52 results about "Turbulent blood flow" patented technology

Prosthetic devices as described for use in the treatment of aortic stenosis in the aortic valve of a patient's heart, the prosthetic device having a compressed state for transarterial delivery and being expandable to an expanded state for implantation. The prosthetic device includes an expandable metal base (10) constructed so as to be implantable in the expanded state of the prosthetic device in the aortic annulus of the aortic valve; and an inner envelope lining (11) tune inner surface of the metal base (10). The inner envelope, in the expanded state of the prosthetic device, extends into the aorta and is of a diverging conical configuration, in which its diameter gradually increases from its proximal end within the aortic annulus to its distal end extending into the aorta, such as to produce, during systole, a non-turbulent blood flow into the aorta with pressure recovery at the distal end of the inner envelope. Preferably, the distal end includes a prosthetic valve which is also concurrently implanted, but such a prosthetic valve may be implanted separately in the aorta Also described are preferred methods of implanting such prosthetic devices.

The present invention relates to apparatus for influencing fluid flow over a surface, and more particularly, but not exclusively, to turbulent boundary layer flow drag reduction for an aircraft. The present invention provides such apparatus including a plasma generator comprising first and second spaced-apart independently controllable electrodes operable to cause a change in direction of the flow of the fluid over the surface.

A device for testing a turbulent flow blending flow field in a crosscurrent comprises a blending test section communicated with a main airflow; an atomizing nozzle is arranged on the blending test section and communicated therewith; matt paint is uniformly applied onto the inner wall of the blending test section; a plurality of slits are formed on the lateral wall of the blending test section; a double pulse Nd:YAG laser is arranged on one side of the blending test section, and the slits are formed on the side; a CCD camera is arranged at the outlet of the blending test section; and the double pulse Nd:YAG laser and the CCD camera are connected with a computer through a PIV synchronous controller separately. The invention addresses the difficulties in filming the flow field of a rotating flow centrifugal nozzle in a limited passage during the process of atomizing blending in the cross flow, such as liquid accumulation on the inner wall, the influence of ambient light, the arrangement of the camera and frequent calibration due to the filming of different sections, and at last can obtain a clear blending particle picture, thereby obtaining the important information about the flow field, the velocity field, the distribution of vorticity and the like.

An artificial or modified natural blood flow tubing has a helical-flow inducer to induce helical flow in such a fashion as to eliminate or reduce turbulence. One inducer is a tubular stent of expansible mesh having a helical vane.

A method and apparatus for treating wastewater. The apparatus comprises a reactor having a flow channel generally centrally located in a reactor and immersed in the water or wastewater in the reactor. An agitator is disposed within the flow channel and induces water or wastewater to enter the open upper end thereof and to move downwardly through the flow channel where the water or wastewater is discharged via a flow divider. A reagent is injected into the water or wastewater and the agitator within the flow channel serves to mix the reagent with the water or wastewater passing therethrough and in the process causes at least a slightly turbulent and downward axial flow through the flow channel.

Aspects of the present disclosure include branching fluid passages in an apparatus that reduce turbulent flow and generate evenly distributed fluid pressure as the fluids branch off into the different passages. In some embodiments, the branching passages may be subdivided into two sets: the branching passages for the liquid fuel and the branching passages for the liquid oxidizer. In some embodiments, the two sets of passages are carefully designed in an elegant yet extremely intricate manner that is optimized for proper fluid flow and maximal burn efficiency. The ends of all of the passages meet at the injector interface, which dispense the liquids into the combustion chamber for ignition. Generally, these designs are achieved through additive manufacturing, and would be extremely difficult, if not impossible, to be manufactured using traditional techniques.

Wear is reduced in abrasive slurry service at an outlet into an annular space defined by the wellbore and around the tool. In a gravel packing application with a crossover, the slurry exits a central passage and goes into an internal annulus in the tool. Turning vanes that make at least one full turn and that have a height at least partially the height of the annular space are there to impart a swirl movement to at least a portion of the slurry stream. The swirling motion has beneficial effects of reducing turbulence which allows a velocity reduction for a comparable output volume. As a result of the lower turbulence leading to the final exit from the tool into the surrounding annulus, the exit ports experience reduced erosion and longer service life.

A filtration and monitoring system includes an online monitoring device and a filter block having a chamber therein. An inlet pipe provides fluid to the filter block chamber and has an inlet valve located therein configured to shut off the flow of the fluid through the inlet pipe. An outlet pipe removes fluid from the filter block chamber. A filtered fluid conduit fluidically connects the filter block with the monitoring device. The outlet axis of the outlet pipe is offset from the inlet axis of the inlet pipe such that the fluid undergoes a change of direction while passing through the filter block chamber thereby causing turbulent flow within the filter block chamber. The turbulent flow within the filter block sweeps off particles that accumulate on the filter block chamber-side of the filter element to reduce the buildup of filter cake on the filter element. Closing the inlet valve causes a relatively sharp stop to the flow of fluid through the filter block, resulting in a back-flushing flow of fluid through the filter element from a pressure accumulator located in the filtered fluid conduit to the filter block chamber. The back-flushing flow of fluid dislodges filter cake accumulated on the filter block chamber-side of the filter element.

A gas pressure regulator capable of minimizing vibration and improving overall fluid flow efficiency. The gas pressure regulator achieves these benefits using varying techniques including providing a nozzle having a primary passage, a secondary passage, and a flow channel groove to smooth the fluid flow, reduce turbulence, and improve overall flowrate, without adversely effecting the necessary backpressure required for reliable operation. Additionally, the gas pressure regulator may use angled walls in the low-pressure cavity to enhance deflection and distribution. Still further, the gas pressure regulator may use additional flow channels to permit smooth fluid flow while eliminating fluid impact.

An apparatus and method for electrochemically treating the struts of an intravascular stent is disclosed. An intravascular stent is mounted in a chamber and is electrochemically treated in order to remove a portion of the stent struts in order to form an airfoil shape. The airfoil-shaped stent struts will reduce turbulent blood flow in the vasculature in which the stent is implanted thereby improving clinical outcome.

A device and method is disclosed for reducing turbulent blood flow over stent struts of an intravascular stent implanted in, for example, a coronary artery. An abrasive slurry is passed over the struts of an intravascular stent in order to remove a portion of the stent struts to form an airfoil shape. When the stent having airfoil-shaped struts is implanted in an artery, the flow of blood over the airfoil shape will reduce the likelihood of turbulent blood flow and thereby will reduce the likelihood of turbulent blood flow and thereby reduce the likelihood of a buildup in plaque or injury to the vessel wall.

There is described an arteriovenous fistula stent, having a tubular body comprising a series of sinusoidal shaped struts along the length of the tubular body. A plurality of curvilinear connectors extend between and are attached to adjacent struts wherein a first end of a connector is attached to a distal face of a proximal strut apex and a second end of a connector is attached to a proximal face of a distal strut apex. A pair of unconnected strut apexes are between pairs of connected apexes. When the tubular body is in a stowed configuration a proximal aperture and a distal aperture are circular and when the tubular body is in a deployed configuration the distal aperture is oblong or ovoid. There is also described a method for inserting a stent for use in creation of an arteriovenous fistula by identifying a candidate artery and a candidate vein and dissecting the candidate vein. Next, inserting a stent into the vein and creating a breach in the candidate artery at a desired angle and location. Next, introducing the stent and vein into the candidate artery and forming the stent into a curvature angle selected to minimize turbulent blood flow in an anastomosis formed by the vein and the artery. Optionally, there is a step of fastening a distal portion of the stent to the artery.

The pressure of hydraulic fluid which is supplied to the continuously variable transmission in the power train of a motor vehicle is regulated by an apparatus wherein an adjustable pilot valve can receive fluid from a pilot conduit leading to a pressure reducing valve. The pilot conduit normally receives fluid from a further conduit, wherein the pressure of fluid is at least substantially constant, by way of a flow restrictor. A branch conduit serves to evacuate fluid from the pilot conduit into the pilot valve when the latter is at least partially open. The fluid-discharging end of the flow restrictor confronts the inlet of the branch conduit, and such inlet is narrowed to reduce the likelihood of turbulence developing in the fluid stream flowing from the pilot conduit, across the further conduit and into the inlet of the pilot valve.

This invention presents a Pitot tube design and methodology for determining the flow characteristics of fluids in subsonic and supersonic flow, including the effects of viscosity and turbulence. A new methodology, the Two-Fluid Theory, is developed which treats a real fluid as being composed of two ideal fluids: an inviscid fluid and a Poiseuille fluid. The resulting expression for flow velocity is applicable to a real fluid of any viscosity and to pipes of any L/D ratios, including entrance effects.

Two designs, comprising annular, smooth-bore tubes, with devices for measuring total and static pressures, are presented: one for incompressible flow; one for compressible, supersonic flow. Allowance is made for the viscous component of the flow to become fully developed, in accordance with the Theory.

A method of identifying the presence of turbulence in fluids, e.g. for distinguishing flames from other hot bodies, examines the correlation between adjacent pixels of an array viewing the fluid and particularly the proportion of negative correlation in the presence of strong positive correlation.

A non-imaging diagnostic ultrasound system for carotid artery diagnosis has a two dimensional array probe with a low element count and relatively large element size which can cover an area of the carotid artery at its bifurcation. The elements are operated independently with no phasing, and detect Doppler flow spatially beneath each element. The system produces maps of carotid blood flow in two or three dimensions and can assemble an extended view of the flow by matching segments of the carotid flow as the probe is moved over the vessel. Once the carotid artery has been localized, the degree of stenosis is assessed by automated measurements of peak systolic velocity and blood flow turbulence.