Other

United States Surgical Corporation

Ethicon, Gmbh

Symbion, Inc.

University of Utah Research Foundation

Jervik Heart, Inc.

Jarvik Heart Inc.

Jarvik, Robert

Robert K Jarvik

Daniel E Alesi

Robert J Geiste

Steven J Stern

John F Klinger

Francis X Kaczynski

Steven R Day

Keith Payea

Kenneth G Hammerquist

Mark Howansky

Deborah M Cashin

Robert W Mericle

Stephen J Jewusiak

Patrick K Campbell

Miniature axial flow pumps are implanted inside the heart or major arteries to provide hemodynamic support. These pumps commonly utilize tubular blood conduit tubes to transport blood across the aortic valve. The valve leaflets themselves are very thin and flexible, and will seal against the conduit if it is centered within the valve orifice. The present invention provides a conduit support device that retains the conduit centered within the annulus of the natural heart valve. A leaflet valve stent may be combined with a conduit support device comprised of a ring supported by posts attached to the valve stent ring. A blood pump may be attached to the center of a transvalvular support stent, for optimal fixation of the pump with relation to a trileaflet or bi-leaflet tissue or polymer valve.

Support stent for transvalvular conduit

A centrifugal blood pump uses the 'double suction' arrangement of the blood flow channels, by dividing the blood flow across the impeller into two practically identical streams, one flowing across the upstream side of the impeller and the other flowing across the downstream side. The double suction arrangement is obtained by using a 'flow through cone bearing' mounted to the hub of the impeller. The impeller is attached to the driving motor by three posts, which do not significantly diminish the flow area. The annular flow through the motor &#x201c;air gap&#x201d; reaches the flow channel as a single stream and divides into two streams in the vicinity of the posts. The flow is distributed equally to the two sides of the impeller. After passing across the impeller the two streams combine into one that enters the spiral volute and continues past the pump cutwater and through the outflow channel.

Single inflow double suction centrifugal blood pump

Miniature axial flow pumps are implanted inside the heart or major arteries to provide hemodynamic support. These pumps commonly utilize tubular blood conduit tubes to transport blood across the aortic valve. The valve leaflets themselves are very thin and flexible, and will seal against the conduit if it is centered within the valve orifice. If the conduit is not centered, a leaflet can be pushed to the side of the aorta, preventing the leaflets from sealing and providing a path for backflow. If the blood flow conduit remains pushed against the side of the valve for a long period of time, thrombus may form in the crevice between the conduit and the aorta, causing serious thromboembolic events such as stroke, if the thrombus breaks free. The present invention provides a conduit support device that retains the conduit centered within the annulus of the natural heart valve. A leaflet valve stent may be combined with a conduit support device comprised of a ring supported by posts attached to the valve stent ring. A blood pump may be attached to the center of a transvalvular support stent, for optimal fixation of the pump with relation to a trileaflet or bi-leaflet tissue or polymer valve.

Highly miniaturized electro-mechanical medical implants for certain applications cannot be fit into the available anatomic space unless their diameter can be made small enough. With devices such as rotary blood pumps or linear actuators, using rotary or linear electric motors, a thin motor stator that provides sufficient power must be encased in a corrosion resistant hermetically sealed enclosure into which electric wires must pass. Hermetic feedthroughs of the prior art are not structurally suited to maximal miniaturization with optimal electrical properties because of the need for welding of ferrules or other support components. The sub-miniature medical implants having the robust feedthrough of the present invention integrate the feedthrough wires, insulators, and sealing within a radially extending flange that is part of the end wall of the motor enclosure. This permits the largest feedthrough wire and thickest insulator to be built into the limited available space.

Sub-miniature electromechanical medical implants with integrated hermetic  feedthroughs

Highly miniaturized electromechanical medical implants for certain applications cannot be fit into the available anatomic space unless their diameter can be made small enough. With devices such as rotary blood pumps or linear actuators, using rotary or linear electric motors, a thin motor stator that provides sufficient power must be encased in a corrosion resistant hermetically sealed enclosure into which electric wires must pass. Hermetic feedthroughs of the prior art are not structurally suited to maximal miniaturization with optimal electrical properties because of the need for welding of ferrules or other support components. The sub-miniature medical implants having the robust feedthrough of the present invention integrate the feedthrough wires, insulators, and sealing within a radially extending flange that is part of the end wall of the motor enclosure. This permits the largest feedthrough wire and thickest insulator to be built into the limited available space.

Sub-miniature electromechanical medical implants with integrated hermetic feedthroughs

Rotary hydrodynamic blood pumps have been used to treat over a thousand patients. The Jarvik 2000 has supported a patient for seven years and uses blood immersed bearings washed by high flow to avoid excessive thrombus formation. This permits the pump to be very simple and small. Nonetheless, the present Jarvik 2000 bearings and all other mechanical blood immersed bearings of the prior art have a supporting structure that predisposes to thrombus adjacent to the bearings. The present invention provides a bearing structure that eliminates this predilection site for thrombus formation, and may provide indefinite thrombus free operation. The rotor of the preferred embodiment includes a tapered hub fabricated of wear resistant material supported by three posts at each end of the rotor, upon which the rotor rotates. Blood washes the unobstructed spaces between the posts to prevent the accumulation of a torus of thrombus that could enlarge excessively.

Blood pump bearings with separated contact surfaces

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.

Minimally invasive transvalvular ventricular assist device

A method for providing at least partial bypass of the heart to supplement the pumping function of the heart to thereby enable the surgeon to perform various surgical procedures thereon includes providing a circulatory assist system having a portable extracorporeal axial flow pump with a pump housing, a rotating pumping member disposed in the pump housing and inlet and outlet cannulated tubes respectively connected to inlet and outlet ports of the pump housing, accessing the patient's left atrium of the heart with the inlet cannulated tube, accessing the aorta with the outlet cannulated tube, actuating the rotating pumping member to draw oxygenated blood from the left atrium of the heart through the lumen of the inlet cannulated tube and into the inlet port of the pump housing whereby the pumping member imparts mechanical energy to the oxygenated blood passing through the pump housing and directs the oxygenated blood through the outlet port and through the lumen of the outlet cannulated tube to be transferred by the aorta to the systemic arteries and permitting the right side of the heart to function whereby oxygen-depleted blood returning through the systemic veins to the right atrium is directed through the right ventricle to the patient's lungs for oxygenation and subsequent pulmonary circulation.

Circulatory support system

During coronary artery bypass grafting (CABG) surgery in cases when cardio-pulmonary bypass is not used, at times when the heart is manipulated or lifted the inflow to the right ventricle may be kinked and obstructed. Then flow across the lungs will decrease and left ventricular filling may output will be diminished. To avoid this problem a passive shunt, which in the preferred embodiment is a valved shunt, is used to conduct blood from the inferior vena cava (IVC) via the right atrium to the pulmonary artery (PA) bypassing the right ventricle. The shunt uses large diameter cannulae to keep its resistance low. The valve prevents blood from flowing from the PA into the IVC. The shunt may also use a manually actuated shutoff valve or may have a portion which can be clamped. During surgery, the patient may be fluid loaded so that the right atrial pressure is high, such as 25 mmHg. Then, with the shunt open, if the right ventricular inflow becomes obstructed during manipulation of the heart, blood will flow passively across the shunt and across the lungs. The shunt may also be used with a left ventricular bypass pump during CABG surgery.

Right ventricular bypass devices and methods of their use during heart surgery

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.

Axial force null position magnetic bearing and rotary blood pumps which use them

Implanted medical devices such as heart assist devices powered by electric motors or solenoids require a high amount of power compared to other electric implants such as pacemakers which do not use motors. A percutaneous power transmission system for use with implanted motors includes a skull-mounted post and a highly flexible array of wires implanted in a serpentine configuration to enhance flex life and prevent failure due to excessive longitudinal tension. In the preferred embodiment, a cable passed across the neck in zig-zag fashion includes a separable implanted connector removably attachable within a post fixed by bone screws and a flange to the skull. The implanted connector is passed through smaller incisions and a smaller subcutaneous tunnel then would be required to fit the flange. This reduces surgical trauma, and facilitates healing without infection and with minimal scarring on the neck.

Growing community of inventors

Salt Lake City, UT, United States of America

Robert K Jarvik