2070results about "Blood pumps" patented technology

A system, method and apparatus for performing a renal replacement therapy is provided. In one embodiment, two small high flux dialyzers are connected in series. A restriction is placed between the two dialyzers in the dialysate flow path. The restriction is variable and adjustable in one preferred embodiment. The restriction builds a positive pressure in the venous dialyzer, causing a high degree of intentional backfiltration. That backfiltration causes a significant flow of dialysate through the high flux venous membrane directly into the patient's blood. That backfiltered solution is subsequently ultrafiltered from the patient from the arterial dialyzer. The diffusion of dialysate into the venous filter and removal of dialysate from the arterial dialyzer causes a convective transport of toxins from the patient. Additionally, the dialysate that does not diffuse directly into the patient but instead flows across the membranes of both dialyzers provides a diffusive clearance of waste products.

The catheter device comprises a motor located at the proximal end of the catheter device and a drive shaft, extending from the proximal end section to the distal end section of the catheter device, for driving a rotating element located at the distal end of the catheter device. The catheter device also comprises a hose-like catheter body which encompasses the drive shaft and extends from the proximal end section to the distal end section of the catheter device. At the proximal end of the catheter device, the drive shaft is connected to a motor by a clutch. The clutch is a magnetic clutch with a proximal and a distal magnet unit. The proximal magnet unit is connected to the motor and the distal magnet unit to the drive shaft. The distal magnet unit is mounted fluid-tight in a clutch housing. The proximal end of the catheter body makes a fluid-tight connection with the clutch housing.

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.

An inflatable circulation assist device is disclosed consisting of an inflatable stator housing an impeller with inflatable blades of varying shapes and sizes. The invention is introduced into the patient percutaneously. The circulation assist device is a small pump packaged into a compact form that is attached to a long flexible driveshaft. The pump is inserted along a guidewire to a target location, and then the pump is inflated. The circulation assist device's exterior is designed to expand only so much as to closely fit whatever cardiovascular system element in which it is placed for operation. The vascular assist device can be expanded either by inflation with a fluid. The driveshaft, which connects to the circulation assist device's impeller and extends outside the patient's body, is rotated by an external motor. After the circulation assist device is no longer needed, it is collapsed into a compact form and removed from the patient percutaneously.

A method for deploying a cardiac-assist device is disclosed. In accordance with the illustrative embodiment, an introducing tube, such as a catheter, sheath, or the like is inserted into the vascular system and advanced beyond the aortic arch. The cardiac-assist device is then inserted into the tube, advanced through it, and deployed from its distal end. In some embodiments, the diameter of the cardiac-assist device expands when it deploys from the distal end of the tube.

The present invention generally relates to hemodialysis and similar dialysis systems, including a variety of systems and methods that would make hemodialysis more efficient, easier, and/or more affordable. One aspect of the invention is generally directed to new fluid circuits for fluid flow. In one set of embodiments, a hemodialysis system may include a blood flow path and a dialysate flow path, where the dialysate flow path includes one or more of a balancing circuit, a mixing circuit, and/or a directing circuit. Preparation of dialysate by the preparation circuit, in some instances, may be decoupled from patient dialysis. In some cases, the circuits are defined, at least partially, within one or more cassettes, optionally interconnected with conduits, pumps, or the like. In one embodiment, the fluid circuit and/or the various fluid flow paths may be at least partially isolated, spatially and/or thermally, from electrical components of the hemodialysis system. In some cases, a gas supply may be provided in fluid communication with the dialysate flow path and/or the dialyzer that, when activated, is able to urge dialysate to pass through the dialyzer and urge blood in the blood flow path back to the patient. Such a system may be useful, for example, in certain emergency situations (e.g., a power failure) where it is desirable to return as much blood to the patient as possible. The hemodialysis system may also include, in another aspect of the invention, one or more fluid handling devices, such as pumps, valves, mixers, or the like, which can be actuated using a control fluid, such as air. In some cases, the control fluid may be delivered to the fluid handling devices using an external pump or other device, which may be detachable in certain instances. In one embodiment, one or more of the fluid handling devices may be generally rigid (e.g., having a spheroid shape), optionally with a diaphragm contained within the device, dividing it into first and second compartments.

A wireless power system capable of transmitting power through the skin without percutaneous wires over distances ranging from a few inches to several feet includes an external transmitting coil assembly and a receiving coil assembly. The transmitting coil assembly includes an excitation coil and transmitting resonant coil which are inductively coupled to each other. The receiving coil assembly includes a receiving resonant coil and a power pick-up coil which are also inductively coupled to each other. A high frequency AC power input, such as radio frequency (RF), supplied to the excitation coil inductively causes the transmitting resonant coil to resonate resulting in a local time varying magnetic field. The transmitting and receiving resonant coils are constructed as to have closely matched or identical resonant frequencies so that the magnetic field produced by the transmitting resonant coil is able to cause the receiving resonant coil to resonate strongly also, even when the distance between the two resonant coils greatly exceeds the largest dimension of either coil. The receiving resonant coil then creates its own local time varying magnetic field which inductively produces a voltage in a power pick-up coil to provide power to an active implantable medical device or implantable rechargeable battery.

Methods and apparatus are provided for treating congestive heart by actively or passively enhancing perfusion to the renal arteries. A first embodiment comprises a specially configured balloon catheter and extracorporeal pump, wherein the pump operates in a “once-through” fashion or alternating volume displacement mode. In another embodiment the catheter includes a pair of balloons to isolate a region of the aorta, and a third balloon that directs flow into the renal arteries. In still further embodiments, a stent or cuff having a constricted region is deployed in or around the aorta, respectively, to create a backpressure upstream of the stent or cuff. Methods of enhancing renal perfusion also are provided.

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 reverse flow pump comprising two concentric passageways and an interior compartment having cut out portions in communication with a pump passageway for the directional flow of fluid relative to the pump, and a rotor positioned within the interior compartment for reversing the directional flow of fluid through a region in communication with another pump passageway. A reverse flow pump and cannula system is further provided comprising an inner cannula adjoining a pump passageway, and an outer conduit adjoining another pump passageway for the reverse flow of fluid relative to the pump. A method of transporting fluid between body cavities is also provided comprising the steps of selecting a reverse flow pump and cannula system, forming an opening in a body passageway, positioning the outer conduit through the opening, inserting the inner cannula into the outer conduit so that the distal openings of the inner cannula and the outer conduit are positioned in separated portions of the body, connecting the inlet and the outlet passageways of the pump to the proximal ends of the inner cannula and the outer conduit, and activating the pump to transport fluid between the separated portions of the body.

Disclosed herein are heart pumps that include a catheter assembly and that can be applied percutaneously. Some embodiments include a locking device that prevents components of the catheter assembly from being separated when in use. The catheter assembly can include an expandable tip. In some embodiments, the catheter assembly includes a housing having a wall structure, a portion of which can have a bulbuous shape or can be deformable. In other embodiments, the housing can be configured to reduce fluttering or deflection of the housing and/or to maintain a gap between the housing and an impeller blade disposed therein.

An impeller according to an example of the present invention comprises a hub, and at least one blade supported by the hub. The impeller has a deployed configuration in which the blade extends away from the hub, and a stored configuration in which the impeller is radially compressed, for example by folding the blade towards the hub. The impeller may comprise a plurality of blades, arranged in blade rows, to facilitate radial compression of the blades. The outer edge of a blade may have a winglet, and the base of the blade may have an associated indentation to facilitate folding of the blade.

Methods of and devices for restoring the normal geometry of a heart, including but not limited to the structures supporting the atrioventricular valves. The techniques and devices described herein operate on the principle of displacement, both active and passive, to reverse cardiac remodeling and limit ischemic atrioventricular valve regurgitation.

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.

The present invention provides a human engineered power and control system for artificial hearts or assist devices configured for ease of use, ruggedness, and high reliability. Battery powered systems of the prior art have required multiple cables and connectors that are subject to failure due to damage or wear. In the present invention, direct connection of the batteries to the control system eliminates multiple cables and connectors used with previous designs. A novel method of connecting batteries to the control system and exchanging batteries without interruption of power is provided in a compact user friendly configuration. The control system may provide periodic reductions in assist device flow to permit the natural ventricle to eject blood through the natural outflow valve, open the valve leaflets to prevent them from adhering together, and achieve sufficient washout to prevent thrombosis. Using either software based control or software independent electronic circuitry, the flow pumped by the artificial heart is reduced for a long enough period of time to permit at least a few beats of the natural heart to generate sufficient pressure to open the outflow valve. In a control system embodiment in which the patient manually adjusts the pump speed to incremental settings for rest and exercise conditions, a pulsatile flow mode is disclosed which provides approximately the same flow at a given incremental setting as the pump produces when running in a constant speed mode at the same setting. As the patient learns which speed setting is best for daily activities, the patient may use the same setting with either a pulsatile or constant pump speed mode.