scour presented in this report, “the scour depths adopted [by VTAOT] may differ from the equation values based on engineering judgement” (Richardson and others, 1993, p. 21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, including historical performance during flood events, the geomorphic assessment, and the results of the hydraulic analyses, must be considered to properly assess the validity of abutment scour results.

  1. Insights into the need for permanent pacemaker following implantation of the repositionable LOTUS valve for transcatheter aortic valve replacement in 250 patients: results from the REPRISE II trial with extended cohort.

    PubMed

    Dumonteil, Nicolas; Meredith, Ian T; Blackman, Daniel J; Tchétché, Didier; Hildick-Smith, David; Spence, Mark S; Walters, Darren L; Harnek, Jan; Worthley, Stephen G; Rioufol, Gilles; Lefèvre, Thierry; Modine, Thomas; Van Mieghem, Nicolas; Houle, Vicki M; Allocco, Dominic J; Dawkins, Keith D

    2017-09-20

    This analysis aimed to evaluate the incidence and predictors of the need for permanent pacemaker (PPM) implantation following implantation of the repositionable and fully retrievable LOTUS Aortic Valve Replacement System. The prospective, single-arm, multicentre REPRISE II study with extended cohort enrolled 250 symptomatic, high surgical risk patients with severe aortic stenosis for transfemoral transcatheter aortic valve implantation (TAVI) with a 23 mm or 27 mm LOTUS valve. Echocardiography, computed tomography, and electrocardiography data were evaluated by independent core labs. Post TAVI, 32.0% (72/225) of pacemaker-naïve patients underwent new PPM implantation at 30 days. Most (59/72, 82%) patients were implanted for third-degree atrioventricular block, and >10% overstretch of the LVOT by area was observed in 59.7% (43/72) of PPM patients. Significant independent predictors of PPM at 30 days included baseline RBBB (odds ratio [OR] 12.7, 95% CI: 4.5, 36.2; p<0.001) and LVOT overstretch >10% (OR 3.4, 95% CI: 1.7, 6.7; p<0.001). There was a trend towards a lower 30-day PPM rate in patients with a shallower (≤5 mm) implant depth (23.9% ≤5 mm vs. 36.9% >5 mm depth from LCS; p=0.06). Careful attention to valve sizing and implant depth may help to reduce the rate of PPM with the LOTUS valve.

  2. Safety valve

    DOEpatents

    Bergman, Ulf C.

    1984-01-01

    The safety valve contains a resilient gland to be held between a valve seat and a valve member and is secured to the valve member by a sleeve surrounding the end of the valve member adjacent to the valve seat. The sleeve is movable relative to the valve member through a limited axial distance and a gap exists between said valve member and said sleeve.

  3. Teaching and Learning Spaces; Refurbishment of the W. K. Hancock Science Library at the Australian National University 2011

    ERIC Educational Resources Information Center

    McNamara, Paul

    2012-01-01

    Two floors of the W. K. Hancock Library at the Australian National University (ANU) were refurbished in 2011 as part of a cooperative project between the library and the College of Science. The refurbishment, costing $5 million, was part of a much larger exercise involving the construction of four new science buildings around the Hancock Library.…

  4. Teaching and Learning Spaces; Refurbishment of the W. K. Hancock Science Library at the Australian National University 2011

    ERIC Educational Resources Information Center

    McNamara, Paul

    2012-01-01

    Two floors of the W. K. Hancock Library at the Australian National University (ANU) were refurbished in 2011 as part of a cooperative project between the library and the College of Science. The refurbishment, costing $5 million, was part of a much larger exercise involving the construction of four new science buildings around the Hancock Library.…

  5. Numerical simulation of steady turbulent flow through trileaflet aortic heart valves--II. Results on five models.

    PubMed

    Stevenson, D M; Yoganathan, A P; Williams, F P

    1985-01-01

    Turbulent flow simulations are run for five aortic trileaflet valve geometries, ranging from a valve leaflet orifice area of 1.1 cm2 (Model A1--very stenotic) to 5.0 cm2 (Model A5--natural valve). The simulated data compares well with experimental measurements made downstream of various aortic trileaflet valves by Woo (PhD Thesis, 1984). The location and approximate width and length of recirculation regions are correctly predicted. The less stenotic valve models reattach at the end of the aortic sinus region, 1.1 diameters downstream of the valve. The central jet exiting the less stenotic valve models is not significantly different from fully developed flow, and therefore recovers very quickly downstream of the reattachment point. The more stenotic valves disturb the flow to a greater degree, generating recirculation regions large enough to escape the sinuses and reattach further downstream. Peak turbulent shear stress values downstream of the aortic valve models which approximated prosthetic valves are 125 and 300 Nm-2, very near experimental observations of 150 to 350 Nm-2. The predicted Reynolds stress profiles also present the correct shape, a double peak profile, with the location of the peak occurring at the location of maximum velocity gradient, which occurs near the recirculation region. The pressure drop across model A2 (leaflet orifice area 1.6 cm2) is 20 mmHg at 1.6 diameters downstream. This compares well with values ranging from 19.5 to 26.2 mmHg for valves of similar orifice areas. The pressure drop decreases with decreasing valve stenosis, to a negligible value across the least stenotic valve model. Based on the good agreement between experimental measurements of velocity, shear stress and pressure drop, compared to the simulated data, the model has the potential to be a valuable tool in the analysis of heart valve designs.

  6. An Update on Noise and Performance: Comment on Szalma and Hancock (2011)

    ERIC Educational Resources Information Center

    Smith, Andrew

    2012-01-01

    Reviews of the effects of noise on performance carried out in the 1980s suggested that results depended on the type of noise, nature of the task, and characteristics of the person performing in noise. This general view has been confirmed in the recent meta-analysis and synthesis by Szalma and Hancock (2011). There are, however, some notable…

  7. An Update on Noise and Performance: Comment on Szalma and Hancock (2011)

    ERIC Educational Resources Information Center

    Smith, Andrew

    2012-01-01

    Reviews of the effects of noise on performance carried out in the 1980s suggested that results depended on the type of noise, nature of the task, and characteristics of the person performing in noise. This general view has been confirmed in the recent meta-analysis and synthesis by Szalma and Hancock (2011). There are, however, some notable…

  8. The Hancock County Katrina Relief Initiative: Focusing Collaborative Leadership to Facilitate Recovery after a Natural Disaster

    ERIC Educational Resources Information Center

    McNeese, Rose M.; Peters, Gary

    2009-01-01

    Eighteen months after Hurricane Katrina devastated the Mississippi coastal community of Hancock County on August 29, 2005, volunteers and organizations assisting with recovery in the area found chaos, confusion, and a desperate need for leadership. This qualitative study reflects the efforts of two University of Southern Mississippi professors as…

  9. The Dawn Hancock Animal Farm. Farming Experiences for Children with Mental Handicaps.

    ERIC Educational Resources Information Center

    Lee, Ronald A.

    The Dawn Hancock Animal Farm, which was developed in 1974 with volunteer labor and over $100,000 in donations, provides farm experiences for the mentally handicapped students of the Helen J. Stewart School in Las Vegas, Nevada. The farm and animals are part of the school's emphasis on vocational training, and every effort is made to help prepare…

  10. The Dawn Hancock Animal Farm. Farming Experiences for Children with Mental Handicaps.

    ERIC Educational Resources Information Center

    Lee, Ronald A.

    The Dawn Hancock Animal Farm, which was developed in 1974 with volunteer labor and over $100,000 in donations, provides farm experiences for the mentally handicapped students of the Helen J. Stewart School in Las Vegas, Nevada. The farm and animals are part of the school's emphasis on vocational training, and every effort is made to help prepare…

  11. [Doppler echocardiography in assessing mechanical and biological heart valve prostheses].

    PubMed

    Minardi, G; Di Segni, M; Boccardi, L; Ferrari, O; Giovannini, E

    1988-02-01

    The study was performed to assess Doppler echocardiographic features of mitral and aortic prosthetic valves of different types with both normal and abnormal function. Two hundred and twenty-three patients with 250 prostheses were studied. Two hundred eight valves (111 mitral, 95 aortic and 2 tricuspid) were considered to be functioning normally after clinical examination, phonocardiography and M-mode and 2D echocardiography. This group enabled us to define normal Doppler echocardiographic findings for different types of prosthesis. In mitral position, peak (p) and mean (m) gradients were lower for disc prostheses and higher for ball and biological prosthetic valves; values of effective orifice area (A), calculated by pressure half-time method, were lower for biological and ball prostheses and higher in disc valves. Results were as follows: St. Jude (p 10.6 mmHg, m 3.9 mmHg, A 2.7 cm2), Duromedics (p 10.6, m 4.3, A 2.8), Björk-Shiley (p 10.4, m 4, A 2.3), Omniscience (p 14.2, m 6.2, A 2.1), Starr-Edwards (p 15.9, m 5.4, A 2.1), Hancock (p 14.7, m 6, A 2), Carpentier (p 13.2, m 5.4, A 1.9). Mild regurgitation, considered "physiological", was found in 2/8 Carpentier valves and in 3/34 St. Jude prostheses. In aortic valves lower peak gradients were found in Lillehei (18.3 mmHg), St. Jude (23.8 mmHg), Björk-Shiley (26 mmHg), Duromedics (27 mmHg) and higher values in Starr-Edwards (30.2 mmHg), Hancock (30 mmHg) and Omniscience (35.5 mmHg) prostheses. Mild regurgitation, considered "physiological", was found in 17% of Omniscience valves, 21% of Hancock, 33% of Duromedics, 45% of St. Jude, 60% of Björk-Shiley prostheses. Hancock mitral valves implanted for over 7 years had a mean gradient higher than valves with a shorter period of implantation (7.6 vs 4.85 mmHg, p less than 0.1), whereas the effective orifice area was similar. Hancock aortic valves implanted for over 7 years had a peak gradient slightly higher than the other group (implantation less than 7 years

  12. An in-vitro assessment of the hydraulic characteristics of the mark II Abrams-Lucas mitral valve prosthesis.

    PubMed Central

    Wright, J T

    1977-01-01

    As a result of the durability problems associated with the first Abrams-Lucas mitral valve, a redesigned model has recently been introduced into limited clinical trials. The new valve was subjected to in-vitro pulsatile flow studies, and measurements were made of mean diastolic pressure gradient and volume of reflux on closure. Similar measurements were made on other mitral valve prostheses of comparable size. High-speed cinematography was used to analyse the motion of the occluder during the simulated cardiac cycle, and the flow patterns produced by the valve in the model ventricular cavity were observed and photographed. The pressure gradient of the Abrams-Lucas valve was significantly lower than that of the 29 mm Björk-Shiley valve and all other prostheses tested, but its reflux level was higher at 12 ml per stroke. The valve opened and closed smoothly and the flow visualisation study revealed that the valve produced a large vortex or swirl in the model ventricular cavity. Images PMID:882943

  13. The angiotensin II type 1 receptor blocker losartan attenuates bioprosthetic valve leaflet calcification in a rabbit intravascular implant model.

    PubMed

    Shin, Hong Ju; Kim, Dae-Hyun; Park, Han Ki; Park, Young Hwan

    2016-12-01

    There is evidence that angiotensin II type I receptor blocker (ARB) could reduce structural valve deterioration. However, the anticalcification effect on the bioprosthetic heart valve (BHV) has not been investigated. Thus, we investigated the effects of losartan (an ARB) on calcification of implanted bovine pericardial tissue in a rabbit intravascular implant model. A total of 16 male New Zealand White rabbits (20 weeks old, 2.98-3.34 kg) were used in this study. Commercially available BHV leaflet of bovine pericardium was trimmed to the shape of a 3-mm triangle and implanted to both external jugular veins of the rabbit. The ARB group (n = 8) was given 25 mg/kg of powdered losartan daily until 6 weeks after surgery by direct administration in the buccal pouch of the animals. The control group (n = 8) was given 5 ml of normal saline by the same method. After 6 weeks, quantitative calcium determination, histological evaluation and western blot analysis of interleukin-6 (IL-6), osteopontin and bone morphogenetic protein 2 (BMP-2) were performed to investigate the mechanisms of the anticalcification effect of losartan. No deaths or complications such as infection or haematoma were recorded during the experiment. All animals were euthanized on the planned date. The calcium measurement level in the ARB group (2.28 ± 0.65 mg/g) was significantly lower than that in the control group (3.68 ± 1.00 mg/g) (P = 0.0092). Immunohistochemistry analyses revealed that BMP-2-positive reactions were significantly attenuated in the ARB group. Western blot analysis showed that losartan suppressed the expression of IL-6, osteopontin and BMP-2. Our results indicate that losartan significantly attenuates postimplant degenerative calcification of a bovine pericardial bioprosthesis in a rabbit intravascular implant model. Further studies are required to assess the effects of ARBs on BHV tissue in orthotopic implantations using a large animal model. © The Author 2016. Published by Oxford

  14. 78 FR 78382 - Notice of January 10, 2014, Meeting of the Fort Hancock 21st Century Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ... National Park Service Notice of January 10, 2014, Meeting of the Fort Hancock 21st Century Advisory... meeting of the Fort Hancock 21st Century Advisory Committee will be held on January 10, 2014, at 9:00 a.m... January 10, 2014, from 1:00 p.m.to 1:45 p.m. Written comments will be accepted prior to, during, or...

  15. 78 FR 11901 - Notice of March 12, 2013 Meeting for Fort Hancock 21st Century Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-20

    ... National Park Service Notice of March 12, 2013 Meeting for Fort Hancock 21st Century Advisory Committee... of the Fort Hancock 21st Century Advisory Committee will be held on March 12, 2013, at 9:00 a.m... March 12, 2013, from 4:00 p.m. to 4:45 p.m. Written comments will be accepted prior to, during or after...

  16. Plug valve

    DOEpatents

    Wordin, John J.

    1989-01-01

    An improved plug valve wherein a novel shape for the valve plug and valve chamber provide mating surfaces for improved wear characteristics. The novel shape of the valve plug is a frustum of a body of revolution of a curved known as a tractrix, a solid shape otherwise known as a peudosphere.

  17. Predictors of Paravalvular Regurgitation After Implantation of the Fully Repositionable and Retrievable Lotus Transcatheter Aortic Valve (from the REPRISE II Trial Extended Cohort).

    PubMed

    Blackman, Daniel J; Meredith, Ian T; Dumonteil, Nicolas; Tchétché, Didier; Hildick-Smith, David; Spence, Mark S; Walters, Darren L; Harnek, Jan; Worthley, Stephen G; Rioufol, Gilles; Lefèvre, Thierry; Houle, Vicki M; Allocco, Dominic J; Dawkins, Keith D

    2017-07-15

    Paravalvular leak (PVL) after transcatheter aortic valve replacement is associated with worse long-term outcomes. The Lotus Valve incorporates an innovative Adaptive Seal designed to minimize PVL. This analysis evaluated the incidence and predictors of PVL after implantation of the Lotus transcatheter aortic valve. The REPRISE II (REpositionable Percutaneous Replacement of Stenotic Aortic Valve through Implantation of Lotus Valve System - Evaluation of Safety and Performance) Study With Extended Cohort enrolled 250 high-surgical risk patients with severe symptomatic aortic stenosis. Aortic regurgitation was assessed by echocardiography pre-procedure, at discharge and 30 days, by an independent core laboratory. Baseline and procedural predictors of mild or greater PVL at 30 days (or at discharge if 30-day data were not available) were determined using a multivariate regression model (n = 229). Of the 229 patients, 197 (86%) had no/trace PVL, 30 had mild, and 2 had moderate PVL; no patient had severe PVL. Significant predictors of mild/moderate PVL included device:annulus area ratio (odds ratio [OR] 0.87; 95% CI 0.83 to 0.92; p <0.001), left ventricular outflow tract calcium volume (OR 2.85; 95% CI 1.44 to 5.63; p = 0.003), and annulus area (OR 0.89; 95% CI 0.82 to 0.96; p = 0.002). When the device:annulus area ratio was <1, the rate of mild/moderate PVL was 53.1% (17 of 32). The rates of mild/moderate PVL with 0% to 5%, 5% to 10%, and >10% annular oversizing by area were 17.5% (11 of 63), 2.9% (2 of 70), and 3.2% (2 of 63), respectively. Significant independent predictors of PVL included device:annulus area ratio and left ventricular outflow tract calcium volume. When the prosthetic valve was oversized by ≥5%, the rate of mild or greater PVL was only 3%. In conclusion, the overall rates of PVL with the Lotus Valve are low and predominantly related to device/annulus areas and calcium; these findings have implications for optimal device sizing. Copyright

  18. 21 CFR 868.5870 - Nonrebreathing valve.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Identification. A nonrebreathing valve is a one-way valve that directs breathing gas flow to the patient and vents exhaled gases into the atmosphere. (b) Classification. Class II (performance standards)....

  19. Check valve

    DOEpatents

    Upton, H.A.; Garcia, P.

    1999-08-24

    A check valve for use in a GDCS of a nuclear reactor and having a motor driven disk including a rotatable armature for rotating the check valve disk over its entire range of motion is described. In one embodiment, the check valve includes a valve body having a coolant flow channel extending therethrough. The coolant flow channel includes an inlet end and an outlet end. A valve body seat is located on an inner surface of the valve body. The check valve further includes a disk assembly, sometimes referred to as the motor driven disc, having a counterweight and a disk shaped valve. The disk valve includes a disk base having a seat for seating with the valve body seat. The disk assembly further includes a first hinge pin member which extends at least partially through the disk assembly and is engaged to the disk. The disk valve is rotatable relative to the first hinge pin member. The check valve also includes a motor having a stator frame with a stator bore therein. An armature is rotatably positioned within the stator bore and the armature is coupled to the disk valve to cause the disk valve to rotate about its full range of motion. 5 figs.

  20. Check valve

    DOEpatents

    Upton, Hubert Allen; Garcia, Pablo

    1999-08-24

    A check valve for use in a GDCS of a nuclear reactor and having a motor driven disk including a rotatable armature for rotating the check valve disk over its entire range of motion is described. In one embodiment, the check valve includes a valve body having a coolant flow channel extending therethrough. The coolant flow channel includes an inlet end and an outlet end. A valve body seat is located on an inner surface of the valve body. The check valve further includes a disk assembly, sometimes referred to as the motor driven disc, having a counterweight and a disk shaped valve. The disk valve includes a disk base having a seat for seating with the valve body seat. The disk assembly further includes a first hinge pin member which extends at least partially through the disk assembly and is engaged to the disk. The disk valve is rotatable relative to the first hinge pin member. The check valve also includes a motor having a stator frame with a stator bore therein. An armature is rotatably positioned within the stator bore and the armature is coupled to the disk valve to cause the disk valve to rotate about its full range of motion.

  1. 1-Year Outcomes With the Fully Repositionable and Retrievable Lotus Transcatheter Aortic Replacement Valve in 120 High-Risk Surgical Patients With Severe Aortic Stenosis: Results of the REPRISE II Study.

    PubMed

    Meredith, Ian T; Walters, Darren L; Dumonteil, Nicolas; Worthley, Stephen G; Tchétché, Didier; Manoharan, Ganesh; Blackman, Daniel J; Rioufol, Gilles; Hildick-Smith, David; Whitbourn, Robert J; Lefèvre, Thierry; Lange, Rüdiger; Müller, Ralf; Redwood, Simon; Feldman, Ted E; Allocco, Dominic J; Dawkins, Keith D

    2016-02-22

    This analysis presents the first report of 1-year outcomes of the 120 patients enrolled in the REPRISE II (Repositionable Percutaneous Placement of Stenotic Aortic Valve Through Implantation of Lotus Valve System-Evaluation of Safety and Performance) study. The fully repositionable and retrievable Lotus Valve (Boston Scientific, Marlborough, Massachusetts) was designed to facilitate accurate positioning, early valve function, and hemodynamic stability during deployment and to minimize paravalvular regurgitation in patients undergoing transcatheter aortic valve replacement. The study enrolled 120 symptomatic patients 70 years of age or older at 14 centers in Australia and Europe. Patients had severe calcific aortic stenosis and were deemed to be at high or extreme risk of surgery based on assessment by the heart team. The mean age was 84.4 ± 5.3 years, 57% (68 of 120) of patients were women, and the mean Society of Thoracic Surgeons score was 7.1 ± 4.6. The mean baseline aortic valve area was 0.7 ± 0.2 cm(2), and the mean transvalvular pressure gradient was 46.4 ± 15.0 mm Hg. All patients were successfully implanted with a Lotus Valve, and 1-year clinical follow-up was available for 99.2% (119 of 120 of patients). The mean 1-year transvalvular aortic pressure gradient was 12.6 ± 5.7 mm Hg, and the mean valve area was 1.7 ± 0.5 cm(2). A total of 88.6% patients had no or trivial paravalvular aortic regurgitation at 1 year by independent core lab adjudication, and 97.1% of patients were New York Heart Association functional class I or II. At 1 year, the all-cause mortality rate was 10.9% (13 of 119 patients), disabling stroke rate was 3.4% (4 of 119 patients), disabling bleeding rate was 5.9% (7 of 119 patients), with no repeat procedures for valve-related dysfunction. A total of 31.9% (38 of 119 patients) underwent new permanent pacemaker implantation at 1 year. At 1 year of follow-up, the Lotus Valve demonstrated excellent valve hemodynamics, no moderate or

  2. Predictive Power and Implication of EuroSCORE, EuroSCORE II and STS Score for Isolated Repeated Aortic Valve Replacement.

    PubMed

    Holinski, Sebastian; Jessen, Sören; Neumann, Konrad; Konertz, Wolfgang

    2015-01-01

    We evaluated the predictive power of the EuroSCORE, EuroSCORE II and Society of Thoracic Surgeons (STS) score for isolated redo aortic valve replacement. 78 consecutive patients underwent the aforementioned procedure mainly with a stentless valve prosthesis at our institution. Observed mortality was compared to the predicted mortality, Receiver Operating Characteristics (ROC) curves were calculated and the area under the curve (AUC) analyzed. Observed mortality was 11.5%. EuroSCORE and EuroScore II predicted a mortality of 28.2 ± 21.6% (p <0.001) and 10.2 ± 11.8% (p = 0.75), respectively. AUC of the EuroSCORE was 0.74 (95% CI: 0.62-0.83), p = 0.009 and of the EuroSCORE II 0.86 (95% CI: 0.76-0.93), p <0.0001. Optimal Youden index of the EuroSCORE II was 0.59 referring to a predicted mortality of 9.9% (sensitivity: 77.8% and specificity: 81.2%). Predicted mortality of STS score was 17.8 ± 10.6% (p = 0.08) and AUC was 0.64 (95% CI: 0.53-0.75), p = 0.06. EuroSCORE II calculation was not only superior to EuroSCORE and STS score but led to a very realistic mortality prediction for this special procedure at our institution. A EuroSCORE II greater 10 should encourage to consider an alternative treatment.

  3. EVEREST II randomized clinical trial: predictors of mitral valve replacement in de novo surgery or after the MitraClip procedure.

    PubMed

    Glower, Donald; Ailawadi, Gorav; Argenziano, Michael; Mack, Michael; Trento, Alfredo; Wang, Andrew; Lim, D Scott; Gray, William; Grayburn, Paul; Dent, John; Gillam, Linda; Sethuraman, Barathi; Feldman, Ted; Foster, Elyse; Mauri, Laura; Kron, Irving

    2012-04-01

    The Endovascular Valve Edge-to-Edge Repair Study (EVEREST II) is a prospective, multicenter, randomized controlled trial comparing percutaneous repair with the MitraClip device to mitral valve (MV) surgery in the treatment of mitral regurgitation. The present study analyzed the patient characteristics and treatment effects on mitral repair versus replacement. Of 279 patients enrolled, 80 surgical patients underwent 82 MV operations and 178 underwent an initial MitraClip procedure, of whom 37 underwent a subsequent MV operation within 1 year of their index the MitraClip procedure. A logistic regression model was used to predict MV replacement according to valve pathology, etiology of mitral regurgitation, age, previous cardiac surgery, and treatment group. The rate of percutaneous or surgical MV repair at 1 year was 89% (158/178) in patients initially receiving the MitraClip device versus 84% (67/80) in the surgical patients (P = .36). Surgical repair was performed after the MitraClip procedure in 20 (54%) of 37 patients (P < .001 vs surgery). In both the MitraClip device and surgery groups, MV replacement was significantly associated with anterior leaflet pathology (P = .035). Logistic regression analysis showed that anterior leaflet pathology predicted MV replacement. In 5 (13.5%) of 37 patients undergoing surgery after MitraClip therapy, replacement was performed in part because of MV injury associated with the MitraClip procedure. These data suggest that anterior leaflet pathology is strongly associated with MV replacement in patients undergoing either de novo MV surgery or surgery after MitraClip therapy. MitraClip therapy has a repair rate similar to surgery through 1 year but also imparts a risk of replacement of a potentially repairable valve. Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  4. Fast valve

    SciTech Connect

    Van Dyke, William J.

    1992-01-01

    A fast valve is disclosed that can close on the order of 7 milliseconds. It is closed by the force of a compressed air spring with the moving parts of the valve designed to be of very light weight and the valve gate being of wedge shaped with O-ring sealed faces to provide sealing contact without metal to metal contact. The combination of the O-ring seal and an air cushion create a soft final movement of the valve closure to prevent the fast air acting valve from having a harsh closing.

  5. Fast valve

    DOEpatents

    Van Dyke, W.J.

    1992-04-07

    A fast valve is disclosed that can close on the order of 7 milliseconds. It is closed by the force of a compressed air spring with the moving parts of the valve designed to be of very light weight and the valve gate being of wedge shaped with O-ring sealed faces to provide sealing contact without metal to metal contact. The combination of the O-ring seal and an air cushion create a soft final movement of the valve closure to prevent the fast air acting valve from having a harsh closing. 4 figs.

  6. Agricultural Chemicals in Leary Weber Ditch Basin, Hancock County, Indiana, 2003-04

    USGS Publications Warehouse

    Baker, Nancy T.; Lathrop, Timothy R.

    2006-01-01

    Leary Weber Ditch Basin, Hancock County, Indiana, is part of an Agricultural Chemicals: Source, Transport, and Fate study conducted by the National Water-Quality Assessment Program of the U.S. Geological Survey. Water-quality samples were collected in Leary Weber Ditch and in the major hydrologic compartments of the Leary Weber Ditch Basin during 2003 and 2004. Hydrologic compartments that contribute water and agricultural chemicals to Leary Weber Ditch are rain water, overland-flow water, soil water, tile-drain water, and ground water. Samples were analyzed for selected pesticides, nutrients, and major ions.

  7. Depressurization valve

    DOEpatents

    Skoda, G.I.

    1989-03-28

    A depressurization valve for use in relieving completely the pressure in a simplified boiling water reactor is disclosed. The normally closed and sealed valve is provided with a valve body defining a conduit from an outlet of a manifold from the reactor through a valve seat. A closing valve disk is configured for fitting to the valve seat to normally close the valve. The seat below the disk is provided with a radially extending annulus extending a short distance into the aperture defined by the seat. The disk is correspondingly provided with a longitudinally extending annulus that extends downwardly through the aperture defined by the seat towards the high pressure side of the valve body. A ring shaped membrane is endlessly welded to the seat annulus and to the disk annulus. The membrane is conformed over the confronted surface of the seat and disk in a C-sectioned configuration to seal the depressurization valve against the possibility of weeping. The disk is held to the closed position by an elongate stem extending away from the high pressure side of the valve body. The stem has a flange configured integrally to the stem for bias by two springs. The first spring acts from a portion of the housing overlying the disk on the stem flange adjacent the disk. This spring urges the stem and attached disk away from the seat and thus will cause the valve to open at any pressure. A second spring-preferably of the Belleville variety-acts on a latch plate surrounding and freely moving relative to the end of the stem. This second spring overcomes the bias of the first spring and any pressure acting upon the disk. This Belleville spring maintains through its spring force the valve in the closed position. At the same time, the latch plate with its freedom of movement relative to the stem allows the stem to thermally expand during valve temperature excursion.

  8. Thermal overload protection for electric motors on safety-related motor-operated valves: Generic Issue II. E. 6. 1

    SciTech Connect

    Rothberg, O.

    1988-06-01

    NRC regulatory positions, as stated in Regulatory Guide 1.106, Revision 1, have been identified by the Office for Analysis and Evaluation of Operational Data (AEOD) as potential contributors to valve motor burnout. AEOD is particularly concerned about the allowed policy of bypassing thermal overload devices during normal or accident conditions. Regulatory Guide 1.106 favors compromising the function of thermal overload devices in favor of completing the safety-related action of valves. The purpose of this study was to determine if the guidance contained in Regulatory Guide 1.106 is appropriate and, if not, to recommend the necessary changes. This report describes thermal overload devices commonly used to protect safety-related valve operator motors. The regulatory guidelines stated in Regulatory Guide 1.106 along with the limitations of thermal overload protection are discussed. Supplements and alternatives to thermal overload protection are also described. Findings and conclusions of several AEOD reports are discussed. Information obtained from the standard review plan, standard technical specifications, technical specifications from representative plants, and several papers are cited.

  9. Biaxial mechanical properties of the native and glutaraldehyde-treated aortic valve cusp: Part II--A structural constitutive model.

    PubMed

    Billiar, K L; Sacks, M S

    2000-08-01

    We have formulated the first constitutive model to describe the complete measured planar biaxial stress-strain relationship of the native and glutaraldehyde-treated aortic valve cusp using a structurally guided approach. When applied to native, zero-pressure fixed, and low-pressure fixed cusps, only three parameters were needed to simulate fully the highly anisotropic, and nonlinear in-plane biaxial mechanical behavior. Differences in the behavior of the native and zero- and low-pressure fixed cusps were found to be primarily due to changes in the effective fiber stress-strain behavior. Further, the model was able to account for the effects of small (< 10 deg) misalignments in the cuspal specimens with respect to the biaxial test axes that increased the accuracy of the model material parameters. Although based upon a simplified cuspal structure, the model underscored the role of the angular orientation of the fibers that completely accounted for extreme mechanical anisotropy and pronounced axial coupling. Knowledge of the mechanics of the aortic cusp derived from this model may aid in the understanding of fatigue damage in bioprosthetic heart valves and, potentially, lay the groundwork for the design of tissue-engineered scaffolds for replacement heart valves.

  10. Host plants of Carambola fruit fly, Bactrocera carambolae Drew & Hancock(Diptera:Tephritidae);and provisional list of suitable host plants of Carambola fruit fly,(Bactrocera(Bactrocera) carambolae Drew & Hancock(Diptera:Tep

    USDA-ARS?s Scientific Manuscript database

    Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae), commonly known as the carambola fruit fly, is native to Southeast Asia, but has extended its geographic range to several countries in South America. As with other tephritid fruit fly species, establishment of B.carambolae in areas where it...

  11. 46 CFR 56.20-15 - Valves employing resilient material.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....20-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Valves § 56.20-15 Valves employing resilient material. (a) A valve in which the... piping system manifolds; (ii) Isolation valves in cross-connects between two piping systems, at least one...

  12. 46 CFR 56.20-15 - Valves employing resilient material.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....20-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Valves § 56.20-15 Valves employing resilient material. (a) A valve in which the... piping system manifolds; (ii) Isolation valves in cross-connects between two piping systems, at least one...

  13. 33 CFR 165.T01-0394 - Regulated Navigation Area; Waldo-Hancock Bridge Demolition, Penobscot River, between Prospect and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Regulated Navigation Area; Waldo-Hancock Bridge Demolition, Penobscot River, between Prospect and Verona, ME. 165.T01-0394 Section 165.T01... Bridge Demolition, Penobscot River, between Prospect and Verona, ME. (a) Location. The following area is...

  14. Problem: Heart Valve Stenosis

    MedlinePlus

    ... valve . Learn about the different types of stenosis: Aortic stenosis Tricuspid stenosis Pulmonary stenosis Mitral stenosis Outlook for ... Disease "Innocent" Heart Murmur Problem: Valve Stenosis - Problem: Aortic Valve Stenosis - Problem: Mitral Valve Stenosis - Problem: Tricuspid Valve Stenosis - ...

  15. Ant diversity and distribution (Hymenoptera: Formicidae) throughout Maine lowbush blueberry fields in Hancock and Washington Counties.

    PubMed

    Choate, Beth; Drummond, Francis A

    2012-04-01

    A 6-yr survey (2003-2008) identifying the ant fauna present in Maine lowbush blueberry fields was conducted in Washington and Hancock Counties. Pitfall trapping, leaf litter, and hand collections, as well as protein and sugar baits were used to characterize the resident ant community in this habitat. Estimates of faunal richness as impacted by the blueberry crop stage (pruned or fruit-bearing), methods of pest management (grower standard, reduced-risk, or organic), and location within fields (middle, edge, or forested perimeters) were determined. In total, 42 species were collected from blueberry fields, comprising five subfamilies and 15 genera. Myrmica sculptilis Francoeur, Myrmica americana Weber, and Formica exsectoides Forel were the three most abundant species. Formica ulkei Emery, Myrmecina americana Emery, and Leptothorax canadensis Provancher represent new species records for Maine. Ants were most diverse in organic fields, and along the edge and within the wooded areas surrounding fields. Results suggest insecticide application reduces ant diversity.

  16. A Simple GPU-Accelerated Two-Dimensional MUSCL-Hancock Solver for Ideal Magnetohydrodynamics

    NASA Technical Reports Server (NTRS)

    Bard, Christopher; Dorelli, John C.

    2013-01-01

    We describe our experience using NVIDIA's CUDA (Compute Unified Device Architecture) C programming environment to implement a two-dimensional second-order MUSCL-Hancock ideal magnetohydrodynamics (MHD) solver on a GTX 480 Graphics Processing Unit (GPU). Taking a simple approach in which the MHD variables are stored exclusively in the global memory of the GTX 480 and accessed in a cache-friendly manner (without further optimizing memory access by, for example, staging data in the GPU's faster shared memory), we achieved a maximum speed-up of approx. = 126 for a sq 1024 grid relative to the sequential C code running on a single Intel Nehalem (2.8 GHz) core. This speedup is consistent with simple estimates based on the known floating point performance, memory throughput and parallel processing capacity of the GTX 480.

  17. Depressurization valve

    DOEpatents

    Skoda, George I.

    1989-01-01

    A depressurization valve for use in relieving completely the pressure in a simplified boiling water reactor is disclosed. The normally closed and sealed valve is provided with a valve body defining a conduit from an outlet of a manifold from the reactor through a valve seat. A closing valve disk is configured for fitting to the valve seat to normally close the valve. The seat below the disk is provided with a radially extending annulus extending a short distance into the aperture defined by the seat. The disk is correspondingly provided with a longitudinally extending annulus that extends downwardly through the aperture defined by the seat towards the high pressure side of the valve body. A ring shaped membrane is endlessly welded to the seat annulus and to the disk annulus. The membrane is conformed over the confronted surface of the seat and disk in a C-sectioned configuration to seal the depressurization valve against the possibility of weeping. The disk is held to the closed position by an elongate stem extending away from the high pressure side of the valve body. The stem has a flange configured integrally to the stem for bias by two springs. The first spring acts from a portion of the housing overlying the disk on the stem flange adjacent the disk. This spring urges the stem and attached disk away from the seat and thus will cause the valve to open at any pressure. A second spring--preferably of the Belleville variety--acts on a latch plate surrounding and freely moving relative to the end of the stem. This second spring overcomes the bias of the first spring and any pressure acting upon the disk. This Belleville spring maintains through its spring force the valve in the closed position. At the same time, the latch plate with its freedom of movement relative to the stem allows the stem to thermally expand during valve temperature excursion. The latch plate in surrounding the stem is limited in its outward movement by a boss attached to the stem at the end of

  18. 40 CFR 63.175 - Quality improvement program for valves.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (e.g., ball, gate, check); valve manufacturer; valve design (e.g., external stem or actuating... improvement program. (6) A trial evaluation program shall be conducted at each plant site for which the data... required in § 63.181(h)(5)(ii) of this subpart. (ii) The number of valves in the trial evaluation...

  19. 40 CFR 63.175 - Quality improvement program for valves.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (e.g., ball, gate, check); valve manufacturer; valve design (e.g., external stem or actuating... improvement program. (6) A trial evaluation program shall be conducted at each plant site for which the data... required in § 63.181(h)(5)(ii) of this subpart. (ii) The number of valves in the trial evaluation...

  20. 40 CFR 63.175 - Quality improvement program for valves.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (e.g., ball, gate, check); valve manufacturer; valve design (e.g., external stem or actuating... improvement program. (6) A trial evaluation program shall be conducted at each plant site for which the data... required in § 63.181(h)(5)(ii) of this subpart. (ii) The number of valves in the trial evaluation...

  1. Nuclear radiation actuated valve

    DOEpatents

    Christiansen, David W.; Schively, Dixon P.

    1985-01-01

    A nuclear radiation actuated valve for a nuclear reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

  2. Evaluation of Ventricular Septal Defect with Special Reference to the Spontaneous Closure Rate, Subaortic Ridge, and Aortic Valve Prolapse II.

    PubMed

    Eroglu, Ayse Guler; Atik, Sezen Ugan; Sengenc, Esma; Cig, Gulnaz; Saltik, Irfan Levent; Oztunc, Funda

    2017-06-01

    The medical records of 2283 patients with ventricular septal defect (VSD) were reviewed to determine spontaneous closure, left ventricular-to-right atrial shunt, subaortic ridge, and aortic valve prolapse. One thousand eight hundred and twenty-three patients had been followed 1 month to 26 years (median 4 years) by echocardiography. Most of 460 patients could not be followed due to transportation of the institution. VSD was perimembranous in 68.8% (1255), trabecular muscular in 21.7% (395), muscular outlet in 6% (109), muscular inlet in 2.6% (48), and doubly committed subarterial in 0.9% (16). Defect size was classified in 66.8% (1218) as small, in 15.7% (286) as moderate, and in 17.5% (319) as large. VSD closed spontaneously in 18.8% (343 of 1823 patients) by ages 40 days to 24.9 years (median, 1.8 years). One hundred fifty-seven of 1255 perimembranous defects (12.5%) and 167 of 395 trabecular muscular defects (42%) closed spontaneously (p < 0.001). Defect size became small in 306 (16.8%) of patients with VSD at a median of 2.5 years. Aneurysmal transformation was detected in 32.9% (600), left ventricular-to-right atrial shunt in 9.7% (176), subaortic ridge in 2.6% (48) of 1823 patients who were followed. In 381 (20.9%) of the 1823 patients, the VSD had been closed by a surgical or transcatheter technique. Surgery is required in one-fifth of patients with subaortic ridge or aortic valve prolapse. In conclusion, isolated VSDs are usually benign abnormalities that tend to shrink and close spontaneously.

  3. FLUID MECHANICS OF ARTIFICIAL HEART VALVES

    PubMed Central

    Dasi, Lakshmi P; Simon, Helene A; Sucosky, Philippe; Yoganathan, Ajit P

    2009-01-01

    SUMMARY 1. Artificial heart valves have been in use for over five decades to replace diseased heart valves. Since the first heart valve replacement performed with a caged-ball valve, more than 50 valve designs have been developed, differing principally in valve geometry, number of leaflets and material. To date, all artificial heart valves are plagued with complications associated with haemolysis, coagulation for mechanical heart valves and leaflet tearing for tissue-based valve prosthesis. For mechanical heart valves, these complications are believed to be associated with non-physiological blood flow patterns. 2. In the present review, we provide a bird’s-eye view of fluid mechanics for the major artificial heart valve types and highlight how the engineering approach has shaped this rapidly diversifying area of research. 3. Mechanical heart valve designs have evolved significantly, with the most recent designs providing relatively superior haemodynamics with very low aerodynamic resistance. However, high shearing of blood cells and platelets still pose significant design challenges and patients must undergo life-long anticoagulation therapy. Bioprosthetic or tissue valves do not require anticoagulants due to their distinct similarity to the native valve geometry and haemodynamics, but many of these valves fail structurally within the first 10–15 years of implantation. 4. These shortcomings have directed present and future research in three main directions in attempts to design superior artificial valves: (i) engineering living tissue heart valves; (ii) development of advanced computational tools; and (iii) blood experiments to establish the link between flow and blood damage. PMID:19220329

  4. Probabilistic analysis and operational data in response to NUREG-0737, Item II. K. 3. 2 for Westinghouse NSSS plants. [Modifications to reduce LOCA due to stuck-open power-operated relief valve

    SciTech Connect

    Wood, D.C.; Gottshall, C.L.

    1981-02-01

    This report describes various modifications to Westinghouse plants since TMI and, using probabilistic analysis via event trees, estimates the effect of the post-TMI changes, including an automatic (PORV) (power operated relief valve) isolation concept identified in NUREG-0731 item II.K.3.1. The requested safety valve operational data is included as an appendix. A significant reduction in the frequency of a small break LOCA, due to a stuck open PORV has already been achieved by the modifications made subsequent to TMI. Domestic Westinghouse operating plant data (based on 181 reactor years of operation) has been collected and evaluated. An auto block valve closure system has been evaluated. The analysis is generally applicable to all Westinghouse plants which have incorporated the post-TMI hardware and procedural changes relative to stuck-open PORVs.

  5. Agreement between the new EuroSCORE II, the Logistic EuroSCORE and the Society of Thoracic Surgeons score: implications for transcatheter aortic valve implantation.

    PubMed

    Arangalage, Dimitri; Cimadevilla, Claire; Alkhoder, Soleiman; Chiampan, Andrea; Himbert, Dominique; Brochet, Eric; Iung, Bernard; Nataf, Patrick; Depoix, Jean-Pol; Vahanian, Alec; Messika-Zeitoun, David

    2014-01-01

    The Logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) and the Society of Thoracic Surgeons (STS) score are routinely used to identify patients at high surgical risk as potential candidates for transcatheter aortic valve implantation (TAVI). To compare the new EuroSCORE II with the Logistic EuroSCORE and the STS score. From October 2006 to June 2011, patients with severe symptomatic aortic stenosis who underwent a TAVI were enrolled prospectively. Among 272 patients, the EuroSCORE II was significantly lower and moderately correlated with the Logistic EuroSCORE (9±8% vs. 23±14%, P<0.01; r=0.61, P<0.001), but similar to and poorly correlated with the STS (10±9%, P=0.10; r=0.25, P<0.001). Based on recommended high-risk thresholds (Logistic EuroSCORE≥20%; STS≥10%), a EuroSCORE II≥7% provided the best diagnostic value. However, using the EuroSCORE II, Logistic EuroSCORE or STS score, only 51%, 58% and 37% of patients, respectively, reached these thresholds. Contingency analyses showed that agreements between the EuroSCORE II and the Logistic EuroSCORE or the STS score were modest or poor, respectively, with a risk assessment different in 28% and 36% of patients, respectively. A EuroSCORE II≥7% corresponded to a Logistic EuroSCORE≥20% or STS score≥10%, but correlations and agreements were at best modest and only approximately half of the patients reached these thresholds. Our results highlight the limits of current scoring systems and reinforce the European guidelines stressing the importance of clinical judgment in addition to risk scores. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  6. Aortic Valve Regurgitation

    MedlinePlus

    ... valve. Also, a narrowing of the aortic valve (aortic stenosis) can be associated with leaking. High blood pressure (hypertension). High blood pressure may stretch the root of the aorta where the aortic valve sits. The valve flaps ( ...

  7. Aortic Valve Stenosis

    MedlinePlus

    ... pulmonary valve and aortic valve. Each valve has flaps (cusps or leaflets) that open and close once ... valve consists of three tightly fitting, triangular-shaped flaps of tissue called cusps. Some children are born ...

  8. Wear resistant valve

    NASA Technical Reports Server (NTRS)

    Perkins, Gerald S. (Inventor)

    1980-01-01

    A valve which is resistant to wear caused by particles trapped between the valve seat and the valve member or poppet when the valve closes, including an outlet for directing washing fluid at the valve seat and/or sealing face of the poppet and means for supplying pressured fluid to the outlet at the time when the valve is closing.

  9. A calcified polymeric valve for valve-in-valve applications.

    PubMed

    Falahatpisheh, Ahmad; Morisawa, Daisuke; Toosky, Taraz T; Kheradvar, Arash

    2017-01-04

    The prevalence of aortic valve stenosis (AS) is increasing in the aging society. More recently, novel treatments and devices for AS, especially transcatheter aortic valve replacement (TAVR) have significantly changed the therapeutic approach to this disease. Research and development related to TAVR require testing these devices in the calcified heart valves that closely mimic a native calcific valve. However, no animal model of AS has yet been available. Alternatively, animals with normal aortic valve that are currently used for TAVR experiments do not closely replicate the aortic valve pathology required for proper testing of these devices. To solve this limitation, for the first time, we developed a novel polymeric valve whose leaflets possess calcium hydroxyapatite inclusions immersed in them. This study reports the characteristics and feasibility of these valves. Two types of the polymeric valve, i.e., moderate and severe calcified AS models were developed and tested by deploying a transcatheter valve in those and measuring the related hemodynamics. The valves were tested in a heart flow simulator, and were studied using echocardiography. Our results showed high echogenicity of the polymeric valve, that was correlated to the severity of the calcification. Aortic valve area of the polymeric valves was measured, and the severity of stenosis was defined according to the clinical guidelines. Accordingly, we showed that these novel polymeric valves closely mimic AS, and can be a desired cost-saving solution for testing the performance of the transcatheter aortic valve systems in vitro.

  10. 49 CFR 236.383 - Valve locks, valves, and valve magnets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Valve locks, valves, and valve magnets. 236.383... Inspection and Tests § 236.383 Valve locks, valves, and valve magnets. Valve locks on valves of the non-cut-off type shall be tested at least once every three months, and valves and valve magnets shall...

  11. 49 CFR 236.383 - Valve locks, valves, and valve magnets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Valve locks, valves, and valve magnets. 236.383... Inspection and Tests § 236.383 Valve locks, valves, and valve magnets. Valve locks on valves of the non-cut-off type shall be tested at least once every three months, and valves and valve magnets shall...

  12. 49 CFR 236.383 - Valve locks, valves, and valve magnets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Valve locks, valves, and valve magnets. 236.383... Inspection and Tests § 236.383 Valve locks, valves, and valve magnets. Valve locks on valves of the non-cut-off type shall be tested at least once every three months, and valves and valve magnets shall...

  13. 49 CFR 236.383 - Valve locks, valves, and valve magnets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Valve locks, valves, and valve magnets. 236.383... Inspection and Tests § 236.383 Valve locks, valves, and valve magnets. Valve locks on valves of the non-cut-off type shall be tested at least once every three months, and valves and valve magnets shall...

  14. 49 CFR 236.383 - Valve locks, valves, and valve magnets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Valve locks, valves, and valve magnets. 236.383... Inspection and Tests § 236.383 Valve locks, valves, and valve magnets. Valve locks on valves of the non-cut-off type shall be tested at least once every three months, and valves and valve magnets shall...

  15. Results of the radiological survey at 9 Hancock Street, Lodi, New Jersey (LJ028)

    SciTech Connect

    Cottrell, W.D.; Floyd, L.M.; Francis, M.W.; Mynatt, J.O.

    1989-09-01

    Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally {sup 232}Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, 9 Hancock Street, Lodi, New Jersey (LJ028), was conducted during 1985 and 1986. Some radionuclide measurements were greater than typical background levels in the northern New Jersey area. However, results of the survey demonstrated no radionuclide concentrations in excess of the DOE Formerly Utilized Sites Remedial Action Program criteria. 5 refs., 6 figs., 3 tabs.

  16. Results of the radiological survey at 7 Hancock Street, Lodi, New Jersey (LJ027)

    SciTech Connect

    Cottrell, W.D.; Floyd, L.M.; Francis, M.W.; Mynatt, J.O.

    1989-09-01

    Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. AT the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally {sup 232}Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, 7 Hancock Street, Lodi, New Jersey (LJ027), was conducted during 1985 and 1986. Results of the survey demonstrated radionuclide concentrations in excess of the DOE Formerly Utilized Sites Remedial Action Program criteria. The radionuclide distributions are typical of the type of material originating from the MCW site. 5 refs., 5 figs., 3 tabs.

  17. Results of the radiological survey at 5 Hancock Street, Lodi, New Jersey (LJ029)

    SciTech Connect

    Cottrell, W.D.; Floyd, L.M.; Francis, M.W.; Mynatt, J.O.

    1989-09-01

    Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally {sup 232}Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, 5 Hancock Street, Lodi, New Jersey (LJ029), was conducted during 1985 and 1986. Results of the survey demonstrated concentrations in excess of the DOE Formerly Utilized Sites Remedial Action Program criteria. The radionuclide distributions are typical of the type of the material originating from the MCW site. 5 refs., 6 figs., 3 tabs.

  18. Results of the radiological survey at 10 Hancock Street, Lodi, New Jersey (LJ031)

    SciTech Connect

    Foley, R.D.; Floyd, L.M.; Carrier, R.F.; Crutcher, J.W.

    1989-06-01

    Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally /sup 232/Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling from radionuclide analyses. The survey of this site, 10 Hancock Street, Lodi, New Jersey (LJ031), was conducted during 1985 and 1986. Results of the survey demonstrated radionuclide concentrations in excess of the DOE Formerly Utilized Sites Remedial Action Program criteria. The radionuclide distributions are typical of the type of material originating from the MCW site. 4 refs., 4 figs., 3 tabs.

  19. Results of the radiological survey at 6 Hancock Street, Lodi, New Jersey (LJ033)

    SciTech Connect

    Foley, R.D.; Floyd, L.M.; Carrier, R.F.; Crutcher, J.W.

    1989-06-01

    Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth, earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally /sup 232/Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, 6 Hancock Street, Lodi, New Jersey (LJ033), was conducted during 1985 and 1986. Results of the survey demonstrated radionuclide concentrations in excess of the DOE Formerly Utilized Remedial Action Program criteria. The radionuclide distributions are typical of the type of material originating from the MCW site.

  20. Results of the radiological survey at 4 Hancock Street, Lodi, New Jersey (LJ060)

    SciTech Connect

    Foley, R.D.; Carier, R.F.; Floyd, L.M.; Crutcher, J.W.

    1989-09-01

    Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally {sup 232}Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, 4 Hancock Street, Lodi, New Jersey (LJ060), was conducted during 1985 and 1986. Gamma logging results found during this survey and during a previous survey conducted by Bechtel National, Incorporated, strongly indicated radionuclide concentrations in subsurface soil in excess of DOE remedial action criteria. This finding, coupled with the fact that adjacent properties have been found to be contaminated and that Lodi Brook apparently flows under the property, suggests that it be considered for inclusion in the DOE remedial action program. 5 refs., 4 figs., 4 tabs.

  1. Methyl eugenol aromatherapy enhances the mating competitiveness of male Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae).

    PubMed

    Haq, Ihsan; Vreysen, Marc J B; Cacéres, Carlos; Shelly, Todd E; Hendrichs, Jorge

    2014-09-01

    Males of Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae) are strongly attracted to methyl eugenol (ME) (1,2-dimethoxy-4-(2-propenyl)benzene), a natural compound occurring in variety of plant species. ME-feeding is known to enhance male B. carambolae mating competitiveness 3 days after feeding. Enhanced male mating competitiveness due to ME-feeding can increase the effectiveness of sterile insect technique (SIT) manifolds. However, the common methods for emergence and holding fruit flies prior to field releases do not allow the inclusion of any ME feeding treatment after fly emergence. Therefore this study was planned to assess the effects of ME-aromatherapy in comparison with ME feeding on male B. carambolae mating competitiveness as aromatherapy is pragmatic for fruit flies emergence and holding facilities. Effects of ME application by feeding or by aromatherapy for enhanced mating competitiveness were evaluated 3d after treatments in field cages. ME feeding and ME aromatherapy enhanced male mating competitiveness as compared to untreated males. Males treated with ME either by feeding or by aromatherapy showed similar mating success but mating success was significantly higher than that of untreated males. The results are discussed in the context of application of ME by aromatherapy as a pragmatic approach in a mass-rearing facility and its implications for effectiveness of SIT. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Piezoelectric valve

    SciTech Connect

    Petrenko, Serhiy Fedorovich

    2013-01-15

    A motorized valve has a housing having an inlet and an outlet to be connected to a pipeline, a saddle connected with the housing, a turn plug having a rod, the turn plug cooperating with the saddle, and a drive for turning the valve body and formed as a piezoelectric drive, the piezoelectric drive including a piezoelectric generator of radially directed standing acoustic waves, which is connected with the housing and is connectable with a pulse current source, and a rotor operatively connected with the piezoelectric generator and kinematically connected with the rod of the turn plug so as to turn the turn plug when the rotor is actuated by the piezoelectric generator.

  3. Installation Restoration Program, Phase 2. Confirmation/quantification, Stage 2, Hancock Air National Guard Base, Syracuse, New York. Volume 1. Technical report. Final report, Aug 86-Jun 89

    SciTech Connect

    Spooner, P.; King, J.; Hartwell, S.; Zafran, F.; Kaushik, N.

    1989-06-01

    Seven sites in two zones were investigated during this Phase II, Stage 2 effort at Hancock Field. The sites included one fire training area, three disposal sites, two storage sites, and one spill site. A soil gas survey was conducted at one site and geophysical surveys (magnetometry) were conducted at two sites. Fifteen new ground water monitoring wells were installed. Samples of wastes, ground water, surface water, sediments, and soils were collected and submitted for laboratory analysis. No significant health risk is posed by the presumably site-related metals found in sediments at the two disposal sites. Low concentrations of pesticides were detected in soils around one site, but no significant health risk is posed by these constituents. Sediments, and to a lesser extent surface water, below one site contained residues of organic materials, but pose no significant health risk. Organic compounds also were found in soils but the concentrations found pose no significant risk. Site related organic compounds were detected in soils immediately surrounding the fire training area but no significant health risk is posed. No further action is recommended for all seven sites investigated during this effort.

  4. Excess flow shutoff valve

    DOEpatents

    Kiffer, Micah S.; Tentarelli, Stephen Clyde

    2016-02-09

    Excess flow shutoff valve comprising a valve body, a valve plug, a partition, and an activation component where the valve plug, the partition, and activation component are disposed within the valve body. A suitable flow restriction is provided to create a pressure difference between the upstream end of the valve plug and the downstream end of the valve plug when fluid flows through the valve body. The pressure difference exceeds a target pressure difference needed to activate the activation component when fluid flow through the valve body is higher than a desired rate, and thereby closes the valve.

  5. 49 CFR 192.145 - Valves.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...: (i) With the valve in the fully open position, the shell must be tested with no leakage to a pressure at least 1.5 times the maximum service rating. (ii) After the shell test, the seat must be tested to... valves, test pressure during the seat test must be applied successively on each side of the closed...

  6. 49 CFR 192.145 - Valves.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...: (i) With the valve in the fully open position, the shell must be tested with no leakage to a pressure at least 1.5 times the maximum service rating. (ii) After the shell test, the seat must be tested to... valves, test pressure during the seat test must be applied successively on each side of the closed...

  7. 49 CFR 192.145 - Valves.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: (i) With the valve in the fully open position, the shell must be tested with no leakage to a pressure at least 1.5 times the maximum service rating. (ii) After the shell test, the seat must be tested to... valves, test pressure during the seat test must be applied successively on each side of the closed...

  8. Valve Disease

    MedlinePlus

    ... medicines for the rest of their lives. Valve surgery is usually an open heart technique. This means that surgeons use a heart-lung machine, because the heart must stop beating for a short time during surgery. In some patients, surgeons can repair or replace ...

  9. Dump valve

    SciTech Connect

    Webber, J.C.

    1981-06-23

    A swab assembly is provided having a dump valve responsive to fluid pressure and drag which will dump the fluid load should either fluid load or drag or the effect of both fluid load and drag become abnormal. Also if the fluid pressure and/or drag become abnormal, the fluid load on the cup will be released and wash away foreign material causing abnormal drag. When the cup is dumped the pulling capabilities of the wireline truck can concentrate on overcoming the drag. The dump valve opens to wide open position and remains open to dump the fluid to assist in washing away solid materials above the cup. A swab assembly also is provided which with normal drag and an overload, may be pulled relatively slowly, but if pulled too rapidly will result in the load on the swab being dumped to protect the swab assembly and the pulling apparatus from damage. 15 claims.

  10. ELECTROSTRICTION VALVE

    DOEpatents

    Kippenhan, D.O.

    1962-09-25

    An accurately controlled, pulse gas valve is designed capable of delivering output pulses which vary in length from one-tenth millisecond to one second or more, repeated at intervals of a few milliseconds or- more. The pulsed gas valve comprises a column formed of barium titanate discs mounted in stacked relation and electrically connected in parallel, with means for applying voltage across the discs to cause them to expand and effect a mechanical elongation axially of the column. The column is mounted within an enclosure having an inlet port and an outlet port with an internal seat in communication with the outlet port, such that a plug secured to the end of the column will engage the seat of the outlet port to close the outlet port in response to the application of voltage is regulated by a conventional electronic timing circuit connected to the column. (AEC)

  11. Automatic shutoff valve

    NASA Technical Reports Server (NTRS)

    Hawkins, S. F.; Overbey, C. W.

    1980-01-01

    Cellulose-sponge disk absorbs incoming water and expands with enough force to shut valve. When water recedes, valve opens by squeezing sponge dry to its original size. This direct mechanical action is considered more reliable than solenoid valve.

  12. Automatic shutoff valve

    NASA Technical Reports Server (NTRS)

    Hawkins, S. F.; Overbey, C. W.

    1980-01-01

    Cellulose-sponge disk absorbs incoming water and expands with enough force to shut valve. When water recedes, valve opens by squeezing sponge dry to its original size. This direct mechanical action is considered more reliable than solenoid valve.

  13. Mitral Valve Disease

    MedlinePlus

    ... Tricuspid Valve Disease Cardiac Rhythm Disturbances Thoracic Aortic Aneurysm Pediatric and Congenital Heart Disease Heart abnormalities that are ... Transplantation End-stage Lung Disease Adult Lung Transplantation Pediatric Lung ... Aortic Aneurysm Mitral Valve Disease Overview The mitral valve is ...

  14. Magnetically operated check valve

    NASA Technical Reports Server (NTRS)

    Morris, Brian G. (Inventor); Bozeman, Richard J., Jr. (Inventor)

    1994-01-01

    A magnetically operated check valve is disclosed. The valve is comprised of a valve body and a movable poppet disposed therein. A magnet attracts the poppet to hold the valve shut until the force of fluid flow through the valve overcomes the magnetic attraction and moves the poppet to an unseated, open position. The poppet and magnet are configured and disposed to trap a magnetically attracted particulate and prevent it from flowing to a valve seating region.

  15. Magnetically operated check valve

    NASA Astrophysics Data System (ADS)

    Morris, Brian G.; Bozeman, Richard J., Jr.

    1994-06-01

    A magnetically operated check valve is disclosed. The valve is comprised of a valve body and a movable poppet disposed therein. A magnet attracts the poppet to hold the valve shut until the force of fluid flow through the valve overcomes the magnetic attraction and moves the poppet to an unseated, open position. The poppet and magnet are configured and disposed to trap a magnetically attracted particulate and prevent it from flowing to a valve seating region.

  16. Development of ground-water supplies at Mississippi test facility, Hancock County, Mississippi

    USGS Publications Warehouse

    Newcome, Roy

    1967-01-01

    Potable and industrial water supplies at the National Aeronautics and Space Administration's Mississippi Test Facility in Hancock County, Miss., are obtained from large-capacity wells that tap southward-dipping water-bearing sands of Miocene and Pliocene age. The fresh-water-bearing section is 2,000-3,000 feet thick in the area, and individual aquifers are as thick as 450 feet. Aquifer thickness is not constant over large areas, however; and 100 feet is a more common thickness. Three wells installed for potable water supply are 1,434-1,524 feet deep and have produced 1,100-2,500 gpm (gallons per minute) by natural flow. Artesian pressure is sufficient to provide a static head as high as 90 feet above land surface. Planned use rate for two of the wells is about 600 gpm each and for the third, 1,250 gpm. Water for cooling Saturn rocket test-stand deflectors is obtained from three wells 1,873, 1,695, and 672 feet deep. The production rates of these wells are 3,100, 4,500, and 5,000 gpm, respectively; the wells are capable of supplying 7.5 million gallons in a 10-hour period (18 million gallons per day). Artesian head for the aquifers tapped by these wells ranges from 104 feet above land surface for the deepest aquifer to 15 feet for the shallowest. Aquifer transmissibilities determined in pumping tests range from 81,000 to 200,000 gallons per day per foot. Specific capacities of the wells range from a 15 to 47 gpm per foot of drawdown. Water from the supply wells is soft and of good quality. Dissolved solids range from 236 to 315 parts per million. The water is a sodium bicarbonate type, with high pH. The concentration of iron is less than 0.3 part per million. Water temperatures range from 79?F in the shallowest supply well to 100?F in the deepest.

  17. Fast-Acting Valve

    NASA Technical Reports Server (NTRS)

    Wojciechowski, Bogdan V. (Inventor); Pegg, Robert J. (Inventor)

    2003-01-01

    A fast-acting valve includes an annular valve seat that defines an annular valve orifice between the edges of the annular valve seat, an annular valve plug sized to cover the valve orifice when the valve is closed, and a valve-plug holder for moving the annular valve plug on and off the annular valve seat. The use of an annular orifice reduces the characteristic distance between the edges of the valve seat. Rather than this distance being equal to the diameter of the orifice, as it is for a conventional circular orifice, the characteristic distance equals the distance between the inner and outer radii (for a circular annulus). The reduced characteristic distance greatly reduces the gap required between the annular valve plug and the annular valve seat for the valve to be fully open, thereby greatly reducing the required stroke and corresponding speed and acceleration of the annular valve plug. The use of a valve-plug holder that is under independent control to move the annular valve plug between its open and closed positions is important for achieving controllable fast operation of the valve.

  18. Diagnostic approach to assessment of valvular heart disease using magnetic resonance imaging, part II: a practical approach for native and prosthetic heart valve stenosis

    PubMed Central

    Chaothawee, Lertlak

    2012-01-01

    MRI is already an established diagnostic modality for assessing valvular stenosis although it is not usually used as the initial non-invasive test. The preferred diagnostic modality for valvular stenosis is currently echocardiography. However, MRI has been offered as a good alternative test in the event of inconclusive echocardiography results. During the course of valvular stenosis, the valve orifice area decreases and the pressure gradient across the diseased valve increases. Valvular orifice area is the major core indicator for valvular stenosis severity grading. Compared with valvular regurgitation, assessment with MRI for valvular stenosis is less complicated. The aim of this article is to detail the MRI techniques in assessing native and prosthetic heart valve stenosis. PMID:27326061

  19. Echocardiographic assessment of left ventricular filling after mitral valve surgery.

    PubMed Central

    St John Sutton, M G; Traill, T A; Ghafour, A S; Brown, D J; Gibson, D G

    1977-01-01

    In order to investigate the functional effects of mitral valve surgery, echocardiograms showing left ventricular dimension were recorded and digitised in 14 normal subjects and 129 patients after mitral valve surgery. Measurements were made of peak rate of increase of dimension (dD/dt) and duration of rapid filling, studies on left ventriculograms in 36 patients having shown close correlation between these values and changes in cavity volume. In 14 patients with mitral stenosis, peak dD/dt was reduced to 7-2 +/ 1-5 cm/s, and filling period prolonged to 330 +/- 65 ms, compared with normal (16-0 +/- 3-2 cm/s, and 160 +/- 50 ms, respectively), and after mitral valvotomy, these values improved significantly (10-4 +/- 2-7 cm/s and 245 +/- 55 ms). Characteristic abnormalities were found in 67 patients with mitral prostheses. Values for the Björk-Shiley (10-5 +/- 4-2 cm/s and 180 +/- 80 ms) and Hancock (10-3 +/- 3-7 cm/s, 245 +/- 80 ms) values were similar, and both superior to the Starr-Edwards (7-4 +/- 3-0 cm/s, 295 +/- 105 ms). Results after mitral valve repair in 30 cases were not significantly different from normal (14-4 +/- 5-0 cm/s, 170 +/- 50 ms). Values outside the 95 per cent confidence limits for the valve in question allowed diagnosis of value malfunction in 18 cases. The method is value in comparing different operative procedures and in following up patients after mitral valve surgery. PMID:603728

  20. Microfluidic sieve valves

    DOEpatents

    Quake, Stephen R; Marcus, Joshua S; Hansen, Carl L

    2015-01-13

    Sieve valves for use in microfluidic device are provided. The valves are useful for impeding the flow of particles, such as chromatography beads or cells, in a microfluidic channel while allowing liquid solution to pass through the valve. The valves find particular use in making microfluidic chromatography modules.

  1. Remote actuated valve implant

    DOEpatents

    McKnight, Timothy E; Johnson, Anthony; Moise, Jr., Kenneth J; Ericson, Milton Nance; Baba, Justin S; Wilgen, John B; Evans, III, Boyd McCutchen

    2014-02-25

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  2. Remote actuated valve implant

    DOEpatents

    McKnight, Timothy E.; Johnson, Anthony; Moise, Kenneth J.; Ericson, Milton Nance; Baba, Justin S.; Wilgen, John B.; Evans, Boyd Mccutchen

    2016-05-10

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  3. Rotary pneumatic valve

    DOEpatents

    Hardee, Harry C.

    1991-01-01

    A rotary pneumatic valve which is thrust balanced and the pneumatic pressure developed produces only radial loads on the valve cylinder producing negligible resistance and thus minimal torque on the bearings of the valve. The valve is multiplexed such that at least two complete switching cycles occur for each revolution of the cylinder spindle.

  4. Liquid rocket valve components

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A monograph on valves for use with liquid rocket propellant engines is presented. The configurations of the various types of valves are described and illustrated. Design criteria and recommended practices for the various valves are explained. Tables of data are included to show the chief features of valve components in use on operational vehicles.

  5. Dual stage check valve

    NASA Technical Reports Server (NTRS)

    Whitten, D. E. (Inventor)

    1973-01-01

    A dual stage seat valve head arrangement is described which consists of a primary sealing point located between a fixed orifice seat and a valve poppet, and a secondary sealing point between an orifice poppet and a valve poppet. Upstream of the valve orifice is a flexible, convoluted metal diaphragm attached to the orifice poppet. Downstream of the valve orifice, a finger spring exerts a force against the valve poppet, tending to keep the valve in a closed position. The series arrangement of a double seat and poppet is able to tolerate small particle contamination while minimizing chatter by controlling throttling or metering across the secondary seat, thus preserving the primary sealing surface.

  6. Throttle valve control device

    SciTech Connect

    Nishida, M.; Katashiba, H.

    1988-03-01

    This patent describes a valve control device which comprises: a valve shaft for operating a throttle valve; a differential gear device having first and second drive gears, for driving the valve shaft; first and second electronic control actuators for rotating the first and second drive gear, respectively; and a sensor for detecting the degree of opening of the throttle valve, so that the operation of the throttle valve is controlled by the electronic control actuators while the degree of opening of the throttle valve is being detected.

  7. Bellows sealed plug valve

    DOEpatents

    Dukas, Jr., Stephen J.

    1990-01-01

    A bellows sealed plug valve includes a valve body having an inlet passage and an outlet passage, a valve chamber between the inlet and outlet passages. A valve plug has substantially the same shape as the valve chamber and is rotatably disposed therein. A shaft is movable linearly in response to a signal from a valve actuator. A bellows is sealingly disposed between the valve chamber and the valve actuator and means are located between the bellows and the valve plug for converting linear movement of the shaft connected to the valve actuator to rotational movement of the plug. Various means are disclosed including helical thread mechanism, clevis mechanism and rack and pinion mechanism, all for converting linear motion to rotational motion.

  8. Vacuum breaker valve assembly

    DOEpatents

    Thompson, Jeffrey L.; Upton, Hubert Allen

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening.

  9. Scissor thrust valve actuator

    DOEpatents

    DeWall, Kevin G.; Watkins, John C; Nitzel, Michael E.

    2006-08-29

    Apparatus for actuating a valve includes a support frame and at least one valve driving linkage arm, one end of which is rotatably connected to a valve stem of the valve and the other end of which is rotatably connected to a screw block. A motor connected to the frame is operatively connected to a motor driven shaft which is in threaded screw driving relationship with the screw block. The motor rotates the motor driven shaft which drives translational movement of the screw block which drives rotatable movement of the valve driving linkage arm which drives translational movement of the valve stem. The valve actuator may further include a sensory control element disposed in operative relationship with the valve stem, the sensory control element being adapted to provide control over the position of the valve stem by at least sensing the travel and/or position of the valve stem.

  10. Valve-in-Valve Replacement Using a Sutureless Aortic Valve

    PubMed Central

    Dohmen, Pascal M.; Lehmkuhl, Lukas; Borger, Michael A.; Misfeld, Martin; Mohr, Friedrich W.

    2016-01-01

    Patient: Female, 61 Final Diagnosis: Tissue degeneration Symptoms: Dyspnea Medication: — Clinical Procedure: Redo valve replacement Specialty: Surgery Objective: Rare disease Background: We present a unique case of a 61-year-old female patient with homograft deterioration after redo surgery for prosthetic valve endocarditis with root abscess. Case Report: The first operation was performed for type A dissection with root, arch, and elephant trunk replacement of the thoracic aorta. The present re-redo surgery was performed as valve-in-valve with a sutureless aortic biopros-thesis. The postoperative course was uneventful and the patient was discharged on day 6. Conclusions: The current case report demonstrates that sutureless bioprostheses are an attractive option for surgical valve-in-valve procedures, which can reduce morbidity and mortality. PMID:27694795

  11. Heart valve surgery - series (image)

    MedlinePlus

    There are four valves in the heart: aortic valve, mitral valve, tricuspid valve, and pulmonary valve. The valves are designed to control the direction of blood flow through the heart. The opening and closing of the heart valves produce the heart-beat sounds.

  12. Valve for fluid control

    DOEpatents

    Oborny, Michael C.; Paul, Phillip H.; Hencken, Kenneth R.; Frye-Mason, Gregory C.; Manginell, Ronald P.

    2001-01-01

    A valve for controlling fluid flows. This valve, which includes both an actuation device and a valve body provides: the ability to incorporate both the actuation device and valve into a unitary structure that can be placed onto a microchip, the ability to generate higher actuation pressures and thus control higher fluid pressures than conventional microvalves, and a device that draws only microwatts of power. An electrokinetic pump that converts electric potential to hydraulic force is used to operate, or actuate, the valve.

  13. Magnetically operated check valve

    NASA Astrophysics Data System (ADS)

    Morris, Brian G.; Bozeman, Richard J., Jr.

    1993-03-01

    A magnetically operated check valve is disclosed having, in one aspect, a valve body and a movable poppet disposed therein. A magnet attracts the poppet to hold the valve shut until the force of fluid flow through the valve overcomes the magnetic attraction and moves the poppet to an unseated, open position. The poppet and magnet are configured and disposed to trap a magnetically attracted particulate and prevent it from flowing to a valve seating region.

  14. Lubricator valve apparatus

    SciTech Connect

    Brooks, R. T.

    1984-10-16

    A lubricator valve assembly comprises a reciprocably rotatable ball valve which is operated between open and closed positions solely through the selective application of control pressures and/or tubing pressure above the valve to a double acting sleeve type actuating piston. One end of the actuating piston has a valving piston formed thereon which cooperates with a seal bore in the housing to effect the opening or closing of a bypass fluid passage extending from a region below the ball valve to a region above the ball valve. Such valving piston also functions as part of a lost motion connection between the actuating sleeve piston and a reciprocable actuator for rotating the ball valve. In opening the ball valve, the valving piston first moves upwardly to establish a fluid bypass around the closed ball valve and then establishes contact with the actuator to rotate the ball valve to an open position. The same fluid bypass may be utilized to pump through fluid around the closed ball valve by applying fluid pressure above the ball valve. Improved sealing elements for the ball valve are also provided.

  15. Infective endocarditis following Melody valve implantation: comparison with a surgical cohort.

    PubMed

    O'Donnell, Clare; Holloway, Rhonda; Tilton, Elizabeth; Stirling, John; Finucane, Kirsten; Wilson, Nigel

    2017-03-01

    Infective endocarditis has been reported post Melody percutaneous pulmonary valve implant; the incidence and risk factors, however, remain poorly defined. We identified four cases of endocarditis from our first 25 Melody implants. Our aim was to examine these cases in the context of postulated risk factors and directly compare endocarditis rates with local surgical valves. We conducted a retrospective review of patients post Melody percutaneous pulmonary valve implant in New Zealand (October, 2009-May, 2015) and also reviewed the incidence of endocarditis in New Zealand among patients who have undergone surgical pulmonary valve implants. In total, 25 patients underwent Melody implantation at a median age of 18 years. At a median follow-up of 2.9 years, most were well with low valve gradient (median 27 mmHg) and only mild regurgitation. Two patients presented with life-threatening endocarditis and obstructive vegetations at 14 and 26 months post implant, respectively. Two additional patients presented with subacute endocarditis at 5.5 years post implant. From 2009 to May, 2015, 178 surgical pulmonic bioprostheses, largely Hancock valves and homografts, were used at our institution. At a median follow-up of 2.9 years, four patients (2%) had developed endocarditis in this group compared with 4/25 (16%) in the Melody group (p=0.0089). Three surgical valves have been replaced. The Melody valve offers a good alternative to surgical conduit replacement in selected patients. Many patients have excellent outcomes in the medium term. Endocarditis, however, can occur and if associated with obstruction can be life threatening. The risk for endocarditis in the Melody group was higher in comparison with that in a contemporaneous surgical pulmonary implant cohort.

  16. Quickly Removable Valve

    NASA Technical Reports Server (NTRS)

    Robbins, John S.

    1988-01-01

    Unit removed with minimal disturbance. Valve inlet and outlet ports adjacent to each other on same side of valve body. Ports inserted into special manifold on fluid line. Valve body attached to manifold by four bolts or, alternatively, by toggle clamps. Electromechanical actuator moves in direction parallel to fluid line to open and close valve. When necessary to clean valve, removed simply by opening bolts or toggle clamps. No need to move or separate ports of fluid line. Valve useful where disturbance of fluid line detrimental or where fast maintenance essential - in oil and chemical industries, automotive vehicles, aircraft, and powerplants.

  17. Quickly Removable Valve

    NASA Technical Reports Server (NTRS)

    Robbins, John S.

    1988-01-01

    Unit removed with minimal disturbance. Valve inlet and outlet ports adjacent to each other on same side of valve body. Ports inserted into special manifold on fluid line. Valve body attached to manifold by four bolts or, alternatively, by toggle clamps. Electromechanical actuator moves in direction parallel to fluid line to open and close valve. When necessary to clean valve, removed simply by opening bolts or toggle clamps. No need to move or separate ports of fluid line. Valve useful where disturbance of fluid line detrimental or where fast maintenance essential - in oil and chemical industries, automotive vehicles, aircraft, and powerplants.

  18. Fast acting check valve

    NASA Technical Reports Server (NTRS)

    Perkins, Gerald S. (Inventor)

    1979-01-01

    A check valve which closes more rapidly to prevent wearing of the valve seat and of the valve member that seals thereagainst, including a solenoid or other actuator that aids the normal spring to quickly close the valve at approximately the time when downpath fluid flow would stop, the actuator then being deenergized. The control circuit that operates the actuator can include a pair of pressure sensors sensing pressure both upstream and downstream from the valve seat. Where the valve is utilized to control flow to or from a piston pump, energization of the actuator can be controlled by sensing when the pump piston reaches its extreme of travel.

  19. Ball valve extractor

    DOEpatents

    Herndon, Charles; Brown, Roger A.

    2002-01-01

    An apparatus and process for removing a ball valve is provided. The ball valve removal tool provides a handle sliding along the length of a shaft. One end of the shaft is secured within an interior cavity of a ball valve while the opposite end of the shaft defines a stop member. By providing a manual sliding force to the handle, the handle impacts the stop member and transmits the force to the ball valve. The direction of the force is along the shaft of the removal tool and disengages the ball valve from the ball valve housing.

  20. Transcatheter aortic valve implantation.

    PubMed

    Oliemy, Ahmed; Al-Attar, Nawwar

    2014-01-01

    Transcatheter aortic valve implantation was developed to offer a therapeutic solution to patients with severe symptomatic aortic stenosis who are not candidates for conventional aortic valve replacement. The improvement in transcatheter aortic valve implantation outcomes is still of concern in the areas of stroke, vascular injury, heart block, paravalvular regurgitation and valve durability. Concomitantly, the progress, both technical and in terms of material advances of transcatheter valve systems, as well as in patient selection, renders transcatheter aortic valve implantation an increasingly viable treatment for more and more patients with structural heart disease.

  1. Technical evaluation report, TMI action NUREG-0737 (II.D.1), relief and safety valve testing, Comanche Peak, Unit 2, Docket No. 50-446

    SciTech Connect

    Fineman, C.P.

    1993-01-01

    In the past, safety and relief valves installed in the primary coolant system of light water reactors have performed improperly. As a result, the authors of NUREG-0578 (TMI-2 Lessons Learned Task Force Status Report and Short-Term Recommendations) and, subsequently, NUREG-0737 (Clarification of TMI Action Plan Requirements) recommended development and completion of programs to do two things. First, the programs should reevaluate the functional performance capabilities of pressurized water reactor safety, relief, and block valves. Second, they should verify the integrity of the pressurizer safety and relief valve piping systems for normal, transient, and accident conditions. This report documents the review of those programs by EG&G Idaho, Inc. Specifically, this report documents the review of the Comanche Peak, Unit 2, Applicant response to the requirements of NUREG-0578 and NUREG-0737. This review found the Applicant provided an acceptable response reconfirming they met General Design Criteria 14, 15, and 30 of Appendix A to 10 CFR 50 for the subject equipment.

  2. Programming jammed Codman Hakim programmable valves: study of an explanted valve and successful programming in a patient.

    PubMed

    Wong, Sui-To; Wen, Eleanor; Fong, Dawson

    2013-08-01

    Malfunction of a Codman Hakim programmable valve due to jamming of its programmable component may necessitate shunt revision. The authors report a method for programming jammed Codman Hakim programmable valves by using a Strata II magnet and additional neodymium magnets. The programming method was derived after studying a jammed valve in the laboratory that was explanted from an 10-year-old boy with a history of fourth ventricle ependymoma. Programming the explanted valve with a Codman programmer failed, but rotating a Strata II magnet above the valve resulted in rotation of the spiral cam in the valve. It was found that the Strata II magnet could be used to program the jammed valve by rotating the magnet 90° or multiples of 90° above the valve. The strength of the magnetic field of the Strata II magnet was able to be increased by putting neodymium magnets on it. The programming method was then successfully used in a patient with a jammed Codman Hakim programmable valve. After successful programming using this method, clinical and radiological follow-up of the patient was advised.

  3. Treatment of hydrocephalus determined by the European Orbis Sigma Valve II survey: a multicenter prospective 5-year shunt survival study in children and adults in whom a flow-regulating shunt was used.

    PubMed

    Hanlo, Patrick W; Cinalli, Giuseppe; Vandertop, W Peter; Faber, Joop A J; Bøgeskov, Lars; Børgesen, Svend E; Boschert, Jürgen; Chumas, Paul; Eder, Hans; Pople, Ian K; Serlo, Willy; Vitzthum, Eckehard

    2003-07-01

    The goal of this study was to evaluate the long-term results of a flow-regulating shunt (Orbis Sigma Valve [OSV] II Smart Valve System; Integra NeuroSciences, Sophia Antipolis, France) in the treatment of hydrocephalus, whether it was a first insertion procedure or surgical revision of another type of shunt, in everyday clinical practice in a multicenter prospective study. Patients of any age who had hydrocephalus underwent implantation of an OSV II system. The primary end point of the study was defined as any shunt-related surgery. The secondary end point was a mechanical complication (shunt obstruction, overdrainage, catheter misplacement, migration, or disconnection) or infection. The overall 5-year shunt survival rates and survival as it applied to different patient subgroups were assessed. Five hundred fifty-seven patients (48% of whom were adults and 52% of whom were children) were selected for OSV II shunt implantation; 196 patients reached the primary end point. Shunt obstruction occurred in 75 patients (13.5%), overdrainage in 10 patients (1.8%), and infection in 46 patients (8.2%). The probability of having experienced a shunt failure-free interval at 1 year was 71% and at 2 years it was 67%; thereafter the probability remained quite stable in following years (62% at the 5-year follow-up examination). No difference in shunt survival was observed between the overall pediatric (< or = 16 years of age) and adult populations. In the pediatric age group, however, there was a significantly lower rate of shunt survival in children younger than 6 months of age (55% at the 5-year follow-up examination). In this prospective study the authors demonstrate the effectiveness of flow regulation in the treatment of hydrocephalus both in children and in adults. Flow-regulating shunts limit the incidence of overdrainage and shunt-related complications. The overall 5-year shunt survival rate (62%) compares favorably with rates cited in other recently published series.

  4. Valve-in-Valve Transcatheter Valve Implantation in the Non-Aortic Position

    PubMed Central

    Ranney, David N.; Williams, Judson B.; Wang, Andrew; Gaca, Jeffrey G.

    2016-01-01

    Background Transcatheter valve-in-valve (VIV) procedures are an alternative to standard surgical valve replacement in high risk patients. Methods Cases in which a commercially approved transcatheter aortic valve replacement (TAVR) device was used for a non-aortic VIV procedure between November 2013 and September 2015 are reviewed. Clinical, echocardiographic, and procedural details, patient survival, and symptom severity by NYHA class at follow-up were assessed. Results All patients were heart-team determined high-risk for conventional redo surgery (mean STS PROM = 6.8 ± 2.2%). Five patients underwent VIV replacement in the non-aortic position, 4 for bioprosthetic mitral valve dysfunction and one for bioprosthetic tricuspid valve dysfunction. Bioprosthetic failure was due to stenosis in 3 patients and regurgitation in 2 others. A balloon-expandable device was used for all patients (Edwards Lifesciences, Irvine, CA). Transcatheter VIV replacement was accomplished by the transapical (mitral) and transfemoral venous (tricuspid) approaches. Median post-operative length of stay was 5 days (range 3-12). No deaths occurred at a mean follow-up of 21 months. NYHA class at follow-up decreased from class IV at baseline to class I or II for all patients. No paravalvular leaks greater than trivial were encountered. Median mean gradient following mitral replacement was 6.5 mmHg (range 6-13 mmHg), and following tricuspid replacement was 4 mmHg. Post-operative complications included hematuria, epistaxis, acute kidney injury, and atrial fibrillation. Conclusions Transcatheter VIV implantation in the non-aortic position for dysfunctional bioprostheses can be performed safely with favorable clinical outcomes using a balloon expandable TAVR device. PMID:27059552

  5. A reversible molecular valve

    PubMed Central

    Nguyen, Thoi D.; Tseng, Hsian-Rong; Celestre, Paul C.; Flood, Amar H.; Liu, Yi; Stoddart, J. Fraser; Zink, Jeffrey I.

    2005-01-01

    In everyday life, a macroscopic valve is a device with a movable control element that regulates the flow of gases or liquids by blocking and opening passageways. Construction of such a device on the nanoscale level requires (i) suitably proportioned movable control elements, (ii) a method for operating them on demand, and (iii) appropriately sized passageways. These three conditions can be fulfilled by attaching organic, mechanically interlocked, linear motor molecules that can be operated under chemical, electrical, or optical stimuli to stable inorganic porous frameworks (i.e., by self-assembling organic machinery on top of an inorganic chassis). In this article, we demonstrate a reversibly operating nanovalve that can be turned on and off by redox chemistry. It traps and releases molecules from a maze of nanoscopic passageways in silica by controlling the operation of redox-activated bistable [2]rotaxane molecules tethered to the openings of nanopores leading out of a nanoscale reservoir. PMID:16006520

  6. Valve mechanism having variable valve timing

    SciTech Connect

    Oda, H.; Masuda, S.; Morita, Y.

    1986-04-08

    This patent describes a valve mechanism for an internal combustion engine which consists of a camshaft rotatable about a longitudinal axis and having a cam formed thereon, a swingable member mounted for swinging movement about the longitudinal axis of the camshaft and formed with a tappet receiving hole. A valve tapper is received in the tappet receiving hole for a slidable movement along the tappet receiving hole. The tappet has a cam which engages the surface at one end and a stem engages the surface at the other end. A valve stem is mounted for axial movement and engaged at one end with the stem engaging, surface of the tappet to be actuated thereby. A valve timing control swingably moves the swingable member and the tappet about the camshaft axis in accordance with predetermined engine operating conditions to thereby change valve opening and valve closing timing. The control includes means for holding the swingable member at a first position. The tappet and valve stem are in contact at a first position on the stem engaging surface of the tappet and the direction of the slidable movement of the tappet is aligned with the direction of the axial movement of the valve stem at least under heavy load, high speed engine operation, and for moving the swingable member from the first position to a second position. The tappet and valve stem are in contact at a second position on the stem engaging surface of the tappet at low speed engine operation to effect a change in valve opening and valve closing timing.

  7. Pump isolation valve

    DOEpatents

    Kinney, Calvin L.; Wetherill, Todd M.

    1983-08-02

    The pump isolation valve provides a means by which the pump may be selectively isolated from the remainder of the coolant system while being compatible with the internal hydraulic arrangement of the pump during normal operation of the pump. The valve comprises a valve cylinder disposed around the pump and adjacent to the last pump diffuser with a turning vane attached to the lower end of the valve cylinder in a manner so as to hydraulically match with the discharge diffuser. The valve cylinder is connected to a drive means for sliding the valve cylinder relative to the diffuser support cylinder so as to block flow in either direction through the discharge diffuser when the valve is in the closed position and to aid in the flow of the coolant from the discharge diffuser by means of the turning vane when the valve is in the open position.

  8. Mud separator valve apparatus

    SciTech Connect

    Schneider, S.J.

    1981-12-08

    An automatic cleaning system is provided for a mud separator apparatus. Water and mud inputs to a mud pump feeding the separator are respectively controlled by two butterfly valves ganged for cooperation, and operated by a single valve actuator motor. When the mud separator is shut off, a time delay relay is actuated which keeps the mud separator rotor motor on line during a predetermined flush cycle. The valve actuator opens the water valve, and closes the mud valve, permitting the separator to be flushed with water. Activating the start button returns the valve actuator to the position in which the mud valve is open and the water valve is closed, thereby returning the apparatus to the mud separation cycle.

  9. Valve Health Monitor (VHM)

    NASA Technical Reports Server (NTRS)

    Perotti, Jose M.; Delgado, H. (Technical Monitor)

    2002-01-01

    This presentation reports on progress being made on developing a Valve Health Monitor (VHM) Smart Current Signature Sensor. Topics cover include: design needs, target valves, current signatures, VHM design approach and VHM status/conclusions.

  10. Problem: Heart Valve Regurgitation

    MedlinePlus

    ... Options • Recovery and Healthy Living Goals • Personal Stories Heart Valve Disease Symptoms Dr. Robert Bonow describes the symptoms that may alert you to heart valve disease. Support Network: You're Not Alone Popular Articles ...

  11. Overflow control valve

    DOEpatents

    Hundal, Rolv; Kessinger, Boyd A.; Parlak, Edward A.

    1984-07-24

    An overflow control valve for use in a liquid sodium coolant pump tank which valve can be extended to create a seal with the pump tank wall or retracted to break the seal thereby accommodating valve removal. An actuating shaft which controls valve disc position also has cams which bear on roller surfaces to force retraction of a sliding cylinder against spring tension to retract the cylinder from sealing contact with the pump tank.

  12. Valve technology: A compilation

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A technical compilation on the types, applications and modifications to certain valves is presented. Data cover the following: (1) valves that feature automatic response to stimuli (thermal, electrical, fluid pressure, etc.), (2) modified valves changed by redesign of components to increase initial design effectiveness or give the item versatility beyond its basic design capability, and (3) special purpose valves with limited application as presented, but lending themselves to other uses with minor changes.

  13. Aerodynamic Shutoff Valve

    NASA Technical Reports Server (NTRS)

    Horstman, Raymond H.

    1992-01-01

    Aerodynamic flow achieved by adding fixed fairings to butterfly valve. When valve fully open, fairings align with butterfly and reduce wake. Butterfly free to turn, so valve can be closed, while fairings remain fixed. Design reduces turbulence in flow of air in internal suction system. Valve aids in development of improved porous-surface boundary-layer control system to reduce aerodynamic drag. Applications primarily aerospace. System adapted to boundary-layer control on high-speed land vehicles.

  14. Aerodynamic Shutoff Valve

    NASA Technical Reports Server (NTRS)

    Horstman, Raymond H.

    1992-01-01

    Aerodynamic flow achieved by adding fixed fairings to butterfly valve. When valve fully open, fairings align with butterfly and reduce wake. Butterfly free to turn, so valve can be closed, while fairings remain fixed. Design reduces turbulence in flow of air in internal suction system. Valve aids in development of improved porous-surface boundary-layer control system to reduce aerodynamic drag. Applications primarily aerospace. System adapted to boundary-layer control on high-speed land vehicles.

  15. Stemless Ball Valve

    NASA Technical Reports Server (NTRS)

    Burgess, Robert K.; Yakos, David; Walthall, Bryan

    2012-01-01

    This invention utilizes a new method of opening and closing a ball valve. Instead of rotating the ball with a perpendicular stem (as is the case with standard ball valves), the ball is rotated around a fixed axis by two guide pins. This innovation eliminates the leak point that is present in all standard ball valves due to the penetration of an actuation stem through the valve body. The VOST (Venturi Off-Set-Technology) valve has been developed for commercial applications. The standard version of the valve consists of an off-set venturi flow path through the valve. This path is split at the narrowest portion of the venturi, allowing the section upstream from the venturi to be rotated. As this rotation takes place, the venturi becomes restricted as one face rotates with respect to the other, eventually closing off the flow path. A spring-loaded seal made of resilient material is embedded in the upstream face of the valve, making a leak-proof seal between the faces; thus a valve is formed. The spring-loaded lip seal is the only seal that can provide a class six, or bubble-tight, seal against the opposite face of the valve. Tearing action of the seal by high-velocity gas on this early design required relocation of the seal to the downstream face of the valve. In the stemless embodiment of this valve, inner and outer magnetic cartridges are employed to transfer mechanical torque from the outside of the valve to the inside without the use of a stem. This eliminates the leak path caused by the valve stems in standard valves because the stems penetrate through the bodies of these valves.

  16. A case of SAPIEN XT valve fallen into left ventricle during valve-in-valve transcatheter aortic valve implantation.

    PubMed

    Koizumi, Shigeki; Ehara, Natsuhiko; Nishiya, Kenta; Koyama, Tadaaki

    2017-06-24

    Late transcatheter heart valve embolization is a rare but life-threatening complication of transcatheter aortic valve implantation. Surgical intervention is performed for most cases, but some cases were treated by valve-in-valve transcatheter aortic valve implantation. We describe a patient in whom a 29-mm Edwards SAPIEN XT valve migrated into the left ventricular outflow tract 41 days after the initial implantation. We tried to perform valve-in-valve transcatheter aortic valve implantation using a transfemoral approach. As soon as the second transcatheter heart valve touched the first implanted valve, it fell into the left ventricle. Immediate surgical intervention was required. The first valve was removed, and surgical aortic valve replacement was successfully performed. In conclusion, we should choose surgical aortic valve replacement for late transcatheter heart valve embolization. Even if we need to treat by catheter intervention, transapical approach may be better.

  17. Microblower assisted barometric valve

    DOEpatents

    Rossabi, Joseph; Hyde, Warren K.; Riha, Brian D.; Jackson, Dennis G.; Sappington, Frank

    2005-12-06

    A gas exchange apparatus is provided which provides for both passive fluid flow and blower associated fluid flow through a barometric valve. A battery powered blower is provided which allows for operation of the barometric valve during times when the barometric valve would otherwise be closed, and provides for enhanced volume of gas exchange.

  18. Problem: Mitral Valve Regurgitation

    MedlinePlus

    ... Stroke Vascular Health Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Problem: Mitral Valve Regurgitation Updated:Sep 21,2016 What is mitral valve ... blood flows from the ventricle through the aortic valve — as it should — and some blood flows ...

  19. Dump valve assembly

    DOEpatents

    Owen, T.J.

    1984-01-01

    A dump valve assembly comprising a body having a bore defined by a tapered wall and a truncated spherical valve member adapted to seat along a spherical surface portion thereof against said tapered wall. Means are provided for pivoting said valve member between a closed position engagable with said tapered wall and an open position disengaged therefrom.

  20. Liquid rocket valve assemblies

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The design and operating characteristics of valve assemblies used in liquid propellant rocket engines are discussed. The subjects considered are as follows: (1) valve selection parameters, (2) major design aspects, (3) design integration of valve subassemblies, and (4) assembly of components and functional tests. Information is provided on engine, stage, and spacecraft checkout procedures.

  1. Well safety valve

    SciTech Connect

    Vinzant, M.B.; Hilts, R.L.; Meaders, M.; Speegle, S.C.

    1984-07-24

    A retrievable well safety valve in a cased well system including a tubing string, a dual packer downhole around the tubing sealing with the casing and submersible pump in the tubing string below the packer. The safety valve controls flow of pumped fluids through the tubing to surface and directs gas flow into the casing annulus above the packer. When the safety valve is landed in cooperating tubing nipples above the packer, separated central annular flow passages are formed for pumped fluids and gas respectively. A ball valve in the central flow passage controls pumped fluid flow therethrough and an annular valve coupled to the ball valve controls gas flow from below the packer through the annular flow passage around and by the ball valve. When the ball valve is in the down and open position, the valve ball member engages a lower seat, which maintains the central and annular flow passages separate and prevents comingling flow of fluids and gas. The coupled valves are held open by pressured fluid from surface and are closed automatically on loss of pressure in their control fluid circuits. When the valves close, a circuit of flow passages for recirculating pumped fluids and gas are opened below the ball valve and the pump may continue operation without overload.

  2. Mitral Valve Prolapse

    PubMed Central

    Rosser, Walter W.

    1992-01-01

    The author discusses the pathophysiology of mitral valve prolapse and provides guidelines to identify and treat low-to high-risk mitral valve prolapse. An approach to diagnosing bacterial endocarditis and its prophylaxis are also discussed. The author reviews mitral valve prolapse syndrome and the risk of sudden death.

  3. Double-Poppet Valve

    NASA Technical Reports Server (NTRS)

    Huber, W. C.

    1984-01-01

    New valve design includes two poppet/seat combinations actuated simultaneously. If one fails, other continues to seal against fluid flow. Valve primarily useful for handling dangerous fluids and lighter and more compact than comparable redundant-valve systems used at present.

  4. Disk Valve For Cryogenics

    NASA Technical Reports Server (NTRS)

    Calhoun, Richard B.

    1993-01-01

    Lightweight disk valve designed to have dimensions and capabilities similar to those of valve described in "Lightweight Right-Angle Valve For Cryogenics" (MSC-21889). Simple unit remains leaktight over wide range of pressures and temperatures without need for manual readjustment of packing gland. Weighs less than 60 g and made relatively inexpensively from some commercial and few simple custom-machined components.

  5. Lock For Valve Stem

    NASA Technical Reports Server (NTRS)

    Burley, Richard K.; Guirguis, Kamal S.

    1991-01-01

    Simple, cheap device locks valve stem so its setting cannot be changed by unauthorized people. Device covers valve stem; cover locked in place with standard padlock. Valve lock made of PVC pipe and packing band. Shears, drill or punch, and forming rod only tools needed.

  6. Heart Valve Diseases

    MedlinePlus

    Your heart has four valves. Normally, these valves open to let blood flow through or out of your heart, and then shut to keep it from flowing ... close tightly. It's one of the most common heart valve conditions. Sometimes it causes regurgitation. Stenosis - when ...

  7. Pulmonary Valve Stenosis

    MedlinePlus

    ... or valve or replaces the valve with an artificial valve. Repairs to other congenital heart defects can be made during the surgery, as well. There's a slight risk of bleeding, infection or blood clots associated with the surgery. While there's little ...

  8. How Is Mitral Valve Prolapse Treated?

    MedlinePlus

    ... page from the NHLBI on Twitter. How Is Mitral Valve Prolapse Treated? Most people who have mitral valve ... all hospitals offer this method. Valve Repair and Valve Replacement In mitral valve surgery, the valve is repaired or replaced. ...

  9. Compact valve actuation mechanism

    NASA Technical Reports Server (NTRS)

    Brogdon, James William (Inventor); Gill, David Keith (Inventor)

    2000-01-01

    A valve actuation device. The device may include a free floating valve bridge movably supported within a cavity in the engine housing. The bridge may be provided with a cavity and an orifice arrangement for pumping gases entrained with lubricating fluid toward the piston stems as the bridge reciprocates back and forth. The device may also include a rocker arm that has a U-shaped cross-sectional shape for receiving at least a portion of the valve bridge, valve stem valve spring and spring retainer therein. The rocker arm may be provided with lubrication passages for directing lubrication to the point wherein it is pivotally affixed to the engine housing.

  10. 21 CFR 874.3850 - Endolymphatic shunt tube with valve.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3850 Endolymphatic shunt tube with valve. (a) Identification. An endolymphatic shunt tube with valve is a device that consists... device is the FDA guidance document “Class II Special Controls Guidance Document: Endolymphatic...

  11. 21 CFR 874.3850 - Endolymphatic shunt tube with valve.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3850 Endolymphatic shunt tube with valve. (a) Identification. An endolymphatic shunt tube with valve is a device that consists... device is the FDA guidance document “Class II Special Controls Guidance Document: Endolymphatic...

  12. Main Oxidizer Valve Design

    NASA Technical Reports Server (NTRS)

    Addona, Brad; Eddleman, David

    2015-01-01

    A developmental Main Oxidizer Valve (MOV) was designed by NASA-MSFC using additive manufacturing processes. The MOV is a pneumatically actuated poppet valve to control the flow of liquid oxygen to an engine's injector. A compression spring is used to return the valve to the closed state when pneumatic pressure is removed from the valve. The valve internal parts are cylindrical in shape, which lends itself to traditional lathe and milling operations. However, the valve body represents a complicated shape and contains the majority of the mass of the valve. Additive manufacturing techniques were used to produce a part that optimized mass and allowed for design features not practical with traditional machining processes.

  13. CAM operated fuel valve

    SciTech Connect

    Kelly, S.T.; Katchka, J.R.

    1991-09-03

    This patent describes improvement in a fuel control valve construction comprising a housing means having an inlet means adapted to be interconnected to a fuel source and a main outlet means adapted to be interconnected to a main burner means, the housing means having a main valve seat for interconnecting the inlet means with the main outlet means, the housing means having a movable main valve member for opening and closing the main valve seat, the housing means having a movable lever operatively associated with the main valve member and having a manually operable actuator means for controlling the operating positions of the lever, the lever having an intermediate cam follower portion and opposed ends disposed on each side of the cam follower portion with one end of the opposed ends being pivotally mounted to the housing means and with the other end of the opposed ends for operating the main valve member, the housing means having biasing means operatively interconnected to the lever to tend to pivot the lever in one direction that opens the main valve member away from its the main valve seat. The improvement comprises; the housing means has a thermostatically controlled means that is operatively associated with the lever and is adapted to engage and hold the lever in a position wherein the main valve member is in a closed condition against its the main valve seat when the thermostatically controlled means is in one operating condition thereof and the actuator means is in the on condition thereof.

  14. Bioprosthetic Valve Fracture Improves the Hemodynamic Results of Valve-in-Valve Transcatheter Aortic Valve Replacement.

    PubMed

    Chhatriwalla, Adnan K; Allen, Keith B; Saxon, John T; Cohen, David J; Aggarwal, Sanjeev; Hart, Anthony J; Baron, Suzanne J; Dvir, Danny; Borkon, A Michael

    2017-07-01

    Valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) may be less effective in small surgical valves because of patient/prosthesis mismatch. Bioprosthetic valve fracture (BVF) using a high-pressure balloon can be performed to facilitate VIV TAVR. We report data from 20 consecutive clinical cases in which BVF was successfully performed before or after VIV TAVR by inflation of a high-pressure balloon positioned across the valve ring during rapid ventricular pacing. Hemodynamic measurements and calculation of the valve effective orifice area were performed at baseline, immediately after VIV TAVR, and after BVF. BVF was successfully performed in 20 patients undergoing VIV TAVR with balloon-expandable (n=8) or self-expanding (n=12) transcatheter valves in Mitroflow, Carpentier-Edwards Perimount, Magna and Magna Ease, Biocor Epic and Biocor Epic Supra, and Mosaic surgical valves. Successful fracture was noted fluoroscopically when the waist of the balloon released and by a sudden drop in inflation pressure, often accompanied by an audible snap. BVF resulted in a reduction in the mean transvalvular gradient (from 20.5±7.4 to 6.7±3.7 mm Hg, P<0.001) and an increase in valve effective orifice area (from 1.0±0.4 to 1.8±0.6 cm(2), P<0.001). No procedural complications were reported. BVF can be performed safely in small surgical valves to facilitate VIV TAVR with either balloon-expandable or self-expanding transcatheter valves and results in reduced residual transvalvular gradients and increased valve effective orifice area. © 2017 American Heart Association, Inc.

  15. Valve selection in aortic valve endocarditis

    PubMed Central

    Zubrytska, Yana

    2016-01-01

    Aortic prosthetic valve endocarditis (PVE) is a potentially life-threatening disease. Mortality and incidence of infective endocarditis have been reduced in the past 30 years. Medical treatment of aortic PVE may be successful in patients who have a prompt response after antibiotic treatment and who do not have prosthetic dysfunction. In advanced stages, antibiotic therapy alone is insufficient to control the disease, and surgical intervention is necessary. Surgical treatment may be lifesaving, but it is still associated with considerable morbidity and mortality. The aim of surgery is to perform a radical excision of all infected and necrotic tissue, reconstruction of the left ventricle outflow tract, and replacement of the aortic valve. There is no unanimous consensus on which is the optimal prosthesis to implant in this context, and several surgical techniques have been suggested. We aim to analyze the efficacy of the surgical treatment and discuss the issue of valve selection in patients with aortic valve endocarditis. PMID:27785132

  16. Guide to prosthetic cardiac valves

    SciTech Connect

    Morse, D.; Steiner, R.M.; Fernandez, J.

    1985-01-01

    This book contains 10 chapters. Some of the chapter titles are: The development of artificial heart valves: Introduction and historical perspective; The radiology of prosthetic heart valves; The evaluation of patients for prosthetic valve implantation; Pathology of cardiac valve replacement; and Bioengineering of mechanical and biological heart valve substitutes.

  17. Aortic or Mitral Valve Replacement With the Biocor and Biocor Supra

    ClinicalTrials.gov

    2016-03-09

    Aortic Valve Insufficiency; Aortic Valve Regurgitation; Aortic Valve Stenosis; Aortic Valve Incompetence; Mitral Valve Insufficiency; Mitral Valve Regurgitation; Mitral Valve Stenosis; Mitral Valve Incompetence

  18. Intelligent Flow Control Valve

    NASA Technical Reports Server (NTRS)

    Kelley, Anthony R (Inventor)

    2015-01-01

    The present invention is an intelligent flow control valve which may be inserted into the flow coming out of a pipe and activated to provide a method to stop, measure, and meter flow coming from the open or possibly broken pipe. The intelligent flow control valve may be used to stop the flow while repairs are made. Once repairs have been made, the valve may be removed or used as a control valve to meter the amount of flow from inside the pipe. With the addition of instrumentation, the valve may also be used as a variable area flow meter and flow controller programmed based upon flowing conditions. With robotic additions, the valve may be configured to crawl into a desired pipe location, anchor itself, and activate flow control or metering remotely.

  19. Cryogenic Cam Butterfly Valve

    NASA Technical Reports Server (NTRS)

    McCormack, Kenneth J. (Inventor)

    2016-01-01

    A cryogenic cam butterfly valve has a body that includes an axially extending fluid conduit formed there through. A disc lug is connected to a back side of a valve disc and has a circular bore that receives and is larger than a cam of a cam shaft. The valve disc is rotatable for a quarter turn within the body about a lug axis that is offset from the shaft axis. Actuating the cam shaft in the closing rotational direction first causes the camming side of the cam of the cam shaft to rotate the disc lug and the valve disc a quarter turn from the open position to the closed position. Further actuating causes the camming side of the cam shaft to translate the valve disc into sealed contact with the valve seat. Opening rotational direction of the cam shaft reverses these motions.

  20. Minimally invasive valve surgery.

    PubMed

    Woo, Y Joseph; Seeburger, Joerg; Mohr, Friedrich W

    2007-01-01

    As alternatives to standard sternotomy, surgeons have developed innovative, minimally invasive approaches to conducting valve surgery. Through very small skin incisions and partial upper sternal division for aortic valve surgery and right minithoracotomy for mitral surgery, surgeons have become adept at performing complex valve procedures. Beyond cosmetic appeal, apparent benefits range from decreased pain and bleeding to improved respiratory function and recovery time. The large retrospective studies and few small prospective randomized studies are herein briefly summarized. The focus is then directed toward describing specific intraoperative technical details in current clinical use, covering anesthetic preparation, incision, mediastinal access, cardiovascular cannulation, valve exposure, and valve reconstruction. Finally, unique situations such as pulmonic valve surgery, reoperations, beating heart surgery, and robotics are discussed.

  1. JenaValve.

    PubMed

    Treede, Hendrik; Rastan, Ardawan; Ferrari, Markus; Ensminger, Stephan; Figulla, Hans-Reiner; Mohr, Friedrich-Wilhelm

    2012-09-01

    The JenaValve is a next-generation TAVI device which consists of a well-proven porcine root valve mounted on a low-profile nitinol stent. Feeler guided positioning and clip fixation on the diseased leaflets allow for anatomically correct implantation of the device without rapid pacing. Safety and efficacy of transapical aortic valve implantation using the JenaValve were evaluated in a multicentre prospective study that showed good short and midterm results. The valve was CE-mark released in Europe in September 2011. A post-market registry ensures on-going and prospective data collection in "real-world" patients. The transfemoral JenaValve delivery system will be evaluated in a first-in-man study in the near future.

  2. 21 CFR 868.5870 - Nonrebreathing valve.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonrebreathing valve. 868.5870 Section 868.5870 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... vents exhaled gases into the atmosphere. (b) Classification. Class II (performance standards)....

  3. [Modern mitral valve surgery].

    PubMed

    Bothe, W; Beyersdorf, F

    2016-04-01

    At the beginning of the 20th century, Cutler and Levine performed the first successful surgical treatment of a stenotic mitral valve, which was the only treatable heart valve defect at that time. Mitral valve surgery has evolved significantly since then. The introduction of the heart-lung machine in 1954 not only reduced the surgical risk, but also allowed the treatment of different mitral valve pathologies. Nowadays, mitral valve insufficiency has become the most common underlying pathomechanism of mitral valve disease and can be classified into primary and secondary mitral insufficiency. Primary mitral valve insufficiency is mainly caused by alterations of the valve (leaflets and primary order chords) itself, whereas left ventricular dilatation leading to papillary muscle displacement and leaflet tethering via second order chords is the main underlying pathomechanism for secondary mitral valve regurgitation. Valve reconstruction using the "loop technique" plus annuloplasty is the surgical strategy of choice and normalizes life expectancy in patients with primary mitral regurgitation. In patients with secondary mitral regurgitation, implanting an annuloplasty is not superior to valve replacement and results in high rates of valve re-insufficiency (up to 30 % after 3 months) due to ongoing ventricular dilatation. In order to improve repair results in these patients, we add a novel subvalvular technique (ring-noose-string) to the annuloplasty that aims to prevent ongoing ventricular remodeling and re-insufficiency. In modern mitral surgery, a right lateral thoracotomy is the approach of choice with excellent repair and cosmetic results.

  4. Passively actuated valve

    SciTech Connect

    Modro, S. Michael; Ougouag, Abderrafi M.

    2005-09-20

    A passively actuated valve for isolating a high pressure zone from a low pressure zone and discontinuing the isolation when the pressure in the high pressure zone drops below a preset threshold. If the pressure in the high pressure zone drops below the preset threshold, the valve opens and allows flow from the high pressure zone to the low pressure zone. The valve remains open allowing pressure equalization and back-flow should a pressure inversion between the two pressure zone occur.

  5. Compact gate valve

    DOEpatents

    Bobo, Gerald E.

    1977-01-01

    This invention relates to a double-disc gate valve which is compact, comparatively simple to construct, and capable of maintaining high closing pressures on the valve discs with low frictional forces. The valve casing includes axially aligned ports. Mounted in the casing is a sealed chamber which is pivotable transversely of the axis of the ports. The chamber contains the levers for moving the valve discs axially, and an actuator for the levers. When an external drive means pivots the chamber to a position where the discs are between the ports and axially aligned therewith, the actuator for the levers is energized to move the discs into sealing engagement with the ports.

  6. Engine valve driving apparatus

    SciTech Connect

    Masuda, S.; Uesugi, T.; Oda, H.

    1989-01-03

    An engine valve driving apparatus for an internal combustion engine having a cam driven engine valve is described. It consists of a camshaft rotatable in synchronism with rotation of a crankshaft of an engine and a movable cam member supported by the camshaft for axial movement and prevented from turning relative to the camshaft. The movable cam member can be axially shifted between an operative position wherein the cam member is cooperative with a member of the engine valve so as to cause an operation of the engine valve and an inoperative position wherein the cam member is out of cooperation with the member.

  7. Solid handling valve

    DOEpatents

    Williams, William R.

    1979-01-01

    The present invention is directed to a solids handling valve for use in combination with lock hoppers utilized for conveying pulverized coal to a coal gasifier. The valve comprises a fluid-actuated flow control piston disposed within a housing and provided with a tapered primary seal having a recessed seat on the housing and a radially expandable fluid-actuated secondary seal. The valve seals are highly resistive to corrosion, erosion and abrasion by the solids, liquids, and gases associated with the gasification process so as to minimize valve failure.

  8. Magnetic Check Valve

    NASA Technical Reports Server (NTRS)

    Morris, Brian G.; Bozeman, Richard J., Jr.

    1994-01-01

    Poppet in proposed check valve restored to closed condition by magnetic attraction instead of spring force. Oscillations suppressed, with consequent reduction of wear. Stationary magnetic disk mounted just upstream of poppet, also containing magnet. Valve body nonmagnetic. Forward pressure or flow would push poppet away from stationary magnetic disk so fluid flows easily around poppet. Stop in valve body prevents poppet from being swept away. When flow stopped or started to reverse, magnetic attraction draws poppet back to disk. Poppet then engages floating O-ring, thereby closing valve and preventing reverse flow. Floating O-ring facilitates sealing at low loads.

  9. Transventricular mitral valve operations.

    PubMed

    Joseph Woo, Y; McCormick, Ryan C

    2011-10-01

    We report transventricular mitral valve operations in 2 patients with severe mitral regurgitation and postinfarction left ventricular rupture and pseudoaneurysm. The first patient had direct papillary muscle involvement necessitating replacement of the mitral valve. The second patient had indirect mitral involvement allowing for placement of an atrial mitral annuloplasty ring via the left ventricle. Both patients showed no mitral valve regurgitation after replacement or repair and had uneventful postoperative recoveries. These cases demonstrate a feasible, alternative, transventricular approach to mitral valve replacement and repair.

  10. Modeling the Mitral Valve

    NASA Astrophysics Data System (ADS)

    Kaiser, Alexander

    2016-11-01

    The mitral valve is one of four valves in the human heart. The valve opens to allow oxygenated blood from the lungs to fill the left ventricle, and closes when the ventricle contracts to prevent backflow. The valve is composed of two fibrous leaflets which hang from a ring. These leaflets are supported like a parachute by a system of strings called chordae tendineae. In this talk, I will describe a new computational model of the mitral valve. To generate geometry, general information comes from classical anatomy texts and the author's dissection of porcine hearts. An MRI image of a human heart is used to locate the tips of the papillary muscles, which anchor the chordae tendineae, in relation to the mitral ring. The initial configurations of the valve leaflets and chordae tendineae are found by solving solving an equilibrium elasticity problem. The valve is then simulated in fluid (blood) using the immersed boundary method over multiple heart cycles in a model valve tester. We aim to identify features and mechanisms that influence or control valve function. Support from National Science Foundation, Graduate Research Fellowship Program, Grant DGE 1342536.

  11. Transapical aortic valve and mitral valve in ring prosthesis implantation - a new advance in transcatheter procedures.

    PubMed

    Neves, Paulo C; Paulo, Nelson Santos; Gama, Vasco; Vouga, Luís

    2014-08-01

    Transcatheter valve implantation offers a new treatment modality to those patients whose general condition makes conventional surgery very risky. However, the transcatheter option has only been available for the aortic valve. We describe a case of a successful implantation of two Edwards SAPIEN(®) 26 and 29 mm transapical valves, respectively, in aortic and mitral positions, on a 74-year-old patient with severe aortic and mitral stenosis. The procedure progressed uneventfully. Predischarge echocardiogram showed a peak aortic gradient of 20 mmHg, mild periprosthetic regurgitation, peak and mean mitral gradients of 12 and 4, respectively, and moderate (II/IV) periprosthetic regurgitation. Indications for transapical valve implantation will rapidly increase in the near future. It is essential to individualize the treatment be applied for each patient, in order to optimize the success of the procedure.

  12. Interactions between programmable shunt valves and the iPad 3 with Smart Cover.

    PubMed

    He, Yizheng; Murphy, Rory K J; Roland, Jarod L; Limbrick, David D

    2013-04-01

    In patients with programmable CSF shunt valves, the risk of unintentional valve adjustment associated with the environmental magnetic influence is ever present. We tested whether the iPad 3 with Smart Cover is capable of changing the setting of individual programmable valves ex vivo using direct fluoroscopic visualization. The following valves were tested: Strata NSC Adjustable Pressure Valve, Strata NSC Burr Hole Valve, Strata II small valve, Sophysa Polaris model SPV, Aesculap valve proGAV, and Codman Certas Programmable Valve. The left front edge of the iPad 3 with Smart Cover was found to have the strongest magnetic flux, measuring approximately 1,200 G and was moved linearly directly over the tested valve and then parallel to the first path at approximately 30 cm/s. Also, this area was rotated once at varying distances above the valve at approximately 1 rad/s. Almost all shunt valves were immune to reprogramming by the iPad 3 at varying distances (including direct contact) except for the Strata II small valve, where rotating the peak flux location 4 mm above the valve changed the valve pressure settings every time. The iPad 3 can change pressure settings of the Strata II small valve at a distance comparable to the thickness of certain regions of the scalp. Although the specific rotational motion described here may be uncommon in real life, it is nevertheless recommended that children with hydrocephalus, caregivers, educators, and therapists are informed of the now-apparent risks of close contact with this increasingly popular technology.

  13. Non-plugging injection valve

    DOEpatents

    Carey, Jr., Henry S.

    1985-01-01

    A valve for injecting fluid into a conduit carrying a slurry subject to separation to form deposits capable of plugging openings into the conduit. The valve comprises a valve body that is sealed to the conduit about an aperture formed through the wall of the conduit to receive the fluid to be injected and the valve member of the valve includes a punch portion that extends through the injection aperture to the flow passage, when the valve is closed, to provide a clear channel into the conduit, when the valve is opened, through deposits which might have formed on portions of the valve adjacent the conduit.

  14. Understanding Heart Valve Problems and Causes

    MedlinePlus

    ... affecting the aortic valve, and can lead to aortic stenosis . Mediastinal radiation therapy (radiation to the chest) – Studies ... Disease "Innocent" Heart Murmur Problem: Valve Stenosis - Problem: Aortic Valve Stenosis - Problem: Mitral Valve Stenosis - Problem: Tricuspid Valve Stenosis - ...

  15. How Is Heart Valve Disease Treated?

    MedlinePlus

    ... and replacing it with a man-made or biological valve. Biological valves are made from pig, cow, or human ... the valve. Man-made valves last longer than biological valves and usually don’t have to be ...

  16. Valve mechanisms for at least two simultaneously actuable valves

    SciTech Connect

    Heimburg, F.

    1989-02-21

    This patent describes a valve gear for at least two valves of an internal combustion engine to be operated simultaneously on longitudinal axes, wherein the valve gear comprises a thrust device which is common to all valves and displaceable on an axis by a cam shaft and against which the valves abut by their valve stems to that displacement of the thrust device causes corresponding displacement of the valves, characterized in that the camshaft includes a single cam that is seated on the thrust device eccentrically relative to its axis causing rotation of the thrust device about its axis. When the thrust device is displaced, the thrust device is axially symmetrical, and the valve stems each abut against the thrust device at positions centered on points offset from the longitudinal axes of the valves causing rotation of the valves about their longitudinal axis when the valves are displaced.

  17. Heimlich valve and pneumothorax

    PubMed Central

    Gogakos, Apostolos; Barbetakis, Nikolaos; Lazaridis, George; Papaiwannou, Antonis; Karavergou, Anastasia; Lampaki, Sofia; Baka, Sofia; Mpoukovinas, Ioannis; Karavasilis, Vasilis; Kioumis, Ioannis; Pitsiou, Georgia; Katsikogiannis, Nikolaos; Tsakiridis, Kosmas; Rapti, Aggeliki; Trakada, Georgia; Zissimopoulos, Athanasios; Tsirgogianni, Katerina; Zarogoulidis, Konstantinos

    2015-01-01

    The Heimlich valve is a small one-way valve used for chest drainage that empties into a flexible collection device and prevents return of gases or fluids into the pleural space. The Heimlich valve is less than 13 cm (5 inches) long and facilitates patient ambulation. Currently there are several systems in the market. It can be used in many patients instead of a traditional water seal drainage system. The Heimlich chest drainage valve was developed so that the process of draining the pleural cavity could be accomplished in a safe, relatively simple, and efficient manner. This valve system has replaced the cumbersome underwater drainage bottle system. Moreover; the Heimlich valve system connects to chest tubing and allows fluid and air to pass in one direction only. This system functions in any position, and it does not ever need to be clamped, a regulated suction can be attached to it if necessary. The valve drains into a plastic bag that can be held at any level, allowing the patient undergoing chest drainage to be ambulatory simply by carrying the bag. In the current mini review we will present the Heimlich valve system and method of insertion. PMID:25861609

  18. Coanda effect in valves

    NASA Astrophysics Data System (ADS)

    Uruba, Václav; Procházka, Pavel; Skála, Vladislav

    2016-11-01

    Coanda effect takes place in flow within valves diffuser for certain conditions. The valve plug in half-closed position forms wall-jet, which could be stable or instable, depending on geometry and other conditions. This phenomenon was subject of experimental study using time-resolved PIV technique. For the acquired data analysis the special spatio-temporal methods have been used.

  19. Heimlich valve and pneumothorax.

    PubMed

    Gogakos, Apostolos; Barbetakis, Nikolaos; Lazaridis, George; Papaiwannou, Antonis; Karavergou, Anastasia; Lampaki, Sofia; Baka, Sofia; Mpoukovinas, Ioannis; Karavasilis, Vasilis; Kioumis, Ioannis; Pitsiou, Georgia; Katsikogiannis, Nikolaos; Tsakiridis, Kosmas; Rapti, Aggeliki; Trakada, Georgia; Zissimopoulos, Athanasios; Tsirgogianni, Katerina; Zarogoulidis, Konstantinos; Zarogoulidis, Paul

    2015-03-01

    The Heimlich valve is a small one-way valve used for chest drainage that empties into a flexible collection device and prevents return of gases or fluids into the pleural space. The Heimlich valve is less than 13 cm (5 inches) long and facilitates patient ambulation. Currently there are several systems in the market. It can be used in many patients instead of a traditional water seal drainage system. The Heimlich chest drainage valve was developed so that the process of draining the pleural cavity could be accomplished in a safe, relatively simple, and efficient manner. This valve system has replaced the cumbersome underwater drainage bottle system. Moreover; the Heimlich valve system connects to chest tubing and allows fluid and air to pass in one direction only. This system functions in any position, and it does not ever need to be clamped, a regulated suction can be attached to it if necessary. The valve drains into a plastic bag that can be held at any level, allowing the patient undergoing chest drainage to be ambulatory simply by carrying the bag. In the current mini review we will present the Heimlich valve system and method of insertion.

  20. Temperature-Operated Valve

    NASA Technical Reports Server (NTRS)

    Morrison, Andrew D.

    1994-01-01

    Bimetallic valve stem positions orifice at end of inner pipe orifice so liquid flows to outlet when temperature lies within small range of preset value. If liquid too cold or too hot, orifices misaligned and liquid returned to source. Such as in shower, valve prevents outflow of dangerously hot or uncomfortably cold water.

  1. Temperature-Operated Valve

    NASA Technical Reports Server (NTRS)

    Morrison, Andrew D.

    1994-01-01

    Bimetallic valve stem positions orifice at end of inner pipe orifice so liquid flows to outlet when temperature lies within small range of preset value. If liquid too cold or too hot, orifices misaligned and liquid returned to source. Such as in shower, valve prevents outflow of dangerously hot or uncomfortably cold water.

  2. Minimally invasive valve surgery.

    PubMed

    Woo, Y Joseph

    2009-08-01

    Traditional cardiac valve replacement surgery is being rapidly supplanted by innovative, minimally invasive approaches toward the repair of these valves. Patients are experiencing benefits ranging from less bleeding and pain to faster recovery and greater satisfaction. These operations are proving to be safe, highly effective, and durable, and their use will likely continue to increase and become even more widely applicable.

  3. Valve for abrasive material

    SciTech Connect

    Gardner, Harold S.

    1982-01-01

    A ball valve assembly for controlling the flow of abrasive particulates including an enlarged section at the bore inlet and an enlarged section at the bore outlet. A refractory ceramic annular deflector is positioned in each of the enlarged sections, substantially extending the useful life of the valve.

  4. Linear motion valve

    NASA Technical Reports Server (NTRS)

    Chandler, J. A. (Inventor)

    1985-01-01

    The linear motion valve is described. The valve spool employs magnetically permeable rings, spaced apart axially, which engage a sealing assembly having magnetically permeable pole pieces in magnetic relationship with a magnet. The gap between the ring and the pole pieces is sealed with a ferrofluid. Depletion of the ferrofluid is minimized.

  5. Intermittent stuck valve after aortic valve replacement with a mechanical valve

    PubMed Central

    Luo, Wenzong; Wang, Xinxin; Li, Jing; Mu, Yun; Ni, Yiming

    2017-01-01

    Abstract Background: Intermittent stuck valve after mechanical valve replacement surgery is a very rare and severe complication. Case summary: We present 1 case of a 53-year-old woman after aortic valve replacement for severe aortic valve stenosis combined with hypertrophy septum. She was diagnosed with intermittent stuck valve only 1 day after surgery by clinical symptoms, intraoperative transoesophageal echocardiogram, and intraoperative findings. Conclusions: Although indications for concomitant myectomy during aortic valve replacement are not clear, we recommend myectomy to prevent stuck valve after St Jude Medical Regent prosthesis replacement for severe aortic valve stenosis combined with hypertrophy septum. PMID:28248877

  6. Space Vehicle Valve System

    NASA Technical Reports Server (NTRS)

    Kelley, Anthony R. (Inventor); Lindner, Jeffrey L. (Inventor)

    2014-01-01

    The present invention is a space vehicle valve system which controls the internal pressure of a space vehicle and the flow rate of purged gases at a given internal pressure and aperture site. A plurality of quasi-unique variable dimension peaked valve structures cover the purge apertures on a space vehicle. Interchangeable sheet guards configured to cover valve apertures on the peaked valve structure contain a pressure-activated surface on the inner surface. Sheet guards move outwardly from the peaked valve structure when in structural contact with a purge gas stream flowing through the apertures on the space vehicle. Changing the properties of the sheet guards changes the response of the sheet guards at a given internal pressure, providing control of the flow rate at a given aperture site.

  7. ULTRA HIGH VACUUM VALVE

    DOEpatents

    Fry, W.A.

    1962-05-29

    A valve for high vacuum applications such as the CStellarator where chamber pressures as low as 2 x 10/sup -10/ mm Hg are necessary is designed with a line-of-sight path through the valve for visual inspection of the contents of reactants in such chambers. The valve comprises a turnable resilient metal ball having an aperture therethrough, means for selectively turning the ball to rotate the axis of its line-of-sight path, and soft, deformable opposing orifices that are movable relatively toward said ball to seal with opposite ball surfaces upon said movement of said axis of said line-of-sight path. The valve also includes a bellows seal connected between said orifices and internal actuating means that eliminates the requirement for gasketed turnable valve closing stems. (AEC)

  8. Boston Scientific Lotus valve.

    PubMed

    Meredith, Ian T; Hood, Kristin L; Haratani, Nicole; Allocco, Dominic J; Dawkins, Keith D

    2012-09-01

    As a result of recent randomised controlled trials and registry observations, transcatheter aortic valve replacement (TAVR) enjoys growing appeal for the treatment of patients at high or extreme risk from surgical aortic valve replacement. However, the current technologies and techniques have important limitations, including risk of stroke, vascular complications and paravalvular aortic regurgitation, which may in turn influence survival. While careful patient selection and screening may improve outcomes, new valve designs and iterations are required. The Lotus aortic valve replacement system is a new fully repositionable device designed to facilitate more precise delivery and minimise paravalvular regurgitation. The safety and efficacy of the Lotus valve are being studied systematically in the REPRISE clinical trial programme.

  9. Engine valve train system

    SciTech Connect

    Derringer, J.G.

    1986-12-09

    This patent describes a reciprocating internal combustion engine of the type having an engine block means defining at least one cylinder with an associate pair of ports, a valve located for axial movement in each of the ports with each valve normally biased to a valve closed position relative to its associate port. A rocker shaft support means is fixed to the engine block means, and a valve actuator is spaced from the valves and operable to effect reciprocation of the valves. The improvement described here comprises a rocker shaft pivotably supported by the rocker shaft support means, the rocker shaft having an axial passage adapted to be in continuous flow communication with the pressurized lubricant supply of the engine. It also includes first rocker arm pivotably supported on the rocker shaft in position for engagement with the valve actuator and with one of the valves and actuated in rocking movement whereby it can operate to effect opening and closing movement of one of the valves, and a second rocker arm pivotably supported on the rocker shaft next adjacent to the first rocker arm and operatively engaging the other one of the valves, the second rocker arm having a hydraulic cylinder means therein. A piston is sealingly journaled in the hydraulic cylinder means and located so as to permit engagement of the piston with the first rocker arm, the second rocker arm having a supply/drain passage means therein to the hydraulic cylinder means, and a drain passage which extends to the exterior of the second rocker arm and which is located in circumferentially spaced apart relationship to the supply/drain passage means.

  10. A fascial frustum valve for aortic valve replacement

    PubMed Central

    Yates, A. K.

    1971-01-01

    The promising qualities of autologous fascia lata in heart valve replacement have resulted in a search for improved methods of fascial heart valve manufacture. This paper describes a simply made and inserted and reliably competent unsupported fascial valve for aortic valve replacement. Images PMID:5576536

  11. Echocardiography in Transcatheter Aortic Valve Implantation and Mitral Valve Clip

    PubMed Central

    Luo, Huai

    2012-01-01

    Transcatheter aortic valve implantation and transcatheter mitral valve repair (MitraClip) procedures have been performed worldwide. In this paper, we review the use of two-dimensional and three-dimensional transesophageal echo for guiding transcatheter aortic valve replacement and mitral valve repair. PMID:23019387

  12. Face-Sealing Butterfly Valve

    NASA Technical Reports Server (NTRS)

    Tervo, John N.

    1992-01-01

    Valve plate made to translate as well as rotate. Valve opened and closed by turning shaft and lever. Interactions among lever, spring, valve plate, and face seal cause plate to undergo combination of translation and rotation so valve plate clears seal during parts of opening and closing motions.

  13. Sliding-gate valve

    DOEpatents

    Usnick, George B.; Ward, Gene T.; Blair, Henry O.; Roberts, James W.; Warner, Terry N.

    1979-01-01

    This invention is a novel valve of the slidable-gate type. The valve is designed especially for long-term use with highly abrasive slurries. The sealing surfaces of the gate are shielded by the valve seats when the valve is fully open or closed, and the gate-to-seat clearance is swept with an inflowing purge gas while the gate is in transit. A preferred form of the valve includes an annular valve body containing an annular seat assembly defining a flow channel. The seat assembly comprises a first seat ring which is slidably and sealably mounted in the body, and a second seat ring which is tightly fitted in the body. These rings cooperatively define an annular gap which, together with passages in the valve body, forms a guideway extending normal to the channel. A plate-type gate is mounted for reciprocation in the guideway between positions where a portion of the plate closes the channel and where a circular aperture in the gate is in register with the channel. The valve casing includes opposed chambers which extend outwardly from the body along the axis of the guideway to accommodate the end portions of the gate. The chambers are sealed from atmosphere; when the gate is in transit, purge gas is admitted to the chambers and flows inwardly through the gate-to-seat-ring, clearance, minimizing buildup of process solids therein. A shaft reciprocated by an external actuator extends into one of the sealed chambers through a shaft seal and is coupled to an end of the gate. Means are provided for adjusting the clearance between the first seat ring and the gate while the valve is in service.

  14. Study of multiple cycles valves

    NASA Technical Reports Server (NTRS)

    Wichmann, H.

    1973-01-01

    A discussion is presented regarding valves which can be cycled repeatedly and are available from industry for application in the inlet system for the Pioneer Venus Probe mass spectrometer. Both solenoid type and latching type valves are considered. The study is divided into two principal areas: (1) preparation of a valve specification reflecting the requirements of the inlet system cyclic valves for the Pioneer Venus Probe mass spectrometer and the submittal of this specification to potential valve suppliers for their response and proposal; (2) preparation of a design layout of an optimum cyclic valve meeting all of the valve specification requirements.

  15. Long life valve design concepts

    NASA Technical Reports Server (NTRS)

    Jones, J. R.; Hall, A. H., Jr.

    1975-01-01

    Valve concept evaluation, final candidate selection, design, manufacture, and demonstration testing of a pneumatically actuated 10-inch hybrid poppet butterfly shutoff valve are presented. Conclusions and recommendations regarding those valve characteristics and features which would serve to guide in the formulation of future valve procurements are discussed. The pertinent design goals were temperature range of plus 200 to minus 423 F, valve inlet pressure 35 psia, actuation pressure 750 psia, main seal leakage 3 x 0.00001 sccs at 35 psia valve inlet pressure, and a storage and operating life of 10 years. The valve was designed to be compatible with RP-1, propane, LH2, LO2, He, and N2.

  16. Mesofluidic two stage digital valve

    DOEpatents

    Jansen, John F; Love, Lonnie J; Lind, Randall F; Richardson, Bradley S

    2013-12-31

    A mesofluidic scale digital valve system includes a first mesofluidic scale valve having a valve body including a bore, wherein the valve body is configured to cooperate with a solenoid disposed substantially adjacent to the valve body to translate a poppet carried within the bore. The mesofluidic scale digital valve system also includes a second mesofluidic scale valve disposed substantially perpendicular to the first mesofluidic scale valve. The mesofluidic scale digital valve system further includes a control element in communication with the solenoid, wherein the control element is configured to maintain the solenoid in an energized state for a fixed period of time to provide a desired flow rate through an orifice of the second mesofluidic valve.

  17. Quartz ball valve

    NASA Technical Reports Server (NTRS)

    Goetz, C.; Ingle, W. M. (Inventor)

    1980-01-01

    A ball valve particularly suited for use in the handling of highly corrosive fluids is described. It is characterized by a valve housing formed of communicating segments of quartz tubing, a pair of communicating sockets disposed in coaxial alignment with selected segments of tubing for establishing a pair of inlet ports communicating with a common outlet port, a ball formed of quartz material supported for displacement between the sockets and configured to be received alternately thereby, and a valve actuator including a rod attached to the ball for selectively displacing the ball relative to each of the sockets for controlling fluid flow through the inlet ports.

  18. Occurrence and Transport of Agricultural Chemicals in Leary Weber Ditch Basin, Hancock County, Indiana, 2003-04

    USGS Publications Warehouse

    Baker, Nancy T.; Stone, Wesley W.; Wilson, John T.; Meyer, Michael T.

    2006-01-01

    Leary Weber Ditch Basin, Hancock County, Indiana, is one of seven first-order basins selected from across the United States as part of the Agricultural Chemicals: Source, Transport, and Fate study conducted by the National Water-Quality Assessment Program of the U.S. Geological Survey. The nationwide study was designed to increase the understanding of the links between the sources of water and agricultural chemicals (nutrients and pesticides) and the transport and fate of these chemicals through the environment. Agricultural chemicals were detected in Leary Weber Ditch and in every associated hydrologic compartment sampled during 2003 and 2004. Pesticides were detected more frequently in samples collected from overland flow and from the ditch itself and less frequently in ground-water samples. The lowest concentrations of pesticides and nutrients were detected in samples of rain, soil water, and ground water. The highest concentrations of pesticides and nutrients were detected in samples of tile-drain water, overland flow, and water from Leary Weber Ditch. Samples collected from the tile drain, overland flow and Leary Weber Ditch soon after chemical applications to the fields and coincident with rainfall and increased streamflow had higher concentrations of pesticides and nutrients than samples collected a longer time after the chemicals were applied. A mass-balance mixing analysis based on potassium concentrations indicated that tile drains are the primary contributor of water to Leary Weber Ditch, but overland flow is also an important contributor during periods of high-intensity rainfall. When maximum rainfall intensity was 0.5 inches per hour or lower, overland flow contributed about 10 percent and tile drains contributed about 90 percent of the flow to Leary Weber Ditch. When maximum rainfall intensity was 0.75 inches per hour or greater, overland flow contributed about 40 percent and tile drains contributed about 60 percent of the flow to the ditch. Ground

  19. Programmable shunt valves: in vitro assessment of safety of the magnetic field generated by a portable game machine.

    PubMed

    Nakashima, Koji; Nakajo, Takato; Kawamo, Michiari; Kato, Akihito; Ishigaki, Seiichiro; Murakami, Hidetomo; Imaizumi, Yohichi; Izumiyama, Hitoshi

    2011-01-01

    Cerebrospinal fluid (CSF) shunts are frequently used to treat hydrocephalus. The use of a programmable shunt valve allows physicians to easily change the opening pressure. Since patients with adjustable CSF shunt valves may use portable game machines, the permanent magnets in these machines may alter the shunt valve programmed settings or permanently damage the device. This study investigated the risk of unintentional valve adjustment associated with the use of game machines in patients with programmable CSF shunt valves. Four adjustable valves from 4 different manufacturers, Sophysa Polaris model SPV (Polaris valve), Miethke proGAV (proGAV), Codman Hakim programmable valve (CHPV), and Strata II small valve (Strata valve), were evaluated. Magnetic field interactions were determined using the portable game machine, Nintendo DS Lite (DS). The maximum distance between the valve and the DS that affected the valve pressure setting was measured by x-ray cinematography. The Polaris valve and proGAV were immune to unintentional reprogramming by the DS. However, the settings of the CHPV and Strata valves were randomly altered by the DS. Patients with an implanted shunt valve should be made aware of the risks posed by the magnetic fields associated with portable game machines and commonly used home electronics.

  20. Mitral Valve Prolapse.

    ERIC Educational Resources Information Center

    Bergy, Gordon G.

    1980-01-01

    Mitral valve prolapse is the most common heart disease seen in college and university health services. It underlies most arrhythmia and many chest complaints. Activity and exercise restrictions are usually unnecessary. (Author/CJ)

  1. Mitral valve regurgitation

    MedlinePlus

    ... your provider and dentist if you have a history of heart valve disease or congenital heart disease before treatment. Some people ... In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap ...

  2. Mitral Valve Prolapse

    MedlinePlus

    ... Peripheral Vascular Disease Rheumatic Fever Sick Sinus Syndrome Silent Ischemia Stroke Sudden Cardiac Arrest Valve Disease Vulnerable ... a stethoscope, your doctor may hear a "clicking" sound caused by the flapping of the leaflets. What ...

  3. Mitral Valve Prolapse.

    ERIC Educational Resources Information Center

    Bergy, Gordon G.

    1980-01-01

    Mitral valve prolapse is the most common heart disease seen in college and university health services. It underlies most arrhythmia and many chest complaints. Activity and exercise restrictions are usually unnecessary. (Author/CJ)

  4. Flow metering valve

    DOEpatents

    Blaedel, K.L.

    1983-11-03

    An apparatus for metering fluids at high pressures of about 20,000 to 60,000 psi is disclosed. The apparatus includes first and second plates which are positioned adjacent each other to form a valve chamber. The plates are made of materials which have substantially equal elastic properties. One plate has a planar surface area, and the other a recessed surface area defined by periphery and central lips. When the two plates are positioned in adjacent contacting relationship, a valve chamber is formed between the planar surface area and the recessed surface area. Fluid is introduced into the chamber and exits therefrom when a deformation occurs at positions where they no longer form a valve seat. This permits the metering of fluids at high pressures and at slow variable rates. Fluid then exits from the chamber until an applied external force becomes large enough to bring the valve seats back into contact.

  5. Flow metering valve

    DOEpatents

    Blaedel, Kenneth L.

    1985-01-01

    An apparatus for metering fluids at high pressures of about 20,000 to 60,000 psi is disclosed. The apparatus includes first and second plates which are positioned adjacent each other to form a valve chamber. The plates are made of materials which have substantially equal elastic properties. One plate has a planar surface area, and the other a recessed surface area defined by periphery and central lips. When the two plates are positioned in adjacent contacting relationship, a valve chamber is formed between the planar surface area and the recessed surface area. Fluid is introduced into the chamber and exits therefrom when a deformation occurs at positions where they no longer form a valve seat. This permits the metering of fluids at high pressures and at slow variable rates. Fluid then exits from the chamber until an applied external force becomes large enough to bring the valve seats back into contact.

  6. Get valves repaired properly

    SciTech Connect

    Robert, R.W.

    1988-02-01

    Valve users are generally unanimous in their dissatisfaction with valve reconditioning programs. Their dissatisfaction is expressed in three complaints: poor service, poor quality and total costs which often approach or exceed valve replacement costs. These complaints are clearly legitimate, and the providers of valve reconditioning services must shoulder a significant part of the blame. However, scrutiny of the reasons for dissatisfaction reveals that some portion of the blame must also be borne by the users. Since many of the practices that cause the user's complaints are rooted in the early development of this market, a review of that development is helpful in understanding how these problems arose, and leads to a better understanding of the steps necessary for improvement.

  7. Bidirectional piston valve

    DOEpatents

    Fischer, Harry C.

    1977-01-01

    This invention is a reversing valve having an inlet, an outlet, and an inlet-outlet port. The valve is designed to respond to the introduction of relatively high-pressure fluid at its inlet or, alternatively, of lower-pressure fluid at its inlet-outlet port. The valve includes an axially slidable assembly which is spring-biased to a position where it isolates the inlet and connects the inlet-outlet port to the outlet. The admission of high-pressure fluid to the inlet displaces the slidable assembly to a position where the outlet is isolated and the inlet is connected to the inlet-outlet port. The valve is designed to minimize pressure drops and leakage. It is of a reliable and comparatively simple design.

  8. THERMALLY OPERATED VAPOR VALVE

    DOEpatents

    Dorward, J.G. Jr.

    1959-02-10

    A valve is presented for use in a calutron to supply and control the vapor to be ionized. The invention provides a means readily operable from the exterior of the vacuum tank of the apparatuss without mechanical transmission of forces for the quick and accurate control of the ionizing arc by a corresponding control of gas flow theretos thereby producing an effective way of carefully regulating the operation of the calutron. The invention consists essentially of a tube member extending into the charge bottle of a calutron devices having a poppet type valve closing the lower end of the tube. An electrical heating means is provided in the valve stem to thermally vary the length of the stem to regulate the valve opening to control the flow of material from the charge bottle.

  9. Mitral Valve Prolapse

    MedlinePlus

    ... valve. MVP puts you at risk for infective endocarditis, a kind of heart infection. To prevent it, ... surgeries. Now, only people at high risk of endocarditis need the antibiotics. NIH: National Heart, Lung, and ...

  10. Valve for gas centrifuges

    DOEpatents

    Hahs, Charles A.; Burbage, Charles H.

    1984-01-01

    The invention is a pneumatically operated valve assembly for simultaneously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two of the lines so closed. The valve assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

  11. Liquid blocking check valve

    DOEpatents

    Merrill, John T.

    1984-01-01

    A liquid blocking check valve useful particularly in a pneumatic system utilizing a pressurized liquid fill chamber. The valve includes a floatable ball disposed within a housing defining a chamber. The housing is provided with an inlet aperture disposed in the top of said chamber, and an outlet aperture disposed in the bottom of said chamber in an offset relation to said inlet aperture and in communication with a cutaway side wall section of said housing.

  12. Bicuspid Aortic Valve

    DTIC Science & Technology

    2006-08-01

    Schnell E, Wollenek G, Maurer G, Baumgartner H, Lang IM. Mechanisms underlying aortic dilatation in congenital aortic valve malformation . Circulation...1999; 99(16):2138-2143. 10. Roberts CS, Roberts WC. Dissection of the aorta associated with congenital malformation of the aortic valve. J Am Coll... congenital heart defect, often diagnosed incidentally or as a consequence of an associated condition. Patients with this anomaly are at increased risk

  13. Piston and valve assembly

    SciTech Connect

    Rolder, G. K.

    1985-10-01

    A downhole hydraulically actuated pump assembly of either the free or fixed type lifts formation fluid from the bottom of a borehole to the surface of the ground. The downhole pump has a power piston which actuates a production plunger. A valve means is concentrically arranged within the power piston. A stationary, hollow valve control rod extends through the power piston and through the valve means, with a lower marginal end of the control rod terminating within the production plunger. Power fluid flows through the control rod and to the valve means. As the power piston reciprocates within the engine cylinder, means on the control rod actuates the valve means between two alternant positions so that power fluid is applied to the bottom face of the power piston to thereby cause the power piston to reciprocate upward; and thereafter, the control rod causes the valve means to shift to the other position, whereupon spent power fluid is exhausted from the engine cylinder. The spent power fluid is admixed with production fluid and is conducted to the surface of the ground.

  14. Engine valve train module

    SciTech Connect

    Wirth, R.C.; De Klep, E.L.

    1988-01-26

    In a reciprocating internal combustion engine of the type having an engine block means defining at least one cylinder with a first port and a second port in flow communication therewith, a first valve and a second valve reciprocably located to control flow through the first and second ports, respectively, and normally biased to a port closed position, the improvement is described comprising a valve train module that includes a housing adapted to be secured by machine screws to the engine block means above the first and second valves; an engine driven camshaft having axial spaced apart first and second cam lobes operatively supported for rotation in the housing; a lifter guide bore in the housing located substantially coaxial with the reciprocating axis of the first valve; a direct acting hydraulic lash adjuster operatively supported in the lifter guide bore with one end thereof engaging the first cam lobe and at its opposite end being operatively connected to the first valve. A follower guide bore is in the housing operatively aligned relative to the second cam lobe; a hollow rocker shaft is operatively fixed in the housing in parallel spaced apart relationship to the engine driven camshaft; a rocker arm pivotably supported intermediate its ends by the rocker shaft.

  15. Refinement of the alpha aminooleic acid bioprosthetic valve anticalcification technique.

    PubMed

    Gott, J P; Girardot, M N; Girardot, J M; Hall, J D; Whitlark, J D; Horsley, W S; Dorsey, L M; Levy, R J; Chen, W; Schoen, F J; Guyton, R A

    1997-07-01

    Aminooleic acid treatment has been demonstrated to prevent porcine valve calcification and to protect valvular hemodynamic function. Initial enthusiasm was tempered by histologic studies of these AOA valves, which showed cuspal hematomas, structural loosening, and surface roughening. This prompted a systematic review of the AOA treatment process. Unsolubilized particles of alpha aminooleic acid present in the treatment solution were identified as the cause of mechanical abrasion of valve cusps during processing. These particles were eliminated with a revamped protocol, which included filtration of the AOA solution before valve preparation. Porcine aortic valve cusps treated with this modified AOA protocol (AOA II) were studied in a rat subdermal implant model of mineralization. A juvenile sheep trial was then used to confirm the antimineralization effects of AOA II on glutaraldehyde-fixed porcine aortic roots in a circulatory model of accelerated calcification. Retrieved AOA II-treated cusps from the subdermal model were markedly less calcified than control cusps (AOA II, 1 +/- 0, 17 +/- 4, 23 +/- 6, and 17 +/- 10 versus control, 189 +/- 14, 251 +/- 16, 250 +/- 14, and 265 +/- 10 mg calcium/mg sample at 4, 8, 12, and 16 weeks, respectively; p < 0.0001). Morphologic examination of the AOA II cusps of the valves retrieved from the sheep demonstrated freedom from the structural loosening, surface roughening, and hematoma formation that had limited the utility of the original AOA preparation technique. Cusps from AOA II-treated porcine roots had significantly less calcium than control cusps (AOA II, 5.5 +/- 3.0 mg/g; control, 91.2 +/- 19.5 mg/g; p = 0.0004). The aortic walls had similar levels of calcification (AOA II, 156 +/- 73 mg/g; control, 159 +/- 10 mg/g; p = not significant). These data suggest that the modified AOA technique warrants further evaluation as an antimineralization treatment for glutaraldehyde-fixed porcine bioprostheses.

  16. Mitral disc-valve variance

    PubMed Central

    Berroya, Renato B.; Escano, Fernando B.

    1972-01-01

    This report deals with a rare complication of disc-valve prosthesis in the mitral area. A significant disc poppet and struts destruction of mitral Beall valve prostheses occurred 20 and 17 months after implantation. The resulting valve incompetence in the first case contributed to the death of the patient. The durability of Teflon prosthetic valves appears to be in question and this type of valve probably will be unacceptable if there is an increasing number of disc-valve variance in the future. Images PMID:5017573

  17. Cytoimmunological monitoring after homograft valve replacement.

    PubMed

    Schütz, A; Fischlein, T; Breuer, M; Haushofer, M; Uhlig, A; Detter, C; Kemkes, B M; Hammer, C; Reichart, B

    1994-01-01

    Examination results concerning immunological reactions in cryopreserved allograft valves during the early postoperative course are so far not available. Cytoimmunological monitoring (CIM) is a well established method to prove rejection reaction after allograft transplantation and was used in this study. Allograft valves were harvested from patients who underwent heart transplantation, and did not require sterilizing in antibiotic solutions. The valves were dissected, conserved and subsequently frozen to -40 degrees C and stored in a freezing system at -196 degrees C. During the first 3 weeks following allograft implantation, CIM was performed daily. An activation index (AI) was determined from the cytological evaluation of the mononuclear concentrate in the peripheral blood. An increase of the AI > 1 was defined as an immunological reaction. As control we performed 98 CIM examinations in eight patients who underwent bioprosthetic valve replacement in the aortic position. Echocardiography (TTE and TEE) was used postoperatively as function control. Out of 16 patients who underwent cryopreserved aortic valve implantation in the aortic position, 336 CIM-results were obtained. An immunological reaction could be detected in all patients, starting on the 5th day on average. Comparing ABO-compatible (group I, n = 9) with ABO-incompatible (group II, n = 7) allografts, the AI-maximum in group I was 1.4 with a mean duration of 1.5 days. Group II was characterized by more intensive immunoreactions (mean = 2.3) which proved to be even more prolonged (mean = 3.3 days, P < 0.05). Nevertheless it became apparent that all observed immunological events were completely reversible without the need for immunosuppressive drugs.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Perceval Sutureless Valve – are Sutureless Valves Here?

    PubMed Central

    Chandola, Rahul; Teoh, Kevin; Elhenawy, Abdelsalam; Christakis, George

    2015-01-01

    With the advent of transcatheter aortic valve implantation (TAVI) techniques, a renewed interest has developed in sutureless aortic valve concepts in the last decade. The main feature of sutureless aortic valve implantation is the speed of insertion, thus making implantation easier for the surgeon. As a result, cross clamp times and myocardial ischemia may be reduced. The combined procedures (CABG with AVR in particular) can be done with a short cross clamp time. Perceval valve also provides an increased effective orifice area as compared with a stented bioprosthesis. Sutureless implantation of the Perceval valve is not only associated with shorter cross-clamp and cardiopulmonary bypass times but improved clinical outcomes too. This review covers the sutureless aortic valves and their evolution, with elaborate details on Perceval S valve in particular (which is the most widely used sutureless valve around the globe). PMID:25394851

  19. 9. BUTTERFLY VALVE CONTROL DIABLO POWERHOUSE. BUTTERFLY VALVES WERE MANUFACTURED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. BUTTERFLY VALVE CONTROL DIABLO POWERHOUSE. BUTTERFLY VALVES WERE MANUFACTURED BY THE PELTON WATER WHEEL COMPANY IN 1931, 1989. - Skagit Power Development, Diablo Powerhouse, On Skagit River, 6.1 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  20. Implantation of the CoreValve percutaneous aortic valve.

    PubMed

    Lamarche, Yoan; Cartier, Raymond; Denault, André Y; Basmadjian, Arsène; Berry, Colin; Laborde, Jean-Claude; Bonan, Raoul

    2007-01-01

    Surgical aortic valve replacement is the only recommended treatment for significant aortic valve stenosis. Percutaneous aortic valve replacement appears to be a novel option for high-risk patients. We report the implantation of the ReValving system (CoreValve, Paris, France) in a 64-year-old woman who was refused aortic valve replacement surgery for critical aortic stenosis and left ventricular dysfunction because of severe pulmonary fibrosis. After anesthesia, the patient was put on femorofemoral cardiopulmonary bypass, and underwent a balloon valvuloplasty with subsequent retrograde aortic valve replacement by the ReValving system. Transesophageal echocardiographic monitoring of the patient's hemodynamics showed immediate improvements of the valvular area and left ventricular ejection fraction and only traces of paravalvular leaks. The patient was easily weaned from ventilation and resumed activity soon after the surgery. A multidisciplinary approach is presently necessary to offer a reliable and safe procedure.

  1. [Ileocecal valve reconstruction in dogs].

    PubMed

    Maegawa, Felipe Antonio Boff; de Souza, José Antônio; de Araújo, Edevard José; Koh, Ivan Hong Jun; d'Acampora, Armando José; de Farias, Débora Cadore; Mengarda, Jackson; Volpato, Daniel; da Silva, Luis Gustavo Ferreira; de Córdova, Cleta Selva

    2005-01-01

    The importance of keeping the ileocecal valve in the intestinal ressections has been reported by several authors. When preserved, the ileocecal valve was related to a longer survival and prevention of the short bowel syndrome, due to its ability to block the colonic content reflux into the ileum and to avoid the rapid empting of the ileal content into the cecum. It was assessed a tecnique of ileocecal valve reconstitution, based on vesicoureteral anti-reflux tecniques. Fourteen beagles were operated. Seven underwent ileocecal valve reconstitution following the tecnique proposed and in the other seven a simple end-to-end anastomosis was performed. To assess the new valve, it was done the clinical follow up, the microbiologic analysis and the manometric study. Clinically, during 45 days of follow up, there was no difference between the dogs with and without ileocecal reconstitution. In the aerobic bacteria analysis, the predominant bacterium was Escherichia coli. Quantitatively, the cultures grew in an irregular way, so that it was not able to compare the bacterial growth between the groups with or without ileocecal valve. The new valve had a colo-ileal reflux pressure similar to that of the physiological valve (P > 0.05). However, when compared to the non valve group, the reflux pressures of the physiological valve and new valve were significantly higher, with P < 0.05 and P < 0.001, respectively. In this study, the reconstituted ileocecal valve served as a barrier to the colo-ileal reflux just as the physiological valve does.

  2. Imaging analysis of platelet deposition on the extracardiac valved conduit in humans

    SciTech Connect

    Kawata, H.; Matsuda, H.; Isaka, Y.; Kaneko, M.; Matsuwaka, R.; Kobayashi, J.; Matsuki, O.; Nakano, S.; Kimura, K.; Kawashima, Y. )

    1989-07-01

    In 14 patients (aged 2-29 yr) with Hancock (n = 11) or Carpentier-Edwards extracardiac valved conduits (n = 3), platelet deposition (PD) was investigated using indium 111 ({sup 111}In) platelet imaging. Repeated studies were performed in five patients. By visual analysis, 71% (5/7) of the imagings (7 images/5 patients) showed PD at early study 1-3 months after surgery, 9% (1/11) at intermediate study at 6-46 months (mean 21 mon) (11 images/10 patients) and 0% at late study at 81-132 months (3 images/3 patients). Quantitative analysis was made using relative ratio of radioactivity at the graft area to the area of the brachiocephalic artery (platelet accumulation index or PAI). The PAI was 1.85 {plus minus} 0.47 (mean {plus minus} SD) at early study, 1.51 {plus minus} 0.23 at intermediate, and 1.36 {plus minus} 0.37 at late study (NS). There was no significant difference in the late pressure gradients across the conduit (16-68 mon postoperatively) between the two groups with (n = 3) and without (n = 5) PD at the early stage (1-18 mon postoperatively, n = 8). The result may indicate that PD to the valved conduit in the right ventricular (RV) outflow tract occurs early postoperatively (mostly within 3 mon). The relationship of the PD detected by this method to late obstruction was not clarified in this study.

  3. Fast closing valve

    DOEpatents

    Hanson, Clark L.

    1984-01-10

    A valve is provided for protecting the high vacuum of a particle accelera in the event of air leakage, wherein the valve provides an axially symmetrical passage to avoid disturbance of the partical beam during normal operation, and yet enables very rapid and tight closure of the beam-carrying pipe in the event of air leakage. The valve includes a ball member (30) which can rotate between a first position wherein a bore (32) in the member is aligned with the beam pipe, and a second position out of line with the pipe. A seal member (38) is flexibly sealed to the pipe, and has a seal end which can move tightly against the ball member after the bore has rotated out of line with the pipe, to thereby assure that the seal member does not retard rapid rotation of the ball valve member. The ball valve member can be rapidly rotated by a conductive arm (40) fixed to it and which is rotated by the discharge of a capacitor bank through coils (44, 45) located adjacent to the arm.

  4. Sutureless aortic valve replacement

    PubMed Central

    Phan, Kevin

    2015-01-01

    The increasing incidence of aortic stenosis and greater co-morbidities and risk profiles of the contemporary patient population has driven the development of minimally invasive aortic valve surgery and percutaneous transcatheter aortic valve implantation (TAVI) techniques to reduce surgical trauma. Recent technological developments have led to an alternative minimally invasive option which avoids the placement and tying of sutures, known as “sutureless” or rapid deployment aortic valves. Potential advantages for sutureless aortic prostheses include reducing cross-clamp and cardiopulmonary bypass (CPB) duration, facilitating minimally invasive surgery and complex cardiac interventions, whilst maintaining satisfactory hemodynamic outcomes and low paravalvular leak rates. However, given its recent developments, the majority of evidence regarding sutureless aortic valve replacement (SU-AVR) is limited to observational studies and there is a paucity of adequately-powered randomized studies. Recently, the International Valvular Surgery Study Group (IVSSG) has formulated to conduct the Sutureless Projects, set to be the largest international collaborative group to investigate this technology. This keynote lecture will overview the use, the potential advantages, the caveats, and current evidence of sutureless and rapid deployment aortic valve replacement (AVR). PMID:25870807

  5. Fast closing valve

    SciTech Connect

    Hanson, C.L.

    1984-01-10

    A valve is provided for protecting the high vacuum of a particle accelerator in the event of air leakage, wherein the valve provides an axially symmetrical passage to avoid disturbance of the partical beam during normal operation, and yet enables very rapid and tight closure of the beam-carrying pipe in the event of air leakage. The valve includes a ball member which can rotate between a first position wherein a bore in the member is aligned with the beam pipe, and a second position out of line with the pipe. A seal member is flexibly sealed to the pipe, and has a seal end which can move tightly against the ball member after the bore has rotated out of line with the pipe, to thereby assure that the seal member does not retard rapid rotation of the ball valve member. The ball valve member can be rapidly rotated by a conductive arm fixed to it and which is rotated by the discharge of a capacitor bank through coils located adjacent to the arm.

  6. 81. View of 41 valve house (right) and 42 valve ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    81. View of 4-1 valve house (right) and 4-2 valve house (left); in the foreground is penstock which extends from Penstock No. 1 to the 4-1 valve house; looking south. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  7. 83. Interior of 42 valve house; the motor and valve ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    83. Interior of 4-2 valve house; the motor and valve mechanism is identical to that in the 4-1 valve house. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  8. Aortic valve replacement with the De Bakey valve.

    PubMed

    Paton, B C; Pine, M B

    1976-10-01

    De Bakey prostheses were inserted in 29 patients with aortic valve disease between October, 1970, and May, 1972. Ten patients have died, but all but one of the remaining 19 have beel followed for a minimum of 19 months. Evaluation of the results in these subjects indicates that the function of the De Bakey valve compares favorably with that of other aortic valve prostheses.

  9. Aortic valve surgery - minimally invasive

    MedlinePlus

    ... of the heart is reduced. This is called aortic stenosis. The aortic valve can be replaced using: Minimally ... RN, Wang A. Percutaneous heart valve replacement for aortic stenosis: state of the evidence. Ann Intern Med . 2010; ...

  10. Medications for Heart Valve Symptoms

    MedlinePlus

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Medications for Heart Valve Symptoms Updated:Sep 21,2016 How do medications help people with valve problems? People who are ...

  11. Locking apparatus for gate valves

    DOEpatents

    Fabyan, J.; Williams, C.W.

    A locking apparatus for fluid operated valves having a piston connected to the valve actuator which moves in response to applied pressure within a cylinder housing having a cylinder head, a catch block is secured to the piston, and the cylinder head incorporates a catch pin. Pressure applied to the cylinder to open the valve moves the piston adjacent to the cylinder head where the catch pin automatically engages the catch block preventing further movement of the piston or premature closure of the valve. Application of pressure to the cylinder to close the valve, retracts the catch pin, allowing the valve to close. Included are one or more selector valves, for selecting pressure application to other apparatus depending on the gate valve position, open or closed, protecting such apparatus from damage due to premature closing caused by pressure loss or operational error.

  12. Locking apparatus for gate valves

    DOEpatents

    Fabyan, Joseph; Williams, Carl W.

    1988-01-01

    A locking apparatus for fluid operated valves having a piston connected to the valve actuator which moves in response to applied pressure within a cylinder housing having a cylinder head, a catch block is secured to the piston, and the cylinder head incorporates a catch pin. Pressure applied to the cylinder to open the valve moves the piston adjacent to the cylinder head where the catch pin automatically engages the catch block preventing futher movement of the piston or premature closure of the valve. Application of pressure to the cylinder to close the valve, retracts the catch pin, allowing the valve to close. Included are one or more selector valves, for selecting pressure application to other apparatus depending on the gate valve position, open or closed, protecting such apparatus from damage due to premature closing caused by pressure loss or operational error.

  13. What Is Mitral Valve Prolapse?

    MedlinePlus

    ... may not close tightly. These flaps normally help seal or open the valve. Much of the time, ... and tricuspid valves close. They form a tight seal that prevents blood from flowing back into the ...

  14. Diseases of the Tricuspid Valve

    MedlinePlus

    ... diseases of the tricuspid valve are regurgitation and stenosis. Tricuspid Regurgitation Tricuspid regurgitation is also called tricuspid ... the tricuspid valve may also be needed. Tricuspid Stenosis Tricuspid stenosis is a narrowing or blockage of ...

  15. What Causes Heart Valve Disease?

    MedlinePlus

    ... this page from the NHLBI on Twitter. What Causes Heart Valve Disease? Heart conditions and other disorders, age-related changes, rheumatic fever, or infections can cause acquired heart valve disease. These factors change the ...

  16. Hydrogen gas relief valve

    DOEpatents

    Whittlesey, Curtis C.

    1985-01-01

    An improved battery stack design for an electrochemical system having at least one cell from which a gas is generated and an electrolyte in communication with the cell is described. The improved battery stack design features means for defining a substantially closed compartment for containing the battery cells and at least a portion of the electrolyte for the system, and means in association with the compartment means for selectively venting gas from the interior of the compartment means in response to the level of the electrolyte within the compartment means. The venting means includes a relief valve having a float member which is actuated in response to the level of the electrolyte within the compartment means. This float member is adapted to close the relief valve when the level of the electrolyte is above a predetermined level and open the relief valve when the level of electrolyte is below this predetermined level.

  17. Magnetostrictive valve assembly

    NASA Technical Reports Server (NTRS)

    Richard, James A. (Inventor)

    2008-01-01

    A magnetostrictive valve assembly includes a housing that defines a passage with a seat being formed therein. A magnetically-biased and axially-compressed magnetostrictive assembly slidingly fitted in the passage is configured as a hollow and open-ended conduit adapted to support a flow of a fluid therethrough. Current-carrying coil(s) disposed about the passage in the region of the magnetostrictive assembly generate a magnetic field in the passage when current flows through the coil(s). A hollow valve body with side ports is coupled on one end thereof to an axial end of the magnetostrictive assembly. The other end of the valve body is designed to seal with the seat formed in the housing's passage when brought into contact therewith.

  18. Josephson magnetic rotary valve

    SciTech Connect

    Soloviev, I. I.; Klenov, N. V.; Bakurskiy, S. V.; Bol'ginov, V. V.; Ryazanov, V. V.; Kupriyanov, M. Yu.; Golubov, A. A.

    2014-12-15

    We propose a control element for a Josephson spin valve. It is a complex Josephson device containing ferromagnetic (F) layer in the weak-link area consisting of two regions, representing 0 and π Josephson junctions, respectively. The valve's state is defined by mutual orientations of the F-layer magnetization vector and boundary line between 0 and π sections of the device. We consider possible implementation of the control element by introduction of a thin normal metal layer in a part of the device area. By means of theoretical simulations, we study properties of the valve's structure as well as its operation, revealing such advantages as simplicity of control, high characteristic frequency, and good legibility of the basic states.

  19. Sliding valve pump

    SciTech Connect

    Rupert, C.L.

    1980-09-09

    A sliding valve pump for oil wells which includes a working barrel having a plurality of apertures located in spaced relationship in the wall thereof and a pair of travelling valves fitted within the working barrel and carried by a plunger rod, the valves also having a plurality of apertures or ports for periodic registration with the ports in the working barrel wall to facilitate pumping of fluid from an oil reservoir or pool to the surface. The pump is designed to pull the oil-gas mixture from the reservoir pool into the lower section of the working barrel on the downward stroke, and to subsequently pump the collected oil through the barrel and tubing upwardly toward the surface on the upward stroke.

  20. Variable Valve Actuation

    SciTech Connect

    Jeffrey Gutterman; A. J. Lasley

    2008-08-31

    Many approaches exist to enable advanced mode, low temperature combustion systems for diesel engines - such as premixed charge compression ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or other HCCI-like combustion modes. The fuel properties and the quantity, distribution and temperature profile of air, fuel and residual fraction in the cylinder can have a marked effect on the heat release rate and combustion phasing. Figure 1 shows that a systems approach is required for HCCI-like combustion. While the exact requirements remain unclear (and will vary depending on fuel, engine size and application), some form of substantially variable valve actuation is a likely element in such a system. Variable valve actuation, for both intake and exhaust valve events, is a potent tool for controlling the parameters that are critical to HCCI-like combustion and expanding its operational range. Additionally, VVA can be used to optimize the combustion process as well as exhaust temperatures and impact the after treatment system requirements and its associated cost. Delphi Corporation has major manufacturing and product development and applied R&D expertise in the valve train area. Historical R&D experience includes the development of fully variable electro-hydraulic valve train on research engines as well as several generations of mechanical VVA for gasoline systems. This experience has enabled us to evaluate various implementations and determine the strengths and weaknesses of each. While a fully variable electro-hydraulic valve train system might be the 'ideal' solution technically for maximum flexibility in the timing and control of the valve events, its complexity, associated costs, and high power consumption make its implementation on low cost high volume applications unlikely. Conversely, a simple mechanical system might be a low cost solution but not deliver the flexibility required for HCCI operation. After modeling more than 200 variations of the

  1. Valve-spring Surge

    NASA Technical Reports Server (NTRS)

    Marti, Willy

    1937-01-01

    Test equipment is described that includes a system of three quartz indicators whereby three different pressures could be synchronized and simultaneously recorded on a single oscillogram. This equipment was used to test the reliction of waves at ends of valve spring, the dynamical stress of the valve spring for a single lift of the valve, and measurement of the curve of the cam tested. Other tests included simultaneous recording of the stress at both ends of the spring, spring oscillation during a single lift as a function of speed, computation of amplitude of oscillation for a single lift by harmonic analysis, effect of cam profile, the setting up of resonance, and forced spring oscillation with damping.

  2. Valve thrombosis following transcatheter aortic valve implantation: a systematic review.

    PubMed

    Córdoba-Soriano, Juan G; Puri, Rishi; Amat-Santos, Ignacio; Ribeiro, Henrique B; Abdul-Jawad Altisent, Omar; del Trigo, María; Paradis, Jean-Michel; Dumont, Eric; Urena, Marina; Rodés-Cabau, Josep

    2015-03-01

    Despite the rapid global uptake of transcatheter aortic valve implantation, valve trombosis has yet to be systematically evaluated in this field. The aim of this study was to determine the clinical characteristics, diagnostic criteria, and treatment outcomes of patients diagnosed with valve thrombosis following transcatheter aortic valve implantation through a systematic review of published data. Literature published between 2002 and 2012 on valve thrombosis as a complication of transcatheter aortic valve implantation was identified through a systematic electronic search. A total of 11 publications were identified, describing 16 patients (mean age, 80 [5] years, 65% men). All but 1 patient (94%) received a balloon-expandable valve. All patients received dual antiplatelet therapy immediately following the procedure and continued to take either mono- or dual antiplatelet therapy at the time of valve thrombosis diagnosis. Valve thrombosis was diagnosed at a median of 6 months post-procedure, with progressive dyspnea being the most common symptom. A significant increase in transvalvular gradient (from 10 [4] to 40 [12] mmHg) was the most common echocardiographic feature, in addition to leaflet thickening. Thrombus was not directly visualized with echocardiography. Three patients underwent valve explantation, and the remaining received warfarin, which effectively restored the mean transvalvular gradient to baseline within 2 months. Systemic embolism was not a feature of valve thrombosis post-transcatheter aortic valve implantation. Although a rare, yet likely under-reported complication of post-transcatheter aortic valve implantation, progressive dyspnea coupled with an increasing transvalvular gradient on echocardiography within the months following the intervention likely signifies valve thrombosis. While direct thrombus visualization appears difficult, prompt initiation of oral anticoagulation therapy effectively restores baseline valve function. Copyright © 2014

  3. Repositionable percutaneous aortic valve implantation with the LOTUS valve: 30-day and 1-year outcomes in 250 high-risk surgical patients.

    PubMed

    Meredith, Ian T; Dumonteil, Nicolas; Blackman, Daniel J; Tchétché, Didier; Walters, Darren L; Hildick-Smith, David; Manoharan, Ganesh; Harnek, Jan; Worthley, Stephen G; Rioufol, Gilles; Lefèvre, Thierry; Modine, Thomas; Van Mieghem, Nicolas M; Feldman, Ted; Allocco, Dominic J; Dawkins, Keith D

    2017-09-20

    The REPRISE IIE trial aimed to evaluate outcomes following transcatheter aortic valve implantation of the fully repositionable and retrievable LOTUS valve with a unique seal designed to minimise paravalvular leak (PVL). This prospective, multicentre study enrolled 250 patients with severe aortic stenosis considered high-risk for surgery by a multidisciplinary Heart Team. An independent clinical events committee adjudicated events per Valve Academic Research Consortium criteria. Mean age was 84 years; 77% were in NYHA Class III/IV. LOTUS valve implantation produced significant haemodynamic improvements at one year without valve embolisation, ectopic valve deployment, or additional valve implantation. Primary endpoints were met as the 30-day mortality rate in the extended cohort (4.4%, N=250), and mean valve gradient in the main cohort (11.5±5.2 mmHg, N=120) were below (p<0.001) their predefined performance objectives. At 30 days, disabling stroke was 2.8% and new pacemaker implantation was 28.9% in all patients and 32.0% in pacemaker-naïve patients. By one year, all-cause mortality was 11.6%, disabling stroke was 3.6%, 95% of patients alive were in NYHA Class I/II, and there was no core laboratory-adjudicated moderate/severe PVL. LOTUS valve implantation produced good valve haemodynamics, minimal PVL, sustained significant improvement in functional status, and good clinical outcomes one year post implant.

  4. Conventional versus rapid-deployment aortic valve replacement: a single-centre comparison between the Edwards Magna valve and its rapid-deployment successor†

    PubMed Central

    Andreas, Martin; Wallner, Stephanie; Habertheuer, Andreas; Rath, Claus; Schauperl, Martin; Binder, Thomas; Beitzke, Dietrich; Rosenhek, Raphael; Loewe, Christian; Wiedemann, Dominik; Kocher, Alfred; Laufer, Guenther

    2016-01-01

    OBJECTIVES Sutureless and rapid-deployment valves were recently introduced into clinical practice. The Edwards INTUITY valve system is a combination of the Edwards Magna pericardial valve and a subvalvular stent-frame to enable rapid deployment. We performed a parallel cohort study for comparison of the two valve types. METHODS All patients receiving either an Edwards Magna Ease valve or an Edwards INTUITY valve system due to aortic stenosis from May 2010 until July 2014 were included. Patients undergoing bypass surgery, an additional valve procedure, atrial ablation surgery or replacement of the ascending aorta were excluded. Preoperative characteristics, operative specifications, survival, valve-related adverse events and transvalvulvar gradients were compared. RESULTS One hundred sixteen patients underwent rapid-deployment aortic valve replacement [mean age 75 years (SD: 8); 62% female] and 132 patients underwent conventional aortic valve replacement [70 years (SD: 9); 31% female; P < 0.001]. Conventional valve patients were taller and heavier. The mean EuroSCORE II was 3.1% (SD: 2.7) and 4.4% (SD: 6.0) for rapid-deployment and conventional valve patients, respectively (P = 0.085). The mean implanted valve size was higher in the conventional group [23.2 mm (SD: 2.0) vs 22.5 mm (SD: 2.2); P = 0.007], but postoperative transvalvular mean gradients were comparable [15 mmHg (SD: 6) vs 14 mmHg (SD: 5); P = 0.457]. A subgroup analysis of the most common valve sizes (21 and 23 mm; implanted in 63% of patients) revealed significantly reduced mean postoperative transvalvular gradients in the rapid-deployment group [14 mmHg (SD: 4) vs 16 mmHg (SD: 5); P = 0.025]. A significantly higher percentage received minimally invasive procedures in the rapid-deployment group (59 vs 39%; P < 0.001). The 1- and 3-year survival rate was 96 and 90% in the rapid-deployment group and 95 and 89% in the conventional group (P = 0.521), respectively. Valve-related pacemaker implantations were

  5. Self-regulating valve

    DOEpatents

    Humphreys, D.A.

    1982-07-20

    A variable, self-regulating valve having a hydraulic loss coefficient proportional to a positive exponential power of the flow rate. The device includes two objects in a flow channel and structure which assures that the distance between the two objects is an increasing function of the flow rate. The range of spacing between the objects is such that the hydraulic resistance of the valve is an increasing function of the distance between the two objects so that the desired hydraulic loss coefficient as a function of flow rate is obtained without variation in the flow area.

  6. Pulsatile prosthetic valve flows.

    PubMed

    Phillips, W M; Snyder, A; Alchas, P; Rosenberg, G; Pierce, W S

    1980-01-01

    The laser Doppler system has been established as a useful tool for eliciting the properties of simulated cardiovascular flows, and thus for comparative studies of flow properties of prosthetic valves. Significant differences among valve types and between models of one type have been documented. The complex variations of velocity profiles with time show that comparisons must be made for unsteady pulsatile rather than steady flow, despite the volume and complexity of the data required. Future studies will include methods of compacting the data presentation and improving the details of the experimental stimulation.

  7. Ball valve safety screen

    SciTech Connect

    Bolding, B.H.

    1981-09-01

    A device for preventing unwanted objects from entering the ball assembly of a float collar or float shoe and otherwise damaging or plugging the valve mechanism therein is disclosed. The device comprises a screen constructed of expanded metal and rigidly affixed to the interior of the float collar or float shoe above the ball valve assembly. The screen portion is either mounted to the interior surface of the float collar sleeve by an annular structural member or mounted to a structural band which is partially embedded in the concrete portion of the float collar or casing guide shoe.

  8. Lipomatous hamartoma of mitral valve.

    PubMed

    Bhat, Seetharama P S; Gowda, Girish S L; Chikkatur, Raghavendra; Nanjappa, Manjunath C

    2016-01-01

    Primary cardiac tumors are very rare, and tumors arising from cardiac valves are extremely rare. We present a case of lipomatous hamartoma of the mitral valve in a young female. This is the 6th case of lipomatous hamartoma of the mitral valve to be reported. We discuss the operative and histopathological findings.

  9. Lightweight Valve Closes Duct Quickly

    NASA Technical Reports Server (NTRS)

    Fournier, Walter L.; Burgy, N. Frank

    1991-01-01

    Expanding balloon serves as lightweight emergency valve to close wide duct. Uninflated balloon stored in housing of duct. Pad resting on burst diaphragm protects balloon from hot gases in duct. Once control system triggers valve, balloon inflates rapidly to block duct. Weighs much less than does conventional butterfly, hot-gas, or poppet valve capable of closing duct of equal diameter.

  10. Lightweight Valve Closes Duct Quickly

    NASA Technical Reports Server (NTRS)

    Fournier, Walter L.; Burgy, N. Frank

    1991-01-01

    Expanding balloon serves as lightweight emergency valve to close wide duct. Uninflated balloon stored in housing of duct. Pad resting on burst diaphragm protects balloon from hot gases in duct. Once control system triggers valve, balloon inflates rapidly to block duct. Weighs much less than does conventional butterfly, hot-gas, or poppet valve capable of closing duct of equal diameter.

  11. Well safety and kill valve

    SciTech Connect

    Deaton, T.M.

    1986-12-30

    A valve device is described for use in tubing above a packer set in casing above a well formation comprising: (a) a housing connectable in well tubing and having a longitudinal flow passage therethrough and a flow passage through the housing wall intersecting the longitudinal flow passage; (b) lower ball valve means controlling flow through the longitudinal flow passage; (c) upper sleeve valve means controlling flow through the housing wall flow passages between the valve device exterior and the longitudinal flow passage. The valve means is cooperable such that when the upper valve means is in closed position, the lower valve means is in open position, and when the upper valve means is in open position, the lower valve means is in closed position; (d) locking means for holding the valve means at one position and releasing the valve means for movement to another position; (e) pressure responsive means for releasing the locking means; and (f) operator means for operating the valve means between positions including an operator tube having a shoulder thereon, mounted for longitudinal movement in the housing, an internal shoulder in the housing and a spring disposed around the operator tube between the housing and operator tube shoulders, biasing the operator tube upwardly.

  12. Valve stem and packing assembly

    DOEpatents

    Wordin, John J.

    1991-01-01

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  13. Valve stem and packing assembly

    DOEpatents

    Wordin, J.J.

    1991-09-03

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

  14. Transcatheter Valve-in-Valve: A Cautionary Tale.

    PubMed

    Luc, Jessica G Y; Shanks, Miriam; Tyrrell, Benjamin D; Welsh, Robert C; Butler, Craig R; Meyer, Steven R

    2016-09-01

    Transcatheter aortic valve replacement (TAVR) by valve-in-valve (VIV) implantation is an alternative treatment for high-risk patients with a degenerating aortic bioprosthesis. We present a case of transapical TAVR VIV with a 29-mm Edwards SAPIEN XT (ESV) (Edwards Lifesciences, Irvine, CA) into a 29-mm Medtronic Freestyle stentless bioprosthesis (Medtronic Inc, Minneapolis, MN) in which unanticipated dilatation of the Freestyle bioprosthesis resulted in intraprocedural embolization of the TAVR valve, necessitating urgent conversion to a conventional surgical aortic valve replacement (AVR). Our experience suggests that TAVR VIV with the 29-mm ESV in the setting of a degenerated 29-mm Freestyle stentless bioprosthesis must be undertaken with caution.

  15. Thermostatic Radiator Valve Evaluation

    SciTech Connect

    Dentz, Jordan; Ansanelli, Eric

    2015-01-01

    A large stock of multifamily buildings in the Northeast and Midwest are heated by steam distribution systems. Losses from these systems are typically high and a significant number of apartments are overheated much of the time. Thermostatically controlled radiator valves (TRVs) are one potential strategy to combat this problem, but have not been widely accepted by the residential retrofit market.

  16. Transcatheter aortic valve replacement

    MedlinePlus

    ... fully will restrict blood flow. This is called aortic stenosis. If there is also a leak, it is ... TAVR is used for people with severe aortic stenosis who aren't ... valve . In adults, aortic stenosis usually occurs due to calcium ...

  17. Valve for gas centrifuges

    DOEpatents

    Hahs, C.A.; Rurbage, C.H.

    1982-03-17

    The invention is pneumatically operated valve assembly for simulatenously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two on the lines so closed. The value assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

  18. Mitral Valve Prolapse

    MedlinePlus

    ... Search By Zipcode Search by State SELECT YOUR LANGUAGE Español (Spanish) 简体中文 (Traditional Chinese) 繁体中文 (Simplified Chinese) ... Walk through a step-by-step interactive guide explaining your valve issue and treatment options with helpful ...

  19. Stennis tests shuttle valves

    NASA Image and Video Library

    2009-02-12

    Flames burst from the E-1 Test Stand as Stennis Space Center engineers perform one of dozens of shuttle flow valve tests in early February. Stennis engineers teamed with Innovative Partnership Program partners to perform the tests after NASA officials delayed the launch of the STS-119 mission because of concerns with the shuttle part.

  20. Stennis tests shuttle valves

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Flames burst from the E-1 Test Stand as Stennis Space Center engineers perform one of dozens of shuttle flow valve tests in early February. Stennis engineers teamed with Innovative Partnership Program partners to perform the tests after NASA officials delayed the launch of the STS-119 mission because of concerns with the shuttle part.

  1. Poppet valve tester

    NASA Technical Reports Server (NTRS)

    Tellier, G. F.

    1973-01-01

    Tester investigates fundamental factors affecting cyclic life and sealing performance of valve seats and poppets. Tester provides for varying impact loading of poppet against seat and rate of cycling, and controls amount and type of relative motion between sealing faces of seat and poppet. Relative motion between seat and poppet can be varied in three modes.

  2. Valved molecular beam skimmer

    NASA Astrophysics Data System (ADS)

    Marceca, Ernesto; Becker, Jörg A.; Hensel, Friedrich

    1997-08-01

    Under routine source conditions, the optimum nozzle-skimmer distance to achieve maximum molecular beam intensities is within the range of a few millimeters. In cases where double skimming is additionally required, the distance between the skimmers should be kept small in order to sample a sufficiently large solid angle of the beam and hence maintain a good enough intensity. These two facts make it normally difficult to isolate the first from the second expansion chamber using a commercial vacuum gate valve due to the lack of remaining space. This note presents the design of a vacuum-tight valve which allows the aperture of a skimmer to be closed by plugging a needle directly against its internal conical wall. The valve can be driven manually or pneumatically from outside the vacuum chamber. The helium conductance of the valve was measured to be better than 1×10-8 mbar×l×s-1 for a helium partial pressure difference of 1 bar.

  3. Vent Relief Valve Test

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Shown is the disassembly, examination, refurbishment and testing of the LH2 ( liquid hydrogen) and LOX (liquid oxygen) vent and relief valves for the S-IVB-211 engine stage in support of the Constellation/Ares project. This image is extracted from high definition video and is the highest resolution available.

  4. Valve for cryogenic service

    DOEpatents

    Worwetz, H.A.

    1975-09-02

    This patent relates to a valve for use with a liquefied gas at cryogenic temperatures in which a pair of joined knife edges are bellows controlled to contact an indium alloy seat in an annular slot when flow is to be stopped. The sealing alloy may be renewed by heating in situ. (auth)

  5. Improved Merge Valve

    NASA Technical Reports Server (NTRS)

    George-Falvy, Dez

    1992-01-01

    Circumferential design combines compactness and efficiency. In remotely controlled valve, flow in tributary duct along circumference of primary duct merged with flow in primary duct. Flow in tributary duct regulated by variable throat nuzzle driven by worm gear. Design leak-proof, and most components easily fabricated on lathe.

  6. TUBE SHEARING VALVE

    DOEpatents

    Wilner, L.B.

    1960-05-24

    Explosive operated valves can be used to join two or more containers in fluid flow relationship, one such container being a sealed reservoir. The valve is most simply disposed by mounting it on the reservoir so thst a tube extends from the interior of the reservoir through the valve body, terminating at the bottom of the bore in a closed end; other containers may be similarly connected or may be open connected, as desired. The piston of the valve has a cutting edge at its lower end which shears off the closed tube ends and a recess above the cutting edge to provide a flow channel. Intermixing of the fluid being transferred with the explosion gases is prevented by a copper ring at the top of the piston which is force fitted into the bore at the beginning of the stroke. Although designed to avoid backing up of the piston at pressures up to 10,000 psi in the transferred fluid, proper operation is independent of piston position, once the tube ends were sheared.

  7. Valve assembly for internal combustion engine

    SciTech Connect

    Wakeman, R.J.; Shea, S.F.

    1989-09-05

    This patent describes an improvement in a valve assembly for an internal combustion engine of the type including a valve having a valve stem, a valve guideway for mounting this valve for reciprocal strokes between opened and seated position, and spring means for biasing the valve into the seated position. The improvement comprising a valve spool of greater cross-sectional diameter as compared to the valve stem, and a valve spool guideway within which the valve spool is movable during the strokes of the valve, an upper surface of the valve spool and a portion of the spool guideway collectively establishing a damper chamber which varies in volume during the valve strokes. a feed passage for introducing oil into the damper chamber, and a bleed passage for discharging oil from the damper chamber. The bleed passages each laterally opening into the valve spool guideway.

  8. Multi-port valve assembly

    DOEpatents

    Guggenheim, S. Frederic

    1986-01-01

    A multi-port fluid valve apparatus is used to control the flow of fluids through a plurality of valves and includes a web, which preferably is a stainless steel endless belt. The belt has an aperture therethrough and is progressed, under motor drive and control, so that its aperture is moved from one valve mechanism to another. Each of the valve mechanisms comprises a pair of valve blocks which are held in fluid-tight relationship against the belt. Each valve block consists of a block having a bore through which the fluid flows, a first seal surrounding the bore and a second seal surrounding the first seal, with the distance between the first and second seals being greater than the size of the belt aperture. In order to open a valve, the motor progresses the belt aperture to where it is aligned with the two bores of a pair of valve blocks, such alignment permitting a flow of the fluid through the valve. The valve is closed by movement of the belt aperture and its replacement, within the pair of valve blocks, by a solid portion of the belt.

  9. Miniature Latching Valve

    NASA Technical Reports Server (NTRS)

    Johnson, A. David; Benson, Glendon M.

    2008-01-01

    A miniature latching valve has been invented to satisfy a need for an electrically controllable on/off pneumatic valve that is lightweight and compact and remains in the most recently commanded open or closed state when power is not supplied. The valve includes a poppet that is moved into or out of contact with a seat to effect closure or opening, respectively, of the flow path. Motion of the poppet is initiated by electrical heating of one of two opposing pairs of nickel/titanium shape-memory alloy (SMA) wires above their transition temperature: heated wires contract to their remembered length, applying tension to pull the poppet toward or away from the seat. A latch consisting mainly of a bistable Belleville washer (a conical spring) made of a hardened stainless steel operates between two stable positions corresponding to the fully closed or fully open state, holding the poppet in one of these positions when power is not applied to either pair of SMA wires. To obtain maximum actuation force and displacement, the SMA wires must be kept in tension. The mounting fixtures at the ends of the wires must support large tensile stresses without creating stress concentrations that would limit the fatigue lives of the wires. An earlier design provided for each wire to be crimped in a conical opening with a conical steel ferrule that was swaged into the opening to produce a large, uniformly distributed holding force. In a subsequent design, the conical ferrule was replaced with a larger crimped cylindrical ferrule depicted in the figure. A major problem in designing the valve was to protect the SMA wires from a bake-out temperature of 300 C. The problem was solved by incorporating the SMA wires into an actuator module that is inserted into a barrel of the valve body and is held in place by miniature clip rings.

  10. Micro-valve pump light valve display

    DOEpatents

    Yeechun Lee.

    1993-01-19

    A flat panel display incorporates a plurality of micro-pump light valves (MLV's) to form pixels for recreating an image. Each MLV consists of a dielectric drop sandwiched between substrates, at least one of which is transparent, a holding electrode for maintaining the drop outside a viewing area, and a switching electrode from accelerating the drop from a location within the holding electrode to a location within the viewing area. The sustrates may further define non-wetting surface areas to create potential energy barriers to assist in controlling movement of the drop. The forces acting on the drop are quadratic in nature to provide a nonlinear response for increased image contrast. A crossed electrode structure can be used to activate the pixels whereby a large flat panel display is formed without active driver components at each pixel.

  11. Micro-valve pump light valve display

    DOEpatents

    Lee, Yee-Chun

    1993-01-01

    A flat panel display incorporates a plurality of micro-pump light valves (MLV's) to form pixels for recreating an image. Each MLV consists of a dielectric drop sandwiched between substrates, at least one of which is transparent, a holding electrode for maintaining the drop outside a viewing area, and a switching electrode from accelerating the drop from a location within the holding electrode to a location within the viewing area. The sustrates may further define non-wetting surface areas to create potential energy barriers to assist in controlling movement of the drop. The forces acting on the drop are quadratic in nature to provide a nonlinear response for increased image contrast. A crossed electrode structure can be used to activate the pixels whereby a large flat panel display is formed without active driver components at each pixel.

  12. A low-volume tester for the thrombogenic potential of mechanical heart valve prostheses.

    PubMed

    Linde, Torsten; Hamilton, Kathrin F; Timms, Daniel L; Schmitz-Rode, Thomas; Steinseifer, Ulrich

    2011-09-01

    During the development of a mechanical heart valve prosthesis, many studies are conducted to guarantee its correct function. Currently, investigations into the thrombogenic potential of a valve after its replacement are conducted with expensive and time-consuming chronic animal trials. Hence, the study aim was to develop and test an alternative system to resolve such thrombogenic issues. The Thrombosis Tester of the Helmholtz Institute Aachen (THIA II) has a reasonably small priming volume (220-270 ml) that allows analysis of the thrombogenic potential of two valves, using one human blood bottle. Hydrodynamic evaluation demonstrated an absolutely stable physiological pressure and flow progression at the aortic and pulmonary positions. A sinus geometry of the human aortic root is implemented downstream of the valve in order to guarantee physiological leaflet motion. The tester remained absolutely thrombus-free during several tests carried out with minimally anticoagulated porcine blood, while the valves showed reproducible thrombus formation in reasonable locations. Tests with fully heparinized porcine blood showed that a soft silicon fixture for the valve could reduce hemolysis in the THIA II. This in-vitro test protocol can enable the optimization of a valve design during the early stages of its research and development. The system can provide a unique and suitable supplement to animal trials for testing thrombogenic performance, under constant and reproducible boundary conditions, including considerable physiological and pathological circumstances such as the influence of valve position (aortic, pulmonic), and a comparison of different valve types.

  13. Fast acting multiple element valve

    DOEpatents

    Yang, Jefferson Y. S.; Wada, James M.

    1991-01-01

    A plurality of slide valve elements having plural axial-spaced annular parts and an internal slide are inserted into a bulkhead in a fluid conduit from a downstream side of the bulkhead, locked in place by a bayonet coupling and set screw, and project through the bulkhead into the upstream conduit. Pneumatic lines connecting the slide valve element actuator to pilot valves are brought out the throat of the valve element to the downstream side. Pilot valves are radially spaced around the exterior of the valve to permit the pneumatic lines to be made identical, thereby to minimize adverse timing tolerances in operation due to pressure variations. Ring manifolds surround the valve adjacent respective pilot valve arrangements to further reduce adverse timing tolerances due to pressure variations, the manifolds being directly connected to the respective pilot valves. Position sensors are provided the valve element slides to signal the precise time at which a slide reaches or passes through a particular point in its stroke to initiate a calibrated timing function.

  14. Fast-acting valve and uses thereof

    DOEpatents

    Meyer, James A.

    1982-01-01

    A very fast acting valve capable of producing a very well-defined plug of gas suitable for filling a theta pinch vacuum vessel is given. The valve requires no springs, instead being stopped mainly by a nonlinear force. Thus, the valve is not subject to bouncing; and the ratio of the size of the valve housing to the size of the valve stem is smaller than it would be if springs were needed to stop the valve stem. Furthermore, the valve can be used for thousands of valve firings with no apparent valve damage.

  15. Fast-acting valve and uses thereof

    DOEpatents

    Meyer, J.A.

    1980-05-16

    A very fast acting valve capable of producing a very well-defined plug of gas suitable for filling a theta pinch vacuum vessel is given. The valve requires no springs, instead being stopped mainly by a nonlinear force. Thus, the valve is not subject to bouncing; and the ratio of the size of the valve housing to the size of the valve stem is smaller than it would be if springs were needed to stop the valve stem. Furthermore, the valve can be used for thousands of valve firings with no apparent valve damage.

  16. Bioengineered Human and Allogeneic Pulmonary Valve Conduits Chronically Implanted Orthotopically in Baboons: Hemodynamic Performance and Immunological Consequences

    PubMed Central

    Hopkins, Richard A.; Bert, Arthur A.; Hilbert, Stephen L.; Quinn, Rachael W.; Brasky, Kathleen M.; Drake, William B.; Lofland, Gary K.

    2012-01-01

    Objective This study assesses in a baboon model the hemodynamics and HLA immunogenicity of chronically implanted bioengineered (decellularized with collagen conditioning treatments) human and baboon heart valve scaffolds. Methods Fourteen baboons underwent pulmonary valve replacement, eight with decellularized and conditioned (bioengineered) pulmonary valves derived from either allogeneic (N=3) or xenogeneic (human) (N=5) hearts; for comparison, six baboons received clinically relevant reference cryopreserved or porcine valved conduits. Panel reactive serum antibodies (HLA Class I&II), complement fixing antibodies (C1q binding), and C-reactive protein titers were measured serially until elective sacrifice at 10 or 26 weeks. Serial transesophageal echocardiograms (TEE) measured valve function and geometry. Differences were analyzed with Kruskal-Wallis and Wilcoxon Rank Sum. P≤ 0.05 significant. Results All animals survived and thrived, exhibiting excellent immediate implanted valve function by TEE. Over time, reference valves developed smaller indexed effective orifice areas, EOAI=0.84(1.22) cm2/m2 median (range) while all bioengineered valves remained normal, EOAI=2.45 (1.35) cm2/m2; P=0.005. None of the bioengineered valves developed elevated peak transvalvular gradients, 5.5(6.0) versus 12.5(23.0) mmHg, P=0.003. Cryopreserved valves provoked the most intense antibody responses. Two of five human bioengineered and two of three baboon bioengineered valves did not provoke any Class I antibodies. Bioengineered human (but not baboon) scaffolds provoked Class II antibodies. C1q+ antibodies developed in four recipients. Conclusions Valve dysfunction correlated with markers for more intense inflammatory provocation. The tested bioengineering methods reduced antigenicity of both human and baboon valves. Bioengineered replacement valves from both species were hemodynamically equivalent to native valves. PMID:22841171

  17. Bioprosthetic mitral valve dysfunction due to native valve preserving procedure.

    PubMed

    Matsuno, Yukihiro; Mori, Yoshio; Umeda, Yukio; Takiya, Hiroshi

    2016-03-01

    Mitral valve replacement with preservation of the mitral leaflets and subvalvular apparatus is considered to maintain left ventricular geometry and function and reduce the risk of myocardial rupture. However, the routine use of this technique may lead to early complications such as left ventricular outflow tract obstruction and even mitral inflow obstruction, requiring reoperation. We describe a rare case of bioprosthetic mitral valve dysfunction caused by a native valve preserving procedure.

  18. Performance Characteristics of an Isothermal Freeze Valve

    SciTech Connect

    Hailey, A.E.

    2001-08-22

    This document discusses performance characteristics of an isothermal freeze valve. A freeze valve has been specified for draining the DWPF melter at the end of its lifetime. Two freeze valve designs have been evaluated on the Small Cylindrical Melter-2 (SCM-2). In order to size the DWPF freeze valve, the basic principles governing freeze valve behavior need to be identified and understood.

  19. Rotary multiposition valve

    DOEpatents

    Barclay, John A.; Dyson, Jack E.

    1985-01-01

    The disclosure is directed to a rotary multiposition valve for selectively directing the flow of a fluid through a plurality of paths. The valve comprises an inner member and a hollow housing with a row of ducts on its outer surface. The ducts are in fluid communication with the housing. An engaging section of the inner member is received in the housing. A seal divides the engaging section into a hollow inlet segment and a hollow outlet segment. A plurality of inlet apertures are disposed in the inlet segment and a plurality of outlet apertures are disposed in the outlet segment. The inlet apertures are disposed in a longitudinally and radially spaced-apart pattern that can be a helix. The outlet apertures are disposed in a corresponding pattern. As the inner member is rotated, whenever an inlet aperture overlaps one of the ducts, the corresponding outlet aperture overlaps a different duct, thus forming a fluid pathway.

  20. Rotary multiposition valve

    DOEpatents

    Barclay, J.A.; Dyson, J.E.

    1984-04-06

    The disclosure is directed to a rotary multiposition valve for selectively directing the flow of a fluid through a plurality of paths. The valve comprises an inner member and a hollow housing with a row of ducts on its outer surface. The ducts are in fluid communication with the housing. An engaging section of the inner member is received in the housing. A seal divides the engaging section into a hollow inlet segment and a hollow outlet segment. A plurality of inlet apertures are disposed in the inlet sgegment and a plurality of outlet apertures are disposed in the outlet segment. The inlet apertures are disposed in a longitudinally and radially spaced-apart pattern that can be a helix. The outlet apertures are disposed in a corresponding pattern. As the inner member is rotated, whenever an inlet aperture overlaps one of the ducts, the corresponding outlet aperture overlaps a different duct, thus forming a fluid pathway.

  1. Stemless ball valve

    NASA Technical Reports Server (NTRS)

    Burgess, Kevin (Inventor); Yakos, David (Inventor); Walthall, Bryan (Inventor)

    2011-01-01

    A stemless ball valve comprising two flanges and a ball with a channel, two axis pins and two travel pins. One end of each axis and travel pin is fixedly attached to the ball, and the other end of each axis pin is lodged into a notch in the first or second flange such that the axis pin is allowed to rotate in the notch. The guide sleeve comprises two channels, and one end of each travel pin is situated within one of the two channels in the guide sleeve. An outer magnetic cartridge causes the inner magnetic cartridge and guide sleeve to rotate, and when the guide sleeve rotates, the travel pins move up and down within the channels in the guide sleeve. The movement of the travel pins within the channels in the guide sleeve causes the ball to rotate, thereby opening and closing the ball valve.

  2. Slow opening valve. [valve design for shuttle portable oxygen system

    NASA Technical Reports Server (NTRS)

    Drapeau, D. F. (Inventor)

    1984-01-01

    A valve control is described having a valve body with an actuator stem and a rotating handle connected to the actuator stem by a differential drive mechanism which, during uniform movement of the handle in one direction, initially opens the valve at a relatively slow rate and, thereafter, complete the valve movement at a substantially faster rate. A series of stop rings are received about the body in frictional abutting relationship and serially rotated by the handle to uniformly resist handle movement independently of the extent of handle movement.

  3. Transapical transcatheter aortic valve implantation using the J-Valve system: A 1-year follow-up study.

    PubMed

    Luo, Xiang; Wang, Xu; Li, Xuan; Wang, Xin; Xu, Fei; Liu, Mingzheng; Yu, Bing; Li, Fei; Tong, Minghui; Wang, Wei

    2017-07-01

    Transcatheter aortic valve implantation has become a routine procedure to treat screened inoperable or high-risk patients. In this study, we present the first outcome of echocardiographic midterm using a new second-generation transcatheter aortic valve implantation system, the J-Valve system (Jie Cheng Medical Technologies, Suzhou, China), in patients with aortic stenosis or aortic regurgitation. From July 2014 to June 2015, 21 patients with isolated aortic valve disease at high risk for open surgery received transapical transcatheter aortic valve implantation using the J-Valve system. The primary end point was a combined efficacy end point after 1 year, which included all-cause mortality after more than 30 days and failure of current therapy for aortic stenosis or aortic regurgitation requiring hospitalization for symptoms of valve-related cardiac decompensation or prosthetic heart valve dysfunction. Secondary end points were cardiovascular mortality, major stroke, and life-threatening, disabling, or major bleeding after 6 and 12 months. The mean age of the study cohort was 75.52 ± 5.22 years, the European System for Cardiac Operative Risk Evaluation II score was 11.33% ± 1.28%, and the mean logistic European System for Cardiac Operative Risk Evaluation I score was 31.13% ± 9.68%. Transcatheter aortic valve implantation with the J-Valve system was successfully performed in 19 of the 21 patients (90.5%). For patients with aortic stenosis, 12-month follow-up echocardiography demonstrated an increase in mean effective valve area from 0.62 ± 0.17 cm(2) to 1.52 ± 0.35 cm(2) and a decrease in transvalvular mean gradient from 61 ± 15 mm Hg to 18 ± 9 mm Hg. All surviving patients (n = 18) reported improvements in at least 1 of the New York Heart Association classes. The combined ratio of successful implantation and absence of adverse events in our cohort (n = 21) was 76.19%. The J-Valve system exhibits a convincing midterm performance and

  4. Controlled PCV valve

    SciTech Connect

    Zeigler, T.W. Jr.; Romanczuk, C.S.; Betterton, J.T.; Glover, A.H.

    1987-08-18

    A positive crankcase ventilation control device is described for use with an internal combustion engine and, specifically, for controlling the flow of emission laden vaporous fluids from the crankcase thereof, the control device including selective power means for substantially increasing the flow of emission laden air through the device, comprising: a generally hollow housing with an inlet forming portion adapted to be fluidly connected to the interior spaces of an internal combustion engine to receive emission laden air therefrom; the housing having an outlet forming device adapted to be fluidly connected to the air and fuel inletting portion of the internal combustion engine for disposing of the emission laden air from the engine, the inlet and outlet portions being connected within the interior of the housing by a flow control passage of specific flow area; an elongated valve plug member within the housing and having an end portion with a conically tapered configuration adapted to move progressively into the aforesaid flow control passage thereby decreasing the flow area thereof and, consequently, the total flow through the device; yieldable means urging the elongated valve member toward a position ensuring maximum flow through the flow control passage, but being yieldable to allow the valve member to move so that the conically tapered portion progressively extends further into the flow control passage to thereby decrease the flow area.

  5. Passive bypass valve assembly

    SciTech Connect

    Siedlecki, W.F. Jr.

    1992-05-19

    This patent describes a bypass valve assembly for controlling fluid flow in a gas turbine engine. It comprises an annular frame including an outer casing, an inner casing spaced from the outer casing to define a channel for channeling fluid flow and the outer casing including an annular opening therein; a plurality of circumferentially juxtaposed bypass valve doors disposed in the annular opening, each of the valve doors having an inner surface for facing the fluid flowable in the channel, an outer surface, a first end pivotally connected to the frame, and a second end, the doors being positionable in a first position generally parallel to the outer casing, and in a second position inclined relative to the outer casing, the fluid flow flowable against the door inner surface being effective for generating a fluid force on the door; and means for automatically positioning the doors in first and second positions in response to differential pressure across the door, the positioning means providing a torque on the doors for moving the door from the first to the second positions and including torque adjustment means for reducing the torque for at least a portion of travel of the doors from the second to the first positions.

  6. Self-compensating solenoid valve

    NASA Technical Reports Server (NTRS)

    Woeller, Fritz H. (Inventor); Matsumoto, Yutaka (Inventor)

    1987-01-01

    A solenoid valve is described in which both an inlet and an outlet of the valve are sealed when the valve is closed. This double seal compensates for leakage at either the inlet or the outlet by making the other seal more effective in response to the leakage and allows the reversal of the flow direction by simply switching the inlet and outlet connections. The solenoid valve has a valve chamber within the valve body. Inlet and outlet tubes extend through a plate into the chamber. A movable core in the chamber extends into the solenoid coil. The distal end of the core has a silicone rubber plug. Other than when the solenoid is energized, the compressed spring biases the core downward so that the surface of the plug is in sealing engagement with the ends of the tubes. A leak at either end increases the pressure in the chamber, resulting in increased sealing force of the plug.

  7. Optothermally actuated capillary burst valve

    NASA Astrophysics Data System (ADS)

    Eriksen, Johan; Bilenberg, Brian; Kristensen, Anders; Marie, Rodolphe

    2017-04-01

    We demonstrate the optothermal actuation of individual capillary burst valves in an all-polymer microfluidic device. The capillary burst valves are realised in a planar design by introducing a fluidic constriction in a microfluidic channel of constant depth. We show that a capillary burst valve can be burst by raising the temperature due to the temperature dependence of the fluid surface tension. We address individual valves by using a local heating platform based on a thin film of near infrared absorber dye embedded in the lid used to seal the microfluidic device [L. H. Thamdrup et al., Nano Lett. 10, 826-832 (2010)]. An individual valve is burst by focusing the laser in its vicinity. We demonstrate the capture of single polystyrene 7 μm beads in the constriction triggered by the bursting of the valve.

  8. Sequenced drive for rotary valves

    DOEpatents

    Mittell, Larry C.

    1981-01-01

    A sequenced drive for rotary valves which provides the benefits of applying rotary and linear motions to the movable sealing element of the valve. The sequenced drive provides a close approximation of linear motion while engaging or disengaging the movable element with the seat minimizing wear and damage due to scrubbing action. The rotary motion of the drive swings the movable element out of the flowpath thus eliminating obstruction to flow through the valve.

  9. Streamline coal slurry letdown valve

    DOEpatents

    Platt, R.J.; Shadbolt, E.A.

    1983-11-08

    A streamlined coal slurry letdown valve is featured which has a two-piece throat comprised of a seat and seat retainer. The two-piece design allows for easy assembly and disassembly of the valve. A novel cage holds the two-piece throat together during the high pressure letdown. The coal slurry letdown valve has long operating life as a result of its streamlined and erosion-resistance surfaces. 5 figs.

  10. Streamline coal slurry letdown valve

    DOEpatents

    Platt, Robert J.; Shadbolt, Edward A.

    1983-01-01

    A streamlined coal slurry letdown valve is featured which has a two-piece throat comprised of a seat and seat retainer. The two-piece design allows for easy assembly and disassembly of the valve. A novel cage holds the two-piece throat together during the high pressure letdown. The coal slurry letdown valve has long operating life as a result of its streamlined and erosion-resistance surfaces.

  11. Semi-active compressor valve

    DOEpatents

    Brun, Klaus; Gernentz, Ryan S.

    2010-07-27

    A method and system for fine-tuning the motion of suction or discharge valves associated with cylinders of a reciprocating gas compressor, such as the large compressors used for natural gas transmission. The valve's primary driving force is conventional, but the valve also uses an electromagnetic coil to sense position of the plate (or other plugging element) and to provide an opposing force prior to impact.

  12. Biocor No- React stentless aortic valve--short-term results.

    PubMed

    Von Oppell, U O; Stemmet, F; Levetan, B; Heijke, S A; Brink, J

    2001-01-01

    Short-term results of the bioprosthetic Biocor No-React composite porcine stentless aortic valve (Biocor Industria e Pesquisas LTDA, Belo Horizonte, Brazil) implanted in patients in whom anticoagulation was thought to be contraindicated or expected to be non-compliant. Retrospective review of 52 consecutive prospective patients in whom this valve was implanted, between September 1994 and May 1998. Average age was 44 +/- 17 years; 75% of patients were operated on for rheumatic heart disease and combined procedures were done in 40% of cases. Early mortality was 5.8%, and related to pre-operative ejection fraction ( P < 0.03), New York Heart Association (NYHA) class (P < 0.01), and bacterial endocarditis (P < 0.04). On discharge, 84% of survivors were in NYHA class I and 16% in class II. The average postoperative prosthetic valve peak gradient on echocardiography was 19.9 +/- 11 mmHg and was related to pre-operative ejection fraction and smaller valve sizes. Postoperative residual trivial or mild aortic regurgitation was seen in 19 patients (36.6%), resolved on follow-up in 10 cases, and did not correlate with structural deterioration, re-operation, mortality, or widening of the non-coronary sinus. The non-coronary aortic sinus was widened on closure, because of perceived crowding of the adjacent stentless valve commisures, in 52% of cases. This was thought to be related to the use of an oblique as opposed to transverse aortotomy. Patient survival, inclusive of operative deaths, was 88.5%, and event-free survival was 80.0% at 4 years. The short-term results of this stentless aortic valve in a young predominantly third-world population group are acceptable, and appear to be superior to the results for mechanical valves in a similar patient group. We would recommend a transverse aortotomy above the sinotubular ridge to be the more appropriate aortotomy incision when using stentless aortic valves.

  13. Innovative Stemless Valve Eliminates Emissions

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Big Horn Valve Inc. (BHVI), of Sheridan, Wyoming, won a series of SBIR and Small Business Technology Transfer (STTR) contracts with Kennedy Space Center and Marshall Space Flight Center to explore and develop a revolutionary valve technology. BHVI developed a low-mass, high-efficiency, leak-proof cryogenic valve using composites and exotic metals, and had no stem-actuator, few moving parts, with an overall cylindrical shape. The valve has been installed at a methane coal gas field, and future applications are expected to include in-flight refueling of military aircraft, high-volume gas delivery systems, petroleum refining, and in the nuclear industry.

  14. Potential flow in engine valves

    NASA Technical Reports Server (NTRS)

    Eck, Bruno

    1925-01-01

    The extensive applicability of the hydrodynamic theory to the problems of engine construction is clearly shown in the following attempt to determine by exact methods the nature of the flow in valves under variously restricted conditions. Observation shows that two principal kinds of flow occur in simple flat-seated valves. For small valve lifts, the flow is along the horizontal wall and is therefore deflected 90 degrees, but for greater valve lifts the flow separates and forms a free stream, whose angle of deflection naturally increases with increasing lift. Both these kinds of flow can, in fact, be theoretically explained

  15. Double-disc gate valve

    DOEpatents

    Wheatley, Seth J.

    1979-01-01

    This invention relates to an improvement in a conventional double-disc gate valve having a vertically movable gate assembly including a wedge, spreaders slidably engaged therewtih, a valve disc carried by the spreaders. When the gate assembly is lowered to a selected point in the valve casing, the valve discs are moved transversely outward to close inlet and outlet ports in the casing. The valve includes hold-down means for guiding the disc-and-spreader assemblies as they are moved transversely outward and inward. If such valves are operated at relatively high differential pressures, they sometimes jam during opening. Such jamming has been a problem for many years in gate valves used in gaseous diffusion plants for the separtion of uranium isotopes. The invention is based on the finding that the above-mentioned jamming results when the outlet disc tilts about its horizontal axis in a certain way during opening of the valve. In accordance with the invention, tilting of the outlet disc is maintained at a tolerable value by providing the disc with a rigid downwardly extending member and by providing the casing with a stop for limiting inward arcuate movement of the member to a preselected value during opening of the valve.

  16. Prosthetic valve endocarditis: an overview.

    PubMed

    Gnann, J W; Dismukes, W E

    1983-12-01

    Infection of an intracardiac prosthesis, the incidence of which is about 2.5% among patients having undergone valve replacement, is a serious complication with considerable morbidity and mortality. Early prosthetic valve endocarditis (PVE), with an onset within 60 days of valve replacement, accounts for approximately one-third of all cases, while the remaining two-thirds, occur more than two months postoperatively (late prosthetic valve endocarditis). Prosthetic valve endocarditis is most commonly caused by Staphylococcus epidermidis, less frequently by viridans streptococci, Staphylococcus aureus, and gram-negative bacilli. The most likely pathogenetic mechanisms in prosthetic valve endocarditis are intraoperative contamination and postoperative infections at extracardiac sites. Prominent clinical features include fever, new or changing heart murmurs, leukocytosis, anemia and hematuria. The etiologic microorganism can be isolated in more than 90% of all cases. Patients with proven prosthetic valve endocarditis should be examined daily to detect signs of congestive heart failure and changes in murmurs; electrocardiographic monitoring is essential for documentation of arrhythmias. With limitations, echocardiography, especially two-dimensional, may help to demonstrate vegetations or valvular dehiscence. Cinefluoroscopy may reveal loosening or dehiscence of the sewing ring or impaired motion of a radio-opaque poppet due to thrombus or vegetation. Cardiac catheterization, not always necessary even when surgical intervention is anticipated, may provide valuable information on the degree of dysfunction, multiple valve involvement, left ventricular function and extent of concomitant coronary artery disease. In patients with mechanical valves, prosthetic valve endocarditis may be associated with a high incidence of valve ring and myocardial abscesses; the reported frequency of valve ring abscesses is lower with porcine heterografts. Infections on mechanical valves

  17. Fluid mechanics of heart valves.

    PubMed

    Yoganathan, Ajit P; He, Zhaoming; Casey Jones, S

    2004-01-01

    Valvular heart disease is a life-threatening disease that afflicts millions of people worldwide and leads to approximately 250,000 valve repairs and/or replacements each year. Malfunction of a native valve impairs its efficient fluid mechanic/hemodynamic performance. Artificial heart valves have been used since 1960 to replace diseased native valves and have saved millions of lives. Unfortunately, despite four decades of use, these devices are less than ideal and lead to many complications. Many of these complications/problems are directly related to the fluid mechanics associated with the various mechanical and bioprosthetic valve designs. This review focuses on the state-of-the-art experimental and computational fluid mechanics of native and prosthetic heart valves in current clinical use. The fluid dynamic performance characteristics of caged-ball, tilting-disc, bileaflet mechanical valves and porcine and pericardial stented and nonstented bioprostheic valves are reviewed. Other issues related to heart valve performance, such as biomaterials, solid mechanics, tissue mechanics, and durability, are not addressed in this review.

  18. Latest design of gate valves

    SciTech Connect

    Kurzhofer, U.; Stolte, J.; Weyand, M.

    1996-12-01

    Babcock Sempell, one of the most important valve manufacturers in Europe, has delivered valves for the nuclear power industry since the beginning of the peaceful application of nuclear power in the 1960s. The latest innovation by Babcock Sempell is a gate valve that meets all recent technical requirements of the nuclear power technology. At the moment in the United States, Germany, Sweden, and many other countries, motor-operated gate and globe valves are judged very critically. Besides the absolute control of the so-called {open_quotes}trip failure,{close_quotes} the integrity of all valve parts submitted to operational forces must be maintained. In case of failure of the limit and torque switches, all valve designs have been tested with respect to the quality of guidance of the gate. The guidances (i.e., guides) shall avoid a tilting of the gate during the closing procedure. The gate valve newly designed by Babcock Sempell fulfills all these characteristic criteria. In addition, the valve has cobalt-free seat hardfacing, the suitability of which has been proven by friction tests as well as full-scale blowdown tests at the GAP of Siemens in Karlstein, West Germany. Babcock Sempell was to deliver more than 30 gate valves of this type for 5 Swedish nuclear power stations by autumn 1995. In the presentation, the author will report on the testing performed, qualifications, and sizing criteria which led to the new technical design.

  19. Valve Health Monitoring System Utilizing Smart Instrumentation

    NASA Technical Reports Server (NTRS)

    Jensen, Scott L.; Drouant, George J.

    2006-01-01

    The valve monitoring system is a stand alone unit with network capabilities for integration into a higher level health management system. The system is designed for aiding in failure predictions of high-geared ball valves and linearly actuated valves. It performs data tracking and archiving for identifying degraded performance. The data collection types are cryogenic cycles, total cycles, inlet temperature, body temperature torsional strain, linear bonnet strain, preload position, total travel and total directional changes. Events are recorded and time stamped in accordance with the IRIG B True Time. The monitoring system is designed for use in a Class 1 Division II explosive environment. The basic configuration consists of several instrumentation sensor units and a base station. The sensor units are self contained microprocessor controlled and remotely mountable in three by three by two inches. Each unit is potted in a fire retardant substance without any cavities and limited to low operating power for maintaining safe operation in a hydrogen environment. The units are temperature monitored to safeguard against operation outside temperature limitations. Each contains 902-928 MHz band digital transmitters which meet Federal Communication Commission's requirements and are limited to a 35 foot transmission radius for preserving data security. The base-station controller correlates data from the sensor units and generates data event logs on a compact flash memory module for database uploading. The entries are also broadcast over an Ethernet network. Nitrogen purged National Electrical Manufactures Association (NEMA) Class 4 enclosures are used to house the base-station

  20. Low energy high pressure miniature screw valve

    DOEpatents

    Fischer, Gary J.; Spletzer, Barry L.

    2006-12-12

    A low energy high pressure screw valve having a valve body having an upper portion and a lower portion, said lower portion of said valve body defining an inlet flow passage and an outlet flow passage traversing said valve body to a valve seat, said upper portion of said valve body defining a cavity at said valve seat, a diaphragm restricting flow between said upper portion of said valve body and said lower portion, said diaphragm capable of engaging said valve seat to restrict fluid communication between said inlet passage and said outlet passage, a plunger within said cavity supporting said diaphragm, said plunger being capable of engaging said diaphragm with said valve seat at said inlet and outlet fluid passages, said plunger being in point contact with a drive screw having threads engaged with opposing threads within said upper portion of said valve body such engagement allowing motion of said drive screw within said valve body.

  1. 49 CFR 195.116 - Valves.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Each valve must be both hydrostatically shell tested and hydrostatically seat tested without leakage to... the position of the valve (open, closed, etc.). (f) Each valve must be marked on the body or...

  2. All metal valve structure for gas systems

    DOEpatents

    Baker, Ray W.; Pawlak, Donald A.; Ramey, Alford J.

    1984-11-13

    A valve assembly with a resilient metal seat member is disclosed for providing a gas-tight seal in a gas handling system. The valve assembly also includes a valve element for sealing against the valve seat member; and an actuating means for operating the valve element. The valve seat member is a one-piece stainless steel ring having a central valve port and peripheral mounting flange, and an annular corrugation in between. A groove between the first and second ridges serves as a flexure zone during operation of the valve member and thus provides the seating pressure between the inner ridge or valve seat and the valve element. The outer annular ridge has a diameter less than said valve element to limit the seating motion of the valve element, preventing non-elastic deformation of the seat member.

  3. 46 CFR 169.570 - Lockout valves.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the event of equipment failure during maintenance. (c) The lockout valve design or locking mechanism..., when the valve must be locked in the closed position. (f) Lockout valves added to existing systems must...

  4. Whitey Gauge and Root Valves (VPS)

    SciTech Connect

    MISKA, C.

    2000-09-03

    These valves are 1/2 inch ball valves fabricated of 316 stainless steel: Packing is TFE (standard). They are used as isolation valves for pressure instrumentation in the Vacuum Pumping and Helium System.

  5. When a Heart Murmur Signals Valve Disease

    MedlinePlus

    ... in adults may be related to: Valve calcification Endocarditis Rheumatic fever In children, abnormal heart murmurs may ... Problem: Pulmonary Valve Regurgitation Heart Valves and Infective Endocarditis Left Ventricular Hypertrophy • Risks, Signs and Symptoms • Accurate ...

  6. Surgery for fulminant prosthetic valve endocarditis after transapical transcatheter aortic valve-in-valve implantation.

    PubMed

    Wilbring, Manuel; Tugtekin, Sems Malte; Matschke, Klaus; Kappert, Utz

    2014-02-01

    We report the clinical course of a patient with a history of transapical aortic "valve-in-valve" transcatheter aortic valve implantation (TAVI), actually suffering from prosthetic valve endocarditis. The patient now underwent cardiac surgery as a salvage procedure. The procedure itself was uneventful, but the patient died several days postoperative due to persisting sepsis. The present case raises the question, how to deal with high-risk patients, once considered unsuitable for cardiac surgery in presence of prosthetic valve infection? Up to now, there exists only insufficient knowledge about incidence, clinical course, and effectiveness of treatment strategies for prosthetic valve endocarditis after TAVI. A review of the available literature is given. Georg Thieme Verlag KG Stuttgart · New York.

  7. Safety and efficacy of valve repositioning during transcatheter aortic valve replacement with the Lotus Valve System.

    PubMed

    Rashid, Hashrul N Z; Gooley, Robert; McCormick, Liam; Zaman, Sarah; Ramkumar, Satish; Jackson, Damon; Amiruddin, Ameera; Nasis, Arthur; Cameron, James; Meredith, Ian T

    2017-07-01

    To determine the safety and efficacy of valve repositioning following transcatheter aortic valve replacement (TAVR) with the Lotus Valve System (Boston Scientific, Marlborough, MA, USA). TAVR is a well-established treatment for severe aortic stenosis. The Lotus Valve System is fully repositionable and retrievable. Valve repositioning has the potential to minimize TAVR-related complications caused by valve malposition; however, the effect on adverse event rates such as stroke is unknown. Consecutive patients with severe aortic stenosis treated with the Lotus Valve System (n=125) were prospectively recruited. Patients who did not require valve repositioning (Group A) were compared to patients who required one or more valve repositions (Group B). The primary end-point was 30-day occurrence of major adverse cardiovascular and cerebrovascular events (MACCE). Secondary end-points included each component of the primary end-point, new pacemaker insertion, and procedural or 30-day major adverse events, defined according to VARC-2 definitions. Valve repositioning was utilized in 60.8% (76/125) of patients including 17.1% (13/76) who required full valve resheathing. The most frequent indications for valve repositioning were altering the depth and angulation of initial implantation (69.7%), reducing paravalvular regurgitation (13.2%), and attempt to correct new or worsened heart block (7.9%). Baseline characteristics were similar in both groups. The primary end-point occurred in 12.2% and 6.6% of Group A and B, respectively (p=0.10). Thirty-day new pacemaker implantation was 34.1% and 18.8% in Group A and B, respectively (p=0.06). The secondary end-point measures were not significantly different between the groups. Repositioning facilitated correct anatomical positioning of all devices leading to optimal prosthesis hemodynamics and a trend to lower pacemaker rate without increased risk of MACCE. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All

  8. 241-AN-B valve pit manifold valves and position indication acceptance test procedure

    SciTech Connect

    VANDYKE, D.W.

    1999-08-25

    This document describes the method used to test design criteria for gear actuated ball valves installed in 241-AN-B Valve Pit located at 200E Tank Farms. The purpose of this procedure is to demonstrate the following: Equipment is properly installed, labeled, and documented on As-Built drawings; New Manifold Valves in the 241-AN-B Valve Pit are fully operable using the handwheel of the valve operators; New valve position indicators on the valve operators will show correct valve positions; New valve position switches will function properly; and New valve locking devices function properly.

  9. 241-AN-A valve pit manifold valves and position indication acceptance test procedure

    SciTech Connect

    VANDYKE, D.W.

    1999-08-25

    This document describes the method used to test design criteria for gear actuated ball valves installed in 241-AN-A Valve Pit located at 200E Tank Farms. The purpose of this procedure is to demonstrate the following: Equipment is properly installed, labeled, and documented on As-Built drawings; New Manifold Valves in the 241-AN-A Valve Pit are fully operable using the handwheel of the valve operators; New valve position indicators on the valve operators will show correct valve positions; New valve position switches will function properly; and New valve locking devices function properly.

  10. 5. STILLING BASIN FOR VALVE HOUSE AND ROOF OF VALVE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. STILLING BASIN FOR VALVE HOUSE AND ROOF OF VALVE HOUSE IN PHOTO CENTER, SPILLWAY CHANNEL (lined and unlined at left of photo), LOOKING NORTHEAST - Tieton Dam, Spillway & Drum Gates, South & East side of State Highway 12, Naches, Yakima County, WA

  11. Technical evaluation report TMI action -- NUREG-0737 (II.D.1). Relief and safety valve testing, Watts Bar Nuclear Plant, Units 1 and 2 (Dockets 50-390 and 50-391)

    SciTech Connect

    Fineman, C.P.

    1995-02-01

    In the past, safety and relief valves installed in the primary coolant system of light water reactors have performed improperly. As a result, the authors of NUREG-0578 (TMI-2 Lessons Learned Task Force Status Report and Short-Term Recommendations) and, subsequently, NUREG-0737 (Clarification of TMI Action Plan Requirements) recommended development and completion of programs to do two things. First, they should reevaluate the functional performance capabilities of pressurized water reactor safety, relief, and block valves. Second, they should verify the integrity of the pressurizer safety and relief valve piping systems for normal, transient, and accident conditions. This report documents the review of those programs by Lockheed Idaho Technologies Company. Specifically, this report documents the review of the Watts Bar Nuclear Plant, Units 1 and 2, Applicant response to the requirements of NUREG-0578 and NUREG-0737. This review found the Applicant provided an acceptable response reconfirming they met General Design Criteria 14, 15, and 30 of Appendix A to 10 CFR 50 for the subject equipment. It should also be noted Lockheed Idaho performed this review for both Units 1 and 2. However, the applicability of this review to Unit 2 depends on verifying that the Unit 2 as-built system conforms to the Unit 1 design reviewed in this report.

  12. Mitral valve aneurysm: A serious complication of aortic valve endocarditis.

    PubMed

    Sousa, Maria João; Alves, Vasco; Cabral, Sofia; Antunes, Nuno; Pereira, Luís Sousa; Oliveira, Filomena; Silveira, João; Torres, Severo

    2016-11-01

    Mitral valve aneurysms are rare and occur most commonly in association with aortic valve endocarditis. Transesophageal echocardiography is the most sensitive imaging modality for the diagnosis of this entity and its potential complications, such as leaflet rupture and mitral regurgitation, which mandate prompt surgical intervention. We present the case of a 70-year-old male patient with aortic valve endocarditis complicated with a ruptured aneurysm of the anterior mitral valve leaflet and associated severe mitral regurgitation, diagnosed by transesophageal echocardiography, with impressive images. We hypothesized that the aneurysm developed through direct extension of infection from the aortic valve or from a prolapsing aortic vegetation, with abscess formation and subsequent rupture and drainage. This case highlights the importance of appropriate imaging for early detection and timely surgical intervention (repair or replacement) to prevent fatal outcomes. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  13. Rotary selector valve

    SciTech Connect

    Jones, J.A.; Herndon, J.W.

    1991-02-05

    This paper discusses a multi-port valve which internally supports a rotatable trunnion having an elbow passage between a nozzle portion of the trunnion and a lower end outlet that communicates with a test port of the valve body. The outer end of the nozzle has an axially reciprocable hollow seal piston with a seal support ring whose outer face is formed with an endless groove to receive an O-ring. An actuating shaft is coaxially mounted in an upper end of the trunnion and has a lower end with an eccentric pin engaged in a slot of the seal piston to reciprocate the seal piston into and out of sealing registration around a port selected by rotation of the trunnion. External ends of the actuating shaft and trunnion are respectively drivably coupled to a coaxial sprocket wheel and geneva wheel. A housing on top of the valve contains an input rotor fitted with a cam and a drive roller for engaging radial slots of the geneva wheel alternately with cam engagement of the dwell notches of the geneva wheel. Concurrently and in advance of forward rotation of the geneva wheel, a rotor driven seal actuating yoke a free end engages one of a series of radial slots of the sprocket to rotate the sprocket in a retrograde direction to disengage the seal. When the yoke is disengaged, a detent mechanism temporarily locks the geneva and sprocket wheels together for co-rotation in a forward direction as the geneva drive roller again comes into engagement with the geneva wheel. After the nozzle has been advanced one step, further rotation of the input rotor advances an arm independently pivotally mounted on the yoke to compress a spring mechanism to bias the yoke and sprocket to compress the seal on a seat around the next port.

  14. Overhead-valve engine

    SciTech Connect

    Tamba, S.; Miyake, H.; Fukui, N.

    1987-05-05

    An overhead valve engine is described comprising: push rod receiving bores, at least one of the push rod receiving bores being maintained in communication at one end with a crank chamber and at an opposite end with a rocker arm chamber and at least one other push rod receiving bore being maintained in communication with the rocker arm chamber; push rods contained within push rod receiving bores; and a breather chamber in communication with at least one other push rod receiving bore in the vicinity of a camshaft.

  15. FLUID PURIFIER AND SEALING VALVE

    DOEpatents

    Swanton, W.F.

    1962-04-24

    An improved cold trap designed to condense vapors and collect foreign particles in a flowing fluid is described. In the arrangement, a valve is provided to prevent flow reversal in case of pump failure and to act as a sealing valve. Provision is made for reducing the temperature of the fluid being processed, including a pre-cooling stage. (AEC)

  16. Surge-damping vacuum valve

    DOEpatents

    Bullock, Jack C.; Kelly, Benjamin E.

    1980-01-01

    A valve having a mechanism for damping out flow surges in a vacuum system which utilizes a slotted spring-loaded disk positioned adjacent the valve's vacuum port. Under flow surge conditions, the differential pressure forces the disk into sealing engagement with the vacuum port, thereby restricting the flow path to the slots in the disk damping out the flow surge.

  17. Valve-"Health"-Monitoring System

    NASA Technical Reports Server (NTRS)

    Jensen, Scott L.; Drouant, George J.

    2009-01-01

    A system that includes sensors and data acquisition, wireless data-communication, and data-processing subsystems has been developed as a means of both real-time and historical tracking of information indicative of deterioration in the mechanical integrity and performance of a highgeared ball valve or a linearly actuated valve that operates at a temperature between cryogenic and ambient.

  18. Valve designed with elastic seat

    NASA Technical Reports Server (NTRS)

    Mac Glashan, W. F., Jr.

    1965-01-01

    Absolute valve closure is accomplished by a machined valve with an axially annular channel which changes the outlet passage into a thin tubular elastic seat member with a retainer backup ring. The elasticity of the seat provides tight conformity to ball irregularity.

  19. Air flow through poppet valves

    NASA Technical Reports Server (NTRS)

    Lewis, G W; Nutting, E M

    1920-01-01

    Report discusses the comparative continuous flow characteristics of single and double poppet valves. The experimental data presented affords a direct comparison of valves, single and in pairs of different sizes, tested in a cylinder designed in accordance with current practice in aviation engines.

  20. Variable gas leak rate valve

    DOEpatents

    Eernisse, Errol P.; Peterson, Gary D.

    1976-01-01

    A variable gas leak rate valve which utilizes a poled piezoelectric element to control opening and closing of the valve. The gas flow may be around a cylindrical rod with a tubular piezoelectric member encircling the rod for seating thereagainst to block passage of gas and for reopening thereof upon application of suitable electrical fields.

  1. Improved Photosensor for Light Valves

    NASA Technical Reports Server (NTRS)

    Koda, N. J.

    1983-01-01

    Processing changes improve performance of liquid-crystal light valve for displaying projection TV images. New approach monitors performance of finished light valves for given changes in CdS process and experimentally to optimize process for good sensitivity and low negative memory.

  2. Titanium aluminide automotive engine valves

    SciTech Connect

    Hartfield-Wuensch, S.E.; Sperling, A.A.; Morrison, R.S.; Dowling, W.E. Jr.; Allison, J.E.

    1995-12-31

    The low density and high elevated temperature strength make titanium aluminide alloys an excellent candidate for automotive exhaust valve applications. Lighter weight valve train components allow either improved performance or reduction of valve spring loads which reduce noise and friction, thereby improving fuel economy. The key to successful application of TiAl alloys for automotive engine valves is not optimization of strength and ductility, but rather the development of a low-cost, high-volume manufacturing method. Different manufacturing approaches will be discussed in this paper, along with their advantages and disadvantages. Currently, casting appears to be the lowest-cost alternative that produces adequate material properties and emphasis is being placed on this manufacturing approach. The results of several successful engine tests will also be discussed, including results on a binary TiAl alloy. However, these engine tests have indicated that TiAl alloy valves will require tip protection and stem coating.

  3. Heimlich valve for chest drainage.

    PubMed

    Heimlich, H J

    1983-01-01

    The Heimlich chest drainage valve was developed so that the process of draining the pleural cavity could be accomplished in a safe, relatively simple, and efficient manner. Replacing the cumbersome underwater drainage bottle system, the Heimlich valve connects to chest tubing and allows fluid and air to pass in one direction only. The valve, which functions in any position, need never be clamped, and regulated suction can be attached to it if necessary. The valve drains into a plastic bag that can be held at any level, allowing the patient undergoing chest drainage to be ambulatory simply by carrying the bag. The construction and function of the valve is easily understood by medical and nursing staffs. It is presterilized, stored in a sterile package, and readily utilized on emergency vehicles and in the operating room.

  4. Atmospheric dump valve engineering analysis

    SciTech Connect

    Mendoza, B.; McNemar, P.

    1990-01-01

    This report documents the activities undertaken after the atmospheric dump valves (ADVs) failed to operate following a Unit 3 reactor trip. The activities consisted of testing valves in all three units, examining Palo Verde Nuclear Generating Station (PVNGS) history with the valves, determining causes for failures, and making recommendations. The PVNGS engineering departments performed an in-depth review of the history, operation, maintenance, and design of ADVs. A preliminary mathematical model of the valves' dynamic behavior was developed by Arizona State University. The corrective actions are designed to eliminate the anomalies noted with the Unit 1 and 3 ADVs. Subsequent monitoring and testing activities following the planned modifications will ensure the ADVs remain operable during modes required by the PVNGS technical specifications. Through this increased monitoring and testing program, the valve modifications will be evaluated to confirm that the required level of reliability has been reached for the ADVs. The specific failures have been evaluated and the causes determined.

  5. Electro-Mechanical Coaxial Valve

    NASA Technical Reports Server (NTRS)

    Patterson, Paul R (Inventor)

    2004-01-01

    Coaxial valves usually contain only one moving part. It has not been easy, then, to provide for electric motor actuation. Many actuators being proposed involve designs which lead to bulky packages. The key facing those improving coaxial valves is the provision of suitable linear actuation. The valve herein indudes a valve housing with a flow channel there-through. Arranged in the flow channel is a closing body. In alignment with the closing body is a ball screw actuator which includes a ball nut and a cylindrical screw. The ball nut sounds a threaded portion of the cylindrical screw. The cylindrical screw is provided with a passageway there-through through which fluid flows. The cylindrical screw is disposed in the flow channel to become a control tube adapted to move toward and away from the valve seat. To rotate the ball nut an actuating drive is employed driven by a stepper motor.

  6. A Parylene MEMS Electrothermal Valve

    PubMed Central

    Li, Po-Ying; Givrad, Tina K.; Holschneider, Daniel P.; Maarek, Jean-Michel I.; Meng, Ellis

    2011-01-01

    The first microelectromechanical-system normally closed electrothermal valve constructed using Parylene C is described, which enables both low power (in milliwatts) and rapid operation (in milliseconds). This low-power valve is well suited for applications in wirelessly controlled implantable drug-delivery systems. The simple design was analyzed using both theory and modeling and then characterized in benchtop experiments. Operation in air (constant current) and water (current ramping) was demonstrated. Valve-opening powers of 22 mW in air and 33 mW in water were obtained. Following integration of the valve with catheters, our valve was applied in a wirelessly operated microbolus infusion pump, and the in vivo functionality for the appropriateness of use of this pump for future brain mapping applications in small animals was demonstrated. PMID:21350679

  7. Recirculating valve lash adjuster

    SciTech Connect

    Stoody, R.R.

    1987-02-24

    This patent describes an internal combustion engine with a valve assembly of the type including overhead valves supported by a cylinder head for opening and closing movements in a substantially vertical direction and a rotatable overhead camshaft thereabove lubricated by engine oil pumped by an engine oil pump. A hydraulic lash adjuster with an internal reservoir therein is solely supplied with run-off lubricating oil from the camshaft which oil is pumped into the internal reservoir of the lash adjuster by self-pumping operation of the lash adjuster produced by lateral forces thereon by the rotative operation of the camshaft comprising: a housing of the lash adjuster including an axially extending bore therethrough with a lower wall means of the housing closing the lower end thereof; a first plunger member being closely slidably received in the bore of the housing and having wall means defining a fluid filled power chamber with the lower wall means of the housing; and a second plunger member of the lash adjuster having a portion being loosely slidably received and extending into the bore of the housing for reciprocation therein. Another portion extends upwardly from the housing to operatively receive alternating side-to-side force inputs from operation of the camshaft.

  8. Mitral Valve Annuloplasty

    PubMed Central

    Rausch, Manuel K.; Bothe, Wolfgang; Kvitting, John-Peder Escobar; Swanson, Julia C.; Miller, D. Craig; Kuhl, Ellen

    2012-01-01

    Mitral valve annuloplasty is a common surgical technique used in the repair of a leaking valve by implanting an annuloplasty device. To enhance repair durability, these devices are designed to increase leaflet coaptation, while preserving the native annular shape and motion; however, the precise impact of device implantation on annular deformation, strain, and curvature is unknown. Here we quantify how three frequently used devices significantly impair native annular dynamics. In controlled in vivo experiments, we surgically implanted eleven flexible-incomplete, eleven semi-rigid-complete, and twelve rigid-complete devices around the mitral annuli of 34 sheep, each tagged with 16 equally-spaced tantalum markers. We recorded four-dimensional marker coordinates using biplane videofluoroscopy, first with device and then without, which were used to create mathematical models using piecewise cubic splines. Clinical metrics (characteristic anatomical distances) revealed significant global reduction in annular dynamics upon device implantation. Mechanical metrics (strain and curvature fields) explained this reduction via a local loss of anterior dilation and posterior contraction. Overall, all three devices unfavorably reduced annular dynamics. The flexible-incomplete device, however, preserved native annular dynamics to a larger extent than the complete devices. Heterogeneous strain and curvature profiles suggest the need for heterogeneous support, which may spawn more rational design of annuloplasty devices using design concepts of functionally graded materials. PMID:22037916

  9. Dynamic Spin Valve

    NASA Astrophysics Data System (ADS)

    Demirtas, Sezen; Koymen, Ali; Salamon, Myron

    2010-03-01

    In this study we investigate a dynamic extension of well known classic spin valves. Ultra thin films were dc sputtered in a UHV chamber and their dynamic responses were measured by ferromagnetic resonance (FMR). Two Co layers, separated by a nonmagnetic Ag layer--thick enough to suppress exchange coupling--were deposited, with one of them coupled to a Gd underlayer, forming a Co(1)/Ag/Co(2)/Gd multilayer. At room temperature both Co(1) and Co(2) FMR's are observed for the external magnetic field in the plane of the film. The field for resonance of Co(2) is reduced significantly relative to Co(1), with the paramagnetic moment of the Gd apparently added to the Co magnetization, and the linewidth is broader. Spin pumping effects are minimal since Co(1) and Co(2) do not resonate at the same field.. The Co(2) FMR disappears at the TC of Gd leaving the linewidth of the Co(1) FMR weakly temperature dependent down to the compensation temperature of the Co(2)/Gd bilayer. Below that point, the two Co layers in this dynamic spin valve device are in antiparallel alignment, leading to strong broadening of the Co(1) FMR with decreasing temperature.

  10. Self-Rupturing Hermetic Valve

    NASA Technical Reports Server (NTRS)

    Tucker, Curtis E., Jr.; Sherrit, Stewart

    2011-01-01

    For commercial, military, and aerospace applications, low-cost, small, reliable, and lightweight gas and liquid hermetically sealed valves with post initiation on/off capability are highly desirable for pressurized systems. Applications include remote fire suppression, single-use system-pressurization systems, spacecraft propellant systems, and in situ instruments. Current pyrotechnic- activated rupture disk hermetic valves were designed for physically larger systems and are heavy and integrate poorly with portable equipment, aircraft, and small spacecraft and instrument systems. Additionally, current pyrotechnically activated systems impart high g-force shock loads to surrounding components and structures, which increase the risk of damage and can require additional mitigation. The disclosed mechanism addresses the need for producing a hermetically sealed micro-isolation valve for low and high pressure for commercial, aerospace, and spacecraft applications. High-precision electrical discharge machining (EDM) parts allow for the machining of mated parts with gaps less than a thousandth of an inch. These high-precision parts are used to support against pressure and extrusion, a thin hermetically welded diaphragm. This diaphragm ruptures from a pressure differential when the support is removed and/or when the plunger is forced against the diaphragm. With the addition of conventional seals to the plunger and a two-way actuator, a derivative of this design would allow nonhermetic use as an on/off or metering valve after the initial rupturing of the hermetic sealing disk. In addition, in a single-use hermetically sealed isolation valve, the valve can be activated without the use of potential leak-inducing valve body penetrations. One implementation of this technology is a high-pressure, high-flow-rate rupture valve that is self-rupturing, which is advantageous for high-pressure applications such as gas isolation valves. Once initiated, this technology is self

  11. Transcatheter valve-in-valve implantation for failed mitral prosthesis: the first experience in Japan.

    PubMed

    Tada, Norio; Enta, Yusuke; Sakurai, Mie; Ootomo, Tatsushi; Hata, Masaki

    2017-01-01

    An 82-year-old woman had a history of mitral valve replacement with a 25-mm MOSAIC (Medtronic, USA) for severe mitral regurgitation (MR) 8 years previously. Recently, she developed heart failure due to MR secondary to prosthetic valve failure. She underwent transcatheter valve-in-valve implantation with a 23-mm SAPIEN XT (Edwards Lifesciences, USA) to the prosthetic mitral valve by transapical approach. To our knowledge, this is the first reported case of transcatheter valve implantation for failed mitral prosthetic valve using valve-in-valve technique in Japan.

  12. Lock Culvert Valves; Hydraulic Design Considerations

    DTIC Science & Technology

    2011-06-01

    lock culvert valves with particular emphasis on reverse tainter valves. Hydraulic coefficients, used to quantify energy losses at valves and the jet...due to a sudden culvert expansion did increase the energy losses in the flow as the jet was dissipated. This additional head loss and associated...8 Figure 5. Loss coefficient for vertical-lift valve having a 45 degree lip

  13. 14 CFR 125.137 - Oil valves.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller, unless...

  14. 14 CFR 125.137 - Oil valves.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller, unless...

  15. 14 CFR 125.137 - Oil valves.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller, unless...

  16. 14 CFR 125.137 - Oil valves.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller, unless...

  17. 14 CFR 125.137 - Oil valves.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller,...

  18. Valve for controlling solids flow

    DOEpatents

    Feldman, David K.

    1980-01-01

    A fluidized solids control valve is disclosed that is particularly well adapted for use with a flow of coal or char that includes both large particles and fines. The particles may or may not be fluidized at various times during the operation. The valve includes a tubular body that terminates in a valve seat covered by a normally closed closure plate. The valve body at the seat and the closure plate is provided with aligned longitudinal slots that receive a pivotally supported key plate. The key plate is positionable by an operator in inserted, intermediate and retracted positions respecting the longitudinal slot in the valve body. The key plate normally closes the slot within the closure plate but is shaped and aligned obliquely to the longitudinal slot within the valve body to provide progressively increasing slot openings between the inserted and retracted positions. Transfer members are provided between the operator, key plate and closure plate to move the closure plate into an open position only when the key plate is retracted from the longitudinal slot within the valve body.

  19. Cavitation guide for control valves

    SciTech Connect

    Tullis, J.P.

    1993-04-01

    This guide teaches the basic fundamentals of cavitation to provide the reader with an understanding of what causes cavitation, when it occurs, and the potential problems cavitation can cause to a valve and piping system. The document provides guidelines for understanding how to reduce the cavitation and/or select control valves for a cavitating system. The guide provides a method for predicting the cavitation intensity of control valves, and how the effect of cavitation on a system will vary with valve type, valve function, valve size, operating pressure, duration of operation and details of the piping installation. The guide defines six cavitation limits identifying cavitation intensities ranging from inception to the maximum intensity possible. The intensity of the cavitation at each limit Is described, including a brief discussion of how each level of cavitation influences the valve and system. Examples are included to demonstrate how to apply the method, including making both size and pressure scale effects corrections. Methods of controlling cavitation are discussed providing information on various techniques which can be used to design a new system or modify an existing one so it can operate at a desired level of cavitation.

  20. Minimally invasive aortic valve surgery

    PubMed Central

    Castrovinci, Sebastiano; Emmanuel, Sam; Moscarelli, Marco; Murana, Giacomo; Caccamo, Giuseppa; Bertolino, Emanuela Clara; Nasso, Giuseppe; Speziale, Giuseppe; Fattouch, Khalil

    2016-01-01

    Aortic valve disease is a prevalent disorder that affects approximately 2% of the general adult population. Surgical aortic valve replacement is the gold standard treatment for symptomatic patients. This treatment has demonstrably proven to be both safe and effective. Over the last few decades, in an attempt to reduce surgical trauma, different minimally invasive approaches for aortic valve replacement have been developed and are now being increasingly utilized. A narrative review of the literature was carried out to describe the surgical techniques for minimally invasive aortic valve surgery and report the results from different experienced centers. Minimally invasive aortic valve replacement is associated with low perioperative morbidity, mortality and a low conversion rate to full sternotomy. Long-term survival appears to be at least comparable to that reported for conventional full sternotomy. Minimally invasive aortic valve surgery, either with a partial upper sternotomy or a right anterior minithoracotomy provides early- and long-term benefits. Given these benefits, it may be considered the standard of care for isolated aortic valve disease. PMID:27582764

  1. Proportional valve with a piezoelectric actuator

    NASA Astrophysics Data System (ADS)

    Laski, Pawel Andrzej

    The article concerns a slotted proportional valve for use in pneumatic and hydraulic systems. There is a growing demand for both hydraulic and pneumatic ultrafast proportional valves. The conducted analysis of literature confirms the lack of such solutions for proportional valves. The currently used pneumatic systems for selection and segregation of parts and objects require ultrafast valves. The presented solution for the proportional valve can significantly improve and accelerate this type of technological processes. Furthermore, fast proportional valves can be successfully used for positional control of pneumatic and hydraulic drives. The article presents the design of a slotted divide valve and sets the maximum mass flow rate for service roads.

  2. Check valve with poppet damping mechanism

    NASA Technical Reports Server (NTRS)

    Morris, Brian G. (Inventor)

    1993-01-01

    An inline check valve for a flow line is presented where the valve element is guided for inline travel forward and rearward of a valve sealing member and is spring biased to a closed sealing condition. One of the guides for the valve element includes a dashpot bore and plunger member to control the rate of travel of the valve element in either direction as well as provided a guiding function. The dashpot is not anchored to the valve body so that the valve can be functional even if the plunger member becomes jammed in the dashpot.

  3. Check valve with poppet damping mechanism

    NASA Astrophysics Data System (ADS)

    Morris, Brian G.

    1993-08-01

    An inline check valve for a flow line is presented where the valve element is guided for inline travel forward and rearward of a valve sealing member and is spring biased to a closed sealing condition. One of the guides for the valve element includes a dashpot bore and plunger member to control the rate of travel of the valve element in either direction as well as provided a guiding function. The dashpot is not anchored to the valve body so that the valve can be functional even if the plunger member becomes jammed in the dashpot.

  4. Check valve with poppet damping mechanism

    NASA Astrophysics Data System (ADS)

    Morris, Brian G.

    1992-06-01

    An inline check valve for a flow line is presented where the valve element is guided for inline travel forward and rearward of a valve sealing member and is spring biased to a closed sealing condition. One of the guides for the valve element includes a dashpot bore and plunger member to control the rate of travel of the valve element in either direction as well as provided a guiding function. The dashpot is not anchored to the valve body so that the valve can be functional even if the plunger member becomes jammed in the dashpot.

  5. How back pressure affects safety relief valves

    SciTech Connect

    Papa, D.M.

    1983-05-01

    The prefered valve types to reduce back pressure are the pilot operated valve, the balanced direct spring valve, and the conventional direct spring valve. Back pressure (static pressure at the outlet when the valve is closed), superimposed back pressure, and built up back pressure are defined. The relief characteristics of the pilot, balanced, and direct spring valves are schematicized. Typical safety valve operations are outlined. Methods for sizing discharge piping to avoid piping pressure losses that produce excessive back pressure are recommended. The guidelines discussed improve overpressure protection.

  6. Proportional valve with a piezoelectric actuator

    NASA Astrophysics Data System (ADS)

    Laski, Pawel Andrzej

    2016-11-01

    The article concerns a slotted proportional valve for use in pneumatic and hydraulic systems. There is a growing demand for both hydraulic and pneumatic ultrafast proportional valves. The conducted analysis of literature confirms the lack of such solutions for proportional valves. The currently used pneumatic systems for selection and segregation of parts and objects require ultrafast valves. The presented solution for the proportional valve can significantly improve and accelerate this type of technological processes. Furthermore, fast proportional valves can be successfully used for positional control of pneumatic and hydraulic drives. The article presents the design of a slotted divide valve and sets the maximum mass flow rate for service roads.

  7. FLUID PRESSURE AND CAM OPERATED VACUUM VALVE

    DOEpatents

    Batzer, T.H.

    1963-11-26

    An ultra-high vacuum valve that is bakable, reusable, and capable of being quickly opened and closed is described. A translationally movable valve gate having an annular ridge is adapted to contact an annular soft metal gasket disposed at the valve seat such that the soft metal gasket extends beyond the annular ridge on all sides. The valve gate is closed, by first laterally aligning the valve gate with the valve seat and then bringing the valve gate and valve seat into seating contact by the translational movement of a ramp-like wedging means that engages similar ramp-like stractures at the base of the valve gate to force the valve gate into essentially pressureless contact with the annular soft metal gasket. This gasket is then pressurized from beneath by a fluid thereby effecting a vacuura tight seal between the gasket and the ridge. (AEC)

  8. Thermostatic Radiator Valve Evaluation

    SciTech Connect

    Dentz, J.; Ansanelli, E.

    2015-01-01

    A large stock of multifamily buildings in the Northeast and Midwest are heated by steam distribution systems. Losses from these systems are typically high and a significant number of apartments are overheated much of the time. Thermostatically controlled radiator valves (TRVs) are one potential strategy to combat this problem, but have not been widely accepted by the residential retrofit market. In this project, the ARIES team sought to better understand the current usage of TRVs by key market players in steam and hot water heating and to conduct limited experiments on the effectiveness of new and old TRVs as a means of controlling space temperatures and reducing heating fuel consumption. The project included a survey of industry professionals, a field experiment comparing old and new TRVs, and cost-benefit modeling analysis using BEopt™ (Building Energy Optimization software).

  9. Stemless ball valve

    NASA Technical Reports Server (NTRS)

    Burgess, Kevin (Inventor); Yakos, David (Inventor); Walthall, Bryan (Inventor)

    2012-01-01

    A stemless ball valve comprising: a right flange; left flange; ball with an axis pin and two travel pins; ball seal on either side of the ball; guide sleeve with inner walls comprising two channels; cartridge guide holder; inner magnetic cartridge; and outer magnetic cartridge. The ball is situated inside of the guide sleeve, and a travel pin is located in each of the two channels. The guide sleeve is situated inside of the cartridge guide holder, which is located adjacent to and outside of the inner magnetic cartridge and secured to the inner magnetic cartridge such that when the inner magnetic cartridge rotates, the cartridge guide holder also rotates. The cartridge guide holder is secured to the guide sleeve such that when the cartridge guide holder rotates, the travel pins move within the channels in the inner walls of the guide sleeve, thereby causing the ball to rotate.

  10. Fluid relief and check valve

    DOEpatents

    Blaedel, K.L.; Lord, S.C.; Murray, I.

    1986-07-17

    A passive fluid pressure relief and check valve allows the relief pressure to be slaved to a reference pressure independently of the exhaust pressure. The pressure relief valve is embodied by a submerged vent line in a sealing fluid, the relief pressure being a function of the submerged depth. A check valve is embodied by a vertical column of fluid (the maximum back pressure being a function of the height of the column of fluid). The pressure is vented into an exhaust system which keeps the exhaust out of the area providing the reference pressure.

  11. Ferroelectric Fluid Flow Control Valve

    NASA Technical Reports Server (NTRS)

    Jalink, Antony, Jr. (Inventor); Hellbaum, Richard F. (Inventor); Rohrbach, Wayne W. (Inventor)

    1999-01-01

    An active valve is controlled and driven by external electrical actuation of a ferroelectric actuator to provide for improved passage of the fluid during certain time periods and to provide positive closure of the valve during other time periods. The valve provides improved passage in the direction of flow and positive closure in the direction against the flow. The actuator is a dome shaped internally prestressed ferroelectric actuator having a curvature, said dome shaped actuator having a rim and an apex. and a dome height measured from a plane through said rim said apex that varies with an electric voltage applied between an inside and an outside surface of said dome shaped actuator.

  12. Multi-port valve

    DOEpatents

    Lewin, Keith F.

    1997-04-15

    A multi-port valve for regulating, as a function of ambient air having varying wind velocity and wind direction in an open-field control area, the distribution of a fluid, particularly carbon dioxide (CO.sub.2) gas, in a fluid distribution system so that the control area remains generally at an elevated fluid concentration or level of said fluid. The multi-port valve generally includes a multi-port housing having a plurality of outlets therethrough disposed in a first pattern of outlets and at least one second pattern of outlets, and a movable plate having a plurality of apertures extending therethrough disposed in a first pattern of apertures and at least one second pattern of apertures. The first pattern of apertures being alignable with the first pattern of outlets and the at least one second pattern of apertures being alignable with the second pattern of outlets. The first pattern of apertures has a predetermined orientation with the at least one second pattern of apertures. For an open-field control area subject to ambient wind having a low velocity from any direction, the movable plate is positioned to equally distribute the supply of fluid in a fluid distribution system to the open-field control area. For an open-field control area subject to ambient wind having a high velocity from a given direction, the movable plate is positioned to generally distribute a supply of fluid in a fluid distribution system to that portion of the open-field control area located upwind.

  13. Multi-port valve

    DOEpatents

    Lewin, K.F.

    1997-04-15

    A multi-port valve is described for regulating, as a function of ambient air having varying wind velocity and wind direction in an open-field control area, the distribution of a fluid, particularly carbon dioxide (CO{sub 2}) gas, in a fluid distribution system so that the control area remains generally at an elevated fluid concentration or level of said fluid. The multi-port valve generally includes a multi-port housing having a plurality of outlets there through disposed in a first pattern of outlets and at least one second pattern of outlets, and a movable plate having a plurality of apertures extending there through disposed in a first pattern of apertures and at least one second pattern of apertures. The first pattern of apertures being alignable with the first pattern of outlets and the at least one second pattern of apertures being alignable with the second pattern of outlets. The first pattern of apertures has a predetermined orientation with the at least one second pattern of apertures. For an open-field control area subject to ambient wind having a low velocity from any direction, the movable plate is positioned to equally distribute the supply of fluid in a fluid distribution system to the open-field control area. For an open-field control area subject to ambient wind having a high velocity from a given direction, the movable plate is positioned to generally distribute a supply of fluid in a fluid distribution system to that portion of the open-field control area located upwind. 7 figs.

  14. Energy conservation with automatic flow control valves

    SciTech Connect

    Phillips, D.

    1984-12-01

    Automatic flow control valves are offered in a wide range of sizes starting at 1/2 in. with flow rates of 0.5 gpm and up. They are also provided with materials and end connections to meet virtually any fan-coil system requirement. Among these are copper sweat type valves; ductile iron threaded valves; male/female threaded brass valves; and combination flow control/ball valves with union ends.

  15. Transcatheter pulmonary valve implantation: valve technology and procedural outcome.

    PubMed

    Salavitabar, Arash; Flynn, Patrick; Holzer, Ralf J

    2017-07-18

    Procedural technique and short-term outcomes of transcatheter pulmonary valve implantation (TPVI) have been widely described. The purpose of this article is to provide an update on current valve technology, and to focus on recent data surrounding TPVI in the dilated right ventricular outflow tract (RVOT), hybrid interventions, significant outcomes, and procedural costs. Transcatheter valve technology has expanded with current trials evaluating self-expandable valves that can be implanted in dilated RVOTs. Until those valves are widely available, hybrid techniques have been shown to offer a potential alternative in these patients, as well as in patients of small size. Although medium-term results of TPVI have shown 5-year freedom from reintervention or replacement of 76%, new data have underlined some concerns relating to bacterial endocarditis after the procedure. Procedural costs remain a concern, but vary greatly between institutions and healthcare systems. TPVI has emerged as one of the most innovative procedures in the treatment of patients with dysfunctional RVOT and pulmonary valves. Further device development is likely to expand the procedure to patients of smaller size and with complex, dilated RVOTs.

  16. Percutaneous implantation of the first repositionable aortic valve prosthesis in a patient with severe aortic stenosis.

    PubMed

    Buellesfeld, Lutz; Gerckens, Ulrich; Grube, Eberhard

    2008-04-01

    Percutaneous aortic valve replacement is a new less-invasive alternative for high-risk surgical candidates with aortic stenosis. However, the clinical experience is still limited, and the currently available 'first-generation devices' revealed technical shortcomings, such as lack of repositionability and presence of paravalvular leakages. We report the first-in-man experience with the new self-expanding Lotus Valve prosthesis composed of a nitinol frame with implemented bovine pericardial leaflets which is designed to address these issues, being repositionable and covered by a flexible membrane to seal paravalvular gaps. We implanted this prosthesis in a 93-year old patient presenting with severe symptomatic aortic stenosis (valve area: 0.6 cm(2)). Surgical valve replacement had been declined due to comorbidities. We used a retrograde approach for insertion of the 21-French Lotus catheter loaded with the valve prosthesis via surgical cut-down to the external iliac artery. Positioning of the valve was guided by transesophageal echo and supra-aortic angiograms. The prosthesis was successfully inserted and deployed within the calcified native valve. Echocardiography immediately after device deployment showed a significant reduction of the transaortic mean pressure gradient (32 to 9 mmHg; final valve area 1.7 cm(2)) without evidence of residual aortic regurgitation. The postprocedural clinical status improved from NYHA-IV to NYHA-II. These results remained unchanged up to the 3 month follow-up. Successful percutaneous aortic valve replacement can be performed using the new self-expanding and repositionable Lotus valve for treatment of high-risk patients with aortic valve stenosis. Further studies are mandatory to assess device safety and efficacy in larger patient populations. Copyright 2008 Wiley-Liss, Inc.

  17. Mitral valve surgery - minimally invasive

    MedlinePlus

    ... 2 centimeters) each. The surgeon uses a special computer to control robotic arms during the surgery. A ... heart and mitral valve are displayed on a computer in the operating room. You will need a ...

  18. Mitral Valve Prolapse (For Parents)

    MedlinePlus

    ... Atrial Septal Defect Ventricular Septal Defect Heart and Circulatory System Congenital Heart Defects Getting an EKG (Video) Your Heart & Circulatory System Heart Murmurs Marfan Syndrome Mitral Valve Prolapse EKG ( ...

  19. Simpler valve for reciprocating engines

    NASA Technical Reports Server (NTRS)

    Akkerman, J. W.

    1978-01-01

    Simpler design eliminating camshafts, cams, and mechanical springs should improve reliability of hydrazine powered reciprocating engines. Valve is expected to improve efficiency, and reduce weight of engines in range up to 50 horsepower.

  20. Bipropellant shut-off valve

    NASA Technical Reports Server (NTRS)

    Smith, J. V.

    1971-01-01

    An advanced design of an all metal, fast response, bipropellant, shut-off valve for use on long duration space missions is reported. The valve provides the flow control capability for a 1,000 lb thrust, bipropellant engine using oxygen difluoride and diborane as propellants. The shutoff seal selection is a soft-on-hard metal concept. The soft seal is a spherical shell that seats against a hard conical seat. Beryllium copper and beryllium nickel seals were selected to seal against an electrolyzed Inconel 718 seat. Poppet shaft sealing is achieved by use of hydroformed, Inconel 718 bellows. Two valve assemblies were fabricated and subjected to a series of tests including leak, response time, flow capacity, dry cycles, water cycles, liquid nitrogen cycles, liquid fluorine cycles, and lead-lag operation cycles. These tests demonstrated the ability of the valve to meet design goals.

  1. Mitral Valve Prolapse (For Parents)

    MedlinePlus

    ... be cleared by the doctor to participate in sports. This may involve some additional tests. Although any heart condition can be frightening, mitral valve prolapse likely will not have any effect on your child's everyday life and activities. If ...

  2. Living with Heart Valve Disease

    MedlinePlus

    ... Clinical Trials Links Related Topics Congenital Heart Defects Endocarditis Heart Murmur How the Heart Works Mitral Valve ... your doctor if you have symptoms of infective endocarditis (IE). Symptoms of this heart infection include fever, ...

  3. Magnetic toys: forbidden for pediatric patients with certain programmable shunt valves?

    PubMed

    Zuzak, Tycho J; Balmer, Bettina; Schmidig, Daniel; Boltshauser, Eugen; Grotzer, Michael A

    2009-02-01

    Inadvertent adjustments and malfunctions of programmable valves have been reported in cases in which patients have encountered powerful electromagnetic fields such as those involved in magnetic resonance imaging, but the potential effects of magnetic toys on programmable valves are not well known. The magnetic properties of nine toy magnets were examined. To calculate the effect of a single magnet over a distance, the magnetic flux density was directly measured using a calibrated Hall probe at seven different positions between 0 and 120 mm from the magnet. Strata II small (Medtronic Inc.), Codman Hakim (Codman & Shurtleff), and Polaris (Sophysa) programmable valves were then tested to determine the effects of the toy magnets on each valve type. The maximal flux density of different magnetic toys differed between 17 and 540 mT, inversely proportional to the distance between toy and measurement instrument. Alterations to Strata and Codman valve settings could be effected with all the magnetic toys. The distances that still led to an alteration of the valve settings differed from 10 to 50 mm (Strata), compared with 5 to 30 mm (Codman). Valve settings of Polaris could not be altered by any toy at any distance due to its architecture with two magnets adjusted in opposite directions. This is the first report describing changes in the pressure setting of some adjustable valves caused by magnetic toys in close contact. Parents, surgeons, neurologists, pediatric oncologists, and paramedics should be informed about the potential dangers of magnetic toys to prevent unwanted changes to pressure settings.

  4. Liquid-blocking check valve

    DOEpatents

    Merrill, J.T.

    1982-09-27

    A liquid blocking check valve useful particularly in a pneumatic system utilizing a pressurized liquid fill chamber. The valve includes a floatable ball disposed within a housing defining a chamber. The housing is provided with an inlet aperture disposed in the top of said chamber, and an outlet aperture disposed in the bottom of said chamber in an offset relation to said inlet aperture and in communication with a cutaway side wall section of said housing.

  5. Prosthetic valve endocarditis. A survey.

    PubMed Central

    Ben Ismail, M; Hannachi, N; Abid, F; Kaabar, Z; Rougé, J F

    1987-01-01

    Fifty eight patients (aged 8-59 years, mean 27) treated for prosthetic valve endocarditis from January 1966 to January 1985 were studied retrospectively by review of case notes. There were 12 cases of early and 46 cases of late prosthetic valve endocarditis. These developed in 28 patients with an isolated aortic valve, in 26 with an isolated mitral valve, and in four with both aortic and mitral prosthetic valves. Streptococci were the most commonly isolated microorganisms, followed by staphylococci, Gram negative bacteria, and fungi. A surgical (34 cases) or a necropsy specimen (10 cases) from 44 cases was examined. Eighty two per cent of the patients had congestive heart failure. Twenty four of the 58 patients were medically treated and 17 died (70% mortality). Combined medical and surgical treatment was used in 34 patients; the main indication for surgery was congestive heart failure. Fourteen patients on combined treatment died (40% mortality). Persistent sepsis and prosthetic valve dehiscence were the most common early and late operative complications. The most important influences on outcome were congestive heart failure, the type of micro-organism, the severity and extent of anatomical lesions, the time of onset of prosthetic valve endocarditis, and the type of treatment. This survey indicates that only patients without congestive heart failure or embolic complications and with sensitive micro-organism should be treated medically. In view of the poor prognosis patients with prosthetic valve endocarditis associated with congestive heart failure, persistent sepsis, and repeat arterial emboli should be treated by early surgical intervention. PMID:3620246

  6. Hydraulic Evaluation of Culvert Valves at Eisenhower and Snell Locks, St. Lawrence Seaway

    DTIC Science & Technology

    2015-06-01

    ER D C/ CH L TR -1 5- 7 Hydraulic Evaluation of Culvert Valves at Eisenhower and Snell Locks , St. Lawrence Seaway Co as ta l a nd H...client/default. ERDC/CHL TR-15-7 June 2015 Hydraulic Evaluation of Culvert Valves at Eisenhower and Snell Locks , St. Lawrence Seaway...ERDC/CHL TR-15-7 ii Abstract The aged, double-skin-plate valves of the Eisenhower and Snell Locks on the St. Lawrence Seaway are being replaced

  7. [Late ventricular potentials and mitral valve prolapse].

    PubMed

    Babuty, D; Charniot, J C; Delhomme, C; Fauchier, L; Fauchier, J P; Cosnay, P

    1994-03-01

    In order to determine the predictive value for ventricular arrhythmias of ventricular late potentials (LP) in mitral valve prolapse (MVP) the authors performed high amplification signal-averaging ECG (SA) and 24 hours ambulatory ECG (Holter) monitoring in 68 consecutive patients (34 men, 34 women, average age 48 +/- 17.7 years) with echocardiographically diagnosed MVP. Patients with bundle branch block or associated cardiac disease were excluded. Echocardiography showed 26 patients to have floppy mitral valves (38.2%), 50 patients to have posterior deplacement > or = 5 mm of the mitral valves in systole (73.5%) and 35 patients to have mitral regurgitation (51.4%). Holter monitoring showed 17 patients without ventricular extrasystoles (VES), 15 had Lown Grade I, 6 had Lown Grade II, 3 had Lown Grade III, 15 had Lown Grade IV A and 12 had Lown Grade IV B ventricular arrhythmias. Therefore, 30 patients had complex ventricular arrhythmias (> or = Lown Grade III) and 13 patients had spontaneous non-sustained ventricular tachycardia (NSVT) (one patient had NSVT on resting ECG but not on Holter monitoring). Eighteen patients had LP (26.5%). The incidence of complex ventricular arrhythmias was higher in patients with mitral regurgitation (62.8% versus 27.7%; p < 0.005) whereas the incidence of NSVT was not significantly different (25.7% versus 17.1%; p = 0.15). On the other hand, the frequency of complex ventricular arrhythmias was not significantly different in the presence or absence of LP (61.1% versus 40%: NS) whereas the incidence of NSVT was higher in patients with LP (44.4% versus 10%; p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Valve health monitoring system utilizing smart instrumentation

    NASA Astrophysics Data System (ADS)

    Jensen, Scott L.; Drouant, George J.

    2006-05-01

    The valve monitoring system is a stand alone unit with network capabilities for integration into a higher level health management system. The system is designed for aiding in failure predictions of high-geared ball valves and linearly actuated valves. It performs data tracking and archiving for identifying degraded performance. The data collection types are: cryogenic cycles, total cycles, inlet temperature, outlet temperature, body temperature, torsional strain, linear bonnet strain, preload position, total travel, and total directional changes. Events are recorded and time stamped in accordance with the IRIG B True Time. The monitoring system is designed for use in a Class 1 Division II explosive environment. The basic configuration consists of several instrumentation sensor units and a base station. The sensor units are self contained microprocessor controlled and remotely mountable in three by three by two inches. Each unit is potted in a fire retardant substance without any cavities and limited to low operating power for maintaining safe operation in a hydrogen environment. The units are temperature monitored to safeguard against operation outside temperature limitations. Each contains 902-928 MHz band digital transmitters which meet Federal Communication Commissions requirements and are limited to a 35 foot transmission radius for preserving data security. The base-station controller correlates related data from the sensor units and generates data event logs on a compact flash memory module for database uploading. The entries are also broadcast over an Ethernet network. Nitrogen purged National Electrical Manufactures Association (NEMA) Class 4 Enclosures are used to house the base-station.

  9. Noninvasive valve monitor using alternating electromagnetic field

    DOEpatents

    Eissenberg, David M.; Haynes, Howard D.; Casada, Donald A.

    1993-01-01

    One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

  10. Noninvasive valve monitor using alternating electromagnetic field

    DOEpatents

    Eissenberg, D.M.; Haynes, H.D.; Casada, D.A.

    1993-03-16

    One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

  11. Pressure control valve. [inflating flexible bladders

    NASA Technical Reports Server (NTRS)

    Lambson, K. H. (Inventor)

    1980-01-01

    A control valve is provided which is adapted to be connected between a pressure source, such as a vacuum pump, and a pressure vessel so as to control the pressure in the vessel. The valve comprises a housing having a longitudinal bore which is connected between the pump and vessel, and a transversely movable valve body which controls the air flow through an air inlet in the housing. The valve body includes cylindrical and conical shaped portions which cooperate with reciprocally shaped portions of the housing to provide flow control. A filter in the air inlet removes foreign matter from the air. The bottom end of the valve body is screwed into the valve housing control knob formed integrally with the valve body and controls translation of the valve body, and the opening and closing of the valve.

  12. Preservation and function of heterologous aortic valves

    PubMed Central

    Gunning, A. J.; Meade, J. B.

    1971-01-01

    Heterologous aortic valves are used in many clinics as replacements for diseased human aortic and mitral valves. These valves possess all the advantages of homologous aortic valves and are more easily available to the surgeon. The heterologous valve also provides a greater choice of valve size than does the homograft; this can be of importance when replacing the mitral valve. Heterograft valves, like homografts, are usually preserved for periods ranging from a few days to a few months before insertion into a patient. Four methods of preservation, described, are currently in use. This study compares the effects of these four methods of preservation when pig valves are transplanted into the dog's aorta. Images PMID:5576535

  13. Transapical Transcatheter Valve-in-Valve Implantation for Failed Mitral Bioprostheses: Gradient, Symptoms, and Functional Status in 18 High-Risk Patients Up to 5 Years.

    PubMed

    Cerillo, Alfredo Giuseppe; Gasbarri, Tommaso; Celi, Simona; Murzi, Michele; Trianni, Giuseppe; Ravani, Marcello; Solinas, Marco; Berti, Sergio

    2016-10-01

    The recourse to mitral valve-in-valve implantation is expected to rise consistently owing to the increasing use of bioprostheses and to the risks related to redo valve replacement. However, there is concern that the excellent early results of mitral valve-in-valve could be nullified by the development of significant gradients. We report our experience with mitral valve-in-valve implantation, with particular emphasis on the midterm follow-up. Eighteen patients underwent mitral valve-in-valve implantation at our institution. The mean Society of Thoracic Surgeons score was 10.3. All patients were heavily symptomatic. The mechanisms of bioprosthesis failure were stenosis (3 patients), regurgitation (4 patients) or mixed (11 patients). The mean transprosthetic gradient was 12.8 ± 5.7 mm Hg. All the procedures were transapical. Balloon predilation was never used. In the first patient, the transcatheter valve embolized in the ventricle. The patient died 2 days later of multiorgan failure. There were no other hospital deaths. Four patients died of pneumonia, endocarditis, lung cancer, and stroke at 1, 8, 18, and 46 months, postoperatively. The mean gradient at discharge was 5.1 ± 2.3 mm Hg. At follow-up (median 27 months), all surviving patients were in New York Heart Association functional class II or less. The mean transprosthetic gradient was 7 ± 1.8 mm Hg, and 1 patient had a gradient more than 10 mm Hg. Mitral valve-in-valve implantation allows good clinical and hemodynamic results. In our series, the appearance of a significant gradient at follow-up was not associated with echocardiographic signs of structural deterioration, and was possibly related to the size of the transcatheter and recipient valve. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Development of an effective valve packing program

    SciTech Connect

    Hart, K.A.

    1996-12-01

    Current data now shows that graphite valve packing installed within the guidance of a controlled program produces not only reliable stem sealing but predictable running loads. By utilizing recent technological developments in valve performance monitoring for both MOV`s and AOV`s, valve packing performance can be enhanced while reducing maintenance costs. Once known, values are established for acceptable valve packing loads, the measurement of actual valve running loads via the current MOV/AOV diagnostic techniques can provide indication of future valve stem sealing problems, improper valve packing installation or identify the opportunity for valve packing program improvements. At times the full benefit of these advances in material and predictive technology remain under utilized due to simple past misconceptions associated with valve packing. This paper will explore the basis for these misconceptions, provide general insight into the current understanding of valve packing and demonstrate how with this new understanding and current valve diagnostic equipment the key aspects required to develop an effective, quality valve packing program fit together. The cost and operational benefits provided by this approach can be significant impact by the: elimination of periodic valve repacking, reduction of maintenance costs, benefits of leak-free valve operation, justification for reduced Post Maintenance Test Requirements, reduced radiation exposure, improved plant appearance.

  15. Concomitant aortic valve replacement and myocardial revascularization.

    PubMed Central

    Craver, J M; Jones, E L; Hatcher, C R; Farmer, J H

    1977-01-01

    Twenty-six consecutive patients underwent combined aortic valve replacement and myocardial revascularization at the Emory University Affiliated Hospitals between May, 1973 and March, 1976. Acute myocardial infarction resulted in two operative deaths (8%). There have been four late deaths, all Class IV preoperative. The age range was 37 to 79 years with an average age of 60. Preoperatively all patients were Class IV or late Class III. Twenty-three patients had symptoms of angina pectoris; congestive heart failure was evident in 56%. Postoperatively, 70% are now Class 1 or II. Single coronary bypass was performed in 16 patients, double in 6, and triple in three. Double bypass plus mitral valve replacement was required in two with aneurysmectomy in one. The rate of intraoperative infarction was 27% for the series but only 7% in the last year. The methods of intraoperative myocardial preservation and the technical approach for the operative procedures were variable. Results with each method are correlated, and currently preferred techniques are presented and discussed. Best results were obtained in patients who presented early in their symptomatic course with isolated proximal coronary lesions and good renoff vessels. Excellent results could be achieved despite advanced age of patients, requirement for multiple bypass grafts, and correction of other associated cardiac lesions. Poorest results were obtained when long-standing ventricular failure was combined with poor vessels distal to coronary stenoses. PMID:860881

  16. Annular flow diverter valve

    DOEpatents

    Rider, Robert L.

    1980-01-01

    A valve for diverting flow from the center of two concentric tubes to the annulus between the tubes or, operating in the reverse direction, for mixing fluids from concentric tubes into a common tube and for controlling the volume ratio of said flow consists of a toroidal baffle disposed in sliding engagement with the interior of the inner tube downstream of a plurality of ports in the inner tube, a plurality of gates in sliding engagement with the interior of the inner tube attached to the baffle for movement therewith, a servomotor having a bullet-shaped plug on the downstream end thereof, and drive rods connecting the servomotor to the toroidal baffle, the servomotor thereby being adapted to move the baffle into mating engagement with the bullet-shaped plug and simultaneously move the gates away from the ports in the inner tube and to move the baffle away from the bullet-shaped plug and simultaneously move the gates to cover the ports in the inner tube.

  17. Valve-less microdispenser

    NASA Astrophysics Data System (ADS)

    Tan, Ming Kwang; Xin, Wang; Lee, Weng Kent

    2015-11-01

    We demonstrate the concept of valve-less microdispenser to control of the liquid flow through the nozzle, by incorporating Leidenfrost effect into the nozzle design. When the nozzle is heated above the Leidenfrost point, a thin vapor layer is formed between the heated substrate and the liquid above it. The vapor pressure due to the presence of the vapor layer, together with the effect of surface tension of the liquid, exerted on the liquid-vapor interface, preventing the flow of the liquid through the nozzle. The experimental results shown that nozzles of diameter 400 micrometer and below, the nozzle temperature of 150 degree Celsius is sufficient to prevent the continuous flowing of the liquid, whereas for nozzles of diameter between 400 to 500 micrometer, the nozzle temperature needs to increase to 160 degree Celsius in order to prevent the continuous flowing of the liquid. When nozzle temperature below 160 degree Celsius, intermittent ejection of microdroplets, whose size is a function of nozzle temperature, is observed.

  18. Ischemic mitral valve prolapse

    PubMed Central

    Cristiano, Spadaccio; Nenna, Antonio; Chello, Massimo

    2016-01-01

    Ischemic mitral prolapse (IMP) is a pathologic entity encountered in about one-third among the patients undergoing surgery for ischemic mitral regurgitation (IMR). IMP is generally the result of a papillary muscle injury consequent to myocardial, but the recent literature is progressively unveiling a more complex pathogenesis. The mechanisms underlying its development regards the impairment of one or more components of the mitral apparatus, which comprises the annulus, the chordae tendineae, the papillary muscle and the left ventricular wall. IMP is not only a disorder of valvular function, but also entails coexistent aspects of a geometric disturbance of the mitral valve configuration and of the left ventricular function and dimension and a correct understanding of all these aspects is crucial to guide and tailor the correct therapeutic strategy to be adopted. Localization of prolapse, anatomic features of the prolapsed leaflets and the subvalvular apparatus should be carefully evaluated as also constituting the major determinants defining patient’s outcomes. This review will summarize our current understanding of the pathophysiology and clinical evidence on IMP with a particular focus on the surgical treatment. PMID:28149574

  19. Valve mechanism lubrication system for an overhead valve engine

    SciTech Connect

    Kronich, P.G.

    1986-07-22

    In an internal combustion engine, including a crankcase, an oil sump, push rods for operating the valves of the engine, a rocker box for housing the valve actuating mechanism, a lubrication system for lubricating the valve actuating mechanism is described which consists of: a first hollow tube for housing a first of the push rods, and first tube having one end open to the crankcase, and an opposite end open to the rocker box, for conducting oil mist from the crankcase to the rocker box to lubricate the valve rocker mechanism; a second hollow tube for housing a second push rod, the second tube having one end open to the rocker box and an opposite end open to a breather chamber for conducting liquid oil and oil mist from the rocker box to the breather chamber, the breather chamber being vented to the atmosphere; an oil drain passage for conducting liquid oil from the breather chamber to the oil sump; and baffle means in the rocker box for causing the oil mist entering the rocker box from the first tube to flow past the valve actuating mechanism for lubrication thereof before flowing from the rocker box into the second tube.

  20. Finite Element Modeling of Mitral Valve Repair

    PubMed Central

    Morgan, Ashley E.; Pantoja, Joe Luis; Weinsaft, Jonathan; Grossi, Eugene; Guccione, Julius M.; Ge, Liang; Ratcliffe, Mark

    2016-01-01

    The mitral valve is a complex structure regulating forward flow of blood between the left atrium and left ventricle (LV). Multiple disease processes can affect its proper function, and when these diseases cause severe mitral regurgitation (MR), optimal treatment is repair of the native valve. The mitral valve (MV) is a dynamic structure with multiple components that have complex interactions. Computational modeling through finite element (FE) analysis is a valuable tool to delineate the biomechanical properties of the mitral valve and understand its diseases and their repairs. In this review, we present an overview of relevant mitral valve diseases, and describe the evolution of FE models of surgical valve repair techniques. PMID:26632260

  1. Spring-Loaded Joule-Thomson Valve

    NASA Technical Reports Server (NTRS)

    Jones, J. A.; Britcliffe, M. J.

    1986-01-01

    Improved design reduces clogging and maintains constant pressure drop as flow rate varies. Spring-Loaded Joule-Thomson Valve pressure drop regulated by spring pushing stainless-steel ball against soft brass seat. Pressure drop remains nearly constant, regardless of helium flow rate and of any gas contaminants frozen on valve seat. Because springloaded J-T valve maintains constant pressure drop, upstream roomtemperature throttle valve adjusts flow rate precisely for any given upstream pressure. In addition, new valve relatively invulnerable to frozen gas contaminants, which clog fixed-orifice J-T valves.

  2. Valve system incorporating single failure protection logic

    DOEpatents

    Ryan, Rodger; Timmerman, Walter J. H.

    1980-01-01

    A valve system incorporating single failure protective logic. The system consists of a valve combination or composite valve which allows actuation or de-actuation of a device such as a hydraulic cylinder or other mechanism, integral with or separate from the valve assembly, by means of three independent input signals combined in a function commonly known as two-out-of-three logic. Using the input signals as independent and redundant actuation/de-actuation signals, a single signal failure, or failure of the corresponding valve or valve set, will neither prevent the desired action, nor cause the undesired action of the mechanism.

  3. Robotically assisted mitral valve replacement.

    PubMed

    Gao, Changqing; Yang, Ming; Xiao, Cangsong; Wang, Gang; Wu, Yang; Wang, Jiali; Li, Jiachun

    2012-04-01

    In the present study, we determined the safety and efficacy of robotic mitral valve replacement using robotic technology. From January 2007 through March 2011, more than 400 patients underwent various types of robotic cardiac surgery in our department. Of these, 22 consecutive patients underwent robotically assisted mitral valve replacement. Of the 22 patients with isolated rheumatic mitral valve stenosis (9 men and 13 women), the mean age was 44.7 ± 19.8 years (range, 32-65). Preoperatively, all patients underwent a complete workup, including coronary angiography and transthoracic echocardiography. Of the 22 patients, 15 had concomitant atrial fibrillation. The surgical approach was through 4 right-side chest ports with femoral perfusion. Aortic occlusion was performed with a Chitwood crossclamp, and antegrade cardioplegia was administered directly by way of the anterior chest. Using 3 port incisions in the right side of the chest and a 2.5- to 3.0-cm working port, all the procedures were completed with the da Vinci S robot. All patients underwent successful robotic surgery. Of the 22 patients, 16 received a mechanical valve and 6 a tissue valve. The mean cardiopulmonary bypass time and aortic crossclamp time was 137.1 ± 21.9 minutes (range, 105-168) and 99.3 ± 17.9 minutes (range, 80-133), respectively. No operative deaths, stroke, or other complications occurred, and no incisional conversions were required. After surgery, all the patients were followed up echocardiographically. Robotically assisted mitral valve replacement can be performed safely in patients with isolated mitral valve stenosis, and surgical results are excellent. Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  4. BORED AND ASSEMBLED GATE VALVES RECEIVING PROTECTIVE COATING IN THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BORED AND ASSEMBLED GATE VALVES RECEIVING PROTECTIVE COATING IN THE VALVE PAINT BOOTH OF THE VALVE ASSEMBLY BUILDING. - Stockham Pipe & Fittings Company, Valve Assembly Building, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  5. Total ellipse of the heart valve: the impact of eccentric stent distortion on the regional dynamic deformation of pericardial tissue leaflets of a transcatheter aortic valve replacement

    PubMed Central

    Gunning, Paul S.; Saikrishnan, Neelakantan; Yoganathan, Ajit P.; McNamara, Laoise M.

    2015-01-01

    Transcatheter aortic valve replacements (TAVRs) are a percutaneous alternative to surgical aortic valve replacements and are used to treat patients with aortic valve stenosis. This minimally invasive procedure relies on expansion of the TAVR stent to radially displace calcified aortic valve leaflets against the aortic root wall. However, these calcium deposits can impede the expansion of the device causing distortion of the valve stent and pericardial tissue leaflets. The objective of this study was to elucidate the impact of eccentric TAVR stent distortion on the dynamic deformation of the tissue leaflets of the prosthesis in vitro. Dual-camera stereophotogrammetry was used to measure the regional variation in strain in a leaflet of a TAVR deployed in nominal circular and eccentric (eccentricity index = 28%) orifices, representative of deployed TAVRs in vivo. It was observed that (i) eccentric stent distortion caused incorrect coaptation of the leaflets at peak diastole resulting in a ‘peel-back’ leaflet geometry that was not present in the circular valve and (ii) adverse bending of the leaflet, arising in the eccentric valve at peak diastole, caused significantly higher commissure strains compared with the circular valve in both normotensive and hypertensive pressure conditions (normotension: eccentric = 13.76 ± 2.04% versus circular = 11.77 ± 1.61%, p = 0.0014, hypertension: eccentric = 15.07 ± 1.13% versus circular = 13.56 ± 0.87%, p = 0.0042). This study reveals that eccentric distortion of a TAVR stent can have a considerable impact on dynamic leaflet deformation, inducing deleterious bending of the leaflet and increasing commissures strains, which might expedite leaflet structural failure compared to leaflets in a circular deployed valve. PMID:26674192

  6. Conventional versus rapid-deployment aortic valve replacement: a single-centre comparison between the Edwards Magna valve and its rapid-deployment successor.

    PubMed

    Andreas, Martin; Wallner, Stephanie; Habertheuer, Andreas; Rath, Claus; Schauperl, Martin; Binder, Thomas; Beitzke, Dietrich; Rosenhek, Raphael; Loewe, Christian; Wiedemann, Dominik; Kocher, Alfred; Laufer, Guenther

    2016-06-01

    Sutureless and rapid-deployment valves were recently introduced into clinical practice. The Edwards INTUITY valve system is a combination of the Edwards Magna pericardial valve and a subvalvular stent-frame to enable rapid deployment. We performed a parallel cohort study for comparison of the two valve types. All patients receiving either an Edwards Magna Ease valve or an Edwards INTUITY valve system due to aortic stenosis from May 2010 until July 2014 were included. Patients undergoing bypass surgery, an additional valve procedure, atrial ablation surgery or replacement of the ascending aorta were excluded. Preoperative characteristics, operative specifications, survival, valve-related adverse events and transvalvulvar gradients were compared. One hundred sixteen patients underwent rapid-deployment aortic valve replacement [mean age 75 years (SD: 8); 62% female] and 132 patients underwent conventional aortic valve replacement [70 years (SD: 9); 31% female; P < 0.001]. Conventional valve patients were taller and heavier. The mean EuroSCORE II was 3.1% (SD: 2.7) and 4.4% (SD: 6.0) for rapid-deployment and conventional valve patients, respectively (P = 0.085). The mean implanted valve size was higher in the conventional group [23.2 mm (SD: 2.0) vs 22.5 mm (SD: 2.2); P = 0.007], but postoperative transvalvular mean gradients were comparable [15 mmHg (SD: 6) vs 14 mmHg (SD: 5); P = 0.457]. A subgroup analysis of the most common valve sizes (21 and 23 mm; implanted in 63% of patients) revealed significantly reduced mean postoperative transvalvular gradients in the rapid-deployment group [14 mmHg (SD: 4) vs 16 mmHg (SD: 5); P = 0.025]. A significantly higher percentage received minimally invasive procedures in the rapid-deployment group (59 vs 39%; P < 0.001). The 1- and 3-year survival rate was 96 and 90% in the rapid-deployment group and 95 and 89% in the conventional group (P = 0.521), respectively. Valve-related pacemaker implantations were more common in the rapid

  7. Mitral valve aneurysm associated with aortic valve endocarditis and regurgitation.

    PubMed

    Raval, Amish N; Menkis, Alan H; Boughner, Derek R

    2002-01-01

    Mitral valve aneurysms are rare complications occurring most commonly in association with aortic valve infective endocarditis. [Decroly 1989, Chua 1990, Northridge 1991, Karalis 1992, Roguin 1996, Mollod 1997, Vilacosta 1997, Cai 1999, Vilacosta 1999, Teskey 1999, Chan 2000, Goh 2000, Marcos- Alberca 2000] While the mechanism of the development of this lesion is unclear, complications such as perforation can occur and lead to significant mitral regurgitation. [Decroly 1989, Karalis 1992, Teskey 1999, Vilacosta 1999]; The case of a 69-year-old male with Streptococcus Sanguis aortic valve endocarditis and associated anterior mitral leaflet aneurysm is presented. Following surgery, tissue pathology of the excised lesion revealed myxomatous degeneration and no active endocarditis or inflammatory cells. This may add support to the hypothesis that physical stress due to severe aortic insufficiency and structural weakening, without infection of the anterior mitral leaflet, can lead to the development of this lesion.

  8. Analysis of Complex Valve and Feed Systems

    NASA Technical Reports Server (NTRS)

    Ahuja, Vineet; Hosangadi, Ashvin; Shipman, Jeremy; Cavallo, Peter; Dash, Sanford

    2007-01-01

    A numerical framework for analysis of complex valve systems supports testing of propulsive systems by simulating key valve and control system components in the test loop. In particular, it is designed to enhance the analysis capability in terms of identifying system transients and quantifying the valve response to these transients. This system has analysis capability for simulating valve motion in complex systems operating in diverse flow regimes ranging from compressible gases to cryogenic liquids. A key feature is the hybrid, unstructured framework with sub-models for grid movement and phase change including cryogenic cavitations. The multi-element unstructured framework offers improved predictions of valve performance characteristics under steady conditions for structurally complex valves such as pressure regulator valve. Unsteady simulations of valve motion using this computational approach have been carried out for various valves in operation at Stennis Space Center such as the split-body valve and the 10-in. (approx.25.4-cm) LOX (liquid oxygen) valve and the 4-in. (approx.10 cm) Y-pattern valve (liquid nitrogen). Such simulations make use of variable grid topologies, thereby permitting solution accuracy and resolving important flow physics in the seat region of the moving valve. An advantage to this software includes possible reduction in testing costs incurred due to disruptions relating to unexpected flow transients or functioning of valve/flow control systems. Prediction of the flow anomalies leading to system vibrations, flow resonance, and valve stall can help in valve scheduling and significantly reduce the need for activation tests. This framework has been evaluated for its ability to predict performance metrics like flow coefficient for cavitating venturis and valve coefficient curves, and could be a valuable tool in predicting and understanding anomalous behavior of system components at rocket propulsion testing and design sites.

  9. Transient, three-dimensional flow field simulation through a mechanical, trileaflet heart valve prosthesis.

    PubMed

    Kaufmann, Tim A S; Linde, Torsten; Cuenca-Navalon, Elena; Schmitz, Christoph; Hormes, Marcus; Schmitz-Rode, Thomas; Steinseifer, Ulrich

    2011-01-01

    Thromboembolic complications are one of the major challenges faced by designers and researchers in development of artificial organs with blood-contacting devices such as heart valve prostheses, especially mechanical valves. Besides increasing the thrombogenic potential, these valves change the hydrodynamic performance of the heart. In this study, the flow through a trileaflet, mechanical heart valve prosthesis was modeled with transient computational fluid dynamics to analyze flow patterns causing thrombus formations on valves. The valve was simulated under conditions of a test rig (THIA II), which was specially designed to analyze different valves with respect to thrombosis. The main goal of this study was to mimic the exact conditions of the test rig to be able to compare numerical and experimental results. The boundary conditions were obtained from experimental data as leaflet kinematics and pressure profiles. One complete cycle of the valve was simulated. Numerical flow and pressure results were analyzed and compared with experimental results. Shear stress and shear rates were determined with respect to thrombogenic potential, especially in the pivot regions, which seem to be the main influence for activation and deposition of thrombocytes. Approximately 0.7% of the blood volume moving through the fluid domain of the valve was exposed to shear rates high enough to cause platelet activation. However, shear rates of up to 20,000 s⁻¹ occurred in pivot regions. The pressure differences between the simulation and experimental data were approximately 2.5% during systole and increased up to 25% during diastole. The presented method, however, can be used to gain more information about the flow through different heart valve prostheses and, thus, improve the development process.

  10. [Right-sided prosthetic cardiac valve thrombosis: value of cinefluoroscopy in the diagnosis and follow-up of thrombolytic treatment].

    PubMed

    Hobbach, H-P; Mall, K; Schaeffer, C; Schuster, P

    2009-10-01

    A 33-year-old woman (Pt. A) with a prosthetic cardiac valve in the pulmonary position [CarboMedics bileaflet valve, diameter 23 mm] as part of the repair of a tetralogy of Fallot 4 years previously, and a 51-year-old woman (Pt. B) with a prosthetic cardiac valve [St. Jude Medical bileaflet valve, diameter 31 mm] inserted in tricuspid position as replacement of a degenerated Hancock bioprosthetic valve inserted 15 years previously, 10 years after an episode of endocarditis, were admitted to hospital with dyspnea and chest pain and dyspnea and tachycardia, respectively. Pt. A had a 3 - 4/6 crescendo-decrescendo systolic murmur and a 2/6 early diastolic decrescendo murmur over the 2nd to 4th right intercostal space (ICS), while Pt. B had a 3/6 holosystolic murmur and a 2 - 3/6 diastolic murmur over the 4th right ICS. Closing click was missing in both patients. Blood tests demonstrated an elevated LDH (404 U/l) in Pt. A and an elevated GGT (108 U/l) and fibrinogen (449 mg/dl) in Pt. B. Anticoagulation was below the therapeutic level, with an INR value of 1,65 and 1,93, respectively. The electrocardiogram showed sinus rhythm, right bundle branch block and an isoelectric ST-segment (Pt. A) and a typical high-frequency atrial flutter with a 2:1 block, right bundle branch block and terminal T-wave inversions in leads V1 to V5 (Pt. B). Cinefluoroscopy showed rigid and hypomobile leaflets as a result of prosthetic cardiac valve thrombosis. Doppler echocardiography confirmed the stenosis of the prosthetic valve in the pulmonary position (peak gradient 73 mm Hg, mean gradient 34 mm Hg) and the tricuspid position (mean gradient 8.48 mm Hg, peak gradient 16.73 mm Hg). Both patients were treated with unfractionated heparin and urokinase single-bolus injection of 4400 U/kg over 10 min followed by an infusion of 4400 U/kg/h over 12 h. Both patients had an abnormal opening angle, which improved to a normal opening and closing angle. Doppler echocardiography demonstrated decreased

  11. Mechanical heart valve cavitation in patients with bileaflet valves.

    PubMed

    Johansen, Peter; Andersen, Tina S; Hasenkam, J Michael; Nygaard, Hans; Paulsen, Peter K

    2014-01-01

    Today, the quality of mechanical heart valves is quite high, and implantation has become a routine clinical procedure with a low operative mortality (< 5%). However, patients still face the risks of blood cell damage, thromboembolic events, and material failure of the prosthetic device. One mechanism found to be a possible contributor to these adverse effects is cavitation. In vitro, cavitation has been directly demonstrated by visualization and indirectly in vivo by registering of high frequency pressure fluctuations (HFPF). Tilting disc valves are thought of having higher cavitation potential than bileaflet valves due to higher closing velocities. However, the thromboembolic potential seems to be the same. Further studies are therefore needed to investigate the cavitation potential of bileaflet valves in vivo. The post processing of HFPF have shown difficulties when applied on bileaflet vavles due to asynchronous closure of the two leaflets. The aim of this study was therefore to isolate the pressure signature from each leaflet closure and perform cavitation analyses on each component. Six patients were included in the study (St. Jude Medical (n=3) and CarboMedics (n=3); all aortic bileaflet mechanical heart valves). HFPFs were recorded intraoperatively through a hydrophone at the aortic root. The pressure signature relating to the first and second leaflet closure was isolated and cavitation parameters were calculated (RMS after 50 kHz highpass filtering and signal energy). Data were averaged over 30 heart cycles. For all patients both the RMS value and signal energy of the second leaflet closure were higher than for the first leaflet closure. This indicates that the second leaflet closure is most prone to cause cavitation. Therefore, quantifying cavitation based on the HFPF related to the second leaflet closure may suggest that the cavitation potential for bileaflet valves in vivo may be higher than previous studies have suggested.

  12. Valve packings conquer fugitive emissions

    SciTech Connect

    1995-11-01

    In the early 1990s, when the US Environmental Protection Agency (EPA; Washington, D.C.) declared its intent to regulate fugitive emissions from valve-stem leakage, much of the chemical process industries (CPI) responded with fear and uncertainty. The biggest fear was that valve packing would not meet the required limits on leak rates and that expensive bellows seals may be required on many applications. The uncertainly was about how much it would cost. Today, for the most part, these concerns have been mitigated. It is estimated that about 80--90% of valves satisfy the emission requirements. The rest need some improvement in their packing systems to meet the regulations. Generally, these valves can be brought within compliance if the packing designers follow a few basic principles: Employ less-pliable outer rings and more-pliable inner rings; and don`t use excessive packing. While interest in valve packing remains high, mechanical seals continue to become more user-friendly. Many of those covered below are designed to run dry, and some can even tolerate high shaft-wobble without damage. Also look for improved flange gaskets and a host of seals to protect bearings. Twenty-one summaries are presented on new products and services.

  13. Large Scale Magnetostrictive Valve Actuator

    NASA Technical Reports Server (NTRS)

    Richard, James A.; Holleman, Elizabeth; Eddleman, David

    2008-01-01

    Marshall Space Flight Center's Valves, Actuators and Ducts Design and Development Branch developed a large scale magnetostrictive valve actuator. The potential advantages of this technology are faster, more efficient valve actuators that consume less power and provide precise position control and deliver higher flow rates than conventional solenoid valves. Magnetostrictive materials change dimensions when a magnetic field is applied; this property is referred to as magnetostriction. Magnetostriction is caused by the alignment of the magnetic domains in the material s crystalline structure and the applied magnetic field lines. Typically, the material changes shape by elongating in the axial direction and constricting in the radial direction, resulting in no net change in volume. All hardware and testing is complete. This paper will discuss: the potential applications of the technology; overview of the as built actuator design; discuss problems that were uncovered during the development testing; review test data and evaluate weaknesses of the design; and discuss areas for improvement for future work. This actuator holds promises of a low power, high load, proportionally controlled actuator for valves requiring 440 to 1500 newtons load.

  14. Titanium in Engine Valve Systems

    NASA Astrophysics Data System (ADS)

    Allison, J. E.; Sherman, A. M.; Bapna, M. R.

    1987-03-01

    Titanium alloys offer a unique combination of high strength-to-weight ratio, good corrosion resistance and favorable high temperature mechanical properties. Still, their relatively high cost has discouraged consideration for widespread use in automotive components. Recent demands for increased fuel economy have led to the consideration of these alloys for use as valve train materials where higher costs might be offset by improvements in performance and fuel economy. Lighter weight valve train components permit the use of lower spring loads, thus reducing friction and increasing fuel economy. Camshaft friction measurements made on a typical small displacement engine indicate that a twoto-four percent increase in fuel economy can be achieved. Valve train components are, however, subject to a severe operating environment, including elevated temperatures, sliding wear and high mechanical loads. This paper discusses the details of alloy and heat treatment selection for optimizing valve performance. When properly manufactured, titanium valves have been shown to withstand very stringent durability testing, indicating the technical feasibility of this approach to fuel economy improvement.

  15. Validation of German Aortic Valve Score in a Multi-Surgeon Single Center

    PubMed Central

    Kalender, Mehmet; Baysal, Ahmet Nihat; Karaca, Okay Guven; Boyacioglu, Kamil; Kayalar, Nihan

    2017-01-01

    Objective Risk assessment for operative mortality is mandatory for all cardiac operations. For some operation types such as aortic valve repair, EuroSCORE II overestimates the mortality rate and a new scoring system (German AV score) has been developed for a more accurate assessment of operative risk. In this study, we aimed to validate German Aortic Valve Score in our clinic in patients undergoing isolated aortic valve replacement. Methods A total of 35 patients who underwent isolated open aortic valve replacement between 2010 and 2013 were included. Patients with concomitant procedures and transcatheter aortic valve implantation were excluded. Patients' data were collected and analyzed retrospectively. Patients' risk scores EuroSCORE II were calculated online according to criteria described by EuroSCORE taskforce, Aortic Valve Scores were also calculated. Results The mean age of patients was 61.14±13.25 years (range 29-80 years). The number of female patients was 14 (40%) and body mass index of 25 (71.43%) patients was in range of 22-35. Mean German Aortic Valve Score was 1.05±0.96 (min: 0 max: 4.98) and mean EuroSCORE was 2.30±2.60 (min: 0.62, max: 2.30). The Aortic Valve Score scale showed better discriminative capacity (AUC 0.647, 95% CI 0.439-0.854). The goodness of fit was x2HL=16.63; P=0.436). EuroSCORE II scale had shown less discriminative capacity (AUC 0.397, 95% CI 0.200-0.597). The goodness of fit was good for both scales. The goodness of fit was x2HL=30.10; P=0.610. Conclusion In conclusion, German AV score applies to our population with high predictive accuracy and goodness of fit. PMID:28492787

  16. Coolant-Control Valves For Fluid-Sampling Probes

    NASA Technical Reports Server (NTRS)

    Schultz, Donald F.

    1989-01-01

    Small built-in leaks prevent overheating. Downstream flow-control globe valve replaced with modified gate valve. Modification consists of drilling small hole through valve gate, so valve never turned completely off. This "leaky" valve provides enough flow of coolant to prevent overheating causing probe to fail. Principle also applied to automatic control system by installing small bypass line around control valve.

  17. 46 CFR 56.20-15 - Valves employing resilient material.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Category B, and shall be tested and used as follows: (1) Positive shutoff valves. The closed valve must... Category A or Category B valve. (2) Category A valves. The closed valve must pass less than the greater of...) from functioning as designed. (iii) Valves providing closure for any opening in the shell of the...

  18. 5. DIABLO DAM: DETAIL VIEW OF RELIEF VALVES AT ELEVATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. DIABLO DAM: DETAIL VIEW OF RELIEF VALVES AT ELEVATION 1044. VALVE IN FOREGROUND IS A BUTTERFLY VALVE SIX FEET IN DIAMETER; VALVE TO THE REAR IS A JOHNSON-TYPE NEEDLE VALVE BOTH VALVES WERE MANUFACTURED BY THE PELTON WATER WHEEL COMPANY, 1989. - Skagit Power Development, Diablo Dam, On Skagit River, 6.9 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  19. Improved technique of transapical aortic valve implantation: "the Berlin addition".

    PubMed

    Pasic, Miralem; Dreysse, Stephan; Drews, Thorsten; Buz, Semih; Unbehaun, Axel; Kukucka, Marian; Mladenow, Alexandar; Hetzer, Roland

    2010-06-01

    Transapical aortic valve implantation carries some degree of uncertainty regarding the definitive valve position. We added angiographic visualization of the aortic root while the prosthetic valve is being slowly deployed. It enables easy correction of the position of the valve so that perfect alignment can be achieved of the relationships between the prosthetic valve, aortic valve annulus, aortic cusps, and the coronary arteries.

  20. Pulmonary Valve Replacement With a Trifecta Valve Is Associated With Reduced Transvalvular Gradient

    PubMed Central

    Gulack, Brian C.; Benrashid, Ehsan; Jaquiss, Robert D. B.; Lodge, Andrew J.

    2016-01-01

    Background Outcomes after surgical pulmonary valve replacement (PVR) in patients with congenital cardiac disease are limited by long-term valve deterioration, which may be hastened by turbulent flow. The use of the Trifecta valve (St. Jude Medical, Little Canada, MN) at our institution (Duke University Medical Center, Durham, NC) appears to result in low postimplantation transvalvular gradients. This study was performed to compare the early transvalvular gradient associated with the Trifecta valve with that associated with two other valves commonly used for PVR. Methods We performed a single institution review of patients undergoing PVR with the Perimount valve (Edwards Lifesciences, Irvine, CA), the Biocor valve (St. Jude Medical), or the Trifecta valve between November 1993 and January 2014. Multivariable linear regression modeling was used to determine the adjusted association between valve type and transvalvular gradient as determined by early postoperative echocardiography. Results A total of 186 patients met study criteria; 54 (29%) received a Biocor valve, 87 (47%) received a Perimount valve, and 45 (24%) received a Trifecta valve. There were no baseline differences among the groups, but the peak transvalvular gradient was significantly decreased among patients with the Trifecta valve. After adjustment for age, valve size, patients’ weight, and time to the assessment, as compared with the Trifecta valve, the Biocor valve was associated with a 57% higher peak valve gradient (p < 0.01), whereas the Perimount valve was associated with a 26% higher peak valve gradient (p = 0.04). Conclusions PVR for congenital heart disease with the Trifecta bioprosthetic valve is associated with a reduced early transvalvular gradient. This finding may be associated with reduced valve deterioration over time. PMID:27570156

  1. Cardiac valve replacement in patients with active infective endocarditis.

    PubMed

    Wilson, W R; Geraci, J E

    1983-12-01

    Since the introduction of effective antimicrobial therapy, the leading cause of death in patients with infective endocarditis is no longer sepsis but, rather, congestive heart failure. The mortality is higher in patients with severe heart failure due to infective endocarditis who are treated with medical therapy only than in those who additionally undergo cardiac valve replacement. The mortality is also higher in patients with severe heart failure due to aortic infective endocarditis (40 to 93%) than in those with heart failure due to mitral infective endocarditis (17 to 66%). In patients with and in those without infective endocarditis, surgical intervention can be carried out with comparable mortality not only for aortic valve replacement (9 vs 8.4%) but also overall for valve replacement (10 vs 12%). In patients with class IV heart failure, overall mortality of valve replacement was higher (17%) than in patients with class II (8%) or class III heart failure (7%) and, similarly, comparable with that of matched groups of patients without infective endocarditis. In patients with class IV disability, the mortality of valve replacement was higher in those with active infective endocarditis (19%) than in those with inactive infective endocarditis, possibly due to a higher incidence of sudden onset of severe aortic regurgitation and myocardial abscess. No patient with valve replacement for inactive infective endocarditis developed prosthetic valve endocarditis; a single case of prosthetic valve endocarditis occurred in a patient with active infective endocarditis. In general, early surgical intervention is preferable to procrastination in the management of patients with progressive or severe heart failure due to infective endocarditis. Although, in at least 70% of patients, blood cultures may be rendered sterile within one week of initiation of appropriate antimicrobial therapy, patients with infective endocarditis due to staphylococci, multiply-resistant gram

  2. Aortic valve replacement with the Nicks annulus enlargement procedure 12 years after mitral valve replacement.

    PubMed

    Kazama, S; Kurata, A; Yamashita, Y

    1999-10-01

    An aortic valve replacement was successfully performed employing the Nicks annulus enlargement procedure in a case of aortic valve stenosis with small annulus 12 years after mitral valve replacement. Previous mitral valve replacement does not preclude feasibility of the Nicks procedure.

  3. A retrospective analysis of mitral valve pathology in the setting of bicuspid aortic valves

    PubMed Central

    van Rensburg, Annari; Doubell, Anton

    2017-01-01

    The therapeutic implications of bicuspid aortic valve associations have come under scrutiny in the transcatheter aortic valve implantation era. We evaluate the spectrum of mitral valve disease in patients with bicuspid aortic valves to determine the need for closer echocardiographic scrutiny/follow-up of the mitral valve. A retrospective analysis of echocardiograms done at a referral hospital over five years was conducted in patients with bicuspid aortic valves with special attention to congenital abnormalities of the mitral valve. One hundred and forty patients with a bicuspid aortic valve were included. A congenital mitral valve abnormality was present in eight (5.7%, P = 0.01) with a parachute mitral valve in four (2.8%), an accessory mitral valve leaflet in one (0.7%), mitral valve prolapse in one, a cleft in one and the novel finding of a trileaflet mitral valve in one. Minor abnormalities included an elongated anterior mitral valve leaflet (P < 0.001), the increased incidence of physiological mitral regurgitation (P < 0.001), abnormal papillary muscles (P = 0.002) and an additional chord or tendon in the left ventricle cavity (P = 0.007). Mitral valve abnormalities occur more commonly in patients with bicuspid aortic valves than matched healthy individuals. The study confirms that abnormalities in these patients extend beyond the aorta. These abnormalities did not have a significant functional effect. PMID:28515127

  4. Intro to Valve Guide Reconditioning. Automotive Mechanics. Valves. Instructor's Guide [and] Student Guide.

    ERIC Educational Resources Information Center

    Horner, W.

    This instructional package, one in a series of individualized instructional units on tools and techniques for repairing worn valve guides in motor vehicles, provides practical experience for students in working on cylinder heads. Covered in the module are reaming valve guides that are oversized to match a new oversized valve, reaming valve guides…

  5. Transapical transcatheter valve-in-valve replacement for deteriorated mitral valve bioprosthesis without radio-opaque indicators: the "invisible" mitral valve bioprosthesis.

    PubMed

    Rossi, Marco Luciano; Barbaro, Cristina; Pagnotta, Paolo; Cappai, Antioco; Ornaghi, Diego; Belli, Guido; Presbitero, Patrizia

    2015-02-01

    In view of the high number of bioprosthetic valves implanted during the past 30 years, an increasing number of patients are coming to medical attention because of degenerated bioprostheses. Transcatheter aortic valve-in-valve implantation has been described as a less invasive alternative to re-operation to treat severe structural valve deterioration. As far as degenerated mitral valve bioprostheses are concerned, transcatheter transapical mitral valve-in-valve replacement (TMVR) has been less commonly performed, but may also become a viable alternative to re-do replacement surgery. We describe treatment of a degenerated bioprosthetic mitral valve, characterised by complete absence of any radio-opaque landmarks making the TMVR procedure very challenging. Copyright © 2014 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  6. Design criteria monograph for valve assemblies

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Monograph is limited to valve selection factors for trade-off studies, configuration analyses, actuator selection, and integration of components. Material is organized along lines of valve design sequence.

  7. Flushometer-Valve Toilets Specification and Certification

    EPA Pesticide Factsheets

    Flushometer-valve toilets, also known as flushometer-valve water closets in plumbing standards, are typically found in commercial, institutional, or industrial restrooms, in such places as airports, theaters, stadiums, schools, and office buildings.

  8. Bistable fluidic valve is electrically switched

    NASA Technical Reports Server (NTRS)

    Fiet, O.; Salvinski, R. J.

    1970-01-01

    Bistable control valve is selectively switched by direct application of an electrical field to divert fluid from one output channel to another. Valve is inexpensive, has no moving parts, and operates on fluids which are relatively poor electrical conductors.

  9. Parachute tricuspid valve in an asymptomatic adult

    PubMed Central

    Mohan, Jagdish C.; Shekhar, Chandra; Mohan, Vipul; Kaur, Bimalpreet; Singh, Shivesh Kumar

    2012-01-01

    Parachute tricuspid valve is a rare anomaly usually reported in small children. This report describes transthoracic and trans-oesophageal echocardiographic (TEE) features of parachute mitral valve in an adult patient. PMID:22572436

  10. Geometry of aortic heart valves. [prosthetic design

    NASA Technical Reports Server (NTRS)

    Karara, H. M.

    1975-01-01

    Photogrammetric measurements of the surface topography of the aortic valves obtained from silicon rubber molds of freshly excised human aortic valves are presented. The data are part of an investigation into the design of a new prosthetic valve which will be a central-flow device, like the real valve and unlike previous central-occluding prostheses. Since the maximum stress on the heart valve is induced when the valve is closed and subject to diastolic back-pressure, it was decided to determine the valve geometry during diastole. That is, the molds were formed by pouring the rubber down the excised aortas, causing the valves to close. The molds were made under different pressures (20-120 torr); photogrammetry served as a vehicle for the assessment of the mold topography through the following outputs: digital models, surface profiles, and contour maps.

  11. Abrasion and resistant discharge valve developed

    NASA Technical Reports Server (NTRS)

    Gottwald, W. L.

    1969-01-01

    Discharge valve capable of withstanding intense radiation and high abrasion was developed for use in a fluidized bed reactor. The valve which employs a replaceable Teflon seal, has only one moving part and is designed for remote assembly and disassembly.

  12. SLM Produced Hermetically Sealed Isolation Valve

    NASA Technical Reports Server (NTRS)

    Richard, James

    2014-01-01

    Marshall Space Flight Center (MSFC) has developed a valve concept to replace traditional pyrotechnic-driven isolation valves. This paper will describe the valve design and development process. The valve design uses a stem/wedge to support a disk inside the valve. That disk hermetically seals the pressurized fluids. A release mechanism holds the stem/wedge and a large spring in place. When required to open, a solenoid is energized and pulls the release mechanism allowing the spring to pull the stem/wedge away from the disk. Now the disk is unsupported and the pressure ruptures the disk allowing flow to the outlet of the valve. This paper will provide details of this design, describe the development testing, and show the results from the valve level tests performed. Also, a trade study is presented to show the advantages of this design to a conventional pyrotechnic-based valve.

  13. SLM Produced Hermetically Sealed Isolation Valve

    NASA Technical Reports Server (NTRS)

    Richard, James A.

    2014-01-01

    Marshall Space Flight Center (MSFC) has developed a valve concept to replace traditional pyrotechnic driven isolation valves. This paper will describe the valve design and development process. The valve design uses a stem/wedge to support a disk inside the valve. That disk hermetically seals the pressurized fluids. A release mechanism holds the stem/wedge and a large spring in place. When required to open, a solenoid is energized and pulls the release mechanism allowing the spring to pull the stem/wedge away from the disk. Now the disk is unsupported and the pressure ruptures the disk allowing flow to the outlet of the valve. This paper will provide details of this design, describe the development testing, and show the results from the valve level tests performed. Also, a trade study is presented to show the advantages of this design to a conventional pyrotechnic based valve.

  14. Geometry of aortic heart valves. [prosthetic design

    NASA Technical Reports Server (NTRS)

    Karara, H. M.

    1975-01-01

    Photogrammetric measurements of the surface topography of the aortic valves obtained from silicon rubber molds of freshly excised human aortic valves are presented. The data are part of an investigation into the design of a new prosthetic valve which will be a central-flow device, like the real valve and unlike previous central-occluding prostheses. Since the maximum stress on the heart valve is induced when the valve is closed and subject to diastolic back-pressure, it was decided to determine the valve geometry during diastole. That is, the molds were formed by pouring the rubber down the excised aortas, causing the valves to close. The molds were made under different pressures (20-120 torr); photogrammetry served as a vehicle for the assessment of the mold topography through the following outputs: digital models, surface profiles, and contour maps.

  15. Percutaneous heart valves; past, present and future.

    PubMed

    Rozeik, M M; Wheatley, D J; Gourlay, T

    2014-09-01

    Percutaneous heart valves provide a promising future for patients refused surgery on the grounds of significant technical challenges or high risk for complications. Since the first human intervention more than 10 years ago, over 50 different types of valves have been developed. The CoreValve and Edwards SAPIEN valves have both experienced clinical trials and the latter has gained FDA approval for implantation in patients considered inoperable. Current complications, such as major vascular bleeding and stroke, prevent these valves from being commonly deployed in patients considered operable in conventional surgery. This review focuses on the past and present achievements of these valves and highlights the design considerations required to progress development further. It is envisaged that, with continued improvement in valve design and with increased clinical and engineering experience, percutaneous heart valve replacement may one day be a viable option for lower-risk operable patients. © The Author(s) 2014.

  16. How Is Heart Valve Disease Diagnosed?

    MedlinePlus

    ... the severity of your heart valve disease. Cardiac MRI Cardiac MRI uses a powerful magnet and radio waves to make detailed images of your heart. A cardiac MRI image can confirm information about valve defects or ...

  17. A field operational test on valve-regulated lead-acid absorbent-glass-mat batteries in micro-hybrid electric vehicles. Part II. Results based on multiple regression analysis and tear-down analysis

    NASA Astrophysics Data System (ADS)

    Schaeck, S.; Karspeck, T.; Ott, C.; Weirather-Koestner, D.; Stoermer, A. O.

    2011-03-01

    In the first part of this work [1] a field operational test (FOT) on micro-HEVs (hybrid electric vehicles) and conventional vehicles was introduced. Valve-regulated lead-acid (VRLA) batteries in absorbent glass mat (AGM) technology and flooded batteries were applied. The FOT data were analyzed by kernel density estimation. In this publication multiple regression analysis is applied to the same data. Square regression models without interdependencies are used. Hereby, capacity loss serves as dependent parameter and several battery-related and vehicle-related parameters as independent variables. Battery temperature is found to be the most critical parameter. It is proven that flooded batteries operated in the conventional power system (CPS) degrade faster than VRLA-AGM batteries in the micro-hybrid power system (MHPS). A smaller number of FOT batteries were applied in a vehicle-assigned test design where the test battery is repeatedly mounted in a unique test vehicle. Thus, vehicle category and specific driving profiles can be taken into account in multiple regression. Both parameters have only secondary influence on battery degradation, instead, extended vehicle rest time linked to low mileage performance is more serious. A tear-down analysis was accomplished for selected VRLA-AGM batteries operated in the MHPS. Clear indications are found that pSoC-operation with periodically fully charging the battery (refresh charging) does not result in sulphation of the negative electrode. Instead, the batteries show corrosion of the positive grids and weak adhesion of the positive active mass.

  18. Novel Active Combustion Control Valve

    NASA Technical Reports Server (NTRS)

    Caspermeyer, Matt

    2014-01-01

    This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

  19. Bistable diverter valve in microfluidics

    NASA Astrophysics Data System (ADS)

    Tesař, V.; Bandalusena, H. C. H.

    2011-05-01

    Bistable diverter valves are useful for a large number of no-moving-part flow control applications, and there is a considerable interest in using them also in microfluidics, especially for handling small pressure-driven flows. However, with decreasing Reynolds number, the Coanda effect—on which the flow diverting effect depends—becomes less effective. Authors performed a study, involving flow visualisation, PIV experiments, measurements of the flow rates, and numerical flowfield computations, aimed at clarifying behaviour of a typical fluidic valve at low Reynolds numbers. A typical fluidic valve originally developed for high Re operation was demonstrated to be useful, though with progressively limited efficiency, down to surprisingly low Re values as small as Re = 800. Also observed was a previously not reported discontinuation in the otherwise monotonic decrease in performance at Re between 1,500 and 2,000.

  20. Non-collinear valve actuator

    NASA Technical Reports Server (NTRS)

    Richard, James A. (Inventor)

    2012-01-01

    A non-collinear valve actuator includes a primary actuating system and a return spring system with each applying forces to a linkage system in order to regulate the flow of a quarter-turn valve. The primary actuating system and return spring system are positioned non-collinearly, which simply means the primary actuating system and return spring system are not in line with each other. By positioning the primary actuating system and return spring system in this manner, the primary actuating system can undergo a larger stroke while the return spring system experiences significantly less displacement. This allows the length of the return spring to be reduced due to the minimization of displacement thereby reducing the weight of the return spring system. By allowing the primary actuating system to undergo longer strokes, the weight of the primary actuating system may also be reduced. Accordingly, the weight of the non-collinear valve actuator is reduced.

  1. Propellant isolation shutoff valve program

    NASA Technical Reports Server (NTRS)

    Merritt, F. L.

    1973-01-01

    An analysis and design effort directed to advancing the state-of-the-art of space storable isolation valves for control of flow of the propellants liquid fluorine/hydrazine and Flox/monomethylhydrazine is discussed. Emphasis is on achieving zero liquid leakage and capability of withstanding missions up to 10 years in interplanetary space. Included is a study of all-metal poppet sealing theory, an evaluation of candidate seal configurations, a valve actuator trade-off study and design description of a pneumo-thermally actuated soft metal poppet seal valve. The concepts and analysis leading to the soft seal approach are documented. A theoretical evaluation of seal leakage versus seal loading, related finishes and yield strengths of various materials is provided. Application of a confined soft aluminum seal loaded to 2 to 3 times yield strength is recommended. Use of either an electro-mechanical or pneumatic actuator appears to be feasible for the application.

  2. Active combustion flow modulation valve

    DOEpatents

    Hensel, John Peter; Black, Nathaniel; Thorton, Jimmy Dean; Vipperman, Jeffrey Stuart; Lambeth, David N; Clark, William W

    2013-09-24

    A flow modulation valve has a slidably translating hollow armature with at least one energizable coil wound around and fixably attached to the hollow armature. The energizable coil or coils are influenced by at least one permanent magnet surrounding the hollow armature and supported by an outer casing. Lorentz forces on the energizable coils which are translated to the hollow armature, increase or decrease the flow area to provide flow throttling action. The extent of hollow armature translation depends on the value of current supplied and the direction of translation depends on the direction of current flow. The compact nature of the flow modulation valve combined with the high forces afforded by the actuator design provide a flow modulation valve which is highly responsive to high-rate input control signals.

  3. SLAC Linear Collider waveguide valve

    SciTech Connect

    Dean, N.R.; Fowkes, W.R.; Hoyt, M.W.; Schwarz, H.D.; Tillmann, E.F.

    1987-03-01

    A waveguide valve with a peak rf power handling capability of 70 MW and a reliable vacuum seal was needed for changing the new SLC klystrons. The original SLAC indium seal valve experienced rf breakdown above 35 MW and did not make a reliable vacuum seal. A new design was developed which incorporates the old valve housing but employs a new concept. The indium-knife edge seal has been replaced by an O-ring seal mechanism, which is transported to an rf-free environment during high power operation. The O-ring ''garage door'' seal rf currents are reduced to a manageable level through the use of an rf choke plunger which has a rejection capability in excess of 20 dB. The isolation between the high power rf and the O-ring chamber exceeds 100 dB.

  4. Aortic valve replacement in rheumatoid aortic incompetence.

    PubMed Central

    Devlin, A B; Goldstraw, P; Caves, P K

    1978-01-01

    Rheumatoid aortic valve disease is uncommon. and there are few reports of valve replacement in this condition. Aortic valve replacement and partial pericardiectomy was performed in a patient with acute rheumatoid aortitis and aortic incompetence. Previous reports suggest that any patient with rheumatoid arthritis who develops cardiac symptoms should be carefully assessed for surgically treatable involvement of the pericardium or heart valves. Images PMID:725829

  5. Low pressure piezoelectric valve design

    NASA Astrophysics Data System (ADS)

    Bernard, Y.; Razek, A.

    2012-06-01

    In this paper a ball-type valve actuated by a piezoelectric bender is studied. In this valve different parameters are adjustable allowing different operational aspects. The design procedure is economic and easy to test. Some models are developed to allow an optimization of the structure for special requirements. A prototype has been manufactured to verify the models. The measurement procedure is exposed. This design does not allow high tank pressure but, on this basis, a structure where the pressure locks the ball (reverse structure) is possible.

  6. TWO-WAY FREEZE VALVE

    DOEpatents

    Lantz, K.D.; Clark, P.M.

    1960-01-01

    A valve for closing off the flow of radioactive and corrosive gases and liquids or mixtures thereof and forming a leak tight barrier is described. This valve has no mechanical moving parts which would require design to close tolerances and retention of the usual seal tighthess. Instead, there is provided a cavity in which a fusible metal is contained. Heating and cooling are provided to exercise control over the state of the metal. Baffle chambers are utilized to separate the molten fusible metal from the gas or liquid which is being passed through and return the molten metal to its cavity.

  7. Low-noise nozzle valve

    NASA Astrophysics Data System (ADS)

    Gwin, Hal S.; Aaron, James

    1990-09-01

    A low noise, variable discharage area, valve is constructed having opposed recesses within which a pair of gates are slidably disposed. Each of the gates is provided with upstream edges having a radius thereon, the radius enabling smooth, accelerated, low noise flow therebetween. The gates are further provided with tracks along each side, which in turn slide along splines set in the side walls of the valve. A threaded rod which rotates in a threaded insert in a rear wall of each of the gates, serves to move the gates within their respective recesses.

  8. Fast-acting valve actuator

    DOEpatents

    Cho, Nakwon

    1980-01-01

    A fast-acting valve actuator utilizes a spring driven pneumatically loaded piston to drive a valve gate. Rapid exhaust of pressurized gas from the pneumatically loaded side of the piston facilitates an extremely rapid piston stroke. A flexible selector diaphragm opens and closes an exhaust port in response to pressure differentials created by energizing and de-energizing a solenoid which controls the pneumatic input to the actuator as well as selectively providing a venting action to one side of the selector diaphragm.

  9. Surface spin-valve effect.

    PubMed

    Yanson, I K; Naidyuk, Yu G; Fisun, V V; Konovalenko, A; Balkashin, O P; Triputen, L Yu; Korenivski, V

    2007-04-01

    We report an observation of spin-valve-like hysteresis within a few atomic layers at a ferromagnetic interface. We use phonon spectroscopy of nanometer-sized point contacts as an in situ probe to study the mechanism of the effect. Distinctive energy phonon peaks for contacts with dissimilar nonmagnetic outer electrodes allow localizing the observed spin switching to the top or bottom interfaces for nanometer thin ferromagnetic layers. The mechanism consistent with our data is energetically distinct atomically thin surface spin layers that can form current- or field-driven surface spin-valves within a single ferromagnetic film.

  10. Twenty-two year experience with the omniscience prosthetic heart valve.

    PubMed

    Misawa, Yoshio; Taguchi, Masanobu; Aizawa, Kei; Takahashi, Hideki; Sakano, Yasuhito; Kaminishi, Yuichiro; Oki, Shin-Ichi; Konishi, Hiroaki; Saito, Tsutomu; Kato, Morito

    2004-01-01

    This study was designed to evaluate the long-term clinical results of the Omniscience tilting disc valve. Omniscience valves were implanted in 51 patients (mean age, 50 +/- 10 years); 18 had aortic valve, 24 had mitral valve, and 9 had both aortic and mitral valve replacements. Oral warfarin potassium and dipyridamole were prescribed as our anticoagulant therapy. Preoperatively, 42 patients were in New York Heart Association class III or IV, and 23 of 25 surviving patients were in class I or II after operation. There were 2 (3.9%) early deaths and 23 late deaths (3.5 +/- 0.7% per patient-year). Cardiac related mortality including congestive heart failure, sudden death, and thromboembolism, and hemorrhagic complications were seen in 16 patients. Overall survival at 10, 15, and 20 years was 77 +/- 6%, 62 +/- 7%, and 46 +/- 7%, respectively. Thromboembolic complications were seen in 5 patients, for a rate of 0.8 +/- 0.3% per patient-year; similarly, hemorrhagic complications were also seen in 5 patients. Nonstructural prosthetic valve dysfunction was seen in 4 patients, for a rate of 0.6 +/- 0.3% per patient-year, and sudden death was seen in 2, a rate of 0.3 +/- 0.2% per patient-year. The Omniscience prosthesis demonstrated excellent postoperative clinical status with low rates of valve related complications.

  11. Echocardiographic assessment of prosthetic heart valves.

    PubMed

    Blauwet, Lori A; Miller, Fletcher A

    2014-01-01

    Valvular heart disease is a global health problem. It is estimated that more than 280,000 prosthetic heart valves are implanted worldwide each year. As the world's population is aging, the incidence of prosthetic heart valve implantation and the prevalence of prosthetic heart valves continue to increase. Assessing heart valve prosthesis function remains challenging, as prosthesis malfunction is unpredictable but not uncommon. Transthoracic two-dimensional and Doppler echocardiography is the preferred method for assessing prosthetic valve function. Clinically useful Doppler-derived measures for assessing prosthetic valve hemodynamic profiles have been reported for aortic, mitral, and tricuspid valve prostheses, but echocardiographic data regarding pulmonary valve prostheses remain limited. Complete prosthetic valve evaluation by transthoracic echocardiography (TTE) is sometimes challenging due to acoustic shadowing and artifacts. In these cases, further imaging with transesophageal echocardiography, fluoroscopy and/or gated CT may be warranted, particularly if prosthetic valve dysfunction is suspected. Being able to differentiate pathologic versus functional obstruction of an individual prosthesis is extremely important, as this distinction affects management decisions. Transprosthetic and periprosthetic regurgitation may be difficult to visualize on TTE, so careful review of Doppler-derived data combined with a high index of suspicion is warranted, particularly in symptomatic patients. A baseline TTE soon after valve implantation is indicated in order to "fingerprint" the prosthesis hemodynamic profile. It remains unclear how frequently serial imaging should be performed in order to assess prosthetic valve function, as this issue has not been systematically studied.

  12. 14 CFR 125.133 - Fuel valves.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Fuel valves. 125.133 Section 125.133 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS....133 Fuel valves. Each fuel valve must— (a) Comply with § 125.155; (b) Have positive stops or...

  13. 14 CFR 25.995 - Fuel valves.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel valves. 25.995 Section 25.995... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.995 Fuel valves. In addition to the requirements of § 25.1189 for shutoff means, each fuel valve must— (a) (b) Be supported...

  14. 14 CFR 25.995 - Fuel valves.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel valves. 25.995 Section 25.995... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.995 Fuel valves. In addition to the requirements of § 25.1189 for shutoff means, each fuel valve must— (a) (b) Be supported...

  15. 14 CFR 125.133 - Fuel valves.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Fuel valves. 125.133 Section 125.133 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS....133 Fuel valves. Each fuel valve must— (a) Comply with § 125.155; (b) Have positive stops or...

  16. 14 CFR 25.995 - Fuel valves.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel valves. 25.995 Section 25.995... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.995 Fuel valves. In addition to the requirements of § 25.1189 for shutoff means, each fuel valve must— (a) (b) Be supported...

  17. 14 CFR 125.133 - Fuel valves.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Fuel valves. 125.133 Section 125.133 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS....133 Fuel valves. Each fuel valve must— (a) Comply with § 125.155; (b) Have positive stops or...

  18. 14 CFR 27.995 - Fuel valves.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel valves. 27.995 Section 27.995... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.995 Fuel valves. (a) There must be a positive, quick-acting valve to shut off fuel to each engine individually. (b) The control...

  19. 14 CFR 27.995 - Fuel valves.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel valves. 27.995 Section 27.995... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.995 Fuel valves. (a) There must be a positive, quick-acting valve to shut off fuel to each engine individually. (b) The control...

  20. 14 CFR 29.995 - Fuel valves.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel valves. 29.995 Section 29.995... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.995 Fuel valves. In addition to meeting the requirements of § 29.1189, each fuel valve must— (a) (b) Be supported so that no...

  1. 14 CFR 27.995 - Fuel valves.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel valves. 27.995 Section 27.995... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.995 Fuel valves. (a) There must be a positive, quick-acting valve to shut off fuel to each engine individually. (b) The control...

  2. 14 CFR 29.995 - Fuel valves.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel valves. 29.995 Section 29.995... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.995 Fuel valves. In addition to meeting the requirements of § 29.1189, each fuel valve must— (a) (b) Be supported so that no...

  3. 14 CFR 25.995 - Fuel valves.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel valves. 25.995 Section 25.995... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.995 Fuel valves. In addition to the requirements of § 25.1189 for shutoff means, each fuel valve must— (a) (b) Be supported...

  4. 14 CFR 125.133 - Fuel valves.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Fuel valves. 125.133 Section 125.133 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS....133 Fuel valves. Each fuel valve must— (a) Comply with § 125.155; (b) Have positive stops or...

  5. 14 CFR 29.995 - Fuel valves.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel valves. 29.995 Section 29.995... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.995 Fuel valves. In addition to meeting the requirements of § 29.1189, each fuel valve must— (a) (b) Be supported so that no...

  6. 14 CFR 27.995 - Fuel valves.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel valves. 27.995 Section 27.995... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.995 Fuel valves. (a) There must be a positive, quick-acting valve to shut off fuel to each engine individually. (b) The control...

  7. 14 CFR 29.995 - Fuel valves.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel valves. 29.995 Section 29.995... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.995 Fuel valves. In addition to meeting the requirements of § 29.1189, each fuel valve must— (a) (b) Be supported so that no...

  8. 14 CFR 29.995 - Fuel valves.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel valves. 29.995 Section 29.995... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.995 Fuel valves. In addition to meeting the requirements of § 29.1189, each fuel valve must— (a) (b) Be supported so that no...

  9. 14 CFR 25.995 - Fuel valves.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel valves. 25.995 Section 25.995... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.995 Fuel valves. In addition to the requirements of § 25.1189 for shutoff means, each fuel valve must— (a) (b) Be supported...

  10. 14 CFR 27.995 - Fuel valves.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel valves. 27.995 Section 27.995... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.995 Fuel valves. (a) There must be a positive, quick-acting valve to shut off fuel to each engine individually. (b) The control...

  11. 14 CFR 125.133 - Fuel valves.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fuel valves. 125.133 Section 125.133 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS....133 Fuel valves. Each fuel valve must— (a) Comply with § 125.155; (b) Have positive stops or...

  12. 49 CFR 229.109 - Safety valves.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Safety valves. 229.109 Section 229.109..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Steam Generators § 229.109 Safety valves. Every steam generator shall be equipped with at least two safety valves that have...

  13. 49 CFR 229.109 - Safety valves.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Safety valves. 229.109 Section 229.109..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Steam Generators § 229.109 Safety valves. Every steam generator shall be equipped with at least two safety valves that have...

  14. Aerodynamic Characteristics of Tracheostomy Speaking Valves.

    ERIC Educational Resources Information Center

    Fornataro-Clerici, Lisa; Zajac, David J.

    1993-01-01

    Pressure-flow characteristics were determined for four different one-way valves (Kisner, Montgomery, Olympic, and Passy-Muir) used for speech production in tracheotomy patients. Results indicated significant differences in resistance among the valves, with the resistance of one valve substantially greater than that of the normal upper airways.…

  15. Valve for fuel pin loading system

    DOEpatents

    Christiansen, David W.

    1985-01-01

    A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.

  16. Design criteria monograph for valve components

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Monograph treats valve design technology problems as they were solved in successful development of flightweight operational valves for liquid rocket systems. General practices for cleaning and contamination prevention are summarized. Balance of information is arranged by topic, since detail design requirements apply to most types of valves.

  17. Whitey SCHE Gauge and Root Valves

    SciTech Connect

    VAN KATWIJK, C.

    2000-06-21

    These valves are 1/2 inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They are used as isolation valves for pressure instrumentation in the SCHe System between the helium bottle supply manifolds and safety class helium pressure instrumentation, and in lower pressure SCHe supply line.

  18. Whitey SCHE Gauge and Root Valves

    SciTech Connect

    MISKA, C.R.

    2000-09-03

    These valves are 1/2 inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They are used as isolation valves for pressure instrumentation in the SCHe System between the helium bottle supply manifolds and safety class helium pressure instrumentation, and in lower pressure SCHe supply line.

  19. Whitey SCHE Gauge and Root Valves

    SciTech Connect

    MISKA, C.R.

    2000-09-11

    These valves are 1/2 inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They are used as isolation valves for pressure instrumentation in the SCHa System between the helium bottle supply manifolds and safety class helium pressure instrumentation, and in lower pressure SCHa supply line.

  20. Parachute deformity of the tricuspid valve.

    PubMed Central

    Milo, S; Stark, J; Macartney, F J; Anderson, R H

    1979-01-01

    A parachute deformity of the tricuspid valve occurred in a heart with atrioventricular concordance, double outlet right ventricle, and straddling mitral valve. Although to the best of our knowledge parachute deformity of the tricuspid valve has not previously been reported, in this case its presence was insignificant in relation to the other lesions. Images PMID:505353