Catheter blood pumps with a distal flexible tube providing a circular spacer

Abstract

Catheter blood pumps with an inlet cage, cannula, impeller assembly and a flexible tube are provided and are configured to expand from a first straight configuration to a second configuration having a circular shape formed into a partial or whole circular loop that reside in a plane perpendicular to an axis of the inlet cage to provide a 3-D mechanical spacer between the inlet cage and local tissue.

Description

CATHETER BLOOD PUMPS WITH A DISTAL FLEXIBLE TUBE PROVIDING A CIRCULAR SPACERRELATED APPLICATIONS

[0001] This patent application claims the benefit of and priority to U.S. Provisional Application Serial Number 63 / 518,163, filed August 8, 2023, the contents of which are hereby incorporated by reference as if recited in full herein.FIELD

[0002] This invention relates to catheter blood pumps.BACKGROUND

[0003] Some patients who have heart failure, and some of those at risk for developing it, receive interventions intended to temporarily assist the heart before or during a medical or surgical procedure and / or during a recovery period. The intervention typically lasts for less than a week but can continue for several weeks. These interventions include pharmaceuticals and / or medical devices, including cardiac-assist devices.

[0004] Some cardiac-assist devices include a pump to supplement the heart’s pumping action. By assuming some of the heart’s pumping function, these “blood pumps” unload the heart, helping it to recover. Cardiac-assist devices can be temporary or permanent.

[0005] Some blood pumps have an extracorporeal (z.e., outside the body) impeller to drive blood flow. Some of these extracorporeal blood pumps connect to a patient’s heart and blood vessels directly through the exposed chest using relatively large-diameter tubes (cannulas). Such procedures, performed by cardiac surgeons, are invasive and may require cardiopulmonary bypass. They are, unfortunately, associated with significant complications. Some other extracorporeal blood pumps connect to the patient using relatively wide catheters or cannulas, inserted through peripheral blood vessels.

[0006] Some other blood pumps are percutaneous, wherein the impeller (and in some devices, the pump’s motor) temporarily reside within the patient. These blood pumps are often coupled to a catheter and are consequently referred to as “catheter blood pumps.” Some catheter blood pumps are inserted into the patient using established cath-lab techniques, wherein they are advanced through the vascular system (typically the femoral artery) to a patient’s heart. This approach is significantly less invasive than cardiac surgery or other relatively complicated procedures.

[0007] It is desirable for a catheter blood pump to have as small a diameter as possible to minimize trauma to the vasculature or trauma associated with the surgery performed for minimally invasive insertion into position. It is also desirable for such a pump to have a large pumping capacity, preferably 2 liters per minute or even more, to provide sufficient circulation for a patient, if such a rate can be provided without causing undesired performance issues. Such a pump must avoid, to the extent possible, damaging the blood in the form of hemolysis (ie., destruction of red blood cells).

[0008] Intravascular blood pumps comprise miniaturized blood pumps capable of being percutaneously or surgically introduced into the vascular system of a patient, typically to provide left and / or right heart support. See, e.g., U.S. Patent Number 4,625,712 which describes a multiple stage intravascular axial-flow blood pump which can be percutaneously inserted into an artery for heart assist and U.S. Patent Number 4,846,152 which describes a single-stage intravascular axial flow blood pump, the contents of which are hereby incorporated by reference as if recited in full herein. These blood pumps position the drive unit / motor outside the body (extracorporeal) and use long cable drive systems. The maneuverability and / or durability of these types of blood pumps was often less than desired. During use, components of these devices tended to deteriorate prematurely due to rotational and pulsatile forces experienced by the blood pumps.

[0009] Other intravascular blood pumps are configured so that the drive unit / motor and the impeller are directly connected to each other, with the motor and the impeller (pump) housing having the substantially the same outer diameter. See, e.g., U.S. Patent Number 6,176,848, the contents of which are hereby incorporated by reference as if recited in full herein. While these systems have been used successfully to pump blood, the flow rates provided are typically under 3-4 liters / minute at a counterpressure of about 100 mm Hg. The pumping rate is limited by the low torque limitation of the small “micro” motors.

[0010] Indeed, notwithstanding its attractiveness as a less-invasive alternative, most designs for percutaneously-inserted blood pumps exhibit one of more of the following shortcomings: limited pump flow; some degree of hemolysis; and / or require the use of a large catheter / cannula, with a risk of ischemia.

[0011] There have been previous attempts, mostly unsuccessful, to increase the flow rate through small diameter catheter blood pumps. Simply increasing the rotation speed of the pump’s impeller will increase the flow rate. However, the increased speed results in additional power requirements, which in turn may increase the size and electrical demands of the motor. In devices that use a flexible drive cable to drive the pump’s impeller (rather thanan in-vivo motor sited near the impeller), the increased motor speed may require an increase in the size and stiffness of the flexible drive cable. Furthermore, the increased speed of the impeller can increase shear stress on the blood, resulting in increased hemolysis.

[0012] As mentioned above, catheter blood pumps are usually advanced to the heart through the vascular system. Consequently, there is a limit as to the acceptable diameter of the largest feature of the catheter blood pump. Consider that such a blood pump typically includes various tubes, an impeller housing, an impeller, and a drive cable and / or motor. Since the impeller is rotating at high speed (thousands of rpm), it is important that the impeller does not come into contact with the patient’s anatomy or other parts of the blood pump (e.g., tubing, impeller housing, etc.).

[0013] The blood intake end portion of the catheter blood pump can be provided with a flexible cannula having a suction (blood intake) region with inlet openings at the distal end portion. Such a pumping device is described in EP 0 916 359 Al. Another pumping device is described in WO 99 / 58170. In this pumping device, the pumping portion is prolonged by a flexible cannula adapted to be passed through a cardiac valve. A balloon is provided which is to be entrained by the blood flow in the body when the pumping device is inserted. The contents of these documents are hereby incorporated by reference as if recited in full herein.

[0014] The operation of the catheter blood pump is superposed on the pulsating activity of the heart so that the pump section is subjected to heavily pulsating pressure variations. In this context it may happen that the pump section, together with the associated proximal catheter, can be subjected to substantial changes in position. For example, during systole of a cardiac cycle, the catheter is pressed against the outer side of the aortic arch, whereas it is pressed against the inner side thereof during diastole of the cardiac cycle. Further, the position of the pump can vary during the cardiac cycle and the blood intake or suction region may undesirably contact and suctionally engage tissue inside the heart. This can cause irritations of the heart and / or the pumping capacity is reduced by the obstruction of inlet openings. Finally, it may happen that the cannula adheres to a cardiac valve by suction and damage to the blood may be induced by suction.

[0015] In the past, a pigtail positioned distal to the inlet has been used to provide mechanical spacing from local tissue. See, U.S. Patent No. 9,872,948, the contents of which are hereby incorporated by reference as if recited in full herein.SUMMARY

[0016] Embodiments of the invention provide a flexible circular loop coupled to the cannula or inlet cage distal of the (blood) inlet openings of the inlet cage of the catheter blood pump. The loop has an open longitudinally extending lumen that slidably receives a guidewire. The loop can have a solid outer wall that surrounds the lumen and can be sized and configured to inhibit blood intake. The loop forms a mechanical spacer that extends circumferentially (laterally outward) about a projection of a longitudinal axis of the inlet cage and / or cannula maintaining a distance to neighboring tissue during normal operation in a heart of a patient irrespective of rotational orientation of the cannula and / or catheter coupled to the cannula.

[0017] Embodiments of the present invention are directed to a catheter blood pump that includes: an impeller assembly with an impeller within an impeller cage; and a cannula coupled to a distal end portion of the impeller assembly. The cannula has a longitudinally extending lumen. The catheter blood pump also has an inlet cage provided by or coupled to a distal end portion of the cannula, the inlet cage having a longitudinally extending center axis; and a flexible tube coupled to a distal end portion of the cannula. The flexible tube has a longitudinally extending lumen configured to slidably receive a guidewire. The flexible tube has a tube body configured to have a first configuration with the guidewire extending in the longitudinally extending lumen and a second configuration with the guidewire removed therefrom. In the second configuration, the flexible tube has at least one partial or whole circular loop extending circumferentially about, laterally outward from, a projection of the longitudinally extending center axis of the inlet cage to thereby provide a mechanical spacer between the inlet cage and local tissue.

[0018] The flexible tube can have a wall with a closed outer surface surrounding the longitudinally extending lumen whereby blood is substantially or total blocked from being suctioned into the longitudinally extending lumen.

[0019] The at least one partial or whole circular loop can have a circumferential extent that is at least about 180 degrees.

[0020] The at least one partial or whole circular loop can be a single loop that extends circumferentially in a range of 180-360 degrees.

[0021] The at least one partial or whole circular loop can have loop segments that reside a radial distance in a range of about 0.25 inches and about 2.5 inches away from the projection of the inlet cage center axis.

[0022] The cannula can have a greater longitudinal distance than the flexible tube when the flexible tube is in both of the first and second configurations. The flexible tube can have greater flexibility than the cannula.

[0023] The at least one partial or whole circular loop can have loop segments that reside in different longitudinally spaced apart planes and on different sides of the projection of the center axis of the inlet cage.

[0024] The flexible tube can have a distal end that is open. The at least one partial or whole circular loop can be configured to place the distal end of the loop beneath a proximal end of the flexible tube.

[0025] The distal end of the at least one partial or whole circular loop can reside closer to the projection of the center axis of the inlet cage relative to a more proximal loop segment of the at least one partial or whole circular loop.

[0026] The at least one partial or whole circular loop can be configured to surround the projection of the center axis of the center cage.

[0027] A distal end of the inlet cage can be positioned a distance in a range of about 0.25 inches to about 2.5 inches from the distal end of the flexible tube when the flexible tube is in the second configuration.

[0028] The at least one partial or whole circular loop can be asymmetrically arranged about the projection of the center axis of the inlet cage.

[0029] The at least one partial or whole circular loop can be symmetrically arranged about the projection of the center axis of the inlet cage.

[0030] With the flexible tube in the second configuration, a distalmost end of the at least one partial or whole circular loop can be positioned a distance in a range of about 0.25 inches to about 2.5 inches, optionally in a range of about 1 inch to about 2.5 inches, from a distal end of a blood intake port of the inlet cage.

[0031] The flexible tube has a distal end that can be open and the catheter blood pump can include a guidewire extending through the lumen and out the distal end of the flexible tube whereby the guidewire cooperates with the flexible tube to define a straight orientation of the first configuration.

[0032] The flexible tube can be formed by a polymer or copolymer.

[0033] The flexible tube can have a shape memory material.

[0034] The flexible tube can include a shape memory alloy.

[0035] The flexible tube can have an inner diameter in range of about 0.015 inches to about 0.022 inches defining the lumen.

[0036] The at least one partial or whole loop can reside at least partially in a plane perpendicular to a projection of the center axis of the inlet cage.

[0037] The at least one partial or whole loop can have a diameter in a range of about % inch to about 60 mm.

[0038] A distal end and a proximal end of the flexible tube can reside distal to the inlet cage a distance in a range of about 0.25 inches and about 3 inches from a distal end of intake ports of the inlet cage.

[0039] The catheter blood pump can include a plurality of radiopaque markers on or in the flexible tube. The plurality of radiopaque markers can include at least one radiopaque marker at a predefined bend location at a distal end portion of the flexible tube.

[0040] The flexible tube can cooperate with the guidewire to define a plurality of transitional shapes as the guidewire is withdrawn therefrom including a first “J” shape in a first plane defining a transitional distal end of the flexible tube, then a loop shape that can reside in the first plane, then a loop shape that can reside in a second plane that can be perpendicular to the first plane.

[0041] Embodiments of the invention are directed to methods of providing spacing from local tissue for a catheter blood pump. The methods include: providing a catheter blood pump with an inlet cage configured to intake blood; inserting the catheter blood pump into a heart of a patient with a guidewire extending through a lumen of a flexible tube; positioning the flexible tube in a left ventricle of a patient; removing the guidewire from the lumen allowing the flexible tube; forming the flexible tube into at least one partial or whole loop that extends circumferentially about a longitudinally extending axis of the inlet cage in response to the removing step; then intaking blood into the inlet cage and pumping the blood out of an impeller cage; and mechanically laterally spacing the inlet cage away from local tissue during the intaking in response to contact with the at least one partial or whole loop of the flexible tube to thereby prevent suction of the inlet cage to the local tissue.

[0042] The at least one partial or whole loop can be allowed to float up and down and side to side during a cardiac cycle.

[0043] The at least one partial or whole loop can remain in a substantially fixed longitudinal location relative to the inlet cage during the intake of blood.

[0044] The removing of the guidewire can be carried out to withdraw the guidewire a first distance, allowing the distal end portion of the tube to bend in a first plane, then withdrawing the guidewire a second distance, allowing the distal end portion of the flexibletube to bend to position the at least one partial or whole loop in a second plane that is perpendicular to the first plane.

[0045] The guidewire can be withdrawn the first distance while the inlet cage is above the aortic valve, then the guidewire can be withdrawn the second distance while the inlet cage is below the aortic valve.

[0046] The at least one partial or whole loop can have a diameter in a range of about 6.35 mm to about 6 cm.

[0047] A distal end and a proximal end of the flexible tube reside distal to the inlet cage and reside a distance in a range of about 0.25 inches and about 3 inches from a distal end of intake ports of the inlet cage.

[0048] When the guidewire is fully withdrawn, the at least one partial or whole loop can reside in a plane perpendicular to an axis of the inlet cage and at a distance distal to the inlet cage that is in a range of about 0.25 inches to about 2.5 inches, optionally in a range of about 1 inch to about 2.5 inches.

[0049] The removing step can be carried out whereby the flexible tube cooperates with the guidewire to define a plurality of transitional shapes as the guidewire is withdrawn therefrom including a first shape having a “J” shape in a first plane defining a transitional distal end of the flexible tube, then a second shape having a loop shape in the first plane, then a third shape having a loop shape that resides in a second plane perpendicular to the first plane.

[0050] Further features, advantages and details of the present invention will be appreciated by those of ordinary skill in the art from a reading of the figures and the detailed description of the preferred embodiments that follow, such description being merely illustrative of the present invention.

[0051] It is noted that aspects of the invention described with respect to one embodiment, may be incorporated in a different embodiment although not specifically described relative thereto. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination. Applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to be able to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner. These and other objects and / or aspects of the present invention are explained in detail in the specification set forth below.BRIEF DESCRIPTION OF DRAWINGS

[0052] FIG. 1 is a schematic illustration of a catheter blood pump system in an example intrabody position according to embodiments of the present invention.

[0053] FIG. 2 is an enlarged side perspective view of a flexible tube forming a circular spacer for a catheter blood pump according to embodiments of the present invention.

[0054] FIG. 3 is an enlarged side perspective view of another embodiment of a flexible tube forming a circular spacer for a catheter blood pump according to embodiments of the present invention.

[0055] FIG. 4A is an enlarged schematic view of distal end portion of the flexible tube forming the spacer with a self-sealing cover according to embodiments of the present invention.

[0056] FIGS. 4B and 4C are schematic end views of an expanded circular flexible tube spacer according to embodiments of the present invention.

[0057] FIG. 5 is an enlarged side view of a portion of a catheter blood pump according to embodiments of the present invention.

[0058] FIG. 6 is a side view of a blood pump with a guidewire extending from a distal end portion thereof with the flexible tube in a straight linear orientation for intravascular insertion into a patient, and with one part of a shell handle omitted to reveal internal components, according to embodiments of the present invention.

[0059] FIG. 7 is another side view of the blood pump shown in FIG. 6, rotated at 90 degrees from the orientation shown in FIG. 6 and with a guidewire removed allowing the flexible tube to expand to a predefined circular loop shape according to embodiments of the present invention.

[0060] FIG. 8 is a schematic illustration of a catheter blood pump system according to embodiments of the present invention.

[0061] FIGS. 9A-9L are side perspective views of a sequence of transitional shapes of a flexible tube formed in response to withdrawal of a guidewire for forming a 3-D mechanical spacer for a catheter blood pump according to embodiments of the present invention.

[0062] FIG. 10 is an enlarged side perspective view of another embodiment of a distal end portion of a catheter blood pump according to embodiments of the present invention.

[0063] FIG. 11 is an enlarged side perspective view of a distal end portion of a catheter blood pump according to embodiments of the present invention.

[0064] FIG. 12 is a schematic illustration of a catheter blood pump with a 3-D spacer in an example position in a heart of a patient according to embodiments of the present invention.

[0065] FIG. 13 is a flow chart of an example method of providing a spacer for a catheter blood pump according to embodiments of the present invention.DETAILED DESCRIPTION

[0066] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. The abbreviation “FIG.” may be used interchangeably with “Fig.” and the word “Figure” in the specification and figures. It will be appreciated that although discussed with respect to a certain embodiment, features or operation of one embodiment can apply to others.

[0067] In the drawings, the thickness of lines, layers, features, components and / or regions may be exaggerated for clarity and broken lines (such as those shown in circuit of flow diagrams) illustrate optional features or operations, unless specified otherwise. In addition, the sequence of operations (or steps) is not limited to the order presented in the claims unless specifically indicated otherwise.

[0068] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0069] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as thosedefined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and / or clarity.

[0070] It will be understood that when a feature, such as a layer, region or substrate, is referred to as being "on" another feature or element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another feature or element, there are no intervening elements present. It will also be understood that, when a feature or element is referred to as being "connected" or "coupled" to another feature or element, it can be directly connected to the other element or intervening elements may be present. In contrast, when a feature or element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present. Although described or shown with respect to one embodiment, the features so described or shown can apply to other embodiments. The term “about” means that the noted number can vary by + / - 20%.

[0071] Turning now to FIG. 1, generally stated, placement of the catheter blood pump 10 in preparation for use requires advancing the catheter 30 through a tortuous path associated with a patient’s vascular system to position the impeller assembly 145 at a desired location, wherein pump suction provided by the inlet cage 33, which is distal to the impeller assembly 145 (upstream of the pumped blood flow path whereby pumped blood exits out the cage 44 of the impeller assembly 145), is in a defined position, shown as within the left ventricle of the heart, and the impeller 40 and pumped blood exit cage 44 are positioned in a different defined location, shown as the ascending aorta. The catheter blood pump 10 comprises a cannula 35 that can provide the inlet cage 33 at a distal end portion 35d of the cannula 35 or that can be coupled to the inlet cage 33 at the distal end portion 35d of the cannula 35. A flexible tube 31 configured to provide a distal loop body 31Z with an open longitudinally extending channel 39 is distal to the inlet cage 33.

[0072] The term “flexible” with respect to “tube” means that the flexible tube 31 can take on a first configuration e.g., a straight linear configuration (see, FIG. 5) during tortuous insertion and withdrawal and can change to a second configuration during normal operation of the catheter blood pump 10. The second configuration can automatically occur once a guidewire 131 is removed to allow the distal loop body 31Z to expand to provide at least one loop 34 that extends at least about 180 degrees about a virtual center line projected from anaxial / longitudinal center line A-A of the inlet cage 33 (see, FIGS. 1, 2, 3). The straight configuration can also occur in response to compression applied to the loop body 31Z by vasculature at withdrawal.

[0073] FIG. 1 shows the catheter blood pump 10 in the heart H and the aorta AO. The impeller assembly 145 is shown in the aorta AO while the inlet or intake cage 33 resides in the left ventricle LV and the cannula 35 extends through the aortic valve AK. Thus, the pump draws blood from the left ventricle LV and feeds into the aorta AO. FIG. 1 shows the left atrium LA and the mitral valve MK and the catheter blood pump 10 may alternatively be positioned therein (not shown).

[0074] In some embodiments, the flexible tube 31 can comprise a shape memory material. The flexible tube 31 can comprise a medical grade polymer or copolymer, such as, for example, PEBAX or a medical grade of nylon. In some embodiments, the flexible tube 31 can comprise a shape memory alloy such as NITINOL. The flexible tube 31 can have a durometer in a range of about 45-65, such as about 55.

[0075] The flexible tube 31 can define a flexible mechanical spacer that is able to flex and / or float laterally, side to side, in response to contact with local tissue during cardiac pumping actions while not substantially altering the pumping device hydraulically. The flexible tube 31 can define a partial or whole loop 34 that has a diameter that greater than the outer diameter of the inlet cage 33 and extends perpendicular to the virtual center line projected from an axial / longitudinal center line A-A of the inlet cage 33 at least 180 degrees to thereby prevent the inlet cage 33 from contacting local tissue in the heart during pumping action.

[0076] The inner diameter of the flexible tube 31 can be configured to slidably receive a guidewire 131, which may have an outer diameter in a range of 0.014 inches to about 0.018 inches. The inner diameter of the flexible tube 31 can be in a range of 0.015 inches to 0.022 inches, in some embodiments. The outer diameter of the flexible tube 31 will depend on the wall thickness of the flexible tube 31. In some embodiments, the wall thickness of the flexible tube 31 can be in a range of 0.002 inches to 0.020 inches, depending on the material(s) used to form the flexible tube 31. In some embodiments, the outer diameter of the flexible tube 31 can be in a range of about 0.019 inches to about 0.062 inches.

[0077] It is noted that the guidewire 131 shown in FIG. 2 is shown for illustration only regarding a distance the guidewire 131 can extend from the distal open end 31e of the flexible tube 31. It will be appreciated by those of skill in the art, that the distal loop body 31Z will expand to form the (circular) loop 34 after the guidewire 131 is removed, as with theguidewire in the lumen 39 of the flexible tube 31 it has a straight configuration (FIG. 5), by sliding it proximally out of the flexible tube 31.

[0078] Referring to FIGS. 1-3, the distal loop body 31Z extends radially outward from a projection of the longitudinal axis A-A of the inlet cage 33 and that extends in a circumferential extent that is at least about 180 degrees about the projection of the axis A-A. The distal loop body 31Z can reside in a single plane with a single partial or whole (circular) loop 34 extending about a projection of the axis A-A. The distal loop body 317 can extend radially outward from the proximal end 31p of the flexible tube 31 and extend circumferentially about the projection of the axis A-A to reside in different planes that are perpendicular to the axis A-A.

[0079] The distal loop body 31Z can at least partially encircle and / or surround a projection of the axis A-A. The distal loop body 31Z can have at least one partial or full (circular) loop 34 that extends circumferentially about a projection of the axis A-A in a range of about 180-540 degrees. The loop 34 can have one or more loop segments that reside at a common or different radial distance from the projection of the axis A-A.

[0080] The loop 34 can extend radially outward from a projection of the longitudinal axis A-A of the inlet cage 33 and can extend circumferentially to surround over 180 degrees of a projection of the axis A-A and with the loop 34 providing at least some radially / laterally extending loop segments 34s that are on (diametrically) opposing sides of the projection of the axis A-A. In some embodiments, the loop 34 can reside a distance in a range of about 0.25 inches to about 2.5 inches from the distal end of the cage ports 36.

[0081] A proximal end portion 31p of the tube 31 forming the loop 34 can reside a distance of about 0.020 inches, 0.030 inches, 0.040 inches, 0.050 inches, 0.060 inches, 0.070 inches, 0.080 inches, 0.090 inches, 0.10 inches, 0.20 inches, 0.25 inches, 0.30 inches, 0.40 inches, 0.50 inches, 0.60 inches, 0.70 inches, 0.80 inches, 0.90 inches, 1 inch, 1.1 inch, 1.2 inches, 1.3 inches, 1.4 inches, 1.5 inches, 1.6 inches, 1.7 inches, 1.8 inches, 1.9 inches, about 2 inches, about 2.1 inches, about 2.2 inches, about 2.3 inches, about 2.4 inches, about 2.5 inches, about 2.6 inches, about 2.7 inches, about 2.8 inches, about 2.9 inches and about 3 inches, or any value therebetween, from the distal end 33d of the inlet cage 33 and / or distal end of the cage ports 36. In some embodiments, the distance can be in a range of about 0.25 inches to about 2.5 inches, optionally in a range of about 1 inch to about 2.5 inches, to substantially center the inlet cage 33 in the left ventricle. The distance may vary for different patients whereby smaller distances may be used for pediatric and women with relatively larger distances for men as the length of the left ventricle can vary.

[0082] The straight length of the flexible tube 31 can be selected to be less than the length of the left ventricle and this length can define the diameter of the partial or whole loop 34. In other embodiments, where the guidewire 131 can be partially withdrawn as the distal end of the flexible tube 31 is inserted into the left ventricle before the inlet cage 33 is positioned in the left ventricle, the straight length can be greater than the length of the left ventricle as the loop can form as the flexible tube 31 is positioned in the left ventricle with the inlet cage 33 also in the left ventricle.

[0083] In some embodiments, the distal end of the inlet cage 33 is positioned a distance in a range of about 0.2 inches to about 3 inches from the distal end 31e of the flexible tube 31 when the flexible tube 31 is in the second configuration providing at least one partial or whole circular loop 34. This distance can be about 0.20 inches, about 0.25 inches, about 0.30 inches, about 0.40 inches, about 0.50 inches, about 0.60 inches, about 0.70 inches, about 0.80 inches, about 0.90 inches, about 0.95 inches, about 1 inch, about 1.1 inch, about 1.2 inches, about 1.3 inches, about 1.4 inches, about 1.5 inches, about 1.6 inches, about 1.7 inches, about 1.8 inches, about 1.9 inches, about 2.1 inches, about 2.2 inches, about 2.3 inches, about 2.4 inches, about 2.5 inches, about 2.6 inches, about 2.7 inches, about 2.8 inches, about 2.9 inches and about 3 inches or any value therebetween.

[0084] The partial or whole loop 34 can be configured and positioned relative to the inlet cage 33 to keep the inlet cage 33 off the sides of the left ventricle to prevent suctioning of tissue.

[0085] The partial or whole loop 34 can be configured to have a diameter corresponding to or being at least 50%-90% of a lateral extent or average diameter of a LV valve, or of the left ventricle itself, centering the inlet cage 33 with respect to the lateral dimension of the valve and / or length dimension of the left ventricle and may provide resistance to movement to a ventricle wall during pumping action.

[0086] The partial or whole loop 34 can have a diameter in a range of about 0.25 inches to about 6 cm (the latter sizing may be particularly suitable for where the distal end portion of the flexible tube, when in a first straight orientation, transitions and starts to form the spacer loop configuration prior to the inlet cage 33 being in the left ventricle).

[0087] FIG. 2 illustrates that the distal loop body 31Z can be configured to provide a single loop 34, that extends from the proximal neck portion 31p to a first loop segment 34sithat extends off a first side of the projection of the axis A- A, then curves into a second radially extending loop segment 34si on the opposing side of the projection of the axis A-A, that extends away from the projection of the axis A-A to a segment 34m that is a maximaldistance from the projection of the axis A-A to turn to a third laterally extending loop segment 34S3 that extends toward the projection of the axis A-A and that merges into a fourth laterally extending loop segment 34S4 on the same side of the projection of the axis A-A as the first loop segment 34si. As shown, this configuration provides the distal loop body 31Z as a single loop 34 that extends about 360 degrees and positions the open end 31e of the flexible tube 31 in a different distally positioned plane from the first loop segment 34siand that can be substantially (+ / -20 degrees) coplanar with the third loop segment 34S3.

[0088] The distal end 31e can be substantially perpendicular (+ / - 20 degrees) to the projection of the axis A-A and can reside a short radial distance R from the projection of the axis A-A, typically a distance 3.175 mm (1 / 8 inch) to about 3 cm, more typically 1 / 8 inch to about 1.25 inches.

[0089] FIG. 3 illustrates that the distal loop body 31Z can be configured to provide a (circular) loop 34 that extends greater than 360 degrees with different radially and / or laterally extending loop segments 34 in different planes and on different sides of the projection of the axis A-A. As shown, the loop 34 extends from the proximal neck portion 31p to a first radially extending loop segment 34sithat extends away from a the axis A-A and that curves to a segment 34m at a maximal distance from the projection of the axis A-A to turn to a second radially extending loop segment 34sithat extends toward the projection of the axis A- A and that merges into a third radially extending loop segment 34S3 on the opposing side of the projection of the axis A-A that extends away from the projection of the axis A-A and that curves to a segment 34m at a maximal distance from the projection of the axis A-A, then turns again to extend toward the projection of the axis A-A. As shown, this configuration provides the distal loop body 31Z as a loop 34 that also extends about 360 degrees and positions the open end 31e of the flexible tube 31 in a different distally positioned plane from the first loop segment 34si. The second loop segment 34S2 can angle down to a plane of the third loop segment 34s3. The fourth loop segment 34S4 provides the open end 31e of the flexible tube can be substantially (+ / -20%) coplanar with the third loop segment 34S3.

[0090] The distal loop body 31Z can provide a loop 34 that has a maximal radii R, in a range of about 1 / 8 inch to about 1.25 inches, in some embodiments, whether a partial loop 34, a full single loop 34 or more than one loop 34. The radii R of different laterally extending loop segments 34s of the loop 34 can be the same measured from a center point defined by a point on the projection of the axis A-A or different at different locations.

[0091] In certain embodiments, a maximal radii R, measured from the projection of the axis A-A can be in a range of about 1 / 8 inch to about 3 cm or to about 1.25 inches andthis spacing can extend at least 180 degrees, with the partial or whole loop 34 perpendicular to the cannula 35 (FIG. 6), in some embodiments.

[0092] FIG. 2 shows an asymmetric loop configuration with all laterally extending segments 34S2, 34S3 on one side of the projection of the axis A-A having a greater lateral / radial extent than the laterally extending segments 34si, 34S4 on the other side of the projection of the axis A-A. FIG. 3 shows a relatively symmetrical loop configuration, with the loop 34 centered about the projection of the axis A-A so that all laterally extending segments 34si, 34S2 on one side of the projection of the axis A-A have a radius that is within 20% of the laterally extending segments 34s3, on the other side of the projection of the projection of the axis A-A.

[0093] The distal loop body 31Z can provide a three-dimensional (3-D) mechanical spacer to provide tissue spacing of the inlet cage 33 from local tissue irrespective of rotational position of the flexible tube 31 and cannula 35. In contrast, the pigtails in known conventional prior art blood catheter pump devices provide a 2-D spacing relative to the inlet cage 33. That is, the pigtail is shaped to curve upward (J-like shape) from a distal medial segment to position the tip end above the distal medial segment, with the tip adjacent the axis A-A. Also, the pigtail extends off a single side of the axis A-A, which provides spacing only along one side and when the curve of the pigtail curve is oriented to face the local tissue.

[0094] Referring to FIGS. 2, 3 and 5, the flexible tube 31 is a hollow tube that can have an open distal end 31e and a longitudinally extending center / open lumen 39 that is in communication with the open lumen 35Z of the cannula 35. The lumen 35Z of the cannula 35 and the lumen 39 of the flexible tube 31 are configured to slidably receive a guidewire 131. Although the lumens 35Z and 39 are in fluid communication, the catheter blood pump 10 typically does not suck blood through the flexible tube 31. This is because the inlet openings 36 at the inlet cage 33 can have a much larger cross-sectional area than the lumen 39 of the flexible tube 31 so that due to the lower flow resistance the suction intake is through the inlet openings 36. Any minimal suction effect caused by the open lumen 39 is negligible and is not sufficient to cause adherence by suction to other parts.

[0095] The flexible loop 31 can be configured to be similar to lassos used for cardiac mapping but sized and configured with sufficient flexibility to provide a mechanical spacer distal to the intake cage 33 of a catheter blood pump 10 and to provide an open lumen for the guidewire 131. See, e.g., U.S. Patent Number 6,973,339, the content of which is hereby incorporated by reference herein. See also, the LASSO circular mapping catheter from BioSense Webster, Irvine, California.

[0096] Referring to FIG. 4A, in some embodiments, the distal end 31e of the flexible tube 31 can comprise a self-sealing cover 231. The guidewire 131 can puncture the selfsealing cover 231 and extend a distance distal to the end 31e. The self-sealing cover 231 can seal about the guidewire 131 and close / seal entirely once the guidewire 131 is withdrawn to fluidly close off the distal end 31e of the flexible tube 31 during normal operation of the catheter blood pump 10.

[0097] FIG. 4B and 4C show end views of example flexible tubes 31 in the expanded second configuration providing a circular shape in an end view which can provide the 3-D mechanical spacer functionality with the loop 34 of the distal loop body 31Z laterally / radially spaced apart from the projection of the center axis A-A of the inlet cage 33, providing at least one partial or whole circular loop according to embodiments of the present invention.

[0098] Referring again to FIG. 5, the guidewire 131 can be routed through a window 44w of the cage 44 surrounding the impeller 40 and through the cannula 35 and flexible tube 31, out the end 31e a short distance during placement in the body of a patient to provide a “rapid exchange” configuration rather than an “over the wire” configuration. However, the guidewire 131 may be routed through a skyve in the cannula 35 or catheter body 30 which can still provide the rapid exchange configuration.

[0099] The cage 44 surrounding the impeller 40 (FIGS. 6, 7) can have a maximal outer diameter of 5 mm and a length that is less than that of the cannula 35. For additional discussion of example impeller and cage configurations, see, e.g., co-pending PCT / US2023 / 082427 and priority application U.S. Provisional Patent Application Serial Number 63 / 476,025, the contents of which are hereby incorporated by reference as if recited in full herein.

[0100] The cannula 35 can have a length of about 40 to 100 mm, or longer, and the wall surrounding the lumen 35Z can comprise a coiled wire sandwiched between layers of materials and / or biocompatible and / or non-cytotoxic coatings.

[0101] The flexible tube 31 can have a length (measured at insertion with the guidewire 131 therein) that is shorter than the cannula 35. The flexible tube 31 can be more flexible than the cannula 35. The distal loop body 31Z can float side to side and move up and down, fixed in place relative to the cannula 35 and inlet cage 33, in response to contact or pulsatile forces applied by cardiac cycles while still providing suitable mechanical spacing to prevent obstruction of the inlet cage intake windows / ports 36.

[0102] Referring to FIGS. 1 and 8, the catheter blood pump system 100 can have a control circuit 100c and a display lOOd. The control circuit 100c can be provided as a unitwith all of the control electronics held in a single housing lOOh. The unit can also provide the display lOOd or the display lOOd may be a separate component. The control circuit 100c is in communication with an external (extracorporeal) housing assembly 160 (FIGS. 6, 7, 8). In the embodiment shown in FIG. 8, the extra-corporeal elements of the catheter blood pump system 100 include the control circuit 100c, display lOOd, one or more modules 100m with motor control electronics 101, pressure sensor electronics 102 and monitoring electronics 103 as well as outflow and inflow tubing 1331t, 1333t, respectively.

[0103] The control circuit 100c and / or other electronics can be provided in a cloudbased distributed computer system or in a LAN / WAN distributed computer system or may be entirely provided by a processor(s) in the system housing lOOh.

[0104] Referring to FIGS. 6 and 7, the housing assembly 160 can contain the motor 14 that drives the pump impeller 40, and also includes various connectors / interfaces such as the power connector 129 and at least one pressure sensor connector. The shaft / catheter 30 may be 4 to 6 feet in length, as it must be long enough to be snaked through the vasculature of an adult (typically the devices are not manufactured to be gender specific) so the length is sufficient to accommodate an adult male, terminating near the heart and starting with an insertion point near the groin into the femoral artery, or at the wrist. However, gender and age specific sizing may be used, e.g., male / female, pediatric versus adult and the like.

[0105] FIG. 8 depicts a portion of the catheter 30 with the flexible drive shaft / cable 25 external to the body of the patient, the majority of which resides in a patient’s vasculature during use. Flush fluid 1333, as may be contained in an IV bag, is delivered to the blood pump 10 via a connection 333 at the housing assembly 160. A main control circuit 100c with at least one digital signal processor of the system 100 can be in communication with and / or include a display lOOd, a power supply lOOp, motor controller electronics 101, sensor electronics 102, monitoring electronics 103, and the like. The control circuit 100c provides signals and power for the motor 14, which can be contained within the housing 16 of the housing assembly 160 and receives sensor signals from the blood pump 10. Spent flush fluid (outflow fluid) is conveyed to a collection container 1331, shown as waste bag, from the blood pump 10 via an outflow connector 331 coupled to the housing 16 of the housing assembly 160.

[0106] Referring to FIG. 7, proper placement of the catheter blood pump 10 can be determined by measuring pressure on both sides of the aortic valve to obtain a differential pressure. In the illustrative embodiment, pressure is obtained using first and second fiberoptic pressure sensors 400, 402, respectively. Advantages of such sensors 400, 402include their compact size, and that they are biologically inert and accurate. Moreover, the use of such sensors can avoid measurement pressure losses / dampening, such as if a long narrow lumen were used for remote pressure monitoring.

[0107] Referring to FIGS. 6 and 7, the catheter blood pump 10 comprises the impeller assembly 145 and the (motor) housing assembly 160. The catheter blood pump 10 has a distal end portion lOd that provides the impeller assembly 145 and the suction intake or inlet cage 33. The impeller assembly 145 comprises the impeller 40 and the impeller cage 44 with windows 44w that defines the pumped blood exit path into the heart. The inlet cage 33 is provided distally to the impeller assembly 145. The inlet cage 33 (proximal end portion) can have or be coupled to a cannula 35. The term “cannula” 35 and can be interchangeably referred to as a “snorkel tube”. The cannula 35 and / or the inlet cage 33 can coupled to the flexible tube 31 at a distal end thereof. The cannula 35 can be adjacent a proximal end portion 33p of the inlet cage z.

[0108] A catheter 30 can extend longitudinally out from the housing 16 of the housing assembly 160 to terminate adjacent the impeller assembly 145. In some embodiments, the catheter 30 can enclose the torque / drive cable 25 that connects the motor 14 to the impeller 40 of the impeller assembly 145. Where internal motors are used to rotate the impeller 40, the long drive cable 25 is not required and the external housing assembly 160 can be modified from the embodiments shown to include the power, sensor and fluid connections 331, 333, with the inflow and outflow paths for the purge fluid without requiring the external motor and drive cable.

[0109] Generally stated, when the proximal end portion of the torque cable 25 is mechanically rotated by a motor shaft 114 of the motor 14, optionally located outside the patient's body, it conveys the rotational force through the length of the multi-lumen shaft 30, causing the impeller 40 to spin at high speed near the heart.

[0110] The blood pump 10 can be particularly suitable in providing ventricular assist during surgery or providing temporary bridging support to help a patient survive a crisis.

[0111] Referring to FIGS. 6-7, the catheter 30 has a distal end 30d and a proximal end 30p. The catheter 30 can be interchangeably referred to as a “multi-lumen shaft” that provides at least part of an inflow path and outflow path of flush fluid 1333 (FIG. 8). The multi-lumen shaft / catheter 30 can provide parallel lumens and / or coaxially arranged lumens. Where an extracorporeal motor is used, a (center) lumen 1131 can hold the torque cable 25 and this lumen can be described as a “torque cable lumen.” The torque cable lumen 1131 candefine at least part of a purge liquid out-flow path that extends to the outflow connector 331. The shaft or catheter body 30 can also have at least one inflow lumen 133.

[0112] The motor 14 is arranged to drive the torque cable 25 in the multi -lumen shaft 30 which in turn drives the impeller 40 / pump unit. The motor 14, when operated at an extracorporeal site, can have larger sizes relative to internal / intrabody motors. The multilumen shaft 30 provides continuous lubrication by a biocompatible (purge) liquid. A part of this liquid can exit through a bearing housing / impeller shaft interface and thus enter the blood stream. The remaining (primary) part can be directed to flow through an out-flow path and be collected extracorporeally after passing through an outflow lumen provided in the multilumen shaft 30 that also holds the drive cable 25. The multi-lumen shaft 30 can have at least one inflow lumen 133 that can define at least part of a (purge) fluid inflow path, from connector 333 to the manifold 110 then to the inflow lumen(s) 133.

[0113] As shown in FIG. 6, the flush-fluid inlet connector 333, and the flush-fluid outlet connector 331 can extend adjacently and from a common side portion of the housing 16 of the housing assembly 160 at an angle from horizontal that is in a range of 30-75 degrees. This may facilitate ease of assembly to corresponding flow conduits. Additional discussion of example components of example catheter blood pumps can be found in copending PCT / US2023 / 021351, the contents of which are hereby incorporated by reference as if recited in full herein.

[0114] Referring to FIGS. 6, 7 and 8, the catheter blood pump 10 can include first and second fiberoptic sensors 400, 402, respectively, which terminate proximally into at least one fiberoptic pressure sensor connector 429. The at least one fiberoptic pressure sensor connector 429 can be coupled to the housing assembly 160 and configured for conducting signals between the catheter blood pump 10 and the externally located control circuit 100c with the sensor electronics 102.

[0115] The distal end portion of the first pressure sensor 400 has a sensor head which may comprise a MOMS (micro-optical mechanical systems) structure coupled to the glass fiber of the fiberoptic pressure sensor 400. The distal end portion of the second pressure sensor 402 has a sensor head which may comprise a MOMS (micro-optical mechanical systems) structure coupled to the glass fiber of the second fiberoptic pressure sensor 402.

[0116] The fiberoptic pressure sensors 400, 402 can have respective sensor heads that are configured with a Fabry-Perot (“F-P”) cavity which comprises two parallel reflecting mirrors on either side of a transparent medium, where the distance between the mirrors is known as the cavity length. The reflection spectrum of the F-P cavity has distinct peaks inwavelength as a function of the cavity length, physically corresponding to resonances of the cavity. The pressure transducers can be configured to have a flexible embodiment of the F-P cavity. Generally stated, a deformable membrane is assembled over a vacuumed cavity, forming a small drum-like structure. The bottom of the drum and the inner surface of the flexible membrane form the sensing F-P cavity. When pressure is applied, the membrane is deflected towards the bottom of the drum, thus reducing the cavity length. With sensor calibration, the cavity length will correspond to a very precise pressure value. The signal conditioner is designed to be able to accurately determine the cavity length with (nanometer) precision. See, “Medical Pressure Monitoring” brochure provided by FISO Technologies Inc., a leading developer and manufacturer of fiberoptic sensors and signal conditioners, Quebec, Canada, available via the website “FISO.com” as of June 8, 2023, the contents of which are hereby incorporated by reference as if recited in full herein.

[0117] The multi-lumen shaft 30 can have an aperture 403 (which may be referred to as a “skyve”) in the wall 30w to expose a distal end portion of the second fiberoptic pressure sensor 402 to local environmental conditions (e.g., blood pressure in the heart). The cannula 35 can have an aperture 401 (which may be referred to as a “skyve”) in the (outer) wall 35w to expose the distal end portion of the first pressure sensor 400 to environmental conditions. However, other placements and configurations of the catheter 30, cannula 35 and / or fiberoptic pressure sensors 400, 402 do not require apertures 401, 403 through the outer wall. For additional discussion of example fiberoptic pressure sensors for catheter blood pumps, see, U.S. Patent Application Serial Number 18 / 335,247, the contents of which are hereby incorporated by reference as if recited in full herein.

[0118] Referring again to FIGS. 6 and 7, the catheter blood pump 10 can also have a bearing housing 50 adjacent the impeller 40 with a bearing housing adapter 52 that couples an outer wall 30w of the multi-lumen shaft 30 to the bearing housing 50. The bearing housing 50 can comprise a lateral cross-flow passage that is in fluid communication with a radially extending passage of a bearing / bushing and a longitudinal channel thereof, and that provides part of the out-flow path.

[0119] The blood pump 10 can comprise a (first) support wire 119 that resides inside a least a longitudinally extending segment of a center channel of the torque cable 25. The support wire 119 can have a distal end 119e that terminates a range of 1-3 inches from a manifold 110 of the housing assembly 160 and that extends at least partially through a center channel 114c of the motor shaft 114, shown as extending entirely through the motor shaft 114 in FIG. 6

[0120] As shown in FIG. 6, in some embodiments, the multi-lumen shaft 30 can also include a second support wire 219 that is longitudinally spaced apart from the first support wire 119 and that can reside inside the channel of the torque cable 25. The second support wire 219 can have a proximal end 219e that terminates a range of 1-3 inches from the proximal end of the impeller shaft 140. The first support wire 119 can support the torque cable 25 at a high torque area (at the motor 14) so that the torque cable 25 does not collapse under load. The first support wire 119 can also act as a strain relief when it exits a distal end of the manifold 110. The second support wire 219 can allow the impeller shaft 140 and torque cable 25 to be crimped together by using a proximal bushing without collapsing the (hollow) torque cable 25. The second support wire 219 can also act as a strain relief.

[0121] In some embodiments, the first and second support wires 119, 219 can be provided as a single support wire instead of separate support wires and the single support wire may extend substantially an entire length of the torque cable 25 or reside only at a proximal end portion or only at a distal end portion of the torque cable 25. In some embodiments, no support wire(s) are required.

[0122] Still referring to FIGS. 6 and 7, the housing assembly 160 can have a manifold 110 that is coupled to the motor 14. The manifold 110 has a manifold chamber 110c. The manifold 110 can sealably enclose a sub-length of the shaft 30, typically at least a segment of the proximal end portion 30p of the multi-lumen shaft 30 and can define at least a portion of a (purge) fluid in-flow path of the multi-lumen shaft 30, then into at least one inflow lumen(s) 133 provided by the multi-lumen shaft 30. The term “in-flow” can be used interchangeably with the term “inflow” herein. The term “out-flow” can be used interchangeably with the term “outflow” herein.

[0123] The motor housing 16 can be provided as a cooperating pair of handle shells 16s. The motor housing 16 can be an extracorporeal housing.

[0124] The motor shaft 114 can be metal and may have a diamond like coating (DLC) on an inner and / or outer surface thereof to provide hardness, improved surface finish and lubricity. The outer diameter of the motor shaft 114 is preferred to be as small as possible to reduce the surface speed which improves the lifespan of the seal. In some embodiments, the surface speed is about 773 ft / min when the motor shaft 114 is rotating at about 50,000 rpm. The maximal outer diameter of the motor shaft 114 over at least a major portion of its length (50% or greater) can be in a range of 0.0100 inches to 0.050 inches, such as about 0.060 inches.

[0125] The catheter / multi-lumen shaft 30 can have a proximal end portion 30p that is adjacent the motor 14 and an opposing distal end portion 30d that terminates adjacent the impeller 40. The torque cable 25 also has a proximal end portion 25p that is coupled to the motor 14 and an opposing distal end portion 25d that terminates adjacent the impeller 40. The torque cable 25 can also be interchangeably referred to as a “drive cable”. The torque cable 25 can be directly or indirectly attached to the impeller 40 at the distal end portion 25d of the torque (drive) cable 25 and to the motor 14 at the proximal end portion 25p of the torque (drive) cable 25.

[0126] Further discussion of example components of a catheter blood pump according to some embodiments of the present invention can be found in co-pending PCT / US2023 / 021351, filed May 8, 2023, the contents of which are hereby incorporated by reference as if recited in full herein.

[0127] The multi-lumen shaft 30 and the impeller 40 may be dimensioned to any suitable diameter for intravascular applications. For example, the range of sizes may include, but is not necessarily limited to, 9 French to 30 French, although the range is typically in a range of 14 French to 24 French, and more typically in a range of 18 French to 20 French.

[0128] The impeller 40 can be an expandable impeller 40 or a fixed diameter impeller or a partially radially expandable impeller. See, for example, U.S. Patent No. 9,028,392, U.S. Patent No. 8,079,948, pending U.S. Patent Application Serial No. 17 / 858,615 and U.S. Provisional Patent Application Serial No. 63 / 353,353, the contents of which are hereby incorporated by reference as if recited in full herein.

[0129] The blood pump 10 can be sized and configured for trans- valvular use, such as for left and / or right ventricular assist procedures. By way of example only, such ventricular assist procedures may be employed in cardiac operations including, but not limited to, coronary bypass graft (CABG), cardiopulmonary bypass (CPB), open chest and closed chest (minimally invasive) surgery, bridge-to-transplant and / or failure-to-wean-from-bypass situations. It is to be readily understood, however, that the intravascular blood pump assembly and methods of the present invention are not to be limited to such applications. Moreover, while illustrated and described largely with reference to left-heart assist applications, it is to be readily understood that the principles of the present invention apply equally with regard to right-heart assist application, which are contemplated as within the scope of the present invention. These and other variations and additional features will be described throughout.

[0130] The blood pump 10 can be configured to pump blood through the outlet cage 44 at a rate in a range of 2-7 liters / minute over at least 6 days of continuous intravascular use while continuously providing biocompatible fluid to the in-flow path Fi via at least one inflow lumen 133, then to the out-flow path.

[0131] The blood pump 10 may be configured to provide axial or mixed-flow. As used herein, the term “axial flow” is deemed to include flow characteristics which include both an axial and (slight) radial component.

[0132] The blood pump 10 can be configured to provide right and / or left heart support whereby blood is deliberately re-routed through and past the right and / or left ventricle in an effort to reduce the volume of blood to be pumped by the particular ventricle. While “unloading” the ventricles in this fashion is preferred in certain instances, it is to be understood that the pump and cannula arrangements described herein may also be employed to “preload” the ventricles. Ventricular preloading may be accomplished by positioning the outflow cage from the pump into a given ventricle such that the pump may be employed to fill or preload the ventricle with blood. This may be particularly useful with the right ventricle. On occasion, the right ventricle is not supplied with sufficient levels of blood from the right atrium such that, upon contraction, the right ventricle delivers an insufficient quantity of blood to the pulmonary artery. This may result when the right ventricle and / or right atrium are in a stressed or distorted condition during surgery. Preloading overcomes this problem by actively supplying blood into the right ventricle, thereby facilitating the delivery of blood into the pulmonary artery. The same technique can be used to preload the left ventricle and thus facilitate the delivery of blood from the left ventricle into the aorta.

[0133] The catheter blood pump system 100 can be used for positioning the catheter blood pump in the heart. It is also contemplated that such systems can reduce the costs and facilitate the use of the catheter blood pumps as an improved standard of care during medical procedures.

[0134] Pressure sensors have been proposed to monitor pressure(s) in the heart. See, e.g., U.S. Patent No. 9,669,142; and U.S. Patent No. 5,911,685, the contents of which are hereby incorporated by reference as if recited in full herein. However, embodiments of the present invention provide alternative, reliable, cost-effective pressure sensors for blood pump catheters.

[0135] Turning now to FIGS. 9A-9L, a sequence of shapes formed in situ by the flexible tube 31 as the guidewire 131 is withdrawn is shown. During insertion (intravascular), as shown in FIG. 9A, the flexible tube 31 can have a substantially linearlystraight shape when the guidewire 131 is in the lumen 39 and the distal end 131d of the guidewire 131 can extend distal of the distal end 31e of the flexible tube 31. It is noted that the distal end 131d of the guidewire 131 can remain inside the distal end 31e of the flexible tube 31 during placement and is not required to extend out the distal end of the flexible tube 31

[0136] The flexible tube 31 can have at least one radiopaque marker 150. As shown, the flexible tube 31 has a plurality of longitudinally spaced apart radiopaque markers 150. The radiopaque markers 150 can facilitate visualization of position for placement and operational status and may be positioned at one or more predefined (programmed) flexion points defining bend locations. See, e.g., marker 150b in FIG. 9E. The radiopaque markers 150 can be positioned, for example at a distal tip, a proximal end and at locations therebetween, for example.

[0137] The flexible tube 31 can be configured to have multiple flexion points defining bend locations as the guidewire 131 is withdrawn from the flexible tube 31. FIGS. 9C-9L shown example successive transitional shapes S1-S7 to reach a final shape S8 with a loop configuration at withdrawal of the guidewire 131.

[0138] FIGS. 9C and 9D illustrate a distal end portion of the flexible tube transitioning from the straight linear configuration of FIGS. 9A, 9B to a “J” configuration providing a first transitional shape SI with a first bend location Bi positioning the distal end 31e of the flexible tube substantially parallel to the primary axis A-A as shown in FIG. 9E. At FIG. 9F, a distal end portion 31d of the flexible tube 31 moves upward and inward relative to FIG. 9E, with the distal end 31e closer to the axial line A-A of the inlet cage 33 relative to FIG. 9E. FIG. 9G shows the distal end 31e of the flexible tube 31 closely spaced apart from the proximal end portion 31p of the flexible tube 31 which remains straight. FIG. 9H shows the distal end 31e over or underlying the proximal end portion 31p of the flexible tube 31. FIG. 91 the distal end 31e of the flexible tube crossing over the proximal end 31p of the flexible tube 31. FIGS. 9 J and 9K show successive transitional shapes S6, S7 whereby the loop 34 changes orientation to be in a different plane, perpendicular to the proximal end portion of the flexible tube 31p and / or the axis A-A resulting in the loop 34 with the example configuration shown in FIG. 9L.

[0139] During insertion, if the guidewire 131 and flexible tube 31 are inserted into the left ventricle (LV) in the configuration shown in FIG. 9A, then the length from the inlet cage 33 to the distal end of the flexible tube 31 can be limited by a length of the LV chamber, which is typically in a range of about 4-6 cm, so as to position the inlet cage 33 in the LVchamber while also simultaneously avoiding contact of the distal end of the tube 31e and / or distal end 131d of the guidewire 131 with the LV chamber. This length of the LV chamber can, in some embodiments, limit the diameter of the loop 34 formed by the flexible tube 31.

[0140] In certain embodiments, as the flexible tube 31 has multiple flexion points defining bend locations, the length of the LV chamber is not a limiting factor in providing a straight linear length (FIG. 9A) of the flexible tube 31 and, as such greater diameter loops may be formed. For example, the flexible tube 31 can be allowed to bend during insertion of the catheter blood pump into the LV chamber by withdrawing the guidewire 131 a partial distance during placement of the catheter blood pump before the inlet cage 33 is in the LV chamber but after the distal end 31e and / or the distal end portion 31d of the flexible tube 31 is in the LV chamber, and the insertion of the catheter blood pump 10 can then continue. As such, the length of the flexible tube 31 defining the loop body 34 can be increased to be greater than the length of the LV chamber. That is, the flexible tube 31 can be inserted in the LV chamber with the guidewire as shown in FIGS. 9A, 9B. Once across the aortic valve (FIGS. 1, 12), with the inlet cage 33 at or above the aortic valve, the guidewire 131 can be withdrawn a suitable distance so that the flexible tube 31 bends to form the configuration of SI or S2, FIGS. 9E, 9F. The location of the bend can be confirmed by an imaging modality to identify radiopaque marker(s) 150, such as radiopaque marker 150b, then, the catheter blood pump 10 can be further inserted as the guidewire 131 is further withdrawn as the inlet cage 33 is positioned into the LV chamber allowing for a greater length of the flexible tube 31 and, as a result, a greater maximal diameter of the loop 34, when the guidewire 131 is fully withdrawn (FIGS. 9K, 9L).

[0141] The radiopaque markers 150 can facilitate the insertion by identifying the location of the bend Bi (FIG. 9E) forming the “J-shape, using one or more radiopaque markers 150 on the flexible tube 31, which can mark a transitional distal end of the flexible tube 31 (FIGS. 9E, 9F, 9G, 9H, 91, 9J) for transitional shapes formed in situ until the loop 34 re-orients (FIGS. 9K, 9L) to be perpendicular to the axis A-A of the inlet cage 33 and / or cannula 35 (FIG. 10).

[0142] FIG. 10 shows an example flexible tube 31 providing a mechanical spacer with a diameter DI and positioned so that the loop 34 is at a length L from a distal end 33d of the inlet cage 33. The diameter DI can be in a range of about 17 mm to about 33 mm, in some embodiments. The length L can be in a range of about 0.02 inches to about 2 inches.

[0143] FIG. 11 is an example of a flexible tube 31 configured to provide at least one loop 34 that is arranged to be substantially centered with respect to the inlet cage 33 and / oraxis A-A. The loop configuration 34 can have a first loop with a diameter D2 and a second loop with a diameter DI with the greater diameter loop being the one substantially centered about the axis A-A.

[0144] FIG. 12 illustrates that flexible tube 31 with the loop 34 in an example position during operation of the catheter blood pump 10.

[0145] In certain embodiments, the flexible tube 31 can define a 3-D spacer with a loop 34 having a diameter that is greater than a maximal opening size of the aortic valve during cardiac pumping providing an anchoring function to the spacer function.

[0146] It is contemplated that the 3-D spacer provided by certain embodiments of the flexible tube 31 may be configured to provide an atraumatic configuration that can also provide a drag force that may facilitate positional (at least lateral) stability of the inlet cage during cardiac pumping.

[0147] Turning now to FIG. 13, an example method of providing spacing from local tissue for a catheter blood pump is shown. A catheter blood pump with an inlet cage configured to intake blood is provided (block 200). The catheter blood pump is inserted into a heart of a patient with a guidewire extending in a lumen of the flexible tube (block 210). The flexible tube is positioned in a left ventricle of a patient (block 220). The guidewire is at least partially removed from the lumen allowing the flexible tube to form at least one partial or whole loop that extends circumferentially about a longitudinally extending axis of the inlet cage in response to the removing step (block 230). Blood is intaken into the inlet cage and pumped out of the left ventricle and out of the impeller cage (block 240). The at least one partial or whole loop of the flexible tube can be allowed to move, e.g., float up and down and side to side during the intaking step (block 250). The inlet cage is mechanically laterally spaced away from local tissue during the intaking in response to contact with the at least one partial or whole loop of the flexible tube to thereby prevent suction of the inlet cage to the local tissue (block 260).

[0148] The at least one partial or whole loop can remain in a substantially fixed longitudinal location relative to the inlet cage during the intake of blood.

[0149] The removing of the guidewire can be carried out to withdraw the guidewire a first distance, allowing the distal end portion of the tube to bend in a first plane, then withdrawing the guidewire a second distance, allowing the distal end portion of the flexible tube to bend to position the at least one partial or whole loop in a second plane that is perpendicular to the first plane (block 232).

[0150] The guidewire can be withdrawn the first distance while the inlet cage is above the aortic valve, then the guidewire can be withdrawn the second distance while the inlet cage is below the aortic valve (block 234).

[0151] The at least one partial or whole loop can have a diameter in a range of about % inch to about 6 cm (block 235).

[0152] A distal end and a proximal end of the flexible tube can reside distal to the inlet cage a distance in a range of about 0.25 inches and to about 2.5 inch from a distal end of intake ports of the inlet cage (block 262).

[0153] The at least one partial or whole loop can reside in a plane perpendicular to an axis of the inlet cage and at a distance distal to the inlet cage that can be in a range of 1 inch to 2.5 inches (block 264).

[0154] The at least one partial or whole loop can be provided as only a single partial or whole loop which may allow a larger diameter loop for the same “straight” length of the flexible tube.

[0155] In the drawings and specification, there have been disclosed embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.

[0156] Thus, the foregoing is illustrative of the present invention and is not to be construed as limiting thereof. More particularly, the workflow steps may be carried out in a different manner, in a different order and / or with other workflow steps or may omit some or replace some workflow steps with other steps. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention.

[0157] Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. In the claims, means-plus-function clauses, where used, are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.

[0158] It is to be understood that the disclosure describes a few embodiments and that many variations of the invention can easily be devised by those skilled in the art after reading this disclosure and that the scope of the present invention is to be determined by the following claims.

Claims

What is Claimed:

1. A catheter blood pump, comprising: an impeller assembly comprising an impeller within an impeller cage; a cannula coupled to a distal end portion of the impeller assembly, wherein the cannula has a longitudinally extending lumen; an inlet cage provided by or coupled to a distal end portion of the cannula, the inlet cage having a longitudinally extending center axis; and a flexible tube coupled to a distal end portion of the cannula, wherein the flexible tube has a longitudinally extending lumen configured to slidably receive a guidewire, and wherein the flexible tube comprises a tube body configured to have a first configuration with the guidewire extending in the longitudinally extending lumen and a second configuration with the guidewire removed therefrom, and wherein in the second configuration, the flexible tube has at least one partial or whole circular loop extending circumferentially about, laterally outward from, a projection of the longitudinally extending center axis of the inlet cage to thereby provide a mechanical spacer between the inlet cage and local tissue.

2. The catheter blood pump of Claim 1, wherein the flexible tube has a wall with a closed outer surface surrounding the longitudinally extending lumen whereby blood is substantially or totally blocked from being suctioned into the longitudinally extending lumen.

3. The catheter blood pump of Claim 1, wherein the at least one partial or whole circular loop has a circumferential extent that is at least about 180 degrees.

4. The catheter blood pump of Claim 1, wherein the at least one partial or whole circular loop is a single loop that extends circumferentially in a range of 180-360 degrees.

5. The catheter blood pump of Claim 1, wherein the at least one partial or whole circular loop comprises loop segments that reside a radial distance in a range of about 3.175 mm and about 3 cm inches away from the projection of the center axis of the inlet cage.

6. The catheter blood pump of Claim 1, wherein the cannula has a greater longitudinal distance than the flexible tube when the flexible tube is both of the first and second configurations, and wherein the flexible tube has greater flexibility than the cannula.

7. The catheter blood pump of Claim 1, wherein the at least one partial or whole circular loop comprises loop segments that reside in different longitudinally spaced apart planes and on different sides of the projection of the center axis of the inlet cage.

8. The catheter blood pump of Claim 1, wherein the flexible tube has a distal end that is open, and wherein the at least one partial or whole circular loop places the distal end of the loop beneath a proximal end of the flexible tube.

9. The catheter blood pump of Claim 8, wherein the distal end of the at least one partial or whole circular loop resides closer to the projection of the center axis of the inlet cage relative to a more proximal loop segment of the at least one partial or whole circular loop.

10. The catheter blood pump of Claim 1, wherein the at least one partial or whole circular loop is configured to surround the projection of the center axis of the inlet cage.

11. The catheter blood pump of Claim 1, wherein a distal end of the inlet cage is positioned a distance in a range of about 0.25 inches to about 2.5 inches from the distal end of the flexible tube when the flexible tube is in the second configuration.

12. The catheter blood pump of Claim 1, wherein the at least one partial or whole circular loop is asymmetrically arranged about the projection of the center axis of the inlet cage.

13. The catheter blood pump of Claim 1, wherein the at least one partial or whole circular loop is symmetrically arranged about the projection of the center axis of the inlet cage.

14. The catheter blood pump of Claim 1, wherein, with the flexible tube in the second configuration, a distalmost end of the at least one partial or whole circular loop is positioned a distance in a range of about 0.25 inches to about 2.5 inches from a distal end of a blood intake port of the inlet cage.

15. The catheter blood pump of Claim 1, wherein the flexible tube has a distal end that is open, and wherein the catheter blood pump further comprises a guidewire extending throughthe lumen and out the distal end of the flexible tube whereby the guidewire cooperates with the flexible tube to define a straight orientation of the first configuration.

16. The catheter blood pump of Claim 1, wherein the flexible tube comprises a polymer or copolymer.

17. The catheter blood pump of Claim 1, wherein the flexible tube comprises a shape memory material.

18. The catheter blood pump of Claim 17, wherein the flexible tube comprises a shape memory alloy.

19. The catheter blood pump of Claim 1, wherein the flexible tube comprises an inner diameter in range of about 0.015 inches to about 0.022 inches defining the lumen.

20. The catheter blood pump of Claim 1, wherein the at least one partial or whole loop resides at least partially in a plane perpendicular to a projection of the center axis of the inlet cage, and wherein the at least one partial or whole loop has a diameter in a range of about 6.35 mm to about 6 cm.

21. The catheter blood pump of Claim 1, wherein a distal end and a proximal end of the flexible tube reside distal to the inlet cage a distance in a range of about 1 inch and 3 inches from a distal end of intake ports of the inlet cage.

22. The catheter blood pump of Claim 1, further comprising a plurality of radiopaque markers on or in the flexible tube, wherein the plurality of radiopaque markers comprises at least one radiopaque marker at a predefined bend location at a distal end portion of the flexible tube.

23. The catheter blood pump of Claim 1, wherein the flexible tube is configured to cooperate with the guidewire to define a plurality of transitional shapes as the guidewire is withdrawn therefrom including a first shape having a “J” shape in a first plane defining a transitional distal end of the flexible tube, then a second shape having a loop shape in the first plane, then a third shape having a loop shape that resides in a second plane perpendicular to the first plane.

24. A method of providing spacing from local tissue for a catheter blood pump, comprising: providing a catheter blood pump with an inlet cage configured to intake blood and an impeller cage configured to outflow the intaken blood; inserting the catheter blood pump into a heart of a patient with a guidewire extending in a lumen of a flexible tube; positioning the flexible tube in a left ventricle of a patient; removing the guidewire at least partially from the lumen allowing the flexible tube to form at least one partial or whole loop that extends circumferentially about a longitudinally extending axis of the inlet cage in response to the removing step; then intaking blood into the inlet cage and pumping the blood out of the impeller cage; and mechanically laterally spacing the inlet cage away from local tissue during a cardiac cycle in response to contact with the at least one partial or whole loop of the flexible tube to thereby prevent suction of the inlet cage to the local tissue.

25. The method of Claim 24, wherein the at least one partial or whole loop remains in a substantially fixed longitudinal location relative to the inlet cage during the intake of blood.

26. The method of Claim 24, wherein the removing of the guidewire is carried out to withdraw the guidewire a first distance, allowing the distal end portion of the tube to bend in a first plane, then withdrawing the guidewire a second distance, allowing the distal end portion of the flexible tube to bend to position the at least one partial or whole loop in a second plane that is perpendicular to the first plane.

27. The method of Claim 24, wherein the guidewire is withdrawn the first distance while the inlet cage is above the aortic valve, then the guidewire is withdrawn the second distance while the inlet cage is below the aortic valve.

28. The method of Claim 24, wherein the at least one partial or whole loop has a diameter in a range of about 6.35 mm to about 6 cm.

29. The method of Claim 24, wherein a distal end and a proximal end of the flexible tube reside distal to the inlet cage a distance in a range of 0.25 inches and 2.5 inches from a distal end of intake ports of the inlet cage.

30. The method of Claim 24, wherein removing step is carried out whereby the flexible tube cooperates with the guidewire to define a plurality of transitional shapes as the guidewire is withdrawn therefrom including a first shape having a “J” shape in a first plane defining a transitional distal end of the flexible tube, then a second shape having a loop shape in the first plane, then a third shape having a loop shape that resides in a second plane perpendicular to the first plane.

31. The method of Claim 24, further comprising allowing the at least one partial or whole loop of the flexible tube to float up and down and side to side during the intaking step.

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