JP2001523529A - Cardiac assist system with cannula pump - Google Patents

Abstract

A heart assist pump system includes a cannula having a tip, an inhalation valve associated with the cannula, a release valve associated with the cannula, and a balloon inflatable adjacent to the tip of the cannula. Such an extensible protrusion. The cardiac assist pump system is also a cannula having a tip, including an inhalation valve, a release valve, and an extensible protrusion, such as an inflatable balloon, adjacent the tip of the guide and having a tip to guide the cannula. And a guide for performing the operation. Alternatively or additionally, the pump pumps blood directly from the atrium, such as the right atrium, or a vein that connects to the atrium, such as the vena cava, to an artery that connects to the same side of the heart as the atria, such as the pulmonary artery.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates generally to devices and systems for enhancing cardiac blood flow, and more particularly to an intraventricular cardiac assist pump.

[0002] Intra-aortic and intraventricular cardiac assist devices are well known in the art. These devices are commonly used to reduce the burden on the heart during or after a stroke or during or after surgery. It can also be used to increase blood flow from the left ventricle to the aorta, for example, when cardiac output is insufficient due to, for example, acute or chronic heart disease or interference with normal cardiac function during surgery. .

[0003] One of the best known and most widely used intra-aortic pump systems is the intra-aortic balloon pump (IABP), which is equipped with a catheter and has an inflatable balloon at the tip, which passes through the artery. Is inserted into. Next, in order to assist the left ventricle in pumping blood into the aortic system, the balloon is alternately inflated with an external pump device to alternately block and unblock the aortic blood flow in synchronization with the heartbeat. Shrink. However, IABP only marginally enhances the flow of blood without the natural assistance of the heart and is not enough to overcome heart failure.

[0004] US Pat. No. 4,014,317, which is incorporated herein by reference,
A cardiovascular assist cannula with a balloon pump and cardiac pacing electrodes is described. The cannula is inserted percutaneously through the aorta such that the tip enters the left ventricle. During cardiac contraction, the suction valve of the cannula in the left ventricle opens, and blood flows into the cannula due to contraction of the ventricle. Then, during diastole, blood flows out of the aorta through one or more release valves along the cannula downstream of the inhalation valve. The gas-filled balloon functions similarly to the IABP described above and is connected to the cannula downstream of the release valve. The balloon is typically inflated during diastole and deflated during systole to assist in coronary artery perfusion. However, this cannula has a small stroke volume and uses the contractile force of the heart to pump blood. Therefore, its usefulness for enhancing cardiac blood flow in a weak or diseased heart is limited.

[0005] PCT Publication No. WO 97/02850, which is incorporated herein by reference, describes a cardiac assist system based on a catheter system that inserts the tip of a cannula into the left ventricle via the aorta. An intake valve draws blood from the ventricle and a release valve delivers blood to the aorta. A hydraulic pump mechanism external to the body at the proximal end of the catheter serves as a pump and a container for blood drawn from the ventricles. But,
While this system is useful in alleviating heart failure in a wide variety of problems, it has the limitation that the diameter of the catheter is limited by the arterial tract that the catheter must travel along the way to the ventricle. In addition, the catheter may be problematic because it is inserted in the opposite direction of the leaflet leaflet of the aortic valve.

[0006] PCT application PCT / IL97 / 00201, which is incorporated herein by reference, describes a cannula valve that forms an inlet valve and a discharge valve as a unit located between two tubular sections of the cannula. I have.

Hemopump Cardiac sold by Johnson & Johnson Interventional Systems
In the Assist System, a cannula containing a special small rotor pump mechanism is inserted into the aorta. The pump is driven by an extracorporeal drive unit and continuously pumps blood from the aorta to the rest of the arterial system, thereby supplementing the heart's natural blood output. A system of this type is also described in US Pat. No. 5,092,844, which is incorporated herein by reference. While continuous flow devices are useful for short-term cardiac output enhancement, it is medically known that pulsatile pumps are more effective for long-term support. This is because it is closer to the natural feeding activity of the heart.

All of the above references relate to pumps for increasing blood flow from the left side of the heart.

[0009] Catheters utilize balloons to facilitate movement of the catheter within the bloodstream. However, such balloons to facilitate movement are not used in at least some delivery systems. This is because the cannula used in such a system is generally inserted in a direction opposite to the blood flow.

It is an object of the present invention to provide a cardiac assist pump for improving blood flow from the heart.

In a first aspect of the invention, a cardiac assist pump is utilized to pump blood into a pulmonary artery. In some preferred embodiments of the present invention, the pump pumps blood directly from the vena cava. In some aspects of the invention, the pump delivers blood directly from the right atrium. In some aspects of the invention, the pump pumps blood from the right ventricle.

In a second aspect of the present invention, a cardiac assist system includes a cannula inserted from the right ventricle into a pulmonary artery. The cannula enters the right ventricle through the jugular, femoral, and / or vena cava. Such a system is particularly useful in locations that handle the heart during bypass surgery.

In a third aspect of the invention, the pump comprises a cannula and one-way valve structures are provided on both sides of the cannula to ensure that the alternate inflow and outflow of blood is controlled.

In a fourth aspect of the present invention, there is provided a cannula pump having an extensible protrusion, such as a balloon, mounted thereon. The pump is designed so that blood is between one position and the other, and the structure of the balloon provides sufficient obstruction to blood flow such that the tip of the cannula is guided or carried in the direction of flow. It is configured to be.

In a preferred embodiment of the invention, the ventricular assist pump comprises a cannula, the tip of which is inserted into the pulmonary artery via the vena cava or right ventricle. It also includes a pulsatile drive unit coupled to the cannula at the proximal end. The cannula defines an inner lumen and includes an outer sheath surrounding the inner lumen, the inner lumen adjacent to, and preferably in communication with, the distal end of the cannula and a length of the cannula downstream of the inlet valve. And one or more suction valves arranged radially along the axis. The pulsatile drive unit alternately lowers and increases the blood pressure in the cannula. As the pressure decreases, at least one suction valve opens, one or more discharge valves close, and blood flows through the suction valve into the lumen of the cannula. Next, the internal pressure of the cannula is increased, the suction valve is closed and the release valve is opened, and blood exits the lumen and flows into the pulmonary artery. A generally similar structure cannula can also be used to deliver from the left ventricle to the aorta by inserting the cannula through the left ventricular apex.

In a preferred embodiment of the invention, the balloon is mounted at or near the tip of a cannula. The balloon is inflated between cannula placements. In the inflated state, the balloon creates resistance to blood flow, thereby being carried along with the blood flow. This helps guide the end of the cannula through the curvature in the right atrium and right ventricle and into the pulmonary artery. Similarly, the balloon facilitates positioning of the cannula within the aorta as the cannula is inserted into the aorta from the left ventricle.

Since the cannula is inserted into the pulmonary artery via the vena cava and right ventricle, the cannula has a diameter, especially when entering the blood stream through the major vena cava, compared to prior art cardiac assist devices. Can be very large. The auxiliary pump is
Unlike known prior art cannula pumps, the discharge valve is at or in communication with the tip of the cannula and the suction valve is near the discharge valve. In addition, the release valve can be (and preferably is) coaxial with the cannula so that blood flow from the valve is not obstructed by the wall of the artery to which blood is pumped. This can provide higher pressure and greater flow to the vascular system than prior art assist devices. Further, the inhalation valve is generally on either side of the cannula, the valve is in the vena cava or right ventricle, and the inhalation valve is substantially unobstructed. Since the passage through the ventricle includes many bends, the cannula may have different diameters at the inhalation and the ejection. The suction section of the catheter is preferably of a large diameter to allow for large outflows, which are usually limited by suction pressure and cavitation. Preferably, the distal end of the cannula is thinner and softer to facilitate guiding the cannula.

In some preferred embodiments of the present invention, the pulsatile drive unit includes a fluid container having first and second chambers separated by a buffy membrane, each having a fluid port. The fluid port of the first chamber is connected to the proximal end of the cannula so that blood can flow between the chamber and the cannula. The fluid port of the second chamber is connected to a hydraulic mechanism, which alternately raises and lowers the pressure of the control fluid in the second chamber, so that its volume also increases,
Decrease. The flexible membrane does not directly contact the fluid in the second chamber and the blood in the first chamber,
The pressure change from the second chamber to the first chamber is coupled, thereby controlling the flow of blood into and out of the cannula lumen as described above. Such pumps are described, for example, in the aforementioned PCT publication. Using a hydraulic mechanism, compared to the pneumatic pump drive mechanism commonly used in other cardiac assist pumps known in the art,
The volume of blood that can be pumped becomes very large, increasing efficiency. However, the present invention is not limited to such pumps, and it is advantageous to use other delivery systems for the present invention as known in the art.

In a preferred embodiment of the present invention, as described above, the delivered blood remains completely within the first chamber of the cannula and the fluid container connected thereto and does not substantially circulate outward. The cannula and fluid container are preferably disposable to reduce the likelihood of infection and intended for a single use.

In a preferred embodiment of the invention, the cannula is capable of delivering at least 50 cc, preferably up to 80 cc of blood per stroke of the pulsatile drive unit. However, depending on clinical needs, the cardiac assist pump may be adjusted to deliver smaller volumes, for example, 20 cc per stroke. The pulsatile drive unit preferably operates at approximately the human heart rate, and the speed and volume are:
Adjust to maintain proper flow. The drive is preferably synchronized with the heartbeat to draw blood into the lumen of the cannula during systole and release blood into the artery during diastole.

Alternatively, blood may be drawn into the lumen during diastole and synchronized in order to release during contraction, or may operate asynchronously regardless of heart rate.

In a preferred embodiment of the invention, the cannula is 15-45 French (5-15
cm) or a soft elastic tube having a diameter in the range of even larger. It is preferably inserted from the vena cava during surgery or percutaneously from the jugular or femoral vein through the right atrium into the right ventricle and then through the pulmonary valve into the pulmonary artery.

In some preferred embodiments of the present invention, the inlet and outlet valves comprise a valve unit consisting of an outer hard tube with a radial bore and an inner soft structure. The internal soft structure includes a soft leaflet type release valve and a cylindrical sleeve that covers the hole from inside the tube to form a suction valve.

A fluid container having a variable fluid volume is connected to the proximal end of the cannula so that blood can flow between the lumen and the container, and a pump mechanism alternately increases and decreases the fluid volume in the container. To produce a pulsatile pumping action of blood through the cannula,
Preferably, there is provided a pump drive coupled to the fluid container for controlling the fluid volume in said container.

Thus, according to a preferred embodiment of the present invention, a cardiac assist pump system includes a cannula having a tip, an inhalation valve associated with the cannula, a discharge valve associated with the cannula, and an inflation valve adjacent the tip of the cannula. And an extensible protrusion, such as a flexible balloon.

In accordance with a preferred embodiment of the present invention, there is further provided a cannula having a tip, an inhalation valve, a discharge valve, and an extensible protrusion, such as an inflatable balloon, having a tip adjacent thereto. And a guide for guiding the cannula having a portion.

According to a preferred embodiment of the present invention, there is further provided a cannula having a tip, a suction valve having a suction portion from the circulatory system and coupled to the cannula, and a cannula having a discharge portion to the circulatory system. An associated release valve, such that the distance between the inhalation and the discharge is such that when the cannula is located on the right side of the heart, the discharge is in the pulmonary artery and the inhalation is in the right atrium or vena cava. A heart assist pump system is provided.

According to a preferred embodiment of the present invention, further comprising a cannula having a tip, an inhalation valve associated with the cannula, and a release valve associated with the cannula, coupling the blood to the heart's atrium or its atria. A ventricular assist system is provided for pumping from the vein to the ventricle on the same side of the heart as the atrium and out to the artery.

In a preferred embodiment of the invention, the atrium is the right atrium and the pump is designed to pump blood from the right atrium to the pulmonary artery.

In another preferred embodiment of the invention, the atrium is the right atrium and the pump is designed to pump blood from the vena cava to the pulmonary artery.

In another preferred embodiment of the invention, the atrium is the left atrium and the pump is designed to pump blood from the left atrium to the aorta.

In a preferred embodiment of the invention, the discharge valve communicates with an opening at or near the tip of the cannula, and the suction valve communicates with an opening near the opening with which the discharge valve communicates.

The release valve is preferably an axial valve communicating with an opening at the tip of the cannula.

Preferably, the release valve is a leaflet having a plurality of leaves.

The suction valve preferably comprises a valve through which blood enters the cannula via an orifice in the wall of the cannula. Preferably, the orifice is formed in a portion of a cannula having a cylindrical inner wall, and the suction valve comprises an internal soft tube. The inner soft tube preferably closes the orifice when there is no pressure differential. The inner soft tube is preferably separated from the orifice by a negative internal pressure against the outside of the cannula, opening the orifice. Preferably, the inner soft tube is integrally formed by a release valve.

[0036] Preferably, the cannula is substantially larger in diameter at the suction valve than at its tip.

According to a preferred embodiment of the present invention, there is further provided a method of enhancing blood flow from a vein leading into or into the atrium of the heart to an outlet of an artery connecting to the ventricle of the heart,
The method includes inserting a cannula having a distal end and a proximal end into the heart and arteries such that the distal end of the cannula enters the artery and the more proximal portion of the cannula enters the atria or veins and the atrial via the lumen of the cannula. Or transfer blood from veins to arteries.

[0038] Preferably, the method includes providing an intake valve in communication with the opening of the cannula near the proximal end of the cannula.

[0039] Preferably, the method comprises providing a discharge valve in communication with the opening at the tip of the cannula. Preferably, placement of the release valve includes providing an axial release valve in communication with the opening at the distal end of the cannula.

In a preferred embodiment of the present invention, the method includes a discharge valve in communication with the opening of the cannula at a distal end of the opening in communication with the suction valve.

Transferring blood involves inhaling blood from the atrium or vein through an inhalation valve by a pressure drop in the cannula, and pumping the blood from the cannula through the release valve to the artery through an inhalation valve through an increase in the pressure in the cannula. It preferably comprises releasing.

Preferably, inserting the cannula into the heart or artery comprises inserting the cannula into the artery from the ventricle via a heart valve. Preferably, the method comprises guiding the cannula through the ventricle to an artery. The guide includes an extensible protrusion, such as a balloon, adjacent to the tip of the cannula, stretching the extensible protrusion to inflate the balloon, with the expanded protrusion under the effect of blood flow. It preferably consists of allowing at least part of the cannula to be advanced.

In a preferred embodiment of the invention, the atrium is the right atrium and the artery is the pulmonary artery. Preferably, blood is transferred directly from the right atrium to the pulmonary artery via the cannula.

In a preferred embodiment of the present invention, the vein is the vena cava and the artery is the pulmonary ventricle. Preferably, blood is transferred directly from the vena cava to the pulmonary artery via the cannula.

In a preferred embodiment of the invention, the atrium is the left atrium and the artery is the aorta. Preferably, blood is transferred directly from the left and right atrium to the aorta via the cannula.

Referring now to FIG. 1, which is a schematic cross-sectional view of a cardiac assist pump system 18 according to a preferred embodiment of the present invention. The system includes an intra-aortic cannula 20 having an outer sheath 22 defining and surrounding an inner lumen 24. Cannula 20 is 1
Have a diameter in the range of 5 to 45 French (5 to 15 mm) and are made of a soft elastic material, such as polyurethane reinforced with stainless steel, so that it can be inserted and passed through the main veins of the human body Is preferred. When the cannula is inserted through a thinner vein, the size may be reduced. The cannula 20 is further preferably a leaflet valve and preferably axially disposed, with a discharge valve 26 following the outlet at or near the tip 28 and one or more radially disposed along the cannula sheath 22. And a plurality of suction valves 30.

The release valve 26 and the suction valve 30 allow blood to enter and exit the cannula 20 in substantially only one direction, enter through the suction valve 30 and exit through the discharge valve 26 (as described below, (Corresponding to the direction of blood flow), it is preferably a one-way valve. In the preferred embodiment of the invention shown in FIG. 1, the suction valve is a mechanical flap valve that pivots about a hinge 36 to open and close.

[0048] Preferably, the release valve 26 is a leaflet valve. However, in other preferred embodiments of the present invention, other types of valves, similar to valve 30, that open outwardly may be used. Such leaflet valves are described, for example, in PCT Publication No. WO 97/4, the disclosure of which is incorporated herein by reference.
It is known in the art for use in cardiac assist devices such as those described in US Pat. Another is PCT Patent Application No. PCT / IL, entitled "Apex Cannula Pump," filed November 24, 1997 and incorporated herein by reference.
A valve as described in 97/00386 may be used.

In other preferred embodiments of the present invention, other types of suction valves may be used as well, eg, as described below.

In a preferred embodiment of the present invention, cannula 20 incorporates an extensible protrusion, such as a balloon 45 at or near the tip of the cannula. The balloon 45 is connected via a tube 46 to an air supply source or a fluid supply source (not shown) for inflating the balloon 45. Balloon 45 is used to guide cannula 20 as described below.

FIG. 2 schematically illustrates the use of cannula 20 within human heart 40. The cannula is inserted through the vena cava, right atrium and right ventricle 41 and through the pulmonary valve 42 to the downstream pulmonary artery 44. The length of the cannula 20 is preferably about 120 cm, which is generally sufficient to keep the proximal end 32 outside the jugular or femoral vein incision when the tip 28 is positioned within the pulmonary artery 44. Length.

When inserting the tip of the cannula into the vena cava or jugular or femoral vein, the tip must pass through the right atrium and right ventricle. In a preferred embodiment of the present invention, the balloon 45 is connected to the distal end of the cannula 20 because manipulating the direction of movement of the cannula without the use of a guide system is difficult in an open chest position and not possible in a closed chest position. Used to assist in positioning When gas is filled,
The balloon 45 is designed to expand outward so as to be as close as possible to the shape shown in FIG. When the balloon has this shape, it has a high resistance to flow, thereby being carried along the bloodstream. This is carried through the valve 42 from the right atrium to the right ventricle and most importantly to the right ventricle. The use of blood flow for placement of this heart pump is considered unique and is based, in part, on the direction of cannula insertion that allows the use of blood flow for cannula positioning. I have. Alternatively, an extensible protrusion, such as a balloon 45, may be attached to a guidewire that guides the cannula. In this embodiment of the invention, the extensible protrusion assists in positioning the guidewire, and the guidewire is removed when the cannula is in place.

When the cannula 20 enters a predetermined position, the suction valve 30 opens, and blood flows from the right atrium into the lumen 24. The release valve 26 preferably remains closed while the blood fills the lumen. The proximal end 32 may be temporarily opened to exhaust air or fluid that was inside the cannula 20 before insertion. Then, the suction valve 30 is closed and the discharge valve 26 is opened so that blood can flow out of the lumen into the pulmonary artery 44. The inhalation valve may be located in the right ventricle instead of the right atrium.

In the preferred embodiment of the present invention shown in FIG. 1, the suction valve 30 and the discharge valve 26
Preferably, it opens and closes in response to pressure on cannula 20 via pump system 18 as follows. The proximal end 32 of the cannula 20 is connected to a first chamber 50 of a fluid container 52 through a first fluid port 54. The fluid container 52 further includes a second chamber 56.
, Which is separated from the first chamber 50 by the soft membrane 58. Membrane 58 is preferably made of soft polyurethane and is made of chamber 50 to substantially equalize fluid pressure in the two chambers.
And 56 to change the individual volumes, but prevent the fluids in the first and second chambers from mixing.

The second chamber 56 preferably contains a substantially incompressible liquid, such as water, or another suitable fluid, such as ordinary saline solution. The chamber 56 is connected to a pump drive 64 through a pipe 62 through a second fluid port 60. Pump drive 6
The piston 66 in 4 rises and falls alternately, causing the fluid pressure in the container 52 to rise and fall accordingly, thereby causing blood to flow into and out of the lumen 24.

It will be appreciated that the maximum amount of blood that can be pumped in the first stroke of the piston 66 is substantially determined by the volume of the container 50. Preferably, the maximum stroke feed amount at one time is at least 50 cc, and more preferably at most 80 cc. However, if necessary, the stroke of the piston 66 may be shortened to reduce the amount of rapid feeding. The stroke is preferably adjusted so that, when the pump drive 64 operates at or near the natural rate of the heart, it can deliver enough blood to perfuse substantially the entire body of the person.

Further, it will be appreciated that blood enters cannula 20 and flows only to membrane 58 in first chamber 50. Blood does not flow into tube 62 or pump drive 64. Preferably, cannula 20 and container 52 are disposable and used only once to prevent the transmission of infections and contamination.

The pump driving device 64 is preferably driven by a servo mechanism 68 under the control of a computer 70, and the computer adjusts the speed and stroke amount of the piston 66. Computer 70 preferably receives physiological signal inputs, such as ECG and blood pressure signals, and uses the signals to optimally control pump drive 64 to drive piston 66 at a heart rate.

Preferably, the computer 70 further adjusts the delay of the piston stroke relative to the systolic stroke of the heart. This delay may be adjusted so that the cannula 20 synchronizes with the systole of the heart, synchronizes with diastole, or pushes blood at the appropriate phase in between. Alternatively, the speed of piston 66 may be set independent of the heartbeat, for example, to maintain stable perfusion during arrhythmias or fibrillation.

The auxiliary pump of the preferred embodiment of the invention therefore differs from the pumps described in the known literature in that the discharge valve is at the tip of the cannula and the suction valve is near the tip. Since the cannula is inserted into the pulmonary artery from the right ventricle, the cannula can have a very large diameter compared to prior art cardiac assist devices. further,
The release valve may be coaxial with the cannula so that outflow from the valve is not obstructed by the wall of the artery. This can provide higher pressure and greater flow to the vascular system than prior art auxiliary systems. In addition, although the inhalation valves are generally on either side of the cannula, the valves are in the atria or vena cava with little obstruction of the inhalation valve. Since the path through the ventricle includes many bends, the cannula may be of different diameters at the inhalation and at the evacuation. The inhalation of the catheter (located in the atria or vena cava) is preferably of a large diameter to allow for large outflows, which are usually limited by suction pressure and cavitation. The tip of the cannula is preferably thinner and softer to assist in guiding the cannula.

Further, it will be appreciated that the cannula pump of the present invention must be designed and configured for its intended use. For example, the distance between the inlet to the cannula via the inlet valve and the outlet from the cannula must be the exact distance such that the placement of the inlet and outlet is at the desired location in the circulatory system.

FIGS. 3A and 3B schematically show the structure of a combination intake and discharge valve 80 according to a preferred embodiment of the present invention. The valve unit 80 includes a preferably rigid tube 82, formed of a biocompatible plastic material such as, for example, polycarbonate (Lexan) or metal (stainless steel), or other suitable biocompatible material. Prepare. A hole 86 is formed on the sleeve 82.

The insert / internal component 81 is preferably formed of a soft biocompatible material, such as, for example, silicone or silicone rubber of another suitable material. This preferably comprises two or three leaflets and an axial outlet leaflet valve 83 such as a cylindrical suction valve section 84.

The part 84 is aligned with the hole 86 so that the part 84 and the hole 86 constitute an intake valve. The attachment of the internal part 81 to the pipe 82 is preferably performed by bonding the upper part of the part 84 to the pipe 81 or by another method such as caulking.

FIG. 3A shows the state of the valve when pressure is applied to the valve unit so that blood is injected from the pump into the pulmonary artery. The leaflet valve 83 opens and the site 84 is pressed against the hole 86 to close it, so that no blood enters the pump from the atrium. This pressure is preferably facilitated by the stress relief features at site 84 which serves to close hole 86.

FIG. 3B shows the valve unit 80 during a suction period, where blood is drawn from the vena cava or right atrium. In this state, the valve 83 closes and the site 84 is pushed into the lumen by suction, so that blood can enter the lumen through the hole 86 from the atrium.

FIG. 3C shows a portion of a cannula formed as a separate part where the intake and discharge valves are separate. FIG. 3D shows a cannula with multiple rows of suction valves. The use of several such rows of valves results in better aspiration and reduces the effects of valve placement within the vena cava or atria.

PCT Application PCT / IL96 / 00, the disclosure of which is incorporated herein by reference.
As described at 044, valve 83 partially opens in the absence of a differential pressure, and closure of the valve as shown in FIG. 3B is preferably a result of pump suction.

While the valves shown in FIGS. 1 and 3 are preferred, it should be understood that other intake and release valves as known in the art may be used.

It should be understood that the present invention has been described with reference to the preferred embodiments.
Instead of or in addition to other elements as known in the art, various combinations of the elements shown in the various embodiments, or only some of the features or elements shown in the preferred embodiments Can be used in certain alternative forms of the invention. Therefore, it is to be understood that the scope of this invention is defined by the following claims, and not by the above preferred embodiments.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a heart assist pump according to a preferred embodiment of the present invention.

FIG. 2 is a schematic diagram of a cannula according to a preferred embodiment of the present invention, showing the cannula inserted into the heart.

FIG. 3A is a cross-sectional view of a valve assembly including a suction valve and a discharge valve according to a preferred embodiment of the present invention, showing a first state in which the suction valve is closed and the discharge valve is open.

FIG. 3B shows a second state in which the suction valve is open and the discharge valve is closed,
FIG. 3 is a sectional view of the valve assembly of FIG.

FIG. 3C is a cross-sectional view of another valve assembly according to a preferred embodiment of the present invention.

FIG. 3D is a cross-sectional view of yet another valve assembly according to a preferred embodiment of the present invention.

[Explanation of symbols]

 18 Cardiac assist pump system 20 Cannula 24 Lumen 26 Release valve 28 Inhalation valve 45 Balloon 46 Tube 52 Fluid container 58 Soft membrane

[Procedural Amendment] Submission of translation of Article 34 Amendment of the Patent Cooperation Treaty

[Submission date] February 14, 2000 (2000.2.14)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

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[Claims]

29. The method of claim 28, wherein blood is transferred directly from the left atrium to the aorta via the cannula.

[Procedure amendment]

[Submission date] October 11, 2000 (2000.10.11)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] FIG. 3A

[Correction method] Change

[Correction contents]

FIG. 3A

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] FIG. 3B

[Correction method] Change

[Correction contents]

FIG. 3B

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Fig. 3C

[Correction method] Change

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FIG. 3C

[Procedure amendment 4]

[Document name to be amended] Drawing

[Correction target item name] Fig. 3D

[Correction method] Change

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FIG. 3D

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Claims (26)

[Claims] 1. A cannula having a tip, a suction portion from the circulatory system coupled to the cannula, and a discharge portion to the circulatory system coupled to the cannula, wherein a space between the suction portion and the discharge portion is When the cannula is positioned on the right side of the heart, the discharge is at a distance as in the pulmonary artery and the inhalation is at a distance as in the vena cava. Heart assist pump system. 2. A cannula having a tip, an inhaler coupled to the cannula, and a discharge coupled to the cannula, between the inhaler and the discharge when the cannula is positioned on the left side of the heart. A cardiac assist pump system configured to pump blood from the left atrium of the heart into the aorta, such that the discharge is in the aorta and the suction is in the aorta. 3. The heart assist pump according to claim 1, further comprising: a suction valve connected to the suction unit; and a discharge valve connected to the discharge unit. 4. A cardiac assist pump system comprising: a cannula having a tip; an inhalation valve associated with the cannula; a release valve associated with the cannula; and a radially extendable protrusion adjacent the tip of the cannula. 5. A heart with a cannula having a tip including a suction valve, a release valve, and a guide for guiding a cannula having a tip and having a radially extendable protrusion adjacent thereto. Auxiliary pump system 6. The heart assist pump according to claim 4, wherein the extendable protrusion is an inflatable balloon. 7. A heart assist pump according to any preceding claim, wherein the discharge portion communicates with a tip of the cannula or an adjacent opening, and the suction valve communicates with an opening near the opening with which the discharge valve communicates. 8. The heart assist pump according to claim 1, wherein the discharge valve is an axial valve communicating with the opening at the tip of the cannula. 9. The cardiac assist pump according to claim 1, wherein the release valve is a leaflet having a plurality of leaves. 10. A heart assist pump according to claim 1, wherein the suction valve comprises a valve through which blood enters the cannula via an orifice in the wall of the cannula. 11. The heart assist pump according to claim 10, wherein said orifice is formed in a portion of a cannula having a cylindrical inner wall, and wherein said suction valve is an internal soft tube. 12. The heart assist pump of claim 11, wherein the inner soft tube substantially closes the orifice when there is no pressure differential. 13. The heart assist pump according to claim 12, wherein the inner soft tube is separated from the orifice by a negative internal pressure against the outside of the cannula, opening the orifice. 14. The heart assist pump according to claim 11, wherein the internal soft tube is formed integrally with the release valve. 15. A heart assist pump according to any preceding claim, wherein the cannula is substantially larger in diameter at the suction valve than at its tip. 16. Inserting a cannula having a distal end and a proximal end into the heart and pulmonary arteries such that the distal end of the cannula enters the artery and the more proximal portion of the cannula enters the vena cava, and through the lumen of the cannula. Transferring blood from the vena cava to the artery, comprising: increasing blood flow in the heart. 17. A cannula having a distal end and a proximal end is inserted into the heart and aorta such that the distal end of the cannula enters the aorta and the more proximal portion of the cannula enters the left atrium, and through the lumen of the cannula. Transferring blood from the left atrium to the aorta, comprising: increasing blood flow in the heart. 18. The method of claim 16 or 17 including providing an intake valve in communication with the opening of the cannula near a tip of the cannula. 19. The method according to claim 16, comprising providing a discharge valve in communication with the opening at the tip of the cannula. 20. The method of claim 19, wherein providing a discharge valve comprises providing an axial discharge valve in communication with the opening at a distal end of the cannula. 21. A method according to any of claims 16 to 20, comprising providing a discharge valve in communication with the opening of the cannula on the distal side of the opening in communication with the suction valve. 22. Transferring blood includes: aspirating blood through a suction valve by reducing the pressure in the cannula; and increasing the pressure in the cannula to reduce blood pressure from the cannula through the release valve. 22. The method according to any of claims 16 to 21, comprising: releasing blood into the cell. 23. The method according to any of claims 16 to 22, wherein inserting the cannula into the heart and arteries comprises inserting the cannula from the ventricle into the artery via a heart valve. 24. The method of claim 23, comprising guiding the cannula through the ventricle to an artery. 25. The guide further comprising a radially extendable protrusion adjacent the tip of the cannula, extending the protrusion radially, at least in part under the effect of blood flow at the protrusion. 25. The method of claim 24, comprising allowing the cannula to advance. 26. The method of claim 25, wherein the protrusion is a balloon and stretching the stretched protrusion comprises inflating the balloon.