Blood pump

Abstract

To provide a device and a method used in conjunction with an object venous system including one or more branch blood vessels flowing into a vein at a junction.SOLUTION: A blood pump catheter (70) includes a material (36) configured to be installed in a downstream position downstream of a junction, and to close a blood flow that is flowing in a vein at least partially. The material defines a blood outlet opening (31). A blood pump (24) pumps the blood from a region of the vein adjacent to the junction through the blood outlet opening (31). A blood flow route (60) guides an upstream venous blood flow toward downstream of the material (36) from an upstream position upstream of the junction without pumping it by the pump (24). Other applications are also described.SELECTED DRAWING: Figure 2E

Description

Technical Field

[0001] (Cross - reference to Related Applications) This application claims priority from the following: U.S. Provisional Patent Application No. 62 / 851,769 to Friedland, filed May 23, 2019, entitled "Blood pumps". U.S. Provisional Patent Application No. 62 / 870,822 to Friedland, filed Jul. 5, 2019, entitled "Blood pumps". U.S. Provisional Patent Application No. 62 / 890,177 to Friedland, filed Aug. 22, 2019, entitled "Blood pumps". U.S. Provisional Patent Application No. 62 / 983,786 to Friedland, filed Mar. 2, 2020, entitled "Blood pumps".

[0002] Each of the applications referenced above is hereby incorporated by reference into this application.

[0003] Some applications of the present invention generally relate to medical devices. Specifically, some applications of the present invention relate to devices and methods related to installing pumps in veins or arteries.

Background Art

[0004] It is common for cardiac dysfunction or congestive heart failure to progress to renal dysfunction, which in turn can lead to the manifestation or worsening of symptoms of congestive heart failure. Typically, cardiac dysfunction during systole and / or diastolic periods causes congestion in the systemic veins, which leads to increased renal venous and interstitial pressure. This increased pressure increases fluid retention in the body, typically due to both renal dysfunction and renal neurohormonal activation resulting from the increased renal venous and interstitial pressure. This resulting fluid retention causes an overload of blood volume in the heart and / or increases systemic resistance, thereby manifesting or worsening congestive heart failure. Similarly, it is common for renal dysfunction and / or renal neurohormonal activation to progress to cardiac dysfunction and / or congestive heart failure. In this pathophysiological cycle, where cardiac dysfunction and / or congestive heart failure lead to renal dysfunction and / or renal neurohormonal activation, or renal dysfunction and / or renal neurohormonal activation lead to cardiac dysfunction and / or congestive heart failure, the exacerbation of each dysfunction is called cardiorenal syndrome.

[0005] Experimental studies have shown that elevated renal venous pressure leads to azotemia, as well as decreased glomerular filtration rate, renal blood flow, urine output, and sodium excretion. It has also been shown to increase plasma renin and aldosterone, as well as protein excretion. Furthermore, venous congestion can contribute to anemia through three different pathways: inflammatory responses leading to reduced renal erythropoietin production, hemodilution due to fluid retention, and reduced iron uptake in the gastrointestinal tract.

[0006] Mechanically, an increase in renal venous pressure can lead to an increase in intracapsular pressure, which in turn can lead to an increase in interstitial peritubular pressure. This increase in peritubular pressure can affect tubular function (by reducing sodium excretion) and glomerular filtration by increasing pressure in Bowman's capsule.

[0007] In patients with heart failure, elevated renal venous pressure can result not only from elevated central venous (right atrium) pressure but also from intraperitoneal fluid retention (ascites), which directly pressures the renal veins. In patients with heart failure, reducing intraperitoneal pressure by fluid removal (e.g., using paracentesis and / or ultrafiltration) has been shown to lower plasma creatinine levels.

[0008] Increased venous return resulting from the activation of the "leg muscle pump" during physical activities such as walking can raise systemic venous pressure, particularly in patients with heart failure, potentially leading to reflux into the renal veins. [Overview of the project] [Problems that the invention aims to solve]

[0009] Typically, in patients with acute heart failure, elevated systemic venous pressure leads to increased renal parenchymal pressure and intra-abdominal pressure, which can contribute to the deterioration of renal perfusion and renal function. Furthermore, high systemic venous pressure can impede lymphatic drainage of pulmonary interstitial fluid, potentially leading to worsening and prolonged pulmonary congestion in patients with acute pulmonary edema. [Means for solving the problem]

[0010] According to some applications of the present invention, blood flow in the region of the vena cava adjacent to the junction of the vena cava and renal vein is separated from the vena cava blood flow of the subject upstream and downstream of the junction. The blood is pumped from the region of the vena cava adjacent to the junction to the adrenal gland location within the vena cava using a pump. The blood of the subject can flow from the subrenal gland location to the adrenal gland location within the subject's vena cava without being pumped, by guiding it to bypass the pump.

[0011] In some applications, such a method includes (a) at least partially occluding the blood flow through a vein by placing a downstream occlusion element (material, etc.) at a downstream position downstream of the junction of a vein and one or more branch vessels (e.g., one or more branch veins); (b) pumping blood from a region of the vein adjacent to the junction of the vein and branch vessel through the downstream occlusion element using a pump; and (c) guiding the upstream venous blood flow from an upstream position upstream of the junction of the vein and branch vessel downstream of the occlusion element by guiding it to bypass the pump without pumping the upstream venous blood flow.

[0012] Typically, this method is performed using a blood pump catheter containing a material. This material is positioned downstream of the junction of the vein and its tributary vessel, and is configured to at least partially occlude the blood flow in the vein at that downstream position. This material typically defines a blood outlet opening. The blood pump is typically configured to pump blood from a region of the vein adjacent to the junction of the vein and its tributary vessel through the blood outlet opening defined by the material. The blood flow path (i.e., blood flow channel) typically passes between an inlet opening positioned upstream of the junction of the vein and its tributary vessel and an outlet opening on the downstream side of the material. The blood flow path is configured to guide upstream venous blood flow from the upstream position to the downstream side of the material without pumping it. In some applications, the blood flow path includes a funnel and one or more tubes. The funnel is configured to be positioned upstream of the junction of the vein and its tributary vessel, and one or more tubes are configured to extend from the funnel downstream of the material. The funnel and one or more tubes are configured to guide upstream venous blood flow from an upstream position to the downstream of the material without pumping it.

[0013] Generally, the scope of some applications of the present invention includes devices and methods used with a target venous system that includes branch veins (e.g., renal veins that flow into the vena cava) that drain into a main vein. Typically, such a method includes separating the blood flow in a region of the main vein adjacent to the junction of the main vein and branch veins from the blood flow in the main vein upstream and downstream thereof; pumping the blood from the region of the main vein adjacent to the junction of the vein and branch veins to a location in the main vein downstream of the branch vein using a pump; and directing the target blood from a location in the main vein upstream of the branch vein to a location in the main vein downstream of the branch vein by guiding it to bypass the pump without pumping. The scope of some applications of the present invention further includes devices and methods used with a target venous system that includes branch vessels (e.g., lymphatic vessels) that drain into a vein. Typically, such a method includes separating the flow within a region of a vein adjacent to the junction of a vein and a tributary vessel from the blood flow in the upstream and downstream veins; pumping the blood from the region of the vein adjacent to the junction of a vein and a tributary vessel to a location in the vein downstream of that region using a pump; and directing the target blood from a location in the vein upstream of a tributary vessel to a location in the vein downstream of a tributary vessel by guiding it to bypass the pump without pumping.

[0014] In some applications of the present invention, a blood pump catheter includes an impeller configured to pump blood by rotation, and an impeller housing configured to be positioned around the impeller. The blood pump support frame is typically positioned upstream of the impeller housing and configured to at least partially align the longitudinal axis of the impeller housing with the local longitudinal axis of the blood vessel by contacting the inner wall of the blood vessel. The material extends from the impeller housing to the blood pump support frame and is configured to contact the blood vessel wall and to occlude the blood vessel in the region of the blood vessel surrounding the impeller. In some applications, the material defines a blood outlet opening, and the impeller is configured to pump blood through the blood outlet opening.

[0015] In some applications, the blood pump catheter is configured for use with the descending aorta of the subject. The blood pump catheter includes a material configured to be placed within the descending aorta and to separate the aorta into an upstream and downstream compartment by at least partially occluding the blood flow through the aorta. The material typically defines a blood outlet opening. The blood pump (e.g., an impeller-based blood pump) is configured to pump blood flowing through the descending aorta downstream through the blood outlet opening.

[0016] In general, in this specification and the claims of this application, the term “proximal” and related terms, when used in relation to a device or part of a device, should typically be interpreted to mean the end of the device or part closer to the insertion site when the device or part is inserted into the body of a subject. The term “distal” and related terms, when used in relation to a device or part of a device, should typically be interpreted to mean the end of the device or part further from the insertion site when the device or part is inserted into the body of a subject.

[0017] The terms “downstream” and “upstream,” and related terms, should be interpreted as being defined in relation to the direction of antegrade blood flow through the vascular system in question. For example, the adrenal vena cava is downstream of the inferior vena cava, and the descending aorta is downstream of the aortic arch. When used in relation to devices, the term “upstream” should be interpreted as referring to a portion of the device configured to be positioned relatively upstream, and the term “downstream” should be interpreted as referring to a portion of the device configured to be positioned relatively downstream.

[0018] Accordingly, according to some applications of the present invention, a device is provided for use with a target venous system including one or more tributary vessels that flow into a vein at the junction of a vein and one or more tributary vessels. This device is It is a blood pump catheter, A material defining a blood outlet opening, which is installed in a downstream position downstream of the joint and configured to at least partially occlude the blood flow through the vein at the downstream position, A blood pump configured to pump blood from a vein region adjacent to the junction through a blood outlet opening defined by the material, A blood pump catheter includes a blood flow pathway that passes between (a) a pathway inlet opening located upstream of the joint and (b) a pathway outlet opening that opens downstream of the material, The blood flow pathway is configured to guide upstream venous blood flow from an upstream position to the downstream of the material without pumping it.

[0019] In some applications, the blood pump includes an elongated blood pump tube, which defines a blood inlet area located in the upstream portion of the elongated blood pump tube, a blood outlet area located in the downstream portion of the elongated blood pump tube, and an impeller configured to pump blood into the blood inlet area and further pump it out of the blood outlet area via the elongated blood pump tube.

[0020] In some applications, the blood pump includes an impeller located within a frame, which is configured to pump blood by rotating within the frame.

[0021] In some applications, the blood pump catheter is configured for use with one or more lymphatic vessels that flow into a vein, and the blood pump catheter is configured to be placed inside a vein. The material is positioned downstream of the junction between a vein and one or more lymphatic vessels, and is configured to at least partially occlude the blood flow through the vein at the downstream position. The blood pump is configured to pump blood from a vein region adjacent to the junction of a vein with one or more lymphatic vessels, through a blood outlet opening defined by the material. The blood flow path is configured to pass between (a) a path inlet opening disposed at an upstream position upstream of a region of a vein adjacent to a junction of the vein and one or more lymphatic vessels and (b) a path outlet opening that opens to the downstream side of the material. The blood flow path is configured to direct upstream venous blood flow from the upstream position to the downstream side of the material without pumping by a pump.

[0022] In some applications, the blood pump catheter is configured to be placed within a major vein of a subject, such that the material is placed at a downstream position downstream of the junction of the major vein and one or more renal veins of the subject and is configured to at least partially occlude the blood flow through the major vein at the downstream position. The blood pump is configured to pump blood from a region of the major vein adjacent to the junction of the major vein and one or more renal veins through a blood outlet opening defined by the material. The blood flow path is configured to pass between (a) a path inlet opening disposed at an upstream position upstream of the junction of the major vein and one or more renal veins and (b) a path outlet opening that opens to the downstream side of the material. The blood flow path is configured to direct blood flow from the infrarenal vena cava blood flow to the downstream of the material without pumping the infrarenal vena cava blood flow by a pump.

[0023] In some applications, the device further includes a percutaneous left ventricular assist device configured to assist the function of the left ventricle of the subject.

[0024] In some applications, the blood pump includes an elongate blood pump tube that defines a blood inlet area disposed within an upstream portion of the elongate blood pump tube, a blood outlet area disposed within a downstream portion of the elongate blood pump tube, and an impeller configured to pump blood into the blood inlet area and further pump the blood out of the blood outlet area through the elongate blood pump tube.

[0025] In some applications, the elongated blood pump tubing is configured to be positioned such that the blood outlet area is located within the target pulmonary artery, and to pump blood into the target pulmonary artery via the elongated tubing.

[0026] In some applications, the device further includes an elongated tube that extends downstream from the material and defines an adrenal blood inlet opening configured to be positioned within the adrenal vena cava of the subject, the blood inlet area of ​​the elongated blood pump tube configured to be positioned downstream of the adrenal blood inlet opening, and the elongated blood pump tube configured to pump blood from the adrenal vena cava blood flow into the pulmonary artery of the subject.

[0027] In some applications, the device further includes an elongated tube configured to extend into the pulmonary artery of the subject, and the blood pump is configured to pump blood into the pulmonary artery of the subject via the elongated tube.

[0028] In some applications, an elongated tube defines an adrenal blood inlet opening configured to be positioned within the adrenal vena cava of the subject, and a blood pump is configured to be positioned downstream of the adrenal blood inlet opening and to pump blood from the adrenal vena cava blood flow into the pulmonary artery of the subject.

[0029] In some applications, the diameter of one or more parts of the blood flow pathway can be adjusted so that the flow from the subrenal vena cava to the target right atrium is regulated.

[0030] In some applications, the device further includes a blood pressure sensor configured to detect the blood pressure of a target, and a computer processor configured to receive the blood pressure of the target and to automatically adjust the diameter of one or more portions of the blood flow path in accordance with the detected blood pressure.

[0031] In some applications, the diameter of one or more parts of the blood flow pathway is configured to adjust in response to the input.

[0032] In some applications, the blood flow pathway includes a funnel having a broad end and a narrow end, and one or more tubes, the broad end of the funnel defining the pathway inlet opening, and the narrow end of the funnel extending into one or more tubes.

[0033] In some applications, the funnel and one or more tubes constitute a single continuous blood flow pathway.

[0034] In some applications, the diameter of one or more parts of a blood flow pathway is adjustable so that the flow through the blood flow pathway can be controlled.

[0035] In some applications, the device further includes a blood pressure sensor configured to detect the blood pressure of a target, and a computer processor configured to receive the blood pressure of the target and to automatically adjust the diameter of one or more portions of the blood flow path in accordance with the detected blood pressure.

[0036] In some applications, the diameter of one or more parts of the blood flow pathway is configured to adjust in response to the input.

[0037] Furthermore, according to some application examples of the present invention, an apparatus is provided. This apparatus is It is a blood pump catheter, A material that defines a blood outlet opening, which is placed on a blood pump catheter and configured to at least partially occlude the blood flow through the vein, A blood pump configured to pump blood through a blood outlet opening defined by the material, A blood pump catheter includes a blood flow pathway passing between (a) a pathway inlet opening located proximal to the material and (b) a pathway outlet opening located distal to the material, The blood flow pathway is configured to guide blood flow from the pathway inlet opening to the pathway outlet opening without the need for pumping.

[0038] Furthermore, according to some applications of the present invention, a method is provided for use with a target venous system including a tributary vessel that flows into a vein at the junction of a vein and a tributary vessel. This method is To separate the blood flow in the venous region adjacent to the junction into a separate compartment from the blood flow in the veins upstream of the junction and the blood flow in the veins downstream of the junction, Using a pump, pump blood from one compartment to the downstream of another, By guiding the target blood to bypass the pump without pumping it, it flows from a location in the vein upstream of the compartment to a location downstream of the compartment. Includes.

[0039] In some applications, pumping blood from compartment to compartment downstream includes pumping blood from compartment to compartment downstream via an elongated blood pump tube, the elongated blood pump tube defining a blood inlet area located within the upstream portion of the elongated blood pump tube, a blood outlet area located within the downstream portion of the elongated blood pump tube, and an impeller configured to pump blood into the blood inlet area and further pump it out of the blood outlet area via the elongated blood pump tube.

[0040] In some applications, pumping blood from compartment to downstream of a compartment includes pumping blood from compartment to downstream of a compartment by rotating an impeller.

[0041] In some applications, the method is intended for use with one or more lymphatic vessels that drain into a vein. The method is To separate the blood flow within the vein region adjacent to the junction of a vein with one or more lymphatic vessels into a separate compartment from the blood flow in the vein downstream of the venin region adjacent to the junction of a vein with one or more lymphatic vessels, and from the blood flow in the vein upstream of the venin region adjacent to the junction of a vein with one or more lymphatic vessels, Using a pump, pump blood from one compartment to the downstream of another, By guiding the target blood to bypass the pump without pumping it, it flows from a location in the vein upstream of the compartment to a location downstream of the compartment. Includes.

[0042] In some applications, the method is intended for use in conjunction with the target renal vein and vena cava. The method is: To separate the blood flow within the region of the vena cava adjacent to the junction of the vena cava with one or more renal veins into a separate vena cava compartment from the blood flow within the vena cava downstream of the vena cava compartment and the blood flow within the vena cava upstream of the vena cava compartment, Using a pump, blood is pumped from one vena cava compartment to the downstream compartment. By guiding the target blood to bypass the pump without pumping it, it is possible to move it from an upstream position in the vena cava compartment to a downstream position in the vena cava compartment. Includes.

[0043] In some applications, the method further includes supporting the function of the target left ventricle using a percutaneous left ventricular support device.

[0044] In some applications, pumping blood from one vena cava compartment to its downstream compartment includes pumping blood from one vena cava compartment to its downstream compartment via an elongated blood pump tube, the elongated blood pump tube defining a blood inlet area located within the upstream portion of the elongated blood pump tube, a blood outlet area located within the downstream portion of the elongated blood pump tube, and an impeller configured to pump blood into the blood inlet area and further pump it out of the blood outlet area via the elongated blood pump tube.

[0045] In some applications, pumping blood from one vena cava compartment to its downstream compartment via an elongated blood pump tube includes pumping blood into the target pulmonary artery via the elongated tube.

[0046] In some applications, the method further includes pumping blood from the adrenal vena cava blood flow of the subject into the subject's pulmonary artery via an elongated blood pump tube.

[0047] In some applications, pumping blood from one vena cava compartment to its downstream compartment includes pumping blood into the target pulmonary artery via an elongated tube.

[0048] In some applications, the method further includes pumping blood from the adrenal vena cava blood flow of the subject into the pulmonary artery of the subject via an elongated tube.

[0049] In some applications, guiding blood to bypass the pump includes guiding blood to bypass the pump through a blood flow pathway, and the method further includes regulating blood flow to the right atrium of the subject by adjusting the diameter of one or more portions of the blood flow pathway.

[0050] In some applications, the method further includes detecting the blood pressure of a subject and adjusting the diameter of one or more parts of the blood flow path, or automatically adjusting the diameter of one or more parts of the blood flow path in accordance with the detected blood pressure.

[0051] In some applications, adjusting the diameter of one or more parts of a blood flow pathway includes adjusting the diameter of one or more parts of a blood flow pathway in response to an input.

[0052] In some applications, guiding blood to bypass a pump includes guiding blood to bypass a pump through a blood flow pathway, and the method further includes regulating the blood flow through the blood flow pathway by adjusting the diameter of one or more portions of the blood flow pathway.

[0053] In some applications, the method further includes detecting the blood pressure of a subject and adjusting the diameter of one or more parts of the blood flow path, or automatically adjusting the diameter of one or more parts of the blood flow path in accordance with the detected blood pressure.

[0054] In some applications, adjusting the diameter of one or more parts of a blood flow pathway includes adjusting the diameter of one or more parts of a blood flow pathway in response to an input.

[0055] Furthermore, according to some applications of the present invention, a method is provided for use with a target venous system including a tributary vessel that flows into a vein at the junction of a tributary vessel and a vein. This method is By installing a downstream occlusion element at a downstream position downstream of the junction between a vein and a branch vessel, the blood flow through the vein is to be at least partially occluded. Using a pump, blood is pumped from the vein region adjacent to the junction of the vein and its branch vessels through the downstream occluding element, By guiding the upstream venous blood flow to bypass the pump without pumping it, the blood flow is guided from an upstream position upstream of the junction between the vein and its tributary vessels to downstream of the occluding element. Includes.

[0056] Furthermore, according to some applications of the present invention, a method is provided for use with a target venous system including a tributary vessel that flows into a vein at the junction of a tributary vessel and a vein. This method is To separate the blood flow within the vein region adjacent to the junction from the blood flow in the veins upstream of the vein region adjacent to the junction, and from the blood flow in the veins downstream of the vein region adjacent to the junction, To allow blood to flow from a branch vessel to a downstream location of the branch vessel through the first channel, The process involves flowing the target blood through a second channel from a location within the vein upstream of a branch vessel to a location within the vein downstream of the branch vessel, Controlling blood flow through at least one of the first and second flow channels, Includes.

[0057] Furthermore, according to some applications of the present invention, a device is provided for use with a target arterial system including a major artery and one or more branch arteries branching from the major artery at the junction of the major artery with one or more branch arteries. This device is It is a blood pump catheter, A material for defining a blood inlet opening, which is positioned downstream of the junction between a major artery and a branch artery, and configured to at least partially occlude the blood flow in the major artery at the downstream position, A blood pump configured to pump blood from the main artery to the branching artery through a blood inlet opening, Each funnel is configured to be positioned upstream of the junction between the major artery and the branch artery, A blood pump catheter includes a blood flow pathway that passes between (a) a pathway inlet opening located upstream of the junction of a major artery and a branch artery, and (b) a pathway outlet opening that opens downstream of the material, The blood flow pathway is configured to guide upstream major arterial blood flow from an upstream position to the downstream of the material without pumping it.

[0058] Furthermore, according to some applications of the present invention, a method is provided for use with a target arterial system including a major artery and one or more branch arteries branching from the major artery at the junction of the major artery with one or more branch arteries. This method is To separate the blood flow within the region of the major artery adjacent to the junction into a separate compartment from the blood flow in the major artery downstream of the compartment and the blood flow within the compartment, Using a pump, blood is pumped from the main artery to the branching artery, By guiding the target blood to bypass the pump without pumping it, it can flow from a location in the major artery upstream of the compartment to a location downstream of the compartment. Includes.

[0059] Furthermore, according to some applications of the present invention, a method is provided for use with a target arterial system including a major artery and one or more branch arteries branching from the major artery at the junction of the major artery with one or more branch arteries. This method is By installing a downstream occlusion element at a downstream position downstream of the junction between the major artery and the branch artery, the blood flow through the major artery is to be at least partially occluded. Using a pump, blood is pumped from the major artery to the branching artery via the downstream occluding element, By guiding the blood flow in the upstream major artery to bypass the pump without pumping it, the blood flow is guided from an upstream position upstream of the junction between the major artery and the branch artery downstream of the occluding element. Includes.

[0060] Furthermore, according to some applications of the present invention, a device is provided for use in conjunction with the descending aorta of the subject. This device is It is a blood pump catheter, A material for defining a blood outlet opening, configured to be placed within the descending aorta and to separate the aorta into an upstream and downstream compartment by at least partially occluding the blood flow through the aorta, A blood pump configured to pump blood flowing through the descending aorta downstream through a blood outlet opening, A device including a blood pump catheter.

[0061] Furthermore, according to some applications of the present invention, a method for use in conjunction with the descending aorta is provided. This method is By placing an occlusion element within the descending aorta that at least partially occludes the descending aorta, the descending aorta is separated into an upstream and a downstream compartment. Using a pump, blood is pumped from the upstream section to the downstream section. Includes.

[0062] Furthermore, according to some application examples of the present invention, an apparatus is provided. This apparatus is A blood pump catheter configured to be placed inside the target blood vessel, An impeller configured to pump blood by rotation, An impeller housing configured to be positioned around the impeller, A blood pump support frame is positioned upstream of the impeller housing and configured to align the longitudinal axis of the impeller housing with the local longitudinal axis of the blood vessel by contacting the inner wall of the blood vessel, The blood pump catheter includes a material that defines a blood outlet opening, which extends from the impeller housing to the blood pump support frame and is configured to contact the blood vessel wall and to occlude the blood vessel in the region of the blood vessel surrounding the impeller, and the impeller is configured to pump blood through the blood outlet opening.

[0063] The present invention will be better understood by reading the following detailed description of its embodiments together with the drawings. [Brief explanation of the drawing]

[0064] [Figure 1A] This is a schematic diagram of a blood pump catheter placed in a target vena cava according to several application examples of the present invention. [Figure 1B] This is a schematic diagram of a blood pump catheter placed in a target vena cava according to several application examples of the present invention. [Figure 1C] This is a schematic diagram of a blood pump catheter placed in a target vena cava according to several application examples of the present invention. [Figure 2A] This is a schematic diagram of a blood pump catheter placed in a target vena cava according to several application examples of the present invention. [Figure 2B] This is a schematic diagram of a blood pump catheter placed in a target vena cava according to several application examples of the present invention. [Figure 2C] This is a schematic diagram of a blood pump catheter placed in a target vena cava according to several application examples of the present invention. [Figure 2D]This is a schematic diagram of a blood pump catheter placed in a target vena cava according to some application examples of the present invention, the blood pump having an asymmetric outflow tube. [Figure 2E] This is a schematic diagram of a blood pump catheter placed in a target vena cava according to some application examples of the present invention, the blood pump having a non-axisymmetric outflow tube and a non-axisymmetric impeller. [Figure 2F] Figure 2E is a schematic diagram of a blood pump catheter without the target biological structure, according to some application examples of the present invention. [Figure 3A] This is a schematic diagram of a blood pump catheter according to some other applications of the present invention. [Figure 3B] This is a schematic diagram of a blood pump catheter according to some other applications of the present invention. [Figure 3C] This is a schematic diagram of a blood pump catheter according to some other applications of the present invention. [Figure 3D] This is a schematic diagram of a blood pump catheter according to some other applications of the present invention. [Figure 3E] This is a schematic diagram of a blood pump catheter according to some other applications of the present invention. [Figure 3F] This is a schematic diagram of a blood pump catheter according to some other applications of the present invention. [Figure 3G] This is a schematic diagram of a blood pump catheter according to some other applications of the present invention. [Figure 3H] This is a schematic diagram of a blood pump catheter according to some other applications of the present invention. [Figure 4A] This is a schematic diagram of a blood pump catheter placed in the descending aorta near the renal artery of a target, according to several application examples of the present invention. [Figure 4B] This is a schematic diagram of a blood pump catheter placed in the descending aorta near the renal artery of a target, according to several application examples of the present invention. [Figure 5A]This is a schematic diagram of a blood pump catheter placed in a target descending aorta (e.g., thoracic aorta or abdominal aorta) according to some application examples of the present invention. [Figure 5B] This is a schematic diagram of a blood pump catheter placed in a target descending aorta (e.g., thoracic aorta or abdominal aorta) according to some application examples of the present invention. [Figure 6A] This is a schematic diagram of an impeller or part thereof of a blood pump according to some application examples of the present invention. [Figure 6B] This is a schematic diagram of an impeller or part thereof of a blood pump according to some application examples of the present invention. [Figure 6C] This is a schematic diagram of an impeller or part thereof of a blood pump according to some application examples of the present invention. [Figure 6D] This is a schematic diagram of an impeller or part thereof of a blood pump according to some application examples of the present invention. [Figure 6E] This is a schematic diagram of an impeller or part thereof of a blood pump according to some application examples of the present invention. [Figure 6F] This is a schematic diagram of an impeller or part thereof of a blood pump according to some application examples of the present invention. [Figure 6G] This is a schematic diagram of an impeller or part thereof of a blood pump according to some application examples of the present invention. [Figure 6H] This is a schematic diagram of an impeller or part thereof of a blood pump according to some application examples of the present invention. [Figure 7] This is a schematic diagram of an impeller positioned inside the frame of a blood pump, according to some application examples of the present invention. [Figure 8A] This is a schematic diagram of the impeller and frame of a blood pump in a radially unconstrained state, according to some application examples of the present invention. [Figure 8B] This is a schematic diagram of the impeller and frame of a radially constrained blood pump according to some application examples of the present invention. [Figure 8C]This is a schematic diagram of a typical bearing assembly used in conventional axial impeller-based blood pumps. [Modes for carrying out the invention]

[0065] Refer to Figures 1A to 1C, schematic diagrams of a blood pump catheter 20 placed in a target vena cava 22 according to some applications of the present invention. Typically, the blood pump catheter includes a blood pump 24 comprising an impeller housing 26 and an impeller 50 positioned inside the impeller housing. The impeller housing 26 (e.g., the housing frame 34) typically functions to prevent damage to the vena cava by the impeller and to prevent deformation of the impeller by pressure from the vena cava's inner wall by separating the vena cava's inner wall from the impeller (e.g., in case the vena cava collapses internally due to intraperitoneal pressure). Typically, an axial shaft 92 (shown in Figure 7) passing through the impeller is supported by radial bearings 116, 118 located at the proximal and distal ends of the impeller housing, respectively.

[0066] For explanatory purposes, Figures 1A to 1C (and Figures 2A to 2E, 3A to 3H, 4A to 4B, and 5A to 5B) show three-dimensional diagrams of the blood pump 24, but it should be noted that other elements of the blood pump catheter are shown in cross-sectional views.

[0067] In some such applications, the blood pump support frame 32 is positioned upstream of the impeller housing 26 and configured to contact the inner wall of the vena cava. By contacting the inner wall of the vena cava, the blood pump support frame 32 is configured to align the longitudinal axis of the impeller housing 26, and thereby the impeller 50, with the local longitudinal axis of the vena cava. (It should be noted that in some applications, the blood pump support frame may not perfectly align the longitudinal axis of the impeller with the local longitudinal axis of the vena cava. However, typically, the blood pump support frame maintains a better alignment of the longitudinal axis of the impeller with the local longitudinal axis of the vena cava than would be possible in the absence of this blood pump support frame.) Typically, all other equalities, the greater the effectiveness of blood pumping by the impeller 50, the better the alignment of the longitudinal axis of the impeller with the local longitudinal axis of the vena cava. Nevertheless, it should be noted that even with a slight misalignment between the longitudinal axis of the impeller and the local longitudinal axis of the vena cava (as shown, for example, in Figure 2E), effective blood pumping by the impeller usually occurs.

[0068] In some applications, the impeller housing 26 includes a frame 34 (e.g., a rigid or semi-rigid frame) made of a shape memory element (such as nitinol) that is at least partially coated with material 36 (e.g., a blood-impermeable material such as polyester, polyurethane, and / or different polymers). Typically, in such applications, the rigidity of the frame 34 is sufficiently high that the frame does not deform due to the pressure exerted on the frame 34 by the inner wall of the vena cava. Typically, the material 36 extends from the impeller housing to the blood pump support frame 32 so as to contact the vessel wall and to occlude the vessel in the region of the vessel surrounding and / or upstream of the impeller. The material typically defines a through-hole in the distal portion of the impeller housing. The material is configured to occlude blood backflow around the outside of the impeller but to allow antegrade blood flow in the central region of the vessel near the impeller through a hole that acts as a blood outlet opening 31. In some applications, a portion of the impeller housing is covered (i.e., lined) on the inside of the impeller housing by an inner lining 39, as described below with reference to Figure 7. In some such applications, the inner lining of the impeller housing overlaps with material 36 at least partially. In some applications, the inner lining extends the blood outlet opening defined by material 36.

[0069] Typically, a drive cable 78 is located within the outer tube 77 of the blood pump catheter 20 (the drive cable is shown, for example, in Figure 8A). More typically, the drive cable extends from a motor 79 located outside the body of the subject to an axial shaft 92 (shown in Figure 7) on which the impeller is located. The motor imparts rotational motion to the axial shaft via the drive cable (thus imparting rotational motion to the impeller). Typically, the motor is controlled by a computer processor 10. In some applications, the motor is controlled based on blood pressure measurements performed by a pressure sensor 75.

[0070] In some applications, using material 36 as described above reduces the likelihood of blood backflow due to turbulence caused by the impeller within the vascular region surrounding the impeller. In some applications, the material acts to separate the adrenal vena cava into upstream and downstream compartments, and the impeller is configured to pump blood from the upstream compartment to the downstream compartment, thereby reducing the pressure in the upstream compartment near the renal vein.

[0071] In some applications (not shown), the blood pump support frame 32 and the frame 34 of the impeller housing 26 are formed as a single frame having an upstream portion configured to contact the inner wall of the vena cava and a downstream portion configured to house the impeller.

[0072] Typically, when the blood pump support frame is configured not to be radially constrained, the maximum diameter of the blood pump support frame 32 (i.e., the diameter of the blood pump support frame 32 at one or more longitudinal positions where the diameter of the blood pump support frame 32 is maximum) is at least 1.1 times (at least 1.3 times in some applications) the maximum diameter of the frame 34 of the impeller housing 26 (i.e., the diameter of the frame 34 at one or more longitudinal positions where the diameter of the frame 34 is maximum) when the frame 34 of the impeller housing 26 is configured not to be radially constrained.

[0073] Typically, the blood pump 24 is positioned downstream of the junction between the vena cava and the target renal vein 25 and is configured to pump blood downstream to reduce the pressure within the target renal vein. In some applications, the blood pump catheter 20 includes an occlusion element 40, which is positioned upstream of the junction between the vena cava and the target renal vein and is configured to partially occlude the vena cava at this location. For example, the occlusion element may include a balloon 42, as shown in Figure 1A. Alternatively, or in addition to this, the occlusion element includes a blood-impermeable material 44 defining a through-hole 45, as shown in Figure 1B. In some applications, this material is supported by a frame 46. Typically, the material 44 is configured such that some blood flow is present through the hole in the material, but the blood flow is reduced compared to when the material is absent. Typically, the occlusion element is configured to partially occlude the vena cava upstream of the junction between the vena cava and the renal vein. In some applications (not shown), a nozzle is used as the upstream occlusion element. This is described, for example, in U.S. Patent Application Publication No. 2019 / 0239998 to Tuval, which is included in this application by reference.

[0074] The occlusion element 40 is configured to partially occlude the target vena cava, thereby preventing a significant increase in blood flow from the target's lower body towards the target's heart in response to the pumping of the downstream blood pump, and to create a low-pressure region within the vena cava between the occlusion element and the downstream blood pump, where the blood pressure is lower than the target's central venous pressure. Typically, creating a low-pressure region increases blood flow from the renal vein to the vena cava, thereby lowering renal blood pressure and increasing renal perfusion. It should be noted that the occlusion element partially occludes the vena cava but does not completely occlude it, and is configured to create a low-pressure region within the vena cava while still allowing a considerable amount of blood flow through it.

[0075] In some applications, the blood pump catheter 20 does not include an upstream occlusion element, as shown in Figure 1C, for example. As described above, in some applications, the material 36 acts to separate the adrenal vena cava into an upstream and downstream compartment, and the impeller 50 is configured to pump blood from the upstream compartment to the downstream compartment, thereby reducing the pressure in the upstream compartment near the renal vein. In some applications, the blood pump catheter 20 is configured to generate a low-pressure area in the vena cava near the renal vein, even when there is no upstream occlusion element, as shown in Figure 1C. Typically, generating a low-pressure area increases blood flow from the renal vein to the vena cava, thereby lowering renal blood pressure and increasing renal perfusion.

[0076] The blood pump catheter 20 is typically placed in and operated within the subject's vena cava 22 for acute treatment of subjects suffering from cardiac dysfunction, congestive heart failure, low renal blood flow, high renal vascular resistance, arterial hypertension, diabetes mellitus, and / or renal impairment. For example, the blood pump catheter may be placed in and operated within the subject's vena cava for periods exceeding one hour (e.g., more than one day), less than one week (e.g., less than four days), and / or between one hour and one week (e.g., between one and four days). In some applications, the blood pump catheter is placed in the subject's vena cava for extended periods for long-term treatment of subjects suffering from cardiac dysfunction, congestive heart failure, low renal blood flow, high renal vascular resistance, arterial hypertension, diabetes mellitus, and / or renal impairment. In some applications, the treatment process is applied to the subject over several weeks, months, or years, during which the blood pump catheter is intermittently placed in the subject's vena cava, and the subject is treated intermittently according to the techniques described herein. For example, the patient may be treated intermittently at intervals of several days, weeks, or months.

[0077] With respect to the catheters shown in Figures 1A and 1B, it should be noted that such catheters, including a blood pump 24 positioned distal to the upstream occlusion element, are suitable for insertion into the vena cava from a vein located below the junction of the vena cava and the target renal vein, such as the femoral vein. However, the scope of the present invention includes catheters in which the pump and occlusion element are positioned, but the upstream occlusion element is positioned distal to the downstream pump. Such catheters are typically inserted, with modifications where appropriate, through a vein located above the inferior vena cava, such as the subclavian vein or jugular vein. Similarly, the catheter schematically shown in Figure 1C may be configured, with modifications where appropriate, to be inserted into the adrenal vena cava via a vein located above the inferior vena cava, such as the subclavian vein or jugular vein. Typically, in such cases, the arrangement of the blood pump catheter components relative to the catheter shaft is in the opposite direction to that shown in Figures 1A and 1C.

[0078] Typically, blood pump catheters are inserted under fluoroscopic imaging, or under ultrasound imaging to reduce the patient's exposure to radiation and / or contrast agents.

[0079] As described above, the blood pump catheter 20 is typically placed in the vena cava of a subject suffering from cardiac dysfunction, congestive heart failure, low renal blood flow, high renal vascular resistance, arterial hypertension, diabetes, and / or renal dysfunction. Typically, operating the blood pump catheter in the vena cava of such a subject causes a decrease and flattening of the subject's renal venous pressure profile, although this has additional effects, as well as an increase in the subject's central venous pressure. This is described, for example, with reference to Figure 4B of U.S. Patent Application Publication 2016 / 0022890 for Schwammenthal, which is incorporated herein by reference.

[0080] As described above, the occlusion element is typically configured to partially occlude the vena cava upstream of the junction with the target renal vein. In some applications, the diameter that expands the occlusion element is controllable. For example, the inflation of a balloon may be controllable, or the flame may be expandable (for example, by heating the flame or applying an electric current to the flame). In some applications, the degree to which the occlusion element occludes the vena cava is controlled by the computer processor 10 in response to input from different sensors (for example, a flow sensor and / or an oxygen saturation sensor and / or a heat flow sensor, as described with reference to Figure 22Ai-Cii of U.S. Patent Application Publication No. 2016 / 0022890 for Schwammenthal, included herein by reference) and / or in response to input from the user, according to the blood pressure detected by the blood pressure sensor 75. In some applications, the rate at which the pump 24 pumps blood from the renal vein (e.g., the rate at which the pump's impeller 50 rotates), and / or the degree to which the occluding element occludes the vena cava, is controlled by the computer processor 10 in response to input from different sensors (e.g., a flow sensor and / or an oxygen saturation sensor and / or a heat flow sensor, as described with reference to Figure 22Ai-Cii of U.S. Patent Application Publication No. 2016 / 0022890 for Schwammenthal, included herein by reference), and / or in response to user input, according to the blood pressure detected by the blood pressure sensor 75. In some applications, blood pressure sensors, as described later with reference to Figures 1C and 2C, are used in conjunction with the apparatus and method described above.

[0081] Some applications of the present invention are described with reference to a blood pump, which accordingly includes an impeller; however, the scope of the present invention includes using any other type of pump for pumping blood as described herein, with modifications where appropriate. For example, roller pumps, Archimedes screw pumps, centrifugal pumps, pneumatic pumps, and / or compression pumps may be used.

[0082] With respect to Figures 1A to 1C, it should be noted that the scope of the present invention includes applying similar devices and methods to any venous system of the subject, including tributary veins that flow into major veins. For example, similar techniques can also be applied at the junction of the hepatic vein and the superior vena cava. In some applications, generally similar devices and methods are used in the subclavian vein or jugular vein, at the junction of a vein with one or more lymphatic vessels. In some such applications, the blood pump catheter 20 is configured, with modifications where appropriate, to increase the flow of lymph from the lymphatic vessel into the vein.

[0083] Next, refer to Figures 2A and 2B, schematic diagrams of a blood pump catheter 70 installed in a target vena cava 22 according to some applications of the present invention. Typically, the blood pump catheter 70 includes a blood pump 24, which typically includes an impeller housing 26 and an impeller 50, all of which are generally the same as those described above. The impeller housing 26 (e.g., the housing frame 34) typically functions to prevent damage to the vena cava by the impeller and to prevent deformation of the impeller by pressure from the vena cava's inner wall by separating the vena cava's inner wall from the impeller (for example, in case the vena cava collapses internally due to intraperitoneal pressure). Typically, an axial shaft 92 (shown in Figure 7) passing through the impeller is supported by radial bearings 116, 118 located at the proximal and distal ends of the impeller housing, respectively.

[0084] In some such applications, the blood pump support frame 32 is positioned upstream of the impeller housing 26 and configured to contact the inner wall of the vena cava. By contacting the inner wall of the vena cava, the blood pump support frame 32 is configured to align the longitudinal axis of the impeller housing 26, and thereby the impeller 50, with the local longitudinal axis of the vena cava. (It should be noted that in some applications, the blood pump support frame may not perfectly align the longitudinal axis of the impeller with the local longitudinal axis of the vena cava. However, typically, the blood pump support frame maintains a better alignment of the longitudinal axis of the impeller with the local longitudinal axis of the vena cava than would be possible in the absence of this blood pump support frame.) Typically, all other equalities, the greater the effectiveness of blood pumping by the impeller 50, the better the alignment of the longitudinal axis of the impeller with the local longitudinal axis of the vena cava. As mentioned above, it should be noted that even with a slight misalignment between the longitudinal axis of the impeller and the local longitudinal axis of the vena cava (for example, shown in Figure 2E), effective blood pumping by the impeller usually occurs.

[0085] In some applications, the impeller housing 26 includes a frame 34 (e.g., a rigid or semi-rigid frame) made of a shape memory element (such as nitinol) that is at least partially coated with material 36 (e.g., a blood-impermeable material such as polyester, polyurethane, and / or different polymers). Typically, in such applications, the rigidity of the frame 34 is sufficiently large that the frame does not deform due to the pressure exerted on the frame 34 by the inner wall of the vena cava. Typically, the material 36 extends from the impeller housing to the blood pump support frame 32 so as to contact the vessel wall and to occlude the vessel in the region of the vessel surrounding and / or upstream of the impeller. Typically, the material defines a through-hole in the distal portion of the impeller housing. The material is configured to occlude blood backflow around the outside of the impeller but to allow antegrade blood flow in the central region of the vessel near the impeller through a hole that acts as a blood outlet opening 31. In some applications, a portion of the impeller housing is covered (i.e., lined) on the inside of the impeller housing by an inner lining 39, as described below with reference to Figure 7. In some such applications, the inner lining of the impeller housing overlaps with material 36 at least partially. In some applications, the inner lining extends the blood outlet opening defined by material 36.

[0086] Typically, a drive cable 78 is located within the outer tube 77 of the blood pump catheter 70 (the drive cable is shown, for example, in Figure 8A). Typically, the drive cable extends from a motor 79 located outside the body of the subject to an axial shaft 92 (shown in Figure 7) on which the impeller is located. The motor imparts rotational motion to the axial shaft via the drive cable (thus imparting rotational motion to the impeller). Typically, the motor is controlled by a computer processor 10. In some applications, the motor is controlled based on blood pressure measurements performed by a pressure sensor 75.

[0087] In some applications, the blood pump catheter further includes a funnel 72 extending into tube 74. The funnel is configured to be positioned upstream of the junction between the vena cava and the target renal vein and is configured to guide all blood flow from the inferior vena cava into tube 74. Tube 74 then guides the blood flow from the inferior vena cava to the adrenal gland so that this blood bypasses the blood pump 24 (i.e., without being pumped by the blood pump 24). For example, tube 76 may extend from tube 74 to the adrenal gland while bypassing the blood pump. As shown by the blood flow arrows in Figure 2A, this allows blood to flow from the inferior vena cava to the adrenal vena cava without being pumped by the blood pump 24. In contrast, as shown by the blood flow arrows in Figure 2B, blood is pumped by the blood pump 24 from the region of the vena cava adjacent to the junction between the vena cava and the renal vein to the adrenal vena cava.

[0088] In this way, by deploying the blood pump catheter 70 within the vena cava, the blood flow in the region of the vena cava adjacent to the junction with the renal vein is separated into a compartment 82, distinct from the subrenal vena cava blood flow 84 and the adrenal vena cava blood flow 86. Blood flow from the subrenal vena cava blood flow 84 to the adrenal vena cava blood flow 86 is generated passively (for example, by flowing through the funnel 72, tube 74, and tube 76). Blood is actively pumped from compartment 82 to the adrenal blood flow using the blood pump. In this manner, a low-pressure region is created within the vena cava of compartment 82, where the blood pressure is lower than the central venous pressure of the target. Typically, the creation of a low-pressure region increases blood flow from the renal vein to the vena cava, thereby lowering renal blood pressure and increasing renal perfusion.

[0089] Specific examples of the configurations of funnel 72, tube 74, and tube 76 are shown for illustrative purposes only, and it should be noted that the scope of this application includes using any other configuration of the blood flow pathway 60 (i.e., blood flow channel) for guiding blood from the inferior vena cava to the adrenal vena cava without pumping by the blood pump 24, with modifications where appropriate. Typically, funnel 72, tube 74, and tube 76 comprise each part of a single, continuous blood flow pathway. The blood flow pathway typically passes between a pathway inlet opening 61 located upstream of the junction of the vena cava and the renal vein, and a pathway outlet opening 63 opening downstream of the material 36. Typically, as shown in Figure 2A, funnel 72 defines a broad end 85 and a narrow end 87. The broad end of the funnel typically defines an inlet opening to the blood flow pathway, and the narrow end of the funnel extends into one or more tubes (e.g., tubes 74 and 76).

[0090] Typically, the blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 is substantially unchanged compared to the blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 in the absence of a blood pump catheter. In some applications, the blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 is controlled by controlling the diameter of one or more parts of the blood flow pathway 60. For example, the diameter of one or more parts of the blood flow pathway (e.g., funnel 72, tube 74, and / or one or more tubes 76) can be adjusted (e.g., using an inflatable / contractable component placed inside or outside one of these elements). In this way, preload to the right atrium can be controlled, for example.

[0091] In some applications, the blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 is controlled (e.g., automatically) in response to one or more pressure measurements, such as pressure measurements performed as described herein. Alternatively, or in addition to this, the blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 may be periodically adjusted (e.g., as described above). For example, a healthcare professional (or another person) may periodically adjust the blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 in response to changes in the subject's condition (e.g., as described above).

[0092] In some applications, the diameter of one or more parts of the blood flow pathway 60 (e.g., funnel 72, tube 74, and tube 76) is not adjustable, and the diameter of at least a portion of the blood flow pathway is such that it reduces blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 (compared to the blood flow level in the absence of these components), thereby reducing preload on the right atrium.

[0093] Next, we will refer to Figure 2C, a schematic diagram of a blood pump catheter 70, which is a blood pump catheter including blood pressure measurement tubes 71 and 73, according to some applications of the present invention. We will also refer again to Figure 1C, which shows a blood pump catheter 20 including a blood pressure measurement tube 73, according to some applications of the present invention.

[0094] In some applications, at least one blood pressure measuring tube 71 is configured to extend at least to the outer surface of the funnel 72 and / or tube 74 so that the opening at the distal end of the blood pressure measuring tube is in direct fluid communication with the patient's blood flow (i.e., renal vein blood flow) outside the funnel 72 and / or tube 74. A pressure sensor 75 measures the blood pressure in the blood pressure measuring tube. Typically, by measuring the blood pressure in the blood pressure measuring tube, the blood pressure sensor measures the blood pressure of the subject outside the funnel 72 and / or tube 74, which indicates renal vein blood pressure. Typically, the blood pressure measuring tube 71 extends from outside the subject's body to the opening at the distal end of the tube, and the pressure sensor is located near the proximal end of the tube, for example, outside the subject's body. In some applications, a computer processor 10 receives the measured blood pressure signal and controls the pumping of the blood pressure by the impeller according to the measured blood pressure.

[0095] In some applications of the blood pump catheter 20, blood pump catheter 70, or blood pump catheter 90 (described below), at least one blood pressure measuring tube 73 is configured to extend at least to the outer surface of the material 36 so that the opening at the distal end of the blood pressure measuring tube is in direct fluid communication with the blood flow of the subject outside the material 36 (e.g., adrenal vena cava blood pressure). A pressure sensor 75 measures the blood pressure in the blood pressure measuring tube. Typically, by measuring the blood pressure in the blood pressure measuring tube, the blood pressure sensor measures the blood pressure of the subject outside the material 36, showing adrenal vena cava blood pressure in the examples shown in Figures 1C and 2C. Typically, the blood pressure measuring tube 73 extends from outside the subject's body to the opening at the distal end of the tube, and the pressure sensor is located near the proximal end of the tube, for example, outside the subject's body. In some applications, a computer processor 10 receives the measured blood pressure signal and controls the pumping of the blood pressure by the impeller according to the measured blood pressure. In some applications (for example, when used with a blood pump catheter 70), the computer processor adjusts the blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 in accordance with the measured blood pressure (for example, as described above). In some applications (for example, when used with a blood pump catheter 20 as shown in Figures 1A and 1B), the computer processor adjusts the diameter that expands the occluding element 40 in accordance with the measured blood pressure.

[0096] As described above, typically, the drive cable 78 is located within the outer tube 77 of the blood pump catheters 20, 70, and 90 (the drive cable is shown, for example, in Figure 7A). Typically, the drive cable extends from a motor 79 located outside the body of the subject to an axial shaft 92 on which the impeller is located. The motor imparts rotational motion to the axial shaft via the drive cable (thus imparting rotational motion to the impeller). In some applications, one or more blood pressure measurement tubes 71, 73 are located within the outer tube 77, surrounding the drive cable along at least a portion of the length of the blood pressure measurement tube.

[0097] As shown in Figures 1C and 2C, in some applications of the blood pump catheter 20 or 70, the subrenal vena cava blood pressure is measured using at least one blood pressure measuring tube that defines an opening 83 of an outer tube 77 at its distal end. This blood pressure measuring tube is configured to extend from outside the subject's body to the outer surface of the outer tube 77 inside the subject's subrenal vena cava, so that the opening at the distal end of the blood pressure measuring tube is in direct fluid communication with the subject's subrenal vena cava blood flow. A pressure sensor 75 is configured to measure the subject's subrenal vena cava blood pressure by measuring the blood pressure in the blood pressure measuring tube. In some applications (for example, when used with the blood pump catheter 20 as shown in Figures 1A to 1C), the renal venous pressure is measured in a generally similar manner (for example, using a blood pressure measuring tube that defines an opening located near the junction of the renal vein and vena cava). In some applications, a computer processor 10 receives the measured blood pressure and controls the pumping of the blood pressure by the impeller according to the measured blood pressure. In some applications (for example, when used with a blood pump catheter 70), the computer processor adjusts the blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 in accordance with the measured blood pressure (for example, as described above). In some applications (for example, when used with a blood pump catheter 20 as shown in Figures 1A and 1B), the computer processor adjusts the diameter that expands the occluding element 40 in accordance with the measured blood pressure.

[0098] Typically, there is a relationship between the amount of electrical power required to power an impeller to rotate at a given rotational speed and the pressure difference generated by the impeller. (Typically, the impeller pumps blood pressure into the vena cava region downstream of material 36, thereby reducing the pressure in the vena cava region upstream of material 36, and thus lowering the blood pressure in the upstream region and generating a pressure difference between the upstream and downstream regions.) In some application examples, calibration measurements are performed so that the relationship between (a) the power consumption of the motor required to rotate the impeller at a given rotational speed and (b) the pressure difference generated by the impeller is known.

[0099] In some applications, the blood pressure upstream of the impeller 50 and the covering material 36 is measured using, for example, a blood pressure measuring tube with an opening 83 of an outer tube 77 defined at its distal end, and / or a pressure sensor (e.g., a piezoelectric pressure sensor and / or an optical sensor) located in a subrenal position within the vena cava. In some such applications, the blood pressure downstream of the impeller 50 and the covering material 36 is then calculated by a computer processor based on (a) the measured upstream blood pressure, (b) the power consumption of the motor required to rotate the impeller at a given rotational speed at that time, and (c) a predetermined relationship between the power consumption of the motor required to rotate the impeller at a given rotational speed and the pressure difference generated by the impeller. In some applications, the above technique is performed while maintaining the rotational speed of the impeller at a constant speed. Alternatively or in addition to this, the rotational speed of the impeller is varied, and the variation in the rotational speed of the impeller is taken into account in the above calculations.

[0100] Typically, the blood outlet opening 31 of material 36 has a known cross-sectional area. In some applications, the flow through the blood outlet opening generated by the impeller is determined based on the determined pressure difference generated by the impeller and the known cross-sectional area of ​​the opening. In some applications, such flow calculations incorporate calibration parameters to take into account factors such as flow resistance specific to the blood pump catheter (or type of blood pump catheter) on which the calculation is performed.

[0101] In some applications, the above-described apparatus and method for measuring blood pressure are used, with modifications as necessary, in conjunction with the blood pump catheter 20 described above (referencing Figures 1A to 1C), the blood pump catheter 70 described above (referencing Figures 2A to 2F), the blood pump catheter 90 described later (referencing Figures 3A to 3B), and / or the blood pump catheter 20 described later (referencing Figures 4A to 4B).

[0102] The following diagram shows a schematic representation of a blood pump catheter 70 placed in a target vena cava 22 according to several applications of the present invention, with reference to Figure 2D. The blood pump has an asymmetric outflow tube 76. The blood pump catheter 70 shown in Figure 2D is substantially the same as those illustrated and described with reference to Figures 2A to 2C. However, the blood pump catheters in the examples shown in Figures 2A to 2C included two tubes 76 extending from tube 74 to the adrenal gland location, bypassing the blood pump 24, located on each side of the longitudinal axis of the blood pump catheter. In contrast, the blood pump catheter in the example shown in Figure 2D includes only one tube 76 extending from tube 74 to the adrenal gland location, bypassing the blood pump 24, located on one side of the longitudinal axis of the blood pump catheter, according to several applications of the present invention. In other respects, the blood pump catheter 70 shown in Figure 2D is substantially the same as those illustrated and described with reference to Figures 2A to 2C. In some applications (not shown), the blood pump catheter includes three or more tubes 76 that extend from tube 74 to the adrenal gland location, bypassing the blood pump 24, and are positioned at each location around the longitudinal axis of the blood pump catheter.

[0103] Next, refer to Figure 2E, a schematic diagram of a blood pump catheter 70 placed in the superior vena cava 22 of a subject, according to some applications of the present invention. The blood pump has a non-axisymmetric outflow tube 76 and a non-axisymmetric blood pump 24. Also refer to Figure 2F, a schematic diagram of the blood pump catheter of Figure 2E without the subject biostructure, according to some applications of the present invention. As described above with reference to Figure 2D, in some applications the blood pump catheter includes a single tube 76 that extends from a tube 74 located on one side of the longitudinal axis of the blood pump catheter, bypassing the blood pump 24 to the adrenal gland location. In some such applications, the blood pump 24 is positioned non-axisymmetrically on the opposite side of the longitudinal axis of the blood pump catheter, as shown. In other respects, the blood pump catheter 70 shown in Figures 2E and 2F is substantially the same as that illustrated and described with reference to Figures 2A to 2D.

[0104] In some applications, the techniques described above with reference to Figures 2A to 2E are performed when the blood pump 24 is absent. That is, when the blood pump 24 is absent, the blood flow in the region of the vena cava adjacent to the junction of the vena cava and the renal vein is separated into a separate compartment 82 from the subrenal vena cava blood flow 84 and the adrenal vena cava blood flow 86. In some such applications, the blood flow from the subrenal vena cava blood flow 84 to the adrenal vena cava blood flow 86 is passively controlled (e.g., as described above) without affecting the blood flow from the renal vein to the adrenal vena cava blood flow 86. Alternatively or in addition to this, the blood flow from the renal vein to the adrenal vena cava blood flow 86 is passively controlled without affecting the blood flow from the subrenal vena cava blood flow 84 to the adrenal vena cava blood flow 86.

[0105] With respect to Figures 2A to 2E, it should be noted that the scope of the present invention includes applying similar apparatus and methods to any venous system of a subject, including tributary veins flowing into major veins. For example, similar techniques can also be applied at the junction of the hepatic vein and the superior vena cava. Typically, such a method includes separating the blood flow in the region of the major vein adjacent to the junction of the major vein and the tributary vein from the blood flow in the major vein upstream and downstream thereto; pumping the blood from the region of the major vein adjacent to the junction of the vein and the tributary vein to a location in the major vein downstream of the tributary vein using a pump; and directing the blood of the subject from a location in the major vein upstream of the tributary vein to a location in the major vein downstream of the tributary vein by guiding it to bypass the pump without pumping. In some such applications, generally similar apparatus and methods are used at junctions of veins and lymphatic vessels in the subclavian vein or the jugular vein. In some such applications, the blood pump catheter 70 is configured, with modifications where necessary, to increase the flow of lymph from the lymphatic vessel into the vein. Generally, the scope of some applications of the present invention further includes devices and methods used with the target venous system, including branch vessels (e.g., lymphatic vessels) that flow into the vein. Typically, such a method includes separating the flow in a region of the vein adjacent to the junction of the vein and branch vessel from the blood flow in the veins upstream and downstream thereto; pumping blood from the region of the vein adjacent to the junction of the vein and branch vessel to a location in the vein downstream thereto using a pump; and directing the target blood from a location in the vein upstream of the branch vessel to a location in the vein downstream thereto by guiding it to bypass the pump without pumping it.

[0106] In some applications, such a method includes: at least partially occluding venous blood flow by placing a downstream occlusion element (e.g., material 36) at a downstream position downstream of the junction of the vein and its tributary vessel; pumping blood from a region of the vein adjacent to the junction of the vein and its tributary vessel through the downstream occlusion element using a pump; and guiding upstream venous blood flow from an upstream position upstream of the junction of the vein and its tributary vessel downstream of the occlusion element by guiding it to bypass the pump without pumping the upstream venous blood flow. Typically, such a method is performed using a blood pump catheter (e.g., blood pump catheter 70) containing material 36. Material 36 is configured to be placed at a downstream position downstream of the junction of the vein and its tributary vessel, and to at least partially occlude venous blood flow at that downstream position. This material defines a blood outlet opening 31. The blood pump 24 is typically configured to pump blood from a region of the vein adjacent to the junction of the vein and its tributary vessel through the blood outlet opening defined by the material. The blood flow pathway 60 typically passes between a pathway inlet opening 61 located upstream of the junction of the vein and its tributary vessel, and a pathway outlet opening 63 opening downstream of the material 36. In some applications, the blood flow pathway includes a funnel 72 and one or more tubes (e.g., tubes 74 and 76). The funnel 72 is configured to be located upstream of the junction of the vein and its tributary vessel, and one or more tubes 74, 76 are configured to extend from the funnel downstream of the material. The funnel and one or more tubes (or alternative blood flow pathways) are configured to guide upstream venous blood flow from the upstream position to the downstream of the material without pumping it. Typically, as shown in Figure 2A, the funnel 72 defines a wide end 85 and a narrow end 87. The broad end of the funnel typically defines an inlet opening to the blood flow pathway, while the narrow end of the funnel extends into one or more tubes (e.g., tubes 74 and 76).

[0107] Hereafter, we refer to Figures 3A, 3B, 3C, 3D, 3E, 3F, 3G, and 3H, which are schematic diagrams of a blood pump catheter 70 according to several other applications of the present invention. The blood pump catheter 70 illustrated and described with reference to Figures 3A to 3H is substantially the same as that described with reference to Figures 2A to 2F, except for the differences described below. It should be noted that, as shown in Figures 3A to 3H, the blood pump catheter has substantially the same design as that shown in Figures 2E and 2F (i.e., (a) a single tube 76 is located on one side of the longitudinal axis of the blood pump catheter and extends from the tube 74 to the adrenal gland location, bypassing the blood pump 24; and (b) the blood pump 24 is located in an asymmetric position on the opposite side of the longitudinal axis of the blood pump catheter). However, the scope of this application includes, with modifications where necessary, combining the features of the blood pump catheter 70 described with reference to Figures 3A to 3H with any one of the above-described designs of the blood pump catheter 70 with reference to Figures 2A to 2D.

[0108] Referring next to Figure 3A, in some applications, the elongated tube 109 extends from the frame 34 to the pulmonary artery 110 of the subject, with the blood outlet opening 31 positioned in the pulmonary artery. (It should be noted that in some applications, the material 36 defines the blood outlet opening, and the elongated tube extends from the blood outlet opening defined by the material to the blood outlet opening positioned in the pulmonary artery.) The tube 109 is typically made of a blood-impermeable material. For example, the tube 109 may include polyurethane, polyester, and / or silicone. Alternatively or in addition to this, the tube may be made of polyethylene terephthalate (PET) and / or polyether block amide (e.g., PEBAX (registered commercial)). The blood pump catheter is configured to pump blood directly from compartment 82 into the pulmonary artery of the subject. In this way, the blood pump catheter reduces renal venous pressure without increasing the preload on the right atrium of the subject. As described in Figures 2A to 2F, typically, blood flow from the inferior vena cava 84 to the adrenal vena cava 86 bypasses the elongated tube. Typically, blood flow from the inferior vena cava 84 to the adrenal vena cava 86 occurs passively by flowing through the blood flow pathway 60 (e.g., funnel 72, tube 74, and one or more tubes 76).

[0109] Referring to Figure 3B, in some applications, the elongated tube 109 includes a portion 111 that is positioned within the adrenal vena cava blood flow 86 and defines the adrenal blood inlet opening 112. The impeller 50 and frame 34 are typically positioned downstream of the adrenal blood inlet opening, and the impeller is configured to pump blood from the adrenal vena cava blood flow into the elongated tube 109 via the blood inlet opening 112, in addition to pumping blood from compartment 82 into the elongated tube 109. As described with reference to Figure 3A, typically the elongated tube 109 extends from the frame 34 to the subject's pulmonary artery 110, with the blood outlet opening 31 positioned within the pulmonary artery. A blood pump catheter 70, as configured in Figure 3B, is typically configured to reduce renal venous pressure (by pumping blood from compartment 82) and to support the subject's right ventricular function by pumping blood from the adrenal vena cava blood flow into the pulmonary artery. As described in Figures 2A to 2F, typically, blood flow from the inferior vena cava 84 to the adrenal vena cava 86 bypasses the elongated tube. Typically, blood flow from the inferior vena cava 84 to the adrenal vena cava 86 occurs passively by flowing through the blood flow pathway 60 (e.g., the funnel 72, tube 74, and one or more tubes 76).

[0110] Referring to Figure 3C, in some applications, in addition to reducing renal venous pressure using a blood pump catheter 70 (and optionally supporting right ventricular function as described with reference to Figure 3B), a left ventricular assist device 113 is placed in the target left ventricle 114 to support the target left ventricular function. In some applications, the left ventricular assist device is a left ventricular assist device as described in U.S. Patent Application Publication 16 / 750,354 to Tuval (filed on 23 January 2020, titled "Distal tip element for a ventricular assist device"), U.S. Patent Application Publication 2019 / 0209758 to Tuval, and / or U.S. Patent Application Publication 2019 / 0175806 to Tuval. All of these applications are incorporated herein by reference. In some applications, the left ventricular support device includes left ventricular support devices manufactured by Abiomed® (Massachusetts, USA), such as Impella 2.5®, Impella CP®, Impella 5.5®, and / or Impella 5.0®. While the left ventricular support device 113 is shown to be used in combination with an example of a blood pump catheter 70 shown in Figure 3B, it should be noted that the scope of this application includes using the left ventricular support device 113 in combination with any of the examples of blood pump catheters 70 described herein.

[0111] Referring now to Figure 3D, in some applications, instead of the impeller 50 and frame 34, an elongated blood pump tube 104 (typically including the impeller) is located within the blood outlet opening of the covering material 36. Typically, the covering material 36 and / or inner lining 39 (Figure 7) are sealed and bonded to the outer surface of the elongated blood pump tube. For example, the elongated blood pump tube may include ImpellaRP® manufactured by Abiomed (Massachusetts, USA). Typically, the elongated blood pump tube includes a blood inlet area 105 (located within the upstream portion of the elongated blood pump tube), which is positioned lower (i.e., upstream) relative to the covering material 36 and / or inner lining 39 (Figure 7). The impeller 106 (typically located very close distally to the blood inlet area) pumps blood from compartment 82 into the blood inlet area and further pumps it out of the blood outlet area 107 (located downstream of the elongated blood pump tube) via an elongated blood pump tube. In the example shown in Figure 3A, the blood outlet area is located within the adrenal vena cava, and blood is pumped into the adrenal vena cava blood flow 86. As described in Figures 2A to 2F, typically, blood flow from the inferior vena cava blood flow 84 to the adrenal vena cava blood flow 86 bypasses the elongated blood pump tube. Typically, blood flow from the inferior vena cava blood flow 84 to the adrenal vena cava blood flow 86 is passively generated by flowing through the blood flow pathway 60 (e.g., funnel 72, tube 74, and one or more tubes 76).

[0112] Referring to Figure 3E, in some applications, the elongated blood pump tube 104 is positioned such that the blood inlet area 105 and the impeller 106 are located within the adrenal vena cava. In some such applications, a reinforced tube 115 (e.g., a tube made of polymer supported by a shape memory material (e.g., nitinol) frame and / or a shape memory material (e.g., nitinol) braid) extends from the outlet opening of the covering material 36 and / or inner lining 39 (Figure 7) to the blood inlet area of ​​the elongated blood pump tube, forming a seal between the covering material 36 and / or inner lining 39 and the blood inlet area of ​​the elongated blood pump tube. Thus, the impeller 106 draws blood from compartment 82 into the blood inlet area 105. Typically, the elongated blood pump tube extends from the blood inlet area to a blood outlet area 107 located within the pulmonary artery 110 of the application. In some alternative applications (not shown), the elongated blood pump tube itself extends from upstream of the covering material 36 to the pulmonary artery 110 (i.e., the reinforcing tube 115 is absent). The elongated blood pump tube is configured to pump blood from compartment 82 into the pulmonary artery of the subject. In this way, the blood pump catheter 70 reduces renal venous pressure without increasing the preload on the right atrium of the subject. As described in Figures 2A to 2F, typically, blood flow from the inferior vena cava 84 to the adrenal vena cava 86 bypasses the elongated blood pump tube. Typically, blood flow from the inferior vena cava 84 to the adrenal vena cava 86 occurs passively by flowing through the blood flow pathway 60 (e.g., funnel 72, tube 74, and one or more tubes 76).

[0113] Referring to Figure 3F, in some applications, the reinforced tube 115 defines a blood inlet opening 117 located within the adrenal vena cava. The impeller 106 and blood inlet area 105 are typically located downstream of the blood inlet opening 117, and the impeller is configured to pump blood into the elongated blood pump tube 104, as well as to pump blood from the adrenal vena cava blood flow into the elongated blood pump tube 104 via the blood inlet opening 117. As described with reference to Figure 3E, typically the elongated blood pump tube 104 extends from the adrenal vena cava to the pulmonary artery 110 of the patient, with the blood outlet area 107 located within the pulmonary artery. A blood pump catheter 70, as configured in Figure 3F, is typically configured to reduce renal venous pressure (by pumping blood from compartment 82) and to support the patient's right ventricular function by pumping blood from the adrenal vena cava blood flow into the pulmonary artery. As described in Figures 2A to 2F, typically, blood flow from the inferior vena cava 84 to the adrenal vena cava 86 bypasses the elongated blood pump tube. Typically, blood flow from the inferior vena cava 84 to the adrenal vena cava 86 occurs passively by flowing through the blood flow pathway 60 (e.g., funnel 72, tube 74, and one or more tubes 76).

[0114] Referring to Figure 3G, in some applications, the blood inlet opening 117 is located within the right ventricle 119 of the patient, and the impeller 106 and blood inlet area 105 are located downstream of the blood inlet opening. The impeller is configured to pump blood into the elongated blood pump tube 104, as well as to pump blood from the right ventricle into the elongated blood pump tube 104 via the blood inlet opening 117. Typically, the elongated blood pump tube 104 extends from the right ventricle to the patient's pulmonary artery 110, with the blood outlet area 107 located in the pulmonary artery. A blood pump catheter 70, as configured in Figure 3G, is typically configured to reduce renal venous pressure (by pumping blood from compartment 82) and to support the patient's right ventricular function by pumping blood from the right ventricle to the pulmonary artery. As described in Figures 2A to 2F, typically, blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 bypasses the elongated blood pump tube. Typically, blood flow from the subrenal vena cava 84 to the adrenal vena cava 86 occurs passively through the blood flow pathway 60 (e.g., a funnel 72, a tube 74, and one or more tubes 76).

[0115] Referring next to Figure 3H, in some applications, the blood pump catheter 70 includes an elongated blood pump tube 104 (according to any of the examples described with reference to Figures 3D through 3G), and the blood pump catheter is used together with a left ventricular assist device 113 deployed within the subject's left ventricle 114 to assist the subject's left ventricular function (as described above with reference to Figure 3C). In some applications, the left ventricular assist device is a left ventricular assist device such as those described in U.S. Patent Application Publication 16 / 750,354 to Tuval (filed on 23 January 2020, titled “Distal tip element for a ventricular assist device”), U.S. Patent Application Publication 2019 / 0209758 to Tuval, and / or U.S. Patent Application Publication 2019 / 0175806 to Tuval. All of these applications are incorporated herein by reference. In some applications, the left ventricular support device includes left ventricular support devices manufactured by Abiomed® (Massachusetts, USA), such as Impella 2.5®, Impella CP®, Impella 5.5®, and / or Impella 5.0®. While the left ventricular support device 113 is shown to be used in combination with an example of a blood pump catheter 70 shown in Figure 3F, it should be noted that the scope of this application includes using the left ventricular support device 113 in combination with any of the examples of blood pump catheters 70 described herein.

[0116] Next, refer to Figures 4A and 4B, schematic diagrams of a blood pump catheter 90 placed in the descending aorta 80 near the target renal artery 94, according to some application examples of the present invention. The structure of the blood pump catheter 90 is generally the same as that of the blood pump catheter 70 described above, with reference to Figures 2A to 2F. However, the blood pump 24 of the blood pump catheter 90 is typically configured to pump blood upstream in order to increase tissue perfusion (such as the kidney), as will be detailed below.

[0117] Typically, a blood pump catheter 90 includes a blood pump 24, which typically includes an impeller housing 26 and an impeller 50, all of which are generally similar to those described above. The impeller housing 26 (e.g., the housing frame 34) typically functions to separate the inner wall of the aorta from the impeller, thereby preventing the aorta from being damaged by the impeller and preventing the impeller from being deformed by pressure from the inner wall of the aorta. Typically, an axial shaft 92 (shown in Figure 7) that penetrates the impeller is supported by radial bearings 116, 118 located at the proximal and distal ends of the impeller housing, respectively.

[0118] In some such applications, the blood pump support frame 32 is positioned upstream of the impeller housing 26 and configured to contact the inner wall of the aorta. By contacting the inner wall of the aorta, the blood pump support frame 32 is configured to align the longitudinal axis of the impeller housing 26, and thereby the impeller 50, with the local longitudinal axis of the aorta. (It should be noted that in some applications, the blood pump support frame may not perfectly align the longitudinal axis of the impeller with the local longitudinal axis of the aorta. However, typically, the blood pump support frame maintains a better alignment of the longitudinal axis of the impeller with the local longitudinal axis of the aorta than would be possible in the absence of this blood pump support frame.) Typically, all other equalities, the greater the effectiveness of blood pumping by the impeller 50, the better the alignment of the longitudinal axis of the impeller with the local longitudinal axis of the aorta. As described above, it should be noted that even with a slight misalignment between the longitudinal axis of the impeller and the local longitudinal axis of the blood vessel in which it is located (for example, shown in Figure 2E), effective pumping of blood by the impeller usually occurs.

[0119] In some applications, the impeller housing 26 includes a frame 34 (e.g., a rigid or semi-rigid frame) made of a shape memory element (such as nitinol) that is at least partially coated with material 36 (e.g., a blood-impermeable material such as polyester, polyurethane, and / or different polymers). Typically, in such applications, the rigidity of the frame 34 is sufficiently high so that the frame does not deform due to the pressure exerted on the frame 34 by the inner wall of the aorta. Typically, the material 36 extends from the impeller housing to the blood pump support frame 32 so as to contact the vessel wall and to occlude the vessel in the region of the vessel surrounding and / or upstream of the impeller. Typically, the material defines a through-hole in the distal portion of the impeller housing. This hole is configured to act as a blood inlet opening 98 during blood pumping by the impeller. In some applications, a portion of the impeller housing is covered (i.e., lined) on the inside of the impeller housing by an inner lining 39, as described below with reference to Figure 7. In some such applications, the inner lining of the impeller housing overlaps with material 36 at least partially. In some applications, the inner lining extends the blood inlet opening defined by material 36.

[0120] Typically, a drive cable 78 is located within the outer tube 77 of the blood pump catheter 90 (the drive cable is shown, for example, in Figure 8A). Typically, the drive cable extends from a motor 79 located outside the body of the subject to an axial shaft 92 (shown in Figure 7) on which the impeller is located. The motor imparts rotational motion to the axial shaft via the drive cable (thus imparting rotational motion to the impeller). Typically, the motor is controlled by a computer processor 10. In some applications, the motor is controlled based on blood pressure measurements performed by a pressure sensor 75.

[0121] In some applications, the blood pump catheter further includes a blood flow pathway 60. In some applications, the blood flow pathway 60 includes a funnel 72 extending into a tube 74. The funnel is configured to be positioned upstream of the junction between the aorta and the target renal artery and is configured to guide all blood flow from the adrenal aorta into tube 74. Tube 74 then guides the blood flow from the adrenal aorta to the subrenal aorta so that this blood bypasses the blood pump 24 (i.e., without being pumped by the blood pump 24). For example, one or more tubes 76 may extend from tube 74 to the subrenal aorta while bypassing the blood pump. As shown by the blood flow arrows in Figure 4A, this allows blood to flow from the adrenal aorta to the subrenal aorta without being pumped by the blood pump 24. In contrast, as shown by the blood flow arrows in Figure 4B, the blood is pumped from the subrenal aorta to the renal artery 94 by the blood pump 24. Typically, pumping blood into the renal artery increases renal perfusion.

[0122] In this way, by deploying the blood pump catheter 90, the blood flow in the region of the aorta adjacent to the junction of the aorta and the renal artery is separated into a compartment 97, distinct from the adrenal aortic blood flow 95 and the subrenal aortic blood flow 99. Blood flow from the adrenal aortic blood flow 95 to the subrenal aortic blood flow 99 occurs passively (for example, by flowing through the blood flow pathway 60). Blood is actively pumped from the subrenal aortic blood flow 99 to compartment 97 using the blood pump.

[0123] Specific examples of the configurations of the funnel 72, tube 74, and tube 76 are shown for illustrative purposes only, and it should be noted that the scope of this application includes using any other configuration of the blood flow path for guiding blood from the adrenal aortic blood flow to the subrenal aortic blood flow without pumping by the blood pump 24, with modifications where appropriate. In some applications, the funnel 72, tube 74, and tube 76 comprise parts of a single, continuous blood flow path. The blood flow path typically passes between a path inlet opening 61 located upstream of the junction of the aorta and renal artery and a path outlet opening 63 opening downstream of the material 36. Typically, the funnel 72 defines a broad end 85 and a narrow end 87. The broad end of the funnel typically defines an inlet opening to the blood flow path, and the narrow end of the funnel extends into one or more tubes (e.g., tubes 74 and 76).

[0124] Typically, blood flow from the adrenal aorta 95 to the subrenal aorta 99 is substantially unchanged compared to the blood flow from the adrenal aorta 95 to the subrenal aorta 99 in the absence of a blood pump catheter. In some applications, blood flow from the adrenal aorta 95 to the subrenal aorta 99 is controlled by controlling the diameter of one or more parts of the blood flow pathway. For example, the diameter of one or more parts of the blood flow pathway (e.g., a funnel 72, a tube 74, and / or one or more tubes 76) can be adjusted (e.g., using an inflatable / contractable component placed inside or outside one of these parts). In this way, blood supply to, for example, the lower body can be controlled.

[0125] With respect to Figures 4A to 4B, it should be noted that the scope of the present invention includes applying similar apparatus and methods to any arterial system of a subject, including major arteries that flow into branching arteries (typically supplying tissue). For example, similar techniques can also be applied at the junction of the aorta and the hepatic artery (supplying the liver). Typically, such a method includes separating the blood flow in the region of the major artery adjacent to the junction of the major artery and the branching artery from the blood flow in the major arteries upstream and downstream thereof; increasing tissue perfusion by pumping blood from the major artery to the region of the major artery adjacent to the junction of the major artery and the branching artery using a pump; and directing the blood of the subject from a location in the major artery upstream of the branching artery to a location in the major artery downstream of the branching artery by guiding it to bypass the pump without pumping it. In some applications, such methods include: at least partially occluding blood flow through a major artery by placing a downstream occlusion element (e.g., material 36) at a downstream position downstream of the junction of the major artery and a branch artery; increasing tissue perfusion by pumping blood from the region of the major artery adjacent to the junction of the major artery and a branch artery through the downstream occlusion element using a pump (e.g., blood pump 24); and guiding upstream major artery blood flow from an upstream position upstream of the junction of the major artery and a branch artery to downstream of the occlusion element by guiding it to bypass the pump without pumping the upstream major artery blood flow. Typically, a blood pump catheter such as a blood pump catheter 90 containing material 36 is used. Material 36 is configured to be placed at a downstream position downstream of the junction of the major artery and a branch artery, and to at least partially occlude blood flow through the major artery at that downstream position. This material defines a blood inlet opening 98. The blood pump 24 is typically configured to pump blood from the major artery towards the region of the major artery adjacent to the junction of the major artery and a branch artery through the blood inlet opening. The blood flow pathway 60 typically passes between a pathway inlet opening 61 located upstream of the junction between the major artery and the branch artery, and a pathway outlet opening 63 that opens downstream of the material 36.In some applications, the blood flow pathway includes a funnel 72 and one or more tubes (e.g., tubes 74 and 76). The funnel 72 is configured to be positioned upstream of the junction of the major artery and the branch artery, and one or more tubes 74, 76 (or alternative blood flow pathways) are configured to extend downstream from the funnel to the material. The funnel and one or more tubes (or alternative blood flow pathways) are typically configured to guide the upstream major arterial blood flow from the upstream position to the material downstream without pumping. Typically, the funnel 72 defines a broad end 85 and a narrow end 87. The broad end of the funnel typically defines an inlet opening to the blood flow pathway, and the narrow end of the funnel extends into one or more tubes (e.g., tubes 74 and 76).

[0126] Hereafter, we will refer to Figures 5A to 5B, schematic diagrams of a blood pump catheter 20 installed in the descending aorta 80 of a subject, according to some application examples of the present invention. Typically, the blood pump catheter 20 is as described above and typically includes a blood pump 24, which includes an impeller housing 26 and an impeller 50, all of which are generally the same as described above. The impeller housing 26 (e.g., the housing frame 34) typically functions to separate the inner wall of the aorta from the impeller, thereby preventing the aorta from being damaged by the impeller and preventing the impeller from being deformed by pressure from the inner wall of the aorta. Typically, an axial shaft 92 (shown in Figure 7) that penetrates the impeller is supported by radial bearings 116, 118 located at the proximal and distal ends of the impeller housing, respectively.

[0127] In some such applications, the blood pump support frame 32 is positioned upstream of the impeller housing 26 and configured to contact the inner wall of the aorta. By contacting the inner wall of the aorta, the blood pump support frame 32 is configured to align the longitudinal axis of the impeller housing 26, and thereby the impeller 50, with the local longitudinal axis of the aorta. (It should be noted that in some applications, the blood pump support frame may not perfectly align the longitudinal axis of the impeller with the local longitudinal axis of the aorta. However, typically, the blood pump support frame maintains a better alignment of the longitudinal axis of the impeller with the local longitudinal axis of the aorta than would be possible without the blood pump support frame.) Typically, all other equalities, the greater the effectiveness of blood pumping by the impeller 50, the better the alignment of the longitudinal axis of the impeller with the local longitudinal axis of the aorta.

[0128] In some applications, the impeller housing 26 includes a frame 34 (e.g., a rigid or semi-rigid frame) made of a shape memory element (such as nitinol) that is at least partially coated with material 36 (e.g., a blood-impermeable material such as polyester, polyurethane, and / or different polymers). Typically, in such applications, the rigidity of the frame 34 is sufficiently high so that the frame 34 does not deform due to the pressure exerted on the frame 34 by the inner wall of the aorta. Typically, the material 36 extends from the impeller housing to the blood pump support frame 32 so as to contact the vessel wall and to occlude the vessel in the region of the vessel surrounding and / or upstream of the impeller. Typically, the material defines through-holes in the distal portion of the impeller housing. The material is configured to occlude the backflow of blood around the outside of the impeller, but to allow antegrade blood flow in the central region of the blood vessel near the impeller through a hole that acts as a blood outlet opening 31. In some applications, a portion of the impeller housing is covered (i.e., lined) on the inside of the impeller housing by an inner lining 39, as described below with reference to Figure 7, for example. In some such applications, the inner lining of the impeller housing overlaps at least partially with the material 36. In some applications, the inner lining extends the blood outlet opening defined by the material 36.

[0129] Typically, a drive cable 78 is located within the outer tube 77 of the blood pump catheter 90 (the drive cable is shown, for example, in Figure 8A). Typically, the drive cable extends from a motor 79 located outside the body of the subject to an axial shaft 92 (shown in Figure 7) where the impeller is located. The motor imparts rotational motion to the axial shaft via the drive cable (thus imparting rotational motion to the impeller). Typically, the motor is controlled by a computer processor 10. In some applications, the motor is controlled based on blood pressure measurements performed by a pressure sensor 75. The covering material 36 substantially separates the descending aorta into two compartments, and the blood pump pumps blood from the upstream compartment to the downstream compartment. In this way, the blood pump typically increases aortic blood flow and / or reduces left ventricular afterload.

[0130] Referring to Figure 5A, in some applications, the blood pump is inserted into the descending aorta via an artery located below the descending artery, such as the femoral artery. Alternatively, or in addition to this, as shown in Figure 5B, the blood pump is inserted into the descending aorta via an aorta located above the descending aorta, such as the radial artery or subclavian artery. In some applications, the blood pump catheter is inserted into the aortic arch of the target area rather than the descending aorta, with modifications where appropriate.

[0131] In some applications, the impeller 50, the impeller housing 26, the frame 34, and / or other components of the blood pump catheter described herein have similar features to those of the components described in U.S. Patent Application Publication 16 / 750,354 to Tuval (filed on 23 January 2020, titled “Distal tip element for a ventricular assist device”), U.S. Patent Application Publication 2019 / 0209758 to Tuval, U.S. Patent Application Publication 2019 / 0239998 to Tuval, and / or U.S. Patent Application Publication 2019 / 0175806 to Tuval (all of which are incorporated herein by reference). Some of these features, for example, are described below with reference to Figures 6A to 8C.

[0132] Next, we refer to Figures 6A to 6C, schematic diagrams of an impeller 50 and some of its applications according to several examples of the present invention. Typically, the impeller includes at least one outer helical slender element 52 wound around a central axis spring 54, such that the helical shape defined by the helical slender element is coaxial with the central axis spring. Typically, the impeller includes two or more helical slender elements (e.g., three helical slender elements as shown in Figures 6A to 6C). In some applications, the helical slender elements and the central axis spring are made of a shape memory material, such as a shape memory alloy such as nitinol. Typically, each of the helical slender elements and the central axis spring supports a film 56 of material (e.g., an elastomer such as polyurethane and / or silicone) between them. In some applications, the film of material includes, for example, a nitinol piece embedded inside to reinforce the film of material. For illustrative purposes, the impeller is shown without material in Figure 6A. Figures 6B and 6C show diagrams of an impeller in which the material is supported between a helical slender element and a spring, respectively.

[0133] Each helical slender element, together with a film extending from the helical slender element to the spring, defines an impeller blade. The helical slender element defines the outer edge of the blade, and the axial spring defines the axis of the impeller. Typically, the film of material extends along the spring and covers it. In some applications, a suture 53 (e.g., polyester suture shown in Figures 6B and 6C) is wound around the helical slender element, for example, as described in U.S. Patent Application Publication 2016 / 0022890 for Schwammenthal, which is incorporated herein by reference. Typically, the suture is configured to facilitate bonding between the film of material (typically an elastomer such as polyurethane or silicone) and the helical slender element (typically a shape memory alloy such as Nitinol). In some applications, a suture (e.g., polyester suture, but not shown) is wound around a spring 54. Typically, sutures are designed to facilitate bonding between a film of material (typically an elastomer such as polyurethane or silicone) and a spring (typically a shape memory alloy such as nitinol).

[0134] Enlarged views A and B of Figure 6C show two alternative methods for tying sutures to the helical slender element 52. In some applications, the sutures are tied to the outer surface of the helical slender element, as shown in enlarged view A. Alternatively, as shown in enlarged view B, the helical slender element defines grooves 48 on its outer surface, and the sutures are embedded within these grooves. By embedding the sutures within the grooves, the sutures typically do not enlarge the outer shape of the impeller, and the outer shape of the impeller is defined by the outer surface of the helical slender element.

[0135] Typically, the proximal ends of the spring 54 and the helical slender element 52 extend from the proximal bushing (i.e., sleeve bearing) 64 of the impeller so as to be positioned at similar radial distances from each other from the longitudinal axis of the impeller. Similarly, typically, the distal ends of the spring 54 and the helical slender element 52 extend from the distal bushing 58 of the impeller so as to be positioned at similar radial distances from each other from the longitudinal axis of the impeller. Typically, the spring 54 of the impeller, as well as the proximal and distal bushings 64 and 58, define a lumen 62 within themselves (shown in Figure 6C).

[0136] Next, refer to Figure 7, a schematic diagram of an impeller 50 positioned within a frame 34 of a blood pump catheter 20, 70, or 90 according to some applications of the present invention. In some applications, an inner lining 39 lines the frame inside at least a portion of the frame 34. According to each application, the inner lining partially or completely overlaps with a covering material 36 in the frame portion being lined. In the application shown in Figure 7, the inner lining lines (i.e., covers) the inside of the cylindrical portion 38 of the frame, while the covering material 36 does not cover the cylindrical portion of the frame. In such applications, the inner lining enlarges the blood inlet or blood outlet opening of the blood pump.

[0137] As shown in Figure 7, typically, a gap G exists between the outer edge of the impeller 50 and the inner lining 39, even at the position where the impeller blade width (span) is at its maximum. In some applications, a relatively small gap between the outer edge of the impeller blades and the inner lining 39 is desirable for the impeller to efficiently pump blood. However, to reduce the risk of hemolysis, for example, it is also desirable that the gap between the outer edge of the impeller blades and the inner lining 39 be kept substantially constant throughout the rotation of the impeller within the frame 34.

[0138] In some applications, when the impeller and frame 34 are both arranged in a configuration that is not radially constrained, the gap G between the outer edge of the impeller and the inner lining 39 at the position where the impeller blade width is maximum is greater than 0.05 mm (e.g., greater than 0.1 mm) and / or less than 1 mm (e.g., less than 0.4 mm). For example, the gap G is 0.05 to 1 mm or 0.1 to 0.4 mm. In some applications, when the impeller is arranged in a configuration that is not radially constrained, the outer diameter of the impeller at the position where the impeller outer diameter is maximum is greater than 7 mm (e.g., greater than 8 mm) and / or less than 10 mm (e.g., less than 9 mm). For example, this outer diameter is 7 to 10 mm or 8 to 9 mm. In some applications, when the frame 34 is arranged in a configuration that is not radially constrained, the inner diameter of the cylindrical portion 38 of the frame 34 (measured from the inside of the inner lining 39 on one side of the frame to the inside of the inner lining on the opposite side of the frame) is greater than 7.5 mm (e.g., greater than 8.5 mm) and / or less than 10.5 mm (e.g., less than 9.5 mm). For example, this inner diameter is 7.5 to 10.5 mm or 8.5 to 9.5 mm. In some applications, when the frame is arranged in a configuration that is not radially constrained, the outer diameter of the cylindrical portion 38 of the frame 34 is greater than 8 mm (e.g., greater than 9 mm) and / or less than 13 mm (e.g., less than 12 mm). For example, this outer diameter is 8 to 13 mm or 9 to 12 mm.

[0139] Typically, the axial shaft 92 passes through the lumen 62 of the impeller and through the axis of the impeller 50. More typically, the axial shaft is rigid, for example, a rigid tube. In some applications, the proximal bushing 64 of the impeller is coupled to the shaft such that the axial position of the proximal bushing relative to the shaft is fixed, and the distal bushing 58 of the impeller is slidable relative to the shaft. The axial shaft itself is radially stabilized by a proximal radial bearing 116 and a distal radial bearing 118. (Note that in Figure 7, the distal radial bearing 118 is located below the distal end element 108 and is therefore not visible. However, in other figures, for example in the embodiments shown in Figures 1A to 1C, Figures 2A to 2E, and Figures 4A to 4B, the distal radial bearing is visible). Furthermore, the axial shaft penetrates the lumen 62 defined by the impeller, thereby stabilizing the impeller radially relative to the inner surface of the frame 34. This ensures that even a relatively small gap (such as the gap described above) between the outer edge of the impeller blades and the inner surface of the frame 34 is maintained during the impeller's rotation.

[0140] Referring again to Figures 6A to 6C, in some applications, the impeller includes multiple elongated elements 67 extending from a central axis spring 54 to an outer helical elongated element 52. The elongated elements are typically flexible but substantially inflexible along the axis defined by the elongated element. More typically, each elongated element is configured not to exert force on the helical elongated element, as long as a force acting on the impeller causes the helical elongated element to move radially outward, so that the separation between the helical elongated element and the central axis spring (as would be if the elongated element were not present) does not exceed the length of the elongated element. For example, the elongated elements may include threads (such as polyester, and / or other polymers, or natural materials including fibers), and / or wires (such as nitinol wire, and / or wires made of different alloys or metals).

[0141] In some applications, the elongated elements 67 maintain the helical elongated elements (which define the outer edges of the impeller blades) within a given distance from the central axis spring. In this way, the elongated elements are configured to prevent the outer edges of the impeller from being pushed radially outward by the forces acting on the impeller during its rotation. The elongated elements are thus configured to maintain a gap between the outer edges of the impeller blades and the inner lining 39 of the frame 34 during the impeller's rotation. Typically, two or more (e.g., three or more) and / or seven or fewer (e.g., three or fewer) elongated elements 67 are used in an impeller, and each elongated element is typically doubled (i.e., extending radially from the central axis spring 54 to the outer helical elongated element 52, and then returning from the helical elongated element to the central axis spring). In some applications, multiple slender elements are formed from a single thread or wire, with each slender element extending from a spring to a helical slender element and then returning to the spring. This will be described in detail below.

[0142] In some applications, the impeller is manufactured as follows: A proximal bushing 64, a distal bushing 58, and a helical slender element 52 are cut from a tube of shape memory material such as Nitinol. The cutting of the tube and shaping of the shape memory material are typically carried out using techniques generally similar to those described, for example, in U.S. Patent Application Publication 2016 / 0022890 to Schwammenthal, so that the helical slender element is defined by the shape memory material. Typically, a spring 54 is inserted into the cut and shaped tube so that the spring extends along the length of the tube at least from the proximal bushing to the distal bushing. In some applications, the spring is inserted into the cut and shaped tube in an axially compressed state and is held in place relative to the tube by applying radial forces to the proximal and distal bushings. Alternatively, or in addition to this, the parts of the spring are welded to the proximal and distal bushings. In some applications, the spring is cut from a tube of shape memory material such as Nitinol. In some such applications, when the spring is positioned in a configuration that is not radially constrained (typically where the spring is positioned during the operation of the impeller), the spring is configured such that there is virtually no gap between the windings of the spring and adjacent windings.

[0143] In some applications, after inserting the spring 54 into the tube that has been cut and shaped as described above, the elongated element 67 described above is positioned to extend between the spring and one or more of the helical elongated elements. This is done, for example, as follows: A mandrel (e.g., a polyetheretherketone (PEEK) and / or polytetrafluoroethylene (PTFE) mandrel) is inserted into the lumen defined by the spring and bushing. Then, a thread or wire is attached by (a) extending it from the mandrel to the first helical elongated element, (b) returning it from the first helical elongated element to the mandrel, (c) winding it around the mandrel, further extending it to the second helical elongated element, and (d) returning it from the second helical elongated element to the mandrel, and so on. Once the thread or wire has been extended from the mandrel to each of the helical elongated elements and then returned, the ends of the thread or wire are joined together, for example, by tying them together. In some applications, in the next step of impeller manufacturing, sutures 53 (e.g., polyester sutures) are wrapped around the helical elongation elements (typically a shape memory alloy such as Nitinol) to facilitate bonding between the film of material (typically an elastomer such as polyurethane or silicone) and the helical elongation elements. In some applications, sutures (e.g., polyester sutures, not shown) are wrapped around the spring 54. Typically, the sutures are configured to facilitate bonding between the film of material (typically an elastomer such as polyurethane or silicone) and the spring (typically a shape memory alloy such as Nitinol) in the next step of impeller manufacturing.

[0144] Typically, at this stage, a structure 59 as shown in Figure 6A is assembled. This structure includes a cut and shaped tube that defines a proximal and distal bushing, a helical elongated element, and a spring (and optionally, an elongated element and sutures). This structure is immersed in a material that defines a film 56. In some applications, the assembled structure is immersed in the material with a mandrel placed in the lumen defined by the spring and bushing, although it should be noted that the mandrel is not shown in Figure 6A. Typically, the material used to make the film is silicone and / or polyurethane (and / or similar elastomers), and the assembled structure is immersed in the material while it is in an uncured liquid state. After this, it is cured, for example, by drying the material. Once the material is dry, the mandrel is typically removed from the lumen defined by the bushing and spring.

[0145] As a result of the process described above, typically a continuous film of the material extends between each of the helical elongated elements and the spring, and also extends along the length of the spring, defining a tube in which the spring is embedded. Each portion of the film extending from each of the helical elongated elements to the spring defines an impeller blade. In applications where the impeller includes elongated elements 67, the elongated elements are typically embedded in these portions of the film.

[0146] Typically, the impeller 50 is inserted into the target body in a radially constrained configuration. In a radially constrained configuration, both the helical slender element 52 and the central axis spring 54 are elongated in the axial direction and thus constrained radially. Typically, the film 56 of the material (e.g., silicone and / or polyurethane) changes shape to match the shape changes of the helical slender element and the axial support spring (both supporting the film of the material). Typically, by using the spring to support the inner edge of the film, the spring provides a large surface area for the inner edge of the film to join, so the film can change shape without breaking or collapsing. In some applications, using the spring to support the inner edge of the film allows the diameter of the spring itself to be reduced by elongating the spring in the axial direction, so that the impeller can be radially constrained to a smaller diameter compared to, for example, when the inner edge of the film is supported by a rigid shaft.

[0147] In some applications, the proximal bushing 64 of the impeller 50 is coupled to the axial shaft 92 such that the axial position of the proximal bushing relative to the axial shaft is fixed, and the distal bushing 58 of the impeller is slidable relative to the shaft. In some applications, when the impeller is radially constrained for insertion into or withdrawal from the body of a target, the impeller is axially elongated by the distal bushing sliding distally along the axial shaft. After being released within the body of a target, the impeller becomes unconstrained radially (typically the impeller is positioned during operation), as shown in Figures 6A to 6C.

[0148] It should be noted that, for illustrative purposes, in some figures the impeller 50 is depicted without including all of the features of the impeller illustrated and described in relation to Figures 6A to 6C. The scope of this application includes using an impeller having any of the features illustrated and described in relation to Figures 6A to 6C in combination with any of the apparatus and methods described herein.

[0149] Next, we refer to Figures 6D, 6E, and 6F, which are schematic diagrams of an impeller 50 or a part thereof according to some applications of the present invention. As described above, in some applications the impeller 50 includes a suture 53. The suture 53 is wound around a helical slender element 52 and is configured to facilitate bonding between a film of material (typically an elastomer such as polyurethane or silicone) and the helical slender element (typically a shape memory alloy such as nitinol).

[0150] In some applications, instead of or in addition to the sutures 53, a coil 68 is wound around (or placed on) the helical elongation elements, as shown in Figure 6D. For example, a tightly wound coil (e.g., a tightly wound nitinol coil) can be wound around (or placed around) each of the helical elongation elements. The coil typically facilitates bonding between the film of material and the helical elongation elements by increasing the surface area on which the material joins at the interface between the material and the helical elongation elements. In some applications, the structure 59 is formed modularly (see, for example, Figure 6F, as described later). In some such applications, the coil is placed around each of the elongation elements 52 (for example, by sliding the entire coil on the elongation elements in a single motion) before the elongation elements are joined to the proximal and distal bushings of the impeller.

[0151] Furthermore, in some applications, instead of or in addition to the sutures 53, a sleeve 69 is placed around the helical slender element, as shown in Figure 6E. For example, such a sleeve may be made of a polymer such as polyester. Typically, the sleeve facilitates bonding between the material film and the helical slender element by increasing the surface area on which the material joins at the interface between the material and the helical slender element. In some applications, the sleeve acts as an intermediary between a material that is typically relatively stiff (typically nitinol) used to make the slender element and a material that is typically an elastomer with relatively low stiffness used to make the film 56. The sleeve thereby improves the strength of the bond between the material and the helical slender element when the material dries. In some applications, the sleeve 69 is applied to the structure 59. In some such applications, a longitudinal slit is formed in the sleeve so that it can be placed around the helical slender element 52. After being placed around the helical slender element 52, the slit is closed (for example, by suturing or bonding with the slit closed). In some applications, the structure 59 is formed modularly (see, for example, Figure 6F, as described later). In some such applications, sleeves are placed around the elongated elements 52 before the elongated elements are joined to the proximal and distal bushings of the impeller.

[0152] Furthermore, in some applications, either instead of or in addition to the suture 53, the elongated element 52 has a round (e.g., circular) cross-section, as shown in the right portion of Figure 6F (showing a cross-sectional view of an elongated element with a round cross-section). The left portion of Figure 6F shows a cross-sectional view of the elongated element 52 to which the film 56 material is bonded, when the elongated element has a non-round cross-section (e.g., a square or rectangular cross-section). As shown, the material used to make the film (e.g., silicone and / or polyurethane) may form a thin layer at the corners of the elongated element having a non-round cross-section. In contrast, when the elongated element has a round cross-section, as shown in the left portion of Figure 6F, the material typically forms a layer with substantially uniform thickness at the interface with the elongated element. Therefore, in some applications, the elongated element has a round cross-section.

[0153] In some applications, the proximal and distal bushings 64, 58 and the slender elements 52 are cut from an alloy tube, for example, as described above. In such applications, after cutting the tube, the slender elements typically have non-rounded edges. Therefore, in some applications, after cutting the tube, the edges of the slender elements are rounded, for example, by grinding, sandblasting, tumbling, etching, plasma, surface charging, and / or by adding rounded edges to the slender elements. Alternatively, the proximal and distal bushings and the slender elements can be formed modularly and then joined together (for example, by welding and / or riveting). In some such applications, the slender elements joined to the proximal and distal bushings have a rounded cross-section. As described above with reference to Figure 6E, in some applications, a sleeve 69 is placed on the slender elements before joining the slender elements to the proximal bushing and / or before joining the slender elements to the distal bushing.

[0154] In some such applications, alternative or additional techniques are used to facilitate bonding between the material film and the helical slender elements. For example, the helical slender elements can be treated using surface treatments (grinding, sandblasting, tumbling, etching, plasma, surface charging, etc.) to roughen their outer surfaces.

[0155] As described above in Figures 6A to 6F, in some applications of the present invention, an impeller 50 is manufactured by forming a structure having first and second bushings 64, 58 at the proximal and distal ends. The first and second bushings are interconnected by at least one elongated element 52. The at least one elongated element is fabricated to expand radially by at least partially compressing the structure axially, thereby forming at least one helical elongated element. An elastomer material is bonded to the at least one helical elongated element so that the at least one helical elongated element, together with the bonded elastomer material, defines the impeller blades. Typically, this bonding is carried out such that a layer of material is arranged around the radially outer edge of the at least one helical elongated element. The layer of material forms the effective edge of the impeller blade (i.e., the edge where the blood pumping function of the impeller is substantially ineffective). More typically, this method includes performing a step to improve the bonding of the elastomer material to at least one helical slender element so as not to cause protrusion from the effective edge of the impeller blade. For example, a suture 53 may be placed in a groove defined by at least one helical slender element so as not to protrude from the radially outer edge of the helical slender element. The suture is configured to improve the bonding of the elastomer material to at least one helical slender element. Alternatively or in addition to this, a tightly wound coil 68 may be placed around at least one helical slender element so that the elastomer material forms a substantially smooth layer along the radially outer edge of the coil. The coil is configured to improve the bonding of the elastomer material to at least one helical slender element. Furthermore, alternative or in addition to this, a sleeve 69 may be placed around at least one helical slender element so that the elastomer material forms a substantially smooth layer along the radially outer edge of the sleeve. The sleeve is configured to improve the bonding of the elastomer material to at least one helical slender element.In some applications, at least one helical slender element is given a rounded cross-section so that the elastomer material forms a layer with substantially uniform thickness at the interface between the elastomer material and the helical slender element. As mentioned above, typically, it is desirable that the gap G between the outer edge of the impeller blade and the inner lining 39 (shown in Figure 7) be relatively small. Therefore, it is desirable that there be no protrusions from the effective edge of the impeller blade, because such protrusions would occupy part of the gap between the outer edge of the impeller blade and the lining (and thus require a larger gap) without increasing the effectiveness of the impeller's blood pumping function.

[0156] Next, refer to Figures 6G and 6H, schematic diagrams of elongated elements 67 extending between each of the helical elongated elements 52 and the spring 54, according to some applications of the present invention. In some applications, each loop-shaped elongated element 67 extends between each of the helical elongated elements and the spring. Typically, the loop-shaped elongated element is a closed loop having a predetermined length and being (substantially) non-stretchable. The length of the loop-shaped elongated element is typically predetermined to maintain the helical elongated element (defining the outer edge of the impeller blade) within a given distance from the central axis spring, thereby maintaining the gap between the outer edge of the impeller blade and the inner surface of the frame 34 during the rotation of the impeller, as described above. In some applications, the impeller is formed by wrapping the first ends of the loop-shaped elongated elements around each helical elongated element, as shown in the enlarged sections of Figures 6G and 6H. Next, the spring 54 is inserted into the proximal and distal bushings 64 and 58, and into the second end of the loop-shaped helical slender element.

[0157] In some applications, as shown in Figures 6G and 6H, the spring 54 is shaped such that, at its longitudinal center, it defines a tube 88 (i.e., no windings). Typically, the second end of the loop-shaped slender element is wrapped around the tube at the longitudinal center of the spring. Typically, this reduces the risk of the loop-shaped slender element tearing compared to the case where the second end of the loop-shaped slender element is wrapped around the spring windings. In some applications (not shown), a groove is defined in the tube, and the second end of the loop-shaped slender element is configured to be held within this groove.

[0158] In some applications, the loop-shaped slender element is wrapped around the body of the helical slender element, as shown in the enlarged view of Figure 6G. Enlarged views A and B of Figure 6G show two alternative methods of wrapping the loop-shaped slender element around the body of the helical slender element. In some applications, the loop-shaped slender element is wrapped around the outer surface of the helical slender element, as shown in enlarged view A. Alternatively, as shown in enlarged view B, the helical slender element defines a groove 48 on its outer surface, and the loop-shaped slender element is wrapped around this groove 48 (so as to be embedded in the groove). By embedding the loop-shaped slender element in the groove, the loop-shaped slender element does not usually enlarge the outer shape of the impeller, and the outer shape of the impeller is defined by the outer surface of the helical slender element.

[0159] In some applications, as shown in the enlarged view of Figure 6H, the helical slender element is shaped to define two holes 91 that are positioned very close together, through which a loop-shaped slender element can be wrapped. Enlarged views A and B of Figure 6H show two alternative methods for wrapping the loop-shaped slender element through the holes 91. In some applications, as shown in enlarged view A, the loop-shaped slender element is wrapped through the holes 91 on the outer surface of the helical slender element. Alternatively, as shown in enlarged view B, the helical slender element defines a groove 48 on its outer surface, and the loop-shaped slender element is wrapped through the holes 91 into the groove 48 (so as to be embedded in the groove). By embedding the loop-shaped slender element in the groove, the loop-shaped slender element does not usually enlarge the outer shape of the impeller, and the outer shape of the impeller is defined by the outer surface of the helical slender element.

[0160] Next, refer to Figures 8A and 8B, schematic diagrams of the impeller 50 and frame 34 of a blood pump catheter 20, 70, or 90 in a radially unconstrained and radially constrained state, respectively, according to some applications of the present invention. The impeller and frame are typically positioned in a radially constrained state during transcatheter insertion of the impeller and frame into the body of the subject, and in a radially unconstrained configuration during the operation of the blood pump catheter. As described above, typically, a covering material 36 extends from the frame 34. However, for illustrative purposes, the frame and impeller are shown without the covering material 36 in Figures 8A and 8B. As shown in Figure 8B, the frame and impeller are typically maintained in a radially constrained configuration by the delivery catheter 143.

[0161] Also refer to Figure 8C, which shows a typical bearing assembly used in a prior art axial impeller-based blood pump. Figure 8C is provided for the purpose of serving as a reference for some of the application examples of the present invention described herein. As shown in Figure 8C, the bearing assembly typically includes a radial bearing (indicated by ellipse 200) and a thrust bearing (indicated by circle 202). The radial bearing is configured to reduce the radial motion of the impeller by maintaining the axis of the impeller in a given radial position. In response to the impeller pumping blood in a first direction, the force acting on the impeller typically moves the impeller in the opposite direction to the first direction. The purpose of the thrust bearing is to counteract such impeller motion and maintain the axial position of the impeller. In the example shown in Figure 8C, in response to the impeller pumping blood in the direction of arrow 204, the impeller is pushed in the direction of arrow 206, and the thrust bearing counteracts this motion. Typically, bearings experience significant heating and wear due to the frictional forces applied. Thrust bearings are usually subjected to significant heating and wear. This is because the frictional forces applied to thrust bearings are typically spread across opposing surfaces with a smaller contact area than those applied to radial bearings.

[0162] As described above, typically the axial shaft 92 passes through the lumen 62 of the impeller and through the axis of the impeller 50. Typically, the proximal bushing 64 of the impeller is coupled to the shaft via a coupling element 65 so that the axial position of the proximal bushing relative to the shaft is fixed, and the distal bushing 58 of the impeller is slidable relative to the shaft. The axial shaft itself is radially stabilized by the proximal radial bearing 116 and the distal radial bearing 118.

[0163] Typically, the joint 30 of the frame 34 is connected to the proximal radial bearing 116, for example, by snap-type couplings and / or welding. Typically, at the distal end of the frame 34, a distal support joint 33 is installed in a groove defined by the outer surface of the distal radial bearing 118, the groove being shaped to match the shape of the distal support portion. As shown, the proximal end of the distal end element 108 typically holds the distal support portion closed around the outside of the distal radial bearing 118. In some applications, the device includes a distal extension 121 extending distally from the distal radial bearing. Typically, the extension is configured to reinforce the area of ​​the distal end element into which the distal end of the shaft 92 enters.

[0164] As described above, the axial shaft 92 is radially stabilized by the proximal radial bearing 116 and the distal radial bearing 118. Furthermore, the axial shaft, by passing through the lumen 62 defined by the impeller, radially stabilizes the impeller relative to the inner surface of the frame 34, so that, as described above, even a relatively small gap (e.g., the gap described above) between the outer edge of the impeller blades and the inner surface of the frame 34 or the inner lining 39 is maintained during the rotation of the impeller. In some applications, the axial shaft 92 is made of stainless steel, and the proximal bearing 116 and / or distal bearing 118 are made of hardened steel. Typically, when the impeller and frame are compressed (i.e., radially constrained) for the purpose of inserting the impeller and frame into the body of a target, the distal bushing 58 of the impeller is configured to slide distally along the axial shaft so that the impeller is axially elongated, while the proximal bushing maintains an axially fixed position relative to the axial shaft. More generally, the impeller changes from a radially constrained configuration to a radially unconstrained configuration, and vice versa, by the distal bushing sliding on the axial shaft while the proximal bushing maintains an axially fixed position relative to the axial shaft.

[0165] Typically, the impeller itself is not directly positioned within a radial or thrust bearing, and bearings 116 and 118 act as radial bearings for the axial shaft. Typically, a blood pump catheter does not include a thrust bearing configured to be positioned within the body of the subject and to counteract the thrust generated by the rotation of the impeller. In some applications, one or more thrust bearings are positioned outside the body of the subject (e.g., within a motor unit), and the counteracting of the thrust generated by the rotation of the impeller is provided solely by these one or more thrust bearings located outside the body of the subject. In some applications, mathematical and / or magnetic elements are configured to maintain the impeller within a given axial position range. For example, a magnet positioned at the proximal end of a drive cable may be configured to maintain the impeller within a given axial position range.

[0166] In some alternative applications of the present invention, a thrust bearing is used to maintain the axial position of the impeller, and this thrust bearing is positioned within a portion of the blood pump catheter proximal to the impeller, so as not to come into contact with the blood of the subject. For example, the thrust bearing can be positioned within the outer tube in which the drive shaft of the impeller is located. Alternatively, or in addition to this, the thrust bearing may be positioned outside the body of the subject. In some such applications, since the thrust bearing is positioned outside the body of the subject, the dimensions of the thrust bearing are not constrained by the need to deploy within a small anatomical area. Thus, in such cases, the contact area between the two opposing surfaces of the thrust bearing is typically larger than 20 square millimeters. In some applications (not shown), the thrust bearing is positioned distal to the impeller, in contact with the blood of the subject, so that the thrust bearing is cooled by the blood of the subject.

[0167] Typically, the operations described herein, performed by a computer processor, transform the physical state of memory, which is an actual physical article communicating with the computer processor, so that it has different magnetic poles, charges, etc., depending on the technology of the memory being used. The computer processor 10 is typically a hardware device programmed with computer program instructions to generate a dedicated computer. For example, when programmed to perform the techniques described herein, the computer processor 10 typically acts as a dedicated blood pump computer processor.

[0168] The scope of the present invention includes combining any apparatus and method described herein with any apparatus and method described in one or more of the following examples (all of which are incorporated herein by reference).

[0169] U.S. Patent Application Publication No. 16 / 750,354 to Tuval, filed on January 23, 2020, entitled "Distal tip element for a ventricular assist device".

[0170] U.S. Patent Application Publication No. 2019 / 0209758 to Tuval is a continuation application of the international application PCT / IB2019 / 050186 to Tuval, titled "Ventricular assist device" (published as WO19 / 138350), filed on 10 January 2019, claiming priority from the following: U.S. Provisional Patent Application No. 62 / 615,538, filed on January 10, 2018, to Sohn, entitled "Ventricular assist device". U.S. Provisional Patent Application No. 62 / 665,718, filed on May 2, 2018, to Sohn, entitled "Ventricular assist device". U.S. Provisional Patent Application No. 62 / 681,868 to Tuval, titled "Ventricular assist device," filed on June 7, 2018, and U.S. Provisional Patent Application No. 62 / 727,605 to Tuval, titled "Ventricular assist device," filed on September 6, 2018.

[0171] U.S. Patent Application Publication No. 2019 / 0269840 against Tuval is the U.S. national phase of the international patent application PCT / IL2017 / 051273 (published as WO18 / 096531) against Tuval, titled "Blood pumps," filed on November 21, 2017, claiming priority from U.S. Provisional Patent Application No. 62 / 425,814 against Tuval, filed on November 23, 2016.

[0172] U.S. Patent Application Publication 2019 / 0175806 for Tuval is a continuation application of the international application PCT / IL2017 / 051158 (published as WO18 / 078615) for Tuval, titled "Ventricular assist device," filed on October 23, 2017, claiming priority from U.S. Patent Application Publication 62 / 412,631 for Tuval, filed on October 25, 2016, and U.S. Patent Application Publication 62 / 543,540 for Tuval, filed on August 10, 2017.

[0173] U.S. Patent Application Publication No. 2019 / 0239998 for Tuval is the U.S. national phase of the international patent application PCT / IL2017 / 051092 (published as WO18 / 061002) for Tuval, titled "Blood vessel tube," filed on September 28, 2017, claiming priority from U.S. provisional patent application 62 / 401,403 for Tuval, filed on September 29, 2016.

[0174] U.S. Patent Application Publication No. 2018 / 0169313 for Schwammenthal is the U.S. national phase of the international patent application PCT / IL2016 / 050525 (published as WO16 / 185473) for Schwammenthal, titled "Blood pump," filed on May 18, 2016, claiming priority from U.S. Provisional Patent Application No. 62 / 162,881 for Schwammenthal, titled "Blood pump," filed on May 18, 2015.

[0175] U.S. Patent Application Publication No. 2017 / 0100527 for Schwammenthal is the U.S. national phase of the international patent application PCT / IL2015 / 050532 (published as WO15 / 177793) for Schwammenthal, titled "Blood pump," filed on May 19, 2015, claiming priority from U.S. Provisional Patent Application No. 62 / 000,192 for Schwammenthal, titled "Blood pump," filed on May 19, 2014.

[0176] (a) U.S. Provisional Patent Application No. 61 / 779,803 for Schwammenthal, titled "Renal pump," filed on 13 March 2013, and (b) U.S. National Patent No. 10,039,874 for Schwammenthal, which is the U.S. National Phase of International Patent Application PCT / IL2014 / 050289 (published as WO14 / 141284) for Schwammenthal, titled "Renal pump," filed on 13 March 2014, claiming priority from U.S. Provisional Patent Application No. 61 / 914,475 for Schwammenthal, titled "Renal pump," filed on 11 December 2013.

[0177] U.S. Patent No. 9,764,113 for Tuval, titled "Curved catheter," issued on September 19, 2017, claims priority from U.S. Provisional Patent Application No. 61 / 914,470 for Tuval, titled "Curved catheter," filed on December 11, 2013.

[0178] U.S. Patent No. 9,597,205 for Tuval is the U.S. national phase of the international patent application PCT / IL2013 / 050495 (published as WO13 / 183060) for Tuval, titled "Prosthetic renal valve," filed on June 6, 2013, claiming priority from U.S. Provisional Patent Application No. 61 / 656,244 for Tuval, titled "Prosthetic renal valve," filed on June 6, 2012.

[0179] Those skilled in the art will recognize that the present invention is not limited to what is specifically illustrated and described above. The scope of the present invention includes both combinations and subcombinations of the various features described above, as well as variations and modifications thereof that are not present in the prior art, as will be conjured upon those skilled in the art when reading the preceding description.

Claims

1. A device for use with a target venous system, including the one or more branch vessels that flow into the vein at the junction of a vein and one or more branch vessels, It is a blood pump catheter, A material defining a blood outlet opening, which is installed at a downstream position downstream of the joint and configured to at least partially occlude the blood flow through the vein at the downstream position, A blood pump configured to pump blood from the region of the vein adjacent to the joint through the blood outlet opening defined by the material, A blood pump catheter comprises a blood flow path passing between (a) a path inlet opening located upstream of the joint and (b) a path outlet opening that opens downstream of the material, The apparatus is configured such that the blood flow pathway guides upstream venous blood flow from the upstream position to the downstream of the material without pumping it by the pump.

2. The apparatus according to claim 1, wherein the blood pump comprises an elongated blood pump tube, the elongated blood pump tube comprising a blood inlet area located in the upstream portion of the elongated blood pump tube, a blood outlet area located in the downstream portion of the elongated blood pump tube, and an impeller configured to pump blood into the blood inlet area and further pump it out of the blood outlet area via the elongated blood pump tube.

3. The apparatus according to claim 1, wherein the blood pump comprises an impeller located within a frame, and the impeller is configured to pump blood by rotating within the frame.

4. The blood pump catheter is configured for use with one or more lymphatic vessels that flow into a vein, and the blood pump catheter is configured to be placed inside the vein. The material is positioned downstream of the junction between the vein and one or more lymphatic vessels, and is configured to at least partially occlude the blood flow through the vein at the downstream position. The blood pump is configured to pump blood from a region of the vein adjacent to the junction between the vein and one or more lymphatic vessels, through the blood outlet opening defined by the material. The blood flow path is configured to pass between (a) the inlet opening of the path located upstream of the region of the vein adjacent to the junction of the vein and one or more lymphatic vessels, and (b) the outlet opening of the path opening to the downstream side of the material. The apparatus according to claim 1, wherein the blood flow path is configured to guide upstream venous blood flow from the upstream position to the downstream side of the material without pumping by the pump.

5. The blood pump catheter is configured to be placed in the target vena cava, The material is positioned downstream of the junction between the vena cava and one or more renal veins of the target, and is configured to at least partially occlude the blood flow through the vena cava at the downstream position. The blood pump is configured to pump blood from a region of the vena cava adjacent to the junction between the vena cava and one or more renal veins, through the blood outlet opening defined by the material. The blood flow path is configured to pass between (a) the inlet opening of the path located upstream of the junction between the superior vena cava and one or more renal veins, and (b) the outlet opening of the path opening on the downstream side of the material. The apparatus according to any one of claims 1 to 4, wherein the blood flow pathway is configured to guide blood flow from the inferior vena cava blood flow to the downstream of the material without pumping the inferior vena cava blood flow by the pump.

6. The apparatus according to claim 5, further comprising a percutaneous left ventricular support device configured to support the function of the left ventricle of the subject.

7. The apparatus according to claim 5, wherein the blood pump comprises an elongated blood pump tube, the elongated blood pump tube comprising a blood inlet area located in the upstream portion of the elongated blood pump tube, a blood outlet area located in the downstream portion of the elongated blood pump tube, and an impeller configured to pump blood into the blood inlet area and further pump it out of the blood outlet area via the elongated blood pump tube.

8. The apparatus according to claim 7, wherein the elongated blood pump tube is configured to be positioned such that the blood outlet area is located within the pulmonary artery of the target, and is configured to pump blood into the pulmonary artery of the target via the elongated blood pump tube.

9. The apparatus according to claim 7, further comprising an elongated tube extending downstream from the material and defining an adrenal blood inlet opening configured to be positioned within the adrenal vena cava of the target, wherein the blood inlet area of ​​the elongated blood pump tube is configured to be positioned downstream of the adrenal blood inlet opening, and the elongated blood pump tube is configured to pump blood from the adrenal vena cava blood flow into the pulmonary artery of the target.

10. The apparatus according to claim 5, further comprising an elongated tube configured to extend into the pulmonary artery of the subject, wherein the blood pump is configured to pump blood into the pulmonary artery of the subject via the elongated tube.

11. The apparatus according to claim 10, wherein the elongated tube defines an adrenal blood inlet opening configured to be positioned within the adrenal vena cava of the target, and the blood pump is configured to be positioned downstream of the adrenal blood inlet opening and to pump blood from the adrenal vena cava blood flow into the pulmonary artery of the target.

12. The apparatus according to claim 5, wherein the diameter of one or more portions of the blood flow pathway is adjustable so that the flow from the inferior vena cava blood flow to the right atrium of the target can be adjusted.

13. The apparatus according to claim 12, further comprising: a blood pressure sensor configured to detect the blood pressure of the target; and a computer processor configured to receive the blood pressure of the target and to automatically adjust the diameter of one or more portions of the blood flow path according to the detected blood pressure.

14. The apparatus according to claim 12, wherein the diameter of one or more portions of the blood flow pathway is configured to be adjusted in response to an input.

15. The apparatus according to any one of claims 1 to 4, wherein the blood flow pathway comprises a funnel having a wide end and a narrow end, and one or more tubes, the wide end of the funnel defining the pathway inlet opening, and the narrow end of the funnel extending into the one or more tubes.

16. The apparatus according to claim 15, wherein the funnel and the one or more tubes comprise a single continuous blood flow path.

17. The apparatus according to any one of claims 1 to 4, wherein the diameter of one or more portions of the blood flow path is adjustable so that the flow through the blood flow path can be controlled.

18. The apparatus according to claim 17, further comprising: a blood pressure sensor configured to detect the blood pressure of the target; and a computer processor configured to receive the blood pressure of the target and to automatically adjust the diameter of one or more portions of the blood flow path in accordance with the detected blood pressure.

19. The apparatus according to claim 17, wherein the diameter of one or more portions of the blood flow pathway is configured to be adjusted in response to an input.

20. It is a blood pump catheter, A material that defines a blood outlet opening, which is placed on the blood pump catheter and configured to at least partially occlude the blood flow through the vein, A blood pump configured to pump blood through the blood outlet opening defined by the aforementioned material, A blood pump catheter comprises a blood flow pathway passing between (a) a pathway inlet opening located proximal to the material and (b) a pathway outlet opening located distal to the material, The device is configured such that the blood flow pathway guides the blood flow from the pathway inlet opening to the pathway outlet opening without pumping it by the pump.

Images