1419 results about "Blood pump" patented technology

A prosthetic valve assembly for use in replacing a deficient native valve comprises a replacement valve supported on an expandable valve support. If desired, one or more anchors may be used. The valve support, which entirely supports the valve annulus, valve leaflets, and valve commissure points, is configured to be collapsible for transluminal delivery and expandable to contact the anatomical annulus of the native valve when the assembly is properly positioned. Portions of the valve support may expand to a preset diameter to maintain coaptivity of the replacement valve and to prevent occlusion of the coronary ostia. A radial restraint, comprising a wire, thread or cuff, may be used to ensure expansion does not exceed the preset diameter. The valve support may optionally comprise a drug elution component. The anchor engages the lumen wall when expanded and prevents substantial migration of the valve assembly when positioned in place. The prosthetic valve assembly is compressible about a catheter, and restrained from expanding by an outer sheath. The catheter may be inserted inside a lumen within the body, such as the femoral artery, and delivered to a desired location, such as the heart. A blood pump may be inserted into the catheter to ensure continued blood flow across the implantation site during implantation procedure. When the outer sheath is retracted, the prosthetic valve assembly expands to an expanded position such that the valve and valve support expand at the implantation site and the anchor engages the lumen wall. Insertion of the catheter may optionally be performed over a transseptally delivered guidewire that has been externalized through the arterial vasculature. Such a guidewire provide dual venous and arterial access to the implantation site and allows additional manipulation of the implantation site after arterial implantation of the prosthetic valve. Additional expansion stents may be delivered by venous access to the valve.

A blood pump includes an impeller having a plurality of foldable blades and a cannula having a proximal portion with a fixed diameter, and a distal portion with an expandable diameter. The impeller can reside in the expandable portion of the cannula. The cannula has a collapsed condition for percutaneous delivery to a desired location within the body, and an expanded condition in which the impeller can rotate to pump blood. A flexible drive shaft can extend through the cannula for rotationally driving the impeller within the patient's body.

A generally cylindrical rotor very closely confined between two rigid thrust bearing surfaces is radially suspended by an array of attracting or repelling magnets or by a combination of permanent magnets and ring shaped members composed of ferromagnetic material. The geometry permits very small spacing between magnetic components to achieve high radial stiffness. High magnetic axial forces exerted between the rotor and stationary component on one end of the rotor are counter-balanced by equal and opposite forces at the other end of the rotor. Precise positioning of the rotor in the location where the opposing axial magnetic forces counterballance each other yields a net magnetic axial force on the rotor of near zero, hence the reference to this as the null position. Wear resistant mechanical thrust bearings confine the rotor axially to maintain this position during rotatioin. Precisely balance the magnetic axial forces in the proper geometry with relation to the mechanical thrust bearings. Blood pumps utilizing this type of bearing are disclosed, including both axial flow pump and centrifugal flow pump configurations with high flow washing of the junction of the rotating and stationary parts to prevent thrombus accumulation.

A foldable intravascularly insertable blood pump comprises a rotatable impeller provided with vanes, a flexible shaft extending through a catheter and adapted to drive said impeller, and an envelope enclosing said impeller. For simplifying the technical setup of the blood pump and enhancing its robustness, the impeller comprises radially delivering vanes. The envelope comprises an annular bulge in the region of the impeller, wherein between the radially outer ends of the vanes and the envelope an annular deflection channel is defined. The impeller and the envelope are adapted to be folded by relative displacement of the shaft and the catheter.

A cardiopulmonary bypass system utilizing membrane-based reciprocating positive displacement blood pumps (“pod pumps”). In one aspect, the pod pumps are constructed to provide reduced shear forces on the blood being pumped. In another aspect blood flow through the pod pumps can be controlled by a controller using information from pressure sensors in the control chamber of the pod pumps. In another aspect, the pod pumps are included on a disposable unit that can be received and held by a receptacle means on a base unit, the base unit also providing pressurized control fluid to the pod pumps on the disposable unit through the receptacle means.

In a left ventricular assist device (LVAD) a rotodynamic blood pump (10) is powered by a brushless DC motor (12). A power supply (14) supplies power to the motor (12). Three feedback channels, one for each of voltage, current, and motor speed lead to a microcontroller or microprocessor (18). The three feedback waveforms are analyzed, and from these waveforms, motor input power, patient heart rate, current pump flow rate, and systemic pressure are determined. The microprocessor (18) then calculates a desired flow rate proportional to the patient heart rate. The microprocessor communicates a new power output to a commutation circuit (16), which regulates power to the motor (12). The pump (10) also includes safety checks that are prioritized over desired pump flow. These include prevention of ventricular suction, low pulsatility, minimum and maximum pump speed, minimum speed-relative pump flow, minimum absolute pump flow, minimum and maximum motor input power.

A blood pump (26) includes a stator assembly including a fluid inlet (24) and a fluid outlet (26). A rotor assembly (120) includes an impeller (40) rotatable about an axis (44) to move fluid from the inlet (24) to the outlet (26). A motor (50) imparts rotation of the impeller (40) about the axis (44). The motor (50) includes a motor stator (52) fixed to the stator assembly (122), a motor rotor (54) fixed to the rotor assembly (120), and a radial motor gap (34) between the stator (52) and the rotor (54). The pump (20) is configured to direct a mixed blood flow from the fluid inlet (24) to the fluid outlet (26) and a wash flow through the motor gap (34).

A magnetically-levitated blood pump with an optimization method that enables miniaturization and supercritical operation. The blood pump includes an optimized annular blood gap that increases blood flow and also provides a reduction in bearing stiffness among the permanent magnet bearings. Sensors are configured and placed optimally to provide space savings for the motor and magnet sections of the blood pump. Rotor mass is increased by providing permanent magnet placement deep within the rotor enabled by a draw rod configuration.

The flow rate of blood in an implantable blood pump is determined at least in part based on a parameter related to thrust on the rotor of the pump. The parameter may be a parameter related to displacement of the rotor along its axis, such as a function of the back electromotive force generated in one or more coils of the stator. The back electromotive force may be measured during open-phase periods of a particular coil or set of coils, during which no power is applied to the coil or set of coils by the motor drive circuit. The parameter related to thrust may be used in conjunction with the speed of rotation of the rotor, the magnitude of current supplied to the rotor, or both to determine the flow rate. The pump may be controlled responsive to the determined flow rate.

A tiny electrically powered hydrodynamic blood pump is disclosed which occupies one third of the aortic or pulmonary valve position, and pumps directly from the left ventricle to the aorta or from the right ventricle to the pulmonary artery. The device is configured to exactly match or approximate the space of one leaflet and sinus of valsalva, with part of the device supported in the outflow tract of the ventricular cavity adjacent to the valve. In the configuration used, two leaflets of the natural tri-leaflet valve remain functional and the pump resides where the third leaflet had been. When implanted, the outer surface of the device includes two faces against which the two valve leaflets seal when closed. To obtain the best valve function, the shape of these faces may be custom fabricated to match the individual patient's valve geometry based on high resolution three dimensional CT or MRI images. Another embodiment of the invention discloses a combined two leaflet tissue valve with the miniature blood pump supported in the position usually occupied by the third leaflet. Either stented or un-stented tissue valves may be used. This structure preserves two thirds of the valve annulus area for ejection of blood by the natural ventricle, with excellent washing of the aortic root and interface of the blood pump to the heart. In the aortic position, the blood pump is positioned in the non-coronary cusp. A major advantage of the transvalvular VAD is the elimination of both the inflow and outflow cannulae usually required with heart assist devices.

An integrated disposable cartridge for dialysis or ultrafiltration treatment of blood is disclosed that includes integral miniature pressure sensors. Sensors are embedded in the tubing of the cartridge to measure pressure of blood or other fluids. Cartridge elements form a continuous smooth bore passage for blood that reduces probability of clotting.

A rotary blood pump is provided which includes a pump housing and a rotor mounted for rotation with the housing. The rotor has an impeller. A rotor motor is provided including a plurality of permanent magnets carried by the impeller. A first motor stator is positioned on one side of the impeller and a second motor stator is positioned on an opposite side of the impeller. The motor stators each include a plurality of electrically conductive coils and pole pieces located within the housing. A plurality of wedge-shaped hydrodynamic thrust bearings are located outside of the axis of the rotor. During rotation of the impeller, the hydrodynamic bearings are separated from the housing by a fluid film and are not in direct mechanical contact with the housing.

The presence or absence of a suction condition in an implantable blood pump is determined at least in part based on a parameter related to flow, such as a parameter related to thrust on the rotor of the pump. A local extreme of the parameter representing the minimum flow during ventricular diastole in an earlier interval is used to establish a threshold value. A value of the parameter representing the minimum flow during ventricular diastole in a later interval is compared to this threshold. If the comparison indicates a substantial decline in the minimum flow between the earlier and later intervals is associated with a suction condition. During the absence of a suction condition, the threshold is continually updated, so that the system does not indicate presence of a suction condition if the flow decreases gradually.