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Sample records for blood pump development

  1. Engineering Aspects in Blood Pump Development

    NASA Technical Reports Server (NTRS)

    Golding, Leonard; Veres, Joseph P.

    1997-01-01

    NASA turbomachinery computer codes assisted in the design of the Cleveland Clinic Foundation's centrifugal bladed blood pump. The codes were originally developed for the aerospace industry, but are applicable to the blood pump because of a high degree of synergy with this application. Traditional turbomachinery design criteria were used in the design of the blood pump centrifugal impeller and volute casing. The fluid dynamic performance of the blood pump is meeting the engineering design goals of flow rate and pressure rise.

  2. Blood Pump Development Using Rocket Engine Flow Simulation Technology

    NASA Technical Reports Server (NTRS)

    Kwak, Dochan; Kiris, Cetin

    2001-01-01

    This paper reports the progress made towards developing complete blood flow simulation capability in humans, especially in the presence of artificial devices such as valves and ventricular assist devices. Devices modeling poses unique challenges different from computing the blood flow in natural hearts and arteries. There are many elements needed to quantify the flow in these devices such as flow solvers, geometry modeling including flexible walls, moving boundary procedures and physiological characterization of blood. As a first step, computational technology developed for aerospace applications was extended to the analysis and development of a ventricular assist device (VAD), i.e., a blood pump. The blood flow in a VAD is practically incompressible and Newtonian, and thus an incompressible Navier-Stokes solution procedure can be applied. A primitive variable formulation is used in conjunction with the overset grid approach to handle complex moving geometry. The primary purpose of developing the incompressible flow analysis capability was to quantify the flow in advanced turbopump for space propulsion system. The same procedure has been extended to the development of NASA-DeBakey VAD that is based on an axial blood pump. Due to massive computing requirements, high-end computing is necessary for simulating three-dimensional flow in these pumps. Computational, experimental, and clinical results are presented.

  3. Computational Approach for Developing Blood Pump

    NASA Technical Reports Server (NTRS)

    Kwak, Dochan

    2002-01-01

    This viewgraph presentation provides an overview of the computational approach to developing a ventricular assist device (VAD) which utilizes NASA aerospace technology. The VAD is used as a temporary support to sick ventricles for those who suffer from late stage congestive heart failure (CHF). The need for donor hearts is much greater than their availability, and the VAD is seen as a bridge-to-transplant. The computational issues confronting the design of a more advanced, reliable VAD include the modelling of viscous incompressible flow. A computational approach provides the possibility of quantifying the flow characteristics, which is especially valuable for analyzing compact design with highly sensitive operating conditions. Computational fluid dynamics (CFD) and rocket engine technology has been applied to modify the design of a VAD which enabled human transplantation. The computing requirement for this project is still large, however, and the unsteady analysis of the entire system from natural heart to aorta involves several hundred revolutions of the impeller. Further study is needed to assess the impact of mechanical VADs on the human body

  4. Blood Pump Development Using Rocket Engine Flow Simulation Technology

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin C.; Kwak, Dochan

    2002-01-01

    This viewgraph presentation provides information on the transfer of rocket engine flow simulation technology to work involving the development of blood pumps. Details are offered regarding the design and requirements of mechanical heart assist devices, or VADs (ventricular assist device). There are various computational fluid dynamics issues involved in the visualization of flow in such devices, and these are highlighted and compared to those of rocket turbopumps.

  5. Development of a pump flow estimator for rotary blood pumps to enhance monitoring of ventricular function.

    PubMed

    Granegger, Marcus; Moscato, Francesco; Casas, Fernando; Wieselthaler, Georg; Schima, Heinrich

    2012-08-01

    Estimation of instantaneous flow in rotary blood pumps (RBPs) is important for monitoring the interaction between heart and pump and eventually the ventricular function. Our group has reported an algorithm to derive ventricular contractility based on the maximum time derivative (dQ/dt(max) as a substitute for ventricular dP/dt(max) ) and pulsatility of measured flow signals. However, in RBPs used clinically, flow is estimated with a bandwidth too low to determine dQ/dt(max) in the case of improving heart function. The aim of this study was to develop a flow estimator for a centrifugal pump with bandwidth sufficient to provide noninvasive cardiac diagnostics. The new estimator is based on both static and dynamic properties of the brushless DC motor. An in vitro setup was employed to identify the performance of pump and motor up to 20 Hz. The algorithm was validated using physiological ventricular and arterial pressure waveforms in a mock loop which simulated different contractilities (dP/dt(max) 600 to 2300 mm Hg/s), pump speeds (2 to 4 krpm), and fluid viscosities (2 to 4 mPa·s). The mathematically estimated pump flow data were then compared to the datasets measured in the mock loop for different variable combinations (flow ranging from 2.5 to 7 L/min, pulsatility from 3.5 to 6 L/min, dQ/dt(max) from 15 to 60 L/min/s). Transfer function analysis showed that the developed algorithm could estimate the flow waveform with a bandwidth up to 15 Hz (±2 dB). The mean difference between the estimated and measured average flows was +0.06 ± 0.31 L/min and for the flow pulsatilities -0.27 ± 0.2 L/min. Detection of dQ/dt(max) was possible up to a dP/dt(max) level of 2300 mm Hg/s. In conclusion, a flow estimator with sufficient frequency bandwidth and accuracy to allow determination of changes in ventricular contractility even in the case of improving heart function was developed. PMID:22882439

  6. Development of a portable bridge-to-decision blood pump.

    PubMed

    Yamane, T; Kitamura, K

    2013-01-01

    We are developing an axial-flow pump with a cylindrical-impeller without airfoils. In the mock experiments of HA02 model a pressure of 13.3 kPa was obtained at a rotational speed of 12500 rpm and flow of 5L/min. The obtained pressure with HA02 was almost double than an airfoil-type impeller. The 2D analysis of hydrodynamic bearings for the pump revealed that a section with 3 or more arcs is stable with respect to angular position, and a minimum bearing gap of 100 µm can be attained at a design bearing gap of 150 µm and at a groove depth of 100 µm. PMID:24110291

  7. Rotary blood pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J. (Inventor); Akkerman, James W. (Inventor); Aber, Greg S. (Inventor); Vandamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1993-01-01

    A rotary blood pump is presented. The pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial, and radial clearances of the blades associated with the flow straightener, inducer portion, impeller portion, and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with crosslinked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  8. Rotary Blood Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1996-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  9. Rotary blood pump

    NASA Technical Reports Server (NTRS)

    Benkowski, Robert J. (Inventor); Kiris, Cetin (Inventor); Kwak, Dochan (Inventor); Rosenbaum, Bernard J. (Inventor); Bacak, James W. (Inventor); DeBakey, Michael E. (Inventor)

    1999-01-01

    A blood pump that comprises a pump housing having a blood flow path therethrough, a blood inlet, and a blood outlet; a stator mounted to the pump housing, the stator having a stator field winding for producing a stator magnetic field; a flow straightener located within the pump housing, and comprising a flow straightener hub and at least one flow straightener blade attached to the flow straightener hub; a rotor mounted within the pump housing for rotation in response to the stator magnetic field, the rotor comprising an inducer and an impeller; the inducer being located downstream of the flow straightener, and comprising an inducer hub and at least one inducer blade attached to the inducer hub; the impeller being located downstream of the inducer, and comprising an impeller hub and at least one impeller blade attached to the impeller hub; and preferably also comprising a diffuser downstream of the impeller, the diffuser comprising a diffuser hub and at least one diffuser blade. Blood flow stagnation and clot formation within the pump are minimized by, among other things, providing the inducer hub with a diameter greater than the diameter of the flow straightener hub; by optimizing the axial spacing between the flow straightener hub and the inducer hub, and between the impeller hub and the diffuser hub; by optimizing the inlet angle of the diffuser blades; and by providing fillets or curved transitions between the upstream end of the inducer hub and the shaft mounted therein, and between the impeller hub and the shaft mounted therein.

  10. Development of a Compact Maglev Centrifugal Blood Pump Enclosed in a Titanium Housing

    NASA Astrophysics Data System (ADS)

    Pai, Chi Nan; Shinshi, Tadahiko; Asama, Junichi; Takatani, Setsuo; Shimokohbe, Akira

    A compact centrifugal blood pump consisting of a controlled two-degrees-of-freedom radial magnetic bearing and a brushless DC motor enclosed in a titanium housing has been developed for use as an implantable ventricular assist device. The magnetic bearing also supports axial and angular motions of the impeller via a magnetic coupling. The top housing is made of pure titanium, while the impeller and the stator are coated with pure titanium and Ti-6Al-7Nb, respectively, to improve the biocompatibility of the pump. The combination of pure titanium and titanium alloy was chosen because of the sensitivity of eddy current type displacement sensors through the intervening conducting wall. The dimensions of the pump are 69.0 mm in diameter and 28.5 mm in height. During a pump performance test, axial shifting of the impeller due to hydraulic forces led to variations in the rotational positioning signal, causing loss of control of the rotational speed. This problem was solved by conditioning the rotational positioning signal. With a flow rate of 5 l/min against a head pressure of 100 mmHg, the power consumption and efficiency of the pump were 5.5 W and 20%, respectively. Furthermore, the hemolysis of the blood pump was 43.6% lower when compared to that of a commercially available pump.

  11. Development of miniaturized mass flow meter for an axial flow blood pump.

    PubMed

    Kosaka, Ryo; Maruyama, Osamu; Nishida, Masahiro; Yamane, Takashi

    2007-05-01

    To grasp the conditions of patients and implantable artificial hearts, it is essential to monitor the blood flow rate continuously and noninvasively. However, it is difficult to monitor the pump flow rate in an implantable artificial heart, because the conventional flow meter is too large to implant into the human body, and the flow estimation method is influenced by changes in the blood characteristics and the pump performance. In particular, the power consumption has neither linearity nor uniqueness with respect to the pump flow rate in an axial flow blood pump. In this research, we develop a prototype miniaturized mass flow meter that uses centrifugal force F(c) for discharged patients with an axial flow blood pump. This flow meter measures the F(c) corresponding to the mass flow rate, and implements compensation for static pressure. Because the strain gauges are attached outside of the curved tube, this mass flow meter has no blood contact point, resulting in a compact design. To evaluate the measurement accuracy and the tracking performance, the mass flow meter was compared with the conventional ultrasonic flow meter in a mock-up circulation study. As a result, the measurement error ranging from 0.5 to 5.0 L/min was less than +/-10% with respect to the maximum flow rate. The tracking performance of pulsation flow was approximately equivalent to that of the conventional flow meter. These experiments demonstrated that the prototype miniaturized mass flow meter using F(c) could accurately measure the mass flow rate continuously and noninvasively. PMID:17470214

  12. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    2000-01-01

    An apparatus is provided for a blood pump bearing system within a pump housing to support long-term highspeed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the Ir shaft to support big speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  13. Blood Pump Bearing System

    NASA Technical Reports Server (NTRS)

    Aber, Gregory S. (Inventor)

    1999-01-01

    Methods and apparatus are provided for a blood pump bearing system within a pump housing to support long-term high-speed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the shaft to support high speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  14. Development of magnetic bearing system for a new third-generation blood pump.

    PubMed

    Lee, Jung Joo; Ahn, Chi Bum; Choi, Jaesoon; Park, Jun Woo; Song, Seung-Joon; Sun, Kyung

    2011-11-01

    A magnetic bearing system is a crucial component in a third-generation blood pump, particularly when we consider aspects such as system durability and blood compatibility. Many factors such as efficiency, occupying volume, hemodynamic stability in the flow path, mechanical stability, and stiffness need to be considered for the use of a magnetic bearing system in a third-generation blood pump, and a number of studies have been conducted to develop novel magnetic bearing design for better handling of these factors. In this study, we developed and evaluated a new magnetic bearing system having a motor for a new third-generation blood pump. This magnetic bearing system consists of a magnetic levitation compartment and a brushless direct current (BLDC) motor compartment. The active-control degree of freedom is one; this control is used for controlling the levitation in the axial direction. The levitation in the radial direction has a passive magnetic levitation structure. In order to improve the system efficiency, we separated the magnetic circuit for axial levitation by using a magnetic circuit for motor drive. Each magnetic circuit in the bearing system was designed to have a minimum gap by placing mechanical parts, such as the impeller blades, outside the circuit. A custom-designed noncontact gap sensor was used for minimizing the system volume. We fabricated an experimental prototype of the proposed magnetic bearing system and evaluated its performance by a control system using the Matlab xPC Target system. The noncontact gap sensor was an eddy current gap sensor with an outer diameter of 2.38 mm, thickness of 0.88 mm, and resolution of 5 µm. The BLDC motor compartment was designed to have an outer diameter of 20 mm, length of 28.75 mm, and power of 4.5 W. It exhibited a torque of 8.6 mNm at 5000 rpm. The entire bearing system, including the motor and the sensor, had an outer diameter of 22 mm and a length of 97 mm. The prototype exhibited sufficient levitation

  15. Rapid manufacturing techniques in the development of an axial blood pump impeller.

    PubMed

    Chan, W K; Wong, Y W; Chua, C K; Lee, C W; Feng, C

    2003-01-01

    This paper presents a comparison of manufacturing techniques used in the development of an axial blood pump impeller. In this development process the impeller was designed and its performance was evaluated with the aid of computational fluid dynamics (CFD). Prototypes of those designs where the CFD results show promise were needed in sufficient quantities at a low cost for experimental validation of the CFD results. As the impeller is less than 16 mm in diameter with a maximum blade thickness of about 1.5 mm, innovative manufacturing techniques are explored in this paper to determine the best process for quick fabrication of prototypes that are dimensionally accurate, structurally robust and low in cost. Four rapid prototyping techniques were explored. The completed parts were compared on the basis of manufacturing time, quality and strength of parts obtained, manufacturing cost and also in vitro performances. Based on these studies, it was concluded that selective laser sintering (SLS) is the most appropriate method for the quick production of prototype parts for evaluation of pump performance. PMID:14702984

  16. Development of a compact, sealless, tripod supported, magnetically driven centrifugal blood pump.

    PubMed

    Yuhki, A; Nogawa, M; Takatani, S

    2000-06-01

    In this study, a tripod supported sealless centrifugal blood pump was designed and fabricated for implantable application using a specially designed DC brushless motor. The tripod structure consists of 3 ceramic balls mounted at the bottom surface of the impeller moving in a polyethylene groove incorporated at the bottom pump casing. The follower magnet inside the impeller is coupled to the driver magnet of the motor outside the bottom pump casing, thus allowing the impeller to slide-rotate in the polyethylene groove as the motor turns. The pump driver has a weight of 230 g and a diameter of 60 mm. The acrylic pump housing has a weight of 220 g with the priming volume of 25 ml. At the pump rpm of 1,000 to 2,200, the generated head pressure ranged from 30 to 150 mm Hg with the maximum system efficiency being 12%. When the prototype pump was used in the pulsatile mock loop to assist the ventricle from its apex to the aorta, a strong correlation was obtained between the motor current and bypass flow waveforms. The waveform deformation index (WDI), defined as the ratio of the fundamental to the higher order harmonics of the motor current power spectral density, was computed to possibly detect the suction occurring inside the ventricle due to the prototype centrifugal pump. When the WDI was kept under the value of 0.20 by adjusting the motor rpm, it was successful in suppressing the suction due to the centrifugal pump in the ventricle. The prototype sealless, centrifugal pump together with the control method based on the motor current waveform analysis may offer an intermediate support of the failing left or right ventricle bridging to heart transplantation. PMID:10886073

  17. Mechanical drive for blood pump

    DOEpatents

    Bifano, N.J.; Pouchot, W.D.

    1975-07-29

    This patent relates to a highly efficient blood pump to be used as a replacement for a ventricle of the human heart to restore people disabled by heart disease. The mechanical drive of the present invention is designed to operate in conjunction with a thermoelectric converter power source. The mechanical drive system essentially converts the output of a rotary power into pulsatile motion so that the power demand from the thermoelectric converter remains essentially constant while the blood pump output is pulsed. (auth)

  18. Development of Lorentz force-type self-bearing motor for an alternative axial flow blood pump design.

    PubMed

    Lim, Tau Meng; Zhang, Dongsheng

    2006-05-01

    A Lorentz force-type self-bearing motor was developed to provide delivery of both motoring torque and levitation force for an alternative axial flow blood pump design with an enclosed impeller. The axial flow pumps currently available introduce electromagnetic coupling from the motor's stator to the impeller by means of permanent magnets (PMs) embedded in the tips of the pump's blades. This design has distinct disadvantages, for example, pumping efficiency and electromagnetic coupling transmission are compromised by the constrained or poor geometry of the blades and limited pole width of the PMs, respectively. In this research, a Lorentz force-type self-bearing motor was developed. It is composed of (i) an eight-pole PM hollow-cylindrical rotor assembly supposedly to house and enclose the impeller of an axial flow blood pump, and (ii) a six-pole stator with two sets of copper wire and different winding configurations to provide the motoring torque and levitating force for the rotor assembly. MATLAB's xPC Target interface hardware was used as the rapid prototyping tool for the development of the controller for the self-bearing motor. Experimental results on a free/simply supported rotor assembly validated the design feasibility and control algorithm effectiveness in providing both the motoring torque and levitation force for the rotor. When levitated, a maximum orbital displacement of 0.3 mm corresponding to 1050 rpm of the rotor was measured by two eddy current probes placed in the orthogonal direction. This design has the advantage of eliminating the trade-off between motoring torques, levitating force, and pumping efficiency of previous studies. It also indicated the benefits of enclosed-impeller design as having good dynamic response, linearity, and better reliability. The nonmechanical contact feature between rotating and stationary parts will further reduce hemolysis and thromboembolitic tendencies in a typical blood pump application. PMID:16683951

  19. The valvo-pump. An axial, nonpulsatile blood pump.

    PubMed

    Mitamura, Y; Yozu, R; Tanaka, T; Yamazaki, K

    1991-01-01

    The valvo-pump, an axial, nonpulsatile blood pump implanted at the heart valve position while preserving diseased heart muscle, has several advantages over an artificial heart replacement, including 1) a good anatomic fit to the natural heart, 2) less blood contacting surface, and 3) ease of implantation. The housing for the pump is a tube, 37 mm in diameter (maximum) and 33 mm in length. Within the housing there is an impeller with either 10 vanes (33 mm in diameter) or 5 vanes (22 mm in diameter). The impeller is connected to a samarium-cobalt-rare-earth magnet direct current (DC) brushless motor measuring 23.8 mm in diameter and 30.2 mm in length. Sealing is achieved by means of a magnetic fluid seal. A guiding wheel with 4 vanes is located behind the impeller. The pump was studied on a hydraulic mock circulatory system to evaluate its performance characteristics. A pump flow of 6.9 L/min was obtained at a pump differential pressure of 48 mmHg, and flow of 3.1 L/min was obtained at 58 mmHg. The valvo-pump can be made feasible by developing a small, high-output, power motor and an endurable seal, as well as by optimizing the impeller design. PMID:1751257

  20. Method for Reducing Pumping Damage to Blood

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George Arthur (Inventor); Bacak, James W. (Inventor); Svejkovsky, Robert J. (Inventor); Benkowski, Robert J. (Inventor)

    1997-01-01

    Methods are provided for minimizing damage to blood in a blood pump wherein the blood pump comprises a plurality of pump components that may affect blood damage such as clearance between pump blades and housing, number of impeller blades, rounded or flat blade edges, variations in entrance angles of blades, impeller length, and the like. The process comprises selecting a plurality of pump components believed to affect blood damage such as those listed herein before. Construction variations for each of the plurality of pump components are then selected. The pump components and variations are preferably listed in a matrix for easy visual comparison of test results. Blood is circulated through a pump configuration to test each variation of each pump component. After each test, total blood damage is determined for the blood pump. Preferably each pump component variation is tested at least three times to provide statistical results and check consistency of results. The least hemolytic variation for each pump component is preferably selected as an optimized component. If no statistical difference as to blood damage is produced for a variation of a pump component, then the variation that provides preferred hydrodynamic performance is selected. To compare the variation of pump components such as impeller and stator blade geometries, the preferred embodiment of the invention uses a stereolithography technique for realizing complex shapes within a short time period.

  1. A teaspoon pump for pumping blood with high hydraulic efficiency and low hemolysis potential.

    PubMed

    Dame, D

    1996-06-01

    Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required. PMID:8817965

  2. Characteristics of a nonocclusive pressure-regulated blood roller pump.

    PubMed

    Durandy, Yves

    2013-01-01

    For decades, extracorporeal life support (ECLS) systems have relied on pumps designed for short-term cardiopulmonary bypass. In the past, occlusive roller pumps were the standard. They are being progressively replaced by centrifugal pumps and devices developed specifically for ECLS. However, the ideal pump for long-term bypass is yet to be created. One interesting alternative is the Rhône-Poulenc 06 pump that is a nonocclusive pressure-regulated blood pump developed in France in the 1970s. This pump is composed of a double-stage rotor with three rollers at each level. The raceway tubing is stretched on the roller and pump occlusivity depends on the tension of the chamber on the rotor. The pump is able to deliver physiological blood flow values without generating dangerous negative or positive pressures. The specific design of the chamber allows the pump to generate a pulsatile flow, inducing minimal blood trauma, and to act as a bubble trap, making it inherently safe. This pump has been used for cardiopulmonary bypass, extracorporeal lung support, and more specifically single-lumen single-cannula venovenous membrane oxygenation for neonates, left-heart or right-heart assist, and venovenous bypass during liver transplant. In conclusion, this old-fashion pump is perfectly adapted for any kind of short- or long-term bypass. PMID:23305578

  3. [Hemodynamic analysis of a centrifugal blood pump].

    PubMed

    Wang, Yang; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Li, Qilei; Xu, Liang

    2015-01-01

    This paper built the mathematical model of a centrifugal blood pump, which was designed by ourselves, combined it with that of the human cardiovascular system and simulated the coupling system using Matlab. Then we set up the experiment platform, linked the blood pump to mock human cardiovascular system in case of three-stage heart failure, and measured aortic pressure and flow under different speed. The comparison between experiment results and simulation results not only indicates the coupling model is correct and the blood pump works well, but also shows that with the increase of blood pump speed, the pulsation of aortic pressure and flow will be reduced, this situation will affect the structure and function of blood vessels. PMID:26027287

  4. Numerical simulation of an axial blood pump.

    PubMed

    Chua, Leok Poh; Su, Boyang; Lim, Tau Meng; Zhou, Tongming

    2007-07-01

    The axial blood pump with a magnetically suspended impeller is superior to other artificial blood pumps because of its small size. In this article, the distributions of velocity, path line, pressure, and shear stress in the straightener, the rotor, and the diffuser of the axial blood pump, as well as the gap zone were obtained using the commercial software, Fluent (version 6.2). The main focus was on the flow field of the blood pump. The numerical results showed that the axial blood pump could produce 5.14 L/min of blood at 100 mm Hg through the outlet when rotating at 11,000 rpm. However, there was a leakage flow of 1.06 L/min in the gap between the rotor cylinder and the pump housing, and thus the overall flow rate the impeller could generate was 6.2 L/min. The numerical results showed that 75% of the scalar shear stresses (SSs) were less than 250 Pa, and 10% were higher than 500 Pa within the whole pump. The high SS region appeared around the blade tip where a large variation of velocity direction and magnitude was found, which might be due to the steep angle variation at the blade tip. Because the exposure time of the blood cell at the high SS region within the pump was relatively short, it might not cause serious damage to the blood cells, but the improvement of blade profile should be considered in the future design of the axial pump. PMID:17584481

  5. Fluid dynamics aspects of miniaturized axial-flow blood pump.

    PubMed

    Kang, Can; Huang, Qifeng; Li, Yunxiao

    2014-01-01

    Rotary blood pump (RBP) is a kind of crucial ventricular assist device (VAD) and its advantages have been evidenced and acknowledged in recent years. Among the factors that influence the operation performance and the durability of various rotary blood pumps, medium property and the flow features in pump's flow passages are conceivably significant. The major concern in this paper is the fluid dynamics aspects of such a kind of miniaturized pump. More specifically, the structural features of axial-flow blood pump and corresponding flow features are analyzed in detail. The narrow flow passage between blade tips and pump casing and the rotor-stator interaction (RSI) zone may exert a negative effect on the shear stress distribution in the blood flow. Numerical techniques are briefly introduced in view of their contribution to facilitating the optimal design of blood pump and the visualization of shear stress distribution and multiphase flow analysis. Additionally, with the development of flow measurement techniques, the high-resolution, effective and non-intrusive flow measurement techniques catering to the measurement of the flows inside rotary blood pumps are highly anticipated. PMID:24211957

  6. Inverse design and CFD investigation of blood pump impeller.

    PubMed

    Li, H; Chan, W K

    2000-01-01

    In this paper, a three-dimensional inverse design method using mean swirl specification is applied to the design of centrifugal blood pump impeller blades. CFD investigation of the passage flows is carried out to analyze the flow field and pressure generated across the blade. The results show that the possibility of blood cells' damage may not be increased when the pressure developed is increased. This technique can provide designers valuable insight on the development of efficient blood pump with reduced risk of blood traumatization. PMID:10999368

  7. Development of a disposable maglev centrifugal blood pump intended for one-month support in bridge-to-bridge applications: in vitro and initial in vivo evaluation.

    PubMed

    Someya, Takeshi; Kobayashi, Mariko; Waguri, Satoshi; Ushiyama, Tomohiro; Nagaoka, Eiki; Hijikata, Wataru; Shinshi, Tadahiko; Arai, Hirokuni; Takatani, Setsuo

    2009-09-01

    MedTech Dispo, a disposable maglev centrifugal blood pump with two degrees of freedom magnetic suspension and radial magnetic coupling rotation, has been developed for 1-month extracorporeal circulatory support. As the first stage of a two-stage in vivo evaluation, 2-week evaluation of a prototype MedTech Dispo was conducted. In in vitro study, the pump could produce 5 L/min against 800 mm Hg and the normalized index of hemolysis was 0.0054 +/- 0.0008 g/100 L. In in vivo study, the pump, with its blood-contacting surface coated with biocompatible 2-methacryloyloxyethyl phosphorylcholine polymer, was implanted in seven calves in left heart bypass. Pump performance was stable with a mean flow of 4.49 +/- 0.38 L/min at a mean speed of 2072.1 +/- 64.5 rpm. The maglev control revealed its stability in rotor position during normal activity by the calves. During 2 weeks of operation in two calves which survived the intended study period, no thrombus formation was seen inside the pump and levels of plasma free hemoglobin were maintained below 4 mg/dL. Although further experiments are required, the pump demonstrated the potential for sufficient and reliable performance and biocompatibility in meeting the requirements for cardiopulmonary bypass and 1-week circulatory support. PMID:19775262

  8. Design of a Bearingless Blood Pump

    NASA Technical Reports Server (NTRS)

    Barletta, Natale; Schoeb, Reto

    1996-01-01

    In the field of open heart surgery, centrifugal blood pumps have major advantages over roller pumps. The main drawbacks to centrifugal pumps are however problems with the bearings and with the sealing of the rotor shaft. In this paper we present a concept for a simple, compact and cost effective solution for a blood pump with a totally magnetically suspended impeller. It is based on the new technology of the 'Bearingless Motor' and is therefore called the 'Bearingless Blood Pump.' A single bearingless slice motor is at the same time a motor and a bearing system and is able to stabilize the six degrees of freedom of the pump impeller in a very simple way. Three degrees of freedom are stabilized actively (the rotation and the radial displacement of the motor slice). The axial and the angular displacement are stabilized passively. The pump itself (without the motor-stator and the control electronics) is built very simply. It consists of two parts only: the impeller with the integrated machine rotor and the housing. So the part which gets in contact with blood and has therefore to be disposable, is cheap. Fabricated in quantities, it will cost less than $10 and will therefore be affordable for the use in a heart-lung-machine.

  9. In vivo evaluation of centrifugal blood pump for cardiopulmonary bypass-Spiral Pump.

    PubMed

    da Silva, Cibele; da Silva, Bruno Utiyama; Leme, Juliana; Uebelhart, Beatriz; Dinkhuysen, Jarbas; Biscegli, José F; Andrade, Aron; Zavaglia, Cecília

    2013-11-01

    The Spiral Pump (SP), a centrifugal blood pump for cardiopulmonary bypass (CPB), has been developed at the Dante Pazzanese Institute of Cardiology/Adib Jatene Foundation laboratories, with support from Sintegra Company (Pompeia, Brazil). The SP is a disposable pump with an internal rotor-a conically shaped fuse with double entrance threads. This rotor is supported by two ball bearings, attached to a stainless steel shaft fixed to the housing base. Worm gears provide axial motion to the blood column, and the rotational motion of the conically shaped impeller generates a centrifugal pumping effect, improving pump efficiency without increasing hemolysis. In vitro tests were performed to evaluate the SP's hydrodynamic performance, and in vivo experiments were performed to evaluate hemodynamic impact during usual CPB. A commercially available centrifugal blood pump was used as reference. In vivo experiments were conducted in six male pigs weighing between 60 and 90 kg, placed on CPB for 6 h each. Blood samples were collected just before CPB (T0) and after every hour of CPB (T1-T6) for hemolysis determination and laboratory tests (hematological and biochemical). Values of blood pressure, mean flow, pump rotational speed, and corporeal temperature were recorded. Also, ergonomic conditions were recorded: presence of noise, difficulty in removing air bubbles, trouble in installing the pump in the drive module (console), and difficulties in mounting the CPB circuit. Comparing the laboratory and hemolysis results for the SP with those of the reference pump, we can conclude that there is no significant difference between the two devices. In addition, reports made by medical staff and perfusionists described a close similarity between the two devices. During in vivo experiments, the SP maintained blood flow and pressure at physiological levels, consistent with those applied in cardiac surgery with CPB, without presenting any malfunction. Also, the SP needed lower rotational

  10. Evaluation of four blood pump geometries: the optical tracer technique.

    PubMed

    Rose, M L; Mackay, T G; Martin, W; Wheatley, D J

    2000-01-01

    Artificial blood pump assistance of the failing human heart can allow it to recover. Analysis of blood pump fluid flow is a useful tool for design development and thrombosis minimization. The aim of this study was to investigate fluid flow, particularly ventricular clearance rate and stagnation areas, in four different blood pump geometries and to determine the best design. The blood pumps consisted of a polyurethane ventricle, and combinations of inlet/outlet pipe angles and compression plate shapes. A video camera recorded the motion of fluid labelled with an optical tracer (Methyl Blue histological dye). A novel processing method was developed to produce colour maps of tracer concentration, experimentally calibrated. An overall picture of fluid flow in each pump geometry was generated by considering clearance curves, tracer concentration maps and inflow jet animations. Overall and local mixing coefficients are calculated for each pump. The best geometry featured straight inlet/outlet pipes and a domed compression plate. This optical tracer technique has proven convenient, economical, sensitive to low concentrations of tracer and provides instantaneous pictures of tracer distribution in a ventricle. PMID:10997058

  11. Piezohydraulic Pump Development

    NASA Technical Reports Server (NTRS)

    Lynch, Christopher S.

    2005-01-01

    Reciprocating piston piezohydraulic pumps were developed originally under the Smart Wing Phase II program (Lynch) and later under the CHAP program (CSA, Kinetic Ceramics). These pumps focused on 10 cm scale stack actuators operating below resonance and, more recently, at resonance. A survey of commercially available linear actuators indicates that obtaining power density and specific power greater than electromagnetic linear actuators requires driving the stacks at frequencies greater than 1 KHz at high fields. In the case of 10 cm scale actuators the power supply signal conditioning becomes large and heavy and the soft PZT stack actuators generate a lot of heat due to internal losses. Reciprocation frequencies can be increased and material losses significantly decreased through use of millimeter scale single crystal stack actuators. We are presently targeting the design of pumps that utilize stacks at the 1-10 mm length scale and run at reciprocating frequencies of 20kHz or greater. This offers significant advantages over current approaches including eliminating audible noise and significantly increasing the power density and specific power of the system (including electronics). The pump currently under development will comprise an LC resonant drive of a resonant crystal and head mass operating against a resonant fluid column. Each of these resonant systems are high Q and together should produce a single high Q second order system.

  12. Design optimization of flow channel and performance analysis for a new-type centrifugal blood pump

    NASA Astrophysics Data System (ADS)

    Ji, J. J.; Luo, X. W.; Y Wu, Q.

    2013-12-01

    In this paper, a new-type centrifugal blood pump, whose impeller is suspended inside a pump chamber with hydraulic bearings, is presented. In order to improve the hydraulic performance of the pump, an internal flow simulation is conducted to compare the effects of different geometrical parameters of pump flow passage. Based on the numerical results, the pumps can satisfy the operation parameters and be free of hemolysis. It is noted that for the pump with a column-type supporter at its inlet, the pump head and hydraulic efficiency decreases compared to the pump with a step-type support structure. The performance drop is caused by the disturbed flow upstream impeller inlet. Further, the unfavorable flow features such as reverse flow and low velocity in the pump may increases the possibility of thrombus. It is also confirmed that the casing shape can little influence pump performance. Those results are helpful for design optimization in blood pump development.

  13. Gas-heat-pump development

    NASA Astrophysics Data System (ADS)

    Creswick, F. A.

    Incentives for the development of gas heat pumps are discussed. Technical progress made on several promising technologies was reviewed. The status of development of gas-engine-driven heat pumps, the absorption cycle for the near- and long-term gas heat pump systems, the Stirling engine, the small Rankine-cycle engines, and gas-turbine-driven heat pump systems were briefly reviewed. Progress in the US, Japan, and Europe is noted.

  14. Transformation of vibration signals in rotary blood pumps: the diagnostic potential of pump failure.

    PubMed

    Kawahito, Koji

    2013-09-01

    Although non-destructive and continuous monitoring is indispensable for long-term circulatory support with rotary blood pumps, a practical monitoring system has not yet been developed. The objective of this study was to investigate the possibility of detecting pump failure caused by thrombus formation through the monitoring of vibration signals. The data acquisition equipment included vibration pickups, a charge amplifier, vibration analysis systems, and exclusive hardware. A pivot-bearing centrifugal pump with a mock circuit was investigated for vibration analysis. To simulate the four common areas of thrombus formation, we used a piece of silicon attached to each of the following four locations: the total area of the bottom of the impeller, an eccentric shape on the bottom of the impeller, a circular shape around the shaft top, and an eccentric shape on the top of the impeller. Vibration signals were picked up, and the power spectrum density analysis was performed at pump rotational speeds of 2100, 2400, and 3000 rpm. In this study, pump failure could be detected, and the types of imitation thrombi could be determined. We conclude that vibration detection with a computerized analysis system is a potentially valuable diagnostic tool for long-term circulatory support with rotary blood pumps. PMID:23625149

  15. Effects of muscle pump on rotary blood pumps in dynamic exercise: a computer simulation study.

    PubMed

    Wu, Yi; Lim, Scott

    2008-09-01

    Computer simulation is an important tool to study the interaction between rotary blood pumps (RBPs) and human circulatory system. This interaction is critical for the development of reliable physiological control systems of long-term RBPs. This paper presents a numerical model of the human circulatory system, which innovatively takes the muscle pump into account in dynamic exercise. Simulation results demonstrate that the inclusion of muscle pump will change the response of hemodynamic variables and RBP parameters. These findings also show the necessity to verify the performance of RBPs and their physiological control systems in dynamic exercise with the muscle pump taken into account. By using Matlab Simulink software to simulate real-time circulatory properties, this study provides the bench-top test environment for long-term RBPs and their physiological controller. PMID:18563564

  16. Mechanical axial flow blood pump to support cavopulmonary circulation.

    PubMed

    Throckmorton, A L; Kapadia, J; Madduri, D

    2008-11-01

    We are developing a collapsible, percutaneously inserted, axial flow blood pump to support the cavopulmonary circulation in infants with a failing single ventricle physiology. An initial design of the impeller for this axial flow blood pump was performed using computational fluid dynamics analysis, including pressure-flow characteristics, scalar stress estimations, blood damage indices, and fluid force predictions. A plastic prototype was constructed for hydraulic performance testing, and these experimental results were compared with the numerical predictions. The numerical predictions and experimental findings of the pump performance demonstrated a pressure generation of 2-16 mm Hg for 50-750 ml/min over 5,500-7,500 RPM with deviation found at lower rotational speeds. The axial fluid forces remained below 0.1 N, and the radial fluid forces were determined to be virtually zero due to the centered impeller case. The scalar stress levels remained below 250 Pa for all operating conditions. Blood damage analysis yielded a mean residence time of the released particles, which was found to be less than 0.4 seconds for both flow rates that were examined, and a maximum residence time was determined to be less than 0.8 seconds. We are in the process of designing a cage with hydrodynamically shaped filament blades to act as a diffuser and optimizing the impeller blade shape to reduce the flow vorticity at the pump outlet. This blood pump will improve the clinical treatment of patients with failing Fontan physiology and provide a unique catheter-based therapeutic approach as a bridge to recovery or transplantation. PMID:19089799

  17. Blood Pump Having a Magnetically Suspended Rotor

    NASA Technical Reports Server (NTRS)

    Antaki, James F. (Inventor); Paden, Bradley (Inventor); Burgreen, Gregory (Inventor); Groom, Nelson J. (Inventor)

    2002-01-01

    A blood pump preferably has a magnetically suspended rotor that rotates within a housing. The rotor may rotate about a stator disposed within the housing. Radial magnetic bearings may be defined within the stator and the rotor in order to suspend the rotor. The radial magnetic bearings may be passive magnetic bearings that include permanent magnets disposed within the stator and the rotor or active magnetic bearings. The pump may further include an axial magnetic bearing that may be either a passive or an active magnetic bearing. A motor that drives the rotor may be disposed within the housing in order to more easily dissipate heat generated by the motor. A primary flow path is defined between the rotor and the stator, and a secondary flow path is defined between the stator and the rotor. Preferably, a substantial majority of blood passes through the primary flow path. The secondary flow path is large enough so that it provides adequate flushing of the secondary flow path while being small enough to permit efficient operation of the radial magnet bearings across the secondary flow path.

  18. Blood Pump Having a Magnetically Suspended Rotor

    NASA Technical Reports Server (NTRS)

    Antaki, James F. (Inventor); Paden, Bradley (Inventor); Burgreen, Gregory (Inventor); Groom, Nelson J. (Inventor)

    2001-01-01

    A blood pump preferably has a magnetically suspended rotor that rotates within a housing. The rotor may rotate about a stator disposed within the housing. Radial magnetic bearings may be defined within the stator and the rotor in order to suspend the rotor. The radial magnetic bearings may be passive magnetic bearings that include permanent magnets disposed within the stator and the rotor or active magnetic bearings. The pump may further include an axial magnetic bearing that may be either a passive or an active magnetic bearing. A motor that drives the rotor may be disposed within the housing in order to more easily dissipate heat generated by the motor. A primary flow path is defined between the rotor and the stator, and a secondary flow path is defined between the stator and the rotor. Preferably, a substantial majority of blood passes through the primary flow path. The secondary flow path is large enough so that it provides adequate flushing of the secondary flow path while being small enough to permit efficient operation of the radial magnet bearings across the secondary flow path.

  19. Modified fabrication techniques lead to improved centrifugal blood pump performance.

    PubMed

    Pacella, J J; Goldstein, A H; Magovern, G J; Clark, R F

    1994-01-01

    The authors are developing an implantable centrifugal blood pump for short- and medium-term (1-6 months) left ventricular assist. They hypothesized that the application of result dependent modifications to this pump would lead to overall improved performance in long-term implantation studies. Essential requirements for pump operation, such as durability and resistance to clot formation, have been achieved through specialized fabrication techniques. The antithrombogenic character of the pump has been improved through coating at the cannula-housing interfaces and the baffle seal, and through changing the impeller blade material from polysulfone to pyrolytic carbon. The electronic components of the pump have been sealed for implantable use through specialized processes of dipping and potting, and the surfaces of the internal pump components have been treated to increase durability. The device has demonstrated efficacy in five chronic sheep implantation studies of 14, 10, 28, 35, and 154 day duration. Post mortem findings from the 14 day experiment showed stable fibrin entangled around the impeller shaft and blades. After pump modification, autopsy findings of the 10 day study showed no evidence of clot. Additionally, the results of the 28 day experiment showed only a small (2.0 mm) ring of fibrin at the shaft-seal interface. In the 35 and 154 day experiments, redesign of the stators have resulted in improved motor corrosion resistance. The 35 day study showed a small, 0.5 mm wide fibrin deposit at the lip seal, but no motor failure. In the 154 day experiment, the motor failed because of stator fluid corrosion, while the explanted pump was devoid of thrombus. Based on these findings, the authors believe that these pump refinements have contributed significantly to improvements in durability and resistance to clot formation. PMID:8555619

  20. High efficiency magnetic bearing for a rotary blood pump.

    PubMed

    Chen, H M; Smith, W A; Walton, J F

    1998-01-01

    Mohawk Innovative Technology, Inc. (MiTi; Albany, NY) and the Cleveland Clinic Foundation (Cleveland, OH) have been engaged in a joint project to develop a new, high efficiency magnetic bearing for use in a rotary blood pump. Such a bearing would have some advantages with respect to permitting large, low shear clearances and avoiding crevice-like pivot interfaces and surface wear related issues. While magnetically suspended blood pumps have been demonstrated, other prototypes reported in the literature consume 5-15 W of power to energize the bearing. The MiTi bearing has been prototyped and tested. The design is a hybrid configuration, radially passive and axially active. The rotor-and-bearing system has been run in air and in blood analog solution, in all orientations. Measurements show a bearing power consumption below 0.5 W. Vibration peaked at 0.2 g in blood analog solution; frequency analysis indicated that this was primarily related to motor design features. Measured displacements from the equilibrium position were less than 0.005 cm. Based on this highly successful bearing prototype, an integrated pump/bearing system is now being developed. PMID:9804532

  1. Physiologic control algorithms for rotary blood pumps using pressure sensor input.

    PubMed

    Bullister, Edward; Reich, Sanford; Sluetz, James

    2002-11-01

    Hierarchical algorithms have been developed for enhanced physiologic control and monitoring of blood pumps using pressure inputs. Pressures were measured at pump inlet and outlet using APEX pressure sensors (APSs). The APS is a patented, long-term implantable, flow-through blood pressure sensor and designed to control implantable heart pumps. The algorithms have been tested using a Donavan circulatory mock-loop setup, a generic rotary pump, and LabVIEW software. The hierarchical algorithms control pump speed using pump inlet pressure as a primary independent variable and pump outlet pressure as a secondary dependent variable. Hierarchical control algorithms based on feedback from pressure sensors can control the speed of the pump to stably maintain ventricular filling pressures and arterial pressures. Monitoring algorithms based on pressure inputs are able to approximate flow rate and hydraulic power for the pump and the left ventricle. PMID:12406146

  2. A multiple disk centrifugal pump as a blood flow device.

    PubMed

    Miller, G E; Etter, B D; Dorsi, J M

    1990-02-01

    A multiple disk, shear force, valveless centrifugal pump was studied to determine its suitability as a blood flow device. A pulsatile version of the Tesla viscous flow turbine was designed by modifying the original steady flow pump concept to produce physiological pressures and flows with the aid of controlling circuitry. Pressures and flows from this pump were compared to a Harvard Apparatus pulsatile piston pump. Both pumps were connected to an artificial circulatory system. Frequency and systolic duration were varied over a range of physiological conditions for both pumps. The results indicated that the Tesla pump, operating in a pulsatile mode, is capable of producing physiologic pressures and flows similar to the Harvard pump and other pulsatile blood pumps. PMID:2312140

  3. Application of computational fluid dynamics techniques to blood pumps.

    PubMed

    Sukumar, R; Athavale, M M; Makhijani, V B; Przekwas, A J

    1996-06-01

    Present-day computational fluid dynamics (CFD) techniques can be used to analyze the behavior of fluid flow in a variety of pumps. CFD can be a powerful tool during the design stage for rapid virtual prototyping of different designs, analyzing performance parameters, and making design improvements. Computational flow solutions provide information such as the location and size of stagnation zones and the local shear rate. These parameters can be correlated to the extent of hemolysis and thrombus formation and are critical to the success of a blood pump. CFD-ACE, an advanced commercial CFD code developed by CFD Research Corporation, has been applied to fluid flows in rotary machines, such as axial flow pumps and inducers. Preprocessing and postprocessing tools for efficient grid generation and advanced graphical flow visualization are integrated seamlessly with CFD-ACE. The code has structured multiblock grid capability, non-Newtonian fluid treatment, a variety of turbulence models, and an Eulerian-Langrangian particle tracking model. CFD-ACE has been used successfully to study the flow characteristics in an axial flow blood pump. An unstructured flow solver that greatly automates the process of grid generation and speeds up the flow simulation is under development. PMID:8817950

  4. Assessment of aortic valve opening during rotary blood pump support using pump signals.

    PubMed

    Granegger, Marcus; Schima, Heinrich; Zimpfer, Daniel; Moscato, Francesco

    2014-04-01

    During left ventricular support by rotary blood pumps (RBPs), the biomechanics of the aortic valve (AV) are altered, potentially leading to adverse events like commissural fusion, valve insufficiency, or thrombus formation. To avoid these events, assessment of AV opening and consequent adaptation of pump speed seem important. Additionally, this information provides insight into the heart-pump interaction. The aim of this study was to develop a method to assess AV opening from the pump flow signal. Data from a numerical model of the cardiovascular system and animal experiments with an RBP were employed to detect the AV opening from the flow waveform under different hemodynamic conditions. Three features calculated from the pump flow waveform were used to classify the state of the AV: skewness, kurtosis, and crest factor. Three different classification algorithms were applied to determine the state of the AV based on these features. In the model data, the best classifier resulted in a percentage of correctly identified beats with a closed AV (specificity) of 99.9%. The percentage of correctly identified beats with an open AV (sensitivity) was 99.5%. In the animal experiments, specificity was 86.8% and sensitivity reached 96.5%. In conclusion, a method to detect AV opening independently from preload, afterload, heart rate, contractility, and degree of support was developed. This algorithm makes the evaluation of the state of the AV possible from pump data only, allowing pump speed adjustment for a frequent opening of the AV and providing information about the interaction of the native heart with the RBP. PMID:24102321

  5. Implantable axialflow blood pump for left ventricular support.

    PubMed

    Untaroiu, Alexandrina; Wood, Houston G; Allaire, Paul E

    2008-01-01

    Artificial blood pumps, either ventricular assist devices (VADs) or total artificial hearts, are currently employed for bridge to recovery, bridge to transplant, and destination therapy situations. The clinical effectiveness of VADs has been demonstrated; however, all of the currently available pumps have a limited life because of either the damage they cause to blood or their limited mechanical design life. A magnetically suspended rotary blood pump offers the potential to meet the requirements of both extending design life and causing negligible blood damage due to superior hemodynamics. Therefore, over the last few years, efforts of an interdisciplinary research team at University of Virginia have been concentrated on the design and development of a fully implantable axial flow VAD with a magnetically levitated impeller (LEV-VAD). This paper details the second generation developmental prototype (LEV-VAD2 design configuration) and includes a complete CFD analysis of device performance. Based on encouraging results of the first design stage, including a good agreement between the CFD performance estimations and the experimental measurements, a second design phase was initiated in an attempt to enhance device flow performance and suspension system capabilities. Using iterative design optimization stages, the design of the impeller and the geometry of the stationary and rotating blades have been reevaluated. A thorough CFD analysis allowed for optimization of the blood flow path such that an optimal trade-off among the hydraulic performance, specific requirements of a blood pump, and manufacturing requirements has been achieved. Per the CFD results, the LEV-VAD2 produces 6 lpm and 100 mmHg at a rotational speed of 7,000 rpm. The pressure-flow performance predictions indicate the LEV-VAD2's ability to deliver adequate flow over physiologic pressures for rotational speeds varying from 5,000 to 8,000 rpm. The blood damage numerical predictions also demonstrate

  6. Particle image velocimetry experimental and computational investigation of a blood pump

    NASA Astrophysics Data System (ADS)

    Yang, Xiaochen; Gui, Xingmin; Huang, Hui; Shen, Yongbin; Yu, Ziwen; Zhang, Yan

    2012-06-01

    Blood pumps have been adopted to treat heart failure over the past decades. A novel blood pump adopting the rotor with splitter blades and tandem cascade stator was developed recently. A particle image velocimetry (PIV) experiment was carried out to verify the design of the blood pump based on computational fluid dynamics (CFD) and further analyze the flow properties in the rotor and stator. The original sized pump model with an acrylic housing and an experiment loop were constructed to perform the optical measurement. The PIV testing was carried out at the rotational speed of 6952±50 r/min with the flow rate of 3.1 l/min and at 8186±50 r/min with 3.5 l/min, respectively. The velocity and the Reynolds shear stress distributions were investigated by PIV and CFD, and the comparisons between them will be helpful for the future blood pump design.

  7. Recent progress in developing durable and permanent impeller pump.

    PubMed

    Qian, K X; Zeng, P; Ru, W M; Yuan, H Y

    2002-04-01

    Since 1980s, the author's impeller pump has successively achieved the device implantability, blood compatibility and flow pulsatility. In order to realize a performance durability, the author has concentrated in past years on solving the bearing problems of the impeller pump. Recent progress has been obtained in developing durable and permanent impeller blood pumps. At first, a durable impeller pump with rolling bearing and purge system has been developed, in which the wear-less rollers made of super-high-molecular weight polythene make the pump to work for years without mechanical wear; and the purge system enables the bearing to work in saline and heparin, and no thrombus therefore could be formed. Secondly, a durable centrifugal pump with rolling bearing and axially reciprocating impeller has been developed, the axial reciprocation of rotating impeller makes the fresh blood in and out of the bearing and to wash the rollers once a circle; in such way, no thrombus could be formed and no fluid infusion is necessary, which may bring inconvenience and discomfort to the receptors. Finally, a permanent maglev impeller pump has been developed, its rotor is suspended and floating in the blood under the action of permanent magnetic force and nonmagnetic forces, without need for position measurement and feed-back control. In conclusion, an implantable, pulsatile, and blood compatible impeller pump with durability may have more extensive applications than ever before and could replace the donor heart for transplantation in the future. PMID:12099505

  8. Concept designs of nonrotating-type centrifugal blood pump and basic study on output characteristics of the oscillating disk-type centrifugal pump.

    PubMed

    Kabei, N; Tuichiya, K; Sakurai, Y

    1994-09-01

    When designing a turbo-type blood pump as an artificial heart, the gap between a rotating shaft and a pump housing should be perfectly sealed to prevent any leakage or contamination through a seal. In addition, blood coagulation in a blood chamber must be avoided. To overcome these problems, we proposed five different nonrotating-type turbo pumps: a caudal-fin-type axial-flow pump, a caudal-fin-type centrifugal pump, a nutating-column-type centrifugal pump, a nutating-collapsible-tube-type centrifugal pump, and an oscillating-disk-type centrifugal pump. We selected and developed the oscillating-disk-type centrifugal pump that consists of a disk, a driving rod, a seal, an oscillation mechanism, and a pump housing. The disk is mounted on the end of the rod, which is connected to a high-speed DC motor through an oscillation mechanism. The rod and the disk do not rotate, but they oscillate in the pump housing. This movement of the disk generates forward fluid flow around the axis (i.e., the rotational fluid flow). Centrifugal force due to fluid rotation supports the pressure difference between the outlet and the inlet. The diameter of the disk is 39 mm, the maximum inner diameter of the pump housing is 40 mm, and the volume of the blood chamber for 25 degrees' oscillation is 16.9 ml. The performance of the pump was tested in a mock circulatory system.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7998882

  9. Computational Fluid Dynamics-Based Design Optimization Method for Archimedes Screw Blood Pumps.

    PubMed

    Yu, Hai; Janiga, Gábor; Thévenin, Dominique

    2016-04-01

    An optimization method suitable for improving the performance of Archimedes screw axial rotary blood pumps is described in the present article. In order to achieve a more robust design and to save computational resources, this method combines the advantages of the established pump design theory with modern computer-aided, computational fluid dynamics (CFD)-based design optimization (CFD-O) relying on evolutionary algorithms and computational fluid dynamics. The main purposes of this project are to: (i) integrate pump design theory within the already existing CFD-based optimization; (ii) demonstrate that the resulting procedure is suitable for optimizing an Archimedes screw blood pump in terms of efficiency. Results obtained in this study demonstrate that the developed tool is able to meet both objectives. Finally, the resulting level of hemolysis can be numerically assessed for the optimal design, as hemolysis is an issue of overwhelming importance for blood pumps. PMID:26526039

  10. Inlet and outlet devices for rotary blood pumps.

    PubMed

    Song, Xinwei; Wood, Houston G; Allaire, Paul E; Antaki, James F; Olsen, Don B

    2004-10-01

    The purposes of inlet and outlet devices for rotary blood pumps, including inducers and diffusers for axial pumps, inlet and exit volutes for centrifugal pumps, and inlet and outlet cannulas, are to guide the blood into the impeller, where the blood is accelerated, and to convert the high kinetic energy into pressure after the impeller discharge, respectively. The designs of the inlet and outlet devices have an important bearing on the pump performance. Their designs are highly dependent on computational fluid dynamics (CFD) analysis, guided by intuition and experience. For inlet devices, the design objectives are to eliminate separated flow, to minimize recirculation, and to equalize the radial components of velocity. For outlet devices, the design goals are to reduce speed, to minimize energy loss, and to avoid flow separation and whirl. CFD analyses indicate the velocity field and pressure distribution. Geometrical optimization of these components has been implemented in order to improve the flow pattern. PMID:15384997

  11. Rotary blood pump control using integrated inlet pressure sensor.

    PubMed

    Cysyk, Joshua; Jhun, Choon-Sik; Newswanger, Ray; Weiss, William; Rosenberg, Gerson

    2011-01-01

    Due to improved reliability and reduced risk of thromboembolic events, continuous flow left ventricular assist devices are being used more commonly as a long term treatment for end-stage heart failure. As more and more patients with these devices are leaving the hospital, a reliable control system is needed that can adjust pump support in response to changes in physiologic demand. An inlet pressure sensor has been developed that can be integrated with existing assist devices. A control system has been designed to adjust pump speed based on peak-to-peak changes in inlet pressure. The inlet pressure sensor and control system have been tested with the HeartMate II axial flow blood pump using a mock circulatory loop and an active left ventricle model. The closed loop control system increased total systemic flow and reduced ventricular load following a change in preload as compared to fixed speed control. The increase in systemic flow occurred under all operating conditions, and maximum unloading occurred in the case of reduced ventricular contractility. PMID:22254326

  12. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  13. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  14. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  15. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  16. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  17. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  18. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  19. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  20. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  1. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  2. An original versatile nonocclusive pressure-regulated blood roller pump for extracorporeal perfusion.

    PubMed

    Durandy, Yves; Wang, Shigang; Ündar, Akif

    2014-06-01

    Currently, only a small number of centrifugal pumps are being used for hemodynamic and/or respiratory support, but all of them have limitations. This article aims to present the Rhône-Poulenc 06 nonocclusive pressure-regulated blood pump. This pump was developed in France in the 1970s and used for decades in perfusion for cardiopulmonary bypass procedures, cardiac or lung assist as well as venovenous bypass during liver transplant. The intrinsic properties of this pump allowed us to describe a new technique for extracorporeal lung support in the 1980s, using a single cannula tidal flow venovenous bypass. This pump compared favorably with conventional pumps in terms of flow and pressure, hemolysis, pulsatility, safety, and cost-effectiveness. We believe that this simple pump could be an alternative to more sophisticated and expensive devices. PMID:24125196

  3. Preliminary validation of a new magnetic wireless blood pump.

    PubMed

    Kim, Sung Hoon; Ishiyama, Kazushi; Hashi, Shuichiro; Shiraishi, Yasuyuki; Hayatsu, Yukihiro; Akiyama, Masatoshi; Saiki, Yoshikatsu; Yambe, Tomoyuki

    2013-10-01

    In general, a blood pump must be small, have a simple configuration, and have sufficient hydrodynamic performance. Herein, we introduce new mechanisms for a wireless blood pump that is small and simple and provides wireless and battery-free operation. To achieve wireless and battery-free operation, we implement magnetic torque and force control methods that use two external drivers: an external coil and a permanent magnet with a DC-motor, respectively. Power harvesting can be used to drive an electronic circuit for wireless monitoring (the observation of the pump conditions and temperature) without the use of an internal battery. The power harvesting will be used as a power source to drive other electronic devices, such as various biosensors with their driving circuits. To have both a compact size and sufficient pumping capability, the fully magnetic impeller has five stages and each stage includes four backward-curved blades. The pump has total and inner volumes of 20 and 9.8 cc, respectively, and weighs 52 g. The pump produces a flow rate of approximately 8 L/min at 80 mm Hg and the power generator produces 0.3 W of electrical power at 120 Ω. The pump also produces a minimum flow rate of 1.5 L/min and a pressure of 30 mm Hg for circulation at a maximum distance of 7.5 cm. PMID:23634711

  4. Experimental and computational studies of the relative flow field in a centrifugal blood pump.

    PubMed

    Ng, B T; Chan, W K; Yu, S C; Li, H D

    2000-01-01

    The relative flow field within the impeller passage of a centrifugal blood pump had been examined using flow visualization technique and computational fluid dynamics. It was found that for a seven-blade radial impeller design, the required flow rate and static pressure rise across the pump could be achieved but the flow field within the blades was highly undesirable. Two vortices were observed near the suction side and these could lead to thrombus formation. Preliminary results presented in this article are part of our overall effort to minimize undesirable flow patterns such flow separation and high shear stress regions within the centrifugal blood pump. This will facilitate the future progress in developing a long-term clinically effective blood pump. PMID:10999375

  5. An implantable centrifugal blood pump with a recirculating purge system (Cool-Seal system).

    PubMed

    Yamazaki, K; Litwak, P; Tagusari, O; Mori, T; Kono, K; Kameneva, M; Watach, M; Gordon, L; Miyagishima, M; Tomioka, J; Umezu, M; Outa, E; Antaki, J F; Kormos, R L; Koyanagi, H; Griffith, B P

    1998-06-01

    A compact centrifugal blood pump has been developed as an implantable left ventricular assist system. The impeller diameter is 40 mm, and pump dimensions are 55 x 64 mm. This first prototype, fabricated from titanium alloy, resulted in a pump weight of 400 g including a brushless DC motor. The weight of a second prototype pump was reduced to 280 g. The entire blood contacting surface is coated with diamond like carbon (DLC) to improve blood compatibility. Flow rates of over 7 L/min against 100 mm Hg pressure at 2,500 rpm with 9 W total power consumption have been measured. A newly designed mechanical seal with a recirculating purge system (Cool-Seal) is used for the shaft seal. In this seal system, the seal temperature is kept under 40 degrees C to prevent heat denaturation of blood proteins. Purge fluid also cools the pump motor coil and journal bearing. Purge fluid is continuously purified and sterilized by an ultrafiltration unit which is incorporated in the paracorporeal drive console. In vitro experiments with bovine blood demonstrated an acceptably low hemolysis rate (normalized index of hemolysis = 0.005 +/- 0.002 g/100 L). In vivo experiments are currently ongoing using calves. Via left thoracotomy, left ventricular (LV) apex descending aorta bypass was performed utilizing an expanded polytetrafluoroethylene (ePTFE) vascular graft with the pump placed in the left thoracic cavity. In 2 in vivo experiments, the pump flow rate was maintained at 5-9 L/min, and pump power consumption remained stable at 9-10 W. All plasma free Hb levels were measured at less than 15 mg/dl. The seal system has demonstrated good seal capability with negligible purge fluid consumption (<0.5 ml/day). In both calves, the pumps demonstrated trouble free continuous function over 6 month (200 days and 222 days). PMID:9650667

  6. Performance of enlarged blood pump models with five different impellers.

    PubMed

    Chua, L P; Yu, S C; Leo, H L

    2000-01-01

    In earlier studies, a 5:1 enlarged pump model of the Kyoto-NTN Magnetically Suspended Centrifugal Blood Pump had been constructed and the flow characteristics investigated. Although the results obtained were satisfactory, the medium used was air. A 5:1 enlarged pump model using water as the medium thus was designed and constructed. Five different impeller blade profile designs were used in the present study. By varying (1) the blade profile design: forward, radial, and backward, (2) the number of blades used, and (3) the rotating speed, the flow characteristics of the pump were investigated. It was found that the impeller with the higher number of blades, used in the forward and straight blade profiles, have the best performance. PMID:10999376

  7. Numerical analysis of blood flow in the clearance regions of a continuous flow artificial heart pump.

    PubMed

    Anderson, J; Wood, H G; Allaire, P E; Olsen, D B

    2000-06-01

    The CFVAD3 is the third prototype of a continuous flow ventricular assist device being developed for implantation in humans. The pump consists of a fully shrouded 4-blade impeller supported by magnetic bearings. On either side of this suspended rotating impeller is a small clearance region through which the blood flows. The spacing and geometry of these clearance regions are very important to the successful operation of this blood pump. Computational fluid dynamics (CFD) solutions for this flow were obtained using TascFlow, a software package available from AEA Technology, U.K. Flow in these clearance regions was studied parametrically by varying the size of the clearance, the blood flow rate into the pump, and the rotational speed of the pump. The numerical solutions yield the direction and magnitude of the flow and the dynamic pressure. Experimentally measured pump flow rates are compared to the numerical study. The results of the study provide guidance for improving pump efficiency. It is determined that current clearances can be significantly reduced to improve pump efficiency without negative impacts. PMID:10886072

  8. Effect of parameter variations on the hemodynamic response under rotary blood pump assistance.

    PubMed

    Lim, Einly; Dokos, Socrates; Salamonsen, Robert F; Rosenfeldt, Franklin L; Ayre, Peter J; Lovell, Nigel H

    2012-05-01

    Numerical models, able to simulate the response of the human cardiovascular system (CVS) in the presence of an implantable rotary blood pump (IRBP), have been widely used as a predictive tool to investigate the interaction between the CVS and the IRBP under various operating conditions. The present study investigates the effect of alterations in the model parameter values, that is, cardiac contractility, systemic vascular resistance, and total blood volume on the efficiency of rotary pump assistance, using an optimized dynamic heart-pump interaction model previously developed in our laboratory based on animal experimental measurements obtained from five canines. The effect of mean pump speed and the circulatory perturbations on left and right ventricular pressure volume loops, mean aortic pressure, mean cardiac output, pump assistance ratio, and pump flow pulsatility from both the greyhound experiments and model simulations are demonstrated. Furthermore, the applicability of some of the previously proposed control parameters, that is, pulsatility index (PI), gradient of PI with respect to pump speed, pump differential pressure, and aortic pressure are discussed based on our observations from experimental and simulation results. It was found that previously proposed control strategies were not able to perform well under highly varying circulatory conditions. Among these, control algorithms which rely on the left ventricular filling pressure appear to be the most robust as they emulate the Frank-Starling mechanism of the heart. PMID:22489771

  9. Feasibility of the optical imaging of thrombus formation in a rotary blood pump by near-infrared light.

    PubMed

    Sakota, Daisuke; Murashige, Tomotaka; Kosaka, Ryo; Nishida, Masahiro; Maruyama, Osamu

    2014-09-01

    Blood coagulation is one of the primary concerns when using mechanical circulatory support devices such as blood pumps. Noninvasive detection and imaging of thrombus formation is useful not only for the development of more hemocompatible devices but also for the management of blood coagulation to avoid risk of infarction. The objective of this study is to investigate the use of near-infrared light for imaging of thrombus formation in a rotary blood pump. The optical properties of a thrombus at wavelengths ranging from 600 to 750 nm were analyzed using a hyperspectral imaging (HSI) system. A specially designed hydrodynamically levitated centrifugal blood pump with a visible bottom area was used. In vitro antithrombogenic testing was conducted five times with the pump using bovine whole blood in which the activated blood clotting time was adjusted to 200 s prior to the experiment. Two halogen lights were used for the light sources. The forward scattering through the pump and backward scattering on the pump bottom area were imaged using the HSI system. HSI showed an increase in forward scattering at wavelengths ranging from 670 to 750 nm in the location of thrombus formation. The time at which the thrombus began to form in the impeller rotating at 2780 rpm could be detected. The spectral difference between the whole blood and the thrombus was utilized to image thrombus formation. The results indicate the feasibility of dynamically detecting and imaging thrombus formation in a rotary blood pump. PMID:25234757

  10. Interaction of an idealized cavopulmonary circulation with mechanical circulatory assist using an intravascular rotary blood pump.

    PubMed

    Bhavsar, Sonya S; Moskowitz, William B; Throckmorton, Amy L

    2010-10-01

    This study evaluated the performance of an intravascular, percutaneously-inserted, axial flow blood pump in an idealized total cavopulmonary connection (TCPC) model of a Fontan physiology. This blood pump, intended for placement in the inferior vena cava (IVC), is designed to augment pressure and blood flow from the IVC to the pulmonary circulation. Three different computational models were examined: (i) an idealized TCPC without a pump; (ii) an idealized TCPC with an impeller pump; and (iii) an idealized TCPC with an impeller and diffuser pump. Computational fluid dynamics analyses of these models were performed to assess the hydraulic performance of each model under varying physiologic conditions. Pressure-flow characteristics, fluid streamlines, energy augmentation calculations, and blood damage analyses were evaluated. Numerical predictions indicate that the pump with an impeller and diffuser blade set produces pressure generations of 1 to 16 mm Hg for rotational speeds of 2000 to 6000 rpm and flow rates of 1 to 4 L/min. In contrast, for the same flow range, the model with the impeller only in the IVC demonstrated pressure generations of 1 to 9 mm Hg at rotational speeds of 10,000 to 12,000 rpm. Influence of blood viscosity was found to be insignificant at low rotational speeds with minimal performance deviation at higher rotational speeds. Results from the blood damage index analyses indicate a low probability for damage with maximum damage index levels less than 1% and maximum fluid residence times below 0.6 s. The numerical predictions further indicated successful energy augmentation of the TCPC with a pump in the IVC. These results support the continued design and development of this cavopulmonary assist device. PMID:20964699

  11. Survey of blood pump diaphragm damage in the NIPRO-ventricular assist device.

    PubMed

    Kashiwa, Koichi; Nishimura, Takashi; Nakahata, Aoi; Momose, Naoki; Umeda, Chinori; Kubo, Hitoshi; Tamai, Hisayoshi; Kinugawa, Koichiro; Adachi, Hideo; Yamaguchi, Atsushi; Yambe, Tomoyuki; Katohgi, Toshiyuki; Kyo, Shunei; Ono, Minoru

    2012-12-01

    We surveyed the incidence of blood pump diaphragm damage (rupture or crack) in the NIPRO-ventricular assist device (VAD). In the cases in which rupture or suspected blood pump crack was detected, we disassembled the pumps to visually check the condition of the diaphragm after replacement or use. Of 366 blood pumps surveyed, diaphragm damage was observed in 2.7 %. The duration of use of the blood pumps with diaphragm damage was significantly longer than that of pumps without damage. The incidence of diaphragm damage increased with longer duration of use. On the basis of these findings, blood pump diaphragm damage in the NIPRO-VAD may be associated with duration of use. However, some blood pumps were used for prolonged periods without diaphragm damage. All blood pumps with damage had a crack in the diaphragm on the air chamber side near the diaphragm-housing (D-H) junction. Cracks were not found in any specific part of the diaphragm. In blood pumps with diaphragm rupture, the crack had a through-hole reaching the blood-contacting surface. Although we were unable to identify the causes of the cracks, it is suggested that when a crack appears in the diaphragm it will gradually expand and eventually lead to rupture. If a crack is detected in a blood pump, we advocate replacing the pump before it grows. When the NIPRO-VAD is used, it is necessary to keep in mind that blood pump diaphragm damage may occur. PMID:22923169

  12. [Study on optimal selection of structure of vaneless centrifugal blood pump with constraints on blood perfusion and on blood damage indexes].

    PubMed

    Hu, Zhaoyan; Pan, Youlian; Chen, Zhenglong; Zhang, Tianyi; Lu, Lijun

    2012-12-01

    This paper is aimed to study the optimal selection of structure of vaneless centrifugal blood pump. The optimal objective is determined according to requirements of clinical use. Possible schemes are generally worked out based on structural feature of vaneless centrifugal blood pump. The optimal structure is selected from possible schemes with constraints on blood perfusion and blood damage indexes. Using an optimal selection method one can find the optimum structure scheme from possible schemes effectively. The results of numerical simulation of optimal blood pump showed that the method of constraints of blood perfusion and blood damage is competent for the requirements of selection of the optimal blood pumps. PMID:23469557

  13. Magnetically suspended centrifugal blood pump with an axially levitated motor.

    PubMed

    Masuzawa, Toru; Ezoe, Shiroh; Kato, Tsuyoshi; Okada, Yohji

    2003-07-01

    The longevity of a rotary blood pump is mainly determined by the durability of its wearing mechanical parts such as bearings and seals. Magnetic suspension techniques can be used to eliminate these mechanical parts altogether. This article describes a magnetically suspended centrifugal blood pump using an axially levitated motor. The motor comprises an upper stator, a bottom stator, and a levitated rotor-impeller between the stators. The upper stator has permanent magnets to generate an attractive axial bias force on the rotor and electric magnets to control the inclination of the rotor. The bottom stator has electric magnets to generate attractive forces and rotating torque to control the axial displacement and rotation of the rotor. The radial displacement of the rotor is restricted by passive stability. A shrouded impeller is integrated within the rotor. The performance of the magnetic suspension and pump were evaluated in a closed mock loop circuit filled with water. The maximum amplitude of the rotor displacement in the axial direction was only 0.06 mm. The maximum possible rotational speed during levitation was 1,600 rpm. The maximum pressure head and flow rate were 120 mm Hg and 7 L/min, respectively. The pump shows promise as a ventricular assist device. PMID:12823418

  14. A magnetically suspended and hydrostatically stabilized centrifugal blood pump.

    PubMed

    Hart, R M; Filipenco, V G; Kung, R T

    1996-06-01

    A magnetically suspended centrifugal blood pump intended for application as a long-term implantable ventricular assist device has been built and tested. The rotor is freely suspended in the blood by magnetic and hydrostatic restoring forces. This design obviates the need for bearings and shaft seals, and eliminates the problems of reliability and thrombogenicity associated with them. The positional stability and hydrodynamic performance of the pump has been characterized in vitro at flows of up to 10 L/min at physiologic pressures. Radial position control is realized by an analog electronic feedback control system. The pressure distribution in the fluid surrounding the rotor provides dynamic control in the axial direction with no active feedback. Rotor excursion is less than 50 microns (mu) when the housing receives an impulse peaking at an acceleration of 40 g or upon sudden blockage of the flow. In vitro blood measurements indicate an acceptable level of hemolysis compared with that of a standard centrifugal pump. PMID:8817962

  15. Magnetically suspended rotary blood pump with radial type combined motor-bearing.

    PubMed

    Masuzawa, T; Kita, T; Matsuda, K; Okada, Y

    2000-06-01

    A magnetically suspended centrifugal blood pump is being developed with a combined motor-bearing for long-term ventricular assist systems. The combined motor-bearing actively suspends a rotor in a radial direction to deal with radial force unbalance in the pump and rotates the rotor by using the electric magnetic field. Therefore, the pump has no mechanical parts such as bearings of the motor and has a long lifetime. The developed pump consists of a thin rotor with a semi open-type 6 vane impeller and a stator to suspend and rotate the rotor. The rotor has 4-pole permanent magnets on the circumferential surface. The outer diameter and the thickness of the rotor are 60 mm and 8 mm, respectively. Axial movement and tilt of the rotor are restricted by passive stability based on the thin rotor structure. Radial movements of the rotor, such as levitation in radial direction and rotation, are controlled actively by using electric magnets of the stator. The electric magnet coils to produce levitation and rotation forces are constructed on the periphery stator. The p +/- 2-pole algorithm and the synchronous motor mechanism are adopted to levitate and rotate the rotor. The radial gap between the rotor and the stator is 1 mm. A closed-loop circuit filled with water was connected to the developed pump to examine the basic performance of the pump and the magnetic suspension system. Maximum rotational speed, flow rate, and head were 2,800 rpm, 11 L/min, and 270 mm Hg, respectively. The rotor with the impeller could be suspended completely during the entire pumping process. We conclude the pump with the combined motor-bearing has sufficient performance for the blood pump. PMID:10886067

  16. Evaluation of erythrocyte flow at a bearing gap in a hydrodynamically levitated centrifugal blood pump.

    PubMed

    Murashige, Tomotaka; Kosaka, Ryo; Sakota, Daisuke; Nishida, Masahiro; Kawaguchi, Yasuo; Yamane, Takashi; Maruyama, Osamu

    2015-01-01

    We have developed a hydrodynamically levitated centrifugal blood pump for extracorporeal circulatory support. In the blood pump, a spiral groove bearing was adopted for a thrust bearing. In the spiral groove bearing, separation of erythrocytes and plasma by plasma skimming has been postulated to occur. However, it is not clarified that plasma skimming occurs in a spiral groove bearing. The purpose of this study is to verify whether plasma skimming occurs in the spiral groove bearing of a hydrodynamically levitated centrifugal blood pump. For evaluation of plasma skimming in the spiral groove bearing, an impeller levitation performance test using a laser focus displacement meter and a microscopic visualization test of erythrocyte flow using a high-speed microscope were conducted. Bovine blood diluted with autologous plasma to adjust hematocrit to 1.0% was used as a working fluid. Hematocrit on the ridge region in the spiral groove bearing was estimated using image analysis. As a result, hematocrits on the ridge region with gaps of 45 μm, 31 μm, and 25 μm were calculated as 1.0%, 0.6%, and 0.3%, respectively. Maximum skimming efficiency in this study was calculated as 70% with a gap of 25 μm. We confirmed that separation of erythrocyte and plasma occurred in the spiral groove bearing with decrease in bearing gap in a hydrodynamically levitated centrifugal blood pump. PMID:26736252

  17. Water Pump Development for the EVA PLSS

    NASA Technical Reports Server (NTRS)

    Schuller, Michael; Kurwitz, Cable; Goldman, Jeff; Morris, Kim; Trevino, Luis

    2009-01-01

    This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell for NASA to design, fabricate, and test a preflight prototype pump for use in the Extravehicular activity (EVA) portable life support subsystem (PLSS). Major design decisions were driven by the need to reduce the pump s mass, power, and volume compared to the existing PLSS pump. In addition, the pump will accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure drop when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure drops. An additional benefit of selecting a gear pump design is that it is self priming and capable of ingesting noncondensable gas without becoming "air locked." The chosen pump design consists of a 28 V DC, brushless, sealless, permanent magnet motor driven, external gear pump that utilizes a Honeywell development that eliminates the need for magnetic coupling. Although the planned flight unit will use a sensorless motor with custom designed controller, the preflight prototype to be provided for this project incorporates Hall effect sensors, allowing an interface with a readily available commercial motor controller. This design approach reduced the cost of this project and gives NASA more flexibility in future PLSS laboratory testing. The pump design was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the key features of the flight pump. Testing at TEES will simulate the vacuum environment in which the flight pump will operate. Testing will verify that the pump meets design requirements for range of flow rates, pressure rise, power consumption, working fluid temperature, operating time, and restart capability. Pump testing is currently

  18. Numerical simulation and comparative analysis of flow field in axial blood pumps.

    PubMed

    Peng, Yuhua; Wu, Yaqin; Tang, Xiaoying; Liu, Weifeng; Chen, Duanduan; Gao, Tianxin; Xu, Yong; Zeng, Yanjun

    2014-05-01

    The objective study was to estimate the rheological properties and physiological compatibility of the blood pump by simulating the internal flow field of the blood pump. In this study we use computational fluid dynamics method to simulate and analyse two models of axial blood pumps with a three-blade diffuser and a six-blade diffuser, named pump I and pump II, respectively, and to compare the flow patterns of these two kinds of blood pumps while both of them satisfy the conditions of the normal human blood differential pressure and blood flow. Results indicate that (i) the high shear force occurs between the diffuser and the rotor in which the crucial place leads to haemolysis and (ii) under the condition of 100 mmHg pressure head and 5 l/min flow rate, the difference between the two kinds of blood pumps, as far as the haemolytic performance is concerned, is notable. The haemolysis index of the two pumps is 0.32% and 0.2%. In conclusion, the performance of the blood pump is influenced by the diffusers' blade number. Pump II performed better than pump I, which can be the basic model for blood pump option. PMID:22974125

  19. Twenty-four hour left ventricular bypass with a centrifugal blood pump.

    PubMed Central

    Berstein, E F; DeLaria, G A; Johansen, K H; Shuman, R L; Stasz, P; Reich, S

    1975-01-01

    A new centrifugal blood pump system has been developed for left ventricular bypass by the addition of non-thrombogenic blood surface materials and an ultrathin-walled cannula for the retrograde cannulation of the left ventricle. Partial LV bypass at 3 to 6 L/min was undertaken in 55 calves without thoracotomy. In 20 it was continued for 24 hours, with 13 survivors who were eventually sacrificed. Eleven of the last 14 experiments were completed without mishap. Heparin was employed only during pump insertion. Hematologic changes were limited to moderate platelet depression, and tolerable hemolysis (average serum level 21 mg% in the last 13 experiments). Normal clotting parameters and the absence of significant fibrin split product formation correlated with the absence of gross thrombosis and few minor renal emboli observed at autopsy. This pump system appears to have several advantages over previously described equipment for LV bypass. Images Fig. 1. Fig. 2. Fig. 3. PMID:1130859

  20. Pumped limiter development on ISX

    SciTech Connect

    Mioduszewski, P.K.; Edmonds, P.H.; Sheffield, J.

    1981-01-01

    Pumped limiter configurations are being suggested for FED and INTOR for helium ash exhaust and fuel particle control. The goal of the pump limiter studies in ISX is the selection of the most promising concept and its evaluation in the ISX-C device under the following conditions: (1) quasi steady state operation (less than or equal to 30s), (2) high edge power densities, and (3) particle control by means of mechanical devices. We are considering various options, including particle scraper and ballistic particle collection concepts as well as the current FED design. In ISX-B we will test a full-size pump limiter and directly compare the heat removal and particle control capabilities with a bundle divertor. In ISX-C the steady state operation characteristics of pump limiters will be explored.

  1. PIV Investigations of the Flow Field in the Volute of a Rotary Blood Pump

    NASA Technical Reports Server (NTRS)

    Sankovic, John M.; Kadambi, Jaikrishnan R.; Smith, William A.; Wernet, Mark P.

    2004-01-01

    A full-size acrylic model of a rotary blood pump was developed in order to utilize Particle Image Velocimetry (PIV) to make measurements of the fluid velocities and turbulent stresses throughout the device. The development of an understanding of the hemodynamics within the blood pump is critical to the development and validation of computational models. A blood analog solution, consisting of sodium iodide solution and glycerin, was developed to match physiological kinematic viscosity. The refractive indices of the fluid, the pump casing, and the impeller were matched to facilitate the use of PIV to make velocity measurements. Velocity measurements made in the volute exit/diffuser region are presented for pumps speeds of 3000-3850 rpm. At each speed data were obtained at a physiological pressure of 12 kPa and at a maximum flow condition. Four hundred data pairs were used for each resultant mean velocity vector value, representing greater than an order of magnitude more data pairs than reported previously in the literature on similar devices and resulting in velocity uncertainty levels of approximately 22.9%.

  2. PIV Investigations of the Flow Field in the Volute of a Rotary Blood Pump

    NASA Technical Reports Server (NTRS)

    Sankovic, John M.; Kadambi, Jaikrishnan R.; Mehta, Mehul; Smith, William A.; Wernet, Mark P.

    2004-01-01

    A full-size acrylic model of a rotary blood pump was developed in order to utilize Particle Image Velocimetry (PIV) to make measurements of the fluid velocities and turbulent stresses throughout the device. The development of an understanding of the hemodynamics within the blood pump is critical to the development and validation of computational models. A blood analog solution, consisting of sodium iodide solution and glycerin, was developed to match physiological kinematic viscosity. The refractive indecies of the fluid, the pump casing and the impeller were matched to facilitate the use of PIV to make velocity measurements. Velocity measurements made in the volute exit/diffuser region are presented for pumps speeds of 3000-3850 rpm. At each speed data were obtained at a physiological pressure of 90 mmHg and at a maximum flow condition. Four hundred data pairs were used for each resultant mean velocity vector value, representing greater than an order of magnitude more data pairs than reported previously in the literature on similar devices and resulting in velocity uncertainty levels of approximately 2.9%.

  3. Controlled pitch-adjustment of impeller blades for an intravascular blood pump.

    PubMed

    Throckmorton, Amy L; Sciolino, Michael G; Downs, Emily A; Saxman, Robert S; López-Isaza, Sergio; Moskowitz, William B

    2012-01-01

    Thousands of mechanical blood pumps are currently providing circulatory support, and the incidence of their use continues to increase each year. As the use of blood pumps becomes more pervasive in the treatment of those patients with congestive heart failure, critical advances in design features to address known limitations and the integration of novel technologies become more imperative. To advance the current state-of-the-art in blood pump design, this study investigates the inclusion of pitch-adjusting blade features in intravascular blood pumps as a means to increase energy transfer; an approach not explored to date. A flexible impeller prototype was constructed with a configuration to allow for a variable range of twisted blade geometries of 60-250°. Hydraulic experiments using a blood analog fluid were conducted to characterize the pressure-flow performance for each of these twisted positions. The flexible, twisted impeller was able to produce 1-25 mmHg for 0.5-4 L/min at rotational speeds of 5,000-8,000 RPM. For a given twisted position, the pressure rise was found to decrease as a function of increasing flow rate, as expected. Generally, a steady increase in the pressure rise was observed as a function of higher twisted degrees for a constant rotational speed. Higher rotational speeds for a specific twisted impeller configuration resulted in a more substantial pressure generation. The findings of this study support the continued exploration of this unique design approach in the development of intravascular blood pumps. PMID:22691415

  4. Tiny magnetic wireless pump: Fabrication of magnetic impeller and magnetic wireless manipulation for blood circulation in legs

    NASA Astrophysics Data System (ADS)

    Kim, Sung Hoon; Yu, Chang Ho; Ishiyama, K.

    2015-05-01

    This paper introduces a wireless pump that uses magnetic wireless manipulation to pump blood in the legs. A compact size and sufficient hydrodynamic performance were the most important requirements. Because the bonded magnet technique allows for a complex shape and various magnetization orientations, we fabricated a magnetic impeller from magnetic SmFeN powder. The impellers demonstrated a magnetic moment of 2772.64 emu and coercive force of 7.55 kOe. Using the impeller, we developed a tiny blood pump with a diameter of 22 mm and height of 6 mm. The pump allows for a maximum flow rate of 2.7 l/min and maximum pump head of approximately 170 mm Hg at a rotating speed of 6000 rpm. This level of hydrodynamic performance is sufficient to circulate blood in the legs. In this paper, we present the magnetic properties of the magnetic impeller and the hydrodynamic performance with wireless operation.

  5. A novel permanent maglev impeller TAH: most requirements on blood pumps have been satisfied.

    PubMed

    Qian, K X; Zeng, P; Ru, W M; Yuan, H Y

    2003-07-01

    Based on the development of an impeller total artificial heart (TAH) (1987) and a permanent maglev (magnetic levitation) impeller pump (2002), as well as a patented magnetic bearing and magnetic spring (1996), a novel permanent maglev impeller TAH has been developed. The device consists of a rotor and a stator. The rotor is driven radially. Two impellers with different dimensions are fixed at both the ends of the rotor. The levitation of the rotor is achieved by using two permanent magnetic bearings, which have double function: radial bearing and axial spring. As the rotor rotates at a periodic changing speed, two pumps deliver the pulsatile flow synchronously. The volume balance between the two pumps is realized due to self-modulation property of the impeller pumps, without need for detection and control. Because the hemo-dynamic force acting on the left impeller is larger than that on the right impeller, and this force during systole is larger than that during diastole, the rotor reciprocates axially once a cycle. This is beneficial to prevent the thrombosis in the pump. Furthermore, a small flow via the gap between stator and rotor from left pump into right pump comes to a full washout in the motor and the pumps. Therefore, it seems neither mechanical wear nor thrombosis could occur. The previously developed prototype impeller TAH had demonstrated that it could operate in animal experiments indefinitely, if the bearing would not fail to work. Expectantly, this novel permanent magnetic levitation impeller TAH with simplicity, implantability, pulsatility, compatibility and durability has satisfied the most requirements on blood pumps and will have more extensive applications in experiments and clinics. PMID:12873075

  6. Testing of a centrifugal blood pump with a high efficiency hybrid magnetic bearing.

    PubMed

    Locke, Dennis H; Swanson, Erik S; Walton, James F; Willis, John P; Heshmat, Hooshang

    2003-01-01

    The purpose of this article is to present test results for a second generation, high efficiency, nonpulsatile centrifugal blood pump that is being developed for use as a left ventricular assist device (LVAD). The LVAD pump uses a hybrid passive-active magnetic bearing support system that exhibits extremely low power loss, low vibration, and high reliability under transient conditions and varying pump orientations. A unique feature of the second generation design configuration is the very simple and direct flow path for both main and washing blood flows. The pump was tested in both vertical and horizontal orientations using a standard flow loop to demonstrate the performance and durability of the second generation LVAD. Steady state and transient orientation pump operating characteristics including pressure, flow, speed, temperatures, vibration, and rotor orientation were measured. During the tests, pump performance was mapped at several operating conditions including points above and below the nominal design of 5 L/min at 100 mm Hg pressure rise. Flow rates from 2 to 7 L/min and pressure rises from 50 to 150 mm Hg were measured. Pump speeds were varied during these tests from 2,500 to 3,500 rpm. The nominal design flow of 5 L/min at 100 mm Hg pressure rise was successfully achieved at the design speed of 3,000 rpm. After LVAD performance testing, both 28 day continuous duty and 5 day transient orientation durability tests were completed without incident. A hydrodynamic backup bearing design feasibility study was also conducted. Results from this design study indicate that an integral hydrodynamic backup bearing may be readily incorporated into the second generation LVAD and other magnetically levitated pump rotors. PMID:14655745

  7. An intraventricular axial flow blood pump integrated with a bearing purge system.

    PubMed

    Yamazaki, K; Kormos, R; Mori, T; Umezu, M; Kameneva, M; Antaki, J; Outa, E; Litwak, P; Kerrigan, J; Tomczak, J

    1995-01-01

    The future development of implantable axial flow blood pumps must address two major issues: mechanically induced hemolysis and shaft seal reliability. The recent revisions to our miniature intraventricular axial flow left ventricular assist device (LVAD) were aimed particularly at addressing these concerns. To improve hemocompatibility, a new impeller has been designed according to the following criteria: 1) gradual pressure rise along the blade chord; 2) minimized local fluid acceleration to prevent cavitation; 3) minimum surface roughness; and 4) radius edges. Subsequent in vitro hemolysis tests conducted with bovine and ovine blood have demonstrated very low hemolysis (normalized index of hemolysis = 0.0051 +/- 0.0047 g/100 L) with this new impeller design. To address the need for a reliable seal, we have developed a purged seal system consisting of a miniature lip seal and ceramic pressure groove journal bearing that also acts as a purge pump. Several spiral grooves formed on the bearing surface provide viscous pumping of the purge fluid, generating more than 3,000 mmHg at 10,000 rpm. This purge flow flushes the lip seal and prevents blood backflow into the bearing. We have found this purge pump to offer several advantages because it is simple, compact, durable, does not require separate actuation, and offers a wide range of flow, depending upon the groove design. In vivo animal tests demonstrated the potential of the purged seal system. PMID:8573818

  8. Coal pump development phase 3

    NASA Technical Reports Server (NTRS)

    Kushida, R. O.; Sankur, V. D.; Gerbracht, F. G.; Mahajan, V.

    1980-01-01

    Techniques for achieving continuous coal sprays were studied. Coazial injection with gas and pressure atomization were studied. Coal particles, upon cooling, were found to be porous and fragile. Reactivity tests on the extruded coal showed overall conversion to gases and liquids unchanged from that of the raw coal. The potentials for applications of the coal pump to eight coal conversion processes were examined.

  9. Study of a centrifugal blood pump in a mock loop system.

    PubMed

    Uebelhart, Beatriz; da Silva, Bruno Utiyama; Fonseca, Jeison; Bock, Eduardo; Leme, Juliana; da Silva, Cibele; Leão, Tarcísio; Andrade, Aron

    2013-11-01

    An implantable centrifugal blood pump (ICBP) is being developed to be used as a ventricular assist device (VAD) in patients with severe cardiovascular diseases. The ICBP system is composed of a centrifugal pump, a motor, a controller, and a power supply. The electricity source provides power to the controller and to a motor that moves the pump's rotor through magnetic coupling. The centrifugal pump is composed of four parts: external conical house, external base, impeller, and impeller base. The rotor is supported by a pivot bearing system, and its impeller base is responsible for sheltering four permanent magnets. A hybrid cardiovascular simulator (HCS) was used to evaluate the ICBP's performance. A heart failure (HF) (when the heart increases beat frequency to compensate for decrease in blood flow) was simulated in the HCS. The main objective of this work is to analyze changes in physiological parameters such as cardiac output, blood pressure, and heart rate in three situations: healthy heart, HF, and HF with left circulatory assistance by ICBP. The results showed that parameters such as aortic pressure and cardiac output affected by the HF situation returned to normal values when the ICBP was connected to the HCS. In conclusion, the test results showed satisfactory performance for the ICBP as a VAD. PMID:24237361

  10. Development of the sonic pump levitation

    NASA Technical Reports Server (NTRS)

    Dunn, S. A.

    1984-01-01

    A prototype levitating/positioning device termed the Sonic Pump Levitator was designed, built and successfully tested in full gravity and in the reduced gravity of the parabolic flight regime of the KC-135. Positioning is achieved by timely and appropriate application of gas momentum from one or more of six sonic pumps. The sonic pumps, which are arranged orthogonally in opposed pairs about the levitation region, are activated by an electro-optical, computer controlled, feedback system. The sonic pump is a transducer which is capable of converting sound energy into a directed flow of gas. It consists of a loudspeaker whose face is sealed by a closure perforated by one or more orifices. The diaphragm of the loudspeaker is the only moving part of the sonic pump, no valves being needed. This very low inertia electromechanical device was developed to provide the short response time necessary to keep pace with the demands of computerized position keeping.

  11. New concepts and new design of permanent maglev rotary artificial heart blood pumps.

    PubMed

    Qian, K X; Zeng, P; Ru, W M; Yuan, H Y

    2006-05-01

    According to tradition, permanent maglev cannot achieve stable equilibrium. The authors have developed, to the contrary, two stable permanent maglev impeller blood pumps. The first pump is an axially driven uni-ventricular assist pump, in which the rotor with impeller is radially supported by two passive magnetic bearings, but has one point contact with the stator axially at standstill. As the pump raises its rotating speed, the increasing hydrodynamic force of fluid acting on the impeller will make the rotor taking off from contacting point and disaffiliate from the stator. Then the rotor becomes fully suspended. The second pump is a radially driven bi-ventricular assist pump, i.e., an impeller total artificial heart. Its rotor with two impellers on both ends is supported by two passive magnetic bearings, which counteract the attractive force between rotor magnets and stator coil iron core. The rotor is affiliated to the stator radially at standstill and becomes levitated during rotation. Therefore, the rotor keeps concentric with stator during rotation but eccentric at standstill, as is confirmed by rotor position detection with Honeywell sensors. It concludes that the permanent maglev needs action of a non-magnetic force to achieve stability but a rotating magnetic levitator with high speed and large inertia can maintain its stability merely with passive magnetic bearings. PMID:16183322

  12. Third-generation blood pumps with mechanical noncontact magnetic bearings.

    PubMed

    Hoshi, Hideo; Shinshi, Tadahiko; Takatani, Setsuo

    2006-05-01

    This article reviews third-generation blood pumps, focusing on the magnetic-levitation (maglev) system. The maglev system can be categorized into three types: (i) external motor-driven system, (ii) direct-drive motor-driven system, and (iii) self-bearing or bearingless motor system. In the external motor-driven system, Terumo (Ann Arbor, MI, U.S.A.) DuraHeart is an example where the impeller is levitated in the axial or z-direction. The disadvantage of this system is the mechanical wear in the mechanical bearings of the external motor. In the second system, the impeller is made into the rotor of the motor, and the magnetic flux, through the external stator, rotates the impeller, while the impeller levitation is maintained through another electromagnetic system. The Berlin Heart (Berlin, Germany) INCOR is the best example of this principle where one-axis control combination with hydrodynamic force achieves high performance. In the third system, the stator core is shared by the levitation and drive coil to make it as if the bearing does not exist. Levitronix CentriMag (Zürich, Switzerland), which appeared recently, employs this concept to achieve stable and safe operation of the extracorporeal system that can last for a duration of 14 days. Experimental systems including HeartMate III (Thoratec, Woburn, MA, U.S.A.), HeartQuest (WorldHeart, Ottawa, ON, Canada), MagneVAD (Gold Medical Technologies, Valhalla, NY, U.S.A.), MiTiHeart (MiTi Heart, Albany, NY, U.S.A.), Ibaraki University's Heart (Hitachi, Japan) and Tokyo Medical and Dental University/Tokyo Institute of Technology's disposable and implantable maglev blood pumps are also reviewed. In reference to second-generation blood pumps, such as the Jarvik 2000 (Jarvik Heart, New York, NY, U.S.A.), which is showing remarkable achievement, a question is raised whether a complicated system such as the maglev system is really needed. We should pay careful attention to future clinical outcomes of the ongoing clinical

  13. Advanced heat pump research and development

    NASA Astrophysics Data System (ADS)

    Kuliasha, M. A.

    The Office of Building Energy Research and Development of the U.S. Department of Energy (DOE), has been funding R&D in advanced heat pumps and appliances since 1976. Much of that research has been managed for DOE by the Oak Ridge National Laboratory (ORNL). The objective of the Building Equipment Research (BER) program at ORNL has been to generate new concepts and develop a technology base for improving the energy efficiency and load characteristics of energy conversion equipment used in residential and commercial buildings. The research being pursued to achieve these objectives falls under three general areas: thermally activated heat pumps (TAHP), refrigeration systems, and building equipment systems. The TAHP work is concentrated on three technologies: (1) absorption heat pumps; (2) Stirling engine-driven heat pumps; and (3) internal combustion (IC) engine-driven heat pumps. Major project areas in refrigeration systems research include electric heat pumps, ground-coupled heat pumps, and refigerant mixtures. In the building equipment systems areas, project areas include advanced distribution systems, advanced insulation for appliances, and commercial building equipment.

  14. Fault-tolerant strategies for an implantable centrifugal blood pump using a radially controlled magnetic bearing.

    PubMed

    Pai, Chi Nan; Shinshi, Tadahiko

    2011-10-01

    In our laboratory, an implantable centrifugal blood pump (CBP) with a two degrees-of-freedom radially controlled magnetic bearing (MB) to support the impeller without contact has been developed to assist the pumping function of the weakened heart ventricle. In order to maintain the function of the CBP after damage to the electromagnets (EMs) of the MB, fault-tolerant strategies for the CBP are proposed in this study. Using a redundant MB design, magnetic levitation of the impeller was maintained with damage to up to two out of a total of four EMs of the MB; with damage to three EMs, contact-free support of the impeller was achieved using hydrodynamic and electromagnetic forces; and with damage to all four EMs, the pump operating point, of 5 l/min against 100 mmHg, was achieved using the motor for rotation of the impeller, with contact between the impeller and the stator. PMID:21382738

  15. Measurements of enlarged blood pump models using Laser Doppler Anemometer.

    PubMed

    Chua, L P; Yu, S C; Leo, H L

    2000-01-01

    In an earlier study (Chua et al., 1998, 1999a), a 5:1 enlarged model of the Kyoto-NTN Magnetically Suspended Centrifugal Blood Pump (Akamatsu et al., 1995) with five different impeller blade profiles was designed and constructed. Their respective flow characteristics with respect to (1) the three different blade profile designs: forward, radial, and backward, (2) the number of blades used, and (3) the rotating speed were investigated. Among the five impeller designs, the results obtained suggested that impellers A and C designs should be adopted if higher head is required. Impellers A and C therefore were selected for the flow in between their blades to be measured using Laser Doppler Anemometer (LDA), so as to have a better understanding of the flow physics with respect to the design parameters. PMID:10999377

  16. Shape optimization of the diffuser blade of an axial blood pump by computational fluid dynamics.

    PubMed

    Zhu, Lailai; Zhang, Xiwen; Yao, Zhaohui

    2010-03-01

    Computational fluid dynamics (CFD) has been a viable and effective way to predict hydraulic performance, flow field, and shear stress distribution within a blood pump. We developed an axial blood pump with CFD and carried out a CFD-based shape optimization of the diffuser blade to enhance pressure output and diminish backflow in the impeller-diffuser connecting region at a fixed design point. Our optimization combined a computer-aided design package, a mesh generator, and a CFD solver in an automation environment with process integration and optimization software. A genetic optimization algorithm was employed to find the pareto-optimal designs from which we could make trade-off decisions. Finally, a set of representative designs was analyzed and compared on the basis of the energy equation. The role of the inlet angle of the diffuser blade was analyzed, accompanied by its relationship with pressure output and backflow in the impeller-diffuser connecting region. PMID:20447042

  17. Electro-elastic modeling of a dielectric elastomer diaphragm for a prosthetic blood pump

    NASA Astrophysics Data System (ADS)

    Goulbourne, Nakhiah C.; Frecker, Mary I.; Mockensturm, Eric

    2004-07-01

    A dielectric elastomer diaphragm is to be designed for potential use in a prosthetic blood pump. Application of an electric field deforms the membrane such that it moves from an initially flat configuration to an inflated state. This motion creates positive displacement of blood from the cardiac chambers thus mimicking the pump-like behavior of the natural heart. A comprehensive large deformation model accounting for the combined dielectric and elastic effect has been formulated. This paper presents recent developments in the model to further incorporate the entire nonlinear range of material elastic behavior and to more accurately represent the applied electric field by keeping the voltage constant as the membrane thickness decreases. The updated model is used to calculate the effects of varying system parameters such as pressure, voltage, prestretch, material constants, and membrane geometry. Analytical results are obtained for biaxially stretched 3M VHB 4905 polyacrylate films.

  18. Survey of advanced-heat-pump developments for space conditioning

    SciTech Connect

    Fairchild, P.D.

    1981-01-01

    A survey of heat pump projects with special emphasis on those supported by DOE, EPRI, and the Gas Research Institute is presented. Some historical notes on heat pump development are discussed. Market and equipment trends, well water and ground-coupled heat pumps, heat-actuated heat pump development, and international interest in heat pumps are also discussed. 30 references.

  19. Comparison of a pulsatile blood pump and a peristaltic roller pump during hemoperfusion treatment in a canine model of paraquat poisoning.

    PubMed

    Lee, Jung Chan; Park, Chan Young; Choi, Seong Wook; Kim, Jeong Chul; Lim, Ki Moo; Kim, Kyuseok; Jung, Sung Koo; Kwak, Young Ho; Shin, Sang Do; Jo, Ik Joon; Suh, Gil Joon; Min, Byoung Goo

    2008-07-01

    This study examined the treatment efficacy and the damage to the blood during hemoperfusion for treating paraquat poisoning using two blood pump mechanisms. Paraquat-poisoned animal models were prepared. A conventional hemodialysis machine, AK90, with a peristaltic roller pump and a cardiopulmonary support system, T-PLS, with a pulsatile blood pump were used during the animal experiments. A total of 12 dogs were treated with hemoperfusion using a charcoal column. Six dogs were treated with hemoperfusion and T-PLS, and the other six were treated with AK90. A paraquat dose of 30 mg/kg was administrated by an intravenous injection. Both pumps maintained blood flow rates of 125 mL/min measured by an ultrasonic flowmeter. For anticoagulation, heparin was administrated by an initial bolus (250 IU/kg) and a continuous injection (100 IU/kg/h). During the experiments, T-PLS and AK90 showed a similar toxin removal efficacy. Both devices decreased the plasma paraquat concentration to 10% of the initial dose within 4-h hemoperfusion. The two pumps showed similar hemolysis properties with acceptable levels. Although T-PLS was developed as a cardiopulmonary bypass system, it can also be used as a hemoperfusion treatment device. PMID:18638308

  20. In vivo experimental testing of the FW axial blood pump for left ventricular support in Fu Wai Hospital.

    PubMed

    Zhang, Yan; Hu, Sheng-Shou; Zhou, Jian-Ye; Sun, Han-Song; Tang, Yue; Zhang, Hao; Zheng, Zhe; Li, Guo-Rong; Zhu, Xiao-Dong; Gui, Xin-Min

    2009-01-01

    A fully implantable, axial flow blood pump has been developed in Fu Wai Hospital aiming for clinical use. This ventricular assist device (VAD), which was developed after numerous CFD analyses for the flow characteristics of the pump, is 58.5-mm long, 30-mm wide (including DC motor), and weighs 240 g. The pump can deliver 5 L/min for pressures of 100 mm Hg over 8,000 rpm. In this study, short-term hemocompatibility effects of the axial left ventricular assist device (LVAD) (FW blood pump) were evaluated in four healthy sheep. The device was implanted into the left ventricular apex of beating hearts. The outflow graft of each device was anastomosed to the descending aorta. The hemolysis, which was evaluated in vivo by free hemoglobin value, was below 30 mg/dL. Evaluation of serum biochemical data showed that implantation of the FW blood pump in sheep with normal hearts did not impair end organ function. Gross and microscopic sections of kidney, liver, and lung revealed no evidence of microemboli. Performance of the pump in vivo was considered sufficient for a LVAD, although further design improvement is necessary in terms of hemolysis and antithrombosis to improve biocompatibility of the pump. PMID:19092667

  1. Centrifugal blood pump for temporary ventricular assist devices with low priming and ceramic bearings.

    PubMed

    Leme, Juliana; da Silva, Cibele; Fonseca, Jeison; da Silva, Bruno Utiyama; Uebelhart, Beatriz; Biscegli, José F; Andrade, Aron

    2013-11-01

    A new model of centrifugal blood pump for temporary ventricular assist devices has been developed and evaluated. The design of the device is based on centrifugal pumping principles and the usage of ceramic bearings, resulting in a pump with reduced priming (35 ± 2 mL) that can be applied for up to 30 days. Computational fluid dynamic (CFD) analysis is an efficient tool to optimize flow path geometry, maximize hydraulic performance, and minimize shear stress, consequently decreasing hemolysis. Initial studies were conducted by analyzing flow behavior with different impellers, aiming to determine the best impeller design. After CFD studies, rapid prototyping technology was used for production of pump prototypes with three different impellers. In vitro experiments were performed with those prototypes, using a mock loop system composed of Tygon tubes, oxygenator, digital flow meter, pressure monitor, electronic driver, and adjustable clamp for flow control, filled with a solution (1/3 water, 1/3 glycerin, 1/3 alcohol) simulating blood viscosity and density. Flow-versus-pressure curves were obtained for rotational speeds of 1000, 1500, 2000, 2500, and 3000 rpm. As the next step, the CFD analysis and hydrodynamic performance results will be compared with the results of flow visualization studies and hemolysis tests. PMID:24219168

  2. A new design for a compact centrifugal blood pump with a magnetically levitated rotor.

    PubMed

    Asama, Junichi; Shinshi, Tadahiko; Hoshi, Hideo; Takatani, Setsuo; Shimokohbe, Akira

    2004-01-01

    A compact centrifugal blood pump has been developed using a radial magnetic bearing with a two-degree of freedom active control. The proposed magnetic bearing exhibits high stiffness, even in passively controlled directions, and low power consumption because a permanent magnet, incorporated with the rotor, suspends its weight. The rotor is driven by a Lorentz force type of built-in motor, avoiding mechanical friction and material wear. The built-in motor is designed to generate only rotational torque, without radial and axial attractive forces on the rotor, leading to low power consumption by the magnetic bearing. The fabricated centrifugal pump measured 65 mm in diameter and 45 mm in height and weighed 0.36 kg. In the closed loop circuit filled with water, the pump provided a flow rate of 4.5 L/min at 2,400 rpm against a pressure head of 100 mm Hg. Total power consumption at that point was 18 W, including 2 W required for magnetic levitation, with a total efficiency of 5.7%. The experimental results showed that the design of the compact magnetic bearing was feasible and effective for use in a centrifugal blood pump. PMID:15672787

  3. Pulsatile blood pump with a linear drive actuator.

    PubMed

    Fukunaga, Kazuyoshi; Homma, Akihiko; Funakubo, Akio; Tatsumi, Eisuke; Taenaka, Yoshiyuki; Kitamura, Soichiro; Fukui, Yasuhiro

    2007-01-01

    The main purpose of this study was to develop an implantable direct-electromagnetic left ventricular assist system driven by a linear actuator (linear LVAS). The linear LVAS is a pulsatile pump with a pusher plate that is driven directly by a linear oscillatory actuator (LOA) without any movement converters. This prototype pump unit with a LOA was 100 mm in diameter, 50 mm in thickness, and weighed 740 g. The full-fill/full-eject driving method was applied to the control algorithm. In addition, a mechanism to detect and release sucking was realized to overcome this problem that accompanies the active-filling type of VAS. The performance of the linear LVAS was evaluated in a long-term animal experiment using a goat (56 kg). The goat survived for 42 days. The reason why we terminated this experiment was that thrombus was found in the pump. There was no frictional debris found around the LOA. The linear LVAS did not exhibit electrical or mechanical problems during the first animal experiment. PMID:17574509

  4. Concept for a new hydrodynamic blood bearing for miniature blood pumps.

    PubMed

    Kink, Thomas; Reul, Helmut

    2004-10-01

    The most crucial element of a long-term implantable rotary blood pump is the rotor bearing. Because of heat generation and power loss resulting from friction, seals within the devices have to be avoided. Actively controlled magnetic bearings, although maintenance-free, increase the degree of complexity. Hydrodynamic bearings for magnetically coupled rotors may offer an alternative solution to this problem. Additionally, for miniature pumps, the load capacity of hydrodynamic bearings scales slower than that of, for example, magnetic bearings because of the cube-square-law. A special kind of hydrodynamic bearing is a spiral groove bearing (SGB), which features an excellent load capacity. Mock-loop tests showed that SGBs do not influence the hydraulic performance of the tested pumps. Although, as of now, the power consumption of the SBG is higher than for a mechanical pivot bearing, it is absolutely contact-free and has an unlimited lifetime. The liftoff of the rotor occurs already at 10% of design speed. Further tests and flow visualization studies on scaled-up models must demonstrate its overall blood compatibility. PMID:15384998

  5. Infusion pump development and implications for nurses.

    PubMed

    Lee, Paul

    Infusion pumps are commonplace in today's healthcare settings and their design and development has kept pace with technology over the decades. In the 1970s and 1980s infusion pumps began to emerge in the UK market and were basic, mechanical devices with limited functions. Today, infusion pumps have a plethora of functions and features and a range of alarms to help alert the user and the patient that infusions are nearing completion, have ended or their range of sensors has detected that the infusion pump, or patient, requires attention. The role of the nurse in safely managing this ever-changing technology should not be underestimated. This paper reviews the progress made over the past 40 years in the UK healthcare setting and how the nurses have had to keep up to speed with the technology as it develops. It highlights the importance of fully integrating infusion pumps into intravenous (IV) therapy training and assessment. The important role the nurse plays is highlighted as well as exploring how he or she can help organisations better understand infusion pumps in the day-to-day management of patients undergoing intravenous therapy. PMID:26496875

  6. Minimal sensor count approach to fuzzy logic rotary blood pump flow control.

    PubMed

    Casas, Fernando; Ahmed, Nisar; Reeves, Andrew

    2007-01-01

    A rotary blood pump fuzzy logic flow controller without flow sensors was developed and tested in vitro. The controller, implemented in LabView, was set to maintain a flow set point in the presence of external pressure disturbances. Flow was estimated as a function of measured pump's delta P and speed, using a steady-state, nonlinear approximation. The fuzzy controller used the pump's flow estimate and delta P as feedback variables. The defuzzified control output manipulated the pump speed. Membership functions included flow error, delta P, and pump speed. Experimental runs in a mock loop (water/glycerin 3.5 cPs, 37 degrees C), using the estimated flow, were compared with those using a Transonic flow meter for nine conditions of flow and delta P (4 to 6 L/min, 150 to 350 mm Hg). Pressure disturbances generated by a servo pinch valve ranged from +/-23 to +/-47 mm Hg. Results indicated that the fuzzy controller ably regulated the flow set point to within +/-10% of the baseline even under large swings in pressure. There was no difference in controller performance between the ultrasonic flow measurement and the estimated flow calculation scenarios. These tests demonstrated that the fuzzy controller is capable of rejecting disturbances and regulating flow to acceptable limits while using a flow estimate. PMID:17413551

  7. Numerical investigation of the effect of blade geometry on blood trauma in a centrifugal blood pump.

    PubMed

    Chan, W K; Wong, Y W; Ding, Y; Chua, L P; Yu, S C M

    2002-09-01

    Fluid dynamic forces in centrifugal blood pump impellers are of key importance in destruction of red blood cells (RBCs) because high rotational speed leads to strong interaction between the impeller and the RBCs. In this paper, three-dimensional models of five different blade geometries are investigated numerically using the commercial software CFX-TASCflow, and the streaklines of RBCs are obtained using the Lagrangian particle tracking method. In reality, RBCs pass through the pump along complicated paths resulting in a highly irregular loading condition for each RBC. In order to enable the prediction of blood damage under the action of these complex-loading conditions, a cumulative damage model for RBCs was adopted in this paper. The numerically simulated percent hemoglobin (%HB) released as RBCs traversed the impeller and volute was examined. It was observed that the residence time of particles in the blade passage is a critical factor in determining hemolytic effects. This, in turn, is a function of the blade geometry. In addition, it was observed that the volute profile is an important influence on the computed HB% released. PMID:12197935

  8. A cost-effective extracorporeal magnetically-levitated centrifugal blood pump employing a disposable magnet-free impeller.

    PubMed

    Hijikata, W; Mamiya, T; Shinshi, T; Takatani, S

    2011-12-01

    In the field of rotary blood pumps, contactless support of the impeller by a magnetic bearing has been identified as a promising method to reduce blood damage and enhance durability. The authors developed a two-degrees-of-freedom radial controlled magnetic bearing system without a permanent magnet in the impeller in order that a low-cost disposable pump-head for an extracorporeal centrifugal blood pump could be manufactured more easily. Stable levitation and contactless rotation of the 'magnet-free' impeller were realized for a prototype blood-pump that made use of this magnetic bearing. The run-out of the impeller position at between 1000 r/min and 3000 r/min was less than 40 microm in the radial-controlled directions. The total power consumption of the magnetic bearing was less than 1 W at the same rotational speeds. When the pump was operated, a flow rate of 5 l/min against a head pressure of 78.66 kPa was achieved at a rotational speed of 4000 r/min, which is sufficient for extracorporeal circulation support. The proposed technology offers the advantage of low-cost mass production of disposable pump heads. PMID:22320054

  9. Automatic system for noninvasive blood pressure determination in rotary pump recipients.

    PubMed

    Schima, Heinrich; Boehm, Herbert; Huber, Leopold; Schmallegger, Helmut; Vollkron, Michael; Hiesmayr, Michael; Noisser, Robert; Wieselthaler, Georg

    2004-05-01

    In patients with implanted rotary pumps, the arterial pressure pulsatility is usually far lower than in normal individuals. Depending on the remaining degree of pulsatility, cuff-based systems such as the classical Riva-Rocci-determination of arterial blood pressure and correlated sounds or pressure measurements based on cuffpressure oscillations become inaccurate or even impossible. Therefore, a system was developed which evaluates the flow in the radial artery using an ultrasound wristwatch sensor, and this additional information is used for pressure determination. A computerized data acquisition and cuff-control system based on a PC using Matlab software, a wristwatch ultrasound device, and a compressor-driven pressure cuff was set up. The cuff was controlled for automatic inflation and deflation cycles. Cuff pressure and arterial flow was recorded. Several algorithm strategies were developed, which gave data for systolic blood pressure and heart rate together with a reliability index for data quality. Finally, the new algorithms were implemented in a microcontroller system. Comparisons with invasive measurements showed excellent correlation with systolic blood pressure (mean deltaP -0.3 mm Hg, n = 28). During exercise of rotary pump patients and therefore enhanced pulsatility the difference from manual evaluation was -2.1 mm Hg (n = 18). In conclusion, adaptation of the classical cuff-pressure method with ultrasound evaluation of peripheral flow allows reliable determination of blood pressure in patients with low pulsatility resulting from implanted rotary cardiac assist pumps. By development of a wristwatch sensor and an automatic control system a robust method for daily use could be developed. PMID:15113339

  10. The effects of residual pump blood on patient plasma free haemoglobin levels post cardiac surgery.

    PubMed

    H, Schotola; Aj, Wetz; Af, Popov; I, Bergmann; Bc, Danner; Fa, Schöndube; M, Bauer; A, Bräuer

    2016-09-01

    At the end of cardiopulmonary bypass, there are invariably several hundred millilitres of residual pump blood in the reservoir, which can either be re-transfused or discarded. The objective of this prospective observational study was to investigate the quality of the residual pump blood, focusing on plasma free haemoglobin (pfHb) and blood cell counts. Fifty-one consecutive patients were included in the study. Forty-nine units of residual pump blood and 58 units of transfused red blood cell (RBC) concentrates were analysed. The mean preoperative pfHb of the patients was 0.057 ± 0.062 g/l, which increased gradually to 0.55 ± 0.36 g/l on arrival in the intensive care unit postoperatively. On the first postoperative day, the mean pfHb had returned to within the normal range. Our data showed that haemoglobin, haematocrit, and erythrocyte counts of residual pump blood were approximately 40% of the values in standardised RBC concentrates. Plasma free haemoglobin was significantly higher in residual pump blood compared to RBC concentrates, and nearly twice as high as the pfHb in patient blood samples taken contemporaneously. Our findings indicate that residual pump blood pfHb levels are markedly higher compared to patients' blood and RBC concentrates, but that its administration does not significantly increase patients' pfHb levels. PMID:27608341

  11. Mechanical cavopulmonary assist for the univentricular Fontan circulation using a novel folding propeller blood pump.

    PubMed

    Throckmorton, Amy L; Ballman, Kimberly K; Myers, Cynthia D; Litwak, Kenneth N; Frankel, Steven H; Rodefeld, Mark D

    2007-01-01

    A blood pump specifically designed to operate in the unique anatomic and physiologic conditions of a cavopulmonary connection has never been developed. Mechanical augmentation of cavopulmonary blood flow in a univentricular circulation would reduce systemic venous pressure, increase preload to the single ventricle, and temporarily reproduce a scenario analogous to the normal two-ventricle circulation. We hypothesize that a folding propeller blood pump would function optimally in this cavopulmonary circulation. The hydraulic performance of a two-bladed propeller prototype was characterized in an experimental flow loop using a blood analog fluid for 0.5-3.5 lpm at rotational speeds of 3,600-4,000 rpm. We also created five distinctive blood pump designs and evaluated their hydraulic performance using computational fluid dynamics (CFD). The two-bladed prototype performed well over the design range of 0.5-3.5 lpm, producing physiologic pressure rises of 5-18 mm Hg. Building upon this proof-of-concept testing, the CFD analysis of the five numerical models predicted a physiologic pressure range of 5-40 mm Hg over 0.5-4 lpm for rotational speeds of 3,000-7,000 rpm. These preliminary propeller designs and the two-bladed prototype achieved the expected hydraulic performance. Optimization of these configurations will reduce fluid stress levels, remove regions of recirculation, and improve the hydraulic performance of the folding propeller. This propeller design produces the physiologic pressures and flows that are in the ideal range to mechanically support the cavopulmonary circulation and represents an exciting new therapeutic option for the support of a univentricular Fontan circulation. PMID:18043158

  12. Noninvasive blood-flow meter using a curved cannula with zero compensation for an axial flow blood pump.

    PubMed

    Kosaka, Ryo; Fukuda, Kyohei; Nishida, Masahiro; Maruyama, Osamu; Yamane, Takashi

    2013-01-01

    In order to monitor the condition of a patient using a left ventricular assist system (LVAS), blood flow should be measured. However, the reliable determination of blood-flow rate has not been established. The purpose of the present study is to develop a noninvasive blood-flow meter using a curved cannula with zero compensation for an axial flow blood pump. The flow meter uses the centrifugal force generated by the flow rate in the curved cannula. Two strain gauges served as sensors. The first gauges were attached to the curved area to measure static pressure and centrifugal force, and the second gauges were attached to straight area to measure static pressure. The flow rate was determined by the differences in output from the two gauges. The zero compensation was constructed based on the consideration that the flow rate could be estimated during the initial driving condition and the ventricular suction condition without using the flow meter. A mock circulation loop was constructed in order to evaluate the measurement performance of the developed flow meter with zero compensation. As a result, the zero compensation worked effectively for the initial calibration and the zero-drift of the measured flow rate. We confirmed that the developed flow meter using a curved cannula with zero compensation was able to accurately measure the flow rate continuously and noninvasively. PMID:24110631

  13. Development of a centrifugal pump with thick blades.

    PubMed

    Kim, W G; Chung, C H; Yang, W S; Park, Y N; Kim, H I; Kim, H C; Kang, S H

    2000-02-01

    We have developed a centrifugal blood pump with thick impeller blades (60% of pitch) to obtain a small tip clearance. An unshrouded impeller with 6 backward curved thick blades was used to reduce the dead zone between the shroud and upper casing. A streamline angle in volute was uniform in circumferential direction by continuity and angular momentum conservation. To prove the effectiveness of small tip clearance, performance and hemolysis tests were conducted on pumps with a tip clearance of 0.5, 1.5, and 2.0 mm at exit with the blade thickness of 60% of pitch, and with that of 1.0, 2.0, and 2.5 mm at exit with the thickness of 40% of pitch. The results showed that the smaller the tip clearance, the better the hydrodynamic and hemolytic performance. The best result was seen in the pump with tip clearance of 0.5 mm with a blade thickness of 60% of pitch. These results suggest that a centrifugal pump with thick blades and a small tip clearance can be a promising alternative as a cardiopulmonary bypass pump. PMID:10718771

  14. Rotary blood pump control strategy for preventing left ventricular suction.

    PubMed

    Wang, Yu; Koenig, Steven C; Slaughter, Mark S; Giridharan, Guruprasad A

    2015-01-01

    The risk for left ventricular (LV) suction while maintaining adequate perfusion over a range of physiologic conditions during continuous flow LV assist device (LVAD) support is a significant clinical concern. To address this challenge, we developed a suction prevention and physiologic control (SPPC) algorithm for use with axial and centrifugal LVADs. The SPPC algorithm uses two gain-scheduled, proportional-integral controllers that maintain a differential pump speed (ΔRPM) above a user-defined threshold to prevent LV suction, while maintaining an average reference differential pressure (ΔP) between the LV and aorta to provide physiologic perfusion. Efficacy and robustness of the proposed algorithm were evaluated in silico during simulated rest and exercise test conditions for (1) ΔP/ΔRPM excessive setpoint (ES); (2) rapid eightfold increase in pulmonary vascular resistance (PVR); and (3) ES and PVR. Hemodynamic waveforms (LV pressure and volume; aortic pressure and flow) were simulated and analyzed to identify suction event(s), quantify total flow output (pump + cardiac output), and characterize the performance of the SPPC algorithm. The results demonstrated that the proposed SPPC algorithm prevented LV suction while maintaining physiologic perfusion for all simulated test conditions, and warrants further investigation in vivo. PMID:25248043

  15. Computational flow study of the continuous flow ventricular assist device, prototype number 3 blood pump.

    PubMed

    Anderson, J B; Wood, H G; Allaire, P E; Bearnson, G; Khanwilkar, P

    2000-05-01

    A computational fluid dynamics study of blood flow in the continuous flow ventricular assist device, Prototype No. 3 (CFVAD3), which consists of a 4 blade shrouded impeller fully supported in magnetic bearings, was performed. This study focused on the regions within the pump where return flow occurs to the pump inlet, and where potentially damaging shear stresses and flow stagnation might occur: the impeller blade passages and the narrow gap clearance regions between the impeller-rotor and pump housing. Two separate geometry models define the spacing between the pump housing and the impeller's hub and shroud, and a third geometry model defines the pump's impeller and curved blades. The flow fields in these regions were calculated for various operating conditions of the pump. Pump performance curves were calculated, which compare well with experimentally obtained data. For all pump operating conditions, the flow rates within the gap regions were predicted to be toward the inlet of the pump, thus recirculating a portion of the impeller flow. Two smaller gap clearance regions were numerically examined to reduce the recirculation and to improve pump efficiency. The computational and geometry models will be used in future studies of a smaller pump to determine increased pump efficiency and the risk of hemolysis due to shear stress, and to insure the washing of blood through the clearance regions to prevent thrombosis. PMID:10848679

  16. Numerical analysis of the internal flow field in screw centrifugal blood pump based on CFD

    NASA Astrophysics Data System (ADS)

    Han, W.; Han, B. X.; Y Wang, H.; Shen, Z. J.

    2013-12-01

    As to the impeller blood pump, the high speed of the impeller, the local high shear force of the flow field and the flow dead region are the main reasons for blood damage. The screw centrifugal pump can effectively alleviate the problems of the high speed and the high shear stress for the impeller. The softness and non-destructiveness during the transfer process can effectively reduce the extent of the damage. By using CFD software, the characteristics of internal flow are analyzed in the screw centrifugal pump by exploring the distribution rules of the velocity, pressure and shear deformation rate of the blood when it flows through the impeller and the destructive effects of spiral blades on blood. The results show that: the design of magnetic levitation solves the sealing problems; the design of regurgitation holes solves the problem of the flow dead zone; the magnetic levitated microcirculation screw centrifugal pump can effectively avoid the vortex, turbulence and high shear forces generated while the blood is flowing through the pump. Since the distribution rules in the velocity field, pressure field and shear deformation rate of the blood in the blood pump are comparatively uniform and the gradient change is comparatively small, the blood damage is effectively reduced.

  17. A compact highly efficient and low hemolytic centrifugal blood pump with a magnetically levitated impeller.

    PubMed

    Asama, Junichi; Shinshi, Tadahiko; Hoshi, Hideo; Takatani, Setsuo; Shimokohbe, Akira

    2006-03-01

    A magnetically levitated (maglev) centrifugal blood pump (CBP), intended for use as a ventricular assist device, needs to be highly durable and reliable for long-term use without any mechanical failure. Furthermore, maglev CBPs should be small enough to be implanted into patients of various size and weight. We have developed a compact maglev CBP employing a two-degree-of-freedom controlled magnetic bearing, with a magnetically suspended impeller directly driven by an internal brushless direct current (DC) motor. The magnetic bearing actively controls the radial motion of the impeller and passively supports axial and angular motions using a permanent magnet embedded in the impeller. The overall dimensions of the maglev CBP are 65 mm in diameter and 40 mm in height. The total power consumption and pump efficiency for pumping 6 L/min against a head pressure of 105 mm Hg were 6.5 W and 21%, respectively. To evaluate the characteristics of the maglev CBP when subjected to a disturbance, excitation of the base, simulating the movement of the patient in various directions, and the sudden interception of the outlet tube connected with the pump in a mock circulatory loop, simulating an unexpected kink and emergent clamp during a heart surgery, were tested by monitoring the five-degree-of-freedom motion of the impeller. Furthermore, the hemolytic characteristics of the maglev CBP were compared with those of the Medtronic Biomedicus BPX-80, which demonstrated the superiority of the maglev CBP. PMID:16480390

  18. [Numerical assessment of impeller features of centrifugal blood pump based on fast hemolysis approximation model].

    PubMed

    Shou, Chen; Guo, Yongjun; Su, Lei; Li, Yongqian

    2014-12-01

    The impeller profile, which is one of the most important factors, determines the creation of shear stress which leads to blood hemolysis in the internal flow of centrifugal blood pump. The investigation of the internal flow field in centrifugal blood pump and the estimation of the hemolysis within different impeller profiles will provide information to improve the performance of centrifugal blood pump. The SST kappa-omega with low Reynolds correction was used in our laboratory to study the internal flow fields for four kinds of impellers of centrifugal blood pump. The flow fields included distributions of pressure field, velocity field and shear stress field. In addition, a fast numerical hemolysis approximation was adopted to calculate the normalized index of hemolysis (NIH). The results indicated that the pressure field distribution in all kinds of blood pump were reasonable, but for the log spiral impeller pump, the vortex and backflow were much lower than those of the other pumps, and the high shear stress zone was just about 0.004%, and the NIH was 0.0089. PMID:25868241

  19. Magnetic drive system for a new centrifugal rotary blood pump.

    PubMed

    Hilton, Andrew; Tansley, Geoff

    2008-10-01

    The purpose of this investigation was to design a novel magnetic drive and bearing system for a new centrifugal rotary blood pump (CRBP). The drive system consists of two components: (i) permanent magnets within the impeller of the CRBP; and (ii) the driving electromagnets. Orientation of the magnets varies from axial through to 60 degrees included out-lean (conical configuration). Permanent magnets replace the electromagnet drive to allow easier characterization. The performance characteristics tested were the axial force of attraction between the stator and rotor at angles of rotational alignment, Ø, and the corresponding torque at those angles. The drive components were tested for various magnetic cone angles, theta. The test was repeated for three backing conditions: (i) non-backed; (ii) steel-cupped; and (iii) steel plate back-iron, performed on an Instron tensile testing machine. Experimental results were expanded upon through finite element and boundary element analysis (BEM). The force/torque characteristics were maximal for a 12-magnet configuration at 0 degree cone angle with steel-back iron (axial force = 60 N, torque = 0.375 Nm). BEM showed how introducing a cone angle increases the radial restoring force threefold while not compromising axial bearing force. Magnets in the drive system may be orientated not only to provide adequate coupling to drive the CRBP, but to provide significant axial and radial bearing forces capable of withstanding over 100 m/s(2) shock excitation on the impeller. Although the 12 magnet 0 degree (theta) configuration yielded the greatest force/torque characteristic, this was seen as potentially unattractive as this magnetic cone angle yielded poor radial restoring force characteristics. PMID:18959665

  20. Recent Development in Hydrogen Peroxide Pumped Propulsion

    SciTech Connect

    Ledebuhr, A G; Antelman, D R; Dobie, D W; Gorman, T S; Jones, M S; Kordas, J F; McMahon, D H; Ng, L C; Nielsen, D P; Ormsby, A E; Pittenger, L C; Robinson, J A; Skulina, K M; Taylor, W G; Urone, D A; Wilson, B A

    2004-03-22

    This paper describes the development of a lightweight high performance pump-fed divert and attitude control system (DACS). Increased kinetic Kill Vehicles (KV) capabilities (higher .v and acceleration capability) will especially be needed for boost phase engagements where a lower mass KV DACS enables smaller overall interceptors. To increase KV performance while reducing the total DACS dry mass (<10 kg), requires a design approach that more closely emulates those found in large launch vehicles, where pump-fed propulsion enables high propellant-mass-fraction systems. Miniaturized reciprocating pumps, on a scale compatible with KV applications, offer the potential of a lightweight DACS with both high {Delta}v and acceleration capability, while still enabling the rapid pulsing of the divert thrusters needed in the end-game fly-in. Pumped propulsion uses lightweight low-pressure propellant tanks, as the main vehicle structure and eliminates the need for high-pressure gas bottles, reducing mass and increasing the relative propellant load. Prior work used hydrazine and demonstrated a propellant mass fraction >0.8 and a vehicle propulsion dry mass of {approx}3 kg. Our current approach uses the non-toxic propellants 90% hydrogen peroxide and kerosene. This approach enables faster development at lower costs due to the ease of handling. In operational systems these non-toxic propellants can simplify the logistics for manned environments including shipboard applications. This DACS design configuration is expected to achieve sufficient mass flows to support divert thrusters in the 1200 N to 1330 N (270 lbf to 300 lbf) range. The DACS design incorporates two pairs of reciprocating differential piston pumps (oxidizer and fuel), a warm-gas drive system, compatible bi-propellant thrusters, lightweight valves, and lightweight low-pressure propellant tanks. This paper summarizes the current development status and plans.

  1. Inducer analysis/pump model development

    NASA Technical Reports Server (NTRS)

    Cheng, Gary C.

    1994-01-01

    Current design of high performance turbopumps for rocket engines requires effective and robust analytical tools to provide design information in a productive manner. The main goal of this study was to develop a robust and effective computational fluid dynamics (CFD) pump model for general turbopump design and analysis applications. A finite difference Navier-Stokes flow solver, FDNS, which includes an extended k-epsilon turbulence model and appropriate moving zonal interface boundary conditions, was developed to analyze turbulent flows in turbomachinery devices. In the present study, three key components of the turbopump, the inducer, impeller, and diffuser, were investigated by the proposed pump model, and the numerical results were benchmarked by the experimental data provided by Rocketdyne. For the numerical calculation of inducer flows with tip clearance, the turbulence model and grid spacing are very important. Meanwhile, the development of the cross-stream secondary flow, generated by curved blade passage and the flow through tip leakage, has a strong effect on the inducer flow. Hence, the prediction of the inducer performance critically depends on whether the numerical scheme of the pump model can simulate the secondary flow pattern accurately or not. The impeller and diffuser, however, are dominated by pressure-driven flows such that the effects of turbulence model and grid spacing (except near leading and trailing edges of blades) are less sensitive. The present CFD pump model has been proved to be an efficient and robust analytical tool for pump design due to its very compact numerical structure (requiring small memory), fast turnaround computing time, and versatility for different geometries.

  2. Sensorless Viscosity Measurement in a Magnetically-Levitated Rotary Blood Pump.

    PubMed

    Hijikata, Wataru; Rao, Jun; Abe, Shodai; Takatani, Setsuo; Shinshi, Tadahiko

    2015-07-01

    Controlling the flow rate in an implantable rotary blood pump based on the physiological demand made by the body is important. Even though various methods to estimate the flow rate without using a flow meter have been proposed, no adequate method for measuring the blood viscosity, which is necessary for an accurate estimate of the flow rate, without using additional sensors or mechanisms in a noninvasive way, has yet been realized. We have developed a sensorless method for measuring viscosity in magnetically levitated rotary blood pumps, which requires no additional sensors or mechanisms. By applying vibrational excitation to the impeller using a magnetic bearing, we measured the viscosity of the working fluid by measuring the phase difference between the current in the magnetic bearing and the displacement of the impeller. The measured viscosity showed a high correlation (R(2)  > 0.992) with respect to a reference viscosity. The mean absolute deviation of the measured viscosity was 0.12 mPa·s for several working fluids with viscosities ranging from 1.18 to 5.12 mPa·s. The proposed sensorless measurement method has the possibility of being utilized for estimating flow rate. PMID:25920684

  3. Development of a simulated smart pump interface.

    PubMed

    Elias, Beth L; Moss, Jacqueline A; Shih, Alan; Dillavou, Marcus

    2014-01-01

    Medical device user interfaces are increasingly complex, resulting in a need for evaluation in clinicallyaccurate settings. Simulation of these interfaces can allow for evaluation, training, and use for research without the risk of harming patients and with a significant cost reduction over using the actual medical devices. This pilot project was phase 1 of a study to define and evaluate a methodology for development of simulated medical device interface technology to be used for education, device development, and research. Digital video and audio recordings of interface interactions were analyzed to develop a model of a smart intravenous medication infusion pump user interface. This model was used to program a high-fidelity simulated smart intravenous medication infusion pump user interface on an inexpensive netbook platform. PMID:24189715

  4. In Vitro Testing of a Novel Blood Pump Designed for Temporary Extracorporeal Support

    PubMed Central

    Spurlock, DJ; Ranney, DN; Fracz, E; Mazur, DE; Bartlett, RH; Haft, JW

    2012-01-01

    Extracorporeal blood pumps are used as temporary ventricular assist devices or for extracorporeal membrane oxygenation. The ideal pump would be intrinsically self-regulating, carry no risk of cavitation or excessive inlet suction, be afterload insensitive, and valveless thus reducing thrombogenicity. Currently used technology, including roller, centrifugal, and pneumatic pulsatile pumps, does not meet these requirements. We studied a non-occlusive peristaltic pump (M-Pump) in two mock circulatory loops, and compared the performance to a frequently used centrifugal pump and a modified prototype of the M-Pump (the BioVAD). The simple resistance loop consisted of the investigated pump, a fixed height reservoir at 150 mmHg, and a variable inflow reservoir. The pulsatile circulation utilized a mock patient simulator with adjustable resistance elements connected to a pneumatic pulsatile pump. The M-Pump intrinsically regulated flow with changing preload, was afterload insensitive, and did not cavitate, unlike the centrifugal pump. The BioVAD also demonstrated these features, and could augment output with use of vacuum assistance. A non-occlusive peristaltic pump may be superior for short term extracorporeal circulatory assist by mitigating risks of excessive inlet suction, afterload sensitivity, and thrombosis. PMID:22236624

  5. In vitro testing of a novel blood pump designed for temporary extracorporeal support.

    PubMed

    Spurlock, David J; Ranney, David N; Fracz, Emilia M; Mazur, Daniel E; Bartlet, R H; Haft, Jonathan W

    2012-01-01

    Extracorporeal blood pumps are used as temporary ventricular assist devices or for extracorporeal membrane oxygenation. The ideal pump would be intrinsically self-regulating, carry no risk of cavitation or excessive inlet suction, be afterload insensitive, and valveless thus reducing thrombogenicity. Currently used technology, including roller, centrifugal, and pneumatic pulsatile pumps, does not meet these requirements. We studied a nonocclusive peristaltic pump (M-Pump) in two mock circulatory loops and compared the performance to a frequently used centrifugal pump and a modified prototype of the M-Pump (the BioVAD). The simple resistance loop consisted of the investigated pump, a fixed height reservoir at 150 mm Hg, and a variable inflow reservoir. The pulsatile circulation used a mock patient simulator with adjustable resistance elements connected to a pneumatic pulsatile pump. The M-Pump intrinsically regulated flow with changing preload, was afterload insensitive, and did not cavitate, unlike the centrifugal pump. The BioVAD also demonstrated these features and could augment output with the use of vacuum assistance. A nonocclusive peristaltic pump may be superior for short-term extracorporeal circulatory assist by mitigating risks of excessive inlet suction, afterload sensitivity, and thrombosis. PMID:22236624

  6. Elementary theory of synchronous arterio-arterial blood pumps

    NASA Technical Reports Server (NTRS)

    Jones, R. T.; Petscheck, H. E.; Kantrowitz, A. R.

    1976-01-01

    In the technique of arterio-arterial pumping, a volume of fluid is withdrawn from the aorta during systole and reinjected during diastole, thereby reducing the systolic pressure of the heart and adding energy to the systemic circulation. It is found that an upper bound for the effectiveness of such devices is given by a formula that considers stroke output of the unaided heart and the increment caused by the pump with a stroke. The division of effort of the pump between the reduction of pressure and the increase of flow depends on the physiological mechanical impedance of the heart. The total effect is, however, independent of the impedance.

  7. Numerical study of a centrifugal blood pump with different impeller profiles.

    PubMed

    Song, Guoliang; Chua, Leok Poh; Lim, Tau Meng

    2010-01-01

    Computational fluid dynamic simulations of the Kyoto-NTN magnetically suspended centrifugal blood pump with 16 forward-bending blades (16FB), 16 straight blades (16SB), and eight backward-bending blades (8BB) impellers were performed in this study. Commercial CFD software package FLUENT were used as the solver. The purpose of this study is to find out how the impeller blade profiles affect the inner flow and the performance of the centrifugal blood pump. The simulations were carried out with the same impeller rotating speed of 2,000 rpm and pump flow rate of 5 L/min to compare the three pump models. It was found that the 16SB impeller can produce higher pressure head than the 16FB and 8BB impellers under the same impeller rotating speed and pump flow rate. The flow particle tracing was carried out to estimate the blood damage level caused by the three different impeller profiles. It was found that the 16FB and 8BB models have caused the highest and lowest blood damage, respectively. The 16SB is recommended among the three pumps because it can generate the highest pressure head and induce mild blood damage index, although it was higher than that of the 8BB model. PMID:20019595

  8. Development of a centrifugal pump with improved antithrombogenicity and hemolytic property for chronic circulatory support.

    PubMed

    Taenaka, Y; Wakisaka, Y; Masuzawa, T; Tatsumi, E; Toda, K; Miyazaki, K; Eya, K; Baba, Y; Nakatani, T; Ohno, T; Nishimura, T; Takano, H

    1996-06-01

    A centrifugal pump with a unique structure has been developed for chronic support. The pump is driven by a magnetic coupling and has no rotating shaft, no seal around the rotating part, and a balancing hole at the center of the impeller and the thrust bearing. The pump was improved in stepwise fashion to realize good antithrombogenicity and low hemolysis. The first pump, the National Cardiovascular Center (NCVC)-0, had an impeller with 4 rectangular and curved vanes; 6 triangularly shaped curved vanes were employed in the second model, the NCVC-1, to reduce trauma to the blood. In the third design, the NCVC-2, the central hole was enlarged, and the thrust bearing shoulder was rounded so that blood washing was enhanced around the impeller; stream lines also were smoothed for improved antithrombogenicity. The hemolytic property of the device was evaluated in vitro with heparinized fresh goat blood; hemolysis indexes of the NCVC-0, -1, and -2 were 0.05, 0.01, and 0.006 g per 100 L, respectively. Antithrombogenicity of the pumps was examined in animal experiments as a left heart bypass device in goals weighing 52-75 kg. Six NCVC-0 pumps were driven for 14 to 33 (22.0 +/- 7.6) days in goats receiving the antiplatelet drug cilostazol orally. Four NCVC-1 pumps ran for 1 to 80 (28.5 +/- 30.6) days with the same drug regimen in 2 cases and with no anticoagulation therapy in 2 cases. After 3 preliminary 1-week tests of NCVC-2 pumps in animals, the pump was installed in 3 goats; 2 pumps were still running on the 182nd and 58th pumping day. Intracorporeal implantation also was attempted successfully. The results indicate that this pump has promising features for chronic support although longer term and additional evaluations are necessary. PMID:8817945

  9. Design and parameter estimation of hybrid magnetic bearings for blood pump applications

    NASA Astrophysics Data System (ADS)

    Lim, Tau Meng; Zhang, Dongsheng; Yang, Juanjuan; Cheng, Shanbao; Low, Sze Hsien; Chua, Leok Poh; Wu, Xiaowei

    2009-10-01

    This paper discusses the design and parameter estimation of the dynamics characteristics of a high-speed hybrid magnetic bearings (HMBs) system for axial flow blood pump applications. The rotor/impeller of the pump is driven by a three-phase permanent magnet (PM) brushless and sensorless DC motor. It is levitated by two HMBs at both ends in five-degree-of-freedom with proportional-integral-derivative (PID) controllers; among which four radial directions are actively controlled and one axial direction is passively controlled. Test results show that the rotor can be stably supported to speeds of 14,000 rpm. The frequency domain parameter estimation technique with statistical analysis is adopted to validate the stiffness and damping coefficients of the HMBs system. A specially designed test rig facilitated the estimation of the bearing's coefficients in air—in both the radial and axial directions. The radial stiffness of the HMBs is compared to the Ansoft's Maxwell 2D/3D finite element magnetostatic results. Experimental estimation showed that the dynamics characteristics of the HMBs system are dominated by the frequency-dependent stiffness coefficients. The actuator gain was also successfully calibrated and may potentially extend the parameter estimation technique developed in the study of identification and monitoring of the pump's dynamics properties under normal operating conditions with fluid.

  10. Development of an algorithm to regulate pump output for a closed air-loop type pneumatic biventricular assist device.

    PubMed

    Nam, Kyoung Won; Lee, Jung Joo; Hwang, Chang Mo; Choi, Jaesoon; Choi, Hyuk; Choi, Seong Wook; Sun, Kyung

    2009-12-01

    The closed air space-type of extracorporeal pneumatic ventricular assist device (VAD) developed by the Korea Artificial Organ Center utilizes a bellows-transforming mechanism to generate the air pressure required to pump blood. This operating mechanism can reduce the size and weight of the driving unit; however, the output of the blood pump can be affected by the pressure loading conditions of the blood sac. Therefore, to guarantee a proper pump output level, regardless of the pressure loading conditions that vary over time, automatic pump output regulation of the blood pump is required. We describe herein a pump output regulation algorithm that was developed to maintain pump output around a reference level against various afterload pressures, and verified the pump performance in vitro. Based on actual operating conditions in animal experiments, the pumping rate was limited to 40-84 beats per minute, and the afterload pressure was limited to 80-150 mm Hg. The tested reference pump output was 4.0 L/min. During experiments, the pump output was successfully and automatically regulated within the preset area regardless of the varying afterload conditions. The results of this preliminary experiment can be used as the basis for an automatic control algorithm that can enhance the stability and reliability of the applied VAD. PMID:19604228

  11. Disposable MagLev centrifugal blood pump utilizing a cone-shaped impeller.

    PubMed

    Hijikata, Wataru; Sobajima, Hideo; Shinshi, Tadahiko; Nagamine, Yasuyuki; Wada, Suguru; Takatani, Setsuo; Shimokohbe, Akira

    2010-08-01

    To enhance the durability and reduce the blood trauma of a conventional blood pump with a cone-shaped impeller, a magnetically levitated (MagLev) technology has been applied to the BioPump BPX-80 (Medtronic Biomedicus, Inc., Minneapolis, MN, USA), whose impeller is supported by a mechanical bearing. The MagLev BioPump (MagLev BP), which we have developed, has a cone-shaped impeller, the same as that used in the BPX-80. The suspension and driving system, which is comprised of two degrees of freedom, radial-controlled magnetic bearing, and a simply structured magnetic coupling, eliminates any physical contact between the impeller and the housing. To reduce both oscillation of the impeller and current in the coils, the magnetic bearing system utilizes repetitive and zero-power compensators. In this article, we present the design of the MagLev mechanism, measure the levitational accuracy of the impeller and pressure-flow curves (head-quantity [HQ] characteristics), and describe in vitro experiments designed to measure hemolysis. For the flow-induced hemolysis of the initial design to be reduced, the blood damage index was estimated by using computational fluid dynamics (CFD) analysis. Stable rotation of the impeller in a prototype MagLev BP from 0 to 2750 rpm was obtained, yielding a flow rate of 5 L/min against a head pressure in excess of 250 mm Hg. Because the impeller of the prototype MagLev BP is levitated without contact, the normalized index of hemolysis was 10% less than the equivalent value with the BPX-80. The results of the CFD analysis showed that the shape of the outlet and the width of the fluid clearances have a large effect on blood damage. The prototype MagLev BP satisfied the required HQ characteristics (5 L/min, 250 mm Hg) for extracorporeal circulation support with stable levitation of the impeller and showed an acceptable level of hemolysis. The simulation results of the CFD analysis indicated the possibility of further reducing the blood damage of

  12. Recent Developments in Magnetically Coupled Vane Pumps for Tritium Service

    SciTech Connect

    Capuder, F. C.; Quigley, L. T.; Baker, C. K.

    1985-04-01

    Despite advances in shaft sealing, a totally reliable shaft seal for two-stage vane pumps has never been developed. Therefore, the magnetically coupled vane pump drive was developed to solve the critical problem of tritium leakage at the shaft seals of vane pumps. As a result, radioactive contamination of the work area and loss of valuable material can now be prevented.

  13. Geometric optimization of a step bearing for a hydrodynamically levitated centrifugal blood pump for the reduction of hemolysis.

    PubMed

    Kosaka, Ryo; Yada, Toru; Nishida, Masahiro; Maruyama, Osamu; Yamane, Takashi

    2013-09-01

    A hydrodynamically levitated centrifugal blood pump with a semi-open impeller has been developed for mechanical circulatory assistance. However, a narrow bearing gap has the potential to cause hemolysis. The purpose of the present study is to optimize the geometric configuration of the hydrodynamic step bearing in order to reduce hemolysis by expansion of the bearing gap. First, a numerical analysis of the step bearing, based on lubrication theory, was performed to determine the optimal design. Second, in order to assess the accuracy of the numerical analysis, the hydrodynamic forces calculated in the numerical analysis were compared with those obtained in an actual measurement test using impellers having step lengths of 0%, 33%, and 67% of the vane length. Finally, a bearing gap measurement test and a hemolysis test were performed. As a result, the numerical analysis revealed that the hydrodynamic force was the largest when the step length was approximately 70%. The hydrodynamic force calculated in the numerical analysis was approximately equivalent to that obtained in the measurement test. In the measurement test and the hemolysis test, the blood pump having a step length of 67% achieved the maximum bearing gap and reduced hemolysis, as compared with the pumps having step lengths of 0% and 33%. It was confirmed that the numerical analysis of the step bearing was effective, and the developed blood pump having a step length of approximately 70% was found to be a suitable configuration for the reduction of hemolysis. PMID:23834855

  14. Computational fluid dynamics-based hydraulic and hemolytic analyses of a novel left ventricular assist blood pump.

    PubMed

    Yang, Xiao-Chen; Zhang, Yan; Gui, Xing-Min; Hu, Sheng-Shou

    2011-10-01

    The advent of various technologies has allowed mechanical blood pumps to become more reliable and versatile in recent decades. In our study group, a novel structure of axial flow blood pump was developed for assisting the left ventricle. The design point of the left ventricular assist blood pump 25 (LAP-25) was chosen at 4 Lpm with 100 mm Hg according to our clinical practice. Computational fluid dynamics was used to design and analyze the performance of the LAP-25. In order to obtain a required hydraulic performance and a satisfactory hemolytic property in the LAP-25 of a smaller size, a novel structure was developed including an integrated shroud impeller, a streamlined impeller hub, and main impeller blades with splitter blades; furthermore, tandem cascades were introduced in designing the diffuser. The results of numerical simulation show the LAP-25 can generate flow rates of 3-5 Lpm at rotational speeds of 8500-10,500 rpm, producing pressure rises of 27.5-148.3 mm Hg with hydraulic efficiency points ranging from 13.4 to 27.5%. Moreover, the fluid field and the hemolytic property of the LAP-25 were estimated, and the mean hemolysis index of the pump was 0.0895% with Heuser's estimated model. In conclusion, the design of the LAP-25 shows an acceptable result. PMID:21517911

  15. Power consumption of rotary blood pumps: pulsatile versus constant-speed mode.

    PubMed

    Pirbodaghi, Tohid; Cotter, Chris; Bourque, Kevin

    2014-12-01

    We investigated the power consumption of a HeartMate III rotary blood pump based on in vitro experiments performed in a cardiovascular simulator. To create artificial-pulse mode, we modulated the pump speed by decreasing the mean speed by 2000 rpm for 200 ms and then increasing speed by 4000 rpm (mean speeds plus 2000 rpm) for another 200 ms, creating a square waveform shape. The HeartMate III was connected to a cardiovascular simulator consisting of a hydraulic pump system to simulate left ventricle pumping action, arterial and venous compliance chambers, and an adjustable valve for peripheral resistance to facilitate the desired aortic pressure. The simulator operated based on Suga's elastance model to mimic the Starling response of the heart, thereby reproducing physiological blood flow and pressure conditions. We measured the instantaneous total electrical current and voltage of the pump to evaluate its power consumption. The aim was to answer these fundamental questions: (i) How does pump speed modulation affect pump power consumption? (ii) How does the power consumption vary in relation to external pulsatile flow? The results indicate that speed modulation and external pulsatile flow both moderately increase the power consumption. Increasing the pump speed reduces the impact of external pulsatile flow. PMID:24842216

  16. Development of a miniature undulation pump for the distributed artificial heart.

    PubMed

    Abe, Y; Ono, T; Isoyama, T; Mochizuki, S; Iwasaki, K; Chinzei, T; Saito, I; Kouno, A; Imachi, K

    2000-08-01

    Research of the distributed artificial heart is important not only to acquire the means of individual organ perfusion but also to clarify the characteristics of the organ and the mechanism of blood distribution. To investigate the distributed artificial heart, the miniature undulation pump was developed. The outer diameter and the thickness of the developed pump were 38 mm and 11 mm, respectively. The priming volume of the pump was 3.2 ml. The total size including the motor unit was 38 mm in diameter and 32 mm in length. The total weight was 67.5 g. The total volume was 27.5 ml. The pump was driven with pulse width modulation by using a 1 chip motor controller. More than 5 L/min of continuous output could be obtained. The results showed that the developed miniature undulation pump system had enough performance for individual organ perfusion. PMID:10971257

  17. Infusion pumps and red blood cell damage in transfusion therapy: an integrative revision of the academic literature 1

    PubMed Central

    Wilson, Ana Maria Miranda Martins; Peterlini, Maria Angélica Sorgini; Pedreira, Mavilde da Luz Gonçalves

    2016-01-01

    ABSTRACT Objectives: to obtain information from scientific literature concerning infusion pumps used in administering erythrocyte (red blood cells) and to evaluate the implications in the practical use of this equipment by nurses when conducting transfusions. Method: an integrative revision of the following scientific databases: Pubmed/Medline, Scopus, the Virtual Library for Health, SciELO, Web of Science and Cochrane. The following descriptors were used: "infusion pumps", "blood transfusion", "transfused erythrocyte" and "hemolyis". There were no restrictions on the scope of the initial data and it was finalized in December 2014. 17 articles were identified in accordance with the inclusion and exclusion criteria. Results: all of the publications included in the studies were experimental in vitro and covered the use of infusion pumps in transfusion therapy. A summary of the data was presented in a synoptic chart and an analysis of it generated the following categories: cellular damage and the infusion mechanism. Conclusion: infusion pumps can be harmful to erythrocytes based on the infusion mechanism that is used, as the linear peristaltic pump is more likely to cause hemolysis. Cellular damage is related to the plasmatic liberation of markers that largely dominate free hemoglobin and potassium. We reiterate the need for further research and technological investments to guide the development of protocols that promote safe practices and that can contribute to future clinical studies. PMID:27533272

  18. Fault detection in rotary blood pumps using motor speed response.

    PubMed

    Soucy, Kevin G; Koenig, Steven C; Sobieski, Michael A; Slaughter, Mark S; Giridharan, Guruprasad A

    2013-01-01

    Clinical acceptance of ventricular assist devices (VADs) as long-term heart failure therapy requires safe and effective circulatory support for a minimum of 5 years. Yet, VAD failure beyond 2 years of support is still a concern. Currently, device controllers cannot consistently predict VAD failure modes, and undetected VAD faults may lead to catastrophic device failure. To minimize this risk, a model-based algorithm for reliable VAD fault detection that only requires VAD revolutions per minute (rpm) was developed. The algorithm was tested using computer models of the human cardiovascular system simulating heart failure and axial flow (AF) or centrifugal flow (CF) VADs. Ventricular assist device rpm was monitored after a step down of motor current for normal and simulated fault conditions (>750 faults). The ability to detect fault conditions with 1%, 5%, and 10% rpm measurement noise was evaluated. All failure modes affected the VAD rpm responses to the motor current step down. Fault detection rates were >95% for AF and >89% for CF VADs, even with 10% rpm measurement noise. The VAD rpm responses were significantly altered by blood viscosity (3.5-6.2 cP), which should be accounted for in clinical application. The proposed VAD fault detection algorithm may deliver a convenient and nonintrusive way to minimize catastrophic device failures. PMID:23820281

  19. Parametric study of blade tip clearance, flow rate, and impeller speed on blood damage in rotary blood pump.

    PubMed

    Kim, Nahn Ju; Diao, Chenguang; Ahn, Kyung Hyun; Lee, Seung Jong; Kameneva, Marina V; Antaki, James F

    2009-06-01

    Phenomenological studies on mechanical hemolysis in rotary blood pumps have provided empirical relationships that predict hemoglobin release as an exponential function of shear rate and time. However, these relations are not universally valid in all flow circumstances, particularly in small gap clearances. The experiments in this study were conducted at multiple operating points based on flow rate, impeller speed, and tip gap clearance. Fresh bovine red blood cells were resuspended in phosphate-buffered saline at about 30% hematocrit, and circulated for 30 min in a centrifugal blood pump with a variable tip gap, designed specifically for these studies. Blood damage indices were found to increase with increased impeller speed or decreased flow rate. The hemolysis index for 50-microm tip gap was found to be less than 200-microm gap, despite increased shear rate. This is explained by a cell screening effect that prevents cells from entering the smaller gap. It is suggested that these parameters should be reflected in the hemolysis model not only for the design, but for the practical use of rotary blood pumps, and that further investigation is needed to explore other possible factors contributing to hemolysis. PMID:19473143

  20. Real-Time Observation of Thrombus Growth Process in an Impeller of a Hydrodynamically Levitated Centrifugal Blood Pump by Near-Infrared Hyperspectral Imaging.

    PubMed

    Sakota, Daisuke; Murashige, Tomotaka; Kosaka, Ryo; Fujiwara, Tatsuki; Nishida, Masahiro; Maruyama, Osamu

    2015-08-01

    Understanding the thrombus formation in cardiovascular devices such as rotary blood pumps is the most important issue in developing more hemocompatible devices. The objective of this study was to develop a hyperspectral imaging (HSI) method to visualize the thrombus growth process within a rotary blood pump and investigate the optical properties of the thrombus. An in vitro thrombogenic test was conducted using fresh porcine blood and a specially designed hydrodynamically levitated centrifugal blood pump with a transparent bottom. The pump rotating at 3000 rpm circulated the blood at 1.0 L/min. The bottom surface of the pump was illuminated with white light pulsed at the same frequency as the pump rotation, and the backward-scattered light was imaged using the HSI system. Using stroboscopic HSI and an image construction algorithm, dynamic spectral imaging at wavelengths ranging from 608 to 752 nm within the rotating pump was achieved. After completing the experiment, we collected the red thrombus formed in the pump impeller and quantified the thrombus hemoglobin concentration (Hbthrombus ). The spectrum changed around the center of the impeller, and the area of change expanded toward the impeller flow path. The shape corresponded approximately to the shape of the thrombus. The spectrum change indicated that the light scattering derived from red blood cells decreased. The Hbthrombus was 4.7 ± 1.3 g/dL versus a total hemoglobin of 13 ± 0.87 g/dL. The study revealed that Hbthrombus was reduced by the surrounding blood flow. PMID:26234451

  1. Comparison of Warm Blood Cardioplegia Delivery With or Without the Use of a Roller Pump

    PubMed Central

    Faber, Mizja M.; Noordzij, Peter G.; Hennink, Simon; Kelder, Hans; de Vroege, Roel; Waanders, Frans G.; Daeter, Edgar; Stehouwer, Marco C.

    2015-01-01

    Abstract: Various techniques for administration of blood cardioplegia are used worldwide. In this study, the effect of warm blood cardioplegia administration with or without the use of a roller pump on perioperative myocardial injury was studied in patients undergoing coronary artery bypass grafting using minimal extra-corporeal circuits (MECCs). Sixty-eight patients undergoing elective coronary bypass surgery with an MECC system were consecutively enrolled and randomized into a pumpless group (PL group: blood cardioplegia administration without roller pump) or roller pump group (RP group: blood cardioplegia administration with roller pump). No statistically significant differences were found between the PL group and RP group regarding release of cardiac biomarkers. Maximum postoperative biomarker values reached at T1 (after arrival intensive care unit) for heart-type fatty acid binding protein (2.7 [1.5; 6.0] ng/mL PL group vs. 3.2 [1.6; 6.3] ng/mL RP group, p = .63) and at T3 (first postoperative day) for troponin T high-sensitive (22.0 [14.5; 29.3] ng/L PL group vs. 21.1 [15.3; 31.6] ng/L RP group, p = .91), N-terminal pro-brain natriuretic peptide (2.1 [1.7; 2.9] ng/mL PL group vs. 2.6 [1.6; 3.6] ng/mL RP group, p = .48), and C-reactive protein (138 [106; 175] μg/mL PL group vs. 129 [105; 161] μg/mL RP group, p = .65). Besides this, blood cardioplegia flow, blood cardioplegia line pressure, and aortic root pressure during blood cardioplegia administration were similar between the two groups. Administration of warm blood cardioplegia with or without the use of a roller pump results in similar clinically acceptable myocardial protection. PMID:26834282

  2. Validation of an axial flow blood pump: computational fluid dynamics results using particle image velocimetry.

    PubMed

    Su, Boyang; Chua, Leok Poh; Wang, Xikun

    2012-04-01

    A magnetically suspended axial flow blood pump is studied experimentally in this article. The pump casing enclosed a three-blade straightener, a two-blade impeller shrouded by a permanent magnet-embedded cylinder, and a three-blade diffuser. The internal flow fields were simulated earlier using computational fluid dynamics (CFD), and the pump characteristic curves were determined. The simulation results showed that the internal flow field was basically streamlined, except the diffuser region. Particle image velocimetry (PIV) measurement of the 1:1 pump model was conducted to validate the CFD result. In order to ensure the optical access, an acrylic prototype was fabricated with the impeller driven by a servomotor instead, as the magnet is opaque. In addition to the transparent model, the blood analog fluid with the refractive index close to that of acrylic was used to avoid refraction. According to the CFD results, the axial flow blood pump could generate adequate pressure head at the rotating speed of 9500rpm and flow rate of 5L/min, and the same flow condition was applied during the PIV measurement. Through the comparisons, it was found that the experimental results were close to those obtained by CFD and had thus validated the CFD model, which could complement the limitation of the measurement in assessing the more detailed flow fields of the axial flow pump. PMID:22040356

  3. Pediatric ECMO outcomes: comparison of centrifugal versus roller blood pumps using propensity score matching.

    PubMed

    Barrett, Cindy S; Jaggers, James J; Cook, E Francis; Graham, Dionne A; Yarlagadda, Vasmi V; Teele, Sarah A; Almond, Christopher S; Bratton, Susan L; Seeger, John D; Dalton, Heidi J; Rycus, Peter T; Laussen, Peter C; Thiagarajan, Ravi R

    2013-01-01

    Centrifugal blood pumps are being increasingly utilized in children supported with extracorporeal membrane oxygenation (ECMO). Our aim was to determine if survival and ECMO-related morbidities in children supported with venoarterial (VA) ECMO differed by blood pump type.Children aged less than 18 years who underwent VA ECMO support from 2007 to 2009 and reported to the Extracorporeal Life Support Organization registry were propensity score matched (Greedy 1:1 matching) using pre-ECMO characteristics.A total of 2,656 (centrifugal = 2,231, roller = 425) patients were identified and 548 patients (274 per pump type) were included in the propensity score-matched cohort. Children supported with centrifugal pumps had increased odds of hemolysis (odds ratio [OR], 4.03 95% confidence interval [CI], 2.37-6.87), hyperbilirubinemia (OR, 5.48; 95% CI, 2.62-11.49), need for inotropic support during ECMO (OR, 1.54; 95% CI, 1.09-2.17), metabolic alkalosis (blood pH > 7.6) during ECMO (OR, 3.13; 95% CI, 1.49-6.54), and acute renal failure (OR, 1.61; 95% CI, 1.10-2.39). Survival to hospital discharge did not differ by pump type.In a propensity score-matched cohort of pediatric ECMO patients, children supported with centrifugal pumps had increased odds of ECMO-related complications. There was no difference in survival between groups. PMID:23438777

  4. Disposable magnetically levitated centrifugal blood pump: design and in vitro performance.

    PubMed

    Hoshi, Hideo; Asama, Junichi; Shinshi, Tadahiko; Ohuchi, Katsuhiro; Nakamura, Makoto; Mizuno, Tomohiro; Arai, Hirokuni; Shimokohbe, Akira; Takatani, Setsuo

    2005-07-01

    A magnetically levitated (MagLev) centrifugal blood pump (CBP) with a disposable pump head has been designed to realize a safe, easy-to-handle, reliable, and low-cost extracorporeal blood pump system. It consisted of a radial magnetic-coupled driver with a magnetic bearing having a two-degree freedom control and a disposable pump head unit with a priming volume of 24 mL. The easy on-off disposable pump head unit was made into a three-piece system consisting of the top and bottom housings, and the impeller-rotor assembly. The size and weight of the disposable pump unit were 75 mm x 45 mm and 100 g, respectively. Because the structure of the pump head unit is easily attachable and removable, the gap between the electromagnets of the stator and the target material in the rotor increased to 1.8 mm in comparison to the original integrated bearing system of 1.0 mm. The pump performance, power requirements, and controllability of the magnetic bearing revealed that from 1400 to 2400 rpm, the pump performance remained fairly unchanged. The amplitudes of the X- and Y-axis rotor oscillation increased to +/- 24 microm. The axial displacement of the rotor, 0.4 mm, toward the top housing was also observed at the pump rpm between 1400 and 2400. The axial and rotational stiffness of the bearing were 15.9 N/mm and 4.4 Nm/rad, respectively. The MagLev power was within 0.7 Watts. This study demonstrated the feasibility of a disposable, magnetically suspended CBP as the safe, reliable, easy-to-handle, low-cost extracorporeal circulation support device. PMID:15982279

  5. Hemolytic performance of a MagLev disposable rotary blood pump (MedTech Dispo): effects of MagLev gap clearance and surface roughness.

    PubMed

    Hoshi, Hideo; Asama, Junichi; Hijikata, Wataru; Hara, Chikara; Shinshi, Tadahiko; Yasuda, Toshitaka; Ohuchi, Katsuhiro; Shimokohbe, Akira; Takatani, Setsuo

    2006-12-01

    Mechanical shaft seal bearing incorporated in the centrifugal blood pumps contributes to hemolysis and thrombus formation. In addition, the problem of durability and corrosion of mechanical shaft seal bearing has been recently reported from the safety point of view. To amend the shortcomings of the blood-immersed mechanical bearings, a magnetic levitated centrifugal rotary blood pump (MedTech Dispo Model 1; Tokyo Medical and Dental University, Tokyo, Japan) has been developed for extracorporeal disposable application. In this study, the hemolytic performance of the MedTech Dispo Model 1 centrifugal blood pump system was evaluated, with special focus on the narrow blood path clearance at the magnetic bearing between rotor and stator, and on the pump housing surface roughness. A pump flow of 5 L/min against the head pressure of 100 mm Hg for 4 h was included in the hemolytic test conditions. Anticoagulated fresh porcine blood was used as a working fluid. The clearance of blood path at the magnetic bearing was in the range of 100-250 micro m. Pump housing surface roughness was controlled to be around Ra = 0.1-1.5 micro m. The lowest hemolytic results were obtained at the clearance of 250 micro m and with the polished surface (Ra = 0.1 micro m) yielding the normalized index of hemolysis (NIH) of less than 0.001 g/100 L, which was 1/5 of the Biopump BP-80 (Medtronic Inc., Minneapolis, MN, USA, and 1/4 of the BPX-80. In spite of rough surface and narrow blood path, NIH levels were less than clinically acceptable level of 0.005 g/100 L. The noncontact, levitated impeller system is useful to improve pump performance in blood environment. PMID:17181835

  6. Numerical Analysis of Blood Damage Potential of the HeartMate II and HeartWare HVAD Rotary Blood Pumps.

    PubMed

    Thamsen, Bente; Blümel, Bastian; Schaller, Jens; Paschereit, Christian O; Affeld, Klaus; Goubergrits, Leonid; Kertzscher, Ulrich

    2015-08-01

    Implantable left ventricular assist devices (LVADs) became the therapy of choice in treating end-stage heart failure. Although survival improved substantially and is similar in currently clinically implanted LVADs HeartMate II (HM II) and HeartWare HVAD, complications related to blood trauma are frequently observed. The aim of this study was to compare these two pumps regarding their potential blood trauma employing computational fluid dynamics. High-resolution structured grids were generated for the pumps. Newtonian flow was calculated, solving Reynolds-averaged Navier-Stokes equations with a sliding mesh approach and a k-ω shear stress transport turbulence model for the operating point of 4.5 L/min and 80 mm Hg. The pumps were compared in terms of volumes subjected to certain viscous shear stress thresholds, below which no trauma was assumed (von Willebrand factor cleavage: 9 Pa, platelet activation: 50 Pa, and hemolysis: 150 Pa), and associated residence times. Additionally, a hemolysis index was calculated based on a Eulerian transport approach. Twenty-two percent of larger volumes above 9 Pa were observed in the HVAD; above 50 Pa and 150 Pa the differences between the two pumps were marginal. Residence times were higher in the HVAD for all thresholds. The hemolysis index was almost equal for the HM II and HVAD. Besides the gap regions in both pumps, the inlet regions of the rotor and diffuser blades have a high hemolysis production in the HM II, whereas in the HVAD, the volute tongue is an additional site for hemolysis production. Thus, in this study, the comparison of the HM II and the HVAD using numerical methods indicated an overall similar tendency to blood trauma in both pumps. However, influences of turbulent shear stresses were not considered and effects of the pivot bearing in the HM II were not taken into account. Further in vitro investigations are required. PMID:26234447

  7. Development of a hybrid chemical/mechanical heat pump

    NASA Technical Reports Server (NTRS)

    Grzyll, Lawrence R.; Silvestri, John J.; Scaringe, Robert P.

    1991-01-01

    The authors present the current development status of a hybrid chemical/mechanical heat pump for low-lift applications. The heat pump provides electronics cooling by evaporating a pure refrigerant from an absorbent/refrigerant mixture in a generator/cold plate. The current development focused on evaluation of absorbent/refrigerant pairs, corrosion testing, pump and compressor design, and electronic cold plate design. Two cycle configurations were considered. The first configuration utilized a standard mechanical compressor and pump. The second cycle configuration investigated pumps and compressors with non-moving parts. An innovative generator/cold plate design is also presented. The development to date shows that this cycle has about the same performance as standard vapor compression heat pumps with standard refrigerants but may have some performance and reliability advantages over vapor compression heat pumps.

  8. Application of Drag-Reducing Polymer Solutions as Test Fluids for In Vitro Evaluation of Potential Blood Damage in Blood Pumps

    PubMed Central

    Daly, Amanda R.; Sobajima, Hideo; Olia, Salim E.; Takatani, Setsuo; Kameneva, Marina V.

    2011-01-01

    In vitro evaluation of the potential of a circulatory-assist device to damage blood cells has generally been performed using blood from various species. Problems with this approach include the variability of blood sensitivity to mechanical stress in different species, preparation of blood including the adjustment of hematocrit to a standard value, changes in the mechanical properties of blood that occur during storage, and necessity to pool blood samples to obtain an adequate amount of blood for in vitro circulating systems. We investigated whether the mechanical degradation of a drag-reducing polymer (DRP) solution resulting in the loss of drag-reducing ability can indicate the degree of shear-induced blood damage within blood pumps. DRP solution (polyethylene oxide, 4,500 kDa, 1,000 ppm) or porcine blood were driven through a turbulent flow system by a centrifugal pump, either the Bio-Pump BPX-80 (Medtronic, Inc.) or CentriMag (Levitronix LLC) at a constant pressure gradient of 300 mm Hg for 120 minutes. DRP mechanical degradation was evaluated by reduction of flow rate and solution viscosity. A proposed index of DRP mechanical degradation (PDI) is similar to the normalized index of hemolysis (NIH) typically used to quantify the results of in vitro testing of blood pumps. Results indicate that the mechanical degradation of DRP solutions may provide a sensitive standard method for the evaluation of potential blood trauma produced by blood pumps without the use of blood. PMID:20019596

  9. Numerical study of a bio-centrifugal blood pump with straight impeller blade profiles.

    PubMed

    Song, Guoliang; Chua, Leok Poh; Lim, Tau Meng

    2010-02-01

    Computational fluid dynamic simulations of the flow in the Kyoto-NTN (Kyoto University, Kyoto, Japan) magnetically suspended centrifugal blood pump with a 16-straight-bladed impeller were performed in the present study. The flow in the pump was assumed as unsteady and turbulent, and blood was treated as a Newtonian fluid. At the impeller rotating speed of 2000 rpm and flow rate of 5 L/min, the pump produces a pressure head of 113.5 mm Hg according to the simulation. It was found that the double volute of the pump has caused symmetrical pressure distribution in the volute passages and subsequently caused symmetrical flow patterns in the blade channels. Due to the tangentially increasing pressure in the volute passages, the flow through the blade channels initially increases at the low-pressure region and then decreases due to the increased pressure. The reverse flow and vortices have been identified in the impeller blade channels. The high shear stress of the flow in the pump mainly occurred at the inlet and outlet of the blade channels, the beginning of the volute passages and the regions around the tips of the cutwater and splitter plate. Higher shear stress is obtained when the tips of the cutwater and splitter plate are located at the impeller blade trailing edges than when they are located at the middle of the impeller blade channel. It was found that the blood damage index assessed based on the blood corpuscle path tracing of the present pump was about 0.94%, which has the same order of magnitude as those of the clinical centrifugal pumps reported in the literature. PMID:19817732

  10. Transient Stress- and Strain-Based Hemolysis Estimation in a Simplified Blood Pump

    PubMed Central

    Pauli, L.; Nam, J.; Pasquali, M.; Behr, M.

    2014-01-01

    SUMMARY We compare two approaches to numerical estimation of mechanical hemolysis in a simplified blood pump model. The stress-based model relies on the instantaneous shear stress in the blood flow, whereas the strain-based model uses an additional tensor equation to relate distortion of red blood cells to a shear stress measure. We use the newly proposed least-squares finite element method (LSFEM) to prevent negative concentration fields and show a stable and volume preserving LSFEM for the tensor equation. Application of both models to a simplified centrifugal blood pump at three different operating conditions show that the stress-based model overestimates the rate of hemolysis. The strain-based model is found to deliver lower hemolysis rates since it incorporates a more detailed description of biophysical phenomena into the simulation process. PMID:23922311

  11. Transient stress-based and strain-based hemolysis estimation in a simplified blood pump.

    PubMed

    Pauli, Lutz; Nam, Jaewook; Pasquali, Matteo; Behr, Marek

    2013-10-01

    We compare two approaches to numerical estimation of mechanical hemolysis in a simplified blood pump model. The stress-based model relies on the instantaneous shear stress in the blood flow, whereas the strain-based model uses an additional tensor equation to relate distortion of red blood cells to a shear stress measure. We use the newly proposed least-squares finite element method (LSFEM) to prevent negative concentration fields and show a stable and volume preserving LSFEM for the tensor equation. Application of both models to a simplified centrifugal blood pump at three different operating conditions shows that the stress-based model overestimates the rate of hemolysis. The strain-based model is found to deliver lower hemolysis rates because it incorporates a more detailed description of biophysical phenomena into the simulation process. PMID:23922311

  12. Feasibility of Pump Speed Modulation for Restoring Vascular Pulsatility with Rotary Blood Pumps.

    PubMed

    Ising, Mickey S; Sobieski, Michael A; Slaughter, Mark S; Koenig, Steven C; Giridharan, Guruprasad A

    2015-01-01

    Continuous flow (CF) left ventricular assist devices (LVAD) diminish vascular pressure pulsatility, which may be associated with clinically reported adverse events including gastrointestinal bleeding, aortic valve insufficiency, and hemorrhagic stroke. Three candidate CF LVAD pump speed modulation algorithms designed to augment aortic pulsatility were evaluated in mock flow loop and ischemic heart failure (IHF) bovine models by quantifying hemodynamic performance as a function of mean pump speed, modulation amplitude, and timing. Asynchronous and synchronous copulsation (high revolutions per minute [RPM] during systole, low RPM during diastole) and counterpulsation (low RPM during systole, high RPM during diastole) algorithms were tested for defined modulation amplitudes (±300, ±500, ±800, and ±1,100 RPM) and frequencies (18.75, 37.5, and 60 cycles/minute) at low (2,900 RPM) and high (3,200 RPM) mean LVAD speeds. In the mock flow loop model, asynchronous, synchronous copulsation, and synchronous counterpulsation algorithms each increased pulse pressure (ΔP = 931%, 210%, and 98% and reduced left ventricular external work (LVEW = 20%, 22%, 16%). Similar improvements in vascular pulsatility (1,142%) and LVEW (40%) were observed in the IHF bovine model. Asynchronous modulation produces the largest vascular pulsatility with the advantage of not requiring sensor(s) for timing pump speed modulation, facilitating potential clinical implementation. PMID:26102173

  13. Custom Unit Pump Development for the EVA PLSS

    NASA Technical Reports Server (NTRS)

    Schuller, Michael; Kurwitz, Cable; Little, Frank; Oinuma, Ryoji; Larsen, Ben; Goldman, Jeff; Reinis, Filip; Trevino, Luis

    2010-01-01

    This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell for NASA to design and test a pre-flight prototype pump for use in the Extra-vehicular activity (EVA) portable life support subsystem (PLSS). Major design decisions were driven by the need to reduce the pump s mass, power, and volume compared to the existing PLSS pump. In addition, the pump must accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure drop when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure drops. An additional benefit of selecting a gear pump design is that it is self priming and capable of ingesting non-condensable gas without becoming air locked. The chosen pump design consists of a 28 V DC, brushless, seal-less, permanent magnet motor driven, external gear pump that utilizes a Honeywell development that eliminates the need for magnetic coupling. The pump design was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the key features of the flight pump. Testing at TEES verified that the pump meets the design requirements for range of flow rates, pressure drop, power consumption, working fluid temperature, operating time, gas ingestion, and restart capability under both ambient and vacuum conditions. The pump operated at 40 to 240 lbm/hr flow rate, 35 to 100 oF pump temperature, and 5 to 10 psid pressure rise. Power consumption of the pump controller at the nominal operating point in both ambient and vacuum conditions was 9.5 W, which was less than the 12 W predicted. Gas ingestion capabilities were tested by injecting 100 cc of air into the fluid line; the pump operated normally throughout this test.

  14. Effects of fluid viscoelasticity on the performance of an axial blood pump model.

    PubMed

    Hu, Qi-Hui; Li, Jing-Yin; Zhang, Ming-Yuan

    2012-01-01

    An aqueous Xanthan gum solution (XGS) was used as blood analog fluid to explore the influence of fluid viscoelasticity on the performance of an axial blood pump model. For comparison, a 39 wt% Newtonian aqueous glycerin solution (GS), the common fluid in blood pump tests, was also used as a working fluid. The experimental results showed that a higher head curve was obtained using XGS in the pump than using GS. The heads of the XGS that were computed using the viscoelastic turbulence model agreed well with the measured data. In contrast, the standard k-ε turbulence model failed to provide satisfactory predictions for the XGS. The computational results revealed that in most parts of the pump model flow fields, the Reynolds shear stress values and turbulent dissipation rates of the XGS were all lower than those of the GS. The hemolysis index of the pump model using the XGS was calculated to be only one-third of that using the GS. PMID:22210649

  15. A fluid dynamic analysis of a rotary blood pump for design improvement.

    PubMed

    Treichler, J; Rosenow, S E; Damm, G; Naito, K; Ohara, Y; Mizuguchi, K; Makinouchi, K; Takatani, S; Nosé, Y

    1993-09-01

    The proper design of a left ventricular assist device (LVAD) requires an understanding of the pump's fluid dynamic and biocompatible properties. A hydraulically efficient system minimizes the power required for pumping. Biocompatibility refers to the ability to pump blood with minimal hemolysis and thrombus formation. Typically, shear stresses below a threshold level will not damage blood significantly. A fluid dynamic analysis of a prototype centrifugal pump designed for use as an LVAD was performed to establish flow characteristics. A flow visualization technique using Amberlite particles suspended in a glycerin/water blood analogue was used. The system was illuminated with a 1 mm planar beam strobed helium-neon laser, and the results were recorded photographically. An analysis of photographs revealed laminar and turbulent flows with vortices within an illuminated plane in both the inlet and outlet port areas. From these data, velocity and shear stress profiles were generated that showed possible areas of improvement. It was concluded that the outlet port design could be improved by changing its angle and the continuity of its expansion. The inlet port could also be improved by smoothing the transition area between the inlet tube and the pump body to allow for gradual acceleration of the entering fluid. PMID:8240074

  16. The activation of the sodium pump in pig red blood cells by internal and external cations.

    PubMed

    Brand, S C; Whittam, R

    1985-05-30

    A study has been made with pig red blood cells of the activation of the sodium pump by internal and external cations. Cell Na and K concentrations were altered using a PCMBS cation loading procedure. The procedure was characterised for resultant ionic conditions, maintenance of ATP levels and fragility. The activation of the sodium pump by external K was measured in cells suspended in choline (Na-free) solutions. External Cs was used as a substitute for K and elicited lower rates of pump activity. Both the Vmax and apparent Km for 42K influx and 134Cs influx increased as internal Na concentration was raised (within the non-saturating range). Vmax/apparent Km ratios for cation influx were constant. Raising external Cs concentration exerted a similar influence on pump activation by internal Na: both the maximum pump velocity and the apparent Na-site dissociation constant (K'Na) increased. The results provide evidence for a transmembrane connection between cation binding sites on opposite faces of the membrane and are consistent with a consecutive model for the sodium pump in pig red blood cells. PMID:2581622

  17. Multimodal flow visualization and optimization of pneumatic blood pump for sorbent hemodialysis system.

    PubMed

    Shu, Fangjun; Parks, Robert; Maholtz, John; Ash, Steven; Antaki, James F

    2009-04-01

    Renal Solutions Allient Sorbent Hemodialysis System utilizes a two-chambered pneumatic pump (Pulsar Blood Pump, Renal Solutions, Inc., Warrendale, PA, USA) to avoid limitations associated with peristaltic pumping systems. Single-needle access is enabled by counter-pulsing the two pump chambers, thereby obviating compliance chambers or blood reservoirs. Each chamber propels 20 cc per pulse of 3 s (dual access) or 6 s (single access) duration, corresponding to a peak Reynolds number of approximately 8000 (based on inlet velocity and chamber diameter). A multimodal series of flow visualization studies (tracer particle, dye washout, and dye erosion) was conducted on a sequence of pump designs with varying port locations and diaphragms to improve the geometry with respect to risk of thrombogenesis. Experiments were conducted in a simplified flow loop using occluders to simulate flow resistance induced by tubing and dialyzer. Tracer visualization revealed flow patterns and qualitatively indicated turbulence intensity. Dye washout identified dwell volume and areas of flow stagnation for each design. Dye erosion results indicated the effectiveness and homogeneity of surface washing. Compared to a centered inlet which resulted in a fluid jet that produced two counter-rotating vortices, a tangential inlet introduced a single vortex, and kept the flow laminar. It also provided better surface washing on the pump inner surface. However, a tangential outlet did not present as much benefit as expected. On the contrary, it created a sharp defection to the flow when transiting from filling to ejection. PMID:19335410

  18. Numerical simulation and experimental research on passive hydrodynamic bearing in a blood pump

    NASA Astrophysics Data System (ADS)

    Han, Qing; Ruan, Xiaodong; Chen, Wenyu; Fu, Xin

    2013-09-01

    The current research of hydrodynamic bearing in blood pump mainly focuses on the bearing structure design. Compared with the typical plane slider bearing and Rayleigh step bearing, spiral groove bearing has excellent performance in load-carrying capacity. However, the load-carrying capacity would decrease significantly with increasing flow rate in conventional designs. In this paper, the special treatment is made to the upper spiral groove bearing to make sure that both the circulatory flowing and load-carrying capacity are high. Three-dimensional computational fluid dynamics(CFD) models in the space between rotor and shaft are developed by using FLUENT software. Effects of groove number, film height and groove depth on load-carrying capacity of the spiral groove bearings are investigated by orthogonal experiment design. The experimental results show that film height is the most remarkable factor to the load-carrying capacity. The variation tendency of load-carrying capacity reveals that the best combination of geometry is the one with groove number of 8, film height 0.03 mm and groove depth 0.08 mm. The velocity and pressure distributions in spiral groove bearings are also analyzed, and the analysis result shows that the distributions are in conformity with the design of the blood pump based on the principle of hydrodynamic bearing. The displacement of the rotor with the best combination parameters is tested by using laser displacement sensors, the testing result shows that the suspending performance is satisfactory both in axial and radial directions. This research proposes a bearing design method which has sufficient load-carrying capacity to support rotor as an effective passive hydrodynamic bearing.

  19. Development of blood extraction system for health monitoring system

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Kazuyoshi; Nakanishi, Naoyuki; Nakamachi, Eiji

    2004-03-01

    The purpose of this research is to develop the compact human blood sampling device applied for a health monitoring system(HMS), which is called "Mobile Hospital". The HMS consists of (1) a micro electrical pumping system for blood extraction, (2) a bio-sensor to detect and evaluate an amount of Glucose, Cholesterol and Urea in extracted blood, by using enzyme such as Glucoseoxidase (GOD), Cholesteroloxidase and Urease. The mechanical design elements of the device are bio-compatible microneedle, indentation unit using a shape memory alloy(SMA) actuator and pumping unit using a piezoelectric microactuator. The design concept is the biomimetic micromachine of female mosquito"s blood sampling mechanism. The performances of the main mechanical elements such as indentation force of the microneedle, actual stroke of the indentation unit using a SMA actuator and liquid sampling ability of the pumping unit using PZT piezoelectric microactuator were measured. The 3 mm stroke of the indentation load generated by SMA actuator was 0.8mN. The amount of imitation blood extracted by using bimorph PZT actuators was about 0.5 microliters for 10 sec. A 60-micrometer outer diameter and 25-micrometer inner diameter Titanium microneedle, which size is same as female mosquito"s labium, was produced by sputter deposition.

  20. Microhaemodynamics within the blade tip clearance of a centrifugal turbodynamic blood pump.

    PubMed

    Antaki, J F; Diao, C-G; Shu, F-J; Wu, J-C; Zhao, R; Kameneva, M V

    2008-05-01

    A persistent challenge facing the quantitative design of turbodynamic blood pumps is the great disparity of spatial scales between the primary and auxiliary flow paths. Fluid passages within journals and adjacent to the blade tips are often on the scale of several blood cells, confounding the application of macroscopic continuum models. Yet, precisely in these regions there exists the highest shear stress, which is most likely to cause cellular trauma. This disparity has motivated these microscopic studies to visualize the kinematics of the blood cells within the small clearances of a miniature turbodynamic blood pump. A transparent model of a miniature centrifugal pump having an adjustable tip clearance (50-200 microm) was prepared for direct optical visualization of the region between the impeller blade tip and the stationary housing. Synchronized images of the blood cells were obtained by a microscopic visualization system, consisting of an inverted microscope fitted with long-working-distance objective lens (40x), mercury lamp, and high-resolution charge-coupled device camera electronically triggered by the rotation of the impeller. Experiments with 7 microm fluorescent particles revealed the influence of the gap dimension on the trajectory across the blade thickness. The lateral component of velocity (perpendicular to the blade) was dramatically enhanced in the 50 microm gap compared with the 200 microm gap, thereby reducing the exposure time. Studies with diluted bovine blood (Ht = 0.5 per cent) showed that the concentration of cells traversing the gap is also reduced dramatically (30 per cent) as the blade tip clearance is reduced from 200 microm to 50 microm. These results motivate further investigation into the microfluidic phenomena responsible for cellular trauma within turbodynamic blood pumps. PMID:18595366

  1. Development of blood extraction system designed by female mosquito's blood sampling mechanism for bio-MEMS

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Kazuyoshi; Nakanishi, Naoyuki; Nakamachi, Eiji

    2005-02-01

    A compact and wearable wristwatch type Bio-MEMS such as a health monitoring system (HMS) to detect blood sugar level for diabetic patient, was newly developed. The HMS consists of (1) a indentation unit with a microneedle to generate the skin penetration force using a shape memory alloy(SMA) actuator, (2) a pumping unit using a bimorph PZT piezoelectric actuator to extract the blood and (3) a gold (Au) electrode as a biosensor immobilized GOx and attached to the gate electrode of MOSFET to detect the amount of Glucose in extracted blood. GOx was immobilized on a self assembled spacer combined with an Au electrode by the cross-link method using BSA as an additional bonding material. The device can extract blood in a few microliter through a painless microneedle with the negative pressure by deflection of the bimorph PZT piezoelectric actuator produced in the blood chamber, by the similar way the female mosquito extracts human blood with muscle motion to flex or relax. The performances of the liquid sampling ability of the pumping unit through a microneedle (3.8mm length, 100μm internal diameter) using the bimorph PZT piezoelectric microactuator were measured. The blood extraction micro device could extract human blood at the speed of 2μl/min, and it is enough volume to measure a glucose level, compared to the amount of commercial based glucose level monitor. The electrode embedded in the blood extraction device chamber could detect electrons generated by the hydrolysis of hydrogen peroxide produced by the reaction between GOx and glucose in a few microliter extracted blood, using the constant electric current measurement system of the MOSFET type hybrid biosensor. The output voltage for the glucose diluted in the chamber was increased lineally with increase of the glucose concentration.

  2. Numerical analysis of the inner flow field of a biocentrifugal blood pump.

    PubMed

    Chua, Leok Poh; Song, Guoliang; Lim, Tau Meng; Zhou, Tongming

    2006-06-01

    Implantable ventricular assist devices have been regarded as a promising instrument in the clinical treatment of patients with severe heart failures. In this article, a three-dimensional model of the Kyoto-NTN magnetically suspended centrifugal blood pump was generated and a computational fluid dynamics solution of the inner flow field of the pump including the static pressure distributions, velocity profiles, and the shear stress distributions of the blood was presented. The results revealed that reverse flow generally occurred in the impeller blade channels during the operation of the pump, due to the imbalance of the flow and the pressure gradient generated in the blade channels. The flow pattern at the exit of the blade channels was varying with its angular positions in the pump. The reverse flow at the exit of the impeller blade channels was found to be closely related with the static pressure distribution in the volute passage. Higher pressure in the volute caused severe backflow from the volute into the blade channels. To clarify the effects of a moving impeller on the blood, shear stresses of the blood in the pump were investigated according to the simulation results. The studies indicated that at the beginning of the splitter plate and the cutwater, the highest shear stress exceeded 700 Pa. At other regions such as the inlet and outlet of the impeller blade channels and some regions in the volute passage, shear stresses were found to be about 200 Pa. These areas are believed to have a high possibility of rendering blood trauma. PMID:16734599

  3. Comparison of hydraulic and hemolytic properties of different impeller designs of an implantable rotary blood pump by computational fluid dynamics.

    PubMed

    Arvand, Arash; Hahn, Nicole; Hormes, Marcus; Akdis, Mustafa; Martin, Michael; Reul, Helmut

    2004-10-01

    A mixed-flow blood pump for long-term applications has been developed at the Helmholtz-Institute in Aachen, Germany. Central features of this implantable pump are a centrally integrated motor, a blood-immersed mechanical bearing, magnetic coupling of the impeller, and a shrouded impeller, which allows a relatively wide clearance. The aim of the study was a numerical analysis of hydraulic and hemolytic properties of different impeller design configurations. In vitro testing and numerical simulation techniques (computational fluid dynamics [CFD]) were applied to achieve a comprehensive overview. Pressure-flow charts were experimentally measured in a mock loop in order to validate the CFD data. In vitro hemolysis tests were performed at the main operating point of each impeller design. General flow patterns, pressure-flow charts, secondary flow rates, torque, and axial forces on the impeller were calculated by means of CFD. Furthermore, based on streak line techniques, shear stress (stress loading), exposure times, and volume percentage with critical stress loading have been determined. Comparison of CFD data with pressure head measurements showed excel-lent agreement. Also, impressive trend conformity was observed between in-vitro hemolysis results and numerical data. Comparison of design variations yielded clear trends and results. Design C revealed the best hydraulic and hemolytic properties and was chosen as the final design for the mixed-flow rotary blood pump. PMID:15384994

  4. Diode pumped Nd:YAG laser development

    NASA Technical Reports Server (NTRS)

    Reno, C. W.; Herzog, D. G.

    1976-01-01

    A low power Nd:YAG laser was constructed which employs GaAs injection lasers as a pump source. Power outputs of 125 mW TEM CW with the rod at 250 K and the pump at 180 K were achieved for 45 W input power to the pump source. Operation of the laser, with array and laser at a common heat sink temperature of 250 K, was inhibited by difficulties in constructing long-life GaAs LOC laser arrays. Tests verified pumping with output power of 20 to 30 mW with rod and pump at 250 K. Although life tests with single LOC GaAs diodes were somewhat encouraging (with single diodes operating as long as 9000 hours without degradation), failures of single diodes in arrays continue to occur, and 50 percent power is lost in a few hundred hours at 1 percent duty factor. Because of the large recent advances in the state of the art of CW room temperature AlGaAs diodes, their demonstrated lifetimes of greater than 5,000 hours, and their inherent advantages for this task, it is recommended that these sources be used for further CW YAG injection laser pumping work.

  5. Development of a magnetically suspended centrifugal pump as a cardiac assist device for long-term application.

    PubMed

    Nishimura, K; Park, C H; Akamatsu, T; Yamada, T; Ban, T

    1996-01-01

    To overcome problems with the shaft seal in conventional centrifugal pumps, the authors have been developing a magnetically suspended centrifugal pump (MSCP) that operates as a valveless, sealless, and bearingless pump. The prototype of the MSCP was modified with respect to size of the volute diffuser and impeller blade profiles. A hemolysis test in vitro using a new version of the MSCP was performed in comparison with a commercially available centrifugal pump. The test circuit for the hemolysis test comprised a blood reservoir, a pump, and polyvinyl tubes, and was filled with fresh heparinized bovine blood. The pumping conditions were a flow rate of 5 L/min and a pump head afterload of 100 mmHg. The index of hemolysis in the MSCP was significantly lower than that in the Biomedicus pump (0.0035 +/- 0.0025 versus 0.0097 +/- 0.0056 g/100 L, p < 0.05). Reduction in the platelet count during pumping also was lower in the MSCP compared with the Biomedicus pump at both 6 hrs and 12 hrs of pumping (p < 0.01). This MSCP may be advantageous for extended use of assist devices, not only from the theoretical point of view, but in a practical sense after the results of the current hemolysis test. PMID:8808462

  6. PIV measurements of flow in a centrifugal blood pump: time-varying flow.

    PubMed

    Day, Steven W; McDaniel, James C

    2005-04-01

    Measurements of the time-varying flow in a centrifugal blood pump operating as a left ventricular assist device (LVAD) are presented. This includes changes in both the pump flow rate as a function of the left ventricle contraction and the interaction of the rotating impeller and fixed exit volute. When operating with a pulsing ventricle, the flow rate through the LVAD varies from 0-11 L/min during each cycle of the heartbeat. Phase-averaged measurements of mean velocity and some turbulence statistics within several regions of the pump, including the inlet, blade passage, exit volute, and diffuser, are reported at 20 phases of the cardiac cycle. The transient flow fields are compared to the constant flow rate condition that was reported previously in order to investigate the transient effects within the pump. It is shown that the quasi-steady assumption is a fair treatment of the time varying flow field in all regions of this representative pump, which greatly simplifies the comprehension and modeling of this flow field. The measurements are further interpreted to identify the effects that the transient nature of the flow field will have on blood damage. Although regions of recirculation and stagnant flow exist at some phases of the cardiac cycle, there is no location where flow is stagnant during the entire heartbeat. PMID:15971703

  7. Modeling of a dielectric elastomer diaphragm for a prosthetic blood pump

    NASA Astrophysics Data System (ADS)

    Goulbourne, Nakhiah; Frecker, Mary I.; Mockensturm, Eric M.; Snyder, Alan J.

    2003-07-01

    The electromechanical behavior of dielectric elastomers is to be exploited for medical application in artificial blood pumps. It is required that the pump diaphragm achieves a swept volume increase of 70 cc into a systolic pressure of 120 mmHg with the main design objective being volumetric efficiency. As such, a model that accommodates large deformation behavior is used. In order to design prosthetic blood pumps that closely mimic the natural pumping chambers of the heart, a dielectric elastomer diaphragm design is proposed. The elastomer's change in shape in response to the applied electric field will permit it to be the active element of the pump just as the ventricular walls are in the natural heart. A comprehensive analytical model that accounts for the combined elastic and dielectric behavior of the membrane is used to compute the stresses and deformations of the inflated membrane. Dielectric elastomers are often pre-strained in order to obtain optimal electromechanical performance. The resulting model incorporates pre-strain and shows how system parameters such as pre-strain, pressure, electric field, and edge constraints affect membrane deformation. The model predicts more than adequate volume displacement for moderate pre-strain of the elastomer.

  8. Heat Pump Clothes Dryer Model Development

    SciTech Connect

    Shen, Bo

    2016-01-01

    A heat pump clothes dryer (HPCD) is an innovative appliance that uses a vapor compression system to dry clothes. Air circulates in a closed loop through the drum, so no vent is required. The condenser heats air to evaporate moisture out of the clothes, and the evaporator condenses water out of the air stream. As a result, the HPCD can achieve 50% energy savings compared to a conventional electric resistance dryer. We developed a physics-based, quasi-steady-state HPCD system model with detailed heat exchanger and compressor models. In a novel approach, we applied a heat and mass transfer effectiveness model to simulate the drying process of the clothes load in the drum. The system model is able to simulate the inherently transient HPCD drying process, to size components, and to reveal trends in key variables (e.g. compressor discharge temperature, power consumption, required drying time, etc.) The system model was calibrated using experimental data on a prototype HPCD. In the paper, the modeling method is introduced, and the model predictions are compared with experimental data measured on a prototype HPCD.

  9. Development and evaluation of oral osmotic pump of butorphanol tartrate.

    PubMed

    Shah, Bhavik; Raichandani, Yogesh; Misra, Ambikanandan

    2014-11-01

    Butorphanol is potent analgesic useful in pain management. However, because of high first-pass metabolism butorphanol is not available in market as oral dosage form. Drugs that undergo extensive first-pass metabolism can be delivered orally if protected in the stomach, and proximal small intestine. An oral controlled porosity osmotic pump (CPOP) was designed to deliver butorphanol tartrate that can maintain therapeutic blood concentration up to 24 h. The target release profile for extended release formulation was calculated by Wagner Nelson de-convolution using published immediate release blood concentration data for oral route. Composition of the core and coating were optimized using USFDA approved ingredients by evaluation of the drug release. Drug release from the developed system was inversely proportional to the weight gain and directly related to the level of pore former. Scanning electron microscopy (SEM) confirmed the formation of pores in the coating membrane on contact with water which lead to drug to release. Kinetic models were applied to drug release data to establish the drug release mechanism. The developed osmotic system effectively delivers selected drug at a predetermined rate for extended period. PMID:24079361

  10. PIV measurements of flow in a centrifugal blood pump: steady flow.

    PubMed

    Day, Steven W; McDaniel, James C

    2005-04-01

    Magnetically suspended left ventricular assist devices have only one moving part, the impeller. The impeller has absolutely no contact with any of the fixed parts, thus greatly reducing the regions of stagnant or high shear stress that surround a mechanical or fluid bearing. Measurements of the mean flow patterns as well as viscous and turbulent stresses were made in a shaft-driven prototype of a magnetically suspended centrifugal blood pump at several constant flow rates (3-9 L/min) using particle image velocimetry (PIV). The chosen range of flow rates is representative of the range over which the pump may operate while implanted. Measurements on a three-dimensional measurement grid within several regions of the pump, including the inlet, blade passage, exit volute, and diffuser are reported. The measurements are used to identify regions of potential blood damage due to high shear stress and/or stagnation of the blood, both of which have been associated with blood damage within artificial heart valves and diaphragm-type pumps. Levels of turbulence intensity and Reynolds stresses that are comparable to those in artificial heart valves are reported. At the design flow rate (6 L/min), the flow is generally well behaved (no recirculation or stagnant flow) and stress levels are below levels that would be expected to contribute to hemolysis or thrombosis. The flow at both high (9 L/min) and low (3 L/min) flow rates introduces anomalies into the flow, such as recirculation, stagnation, and high stress regions. Levels of viscous and Reynolds shear stresses everywhere within the pump are below reported threshold values for damage to red cells over the entire range of flow rates investigated; however, at both high and low flow rate conditions, the flow field may promote activation of the clotting cascade due to regions of elevated shear stress adjacent to separated or stagnant flow. PMID:15971702

  11. New mechanism to reduce the size of the monopivot magnetic suspension blood pump: direct drive mechanism.

    PubMed

    Yamane, T; Nishida, M; Kijima, T; Maekawa, J

    1997-07-01

    Size reduction of the monopivot magnetic suspension blood pump has been achieved by reducing the size of the magnetic suspension and employing a direct drive mechanism in place of a brushless DC motor and a magnetic coupling. The flow has also been improved using a closed hollow impeller to remove flow obstruction at the inlet and using radial straight vanes to reduce the impeller speed by 30%. Hemolysis testing was conducted for the new models. Results showed that model DD1 presented only a slightly higher level of hemolysis than a regular extracorporeal centrifugal pump. PMID:9212927

  12. Onset of Buccal Pumping in Catshark Embryos: How Breathing Develops in the Egg Capsule

    PubMed Central

    Tomita, Taketeru; Nakamura, Masaru; Sato, Keiichi; Takaoka, Hiroko; Toda, Minoru; Kawauchi, Junro; Nakaya, Kazuhiro

    2014-01-01

    Respiration in fishes involves buccal pumping, which is characterized by the generation of nearly continuous water flow over the gills because of the rhythmic expansion/compression of the pharyngeal cavity. This mechanism is achieved by the functions of the vascular, skeletal, and muscular systems. However, the process by which the embryo establishes the mechanism remains a mystery. Morphological and kinematical observations on captive cloudy catsharks, Scyliorhinus torazame, have suggested that the embryo starts buccal pumping just before the respiratory slits open on the egg capsule. During the pre-opening period, the embryo acquires oxygen mainly via the external gill filaments. After slit opening, respiration of the embryo involves buccal pumping to pass water over the “internal gills.” The onset of buccal pumping accompanies four morphological changes: (1) regression of the external gill filaments, (2) development of blood vessels within the “internal gills,” (3) completion of the development of hyoid skeletal and muscular elements, and (4) development of the oral valve. A previous study showed that buccal pumping allows the embryo to actively regulate oxygen intake by changing the pumping frequency. Thus, establishment of buccal pumping in the egg capsule is probably important for embryo survival in the unstable oxygen environment of the egg capsule after slit opening. PMID:25329313

  13. Non-invasive estimation and control of inlet pressure in an implantable rotary blood pump for heart failure patients.

    PubMed

    Alomari, A H; Savkin, A V; Ayre, P J; Lim, E; Mason, D G; Salamonsen, R F; Fraser, J F; Lovell, N H

    2011-08-01

    We propose a dynamical model for mean inlet pressure estimation in an implantable rotary blood pump during the diastolic period. Non-invasive measurements of pump impeller rotational speed (ω), motor power (P), and pulse width modulation signal acquired from the pump controller were used as inputs to the model. The model was validated over a wide range of speed ramp studies, including (i) healthy (C1), variations in (ii) heart contractility (C2); (iii) afterload (C2, C3, C4), and (iv) preload (C5, C6, C7). Linear regression analysis between estimated and extracted mean inlet pressure obtained from in vivo animal data (greyhound dogs, N = 3) resulted in a highly significant correlation coefficients (R(2) = 0.957, 0.961, 0.958, 0.963, 0.940, 0.946, and 0.959) and mean absolute errors of (e = 1.604, 2.688, 3.667, 3.990, 2.791, 3.215, and 3.225 mmHg) during C1, C2, C3, C4, C5, C6, and C7, respectively. The proposed model was also used to design a controller to regulate mean diastolic pump inlet pressure using non-invasively measured ω and P. In the presence of model uncertainty, the controller was able to track and settle to the desired input within a finite number of sampling periods and minimal error (0.92 mmHg). The model developed herein will play a crucial role in developing a robust control system of the pump that detects and thus avoids undesired pumping states by regulating the inlet pressure within a predefined physiologically realistic limit. PMID:21666292

  14. Development and test of a plastic deep-well pump

    NASA Astrophysics Data System (ADS)

    Zhang, Q. H.; Gao, X. F.; Xu, Y.; Shi, W. D.; Lu, W. G.; Liu, W.

    2013-12-01

    To develop a plastic deep-well pump, three methods are proposed on structural and forming technique. First, the major hydraulic components are constructed by plastics, and the connection component is constructed by steel. Thus the pump structure is more concise and slim, greatly reducing its weight and easing its transportation, installation, and maintenance. Second, the impeller is designed by maximum diameter method. Using same pump casing, the stage head is greatly increased. Third, a sealing is formed by impeller front end face and steel end face, and two slots are designed on the impeller front end face, thus when the two end faces approach, a lubricating pair is formed, leading to an effective sealing. With above methods, the pump's axial length is greatly reduced, and its stage head is larger and more efficient. Especially, the pump's axial force is effectively balanced. To examine the above proposals, a prototype pump is constructed, and its testing results show that the pump efficiency exceeds the national standard by 6%, and the stage head is improved by 41%, meanwhile, its structure is more concise and ease of transportation. Development of this pump would provide useful experiences for further popularity of plastic deep-well pumps.

  15. Effect of a bearing gap on hemolytic property in a hydrodynamically levitated centrifugal blood pump with a semi-open impeller.

    PubMed

    Kosaka, Ryo; Nishida, Masahiro; Maruyama, Osamu; Yambe, Tomoyuki; Imachi, Kou; Yamane, Takashi

    2013-01-01

    We have developed a hydrodynamically levitated centrifugal blood pump with a semi-open impeller for long-term circulatory assist. The pump uses hydrodynamic bearings to enhance durability and reliability without additional displacement-sensors or control circuits. However, a narrow bearing gap of the pump has a potential for hemolysis. The purpose of this study is to develop the hydrodynamically levitated centrifugal blood pump with a semi-open impeller, and to evaluate the effect of a bearing gap on hemolytic property. The impeller levitates using a spiral-groove type thrust bearing, and a herringbone-groove type radial bearing. The pump design was improved by adopting a step type thrust bearing and optimizing the pull-up magnetic force. The pump performance was evaluated by a levitation performance test, a hemolysis test and an animal experiment. In these tests, the bearing gap increased from 1 to 63 μm. In addition, the normalized index of hemolysis (NIH) improved from 0.415 to 0.005 g/100 l, corresponding to the expansion of the bearing gap. In the animal experiment for 24 h, the plasma-free hemoglobin remained within normal ranges (<4.0 mg/dl). We confirmed that the hemolytic property of the pump was improved to the acceptable level by expanding the bearing gap greater than 60 μm. PMID:23442235

  16. Development of the sonic pump levitator

    NASA Technical Reports Server (NTRS)

    Dunn, S. A.

    1985-01-01

    The process and mechanism involved in producing glass microballoons (GMBs) of acceptable quality for laser triggered inertial fusion through use of glass jet levitation and manipulation are considered. The gas jet levitation device, called sonic pumps, provides positioning by timely and appropriate application of gas mementum from one or more of six sonic pumps which are arranged orthogonally in opposed pairs about the levitation region and are activated by an electrooptical, computer controlled, feedback system. The levitation device was fabricated and its associated control systems were assembled into a package and tested in reduced gravity flight regime of the NASA KC-135 aircraft.

  17. FIELD TRIALS OF NEWLY DEVELOPED POSITIVE DISPLACEMENT SUBMERSIBLE PUMP

    SciTech Connect

    Rob Beard; Leland Traylor

    2002-12-01

    The purpose of this grant was to evaluate under real world conditions the performance of a new type of downhole pump, the hydraulically driven submersible diaphragm pump. This pump is supplied by Pumping Solutions Incorporated, Albuquerque NM. The original scope of the project was to install 10 submersible pumps, and compare that to 10 similar installations of rod pumps. As an operator, the system as tested was not ready for prime time. The PSI group did improve the product and offered excellent service. The latest design appears to be much better, but more test data is needed to show short run life is not a problem. This product should continue to be developed; the testing did not uncover any fundamental problems that would preclude it's widespread use. On the positive side, the pump was easy to run, was more power efficient then a rod pump, and is the only submersible that could handle the large quantities of solids typical of CBM production. The product shows much promise for the future, and with continued design and testing, this type of submersible pump has the potential to become the standard of the industry.

  18. A miniaturized extracorporeal membrane oxygenator with integrated rotary blood pump: preclinical in vivo testing.

    PubMed

    Kopp, Ruedger; Bensberg, Ralf; Arens, Jutta; Steinseifer, Ulrich; Schmitz-Rode, Thomas; Rossaint, Rolf; Henzler, Dietrich

    2011-01-01

    Extracorporeal membrane oxygenation can achieve sufficient gas exchange in severe acute respiratory distress syndrome. A highly integrated extracorporeal membrane oxygenator (HEXMO) was developed to reduce filling volume and simplify management. Six female pigs were connected to venovenous HEXMO with a total priming volume of 125 ml for 4 hours during hypoxemia induced by a hypoxic inspired gas mixture. Animals were anticoagulated with intravenous heparin. Gas exchange, hemodynamics, hemolysis, and coagulation activation were examined. One device failed at the magnetic motor coupling of the integrated diagonal pump. In the remaining five experiments, the oxygenation increased significantly (arterial oxygen saturation [SaO2] from 79 ± 5% before HEXMO to 92% ± 11% after 4 hours) facilitated by a mean oxygen transfer of 66 ± 29 ml/dl through the oxygenator. The CO2 elimination by the HEXMO reduced arterial PaCO2 only marginal. Extracorporeal blood flow was maintained at 32% ± 6% of cardiac output. Hemodynamic instability or hemolysis was not observed. The plasmatic coagulation was only mildly activated without significant platelet consumption. The HEXMO prototype provided sufficient gas exchange to prevent hypoxemia. This proof of concept study supports further development and design modifications to increase performance and to reduce coagulation activation for potential long-term application. PMID:21317635

  19. Optimal bearing gap of a multiarc radial bearing in a hydrodynamically levitated centrifugal blood pump for the reduction of hemolysis.

    PubMed

    Kosaka, Ryo; Yasui, Kazuya; Nishida, Masahiro; Kawaguchi, Yasuo; Maruyama, Osamu; Yamane, Takashi

    2014-09-01

    We have developed a hydrodynamically levitated centrifugal pump as a bridge-to-decision device. The purpose of the present study is to determine the optimal bearing gap of a multiarc radial bearing in the developed blood pump for the reduction of hemolysis. We prepared eight pump models having bearing gaps of 20, 30, 40, 80, 90, 100, 180, and 250 μm. The driving conditions were set to a pressure head of 200 mm Hg and a flow rate of 4 L/min. First, the orbital radius of the impeller was measured for the evaluation of the impeller stability. Second, the hemolytic property was evaluated in an in vitro hemolysis test. As a result, the orbital radius was not greater than 15 μm when the bearing gap was between 20 and 100 μm. The relative normalized index of hemolysis (NIH) ratios in comparison with BPX-80 were 37.67 (gap: 20 μm), 0.95 (gap: 30 μm), 0.96 (gap: 40 μm), 0.82 (gap: 80 μm), 0.77 (gap: 90 μm), 0.92 (gap: 100 μm), 2.76 (gap: 180 μm), and 2.78 (gap: 250 μm). The hemolysis tended to increase at bearing gaps of greater than 100 μm due to impeller instability. When the bearing gap decreased from 30 to 20 μm, the relative NIH ratios increased significantly from 0.95 to 37.67 times (P < 0.01) due to high shear stress. We confirmed that the optimal bearing gap was determined between 30 and 100 μm in the developed blood pump for the reduction of hemolysis. PMID:25234763

  20. Wear-resistant, hemocompatible Ti-Nb-Zr and Zr-Nb alloys to improve blood pump design and performance.

    PubMed

    Davidson, J A; Daigle, K P; Kovacs, P

    1996-06-01

    Over the past several years, we have developed novel titanium-niobium-zirconium (Ti-Nb-Zr) alloys to address the long-term performance needs of orthopedic implants. The unique properties of these alloys also render them promising candidates for blood pumps. These properties include excellent biocompatibility in combination with high strength and toughness, and low elastic modulus (low stiffness). Additionally, these metal alloys are readily hot or cold worked into complex shapes including wire, foil, tubing and bar. They are readily machined and polished, and they can be surface oxidized to form a hard, wear-resistant, low-friction ceramic surface layer. In this diffusion-hardened condition, oxygen also hardens the underlying metal to optimize the bone between the ceramic oxide surface and the tough metal substrate. Unlike metal surfaces, oxidative wear, which can alter surface energy, friction, and hemocompatibility, does not occur. Consequently, the combined benefits of a stable, wear-resistant, low-friction ceramic surface layer with the toughness, strength, formability, and thermal conductivity of metal may provide improvements in the design and performance of blood pumps and peripheral graft and percutaneous (power) components of the pump. PMID:8817948

  1. Improvement of hemocompatibility in centrifugal blood pump with hydrodynamic bearings and semi-open impeller: in vitro evaluation.

    PubMed

    Kosaka, Ryo; Maruyama, Osamu; Nishida, Masahiro; Yada, Toru; Saito, Sakae; Hirai, Shusaku; Yamane, Takashi

    2009-10-01

    We have developed a noncontact-type centrifugal blood pump with hydrodynamic bearings and a semi-open impeller for mechanical circulatory assist. The impeller is levitated by an original spiral-groove thrust bearing and a herringbone-groove journal bearing, without any additional displacement-sensing module or additional complex control circuits. The pump was improved by optimizing the groove direction of the spiral-groove thrust bearing and the pull-up magnetic force between the rotor magnet and the stator coil against the impeller. To evaluate hemocompatibility, we conducted a levitation performance test and in vitro hemocompatibility tests by means of a mock-up circulation loop. In the hemolysis test, the normalized index of hemolysis was reduced from 0.721 to 0.0335 g/100 L corresponding to an expansion of the bearing gap from 1.1 to 56.1 microm. In the in vitro antithrombogenic test, blood pumps with a wide thrust bearing gap were effective in preventing thrombus formation. Through in vitro evaluation tests, we confirmed that hemocompatibility was improved by balancing the hydrodynamic fluid dynamics and magnetic forces. PMID:19681836

  2. Development of efflux pump inhibitors in antituberculosis therapy.

    PubMed

    Song, Lele; Wu, Xueqiong

    2016-06-01

    Resistance and tolerance to antituberculosis (anti-TB) drugs, especially the first-line drugs, has become a serious problem in anti-TB therapy. Efflux of antimicrobial agents via bacterial efflux pumps is one of the main reasons for drug resistance. Efflux pump inhibitors (EPIs) bind to efflux pumps to inhibit drug efflux and thus enhance the drug effect and reduce drug resistance. Studies on EPIs targeting the efflux pumps of Mycobacterium tuberculosis (Mtb) help to understand Mtb resistance and to identify the potential drug target and are of significance in guiding the development of new anti-TB drugs and optimal combinations. Currently, there are many potential EPIs under study, but none of them has been used clinically for anti-TB therapy. In this article, we will provide an overview on the current development of EPIs targeting the efflux pumps of Mtb and discuss their potential clinical applications. PMID:27211826

  3. Generic Safety Requirements for Developing Safe Insulin Pump Software

    PubMed Central

    Zhang, Yi; Jetley, Raoul; Jones, Paul L; Ray, Arnab

    2011-01-01

    Background The authors previously introduced a highly abstract generic insulin infusion pump (GIIP) model that identified common features and hazards shared by most insulin pumps on the market. The aim of this article is to extend our previous work on the GIIP model by articulating safety requirements that address the identified GIIP hazards. These safety requirements can be validated by manufacturers, and may ultimately serve as a safety reference for insulin pump software. Together, these two publications can serve as a basis for discussing insulin pump safety in the diabetes community. Methods In our previous work, we established a generic insulin pump architecture that abstracts functions common to many insulin pumps currently on the market and near-future pump designs. We then carried out a preliminary hazard analysis based on this architecture that included consultations with many domain experts. Further consultation with domain experts resulted in the safety requirements used in the modeling work presented in this article. Results Generic safety requirements for the GIIP model are presented, as appropriate, in parameterized format to accommodate clinical practices or specific insulin pump criteria important to safe device performance. Conclusions We believe that there is considerable value in having the diabetes, academic, and manufacturing communities consider and discuss these generic safety requirements. We hope that the communities will extend and revise them, make them more representative and comprehensive, experiment with them, and use them as a means for assessing the safety of insulin pump software designs. One potential use of these requirements is to integrate them into model-based engineering (MBE) software development methods. We believe, based on our experiences, that implementing safety requirements using MBE methods holds promise in reducing design/implementation flaws in insulin pump development and evolutionary processes, therefore improving

  4. Analysis of pressure head-flow loops of pulsatile rotodynamic blood pumps.

    PubMed

    Jahren, Silje E; Ochsner, Gregor; Shu, Fangjun; Amacher, Raffael; Antaki, James F; Vandenberghe, Stijn

    2014-04-01

    The clinical importance of pulsatility is a recurring topic of debate in mechanical circulatory support. Lack of pulsatility has been identified as a possible factor responsible for adverse events and has also demonstrated a role in myocardial perfusion and cardiac recovery. A commonly used method for restoring pulsatility with rotodynamic blood pumps (RBPs) is to modulate the speed profile, synchronized to the cardiac cycle. This introduces additional parameters that influence the (un)loading of the heart, including the timing (phase shift) between the native cardiac cycle and the pump pulses, and the amplitude of speed modulation. In this study, the impact of these parameters upon the heart-RBP interaction was examined in terms of the pressure head-flow (HQ) diagram. The measurements were conducted using a rotodynamic Deltastream DP2 pump in a validated hybrid mock circulation with baroreflex function. The pump was operated with a sinusoidal speed profile, synchronized to the native cardiac cycle. The simulated ventriculo-aortic cannulation showed that the level of (un)loading and the shape of the HQ loops strongly depend on the phase shift. The HQ loops displayed characteristic shapes depending on the phase shift. Increased contribution of native contraction (increased ventricular stroke work [WS ]) resulted in a broadening of the loops. It was found that the previously described linear relationship between WS and the area of the HQ loop for constant pump speeds becomes a family of linear relationships, whose slope depends on the phase shift. PMID:23889536

  5. Flow visualization in the outflow cannula of an axial blood pump.

    PubMed

    Liu, Guangmao; Zhang, Yan; Chen, Haibo; Sun, Hansong; Zhou, Jianye; Hu, Shengshou

    2014-01-01

    The properties of blood flow in the outflow cannula of an axial blood pump play a critical role in potential thrombus formation and vascular injury. In this study, an in vitro flow visualization technique using particle image velocimetry (PIV) was applied to investigate the flow characteristics in the outflow cannula of a FW-2 model axial pump. The two-dimensional (2-D) flow field in the axial central section and the three-dimensional (3-D) flow field in the whole outflow cannula were examined with the PIV system. Tests were carried out with a blood-mimic working fluid in the axial pump at a rotational speed of 8500 ± 20 rpm with a flow rate of 5 L/min. The velocity distribution in the outflow cannula was analyzed to evaluate the flow characteristics. There was no backflow or stagnant flow in the tested area, while the flow velocity rapidly increased outside the boundary layer. A spiral flow was observed near the boundary layer, but this was worn off within the tested area. Based on the results, hemolysis and thrombus formation in the cannula, and injury to aortic endothelium are unlikely to occur due to spiral flow. PMID:24211890

  6. Solar-pumped gas laser development

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1980-01-01

    A survey of gas properties through detailed kinetic models led to the identification of critical gas parameters for use in choosing appropriate gas combinations for solar pumped lasers. Broadband photoabsorption in the visible or near UV range is required to excite large volumes of gas and to insure good solar absorption efficiency. The photoexcitation density is independent of the absorption bandwidth. The state excited must be a metastable state which is not quenched by the parent gas. The emission bandwidth must be less than 10 A to insure lasing threshold over reasonable gain lengths. The system should show a high degree of chemical reversibility and an insensitivity to increasing temperature. Other properties such as good quantum efficiency and kinetic efficiency are also implied. Although photoexcitation of electronic vibrational transitions is considered as a possible system if the emission bands sufficiently narrow, it appears that photodissociation into atomic metastables is more likely to result in a successful solar pumped laser system.

  7. Anatomy and Physiology of Left Ventricular Suction Induced by Rotary Blood Pumps.

    PubMed

    Salamonsen, Robert Francis; Lim, Einly; Moloney, John; Lovell, Nigel Hamilton; Rosenfeldt, Franklin L

    2015-08-01

    This study in five large greyhound dogs implanted with a VentrAssist left ventricular assist device focused on identification of the precise site and physiological changes induced by or underlying the complication of left ventricular suction. Pressure sensors were placed in left and right atria, proximal and distal left ventricle, and proximal aorta while dual perivascular and tubing ultrasonic flow meters measured blood flow in the aortic root and pump outlet cannula. When suction occurred, end-systolic pressure gradients between proximal and distal regions of the left ventricle on the order of 40-160 mm Hg indicated an occlusive process of variable intensity in the distal ventricle. A variable negative flow difference between end systole and end diastole (0.5-3.4 L/min) was observed. This was presumably mediated by variable apposition of the free and septal walls of the ventricle at the pump inlet cannula orifice which lasted approximately 100 ms. This apposition, by inducing an end-systolic flow deficit, terminated the suction process by relieving the imbalance between pump requirement and delivery from the right ventricle. Immediately preceding this event, however, unnaturally low end-systolic pressures occurred in the left atrium and proximal left ventricle which in four dogs lasted for 80-120 ms. In one dog, however, this collapse progressed to a new level and remained at approximately -5 mm Hg across four heart beats at which point suction was relieved by manual reduction in pump speed. Because these pressures were associated with a pulmonary capillary wedge pressure of -5 mm Hg as well, they indicate total collapse of the entire pulmonary venous system, left atrium, and left ventricle which persisted until pump flow requirement was relieved by reducing pump speed. We suggest that this collapse caused the whole vascular region from pulmonary capillaries to distal left ventricle to behave as a Starling resistance which further reduced right

  8. Design analysis and performance assessment of hybrid magnetic bearings for a rotary centrifugal blood pump.

    PubMed

    Ren, Zhaohui; Jahanmir, Said; Heshmat, Hooshang; Hunsberger, Andrew Z; Walton, James F

    2009-01-01

    A hybrid magnetic bearing system was designed for a rotary centrifugal blood pump being developed to provide long-term circulatory support for heart failure patients. This design consists of two compact bearings to suspend the rotor in five degrees-of-freedom with single axis active control. Permanent magnets are used to provide passive radial support and electromagnets to maintain axial stability of the rotor. Characteristics of the passive radial and active thrust magnetic bearing system were evaluated by the electromagnetic finite element analysis. A proportional-integral-derivative controller with force balance algorithm was implemented for closed loop control of the magnetic thrust bearing. The control position is continuously adjusted based on the electrical energy in the bearing coils, and thus passive magnetic forces carry static thrust loads to minimize the bearing current. Performance of the magnetic bearing system with associated control algorithm was evaluated at different operating conditions. The bearing current was significantly reduced with the force balance control method and the power consumption was below 0.5 W under various thrust loads. The bearing parameters predicted by the analysis were validated by the experimental data. PMID:19381082

  9. Mathematical model development and simulation of heat pump fruit dryer

    SciTech Connect

    Achariyaviriya, S.; Soponronnarit, S.; Terdyothin, A.

    2000-01-01

    A mathematical model of a heat pump fruit dryer was developed to study the performance of heat pump dryers. Using the moisture content of papaya glace drying, the refrigerant temperature at the evaporator and condenser and the performance, was verified. It was found that the simulated results using closed loop heat pump dryer were close to the experimental results. The criteria for evaluating the performance were specific moisture extraction rate and drying rate. The results showed that ambient conditions affected significantly on the performance of the open loop dryer and the partially closed loop dryer. Also, the fraction of evaporator bypass air affected markedly the performance of all heat pump dryers. In addition, it was found that specific air flow rate and drying air temperature affected significantly the performance of all heat pump dryers.

  10. A new technique to control brushless motor for blood pump application.

    PubMed

    Fonseca, Jeison; Andrade, Aron; Nicolosi, Denys E C; Biscegli, José F; Legendre, Daniel; Bock, Eduardo; Lucchi, Júlio César

    2008-04-01

    This article presents a back-electromotive force (BEMF)-based technique of detection for sensorless brushless direct current motor (BLDCM) drivers. The BLDCM has been chosen as the energy converter in rotary or pulsatile blood pumps that use electrical motors for pumping. However, in order to operate properly, the BLDCM driver needs to know the shaft position. Usually, that information is obtained through a set of Hall sensors assembled close to the rotor and connected to the electronic controller by wires. Sometimes, a large distance between the motor and controller makes the system susceptible to interference on the sensor signal because of winding current switching. Thus, the goal of the sensorless technique presented in this study is to avoid this problem. First, the operation of BLDCM was evaluated on the electronic simulator PSpice. Then, a BEMF detector circuitry was assembled in our laboratories. For the tests, a sensor-dependent system was assembled where the direct comparison between the Hall sensors signals and the detected signals was performed. The obtained results showed that the output sensorless detector signals are very similar to the Hall signals at speeds of more than 2500 rpm. Therefore, the sensorless technique is recommended as a responsible or redundant system to be used in rotary blood pumps. PMID:18370953

  11. Seal-less centrifugal blood pump with magnetically suspended rotor: rot-a-flot.

    PubMed

    Mendler, N; Podechtl, F; Feil, G; Hiltmann, P; Sebening, F

    1995-07-01

    Limitations of current centrifugal blood pumps are related to heat generation of bearings and leakage of seals, to dead water zones, and to poor efficiency. A new concept is proposed in this paper to ameliorate these problems based on a miniaturized magnetic drive, and a prototype is introduced. The pump rotor is suspended and driven by a radial permanent magnetic field that stabilizes the impeller in 4 of the 6 spatial degrees of freedom and allows it to be top-spun on a single blood-flushed pivot bearing with minimal load and friction. A shrouded impeller with an open center and 4 logarithmically curved channels is run inside a cone-and-plate-type housing with a spiral volute chamber. In vitro testing was performed comparing this design with the BioMedicus, St. Jude, and Sarns pumps. The prototype is demonstrated to have the smallest internal volume (35 ml), surface (190 qcm), and passage time (0.5 s at 4 L/min), as well as the highest hydraulic efficiency (up to 0.4) of all devices studied. PMID:8572962

  12. Optimization of a Hybrid Magnetic Bearing for a Magnetically Levitated Blood Pump via 3-D FEA.

    PubMed

    Cheng, Shanbao; Olles, Mark W; Burger, Aaron F; Day, Steven W

    2011-10-01

    In order to improve the performance of a magnetically levitated (maglev) axial flow blood pump, three-dimensional (3-D) finite element analysis (FEA) was used to optimize the design of a hybrid magnetic bearing (HMB). Radial, axial, and current stiffness of multiple design variations of the HMB were calculated using a 3-D FEA package and verified by experimental results. As compared with the original design, the optimized HMB had twice the axial stiffness with the resulting increase of negative radial stiffness partially compensated for by increased current stiffness. Accordingly, the performance of the maglev axial flow blood pump with the optimized HMBs was improved: the maximum pump speed was increased from 6000 rpm to 9000 rpm (50%). The radial, axial and current stiffness of the HMB was found to be linear at nominal operational position from both 3-D FEA and empirical measurements. Stiffness values determined by FEA and empirical measurements agreed well with one another. The magnetic flux density distribution and flux loop of the HMB were also visualized via 3-D FEA which confirms the designers' initial assumption about the function of this HMB. PMID:22065892

  13. Optimization of a Hybrid Magnetic Bearing for a Magnetically Levitated Blood Pump via 3-D FEA

    PubMed Central

    Cheng, Shanbao; Olles, Mark W.; Burger, Aaron F.; Day, Steven W.

    2011-01-01

    In order to improve the performance of a magnetically levitated (maglev) axial flow blood pump, three-dimensional (3-D) finite element analysis (FEA) was used to optimize the design of a hybrid magnetic bearing (HMB). Radial, axial, and current stiffness of multiple design variations of the HMB were calculated using a 3-D FEA package and verified by experimental results. As compared with the original design, the optimized HMB had twice the axial stiffness with the resulting increase of negative radial stiffness partially compensated for by increased current stiffness. Accordingly, the performance of the maglev axial flow blood pump with the optimized HMBs was improved: the maximum pump speed was increased from 6000 rpm to 9000 rpm (50%). The radial, axial and current stiffness of the HMB was found to be linear at nominal operational position from both 3-D FEA and empirical measurements. Stiffness values determined by FEA and empirical measurements agreed well with one another. The magnetic flux density distribution and flux loop of the HMB were also visualized via 3-D FEA which confirms the designers’ initial assumption about the function of this HMB. PMID:22065892

  14. A novel integrated rotor of axial blood flow pump designed with computational fluid dynamics.

    PubMed

    Zhang, Yan; Xue, Song; Gui, Xing-min; Sun, Han-song; Zhang, Hao; Zhu, Xiao-dong; Hu, Sheng-Shou

    2007-07-01

    Due to the smaller size, smaller artificial surface, and higher efficiency, axial blood pumps have been widely applied in clinic in recent years. However, because of its high rotor speed, axial flow pump always has a high risk for hemolysis, which the red blood cells devastated by the shearing of tip clearance flow. We reported a novel design with the integrated blade-shroud structure that was expected to solve this problem by abolishing the radial clearance between blade and casing designed with the techniques of computational fluid dynamics (CFD). However, the numerical simulation result of the newly designed structure showed an unexpected backflow (where flow velocity is reverse of the main flow direction) at the blade tip. In order to eliminate this backflow, four flow passes were attempted, and the expansion angles (which reflect the radial amplification of the flow pass, on the meridional section, and should be defined as the angle between the center line of the flow pass and the axial direction) of the blades of the integrated rotor are 0 degrees, 8 degrees, 15 degrees, and 20 degrees, respectively. In the CFD result, it could be easily found as the expansion angles increased, the backflow was restrained gradually, and was eliminated at last. After numerous "cut and try" circles, the pump model was finally optimized. The numerical simulation of this model also showed a stable hydraulic characteristic. PMID:17584484

  15. The Aachen MiniHLM--a miniaturized heart-lung machine for neonates with an integrated rotary blood pump.

    PubMed

    Arens, Jutta; Schnoering, Heike; Pfennig, Michael; Mager, Ilona; Vázquez-Jiménez, Jaime F; Schmitz-Rode, Thomas; Steinseifer, Ulrich

    2010-09-01

    The operation of congenital heart defects in neonates often requires the use of heart-lung machines (HLMs) to provide perfusion and oxygenation. This is prevalently followed by serious complications inter alia caused by hemodilution and extrinsic blood contact surfaces. Thus, one goal of developing a HLM for neonates is the reduction of priming volume and contact surface. The currently available systems offer reasonable priming volumes for oxygenators, reservoirs, etc. However, the necessary tubing system contains the highest volumes within the whole system. This is due to the use of roller pumps; hence, the resulting placement of the complete HLM is between 1 and 2 m away from the operating table due to connective tubing between the components. Therefore, we pursued a novel approach for a miniaturized HLM (MiniHLM) by integrating all major system components in one single device. In particular, the MiniHLM is a HLM with the rotary blood pump centrically integrated into the oxygenator and a heat exchanger integrated into the cardiotomy reservoir which is directly connected to the pump inlet. Thus, tubing is only necessary between the patient and MiniHLM. A total priming volume of 102 mL (including arterial filter and a/v line) could be achieved. To validate the overall concept and the specific design we conducted several in vitro and in vivo test series. All tests confirm the novel concept of the MiniHLM. Its low priming volume and blood contact surface may significantly reduce known complications related to cardiopulmonary bypass in neonates (e.g., inflammatory reaction and capillary leak syndrome). PMID:20883389

  16. Fluid dynamic characteristics of the VentrAssist rotary blood pump.

    PubMed

    Tansley, G; Vidakovic, S; Reizes, J

    2000-06-01

    The VentrAssist pump has no shaft or seal, and the device is unique in design because the rotor is suspended passively by hydrodynamic forces, and urging is accomplished by an integrated direct current motor rotor that also acts as the pump impeller. This device has led to many challenges in its fluidic design, namely large flow-blockage from impeller blades, low stiffness of bearings with concomitant impeller displacement under pulsatile load conditions, and very small running clearances. Low specific speed and radial blade off-flow were selected in order to minimize the hemolysis. Pulsatile and steady-flow tests show the impeller is stable under normal operating conditions. Computational fluid dynamics (CFD) has been used to optimize flow paths and reduce net axial force imbalance to acceptably small values. The latest design of the pump achieved a system efficiency of 18% (in 30% hematocrit of red blood cells suspended in phosphate-buffered saline), and efficiency was optimized over the range of operating conditions. Parameters critical to improving pump efficiency were investigated. PMID:10886070

  17. Computational fluid dynamics analysis of a centrifugal blood pump with washout holes.

    PubMed

    Tsukamoto, Y; Ito, K; Sawairi, T; Konishi, Y; Yamane, T; Nishida, M; Masuzawa, T; Tsukiya, T; Endo, S; Taenaka, Y

    2000-08-01

    The authors studied avoidance of coagulation occurrence using computational fluid dynamics (CFD) analysis from the fluid dynamical point of view. Concerning centrifugal pumps, blood coagulation sometimes occurs at the region behind the impeller where the flow is generally stagnant. Therefore, we conducted a thorough study with the specimen pump with and without washout holes, mocking up the Nikkiso HPM-15. As the result, the model with washout holes indicated that the fluid rotates rapidly at the vicinity of the shaft and generates washout effects near the stationary rear casing. On the other hand, the model without washout holes showed that fluid cannot be quickly shipped out of the area behind the impeller and rotates mildly around the shaft. To clarify the moving relations between the impeller and the fluid, validation studies by comparing the results of CFD analysis and flow visualization experiments are ongoing; thus far, the studies show that CFD results are similar to the results from flow visualization experiments. PMID:10971255

  18. Blood pressure regulation X: What happens when the muscle pump is lost? Post-exercise hypotension and syncope

    PubMed Central

    Halliwill, John R.; Sieck, Dylan C.; Romero, Steven A.; Buck, Tahisha M.; Ely, Matthew R.

    2013-01-01

    Syncope which occurs suddenly in the setting of recovery from exercise, known as post-exercise syncope, represents a failure of integrative physiology during recovery from exercise. We estimate that between 50 and 80% of healthy individuals will develop pre-syncopal signs and symptoms if subjected to a 15-min head-up tilt following exercise. Post-exercise syncope is most often neurally mediated syncope during recovery from exercise, with a combination of factors associated with post-exercise hypotension and loss of the muscle pump contributing to the onset of the event. One can consider the initiating reduction in blood pressure as the tip of the proverbial iceberg. What is needed is a clear model of what lies under the surface; a model that puts the observational variations in context and provides a rational framework for developing strategic physical or pharmacological countermeasures to ultimately protect cerebral perfusion and avert loss of consciousness. This review summarizes the current mechanistic understanding of post-exercise syncope and attempts to categorize the variation of the physiological processes that arise in multiple exercise settings. Newer investigations into the basic integrative physiology of recovery from exercise provide insight into the mechanisms and potential interventions that could be developed as countermeasures against post-exercise syncope. While physical counter maneuvers designed to engage the muscle pump and augment venous return are often found to be beneficial in preventing a significant drop in blood pressure after exercise, countermeasures that target the respiratory pump and pharmacological countermeasures based on the involvement of histamine receptors show promise. PMID:24197081

  19. Left ventricular volume unloading with axial and centrifugal rotary blood pumps.

    PubMed

    Giridharan, Guruprasad A; Koenig, Steven C; Soucy, Kevin G; Choi, Young; Pirbodaghi, Tohid; Bartoli, Carlo R; Monreal, Gretel; Sobieski, Michael A; Schumer, Erin; Cheng, Allen; Slaughter, Mark S

    2015-01-01

    Axial (AX) and centrifugal (CFG) rotary blood pumps have gained clinical acceptance for the treatment of advanced heart failure. Differences between AX and CFG designs and mechanism of blood flow delivery may offer clinical advantages. In this study, pump characteristics, and acute physiologic responses during support with AX (HeartMate II) and CFG (HVAD) left ventricular assist devices (LVAD) were investigated in mock loop and chronic ischemic heart failure bovine models. In the mock loop model, pump performance was characterized over a range of pump speeds (HeartMate II: 7,000-11,000 rpm, HVAD: 2,000-3,600 rpm) and fluid viscosities (2.7 cP, 3.2 cP, 3.7 cP). In the ischemic heart failure bovine model, hemodynamics, echocardiography, and end-organ perfusion were investigated. CFG LVAD had a flatter HQ curve, required less power, and had a more linear flow estimation relation than AX LVAD. The flow estimation error for the AX LVAD (±0.9 L/min at 2.7 cP, ±0.7 L/min at 3.2 cP, ±0.8 L/min at 3.7 cP) was higher than the CFG LVAD (±0.5 L/min at 2.7 cP, ±0.2 L/min at 3.2 cP, ±0.5 L/min at 3.7 cP). No differences in acute hemodynamics, echocardiography, or end-organ perfusion between AX and CFG LVAD over a wide range of support were statistically discernible. These findings suggest no pronounced acute differences in LV volume unloading between AX and CFG LVAD. PMID:25635936

  20. Bearing gap adjustment for improvement of levitation performance in a hydrodynamically levitated centrifugal blood pump.

    PubMed

    Kosaka, Ryo; Yoshida, Fumihiko; Nishida, Masahiro; Maruyama, Osamu; Kawaguchi, Yasuo; Yamane, Takashi

    2015-01-01

    The purpose of the present study is to investigate a bearing gap adjustment for improvement of levitation performance in a hydrodynamically levitated centrifugal blood pump to realize a blood pump with a low hemolysis level. The impeller levitates axially by balancing a gravitational force, buoyancy, a magnetic force, and hydrodynamic forces on the top and bottom sides of the impeller. To adjust the levitation position of the impeller, the balance of acting forces on the impeller was adjusted by changing the shroud area on the bottom impeller. Three pumps having various shroud area were prepared as tested models: 817 mm(2) (HH-S), 875 mm(2) (HH-M) and 931 mm(2) (HH-L). First, for evaluating the bearing gap adjustment, the bearing gap was estimated by calculating a balancing position of the acting forces on the impeller. We actually measured the gravitational force, buoyancy and the magnetic force, and numerically analyzed hydrodynamic forces on the top and bottom sides of the impeller. Second, to verify accuracy of the estimated bearing gap, the measurement test of the bearing gap was performed. Finally, an in-vitro hemolysis test was performed to evaluate a hemolysis level of the pump. As a result, bottom bearing gaps were estimated as 40 μm (HH-S), 60 μm (HH-M) and 238 μm (HH-L). In the measurement test, bottom bearing gaps were measured as 63 μm (HH-S), 219 μm (HH-M), and 231 μm (HH-L). The estimated bearing gaps had positively correlated with the measured bearing gaps in relation to the shroud area on the impeller. In the hemolysis test, hemolysis level in every model was almost equivalent to that of BPX-80, when the bearing gap was adjusted greater than 60 μm. We could adjust the bearing gap by changing the shroud area on the impeller for improvement of levitation performance to realize a blood pump with a low hemolysis level. PMID:26736996

  1. The Molecular Control of Blood Cell Development

    NASA Astrophysics Data System (ADS)

    Sachs, Leo

    1987-12-01

    The establishment of a cell culture system for the clonal development of blood cells has made it possible to identify the proteins that regulate the growth and differentiation of different blood cell lineages and to discover the molecular basis of normal and abnormal cell development in blood forming tissues. A model system with myeloid blood cells has shown that (i) normal blood cells require different proteins to induce cell multiplication (growth inducers) and cell differentiation (differentiation inducers), (ii) there is a hierarchy of growth inducers as cells become more restricted in their developmental program, and (iii) a cascade of interactions between proteins determines the correct balance between immature and mature cells in normal blood cell development. Gene cloning has shown that there is a family of different genes for these proteins. Normal protein regulators of blood cell development can control the abnormal growth of certain types of leukemic cells and suppress malignancy by incuding differentiation to mature nondividing cells. Chromosome abnormalities that give rise to malignancy in these leukemic cells can be bypassed and their effects nullified by inducing differentiation, which stops cells from multiplying. These blood cell regulatory proteins are active in culture and in the body, and they can be used clinically to correct defects in blood cell development.

  2. PUMPS

    DOEpatents

    Thornton, J.D.

    1959-03-24

    A pump is described for conveving liquids, particure it is not advisable he apparatus. The to be submerged in the liquid to be pumped, a conduit extending from the high-velocity nozzle of the injector,and means for applying a pulsating prcesure to the surface of the liquid in the conduit, whereby the surface oscillates between positions in the conduit. During the positive half- cycle of an applied pulse liquid is forced through the high velocity nozzle or jet of the injector and operates in the manner of the well known water injector and pumps liquid from the main intake to the outlet of the injector. During the negative half-cycle of the pulse liquid flows in reverse through the jet but no reverse pumping action takes place.

  3. Development of a jet pump-assisted arterial heat pipe

    NASA Technical Reports Server (NTRS)

    Bienert, W. B.; Ducao, A. S.; Trimmer, D. S.

    1977-01-01

    The development of a jet pump assisted arterial heat pipe is described. The concept utilizes a built-in capillary driven jet pump to remove vapor and gas from the artery and to prime it. The continuous pumping action also prevents depriming during operation of the heat pipe. The concept is applicable to fixed conductance and gas loaded variable conductance heat pipes. A theoretical model for the jet pump assisted arterial heat pipe is presented. The model was used to design a prototype for laboratory demonstration. The 1.2 m long heat pipe was designed to transport 500 watts and to prime at an adverse elevation of up to 1.3 cm. The test results were in good agreement with the theoretical predictions. The heat pipe carried as much as 540 watts and was able to prime up to 1.9 cm. Introduction of a considerable amount of noncondensible gas had no adverse effect on the priming capability.

  4. Estimation of the radial force using a disturbance force observer for a magnetically levitated centrifugal blood pump.

    PubMed

    Pai, C N; Shinshi, T; Shimokohbe, A

    2010-01-01

    Evaluation of the hydraulic forces in a magnetically levitated (maglev) centrifugal blood pump is important from the point of view of the magnetic bearing design. Direct measurement is difficult due to the absence of a rotor shaft, and computational fluid dynamic analysis demands considerable computational resource and time. To solve this problem, disturbance force observers were developed, using the radial controlled magnetic bearing of a centrifugal blood pump, to estimate the radial forces on the maglev impeller. In order to design the disturbance observer, the radial dynamic characteristics of a maglev impeller were evaluated under different working conditions. It was observed that the working fluid affects the additional mass and damping, while the rotational speed affects the damping and stiffness of the maglev system. Based on these results, disturbance force observers were designed and implemented. The designed disturbance force observers present a bandwidth of 45 Hz. In non-pulsatile conditions, the magnitude of the estimated radial thrust increases in proportion to the flowrate, and the rotational speed has little effect on the force direction. At 5 l/min against 100 mmHg, the estimated radial thrust is 0.95 N. In pulsatile conditions, this method was capable of estimating the pulsatile radial thrust with good response. PMID:20839658

  5. Studies of turbulence models in a computational fluid dynamics model of a blood pump.

    PubMed

    Song, Xinwei; Wood, Houston G; Day, Steven W; Olsen, Don B

    2003-10-01

    Computational fluid dynamics (CFD) is used widely in design of rotary blood pumps. The choice of turbulence model is not obvious and plays an important role on the accuracy of CFD predictions. TASCflow (ANSYS Inc., Canonsburg, PA, U.S.A.) has been used to perform CFD simulations of blood flow in a centrifugal left ventricular assist device; a k-epsilon model with near-wall functions was used in the initial numerical calculation. To improve the simulation, local grids with special distribution to ensure the k-omega model were used. Iterations have been performed to optimize the grid distribution and turbulence modeling and to predict flow performance more accurately comparing to experimental data. A comparison of k-omega model and experimental measurements of the flow field obtained by particle image velocimetry shows better agreement than k-epsilon model does, especially in the near-wall regions. PMID:14616539

  6. Blood flow analysis for the secondary impeller of an IVAS heart pump.

    PubMed

    Nakamura, S; Ding, W; Smith, W A; Golding, L A

    1997-01-01

    The rotodynamic heart pump (IVAS), designed by the Cleveland Clinic Foundation, includes a secondary flow path along the journal bearing, through a secondary impeller, and over the rotor outer surface. The flow behaviors of the blood through the journal bearing and the secondary impeller are investigated by a computational fluid dynamics method that solves the 3-dimensional Navier-Stokes equations using a new solution algorithm. Results of the analyses include: 1) the blood flow patterns within the journal bearing, 2) the effect of the non-uniform bearing clearance on the flow patterns of the impeller cavity, 3) the flow patterns around a secondary impeller blade that include effects of tip clearance and the gap between the blade and the inner or outer side wall, 4) effects of the blade angles on the secondary impeller performance, and 5) the shear stress distribution. PMID:9360151

  7. Direct detection of cancer biomarkers in blood using a “place n play” modular polydimethylsiloxane pump

    PubMed Central

    Zhang, Honglian; Li, Gang; Liao, Lingying; Mao, HongJu; Jin, Qinghui; Zhao, Jianlong

    2013-01-01

    Cancer biomarkers have significant potential as reliable tools for the early detection of the disease and for monitoring its recurrence. However, most current methods for biomarker detection have technical difficulties (such as sample preparation and specific detector requirements) which limit their application in point of care diagnostics. We developed an extremely simple, power-free microfluidic system for direct detection of cancer biomarkers in microliter volumes of whole blood. CEA and CYFRA21-1 were chosen as model cancer biomarkers. The system automatically extracted blood plasma from less than 3 μl of whole blood and performed a multiplex sample-to-answer assay (nano-ELISA (enzyme-linked immunosorbent assay) technique) without the use of external power or extra components. By taking advantage of the nano-ELISA technique, this microfluidic system detected CEA at a concentration of 50 pg/ml and CYFRA21-1 at a concentration of 60 pg/ml within 60 min. The combination of PnP polydimethylsiloxane (PDMS) pump and nano-ELISA technique in a single microchip system shows great promise for the detection of cancer biomarkers in a drop of blood. PMID:24404025

  8. A novel design of spiral groove bearing in a hydrodynamically levitated centrifugal rotary blood pump.

    PubMed

    Han, Qing; Zou, Jun; Ruan, Xiaodong; Fu, Xin; Yang, Huayong

    2012-08-01

    Good washout is very important in spiral groove bearing (SGB) designs when applied to blood pumps due to the micrometer scales of lubrication films and groove depths. To improve washout, flow rate or leakage through SGBs should be as large as possible. However, this special goal violates conventional SGB designs in which no leakage is desired as the leakage would decrease load-carrying capacity significantly. So, a design concept is formed fulfilling the two goals of high load-carrying capacity and large flow rate: let groove width decrease along flow path and the mating surface of the rotor rotate with a direction facilitating the flow through the grooves. Under this concept, a novel SGB is designed, contrary to conventional ones, with groove width decreasing with increasing spiral radius. This SGB is mounted on the motionless upper plate of our designed centrifugal blood pump, with the mating surface of rotor rotating with a direction facilitating the outward flow. To assess SGB designs, a characteristic plane is originally presented relating to pressure-normalized load-carrying capacity and flow rate. Comparisons between various kinds of SGB designs are made, and computational fluid dynamics (CFD) results are plotted in this characteristic plane from which load/flow performances can be directly read out. CFD and comparison results show that the new designs have superior load/flow characteristics. However, the impact of SGB designs upon hemolysis/thrombus formation is still to be verified according to the concept presented. PMID:22747897

  9. Current Advances in Developing Inhibitors of Bacterial Multidrug Efflux Pumps.

    PubMed

    Mahmood, Hannah Y; Jamshidi, Shirin; Sutton, J Mark; Rahman, Khondaker M

    2016-01-01

    Antimicrobial resistance represents a significant challenge to future healthcare provision. An acronym ESKAPEE has been derived from the names of the organisms recognised as the major threats although there are a number of other organisms, notably Neisseria gonorrhoeae, that have become equally challenging to treat in the clinic. These pathogens are characterised by the ability to rapidly develop and/or acquire resistance mechanisms in response to exposure to different antimicrobial agents. A key part of the armoury of these pathogens is a series of efflux pumps, which effectively exclude or reduce the intracellular concentration of a large number of antibiotics, making the pathogens significantly more resistant. These efflux pumps are the topic of considerable interest, both from the perspective of basic understanding of efflux pump function, and its role in drug resistance but also as targets for the development of novel adjunct therapies. The necessity to overcome antimicrobial resistance has encouraged investigations into the characterisation of resistance-modifying efflux pump inhibitors to block the mechanisms of drug extrusion, thereby restoring antibacterial susceptibility and returning existing antibiotics into the clinic. A greater understanding of drug recognition and transport by multidrug efflux pumps is needed to develop clinically useful inhibitors, given the breadth of molecules that can be effluxed by these systems. This review discusses different bacterial EPIs originating from both natural source and chemical synthesis and examines the challenges to designing successful EPIs that can be useful against multidrug resistant bacteria. PMID:26947776

  10. [Research on magnetic coupling centrifugal blood pump control based on a self-tuning fuzzy PI algorithm].

    PubMed

    Yang, Lei; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Wang, Wei; Zhang, Haibo; Han, Lu; Xu, Liang

    2014-10-01

    The purpose of this paper is to report the research and design of control system of magnetic coupling centrifugal blood pump in our laboratory, and to briefly describe the structure of the magnetic coupling centrifugal blood pump and principles of the body circulation model. The performance of blood pump is not only related to materials and structure, but also depends on the control algorithm. We studied the algorithm about motor current double-loop control for brushless DC motor. In order to make the algorithm adjust parameter change in different situations, we used the self-tuning fuzzy PI control algorithm and gave the details about how to design fuzzy rules. We mainly used Matlab Simulink to simulate the motor control system to test the performance of algorithm, and briefly introduced how to implement these algorithms in hardware system. Finally, by building the platform and conducting experiments, we proved that self-tuning fuzzy PI control algorithm could greatly improve both dynamic and static performance of blood pump and make the motor speed and the blood pump flow stable and adjustable. PMID:25764720

  11. Development of a nonthrombogenic collagenous blood-prosthetic interface.

    PubMed Central

    Bernhard, W F; Colo, N A; Szycher, M; Wesolowski, J S; Haudenschild, C C; Franzblau, C C; Parkman, R; Liss, R H

    1980-01-01

    Investigations to develop an implantable assist pump for prolonged circulatory support have been impeded by accumulation of friable thrombus on the prosthetic interface, with subsequent embolization. To circumvent this problem, the textured, fibril surface of a polyurethane pump chamber (mat thickness 430 microns) was inoculated with cultured bovine fetal fibroblasts (labelled with thymidine-14C) prior to animal implantation. The pneumatically actuated device (stroke volume 75 ml), maintained a pulsatile blood flow throughout each study. In 20 calf experiments, extending up to 335 days, 30 X 10(6) fibroblasts (in 50 ml media) derived from a single Holstein fetus were distributed on the urethane surface (360 +/- 50 cells/mm2) by rotation of a sealed device for three hours (12 revolutions/hour). Following connection to the circulation, cell washout was minimal. Resultant biologic linings, examined after animal sacrifice, were densely adherent to the underlying polymer matrix, and varied in thickness from 250 micron-1.5 mm. Microscopically, fibroblasts were identified from the surface to base, accompanied by numerous collagen bundles and abundant ground substance. Amino acid analysis in 10/20 pumps implanted for 31--335 days, revealed 50 +/- 5 Hydroxyproline residues/1000 residues (50% collagen) and scant elastin. Donor fibroblasts were identified by radioautography and karyotyping. Lack of immunologic response in 12 Hereford pump recipients as confirmed by serial fibroblast cytotoxicity assays. In conclusion, an induced collagenous-blood interface permitted prolonged mechanical circulatory support in animals without thromboembolic complications. Images Fig. 1. Fig. 2. Figs. 3A and B. Fig. 4A. Fig. 4B. PMID:6448027

  12. Ankle positions and exercise intervals effect on the blood flow velocity in the common femoral vein during ankle pumping exercises

    PubMed Central

    Toya, Kaori; Sasano, Ken; Takasoh, Tomomi; Nishimoto, Teppei; Fujimoto, Yuta; Kusumoto, Yasuaki; Yoshimatsu, Tatsuki; Kusaka, Satomi; Takahashi, Tetsuya

    2016-01-01

    [Purpose] The aim of this study was to identify the most effective method of performing ankle pumping exercises. [Subjects and Methods] The study subjects were 10 men. We measured time-averaged maximum flow velocity and peak systolic velocity in the common femoral vein using a pulse Doppler method with a diagnostic ultrasound system during nine ankle pumping exercises (three different ankle positions and three exercise intervals). Changes of blood flow velocity during ankle pumping exercises with different ankle positions and exercise intervals were compared. [Result] Peak systolic velocity of the leg-up position showed significantly lower values than those of the supine and head-up positions. For all exercise intervals, the increased amount of blood flow velocity in the leg-up position was significantly lower than that in the head-up and supine positions. [Conclusion] Ankle positions and exercise intervals must be considered when performing effective ankle pumping exercises. PMID:27065564

  13. Development and Optimized Design of Propeller Pump System & Structure with VFD in Low-head Pumping Station

    NASA Astrophysics Data System (ADS)

    Rentian, Zhang; Honggeng, Zhu; Arnold, Jaap; Linbi, Yao

    2010-06-01

    Compared with vertical-installed pumps, the propeller (bulb tubular) pump systems can achieve higher hydraulic efficiencies, which are particularly suitable for low-head pumping stations. More than four propeller pumping stations are being, or will be built in the first stage of the S-to-N Water Diversion Project in China, diverting water from Yangtze River to the northern part of China to alleviate water-shortage problems and develop the economy. New structures of propeller pump have been developed for specified pumping stations in Jiangsu and Shandong Provinces respectively and Variable Frequency Drives (VFDs) are used in those pumping stations to regulate operating conditions. Based on the Navier-Stokes equations and the standard k-e turbulent model, numerical simulations of the flow field and performance prediction in the propeller pump system were conducted on the platform of commercial software CFX by using the SIMPLEC algorithm. Through optimal design of bulb dimensions and diffuser channel shape, the hydraulic system efficiency has improved evidently. Furthermore, the structures of propeller pumps have been optimized to for the introduction of conventional as well as permanent magnet motors. In order to improve the hydraulic efficiency of pumping systems, both the pump discharge and the motor diameter were optimized respectively. If a conventional motor is used, the diameter of the pump casing has to be increased to accommodate the motor installed inside. If using a permanent magnet motor, the diameter of motor casing can be decreased effectively without decreasing its output power, thus the cross-sectional area is enlarged and the velocity of flowing water decreased favorably to reduce hydraulic loss of discharge channel and thereby raising the pumping system efficiency. Witness model tests were conducted after numerical optimization on specific propeller pump systems, indicating that the model system hydraulic efficiencies can be improved by 0.5%˜3.7% in

  14. Development of a mercury electromagnetic centrifugal pump for the SNAP-8 refractory boiler development program

    NASA Technical Reports Server (NTRS)

    Fuller, R. A.; Schnacke, A. W.

    1974-01-01

    An electromagnetic pump, in which pressure is developed in mercury because of the interaction of the magnetic field and current which flows as a result of the voltage induced in the mercury contained in the pump duct, was developed for the SNAP-8 refractory boiler test facility. Pump performance results are presented for ten duct configurations and two stator sizes. These test results were used to design and fabricate a pump which met the SNAP-8 criteria of 530 psi developed pressure at 12,500 lb/hr. The pump operated continuously for over 13,000 hours without failure or performance degradation. Included in this report are descriptions of the experimental equipment, measurement techniques, all experimental data, and an analysis of the electrical losses in the pump.

  15. ADRC or adaptive controller--A simulation study on artificial blood pump.

    PubMed

    Wu, Yi; Zheng, Qing

    2015-11-01

    Active disturbance rejection control (ADRC) has gained popularity because it requires little knowledge about the system to be controlled, has the inherent disturbance rejection ability, and is easy to tune and implement in practical systems. In this paper, the authors compared the performance of an ADRC and an adaptive controller for an artificial blood pump for end-stage congestive heart failure patients using only the feedback signal of pump differential pressure. The purpose of the control system was to provide sufficient perfusion when the patients' circulation system goes through different pathological and activity variations. Because the mean arterial pressure is equal to the total peripheral flow times the total peripheral resistance, this goal was converted to an expression of making the mean aortic pressure track a reference signal. The simulation results demonstrated that the performance of the ADRC is comparable to that of the adaptive controller with the saving of modeling and computational effort and fewer design parameters: total peripheral flow and mean aortic pressure with ADRC fall within the normal physiological ranges in activity variation (rest to exercise) and in pathological variation (left ventricular strength variation), similar to those values of adaptive controller. PMID:26409226

  16. Shaft/shaft-seal interface characteristics of a multiple disk centrifugal blood pump.

    PubMed

    Manning, K B; Miller, G E

    1999-06-01

    A multiple disk centrifugal pump (MDCP) is under investigation as a potential left ventricular assist device. As is the case with most shaft driven pumps, leakage problems around the shaft/shaft seal interface are of major interest. If leakage were to occur during or after implantation, potential events such as blood loss, clotting, blood damage, and/or infections might result in adverse effects for the patient. Because these effects could be quite disastrous, potential shaft and shaft seal materials have been investigated to determine the most appropriate course to limit these effects. Teflon and nylon shaft seals were analyzed as potential candidates along with a stainless steel shaft and a Melonite coated shaft. The materials and shafts were evaluated under various time durations (15, 30, 45, and 60 min), motor speeds (800, 1,000, 1,200, and 1,400 rpm), and outer diameters (1/2 and 3/4 inches). The motor speed and geometrical configurations were typical for the MDCP under normal physiologic conditions. An air and water study was conducted to analyze the inner diameter wear, the inner temperature values, and the outer temperature values. Statistical comparisons were computed for the shaft seal materials, the shafts, and the outer diameters along with the inner and outer temperatures. The conclusions made from the results indicate that both the tested shaft seal materials and shaft materials are not ideal candidates to be used for the MDCP. Teflon experienced a significant amount of wear in air and water studies. Nylon did experience little wear, but heat generation was an evident problem. A water study on nylon was not conducted because of its molecular structure. PMID:10392284

  17. The flow patterns within the impeller passages of a centrifugal blood pump model.

    PubMed

    Yu, S C; Ng, B T; Chan, W K; Chua, L P

    2000-07-01

    The effects of impeller geometry on the performance of a centrifugal blood pump model [the MSCBP design of Akamatsu and Tsukiya (The Seventh Asian Congress of Fluid Mechanics (1997), 7-10) at a 1:1 scale] have been investigated both experimentally and computationally. Four impeller designs were tested for pump hydraulic performance at the operating point (i.e. 2000 rpm), using blood analog as the working fluid. Each impeller has seven blades with different configurations including the radial straight blade and backward swept blade designs. The results show that both designs can achieve a stable head of about 100 mm Hg at the operating point. Subsequent investigations involved the visualization of the relative flow field within the impeller passages via the image de-rotation system coupled with a 2.5 W argon ion laser. Flow structures in all sectors of each impeller were examined and discussed. To further quantify the possible effects of blade geometry to thrombus formation and hemolysis, computational fluid dynamics (CFD) was used to simulate a simplified two-dimensional blade-to-blade flow analysis so as to estimate the shear stress levels. The results indicate that the stress levels found within the blade passages are generally below the threshold level of 150 N/m(2) for extensive erythrocyte damage to occur. There are some localized regions near the leading edge of the blades where the stress levels are 60% above the threshold level. However, given such a short residence time for the fluid particles to go through these high shear stress regions, their effects appear to be insignificant. PMID:11086249

  18. Dual-Pump CARS Development and Application to Supersonic Combustion

    NASA Technical Reports Server (NTRS)

    Magnotti, Gaetano; Cutler, Andrew D.

    2012-01-01

    A dual-pump Coherent Anti-Stokes Raman Spectroscopy (CARS) instrument has been developed to obtain simultaneous measurements of temperature and absolute mole fractions of N2, O2 and H2 in supersonic combustion and generate databases for validation and development of CFD codes. Issues that compromised previous attempts, such as beam steering and high irradiance perturbation effects, have been alleviated or avoided. Improvements in instrument precision and accuracy have been achieved. An axis-symmetric supersonic combusting coaxial jet facility has been developed to provide a simple, yet suitable flow to CFD modelers. Approximately one million dual-pump CARS single shots have been collected in the supersonic jet for varying values of flight and exit Mach numbers at several locations. Data have been acquired with a H2 co-flow (combustion case) or a N2 co-flow (mixing case). Results are presented and the effects of the compressibility and of the heat release are discussed.

  19. Classification of Unsteady Flow Patterns in a Rotodynamic Blood Pump: Introduction of Non-Dimensional Regime Map.

    PubMed

    Shu, Fangjun; Vandenberghe, Stijn; Brackett, Jaclyn; Antaki, James F

    2015-09-01

    Rotodynamic blood pumps (also known as rotary or continuous flow blood pumps) are commonly evaluated in vitro under steady flow conditions. However, when these devices are used clinically as ventricular assist devices (VADs), the flow is pulsatile due to the contribution of the native heart. This study investigated the influence of this unsteady flow upon the internal hemodynamics of a centrifugal blood pump. The flow field within the median axial plane of the flow path was visualized with particle image velocimetry (PIV) using a transparent replica of the Levacor VAD. The replica was inserted in a dynamic cardiovascular simulator that synchronized the image acquisition to the cardiac cycle. As compared to steady flow, pulsatile conditions produced periodic, transient recirculation regions within the impeller and separation in the outlet diffuser. Dimensional analysis revealed that the flow characteristics could be uniquely described by the non-dimensional flow coefficient (Φ) and its time derivative ([Formula: see text]), thereby eliminating impeller speed from the experimental matrix. Four regimes within the Φ-[Formula: see text] plane were found to classify the flow patterns, well-attached or disturbed. These results and methods can be generalized to provide insights for both design and operation of rotodynamic blood pumps for safety and efficacy. PMID:26577357

  20. Dual-Pump CARS Development and Application to Supersonic Combustion

    NASA Astrophysics Data System (ADS)

    Magnotti, Gaetano

    Successful design of hypersonic air-breathing engines requires new computational fluid dynamics (CFD) models for turbulence and turbulence-chemistry interaction in supersonic combustion. Unfortunately, not enough data are available to the modelers to develop and validate their codes, due to difficulties in taking measurements in such a harsh environment. Dual-pump coherent anti-Stokes Raman spectroscopy (CARS) is a non-intrusive, non-linear, laser-based technique that provides temporally and spatially resolved measurements of temperature and absolute mole fractions of N2, O2 and H2 in H2-air flames. A dual-pump CARS instrument has been developed to obtain measurements in supersonic combustion and generate databases for the CFD community. Issues that compromised previous attempts, such as beam steering and high irradiance perturbation effects, have been alleviated or avoided. Improvements in instrument precision and accuracy have been achieved. An axis-symmetric supersonic combusting coaxial jet facility has been developed to provide a simple, yet suitable flow to CFD modelers. The facility provides a central jet of hot "vitiated air" simulating the hot air entering the engine of a hypersonic vehicle flying at Mach numbers between 5 and 7. Three different silicon carbide nozzles, with exit Mach number 1, 1.6 and 2, are used to provide flows with the effects of varying compressibility. H2 co-flow is available in order to generate a supersonic combusting free jet. Dual-pump CARS measurements have been obtained for varying values of flight and exit Mach numbers at several locations. Approximately one million Dual-pump CARS single shots have been collected in the supersonic jet for varying values of flight and exit Mach numbers at several locations. Data have been acquired with a H2 co-flow (combustion case) or a N 2 co-flow (mixing case). Results are presented and the effects of the compressibility and of the heat release are discussed.

  1. LED pumped Nd:YAG laser development program

    NASA Technical Reports Server (NTRS)

    Farmer, G. I.; Kiang, Y. C.; Lynch, R. J.

    1973-01-01

    The results of a development program for light emitting diode (LED) pumped Nd:YAG lasers are described. An index matching method to increase the coupling efficiency of the laser is described. A solid glass half-cylinder of 5.0 by 5.6 centimeters was used for index matching and also as a pumping cavity reflector. The laser rods were 1.5 by 56 millimeters with dielectric coatings on both end surfaces. The interfaces between the diode array, glass cylinder, and laser rod were filled with viscous fluid of refractive index n = 1.55. Experiments performed with both the glass cylinder and a gold coated stainless steel reflector of the same dimensions under the same operating conditions indicate that the index matching cylinder gave 159 to 200 percent improvement of coupling efficiency over the metal reflector at various operating temperatures.

  2. Recent developments in blood cell labeling research

    SciTech Connect

    Srivastava, S.C.; Straub, R.F.; Meinken, G.E.

    1988-09-07

    A number of recent developments in research on blood cell labeling techniques are presented. The discussion relates to three specific areas: (1) a new in vitro method for red blood cell labeling with /sup 99m/Tc; (2) a method for labeling leukocytes and platelets with /sup 99m/Tc; and (3) the use of monoclonal antibody technique for platelet labeling. The advantages and the pitfalls of these techniques are examined in the light of available mechanistic information. Problems that remain to be resolved are reviewed. An assessment is made of the progress as well as prospects in blood cell labeling methodology including that using the monoclonal antibody approach. 37 refs., 4 figs.

  3. Development of an optically pumped polarized deuterium target

    SciTech Connect

    Young, L.; Holt, R.J.; Green, M.C.; Kowalczyk, R.

    1987-01-01

    The development of a polarized deuterium target for internal use at an electron storage ring is of great interest for fundamental studies in nuclear physics. In order to achieve the maximum allowable target thickness, 10/sup 14/ nuclei/cm/sup 2/, consistent with various constraints imposed by the storage ring environment, a flux of 4 x 10/sup 17/ polarized atom/s must be provided. This flux exceeds the capability of conventional atomic beam sources by an order of magnitude. We have been developing an alternative source based upon the spin-exchange optical pumping method in which the flux is limited only by laser power. 7 refs., 1 fig.

  4. Development of a vapor compression heat pump for space use

    NASA Astrophysics Data System (ADS)

    Berner, F.; Savage, C. J.

    1981-06-01

    A heat pump is presently developed for use in Spacelab as a stand-alone refrigeration unit as well as within a fluid loop system. It is expected to feature a high coefficient of performance because its power requirement is minimized through continuous adjustment of two operating parameters of its vapor compression cycle, i.e., evaporator pressure and compressor speed, to the instantaneous cooling requirements and heat rejection conditions. The heat pump system will achieve the highest possible cooling rate as long as the temperature of the payload to be cooled is significantly above the desired level, and it will minimize the difference between actual and set heat source temperature when this difference has become small. The most complicated component of the heat pump is the reciprocating vapor compressor. This component's main features are described and its experimentally determined performance parameters are given. Based on these parameters, operating maps, showing achievable heat source temperatures and cooling rates with curves of constant power consumption included, are presented for different temperatures of the fluid to which the heat is rejected.

  5. Development and optimization of buspirone oral osmotic pump tablet.

    PubMed

    Derakhshandeh, K; Berenji, M Ghasemnejad

    2014-01-01

    The aim of the current study was to design a porous osmotic pump-based drug delivery system for controlling the release of buspirone from the delivery system. The osmotic pump was successfully developed using symmetric membrane coating. The core of the tablets was prepared by direct compression technique and coated using dip-coating technique. Drug release from the osmotic system was studied using USP paddle type apparatus. The effect of various processing variables such as the amount of osmotic agent, the amount of swellable polymer, concentration of the core former, concentration of the plasticizer, membrane thickness, quantum of orifice on drug release from osmotic pump were evaluated. Different kinetic models (zero order, first order and Higuchi model) were applied to drug release data in order to establish the kinetics of drug release. It was found that the drug release was mostly affected by the amount of NaCl as osmotic agent, the swellable polymer; hydroxy propyl methyl cellulose (HPMC), the amount of PEG-400 and cellulose acetate in the coating solution and thickness of the semipermeable membrane. The optimized formulation released buspirone independent of pH and orifice quantum at the osmogen amount of 42%, hydrophilic polymer of 13% and pore size of 0.8 mm on the tablet surface. The drug release of osmotic formulation during 24 h showed zero order kinetics and could be suggested that this formulation as a once-daily regimen improves pharmacokinetic parameters of the drug and enhances patient compliance. PMID:25657794

  6. Estimation of changes in dynamic hydraulic force in a magnetically suspended centrifugal blood pump with transient computational fluid dynamics analysis.

    PubMed

    Masuzawa, Toru; Ohta, Akiko; Tanaka, Nobuatu; Qian, Yi; Tsukiya, Tomonori

    2009-01-01

    The effect of the hydraulic force on magnetically levitated (maglev) pumps should be studied carefully to improve the suspension performance and the reliability of the pumps. A maglev centrifugal pump, developed at Ibaraki University, was modeled with 926 376 hexahedral elements for computational fluid dynamics (CFD) analyses. The pump has a fully open six-vane impeller with a diameter of 72.5 mm. A self-bearing motor suspends the impeller in the radial direction. The maximum pressure head and flow rate were 250 mmHg and 14 l/min, respectively. First, a steady-state analysis was performed using commercial code STAR-CD to confirm the model's suitability by comparing the results with the real pump performance. Second, transient analysis was performed to estimate the hydraulic force on the levitated impeller. The impeller was rotated in steps of 1 degrees using a sliding mesh. The force around the impeller was integrated at every step. The transient analysis revealed that the direction of the radial force changed dynamically as the vane's position changed relative to the outlet port during one circulation, and the magnitude of this force was about 1 N. The current maglev pump has sufficient performance to counteract this hydraulic force. Transient CFD analysis is not only useful for observing dynamic flow conditions in a centrifugal pump but is also effective for obtaining information about the levitation dynamics of a maglev pump. PMID:19894088

  7. Cardiovascular devices; reclassification of nonroller-type cardiopulmonary bypass blood pumps for cardiopulmonary and circulatory bypass; effective date of requirement for premarket approval for nonroller-type cardiopulmonary bypass blood pumps for temporary ventricular support. Final order.

    PubMed

    2015-06-01

    The Food and Drug Administration (FDA) is issuing a final order to reclassify nonroller-type cardiopulmonary bypass blood pump (NRP) devices for cardiopulmonary and circulatory bypass, a preamendments class III device, into class II (special controls), and to require the filing of a premarket approval application (PMA) for NRP devices for temporary ventricular support. FDA is also revising the title and identification of the regulation for NRP devices in this order. PMID:26054096

  8. Thrombosis and blood cells in atherosclerosis development.

    PubMed

    Santolaya, C; Hernández, M R; Villaverde, C A

    1988-06-01

    Hemorheological changes produced in blood cells seem to be essential in atheroma plaque development and thrombotic episodes. In this study, we investigated the relationship between blood cells count, thrombogenic situations and morphological mesenteric alterations in atherosclerotic rats. Atherosclerosis was induced by an atherogenic diet made up of two phases, the first a hypervitaminic diet, and the second a hyperlipidic one. Cell counts were performed with Thoma's camera. Morphological changes were observed directly in rat mesentery. Thrombogenic situations were investigated by a mesenteric microthrombosis induction method. In atherosclerotic animals we can observe a higher mesenteric opacity, increase in blood viscosity and a thickness in vessel wall. Thrombosis time is shortened at 3 days, which indicates a thrombogenic situation although at 10 days there is a lenthening in this parameter. Blood cell counts were not modified significantly, but modifications in differential leukocyte counts were significant. We found a direct relationship between lymphocyte number and thrombosis time whereas with granulocytes this relationship was inverse: shortening in thrombosis time appearing simultaneously with an increase in cell number. PMID:3419397

  9. In vitro study to estimate particle release from a centrifugal blood pump.

    PubMed

    Takami, Yoshiyuki

    2006-05-01

    Centrifugal pumps have been increasingly used in clinical settings. Like roller pumps, centrifugal pumps can cause debris release due to mechanical stress. The objectives of this study were to evaluate in vitro the particle release from a centrifugal pump, Gyro Pump (Japan Medical Materials Co., Osaka, Japan), which is a pivot-bearing supported pump clinically used in Japan, and to identify the released particles. In the clean room Class 10,000, the pump was operated for 24 h at 4000 rpm and 6 L/min in a mock loop filled with lactated Ringer's solution. After 24 h, the sample fluid and a blank were filtered with a 0.45-microm membrane filter for microscopic counting, followed by observation with a scanning electron microscope and element analysis with an X-ray spectrometer. Microscopic countings were 128 +/- 42 in the test samples (n = 10) of the Gyro Pump and 98 +/- 42 in the blank samples (n = 10) (P = 0.12). The oxygen/carbon atomic ratio of the particles in the test samples was 0.32 +/- 0.06, which was similar to the ratio of the particles in the blank sample (0.34 +/- 0.06). The profiles of elements with an X-ray spectrometer showed that the released particles from the Gyro Pump were not derived from the pump materials. In conclusion, an in vitro test system has been established for estimation of particle release from a centrifugal pump. Based upon the results with the system, the Gyro Pump with a pivot-bearing system has little risk to release debris particles even in a severe condition. PMID:16683955

  10. FIELD TRIALS OF NEWLY DEVELOPED POSITIVE DISPLACEMENT SUBMERSIBLE PUMP

    SciTech Connect

    Rob Beard

    2003-10-01

    The purpose of this grant was to evaluate under real world conditions the performance of a new type of downhole pump, the hydraulically driven submersible diaphragm pump. This pump is supplied by Pumping Solutions Incorporated, Albuquerque NM. The original scope of the project was to install 10 submersible pumps, and compare that to 10 similar installations of rod pumps. As an operator, the system as tested was not ready for prime time, but has shown the ability to reduce costs, and increase production, if run times can be improved. The PSI group did improve the product and offered excellent service. The latest design appears to be much better, but more test data is needed to show short run life is not a problem. PSI and Beard Oil intend to continue testing the pump with non-government funding. The testing to date did not uncover any fundamental problems that would preclude the widespread use of this pump, and as an operator, I believe that with further improvement and testing, the pump can have a significant impact on stripper well costs. On the positive side, the pump was easy to run, was more power efficient then a rod pump, and is the only submersible that could handle the large quantities of solids typical of the production environment found at the Weber field and in CMB production. The product shows much promise for the future, and with continued design and testing, this type of submersible pump has the potential to become the standard of the industry.

  11. DEVELOPMENT OF A HIGH PERFORMANCE COLD CLIMATE HEAT PUMP

    SciTech Connect

    Horton, W. Travis; Groll, Eckhard A.; Braun, James E.

    2014-06-01

    The primary goals of the proposed project were to develop, test, and evaluate a high performance and cost-effective vapor compression air-source heat pump for use in cold climate regions. Vapor compression heat pumps are a proven technology, and have been used for many years to meet heating requirements for buildings in residential, commercial, and industrial applications. However, in climate regions that experience very low outdoor ambient temperatures both the heating capacity and coefficient of performance (COP) of traditional air-source vapor compression heat pumps drops dramatically with a decrease in the outdoor air temperature. The efficiency of heat pumping equipment has improved substantially over the past 20 years; however, the efficiencies of the highest rated equipment on the market are approaching practical limits that cannot be surpassed without modifications to the basic cycle and possibly the use of additional hardware. In this report, three technologies to improve the efficiency of vapor compression systems are described. These are a) vapor injected compression, b) oil flooded compression and c) hybrid flow control of the evaporator. Compressor prototypes for both, oil flooded and vapor injected compression were developed by Emerson Climate Technologies. For the oil flooded compressor, the oil injection port location was optimized and an internal oil separator was added using several design iterations. After initial testing at Emerson Climate Technologies, further testing was done at Purdue University, and compressor models were developed. These models were then integrated into a system model to determine the achievable improvement of seasonal energy efficiency (SEER) for Minneapolis (Minnesota) climate. For the oil flooded compression, a 34% improvement in seasonal energy efficiency was found while a 21% improvement in seasonal energy efficiency ratio was found for the vapor injected compression. It was found that one benefit of both tested

  12. A computational study of the effects of inlet guide vanes on the performance of a centrifugal blood pump.

    PubMed

    Chan, W K; Wong, Y W; Yu, S C M; Chua, L P

    2002-06-01

    This article presents computational studies on the effects of inlet guide vanes (IGVs) on the flow pattern and shear stress in a centrifugal blood pump. The effect of IGVs is to introduce a pre-swirl to fluid particles entering the impeller with the intention that the fluid particles will travel along the blade profile. Currently, most commercial centrifugal blood pumps employ straight radial impeller blades that are not hydrodynamically ideal for a good flow pattern within the blade passage. Flow separation and formation of vortices within the blade passage are believed to increase the degree of hemolysis and thrombosis. These are causes for blood clotting that will lead to malfunctioning of ventricular assist devices. Four IGVs of different geometrical profiles have been numerically investigated using a commercial software program CFX-Tascflow. The pump is operated at 2,000 rpm, and the results revealed that the relative flow patterns in the blade passage have been dramatically altered. The size of the vortices was reduced, and the pressure contours indicated a gradual rise from the impeller leading edge to the trailing edge. However, inclusion of IGV causes a drop in the pressure head generated. Higher frictional losses are incurred as fluid particles passed through the IGV. In addition, the IGV modifies the inlet velocity triangles, and this also contributes to a drop in the pressure head generated that is consistent with Euler's pump theory. The change in the flow patterns and the gradual variation of the pressure contours have led to lower shear stress within the blade passages as compared to the case without IGVs. PMID:12072110

  13. Development of a Compact, Efficient Cooling Pump for Space Suit Life Support Systems

    NASA Technical Reports Server (NTRS)

    van Boeyen, Roger; Reeh, Jonathan; Trevino, Luis

    2009-01-01

    A compact, low-power electrochemically-driven fluid cooling pump is currently being developed by Lynntech, Inc. With no electric motor and minimal lightweight components, the pump is significantly lighter than conventional rotodynamic and displacement pumps. Reliability and robustness is achieved with the absence of rotating or moving components (apart from the bellows). By employing sulfonated polystyrene-based proton exchange membranes, rather than conventional Nafion membranes, a significant reduction in the actuator power consumption was demonstrated. Lynntech also demonstrated that these membranes possess the necessary mechanical strength, durability, and temperature range for long life space operation. The preliminary design for a Phase II prototype pump compares very favorably to the fluid cooling pumps currently used in space suit primary life support systems (PLSSs). Characteristics of the electrochemically-driven pump are described and the benefits of the technology as a replacement for electric motor pumps in mechanically pumped single-phase fluid loops is discussed.

  14. Centrifugal Force Based Magnetic Micro-Pump Driven by Rotating Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Kim, S. H.; Hashi, S.; Ishiyama, K.

    2011-01-01

    This paper presents a centrifugal force based magnetic micro-pump for the pumping of blood. Most blood pumps are driven by an electrical motor with wired control. To develop a wireless and battery-free blood pump, the proposed pump is controlled by external rotating magnetic fields with a synchronized impeller. Synchronization occurs because the rotor is divided into multi-stage impeller parts and NdFeB permanent magnet. Finally, liquid is discharged by the centrifugal force of multi-stage impeller. The proposed pump length is 30 mm long and19 mm in diameter which much smaller than currently pumps; however, its pumping ability satisfies the requirement for a blood pump. The maximum pressure is 120 mmHg and the maximum flow rate is 5000ml/min at 100 Hz. The advantage of the proposed pump is that the general mechanical problems of a normal blood pump are eliminated by the proposed driving mechanism.

  15. [The on-line simulation of blood propofol concentration by personal computer transmitting settings of the syringe pump via a digital port].

    PubMed

    Nakao, M

    1997-02-01

    A program for on-line simulation of blood propofol concentration was developed. Various pharmacokinetic model programs are available for the estimation of intravenous anesthetic concentration. But manual entry of data such as body weight, rate of infusion and the timing of changing the flow rate is mandatory in these programs. This limited the use of these programs for investigational use only. In a new program, the data required such as total dose, flow rate, body weight and time were collected automatically on-line via the digital outlet of the syringe driven pump (Terumo STC525X, Japan and Graseby 3500, UK) to a personal computer (Apple Macintosh Power Book Duo230 or Power Book 520, USA). Based on the obtained data, pharmacokinetic model was solved with personal computer. Calculated blood concentrations of propofol were displayed in a numeric form and a trend graph was obtained. This program provides useful information for maintainance of anesthesia with propofol. PMID:9071117

  16. Blood flow measurements within optic nerve head during on-pump cardiovascular operations. A window to the brain?

    PubMed

    Nenekidis, Ioannis; Geiser, Martial; Riva, Charles; Pournaras, Constantin; Tsironi, Evangelia; Vretzakis, Georgios; Mitilis, Vasilios; Tsilimingas, Nikolaos

    2011-05-01

    This observational study is conducted to demonstrate optic nerve head (ONH) blood flow alterations during extracorporeal circulation (ECC) in routine on-pump cardiovascular operations in order to evaluate the perfusion status of important autoregulatory tissue vascular beds during moderate hypothermia. Twenty-one patients free from eye disease were prospectively enrolled in our database. Perioperative ONH blood flow measurements were performed using a hand-held portable ocular laser Doppler flowmeter just after administration of general anesthesia and during cardiopulmonary bypass (CPB) upon the lowest temperature point of moderate hypothermia. Important operative flow variables were correlated to optic nerve blood flow during surgical phases. Statistical analysis showed significant reduction of 32.1 ± 14.5% of mean ONH blood flow in phase 2 (P < 0.0001) compared to the reference flow values of phase 1. A negative univariate association between ECC time and ONH blood flow in phase 2 (P = 0.031) is noted. This angiokinetic approach can detect changes of flow within autoregulatory vascular tissue beds like ONH, thus creating a 'window' on cerebral microvasculature. ONH blood flow is reduced during CPB. Our data suggest that it is of paramount importance to avoid extracorporeal prolongation even in moderate hypothermic cardiovascular operations. PMID:21297131

  17. Pressure-Flow Experimental Performance of New Intravascular Blood Pump Designs for Fontan Patients.

    PubMed

    Chopski, Steven G; Fox, Carson S; Riddle, Michelle L; McKenna, Kelli L; Patel, Jay P; Rozolis, John T; Throckmorton, Amy L

    2016-03-01

    An intravascular axial flow pump is being developed as a mechanical cavopulmonary assist device for adolescent and adult patients with dysfunctional Fontan physiology. Coupling computational modeling with experimental evaluation of prototypic designs, this study examined the hydraulic performance of 11 impeller prototypes with blade stagger or twist angles varying from 100 to 600 degrees. A refined range of twisted blade angles between 300 and 400 degrees with 20-degree increments was then selected, and four additional geometries were constructed and hydraulically evaluated. The prototypes met performance expectations and produced 3-31 mm Hg for flow rates of 1-5 L/min for 6000-8000 rpm. A regression analysis was completed with all characteristic coefficients contributing significantly (P < 0.0001). This analysis revealed that the impeller with 400 degrees of blade twist outperformed the other designs. The findings of the numerical model for 300-degree twisted case and the experimental results deviated within approximately 20%. In an effort to simplify the impeller geometry, this work advanced the design of this intravascular cavopulmonary assist device closer to preclinical animal testing. PMID:26333131

  18. Development of a Residential Ground-Source Integrated Heat Pump

    SciTech Connect

    Rice, C Keith; Baxter, Van D; Hern, Shawn; McDowell, Tim; Munk, Jeffrey D; Shen, Bo

    2013-01-01

    A residential-size ground-source integrated heat pump (GSIHP) system has been developed and is currently being field tested. The system is a nominal 2-ton (7 kW) cooling capacity, variable-speed unit, which is multi-functional, e.g. space cooling, space heating, dedicated water heating, and simultaneous space cooling and water heating. High-efficiency brushless permanent-magnet (BPM) motors are used for the compressor, indoor blower, and pumps to obtain the highest component performance and system control flexibility. Laboratory test data were used to calibrate a vapor-compression simulation model (HPDM) for each of the four primary modes of operation. The model was used to optimize the internal control options and to simulate the selected internal control strategies, such as controlling to a constant air supply temperature in the space heating mode and a fixed water temperature rise in water heating modes. Equipment performance maps were generated for each operation mode as functions of all independent variables for use in TRNSYS annual energy simulations. These were performed for the GSIHP installed in a well-insulated 2600 ft2(242 m2) house and connected to a vertical ground loop heat exchanger(GLHE). We selected a 13 SEER (3.8 CSPF )/7.7 HSPF (2.3 HSPF, W/W) ASHP unit with 0.90 Energy Factor (EF) resistance water heater as the baseline for energy savings comparisons. The annual energy simulations were conducted over five US climate zones. In addition, appropriate ground loop sizes were determined for each location to meet 10-year minimum and maximum design entering water temperatures (EWTs) to the equipment. The prototype GSIHP system was predicted to use 52 to 59% less energy than the baseline system while meeting total annual space conditioning and water heating loads.

  19. Numerical investigation of the effects of the clearance gap between the inducer and impeller of an axial blood pump.

    PubMed

    Chan, Weng-Kong; Wong, Yew-Wah; Ong, Wendy; Koh, Sy-Yuan; Chong, Victor

    2005-03-01

    A series of numerical models are generated to investigate the flow characteristics and performance of an axial blood pump. The pump model includes a straightener, an inducer-impeller, and diffuser. Numerical studies of the effects of angular alignment of the inducer and impeller blades and the axial clearance gap between the inducer and impeller are presented in this article. The pump characteristics derived from numerical simulation are validated with experimental data. Numerically simulated results showed a sinusoidal variation in the pressure generated across the pump with changes in angular alignment between the inducer and impeller. This is attributed to additional losses when flow is forced or diverted from the trailing edge of the inducer to either the pressure or suction side of the impeller blade when the alignment between the two sets of blades is not optimal. The pressure generated is a maximum when the impeller blades are at 0 or 30 degrees with respect to the inducer. The effect of rotating the impeller with respect to the inducer causes the sinusoidal pressure variation. In addition, it was observed that when the clearance gap between the inducer and impeller is reduced to 1 mm, the pressure generated is a minimum when compared to the other models. This is attributed to the interference between the inducer and impeller when the gap separating them is too small. The location of the maximum pressure on the pressure side of the impeller blade shifts upstream while its magnitude decreases for small clearance gap between the inducer and the impeller. There was no flow separation in the inducer while small regions of backflow are observed at the impeller trailing edge. Recommendations for future modifications and improvements to the pump design and model simulation are also given. PMID:15725228

  20. Development of an Ionic-Liquid Absorption Heat Pump

    SciTech Connect

    Holcomb, Don

    2011-03-29

    Solar Fueled Products (SFP) is developing an innovative ionic-liquid absorption heat pump (ILAHP). The development of an ILAHP is extremely significant, as it could result in annual savings of more than 190 billion kW h of electrical energy and $19 billion. This absorption cooler uses about 75 percent less electricity than conventional cooling and heating units. The ILAHP also has significant environmental sustainability benefits, due to reduced CO2 emissions. Phase I established the feasibility and showed the economic viability of an ILAHP with these key accomplishments: • Used the breakthrough capabilities provided by ionic liquids which overcome the key difficulties of the common absorption coolers. • Showed that the theoretical thermodynamic performance of an ILAHP is similar to existing absorption-cooling systems. • Established that the half-effect absorption cycle reduces the peak generator temperature, improving collector efficiency and reducing collector area. • Component testing demonstrated that the most critical components, absorber and generator, operate well with conventional heat exchangers. • Showed the economic viability of an ILAHP. The significant energy savings, sustainability benefits, and economic viability are compelling reasons to continue the ILAHP development.

  1. Development of a nonazeotropic heat pump for crew hygiene water heating

    NASA Technical Reports Server (NTRS)

    Walker, David H.; Deming, Glenn I.

    1991-01-01

    A heat pump system is currently under development to produce hot water for crew hygiene on future manned space missions. The heat pump uses waste heat sources and a nonazeotropic working fluid in a highly efficient cycle. The potential benefits include a reduction in peak power draw from 2 to 5 kW for electric cartridge heaters to just more than 100 W for the heat pump. As part of the heat pump development project, a unique high efficiency compressor was developed to maintain lubrication in a zero-gravity environment.

  2. Ground Source Integrated Heat Pump (GS-IHP) Development

    SciTech Connect

    Baxter, V. D.; Rice, K.; Murphy, R.; Munk, J.; Ally, Moonis; Shen, Bo; Craddick, William; Hearn, Shawn A.

    2013-05-24

    Between October 2008 and May 2013 ORNL and ClimateMaster, Inc. (CM) engaged in a Cooperative Research and Development Agreement (CRADA) to develop a groundsource integrated heat pump (GS-IHP) system for the US residential market. A initial prototype was designed and fabricated, lab-tested, and modeled in TRNSYS (SOLAR Energy Laboratory, et al, 2010) to predict annual performance relative to 1) a baseline suite of equipment meeting minimum efficiency standards in effect in 2006 (combination of air-source heat pump (ASHP) and resistance water heater) and 2) a state-of-the-art (SOA) two-capacity ground-source heat pump with desuperheater water heater (WH) option (GSHPwDS). Predicted total annual energy savings, while providing space conditioning and water heating for a 2600 ft{sup 2} (242 m{sup 2}) house at 5 U.S. locations, ranged from 52 to 59%, averaging 55%, relative to the minimum efficiency suite. Predicted energy use for water heating was reduced 68 to 78% relative to resistance WH. Predicted total annual savings for the GSHPwDS relative to the same baseline averaged 22.6% with water heating energy use reduced by 10 to 30% from desuperheater contributions. The 1st generation (or alpha) prototype design for the GS-IHP was finalized in 2010 and field test samples were fabricated for testing by CM and by ORNL. Two of the alpha units were installed in 3700 ft{sup 2} (345 m{sup 2}) houses at the ZEBRAlliance site in Oak Ridge and field tested during 2011. Based on the steady-state performance demonstrated by the GS-IHPs it was projected that it would achieve >52% energy savings relative to the minimum efficiency suite at this specific site. A number of operational issues with the alpha units were identified indicating design changes needed to the system before market introduction could be accomplished. These were communicated to CM throughout the field test period. Based on the alpha unit test results and the diagnostic information coming from the field test

  3. THz Pump and X-Ray Probe Development at LCLS

    SciTech Connect

    Fisher, Alan S; Durr, Hermann; Lindenberg, Aaron; Stanford U., Materials Sci.Dept.; Reis, David; Frisch, Josef; Loos, Henrik; Petree, Mark; Daranciang, Dan; Fuchs, Matthias; Ghimire, Shambhu; Goodfellow, John; /Stanford U., Materials Sci. Dept.

    2011-11-08

    We report on measurements of broadband, intense, coherent transition radiation at terahertz frequencies, generated as the highly compressed electron bunches in Linear Coherent Light Source (LCLS) pass through a thin metal foil. The foil is inserted at 45{sup o} to the electron beam, 31 m downstream of the undulator. The THz emission passes downward through a diamond window to an optical table below the beamline. A fully compressed 350-pC bunch produces up to 0.5 mJ in a nearly half-cycle pulse of 50 fs FWHM with a spectrum peaking at 10 THz. We estimate a peak field at the focus of over 2.5 GV/m. A 20-fs Ti:sapphire laser oscillator has recently been installed for electro-optic measurements. We are developing plans to add an x-ray probe to this THz pump, by diffracting FEL x rays onto the table with a thin silicon crystal. The x rays would arrive with an adjustable time delay after the THz. This will provide a rapid start to user studies of materials excited by intense single-cycle pulses and will serve as a step toward a THz transport line for LCLS-II.

  4. Development and Verification of a TOPAZ-II Electromagnetic Pump Model

    NASA Astrophysics Data System (ADS)

    El-Genk, Mohamed S.; Paramonov, Dmitry V.

    1994-07-01

    An integrated model of the TOPAZ-II electromagnetic (EM) pump is developed and incorporated into the Thermionic Transient Analysis Model (TITAM). The magnetic field strength of the induction coil depends not only on the current supplied by the pump TFEs, but also on the temperature of the coil. All electric and thermal properties of the coolant, wall material of pump ducts, and the electric leads are taken to be temperature dependent. The pump model is benchmarked with experimental data at different coolant temperatures. Results show the pump model to be in good agreement with experimental data. The maximum deviation in the mass flow predictions obtained at different coolant temperatures and pump currents is less than 0.1 kg/s.

  5. Design and Evaluation of a Fully Implantable Control Unit for Blood Pumps

    PubMed Central

    Unthan, Kristin; Gräf, Felix; Laumen, Marco; Finocchiaro, Thomas; Sommer, Christoph; Lanmüller, Hermann; Steinseifer, Ulrich

    2015-01-01

    As the number of donor hearts is limited while more and more patients suffer from end stage biventricular heart failure, Total Artificial Hearts become a promising alternative to conventional treatment. While pneumatic devices sufficiently supply the patients with blood flow, the patient's quality of life is limited by the percutaneous pressure lines and the size of the external control unit. This paper describes the development of the control unit of the ReinHeart, a fully implantable Total Artificial Heart. General requirements for any implantable control unit are defined from a technical and medical point of view: necessity of a Transcutaneous Energy Transmission, autonomous operation, safety, geometry, and efficiency. Based on the requirements, a prototype is designed; it incorporates a LiFePo4 battery pack with charger, a rectifier for transcutaneous energy transmission, the motor's driver electronics, and a microcontroller which monitors and controls all functions. In validation tests, the control unit demonstrated a stable operation on TET and battery supply and a safe switching from one supply to the other. The overall mean efficiency is 14% on TET and 22% on battery supply. The control unit is suitable for chronic animal trials of the ReinHeart. PMID:26583095

  6. Design and Evaluation of a Fully Implantable Control Unit for Blood Pumps.

    PubMed

    Unthan, Kristin; Gräf, Felix; Laumen, Marco; Finocchiaro, Thomas; Sommer, Christoph; Lanmüller, Hermann; Steinseifer, Ulrich

    2015-01-01

    As the number of donor hearts is limited while more and more patients suffer from end stage biventricular heart failure, Total Artificial Hearts become a promising alternative to conventional treatment. While pneumatic devices sufficiently supply the patients with blood flow, the patient's quality of life is limited by the percutaneous pressure lines and the size of the external control unit. This paper describes the development of the control unit of the ReinHeart, a fully implantable Total Artificial Heart. General requirements for any implantable control unit are defined from a technical and medical point of view: necessity of a Transcutaneous Energy Transmission, autonomous operation, safety, geometry, and efficiency. Based on the requirements, a prototype is designed; it incorporates a LiFePo4 battery pack with charger, a rectifier for transcutaneous energy transmission, the motor's driver electronics, and a microcontroller which monitors and controls all functions. In validation tests, the control unit demonstrated a stable operation on TET and battery supply and a safe switching from one supply to the other. The overall mean efficiency is 14% on TET and 22% on battery supply. The control unit is suitable for chronic animal trials of the ReinHeart. PMID:26583095

  7. Peristaltic Pumping of Blood Through Small Vessels of Varying Cross-Section

    NASA Astrophysics Data System (ADS)

    Misra, J. C.; Maiti, S.

    2012-11-01

    The paper is devoted to a study of the peristaltic motion of blood in the micro-circulatory system. The vessel is considered to be of varying cross-section. The progressive peristaltic waves are taken to be of sinusoidal nature. Blood is considered to be a Herschel-Bulkley fluid. Of particular concern here is to investigate the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, streamline pattern and wall shear stress. On the basis of the derived analytical expression, extensive numerical calculations have been made. The study reveals that velocity of blood and wall shear stress are appreciably affected due to the non-uniform geometry of blood vessels. They are also highly sensitive to the magnitude of the amplitude ratio and the value of the fluid index.

  8. Development of a Compact Efficient Cooling Pump for Space Suit Life Support Systems

    NASA Technical Reports Server (NTRS)

    vanBoeyen, Roger W.; Reeh, Jonathan A.; Trevino, Luis

    2008-01-01

    With the increasing demands placed on extravehicular activity (EVA) for the International Space Station (ISS) assembly and maintenance, along with planned lunar and Martian missions, the need for increased human productivity and capability becomes ever more critical. This is most readily achieved by reduction in space suit weight and volume, and increased hardware reliability, durability, and operating lifetime. Considerable progress has been made with each successive generation of space suit design; from the Apollo A7L suit, to the current Shuttle Extravehicular Mobile Unit (EMU) suit, and the next generation Constellation Space Suit Element (CSSE). However, one area of space suit design which has continued to lag is the fluid pump used to drive the water cooling loop of the Primary Life Support System (PLSS). The two main types of fluid pumps typically used in space applications are rotodynamic pumps (pumping is achieved through a rotary vaned impeller) and displacement pumps (which includes rotary and diaphragm pumps). The rotating and moving parts found in the pumps and electric motor add significantly to the susceptibility to wear and friction, thermal mismatch, and complexity of the pumps. Electric motor-driven pumps capable of achieving high operational reliability are necessarily large, heavy, and energy inefficient. This report describes a development effort conducted for NASA by Lynntech, Inc., who recently demonstrated the feasibility of an electrochemically-driven fluid cooling pump. With no electric motor and minimal lightweight components, an electrochemically-driven pump is expected to be significantly smaller, lighter and achieve a longer life time than conventional rotodynamic and displacement pumps. By employing sulfonated polystyrene-based proton exchange membranes, rather than conventional Nafion membranes, a significant reduction in the actuator power consumption was demonstrated. It was also demonstrated that these membranes possess the

  9. Development of the Geothermal Heat Pump Market in China; Renewable Energy in China

    SciTech Connect

    Not Available

    2006-03-01

    This case study is one in a series of Success Stories on developing renewable energy technologies in China for a business audience. It focuses on the development of the geothermal heat pump market in China.

  10. Development, testing, and certification of Calmac Mfg. Corp. solar collector and solar operated pump

    NASA Technical Reports Server (NTRS)

    Parker, J. C.

    1979-01-01

    Development of a rubber tube solar collector and solar operated pump for use with solar heating and cooling systems is discussed. The development hardware, problems encountered during fabrication and testing, and certification statements of performance are included.

  11. Finite element analysis of stresses developed in the blood sac of a left ventricular assist device.

    PubMed

    Haut Donahue, T L; Dehlin, W; Gillespie, J; Weiss, W J; Rosenberg, G

    2009-05-01

    The goal of this research is to develop a 3D finite element (FE) model of a left ventricular assist device (LVAD) to predict stresses in the blood sac. The hyperelastic stress-strain curves for the segmented poly(ether polyurethane urea) (SPEUU) blood sac were determined in both tension and compression using a servo-hydraulic testing system at various strain rates. Over the range of strain rates studied, the sac was not strain rate sensitive, however the material response was different for tension versus compression. The experimental tension and compression properties were used in a FE model that consisted of the pusher plate, blood sac and pump case. A quasi-static analysis was used to allow for nonlinearities due to contact and material deformation. The 3D FE model showed that blood sac stresses are not adversely affected by the location of the inlet and outlet ports of the device and that over the systolic ejection phase of the simulation the prediction of blood sac stresses from the full 3D model and an axisymmetric model are the same. Minimizing stresses in the blood sac will increase the longevity of the blood sac in vivo. PMID:19131267

  12. [Evaluation of estimated blood concentration of propofol on wake-up using "ConGrase", a software to control the syringe pump for propofol infusion].

    PubMed

    Nagata, O; Sawada, K; Sato, M; Sekiyama, H; Yajima, C; Hanaoka, K

    1998-10-01

    We developed a software to control a Graseby 3500 syringe pump for propofol infusion through the serial port of Apple Macintosh/Power-Macintosh computer. This software, "ConGrase", was developed with Metrowerks CodeWarrior Professional (CWP 1) and PowerPlant framework using C++. ConGrase communicates with the syringe pump at least every three seconds, and calculates the estimated blood concentration (EBC) of propofol based on the amount of propofol actually infused by applying either the Euler or Runge-Kutta method using the three-compartment pharmacokinetic model. The parameter sets reported by Gepts et al. are used. ConGrase was released at the 44 th Annual Meeting of the Japan Society of Anesthesiology, and is distributed freely. The mean and S.D. of the emergence EBC calculated by ConGrase were 1.22 micrograms.ml-1 and 0.16 microgram.ml-1, respectively. These values are almost the same as values already reported outside Japan. The necessary wake-up time can be calculated with this estimated concentration. With this system, anesthetists can control the EBC at the required level and avoid long delays before the patients wake up after anesthesia. PMID:9834602

  13. Capillary Pump Loop (CPL) heat pipe development status report

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The capillary pump loop (CPL) was re-introduced as a potential candidate for the management of large heat loads. It is currently being evaluated for application in the thermal management of large space structures. Test efforts were conducted to establish the feasibility of the CPL heat pipe design.

  14. Oxygenation to Bovine Blood in Artificial Heart and Lung Using Vibrating Flow Pump: Experiment and Numerical Analysis Based on Non-Newtonian Model

    NASA Astrophysics Data System (ADS)

    Shintaku, Hirofumi; Yonemura, Tsubasa; Tsuru, Kazuaki; Isoyama, Takashi; Yambe, Tomoyuki; Kawano, Satoyuki

    In this study, we construct an experimental apparatus for a prototype artificial heart and lung (AHL) by installing hollow fibers into the cylindrical tube of the vibrating flow pump (VFP). The oxygenation characteristics are investigated both by experiments using bovine blood and by numerical analyses based on the computational fluid dynamics. The analyses are carried out at the Reynolds numbers Re ranged from O(1) to O(103), which are determined based on the experimental conditions. The blood flow and the diffusion of oxygen gas are analyzed based on the Newtonian/non-Newtonian, unsteady, incompressible and axisymmetric Navier-Stokes equations, and the advection-diffusion equation. The results show that the oxygenation rate increases in proportion to Re1/3, where the phenomenon corresponds to the decreasing thickness of the concentration boundary layer with Re. Although the effects of the vibrating flow and the rheology of the blood are clearly appeared on the velocity field, their effects on the gas exchange are relatively small at the ranges of prescribed Reynolds numbers. Furthermore, the numerical results in terms of the oxygenation rate are compared with the experimental ones. The basic design data of VFP were accumulated for the development of AHL in the clinical applications.

  15. Problems and Approaches for Blood Transfusion in the Developing Countries.

    PubMed

    Roberts, David J; Field, Stephen; Delaney, Meghan; Bates, Imelda

    2016-04-01

    A safe supply of blood and the knowledge, skill, and resources for the appropriate use of blood are essential for medical services. Many problems are faced in the development of transfusion services in low- or medium-income countries (LMICs). Unfortunately, in many countries, providing safe blood is made more difficult by a lack of blood donors and the high frequency of transfusion-transmissible infections. The problems are compounded by the frequent need for urgent life-saving transfusions. This article examines the problems in supply, safety, and use of blood and how they are being addressed in LMICs, predominantly focusing on sub-Saharan Africa. PMID:27040966

  16. The Importance of Intraoperative Selenium Blood Levels on Organ Dysfunction in Patients Undergoing Off-Pump Cardiac Surgery: A Randomised Controlled Trial

    PubMed Central

    Stevanovic, Ana; Coburn, Mark; Menon, Ares; Rossaint, Rolf; Heyland, Daren; Schälte, Gereon; Werker, Thilo; Wonisch, Willibald; Kiehntopf, Michael; Goetzenich, Andreas; Rex, Steffen; Stoppe, Christian

    2014-01-01

    Introduction Cardiac surgery is accompanied by an increase of oxidative stress, a significantly reduced antioxidant (AOX) capacity, postoperative inflammation, all of which may promote the development of organ dysfunction and an increase in mortality. Selenium is an essential co-factor of various antioxidant enzymes. We hypothesized a less pronounced decrease of circulating selenium levels in patients undergoing off-pump coronary artery bypass (OPCAB) surgery due to less intraoperative oxidative stress. Methods In this prospective randomised, interventional trial, 40 patients scheduled for elective coronary artery bypass grafting were randomly assigned to undergo either on-pump or OPCAB-surgery, if both techniques were feasible for the single patient. Clinical data, myocardial damage assessed by myocard specific creatine kinase isoenzyme (CK-MB), circulating whole blood levels of selenium, oxidative stress assessed by asymmetric dimethylarginine (ADMA) levels, antioxidant capacity determined by glutathionperoxidase (GPx) levels and perioperative inflammation represented by interleukin-6 (IL-6) levels were measured at predefined perioperative time points. Results At end of surgery, both groups showed a comparable decrease of circulating selenium concentrations. Likewise, levels of oxidative stress and IL-6 were comparable in both groups. Selenium levels correlated with antioxidant capacity (GPx: r = 0.720; p<0.001) and showed a negative correlation to myocardial damage (CK-MB: r = −0.571, p<0.001). Low postoperative selenium levels had a high predictive value for the occurrence of any postoperative complication. Conclusions OPCAB surgery is not associated with less oxidative stress and a better preservation of the circulating selenium pool than on-pump surgery. Low postoperative selenium levels are predictive for the development of complications. Trial registration ClinicalTrials.gov NCT01409057 PMID:25118980

  17. Interbeat control of a ventricular assist device for variable pump performance.

    PubMed

    Tanaka, Akira; Moriya, Aoi; Yoshizawa, Makoto; Shiraishi, Yasuyuki; Yambe, Tomoyuki

    2013-01-01

    Pump performance is very important property in rotary blood pumps. Suitable pump performance often creates suitable blood flow regulation in long-term circulatory support. However, it is difficult to develop the blood pump with specific pump performance. In addition, optimal pump performance is still unknown. In this study, we have proposed a control method to implement variable pump performance in a single pump and evaluated the validity of the control method using computer simulation. The controller controls the dynamic change in the relationship between pump pressure head and flow rate by interbeat control. A repetitive control method was adopted in order to reduce cyclic error derived from the heartbeat. Simulation results indicate the possibility that the proposed controller can regulate so that the dynamic relationship between pressure head and pump flow is that of various type centrifugal pump. PMID:24111040

  18. Pulse-pressure-enhancing controller for better physiologic perfusion of rotary blood pumps based on speed modulation.

    PubMed

    Huang, Feng; Ruan, Xiaodong; Fu, Xin

    2014-01-01

    Sufficient pulsation is important for physiologic perfusion if adequate flow is to be guaranteed. A fuzzy control method for rotary blood pumps using active speed modulation is proposed in this article. It maintains the mean aortic pressure to provide sufficient perfusion while it simultaneously enhances the pulse pressure. The controller uses the indices extracted from the aortic pressure as feedback to determine the amplitude and offset of the rectangular speed modulation waveform, which is synchronous with the cardiac cycle. An additional algorithm is included to prevent regurgitation. The controller is tested both in a baroreflex-cardiovascular model and in a preliminary in vitro experiment. Simulation results demonstrate that the controller is able to increase the pulse pressure to approximately 20 mm Hg and at the same time maintains the mean pressure at 100 mm Hg, when heart failure occurs. It is also quite robust under various physiologic disturbances. Experimental results show that the speed modulation can be implemented in real pumps and that the controller is feasible in practice. PMID:24614360

  19. An experimental study of Newtonian and non-Newtonian flow dynamics in an axial blood pump model.

    PubMed

    Hu, Qi-Hui; Li, Jing-Yin; Zhang, Ming-Yuan; Zhu, Xian-Ran

    2012-04-01

    The head curves of a 1.5:1 new axial blood pump model were measured using five working fluids at five rotational speeds. The working fluids were water, a 39wt% aqueous glycerin solution (GS), and three aqueous xanthan gum solutions (XGSs) with different concentrations. The flow velocities and shear stresses in the mechanical clearance between the casing and rotor were investigated using a laser Doppler velocimeter and hot-film sensor. At every rotational speed, the experiment in which viscous GS was used in the pump model showed a head curve lower than that obtained using water, whereas the head obtained using viscoelastic XGS was higher than that generated using water. A maximum difference of 65.8% between the heads measured in the 0.06% XGS and GS experiments was detected. The higher head produced by the XGS may have originated from the drag-reduction effect of XGS viscoelasticity. The measurements showed that a reverse washout flow at a velocity of 0.05-0.11m/s occurs in the clearance. This reverse washout flow is crucial to preventing flow stagnation and accompanying thrombus formation. The wall shear stress and the Taylor number of the rotating Couette-like flow in the clearance both indicated that it is a turbulent flow. PMID:21995643

  20. Evaluation of a Spiral Groove Geometry for Improvement of Hemolysis Level in a Hydrodynamically Levitated Centrifugal Blood Pump.

    PubMed

    Murashige, Tomotaka; Kosaka, Ryo; Sakota, Daisuke; Nishida, Masahiro; Kawaguchi, Yasuo; Yamane, Takashi; Maruyama, Osamu

    2015-08-01

    The purpose of this study is to evaluate a spiral groove geometry for a thrust bearing to improve the hemolysis level in a hydrodynamically levitated centrifugal blood pump. We compared three geometric models: (i) the groove width is the same as the ridge width at any given polar coordinate (conventional model); (ii) the groove width contracts inward from 9.7 to 0.5 mm (contraction model); and (iii) the groove width expands inward from 0.5 to 4.2 mm (expansion model). To evaluate the hemolysis level, an impeller levitation performance test and in vitro hemolysis test were conducted using a mock circulation loop. In these tests, the driving conditions were set at a pressure head of 200 mm Hg and a flow rate of 4.0 L/min. As a result of the impeller levitation performance test, the bottom bearing gaps of the contraction and conventional models were 88 and 25 μm, respectively. The impeller of the expansion model touched the bottom housing. In the hemolysis test, the relative normalized index of hemolysis (NIH) ratios of the contraction model in comparison with BPX-80 and HPM-15 were 0.6 and 0.9, respectively. In contrast, the relative NIH ratios of the conventional model in comparison with BPX-80 and HPM-15 were 9.6 and 13.7, respectively. We confirmed that the contraction model achieved a large bearing gap and improved the hemolysis level in a hydrodynamically levitated centrifugal blood pump. PMID:26146791

  1. Fundamental study to develop a fiber-optic gap sensor for a rotary undulation pump.

    PubMed

    Mitsumune, Norihiko; Saito, Itsuro; Mochizuki, Shuichi; Abe, Yusuke; Isoyama, Takashi; Nakagawa, Hidemoto; Ono, Toshiya; Kouno, Akimasa; Sugino, Ayaka; Chinzei, Tsuneo

    2007-01-01

    The rotary undulation pump is believed to be a good candidate for the next-generation artificial heart. Due to its complex movement, it is desirable to magnetically levitate the rotor and dynamically control the gap. In this article, the applicability of a fiber-optic gap sensor to the dynamic position control of the rotor in the rotary undulation pump was investigated. The fiber-optic gap sensor consisted of two plastic-core fibers and a reflection plate. Two 1-mm-diameter optical fibers were aligned parallel: one for source light propagation and the other for reflected light transmission. The basic properties of gap sensors using four different light sources were explored in five media (air, physiologic saline, and blood samples with three different hematocrit levels). The influence of the oxygen saturation level in the blood on sensing was investigated with two types of light sources. It is desirable to use a light source the wavelength of which shows similar absorption coefficients for both oxygenated blood and deoxygenated blood. The effect of the distance between the two fibers on the sensing and range was also investigated. The results indicated that the fiber-optic gap sensor is quite promising for the active control of rotor positioning in the rotary undulation pump. PMID:18071854

  2. The development of a kinematic Stirling-engine-driven heat pump

    SciTech Connect

    Monahan, R.E.; Kountz, K.J.; Clinch, J.M.

    1987-06-01

    The continuing development of a 10-ton light commercial natural-gas-fired kinematic Stirling-engine-driven heat pump system is described. Basic Stirling cycle thermodynamics are presented, and a complete engine heat balance is shown to detail the inherent advantages of the V160 Stirling engine as a prime mover in a heat pump package. Results from environmental laboratory testing of a breadboard prototype are reviewed, and the test procedures used in the evaluation are explained. Seasonal performance of the heat pump package was predicted using a bin-temperature method based on Chicago and Dallas climatic data. Annual energy costs, as predicted by the seasonal performance analytical computer program, have been calculated for a gas furnace, standard electric heat pump, and the Stirling engine-driven prototype heat pump package. These computed costs for these systems are listed and compared.

  3. Development of a Prototype Water Pump for Future Space Suit Applications

    NASA Technical Reports Server (NTRS)

    Hartman, David; Hodgson, Edward; Dionne, Steven; Gervais, Edward, III; Trevino, Luis

    2009-01-01

    NASA's next generation of space suit systems will place new demands on the pump used to circulate cooling water through the life support system and the crew's liquid cooling garment. Long duration missions and frequent EVA require increased durability and reliability; limited resupply mass requirements demand compatibility with recycled water, and changing system design concepts demand increased tolerance for dissolved and free gas and the ability to operate over a broader range of flow rates and discharge pressure conditions. This paper describes the development of a positive displacement prototype pump to meet these needs. A gerotor based design has been adapted to meet pump performance, gas tolerance, and durability requirements while providing a small, lightweight pump assembly. This design has been detailed and implemented using materials selected to address anticipated water quality and mission needs as a prototype unit for testing in NASA laboratories. Design requirements, pump technology selection and design, performance testing and test results will be discussed.

  4. Development of a Prototype Water Pump for Future Space Suit Applications

    NASA Technical Reports Server (NTRS)

    Hartman, David; Hodgson, Edward; Gervais, Edward, III; Trevino, Luis

    2008-01-01

    NASA s next generation of space suit systems will place new demands on the pump used to circulate cooling water through the life support system and the crew s liquid cooling garment. Long duration missions and frequent EVA require increased durability and reliability; limited resupply mass requirements demand compatibility with recycled water, and changing system design concepts demand increased tolerance for dissolved and free gas and the ability to operate over a broader range of flow rates and discharge pressure conditions. This paper describes the development of a positive displacement prototype pump to meet these needs. A gerotor based design has been adapted to meet pump performance, gas tolerance, and durability requirements while providing a small, lightweight pump assembly. This design has been detailed and implemented using materials selected to address anticipated water quality and mission needs as a prototype unit for testing in NASA laboratories. Design requirements, pump technology selection and design, performance testing and test results will be discussed.

  5. Spallation and migration of silicone from blood-pump tubing in patients on hemodialysis

    SciTech Connect

    Leong, A.S.; Disney, A.P.; Gove, D.W.

    1982-01-21

    Spalled particles of silicone were observed in the livers of patients with chronic renal failure treated by hemodialysis. The refractile particles of silicone were associated with various degrees of hepatic inflammation and fibrosis, and granulomatous hepatitis was evident in nine cases. Retrospective examination revealed the material in 18 of 38 liver-biopsy samples from patients on hemodialysis who had clinical hepatic dysfunction. Of 31 autopsies of patients who had undergone hemodialysis, 22 revealed silicone in the liver, and silicone was also present in the spleen in all cases and in the marrow, lungs, and nodes in some. Giant cells containing silicone were also observed in these organs. Silicone was present in patients who had undergone hemodialysis for six weeks to 84 months (mean, 24 months). The identity of the material was confirmed by atomic absorption and by electron microprobe analysis. The silicone was traced to a segment of silicone tubing located in the roller pump of the dialysis machine.

  6. Comparison of hemolysis between CentriMag and RotaFlow rotary blood pumps during extracorporeal membrane oxygenation.

    PubMed

    Palanzo, David A; El-Banayosy, Aly; Stephenson, Edward; Brehm, Christoph; Kunselman, Allen; Pae, Walter E

    2013-09-01

    The purpose of this investigation was to compare the hemolysis levels for patients on extracorporeal membrane oxygenation (ECMO) incorporating two different rotary blood pumps (CentriMag [CMAG] and RotaFlow [RF]) in identical circuits otherwise. The difference between the two pumps is the cost. One is 20-30 times less expensive than the other. A retrospective analysis of all patients placed on ECMO from June 2008 through May 2012 was done to evaluate hemolysis. Daily plasma hemoglobin (pHb), lactate dehydrogenase (LDH), and lactate levels were collected on all patients. Values were compared between those patients who received a CMAG and those who received an RF. Patients had to be on ECMO for more than 2 days to be included in the study. Linear mixed effects models were fit to the data to assess differences over time for each continuous outcome. Forty patients were placed on ECMO incorporating CMAG, whereas 40 patients received an RF. There were no significant statistical differences between CMAG and RF groups when comparing days on support (8.7 ± 5.0; 8.4 ± 5.7), age (44.8 ± 18.3; 46.1 ± 16.0), body surface area (2.03 ± 0.36; 1.96 ± 0.31), gender (male: 58%, female: 42%; male: 55%, female: 45%), etiology, type of support (veno-arterial [VA)]: 78%, veno-venous [VV)]: 22%; VA: 82%, VV: 18%) and pre-ECMO LDH levels (4004.0 ± 3583.2; 3603.7 ± 3354.1). There were also no significant differences between the CMAG and RF groups when comparing the mean values for daily pHb levels (5.7 ± 3.6; 5.7 ± 4.2), lactate levels (2.8 ± 1.9; 3.0 ± 2.1), and LDH levels (2656.3 ± 1606.8; 2688.6 ± 1726.1) or daily lactate, LDH, and pHb levels for the first 10 days of support. From our investigation, there is no difference between the CMAG and the RF blood pumps in regard to the creation of hemolysis during ECMO. The difference in cost of the devices does not correlate with the performance and outcomes. PMID:23981131

  7. Blood

    MedlinePlus

    ... solid part of your blood contains red blood cells, white blood cells, and platelets. Red blood cells (RBC) deliver oxygen from your lungs to your tissues and organs. White blood cells (WBC) fight infection and are part of your ...

  8. An artificial neural network-based noninvasive detector for suction and left atrium pressure in the control of rotary blood pumps: an in vitro study.

    PubMed

    Stöcklmayer, C; Dorffner, G; Schmidt, C; Schima, H

    1995-07-01

    Rotary blood pumps are used in clinical applications to assist circulation via pumping blood from the left atrium to the aorta. Negative inflow pressures at high flow rates can cause suction of the cannula in the left atrium with deleterious effects on the atrial wall, the blood, and the lung. Therefore, stable and reliable detection of suction and the prediction of the left atrium pressure (LAP) would be of major interest for the control of these pumps. This work reports about an in vitro study of such a detector based on artificial neural networks (ANN). In the first project phase, an ANN was used to estimate the LAP based on pump speed, pump flow, and aortic pressure, obtained from a mock circulation. The inputs for the ANN were 11 characteristic values computed from these three parameters. In the second phase, another ANN was trained to classify various system states, such as suction, danger of suction (a state close to actual suction), and no suction. The first ANN was able to estimate the LAP with an accuracy of +/- 1.8 mm Hg. The discrimination of suction versus the other two states could be performed with a sensitivity and specificity of about 95% while the more interesting task of distinguishing danger of suction from no suction reached a sensitivity and specificity of about 65% (leaving 25% of each class unclassified and 10% of each class incorrectly classified).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8572982

  9. Development of a Proof of Concept Low Temperature Superfluid Magnetic Pump with Applications

    NASA Astrophysics Data System (ADS)

    Jahromi, Amir E.

    State of the art particle and photon detectors such as Transition Edge Sensors (TES) and Microwave Kinetic Inductance Detectors (MKID) use large arrays of sensors or detectors for space science missions. As the size of these space science detectors increases, future astrophysics missions will require sub-Kelvin coolers over larger areas. This leads to not only increased cooling power requirements, but also a requirement for distributed sub-Kelvin cooling. Development of a proof of concept Superfluid Magnetic Pump is discussed in this work. This novel low temperature, no moving part pump can replace the existing bellows-piston driven 4He or 3He- 4He mixture compressor/circulators used in various sub Kelvin refrigeration systems such as dilution, Superfluid pulse tube, or active magnetic regenerative refrigerators. Due to its superior thermal transport properties this pump can also be used as a simple circulator of sub-Lambda 4He to distribute cooling over large surface areas. The pump discussed in this work was experimentally shown to produce a maximum flow rate of 440 mg/s (averaged over cycle), 665 mg/s (peak) and produced a maximum pressure difference of 2323 Pascal. This pump worked in an "ideal" thermodynamic state: The experimental results matched with the theoretical values predicted by a computer model. Pump curves were developed to map the performance of this pump. This successful demonstration will enable this novel pump to be put to test in suitable sub Kelvin refrigeration systems. Numerical modeling of an Active Magnetic Regenerative Refrigerator (AMRR) that uses the Superfluid Magnetic Pump (SMP) to circulate liquid 3He-4He through a magnetic regenerator is presented as a potential application of such a pump.

  10. Development of the MOSFET hybrid biosensor for self-monitoring of blood glucose

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Kazuyoshi; Kuroda, Tatsuro; Hirai, Yasutomo; Iwamoto, Naoyuki; Nakanishi, Naoyuki; Uetsuji, Yasutomo; Nakamachi, Eiji

    2006-01-01

    We focus on the research to develop a compact Self Monitoring of Blood Glucose (SMBG). The SMBG consists of (1) a micro electrical pumping system for blood extraction, (2) a painless microneedle as same size as a female mosquito's labium and (3) a biosensor to detect and evaluate an amount of glucose in extracted blood, by using enzyme such as glucose oxidase (GOx). A gold (Au) plate immobilized GOx was used as a biosensor and attached to the gate electrode of MOSFET. GOx was immobilized on a self-assembled spacer combined with an Au electrode by the cross-link method using BSA (bovine serum albumin) as an additional bonding material. The electrode could detect electrons generated by the hydrolysis of hydrogen peroxide produced by the reaction between GOx and glucose using the constant electric current measurement system of the MOSFET type hybrid biosensor system. The system can measure the change of gate voltage. The extracting speed for whole blood using the micro electrical pumping system was about 2 μl/min. The extracted volume was sufficient to determine the glucose level in the blood; it was comparable to the volume extracted in a commercial glucose level monitor. In the functional evaluation of the biosensor system using hydrogen peroxide solution, it is shown that the averaged output voltage increases in alignment to hydrogen peroxide concentration. The linear value was shown with the averaged output voltage in corresponding hydrogen peroxide concentration with the averaged output voltage obtained from the biosensor system by glucose solution concentration. Furthermore, it is confirmed that the averaged output voltage from the biosensor system obtained by whole blood showed the same voltage in corresponding glucose solution concentration. The hybrid biosensor obtained the useful performance for the SMBG.

  11. Axial Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George Arthur (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1997-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  12. In-vitro investigation of cerebral-perfusion effects of a rotary blood pump installed in the descending aorta.

    PubMed

    Rezaienia, Mohammad Amin; Paul, Gordon; Avital, Eldad; Rahideh, Akbar; Rothman, Martin Terry; Korakianitis, Theodosios

    2016-06-14

    This study describes use of a cardiovascular simulator to replicate the hemodynamic responses of the cerebrovascular system with a mechanical circulatory support device operating in the descending aorta. To do so, a cerebral autoregulation unit was developed which replicates the dilation and constriction of the native cerebrovascular resistance system and thereby regulates the cerebral flow rate within defined limits. The efficacy of the replicated autoregulation mechanism was investigated by introducing a number of step alterations in mean aortic pressure and monitoring the cerebral flow. The steady responses of the cerebral flow to changes in mean aortic pressure were in good agreement with clinical data. Next, a rotary pump, modeling a mechanical circulatory support device, was installed in the descending aorta and the hemodynamic responses of the cerebral system were investigated over a wide range of pump operating conditions. Insertion of a mechanical circulatory support device in the descending aorta presented an improved cardiac output as a result of afterload reduction. It was observed that the primary drop in cerebral flow, caused by the pump in the descending aorta, was compensated over the course of five seconds due to a gradual decrease in cerebrovascular resistance. The experimental results suggest that the implantation of a mechanical circulatory support device in the descending aorta, a less invasive procedure than typical mechanical circulatory support implantation, will not have an adverse effect on the cognitive function, provided that the cerebral autoregulation is largely unimpaired. PMID:27155746

  13. Development of the hydrotransport boost pump. Open file report September 1981-December 1984

    SciTech Connect

    Rubin, L.S.; Cardenas, R.L.; Burnette, M.; Roberge, J.; Harvey, A.

    1984-12-31

    A ventilated helical boost pump was developed that can handle varying flow rates and/or solids concentrations while operating at a single rotational speed and without computer assisted feedback controls. The boost pump developed and briefly tested during this program was designed to accomodate flows suitable for a 3-in-diam pipeline. The boost pump's ventilated design provides the automatic pressure regulation needed to meet the system's requirements for supporting transient pipeline flow. A maximum discharge pressure of 120 psi was achieved at an operating speed of 3,000 rpm. The boost pump efficiency at maximum discharge pressure was 65 pct. Coal flow rates of up to 1,000 lb/min were successfully processed with a nonshrouded single vane impeller. Further redesign is required to develop a shrouded impeller that can be combined with stationary wear rings to minimize impeller wear.

  14. The CentriMag centrifugal blood pump as a benchmark for in vitro testing of hemocompatibility in implantable ventricular assist devices.

    PubMed

    Chan, Chris H H; Pieper, Ina Laura; Hambly, Rebecca; Radley, Gemma; Jones, Alyssa; Friedmann, Yasmin; Hawkins, Karl M; Westaby, Stephen; Foster, Graham; Thornton, Catherine A

    2015-02-01

    Implantable ventricular assist devices (VADs) have proven efficient in advanced heart failure patients as a bridge-to-transplant or destination therapy. However, VAD usage often leads to infection, bleeding, and thrombosis, side effects attributable to the damage to blood cells and plasma proteins. Measuring hemolysis alone does not provide sufficient information to understand total blood damage, and research exploring the impact of currently available pumps on a wider range of blood cell types and plasma proteins such as von Willebrand factor (vWF) is required to further our understanding of safer pump design. The extracorporeal CentriMag (Thoratec Corporation, Pleasanton, CA, USA) has a hemolysis profile within published standards of normalized index of hemolysis levels of less than 0.01 g/100 L at 100 mm Hg but the effect on leukocytes, vWF multimers, and platelets is unknown. Here, the CentriMag was tested using bovine blood (n = 15) under constant hemodynamic conditions in comparison with a static control for total blood cell counts, hemolysis, leukocyte death, vWF multimers, microparticles, platelet activation, and apoptosis. The CentriMag decreased the levels of healthy leukocytes (P < 0.006), induced leukocyte microparticles (P < 10(-5) ), and the level of high molecular weight of vWF multimers was significantly reduced in the CentriMag (P < 10(-5) ) all compared with the static treatment after 6 h in vitro testing. Despite the leukocyte damage, microparticle formation, and cleavage of vWF multimers, these results show that the CentriMag is a hemocompatible pump which could be used as a standard in blood damage assays to inform the design of new implantable blood pumps. PMID:25066768

  15. The development of a cryogenic over-pressure pump

    NASA Astrophysics Data System (ADS)

    Alvarez, M.; Cease, H.; Flaugher, B.; Flores, R.; Garcia, J.; Lathrop, A.; Ruiz, F.

    2014-01-01

    A cryogenic over-pressure pump (OPP) was tested in the prototype telescope liquid nitrogen (LN2) cooling system for the Dark Energy Survey (DES) Project. This OPP consists of a process cylinder (PC), gas generator, and solenoid operated valves (SOVs). It is a positive displacement pump that provided intermittent liquid nitrogen (LN2) flow to an array of charge couple devices (CCDs) for the prototype Dark Energy Camera (DECam). In theory, a heater submerged in liquid would generate the drive gas in a closed loop cooling system. The drive gas would be injected into the PC to displace that liquid volume. However, due to limitations of the prototype closed loop nitrogen system (CCD cooling system) for DECam, a quasiclosed-loop nitrogen system was created. During the test of the OPP, the CCD array was cooled to its designed set point temperature of 173K. It was maintained at that temperature via electrical heaters. The performance of the OPP was captured in pressure, temperature, and flow rate in the CCD LN2 cooling system at Fermi National Accelerator Laboratory (FNAL).

  16. The development of a cryogenic over-pressure pump

    SciTech Connect

    Alvarez, M.; Cease, H.; Flaugher, B.; Flores, R.; Lathrop, A.; Garcia, J.; Ruiz, F.

    2014-01-29

    A cryogenic over-pressure pump (OPP) was tested in the prototype telescope liquid nitrogen (LN2) cooling system for the Dark Energy Survey (DES) Project. This OPP consists of a process cylinder (PC), gas generator, and solenoid operated valves (SOVs). It is a positive displacement pump that provided intermittent liquid nitrogen (LN2) flow to an array of charge couple devices (CCDs) for the prototype Dark Energy Camera (DECam). In theory, a heater submerged in liquid would generate the drive gas in a closed loop cooling system. The drive gas would be injected into the PC to displace that liquid volume. However, due to limitations of the prototype closed loop nitrogen system (CCD cooling system) for DECam, a quasiclosed-loop nitrogen system was created. During the test of the OPP, the CCD array was cooled to its designed set point temperature of 173K. It was maintained at that temperature via electrical heaters. The performance of the OPP was captured in pressure, temperature, and flow rate in the CCD LN2 cooling system at Fermi National Accelerator Laboratory (FNAL)

  17. LH2 pump component development testing in the electric pump room at test cell C inducer no. 1

    NASA Technical Reports Server (NTRS)

    Andrews, F. X.; Brunner, J. J.; Kirk, K. G.; Mathews, J. P.; Nishioka, T.

    1972-01-01

    The characteristics of a turbine pump for use with the nuclear engine for rocket vehicles are discussed. It was determined that the pump will be a two stage centrifugal pump with both stages having backswept impellers and an inducer upstream of the first stage impeller. The test program provided demonstration of the ability of the selected design to meet the imposed requirements.

  18. NEURONAL ACTION ON THE DEVELOPING BLOOD VESSEL PATTERN

    PubMed Central

    James, Jennifer M.; Mukouyama, Yoh-suke

    2011-01-01

    The nervous system relies on a highly specialized network of blood vessels for development and neuronal survival. Recent evidence suggests that both the central and peripheral nervous systems (CNS and PNS) employ multiple mechanisms to shape the vascular tree to meet its specific metabolic demands, such as promoting nerve-artery alignment in the PNS or the development the blood brain barrier in the CNS. In this article we discuss how the nervous system directly influences blood vessel patterning resulting in neuro-vascular congruence that is maintained throughout development and in the adult. PMID:21978864

  19. Development and numerical analysis of low specific speed mixed-flow pump

    NASA Astrophysics Data System (ADS)

    Li, H. F.; Huo, Y. W.; Pan, Z. B.; Zhou, W. C.; He, M. H.

    2012-11-01

    With the development of the city, the market of the mixed flow pump with large flux and high head is prospect. The KSB Shanghai Pump Co., LTD decided to develop low speed specific speed mixed flow pump to meet the market requirements. Based on the centrifugal pump and axial flow pump model, aiming at the characteristics of large flux and high head, a new type of guide vane mixed flow pump was designed. The computational fluid dynamics method was adopted to analyze the internal flow of the new type model and predict its performances. The time-averaged Navier-Stokes equations were closed by SST k-ω turbulent model to adapt internal flow of guide vane with larger curvatures. The multi-reference frame(MRF) method was used to deal with the coupling of rotating impeller and static guide vane, and the SIMPLEC method was adopted to achieve the coupling solution of velocity and pressure. The computational results shows that there is great flow impact on the head of vanes at different working conditions, and there is great flow separation at the tailing of the guide vanes at different working conditions, and all will affect the performance of pump. Based on the computational results, optimizations were carried out to decrease the impact on the head of vanes and flow separation at the tailing of the guide vanes. The optimized model was simulated and its performance was predicted. The computational results show that the impact on the head of vanes and the separation at the tailing of the guide vanes disappeared. The high efficiency of the optimized pump is wide, and it fit the original design destination. The newly designed mixed flow pump is now in modeling and its experimental performance will be getting soon.

  20. Development of a nonazeotropic heat pump for crew hygiene water heating

    NASA Technical Reports Server (NTRS)

    Walker, David H.; Deming, Glenn I.

    1991-01-01

    A Phase 2 SBIR Program funded by the NASA Marshall Space Flight Center to develop a Nonazeotropic Heat Pump is described. The heat pump system which was designed, fabricated, and tested in the Foster-Miller laboratory, is capable of providing crew hygiene water heating for future manned missions. The heat pump utilizes a nonazeotropic refrigerant mixture which, in this application, provides a significant Coefficient of Performance improvement over a single-constituent working fluid. In order to take full advantage of the refrigerant mixture, compact tube-in-tube heat exchangers were designed. A high efficiency scroll compressor with a proprietary lubrication system was developed to meet the requirements of operation in zero-gravity. The prototype heat pump system consumes less than 200W of power compared to the alternative of electric cartridge heaters which would require 2 to 5 kW.

  1. Development and Uncertainty Analysis of an Automatic Testing System for Diffusion Pump Performance

    NASA Astrophysics Data System (ADS)

    Zhang, S. W.; Liang, W. S.; Zhang, Z. J.

    A newly developed automatic testing system used in laboratory for diffusion pump performance measurement is introduced in this paper. By using two optical fiber sensors to indicate the oil level in glass-buret and a needle valve driven by a stepper motor to regulate the pressure in the test dome, the system can automatically test the ultimate pressure and pumping speed of a diffusion pump in accordance with ISO 1608. The uncertainty analysis theory is applied to analyze pumping speed measurement results. Based on the test principle and system structure, it is studied how much influence each component and test step contributes to the final uncertainty. According to differential method, the mathematical model for systematic uncertainty transfer function is established. Finally, by case study, combined uncertainties of manual operation and automatic operation are compared with each other (6.11% and 5.87% respectively). The reasonableness and practicality of this newly developed automatic testing system is proved.

  2. Keeping Hearts Pumping

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A collaboration between NASA, Dr. Michael DeBakey, Dr. George Noon, and MicroMed Technology, Inc., resulted in a life-saving heart pump for patients awaiting heart transplants. The MicroMed DeBakey VAD functions as a "bridge to heart transplant" by pumping blood throughout the body to keep critically ill patients alive until a donor heart is available. Weighing less than 4 ounces and measuring 1 inch by 3 inches, the pump is approximately one-tenth the size of other currently marketed pulsatile VADs. This makes it less invasive and ideal for smaller adults and children. Because of the pump's small size, less than 5 percent of the patients implanted developed device-related infections. It can operate up to 8 hours on batteries, giving patients the mobility to do normal, everyday activities.The MicroMed DeBakey VAD is a registered trademark of MicroMed Technology, Inc.

  3. Development of a pump-turbine runner based on multiobjective optimization

    NASA Astrophysics Data System (ADS)

    Xuhe, W.; Baoshan, Z.; Lei, T.; Jie, Z.; Shuliang, C.

    2014-03-01

    As a key component of reversible pump-turbine unit, pump-turbine runner rotates at pump or turbine direction according to the demand of power grid, so higher efficiencies under both operating modes have great importance for energy saving. In the present paper, a multiobjective optimization design strategy, which includes 3D inverse design method, CFD calculations, response surface method (RSM) and multiobjective genetic algorithm (MOGA), is introduced to develop a model pump-turbine runner for middle-high head pumped storage plant. Parameters that controlling blade shape, such as blade loading and blade lean angle at high pressure side are chosen as input parameters, while runner efficiencies under both pump and turbine modes are selected as objective functions. In order to validate the availability of the optimization design system, one runner configuration from Pareto front is manufactured for experimental research. Test results show that the highest unit efficiency is 91.0% under turbine mode and 90.8% under pump mode for the designed runner, of which prototype efficiencies are 93.88% and 93.27% respectively. Viscous CFD calculations for full passage model are also conducted, which aim at finding out the hydraulic improvement from internal flow analyses.

  4. Effect of Impeller Geometry on Lift-Off Characteristics and Rotational Attitude in a Monopivot Centrifugal Blood Pump.

    PubMed

    Nishida, Masahiro; Nakayama, Kento; Sakota, Daisuke; Kosaka, Ryo; Maruyama, Osamu; Kawaguchi, Yasuo; Kuwana, Katsuyuki; Yamane, Takashi

    2016-06-01

    The effect of the flow path geometry of the impeller on the lift-off and tilt of the rotational axis of the impeller against the hydrodynamic force was investigated in a centrifugal blood pump with an impeller supported by a single-contact pivot bearing. Four types of impeller were compared: the FR model with the flow path having both front and rear cutouts on the tip, the F model with the flow path having only a front cutout, the R model with only a rear cutout, and the N model with a straight flow path. First, the axial thrust and the movement about the pivot point, which was loaded on the surface of the impeller, were calculated using computational fluid dynamics (CFD) analysis. Next, the lift-off point and the tilt of the rotational axis of the impeller were measured experimentally. The CFD analysis showed that the axial thrust increased gently in the FR and R models as the flow rate increased, whereas it increased drastically in the F and N models. This difference in axial thrust was likely from the higher pressure caused by the smaller circumferential velocity in the gap between the top surface of the impeller and the casing in the FR and R models than in the F and N models, which was caused by the rear cutout. These results corresponded with the experimental results showing that the impellers lifted off in the F and N models as the flow rate increased, whereas it did not in the FR and R models. Conversely, the movement about the pivot point increased in the direction opposite the side with the pump outlet as the flow rate increased. However, the tilt of the rotational axis of the impeller, which oriented away from the pump outlet, was less than 0.8° in any model under any conditions, and was considered to negligibly affect the rotational attitude of the impeller. These results confirm that a rear cutout prevents lift-off of the impeller caused by a decrease in the axial thrust. PMID:27097844

  5. A Computational Model Predicting Disruption of Blood Vessel Development

    EPA Science Inventory

    Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis) and remodeling (angiogenesis) come from a varie...

  6. Development of a blood vessel searching device for HMS

    NASA Astrophysics Data System (ADS)

    Kuroda, Tatsuro; Uenoya, Toshiyuki; Tsuchiya, Kazuyoshi; Uetsuji, Yasutomo; Nakamachi, Eiji

    2007-12-01

    In this study, an automatic blood vessel searching system (BVSS) is newly developed, which is built in the health monitoring system (HMS) and the drug delivery system (DDS) to extract the blood, evaluates the blood sugar level and injects the insulin for the diabetic patients. Main subjects of our BVSS development are 1) a transmittance photo imaging of the finger by using the LED light as a near-infrared light source with peak wave length of 870 nm, and 2) an image processing to detect the location of the center of the blood vessel cross section. The sharp edge focus method was applied in our BVSS to detect the depth of blood vessel. We carried out experiments by using blood vessel phantoms, which consist of an artificial cylindrical blood vessel and skin tissue, which are made of the teflon tube and the silicone rubber. The teflon tube has the size of 0.6 mm in diameter and is filled with the human blood. The experimental results demonstrated that the estimated depth, which is obtained by image analysis corresponding to given depths, shows a good agreement with the real values, and consequently the availability of our BVSS is confirmed.

  7. Phase 1-A development kinematic Sterling/Rankine commercial gas-fired heat pump research program

    NASA Astrophysics Data System (ADS)

    Johansson, L.; Agno, J. G.; Houtman, W. H.

    1984-07-01

    Heat pumps driven by electric motors are successfully sold as energy saving systems in the space conditioning marketplace. By utilizing an on-site natural gas fueled Stirling cycle engine to drive a refrigerating compressor, energy consumption of such a heat pump can be reduced in both heating and cooling modes of operation. The achievements reached in Phase 1-A indicate that the goal of developing a technically and economically feasible commercial heat pump, using the V-160 Stirling engine, is practical and can be accomplished within a reasonable period of time. This initial investigation also indicates that the potential heat pump system can be responsive to a large market segment as well as providing a technological base for expanding into other gas market segments.

  8. Coal slurry pump development: fossil energy annual summary, technical information report

    SciTech Connect

    Wong, G.S.

    1980-10-30

    This is a twenty-four month program on Coal Slurry Pump Development being conducted for the Department of Energy, Division of Coal Conversion, under Contract DE-AC03-79ET14842. The program consists of two phases. In the first phase an experimental prototype of a two-stage, high-pressure, centrifugal slurry pump will be fabricated and assembled into a test unit. In the second phase the experimental pump will be delivered to a DOE field test facility for initial testing in hot oil and for subsequent testing in an actual coal-oil slurry environment. During the program, Rocketdyne will supply technical support and coordination on test facility interfact requirements and for testing of the experimental pump to evaluated hydraulic, mechanical, material and operational performance characteristics.

  9. Development of a High Performance Air Source Heat Pump for the US Market

    SciTech Connect

    Abdelaziz, Omar; Shen, Bo; Gao, Zhiming; Baxter, Van D; Iu, Ipseng

    2011-01-01

    Heat pumps present a significant advantage over conventional residential heating technologies due to higher energy efficiencies and less dependence on imported oil. The US development of heat pumps dates back to the 1930 s with pilot units being commercially available in the 1950 s. Reliable and cost competitive units were available in the US market by the 1960 s. The 1973 oil embargo led to increased interest in heat pumps prompting significant research to improve performance, particularly for cold climate locations. Recent increasing concerns on building energy efficiency and environmental emissions have prompted a new wave of research in heat pump technology with special emphasis on reducing performance degradation at colder outdoor air temperatures. A summary of the advantages and limitations of several performance improvement options sought for the development of high performance air source heat pump systems for cold climate applications is the primary focus of this paper. Some recommendations for a high performance cold climate heat pump system design most suitable for the US market are presented.

  10. Insulin patch pumps: their development and future in closed-loop systems.

    PubMed

    Anhalt, Henry; Bohannon, Nancy J V

    2010-06-01

    Steady progress is being made toward the development of a so-called "artificial pancreas," which may ultimately be a fully automated, closed-loop, glucose control system comprising a continuous glucose monitor, an insulin pump, and a controller. The controller will use individualized algorithms to direct delivery of insulin without user input. A major factor propelling artificial pancreas development is the substantial incidence of-and attendant patient, parental, and physician concerns about-hypoglycemia and extreme hyperglycemia associated with current means of insulin delivery for type 1 diabetes mellitus (T1DM). A successful fully automated artificial pancreas would likely reduce the frequency of and anxiety about hypoglycemia and marked hyperglycemia. Patch-pump systems ("patch pumps") are likely to be used increasingly in the control of T1DM and may be incorporated into the artificial pancreas systems of tomorrow. Patch pumps are free of tubing, small, lightweight, and unobtrusive. This article describes features of patch pumps that have been approved for U.S. marketing or are under development. Included in the review is an introduction to control algorithms driving insulin delivery, particularly the two major types: proportional integrative derivative and model predictive control. The use of advanced algorithms in the clinical development of closed-loop systems is reviewed along with projected next steps in artificial pancreas development. PMID:20515308

  11. In-vitro evaluation of physiological controller response of rotary blood pumps to changes in patient state.

    PubMed

    Pauls, Jo P; Gregory, Shaun D; Stevens, Michael; Tansley, Geoff

    2014-01-01

    Rotary blood pumps (RBPs) have a low sensitivity to preload changes when run at constant speed, which can lead to harmful ventricular suction events. Therefore a control mechanism is needed to adjust RBP speed in response to patient demand, but an appropriate response time for physiological control strategies to these changes in patient demand has not been determined. This paper aims to evaluate the response of a simulated healthy heart with those of different RBP control techniques during exercise simulations and a Valsalva manoeuver. A mock circulation loop was used to simulate the response of a healthy heart to these changes in patient state. The generated data was compared with a simulated RBP (VentrAssist) supported left heart failure condition. A range of control techniques including constant speed, proportional integral (PI) (active control) and a compliant inflow cannula (passive control) were used to achieve restored haemodynamics and evaluate controller response time. Controllers that responded faster (active control) or slower (active control and constant speed mode) than the native heart's response led to ventricular suction. Active control systems can respond both faster or slower than the heart depending on the controller gains. A control system that responded similar to the native heart was able to prevent ventricular suction. This study concluded that a physiological control system should mimic the response of the native heart to changes in patient state in order to prevent ventricular suction. PMID:25569955

  12. Concentrating Solar Power - Molten Salt Pump Development, Final Technical Report (Phase 1)

    SciTech Connect

    Michael McDowell; Alan Schwartz

    2010-03-31

    The purpose of this project is to develop a long shafted pump to operate at high temperatures for the purpose of producing energy with renewable resources. In Phase I of this three phase project we developed molten salt pump requirements, evaluated existing hardware designs for necessary modifications, developed a preliminary design of the pump concept, and developed refined cost estimates for Phase II and Phase III of the project. The decision has been made not to continue the project into Phases II and III. There is an ever increasing world-wide demand for sources of energy. With only a limited supply of fossil fuels, and with the costs to obtain and produce those fuels increasing, sources of renewable energy must be found. Currently, capturing the sun's energy is expensive compared to heritage fossil fuel energy production. However, there are government requirements on Industry to increase the amount of energy generated from renewable resources. The objective of this project is to design, build and test a long-shafted, molten salt pump. This is the type of pump necessary for a molten salt thermal storage system in a commercial-scale solar trough plant. This project is under the Department of Energy (DOE) Solar Energy Technologies Program, managed by the Office of Energy Efficiency and Renewable Energy. To reduce the levelized cost of energy (LCOE), and to meet the requirements of 'tomorrows' demand, technical innovations are needed. The DOE is committed to reducing the LCOE to 7-10 cents/kWh by 2015, and to 5-7 cents/kWh by 2020. To accomplish these goals, the performance envelope for commercial use of long-shafted molten salt pumps must be expanded. The intent of this project is to verify acceptable operation of pump components in the type of molten salt (thermal storage medium) used in commercial power plants today. Field testing will be necessary to verify the integrity of the pump design, and thus reduce the risk to industry. While the primary goal is to

  13. Development of blood vessel searching system for HMS

    NASA Astrophysics Data System (ADS)

    Kandani, Hirofumi; Uenoya, Toshiyuki; Uetsuji, Yasutomo; Nakamachi, Eiji

    2008-08-01

    In this study, we develop a new 3D miniature blood vessel searching system by using near-infrared LED light, a CMOS camera module with an image processing unit for a health monitoring system (HMS), a drug delivery system (DDS) which requires very high performance for automatic micro blood volume extraction and automatic blood examination. Our objective is to fabricate a highly reliable micro detection system by utilizing image capturing, image processing, and micro blood extraction devices. For the searching system to determine 3D blood vessel location, we employ the stereo method. The stereo method is a common photogrammetric method. It employs the optical path principle to detect 3D location of the disparity between two cameras. The principle for blood vessel visualization is derived from the ratio of hemoglobin's absorption of the near-infrared LED light. To get a high quality blood vessel image, we adopted an LED, with peak a wavelength of 940nm. The LED is set on the dorsal side of the finger and it irradiates the human finger. A blood vessel image is captured by a CMOS camera module, which is set below the palmer side of the finger. 2D blood vessel location can be detected by the luminance distribution of a one pixel line. To examine the accuracy of our detecting system, we carried out experiments using finger phantoms with blood vessel diameters of 0.5, 0.75, 1.0mm, at the depths of 0.5 ~ 2.0 mm from the phantom's surface. The experimental results of the estimated depth obtained by our detecting system shows good agreements with the given depths, and the viability of this system is confirmed.

  14. Effect of stationary guiding vanes on improvement of the washout behind the rotor in centrifugal blood pumps.

    PubMed

    Schima, H; Huber, L; Melvin, D; Trubel, W; Prodinger, A; Losert, U; Thoma, H; Wolner, E

    1992-01-01

    In centrifugal pumps, there always exists an area of stagnation between the rear of the rotor and the rear housing wall that promotes thrombus formation around the axle. Some current devices overcome the problem by using holes in the rotor plane, leading to increased hydrodynamic losses and shear stress. In this study, a simple apparatus was developed to overcome this problem. Guiding vanes were fixed to the rear housing wall. These vanes decrease the tangential velocity of the fluid and thus the centrifugal force, leading to an increased secondary flow toward the axle. The effect of such vanes was studied in videographic and ultrasound studies. An increase of washout and mixing between the flow layers could be demonstrated (stay time < 200 msec versus several seconds without vanes). In the first animal experiment using nonoptimized vanes, there was no thrombus at the back plane or the seal, and only a small thrombus at the transition between axle and rotor. Hemolysis was slightly elevated (3.2 mg/dl versus 2.5 mg/dl in control experiments). In conclusion, it is highly likely that this simple system will improve the flow characteristics in centrifugal pumps. PMID:1457852

  15. Blood flow

    MedlinePlus Videos and Cool Tools

    As the heart pumps, the arteries carry oxygen-rich blood (shown in red) away from the heart and toward the body’s tissues and ... returns to the heart from the lungs, which pumps it throughout the body.

  16. Development of a portable blood irradiator for potential clinical uses

    SciTech Connect

    Hungate, F.P.

    1988-12-01

    This document provides an account of the development of a fully portable blood irradiator and the evaluation of its safety and efficacy when implanted in goats, sheep, a baboon and dogs. The program was initiated because the control of lymphocyte populations by irradiation is a potential method for improving success in organ or tissue transplantation and for treating a variety of blood diseases. 15 refs., 27 figs., 2 tabs.

  17. Blood

    MedlinePlus

    ... fight infection and are part of your body's defense system. Platelets help blood to clot when you have a cut or wound. Bone marrow, the spongy material inside your bones, makes new blood cells. Blood cells ...

  18. Rethinking blood components and patients: Patient blood management. Possible ways for development in France.

    PubMed

    Folléa, Gilles

    2016-01-01

    As any therapeutic means, blood transfusion requires regular evaluation, particularly for its indications, effectiveness and risks. A better awareness of the risks of blood transfusion, the availability of randomized clinical trials, the evolution of the quality of blood components, and the economic constraints shared by all countries, all have led to rethink both transfusion therapy as a whole and the organization of the transfusion chain from donor to recipient. In this context, patient blood management (PBM) appears as an evidence-based, patient centred, multidisciplinary approach, aiming to optimise the care of patients who might need transfusion and consequently the use of blood products. This paper presents updated scientific bases of PBM and the three pillars founding it. As PBM is developing fast in other European countries, this review proposes ways to explore for its development in France. It finally proposes to integrate PBM in a wider and coordinated approach of the blood supply management, with tools to improve the effectiveness and efficiency of the transfusion chain, starting with the needs of the patients and ending with an optimum treatment of the patient, including the appropriate number of blood components of the required quality. A better understanding, implementation and assessment of this coordinated global approach, allowing to adapt donor collections to the patients' needs in compliance with safety requirements for patients and donors, in a coordinated way, will certainly be a major challenge for transfusion medicine in the near future, for the benefit of patients, donors and all other stakeholders involved in the transfusion chain. PMID:27476011

  19. High power diode pumped solid state laser development at Lawrence Livermore National Laboratory

    SciTech Connect

    Solarz, R.; Albrecht, G.; Hackel, L.

    1994-03-01

    The authors recent developments in high powered diode pumped solid state lasers at Lawrence Livermore National Laboratory. Over the past year the authors have made continued improvements to semiconductor pump array technology which includes the development of higher average power and lower cost pump modules. They report the performance of high power AlGaAs, InGaAs, and AlGaInP arrays. They also report on improvement to the integrated micro-optics designs in conjunction with lensing duct technology which gives rise to very high performance end pumping designs for solid state lasers which have major advantages which they detail. Substantial progress on beam quality improvements to near the diffraction limit at very high power have also been made and will be reported. They also will discuss recent experiments on high power non-linear materials for q-switches, harmonic converters, and parametric oscillators. Advances in diode pumped devices at LLNL which include tunable Cr:LiSrAlF{sub 6}, mid-IR Er:YAG, holmium based lasers and other developments will also be outlined. Concepts for delivering up to 30 kilowatts of average power from a DPSSL oscillator will be described.

  20. Effect of lobe pumping on human albumin: development of a lobe pump simulator using smoothed particle hydrodynamics.

    PubMed

    Gomme, Peter T; Prakash, Mahesh; Hunt, Ben; Stokes, Nick; Cleary, Paul; Tatford, Owen C; Bertolini, Joseph

    2006-02-01

    Using SPH (smoothed particle hydrodynamics), the motion of a lobe pump under load was simulated in order to predict the level of shear stress experienced by a protein solution. By varying the gap size between the lobes and pump housing, variations in pump efficiency and shear stress were determined. The simulations indicated that pump shear was dependent on gap size, with shear stress levels (0-40 Pa) correlating with those estimated in previous albumin-pumping studies. As gap size increased, the number of fluid particles experiencing low shear (<10 Pa) increased, whereas those experiencing high shear (>20 Pa) showed a decreasing trend. The pump efficiency, however, decreased with gap size, requiring more lobe revolutions to pass a unit volume. Taken together, these observations indicate that lobe pumps operated with increased gaps between the rotors and the housing result in larger number of particles within the fluid experiencing shear stresses. Moreover, the simulations indicate that it is best to use larger lobe pumps operated at high efficiency to transfer protein-containing solutions. PMID:16246177

  1. The invention and development of blood gas analysis apparatus.

    PubMed

    Severinghaus, John W

    2002-07-01

    In 1953, the doctor draft interrupted Dr. Severinghaus' anesthesia and physiology training and sent him to the National Institutes of Health as director of anesthesia research at the newly opened Clinical Center. He developed precise laboratory partial pressure of carbon dioxide (PCO(2)) and pH analysis to investigate lung blood gas exchange during hypothermia. Constants for carbon dioxide solubility and pK' were more accurately determined. In August 1954, he heard Richard Stow describe invention of a carbon dioxide electrode and immediately built one, improved its stability, and tested its response characteristics. In April 1956, he also heard Leland Clark reveal his invention of an oxygen electrode. Dr. Severinghaus obtained one and constructed a stirred cuvette in which blood partial pressure of oxygen (PO(2)) could be accurately measured. Technician Bradley and Dr. Severinghaus combined these, making the first blood gas analysis system in 1957 and 1958, and shortly thereafter, they added a pH electrode. Blood gas analyzers rapidly developed commercially. Dr. Severinghaus collaborated with Astrup and other Danes on the Haldane and Bohr effects and their concepts of base excess during two sabbaticals in Copenhagen. Work with both Astrup and Roughton on the oxygen dissociation curve led Dr. Severinghaus to devise a modified Hill equation that closely fit their new, better human oxygen dissociation curve and a blood gas slide rule that solved oxygen dissociation curve, PCO(2), pH, and acid-base questions. Blood gas analysis revolutionized both clinical medicine and cardiorespiratory and metabolic physiology. PMID:12131126

  2. Development of a nanosecond-laser-pumped Raman amplifier for short laser pulses in plasma

    NASA Astrophysics Data System (ADS)

    Ping, Y.; Kirkwood, R. K.; Wang, T.-L.; Clark, D. S.; Wilks, S. C.; Meezan, N.; Berger, R. L.; Wurtele, J.; Fisch, N. J.; Malkin, V. M.; Valeo, E. J.; Martins, S. F.; Joshi, C.

    2009-12-01

    Progress on developing a plasma amplifier/compressor based on stimulated Raman scattering of nanosecond laser pulses is reported. Generation of a millijoule seed pulse at a wavelength that is redshifted relative to the pump beam has been achieved using an external Raman gas cell. By interacting the shifted picosecond seed pulse and the nanosecond pump pulse in a gas jet plasma at a density of ˜1019 cm-3, the upper limit of the pump intensity to avoid angular spray of the amplified seed has been determined. The Raman amplification has been studied as a function of the pump and seed intensities. Although the heating of plasma by the nanosecond pump pulse results in strong Landau damping of the plasma wave, an amplified pulse with an energy of up to 14 mJ has been demonstrated, which is, to the best of our knowledge, the highest output energy so far by Raman amplification in a plasma. One-dimensional particle-in-cell simulations indicate that the saturation of amplification is consistent with onset of particle trapping, which might be overcome by employing a shorter seed pulse.

  3. Development of a nanosecond-laser-pumped Raman amplifier for short laser pulses in plasma

    SciTech Connect

    Ping, Y.; Kirkwood, R. K.; Clark, D. S.; Wilks, S. C.; Meezan, N.; Berger, R. L.; Wang, T.-L.; Martins, S. F.; Joshi, C.; Wurtele, J.; Fisch, N. J.; Malkin, V. M.; Valeo, E. J.

    2009-12-15

    Progress on developing a plasma amplifier/compressor based on stimulated Raman scattering of nanosecond laser pulses is reported. Generation of a millijoule seed pulse at a wavelength that is redshifted relative to the pump beam has been achieved using an external Raman gas cell. By interacting the shifted picosecond seed pulse and the nanosecond pump pulse in a gas jet plasma at a density of approx10{sup 19} cm{sup -3}, the upper limit of the pump intensity to avoid angular spray of the amplified seed has been determined. The Raman amplification has been studied as a function of the pump and seed intensities. Although the heating of plasma by the nanosecond pump pulse results in strong Landau damping of the plasma wave, an amplified pulse with an energy of up to 14 mJ has been demonstrated, which is, to the best of our knowledge, the highest output energy so far by Raman amplification in a plasma. One-dimensional particle-in-cell simulations indicate that the saturation of amplification is consistent with onset of particle trapping, which might be overcome by employing a shorter seed pulse.

  4. Development and integration of the capillary pumped loop GAS and Hitchhiker flight experiments

    NASA Technical Reports Server (NTRS)

    Butler, D.; Mcintosh, R.

    1990-01-01

    The Capillary Pumped Loop (CPL) is a thermal control system with high density heat acquisition and transport capability. A small spaceflight version of the CPL was built and flown as a GAS experiment on STS 51-D in April 1985 and STS 51-G in June 1985, and as a Hitchhiker-G experiment on STS 61-C in January 1986. The purpose of the experiments was to demonstrate the capability of a capillary pumped system under microgravity conditions for use in the thermal control of large scientific instruments, advanced orbiting spacecraft, and space station components. The development, integration, and test activities of the CPL are described.

  5. Measuring Problematic Mobile Phone Use: Development and Preliminary Psychometric Properties of the PUMP Scale

    PubMed Central

    Merlo, Lisa J.; Stone, Amanda M.; Bibbey, Alex

    2013-01-01

    This study aimed to develop and assess the psychometric properties of an English language measure of problematic mobile phone use. Participants were recruited from a university campus, health science center, and other public locations. The sample included 244 individuals (68.4% female) aged 18–75. Results supported a unidimensional factor structure for the 20-item self-report Problematic Use of Mobile Phones (PUMP) Scale. Internal consistency was excellent (α = 0.94). Strong correlations (r = .76, P < .001) were found between the PUMP Scale and an existing scale of cellular phone dependency that was validated in Asia, as well as items assessing frequency and intensity of mobile phone use. Results provide preliminary support for the use of the PUMP Scale to measure problematic use of mobile phones. PMID:24826371

  6. Fuel savings with conventional hot water space heating systems by incorporating a natural gas powered heat pump. Preliminary project: Development of heat pump technology

    NASA Astrophysics Data System (ADS)

    Vanheyden, L.; Evertz, E.

    1980-12-01

    Compression type air/water heat pumps were developed for domestic heating systems rated at 20 to 150 kW. The heat pump is driven either by a reciprocating piston or rotary piston engine modified to operate on natural gas. Particular features of natural gas engines as prime movers, such as waste heat recovery and variable speed, are stressed. Two systems suitable for heat pump operation were selected from among five different mass produced car engines and were modified to incorporate reciprocating piston compressor pairs. The refrigerants used are R 12 and R 22. Test rig data transferred to field conditions show that the fuel consumption of conventional boilers can be reduced by 50% and more by the installation of engine driven heat pumps. Pilot heat pumps based on a 1,600 cc reciprocating piston engine were built for heating four two-family houses. Pilot pump operation confirms test rig findings. The service life of rotary piston and reciprocating piston engines was investigated. The tests reveal characteristic curves for reciprocating piston engines and include exhaust composition measurements.

  7. Physics-driven impeller designs for a novel intravascular blood pump for patients with congenital heart disease.

    PubMed

    Chopski, Steven G; Fox, Carson S; McKenna, Kelli L; Riddle, Michelle L; Kafagy, Dhyaa H; Stevens, Randy M; Throckmorton, Amy L

    2016-07-01

    Mechanical circulatory support offers an alternative therapeutic treatment for patients with dysfunctional single ventricle physiology. An intravascular axial flow pump is being developed as a cavopulmonary assist device for these patients. This study details the development of a new rotating impeller geometry. We examined the performance of 8 impeller geometries with blade stagger or twist angles varying from 100° to 800° using computational methods. A refined range of blade twist angles between 300° and 400° was then identified, and 4 additional geometries were evaluated. Generally, the impeller designs produced 4-26mmHg for flow rates of 1-4L/min for 6000-8000 RPM. A data regression analysis was completed and found the impeller with 400° of blade twist to be the superior performer. A hydraulic test was conducted on a prototype of the 400° impeller, which generated measurable pressure rises of 7-28mmHg for flow rates of 1-4L/min at 6000-8000 RPM. The findings of the numerical model and experiment were in reasonable agreement within approximately 20%. These results support the continued development of an axial-flow, mechanical cavopulmonary assist device as a new clinical therapeutic option for Fontan patients. PMID:27129783

  8. Development of solar driven absorption air conditioners and heat pumps

    NASA Astrophysics Data System (ADS)

    Dao, K.; Wahlig, M.; Wali, E.; Rasson, J.; Molishever, E.

    1980-03-01

    The development of absorption refrigeration systems for solar active heating and cooling applications is discussed. The approaches investigated are those using air-cooled condenser-absorber and those leading to coefficient of performances (COP) that increase continuously with heat source temperature. This is primarily an experimental project, with the emphasis on designing, fabricating and testing absorption chillers in operating regimes that are particularly suited for solar energy applications. Its demonstrated that the conventional single-effect ammonia-water absorption cycle can be used (with minor modifications) for solar cooling.

  9. Maternal antibodies and developing blood-brain barrier.

    PubMed

    Kowal, Czeslawa; Athanassiou, Andrew; Chen, Huiyi; Diamond, Betty

    2015-12-01

    We briefly review the protective role of maternal antibodies during fetal development and at early postnatal stages. We describe antibody delivery to fetuses, particularly in the context of the developing blood-brain barrier (BBB), and present the essential concepts regarding the adult BBB, together with existing information on the prenatal developing BBB. We focus on maternal antibody transfer to the developing brain and the consequences of the presence of pathogenic antibodies at early stages of brain development on subsequent brain dysfunction. PMID:26507553

  10. Development of High Efficiency Carbon Dioxide Commercial Heat Pump Water Heater

    SciTech Connect

    Michael PETERSEN; Chad D. BOWERS; Stefan ELBEL; Pega HRNJAK

    2012-07-01

    Although heat pump water heaters are today widely accepted in both Japan and Europe, where energy costs are high and government incentives for their use exist, acceptance of such products in the US has been limited. While this trend is slowly changing with the introduction of heat pump water heaters into the residential market, but acceptance remains low in the commercial sector. The objective of the presented work is the development of a high efficiency R744 heat pump water heater for commercial applications with effective utilization of the cooling capability for air conditioning and/or refrigeration. The ultimate goal is to achieve total system COP of up to 8. This unit will be targeted at commercial use where some cooling load is typically needed year round, such as restaurants, hotels, nursing homes, and hospitals. This paper presents the performance results from the development of four R744 commercial heat pump water heater packages of approximately 35 kW and comparison to a commercially available baseline R134a unit of the same capacity and footprint. In addition, the influences of an internal heat exchanger and an enhanced evaporator on the system performance are described and recommendations are made for further improvements of the R744 system.

  11. Development and Validation of a Gas-Fired Residential Heat Pump Water Heater - Final Report

    SciTech Connect

    Michael Garrabrant; Roger Stout; Paul Glanville; Janice Fitzgerald; Chris Keinath

    2013-01-21

    For gas-fired residential water heating, the U.S. and Canada is predominantly supplied by minimum efficiency storage water heaters with Energy Factors (EF) in the range of 0.59 to 0.62. Higher efficiency and higher cost ($700 - $2,000) options serve about 15% of the market, but still have EFs below 1.0, ranging from 0.65 to 0.95. To develop a new class of water heating products that exceeds the traditional limit of thermal efficiency, the project team designed and demonstrated a packaged water heater driven by a gas-fired ammonia-water absorption heat pump. This gas-fired heat pump water heater can achieve EFs of 1.3 or higher, at a consumer cost of $2,000 or less. Led by Stone Mountain Technologies Inc. (SMTI), with support from A.O. Smith, the Gas Technology Institute (GTI), and Georgia Tech, the cross-functional team completed research and development tasks including cycle modeling, breadboard evaluation of two cycles and two heat exchanger classes, heat pump/storage tank integration, compact solution pump development, combustion system specification, and evaluation of packaged prototype GHPWHs. The heat pump system extracts low grade heat from the ambient air and produces high grade heat suitable for heating water in a storage tank for domestic use. Product features that include conventional installation practices, standard footprint and reasonable economic payback, position the technology to gain significant market penetration, resulting in a large reduction of energy use and greenhouse gas emissions from domestic hot water production.

  12. The development of a blood pressure simulator in KRISS.

    PubMed

    Song, Han Wook; Lee, SungJun; Park, Yon Kyu; Choi, In Mook; Woo, Sam Yong

    2008-01-01

    Blood pressure is defined as the amount of force at unit area which the blood exerts on a wall of a blood vessel. The BP has a clinical importance as the basic index in the medical examination of patients. Especially, the percentage of the hypertensive is more than 15% in an adult population of Korea and hypertension is notorious as 'a silent killer' because it has no prior symptoms. The most important thing in the diagnosis, treatment and prognosis of hypertension is the accurate measurement of the BP. In this study, we developed the blood pressure simulator for the monitoring of oscillometric BP devices and compared this KRISS simulator with commercial simulators. Finally, we tested the commercial oscillometric BP devices (6 models from 5 manufacturers) using the KRISS simulator. The KRISS simulator has the repeatability error below 0.1% for the pressure generation and we expected to develop the BP simulator for Korean by the collection of clinical data from Koreans. PMID:19163409

  13. A magnetic fluid seal for rotary blood pumps: image and computational analyses of behaviors of magnetic fluids.

    PubMed

    Mitamura, Yoshinori; Yano, Tetsuya; Okamoto, Eiji

    2013-01-01

    A magnetic fluid (MF) seal has excellent durability. The performance of an MF seal, however, has been reported to decrease in liquids (several days). We have developed an MF seal that has a shield mechanism. The seal was perfect for 275 days in water. To investigate the effect of a shield, behaviors of MFs in a seal in water were studied both experimentally and computationally. (a) Two kinds of MF seals, one with a shield and one without a shield, were installed in a centrifugal pump. Behaviors of MFs in the seals in water were observed with a video camera and high-speed microscope. In the seal without a shield, the surface of the water in the seal waved and the turbulent flow affected behaviors of the MFs. In contrast, MFs rotated stably in the seal with a shield in water even at high rotational speeds. (b) Computational fluid dynamics analysis revealed that a stationary secondary flow pattern in the seal and small velocity difference between magnetic fluid and water at the interface. These MF behaviors prolonged the life of an MF seal in water. PMID:24109774

  14. A magnetic fluid seal for rotary blood pumps: Behaviors of magnetic fluids in a magnetic fluid seal.

    PubMed

    Mitamura, Yoshinori; Yano, Tetsuya; Nakamura, Wataru; Okamoto, Eiji

    2013-01-01

    A magnetic fluid (MF) seal has excellent durability. The performance of an MF seal, however, has been reported to decrease in liquids (several days). We have developed an MF seal that has a shield mechanism. The seal was perfect for 275 days in water. To investigate the effect of a shield, behaviors of MFs in a seal in water were studied both experimentally and computationally. (a) Two kinds of MF seals, one with a shield and one without a shield, were installed in a centrifugal pump. Behaviors of MFs in the seals in water were observed with a video camera and high-speed microscope. In the seal without a shield, the surface of the water in the seal waved and the turbulent flow affected behaviors of the MFs. In contrast, MFs rotated stably in the seal with a shield in water even at high rotational speeds. (b) Computational fluid dynamics analysis revealed that a stationary secondary flow pattern in the seal and small velocity difference between magnetic fluid and water at the interface. These MF behaviors prolonged the life of an MF seal in water. PMID:23442238

  15. An update of free-piston Stirling engine heat pump development

    SciTech Connect

    Ackermann, R.A.; Clinch, J.M.; Privon, G.T.

    1986-01-01

    A Free-Piston Stirling Engine Heat Pump (FPSE/HP) for residential applications has been under development for the past five years. The system consists of a natural gas combustor, free-piston Stirling engine, and a variable-stroke resonant piston refrigerant compressor. The compressor is linked to the engine via a unique hydraulic transmission that provides for both efficient power transfer and hermetic sealing between the engine working fluid (helium) and the compressor refrigerant. This development effort has led to a breadboard heat pump power module, engine/transmission/compressor, that has undergone a comprehensive test program to evaluate the performance of an FPSE/HP and to judge its potential for further development. The results obtained from this testing are presented in this paper.

  16. Development of Off-pump Mitral Valve Replacement in a Porcine Model

    PubMed Central

    Gillespie, Matthew J.; Aoki, Chikashi; Satoshi, Takebayashi; Shimaoka, Toru; McGarvey, Jeremy R.; Gorman, Robert C.; Gorman, Joseph H.

    2015-01-01

    Purpose We describe our initial experience with on-bypass and off-bypass (off-pump) mitral valve replacement with the modified version of our novel catheter-based sutureless mitral valve (SMV2) technology, which was developed to atraumatically anchor and seal in the mitral position. Description The SMV is a self-expanding device consisting of a custom designed nitinol framework and a pericardial leaflet valve mechanism. For the current studies our original device was modified (SMV2) to reduce the delivery profile and to allow for controlled deployment whilst still maintaining the key principles necessary for atraumatic anchoring and sealing in the MV position. Evaluation Ten Yorkshire pigs underwent successful SMV2 device implantation via a left atriotomy (on-pump N=6; off-pump N=4). Echocardiography and angiography revealed excellent LV systolic function, no significant perivalvular leak, no MV stenosis, no left ventricular (LV) outflow tract obstruction and no aortic valve insufficiency. Necropsy demonstrated that the SMV2 devices were anchored securely. Conclusions This study demonstrates the feasibility and short-term success of off-pump mitral valve replacement using a novel, catheter-based device in a porcine model. PMID:25841820

  17. Design and development of a split-evaporator heat-pump system

    SciTech Connect

    Somerville, M.H.; Penoncello, S.G.

    1981-12-01

    The designs and experimental results of three types of multiple source heat pumps are presented. The three designs are the parallel evaporator, the series evaporator, and the parallel evaporator with active subcooling, with the parallel evaporator with the active subcooling showing the most promise for solving the problem of defrosting of air evaporators. Three design procedures for multiple source heat pumps were developed. One of these is a hand calculational procedure, the others are computer based. The models are based upon the refrigerant flow rate, rather than the refrigeration effect of the evaporator. The technical results of a detailed analytical and experimental model of the heat transfer rates on a flat plate ice maker are presented. It is shown, both analytically and experimentally, that the temperature of the air surrounding the flat plate ice maker can play a dominant role in the rate of ice formation. A detailed weather analysis for forty cities located throughout the nation was completed. These data were processed to allow easy computation of thermal storage requirements for full, partial, or minimum ACES systems, or upon other design requirements, such as off-peak air conditioning. The results of an innovative ice storage system that is thermally coupled to the earth are described. This system has the potential for meeting both the off-peak air conditioning needs and the thermal storage requirements for the heating cycle. An economic and energy comparison of multiple source heat pumps with ACES, and air-to-air heat pump systems is presented.

  18. Basic study to develop an electromagnetic drive method for the rotary undulation pump.

    PubMed

    Abe, Yusuke; Chinzei, Tsuneo; Isoyama, Takashi; Saito, Itsuro; Ono, Toshiya; Mochizuki, Shuichi; Kouno, Akimasa; Imachi, Kou

    2003-10-01

    The rotary undulation pump, which is composed of a disk with a convex shape on both sides and a pump housing with one narrow side and one wide side, is a unique continuous flow pump with a new principle. The concept of the levitation drive method for this pump was proposed. The electromagnetic driver model and drive circuit were developed to examine the possibility and the difference among the delta wired, Y wired, and repulsion methods. In the repulsion method, the disk was driven by magnetic repulsion. The model could be driven with either method, and the repulsion method was demonstrated to also be possible. With either method, owing to the wide gap between the permanent magnets and coils, the output was not enough when the load was high. The efficiency was almost the same in the delta wired and Y wired methods. In the repulsion method, however, it was less than 50% of that in the other two methods. From the results, the delta wired and Y wired methods with an active control of the gap distance were considered to be better than the repulsion method, which required no active gap control. PMID:14616528

  19. A new approach using high volume blood patch for prevention of post-dural puncture headache following intrathecal catheter pump exchange

    PubMed Central

    Abdulla, Susanne; Vielhaber, Stefan; Heinze, Hans-Jochen; Abdulla, Walied

    2015-01-01

    Background: In an observational study, complications of intrathecal catheter pumps necessitating surgical exchange were analyzed. Also the use of a high-volume prophylactic epidural blood patch (EBP) during surgery for preventing post-dural puncture headache (PDPH) with a follow-up for 1 year is described. Materials and Methods: In 22 patients with refractory chronic pain of cancer/noncancer origin or severe spasticity, who were receiving intrathecal morphine including adjuvants or baclofen for symptom relief, catheter exchange with or without pump was performed. In patients with documented symptoms of PDPH following initial intrathecal catheter implantation, a prophylactic EBP with a high blood volume was used for PDPH prevention during surgery. Catheters were replaced using 40 mL EBP before entering dural space at a speed of 5mL/min into the epidural space. Patients were asked to quantify pain experience and functional ability. Results: From a sample of 72 patients admitted for catheter exchange with or without pump, 22 patients (33%) (12 male, 10 female) had a history of PDPH following initial implantation. Diagnostic and therapeutic measures occurring with malfunction of intrathecal catheter pump systems were described. Twenty-one patients were successfully treated with prophylactic EBP, while one patient could not be properly evaluated because of intracranial bleeding as the underlying disease. Conclusions: A new approach using a high-volume prophylactic EBP for preventing PDPH following catheter exchange is presented. The efficacy and safety of this technique for 1 year follow-up have been evaluated and was found to be safe and potentially effective. PMID:26157652

  20. Left ventricular assist using a jet pump.

    PubMed

    Rhee, K; Blackshear, P L

    1990-01-01

    A simple, effective, cardiac assist device was developed using a jet pump, a device that performs pumping by energy transfer from a high speed jet to low speed surrounding fluids. This jet pump is inserted retrograde through the aorta and placed in the left ventricle transvalvularly. The jet of oxygenated venous blood entrains blood inside the left ventricle and pumps into the aorta through the aortic valve. Jet velocity is kept below the hemolytic threshold of 1000 cm/sec. The device was placed in a mock circulatory system that stimulates the left ventricle and vascular system by generating a pressure wave (120/75 mmHg) with a 4 L/min cardiac output (CO). A bypass loop (from the venous reservoir to aorta using a Biomedicus pump, Biomedicus Inc., Eden Prairie, MN) was set up, and the jet pump was installed. When the jet pump is turned on, bypass flow rate (BF) is 2.5 L/min, entrainment pumping 1.5 L/min, and peak ventricular pressure (VP) falls below aortic pressure (AP), while maintaining the mean AP. Time tension index (TTI) is decreased 31%. This result, when compared with simple bypass at differing BF, shows more than a 20% reduction in TTI. This simple jet pump provided significant unloading of the left ventricle and may be potentially useful as a left ventricular assist device. PMID:2252738

  1. Numerical study of 3-D inducer and impeller for pump model development

    NASA Technical Reports Server (NTRS)

    Cheng, G. C.; Chen, Y. S.; Garcia, R.; Williams, R. W.

    1993-01-01

    Current design of high-performance turbopumps for rocket engines requires effective and robust analytical tools to provide design information in a productive manner. The main goal of this study is to develop a robust and effective CFD pump model for general turbopump design and analysis applications. A finite difference Navier-Stokes flow solver, FDNS, which includes an extended k-epsilon turbulence model and appropriate moving zonal interface boundary conditions, was developed to analyze turbulent flows in turbomachinery devices. In the present study, two key components of the turbopump, the inducer and impeller, were investigated by the proposed pump model, and the numerical results were benchmarked by the experimental data provided by Rocketdyne.

  2. Development of Ho:YLF laser pumped by Tm:fiber laser

    NASA Astrophysics Data System (ADS)

    Mizutani, Kohei; Ishii, Shoken; Itabe, Toshikazu; Asai, Kazuhiro; Sato, Atsushi

    2014-11-01

    We are developing a 2-micron Ho:YLF laser end-pumped by Tm:fiber laser. The oscillator has ring resonator of 3m length. The laser is operated at high repetition rate of 200-5000 Hz in room temperature. The oscillator and amplifier system showed outputs of about 9W in CW and more than 6W in Q-switched operation. This laser will be used for wind and CO2 concentration measurements.

  3. Development of New Air-Cooled Heat Pump Chiller 'Compact Cube'

    NASA Astrophysics Data System (ADS)

    Ookoshi, Yasushi; Ito, Takuya; Yamaguchi, Hiroshi; Kato, Yohei; Ochiai, Yasutaka; Tanaka, Kosuke; Uji, Yoshihiro; Nakayama, Hiroshi

    Further improvement of the performance is requested to air-cooled heat pump chiller from the viewpoint of the global warming prevention. Smaller unit is needed to facilitate the renewal from absorption chiller to air-cooled heat pump chiller. To meet such needs, we developed compact new air-cooled heat pump chiller with high efficiency, 'Compact cube'. The developed machine is side-flow type with U-shaped fin and tube heat exchangers. With this structure, the uniform air velocity, high packed density of the heat exchangers, and the unit miniaturization have been implemented. The refrigeration cycle with two-evaporating temperature has also been implemented. The cooling COP of this cycle is 2% higher compared with conventional one-evaporating temperature cycle because of the rise of average evaporating temperature. In a new model, a new control system, which controls both capacity of compressors and air flow rate corresponding to heat load, has been implemented. As a result, the developed machine achieved IPLV(Integrated Part load Value) to 6.2(MCHV-P1800AE) which is 29% better than the conventional unit.

  4. Final Technical Report: Electromagnetic Pump Insulation Materials Development and Testing (PLM-DOC-0005-2465) Report # DOEGEHB00613

    SciTech Connect

    Krahn, John; Reed, Claude; Loewen, Eric

    2015-10-29

    Final Technical Report: Electromagnetic Pump Insulation Materials Development and Testing (Report # DOEGEHB00613) summarizes the information gathered from the analysis of the 160 m3/min EM Pump insulation that was tested in 2000-2002 and additional evaluations of new resilient, engineered insulation system evaluated and tested at both GRC and ANL. This report provides information on Tasks 1 and 2 of the entire project. This report also provides information in three broad areas: Historical and current data; Conclusions based on test data; and Insulation specifications for use in EM Pumps. The research for Task 2 builds upon Task 1: Update EM Pump Databank, which is summarized within this report. Where research for Task 3 and 4 Next-Generation EM Pump Analysis Tools identified parameters or analysis model that benefits Task 2 research, those items are noted within this report. The important design variables for the manufacture and operation of an EM Pump that the insulation research can evaluate are: space constraints; voltage capability of insulation system; maximum flux density through iron; flow rate and outlet pressure; efficiency and manufacturability. The development summary of the Electromagnetic Pump Insulation Materials Development and Testing was completed to include: Historical and current data; Conclusions based on test data; and Insulation specifications for use in EM Pumps.

  5. Development of blood vessel searching system using near-infrared light stereo method for clinical blood sampling

    NASA Astrophysics Data System (ADS)

    Cheng, Kai; Morita, Yusuke; Nakamachi, Eiji; Honda, Norihiro; Awazu, Kunio

    2014-10-01

    We developed an accurate three-dimensional blood vessel search (3D BVS) system using NIR light for the clinical blood sampling. In the previous study, the 3D BVS system, which used near-infrared (NIR) light imaging and the stereo method to locate blood vessel accurately in three dimensions has been developed(1). However, as NIR lights could not transmit the human arm, this system could not be used for the subcutaneous blood vessel detection. In this study, we developed a BVS by using the reflecting NIR light for blood sampling assist. The light scattering in human tissue will cause blur of blood vessel edge in image, that makes the diameter of blood vessel became uncertain. In this study, a light propagation simulation and a multilayer phantom were adopted to estimate the measurement error of blood vessel diameter in our BSV system. In the simulation, the optical properties of scattering coefficient, absorption coefficient, and refractive index were set similar with human skin. Next, we fabricated a multilayer phantom, which has the similar structure and optical properties with the human skin to confirm availability of the simulation. Also, the optical properties of our phantom are adjustable in our phantom to imitate the different color of skin. We established the estimation algorithm to detect the blood vessel accurately. Finally, we confirm the availability of our BVS for the blood sampling assist system.

  6. Design, development and test of a capillary pump loop heat pipe

    NASA Technical Reports Server (NTRS)

    Kroliczek, E. J.; Ku, J.; Ollendorf, S.

    1984-01-01

    The development of a capillary pump loop (CPL) heat pipe, including computer modeling and breadboard testing, is presented. The computer model is a SINDA-type thermal analyzer, combined with a pressure analyzer, which predicts the transients of the CPL heat pipe during operation. The breadboard is an aluminum/ammonia transport system which contains multiple parallel evaporator and condenser zones within a single loop. Test results have demonstrated the practicality and reliability of such a design, including heat load sharing among evaporators, liquid inventory/temperature control feature, and priming under load. Transport capability for this system is 65 KW-M with individual evaporator pumps managing up to 1.7 KW at a heat flux of 15 W/sq cm. The prediction of the computer model for heat transport capabilities is in good agreement with experimental results.

  7. Advanced electric heat pump dual-stroke compressor and system development

    NASA Astrophysics Data System (ADS)

    Veyo, S. E.; Fagan, T. J.

    1983-12-01

    The development of an advanced electric heat pump is discussed. A two-capacity, residential, advanced electric heat pump utilizing a unique dual-stroke compressor was developed. Two nearly identical preprototype split systems of nominally 3.5 tons maximum cooling capacity were designed, built and laboratory tested. The estimated annual energy efficiency of this advanced system is 20 percent better than a two-speed electric heat pump available at contract inception in 1979. This superior performance is due to the synergism of a high-efficiency, dual-stroke reciprocating compressor, a dual-strength high-efficiency single-speed single-phase hermetic drive motor, a single-width, single-entry high-efficiency indoor blower with backward curved cambered plate blades, a high-efficiency multivane axial flow outdoor fan, high-efficiency two-speed air mover motors and a microprocessor control system. The relative proportions of heat exchangers, air flows and compressor size as well as the ratio between high and low capacity were optimized so as to minimize the annual cost of ownership in a northern climate. Constraints placed upon the optimization and design process to ensure comfort provide heating air with a temperature of at least 90(0)F and provide cooling with a sensible-to-total capacity ratio of not more than 0.7. System performance was measured in the laboratory in accordance with applicable codes and procedures. Performance data plus hardware details are provided.

  8. Paper pump for passive and programmable transport

    PubMed Central

    Wang, Xiao; Hagen, Joshua A.; Papautsky, Ian

    2013-01-01

    In microfluidic systems, a pump for fluid-driving is often necessary. To keep the size of microfluidic systems small, a pump that is small in size, light-weight and needs no external power source is advantageous. In this work, we present a passive, simple, ultra-low-cost, and easily controlled pumping method based on capillary action of paper that pumps fluid through conventional polymer-based microfluidic channels with steady flow rate. By using inexpensive cutting tools, paper can be shaped and placed at the outlet port of a conventional microfluidic channel, providing a wide range of pumping rates. A theoretical model was developed to describe the pumping mechanism and aid in the design of paper pumps. As we show, paper pumps can provide steady flow rates from 0.3 μl/s to 1.7 μl/s and can be cascaded to achieve programmable flow-rate tuning during the pumping process. We also successfully demonstrate transport of the most common biofluids (urine, serum, and blood). With these capabilities, the paper pump has the potential to become a powerful fluid-driving approach that will benefit the fielding of microfluidic systems for point-of-care applications. PMID:24403999

  9. Development of Environmentally Benign Heat Pump Water Heaters for the US Market

    SciTech Connect

    Abdelaziz, Omar; Wang, Kai; Vineyard, Edward Allan; Roetker, Jack

    2012-01-01

    Improving energy efficiency in water heating applications is important to the nation's energy strategies. Water heating in residential and commercial buildings accounts for about 10% of U.S. buildings energy consumption. Heat pump water heating (HPWH) technology is a significant breakthrough in energy efficiency, as an alternative to electric resistance water heating. Heat pump technology has shown acceptable payback period with proper incentives and successful market penetration is emerging. However, current HPWH require the use of refrigerants with high Global Warming Potential (GWP). Furthermore, current system designs depend greatly on the backup resistance heaters when the ambient temperature is below freezing or when hot water demand increases. Finally, the performance of current HPWH technology degrades greatly as the water set point temperature exceeds 330 K. This paper presents the potential for carbon dioxide, CO2, as a natural, environmentally benign alternative refrigerant for HPWH technology. In this paper, we first describe the system design, implications and opportunities of operating a transcritical cycle. Next, a prototype CO2 HPWH design featuring flexible component evaluation capability is described. The experimental setup and results are then illustrated followed by a brief discussion on the measured system performance. The paper ends with conclusions and recommendations for the development of CO2 heat pump water heating technology suitable for the U.S. market.

  10. CO2 emission mitigation by geothermal development - especially with geothermal heat pumps

    NASA Astrophysics Data System (ADS)

    Rybach, L.

    2009-04-01

    Geothermal technologies for power generation or direct use operate with little or no greenhouse gas emissions. Since no burning processes are involved they are low in CO2 emissions. Geothermal energy development has thus great CO2 emission reduction potential when substituting fossil sources of energy. Geothermal heat pumps (GHP) represent the fastest growing branch of geothermal technology; they use the ubiquitous shallow geothermal resource. GHPs are electricity consumers, nevertheless they can contribute to the fight against climatic warming. Such systems are now increasingly used for space heating, cooling, and to provide domestic hot water. With heat pump systems the use of fossil primary energy sources can be avoided, thus GHPs contribute to energy security: many countries must rely in their space heating systems on imported fossil fuels. The degree of dependence on these can be reduced. Since heat pumps are usually driven by electric components the origin of the electricity and the corresponding CO2 emission must be considered. A compilation shows that there are great differences in this respect from country to country. The same (=electricity need with CO2 emission consequences) applies to GHPs too. This means that by new geothermal heat pumps only additional CO2 emission can be avoided ("saving"), not a reduction of actual emissions. When GHPs are installed in refurbishment (to replace fossil-fueled systems) actual emission reduction can be achieved. Emission reduction is also evident when electric heater/cooler installations, driven by fossil-based electricity, are replaced by GHP systems. Numerical examples are presented about saving and reduction.

  11. Development of trivalent ytterbium doped fluorapatites for diode-pumped laser applications

    NASA Astrophysics Data System (ADS)

    Bayramian, Andrew James

    2000-11-01

    A major motivator of this work is the Mercury Project, a one kilowatt diode-pumped solid-state laser system under development at Lawrence Livermore National Laboratory (LLNL), which incorporates ytterbium doped strontium fluorapatite, Sr5(PO4)3F (S-FAP), as the amplifier gain medium. The primary focus of this thesis is a full understanding of the properties of this material, which is necessary for proper design and modeling of the system. Ytterbium-doped fluorapatites were investigated at LLNL prior to this work and found to be ideal candidate materials for high-power amplifier systems providing high absorption and emission cross sections, long radiative lifetimes, and high efficiency. A family of barium substituted S-FAP crystals was grown in an effort to modify the pump and emission bandwidths for application to broadband diode pumping and short pulse generation. Crystals of Yb 3+:Srs5-xBax(PO4) 3F where x < 1 showed homogeneous lines offering 8.4 nm (1.8X enhancement) of absorption bandwidth and 6.9 nm (1.4X enhancement) of emission bandwidth. The gain saturation fluence of Yb:S-FAP was measured to be 3.2 J/cm 2 with homogeneous extraction using a pump-probe experiment where the probe laser was a high intensity Q-switched master oscillator power amplifier system. The crystal quality of Czochralski grown Yb:S-FAP boules, which is effected by defects such as cracking, cloudiness, bubble core, slip dislocations, and anomalous absorption, was investigated interferometrically and quantified by means of Power Spectral Density (PSD) plots. Stimulated Raman Scattering (SRS) losses were evaluated by first measuring the SRS gain coefficient to be 1.3 cm/GW, then modeling the losses in the Mercury amplifier system. Countermeasures including the addition of bandwidth to the extraction beam and wedging of amplifier surfaces are shown to reduce the SRS losses allowing efficient laser gain extraction at higher intensities. Finally, an efficient Q-switched Yb:S-FAP oscillator

  12. Quantification of Blood Flow and Topology in Developing Vascular Networks

    PubMed Central

    Kloosterman, Astrid; Hierck, Beerend; Westerweel, Jerry; Poelma, Christian

    2014-01-01

    Since fluid dynamics plays a critical role in vascular remodeling, quantification of the hemodynamics is crucial to gain more insight into this complex process. Better understanding of vascular development can improve prediction of the process, and may eventually even be used to influence the vascular structure. In this study, a methodology to quantify hemodynamics and network structure of developing vascular networks is described. The hemodynamic parameters and topology are derived from detailed local blood flow velocities, obtained by in vivo micro-PIV measurements. The use of such detailed flow measurements is shown to be essential, as blood vessels with a similar diameter can have a large variation in flow rate. Measurements are performed in the yolk sacs of seven chicken embryos at two developmental stages between HH 13+ and 17+. A large range of flow velocities (1 µm/s to 1 mm/s) is measured in blood vessels with diameters in the range of 25–500 µm. The quality of the data sets is investigated by verifying the flow balances in the branching points. This shows that the quality of the data sets of the seven embryos is comparable for all stages observed, and the data is suitable for further analysis with known accuracy. When comparing two subsequently characterized networks of the same embryo, vascular remodeling is observed in all seven networks. However, the character of remodeling in the seven embryos differs and can be non-intuitive, which confirms the necessity of quantification. To illustrate the potential of the data, we present a preliminary quantitative study of key network topology parameters and we compare these with theoretical design rules. PMID:24823933

  13. Metal hydride/chemical heat-pump development project, phase 1

    NASA Astrophysics Data System (ADS)

    Argabright, T. A.

    1982-02-01

    The metal hydride/chemical heat pump (MHHP) is a chemical heat pump containing two hydrides for the storage and/or recovery of thermal energy. It utilizes the heat of reaction of hydrogen with specific metal alloys. The MHHP design can be tailored to provide heating and/or cooling or temperature upgrading over a wide range of input and ambient temperatures. The system can thus be used with a variety of heat sources including waste heat, solar energy or a fossil fuel. The conceptual design of the MHHP was developed. A national market survey including a study of applications and market sectors was conducted. The technical tasks including conceptual development, thermal and mechanical design, laboratory verification of design and material performance, cost analysis and the detailed design of the Engineering Development Test Unit (EDTU) were performed. As a result of the market study, the temperature upgrade cycle of the MHHP was chosen for development. Operating temperature ranges for the upgrader were selected to be from 70 to 1100 C (160 to 2300 F) for the source heat and 140 to 1900 C (280 to 3750 F) for the product heat.

  14. Arterial α2-Na+ pump expression influences blood pressure: lessons from novel, genetically engineered smooth muscle-specific α2 mice

    PubMed Central

    Chen, Ling; Song, Hong; Wang, Youhua; Lee, Jane C.; Kotlikoff, Michael I.; Pritchard, Tracy J.; Paul, Richard J.; Zhang, Jin

    2015-01-01

    Arterial myocytes express α1-catalytic subunit isoform Na+ pumps (75–80% of total), which are ouabain resistant in rodents, and high ouabain affinity α2-Na+ pumps. Mice with globally reduced α2-pumps (but not α1-pumps), mice with mutant ouabain-resistant α2-pumps, and mice with a smooth muscle (SM)-specific α2-transgene (α2SM-Tg) that induces overexpression all have altered blood pressure (BP) phenotypes. We generated α2SM-DN mice with SM-specific α2 (not α1) reduction (>50%) using nonfunctional dominant negative (DN) α2. We compared α2SM-DN and α2SM-Tg mice to controls to determine how arterial SM α2-pumps affect vasoconstriction and BP. α2SM-DN mice had elevated basal mean BP (mean BP by telemetry: 117 ± 4 vs. 106 ± 1 mmHg, n = 7/7, P < 0.01) and enhanced BP responses to chronic ANG II infusion (240 ng·kg−1·min−1) and high (6%) NaCl. Several arterial Ca2+ transporters, including Na+/Ca2+ exchanger 1 (NCX1) and sarcoplasmic reticulum and plasma membrane Ca2+ pumps [sarco(endo)plasmic reticulum Ca2+-ATPase 2 (SERCA2) and plasma membrane Ca2+-ATPase 1 (PMCA1)], were also reduced (>50%). α2SM-DN mouse isolated small arteries had reduced myogenic reactivity, perhaps because of reduced Ca2+ transporter expression. In contrast, α2SM-Tg mouse aortas overexpressed α2 (>2-fold), NCX1, SERCA2, and PMCA1 (43). α2SM-Tg mice had reduced basal mean BP (104 ± 1 vs. 109 ± 2 mmHg, n = 15/9, P < 0.02) and attenuated BP responses to chronic ANG II (300–400 ng·kg−1·min−1) with or without 2% NaCl but normal myogenic reactivity. NCX1 expression was inversely related to basal BP in SM-α2 engineered mice but was directly related in SM-NCX1 engineered mice. NCX1, which usually mediates arterial Ca2+ entry, and α2-Na+ pumps colocalize at plasma membrane-sarcoplasmic reticulum junctions and functionally couple via the local Na+ gradient to help regulate cell Ca2+. Altered Ca2+ transporter expression in SM-α2 engineered mice apparently compensates to

  15. Development of inexpensive blood imaging systems: where are we now?

    PubMed

    Chu, Kaiqin; Smith, Zachary J; Wachsmann-Hogiu, Sebastian

    2015-01-01

    Clinical applications in the developing world, such as malaria and anemia diagnosis, demand a change in the medical paradigm of expensive care given in central locations by highly trained professionals. There has been a recent explosion in optical technologies entering the consumer market through the widespread adoption of smartphones and LEDs. This technology commoditization has enabled the development of small, portable optical imaging systems at an unprecedentedly low cost. Here, we review the state-of-the-field of the application of these systems for low-cost blood imaging with an emphasis on cellular imaging systems. In addition to some promising results addressing specific clinical issues, an overview of the technology landscape is provided. We also discuss several key issues that need to be addressed before these technologies can be commercialized. PMID:26305840

  16. A superconductive electromagnetic pump without any mechanical moving parts.

    PubMed

    Qian, K X; Wang, S S; Chu, S H

    1993-01-01

    Mechanical reliability is one of the main obstacles to long-term performance of an artificial heart. To solve this problem a superconductive electromagnetic pump was developed. Two concentric cone-shaped cylinders serve as the pump housings and electrodes. As a current passes through the blood between the inner and outer housings, the blood rotates under the action of a superconductive magnetic field. Therefore, this is a rotary pump without a rotor or any mechanical moving parts. The device was tested in a super-conductive magnetic field with 7 Tesla. By 5 V, and 1 A, a 0.9% saline flow of approximately 1 L/min, and 10 mm H2O was obtained. For further development, a stronger magnetic field with ca. 20 Tesla is desirable. Contrary to traditional thought, blood and saline have almost the same conductibility as any other conductors. For blood damage testing, fresh porcine blood was used. The circulation was maintained by an impeller pump, with the electromagnetic pump serving only as electrodes. Comparing the first and second periods of testing with and without a current of 1 A, the difference in hematologic variations evaluated the blood damage by the electric current passing directly through the blood. Results indicated that the electric current causes no serious blood damage. PMID:8268618

  17. Mother-plant-mediated pumping of zinc into the developing seed.

    PubMed

    Olsen, Lene Irene; Hansen, Thomas H; Larue, Camille; Østerberg, Jeppe Thulin; Hoffmann, Robert D; Liesche, Johannes; Krämer, Ute; Surblé, Suzy; Cadarsi, Stéphanie; Samson, Vallerie Ann; Grolimund, Daniel; Husted, Søren; Palmgren, Michael

    2016-01-01

    Insufficient intake of zinc and iron from a cereal-based diet is one of the causes of 'hidden hunger' (micronutrient deficiency), which affects some two billion people(1,2). Identifying a limiting factor in the molecular mechanism of zinc loading into seeds is an important step towards determining the genetic basis for variation of grain micronutrient content and developing breeding strategies to improve this trait(3). Nutrients are translocated to developing seeds at a rate that is regulated by transport processes in source leaves, in the phloem vascular pathway, and at seed sinks. Nutrients are released from a symplasmic maternal seed domain into the seed apoplasm surrounding the endosperm and embryo by poorly understood membrane transport processes(4-6). Plants are unique among eukaryotes in having specific P1B-ATPase pumps for the cellular export of zinc(7). In Arabidopsis, we show that two zinc transporting P1B-ATPases actively export zinc from the mother plant to the filial tissues. Mutant plants that lack both zinc pumps accumulate zinc in the seed coat and consequently have vastly reduced amounts of zinc inside the seed. Blockage of zinc transport was observed at both high and low external zinc supplies. The phenotype was determined by the mother plant and is thus due to a lack of zinc pump activity in the seed coat and not in the filial tissues. The finding that P1B-ATPases are one of the limiting factors controlling the amount of zinc inside a seed is an important step towards combating nutritional zinc deficiency worldwide. PMID:27243644

  18. Fluid seals development for coal liquefaction slurry pumps. Quarterly technical progress report No. 10, 1 January 1985-31 March 1985. [Reciprocating and centrifugal pumps

    SciTech Connect

    Burcham, R.E.

    1985-04-22

    This quarterly progress report covers the work performed during the period January 1, 1985 to March 31, 1985 on the Fluid Seals Development for Coal Liquefaction Slurry Pumps Program. The work was sponsored by the Department of Energy, Pittsburgh Technology Center, to develop technology for hydrostatic fluid seals to be used in coal slurry centrifugal and reciprocating pumps. The scope of the program consists of the following tasks: (1) Task 1A, survey of current practices for centrifugal and reciprocating coal slurry pump seals; (2) Task 1B, preliminary evaluation of three alternative centrifugal and reciprocating fluid seal concepts; (3) Task 2, detail evaluation of the best two centrifugal and reciprocating fluid seal concepts; (4) Task 3A, design and fabrication of the selected centrifugal and reciprocating fluid seal concept, design and fabrication of the centrifugal and reciprocating seal testers; (5) Task 3B, laboratory seal testing of the centrifugal and reciprocating fluid seals; (6) Task 4, field testing of the centrifugal and reciprocating fluid seals. Tasks 1, 2, 3A, and 3B have been completed. Task 4 is pending Department of Energy approval. 2 figs., 1 tab.

  19. Fluid seals development for coal liquefaction slurry pumps. Quarterly technical progress report No. 11, 1 April 1985-30 June 1985. [Reciprocating pumps

    SciTech Connect

    Burcham, R.E.

    1985-07-22

    This quarterly progress report covers the work performed during the period 1 April 1985 to 30 June 1985 on the Fluid Seals Development for Coal Liquefaction Slurry Pumps Program. The work was sponsored by the Department of Energy, Pittsburgh Technology Center, to develop technology for hydrostatic fluid seals to be used in coal slurry centrifugal and reciprocating pumps. The scope of the program consists of the following tasks: (1) Task 1A: Survey of current practices for centrifugal and reciprocating coal slurry pump seals; (2) Task 1B: Preliminary evaluation of three alternative centrifugal and reciprocating fluid seal concepts; (3) Task 2: Detail evaluation of the best two centrifugal and reciprocating fluid seal concepts; (4) Task 3A: Design and fabrication of the selected centrifugal and reciprocating fluid seal concept, Design and fabrication of the centrifugal and reciprocating seal testers; (5) Task 3B: Laboratory seal testing of the centrifugal and reciprocating fluid seals; and (6) Task 4: Field testing of the centrifugal and reciprocating fluid seals. Tasks 1, 2, 3A, and 3B have been completed. Task 4 is in progress. 2 figs.

  20. Development and Remodeling of the Vertebrate Blood-Gas Barrier

    PubMed Central

    Makanya, Andrew; Anagnostopoulou, Aikaterini; Djonov, Valentin

    2013-01-01

    During vertebrate development, the lung inaugurates as an endodermal bud from the primitive foregut. Dichotomous subdivision of the bud results in arborizing airways that form the prospective gas exchanging chambers, where a thin blood-gas barrier (BGB) is established. In the mammalian lung, this proceeds through conversion of type II cells to type I cells, thinning, and elongation of the cells as well as extrusion of the lamellar bodies. Subsequent diminution of interstitial tissue and apposition of capillaries to the alveolar epithelium establish a thin BGB. In the noncompliant avian lung, attenuation proceeds through cell-cutting processes that result in remarkable thinning of the epithelial layer. A host of morphoregulatory molecules, including transcription factors such as Nkx2.1, GATA, HNF-3, and WNT5a; signaling molecules including FGF, BMP-4, Shh, and TFG-β and extracellular proteins and their receptors have been implicated. During normal physiological function, the BGB may be remodeled in response to alterations in transmural pressures in both blood capillaries and airspaces. Such changes are mitigated through rapid expression of the relevant genes for extracellular matrix proteins and growth factors. While an appreciable amount of information regarding molecular control has been documented in the mammalian lung, very little is available on the avian lung. PMID:23484070

  1. Development of the choroid plexus and blood-CSF barrier

    PubMed Central

    Liddelow, Shane A.

    2015-01-01

    Well-known as one of the main sources of cerebrospinal fluid (CSF), the choroid plexuses have been, and still remain, a relatively understudied tissue in neuroscience. The choroid plexus and CSF (along with the blood-brain barrier proper) are recognized to provide a robust protective effort for the brain: a physical barrier to impede entrance of toxic metabolites to the brain; a “biochemical” barrier that facilitates removal of moieties that circumvent this physical barrier; and buoyant physical protection by CSF itself. In addition, the choroid plexus-CSF system has been shown to be integral for normal brain development, central nervous system (CNS) homeostasis, and repair after disease and trauma. It has been suggested to provide a stem-cell like repository for neuronal and astrocyte glial cell progenitors. By far, the most widely recognized choroid plexus role is as the site of the blood-CSF barrier, controller of the internal CNS microenvironment. Mechanisms involved combine structural diffusion restraint from tight junctions between plexus epithelial cells (physical barrier) and specific exchange mechanisms across the interface (enzymatic barrier). The current hypothesis states that early in development this interface is functional and more specific than in the adult, with differences historically termed as “immaturity” actually correctly reflecting developmental specialization. The advanced knowledge of the choroid plexus-CSF system proves itself imperative to understand a range of neurological diseases, from those caused by plexus or CSF drainage dysfunction (e.g., hydrocephalus) to more complicated late-stage diseases (e.g., Alzheimer's) and failure of CNS regeneration. This review will focus on choroid plexus development, outlining how early specializations may be exploited clinically. PMID:25784848

  2. A mini axial and a permanent maglev radial heart pump.

    PubMed

    Qian, Kun-Xi; Ru, Wei-Min; Wang, Hao; Jing, Teng

    2007-01-01

    The implantability and durability have been for decades the focus of artificial heart R&D. A mini axial and a maglev radial pump have been developed to meet with such requirements.The mini axial pump weighing 27g (incl.5g rotor) has an outer diameter of 21mm and a length of 10mm in its largest point, but can produce a maximal blood flow of 6l/min with 50mmHg pressure increase. Therefore, it is suitable for the patients of 40-60kg body weight. For other patients of 60-80kg or 80-100kg body weight, the mini axial pumps of 23mm and 25mm outer diameter had been developed before, these devices were acknowledged to be the world smallest LVADs by Guinness World Record Center in 2004.The permanent maglev radial pump weighing 150g is a shaft-less centrifugal pump with permanent magnetic bearings developed by the author. It needs no second coil for suspension of the rotor except the motor coil, different from all other maglev pumps developed in USA, Japan, European, etc. Thus no detecting and controlling systems as well as no additional power supply for maglev are necessary. The pump can produce a blood flow up to as large as 10l/min against 100mmHg pressure.An implantable and durable blood pump will be a viable alternative to natural donor heart for transplantation. PMID:19662120

  3. Eosinophilic esophagitis that develops during therapy with proton pump inhibitors : case series and possible mechanisms.

    PubMed

    Orel, R; Murch, S; Amil Dias, J; Vandenplas, Y; Homan, M

    2016-01-01

    Therapy with proton-pump inhibitors (PPIs) results in remission in at least one third of patients with esophageal eosinophilia, presumably because of both their acid-related and anti-inflammatory mechanisms of action. However, eosinophilic esophagitis (EoE) may also develop during therapy with PPIs. We present a case series of four children who were initially diagnosed with infectious esophagitis, gastroesophageal reflux disease or gastric ulcer, who had no eosinophilic infiltration of the esophagus, but subsequently developed symptoms, endoscopic features and histological picture of typical EoE. We discuss mechanisms of action of PPIs of likely relevance to an increased risk of development of EoE in some patients, such as their influence on mucosal barrier function, interference with pH-related protein digestion by pepsin, and antigen processing by immune cells. PMID:27382946

  4. The Development of a Wireless Implantable Blood Flow Monitor.

    PubMed

    Unadkat, Jignesh V; Rothfuss, Michael; Mickle, Marlin H; Sejdic, Ervin; Gimbel, Michael L

    2015-07-01

    Microvascular anastomotic failure remains an uncommon but devastating problem. Although the implantable Doppler probe is helpful in flap monitoring, the devices are cumbersome, easily dislodged, and plagued by false-positive results. The authors have developed an implantable wireless Doppler monitor prototype from off-the-shelf components and tested it in a swine model. The wireless probe successfully distinguished between femoral vein flow, occlusion, and reflow, and wirelessly reported the different signals reliably. This is the first description of a wireless implantable blood flow sensor for flap monitoring. Future iterations will incorporate an integrated microchip-based Doppler system that will decrease the size to 1 mm, small enough to fit onto an anastomotic coupler. PMID:26111323

  5. Development of automatic blood extraction device with a micro-needle for blood-sugar level measurement

    NASA Astrophysics Data System (ADS)

    Kawanaka, Kaichiro; Uetsuji, Yasutomo; Tsuchiya, Kazuyoshi; Nakamachi, Eiji

    2008-12-01

    In this study, a portable type HMS (Health Monitoring System) device is newly developed. It has features 1) puncturing a blood vessel by using a minimally invasive micro-needle, 2) extracting and transferring human blood and 3) measuring blood glucose level. This miniature SMBG (Self-Monitoring of Blood Glucose) device employs a syringe reciprocal blood extraction system equipped with an electro-mechanical control unit for accurate and steady operations. The device consists of a) a disposable syringe unit, b) a non-disposable body unit, and c) a glucose enzyme sensor. The syringe unit consists of a syringe itself, its cover, a piston and a titanium alloy micro-needle, whose inner diameter is about 100µm. The body unit consists of a linear driven-type stepping motor, a piston jig, which connects directly to the shaft of the stepping motor, and a syringe jig, which is driven by combining with the piston jig and slider, which fixes the syringe jig. The required thrust to drive the slider is designed to be greater than the value of the blood extraction force. Because of this driving mechanism, the automatic blood extraction and discharging processes are completed by only one linear driven-type stepping motor. The experimental results using our miniature SMBG device was confirmed to output more than 90% volumetric efficiency under the driving speed of the piston, 1.0mm/s. Further, the blood sugar level was measured successfully by using the glucose enzyme sensor.

  6. Clinical results and pump analysis of the Gyro pump for long-term extracorporeal life support.

    PubMed

    Terasaki, Takamitsu; Takano, Tamaki; Michinaga, Yuuki; Yokokawa, Michihiro; Wada, Yuko; Seto, Tatsuichirou; Fukui, Daisuke; Amano, Jun

    2013-09-01

    Rescuing patients in severe cardiac failure with extracorporeal support remains challenging. The Gyro pump is a centrifugal blood pump and was now used for cardiopulmonary bypass, although it was originally developed for long-term cardiac assist. Little is known about clinical experiences using this pump. Here, we report on the clinical results of long-term extracorporeal life support for over 4 days using the Gyro pump with Excelung, a hollow fiber oxygenator coated with silicone and heparin. Seven patients underwent extracorporeal life support with 15 pump and oxygenator combinations. Gyro and Excelung were used for venoarterial extracorporeal support in six patients and for right ventricular support in one patient. Patient characteristics, pump driving conditions, and blood chemistry were obtained retrospectively. All pumps were subsequently disassembled and examined macroscopically, with 6 of 15 pumps also examined by scanning electron microscopy (SEM). The patient mortality rate was 57.1%. Mean duration of support was 10.5 ± 7.2 days per pump and oxygenator combination. Lactate dehydrogenase and aspartate aminotransferase were generally maintained below 1000 and 100 IU/L, respectively, after the first 4 days of pump driving. Thrombi were found in two pumps, one used without anticoagulation and the other driven at a very slow rotational speed. SEM revealed no wear in the male bearings and very low wear and deformation (0.02 ± 0.03 mm) in the female bearings. The combination of Gyro and Excelung may be applicable for long-term biventricular and right ventricular support, although proper anticoagulation should be administrated to avoid thrombus formation inside the pump. PMID:24021058

  7. Pumping speed offered by activated carbon at liquid helium temperatures by sorbents adhered to indigenously developed hydroformed cryopanel

    NASA Astrophysics Data System (ADS)

    Gangradey, Ranjana; Shanti Mukherjee, Samiran; Panchal, Paresh; Nayak, Pratik; Agarwal, Jyoti; Rana, Chirag; Kasthurirengan, S.; Shankar Mishra, Jyoti; Patel, Haresh; Bairagi, Pawan; Lambade, Vrushabh; Sayani, Reena

    2015-12-01

    Towards the aim of developing a pump with large pumping speed of the order of 1 L/(s-cm2) or above for gases like hydrogen and helium through physical adsorption, development of activated carbon based sorbents like granules, spheres, flocked fibres, knitted and non -knitted cloth was carried out. To investigate the pumping speed offered, a test facility SSCF (Small Scale Cryopump Facility) which can take samples of hydroformed cryopanel (a technology developed in India) of size ∼500 mm × 100 mm was set up as per international standards comprising a dome mounted with gauges, calibrated leak valve, gas analyser, sorbent adhered to cryopanel etc. The cryopanel was shielded by chevron baffles. Pumping speed measurements were carried out for gases like hydrogen, helium and argon at a constant panel temperature in the pressure range of 1×10-7 to 1×10-4 mbar, and pumping speed was found to be in the range of 2000 L/s for a pressure range 1×10-6 to 1×10-4 mbar, and 4000 L/s for pressure range 1×10-7mbar and below for a pumping surface area of ∼1000 cm2 thus giving an average pumping speed of about 2 L/(s-cm2). Using the Monte Carlo codes SSCF was modelled and simulation studies performed. Parameters like sticking coefficient, capture coefficients affecting the pumping speed were studied. This paper describes the experimental setup of SSCF, experimental results and its correlation with Monte-Carlo simulation.

  8. In Vitro Mean Red Blood Cell Volume Change Induced by Diode Pump Solid State Low-Level Laser of 405 nm

    PubMed Central

    Jafar, Mohamad Suhaimi; Al-Gailani, Bassam T.; Ahmed, Naser Mahmoud; Suhaimi, Fatanah Mohamad; Suardi, Nursakinah

    2016-01-01

    Abstract Objective: This study was conducted to investigate the effects of low-level laser (LLL) doses on human red blood cell volume. The effects of exposure to a diode pump solid state (DPSS) (λ = 405 nm) laser were observed. Background data: The response of human blood to LLL irradiation gives important information about the mechanism of interaction of laser light with living organisms. Materials and methods Blood samples were collected into ethylenediaminetetraacetic acid (EDTA)-containing tubes, and each sample was divided into two equal aliquots, one to serve as control and the other for irradiation. The aliquot was subjected to laser irradiation for 20, 30, 40, or 50 min at a fixed power density of 0.03 W/cm2. Mean cell volume (MCV) and red blood cell (RBC) counts were measured immediately after irradiation using a computerized hemtoanalyzer. Results: Significant decrease in RBC volume (p < 0.05, p < 0.0001, p < 0.0001, and p < 0.05, respectively) was induced with variation in laser doses.The highest response was observed with an exposure time of 40 min. This result was reproduced in RBCs suspended in a buffered NaCl solution. In contrast to this finding, laser-induced RBC volume change was completely abolished by suspending RBCs in a solution containing a higher concentration of EDTA. Conclusions: It was suggested that LLL can reduce RBC volume possibly because of the increased free intracellular Ca+2 concentrations, which activate Ca+2-dependent K+ channels with consequent K+ ion efflux and cell shrinkage. PMID:26966989

  9. Design and development of a high-power LED-pumped Ce:Nd:YAG laser.

    PubMed

    Villars, Brenden; Steven Hill, E; Durfee, Charles G

    2015-07-01

    By studying quasi-continuous wave (QCW) operation of a Ce:Nd:YAG solid-state laser directly pumped by LED arrays, we demonstrate the feasibility of direct-LED pumping as an alternative to direct-diode or flashlamp pumping. LEDs emitting either at 460 or 810 nm were used to pump an uncooled Ce:Nd:YAG laser rod (at 30-Hz repetition rate for tens of seconds). Pumping at 460 nm was made possible by the Ce(3+) co-dopant that enables transfer of excitations near to Nd(3+) ions in the YAG lattice. Comparison of these two pumping schemes has allowed for a thorough analysis of the performance and efficiency of this laser system. QCW output energies as high as 18 mJ/pulse are reported, which to the best of our knowledge is the highest output pulse energy achieved by an LED-pumped solid-state laser to date. PMID:26125364

  10. The Blood-Brain Barrier: Bottleneck in Brain Drug Development

    PubMed Central

    Pardridge, William M.

    2005-01-01

    Summary: The blood-brain barrier (BBB) is formed by the brain capillary endothelium and excludes from the brain ∼100% of large-molecule neurotherapeutics and more than 98% of all small-molecule drugs. Despite the importance of the BBB to the neurotherapeutics mission, the BBB receives insufficient attention in either academic neuroscience or industry programs. The combination of so little effort in developing solutions to the BBB problem, and the minimal BBB transport of the majority of all potential CNS drugs, leads predictably to the present situation in neurotherapeutics, which is that there are few effective treatments for the majority of CNS disorders. This situation can be reversed by an accelerated effort to develop a knowledge base in the fundamental transport properties of the BBB, and the molecular and cellular biology of the brain capillary endothelium. This provides the platform for CNS drug delivery programs, which should be developed in parallel with traditional CNS drug discovery efforts in the molecular neurosciences. PMID:15717053

  11. Aquifer characterization using transient streaming potentials generated by flow during pumping tests - New developments

    NASA Astrophysics Data System (ADS)

    Malama, B.; Kuhlman, K. L.; Revil, A.

    2009-12-01

    Traditional methods of aquifer characterization, namely pumping and slug tests, provide the most direct way of measuring system state variables (hydraulic head) and estimating hydraulic parameters (hydraulic conductivity, specific storage and specific yield) of aquifers. Despite this significant advantage, such methods have some serious limitations: they can be laborious, expensive, are intusive and yield spatially sparse data. Hydrogeophysical methods offer some promise to overcome some of these limitations. We discuss recently developed semi-analytical solutions for transient streaming potentials associated with pumping tests conducted in homogeneous confined and unconfined aquifers. Using these solutions, data obtained from field tests conducted (a) in a confined aquifer at a site located near Montalto Uffugo, in the region of Calabria in Southern Italy, and (b) in an unconfined aquifer at the Boise Hydrogeophysical Research Site (BHRS) in Idaho, US. Estimates of hydraulic parameters that compare well to those obtained by traditional methods were obtained. Our work indicates that transient streaming potential data, collected at land surface, may be used to provide preliminary estimates of hydraulic aquifer properties quickly and cheaply.

  12. Heat-pump-centered integrated community energy systems: system development summary

    SciTech Connect

    Calm, J.M.

    1980-02-01

    An introduction to district heating systems employing heat pumps to enable use of low-temperature energy sources is presented. These systems operate as thermal utilities to provide space heating and may also supply space cooling, service-water heating, and other thermal services. Otherwise-wasted heat from industrial and commercial processes, natural sources including solar and geothermal heat, and heat stored on an annual cycle from summer cooling may be effectively utilized by the systems described. These sources are abundant, and their use would conserve scarce resources and reduce adverse environmental impacts. More than one-quarter of the energy consumed in the United States is used to heat and cool buildings and to heat service water. Natural gas and oil provide approximately 83% of this energy. The systems described show potential to reduce net energy consumption for these services by 20 to 50% and to allow fuel substitution with less-scarce resources not practical in smaller, individual-building systems. Seven studies performed for the system development phase of the Department of Energy's Heat-Pump-Centered Integrated Community Energy Systems Project and to related studies are summarized. A concluding chapter tabulates data from these separately published studies.

  13. Development of a Dual-Pump CARS System for Measurements in a Supersonic Combusting Free Jet

    NASA Technical Reports Server (NTRS)

    Magnotti, Gaetano; Cutler, Andrew D.; Danehy, Paul

    2012-01-01

    This work describes the development of a dual-pump CARS system for simultaneous measurements of temperature and absolute mole fraction of N2, O2 and H2 in a laboratory scale supersonic combusting free jet. Changes to the experimental set-up and the data analysis to improve the quality of the measurements in this turbulent, high-temperature reacting flow are described. The accuracy and precision of the instrument have been determined using data collected in a Hencken burner flame. For temperature above 800 K, errors in absolute mole fraction are within 1.5, 0.5, and 1% of the total composition for N2, O2 and H2, respectively. Estimated standard deviations based on 500 single shots are between 10 and 65 K for the temperature, between 0.5 and 1.7% of the total composition for O2, and between 1.5 and 3.4% for N2. The standard deviation of H2 is 10% of the average measured mole fraction. Results obtained in the jet with and without combustion are illustrated, and the capabilities and limitations of the dual-pump CARS instrument discussed.

  14. Development of a solenoid pumped in situ zinc analyzer for environmental monitoring

    USGS Publications Warehouse

    Chapin, T.P.; Wanty, R.B.

    2005-01-01

    A battery powered submersible chemical analyzer, the Zn-DigiScan (Zn Digital Submersible Chemical Analyzer), has been developed for near real-time, in situ monitoring of zinc in aquatic systems. Microprocessor controlled solenoid pumps propel sample and carrier through an anion exchange column to separate zinc from interferences, add colorimetric reagents, and propel the reaction complex through a simple photometric detector. The Zn-DigiScan is capable of self-calibration with periodic injections of standards and blanks. The detection limit with this approach was 30 ??g L-1. Precision was 5-10% relative standard deviation (R.S.D.) below 100 ??g L-1, improving to 1% R.S.D. at 1000 ??g L-1. The linear range extended from 30 to 3000 ??g L-1. In situ field results were in agreement with samples analyzed by inductively coupled plasma mass spectrometry (ICPMS). This pump technology is quite versatile and colorimetric methods with complex online manipulations such as column reduction, preconcentration, and dilution can be performed with the DigiScan. However, long-term field deployments in shallow high altitude streams were hampered by air bubble formation in the photometric detector. ?? 2005 Elsevier B.V. All rights reserved.

  15. Metal hydride/chemical heat-pump development project. Phase I. Final report

    SciTech Connect

    Argabright, T.A.

    1982-02-01

    The metal hydride/chemical heat pump (MHHP) is a chemical heat pump containing two hydrides for the storage and/or recovery of thermal energy. It utilizes the heat of reaction of hydrogen with specific metal alloys. The MHHP design can be tailored to provide heating and/or cooling or temperature upgrading over a wide range of input and ambient temperatures. The system can thus be used with a variety of heat sources including waste heat, solar energy or a fossil fuel. The conceptual design of the MHHP was developed. A national market survey including a study of applications and market sectors was conducted. The technical tasks including conceptual development, thermal and mechanical design, laboratory verification of design and material performance, cost analysis and the detailed design of the Engineering Development Test Unit (EDTU) were performed. As a result of the market study, the temperature upgrade cycle of the MHHP was chosen for development. Operating temperature ranges for the upgrader were selected to be from 70 to 110/sup 0/C (160 to 230/sup 0/F) for the source heat and 140 to 190/sup 0/C (280 to 375/sup 0/F) for the product heat. These ranges are applicable to many processes in industries such as food, textile, paper and pulp, and chemical. The hydride pair well suited for these temperatures is LaNi/sub 5//LaNi/sub 4/ /sub 5/Al/sub 0/ /sub 5/. The EDTU was designed for the upgrade cycle. It is a compact finned tube arrangement enclosed in a pressure vessel. This design incorporates high heat transfer and low thermal mass in a system which maximizes the coefficient of performance (COP). It will be constructed in Phase II. Continuation of this effort is recommended.

  16. Development of Trivalent Ytterbium Doped Fluorapatites for Diode-Pumped Laser Applications

    SciTech Connect

    Bayramian, A.J.

    2000-06-21

    One of the major motivators of this work is the Mercury Project, which is a 1 kW scalable diode-pumped solid-state laser system under development at Lawrence Livermore National Laboratory (LLNL). Major goals include 100 J pulses, 10% wallplug efficiency, 10 Hz repetition rate, and a 5 times diffraction limited beam. To achieve these goals the Mercury laser incorporates ytterbium doped Sr{sub 5}(PO{sub 4}){sub 3}F (S-FAP) as the amplifier gain medium. The primary focus of this thesis is a full understanding of the properties of this material which are necessary for proper design and modeling of the system. Ytterbium doped fluorapatites, which were previously investigated at LLNL, were found to be ideal candidate materials for a high power amplifier systems providing high absorption and emission cross sections, long radiative lifetimes, and high efficiency. A family of barium substituted S-FAP crystals were grown in an effort to modify the pump and emission bandwidths for application to broadband diode pumping and short pulse generation. Crystals of Yb{sup 3+}:Sr{sub 5-x}Ba{sub x}(PO{sub 4}){sub 3}F where x < 1 showed homogeneous lines offering 8.4 nm (1.8 times enhancement) of absorption bandwidth and 6.9 nm (1.4 times enhancement) of emission bandwidth. The gain saturation fluence of Yb:S-FAP was measured to be 3.2 J/cm{sup 2} using a pump-probe experiment where the probe laser was a high intensity Q-switched master oscillator power amplifier system. The extraction data was successfully fit to a homogeneous extraction model. The crystal quality of Czochralski grown Yb:S-FAP crystals, which have been plagued by many defects such as cracking, cloudiness, bubble core, slip dislocations, and anomalous absorption, was investigated interferometrically and quantified by means of Power Spectral Density (PSD) plots. The very best crystals grown to date were found to have adequate crystal quality for use in the Mercury laser system. In addition to phase distortions which are

  17. Advanced variable speed air source integrated heat pump (AS-IHP) development - CRADA final report

    SciTech Connect

    Baxter, Van D.; Rice, C. Keith; Munk, Jeffrey D.; Ally, Moonis Raza; Shen, Bo

    2015-09-30

    Between August 2011 and September 2015, Oak Ridge National Laboratory (ORNL) and Nordyne, LLC (now Nortek Global HVAC LLC, NGHVAC) engaged in a Cooperative Research and Development Agreement (CRADA) to develop an air-source integrated heat pump (AS-IHP) system for the US residential market. Two generations of laboratory prototype systems were designed, fabricated, and lab-tested during 2011-2013. Performance maps for the system were developed using the latest research version of the DOE/ORNL Heat Pump Design Model, or HPDM, (Rice 1991; Rice and Jackson 2005; Shen et al 2012) as calibrated against the lab test data. These maps were the input to the TRNSYS (SOLAR Energy Laboratory, et al, 2010) system to predict annual performance relative to a baseline suite of equipment meeting minimum efficiency standards in effect in 2006 (combination of 13 SEER air-source heat pump (ASHP) and resistance water heater with Energy Factor (EF) of 0.9). Predicted total annual energy savings, while providing space conditioning and water heating for a tight, well insulated 2600 ft2 (242 m2) house at 5 U.S. locations, ranged from 46 to 61%, averaging 52%, relative to the baseline system (lowest savings at the cold-climate Chicago location). Predicted energy use for water heating was reduced 62 to 76% relative to resistance WH. Based on these lab prototype test and analyses results a field test prototype was designed and fabricated by NGHVAC. The unit was installed in a 2400 ft2 (223 m2) research house in Knoxville, TN and field tested from May 2014 to April 2015. Based on the demonstrated field performance of the AS-IHP prototype and estimated performance of a baseline system operating under the same loads and weather conditions, it was estimated that the prototype would achieve ~40% energy savings relative to the minimum efficiency suite. The estimated WH savings were >60% and SC mode savings were >50%. But estimated SH savings were only about 20%. It is believed that had the test

  18. Development of a Gravity-Insensitive Heat Pump for Lunar Applications

    NASA Technical Reports Server (NTRS)

    Cole, Gregory S.; Scaringe, Robert P.; Grzyll, Lawrence R.; Ewert, Michael K.

    2006-01-01

    Mainstream Engineering Corporation is developing a gravity-insensitive system that will allow a vapor-compression-cycle heat pump to be used in both microgravity (10(exp -6)g) and lunar (10(exp -6)g) environments. System capacity is 5 kW to 15 kW at design refrigerant operating conditions of 4.44 C and 60 C evaporating and condensing temperatures, respectively. The current program, performed for NASA Johnson Space Center (JSC) and presented in this paper, includes compressor performance analysis, detailed system design, and thermal analysis. Future efforts, including prototype fabrication, integration of a solar power source and controls, ground-testing, and flight-testing support, are also discussed.

  19. DOE/GRI development and testing of a downhole pump for jet-assist drilling

    SciTech Connect

    1995-07-01

    The objective of this project is to accelerate development and commercialization of a high pressure downhole pump (DHP{trademark}) to be used for ultra-high pressure, jet-assisted drilling. The purpose of jet-assisted drilling is to increase the rate of penetration (ROP) in the drilling of deeper gas and oil wells where the rocks become harder and more difficult to drill. As a means to accomplishing this objective, a second generation commercial prototype of a DHP is to be designed, fabricated, tested in the laboratory, and eventually tested in the field. The design of the DOE commercial prototype DHP is current in progress. The layout of the complete DHP is expected to be completed by mid-April. Fabrication and laboratory experimentation is expected to be completed in September. Pending successful completion of the laboratory testing phase, the DOE commercial DHP should be ready for testing in the field by the end of the calendar year.

  20. DEVELOPMENT OF COLD CLIMATE HEAT PUMP USING TWO-STAGE COMPRESSION

    SciTech Connect

    Shen, Bo; Rice, C Keith; Abdelaziz, Omar; Shrestha, Som S

    2015-01-01

    This paper uses a well-regarded, hardware based heat pump system model to investigate a two-stage economizing cycle for cold climate heat pump applications. The two-stage compression cycle has two variable-speed compressors. The high stage compressor was modelled using a compressor map, and the low stage compressor was experimentally studied using calorimeter testing. A single-stage heat pump system was modelled as the baseline. The system performance predictions are compared between the two-stage and single-stage systems. Special considerations for designing a cold climate heat pump are addressed at both the system and component levels.

  1. Deposition of novel nanocomposite films by a newly developed differential pumping co-sputtering system

    SciTech Connect

    Nose, Masateru; Kurimoto, Takeshi; Saiki, Atsushi; Matsuda, Kenji; Terayama, Kiyoshi

    2012-01-15

    A differential pumping co-sputtering system was developed to facilitate a controlled, but flexible fabrication of multifunctional nanocomposite films with compositions not limited by thermodynamic restrictions. This system features a multichamber design with a differential pumping system. Dividing atmospheres with this set up greatly reduced the cross-contamination between chambers, and each material could be co-deposited by rapid rotation of the substrate. The clearance between the substrate holder and the chamber was set at 1-2 mm, and the conductance of the clearance was examined roughly using conductance equations for typical types of orifices. It was found that the potential difference (PD) value of the clearance between the two chambers was less than 0.01; the gas flow between the two chambers through the clearance thus appears to be a practical molecular flow. The PD value, where P is a pressure (Pa) and D is a diameter of an orifice or a pipe (m), is a gas flow indicator or parameter obtained from an equation of Knudsen number. The changes in the oxygen partial pressure and glow discharge plasma in the left chamber were investigated using a process gas monitor (PGM) and optical emission spectroscope (OES) by introducing different gases to each chamber. The PGM results revealed that the cross-contamination of oxygen from the other chamber was suppressed to 10 {+-} 3% of the original. In addition, the OES measurement for glow discharge plasma did not detect substantial oxygen contamination from the other chamber. Using the newly developed system, an AlN/SiO{sub x} nanocomposite film consisting of B4-type AlN and amorphous SiO{sub x} was obtained successfully.

  2. Current concepts of blood-brain barrier development.

    PubMed

    Liebner, Stefan; Czupalla, Cathrin J; Wolburg, Hartwig

    2011-01-01

    Homeostasis of the central nervous system (CNS) microenvironment is essential for its normal function and is maintained by the blood-brain barrier (BBB). The BBB proper is made up of endothelial cells (ECs) interconnected by tight junctions (TJs) that reveal a unique morphology and biochemical composition of the body's vasculature. In this article, we focus on developmental aspects of the BBB and describe morphological as well as molecular special features of the neuro-vascular unit (NVU) involved in barrier induction. Recently, we and others identified the Wnt/b-catenin pathway as crucial for brain angiogenesis, TJ and BBB formation. Based on these findings we discuss other pathways and molecular interactions for BBB establishment and maintenance. At the morphological level, our concept favors a major role for polarized astrocytes (ACs) therein. Orthogonal arrays of particles (OAPs) that are the morphological correlate of the water channel protein aquaporin-4 (AQP4) are specifically formed in the membrane of the AC endfoot. The polarized AC endfoot and hence OAPs are dependent on agrin and dystroglycan, of which agrin is a developmentally regulated extracellular matrix (ECM) component. Understanding the mechanisms leading to BBB development will be key to the understanding of barrier maintenance that is crucial for, but frequently disturbed, in the diseased adult brain. PMID:21769778

  3. Membrane mediated development of the vertebrate blood-gas-barrier.

    PubMed

    Makanya, Andrew N

    2016-03-01

    During embryonic lung development, establishment of the gas-exchanging units is guided by epithelial tubes lined by columnar cells. Ultimately, a thin blood-gas barrier (BGB) is established and forms the interface for efficient gas exchange. This thin BGB is achieved through processes, which entail lowering of tight junctions, stretching, and thinning in mammals. In birds the processes are termed peremerecytosis, if they involve cell squeezing and constriction, or secarecytosis, if they entail cutting cells to size. In peremerecytosis, cells constrict at a point below the protruding apical part, resulting in fusion of the opposing membranes and discharge of the aposome, or the cell may be squeezed by the more endowed cognate neighbors. Secarecytosis may entail formation of double membranes below the aposome, subsequent unzipping and discharge of the aposome, or vesicles form below the aposome, fuse in a bilateral manner, and release the aposome. These processes occur within limited developmental windows, and are mediated through cell membranes that appear to be of intracellular in origin. In addition, basement membranes (BM) play pivotal roles in differentiation of the epithelial and endothelial layers of the BGB. Laminins found in the BM are particularly important in the signaling pathways that result in formation of squamous pneumocytes and pulmonary capillaries, the two major components of the BGB. Some information exists on the contribution by BM to BGB formation, but little is known regarding the molecules that drive peremerecytosis, or even the origins and composition of the double and vesicular membranes involved in secarecytosis. PMID:26991887

  4. Comparison of a New Miniaturized Extracorporeal Membrane Oxygenation System With Integrated Rotary Blood Pump to a Standard System in a Porcine Model of Acute Lung Injury.

    PubMed

    Pilarczyk, Kevin; Heckmann, Jens; Lyskawa, Kathrin; Strauß, Andreas; Haake, Nils; Wiese, Ingo; Jakob, Heinz; Kamler, Markus; Pizanis, Nikolaus

    2016-07-01

    Extracorporeal membrane oxygenation (ECMO) is used for severe acute respiratory distress syndrome. However, available ECMO systems are large and not well designed for fast delivery, emergency implantation, and interhospital transfer. Therefore, a new miniaturized oxygenator with integrated rotary blood pump (ILIAS) was developed and compared with a standard ECMO system in a large animal model. Acute lung injury was induced with repeated pulmonary saline lavage in 14 pigs until PaO2 /FiO2 -ratio was <100 mm Hg with a positive-end-expiratory-pressure of 5 mbar. Pigs were assigned to the following three groups: group 1 (n = 4): control group with conventional ventilation; group 2 (n = 5): standard vv-ECMO; group 3 (n = 5): vv-ILIAS. Gas exchange, hemodynamics, hemolysis, and coagulation activation were examined over a period of 8 h. No device failed during the observation period. PaCO2 decreased from 59.40 ± 4.14 mm Hg to 48.62 ± 4.50 mm Hg after 1 h in the ILIAS group compared with an improvement of PaCO2 from 48.86 ± 7.45 to 40.10 ± 6.02 in the conventional ECMO group (P = not significant [n.s.]). ARDS-induced respiratory acidosis was controlled promptly with a pH of 7.2 ± 0.1 at baseline increasing to 7.4 ± 0.1 in both study groups after 60 min of ECMO support. Mean carbon dioxide transfer was comparable between the conventional ECMO and ILIAS (211.36 ± 78.39 mL/min vs. 219.99 ± 76.72 mL/min, P = n.s.). PaO2 /FiO2 increased from 118.4 ± 15.5 mm Hg to 179.1 ± 72.4 mm Hg in the ILIAS group compared with an improvement of oxygenation from 107.1 ± 24.9 mm Hg to 179.0 ± 45.7 mm Hg in the standard ECMO group (P = n.s.). Mean oxygen transfer was calculated with 136.09 ± 30.25 mL/min for the ILIAS and 129.05 ± 36.28 mL/min for the standard ECMO. Hemodynamic instability or significant activation of the plasmatic coagulation was not

  5. Design and development of microcontroller-based clinical chemistry analyser for measurement of various blood biochemistry parameters.

    PubMed

    Taneja, S R; Gupta, R C; Kumar, Jagdish; Thariyan, K K; Verma, Sanjeev

    2005-01-01

    Clinical chemistry analyser is a high-performance microcontroller-based photometric biochemical analyser to measure various blood biochemical parameters such as blood glucose, urea, protein, bilirubin, and so forth, and also to measure and observe enzyme growth occurred while performing the other biochemical tests such as ALT (alkaline amino transferase), amylase, AST (aspartate amino transferase), and so forth. These tests are of great significance in biochemistry and used for diagnostic purposes and classifying various disorders and diseases such as diabetes, liver malfunctioning, renal diseases, and so forth. An inexpensive clinical chemistry analyser developed by the authors is described in this paper. This is an open system in which any reagent kit available in the market can be used. The system is based on the principle of absorbance transmittance photometry. System design is based around 80C31 microcontroller with RAM, EPROM, and peripheral interface devices. The developed system incorporates light source, an optical module, interference filters of various wave lengths, peltier device for maintaining required temperature of the mixture in flow cell, peristaltic pump for sample aspiration, graphic LCD display for displaying blood parameters, patients test results and kinetic test graph, 40 columns mini thermal printer, and also 32-key keyboard for executing various functions. The lab tests conducted on the instrument include versatility of the analyzer, flexibility of the software, and treatment of sample. The prototype was tested and evaluated over 1000 blood samples successfully for seventeen blood parameters. Evaluation was carried out at Government Medical College and Hospital, the Department of Biochemistry. The test results were found to be comparable with other standard instruments. PMID:18924737

  6. Initial Acute Animal Experiment Using a New Miniature Axial Flow Pump in Series With the Natural Heart.

    PubMed

    Okamoto, Eiji; Yano, Tetsuya; Shiraishi, Yasuyuki; Miura, Hidekazu; Yambe, Tomoyuki; Mitamura, Yoshinori

    2015-08-01

    We have advocated an axial flow blood pump called "valvo pump" that is implanted at the aortic valve position, and we have developed axial flow blood pumps to realize the concept of the valvo pump. The latest model of the axial flow blood pump mainly consists of a stator, a directly driven impeller, and a hydrodynamic bearing. The axial flow blood pump has a diameter of 33 mm and length of 74 mm, and the length of anatomical occupation is 33 mm. The axial flow blood pump is anastomosed to the aorta with polytetrafluoroethylene (PTFE) cuffs worn on the inflow and outflow ports. Dp-Q curves of the axial flow blood pump are flatter than those of ordinary axial flow pumps, and pump outflow of 5 L/min was obtained against a pressure difference of 50 mm Hg at a rotational speed of 9000 rpm in vitro. The axial flow blood pump was installed in a goat by anastomosing with the thoracic descending aorta using PTFE cuffs, and it was rotated at a rotational speed of 8000 rpm. Unlike in case of the ventricular assistance in parallel with the natural heart, pulsatilities of aortic pressure and aortic flow were preserved even when the pump was on, and mean aortic flow was increased by 1.5 L/min with increase in mean aortic pressure of 30 mm Hg. In conclusion, circulatory assistance in series with the natural heart using the axial flow blood pump was able to improve hemodynamic pulsatility, and it would contribute to improvement of end-organ circulation. . PMID:26234449

  7. Allogeneic Blood Product Usage in Coronary Artery Bypass Grafting (CABG) with minimalized Extracorporeal Circulation System (MECC) Versus Standard On-Pump Coronary Artery Bypass Grafting

    PubMed Central

    Lisy, M.; Schmid, E.; Kozok, J.; Rosenberger, P.; Stock, U.A.; Kalender, G.

    2016-01-01

    Aim: Intraoperative allogeneic blood product transfusion (ABPT) in cardiac surgery is associated with worse overall outcome, including mortality. The objective of this study was to evaluate the ABPTs in minimalized extracorporeal cardiopulmonary (MECCTM) compared with standard open system on-pump coronary revascularization. Methods: Data of 156 patients undergoing myocardial revascularization between September 2008 and September 2010 were reviewed. 83 patients were operated by the MECC technique and 73 were treated by standard extracorporeal circulation (sECC). ABPT and overall early postoperative complications were analyzed. Results: Operative mortality and morbidity were similar in both groups. ABPT in the MECC group was significantly lower than in the sECC group both intraoperatively (7.2 vs. 60.3% of patients p<0.001) and during the first five postoperative days (19.3 vs. 57.5%; p<0.001). “Skin to skin”- (214 ± 45 vs. 232 ± 45 min; p=0.012), cardiopulmonary bypass (CPB) - (82 ± 25 vs. 95 ± 26 min; p=0.014), and X-clamp- times (50 ± 16 vs. 56 ± 17 min; p=0.024) were significantly lower in the MECC group than in the sECC group. Length of ICU (intensive care unit) - and hospital stay were also significantly lower in the MECC group vs. the sECC group (26.7 ± 20.2 vs. 54.5 ± 68.9 h; p<0.001, and 12.0 ± 4.1 vs. 14.5 ± 4.6 days; p<0.001). Conclusion: Application of MECC as on-pump coronary artery bypass graft (CABG) results in significantly lower ABPT as well as shorter ICU and in-hospital stay. In order to achieve these benefits of MECC autologous retrograde priming, Bispectral index (BIS) monitoring, intraoperative cell salvage, meticulous hemostasis and strict peri- and postoperative volume management are crucial. PMID:27499818

  8. A computational model predicting disruption of blood vessel development.

    PubMed

    Kleinstreuer, Nicole; Dix, David; Rountree, Michael; Baker, Nancy; Sipes, Nisha; Reif, David; Spencer, Richard; Knudsen, Thomas

    2013-04-01

    Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis) and remodeling (angiogenesis) come from a variety of biological pathways linked to endothelial cell (EC) behavior, extracellular matrix (ECM) remodeling and the local generation of chemokines and growth factors. Simulating these interactions at a systems level requires sufficient biological detail about the relevant molecular pathways and associated cellular behaviors, and tractable computational models that offset mathematical and biological complexity. Here, we describe a novel multicellular agent-based model of vasculogenesis using the CompuCell3D (http://www.compucell3d.org/) modeling environment supplemented with semi-automatic knowledgebase creation. The model incorporates vascular endothelial growth factor signals, pro- and anti-angiogenic inflammatory chemokine signals, and the plasminogen activating system of enzymes and proteases linked to ECM interactions, to simulate nascent EC organization, growth and remodeling. The model was shown to recapitulate stereotypical capillary plexus formation and structural emergence of non-coded cellular behaviors, such as a heterologous bridging phenomenon linking endothelial tip cells together during formation of polygonal endothelial cords. Molecular targets in the computational model were mapped to signatures of vascular disruption derived from in vitro chemical profiling using the EPA's ToxCast high-throughput screening (HTS) dataset. Simulating the HTS data with the cell-agent based model of vascular development predicted adverse effects of a reference anti-angiogenic thalidomide analog, 5HPP-33, on in vitro angiogenesis with respect to both concentration-response and morphological consequences. These findings support the utility of cell agent-based models for simulating a morphogenetic

  9. Development of blood compatible materials by glow discharge-treatment

    NASA Astrophysics Data System (ADS)

    Ishikawa, Y.; Sasakawa, S.

    Glow discharge-treatment was applied to preparation of blood compatible materials. Plasticized polyvinylchloride (PVC) which is used for blood bags was treated in the presence of various gases or monomers. Wettability of PVC was modified by the treatment over a wide range. And leakage of plasticizer, di-(2-ethylhexyl)phthalate (DEHP), was prevented. When platelet concentrates were stored in the treated PVC bags, impairment of platelet functions was suppressed by the prevention of DEHP leakage. But platelet adhesion to the surfaces increased by the treatments. Aldehyde groups were grafted on polyethylene film (PE) by glow discharge-treatment in the presence of formaldehyde gas. Although the aldehyde-grafted PE (HCHO-PE) had higher reactivity with platelet than PE after albumin coating, it exhibited excellent antithrombogenicity after blood plasma coating. HCHO-PE adsorbed proteins with almost the same composition as blood plasma, although non-treated PE adsorbed proteins with higher fibinogen/albumin ratio. Segmented-polyurethane which is well known to exhibit good antithrombogenicity, also formed the adsorption layer having composition like that of blood plasma. These results suggest that protein layer adsorbed with blood plasma composition is hardly recognized by platelets. Glow discharge-treatment is a simple and effective method for surface modification of medical polymers.

  10. Assessment and development of an advanced heat pump for recovery of volatile organic compounds. Final report

    SciTech Connect

    Not Available

    1992-06-01

    This report documents Phase 1 of a project conducted by Mechanical Technology Incorporated (MTI) for the assessment and development of an advanced heat pump for recovery of VOC solvents from process gas streams. In Phase 1, MTI has evaluated solvent recovery applications within New York State (NYS), identified host sites willing to implement their application, and conducted a preliminary design of the equipment required. The design and applications were evaluated for technical and economic feasibility. The solvent recovery heat pump system concept resulting from the Phase 1 work is one of a mobile unit that would service multiple stationary adsorbers. A large percentage of solvent recovery applications within the state can be serviced by on-site carbon bed adsorbers that are desorbed at frequencies ranging from once per to once per month. In this way, many users can effectively ``share`` the substantial capital investment associated with the system`s reverse Brayton hardware, providing it can be packaged as a mobile unit. In a typical operating scenario, a carbon adsorption module will be located permanently at the industrial site. The SLA will be ducted through the adsorber and the solvents removed, thus eliminating an air emission problem. Prior to VOC breakthrough, by schedule or by request, the mobile unit would arrive at the site to recover the concentrated solvent. An engine driven, natural gas fueled system, the mobile unit utilizes conditioned engine exhaust gases as the inert gas for desorption. Hot inert gas is directed through the carbon bed, heating it and volatilizing the adsorbed solvent. Using a revere Brayton-cycle refrigeration system to create low temperatures, the solvent vapors are condensed and collected from the inert gas stream. The solvent can then be recycled to the production process or sold for other uses and the adsorber returned to service.

  11. Assessment and development of an advanced heat pump for recovery of volatile organic compounds

    SciTech Connect

    Not Available

    1992-06-01

    This report documents Phase 1 of a project conducted by Mechanical Technology Incorporated (MTI) for the assessment and development of an advanced heat pump for recovery of VOC solvents from process gas streams. In Phase 1, MTI has evaluated solvent recovery applications within New York State (NYS), identified host sites willing to implement their application, and conducted a preliminary design of the equipment required. The design and applications were evaluated for technical and economic feasibility. The solvent recovery heat pump system concept resulting from the Phase 1 work is one of a mobile unit that would service multiple stationary adsorbers. A large percentage of solvent recovery applications within the state can be serviced by on-site carbon bed adsorbers that are desorbed at frequencies ranging from once per to once per month. In this way, many users can effectively share'' the substantial capital investment associated with the system's reverse Brayton hardware, providing it can be packaged as a mobile unit. In a typical operating scenario, a carbon adsorption module will be located permanently at the industrial site. The SLA will be ducted through the adsorber and the solvents removed, thus eliminating an air emission problem. Prior to VOC breakthrough, by schedule or by request, the mobile unit would arrive at the site to recover the concentrated solvent. An engine driven, natural gas fueled system, the mobile unit utilizes conditioned engine exhaust gases as the inert gas for desorption. Hot inert gas is directed through the carbon bed, heating it and volatilizing the adsorbed solvent. Using a revere Brayton-cycle refrigeration system to create low temperatures, the solvent vapors are condensed and collected from the inert gas stream. The solvent can then be recycled to the production process or sold for other uses and the adsorber returned to service.

  12. Development of a handheld blood flow measurement system using laser speckle flowgraphy

    NASA Astrophysics Data System (ADS)

    Lee, Min-Chul; Konishi, Naoki; Fujii, Hitoshi

    2015-04-01

    A new handheld blood flow measurement system using laser speckle flowgraphy was developed for easy measurement of blood flow. The developed system features a small display unit that allows measurement results to be viewed without a PC. The system is miniaturized, integrated with a microcontroller, a line sensor, and a laser unit. Our experiment was carried out to confirm the usefulness of the developed system to measure the blood flow variation.

  13. Axial pumps for propulsion systems

    NASA Technical Reports Server (NTRS)

    Huppert, M. C.; Rothe, K.

    1974-01-01

    The development of axial flow hydrogen pumps is examined. The design features and the performance data obtained during the course of the development programs are discussed. The problems created by the pump characteristics are analyzed. Graphs of four stage pump performance for various turbine blade configurations are developed. The characteristics and performance of a variety of pumps are included.

  14. Development of a Low Cost Heat Pump Water Heater - Second Prototype

    SciTech Connect

    Mei, V. C.; Craddick, William G

    2007-09-01

    Since the 1980s various attempts have been made to apply the efficiency of heat pumps to water heating. The products generated in the 80s and 90s were not successful, due in part to a lack of reliability and difficulties with installation and servicing. At the turn of the century, EnvironMaster International (EMI) produced a heat pump water heater (HPWH) based on a design developed by Arthur D. Little (ADL), with subsequent developmental assistance from Oak Ridge National Laboratory (ORNL) and ADL. This design was a drop-in replacement for conventional electric water heaters. In field and durability testing conducted by ORNL, it proved to be reliable and saved on average more than 50% of the energy used by the best conventional electric water heater. However, the retail price set by EMI was very high, and it failed in the market. ORNL was tasked to examine commercially available HPWH product technology and manufacturing processes for cost saving opportunities. Several cost saving opportunities were found. To verify the feasibility of these cost saving measures, ORNL completed a conceptual design for an HPWH based on an immersed condenser coil that could be directly inserted into a standard water tank through a sleeve affixed to one of the standard penetrations at the top of the tank. After some experimentation, a prototype unit was built with a double-wall coil inserted into the tank. When tested it achieved an energy factor (EF) of 2.12 to 2.2 using DOE-specified test procedures. A.O. Smith contacted ORNL in May 2006 expressing their interest in the ORNL design. The prototype unit was shipped to A.O. Smith to be tested in their laboratory. After they completed their test, ORNL analyzed the raw test data provided by A.O. Smith and calculated the EF to be approximately 1.92. The electric resistance heating elements of a conventional electric water heater are typically retained in a heat pump water heater to provide auxiliary heating capacity in periods of high

  15. Insulin pumps.

    PubMed

    Pickup, J

    2011-02-01

    The last year has seen a continued uptake of insulin pump therapy in most countries. The USA is still a leader in pump use, with probably some 40% of type 1 diabetic patients on continuous subcutaneous insulin infusion (CSII), but the large variation in usage within Europe remains, with relatively high use (> 15%) in, for example, Norway, Austria, Germany and Sweden and low use (< 5%) in Spain, the UK, Finland and Portugal. There is much speculation on the factors responsible for this variation, and the possibilities include physician attitudes to CSII and knowledge about its benefits and indications for its use (and inappropriate beliefs about dangers), the availability of reimbursement from insurance companies or funding from national health services, the availability of sufficient diabetes nurse educators and dietitians trained in pump procedures, and clear referral pathways for the pump candidate from general practitioner or general hospital to specialist pump centre. There are now several comprehensive national guidelines on CSII use (see ATTD Yearbook 2009) but more work needs to be done in unifying uptake and ensuring all those who can benefit do so. Technology developments recently include increasing use of pumps with continuous glucose monitoring (CGM) connectivity (see elsewhere in this volume) and the emergence of numerous manufacturers developing so-called 'patch pumps', often for the type 2 diabetes market. Interestingly, the evidence base for CSII in this group is not well established, and for this reason the selected papers on CSII in this section include several in this area. The use of CSII in diabetic pregnancy is a long-established practice, in spite of the lack of evidence that it is superior to multiple daily injections (MDI), and few randomised controlled trials have been done in recent years. Several papers in this field this year continue the debate about the usefulness of CSII in diabetic pregnancy and are reviewed here. It is pleasing

  16. Development of a blood extraction device for a miniature SMBG system

    NASA Astrophysics Data System (ADS)

    Matsuura, Yoshimitsu; Uenoya, Toshiyuki; Tsuchiya, Kazuyoshi; Uetsuji, Yasutomo; Nakamachi, Eiji

    2007-12-01

    In this study, a vacuum driven blood extraction device for the self-monitoring of blood glucose (SMBG) was newly developed. The health monitoring system (HMS) for SMBG consists of a blood extracting system and a drug delivery system (DDS). Our HMS extracts the blood through a micro-needle and measures the blood sugar level accurately. The main purpose of this work in HMS development are, 1) minimally invasive blood extraction, 2) a handy type automatic blood extraction, and 3) a continuous measurement of the blood sugar level. We adopted a vacuum driven type blood extraction mechanism. The vacuum driven blood extraction unit consists of a) a puncture part to open the vacuum part, b) an extraction part, and c) a measurement part. The puncture and extraction parts consist of a minimally invasive micro-needle, whose inner diameter is less than 100μm and made of titanium alloy, and a vacuum chamber, which is covered by a very thin membrane. A SMA spring and two bias springs are employed to penetrate the blood vessel through the skin with the micro-needle, and to execute the punctuation to slash the membrane in order to open the vacuum chamber. The blood is extracted into the vacuum chamber, seeps into the unwoven cloth according to the capillary principle, and is finally deposited on the blood sugar level sensor. Results show, our vacuum driven blood extraction device succeeded in extracting 12.7μl of human blood within 2 seconds. The blood sugar level was measured successfully by using a glucose enzyme sensor. Finally, the availability of our HMS device was confirmed.

  17. Apparatus for Pumping a Fluid

    NASA Technical Reports Server (NTRS)

    Boeyen, Robert Van; Reeh, Jonathan

    2013-01-01

    A fluid pump has been developed for mechanically pumped fluid loops for spacecraft thermal control. Lynntech's technology utilizes a proprietary electrochemically driven pumping mechanism. Conventional rotodynamic and displacement pumps typically do not meet the stringent power and operational reliability requirements of space applications. Lynntech's developmental pump is a highly efficient solid-state pump with essentially no rotating or moving components (apart from metal bellows).

  18. [Development of ultrasound-based monitor of relative blood volume].

    PubMed

    Jiang, Shunzhong; Hu, Xiao; Liang, Zhongwei; Fan, Jianghong; Xia, Wubing; Zhou, Hongbo; Yi, Wei

    2013-12-01

    Assessing dry weight accurately is crucial in providing effective and safe haemodialysis. Biases towards dry weight assessment may bring a series of dialysis complications. This study introduces an online detection technique of relative blood volume (RBV) based on ultrasound, which analyzes the correlation between changes in blood density and sound speed. By measuring the attenuation in sound velocity, this method was employed to calculate RBV, and then to evaluate the dry weight of patients on dialysis. TDC-GP2 time measurement chip and MSP430 Single-chip Microcontroller (SCM) were used in the system to measure the ultrasonic travel time. In the clinical trials, RBV values range between 71.3% and 108.1%, showing consistent result with Fresenius 4008S blood volume monitor (BVM). This detection method possesses several advantages, such as real time, convenient, reproducible, non-invasive, and etc. PMID:24645597

  19. Photovoltaic pump systems

    NASA Astrophysics Data System (ADS)

    Klockgether, J.; Kiessling, K. P.

    1983-09-01

    Solar pump systems for the irrigation of fields and for water supply in regions with much sunshine are discussed. For surface water and sources with a hoisting depth of 12 m, a system with immersion pumps is used. For deep sources with larger hoisting depths, an underwater motor pump was developed. Both types of pump system meet the requirements of simple installation and manipulation, safe operation, maintenance free, and high efficiency reducing the number of solar cells needed.

  20. Phase 1 supplemental development of a kinematic Stirling/Rankine commercial gas-fired heat pump system

    NASA Astrophysics Data System (ADS)

    Monahan, Russell E.

    1989-06-01

    The Kinematic Stirling/Rankine gas heat pump concept is based on the application of a Stirling engine that was under development for over a decade. The engine was converted to natural gas and is characterized with many thousand hours of operating experience. The goal is to develop a commercial size Stirling engine-driven gas heat pump with a cooling capacity of 10-tons, a COP (heating) of 1.8 and a COP (cooling) of 1.1. The project is a multi-phase development with commercialization planned for the mid-1990's. In previous phases, an HVAC systems manufacturer was working with SPS to develop a prototype gas heat pump system. To date, two generations of prototype GHP systems were built and tested and have demonstrated significant operating cost savings over the conventional electric heat pump. Under the program a number of design and manufacturing process changes were made to the engine to reduce costs and improve endurance and shaft efficiency and are described. The adaptation and operation of a computer optimization code was accomplished under the program and is reported.

  1. Prenatal exposure to H2 blockers and to proton pump inhibitors and asthma development in offspring.

    PubMed

    Yitshak-Sade, Maayan; Gorodischer, Rafael; Aviram, Micha; Novack, Lena

    2016-01-01

    Fetal exposure to H2 blockers (H2 Bs) or proton pump inhibitors (PPIs) has been reported to be associated with asthma in children. We evaluated the risk of asthma in offspring following prenatal H2 Bs. We enrolled 91 428 children and their mothers who resided in southern Israel during 1998-2011. The computerized medications database was linked with records from the district hospital. Of the eligible children, 11 227 developed asthma, and overall 5.5% had been exposed to H2 Bs or PPIs prenatally. The risk of developing asthma was slightly higher in the group exposed to H2 Bs or PPIs (RR, 1.09; P = .023). At greater risk were children whose mothers purchased these medications more than 3 times (RR, 1.22; P = .038) or exposed to >20 defined daily doses or prenatally exposed to lansoprazole. The statistical association was significant and depended on magnitude of exposure and specific medication, but the absolute risk was low. The association between maternal consumption of H2 Bs or PPIs and asthma and childhood remained statistically significant 2 years after delivery, raising the possibility of confounding by the indication phenomenon. In view of the findings, a causal relationship could not be ascertained, and an unidentified etiological factor could be operative. PMID:26096778

  2. The alpha 1 Na(+)-K+ pump of the Dahl salt-sensitive rat exhibits altered Na+ modulation of K+ transport in red blood cells.

    PubMed

    Canessa, M; Romero, J R; Ruiz-Opazo, N; Herrera, V L

    1993-06-01

    The properties of the alpha 1 Na(+)-K+ pump were compared in Dahl salt-sensitive (DS) and salt-resistant (DR) strains by measuring ouabain-sensitive fluxes (mmol/liter cell x hr = FU, Mean +/- SE) in red blood cells (RBCs) and varying internal (i) and external (o) Na+ and K+ concentrations. Kinetic parameters of several modes of operation, i.e., Na+/K+, K+/K+, Na+/Na+ exchanges, were characterized and analyzed for curve-fitting using the Enzfitter computer program. In unidirectional flux studies (n = 12 rats of each strain) into fresh cells incubated in 140 mM Na(+) + 5 mM K+, ouabain-sensitive K+ influx was substantially lower in the DS than in DR RBCs, while ouabain-sensitive Na+ efflux and Nai were similar in both strains. Thus, the coupling ratio between unidirectional Na+:K+ fluxes was significantly higher in DS than in DR cells at similar RBC Na+ content. In the presence of 140 mM Nao, activation of ouabain-sensitive K+ influx by Ko had a lower Km and Vmax in DS as estimated by the Garay equation (N = 2.70 +/- 0.33, Km 0.74 +/- 0.09 mM; Vmax 2.87 +/- 0.09 FU) than in DR rats (N = 1.23 +/- 0.36, Km 2.31 +/- 0.16 mM; Vmax 5.70 +/- 0.52 FU). However, the two kinetic parameters were similar following Nao removal. The activation of ouabain-sensitive K+ influx by Nai had significantly lower Vmax in DS (9.3 +/- 0.4 FU) than in DR (14.5 +/- 0.6 FU) RBCs but similar Km. These data suggest that the low K+ influx in DS cells is caused by a defect in modulation by Nao and Nai. Na+ efflux showed no differences in Nai activation or trans effects by Nao and Ko, thus accounting for the different Na+:K+ coupling ratio in the Dahl strains. Further evidence for the differences in the coupling of ouabain-sensitive fluxes was found in studies of net Na+ and K+ fluxes, where the net ouabain-sensitive Na+ losses showed similar magnitudes in the two Dahl strains while the net ouabain-sensitive K+ gains were significantly greater in the DR than the DS RBCs. Ouabain-sensitive Na

  3. Development of a component design tool for metal hydride heat pumps

    NASA Astrophysics Data System (ADS)

    Waters, Essene L.

    Given current demands for more efficient and environmentally friendly energy sources, hydrogen based energy systems are an increasingly popular field of interest. Within the field, metal hydrides have become a prominent focus of research due to their large hydrogen storage capacity and relative system simplicity and safety. Metal hydride heat pumps constitute one such application, in which heat and hydrogen are transferred to and from metal hydrides. While a significant amount of work has been done to study such systems, the scope of materials selection has been quite limited. Typical studies compare only a few metal hydride materials and provide limited justification for the choice of those few. In this work, a metal hydride component design tool has been developed to enable the targeted down-selection of an extensive database of metal hydrides to identify the most promising materials for use in metal hydride thermal systems. The material database contains over 300 metal hydrides with various physical and thermodynamic properties included for each material. Sub-models for equilibrium pressure, thermophysical data, and default properties are used to predict the behavior of each material within the given system. For a given thermal system, this tool can be used to identify optimal materials out of over 100,000 possible hydride combinations. The selection tool described herein has been applied to a stationary combined heat and power system containing a high-temperature proton exchange membrane (PEM) fuel cell, a hot water tank, and two metal hydride beds used as a heat pump. A variety of factors can be used to select materials including efficiency, maximum and minimum system pressures, pressure difference, coefficient of performance (COP), and COP sensitivity. The targeted down-selection of metal hydrides for this system focuses on the system's COP for each potential pair. The values of COP and COP sensitivity have been used to identify pairs of highest interest for

  4. Performance of mosquito's pump

    NASA Astrophysics Data System (ADS)

    Kikuchi, Kenji

    2005-11-01

    The flow of human blood in Mosquito's proboscis on Hagen-Poiseuille flow is investigated by using micro PIV system to apply mosquito's sucking system for micro-TAS devises. We want to know how high the power of Mosquito's pump is and how small the resistance in a proboscis is, a structure of Mosquito's sucking pump, and its characteristics as mechanical pump. We made the mosquito suck blood of our arm to obtain the average value, made many slices of a mosquito with 2μm thickness after fixed by wax. We anatomized the mosquito's head and picked up the sucking pump under the microscope to know its volume. Mosquito's pump shows high performance compared with the artificial pumps. The surfaces of proboscis were taken by using SEM, AFM because it is important factor for interaction between flow and its wall. Visualization of the blood flows near the tip of and inside proboscis are taken by micro PIV system to know the flow rate. We estimate the power of pump and the friction drag of proboscis by using these data.

  5. Heart Pump Design for Cleveland Clinic Foundation

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Through a Lewis CommTech Program project with the Cleveland Clinic Foundation, the NASA Lewis Research Center is playing a key role in the design and development of a permanently implantable, artificial heart pump assist device. Known as the Innovative Ventricular Assist System (IVAS), this device will take on the pumping role of the damaged left ventricle of the heart. The key part of the IVAS is a nonpulsatile (continuous flow) artificial heart pump with centrifugal impeller blades, driven by an electric motor. Lewis is part of an industry and academia team, led by the Ohio Aerospace Institute (OAI), that is working with the Cleveland Clinic Foundation to make IVAS a reality. This device has the potential to save tens of thousands of lives each year, since 80 percent of heart attack victims suffer irreversible damage to the left ventricle, the part of the heart that does most of the pumping. Impeller blade design codes and flow-modeling analytical codes will be used in the project. These codes were developed at Lewis for the aerospace industry but will be applicable to the IVAS design project. The analytical codes, which currently simulate the flow through the compressor and pump systems, will be used to simulate the flow within the blood pump in the artificial heart assist device. The Interdisciplinary Technology Office heads up Lewis' efforts in the IVAS project. With the aid of numerical modeling, the blood pump will address many design issues, including some fluid-dynamic design considerations that are unique to the properties of blood. Some of the issues that will be addressed in the design process include hemolysis, deposition, recirculation, pump efficiency, rotor thrust balance, and bearing lubrication. Optimum pumping system performance will be achieved by modeling all the interactions between the pump components. The interactions can be multidisciplinary and, therefore, are influenced not only by the fluid dynamics of adjacent components but also by

  6. Developing a device for monitoring O2 saturation in blood

    NASA Astrophysics Data System (ADS)

    Sánchez-Pérez, Karla J.; Herrera-Vega, Javier; Sucar-Succar, Enrique; Orihuela-Espina, Felipe; Treviño-Palacios, Carlos G.

    2014-11-01

    We present a single-channel device for monitoring oxygen saturation in blood using near infrared light (NIR). This device measures the differential absorption of both oxi-hemoglobin (HbO2) and deoxi-hemoglobin (HHb) concentrations using wavelengths within the biophotonic window (700 nm - 1100 nm). Our device works with two wavelengths: the first source (λ1 = 632 nm) operates in continuous wave (CW) and the second (λ2 = 940 nm) operates in pulsed mode. The pulsed signal at λ2 operates in a 20% fill factor. The CW signal provides information related to the arterial pulse, whereas both CW and pulsed signal provide information about blood oxygenation. Light emitted from the sources travels through the tissue and are collected on the detector by transmission. Measurements of blood oxygenation measured in transmission on fingers tips are presented which are comparable to commercial devices. The values obtained are above 90.0% blood oxygenation in healthy tests subjects with 0.1% accuracy in the measurements.

  7. Sizing pumps for slurries

    SciTech Connect

    Akhtar, S.Z.

    1996-11-01

    Slurry characteristics have a significant impact on centrifugal pump performance. For instance, as particle size increases or the percent solids concentration increases, pump head and efficiency decrease. Therefore, before a slurry pump is selected, it is important to define the slurry characteristics as accurately as possible. The effect of the slurry characteristics on the head and efficiency of the centrifugal pump will be emphasized (the effect on flowrate is less significant). The effect of slurry characteristics is more predominant in smaller pumps (with smaller diameter impellers) than in larger pumps. The data and relationship between the various slurry parameters have been developed from correlations and nomographs published by pump vendors from their field data and test results. The information helps to avoid specifying an undersized pump/motor assembly for slurry service.

  8. Development of the Roller Pump for Use in the Cardiopulmonary Bypass Circuit

    PubMed Central

    Cooley, Denton A.

    1987-01-01

    In 1937, John Gibbon proposed his concept of extracorporeal circulation as an aid to cardiac surgery. Subsequently, a number of different types of pumps were tried in the extracorporeal circuit. Today, the pump used most often is a positive displacement twin roller pump, originally patented by Porter and Bradley in 1855. The rotary pump has undergone some minor modifications prior to its use in clinical cardiopulmonary bypass. Cardiovascular surgeons owe much to Porter and Bradley for an invention that has proved both efficient and effective for cardiopulmonary bypass and has allowed operations on an open heart in a relatively dry, bloodless field. (Texas Heart Institute Journal 1987; 14:113-118) Images PMID:15229729

  9. Progress report on pump limiter developments for the TEXTOR tokamak: ALT-I

    SciTech Connect

    Pontau, A.E.; Campbell, G.A.; Doyle, B.L.; Finken, F.H.; Gauster, W.B.; Guthrie, S.E.; Malinowski, M.E.; Ver Berkmoes, A.A.; Watson, R.D.; Whitley, J.B.

    1984-09-01

    A collaborative program is underway to field a comprehensive pump limiter experimental program on TEXTOR: Advanced Limiter Test-I (ALT-I). Either of two interchangeable limiter modules may be attached to an insertion/rotation mechanism to direct particles to the about1 m/sup 3/ pumping chamber. Pumping is provided primarily by a solid getter assembly at about20,000 1/sec. Variation of geometric dimensions and gas puffing in the modules will allow the study of plasma and neutral interaction in differing recycle regimes. Multiple diagnostic systems are incorporated into the pump limiter design for use in conjunction with TEXTOR plasma diagnostics. Initial experiments are scheduled for December 1983.

  10. Development of a flashlamp-pumped Cr:LiSAF laser operating at 30 Hz

    NASA Astrophysics Data System (ADS)

    Elgul Samad, Ricardo; Calvo Nogueira, Gesse Eduardo; Licia Baldochi, Sonia; Dias Vieira, Nilson, Jr.

    2006-05-01

    Cr3+:LiSrAlF6 crystals are an interesting laser medium because of their spectroscopic characteristics: They present a broad emission band in the near infrared and can be pumped either by a flashlamp or by diodes. Up to now, their limitation has been mostly due to their poor thermal properties that limit the laser performance either in the repetition rate in a pulsed system or output power in cw systems. We have designed and constructed a flashlamp-pumped laser using a standard rod pumping cavity that avoids most of the heat generated in the pumping process and allows operation at a fairly high repetition rate of 30 Hz with a high average power of 20 W in a conservative operation mode.

  11. Optimization of the weekly operation of a multipurpose hydroelectric development, including a pumped storage plant

    NASA Astrophysics Data System (ADS)

    Popa, R.; Popa, F.; Popa, B.; Zachia-Zlatea, D.

    2010-08-01

    It is presented an optimization model based on genetic algorithms for the operation of a multipurpose hydroelectric power development consisting in a pumped storage plant (PSP) with weekly operation cycle. The lower reservoir of the PSP is supplied upstream from a peak hydropower plant (HPP) with a large reservoir and supplies the own HPP which provides the required discharges towards downstream. Under these conditions, the optimum operation of the assembly consisting in 3 reservoirs and hydropower plants becomes a difficult problem if there are considered the restrictions as regards: the gradients allowed for the reservoirs filling/emptying, compliance with of a long-term policy of the upper reservoir from the hydroelectric development and of the weekly cycle for the PSP upper reservoir, correspondence between the power output/consumption in the weekly load schedule, turning to account of the water resource at maximum overall efficiencies, etc. Maximization of the net energy value (generated minus consumed) was selected as performance function of the model, considering the differentiated price of the electric energy over the week (working or weekend days, peak, half-peak or base hours). The analysis time step was required to be of 3 hours, resulting a weekly horizon of 56 steps and 168 decision variables, respectively, for the 3 HPPs of the system. These were allowed to be the flows turbined at the HPP and the number of working hydrounits at PSP, on each time step. The numerical application has considered the guiding data of Fantanele-Tarnita-Lapustesti hydroelectric development. Results of various simulations carried out proved the qualities of the proposed optimization model, which will allow its use within a decisional support program for such a development.

  12. Development of an oral push–pull osmotic pump of fenofibrate-loaded mesoporous silica nanoparticles

    PubMed Central

    Zhao, Zongzhe; Wu, Chao; Zhao, Ying; Hao, Yanna; Liu, Ying; Zhao, Wenming

    2015-01-01

    In this study, mesoporous silica nanoparticles (MSNs) were used to prepare an oral push–pull osmotic pump. Fenofibrate, the selected model drug, was firstly loaded into the MSNs, followed by a suspending agent consisting of a drug layer of push–pull osmotic pump. Fenofibrate-loaded MSNs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption analysis, differential scanning calorimetry (DSC), powder X-ray diffractometry (PXRD) analysis, and Fourier-transform infrared (FT-IR) spectroscopy. Polyethylene oxide of molecular weight (MW) 100,000 and polyethylene oxide of MW 6,000,000 were selected as the suspending agent and the expanding agent, respectively. Cellulose acetate was used as the semipermeable membrane, along with polyethylene glycol 6,000 to increase the flexibility and control the membrane permeability. The in vitro dissolution studies indicated that the osmotic pump tablet combined with MSNs was able to deliver fenofibrate in an approximately zero-order manner in 24 hours. A pharmacokinetic study showed that, although the maximum plasma concentration of the osmotic pump was lower than that of the reference formulation, the relative bioavailability was increased, indicating that the osmotic pump was more efficient than the reference tablets. Therefore, using MSNs as a carrier for poorly water-soluble drugs is an effective method for preparing osmotic pump tablets. PMID:25784799

  13. Development of a Variable-Speed Residential Air-Source Integrated Heat Pump

    SciTech Connect

    Rice, C Keith; Shen, Bo; Munk, Jeffrey D; Ally, Moonis Raza; Baxter, Van D

    2014-01-01

    A residential air-source integrated heat pump (AS-IHP) is under development in partnership with a U.S. manufacturer. A nominal 10.6 kW (3-ton) cooling capacity variable-speed unit, the system provides both space conditioning and water heating. This multi-functional unit can provide domestic water heating (DWH) in either full condensing (FC) (dedicated water heating or simultaneous space cooling and water heating) or desuperheating (DS) operation modes. Laboratory test data were used to calibrate a vapor-compression simulation model for each mode of operation. The model was used to optimize the internal control options for efficiency while maintaining acceptable comfort conditions and refrigerant-side pressures and temperatures within allowable operating envelopes. Annual simulations were performed with the AS-IHP installed in a well-insulated house in five U.S. climate zones. The AS-IHP is predicted to use 45 to 60% less energy than a DOE minimum efficiency baseline system while meeting total annual space conditioning and water heating loads. Water heating energy use is lowered by 60 to 75% in cold to warmer climates, respectively. Plans are to field test the unit in Knoxville, TN.

  14. Development of an analytic model to determine pump performance under two-phase flow conditions. Final report

    SciTech Connect

    Furuya, O.

    1984-05-01

    During a hypothetical LOCA (loss of coolant accident), the recirculating coolant of PWR (pressurized water reactor) may flash into steam due to a loss of line pressure. Under such two-phase flow conditions, it is well known that the recirculation pump becomes unable to generate the same head as that of the single-phase flow case. Based on the one dimensional control volume method, an analytical method has been developed to determine the performance of pumps operating under two-phase flow conditions. The analytical method has incorporated pump geometry, void fraction, flow slippage and flow regime into the basic formula, but neglected the compressibility and condensation effects. During the course of model development, it has been found that the head degradation is mainly caused by higher acceleration on liquid phase and deceleration on gas phase than in the case of single-phase flows. The numerical results for head and torque degradations were obtained with the model and favorably compared with the test data of air/water two-phase flow pumps of Babcock and Wilcox (1/3 scale) and Creare (1/20 scale).

  15. Development of Noninvasive Blood Glucose Sensor Using the Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Fujita, Keiichi; Tamura, Kazuto; Kaneko, Wataru; Ishizawa, Hiroaki; Toba, Eiji

    Recently, diabetics have been steadily increasing, because change of diet, lack of exercise, increase an alcoholic intake, and increase a stress. It is a very serious problem for us. About 23.6 millions of people in Japan approach the danger of diabetes. Therefore, it is necessary to get insulin injection. And they have to measure blood glucose again and again a day. So, they are burden too heavy. This paper describes a new noninvasive measurement of blood glucose based on optical sensing. This uses Fourier transform infrared spectroscopy of attenuated total reflection. Non-invasive measurement was carried out by using 3 methods. And standard error of prediction is about ±20mg/dl by 3 method. This paper also describes practical application of this method.

  16. The helical flow pump with a hydrodynamic levitation impeller.

    PubMed

    Abe, Yusuke; Ishii, Kohei; Isoyama, Takashi; Saito, Itsuro; Inoue, Yusuke; Ono, Toshiya; Nakagawa, Hidemoto; Nakano, Emiko; Fukazawa, Kyoko; Ishihara, Kazuhiko; Fukunaga, Kazuyoshi; Ono, Minoru; Imachi, Kou

    2012-12-01

    The helical flow pump (HFP) is a novel rotary blood pump invented for developing a total artificial heart (TAH). The HFP with a hydrodynamic levitation impeller, which consists of a multi-vane impeller involving rotor magnets, stator coils at the core position, and double helical-volute pump housing, was developed. Between the stator and impeller, a hydrodynamic bearing is formed. Since the helical volutes are formed at both sides of the impeller, blood flows with a helical flow pattern inside the pump. The developed HFP showed maximum output of 19 l/min against 100 mmHg of pressure head and 11 % maximum efficiency. The profile of the H-Q (pressure head vs. flow) curve was similar to that of the undulation pump. Hydrodynamic levitation of the impeller was possible with higher than 1,000 rpm rotation speed. The normalized index of the hemolysis ratio of the HFP to centrifugal pump (BPX-80) was from 2.61 to 8.07 depending on the design of the bearing. The HFP was implanted in two goats with a left ventricular bypass method. After surgery, hemolysis occurred in both goats. The hemolysis ceased on postoperative days 14 and 9, respectively. In the first experiment, no thrombus was found in the pump after 203 days of pumping. In the second experiment, a white thrombus was found in the pump after 23 days of pumping. While further research and development are necessary, we are expecting to develop an excellent TAH with the HFP. PMID:22926404

  17. What`s new in artificial lift. Part 2: Advances in electrical submersible pumping equipment and instrumentation/control, plus other new artificial lift developments

    SciTech Connect

    Lea, J.F.; Winkler, H.W.

    1996-04-01

    The Part 1 article presented last month discussed recent industry artificial lift innovations for sucker rod pumping, progressing cavity pumping and gas lift. Described in this presentation are 22 advances recently introduced by 15 different companies for electrical submersible pumping (ESP), and other new developments related to artificial lift field operations. ESP innovations include contributions ranging from new downhole pump equipment, gas separators and cables to various surface controllers/monitors. Other R and D contributions cover desangers, separators, fluid level measurements, chemical injection and well-heads.

  18. Transesophageal echocardiography estimation of coronary sinus blood flow for the adequacy of revascularization in patients undergoing off-pump coronary artery bypass graft

    PubMed Central

    Nagaraja, P. S.; Singh, Naveen G.; Patil, T. A.; Manjunath, V.; Prasad, S. R.; Jagadeesh, A. M.; Kumar, K. Ashok

    2015-01-01

    Aims and Objectives: Physiologically coronary sinus (CS) drains the left coronary artery (LCA) territory. Stenosis of the branches of LCA may decrease the coronary sinus blood flow (CSBF). Any intervention that aims at restoring the flow of the stenosed vessel increases coronary artery flow that should consequently increase the CSBF. Hence, this study was undertaken to assess the CSBF before and after each branch of LCA to determine the adequacy of surgical revascularization in patients undergoing elective off pump coronary artery bypass grafting (OPCAB) using transesophageal echocardiography (TEE). Materials and Methods: Thirty consecutive patients scheduled for elective OPCAB were enrolled. CSBF was assessed before and after each branch of LCA revascularization using TEE. Left internal mammary artery (LIMA) Doppler was also obtained post LIMA to left anterior descending (LAD) grafting. Results: Hemodynamic and echocardiographic variables were compared by means of Student's t-test for paired data before and after revascularization. The CSBF per beat (1.28 ± 0.71), CSBF per minute (92.59 ± 59.32) and total velocity time integral (VTI) (8.93 ± 4.29) before LAD grafting showed statistically significant increase to CSBF per beat (1.70 ± 0.89), CSBF per minute (130.72 ± 74.22) and total VTI (11.96 ± 5.68) after LAD revascularization. The CSBF per beat (1.67 ± 1.03), CSBF per minute (131.91 ± 86.59) and total VTI (11.00 ± 5.53) before obtuse marginal (OM) grafting showed statistically significant increase to CSBF per beat (1.91 ± 1.03), CSBF per min (155.20 ± 88.70) and total VTI (12.09 ± 5.43) after OM revascularization. In 9 patients, color flow Doppler of LIMA could be demonstrated which showed diastolic predominant blood flow after LIMA to LAD grafting. Conclusion: Demonstration of CSBF was simple and monitoring the trend of CSBF values before and after each graft of LCA territory will guide to determine the adequacy of surgical revascularization. PMID

  19. Blood tests: One too many? Evaluating blood requesting guidance developed for acute patients admitted to trauma and orthopaedic units.

    PubMed

    Faulkner, Alastair; Reidy, Mike; Scicluna, Gabrielle; Love, Gavin J; Joss, Judith

    2016-03-01

    In a recently published report from the Academy of Medical Royal Colleges, around 20% of clinical practice which encompasses blood science investigations is considered wasteful. Blood tests including liver function tests (LFTs), C-reactive protein (CRP), coagulation screens, and international normalising ratios (INR) are frequently requested for patients who undergo emergency hospital admission. The paucity of guidance available for blood requesting in acute trauma and orthopaedic admissions can lead to inappropriate requesting practices and over investigation. Acute admissions over a period of one month were audited retrospectively for the frequency and clinical indications of requests for LFTs, coagulation screens/INR, and CRP. The total number of blood tests requested for the duration of the patient's admission was recorded. Initial auditing of 216 admissions in January 2014 demonstrated a striking amount of over-investigation. Clinical guidelines were developed with multidisciplinary expert input and implemented within the department. Re-audit of 233 admissions was carried out in September 2014. Total no. of LFTs requested: January 895, September 336 (-62.5%); coagulation screens/INR requested: January 307, September 210 (-31.6%); CRPs requested: January 894, September 317 (-64.5%). No. of blood requests per patient: January (M=4.81, SD 4.75), September (M=3.60, SD=4.70). Approximate combined total cost of LFT, coagulation/INR, CRP in January £2674.14 and September £1236.19 (-£1437.95, -53.77%). A large decrease was observed in admission requesting and subsequent monitoring (p<0.01) following the implementation. This both significantly reduced cost and venepuncture rates. PMID:26696248

  20. Platelet utilization: a Canadian Blood Services research and development symposium.

    PubMed

    Webert, Kathryn E; Alam, Asim Q; Chargé, Sophie B; Sheffield, William P

    2014-04-01

    Considerable progress has been made in recent years in understanding platelet biology and in strengthening the clinical evidence base around platelet transfusion thresholds and appropriate platelet dosing. Platelet alloimmunization rates have also declined. Nevertheless, controversies and uncertainties remain that are relevant to how these products can best be used for the benefit of platelet transfusion recipients. Platelets are unique among the blood products directly derived from whole blood or apheresis donations in requiring storage, with shaking, at ambient temperature. Storage is accordingly constrained between the need to limit the growth of any microbes in the product and the need to minimize losses in platelet function associated with storage. Proteomic and genomic approaches are being applied to the platelet storage lesion. Platelet inventory management is made challenging by these constraints. Although bacterial screening has enhanced the safety of platelet transfusions, pathogen reduction technology may offer further benefits. Continuing clinical investigations are warranted to understand the value of transfusing platelets prophylactically or only in response to bleeding in different patient groups and how best to manage the most grievously injured trauma patients. Patients refractory to platelet transfusions also require expert clinical management. The engineering of platelet substitute products is an active area of research, but considerable hurdles remain before any clinical uses may be contemplated. Roles for platelets in biological areas distinct from hemostasis are also emerging. Platelet utilization is variably affected by all of the above factors, by demographic changes, by new medications, and by new patient care approaches. PMID:24629305

  1. Note: Development of a compact electromagnetic hydraulic pump for a microrobot joint driving system.

    PubMed

    Chen, Naijian; Wang, Sun'an; Zhang, Jinhua

    2010-04-01

    This note describes a compact electromagnetic hydraulic pump (EMHP) designed primarily to build a microdriving system for a robot joint actuator. A characteristic mathematical model integrating electricity, magnetism, and hydraulics is constructed to represent the working process of the EMHP. Tests show that a volumetric flow rate of up to 430 cm(3)/min and load pressure of up to 2.5 MPa can be achieved. The prototype pump can supply stable pressure of 0-2.4 MPa and acceleration of 1.2 MPa/s for the robot joint actuator. PMID:20441378

  2. Further developments in the design of a free-piston Stirling engine heat pump for residential applications

    SciTech Connect

    Ackermann, R.A.; Clinch, J.M.; Privon, G.T.

    1987-01-01

    During the past year (1986/1987), the development of an improved Stirling engine driver for the Free-Piston Stirling Engine Heat Pump (FPSE/HP) has led to a significant increase in heat pump performance. With the improved engine, named the MARK I, the FPSE/HP has achieved its two critical milestones of producing 3.0 refrigeration tons (RT) at the 35/sup 0/C (95/sup 0/F) ambient temperature conditions and an engine efficiency of 25%, as measured from the fuel input energy, based on the higher heating value of the natural gas and mechanical power developed by the engine. This paper describes the latest configuration of the FPSE/HP module and presents measured performance data. Performance has been measured over a broad range of ambient temperature conditions and engine operating parameters. The results obtained from this testing are presented.

  3. Further developments in the design of a free-piston Stirling engine heat pump for residential applications

    SciTech Connect

    Ackerman, R.A.; Clinch, J.M.; Privon, G.

    1987-06-01

    During the past year (1986/1987), the development of an improved Stirling engine driver for the Free-Piston Stirling Engine Heat Pump (FPSE/HP) has led to a significant increase in heat pump performance. With the improved engine, the MARK I, the FPSE/HP has achieved its two critical milestones of producing 3.0 refrigeration tons (RT) at the 95 F (35/sup 0/C) ambient temperature conditions and an engine efficiency of 25%, as measured from the fuel input energy, based on the higher heating value of the natural gas and mechanical power developed by the engine. This paper describes the latest configuration of the FPSE/HP module and presents measured performance data. Performance has been measured over a broad range of ambient temperature conditions and engine operating parameters. The results obtained from this testing are presented.

  4. Development of an optically-pumped cesium standard at the Aerospace Corporation

    NASA Astrophysics Data System (ADS)

    Chan, Yat C.

    1992-07-01

    We have initiated a research program to study the performance of compact optically-pumped cesium (Cs) frequency standards, which have potential for future timekeeping applications in space. A Cs beam clock apparatus has been assembled. Basic functions of the frequency standard have been demonstrated. Clock signals are observed with optical pumping schemes using one or two lasers. With two laser pumping, we are able to selectively place up to 80 percent of the atomic population into one of the clock transition states. The observed pattern of clock signal indicates that the velocity distribution of the Cs atoms contributing to the microwave signal is beam-Maxwellian. Thus, in the optically-pumped Cs frequency standards, the entire Cs population in the atomic beam could be utilized to generate the clock signals. This is in contrast to the conventional Cs beam standards where only approx. 1 percent of the atoms in the beam are used. More efficient Cs consumption can lead to improved reliability and increased useful lifetime of the clock.

  5. DEVELOPMENT OF AN ECONOMICAL AND SUSTAINABLE IRRIGATION RAM PUMP FOR COMMUNITY GARDENING IN SOUTH AFRICA

    EPA Science Inventory

    The Johns Hopkins Chapter of Engineers Without Borders (EWB-JHU) is working with local partners in KZN to improve and promote a locally designed (“Alcock”) ram pump as an appropriate and sustainable solution to problems of irrigation in much needed community vegeta...

  6. DEVELOPMENT OF A LINEAR COMPRESSOR FOR AIR CONDITIONERS AND HEAT PUMPS

    EPA Science Inventory

    The report discusses the design, building, testing, and delivering to the Environmental Protection Agency of a linear compressor for operation in a 3.0- ton (10.5 kW) residential air-conditioning and heat pumping system. The compressor design evolved from a linear resonant piston...

  7. Development of an optically-pumped cesium standard at the Aerospace Corporation

    NASA Technical Reports Server (NTRS)

    Chan, Yat C.

    1992-01-01

    We have initiated a research program to study the performance of compact optically-pumped cesium (Cs) frequency standards, which have potential for future timekeeping applications in space. A Cs beam clock apparatus has been assembled. Basic functions of the frequency standard have been demonstrated. Clock signals are observed with optical pumping schemes using one or two lasers. With two laser pumping, we are able to selectively place up to 80 percent of the atomic population into one of the clock transition states. The observed pattern of clock signal indicates that the velocity distribution of the Cs atoms contributing to the microwave signal is beam-Maxwellian. Thus, in the optically-pumped Cs frequency standards, the entire Cs population in the atomic beam could be utilized to generate the clock signals. This is in contrast to the conventional Cs beam standards where only approx. 1 percent of the atoms in the beam are used. More efficient Cs consumption can lead to improved reliability and increased useful lifetime of the clock.

  8. PUMP CONSTRUCTION

    DOEpatents

    Strickland, G.; Horn, F.L.; White, H.T.

    1960-09-27

    A pump which utilizes the fluid being pumped through it as its lubricating fluid is described. This is achieved by means of an improved bearing construction in a pump of the enclosed or canned rotor type. At the outlet end of the pump, adjacent to an impeller mechanism, there is a bypass which conveys some of the pumped fluid to a chamber at the inlet end of the pump. After this chamber becomes full, the pumped fluid passes through fixed orifices in the top of the chamber and exerts a thrust on the inlet end of the pump rotor. Lubrication of the rotor shaft is accomplished by passing the pumped fluid through a bypass at the outlet end of the rotor shaft. This bypass conveys Pumped fluid to a cooling means and then to grooves on the surface of the rotor shait, thus lubricating the shaft.

  9. Industrial Pumps

    NASA Technical Reports Server (NTRS)

    1986-01-01

    A flow inducer is a device that increases the pump intake capacity of a Worthington Centrifugal pump. It lifts the suction pressure sufficiently for the rotating main impeller of the centrifugal pump to operate efficiently at higher fluid intake levels. The concept derives from 1960's NASA technology which was advanced by Worthington Pump Division. The pumps are used to recirculate wood molasses, a highly viscous substance.

  10. Hydraulic development of high specific-speed pump-turbines by means of an inverse design method, numerical flow-simulation (CFD) and model testing

    NASA Astrophysics Data System (ADS)

    Kerschberger, P.; Gehrer, A.

    2010-08-01

    In recent years an increased interest in pump-turbines has been recognized in the market. The rapid availability of pumped storage schemes and the benefits to the power system by peak lopping, providing reserve and rapid response for frequency control are becoming of growing advantage. In that context it is requested to develop pump-turbines that reliably stand dynamic operation modes, fast changes of the discharge rate by adjusting the variable diffuser vanes as well as fast changes from pump to turbine operation. Within the present study various flow patterns linked to the operation of a pump-turbine system are discussed. In that context pump and turbine mode are presented separately and different load cases at both operation modes are shown. In order to achieve modern, competitive pump-turbine designs it is further explained which design challenges should be considered during the geometry definition of a pump-turbine impeller. Within the present study a runner-blade profile for a low head pump-turbine has been developed. For the initial hydraulic runner-blade design, an inverse design method has been applied. Within this design procedure, a first blade geometry is generated by imposing the pressure loading-distribution and by means of an inverse 3D potential-flow-solution. The hydraulic behavior of both, pump-mode and turbine-mode is then evaluated by solving the full 3D Navier-Stokes equations in combination with a robust turbulence model. Based on this initial design the blade profile has been further optimized and redesigned considering various hydraulic pump-turbine requirements. Finally, the progress in hydraulic design is demonstrated by model test results which show a significant improvement in hydraulic performance compared to an existing reference design.

  11. A Mini Axial and a Permanent Maglev Radial Heart Pump§

    PubMed Central

    Qian, Kun-Xi; Ru, Wei-Min; Wang, Hao; Jing, Teng

    2007-01-01

    The implantability and durability have been for decades the focus of artificial heart R&D. A mini axial and a maglev radial pump have been developed to meet with such requirements. The mini axial pump weighing 27g (incl.5g rotor) has an outer diameter of 21mm and a length of 10mm in its largest point, but can produce a maximal blood flow of 6l/min with 50mmHg pressure increase. Therefore, it is suitable for the patients of 40-60kg body weight. For other patients of 60-80kg or 80-100kg body weight, the mini axial pumps of 23mm and 25mm outer diameter had been developed before, these devices were acknowledged to be the world smallest LVADs by Guinness World Record Center in 2004. The permanent maglev radial pump weighing 150g is a shaft-less centrifugal pump with permanent magnetic bearings developed by the author. It needs no second coil for suspension of the rotor except the motor coil, different from all other maglev pumps developed in USA, Japan, European, etc. Thus no detecting and controlling systems as well as no additional power supply for maglev are necessary. The pump can produce a blood flow up to as large as 10l/min against 100mmHg pressure. An implantable and durable blood pump will be a viable alternative to natural donor heart for transplantation. PMID:19662120

  12. Development and Validation of a Fully Automated Platform for Extended Blood Group Genotyping.

    PubMed

    Boccoz, Stephanie A; Le Goff, Gaelle C; Mandon, Celine A; Corgier, Benjamin P; Blum, Loïc J; Marquette, Christophe A

    2016-01-01

    Thirty-five blood group systems, containing >300 antigens, are listed by the International Society of Blood Transfusion. Most of these antigens result from a single nucleotide polymorphism. Blood group typing is conventionally performed by serology. However, this technique has some limitations and cannot respond to the growing demand of blood products typed for a large number of antigens. The knowledge of the molecular basis of these red blood cell systems allowed the implementation of molecular biology methods in immunohematology laboratories. Here, we describe a blood group genotyping assay based on the use of TKL immobilization support and microarray-based HIFI technology that takes approximately 4 hours and 30 minutes from whole-blood samples to results analysis. Targets amplified by multiplex PCR were hybridized on the chip, and a revelation step allowed the simultaneous identification of up to 24 blood group antigens, leading to the determination of extended genotypes. Two panels of multiplex PCR were developed: Panel 1 (KEL1/2, KEL3/4; JK1/2; FY1/2; MNS1/2, MNS3/4, FY*Fy et FY*X) and Panel 2 (YT1/2; CO1/2; DO1/2, HY+, Jo(a+); LU1/2; DI1/2). We present the results of the evaluation of our platform on a panel of 583 and 190 blood donor samples for Panel 1 and 2, respectively. Good correlations (99% to 100%) with reference were obtained. PMID:26621100

  13. New slurry pumps in China

    SciTech Connect

    Li, Z.; Wang, W.; Shi, Z.

    1998-07-01

    Wet parts of centrifugal slurry pumps are naturally subjected to wear, but local wear in pumps could be avoided, at least partly. Through studying the wear phenomenon of slurry pumps in industrial applications, a series of much more advanced slurry pumps was developed in China. Laboratory tests and industrial applications show that the new pumps are high in efficiency when transporting slurries, and uniform wear can be expected from them.

  14. New slurry pumps in China

    SciTech Connect

    Zhengwang Li; Wenlie Wang; Zhongyin Shi

    1998-04-01

    Wet parts of centrifugal slurry pumps are naturally subjected to wear, but local wear in pumps could be avoided, at least partly. Through studying the wear phenomenon of slurry pumps in industrial applications, a series of much more advanced slurry pumps was developed in China. Laboratory tests and industrial applications show that the new pumps are high in efficiency when transporting slurries, and uniform wear can be expected from them.

  15. Development of portable health monitoring system for automatic self-blood glucose measurement

    NASA Astrophysics Data System (ADS)

    Kim, Huijun; Mizuno, Yoshihumi; Nakamachi, Eiji; Morita, Yusuke

    2010-02-01

    In this study, a new HMS (Health Monitoring System) device is developed for diabetic patient. This device mainly consists of I) 3D blood vessel searching unit and II) automatic blood glucose measurement (ABGM) unit. This device has features such as 1)3D blood vessel location search 2) laptop type, 3) puncturing a blood vessel by using a minimally invasive micro-needle, 4) very little blood sampling (10μl), and 5) automatic blood extraction and blood glucose measurement. In this study, ABGM unit is described in detail. It employs a syringe type's blood extraction mechanism because of its high accuracy. And it consists of the syringe component and the driving component. The syringe component consists of a syringe itself, a piston, a magnet, a ratchet and a micro-needle whose inner diameter is about 80μm. And the syringe component is disposable. The driving component consists of body parts, a linear stepping motor, a glucose enzyme sensor and a slider for accurate positioning control. The driving component has the all-in-one mechanism with a glucose enzyme sensor for compact size and stable blood transfer. On designing, required thrust force to drive the slider is designed to be greater than the value of the blood extraction force. Further, only one linear stepping motor is employed for blood extraction and transportation processes. The experimental result showed more than 80% of volume ratio under the piston speed 2.4mm/s. Further, the blood glucose was measured successfully by using the prototype unit. Finally, the availability of our ABGM unit was confirmed.

  16. Development of standard definitions for surveillance of complications related to blood donation.

    PubMed

    Goldman, M; Land, K; Robillard, P; Wiersum-Osselton, J

    2016-02-01

    Standard definitions of donor reactions allow each blood establishment to monitor donor adverse events and compare with other organizations to develop best practices. The ISBT Haemovigilance Working Party leads a multi-organizational effort to update the 2008 ISBT standard for surveillance of complications related to blood donation. Revised definitions have been developed and endorsed by the ISBT, AABB, International Haemovigilance Network (IHN) and other international organizations. PMID:26361365

  17. Developing Efficient Coordination Schemes to Control Over-Pumping in the Heihe River Basin, China

    NASA Astrophysics Data System (ADS)

    Pedrazzini, G.

    2015-12-01

    Many wicked water resources problems are approached in a social planner perspective. This not always matches the real institutional and policy-making context, where, rather, multiple decision-makers (DMs) can act independently, or weakly cooperate, ultimately producing system-wide inefficient trade-offs. The idea in this work is to adopt a more realistic approach, where the multi-DMs nature of the problem is preserved and the uncoordinated DMs are driven, thorough coordination mechanisms, towards a more system-wide efficient solution. An agent-based modelling framework linked to a surface and groundwater model is used to design these coordination mechanisms as constraints to the independent agents (i.e., DMs) behaviour. In the Heihe Basin the ongoing introduction of smart meter IC-card systems on farmers' pumping wells will soon allow monitoring and control of abstractions with the goal of preventing further depletion of the resource. The major interest of policy makers in the region concerns the development of new and the improvement of existing legislation on pricing schemes and/or groundwater quotas. The model outcome where agents act rationally but selfishly is compared to the optimal solution at system-level assuming perfect coordination and cooperation. The optimal solutions with respect to the given utility functions are computed using nonlinear optimization with a rolling out time horizon. The Pareto-Frontier is synthesized through an exhaustive sampling of the weight coefficient space and related to the current and to the historical management of the last 4 decades. The best parameter values for the proposed coordination mechanisms are determined and the alternatives are compared with respect to their efficiency and acceptability. Preliminary results suggest that a regulatory tax on groundwater of about a factor 10 of the current resource fee is required to increase the elasticity of the groundwater demand curve such that reducing consumption becomes

  18. Development of a tritium monitor combined with an electrochemical tritium pump using a proton conducting oxide

    SciTech Connect

    Tanaka, M.; Sugiyama, T.

    2015-03-15

    The detection of low level tritium is one of the key issues for tritium management in tritium handling facilities. Such a detection can be performed by tritium monitors based on proton conducting oxide technique. We tested a tritium monitoring system composed of a commercial proportional counter combined with an electrochemical hydrogen pump equipped with CaZr{sub 0.9}In{sub 0.1}O{sub 3-α} as proton conducting oxide. The hydrogen pump operated at 973 K under electrolysis conditions using tritiated water vapor (HTO). The proton conducting oxide extracts tritium molecules (HT) from HTO and tritium concentration is measured by the proportional counter. The advantage of the proposed tritium monitoring system is that it is able to convert HTO into molecular hydrogen.

  19. Study and Development of an Air Conditioning System Operating on a Magnetic Heat Pump Cycle

    NASA Technical Reports Server (NTRS)

    Wang, Pao-Lien

    1991-01-01

    This report describes the design of a laboratory scale demonstration prototype of an air conditioning system operating on a magnetic heat pump cycle. Design parameters were selected through studies performed by a Kennedy Space Center (KSC) System Simulation Computer Model. The heat pump consists of a rotor turning through four magnetic fields that are created by permanent magnets. Gadolinium was selected as the working material for this demonstration prototype. The rotor was designed to be constructed of flat parallel disks of gadolinium with very little space in between. The rotor rotates in an aluminum housing. The laboratory scale demonstration prototype is designed to provide a theoretical Carnot Cycle efficiency of 62 percent and a Coefficient of Performance of 16.55.

  20. Development of lasers optimized for pumping Ti:Al2O3 lasers

    NASA Technical Reports Server (NTRS)

    Rines, Glen A.; Schwarz, Richard A.

    1994-01-01

    Laboratory demonstrations that were completed included: (1) an all-solid-state, broadly tunable, single-frequency, Ti:Al2O3 master oscillator, and (2) a technique for obtaining 'long' (nominally 100- to 200-ns FWHM) laser pulses from a Q-switched, Nd oscillator at energy levels commensurate with straightforward amplification to the joule level. A diode-laser-pumped, Nd:YLF laser with intracavity SHG was designed, constructed, and evaluated. With this laser greater than 0.9 W of CW, output power at 523.5 nm with 10 W of diode-laser pump power delivered to the Nd:YLF crystal was obtained. With this laser as a pump source, for the first time, to our knowledge, an all solid-state, single frequency, Ti:Al203 laser with sufficient output power to injection seed a high-energy oscillator over a 20-nm bandwidth was demonstrated. The pulsed laser work succeeded in demonstrating pulse-stretching in a Q-switched Nd:YAG oscillator. Pulse energies greater than 50-mJ were obtained in pulses with 100- to 200-ns pulsewidths (FWHM).

  1. Recent progress in the development of electrically and optically pumped dye vapor lasers

    NASA Astrophysics Data System (ADS)

    Marowsky, G.

    1980-01-01

    This paper reviews new results in the field of organic dye vapor lasers. Gain studies of the scintillator dye POPOP in liquid solution and in the vapor phase show that a dye vapor exhibits optical gain nearly as high as in the solution case under excitation by a N2 laser. Superradiant emission has been observed from both optically excited POPOP vapor and electron-beam excited vapor. The optimum operating conditions of an electron-beam pumped dye vapor-buffer gas system with high purity argon as buffer are reported. Potential energy transfer processes from the rare-gas buffer to the dye vapor are discussed. The metastable ionic species Ar2(+) has been identified as the most likely POPOP excitation source after intense electron pumping of the dense Ar buffer gas at typically 4-5 atm. An estimate of the conversion efficiency from electronic energy deposited in the Ar buffer to stimulated emission of the dye yields 5 percent. These results suggest that an efficient tunable electron beam pumped dye vapor laser is feasible.

  2. Development and application investigation of an ICSHG 532 nm diode-pumped solid-state laser system

    NASA Astrophysics Data System (ADS)

    Nhat Khoa Phan, Thanh; Tu, Trung Chan; Thuat Nguyen, Tran; Chien Nguyen, Thanh; Chien Dang, Mau

    2011-12-01

    A diode-pump solid-state laser system emitting a 532 nm beam has been developed. The pump source is an 808 nm diode laser, which has gained wide acceptance in research as well as in commercial production due to its effectiveness and reasonable price. The active medium was chosen to be Nd:YVO4 (neodymium-doped yttrium orthovanadate), a material with many advantages over traditional Nd:YAG (neodymium-doped yttrium aluminum garnet) such as a low lasing threshold and linearly polarized beam. However, the thermal conductivity of Nd:YVO4 is not as good as Nd:YAG, thus the thermal lens effect inside Nd:YVO4 under high pumping intensity becomes severe and detrimental to the laser performance. Our work showed that careful adjustments of Nd:YVO4 temperature as well as of the cavity's parameters played an important role in the performance of the laser. Potassium titanyl phosphate (KTP), a nonlinear optics crystal, was used to convert the fundamental 1064 nm laser radiation from Nd:YVO4 into 532 nm. The 532 nm laser beam has been successfully proven to cut wood, plastic and aluminum.

  3. Development of an accurate 3D blood vessel searching system using NIR light

    NASA Astrophysics Data System (ADS)

    Mizuno, Yoshifumi; Katayama, Tsutao; Nakamachi, Eiji

    2010-02-01

    Health monitoring system (HMS) and drug delivery system (DDS) require accurate puncture by needle for automatic blood sampling. In this study, we develop a miniature and high accurate automatic 3D blood vessel searching system. The size of detecting system is 40x25x10 mm. Our searching system use Near-Infrared (NIR) LEDs, CMOS camera modules and image processing units. We employ the stereo method for searching system to determine 3D blood vessel location. Blood vessel visualization system adopts hemoglobin's absorption characterization of NIR light. NIR LED is set behind the finger and it irradiates Near Infrared light for the finger. CMOS camera modules are set in front of the finger and it captures clear blood vessel images. Two dimensional location of the blood vessel is detected by luminance distribution of the image and its depth is calculated by the stereo method. 3D blood vessel location is automatically detected by our image processing system. To examine the accuracy of our detecting system, we carried out experiments using finger phantoms with blood vessel diameters, 0.5, 0.75, 1.0mm, at the depths, 0.5 ~ 2.0 mm, under the artificial tissue surface. Experimental results of depth obtained by our detecting system showed good agreements with given depths, and the availability of this system is confirmed.

  4. Development of a lamp-pumped Cr:LiSAF laser operating at 20Hz for a terawatt CPA system

    NASA Astrophysics Data System (ADS)

    Samad, Ricardo E.; Nogueira, Gesse E. C.; Baldochi, Sonia L.; Vieira, Nilson D., Jr.

    2006-02-01

    We report here the development, construction and characterization of a flashlamp pumped Cr:LiSAF rod pumping cavity designed to minimize the thermal load on the crystal. The cavity is a close coupled one with 2 Xe lamps and absorptive filters between the lamps and the Cr:LiSAF rod, and is refrigerated with cooled water. A compact and stable (g I×g II=0.57) resonator was designed for lasers tests and gain medium characterization, and we expected to obtain operation at 20 Hz repetition rate. Nevertheless, the thermal load minimizing design was so successful that allowed laser operation up to 30 Hz with an average power of 20 W. When operating with a 10% transmission output coupler this laser exhibited an overall laser efficiency of 0.6% under 100 J electrical pumping, and a slope efficiency of 0.8%. Under these conditions, a maximum gain per pass of 1.5 was obtained, suitable for regenerative amplifiers. To increase the gain, the intracavity filters were substituted by glass plates, resulting in a gain per pass of 3.6, adequate for multipass amplifiers. In this configuration, and operating as a laser resonator, it showed a maximum overall efficiency of 2.81% under 88 J electrical pumping with a 25% transmission output coupler, and maximum output power of 18 W at 8 Hz. A study of the thermal load on the crystal was conducted by observation of the upper laser level lifetime, and we concluded that there are no noticeable accumulated thermal effects on the Cr:LiSAF emission.

  5. 12. Sewage Ejector Pumps, view to the southwest. These pumps ...

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

    12. Sewage Ejector Pumps, view to the southwest. These pumps are connected to sewage treatment tanks. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  6. Oxygen pumps

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Special considerations to be given to the design, fabrication, and use of centrifugal pumps for liquid O2 to avoid conditions that lead to system failure are given. Emphasis was placed on turbine pumps for flight applications.

  7. Casing pump

    SciTech Connect

    Bass, H.E.; Bass, R.E.

    1987-09-29

    A natural gas operated pump is described for use in the casing of an oil well, comprising: a tubular pump body having an open lower end for admitting well fluids to the interior of the pump body and an open upper end, wherein a downwardly facing seating surface is formed on the inner periphery of the pump body adjacent the upper end thereof; means for forming a seal between the pump body and the casing of the well; a rod extending longitudinally through the seating surface formed in the pump body and protruding from the upper end of the pump body; a valve member mounted on the rod below the seating surface and shaped to mate with the seating surface; and means for vertically positioning the rod in proportion to fluid pressure within the pump body.

  8. Magnetocaloric pump

    NASA Technical Reports Server (NTRS)

    Brown, G. V.

    1973-01-01

    Very cold liquids and gases such as helium, neon, and nitrogen can be pumped by using magnetocaloric effect. Adiabatic magnetization and demagnetization are used to alternately heat and cool slug of pumped fluid contained in closed chamber.

  9. Development of a Whole Blood Staining Device for use During Space Shuttle Flights

    NASA Technical Reports Server (NTRS)

    Sams, Clarence F.; Crucian, Brian E.; Clift, Vaughan L.; Meinelt, Ellen M.

    1999-01-01

    Exposure to microgravity during space flight results in profound physiologic changes. Numerous studies have shown changes in circulating populations of peripheral blood immune cells immediately after space flight. It is currently unknown if these changes result from exposure to microgravity or are caused by the stress of reentry and readaptation to gravity. We have developed the whole blood staining device as a system for the staining of whole blood collected during space flight for subsequent flow cytometric analysis, This device contains all liquids to address safety issues concerned with space flight and also moves the cells through the staining, lyse/fixation and dilution steps.

  10. ELECTROMAGNETIC PUMP

    DOEpatents

    Pulley, O.O.

    1954-08-17

    This patent reiates to electromagnetic pumps for electricity-conducting fluids and, in particular, describes several modifications for a linear conduction type electromagnetic interaction pump. The invention resides in passing the return conductor for the current traversing the fiuid in the duct back through the gap in the iron circuit of the pump. Both the maximum allowable pressure and the efficiency of a linear conduction electromagnetic pump are increased by incorporation of the present invention.

  11. Insulin Pumps: What Every School Nurse Needs to Know

    ERIC Educational Resources Information Center

    Bierschbach, Judy Laver; Cooper, Leslie; Liedl, Jennifer A.

    2004-01-01

    The results of the Diabetes Control and Complications Trial revolutionized the care of people with Type 1 diabetes mellitus (DM). The era of "tight control" of blood sugars to decrease microvascular complications dawned. The subsequent technological development of insulin pumps has made it possible for individuals with Type 1 DM, as well as those…

  12. Blood flow

    MedlinePlus Videos and Cool Tools

    As the heart pumps, the arteries carry oxygen-rich blood (shown in red) away from the heart and toward the body's tissues and vital organs. ... brain, liver, kidneys, stomach, and muscles, including the heart muscle itself. At the same time, the veins ...

  13. Requirements Analysis Study for Master Pump Shutdown System Project Development Specification [SEC 1 and 2

    SciTech Connect

    BEVINS, R.R.

    2000-03-24

    This document has been updated during the definitive design portion of the first phase of the W-314 Project to capture additional software requirements and is planned to be updated during the second phase of the W-314 Project to cover the second phase of the Project's scope. The objective is to provide requirement traceability by recording the analysis/basis for the functional descriptions of the master pump shutdown system. This document identifies the sources of the requirements and/or how these were derived. Each requirement is validated either by quoting the source or an analysis process involving the required functionality, performance characteristics, operations input or engineering judgment.

  14. Performance evaluation of ground-source heat pump system and development of suitability map for its installation

    NASA Astrophysics Data System (ADS)

    Shrestha, G.; Uchida, Y.; Yoshioka, M.; Kuronuma, S.

    2015-12-01

    Ground-source heat pump (GSHP) system is an energy efficient and environment friendly technology that uses natural subsurface heat energy stored in the shallow depth for space-heating, space-cooling, snow-melting, hot water supply etc. In Japan, development of this system is gradually increasing, however the rate is still limited due to higher initial cost caused by oversized design of ground heat exchangers. An efficient system that can lower the installation cost should be developed and evaluated for its performance in order to expand the growth of GSHP system in Japan. In addition, development of suitability map to assess appropriate locations for the system installation is essential for optimum design and sustainability. In this study, GSHP system was constructed utilizing an artesian well as ground heat exchanger (GHE) and evaluated its performance. The objective of this study is to develop low cost and high efficiency system. In areas with abundant groundwater and its flow, higher heat exchange rate can be expected leading to cost reduction and energy saving. Further, suitability map was prepared in regional scale to assess the suitable locations where this type of system can be installed. The suitability map was prepared considering local hydrogeological and thermal data. Average coefficient of performance (COP) was found to be 7 during space-cooling operation and 5 during space-heating operation. These values of COP are higher than that of normal air conditioner (air-source heat pump system).

  15. The role of blood groups in the development of diabetes mellitus after gestational diabetes mellitus

    PubMed Central

    Karagoz, Hatice; Erden, Abdulsamet; Ozer, Ozerhan; Esmeray, Kubra; Cetinkaya, Ali; Avci, Deniz; Karahan, Samet; Basak, Mustafa; Bulut, Kadir; Mutlu, Hasan; Simsek, Yasin

    2015-01-01

    Introduction Gestational diabetes mellitus (GDM) is a common condition that is defined as glucose intolerance of varying degree with onset or first recognition during pregnancy and it affects approximately 5% of all pregnancies all over the world. GDM is not only associated with adverse pregnancy outcomes such as macrosomia, dystocia, birth trauma, and metabolic complications in newborns, but it is also a strong predictor of transitioning to overt DM postpartum. The association of ABO blood groups with DM has been observed before in several epidemiological and genetic studies and resulted with inconsistent findings, but still there are not enough studies in the literature about the association of ABO blood groups with GDM. In this study, we aimed at investigating any possible relationship between the ABO blood group system and GDM and also the transitioning of GDM to overt DM postpartum, in Turkey. Patients and methods A total of 233 patients with GDM from Kayseri Training and Research Hospital between 2002 and 2012 were included in the study. The cases that have serologically determined blood groups and Rh factor in the hospital records were included in the study, and the patients with unknown blood groups were excluded. Patients were classified according to blood groups (A, B, AB, and O) and Rh status (+/−). GDM was diagnosed based on the glucose cut-points of the International Association of the Diabetes and Pregnancy Society Groups. The distributions of blood groups of the patients with GDM were compared with the distribution of blood groups of 17,314 healthy donors who were admitted to the Turkish Red Crescent Blood Service in our city in 2012. Results There was a significant difference between the patients with GDM and control group in terms of distribution of ABO blood groups. Blood group AB was found to be higher in the patients with GDM compared to the control group (P=0.029). When the patients were compared according to the development of DM, the ratio

  16. 20. Station Unwatering Pumps and Sump Pump, view to the ...

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

    20. Station Unwatering Pumps and Sump Pump, view to the north. The station unwatering pumps are the two large units in the center and right foreground of photograph and are marked with the numbers 1 and 2. The sump pump is the smaller unit in left foreground of photograph. These pumps are used for unwatering the draft chests for maintenance. Note the draft tube unwatering valve visible in background between the two unwatering pumps. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  17. Use of expert judgment in the development and evaluation of risk-based inservice testing strategies for pumps and valves

    SciTech Connect

    McAllister, W.J.; Perdue, R.K.; Balkey, K.R.; Closky, N.B.

    1996-12-01

    This paper describes a rigorous approach for quantitatively evaluating inservice testing effectiveness that evolved from two pilot plant studies. These studies prototyped methodologies for designing and selecting inservice testing (IST) strategies in a manner structured to insure that the targeted components will perform their required safety functions while minimizing life cycle inservice testing costs. The paper concentrates on the use of expert judgment in developing test effectiveness measures that move risk-based methods beyond ranking to optimization of plant IST programs. Selected results for check valves and pumps are shown to illustrate the practical significance of the approach.

  18. Design and development of a two-phase reservoir for the Capillary Pumped Loop (CAPL) Flight Experiment

    NASA Technical Reports Server (NTRS)

    Wolf, David A.

    1992-01-01

    The Capillary Pumped Loop (CAPL) Flight Experiment has undergone numerous design modifications to reflect recent changes in the thermal control system baselined for Earth Observation System (EOS) spacecraft. The experiment redesign has also allowed technological advances in two-phase fluid loop components to be incorporated. The experiment's reservoir is one of the components targeted for redesign. The design and development of a new reservoir for the CAPL Flight Experiment is discussed in this paper. A prototype reservoir is described, and a hydrodynamic analysis of its wick structure is included. Testing of the prototype reservoir is also discussed.

  19. Heat pump concepts for nZEB Technology developments, design tools and testing of heat pump systems for nZEB in the USA: Country report IEA HPT Annex 40 Task 2, Task 3 and Task 4 of the USA

    SciTech Connect

    Baxter, Van D.; Payne, W. Vance; Ling, Jiazhen; Radermacher, Reinhard

    2015-12-01

    The IEA HPT Annex 40 "Heat pump concepts for Nearly Zero Energy Buildings" deals with the application of heat pumps as a core component of the HVAC system for Nearly or Net Zero energy buildings (nZEB). This report covers Task 2 on the system comparison and optimisation and Task 3 dedicated to the development of adapted technologies for nZEB and field monitoring results of heat pump systems in nZEB. In the US team three institutions are involved and have worked on the following projects: The Oak Ridge National Laboratory (ORNL) will summarize development activities through the field demonstration stage for several integrated heat pump (IHP) systems electric ground-source (GS-IHP) and air-source (AS-IHP) versions and an engine driven AS-IHP version. The first commercial GS-IHP product was just introduced to the market in December 2012. This work is a contribution to Task 3 of the Annex. The University of Maryland will contribute a software development project to Task 2 of the Annex. The software ThermCom evaluates occupied space thermal comfort conditions accounting for all radiative and convective heat transfer effects as well as local air properties. The National Institute of Standards and Technology (NIST) is working on a field study effort on the NIST Net Zero Energy Residential Test Facility (NZERTF). This residential building was constructed on the NIST campus and officially opened in summer 2013. During the first year, between July 2013 and June 2014, baseline performance of the NZERTF was monitored under a simulated occupancy protocol. The house was equipped with an air-to-air heat pump which included a dedicated dehumidification operating mode. Outdoor conditions, internal loads and modes of heat pump operation were monitored. Field study results with respect to heat pump operation will be reported and recommendations on heat pump optimization for a net zero energy building will be provided. This work is a contribution to Task 3 of the Annex.

  20. Relationship among maternal blood lead, ALAD gene polymorphism and neonatal neurobehavioral development

    PubMed Central

    Yun, Li; Zhang, Weixing; Qin, Kejun

    2015-01-01

    Lead is a widely used heavy metal that can affect children’s nervous system development. ALAD gene polymorphism is associated with lead neurotoxicity. This study aimed to clarify the relationship among maternal blood lead, ALAD gene polymorphism, and neonatal neurobehavioral development through detecting maternal blood lead and ALAD gene polymorphism. 198 maternal and neonatal were selected as the research object. Graphite furnace atomic absorption method was applied to detect the maternal blood lead concentration. PCR-RFLP was used to detect ALAD genotype distribution. Neonatal NANB score was treated as effect indicator. SPSS was used for statistical analysis. The ALAD genotype was 181 cases (91.4%) for ALAD11 and 17 cases (8.6%) for ALAD12. ALAD allele frequency distribution accords with genetics Hardy-Weinberg balance (P > 0.05). Blood lead level in maternal with ALAD12 genotype was significantly higher than with ALAD11 genotype (P < 0.01). NANB score in high blood lead neonatal group was obviously lower than the low blood lead group (P < 0.05). Newborn’s NANB score from the maternal with ALAD11 genotype was lower than from the maternal with ALAD12 genotype (P < 0.01). After ruling out the confounding factors influence by multiple linear regressions, ALAD gene polymorphisms had no significant correlation with neonatal NANB score (P > 0.05). ALAD gene polymorphism is associated with the blood lead level. Low level lead exposure in utero may cause newborn early neurobehavioral maldevelopment. Maternal ALAD gene polymorphism can affect early neonatal neurobehavioral development by influencing the blood lead level. PMID:26261627

  1. Adverse Reactions in Allogeneic Blood Donors: A Tertiary Care Experience from a Developing Country

    PubMed Central

    Sultan, Sadia; Baig, Mohammad Amjad; Irfan, Syed Mohammed; Ahmed, Syed Ijlal; Hasan, Syeda Faiza

    2016-01-01

    Objectives Fragmented blood transfusion services along with an unmotivated blood donation culture often leads to blood shortage. Donor retention is crucial to meet the increasing blood demand, and adverse donor reactions have a negative impact on donor return. The aim of this study was to estimate adverse donor reactions and identify any demographic association.   Methods We conducted a prospective study between January 2011 and December 2013. A total of 41,759 healthy donors were enrolled. Professionally trained donor attendants drew blood and all donors were observed during and following donation for possible adverse events for 20 minutes. Blood donors were asked to report if they suffered from any delayed adverse consequences.   Results Out of 41,759 blood donors, 537 (1.3%) experienced adverse reactions. The incidence was one in every 78 donations. The mean age of donors who experienced adverse events was 26.0±6.8 years, and all were male. Out of 537 donors, 429 (80%) developed vasovagal reaction (VVR), 133 (25%) had nausea, 63 (12%) fainted, 35 (6%) developed hyperventilation, 9 (2%) had delayed syncope, and 9 (2%) developed hematoma. Arterial prick, nerve injury, cardiac arrest, and seizures were not observed. Donors aged less than < 30 years and weighing < 70 kg were significantly associated with VVR, hyperventilation, and nausea (p < 0.005). Undergraduates and Urdu speaking donors also had a significant association with fainting and nausea, respectively (p < 0.05).   Conclusion The prevalence of adverse events was low at our tertiary center. A VVR was the predominant adverse reaction and was associated with age and weight. Our study highlights the importance of these parameters in the donation process. A well-trained and experienced phlebotomist and pre-evaluation counseling of blood donors could further minimize the adverse reactions. PMID:27168923

  2. Development of ultrananocrystalline diamond (UNCD) coatings for multipurpose mechanical pump seals.

    SciTech Connect

    Kovalchenko, A. M.; Elam, J. W.; Erdemir, A.; Carlisle, J. A.; Auciello, O.; Libera, J. A.; Pellin, M. J.; Gruen, D. M.; Hryn, J. N.

    2011-01-01

    The reliability and performance of silicon carbide (SiC) shaft seals on multipurpose mechanical pumps are improved by applying a protective coating of ultrananocrystalline diamond (UNCD). UNCD exhibits extreme hardness (97 GPa), low friction (0.1 in air) and outstanding chemical resistance. Consequently, the application of UNCD coatings to multipurpose mechanical pump seals can reduce frictional energy losses and eliminate the downtime and hazardous emissions from seal failure and leakage. In this study, UNCD films were prepared by microwave plasma chemical vapor deposition utilizing an argon/methane gas mixture. Prior to coating, the SiC seals were subjected to mechanical polishing using different grades of micron-sized diamond powder to produce different starting surfaces with well-controlled surface roughnesses. Following this roughening process, the seals were seeded by mechanical abrasion with diamond nanopowder, and subsequently coated with UNCD. The coated seals were subjected to dynamic wear testing performed at 3600 RPM and 100 psi for up to 10 days during which the seals were periodically removed and inspected. The UNCD-coated seals were examined using Raman microanalysis, scanning electron microscopy, optical profilometry, and adhesion testing before and after the wear testing. These analyses revealed that delamination of the UNCD films was prevented when the initial SiC seal surface had an initial roughness >0.1 {micro}m. In addition, the UNCD surfaces showed no measurable wear as compared to approximately 0.2 {micro}m of wear for the untreated SiC surfaces.

  3. Functional Blood Progenitor Markers in Developing Human Liver Progenitors.

    PubMed

    Goldman, Orit; Cohen, Idan; Gouon-Evans, Valerie

    2016-08-01

    In the early fetal liver, hematopoietic progenitors expand and mature together with hepatoblasts, the liver progenitors of hepatocytes and cholangiocytes. Previous analyses of human fetal livers indicated that both progenitors support each other's lineage maturation and curiously share some cell surface markers including CD34 and CD133. Using the human embryonic stem cell (hESC) system, we demonstrate that virtually all hESC-derived hepatoblast-like cells (Hep cells) transition through a progenitor stage expressing CD34 and CD133 as well as GATA2, an additional hematopoietic marker that has not previously been associated with human hepatoblast development. Dynamic expression patterns for CD34, CD133, and GATA2 in hepatoblasts were validated in human fetal livers collected from the first and second trimesters of gestation. Knockdown experiments demonstrate that each gene also functions to regulate hepatic fate mostly in a cell-autonomous fashion, revealing unprecedented roles of fetal hematopoietic progenitor markers in human liver progenitors. PMID:27509132

  4. OSCILLATORY PUMP

    DOEpatents

    Underwood, N.

    1958-09-23

    This patent relates to a pump suitable fur pumping highly corrosive gases wherein no lubricant is needed in the pumping chamber thus eliminating possible contamination sources. The chamber contains a gas inlet and outlet in each side, with a paddle like piston suspended by a sylphon seal between these pcrts. An external arrangement causes the paddle to oscillate rapidly between the ports, alternately compressing and exhausting the gas trapped on each side of the paddle. Since the paddle does nnt touch the chamber sides at any point, no lubricant is required. This pump is useful for pumping large quantities of uranium hexafluorine.

  5. The challenges of meeting the blood transfusion requirements in Sub-Saharan Africa: the need for the development of alternatives to allogenic blood.

    PubMed

    Osaro, Erhabor; Charles, Adias Teddy

    2011-01-01

    As a resource, allogenic blood has never been more in demand than it is today. Escalating elective surgery, shortages arising from a fall in supply, a lack of national blood transfusion services, policies, appropriate infrastructure, trained personnel, and financial resources to support the running of a voluntary nonremunerated donor transfusion service, and old and emerging threats of transfusion-transmitted infection, have all conspired to ensure that allogenic blood remains very much a vital but limited asset to healthcare delivery particularly in Sub-Saharan Africa. This is further aggravated by the predominance of family replacement and commercially remunerated blood donors, rather than regular benevolent, nonremunerated donors who give blood out of altruism. The demand for blood transfusion is high in Sub-Saharan Africa because of the high prevalence of anemia especially due to malaria and pregnancy-related complications. All stakeholders in blood transfusion have a significant challenge to apply the best available evidenced-based medical practices to the world-class management of this precious product in a bid to using blood more appropriately. Physicians in Sub-Saharan Africa must always keep in mind that the first and foremost strategy to avoid transfusion of allogenic blood is their thorough understanding of the pathophysiologic mechanisms involved in anemia and coagulopathy, and their thoughtful adherence to the evidenced-based good practices used in the developed world in a bid to potentially reduce the likelihood of allogenic blood transfusion in many patient groups. There is an urgent need to develop innovative ways to recruit and retain voluntary low-risk blood donors. Concerns about adverse effects of allogenic blood transfusion should prompt a review of transfusion practices and justify the need to search for transfusion alternatives to decrease or avoid the use of allogenic blood. These strategies should include the correction of anemia using

  6. Detection of pump degradation

    SciTech Connect

    Greene, R.H.; Casada, D.A.; Ayers, C.W.

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

  7. Development of a magnetic separation method to capture sepsis associated bacteria in blood.

    PubMed

    Lopes, Ana Luisa Kalb; Cardoso, Josiane; Dos Santos, Fernanda Roberta Correa Cleto; Silva, Ana Claudia Graziani; Stets, Maria Isabel; Zanchin, Nilson Ivo Tonin; Soares, Maurilio José; Krieger, Marco Aurélio

    2016-09-01

    Bloodstream infections are important public health problems, associated with high mortality due to the inability to detect the pathogen quickly in the early stages of infection. Such inability has led to a growing interest in the development of a rapid, sensitive, and specific assay to detect these pathogens. In an effort to improve diagnostic efficiency, we present here a magnetic separation method for bacteria that is based on mutated lysozyme (LysE35A) to capture S. aureus from whole blood. LysE35A-coated beads were able to bind different MSSA and MRSA isolates in the blood and also other six Gram-positive and two Gram-negative species in whole blood. This system was capable to bind bacteria at low concentrations (10CFU/ml) in spiked blood. Samples captured with the mutated lysozyme showed more responsive amplification of the 16S gene than whole blood at concentrations of 10(3)-10(5)CFU. These data demonstrate detection of S. aureus directly in blood samples, without in vitro cultivation. Our results show that capture with LysE35A-coated beads can be useful to develop a point of care diagnostic system for rapid and sensitive detection of pathogens in clinical settings. PMID:27432342

  8. Detection of pump degradation

    SciTech Connect

    Casada, D.

    1995-04-01

    There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous special vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Pump head and flow rate are also monitored, per code requirements. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition; advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed.

  9. Insulin pump therapy in pregnancy.

    PubMed

    Kesavadev, Jothydev

    2016-09-01

    Control of blood glucose during pregnancy is difficult because of wide variations, ongoing hormonal changes and mood swings. The need for multiple injections, pain at the injection site, regular monitoring and skillful handling of the syringes/pen further makes insulin therapy inconvenient. Insulin pump is gaining popularity in pregnancy because it mimics the insulin delivery of a healthy human pancreas. Multiple guidelines have also recommended the use of insulin pump in pregnancy to maintain the glycaemic control. The pump can release small doses of insulin continuously (basal), or a bolus dose close to mealtime to control the spike in blood glucose after a meal and the newer devices can shut down insulin delivery before the occurrence of hypoglycaemia. Pump insulin of choice is rapid acting analogue insulin. This review underscores the role of insulin pump in pregnancy, their usage, advantages and disadvantages in the light of existing literature and clinic experience. PMID:27582150

  10. Flow Analysis of the Cleveland Clinic Centrifugal Pump

    NASA Technical Reports Server (NTRS)

    Veres, Joseph P.; Golding, Leonard A. R.; Smith, William A.; Horvath, David; Medvedev, Alexander

    1997-01-01

    An implantable ventricular assist rotordynamic blood pump is being developed by the Cleveland Clinic Foundation in cooperation with the NASA Lewis Research Center. At the nominal design condition, the pump provides blood flow at the rate of 5 liters per minute at a pressure rise of 100 mm of mercury and a rotative speed of 3000 RPM. Bench testing of the centrifugal pump in a water/glycerin mixture has provided flow and pressure data at several rotative speeds. A one-dimensional empirical based pump flow analysis computer code developed at NASA Lewis Research Center has been used in the design process to simulate the flow in the primary centrifugal pump stage. The computer model was used to size key impeller and volute geometric parameters that influence pressure rise and flow. Input requirements to the computer model include a simple representation of the pump geometry. The model estimates the flow conditions at the design and at off-design operating conditions at the impeller leading and trailing edges and the volute inlet and exit. The output from the computer model is compared to flow and pressure data obtained from bench testing.

  11. Air-Operated Sump Pump

    NASA Technical Reports Server (NTRS)

    Nolt, Gary D.

    1988-01-01

    Pump removes liquid seepage from small, restricted area and against large pressure head. Developed for moving small amounts of water and oil from sump pit 85 ft (25.91 m) deep. Fits in space only 6 1/2 in. (16.5 cm) in diameter and 18 in. (45.7 cm) long. In discharge part of pumping cycle, air forces liquid out of pump chamber through pipe. During filling part of pumping cycle, water enters pump chamber from sump pit. Float in chamber next to pump chamber controls pressurization through timer and solenoid valve.

  12. Pulsatile driving of the helical flow pump.

    PubMed

    Ishii, Kohei; Hosoda, Kyohei; Isoyama, Takashi; Saito, Itsuro; Ariyoshi, Koki; Inoue, Yusuke; Sato, Masami; Hara, Sintaro; Lee, Xinyang; Wu, Sheng-Yuan; Ono, Toshiya; Nakagawa, Hidemoto; Imachi, Kou; Abe, Yusuke

    2013-01-01

    The helical flow pump (HFP) is newly developed blood pomp for total artificial heart (TAH). HFP can work with lower rotational speed than axial and centrifugal blood pump. It can be seen reasonable feature to generate pulsatile flow because high response performance can be realized. In this article, pulsatility of HFP was evaluated using mock circulation loop. Pulsatile flow was generated by modulating the rotational speed in various amplitude and heart rate. In the experiment, relationship between Pump flow, pump head, rotational speed amplitude, heart rate and power consumption is evaluated. As the result, complete pulsatile flow with mean flow rate of 5 L/min and mean pressure head of 100 mmHg can be obtained at ± 500 rpm with mean rotational speed of 1378 to 1398 rpm in hart rate from 60 to 120. Flow profiles which are non-pulsatile, quasi-pulsatile or complete flow can be adjusted arbitrarily. Therefore, HFP has excellent pulsatility and control flexibility of flow profile. PMID:24110290

  13. Regulation of pumping function of the heart in developing body under changing regimens of motor activity.

    PubMed

    Vafina, E Z; Abzalov, R A; Abzalov, N I; Nikitin, A S; Gulyakov, A A

    2014-06-01

    We analyzed parameters of the pumping function of the heart in rats subjected to enhanced motor activity after a preliminary 70-day hypokinesia under conditions of α- and β-adrenergic receptor stimulation with norepinephrine followed by blockade of β-adrenergic receptor with propranolol (obsidian) and α1-adrenergic receptors with doxazosin. After norepinephrine administration, the HR and cardiac output were higher in rats with enhanced physical activity after preliminary hypokinesia than in rats with low physical activity. After propranolol administration, stroke volume and cardiac output in 100-day-old rats with limited activity were lower, and HR higher was than in rats with enhanced physical activity after preliminary 70-day hypokinesia. After administration of doxazosin, rats with limited motor activity demonstrated more pronounced changes in HR than rats with enhanced physical activity after preliminary 70-day hypokinesia. PMID:24970234

  14. Ten years optically pumped semiconductor lasers: review, state-of-the-art, and future developments

    NASA Astrophysics Data System (ADS)

    Kannengiesser, Christian; Ostroumov, Vasiliy; Pfeufer, Volker; Seelert, Wolf; Simon, Christoph; von Elm, Rüdiger; Zuck, Andreas

    2010-02-01

    Optically Pumped Semiconductor Lasers - OPSLs - have been introduced in 2001. Their unique features such as power scalability and wavelength flexibility, their excellent beam parameters, power stability and reliability opened this pioneering technology access to a wide range of applications such as flow cytometry, confocal microscopy, sequencing, medical diagnosis and therapy, semiconductor inspection, graphic arts, forensic, metrology. This talk will introduce the OPSL principles and compare them with ion, diode and standard solid state lasers. It will revue the first 10 years of this exciting technology, its current state and trends. In particular currently accessible wavelengths and power ranges, frequency doubling, ultra-narrow linewidth possibilities will be discussed. A survey of key applications will be given.

  15. Requirements Analysis Study for Master Pump Shutdown System Project Development Specification [SEC 1 and 2

    SciTech Connect

    BEVINS, R.R.

    2000-09-20

    This study is a requirements document that presents analysis for the functional description for the master pump shutdown system. This document identifies the sources of the requirements and/or how these were derived. Each requirement is validated either by quoting the source or an analysis process involving the required functionality, performance characteristics, operations input or engineering judgment. The requirements in this study apply to the first phase of the W314 Project. This document has been updated during the definitive design portion of the first phase of the W314 Project to capture additional software requirements and is planned to be updated during the second phase of the W314 Project to cover the second phase of the project's scope.

  16. Injection seeded, diode pumped regenerative ring Nd:YAG amplifier for spaceborne laser ranging technology development

    NASA Technical Reports Server (NTRS)

    Coyle, D. Barry; Kay, Richard B.; Degnan, John J.; Krebs, Danny J.; Seery, Bernard D.

    1992-01-01

    A small, all solid state, regenerative ring amplifier designed as a prototype for space application is discussed. Novel features include dual side pumping of the Nd:YAG crystal and a triangular ring cavity design which minimizes the number of optical components and losses. The amplifier is relatively small (3 ns round trip time) even though standard optical elements are employed. The ring regeneratively amplifies a 100 ps single pulse by approximately 10(exp 5) at a repetition rate of 10 to 100 Hz. The amplifier is designed to be injection seeded with a pulsed, 100 ps laser diode at 1.06 microns, but another Nd:YAG laser system supplying higher pulse energies was employed for laboratory experiment. This system is a prototype laser oscillator for the Geoscience Laser Ranging System (GLRS) platform. Results on measurements of beam quality, astigmatism, and gain are given.

  17. The development of blood-retinal barrier during the interaction of astrocytes with vascular wall cells

    PubMed Central

    Yao, Huanling; Wang, Tianshi; Deng, Jiexin; Liu, Ding; Li, Xiaofei; Deng, Jinbo

    2014-01-01

    Astrocytes are intimately involved in the formation and development of retinal vessels. Astrocyte dysfunction is a major cause of blood-retinal barrier injury and other retinal vascular diseases. In this study, the development of the retinal vascular system and the formation of the blood-retinal barrier in mice were investigated using immunofluorescence staining, gelatin-ink perfusion, and transmission electron microscopy. The results showed that the retinal vascular system of mice develops from the optic disc after birth, and radiates out gradually to cover the entire retina, taking the papilla optica as the center. First, the superficial vasculature is formed on the inner retinal layer; then, the vasculature extends into the inner and outer edges of the retinal inner nuclear layer, forming the deep vasculature that is parallel to the superficial vasculature. The blood-retinal barrier is mainly composed of endothelium, basal lamina and the end-feet of astrocytes, which become mature during mouse development. Initially, the naive endothelial cells were immature with few organelles and many microvilli. The basal lamina was uniform in thickness, and the glial end-feet surrounded the outer basal lamina incompletely. In the end, the blood-retinal barrier matures with smooth endothelia connected through tight junctions, relatively thin and even basal lamina, and relatively thin glial cell end-feet. These findings indicate that the development of the vasculature in the retina follows the rules of “center to periphery” and “superficial layer to deep layers”. Its development and maturation are spatially and temporally consistent with the functional performance of retinal neurons and photosensitivity. The blood-retinal barrier gradually becomes mature via the process of interactions between astrocytes and blood vessel cells. PMID:25206758

  18. Development of a 100 mJ, 5 Hz, flashlamp-pumped, Cr,Tm:YAG coherent lidar transmitter

    NASA Technical Reports Server (NTRS)

    Henderson, S.; Johnson, S.

    1993-01-01

    A contract to develop a 100 mJ, 5 Hz, flashlamp-pumped Cr,Tm:YAG coherent lidar transmitter has been awarded to Coherent Technologies, Inc. (CTI). The lidar transmitter will operate at an eyesafe wavelength of 2.01 microns. The development complements work being performed under an SBIR Phase II with Electro-Optics Technology (EOT). EOT is developing continuous wave, low and medium power Tm:YAG oscillators of a unique design. One of the low power oscillators will be used as the injection seeder/local oscillator in the CIT lidar transmitter. The lidar transmitter will require the addition of a receiver section. Once completed, the lidar will be used in atmospheric performance studies, allowing comparison with that of the more mature CO2 lidar technology. The focus of current research and plans for next year are presented.

  19. Development of a reactor-coolant pump monitoring and diagnostic system. Project management report, October 1980-November 1981

    SciTech Connect

    Sommerfield, G. A.; Morris, D. J.

    1982-02-01

    The objective of the project is to develop a reactor coolant pump monitoring and diagnostic system and collect sufficient data to permit analysts to determine why high outleakage and failures occur at Davis-Besse Nuclear Power Station, Unit 1. This report summarizes the work completed during the first period of performance, October 1, 1980, through November 30, 1981. During this period the members of the Project Team were selected and the detailed work management plans developed to take this project from conception, through detailed engineering, and finally to construction in the early part of 1982. The scope of work described includes system design, equipment selection for the computer-based data collection and diagnostic system, and computer software development to permit data collection and analysis.

  20. Defective CFTR Expression and Function Are Detectable in Blood Monocytes: Development of a New Blood Test for Cystic Fibrosis

    PubMed Central

    Angiari, Chiara; Ettorre, Michele; Johansson, Jan; Vezzalini, Marzia; Viviani, Laura; Ricciardi, Mario; Verzè, Genny; Assael, Baroukh Maurice; Melotti, Paola

    2011-01-01

    Background Evaluation of cystic fibrosis transmembrane conductance regulator (CFTR) functional activity to assess new therapies and define diagnosis of cystic fibrosis (CF) is cumbersome. It is known that leukocytes express detectable levels of CFTR but the molecule has not been characterized in these cells. In this study we aim at setting up and validating a blood test to evaluate CFTR expression and function in leukocytes. Description Western blot, PCR, immunofluorescence and cell membrane depolarization analysis by single-cell fluorescence imaging, using the potential-sensitive DiSBAC2(3) probe were utilized. Expression of PKA phosphorylated, cell membrane-localized CFTR was detected in non-CF monocytes, being undetectable or present in truncated form in monocytes derived from CF patients presenting with nonsense mutations. CFTR agonist administration induced membrane depolarization in monocytes isolated from non-CF donors (31 subjects) and, to a lesser extent, obligate CFTR heterozygous carriers (HTZ: 15 subjects), but it failed in monocytes from CF patients (44 subjects). We propose an index, which values in CF patients are significantly (p<0.001) lower than in the other two groups. Nasal Potential Difference, measured in selected subjects had concordant results with monocytes assay (Kappa statistic 0.93, 95%CI: 0.80–1.00). Results and Significance CFTR is detectable and is functional in human monocytes. We also showed that CFTR-associated activity can be evaluated in 5 ml of peripheral blood and devise an index potentially applicable for diagnostic purposes and both basic and translational research: from drug development to evaluation of functional outcomes in clinical trials. PMID:21811577

  1. Efflux transporters in blood-brain interfaces of the developing brain

    PubMed Central

    Strazielle, Nathalie; Ghersi-Egea, Jean-François

    2015-01-01

    The cerebral microvessel endothelium forming the blood-brain barrier (BBB) and the epithelium of the choroid plexuses forming the blood-CSF barrier (BCSFB) operate as gatekeepers for the central nervous system. Exposure of the vulnerable developing brain to chemical insults can have dramatic consequences for brain maturation and lead to life-long neurological diseases. The ability of blood-brain interfaces to efficiently protect the immature brain is therefore an important pathophysiological issue. This is also key to our understanding of drug entry into the brain of neonatal and pediatric patients. Non-specific paracellular diffusion through barriers is restricted early during development, but other neuroprotective properties of these interfaces differ between the developing and adult brains. This review focuses on the developmental expression and function of various classes of efflux transporters. These include the multispecific transporters of the ATP-binding cassette transporter families ABCB, ABCC, ABCG, the organic anion and cation transporters of the solute carrier families SLC21/SLCO and SLC22, and the peptide transporters of the SLC15 family. These transporters play a key role in preventing brain entry of blood-borne molecules such as drugs, environmental toxicants, and endogenous metabolites, or else in increasing the clearance of potentially harmful organic ions from the brain. The limited data available for laboratory animals and human highlight transporter-specific developmental patterns of expression and function, which differ between blood-brain interfaces. The BCSFB achieves an adult phenotype earlier than BBB. Efflux transporters at the BBB appear to be regulated by various factors subsequently secreted by neural progenitors and astrocytes during development. Their expression is also modulated by oxidative stress, inflammation, and exposure to xenobiotic inducers. A better understanding of these regulatory pathways during development, in particular

  2. Development of Two-Photon Pump Polarization Spectroscopy Probe Technique Tpp-Psp for Measurements of Atomic Hydrogen .

    NASA Astrophysics Data System (ADS)

    Satija, Aman; Lucht, Robert P.

    2015-06-01

    Atomic hydrogen (H) is a key radical in combustion and plasmas. Accurate knowledge of its concentration can be used to better understand transient phenomenon such as ignition and extinction in combustion environments. Laser induced polarization spectroscopy is a spatially resolved absorption technique which we have adapted for quantitative measurements of H atom. This adaptation is called two-photon pump, polarization spectroscopy probe technique (TPP-PSP) and it has been implemented using two different laser excitation schemes. The first scheme involves the two-photon excitation of 1S-2S transitions using a linearly polarized 243-nm beam. An anisotropy is created amongst Zeeman states in 2S-3P levels using a circularly polarized 656-nm pump beam. This anisotropy rotates the polarization of a weak, linearly polarized probe beam at 656 nm. As a result, the weak probe beam "leaks" past an analyzer in the detection channel and is measured using a PMT. This signal can be related to H atom density in the probe volume. The laser beams were created by optical parametric generation followed by multiple pulse dye amplification stages. This resulted in narrow linewidth beams which could be scanned in frequency domain and varied in energy. This allowed us to systematically investigate saturation and Stark effect in 2S-3P transitions with the goal of developing a quantitative H atom measurement technique. The second scheme involves the two-photon excitation of 1S-2S transitions using a linearly polarized 243-nm beam. An anisotropy is created amongst Zeeman states in 2S-4P transitions using a circularly polarized 486-nm pump beam. This anisotropy rotates the polarization of a weak, linearly polarized probe beam at 486 nm. As a result the weak probe beam "leaks" past an analyzer in the detection channel and is measured using a PMT. This signal can be related to H atom density in the probe volume. A dye laser was pumped by third harmonic of a Nd:YAG laser to create a laser beam

  3. Development of a Low Cost Heat Pump Water Heater - First Prototype

    SciTech Connect

    Mei, V. C.; Tomlinson, J. J.

    2007-09-01

    Until now the heat pump water heater (HPWH) has been a technical success but a market failure because of its high initial cost. Oak Ridge National Laboratory (ORNL) was tasked to examine commercially available HPWH product technology and manufacturing processes for cost saving opportunities. ORNL was also tasked to verify the technical feasibility of the cost saving opportunities where necessary and appropriate. The objective was to retain most of the HPWH s energy saving performance while reducing cost and simple payback period to approximately three years in a residential application. Several cost saving opportunities were found. Immersing the HPWH condenser directly into the tank allowed the water-circulating pump to be eliminated and a standard electric resistance storage water heater to be used. In addition, designs could be based on refrigerator compressors. Standard water heaters and refrigerator compressors are both reliable, mass produced, and low cost. To verify the feasibility of these cost saving measures, ORNL completed a conceptual design for an HPWH based on an immersed condenser coil that could be directly inserted into a standard water heater tank through a sleeve affixed to one of the standard penetrations at the top of the tank. The sleeve contour causes the bayonet-style condenser to helix while being pushed into the tank, enabling a condenser of sufficient heat transfer surface area to be inserted. Based on this design, ORNL fabricated the first laboratory prototype and completed preliminary laboratory tests in accordance with the DOE Simulated Use Test Procedure. Hardening during double-wall condenser fabrication was not overcome, so the prototype is single-walled with a liner. The prototype unit was found to have an energy factor of 2.02, verifying that the low-cost design retains most of the HPWH s energy saving performance. Industry involvement is being sought to resolve the fabrication issue and quantify progress on reducing cost and

  4. Development of a questionnaire for assessing factors predicting blood donation among university students: a pilot study.

    PubMed

    Jalalian, Mehrdad; Latiff, Latiffah; Hassan, Syed Tajuddin Syed; Hanachi, Parichehr; Othman, Mohamed

    2010-05-01

    University students are a target group for blood donor programs. To develop a blood donation culture among university students, it is important to identify factors used to predict their intent to donate blood. This study attempted to develop a valid and reliable measurement tool to be employed in assessing variables in a blood donation behavior model based on the Theory of Planned Behavior (TPB), a commonly used theoretical foundation for social psychology studies. We employed an elicitation study, in which we determined the commonly held behavioral and normative beliefs about blood donation. We used the results of the elicitation study and a standard format for creating questionnaire items for all constructs of the TPB model to prepare the first draft of the measurement tool. After piloting the questionnaire, we prepared the final draft of the questionnaire to be used in our main study. Examination of internal consistency using Chronbach's alpha coefficient and item-total statistics indicated the constructs "Intention" and "Self efficacy" had the highest reliability. Removing one item from each of the constructs, "Attitude," "Subjective norm," "Self efficacy," or "Behavioral beliefs", can considerably increase the reliability of the measurement tool, however, such action is controversial, especially for the variables "attitude" and "subjective norm." We consider all the items of our first draft questionnaire in our main study to make it a reliable measurement tool. PMID:20578556

  5. Vital and dispensable roles of Plasmodium multidrug resistance transporters during blood- and mosquito-stage development.

    PubMed

    Rijpma, Sanna R; van der Velden, Maarten; Annoura, Takeshi; Matz, Joachim M; Kenthirapalan, Sanketha; Kooij, Taco W A; Matuschewski, Kai; van Gemert, Geert-Jan; van de Vegte-Bolmer, Marga; Siebelink-Stoter, Rianne; Graumans, Wouter; Ramesar, Jai; Klop, Onny; Russel, Frans G M; Sauerwein, Robert W; Janse, Chris J; Franke-Fayard, Blandine M; Koenderink, Jan B

    2016-07-01

    Multidrug resistance (MDR) proteins belong to the B subfamily of the ATP Binding Cassette (ABC) transporters, which export a wide range of compounds including pharmaceuticals. In this study, we used reverse genetics to study the role of all seven Plasmodium MDR proteins during the life cycle of malaria parasites. Four P. berghei genes (encoding MDR1, 4, 6 and 7) were refractory to deletion, indicating a vital role during blood stage multiplication and validating them as potential targets for antimalarial drugs. Mutants lacking expression of MDR2, MDR3 and MDR5 were generated in both P. berghei and P. falciparum, indicating a dispensable role for blood stage development. Whereas P. berghei mutants lacking MDR3 and MDR5 had a reduced blood stage multiplication in vivo, blood stage growth of P. falciparum mutants in vitro was not significantly different. Oocyst maturation and sporozoite formation in Plasmodium mutants lacking MDR2 or MDR5 was reduced. Sporozoites of these P. berghei mutants were capable of infecting mice and life cycle completion, indicating the absence of vital roles during liver stage development. Our results demonstrate vital and dispensable roles of MDR proteins during blood stages and an important function in sporogony for MDR2 and MDR5 in both Plasmodium species. PMID:26991313

  6. The Drosophila blood-brain barrier: development and function of a glial endothelium.

    PubMed

    Limmer, Stefanie; Weiler, Astrid; Volkenhoff, Anne; Babatz, Felix; Klämbt, Christian

    2014-01-01

    The efficacy of neuronal function requires a well-balanced extracellular ion homeostasis and a steady supply with nutrients and metabolites. Therefore, all organisms equipped with a complex nervous system developed a so-called blood-brain barrier, protecting it from an uncontrolled entry of solutes, metabolites or pathogens. In higher vertebrates, this diffusion barrier is established by polarized endothelial cells that form extensive tight junctions, whereas in lower vertebrates and invertebrates the blood-brain barrier is exclusively formed by glial cells. Here, we review the development and function of the glial blood-brain barrier of Drosophila melanogaster. In the Drosophila nervous system, at least seven morphologically distinct glial cell classes can be distinguished. Two of these glial classes form the blood-brain barrier. Perineurial glial cells participate in nutrient uptake and establish a first diffusion barrier. The subperineurial glial (SPG) cells form septate junctions, which block paracellular diffusion and thus seal the nervous system from the hemolymph. We summarize the molecular basis of septate junction formation and address the different transport systems expressed by the blood-brain barrier forming glial cells. PMID:25452710

  7. The Drosophila blood-brain barrier: development and function of a glial endothelium

    PubMed Central

    Limmer, Stefanie; Weiler, Astrid; Volkenhoff, Anne; Babatz, Felix; Klämbt, Christian

    2014-01-01

    The efficacy of neuronal function requires a well-balanced extracellular ion homeostasis and a steady supply with nutrients and metabolites. Therefore, all organisms equipped with a complex nervous system developed a so-called blood-brain barrier, protecting it from an uncontrolled entry of solutes, metabolites or pathogens. In higher vertebrates, this diffusion barrier is established by polarized endothelial cells that form extensive tight junctions, whereas in lower vertebrates and invertebrates the blood-brain barrier is exclusively formed by glial cells. Here, we review the development and function of the glial blood-brain barrier of Drosophila melanogaster. In the Drosophila nervous system, at least seven morphologically distinct glial cell classes can be distinguished. Two of these glial classes form the blood-brain barrier. Perineurial glial cells participate in nutrient uptake and establish a first diffusion barrier. The subperineurial glial (SPG) cells form septate junctions, which block paracellular diffusion and thus seal the nervous system from the hemolymph. We summarize the molecular basis of septate junction formation and address the different transport systems expressed by the blood-brain barrier forming glial cells. PMID:25452710

  8. Development and validation of a magneto-hydrodynamic solver for blood flow analysis

    NASA Astrophysics Data System (ADS)

    Kainz, W.; Guag, J.; Benkler, S.; Szczerba, D.; Neufeld, E.; Krauthamer, V.; Myklebust, J.; Bassen, H.; Chang, I.; Chavannes, N.; Kim, J. H.; Sarntinoranont, M.; Kuster, N.

    2010-12-01

    The objective of this study was to develop a numerical solver to calculate the magneto-hydrodynamic (MHD) signal produced by a moving conductive liquid, i.e. blood flow in the great vessels of the heart, in a static magnetic field. We believe that this MHD signal is able to non-invasively characterize cardiac blood flow in order to supplement the present non-invasive techniques for the assessment of heart failure conditions. The MHD signal can be recorded on the electrocardiogram (ECG) while the subject is exposed to a strong static magnetic field. The MHD signal can only be measured indirectly as a combination of the heart's electrical signal and the MHD signal. The MHD signal itself is caused by induced electrical currents in the blood due to the moving of the blood in the magnetic field. To characterize and eventually optimize MHD measurements, we developed a MHD solver based on a finite element code. This code was validated against literature, experimental and analytical data. The validation of the MHD solver shows good agreement with all three reference values. Future studies will include the calculation of the MHD signals for anatomical models. We will vary the orientation of the static magnetic field to determine an optimized location for the measurement of the MHD blood flow signal.

  9. Development of a laser optically pumped polarized target for use in heavy-ion physics. [/sup 151/ /sup 153/Eu

    SciTech Connect

    Shivakumar, B.; Beene, J.R.; Bemis, C.E. Jr.; Erb, K.A.; Ford, J.L.C. Jr.; Shapira, D.

    1982-01-01

    Important micro- and macroscopic details of heavy-ion reactions may be explicitly determined when nuclear spin aligned (polarized) targets are used. For deformed nuclei, the orientation of the symmetry axis of the nuclear density distribution is determined by the nuclear spin orientation. Polarized targets would thus allow experiments to be performed as a function of the orientation of the symmetry axis of the nuclear density distribution. A polarized target of /sup 151/ /sup 153/Eu is being developed at Oak Ridge and is based on laser depopulation optical pumping. A spatially defined target is provided by a supersonic gas jet and consists of Eu atoms seeded into an inert carrier gas. Detailed time-dependent optical-pumping calculations predict approx. = 90% nuclear spin polarization in a Eu target with an expected thickness in excess of 10/sup 15/ atoms/cm/sup 2/. We present some of the effects that will be observable in heavy-ion reactions when deformed polarized targets are used.

  10. Hemodynamic effects of pressure-volume relation in the atrial contraction model on the total artificial heart using centrifugal blood pumps.

    PubMed

    Shiga, Takuya; Kuroda, Takehito; Tsuboko, Yusuke; Miura, Hidekazu; Shiraishi, Yasuyuki; Yambe, Tomoyuki

    2013-01-01

    Hemodynamic effects of atrial contraction with centrifugal pump type total artificial heart is unknown. In this study, we simulated an atrial contraction in a mock model. By the driving condition with higher pressure in the mock atrial model, the load during atrial contraction increased. Based on these findings, we examined atrial contraction in the animal using adult goats. Prior to the measurement, we installed a centrifugal-type ventricular assist device (VADs), and then clamped both ventricles. We measured the hemodynamic data without ventricular contractile functions in order to obtain the effect of atrial contraction on hemodynamics under the condition of the total artificial heart (TAH) circulatory support model. We could estimate the heart rate by revolution number and voltage of pumps. There might be a possibility that we could regulate autonomic nervous response with the control of cardiac output. PMID:24110062

  11. Recovery act. Development of design and simulation tool for hybrid geothermal heat pump system

    SciTech Connect

    Wang, Shaojie; Ellis, Dan

    2014-05-29

    The ground source heat pump (GSHP) system is one of the most energy efficient HVAC technologies in the current market. However, the heat imbalance may degrade the ability of the ground loop heat exchanger (GLHX) to absorb or reject heat. The hybrid GSHP system, which combines a geothermal well field with a supplemental boiler or cooling tower, can balance the loads imposed on the ground loop heat exchangers to minimize its size while retaining superior energy efficiency. This paper presents a recent simulation-based study with an intention to compare multiple common control strategies used in hybrid GSHP systems, including fixed setpoint, outside air reset, load reset, and wetbulb reset. A small office in Oklahoma City conditioned by a hybrid GSHP system was simulated with the latest version of eQUEST 3.7[1]. The simulation results reveal that the hybrid GSHP system has the excellent capability to meet the cooling and heating setpoints during the occupied hours, balance thermal loads on the ground loop, as well as improve the thermal comfort of the occupants with the undersized well field.

  12. Detection of pump degradation

    SciTech Connect

    Casada, D.

    1994-12-31

    There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous spectral vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition: advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed.

  13. DEVELOPMENT OF THE U.S. EPA HEALTH EFFECTS RESEARCH LABORATORY FROZEN BLOOD CELL REPOSITORY PROGRAM

    EPA Science Inventory

    In previous efforts, we suggested that proper blood cell freezing and storage is necessary in longitudinal studies with reduced between tests error, for specimen sharing between laboratories and for convenient scheduling of assays. e continue to develop and upgrade programs for o...

  14. BLOOD LEAD, HEARING THRESHOLDS, AND NEUROBEHAVIORAL DEVELOPMENT IN CHILDREN AND YOUTH (JOURNAL VERSION)

    EPA Science Inventory

    NHANES II audiometry data were used to confirm a previously observed link between blood lead (PbB) level and hearing threshold. Other indicators of neurological development, such as age at which a child first sat up, walked, and spoke, and the presence of speech difficulties and ...

  15. The development of novel Blood and Cara cara like citrus varieties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2012 the Citrus Research Board took a unique approach to developing novel citrus cultivars – a biotech approach. Blood and the Cara cara orange are special cultivars that are distinguished by their color and distinctive flavor. These cultivars offer variety in flavor, taste, health-benefits and...

  16. Pump system characterization and reliability enhancement

    SciTech Connect

    Staunton, R.H.

    1997-09-01

    Pump characterization studies were performed at the Oak Ridge National Laboratory (ORNL) to review and analyze six years (1990 to 1995) of data from pump systems at domestic nuclear plants. The studies considered not only pumps and pump motors but also pump related circuit breakers and turbine drives (i.e., the pump system). One significant finding was that the number of significant failures of the pump circuit breaker exceeds the number of significant failures of the pump itself. The study also shows how regulatory code testing was designed for the pump only and therefore did not lead to the discovery of other significant pump system failures. Potential diagnostic technologies both experimental and mature, suitable for on-line and off-line pump testing were identified. The study does not select or recommend technologies but proposes diagnostic technologies and monitoring techniques that should be further evaluated/developed for making meaningful and critically needed improvements in the reliability of the pump system.

  17. Development of blood transfusion product pathogen reduction treatments: a review of methods, current applications and demands.

    PubMed

    Salunkhe, Vishal; van der Meer, Pieter F; de Korte, Dirk; Seghatchian, Jerard; Gutiérrez, Laura

    2015-02-01

    Transfusion-transmitted infections (TTI) have been greatly reduced in numbers due to the strict donor selection and screening procedures, i.e. the availability of technologies to test donors for endemic infections, and routine vigilance of regulatory authorities in every step of the blood supply chain (collection, processing and storage). However, safety improvement is still a matter of concern because infection zero-risk in transfusion medicine is non-existent. Alternatives are required to assure the safety of the transfusion product and to provide a substitution to systematic blood screening tests, especially in less-developed countries or at the war-field. Furthermore, the increasing mobility of the population due to traveling poses a new challenge in the endemic screening tests routinely used, because non-endemic pathogens might emerge in a specific population. Pathogen reduction treatments sum a plethora of active approaches to eliminate or reduce potential threatening pathogen load from blood transfusion products. Despite the success of pathogen reduction treatments applied to plasma products, there is still a long way to develop and deploy pathogen reduction treatments to cellular transfusion products (such as platelets, RBCs or even to whole blood) and there is divergence on its acceptance worldwide. While the use of pathogen reduction treatments in platelets is performed routinely in a fair number of European blood banks, most of these treatments are not (or just) licensed in the USA or elsewhere in the world. The development of pathogen reduction treatments for RBC and whole blood is still in its infancy and under clinical trials. In this review, we discuss the available and emerging pathogen reduction treatments and their advantages and disadvantages. Furthermore, we highlight the importance of characterizing standard transfusion products with current and emerging approaches (OMICS) and clinical outcome, and integrating this information on a database

  18. Development of a xenon/computed tomography cerebral blood flow quality assurance phantom

    SciTech Connect

    Good, W.F.; Gur, D.; Herron, J.M.; Kennedy, W.H.

    1987-09-01

    A simple, easy to use, quality assurance and performance test phantom was developed for the xenon/computed tomography (CT) cerebral blood flow method. The phantom combines an inhalation system which allows for the simulation of xenon buildup or washout in the arterial blood as well as a multisection translatable cylinder in which several sections can be scanned during a preselected protocol to simulate the CT enhancement in brain tissue during a study. The phantom and scanning protocol are described and their use is demonstrated. The results compare favorably to the theoretically expected fast, intermediate, and slow flow values designed into the phantom.

  19. Development of a Flexible Implantable Sensor for Postoperative Monitoring of Blood Flow

    PubMed Central

    Cannata, Jonathan M.; Chilipka, Thomas; Yang, Hao-Chung; Han, Sukgu; Ham, Sung W.; Rowe, Vincent L.; Weaver, Fred A.; Shung, K. Kirk; Vilkomerson, David

    2013-01-01

    We have developed a blood flow measurement system using Doppler ultrasound flow sensors fabricated of thin and flexible piezoelectric-polymer films. These flow sensors can be wrapped around a blood vessel and accurately measure flow. The innovation that makes this flow sensor possible is the diffraction-grating transducer. A conventional transducer produces a sound beam perpendicular to its face; therefore, when placed on the wall of a blood vessel, the Doppler shift in the backscattered ultrasound from blood theoretically would be 0. The diffraction-grating transducer produces a beam at a known angle to its face; therefore, backscattered ultrasound from the vessel will contain a Doppler signal. Flow sensors were fabricated by spin coating a poly(vinylidene fluoride–trifluoroethylene) copolymer film onto a flexible substrate with patterned gold electrodes. Custom-designed battery-operated continuous wave Doppler electronics along with a laptop computer completed the system. A prototype flow sensor was evaluated experimentally by measuring blood flow in a flow phantom and the infrarenal aorta of an adult New Zealand White rabbit. The flow phantom experiment demonstrated that the error in average velocity and volume blood flow was less than 6% for 30 measurements taken over a 2.5-hour period. The peak blood velocity through the rabbit infrarenal aorta measured by the flow sensor was 118 cm/s, within 1.7% of the measurement obtained using a duplex ultrasound system. The flow sensor and electronics operated continuously during the course of the 5-hour experiment after the incision on the animal was closed. PMID:23091251

  20. Development of a flexible implantable sensor for postoperative monitoring of blood flow.

    PubMed

    Cannata, Jonathan M; Chilipka, Thomas; Yang, Hao-Chung; Han, Sukgu; Ham, Sung W; Rowe, Vincent L; Weaver, Fred A; Shung, K Kirk; Vilkomerson, David

    2012-11-01

    We have developed a blood flow measurement system using Doppler ultrasound flow sensors fabricated of thin and flexible piezoelectric-polymer films. These flow sensors can be wrapped around a blood vessel and accurately measure flow. The innovation that makes this flow sensor possible is the diffraction-grating transducer. A conventional transducer produces a sound beam perpendicular to its face; therefore, when placed on the wall of a blood vessel, the Doppler shift in the backscattered ultrasound from blood theoretically would be 0. The diffraction-grating transducer produces a beam at a known angle to its face; therefore, backscattered ultrasound from the vessel will contain a Doppler signal. Flow sensors were fabricated by spin coating a poly(vinylidene fluoride-trifluoroethylene) copolymer film onto a flexible substrate with patterned gold electrodes. Custom-designed battery-operated continuous wave Doppler electronics along with a laptop computer completed the system. A prototype flow sensor was evaluated experimentally by measuring blood flow in a flow phantom and the infrarenal aorta of an adult New Zealand White rabbit. The flow phantom experiment demonstrated that the error in average velocity and volume blood flow was less than 6% for 30 measurements taken over a 2.5-hour period. The peak blood velocity through the rabbit infrarenal aorta measured by the flow sensor was 118 cm/s, within 1.7% of the measurement obtained using a duplex ultrasound system. The flow sensor and electronics operated continuously during the course of the 5-hour experiment after the incision on the animal was closed. PMID:23091251

  1. 21 CFR 870.4380 - Cardiopulmonary bypass pump speed control.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pump speed control. 870... Cardiopulmonary bypass pump speed control. (a) Identification. A cardiopulmonary bypass pump speed control is a... control the speed of blood pumps used in cardiopulmonary bypass surgery. (b) Classification. Class...

  2. 21 CFR 870.4380 - Cardiopulmonary bypass pump speed control.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass pump speed control. 870... Cardiopulmonary bypass pump speed control. (a) Identification. A cardiopulmonary bypass pump speed control is a... control the speed of blood pumps used in cardiopulmonary bypass surgery. (b) Classification. Class...

  3. Chemoenzymatic Synthesis of a Type 2 Blood Group A Tetrasaccharide and Development of High-throughput Assays Enables a Platform for Screening Blood Group Antigen-cleaving Enzymes.

    PubMed

    Kwan, David H; Ernst, Sabrina; Kötzler, Miriam P; Withers, Stephen G

    2015-08-01

    A facile enzymatic synthesis of the methylumbelliferyl β-glycoside of the type 2 A blood group tetrasaccharide in good yields is reported. Using this compound, we developed highly sensitive fluorescence-based high-throughput assays for both endo-β-galactosidase and α-N-acetylgalactosaminidase activity specific for the oligosaccharide structure of the blood group A antigen. We further demonstrate the potential to use this assay to screen the expressed gene products of metagenomic libraries in the search for efficient blood group antigen-cleaving enzymes. PMID:25964111

  4. Targeted blood-to-brain drug delivery --10 key development criteria.

    PubMed

    Gaillard, Pieter J; Visser, Corine C; Appeldoorn, Chantal C M; Rip, Jaap

    2012-09-01

    Drug delivery to the brain remains challenging due to the presence of the blood-brain barrier. In this review, 10 key development criteria are presented that are important for successful drug development to treat CNS diseases by targeted drug delivery systems. Although several routes of delivery are being investigated, such as intranasal delivery, direct injections into the brain or CSF, and transient opening of the blood-brain barrier, the focus of this review is on physiological strategies aiming to target endogenous transport mechanisms. Examples from literature, focusing on targeted drug delivery systems that are being commercially developed, will be discussed to illustrate the 10 key development criteria. The first four criteria apply to the targeting of the blood-brain barrier: (1) a proven inherently safe receptor biology, (2) a safe and human applicable ligand, (3) receptor specific binding, and (4) applicable for acute and chronic indications. Next to an efficient and safe targeting strategy, as captured in key criteria 1 to 4, a favorable pharmacokinetic profile is also important (key criterion 5). With regard to the drug carriers, two criteria are important: (6) no modification of active ingredient and (7) able to carry various classes of molecules. The final three criteria apply to the development of a drug from lab to clinic: (8) low costs and straightforward manufacturing, (9) activity in all animal models, and (10) strong intellectual property (IP) protection. Adhering to these 10 key development criteria will allow for a successful brain drug development. PMID:23016639

  5. Development of a Two-Phase Capillary Pumped Heat Transport for Spacecraft Central Thermal Bus

    NASA Astrophysics Data System (ADS)

    Hoang, Triem; Brown, Michael; Baldauff, Robert; Cummings, Sheila

    2003-01-01

    Thermal requirements of future spacecraft and satellites will certainly outgrow the capability of conventional heat pipes in terms of heat transport, heat density, and temperature control. Emerging passive heat transport technologies such as Capillary Pumped Loop (CPL) and Loop Heat Pipe (LHP) have demonstrated in both ground testing and micro-gravity flight experiments that they have the potential to replace heat pipes as primary heat transport devices in next generation thermal control technology. Like heat pipes, CPLs and LHPs are completely passive systems which have no mechanical moving part to wear out or to introduce unwanted vibration to the spacecraft. However, the heat transport capabilities of CPLs and LHPs are at least one order of magnitude higher than those of heat pipes. Despite sharing many operational characteristics. CPLs and LHPs do have differences. CPLs require a lengthy and tedious start-up procedure to prime the wicks before heat is applied to the evaporator plate. Even with the start-up procedure, start-ups are not always successful. LHPs, on the other hand, do not require a wick pre-conditioning process. But the LHP effective thermal conductance is not as high as that of a CPL. Temperature control of a LHP is not easily achieved. A novel concept, which combined a CPL and a LHP into one loop, was proposed to take advantage of selective features of each system without inheriting their shortcomings. The resultant loop was called Advanced Loop Heat Pipe (A-LHP). A proof-of-concept testbed was put together and tested at the Naval Research Laboratory. Test results showed that the A-LHP performed like a CPL without start-up problems associated with CPLs.

  6. Novel maglev pump with a combined magnetic bearing.

    PubMed

    Onuma, Hiroyuki; Murakami, Michiko; Masuzawa, Toru

    2005-01-01

    The newly developed pump is a magnetically levitated centrifugal blood pump in which active and passive magnetic bearings are integrated to construct a durable ventricular assist device. The developed maglev centrifugal pump consists of an active magnetic bearing, a passive magnetic bearing, a levitated impeller, and a motor stator. The impeller is set between the active magnetic bearing and the motor stator. The active magnetic bearing uses four electromagnets to control the tilt and the axial position of the impeller. The radial movement of the levitated impeller is restricted with the passive stability dependent upon the top stator and the passive permanent magnetic bearing to reduce the energy consumption and the control system complexity. The top stator was designed based upon a magnetic field analysis to develop the maglev pump with sufficient passive stability in the radial direction. By implementing this analysis design, the oscillating amplitude of the impeller in the radial direction was cut in half when compared with the simple shape stator. This study concluded that the newly developed maglev centrifugal pump displayed excellent levitation performance and sufficient pump performance as a ventricular assist device. PMID:15745134

  7. Normetex Pump Alternatives Study

    SciTech Connect

    Clark, Elliot A.

    2013-04-25

    A mainstay pump for tritium systems, the Normetex scroll pump, is currently unavailable because the Normetex company went out of business. This pump was an all-metal scroll pump that served tritium processing facilities very well. Current tritium system operators are evaluating replacement pumps for the Normetex pump and for general used in tritium service. An all-metal equivalent alternative to the Normetex pump has not yet been identified. 1. The ideal replacement tritium pump would be hermetically sealed and contain no polymer components or oils. Polymers and oils degrade over time when they contact ionizing radiation. 2. Halogenated polymers (containing fluorine, chlorine, or both) and oils are commonly found in pumps. These materials have many properties that surpass those of hydrocarbon-based polymers and oils, including thermal stability (higher operating temperature) and better chemical resistance. Unfortunately, they are less resistant to degradation from ionizing radiation than hydrocarbon-based materials (in general). 3. Polymers and oils can form gaseous, condensable (HF, TF), liquid, and solid species when exposed to ionizing radiation. For example, halogenated polymers form HF and HCl, which are extremely corrosive upon reaction with water. If a pump containing polymers or oils must be used in a tritium system, the system must be designed to be able to process the unwanted by-products. Design features to mitigate degradation products include filters and chemical or physical traps (eg. cold traps, oil traps). 4. Polymer components can work in tritium systems, but must be replaced regularly. Polymer components performance should be monitored or be regularly tested, and regular replacement of components should be viewed as an expected normal event. A radioactive waste stream must be established to dispose of used polymer components and oil with an approved disposal plan developed based on the facility location and its regulators. Polymers have varying

  8. Ferroelectric Pump

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    A ferroelectric pump has one or more variable volume pumping chambers internal to a housing. Each chamber has at least one wall comprising a dome shaped internally prestressed ferroelectric actuator having a curvature and a dome height that varies with an electric voltage applied between an inside and outside surface of the actuator. A pumped medium flows into and out of each pumping chamber in response to displacement of the ferroelectric actuator. The ferroelectric actuator is mounted within each wall and isolates each ferroelectric actuator from the pumped medium, supplies a path for voltage to be applied to each ferroelectric actuator, and provides for positive containment of each ferroelectric actuator while allowing displacement of the entirety of each ferroelectric actuator in response to the applied voltage.

  9. Development of stable, narrow spectral line-width, fiber delivered laser source for spin exchange optical pumping

    SciTech Connect

    Liu, Bo; Tong, Xin; Jiang, Chenyang; Brown, Daniel R.; Robertson, Lee

    2015-06-05

    In this study, we developed a stable, narrow spectral line-width, fiber delivered laser source for spin exchange optical pumping. An optimized external cavity equipped with an off-the-shelf volume holographic grating narrowed the spectral line-width of a 100 W high-power diode laser and stabilized the laser spectrum. The laser spectrum showed a high side mode suppression ratio of >30 dB and good long-term stability (center wavelength drifting within ±0.002 nm during 220 h of operation). Finally, our laser is delivered by a multimode fiber with power ~70 W, center wavelength of 794.77 nm, and spectral bandwidth of ~0.12 nm.

  10. Fluid Dynamics in Sucker Rod Pumps

    SciTech Connect

    Cutler, R.P.; Mansure, A.J.

    1999-01-14

    Sucker rod pumps are installed in approximately 90% of all oil wells in the U.S. Although they have been widely used for decades, there are many issues regarding the fluid dynamics of the pump that have not been fully investigated. A project was conducted at Sandia National Laboratories to develop unimproved understanding of the fluid dynamics inside a sucker rod pump. A mathematical flow model was developed to predict pressures in any pump component or an entire pump under single-phase fluid and pumping conditions. Laboratory flow tests were conducted on instrumented individual pump components and on a complete pump to verify and refine the model. The mathematical model was then converted to a Visual Basic program to allow easy input of fluid, geometry and pump parameters and to generate output plots. Examples of issues affecting pump performance investigated with the model include the effects of viscosity, surface roughness, valve design details, plunger and valve pressure differentials, and pumping rate.

  11. Indexes of pumps for oil field pumping units

    SciTech Connect

    Ibragimov, E.S.

    1995-07-01

    As reported previously, a series of oil field pumping units has been developed with power outputs of 125, 250, 500, and 1000 kW, designed for injecting working fluids in cementing operations in oil and gas wells, hydraulic fracturing of formations, washing out sand plugs, and other production operations. The units are designed for the use of three-plunger pumps with individual power outputs of 125 or 500 kW. In the 250- and 1000-kW units, two such pumps are used. The 1000-kW pumping unit serves mainly for deep-penetration hydraulic fracturing of formations, and also for fracturing deep formations. The hydraulic fracturing process does not require the use of units with two pumps; this has been demonstrated by experience, both here and in other countries. All units intended for use in hydraulic fracturing are built with a single pump, transmission, and drive. Pumping units for well cementing must have two pumps that will give a high delivery rate. At the start of the operation, a single pump can be used to feed water into the cement mixer, with the second pump used to transfer the cement slurry to the well. Then both pumps are connected to the slurry injection line. The operation of these pumps is described.

  12. 5. Station Unwatering Pumps and Sump Pump for Units 1 ...

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

    5. Station Unwatering Pumps and Sump Pump for Units 1 and 2, view to the west. The unwatering pumps are the two larger items toward the right side of the photograph (one in foreground and one in background. The smaller item toward the left of the photograph is the sump pump. These pumps are used for draining water from the draft chest for maintenance. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  13. Lunar base heat pump

    NASA Technical Reports Server (NTRS)

    Goldman, Jeffrey H.; Tetreault, R.; Fischbach, D.; Walker, D.

    1994-01-01

    A heat pump is a device which elevates the temperature of a heat flow by a means of an energy input. By doing this, the heat pump can cause heat to transfer faster from a warm region to a cool region, or it can cause heat to flow from a cool region to a warmer region. The second case is the one which finds vast commercial applications such as air conditioning, heating, and refrigeration. Aerospace applications of heat pumps include both cases. The NASA Johnson Space Center is currently developing a Life Support Systems Integration Facility (LSSIF, previously SIRF) to provide system-level integration, operational test experience, and performance data that will enable NASA to develop flight-certified hardware for future planetary missions. A high lift heat pump is a significant part of the TCS hardware development associated with the LSSIF. The high lift heat pump program discussed here is being performed in three phases. In Phase 1, the objective is to develop heat pump concepts for a lunar base, a lunar lander, and for a ground development unit for the SIRF. In Phase 2, the design of the SIRF ground test unit is being performed, including identification and evaluation of safety and reliability issues. In Phase 3, the SIRF unit will be manufactured, tested, and delivered to the NASA Johnson Space Center.

  14. Lunar base heat pump

    NASA Astrophysics Data System (ADS)

    Goldman, Jeffrey H.; Tetreault, R.; Fischbach, D.; Walker, D.

    1994-10-01

    A heat pump is a device which elevates the temperature of a heat flow by a means of an energy input. By doing this, the heat pump can cause heat to transfer faster from a warm region to a cool region, or it can cause heat to flow from a cool region to a warmer region. The second case is the one which finds vast commercial applications such as air conditioning, heating, and refrigeration. Aerospace applications of heat pumps include both cases. The NASA Johnson Space Center is currently developing a Life Support Systems Integration Facility (LSSIF, previously SIRF) to provide system-level integration, operational test experience, and performance data that will enable NASA to develop flight-certified hardware for future planetary missions. A high lift heat pump is a significant part of the TCS hardware development associated with the LSSIF. The high lift heat pump program discussed here is being performed in three phases. In Phase 1, the objective is to develop heat pump concepts for a lunar base, a lunar lander, and for a ground development unit for the SIRF. In Phase 2, the design of the SIRF ground test unit is being performed, including identification and evaluation of safety and reliability issues. In Phase 3, the SIRF unit will be manufactured, tested, and delivered to the NASA Johnson Space Center.

  15. Progress on the development of the MediWatch ambulatory blood pressure monitor and related devices.

    PubMed

    Ng, Kim-Gau; Ting, Choon-Meng; Yeo, Joon-Hock; Sim, Kwang-Wei; Peh, Wee-Leng; Chua, Ngak-Hwee; Chua, Ngak-Kwong; Kwong, Frank

    2004-06-01

    The MediWatch is a wrist-mounted noninvasive blood pressure monitor designed to capture the radial pulse waveform using arterial tonometry and yield blood pressure measurements when the waveform is calibrated. An early prototype of this monitor uses a pulse-sensing system with a cylindrical plunger to applanate the radial artery. This prototype was evaluated against simulated blood pressure generated by a pneumatic pressure-pulse generator. The simulation-based results show that the prototype gave accurate pressure measurements when the MediWatch waveforms were calibrated against the simulator's pressure, indicating that the pulse-sensing system was able to measure force accurately. The prototype was clinically evaluated against intra-arterial pressure on post-open heart surgery patients. The results show that, under stationary conditions, for short periods of time and when the MediWatch waveforms were calibrated against the intra-arterial pressure, the prototype gave measurements that satisfy some of the statistical criteria of the 1993 Association for the Advancement of Medical Instrumentation standard, the 1993 British Hypertension Society protocol and the 2002 European Society of Hypertension protocol. These clinical results indicate that, under the stated test conditions, the prototype was able to accurately track changes in the patients' systolic and diastolic pressures. The MediWatch is being developed into an ambulatory device that provides a macroscopic view of the patient's blood pressure through measurement at preprogrammed intervals over 24 h, as well as a microscopic view of the patient's pressure through the pulse waveform captured during each measurement cycle. The design features of the MediWatch are being adapted for other applications that require the arterial pulse waveform, calibrated beat-to-beat blood pressure or both. An improved MediWatch prototype has been developed that provides memory storage for measurement data and functions as an

  16. RENEWABLE LIQUID GETTERING PUMP

    DOEpatents

    Batzer, T.H.

    1962-08-21

    A method and structure were developed for pumping gases by simple absorption into a liquid gettering material. The invention comprises means ror continuously pumping a liquid getterrng material from a reservoir to the top of a generally vertical surface disposed in a vacuum pumping chamber to receive gaseous and other particles in the liquid gettering material which continuously flows downward over the vertical suiface. Means are provided for continuous removal, degassing, and return of a portion of the liquid gettering material from the reservoir connected with collectrng means at the base of the generally vertical plate. (AEC)

  17. Numerical simulation of the pulsating catheter pump: A left ventricular assist device.

    PubMed

    Verkerke, G J; Mihaylov, D; Geertsema, A A; Lubbers, J; Rakhorst, G

    1999-10-01

    The pulsating catheter (PUCA) pump, a left ventricular assist device, consists of a hydraulically or pneumatically driven membrane pump, extracorporeally placed and mounted to a valved catheter. The catheter is introduced into an easily accessible artery and positioned with its distal tip in the left ventricle. Blood is aspirated from the left ventricle during systole and ejected into the ascending aorta during diastole. A numerical model of the PUCA pump has been developed to determine the internal diameter of the PUCA pump catheter that allows a certain blood flow. The model considers a limitation of mechanical blood damage and determines the accompanying pressure and flow profile for driving the pump. For a flow of 5 L/min, a catheter with an internal diameter of at least 6. 95 mm is required. For 3 L/min, the minimal diameter is 5.50 mm. The latter catheter can be introduced in the axillary artery, the former via the aorta during an open thorax