Ventricular assist device

Abstract

This application relates to ventricular assist devices. The document describes an apparatus and method comprising a blood pump (20) configured for placement within the body of a subject, the blood pump comprising an impeller (50) and a frame (34) disposed around the impeller, the impeller comprising a proximal bushing and a distal bushing (64, 58), and the frame comprising a proximal bearing and a distal bearing (116, 118). An axial shaft (92) passes through the proximal and distal bearings (116, 118) of the frame and the proximal and distal bushings (64, 58) of the impeller (50). The impeller (50) defines a radially constrained configuration in which the impeller (50) is introduced into the body of the subject and a non-radially constrained configuration in which the impeller (50) is configured to pump blood within the body of the subject. The impeller (50) changes from its radially constrained configuration to its non-radially constrained configuration by sliding the distal bushing (58) on the axial shaft (92). Other applications are also described herein.

Description

[0001] This application is a divisional application of the application filed on January 10, 2019, with application number 201980007116.9 and invention title "Ventricular Assist Device".

[0002] Cross-references to related applications

[0003] This application claims priority to the following applications:

[0004] Sohn's U.S. Provisional Patent Application No. 62 / 615,538, entitled "Ventricular assist device," filed on January 10, 2018;

[0005] Sohn’s U.S. Provisional Patent Application No. 62 / 665,718, entitled “Ventricular assist device,” filed on May 2, 2018;

[0006] Tuval's U.S. Provisional Patent Application No. 62 / 681,868, entitled "Ventricular assist device," filed June 7, 2018; and

[0007] Tuval's U.S. Provisional Patent Application No. 62 / 727,605, entitled "Ventricular assist device," was filed on September 6, 2018.

[0008] All applications cited above are incorporated herein by reference.

[0009] Field of the implementation scheme of the invention

[0010] Some applications of this invention generally relate to medical devices. Specifically, some applications of this invention relate to ventricular assist devices and methods of using them. background

[0011] Ventricular assist devices (VADs) are mechanical circulatory support devices designed to assist and reduce the load on the heart chambers in order to maintain or increase cardiac output. They are used in patients with failing hearts and in patients at risk of cardiac deterioration during percutaneous coronary intervention. Most commonly, left ventricular assist devices are used in defective hearts to assist left ventricular function. In some cases, right ventricular assist devices are used to assist right ventricular function. Such assist devices are designed to be permanently implanted or mounted on a catheter for temporary placement.

[0012] Overview of the implementation plan

[0013] According to some applications of the invention, a ventricular assist device includes an impeller disposed on an axial shaft, with a frame surrounding the impeller. The ventricular assist device typically includes a tube passing through the aortic valve of a subject, such that a proximal end of the tube is positioned in the subject's aorta, and a distal end of the tube is positioned within the subject's left ventricle. The impeller, axial shaft, and frame are positioned within the distal portion of the tube within the subject's left ventricle. Typically, the impeller is configured to pump blood from the left ventricle into the aorta by rotation. The tube typically defines one or more blood inlet openings at its distal end, through which blood flows from the left ventricle into the tube during operation of the impeller. For some applications, the proximal portion of the tube defines one or more blood outlet openings, through which blood flows from the tube into the ascending aorta during operation of the impeller.

[0014] For some applications, the impeller includes a proximal bushing and a distal bushing, and the frame includes a proximal bearing and a distal bearing. An axial shaft typically passes through the proximal and distal bearings of the frame and the proximal and distal bushings of the impeller. For some applications, (a) the proximal bushing of the impeller is coupled to the axial shaft such that the proximal bushing is held in an axially fixed position relative to the axial shaft, and (b) the distal bushing of the impeller is not coupled to the axial shaft such that the distal bushing is not held in an axially fixed position relative to the axial shaft. Typically, the impeller defines a radially constrained configuration and a non-radial constrained configuration, in which the impeller is introduced into the body of a subject, and in a non-radial constrained configuration, the impeller is configured to pump blood within the body of a subject. For some applications, the impeller changes from its radially constrained configuration to its non-radial constrained configuration by sliding the distal bushing on the axial shaft.

[0015] Typically, the axial shaft is not held in a fixed axial position relative to the proximal and distal bearings. Furthermore, ventricular assist devices (and / or their pump components) typically do not include any thrust bearings configured to be disposed within the subject's body. For some applications, ventricular assist devices include one or more thrust bearings disposed outside the subject's body, and resistance to the thrust generated by the rotation of the impeller is provided solely by one or more thrust bearings disposed outside the subject's body.

[0016] In some applications, a motor drives an impeller to pump blood from the left ventricle to the aorta by rotating the impeller, and the impeller is configured to move axially relative to a frame in response to changes in the pressure difference between the left ventricle and the aorta. In some applications, a computer processor measures an indication of the impeller's axial movement. In some applications, the computer processor derives the subject's cardiac cycle, the pressure difference between the left ventricle and the aorta, and / or the subject's left ventricular pressure based on the measured indication of the impeller's axial movement. In some applications, the computer processor changes the impeller's rotational rate based at least in part on sensor signals. For example, the computer processor may determine the subject's left ventricular pressure based at least in part on sensor signals and may change the impeller's rotational rate based at least in part on the determined left ventricular pressure. In some applications, the computer processor reduces the impeller's rotational rate in response to determining that the subject's left ventricular pressure has decreased. In some applications, the impeller is coupled to a magnet such that axial movement of the impeller causes axial movement of the magnet, and the computer processor measures an indication of the impeller's axial movement by measuring the magnetic flux generated by the magnet.

[0017] Typically, a drive cable extends from the outside of the subject's body to an axial axis and is configured to transmit rotational motion from a motor to an impeller, such that the impeller pumps blood from the left ventricle to the aorta by rotating in a given direction. For some applications, at least a portion of the drive cable includes multiple wires arranged in a coiled configuration, such that, in response to rotation of the drive cable in a given direction of rotation, the coiled multiple wires are at least partially uncoiled, causing that portion of the drive cable to shorten axially. For some applications, an outer tube is disposed around the drive cable, and friction between the outer tube and the drive cable typically generates debris. Optionally or additionally, fluid (e.g., a purification fluid) is disposed between the outer tube and the drive cable. For some such applications, at least a portion of the drive cable is configured such that the coiled multiple wires are configured to pump debris and / or fluid toward the proximal end of the drive cable.

[0018] For some applications, the drive cable includes a first portion and a second portion, the first portion being configured to be at least partially disposed within the aortic arch of the subject, and the second portion being configured to be at least partially disposed within the descending aorta of the subject, with the first portion being more flexible than the second portion. For example, the first portion of the drive cable may include a first number of wires arranged in a coiled configuration, and the second portion of the drive cable may include a second number of wires arranged in a coiled configuration, with the first number being less than the second number. For example, the first portion of the drive cable may include between 4 and 8 wires arranged in a coiled configuration, and the second portion of the drive cable may include between 8 and 12 wires arranged in a coiled configuration.

[0019] For some applications, the impeller includes at least one helical elongated element (and typically three helical elongated elements), and a spring disposed inside the helical elongated element and along the axis around which the helical elongated element is wound. Typically, a film of material (e.g., silicone) is supported between the helical elongated element and the spring. For some applications, at least one elongated element (e.g., a rope or thread) extends from the spring to the helical elongated element and is configured to hold the helical elongated element within a given distance from the spring.

[0020] As described above, for some applications, the frame is positioned around the impeller. For some applications, the ventricular assist device includes a stator comprising multiple curved protrusions coupled to the proximal end of the frame. Typically, the curvature of the curved protrusions is opposite to the direction of rotation of the impeller. For some applications, the curvature of the curved protrusions is such that, from the distal end to the proximal end, the curved protrusions gradually become more parallel to the longitudinal axis of the frame. Typically, the curved protrusions include multiple curved struts integral with the frame, and a flexible material (e.g., silicone) extending from the curved struts. For some applications, the flexible material is shaped to define an inner cavity passing through it.

[0021] As described above, the impeller is typically disposed within a tube (sometimes referred to herein as a "blood pump tube") extending from the subject's left ventricle to the subject's aorta. For some applications, at least one blood pressure measuring tube (which defines an opening at its distal end) extends to at least the outer surface of the blood pump tube, such that the opening at the distal end of the blood pressure measuring tube is in direct fluid communication with the subject's blood flow outside the blood pump tube. A pressure sensor measures blood pressure within the blood pressure measuring tube. For some applications, the blood pressure measuring tube is configured to extend from the proximal end of the blood pump tube along the outer surface of the blood pump tube to the opening at the distal end of the blood pressure measuring tube. Typically, the blood pressure measuring tube is a left ventricular blood pressure measuring tube, which is configured to extend to the outer surface of the blood pump tube near the impeller, positioned within the left ventricle of the subject, and a pressure sensor is configured to measure the subject's left ventricular pressure by measuring the blood pressure within the left ventricular blood pressure measuring tube.

[0022] Typically, a blood pump tubing defines one or more blood inlet openings in its distal portion and one or more blood outlet openings in its proximal portion. For some applications, ventricular assist devices include a radially expandable, non-invasive distal distal portion configured to be distally positioned within the left ventricle of a subject relative to one or more blood inlet openings. The distal distal portion is typically configured to be inserted into the left ventricle in a radially constrained configuration and is configured to present a non-radially constrained configuration within the left ventricle of the subject, wherein at least a radially expandable portion of the distal distal portion expands radially relative to the radially constrained configuration of the distal distal portion. Typically, in its non-radially constrained configuration, the radially expandable portion of the distal distal portion separates the one or more blood inlet openings from the internal structures of the left ventricle, such as the interventricular septum, chordae tendineae, papillary muscles, and / or the apex of the left ventricle. Furthermore, typically, in its non-radially constrained configuration, the radially expandable portion of the distal distal portion separates one or more blood inlet openings from the internal structures of the left ventricle in three dimensions. In some applications, in their non-radial constraint configuration, the radially expandable portion of the distal end portion guides blood flow from the left ventricle into one or more blood inlet openings.

[0023] In some applications, in the radial constraint configuration of the distal distal portion, the distal region of the distal distal portion is configured to be at least semi-rigid and shaped to converge radially toward the distal end of the distal distal portion along the longitudinal direction. Typically, the ventricular assist device is configured to be inserted into the subject's body via a puncture in the subject's body. In some applications, during insertion of the ventricular assist device, the distal region of the distal distal portion is configured to act as an dilator by enlarging the puncture.

[0024] Generally, in the specification and claims of this application, the term "proximal" and related terms, when used with respect to the reference device or a portion thereof, should be interpreted as referring to the end or portion of the device that is generally closer to the location through which the device is inserted into the body of the subject when inserted. The term "distal" and related terms, when used with respect to the reference device or a portion thereof, should be interpreted as referring to the end or portion of the device that is generally farther from the location through which the device is inserted into the body of the subject when inserted.

[0025] The scope of this invention includes the use of the devices and methods described herein in anatomical locations other than the left ventricle and aorta. Therefore, ventricular assist devices and / or portions thereof are sometimes referred to herein (in the specification and claims) as blood pumps.

[0026] According to some applications of the present invention, an apparatus is also provided, the apparatus comprising:

[0027] A blood pump, configured to be placed inside the body of a subject, the blood pump comprising:

[0028] The impeller includes a proximal bushing and a distal bushing;

[0029] A frame configured to be disposed around the impeller, the frame including a proximal bearing and a distal bearing;

[0030] An axial shaft, configured to pass through the proximal and distal bearings of the frame, and the proximal and distal bushings of the impeller.

[0031] The proximal bushing of the impeller is connected to the axial shaft such that the proximal bushing is held in a fixed axial position relative to the axial shaft, and

[0032] The distal bushing of the impeller is not connected to the axial shaft, such that the distal bushing is not held in a fixed axial position relative to the axial shaft, and

[0033] The impeller defines a radially constrained configuration and a non-radial constrained configuration, in which the impeller is introduced into the body of the subject, and in which the impeller is configured to pump blood within the body of the subject, the impeller being configured to change from its radially constrained configuration to its non-radial constrained configuration by sliding on the axial axis via the distal bushing.

[0034] In some applications, the impeller is configured to be placed in the left ventricle of the subject and to pump blood from the left ventricle to the subject's aorta. In some applications, the impeller is configured to be placed in the right ventricle of the subject and to pump blood from the right ventricle to the subject's pulmonary artery. In some applications, the impeller is configured to be placed within a blood vessel of the subject. In some applications, the impeller is configured to be placed within a heart chamber of the subject.

[0035] In some applications, the impeller includes:

[0036] At least one helical elongated element extending from the proximal bushing to the distal bushing;

[0037] A spring, which is disposed within the helical elongated element and along the axis around which the helical elongated element is wound;

[0038] A membrane of material, the membrane of which is supported between the helical elongated element and the spring; and

[0039] At least one flexible elongated element extends from the spring to the helical elongated element and is configured to hold the helical elongated element within a given distance from the spring, the at least one flexible elongated element being selected from the group consisting of: ropes and threads.

[0040] In some applications, the device also includes delivery conduits.

[0041] The delivery conduit is configured to keep the impeller in its radial constraint configuration during the introduction of the impeller into the subject's body.

[0042] When the impeller is released from the delivery conduit, the impeller is configured to self-expand, causing the distal bushing to slide proximally on the axial axis, thus allowing the impeller to exhibit its non-radial constrained configuration, and

[0043] In order to retract the impeller from the subject's body, the delivery conduit is configured such that the distal end of the delivery conduit and the impeller move relative to each other, such that the distal end of the delivery conduit causes the distal bushing to slide distally on the axial axis, thereby causing the impeller to exhibit its radially constrained configuration.

[0044] According to some applications of the present invention, an apparatus is also provided, the apparatus comprising:

[0045] Ventricular assist device, the ventricular assist device comprising:

[0046] An impeller configured to be placed in the left ventricle of the subject;

[0047] A frame, the frame being configured to be disposed around the impeller; and

[0048] A motor configured to drive the impeller by rotating it to pump blood from the left ventricle to the subject's aorta.

[0049] The impeller is configured to move axially back and forth relative to the frame in response to periodic changes in the pressure difference between the left ventricle and the aorta.

[0050] In some applications:

[0051] The impeller includes a proximal bushing and a distal bushing;

[0052] The frame includes a proximal bearing and a distal bearing; and

[0053] The ventricular assist device further includes an axial shaft configured to pass through the proximal and distal bearings defined by the frame, and the proximal and distal bushings of the impeller. The axial shaft:

[0054] At least one of the proximal bushing and the distal bushing connected to the impeller is such that the at least one bushing is held in an axially fixed position relative to the axial axis, but not in an axially fixed position relative to the proximal bearing and the distal bearing.

[0055] In some applications, the ventricular assist device does not include any thrust bearings configured to be placed inside the subject's body.

[0056] In some applications, the ventricular assist device also includes one or more thrust bearings configured to be disposed outside the subject's body, wherein the resistance to the thrust generated by the rotation of the impeller is provided solely by the one or more thrust bearings disposed outside the subject's body.

[0057] In some applications,

[0058] The motor is configured to drive the impeller by rotating it in a given direction of rotation to pump blood from the subject's left ventricle to the subject's aorta; and

[0059] The ventricular assist device also includes:

[0060] An axial shaft, wherein the impeller is disposed on the axial shaft; and

[0061] A drive cable configured to extend from outside the subject's body to the axial axis, the drive cable being configured to transmit rotational motion from the motor to the impeller by rotation, at least a portion of the drive cable comprising a plurality of wires arranged in a coiled configuration such that, in response to rotation of the drive cable in the given rotational direction, the plurality of wires arranged in the coiled configuration are at least partially unwound, causing the portion of the drive cable to shorten axially.

[0062] In some applications, the device also includes:

[0063] A sensor configured to detect indications of axial movement of the impeller, and configured to generate a sensor signal in response thereto; and

[0064] A computer processor configured to receive the sensor signal and to generate an output in response thereto.

[0065] In some applications, the computer processor is configured to generate an output indicative of the subject's cardiac cycle in response to receiving the sensor signal. In some applications, the computer processor is configured to determine the subject's left ventricular pressure based at least in part on the sensor signal. In some applications, the computer processor is configured to change the impeller's rotational rate based at least in part on the sensor signal.

[0066] In some applications, the computer processor is configured as follows:

[0067] The left ventricular pressure of the subject is determined at least in part based on the sensor signals, and

[0068] The rotational rate of the impeller is changed at least in part based on the determined left ventricular pressure.

[0069] In some applications, the computer processor is configured to reduce the rotational rate of the impeller in response to determining that the subject's left ventricular pressure has decreased.

[0070] In some applications, the device also includes:

[0071] A magnet, wherein the impeller is connected to the magnet such that axial movement of the impeller causes axial movement of the magnet;

[0072] A sensor configured to detect magnetic flux generated by the magnet, and configured to generate a sensor signal in response thereto; and

[0073] A computer processor configured to receive the sensor signal and to generate an output in response thereto.

[0074] In some applications, the computer processor is configured to generate an output indicative of the subject's cardiac cycle in response to receiving the sensor signal. In some applications, the computer processor is configured to determine the subject's left ventricular pressure based at least in part on the sensor signal. In some applications, the computer processor is configured to change the impeller's rotational rate based at least in part on the sensor signal.

[0075] In some applications, the computer processor is configured as follows:

[0076] The left ventricular pressure of the subject is determined at least in part based on the sensor signals, and

[0077] The rotational rate of the impeller is changed at least in part based on the determined left ventricular pressure.

[0078] In some applications, the computer processor is configured to reduce the rotational rate of the impeller in response to determining that the subject's left ventricular pressure has decreased.

[0079] In some applications:

[0080] The impeller includes a proximal bushing and a distal bushing;

[0081] The frame includes a proximal bearing and a distal bearing;

[0082] The ventricular assist device also includes an axial shaft configured to pass through the proximal and distal bearings of the frame and the proximal and distal bushings of the impeller;

[0083] The impeller is connected to the axial shaft such that the impeller causes the axial shaft to move axially back and forth relative to the proximal bearing and the distal bearing of the frame.

[0084] In some applications, the axial shaft is configured to clean the interface between the axial shaft and the proximal and distal bearings of the frame by performing the axial reciprocating motion relative to the proximal and distal bearings of the frame. In some applications, the axial shaft is configured to reduce heat buildup at the interface between the axial shaft and the proximal and distal bearings of the frame by performing the axial reciprocating motion relative to the proximal and distal bearings of the frame, compared to a scenario where the axial shaft does not perform the axial reciprocating motion relative to the proximal and distal bearings of the frame.

[0085] According to some applications of the present invention, an apparatus is also provided, the apparatus comprising:

[0086] Blood pump, the blood pump comprising:

[0087] An impeller, comprising a proximal bushing and a distal bushing, configured to pump blood through the subject's body;

[0088] A frame configured to be disposed around the impeller, the frame including a proximal bearing and a distal bearing;

[0089] An axial shaft, configured to pass through the proximal and distal bearings of the frame and the proximal and distal bushings of the impeller, the axial shaft:

[0090] At least one of the proximal bushing and the distal bushing connected to the impeller is held in an axially fixed position relative to the axial axis, and

[0091] The proximal bearing and the distal bearing are not kept in a fixed axial position.

[0092] In some applications, the blood pump does not include any thrust bearings configured to be disposed within the subject's body. In some applications, the blood pump also includes one or more thrust bearings configured to be disposed outside the subject's body, and wherein resistance to the thrust generated by the rotation of the impeller is provided solely by the one or more thrust bearings disposed outside the subject's body.

[0093] In some applications, the device also includes:

[0094] A sensor configured to detect indications of axial movement of the impeller, and configured to generate a sensor signal in response thereto; and

[0095] A computer processor configured to receive the sensor signal and to generate an output in response thereto.

[0096] In some applications, the computer processor is configured to generate an output indicative of the subject's cardiac cycle in response to receiving the sensor signal. In some applications, the computer processor is configured to determine the subject's left ventricular pressure based at least in part on the sensor signal. In some applications, the computer processor is configured to change the impeller's rotational rate based at least in part on the sensor signal.

[0097] In some applications, the computer processor is configured as follows:

[0098] The left ventricular pressure of the subject is determined at least in part based on the sensor signals, and

[0099] The rotational rate of the impeller is changed at least in part based on the determined left ventricular pressure.

[0100] In some applications, the computer processor is configured to reduce the rotational rate of the impeller in response to determining that the subject's left ventricular pressure has decreased.

[0101] In some applications, the device also includes:

[0102] A magnet, wherein the impeller is connected to the magnet such that axial movement of the impeller causes axial movement of the magnet;

[0103] A sensor configured to detect magnetic flux generated by the magnet, and configured to generate a sensor signal in response thereto; and

[0104] A computer processor configured to receive the sensor signal and to generate an output in response thereto.

[0105] In some applications, the computer processor is configured to generate an output indicative of the subject's cardiac cycle in response to receiving the sensor signal. In some applications, the computer processor is configured to determine the subject's left ventricular pressure based at least in part on the sensor signal. In some applications, the computer processor is configured to change the impeller's rotational rate based at least in part on the sensor signal.

[0106] In some applications, the computer processor is configured as follows:

[0107] The left ventricular pressure of the subject is determined at least in part based on the sensor signals, and

[0108] The rotational rate of the impeller is changed at least in part based on the determined left ventricular pressure.

[0109] In some applications, the computer processor is configured to reduce the rotational rate of the impeller in response to determining that the subject's left ventricular pressure has decreased.

[0110] In some applications, the impeller is configured to pump blood from a first location within the subject's body to a second location within the subject's body, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the first and second locations. In some applications, the impeller is configured to pump blood from the subject's left ventricle to the subject's aorta, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the left ventricle and the aorta. In some applications, the impeller is configured to pump blood from the subject's right ventricle to the subject's pulmonary artery, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the right ventricle and the pulmonary artery. In some applications, the impeller is configured to pump blood from the subject's right atrium to the subject's right ventricle, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the right atrium and the right ventricle. In some applications, the impeller is configured to pump blood from the subject's vena cava to the subject's right ventricle, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the vena cava and the right ventricle. In some applications, the impeller is configured to pump blood from the subject's right atrium to the subject's pulmonary artery, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the right atrium and the pulmonary artery. In some applications, the impeller is configured to pump blood from the subject's vena cava to the subject's pulmonary artery, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the vena cava and the pulmonary artery.

[0111] In some applications, the device also includes:

[0112] A motor configured to drive the impeller by rotating it in a given direction of rotation to pump blood through the subject's body; and

[0113] A drive cable configured to extend from outside the subject's body to the axial axis, the drive cable being configured to transmit rotational motion from the motor to the impeller by rotation, at least a portion of the drive cable comprising a plurality of wires arranged in a coiled configuration such that, in response to rotation of the drive cable in the given rotational direction, the plurality of wires arranged in the coiled configuration are at least partially unwound, causing the portion of the drive cable to shorten axially.

[0114] In some applications, the impeller is coupled to the axial shaft such that the impeller causes the axial shaft to reciprocate axially relative to the proximal and distal bearings of the frame. In some applications, the axial shaft is configured to clean the interface between the axial shaft and the proximal and distal bearings of the frame by performing the axial reciprocating motion relative to the proximal and distal bearings of the frame. In some applications, the axial shaft is configured to reduce heat buildup at the interface between the axial shaft and the proximal and distal bearings of the frame by performing the axial reciprocating motion relative to the proximal and distal bearings of the frame, compared to a scenario where the axial shaft does not perform the axial reciprocating motion relative to the proximal and distal bearings of the frame.

[0115] According to some applications of the present invention, an apparatus is also provided, the apparatus comprising:

[0116] Blood pump, the blood pump comprising:

[0117] An impeller, configured to be placed inside the body of a subject and configured to pump blood through the body of the subject;

[0118] A frame, configured to be disposed around the impeller,

[0119] The blood pump does not include any thrust bearings configured to be installed inside the subject's body.

[0120] In some applications, the blood pump also includes one or more thrust bearings configured to be disposed outside the subject's body, and the resistance to the thrust generated by the rotation of the impeller is provided solely by the one or more thrust bearings disposed outside the subject's body.

[0121] In some applications, the device also includes:

[0122] A sensor configured to detect indications of axial movement of the impeller, and configured to generate a sensor signal in response thereto; and

[0123] A computer processor configured to receive the sensor signal and to generate an output in response thereto.

[0124] In some applications, the computer processor is configured to generate an output indicative of the subject's cardiac cycle in response to receiving the sensor signal. In some applications, the computer processor is configured to determine the subject's left ventricular pressure based at least in part on the sensor signal. In some applications, the computer processor is configured to change the impeller's rotational rate based at least in part on the sensor signal.

[0125] In some applications, the computer processor is configured as follows:

[0126] The left ventricular pressure of the subject is determined at least in part based on the sensor signals, and

[0127] The rotational rate of the impeller is changed at least in part based on the determined left ventricular pressure.

[0128] In some applications, the computer processor is configured to reduce the rotational rate of the impeller in response to determining that the subject's left ventricular pressure has decreased.

[0129] In some applications, the device also includes:

[0130] A magnet, wherein the impeller is connected to the magnet such that axial movement of the impeller causes axial movement of the magnet;

[0131] A sensor configured to detect magnetic flux generated by the magnet, and configured to generate a sensor signal in response thereto; and

[0132] A computer processor configured to receive the sensor signal and to generate an output in response thereto.

[0133] In some applications, the computer processor is configured to generate an output indicative of the subject's cardiac cycle in response to receiving the sensor signal. In some applications, the computer processor is configured to determine the subject's left ventricular pressure based at least in part on the sensor signal. In some applications, the computer processor is configured to change the impeller's rotational rate based at least in part on the sensor signal.

[0134] In some applications, the computer processor is configured as follows:

[0135] The left ventricular pressure of the subject is determined at least in part based on the sensor signals, and

[0136] The rotational rate of the impeller is changed at least in part based on the determined left ventricular pressure.

[0137] In some applications, the computer processor is configured to reduce the rotational rate of the impeller in response to determining that the subject's left ventricular pressure has decreased.

[0138] In some applications, the impeller is configured to pump blood from a first location within the subject's body to a second location within the subject's body, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the first and second locations. In some applications, the impeller is configured to pump blood from the subject's left ventricle to the subject's aorta, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the left ventricle and the aorta. In some applications, the impeller is configured to pump blood from the subject's right ventricle to the subject's pulmonary artery, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the right ventricle and the pulmonary artery. In some applications, the impeller is configured to pump blood from the subject's right atrium to the subject's right ventricle, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the right atrium and the right ventricle. In some applications, the impeller is configured to pump blood from the subject's vena cava to the subject's right ventricle, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the vena cava and the right ventricle. In some applications, the impeller is configured to pump blood from the subject's right atrium to the subject's pulmonary artery, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the right atrium and the pulmonary artery. In some applications, the impeller is configured to pump blood from the subject's vena cava to the subject's pulmonary artery, and the impeller is configured to reciprocate axially relative to the frame in response to periodic changes in the pressure difference between the vena cava and the pulmonary artery.

[0139] In some applications, the device also includes:

[0140] A motor configured to drive the impeller by rotating it in a given direction of rotation to pump blood through the subject's body;

[0141] An axial shaft, the impeller being connected to the axial shaft; and

[0142] A drive cable configured to extend from outside the subject's body to the axial axis, the drive cable being configured to transmit rotational motion from the motor to the impeller by rotation, at least a portion of the drive cable comprising a plurality of wires arranged in a coiled configuration such that, in response to rotation of the drive cable in the given rotational direction, the plurality of wires arranged in the coiled configuration are at least partially unwound, causing the portion of the drive cable to shorten axially.

[0143] In some applications:

[0144] The impeller includes a proximal bushing and a distal bushing;

[0145] The frame includes a proximal bearing and a distal bearing;

[0146] The device also includes an axial shaft, the axial shaft being:

[0147] Passing through the proximal bearing and the distal bearing defined by the frame, and the proximal bushing and the distal bushing of the impeller,

[0148] At least one of the proximal bushing and the distal bushing is connected to the impeller such that the at least one bushing is held in an axially fixed position relative to the axial axis.

[0149] Since the proximal bearing and the distal bearing do not remain in a fixed axial position,

[0150] This causes the impeller to cause the axial shaft to move axially back and forth relative to the proximal bearing and the distal bearing of the frame.

[0151] In some applications, the axial shaft is configured to clean the interface between the axial shaft and the proximal and distal bearings of the frame by performing the axial reciprocating motion relative to the proximal and distal bearings of the frame. In some applications, the axial shaft is configured to reduce heat buildup at the interface between the axial shaft and the proximal and distal bearings of the frame by performing the axial reciprocating motion relative to the proximal and distal bearings of the frame, compared to a scenario where the axial shaft does not perform the axial reciprocating motion relative to the proximal and distal bearings of the frame.

[0152] According to some applications of the present invention, the following inventive concepts are also provided:

[0153] Inventive Concept 1. A device comprising:

[0154] Impeller, the impeller comprising:

[0155] At least one helical elongated element;

[0156] A spring, which is disposed within the helical elongated element and along the axis around which the helical elongated element is wound;

[0157] A membrane of material, the membrane of which is supported between the helical elongated element and the spring; and

[0158] At least one flexible elongated element extends from the spring to the helical elongated element and is configured to hold the helical elongated element within a given distance from the spring, the at least one flexible elongated element being selected from the group consisting of: rope and thread.

[0159] Inventive Concept 2. The device according to Inventive Concept 1, wherein the impeller is configured such that, in the non-radial constraint configuration of the impeller, the outer diameter of the impeller at the position where the outer diameter is at its maximum value is less than 8 mm.

[0160] Inventive Concept 3. The device according to Inventive Concept 1, wherein the at least one helical elongated element comprises a plurality of helical elongated elements, and wherein the at least one flexible elongated element extends from the spring to each of the helical elongated elements.

[0161] Inventive Concept 4. The device according to any one of Inventive Concepts 1-3, wherein the impeller is configured to pump blood through the body of a subject.

[0162] Inventive Concept 5. The device according to Inventive Concept 4, wherein the impeller is configured to be placed in the blood vessels of the subject.

[0163] Inventive Concept 6. The device according to Inventive Concept 4, wherein the impeller is configured to be placed in the heart chamber of the subject.

[0164] Inventive Concept 7. The device according to Inventive Concept 4, wherein the impeller is configured to pump blood from the left ventricle of the subject to the aorta of the subject.

[0165] Inventive Concept 8. The device according to Inventive Concept 4, wherein the impeller is configured to pump blood from the right ventricle of the subject to the pulmonary artery of the subject.

[0166] Inventive Concept 9. A method comprising:

[0167] The impeller is placed inside the subject's body. The impeller comprises:

[0168] At least one helical elongated element;

[0169] A spring, which is disposed within a helical elongated element and along the axis around which the helical elongated element is wound;

[0170] A membrane of material, which is supported between a helical elongated element and a spring; and

[0171] At least one flexible elongated element extending from the spring to the helical elongated element, selected from the group consisting of: ropes and threads; and

[0172] Blood is pumped through the subject's body by rotating an impeller. During the rotation of the impeller, a flexible elongated element keeps the spiral elongated element within a given distance from the spring.

[0173] Inventive Concept 10. An apparatus comprising:

[0174] The blood pump includes:

[0175] An impeller configured to be placed inside the subject's heart chamber;

[0176] A frame, configured to be positioned around the impeller; and

[0177] A motor configured to drive an impeller by rotating it to pump blood from the subject's heart chambers into blood vessels.

[0178] The impeller is configured to move axially relative to the frame in response to periodic changes in the pressure difference between the heart chamber and the blood vessels.

[0179] Inventive Concept 11. A method comprising:

[0180] The impeller of the blood pump was placed inside the subject's heart chamber, and a frame was set up around the impeller; and

[0181] The impeller is driven by rotating it to pump blood from the subject's heart chambers into the blood vessels.

[0182] The placement of the impeller within the heart chamber allows the impeller to move axially relative to the frame in response to periodic changes in the pressure difference between the heart chamber and the blood vessels.

[0183] Inventive Concept 12. An apparatus comprising:

[0184] The blood pump includes:

[0185] An impeller configured to be placed within the subject's first blood vessel;

[0186] A frame, configured to be positioned around the impeller; and

[0187] A motor configured to drive an impeller by rotating it to pump blood from a subject's first blood vessel to a second blood vessel.

[0188] The impeller is configured to move axially relative to the frame in response to periodic changes in the pressure difference between the first and second blood vessels.

[0189] Inventive Concept 13. A method comprising:

[0190] The impeller of the blood pump was placed inside the subject's first blood vessel, with a frame surrounding the impeller; and

[0191] The impeller is driven by rotating it to pump blood from the subject's first blood vessel to a second blood vessel.

[0192] The placement of the impeller within the first blood vessel allows the impeller to move axially relative to the frame in response to periodic changes in the pressure difference between the heart chamber and the blood vessel.

[0193] Inventive Concept 14. An apparatus comprising:

[0194] The blood pump includes:

[0195] An impeller, configured to be placed inside the subject's body and configured to rotate, in order to pump blood through the subject's body;

[0196] A frame, configured to be positioned around the impeller; and

[0197] One or more thrust bearings are configured to be disposed outside the subject's body, wherein the resistance to the thrust generated by the rotation of the impeller is provided solely by one or more thrust bearings disposed outside the subject's body.

[0198] Inventive Concept 15. A method comprising:

[0199] The impeller of the blood pump was placed inside the subject's body, surrounded by a frame; and

[0200] The impeller is driven by rotating it to pump blood through the subject's body. The resistance to the thrust generated by the rotation of the impeller is provided only by one or more thrust bearings located outside the subject's body.

[0201] Inventive Concept 16. An apparatus comprising:

[0202] Blood pump tubing;

[0203] A blood pump, configured to be located within a blood pump tube and configured to pump blood through the blood pump tube;

[0204] At least one blood pressure measuring tube, the at least one blood pressure measuring tube defining an opening at its distal end and configured to extend to at least the outer surface of a blood pump tube, such that the opening at the distal end of the blood pressure measuring tube is in direct fluid communication with the blood flow of a subject outside the blood pump tube; and

[0205] At least one pressure sensor is configured to measure the blood flow pressure of a subject outside the blood pump tube by measuring blood pressure inside the blood pressure measuring tube.

[0206] Inventive Concept 17. The device according to Inventive Concept 16, wherein the blood pump includes an impeller configured to pump blood through a blood pump tube by rotation.

[0207] Inventive Concept 18. The device according to Inventive Concept 16, wherein the blood pressure measuring tube is configured to extend from the proximal end of the blood pump tube along the outer surface of the blood pump tube to an opening at the distal end of the blood pressure measuring tube.

[0208] Inventive Concept 19. The device according to Inventive Concept 16 further includes at least one computer processor configured to receive an indication of blood pressure measured in a blood pressure measuring tube and configured to control the pumping of blood through a blood pump in response to blood pressure measured in a blood pump tube.

[0209] Inventive Concept 20. An apparatus according to any one of Inventive Concepts 16-19, wherein at least one blood pressure measuring tube includes at least one left ventricular blood pressure measuring tube, the left ventricular blood pressure measuring tube being configured to extend to the outer surface of a blood pump tube at a location near the blood pump along a tube configured to be in the left ventricle of a subject, and wherein a pressure sensor is configured to measure the left ventricular pressure of the subject by measuring the blood pressure within the left ventricular blood pressure measuring tube.

[0210] Inventive Concept 21. The device according to Inventive Concept 20, wherein at least one blood pressure measuring tube comprises two or more left ventricular blood pressure measuring tubes, the left ventricular blood pressure measuring tubes being configured to extend to the outer surface of a blood pump tube near a blood pump tube configured to be in the left ventricle of a subject, and wherein at least one pressure sensor is configured to measure the left ventricular pressure of the subject by measuring blood pressure within at least one of the left ventricular blood pressure measuring tubes.

[0211] Inventive Concept 22. The device based on Inventive Concept 21,

[0212] At least one of the pressure sensors is configured to measure blood pressure in each of two or more left ventricular blood pressure measuring tubes.

[0213] The device also includes at least one computer processor, which is configured to:

[0214] Receives indications of blood pressure measured in each of two or more left ventricular blood pressure measuring tubes.

[0215] In response, it is determined that the opening of one of two or more left ventricular blood pressure measuring tubes is blocked, and

[0216] In response, the subject's left ventricular pressure is determined based on blood pressure measured in one of two or more left ventricular blood pressure measuring tubes.

[0217] Inventive Concept 23. The device according to Inventive Concept 20, wherein at least one blood pressure measuring tube further includes at least one aortic blood pressure measuring tube, the aortic blood pressure measuring tube being configured to extend along the outer surface of a blood pump tube configured to be within the aorta of the subject, and wherein a pressure sensor is configured to measure the subject's aortic pressure by measuring blood pressure within the aortic blood pressure measuring tube.

[0218] Inventive Concept 24. The device according to Inventive Concept 23, wherein at least one aortic blood pressure measuring tube comprises two or more aortic blood pressure measuring tubes configured to extend along the outer surface of a blood pump tube configured to be within the aorta of a subject, and wherein at least one pressure sensor is configured to measure the subject's aortic pressure by measuring blood pressure within the at least one aortic blood pressure measuring tube.

[0219] Inventive Concept 25. An apparatus according to any one of Inventive Concepts 16-19, wherein at least one blood pressure measuring tube includes at least one aortic blood pressure measuring tube configured to extend along the outer surface of a blood pump tube configured to be within the aorta of a subject, and wherein a pressure sensor is configured to measure the aortic pressure of the subject by measuring blood pressure within the aortic blood pressure measuring tube.

[0220] Inventive Concept 26. The device according to Inventive Concept 25, wherein at least one aortic blood pressure measuring tube comprises two or more aortic blood pressure measuring tubes configured to extend along the outer surface of a blood pump tube configured to be within the aorta of a subject, and wherein at least one pressure sensor is configured to measure the aortic pressure of the subject by measuring the blood pressure within at least one aortic blood pressure measuring tube.

[0221] Inventive Concept 27. The device based on Inventive Concept 26,

[0222] At least one of the pressure sensors is configured to measure blood pressure in each of two or more aortic blood pressure measuring tubes.

[0223] The device also includes at least one computer processor, which is configured to:

[0224] Receives indications of blood pressure measured in each of two or more aortic blood pressure measuring tubes.

[0225] In response, it is determined that the opening of one of two or more aortic blood pressure measuring tubes is blocked, and

[0226] In response, the subject's aortic pressure is determined based on blood pressure measured in one of two or more aortic blood pressure measuring tubes.

[0227] Inventive Concept 28. The device according to any one of Inventive Concepts 16-19, wherein the blood pressure measuring tube is configured to extend from the outside of the subject's body to an opening at a distal end, and wherein the at least one pressure sensor is configured to be disposed outside the subject's body.

[0228] Inventive Concept 29. The device according to Inventive Concept 28, wherein the blood pump includes an impeller disposed on an axial shaft, the impeller being configured to pump blood from the left ventricle to the aorta by rotation, wherein the device further includes:

[0229] A motor, which is located outside the subject's body and configured to drive an impeller to rotate;

[0230] A drive cable extending from outside the subject's body to an axial axis and configured to transmit rotational motion from a motor to an impeller via rotation; and

[0231] The outer tube, configured to extend from outside the subject's body into the blood pump tubing,

[0232] The drive cable and blood pressure measuring tube are configured to be housed inside the outer tube.

[0233] Inventive Concept 30. The device based on Inventive Concept 29,

[0234] The at least one blood pressure measuring tube includes at least one left ventricular blood pressure measuring tube, the left ventricular blood pressure measuring tube being configured to extend to the outer surface of the blood pump tube at a location near the blood pump along a blood pump tube configured to be in the left ventricle of the subject, and wherein the at least one pressure sensor is configured to measure the left ventricular pressure of the subject by measuring the blood pressure within the left ventricular blood pressure measuring tube;

[0235] The device also includes an aortic blood pressure measuring tube that defines an opening at its distal end and is configured to extend from the outside of the subject's body into the subject's aorta, such that the opening at the distal end of the blood pressure measuring tube is in direct fluid communication with the subject's aortic blood flow.

[0236] At least one of the pressure sensors is also configured to measure the subject's aortic pressure by measuring the blood pressure within the aortic blood pressure measuring tube.

[0237] Inventive Concept 31. The device based on Inventive Concept 29,

[0238] The at least one blood pressure measuring tube includes at least one left ventricular blood pressure measuring tube, the left ventricular blood pressure measuring tube being configured to extend to the outer surface of the blood pump tube at a location near the blood pump along a blood pump tube configured to be in the left ventricle of the subject, and wherein the at least one pressure sensor is configured to measure the left ventricular pressure of the subject by measuring the blood pressure within the left ventricular blood pressure measuring tube;

[0239] The device also includes an aortic blood pressure measuring tube that defines an opening at its distal end and is configured to extend from outside the subject's body to a portion of the outer surface of an outer tube disposed within the blood pump tube, such that the opening at the distal end of the blood pressure measuring tube is in direct fluid communication with the subject's aortic blood flow.

[0240] The at least one pressure sensor is also configured to measure the subject's aortic pressure by measuring the blood pressure within the aortic blood pressure measuring tube.

[0241] Inventive Concept 32. The device according to Inventive Concept 29, wherein an outer tube defines a groove in a portion of the outer surface of the outer tube configured to be disposed within a blood pump tube, and wherein, during insertion of the ventricular assist device into the body of a subject, a portion of the blood pressure measuring tube configured to extend from within the blood pump tube to the outer surface of the blood pump tube is configured to be disposed within the groove, such that this portion of the blood pressure measuring tube does not protrude from the outer surface of the outer tube.

[0242] Inventive Concept 33. The device according to Inventive Concept 28, wherein the diameter of the blood pressure measuring tube is less than 0.5 mm, at least in the distal portion of the blood pressure measuring tube.

[0243] Inventive Concept 34. The device according to Inventive Concept 33, wherein the diameter of the blood pressure measuring tube is greater than 0.2 mm, at least in the distal portion of the blood pressure measuring tube.

[0244] Inventive Concept 35. A method comprising:

[0245] Inserted into the subject's body:

[0246] Blood pump tubing

[0247] The blood pump installed inside the blood pump tubing, and

[0248] At least one blood pressure measuring tube, the blood pressure measuring tube defining an opening at its distal end and extending to at least the outer surface of a blood pump tube, such that the opening at the distal end of the blood pressure measuring tube is in direct fluid communication with the blood flow of a subject outside the blood pump tube;

[0249] A blood pump is used to pump blood through the blood pump tubing; and

[0250] The blood flow pressure of the subject outside the blood pump tube is measured by measuring the blood pressure inside the blood pressure measuring tube.

[0251] Inventive Concept 36. An apparatus comprising:

[0252] The blood pump includes:

[0253] Tube;

[0254] An impeller, configured to be disposed within a tube and configured to rotate, in order to pump blood through the tube;

[0255] A frame, which is arranged around the impeller; and

[0256] A stator configured to reduce the rotational flow component of the blood flow generated by the rotation of the impeller, the stator comprising:

[0257] Multiple pillars, which are integral with the frame and are curved; and

[0258] A flexible material is attached to a bending support to form multiple bending protrusions.

[0259] Inventive Concept 37. The device according to Inventive Concept 36, wherein the curvature of the curved protrusion is opposite to the direction of rotation of the impeller.

[0260] Inventive Concept 38. According to the device of Inventive Concept 36, the curvature of the curved protrusion is such that from the distal end of the curved protrusion to the proximal end of the curved protrusion, the curved protrusion gradually becomes closer to being parallel to the longitudinal axis of the frame.

[0261] Inventive Concept 39. The device according to Inventive Concept 36, wherein a flexible material is shaped to define an inner cavity passing through it.

[0262] Inventive Concept 40. A method comprising:

[0263] A blood pump is inserted into the subject's body. The blood pump includes:

[0264] Tube,

[0265] The impeller is configured to be disposed inside the tube.

[0266] The frame, which is set around the impeller, and

[0267] A stator, comprising a plurality of curved struts integral with a frame, and a flexible material connected to the curved struts to form a plurality of curved protrusions; and

[0268] The impeller pumps blood through the tube, and the stator reduces the swirling component of the blood flow generated by the rotation of the impeller.

[0269] Inventive Concept 41. An apparatus comprising:

[0270] A ventricular assist device, comprising:

[0271] Axial axis;

[0272] An impeller, which is mounted on an axial shaft and configured to be placed in the left ventricle of the subject;

[0273] A motor, configured to be located outside the subject's body, and configured to drive an impeller by rotating it to pump blood from the left ventricle to the subject's aorta;

[0274] A drive cable configured to extend from outside the subject's body to an axial axis, the drive cable being configured to transmit rotational motion from a motor to an impeller by rotation, the drive cable comprising a first portion configured to be at least partially disposed within the subject's aortic arch and a second portion configured to be at least partially disposed within the subject's descending aorta.

[0275] The first portion of the drive cable includes a first number of wires arranged in a coiled configuration, and the second portion of the drive cable includes a second number of wires arranged in a coiled configuration, the first number being less than the second number.

[0276] Inventive Concept 42. The device according to Inventive Concept 41, wherein the length of the first portion of the drive cable is between 20 cm and 40 cm.

[0277] Inventive Concept 43. The device according to Inventive Concept 41, wherein the length of the second portion of the drive cable is between 60 cm and 100 cm.

[0278] Inventive Concept 44. The device according to Inventive Concept 41, wherein a first portion of the drive cable includes wires arranged in a coiled configuration between 4 and 8 wires, and a second portion of the drive cable includes wires arranged in a coiled configuration between 8 and 12 wires.

[0279] Inventive Concept 45. An apparatus comprising:

[0280] The blood pump includes:

[0281] Axial axis;

[0282] An impeller, which is mounted on an axial shaft;

[0283] A motor is configured to be located outside the subject's body and is configured to drive an impeller by rotating it to pump blood through the subject's body.

[0284] A drive cable configured to extend from the outside of the subject's body to an axial axis, the drive cable being configured to transmit rotational motion from a motor to an impeller by rotation, the drive cable including a first portion configured to be at least partially disposed within a curved portion of the subject's vascular system, and a second portion configured to be at least partially disposed within a straight portion of the subject's vascular system.

[0285] The first portion of the drive cable includes a first number of wires arranged in a coiled configuration, and

[0286] The second part of the drive cable includes a second number of wires arranged in a coiled configuration, the first number being less than the second number.

[0287] Inventive Concept 46. An apparatus comprising:

[0288] The blood pump includes:

[0289] Axial axis;

[0290] An impeller, which is mounted on an axial shaft;

[0291] A motor configured to be disposed outside the subject's body and configured to drive an impeller by rotating it in a given direction of rotation to pump blood from the distal end of the impeller to the proximal end of the impeller;

[0292] A drive cable, configured to extend from outside the subject's body to an axial axis, is configured to transmit rotational motion from a motor to an impeller via rotation.

[0293] At least a portion of the drive cable includes a plurality of wires arranged in a coiled configuration, such that in response to rotation of the drive cable in a given rotational direction, the plurality of wires arranged in the coiled configuration are at least partially unwound, causing that portion of the drive cable to shorten axially.

[0294] Inventive Concept 47. The device according to Inventive Concept 46, wherein an impeller is configured to pump blood from a first position to a second position, and wherein the impeller is configured to move axially back and forth in response to periodic changes in the pressure difference between the first and second positions.

[0295] Inventive Concept 48. A method comprising:

[0296] A blood pump is inserted into the subject's body. The blood pump includes:

[0297] Axial axis

[0298] The impeller, which is mounted on an axial shaft, and

[0299] A drive cable extends from outside the subject's body to the axial axis; and

[0300] The impeller is driven by transmitting rotational motion to it via a drive cable to pump blood from the distal end of the impeller to the proximal end of the impeller. At least a portion of the drive cable includes multiple wires arranged in a coiled configuration, such that in response to rotation of the drive cable in a given direction of rotation, the multiple wires arranged in the coiled configuration are at least partially unwound, causing that portion of the drive cable to shorten axially.

[0301] Inventive Concept 49. An apparatus comprising:

[0302] The blood pump includes:

[0303] Axial axis;

[0304] An impeller, which is mounted on an axial shaft;

[0305] A motor, configured to be disposed outside the subject's body, and configured to drive an impeller to pump blood in a proximal direction by rotating the impeller in a given direction of rotation;

[0306] A drive cable configured to extend from a proximal end of a drive cable disposed outside the subject's body to a distal end of a drive cable, the drive cable being coupled to an axial shaft, the drive cable being configured to transmit rotational motion from a motor to an impeller by rotation;

[0307] The outer tube, which is positioned around the drive cable; and

[0308] The fluid is disposed between the outer tube and the drive cable.

[0309] At least a portion of the drive cable includes a plurality of wires arranged in a coiled configuration such that, in response to rotation of the drive cable in a given direction of rotation, the plurality of wires are configured to pump fluid toward the proximal end of the drive cable.

[0310] Inventive Concept 50. A method comprising:

[0311] A blood pump is inserted into the subject's body. The blood pump includes:

[0312] Axial axis

[0313] The impeller is mounted on the axial shaft.

[0314] The drive cable extends from the outside of the subject's body to the axial axis.

[0315] The outer tube, which is positioned around the drive cable, and

[0316] A fluid, which is disposed between the drive cable and the outer tube; and

[0317] The impeller is driven by transmitting rotational motion to it via a drive cable to pump blood from the distal end of the impeller to the proximal end of the impeller. At least a portion of the drive cable includes multiple wires arranged in a coiled configuration such that, in response to rotation of the drive cable in a given direction of rotation, the multiple wires are configured to pump fluid toward the proximal end of the drive cable.

[0318] Inventive Concept 51. An apparatus comprising:

[0319] The blood pump includes:

[0320] impeller;

[0321] A motor configured to drive an impeller to pump blood by rotating an impeller, the impeller being configured to move axially in response to changes in pressure differential that the impeller resists in pumping blood;

[0322] The impeller is connected to the magnet, and the axial movement of the impeller causes the magnet to move axially.

[0323] A sensor configured to detect magnetic flux generated by a magnet, and configured to generate a sensor signal in response thereto; and

[0324] A computer processor configured to receive sensor signals and to generate an output in response thereto.

[0325] Inventive Concept 52. The device according to Inventive Concept 51, wherein a computer processor is configured to generate an output indicating the cardiac cycle of a subject in response to receiving a sensor signal.

[0326] Inventive Concept 53. The device according to Inventive Concept 51, wherein a computer processor is configured to determine the left ventricular pressure of a subject based at least in part on sensor signals.

[0327] Inventive Concept 54. An apparatus according to any one of Inventive Concepts 51-53, wherein a computer processor is configured to change the rotational speed of an impeller based at least in part on sensor signals.

[0328] Inventive Concept 55. A device according to Inventive Concept 54, wherein the computer processor is configured as follows:

[0329] The left ventricular pressure of the subject is determined at least in part based on sensor signals, and

[0330] The impeller rotation rate is changed at least in part based on the determined left ventricular pressure.

[0331] Inventive Concept 56. The device according to Inventive Concept 55, wherein a computer processor is configured to reduce the rotational rate of an impeller in response to determining that the left ventricular pressure of a subject has decreased.

[0332] Inventive Concept 57. An apparatus comprising:

[0333] The blood pump includes:

[0334] impeller;

[0335] A motor configured to drive an impeller to pump blood by rotating the impeller, the impeller being configured to move axially in response to changes in pressure differential that the impeller resists in pumping blood;

[0336] A sensor configured to detect indications of axial movement of the impeller, and configured to generate a sensor signal in response thereto; and

[0337] A computer processor configured to receive sensor signals and to generate an output in response thereto.

[0338] Inventive Concept 58. A method comprising:

[0339] A blood pump, which includes an impeller, is placed inside the subject's body.

[0340] The impeller is driven to pump blood by rotating it, and the impeller is configured to move axially in response to changes in the pressure difference that the impeller pumps blood against.

[0341] The sensor detects indications of the impeller's axial movement and generates a sensor signal in response; and

[0342] It receives sensor signals and generates an output in response.

[0343] Inventive Concept 59. An apparatus comprising:

[0344] The blood pump includes:

[0345] impeller;

[0346] frame,

[0347] The impeller and frame are configured to be inserted into the subject's body such that, within the subject's body, the frame is positioned around the impeller; and

[0348] A computer processor configured to drive a motor unit to simultaneously (a) drive an impeller to pump blood through the subject's body by rotating the impeller, and (b) drive the impeller to move axially within the frame in a back-and-forth motion.

[0349] Inventive Concept 60. A method comprising:

[0350] A blood pump, comprising an impeller and a frame, is placed into the subject's body, with the frame positioned around the impeller; and

[0351] at the same time:

[0352] The impeller is driven to rotate to pump blood through the subject's body;

[0353] as well as

[0354] The impeller is driven to move axially within the frame in a reciprocating motion.

[0355] Inventive Concept 61. An apparatus comprising:

[0356] The blood pump includes:

[0357] Axial axis;

[0358] An impeller, which is mounted on an axial shaft and configured to be placed in the left ventricle of the subject;

[0359] A motor, configured to be located outside the subject's body and configured to drive an impeller to rotate;

[0360] A drive cable configured to extend from the subject's outside body to an axial axis via the subject's aortic arch, the drive cable being configured to transmit rotational motion from a motor to an impeller by rotation;

[0361] A tube, the drive cable being configured to be disposed within the tube during rotation of the drive cable, the tube being configured to remain stationary during rotation of the drive cable; and

[0362] Multiple ball bearings are configured to be disposed between the drive cable and the tube to reduce friction between the drive cable and the tube during movement of the drive cable relative to the tube.

[0363] Inventive Concept 62. The device according to Inventive Concept 61, wherein a ball bearing is configured to be disposed between a drive cable and a tube during rotation of the impeller, at least at the portion of the drive cable and tube configured to be disposed within the aortic arch of the subject.

[0364] Inventive Concept 63. An apparatus comprising:

[0365] The blood pump includes:

[0366] Axial axis;

[0367] An impeller, which is mounted on an axial shaft and configured to be placed inside the subject's body;

[0368] A motor, configured to be positioned outside the subject's body;

[0369] A drive cable configured to extend from outside the subject's body to an axial axis;

[0370] Exactly two drive magnets are housed within a drive magnet housing, which is connected to a motor; and

[0371] A driven magnet is connected to a drive cable and positioned between drive magnets such that there is an axial overlap between the drive magnets and the driven magnets. The driven magnet defines a single north pole and a single south pole separated along the axial length of the driven magnet. The motor is configured to rotate the driven magnet by rotating the drive magnet housing in order to rotate the drive cable to transmit rotational motion to the impeller.

[0372] Inventive Concept 64. A method comprising:

[0373] A blood pump is inserted into the subject's body. The blood pump includes:

[0374] Axial axis

[0375] The impeller, which is mounted on an axial shaft, and

[0376] A drive cable extends from outside the subject's body to the axial axis; and

[0377] The impeller is driven to rotate in the following way:

[0378] A motor is used to rotate exactly two drive magnets housed in a drive magnet housing, which is connected to the motor.

[0379] A driving magnet is configured to drive a driven magnet to rotate, the driven magnet being coupled to a driving cable and positioned between the driving magnets such that there is an axial overlap between the driving magnet and the driven magnet, the driven magnet defining a single north pole and a single south pole separated along the axial length of the driven magnet.

[0380] Inventive Concept 65. An apparatus comprising:

[0381] The blood pump includes:

[0382] Axial axis;

[0383] An impeller, which is mounted on an axial shaft and configured to be placed inside the subject's body;

[0384] A motor, configured to be positioned outside the subject's body;

[0385] A drive cable configured to extend from outside the subject's body to an axial axis;

[0386] Exactly two driven magnets, each housed within a driven magnet housing connected to a drive cable; and

[0387] A drive magnet is coupled to a motor and positioned between driven magnets such that there is an axial overlap between the driven magnets and the drive magnet. The drive magnet defines a single north pole and a single south pole separated along the axial length of the drive magnet. The motor is configured to rotate the driven magnet by rotating the drive magnet in order to rotate the drive cable to transmit rotational motion to the impeller.

[0388] Inventive Concept 66. A method comprising:

[0389] A blood pump is inserted into the subject's body. The blood pump includes:

[0390] Axial axis

[0391] The impeller, which is mounted on an axial shaft, and

[0392] A drive cable extends from outside the subject's body to an axial axis; and drives the impeller to rotate in the following manner:

[0393] A motor is used to rotate a drive magnet connected to the motor, the drive magnet defining a single north pole and a single south pole separated along the axial length of the drive magnet.

[0394] The driving magnet is configured to drive the driven magnet to rotate. The driven magnet includes exactly two driven magnets disposed in a driven magnet housing, which is connected to a driving cable and disposed around the driving magnet.

[0395] Inventive Concept 67. An apparatus comprising:

[0396] The blood pump includes:

[0397] Axial axis;

[0398] An impeller, which is mounted on an axial shaft and configured to be placed inside the subject's body;

[0399] A motor, configured to be disposed outside the subject's body, and configured to drive an impeller to pump blood by rotating the impeller in a given direction of rotation;

[0400] A drive cable, configured to extend from outside the subject's body to an axial axis, is configured to transmit rotational motion from a motor to an impeller via rotation, and comprises multiple wires arranged in a coiled configuration and connected to the axial axis.

[0401] The axial shaft defines a groove at the junction between the drive cable and the axial shaft. The groove is configured such that the stress generated by the cable at the junction is distributed over the radius of the groove.

[0402] Inventive Concept 68. An apparatus comprising:

[0403] The blood pump includes:

[0404] Axial axis;

[0405] An impeller, which is mounted on an axial shaft and configured to be placed inside the subject's body;

[0406] A motor, configured to be disposed outside the subject's body, and configured to drive an impeller to pump blood by rotating the impeller in a given direction of rotation;

[0407] A drive cable, configured to extend from outside the subject's body to an axial axis, is configured to transmit rotational motion from a motor to an impeller via rotation, and comprises multiple wires arranged in a coiled configuration and connected to the axial axis.

[0408] The coiled wire is shaped such that as the coiled wire approaches the junction between the drive cable and the axial shaft, the wire pitch increases, thereby reducing the stress at the location where the drive cable is connected to the axial shaft compared to the case where the wire pitch is not increased.

[0409] Inventive Concept 69. An apparatus comprising:

[0410] The blood pump includes:

[0411] Axial axis;

[0412] An impeller, which is mounted on an axial shaft and configured to be placed inside the subject's body;

[0413] A motor, configured to be disposed outside the subject's body, and configured to drive an impeller to pump blood by rotating the impeller in a given direction of rotation;

[0414] A drive cable, configured to extend from outside the subject's body to an axial axis, is configured to transmit rotational motion from a motor to an impeller via rotation.

[0415] The drive cable includes a first portion and a second portion. The first portion includes a first number of wires arranged in a coiled configuration, and the second portion includes a second number of wires arranged in a coiled configuration, wherein the first number is less than the second number.

[0416] The interface component connects the first and second parts of the drive cable to each other.

[0417] The interface component defines a groove at the junction between at least one of the drive cable portions and the interface component, the groove being configured such that the stress generated by the wire at the junction is distributed over the radius of the groove.

[0418] Inventive Concept 70. An apparatus comprising:

[0419] The blood pump includes:

[0420] Axial axis;

[0421] An impeller, which is mounted on an axial shaft and configured to be placed inside the subject's body;

[0422] A motor, configured to be disposed outside the subject's body, and configured to drive an impeller to pump blood by rotating the impeller in a given direction of rotation;

[0423] A drive cable, configured to extend from outside the subject's body to an axial axis, is configured to transmit rotational motion from a motor to an impeller via rotation.

[0424] The drive cable includes a first portion and a second portion. The first portion includes a first number of wires arranged in a coiled configuration, and the second portion includes a second number of wires arranged in a coiled configuration, wherein the first number is less than the second number.

[0425] The interface component connects the first and second parts of the drive cable to each other.

[0426] At least one portion of the drive cable has its coiled wire shaped such that the wire pitch increases as the coiled wire approaches the interface component, thereby reducing the stress at the point where the wire is connected to the interface component compared to the case where the wire pitch does not increase.

[0427] Inventive Concept 71. An apparatus comprising:

[0428] A ventricular assist device, comprising:

[0429] A tube configured to pass through the aortic valve of a subject, such that the proximal portion of the tube is located within the subject's aorta and the distal portion of the tube is located within the subject's left ventricle, the tube defining one or more blood inlet openings within the distal portion of the tube and one or more blood outlet openings within the proximal portion of the tube.

[0430] A blood pump, configured to be disposed within a tube and configured to pump blood from the left ventricle into the tube through one or more blood inlet openings and to pump blood out of the tube into the aorta through one or more blood outlet openings; and

[0431] A radially expandable, non-invasive distal end portion is configured to be disposed distally in the left ventricle of a subject relative to one or more blood inlet openings. The distal end portion is configured to be inserted into the left ventricle with a radially constrained configuration and to present a non-radially constrained configuration within the left ventricle of the subject, wherein at least a radially expandable portion of the distal end portion is radially expanded relative to the radially constrained configuration of the distal end portion.

[0432] Inventive Concept 72. The device according to Inventive Concept 71, wherein the distal end portion comprises a braided shape memory alloy, which is at least partially covered with a blood-impermeable material.

[0433] Inventive Concept 73. The device according to Inventive Concept 71, wherein the distal end portion is configured such that, in a non-radial constraint configuration of the distal end portion, the radially expandable portion of the distal end portion separates one or more blood inlet openings from the interventricular septum in the left ventricle.

[0434] Inventive Concept 74. The device according to Inventive Concept 71, wherein the distal end portion is configured such that, in a non-radial constraint configuration of the distal end portion, the radially expandable portion of the distal end portion separates one or more blood inlet openings from the chordae tendineae in the left ventricle.

[0435] Inventive Concept 75. The device according to Inventive Concept 71, wherein the distal end portion is configured such that, in a non-radial constraint configuration of the distal end portion, the radially expandable portion of the distal end portion separates one or more blood inlet openings from the papillary muscles in the left ventricle.

[0436] Inventive Concept 76. The device according to Inventive Concept 71, wherein the distal end portion is configured such that, in a non-radial constraint configuration of the distal end portion, the radially expandable portion of the distal end portion separates one or more blood inlet openings from the apex of the left ventricle.

[0437] Inventive Concept 77. The device according to Inventive Concept 71, wherein the distal end portion is configured such that, in a non-radial constraint configuration of the distal end portion, the radially expandable portion of the distal end portion separates one or more blood inlet openings from the internal structure of the left ventricle in three dimensions.

[0438] Inventive Concept 78. The device according to Inventive Concept 71, wherein the distal end portion is configured such that, in a non-radial constraint configuration of the distal end portion, the radially expandable portion of the distal end portion directs blood flow from the left ventricle into one or more blood inlet openings.

[0439] Inventive Concept 79. An apparatus according to any one of Inventive Concepts 71-78, wherein:

[0440] In the radially constrained configuration of the distal end portion, the distal region of the distal end portion is configured to be at least semi-rigid and is shaped to converge radially toward the distal end of the distal end portion along the longitudinal direction.

[0441] The ventricular assist device is configured to be inserted into the subject's body through a perforation in the subject's body, and

[0442] During the insertion of a ventricular assist device, the distal region of the distal end portion is configured to act as a dilator by enlarging the perforation.

[0443] Inventive Concept 80. The device according to any one of Inventive Concepts 71-78, wherein the distal end portion is configured such that, in a non-radial constraint configuration of the distal end portion, the distal end of the distal end portion is enclosed within a radially expandable portion of the distal end portion.

[0444] Inventive Concept 81. The device according to Inventive Concept 80, wherein the distal end portion is configured to prevent the distal end portion from becoming entangled with the chordae tendineae of the left ventricle by enclosing the distal end portion within a radially expandable portion of the distal end.

[0445] Inventive Concept 82. The device according to Inventive Concept 80, wherein the distal end portion is configured to prevent damage to the internal structure of the left ventricle by the distal end portion being enclosed within a radially expandable portion of the distal end portion.

[0446] Inventive Concept 83. The device according to Inventive Concept 80, wherein the distal end of the distal end portion is configured to be enclosed within the radially expandable portion of the distal end portion by flipping the distal end of the distal end portion.

[0447] Inventive Concept 84. The device according to Inventive Concept 80, wherein the distal end of the distal end portion is configured such that the distal end is disposed within the radially expandable portion of the distal end portion and is enclosed within the radially expandable portion of the distal end portion by retracting the distal end of the distal end portion proximally.

[0448] Inventive Concept 85. An apparatus comprising:

[0449] A ventricular assist device, configured to be inserted into a subject's body via a perforation, comprising:

[0450] A tube configured to pass through the aortic valve of a subject, such that the proximal portion of the tube is located within the subject's aorta and the distal portion of the tube is located within the subject's left ventricle, the tube defining one or more blood inlet openings within the distal portion of the tube and one or more blood outlet openings within the proximal portion of the tube.

[0451] A blood pump configured to be disposed within a tube and to pump blood from the left ventricle into the tube through one or more blood inlet openings and to pump blood out of the tube into the aorta through one or more blood outlet openings; and

[0452] The distal end portion is configured as follows:

[0453] It has a radially constrained configuration in which the distal region of the distal distal portion is at least partially rigid and is shaped to converge radially toward the distal end of the distal distal portion along the longitudinal direction. This distal region is configured to act as a dilator by widening the perforation during insertion of the ventricular assist device into the subject's body.

[0454] Having a non-radial constraint configuration, the distal terminal region is configured to present the non-radial constraint configuration in the left ventricle of the subject, wherein the radially expandable portion of the distal terminal portion in the non-radial constraint configuration is configured to be non-damaging and is configured to separate one or more blood inlet openings from the internal structure of the subject's left ventricle.

[0455] Inventive Concept 86. A method comprising:

[0456] Operator of the blood pump, which includes:

[0457] Axial axis

[0458] An impeller, which is mounted on an axial shaft and positioned in the left ventricle of the subject;

[0459] A motor, located outside the subject's body, is configured to drive an impeller to rotate.

[0460] A drive cable extends from outside the subject's body, through the subject's aortic arch, to an axial axis, and is configured to transmit rotational motion from a motor to an impeller via rotation.

[0461] A tube, in which the drive cable is disposed, is configured to remain stationary during rotation of the drive cable; and

[0462] While operating the blood pump, fluid is pumped into the space between the drive cable and the tube, so that the fluid fills the space between the drive cable and the tube, but the fluid is not released into the subject's bloodstream.

[0463] Inventive Concept 87. A method comprising:

[0464] Operator of the blood pump, which includes:

[0465] Axial axis

[0466] An impeller, mounted on an axial shaft and positioned within the left ventricle of the subject,

[0467] A motor, located outside the subject's body, is configured to drive an impeller to rotate.

[0468] A drive cable extends from outside the subject's body, through the subject's aortic arch, to an axial axis, and is configured to transmit rotational motion from a motor to an impeller via rotation.

[0469] The drive cable is housed within the tube, which is configured to remain stationary during the rotation of the drive cable.

[0470] Before operating the blood pump, fluid is pumped into the space between the drive cable and tubing, filling the space without releasing fluid into the subject's bloodstream; and

[0471] During operation of the blood pump, fluid is left in the space between the drive cables and tubing.

[0472] Inventive Concept 88. An apparatus comprising:

[0473] A left ventricular assist device configured to assist the operation of the left ventricle in a subject, the left ventricular assist device comprising:

[0474] A tube configured to pass through the subject's aortic valve, such that the proximal portion of the tube is at least partially located within the subject's ascending aorta, and the distal portion of the tube is at least partially located within the subject's left ventricle.

[0475] A frame, disposed within the distal portion of the tube, is configured to hold the distal portion of the tube in the open position.

[0476] The frame is not located within the proximal portion of the tube, and the proximal portion of the tube is therefore configured to collapse inward in response to pressure outside the proximal portion of the tube exceeding pressure inside the proximal portion of the tube.

[0477] A pump, disposed within a frame and configured to pump blood from the subject's left ventricle to the subject's aorta via a tube, such that the proximal portion of the tube remains open when the blood pressure generated by the pump within the proximal portion exceeds the subject's aortic pressure outside the proximal portion of the tube; and

[0478] Multiple elongated connecting elements are disposed within the proximal portion of the tube, such that when the proximal portion of the tube collapses inward, corresponding portions of the circumference of the tube form contacting cusps.

[0479] Inventive Concept 89. The device according to Inventive Concept 88 further includes a computer processor configured to control the pumping of blood through the tube by the blood pump, such that the blood pressure generated by the blood pump in the tube exceeds the subject's systolic aortic pressure and is less than the subject's diastolic aortic pressure.

[0480] Inventive Concept 90. The device according to Inventive Concept 88 further includes a pressure sensor configured to measure the aortic blood pressure of a subject, wherein a computer processor is configured to receive an indication of the measured aortic blood pressure and is configured to control the pumping of blood through the tube by a blood pump in response to the measured aortic blood pressure.

[0481] Inventive Concept 91. The device according to Inventive Concept 88 further includes a pressure sensor configured to measure the left ventricular blood pressure of a subject, wherein a computer processor is configured to receive an indication of the measured left ventricular blood pressure and is configured to control the pumping of blood through a tube by a blood pump in response to the measured left ventricular blood pressure.

[0482] Inventive Concept 92. An apparatus for use with a conveying device, the apparatus comprising:

[0483] impeller;

[0484] A frame, which is set around the impeller,

[0485] The impeller and frame are configured to be inserted into the blood vessel of the subject via a delivery device, while being arranged in a radially constrained configuration, and are configured to present a non-radially constrained configuration upon release from the delivery device; and

[0486] A connecting element comprising a first portion disposed on an impeller and a second portion disposed on a frame and configured to engage the first portion, the connecting element being configured to facilitate radial contraction of the impeller by retaining the end of the impeller, such that the impeller can extend axially without radially contracting the frame.

[0487] Inventive Concept 93. An apparatus comprising:

[0488] Blood pump tubing:

[0489] An impeller is configured to be disposed within a blood pump tube and configured to pump blood from a first position to a second position by pumping blood through the blood pump tube.

[0490] A motor, which is located outside the subject's body and configured to drive an impeller to rotate;

[0491] A drive cable extends from outside the subject's body to an axial axis and is configured to transmit rotational motion from a motor to an impeller via rotation.

[0492] An outer tube, disposed around the drive cable, configured to extend from outside the subject's body into the blood pump tubing, defining a first opening and a second opening on a portion of the outer tube disposed within the blood pump tubing; and

[0493] A flow obstruction is disposed on a first opening such that the first opening is configured as a stagnation pressure tap and the second opening is configured as a static pressure tap.

[0494] At least one pressure sensor, configured to measure the pressure in a stagnation pressure measuring port and the pressure in a static pressure measuring port; and

[0495] A computer processor configured to determine the flow rate through the blood pump tubing based at least in part on the pressure measured in the stagnation pressure measuring port and the pressure measured in the hydrostatic pressure measuring port.

[0496] Inventive Concept 94. A method comprising:

[0497] A blood pump is inserted into the subject's body. The blood pump includes:

[0498] The impeller includes a proximal bushing and a distal bushing.

[0499] A frame, which is arranged around the impeller, includes a proximal bearing and a distal bearing, and

[0500] An axial shaft passes through the proximal and distal bearings of the frame, as well as the proximal and distal bushings of the impeller. The proximal bushing of the impeller is connected to the axial shaft, holding it in a fixed axial position relative to the axial shaft. The distal bushing of the impeller is not connected to the axial shaft, thus not holding it in a fixed axial position relative to the axial shaft.

[0501] While the impeller is inserted into the subject's body, the impeller is held in the radial constraint structure by the delivery conduit;

[0502] When the impeller is positioned within the subject's body, releasing the impeller from the conduit allows the distal bushing to slide along the axial axis, thereby causing the impeller to change from its radially constrained configuration to a non-radially constrained configuration; and

[0503] Blood is pumped through the subject's body using an impeller, which is configured with a non-radial constraint.

[0504] Inventive Concept 95. A method comprising:

[0505] The impeller of the ventricular assist device was placed in the left ventricle of the subject, and a frame was set around the impeller; and

[0506] The impeller is driven by rotating it to pump blood from the subject's left ventricle into the aorta.

[0507] The placement of the impeller within the left ventricle allows the impeller to move axially relative to the frame in response to periodic changes in the pressure difference between the left ventricle and the aorta.

[0508] Inventive Concept 96. A method comprising:

[0509] A blood pump is placed inside the subject's body. The blood pump includes:

[0510] An impeller having a frame disposed around it, the impeller including a proximal bushing and a distal bushing, and the frame including a proximal bearing and a distal bearing, and

[0511] An axial shaft passing through the proximal and distal bearings of the frame and the proximal and distal bushings of the impeller, the axial shaft being coupled to at least one of the proximal and distal bushings of the impeller such that the at least one bushing is held in an axially fixed position relative to the axial shaft, but not in an axially fixed position relative to the proximal and distal bearings; and

[0512] Blood is pumped through the subject's body using an impeller.

[0513] Inventive Concept 97. A method comprising:

[0514] The impeller of the blood pump was placed inside the subject's body, surrounded by a frame; and

[0515] The impeller is driven to pump blood through the subject's body without using any thrust bearings set inside the subject's body to provide resistance to the thrust generated by the rotation of the impeller.

[0516] The invention will be more fully understood from the following detailed description of embodiments thereof, taken in conjunction with the accompanying drawings, in which: Brief description of the attached diagram

[0517] Figure 1A and Figure 1B This is a schematic diagram of a ventricular assist device according to some applications of the present invention, wherein the distal end of the ventricular assist device is disposed in the left ventricle of a subject;

[0518] Figure 2A , Figure 2B and Figure 2C This is a schematic diagram of the pump section of a ventricular assist device according to some applications of the present invention;

[0519] Figure 3A , Figure 3B and Figure 3C This is a schematic diagram of the impeller of a ventricular assist device according to some applications of the present invention;

[0520] Figure 4 This is a schematic diagram of an impeller arranged within a frame of a ventricular assist device according to some applications of the present invention;

[0521] Figure 5A and Figure 5B This is a schematic diagram of the impeller and frame of a ventricular assist device in its non-radial constraint state and radial constraint state, respectively, according to some applications of the present invention.

[0522] Figure 5C This is a schematic diagram of a typical bearing assembly used in an axial impeller-based blood pump in the prior art;

[0523] Figure 6A and Figure 6B This is a schematic diagram of a ventricular assist device at various stages of the motion cycle of the impeller relative to the frame of the ventricular assist device according to some applications of the present invention.

[0524] Figure 6C This is a schematic diagram of the axial shaft receiving tube and the distal end portion of a ventricular assist device according to some applications of the present invention;

[0525] Figure 7This is a schematic diagram of the motor unit of a ventricular assist device according to some applications of the present invention;

[0526] Figure 8A and Figure 8B This is a schematic diagram of the motor unit of a ventricular assist device according to some applications of the present invention;

[0527] Figure 9 It is a graph indicating the change in the length of the drive cable of the ventricular assist device as the pressure gradient resisted by the impeller of the blood pump changes, as measured in experiments performed by the inventors of this application;

[0528] Figure 10A , Figure 10B and Figure 10C This is a schematic diagram of the drive cable of a ventricular assist device according to some applications of the present invention;

[0529] Figure 11A and Figure 11B This is a schematic diagram of an interface component according to some applications of the present invention, which forms an interface between corresponding portions of the drive cable of a ventricular assist device;

[0530] Figure 11C , Figure 11D and Figure 11E This is a schematic diagram of the junction between the drive cable and the axial shaft of a ventricular assist device according to some applications of the present invention;

[0531] Figure 12 This is a schematic diagram of a drive cable for a ventricular assist device according to some applications of the present invention, the drive cable including a friction-reducing element disposed around at least a portion of the drive cable;

[0532] Figure 13 This is a schematic diagram of the procedure for drive cables and / or radial bearings for a ventricular assist device according to some applications of the present invention;

[0533] Figure 14A and Figure 14B This is a schematic diagram of the frame of a ventricular assist device according to some applications of the present invention, with the stator connected to the proximal portion of the frame;

[0534] Figure 15A This is a schematic diagram of the flat outline of a ventricular assist device frame according to some applications of the present invention;

[0535] Figure 15B This is a schematic diagram showing an enlarged view of the proximal end of a ventricular assist device according to some applications of the present invention;

[0536] Figure 15CThis is a schematic diagram of the frame of a ventricular assist device according to some applications of the present invention, with the material defining the curved protrusions connected to the frame;

[0537] Figure 16A , Figure 16B , Figure 16C and Figure 16D This is a schematic diagram of a ventricular assist device including one or more blood pressure measuring tubes according to some applications of the present invention;

[0538] Figure 17A , Figure 17B and Figure 17C This is a schematic diagram of a ventricular assist device according to some applications of the present invention, including a pitot tube configured to measure blood flow through a tube of the device;

[0539] Figure 18 This is a schematic diagram of a ventricular assist device according to some applications of the present invention, wherein the distal portion of the device is a radially expandable, non-invasive distal portion;

[0540] Figure 19A and Figure 19B This is a schematic diagram of a ventricular assist device according to some applications of the present invention, wherein the distal portion of the device is a radially expandable, non-invasive distal portion;

[0541] Figure 20A and Figure 20B This is a schematic diagram of a ventricular assist device according to some applications of the present invention, wherein the distal portion of the device is a radially expandable, non-invasive distal portion;

[0542] Figure 21A , Figure 21B , Figure 21C and Figure 21D This is a schematic diagram of the distal end portion of a ventricular assist device according to some applications of the present invention;

[0543] Figure 22A and Figure 22B This is a schematic diagram of the distal end portion of a ventricular assist device in an axially reinforced configuration and a non-axially reinforced configuration, respectively, according to some applications of the present invention;

[0544] Figure 23A and Figure 23B This is a schematic diagram of the distal end portion of a ventricular assist device in a radially constrained configuration and a non-radially constrained configuration, respectively, according to some applications of the present invention;

[0545] Figure 24A and Figure 24B This is a schematic diagram of the distal end portion of a ventricular assist device in a radially constrained configuration and a non-radially constrained configuration, respectively, according to some applications of the present invention;

[0546] Figure 25A This is a schematic diagram of the first and second portions of a connecting element according to some applications of the present invention, the connecting element being configured to facilitate radial contraction of the impeller (e.g., during a crimp).

[0547] Figure 25B and Figure 25C This is a schematic diagram of the various stages of impeller collapse according to some applications of the present invention;

[0548] Figure 26 This is a schematic diagram of a stopper according to some applications of the invention, the stopper being configured to prevent distal propulsion of the impeller of the ventricular assist device during withdrawal of the ventricular assist device from the body of a subject;

[0549] Figure 27A and Figure 27B This is a schematic diagram of a ventricular assist device according to some applications of the present invention, the device including a valve to prevent backflow of blood, for example in the event of a malfunction in the impeller of the ventricular assist device; and

[0550] Figure 28A , Figure 28B and Figure 28C This is a schematic diagram of a ventricular assist device according to some applications of the present invention, which includes a safety bladder to prevent backflow of blood, for example in the event of a malfunction of the impeller of the ventricular assist device. Detailed Implementation

[0551] Now for reference Figure 1A and Figure 1B , Figure 1A and Figure 1B This is a schematic diagram of a ventricular assist device 20 according to some applications of the present invention, the distal end of which is disposed in the left ventricle 22 of a subject; the ventricular assist device includes a tube 24 that passes through the aortic valve 26 of the subject, such that the proximal end 28 of the tube is disposed in the aorta 30 of the subject, and the distal end 32 of the tube is disposed within the left ventricle 22. The tube 24 (sometimes referred to herein as a "blood pump tube") is generally an elongated tube, the axial length of which is generally significantly greater than its diameter. The scope of the invention includes the use of the devices and methods described herein in anatomical locations other than the left ventricle and the aorta. Therefore, the ventricular assist device and / or portions thereof are sometimes referred to herein (in the specification and claims) as a blood pump.

[0552] like Figure 1B As shown in the figure, Figure 1BThe steps for deploying a ventricular assist device in the left ventricle are illustrated, with the distal end of the ventricular assist device typically guided to the left ventricle via a guide wire 10. During insertion of the distal end of the device into the left ventricle, a delivery catheter 143 is positioned on the distal end of the device. Once the distal end of the device is positioned in the left ventricle, the delivery catheter is typically retracted into the aorta, and the guide wire is withdrawn from the subject's body. Retraction of the delivery catheter typically results in a non-radially constrained configuration of the self-expanding component of the distal end of the device, as described in further detail below. Typically, the ventricular assist device is inserted into the subject's body to provide acute treatment. For some applications, in order to withdraw the left ventricular device from the subject's body at the end of treatment, the delivery catheter is advanced on the distal end of the device, resulting in a radially constrained configuration of the self-expanding component of the distal end of the device. Optionally or additionally, the distal end of the device is retracted into the delivery catheter, resulting in a radially constrained configuration of the self-expanding component of the distal end of the device.

[0553] Also refer to Figure 2A , Figure 2B and Figure 2C , Figure 2A , Figure 2B and Figure 2C This is a schematic diagram of the blood pump portion 27 of a ventricular assist device 20 according to some applications of the present invention; typically, an impeller 50 is disposed within the distal portion 102 of a tube 24 and configured to pump blood from the left ventricle into the aorta by rotation. The tube typically defines one or more blood inlet openings 108 at its distal end, through which blood flows from the left ventricle into the tube during impeller operation. For some applications, the proximal portion of the tube defines one or more blood outlet openings 109, through which blood flows from the tube into the ascending aorta during impeller operation.

[0554] For some applications, the console 21 (which typically includes a computer processor 25) Figure 1A As shown in the diagram, the impeller is driven to rotate. For example, a computer processor can control motor 74 ( Figure 7 (As shown in the diagram), the motor 74 is disposed within the motor unit 23, and the motor 74 is connected via drive cable 130 (also shown in the diagram). Figure 7(As shown in the diagram) the impeller is driven to rotate. For some applications, the computer processor is configured to detect physiological parameters of the subject (such as left ventricular pressure, cardiac afterload, etc.) and is configured to control the rotation of the impeller in response thereto, as described in further detail below. Typically, the operations performed by the computer processor described herein convert the physical state of a memory into different magnetic polarities, charges, etc., depending on the technology of the memory used, which is a real physical object communicating with the computer processor. The computer processor 25 is typically a hardware device programmed with computer program instructions to produce a dedicated computer. For example, when programmed to perform the techniques described herein, the computer processor 25 typically acts as a dedicated ventricular assist computer processor.

[0555] For some applications, the purification system 29 drives a fluid (e.g., a glucose solution) through a portion of the ventricular assist device 20, for example, to cool that portion and / or to remove debris from that portion. The purification system 29 is described in further detail below.

[0556] Typically, a frame 34 is disposed within the tube along the distal portion 102 of the tube 24. The frame is typically made of a shape memory alloy, such as nitinol. For some applications, the shape memory alloy of the frame is shaped such that the frame (and thus the tube) presents a generally circular, elliptical, or polygonal cross-sectional shape without any force applied to the tube. By presenting its generally circular, elliptical, or polygonal cross-sectional shape, the frame is configured to hold the distal portion of the tube in an open position. Typically, during operation of the ventricular assist device, the distal portion of the tube is configured to be placed within the subject's body such that the distal portion of the tube is at least partially located within the left ventricle.

[0557] For some applications (not shown), during operation of the ventricular assist device, the distal portion of the cannula is at least partially positioned within the native aortic valve, and the frame is configured to retain aortic valve opening by exhibiting its generally circular, elliptical, or polygonal cross-sectional shape. For some applications, the cannula 24 is sized to prevent the shape memory alloy of the frame 34 from fully conforming to the dimensions shaped by the shape memory alloy. In this way, the frame is "pre-tensioned" so that even if the aortic valve applies radial compressive forces to the cannula and frame, the frame does not become radially compressed because the frame is held in a partially radially constrained state by the cannula. For some applications, the frame includes a plurality of rigid struts 111 arranged parallel to each other and parallel to the longitudinal axis of the frame. The rigid struts are configured such that at least a portion 110 of the frame (along which the struts are arranged) maintains a generally straight longitudinal axis, even when subjected to anatomical forces within the left ventricle and / or the aortic valve. Typically, the rigid strut is configured such that the length of the rigid strut does not change even if the frame 34 is changed from a radially constrained configuration (in which the frame is typically placed during the introduction of the frame into the subject's body) to a non-radially constrained configuration (in which the frame is typically placed during the operation of the ventricular assist device).

[0558] For some applications, no frame is provided within the proximal portion 106 of tube 24, and therefore the tube is not supported by frame 34 in the open position. Tube 24 is typically made of a collapsible material that is impermeable to blood. For example, tube 24 may include polyurethane, polyester, and / or silicone. Typically, the proximal portion of the tube is configured such that it is at least partially disposed within the ascending aorta of the subject. For some applications, the proximal portion of the tube passes through the aortic valve of the subject, entering the ascending aorta from the left ventricle of the subject, such as... Figure 1B As shown in the diagram. As described above, the tube typically defines one or more blood inlet openings 108 at its distal end, through which blood flows from the left ventricle into the tube during impeller operation. For some applications, the proximal portion of the tube defines one or more blood outlet openings 109, through which blood flows from the tube into the ascending aorta during impeller operation. Typically, the tube defines multiple blood outlet openings 109, for example, between two and eight blood outlet openings (e.g., between two and four blood outlet openings). During impeller operation, the blood flow pressure through the tube typically keeps the proximal portion of the tube open. For some applications, in the event of, for example, impeller failure, the proximal portion of the tube is configured to collapse inward in response to external pressure exceeding internal pressure. In this way, the proximal portion of the tube acts as a safety valve, thereby preventing retrograde blood flow from the aorta into the left ventricle.

[0559] For some applications, the computer processor 25 of console 21 ( Figure 1A The tube 24 (shown in the diagram) is configured to control the pumping of the blood pump (e.g., by controlling the rotation of the impeller) such that the blood pressure generated by the pump within the tube 24 exceeds the subject's aortic systolic pressure during systole but is lower than the subject's aortic diastolic pressure during diastole. During systole, the proximal portion 106 of the tube 24 remains open because the blood pressure within the tube exceeds the aortic pressure applied to the tube from the outside. During diastole, the proximal portion of the tube 24 closes because the aortic pressure applied to the tube from the outside exceeds the blood pressure within the tube. In this way, the impeller pumps blood from the left ventricle to the aorta in a pulsatile manner (i.e., by pumping blood from the left ventricle to the aorta only during diastole). For some applications, the computer processor is configured to measure the subject's aortic pressure, left ventricular pressure, and / or flow rate through the tube 24, for example using the following reference. Figure 9 , Figures 16A-16D And / or the technique described in Figure 17. For some such applications, the computer processor controls the rotation of the impeller in the manner described above, based on the measured aortic pressure, left ventricular pressure, and / or flow rate. Alternatively, the computer processor controls the rotation of the impeller in a different manner than described above, based on the measured aortic pressure, left ventricular pressure, and / or flow rate. For example, the computer processor may be configured to change the rotation rate of the impeller based on the measured aortic pressure, left ventricular pressure, and / or flow rate, but in such a way that the impeller pumps blood from the left ventricle to the aorta in a non-pulsating, continuous manner.

[0560] Normally, the pumping of blood by the impeller increases aortic pressure and decreases left ventricular pressure. Once the flow through tube 24 reaches a critical value (above which aortic pressure is higher than left ventricular pressure, even during ventricular systole), the aortic valve remains closed around the outside of tube 24 throughout the cardiac cycle, and flow from the ventricle to the aorta occurs only through the tube. Normally, above this point where aortic pressure separates from ventricular pressure, the left ventricle no longer performs net external work (defined as volume change multiplied by pressure change) because it does not move any volume. In this mode, the oxygen consumption of the left ventricle depends on the circulatory pressure generated by the closed aortic valve, wall tension due to the size of the left ventricle, wall thickness, and baseline metabolic demands (including calcium circulation). Below this critical point of impeller activity, the aortic valve typically opens at least partially during systole, and left ventricular outflow occurs simultaneously outside the tube and between the aortic valve (by means of left ventricular contraction) and through the tube (by means of impeller rotation and pumping). For a given impeller revolutions per minute, the larger the cross-sectional area of ​​the cannula, the greater the flow rate through the cannula will generally be. At the same time, the larger the cross-sectional area of ​​the cannula, the more space it occupies in the left ventricular outflow tract, the smaller the remaining outflow area, and therefore, the higher the outflow resistance that the left ventricle must overcome when pumping around the outside of the cannula.

[0561] Therefore, there is typically a trade-off between the efficiency of the impeller-assisted left ventricle (which advantageously increases with tube diameter) and the residual outflow resistance around the outside of tube 24 (which disadvantageously increases with tube diameter). The higher the flow rate through the tube provided by the impeller (for a given tube diameter), the less impact the reduced cross-sectional outflow area may have on the effective outflow resistance, because the remaining cross-sectional area may be suitable for the small residual stroke volume that the ventricle must eject; that is, the reduced residual outflow area may not create undue resistance to outflow. However, conversely, once a fixed tube diameter is selected, the effective resistance to outflow increases with a decrease in flow rate through the tube, because a larger proportion of the left ventricular stroke volume now needs to pass through the residual outflow area around the tube. Therefore, for some applications, the left ventricular outflow resistance is configured to be automatically adjustable to compensate for variations in the blood flow through the tube generated by the impeller. For example, the tube can be made of a compliant material whose flexibility reduces the flow through the tube and subsequently lowers the expansion pressure, resulting in a smaller tube diameter and thus increasing the available outflow area of ​​the left ventricle. Typically, the material properties of the compliant material are defined such that (a) maximum tube expansion is reached just at or near the moment when the pressure within the lumen generated by the pumping flow exceeds the aortic pressure (regardless of the moment in the cardiac cycle), and thus remains above the left ventricular pressure throughout the cardiac cycle, and (b) complete tube collapse is achieved when the flow through the tube generated by the impeller becomes zero.

[0562] Now for reference Figure 2B For some applications, multiple elongated connecting elements 107 extend along at least some of the proximal portion 106 of the tube 24. As described above, for some applications, the computer processor 25 is configured to drive the impeller 50 to pump blood from the left ventricle to the aorta in a pulsatile manner. For some applications, the connecting elements are configured to facilitate the opening and closing of the proximal portion of the tube in a manner similar to the opening and closing of natural valve leaflets, wherein corresponding portions of the circumference of the tube form apexes that contact each other when the tube is closed. For some applications, the ventricular assist device includes three elongated connecting elements, and the proximal portion of the tube 24 is configured to close in a manner similar to the closing of a tri-leaflet valve. Figure 2B Such an implementation is depicted, but one of the merging elements is hidden from view. For some applications (not shown), the ventricular assist device includes two elongated merging elements, and the proximal portion of tube 24 is configured to close in a manner similar to the closure of a bi-leaflet valve. For some applications, the proximal portion of tube 24 is positioned such that it passes through the subject's aortic valve, and the merging element is rotated to align with the merging portion of the native valve. In this way, the artificial tip of the proximal portion of the tube is aligned with the native aortic valve leaflet.

[0563] refer to Figures 2A-2C For some applications, the frame 34 is shaped such that it defines a proximal conical portion 36, a central cylindrical portion 38, and a distal conical portion 40. Typically, the proximal conical portion is positioned such that the narrow end of the cone is proximal to the wide end. Additionally, the distal conical portion is typically positioned such that the narrow end of the cone is distal to the wide end. For some applications, the tube 24 extends to the end of the cylindrical portion 38 such that the distal end of the tube defines a single axially facing blood inlet opening 108, such as... Figure 2A and Figure 2B As shown in the diagram. Alternatively, tube 24 extends to the end of the distal conical portion 40, and this tube defines one or more lateral blood inlet openings, such as... Figure 2C As shown in the diagram. For such applications, the tube typically defines two to four lateral blood inlet openings.

[0564] Typically, tube 24 includes a conical proximal portion 42 and a cylindrical central portion 44. Typically, the proximal conical portion is such that the narrow end of the cone is proximal relative to the wide end of the cone. As described above, for some applications, the tube extends to the end of the distal conical portion 40 of frame 34. For such applications, the tube typically defines a distal conical portion 46, wherein the narrow end of the cone is distal relative to the wide end of the cone, such as... Figure 2CAs shown in the diagram. For some applications (not shown), the diameter of tube 24 varies along the length of the central portion of the tube, such that the central portion of the tube has a truncated conical shape. For example, the central portion of the tube may widen from its proximal end to its distal end, or it may narrow from its proximal end to its distal end. For some applications, at its proximal end, the central portion of the tube has a diameter between 5 mm and 7 mm, and at its distal end, the central portion of the tube has a diameter between 8 mm and 12 mm.

[0565] Now for reference Figures 3A-3C , Figures 3A-3C This is a schematic diagram of an impeller 50 according to some applications of the present invention. Typically, the impeller includes at least one outer helical elongated element 52 wound around a central axial spring 54, such that the helical member defined by the helical elongated element is coaxial with the central axial spring. Typically, the impeller includes two or more helical elongated elements (e.g., three helical elongated elements, such as...). Figures 3A-3C (As shown in the diagram). For some applications, the helical elongated element and the central axial spring are made of shape memory materials, such as shape memory alloys like nitinol. Typically, each of the helical elongated element and the central axial spring is supported by a film 56 of material (e.g., polymers such as polyurethane and / or silicone) between them. For illustrative purposes, in Figure 3A The image shows an impeller without any material. Figure 3B and Figure 3C Views of the impeller are shown, with material supported between the helical elongated element and the spring.

[0566] Each helical elongated element, together with a membrane extending from the helical elongated element to the spring, defines a corresponding impeller blade, wherein the helical elongated element defines the outer edge of the blade, and the axial spring defines the axis of the impeller. Typically, the membrane of material extends along and covers the spring. For some applications, the suture 53 (e.g., polyester suture, in...) Figure 3B and Figure 3C The suture (as shown in the image) is wound around a helical elongated element, for example, as described in Schwammenthal's US 2016 / 0022890, which is incorporated herein by reference. Typically, the suture is configured to facilitate bonding between a film of material (typically a polymer, such as polyurethane or silicone) and a helical elongated element (typically a shape memory alloy, such as nitinol). For some applications, the suture (e.g., a polyester suture, not shown) is wound around a spring 54. Typically, the suture is configured to facilitate bonding between a film of material (typically a polymer, such as polyurethane or silicone) and a spring (typically a shape memory alloy, such as nitinol).

[0567] Typically, the proximal ends of spring 54 and helical elongated element 52 extend from the proximal bushing (i.e., sleeve bearing) 64 of the impeller, such that the proximal ends of spring 54 and helical elongated element 52 are positioned at similar radial distances from each other from the longitudinal axis of the impeller. Similarly, typically, the distal ends of spring 54 and helical elongated element 52 extend from the distal bushing 58 of the impeller, such that the distal ends of spring 54 and helical elongated element 52 are positioned at similar radial distances from each other from the longitudinal axis of the impeller. Typically, spring 54, as well as the proximal bushing 64 and distal bushing 58 of the impeller, define an inner cavity 62 passing through it.

[0568] Now for reference Figure 4 , Figure 4 This is a schematic diagram of an impeller 50 disposed within a frame 34 of a ventricular assist device 20 according to some applications of the present invention. As shown, a gap G typically exists between the outer edge of the impeller 50 and the inner surface of the frame 34, even when the span of the impeller is at its maximum. For some applications, it is desirable that the gap between the outer edge of the impeller blades and the inner surface of the frame 34 be relatively small so that the impeller can effectively pump blood from the subject's left ventricle into the subject's aorta. However, it is also desirable to maintain the gap between the outer edge of the impeller blades and the inner surface of the frame 34, for example, to reduce the risk of hemolysis.

[0569] For some applications, the clearance G between the outer edge of the impeller and the inner surface of the frame 34 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) at the position where the impeller span is at its maximum, for example, 0.05 mm–1 mm or 0.1 mm–0.4 mm. For some applications, the outer diameter of the impeller at the position where the impeller outer diameter is at its maximum is greater than 6 mm (e.g., greater than 6.5 mm) and / or less than 8 mm (e.g., less than 7 mm), for example, 6 mm–8 mm or 6.5 mm–7 mm. For some applications, the inner diameter of the frame 34 is greater than 6.5 mm (e.g., greater than 7 mm) and / or less than 8.5 mm (e.g., less than 7.5 mm), for example, 6.5 mm–8.5 mm or 7 mm–7.5 mm.

[0570] Typically, the axial shaft 92 passes through the impeller 50's axis via the impeller's inner cavity 62. Typically, the impeller's proximal bushing 64 is coupled to the shaft such that the proximal bushing's axial position relative to the shaft is fixed, and the impeller's distal bushing 58 is slidable relative to the shaft. The axial shaft itself is radially stabilized via the proximal radial bearing 116 and the distal radial bearing 118 defined by the frame 34. In turn, by passing through the inner cavity 62 defined by the impeller, the axial shaft radially stabilizes the impeller relative to the inner surface of the frame 34, such that even relatively small clearances (e.g., clearances as described above) between the outer edges of the impeller blades and the inner surface of the frame 34 are maintained during impeller rotation.

[0571] Refer again Figures 3A-3C For some applications, the impeller includes a plurality of elongated elements 67 extending radially from a central axial spring 54 to an outer helical elongated element 52. The elongated elements are typically flexible, but generally instretchable along the axis defined by the elongated elements. Additionally, each elongated element is typically configured not to exert a force on the helical elongated element unless a force is applied to the impeller causing the helical elongated element to move radially outward, such that (in the absence of elongated elements) the gap between the helical elongated element and the central axial spring will be greater than the length of the elongated element. For example, the elongated elements may comprise cords (such as polyester and / or another polymer or natural materials containing fibers) and / or threads (such as nitinol thread and / or threads made of different alloys or metals).

[0572] For some applications, the elongated element 67 holds the helical elongated element (which defines the outer edge of the impeller blade) within a given distance relative to the central axial spring. In this way, the elongated element is configured to prevent the outer edge of the impeller from being pushed radially outward due to the forces applied to the impeller during its rotation. The elongated element is thus configured to maintain a gap between the outer edge of the impeller blade and the inner surface of the frame 34 during the rotation of the impeller. Typically, more than one (e.g., more than two) and / or fewer than eight (e.g., fewer than four) elongated elements 67 are used in the impeller, each typically doubled (i.e., extending radially from the central axial spring 54 to the outer helical elongated element 52, and then returning from the helical elongated element to the central axial spring). For some applications, multiple elongated elements are formed from a single piece of string or a single thread, each of the multiple elongated elements extending from the spring to the corresponding helical elongated element and returning to the spring, as described in further detail below.

[0573] For some applications, the impeller is manufactured as follows: A proximal bushing 64, a distal bushing 58, and a helical elongated element 52 are cut from a tube of shape memory material such as nitinol. The cutting of the tube and the shaping of the shape memory material are typically performed such that the helical elongated element is defined by the shape memory material, for example, using a technique substantially similar to that described in Schwammenthal's US 2016 / 0022890. Typically, a spring 54 is inserted into the cut and shaped tube such that the spring extends along the length of the tube from at least the proximal bushing to the distal bushing. For some applications, the spring is inserted into the cut and shaped tube while in a state of axial compression, and the spring is configured to be held in place relative to the tube by applying radial forces on the proximal and distal bushings. Optionally or additionally, portions of the spring are welded to the proximal and distal bushings. For some applications, the spring is cut from a tube of shape memory material such as nitinol. For some such applications, the spring is configured such that when the spring is set in a non-radial constraint configuration (in which the spring is typically set during impeller operation), there is substantially no gap between the winding portion of the spring and the winding portion adjacent to it.

[0574] For some applications, at this stage, the elongated element 67, as described above, is positioned such that it extends between the spring and one or more helical elongated elements (e.g., in the following manner). A mandrel (e.g., a polyetheretherketone (PEEK) and / or polytetrafluoroethylene (PTFE) mandrel) is inserted through the cavity defined by the spring and bushing. A string or thread is then passed through such that it (a) from the mandrel to the first helical elongated element, (b) from the first helical elongated element back to the mandrel, (c) around the mandrel and to the second helical elongated element, (d) from the second helical elongated element back to the mandrel, and so on. Once the string or thread has passed from the mandrel to each helical elongated element and back again, the ends of the string or thread are joined together, for example by tying them to each other. For some applications, a suture 53 (e.g., polyester suture) is wound around the helical elongated elements to facilitate bonding between the membrane of the material (typically a polymer, such as polyurethane or silicone) and the helical elongated elements (typically a shape memory alloy, such as nitinol) in subsequent stages of impeller manufacturing. For some applications, a suture (e.g., polyester suture, not shown) is wound around the spring 54. Typically, the suture is configured to facilitate bonding between a membrane of material (typically a polymer, such as polyurethane or silicone) and the spring (typically a shape memory alloy, such as nitinol) in later stages of impeller manufacturing.

[0575] Typically, at this stage, such as Figure 3AAs shown, structure 59 has been assembled. This structure includes a tube that has been cut and shaped to define proximal and distal bushings and a helical elongated element, a spring and optionally an elongated element, and a suture. The structure is immersed in the material defining membrane 56. For some applications, the assembled structure is immersed in the material with its central axis positioned through the cavity defined by the spring and bushing, although it is noted that the mandrel is not in the... Figure 3A As shown in the diagram. Typically, the material used to make the membrane is silicone (and / or a similar polymer), and the assembled structure is immersed in this material while it is in an uncured liquid state. Subsequently, the material is cured, causing it to solidify, for example, by allowing it to dry. Once the material has dried, the mandrel is typically removed from the cavity defined by the bushing and spring.

[0576] The result of the process described above is typically a continuous membrane of material that extends between each helical elongated element and into the spring, and also extends along the length of the spring to define a tube in which the spring is embedded. The portion of the membrane extending from each helical elongated element into the spring defines the impeller blades. For applications where the impeller includes elongated elements 67, these elongated elements are typically embedded in these portions of the membrane.

[0577] Typically, impeller 50 is transcatheterically inserted into the left ventricle, while simultaneously being in a radially constrained configuration. In this configuration, both the helical elongated element 52 and the central axial spring 54 become axially elongated and radially constrained. Typically, a membrane 56 of material (e.g., silicone) is shaped to conform to the shape changes of the helical elongated element and the axially supporting spring, both of which support the membrane. Using a spring to support the inner edge of the membrane typically allows the membrane to change shape without breaking or collapsing because the spring provides a large surface area for connecting the inner edge of the membrane. For some applications, using a spring to support the inner edge of the membrane reduces the diameter to which the impeller can be radially constrained compared to, for example, using a rigid shaft to support the inner edge, because the diameter of the spring itself can be reduced by axially elongating the spring.

[0578] As described above, for 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 shaft is fixed, and the distal bushing 58 of the impeller is slidable relative to the shaft. For some applications, when the impeller is radially constrained for the purpose of inserting the impeller into the ventricle or for the purpose of removing the impeller from the subject's body, the impeller axially elongates by sliding distally along the axial direction via the distal bushing.

[0579] like Figures 3A-3CAs shown, after being released into the subject's body, the impeller assumes its non-radial constraint configuration (in which the impeller is typically positioned during operation). Typically, when the impeller 50 is in the non-radial constraint configuration (e.g., within the subject's ventricle), the pitch of each helical elongated element 52 is greater than 1 mm (e.g., greater than 6 mm) and / or less than 20 mm (e.g., less than 10 mm). Generally, other factors being equal, the larger the pitch of the helical elongated element (and therefore the impeller blades), the greater the blood flow generated by the impeller. Therefore, as described, when the impeller 50 is in the non-radial constraint configuration, the pitch of the helical elongated element 52 is typically greater than 1 mm (e.g., greater than 6 mm). On the other hand, it is generally desirable for the impeller to obstruct blood return into the subject's left ventricle. Other factors being equal, generally, the smaller the pitch of the helical elongated element (and therefore the impeller blades), the greater the obstruction provided by the impeller. Therefore, as described, when the impeller 50 is in a non-radial constraint configuration, the pitch of the helical elongated element 52 is typically less than 20 mm (e.g., less than 10 mm).

[0580] For some applications, at least when the impeller is in a non-radial constraint configuration, the pitch of the helical elongated element (and therefore the impeller blades) varies along the length of the helical elongated element. Typically, for such applications, the pitch increases from the distal end of the impeller (i.e., the end inserted further into the subject's body and positioned upstream relative to the antegrade blood flow direction) to the proximal end of the impeller (i.e., the end positioned downstream relative to the antegrade blood flow direction), thus increasing the pitch in the blood flow direction. Typically, the blood flow velocity increases along the impeller and in the blood flow direction. Therefore, the pitch increases in the blood flow direction to further accelerate the blood flow.

[0581] Note that, for illustrative purposes, in some of the accompanying drawings, the impeller 50 is shown as not including, as referenced. Figures 3A-3C All features of the impeller shown and described. For example, some figures show an impeller excluding the stitching 53 and / or the elongated element 67. The scope of this application includes the use of impellers with reference to any device and method described herein. Figures 3A-3C The impeller with any features shown and described.

[0582] Now for reference Figure 5A and Figure 5B , Figure 5A and Figure 5BThis is a schematic diagram of the impeller 50 and frame 34 of a ventricular assist device 20, respectively in its non-radial restraint state and radial restraint state, according to some applications of the present invention. During insertion of the impeller and frame into the body of a subject via a catheter, the impeller and frame are generally configured in a radial restraint state, and during operation of the impeller within the left ventricle of the subject, the impeller and frame are configured in a non-radial restraint state. As described above, the tube 24 generally extends from at least the distal portion of the frame and proximally. However, for illustrative purposes, the frame and impeller are in... Figures 5A-5B The image shows tube 24 without a tube. (Example) Figure 5B As indicated, the frame and impeller are typically held in a radially constrained configuration by the delivery conduit 143.

[0583] Also refer to Figure 5C , Figure 5C This illustrates a typical bearing assembly used in a prior art axial impeller-based blood pump. Figure 5C This is for the purpose of serving as a reference point for some applications of the invention described herein. For example... Figure 5C As shown, 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 movement of the impeller by holding the impeller's axis at a given radial position. In response to the impeller pumping blood in a first direction, forces acting on the impeller typically propel the impeller in the opposite direction. The purpose of the thrust bearing is to counteract this movement of the impeller and maintain its axial position. Figure 5C In the example shown, in response to the impeller pumping blood in the direction of arrow 204, the impeller is propelled in the direction of arrow 206, and the thrust bearing resists this motion. Typically, bearings experience significant heating and wear due to the frictional forces applied to them. Thrust bearings are generally subject to substantial heating and wear because the frictional forces applied to them are typically distributed across opposing surfaces, which have a smaller contact area between them compared to radial bearings.

[0584] As described above, the axial shaft 92 typically passes through the impeller 50's axis of rotation via the impeller's inner cavity 62. Typically, the impeller's proximal bushing 64 is coupled to the shaft via a coupling element 65, such that the proximal bushing is axially fixed relative to the shaft, and the impeller's distal bushing 58 is slidable relative to the shaft. The axial shaft itself is radially stabilized via proximal radial bearings 116 and distal radial bearings 118 defined by the frame 34. In turn, by passing through the inner cavity 62 defined by the impeller, the axial shaft radially stabilizes the impeller relative to the inner surface of the frame 34, such that even relatively small clearances (e.g., clearances as described above) between the outer edges of the impeller blades and the inner surface of the frame 34 are maintained during impeller rotation, as described above. For some applications, the axial shaft 92 is made of stainless steel, and the proximal bearing 116 and / or the distal bearing 118 are made of hardened steel. Typically, when the impeller and frame are crushed (i.e., radially constrained) for the purpose of inserting the impeller and frame into the subject's body, the distal bushing 58 of the impeller is configured to slide along the axial axis in the distal direction, causing the impeller to become axially elongated, as described above. More generally, by sliding the distal bushing along the axial axis, the impeller changes from its radially constrained configuration to its non-radially constrained configuration, and vice versa.

[0585] Typically, the impeller itself is not directly housed within any radial or thrust bearing. Instead, bearings 116 and 118 act as radial bearings about the axial axis. For some applications, there is no thrust bearing in contact with any surface to generate thrust during impeller rotation, because the impeller is configured to move axially within frame 34 while rotating, as described in further detail below. Typically, pump section 27 (and more generally ventricular assist device 20) does not include any thrust bearing configured to be disposed within the subject's body and configured to counteract the thrust generated by the impeller's rotation. For some applications, one or more thrust bearings are disposed outside the subject's body (e.g., in...). Figure 1A , Figure 7 and Figures 8A-8B Within the motor unit 23 shown, the force counteracting the thrust generated by the rotation of the impeller is provided solely by one or more thrust bearings disposed outside the subject's body. For some applications, mechanical and / or magnetic elements are configured to hold the impeller within a given axial position range. For example, a magnet (e.g., magnet 82, referred to below) disposed near the proximal end of the drive cable (e.g., outside the subject's body). Figure 7 The description can be configured to transmit axial motion to the impeller and to hold the impeller within a given axial position range.

[0586] For some alternative applications of the invention, the ventricular assist device includes an impeller that is not configured to move in an axial reciprocating manner. For some such applications (not shown), a thrust bearing is used to maintain the axial position of the impeller, and the thrust bearing is disposed within the portion of the ventricular assist device near the impeller such that the thrust bearing does not come into contact with the subject's blood. For example, the thrust bearing may be disposed within an outer tube in which the impeller's drive shaft is located. Alternatively or additionally, the thrust bearing may be disposed outside the subject's body. For some such applications, because the thrust bearing is disposed outside the subject's body, the size of the thrust bearing is not limited by the need for deployment in a small anatomical location. Therefore, in such cases, the contact area between the two opposing surfaces of the thrust bearing is typically greater than 20 square millimeters. For some applications (not shown), the thrust bearing is disposed distal to the impeller and in contact with the subject's blood, such that the thrust bearing is cooled by the subject's blood.

[0587] Now for reference Figure 6A and Figure 6B , Figure 6A and Figure 6B This is a schematic diagram of a ventricular assist device 20 at various stages of the motion cycle of the impeller 50 relative to the frame 34 of the ventricular assist device according to some applications of the present invention. In some applications, while the impeller pumps blood through the tube 24 by rotation, an axial shaft 92 (to which the impeller is fixed) is driven to move the impeller axially back and forth within the frame 34 via the axial shaft, as described below. Figure 7 Further detailed description. Optionally or additionally, the impeller and axial shaft are configured to move axially back and forth within the frame 34 in response to a force acting on the impeller, and the axial shaft does not require active drive to move in a axially back and forth manner, as shown in the following example reference. Figure 9 Further detailed description.

[0588] In some applications, the portion of the axial shaft in contact with the proximal bearing 116 and the distal bearing 118 changes continuously as it moves back and forth. In some such applications, with other factors remaining constant, this distributes the frictional force exerted on the axial shaft by the bearings over a larger area of ​​the axial shaft compared to if the axial shaft did not move relative to the bearings, thereby reducing wear on the axial shaft. Optionally or additionally, by moving the axial shaft back and forth relative to the bearings, any residue, such as blood residue, is removed from the interface between the axial shaft and the bearings.

[0589] For some applications, when the frame 34 and impeller 50 are in their non-radially constrained configuration (e.g., when the frame and impeller are deployed in the left ventricle), the length of the frame exceeds the length of the impeller by at least 2 mm (e.g., at least 4 mm, or at least 8 mm). Typically, the proximal bearing 116 and the distal bearing 118 are each 2 mm to 4 mm in length. Furthermore, the impeller and axial shaft are typically configured to move axially within the frame in a reciprocating manner, at least along the length of each of the proximal and distal bearings, or at least along twice the length of each of the bearings. Thus, during the reciprocating axial movement of the axial shaft, the axial shaft is cleaned on either side of each of the bearings.

[0590] Refer again Figure 6A and Figure 6B And also refer to Figure 6C , Figure 6C This is a schematic diagram of the axial receiving tube 126 and distal end portion 120 of a ventricular assist device 20 according to some applications of the present invention. For some applications, the distal end portion of the ventricular assist device is configured to be soft, such that the distal end portion is configured not to damage the subject's tissues, even if the distal end portion comes into contact with tissues (e.g., tissues of the left ventricle). For example, the distal end portion may be made of silicone. For some applications, the distal end portion defines an inner lumen 122 passing through it. For some such applications, during insertion of the ventricular assist device into the left ventricle, for example, according to known techniques, a guide wire 10 ( Figure 1B The ventricular assist device is first inserted into the left ventricle. The distal end portion of the ventricular assist device is then guided into the left ventricle by advancing the distal distal portion of the guideline, which is disposed within the lumen 122. For some applications, a hemostatic valve 152 is disposed at the distal end of the lumen 122 of the distal distal portion 120, such that the distal distal portion becomes sealed after the guideline retracts from the lumen 122. Typically, during insertion of the ventricular assist device into the subject's ventricle, the delivery catheter 143 is positioned on the impeller 50 and frame 34, and the impeller and frame are held in their radially constrained configuration. For some applications, the distal distal portion 120 extends distally from the delivery catheter during insertion into the subject's ventricle. For some applications, at the proximal end of the distal distal portion, the distal distal portion has a flared portion 124 that acts as a stop and prevents the delivery catheter from advancing beyond the flared portion.

[0591] For some applications, the axial shaft receiving tube 126 extends proximally from the distal end portion 120. As described above, the axial shaft typically reciprocates axially during operation of the impeller 50. The shaft receiving tube 126 defines a cavity 127 configured to receive the axial shaft when it extends beyond the distal bearing 118. For some applications, the shaft receiving tube defines a stop 128 at its distal end, configured to prevent the axial shaft from advancing beyond the stop. For some applications, the stop includes a rigid member inserted (e.g., embedded) into the distal end of the shaft receiving tube. Alternatively, the stop includes a shoulder between the cavity 127 of the axial shaft receiving tube and the cavity 122 of the end portion 120. Typically, such a shoulder exists because the cavity 122 of the end portion 120 is narrower than the cavity 127. (This is because the inner cavity 127 is typically configured to receive the axial shaft, while the inner cavity 122 is configured to receive the guide wire 10, and the axial shaft is typically wider than the guide wire 10 because the axial shaft itself is configured to receive the guide wire 10 within the inner cavity 132 of the axial shaft.) Figure 10B and Figure 10C As shown in the diagram). Typically, during normal operation of the impeller, even when the drive cable 130 (in...) Figure 7 (As shown in the diagram) When fully extended, the axial shaft will not extend into the stopper 128. However, the stopper 128 is configured to prevent the axial shaft from extending into the distal portion during the advance of the delivery catheter over the impeller 50 and frame 34 as the ventricular assist device 20 retracts from the subject's ventricle. In some cases, there is a risk of the drive cable breaking during the advance of the delivery catheter over the frame and impeller. Without the stopper 128, the axial shaft could extend into the distal portion in such a situation. The stopper 128 prevents this from happening, even in the event of a broken drive cable.

[0592] Typically, during operation of the ventricular assist device and throughout the entire axial cycle of the impeller, the impeller is positioned relatively close to the distal end portion. For example, during the entire axial cycle of the impeller's reciprocating motion, the distance from the impeller to the distal end portion can be within 50 percent of the farthest end of tube 24, such as 30 percent (or 20 percent) of the farthest end.

[0593] For some applications (not shown), a portion of frame 34 extends into the proximal portion of the distal distal portion 120. This portion of the frame is configured such that by shaping this portion of the frame into a radially expanding configuration, the proximal portion of the distal end expands radially when deployed into the left ventricle of the subject. For some applications, the entire distal portion is made of a material with uniform stiffness, but the portion of frame 34 extending into the proximal portion of the distal end imparts stiffness to the proximal portion of the distal end, such that the proximal portion of the distal end has greater stiffness than the distal portion of the distal end.

[0594] For some applications, the end portion has the same characteristics as... Figure 6C The different constructions shown below are described in further detail, for example, see reference. Figures 18-24B As described. For some applications, the distal end portion will refer to... Figure 6C Some of the features described are similar to those described below (e.g., references). Figure 13 And refer to Figures 18-24B The described features are combined. For example, the internal structure of the end portion and the proximal extension of the axial shaft receiving tube 126 from the end portion can be as shown in Figure 6 and / or Figure 13 As described, and the external shape of the end portion can be as referenced. Figures 18-24B Any of the descriptions.

[0595] Now for reference Figure 7 , Figure 7 This is a schematic exploded view of the motor unit 23 of a ventricular assist device 20 according to some applications of the present invention. For some applications, a control console 21 controls the rotation of the impeller 50. Figure 1A The computer processor 25 is also configured to control the reciprocating motion of the axial axis. Typically, both types of motion are generated using the motor unit 23. The scope of the invention includes controlling the reciprocating motion at any frequency. For some applications, an indication of the subject's cardiac cycle is detected (e.g., by detecting the subject's ECG), and the reciprocating motion of the axial axis is synchronized with the subject's cardiac cycle.

[0596] Typically, motor unit 23 includes a motor 74 configured to transmit rotational motion to impeller 50 via drive cable 130. As described further below, the motor is typically magnetically coupled to the drive cable. For some applications, axial motion driver 76 is configured to drive the motor in an axial reciprocating motion, as indicated by the double-headed arrow 79. Typically, the motor transmits the reciprocating motion to the drive cable via the magnetic coupling between the motor and the drive cable, which in turn transmits the motion to the impeller. As described below, for some applications, the drive cable, impeller, and / or axial shaft reciprocate passively, for example, due to periodic changes in pressure gradients resisted by the impeller pumping blood. Typically, for such applications, motor unit 23 does not include axial motion driver 76.

[0597] For some applications, the magnetic connection of the motor drive cable is such as... Figure 7 As shown in the image. Figure 7As shown, a set of drive magnets 77 are coupled to a motor via a drive magnet housing 78. For some applications, the drive magnet housing includes a ring 81 (e.g., a steel ring), and the drive magnets are adhered to the inner surface of the ring. For some applications, as shown, a spacer 85 is adhered to the inner surface of the ring 81 between two drive magnets. A driven magnet 82 is disposed between the drive magnets such that there is axial overlap between the drive and driven magnets, and the driven magnet 82 is coupled to the proximal end of the drive cable 130. For example, the driven magnet may be cylindrical and define a hole through it, and the proximal end of the drive cable may be adhered to the inner surface of the driven magnet defining the hole. For some applications, the driven magnet is cylindrical, and the magnet includes a north pole and a south pole, as shown, which are separated from each other along the length of the cylinder by a line 83 that divides the cylinder in two. For some applications, the driven magnet is housed within a cylindrical housing 87.

[0598] Magnetic bonding is strongest when the field density is at its maximum. Therefore, it is desirable to use relatively strong magnets for both the driving and driven magnets, with a small air gap between them, and to minimize fieldline leakage. Typically, the driving and driven magnets are relatively strong neodymium magnets. Furthermore, the gap between each of the driving and driven magnets is typically less than 2 mm, for example, about 1 mm. To reduce fieldline leakage, fewer than four magnets (e.g., exactly two magnets as shown) are typically used as the driving magnets for the following reasons.

[0599] Typically, it is desirable to minimize the diameter of the driven magnet, for example, to stabilize it. As described above, the driven magnet is cylindrical and comprises a north pole and a south pole separated from each other along a dividing line 83 along the length of the cylinder. In the region of the circumference of the driven magnet closest to the dividing line between the north and south poles, magnetic field lines pass directly from the north pole to the south pole, instead of passing through the air gap to the first outer magnet, through the outer magnet, around ring 81, and across the second driving magnet back to the south pole of the driven magnet. As an approximation, any field line whose length, at least less than the sum of the air gaps between the driven and driving magnets, can be drawn between the north and south poles will pass from the north pole to the south pole of the driven magnet, instead of taking an alternative route. It is assumed that all field lines extending around 2 mm (i.e., a total of 4 mm in the total circumference of the driven magnet) on either side of the dividing line between the north and south poles of the driven magnet would not contribute to the magnetic connection between the driving and driven magnets. If exactly two magnetic poles are replaced, the driven magnet has four magnetic poles, and correspondingly four driving magnets, then there will be four wasted circumferential sections of 2 mm in length throughout the circumference. This will result in a total of 8 mm of wasted field lines within the 12 mm circumference of the internal magnet. Some of this loss will be compensated for by adding two additional driving magnets, which increases the magnetic field strength. However, the additional external magnets will be relatively close to each other, which will cause magnetic field leakage between the driving magnets. Given the above, typically, the motor unit includes fewer than four magnets (e.g., exactly two magnets as shown) as driving magnets, and the driven magnet is divided into fewer than four magnetic poles (e.g., exactly two magnetic poles as shown).

[0600] Note that in Figure 7 In the application shown, the driving magnet is positioned outside the driven magnet. However, the scope of this application includes reversing the configuration of the driving and driven magnets, with necessary modifications. For example, the proximal end of the drive cable may be connected to two or more driven magnets positioned around the driving magnet, such that there is axial overlap between the driven and driving magnets. The above discussion regarding the number of magnets that should be used as external magnets and the number of poles that the internal magnets should be divided into also applies to such a configuration. That is, for such a configuration, typically, the motor unit includes fewer than four magnets (e.g., exactly two magnets as shown) as driven magnets, and the driving magnet is divided into fewer than four poles (e.g., exactly two poles as shown).

[0601] As described above, the typical purification system 29 ( Figure 1A(As shown in the diagram) for use with ventricular assist device 20. Typically, motor unit 23 includes an inlet 86 and an outlet 88 for use with a purification system. In some applications, purification fluid is continuously or periodically pumped into the ventricular assist device via inlet 86 and pumped out of the ventricular assist device via outlet 88. In some applications, purification fluid is pumped into the ventricular assist device, and the inlet and outlet ports are positioned in fluid communication with each other, such that a given volume of purification fluid circulates within the device for a continuous period of time. Further aspects of the purification system are described below.

[0602] Now for reference Figure 8A and Figure 8B , Figure 8A and Figure 8B This is a schematic diagram of a motor unit 23 according to some applications of the present invention. Generally, as... Figure 8A and Figure 8B The motor unit 23 shown is similar to Figure 7 The motor unit shown in the figure, and unless otherwise described, as Figure 8A and 8B The motor unit 23 shown includes, with Figure 7 Similar components to the motor unit 23 shown. For some applications, the motor unit includes a radiator 90 configured to dissipate heat generated by the motor. Optionally or additionally, the motor unit includes a vent 93 configured to facilitate heat dissipation generated by the motor. For some applications, the motor unit includes vibration dampers 94 and 96 configured to suppress vibrations of the motor unit caused by rotational and / or axial reciprocating motion of components of the ventricular assist device.

[0603] For some applications, impeller 50 and axial shaft 92 are configured to move axially back and forth within frame 34 in response to forces acting on the impeller, without requiring active driving of the axial shaft to move in this axially back and forth manner. Typically, during a subject's cardiac cycle, the pressure difference between the left ventricle and aorta changes from approximately zero during ventricular systole (hereinafter "systole") to a relatively large pressure difference (e.g., 60 mmHg–100 mmHg) during ventricular diastole (hereinafter "diastole"). For some applications, due to the increased pressure difference resisted by the impeller pumping during diastole, the impeller is pushed distally relative to frame 34 relative to its position during systole. Conversely, because the impeller is connected to the axial shaft, the axial shaft moves forward. During systole, the impeller (and, in turn, the axial shaft) returns to their systolic position. In this way, the axial back and forth movement of the impeller and axial shaft is generated passively, i.e., without requiring active driving of the axial shaft and impeller to perform this movement.

[0604] Now for reference Figure 9 , Figure 9 This is a graph indicating the change in the length of the drive cable of the ventricular assist device as the impeller resists a change in pressure gradient, as measured in experiments performed by the inventors of this application. The impeller and drive cable, as described herein, are used to pump a glycerol-based solution through a chamber configured to replicate the left ventricle and aorta, and the solution has properties similar to blood (such as density and viscosity). The impeller pumping resists a change in pressure gradient due to the increase in the volume of fluid contained within the chamber (in which the impeller is pumping). Simultaneously, the movement of the drive cable is imaged, and changes in the length of the drive cable are determined via machine vision analysis of the images. Figure 9 The graph shown indicates the variation in the length of the drive cable as measured by the pressure gradient. Figure 9 The y-axis of the graph shown is as follows: 0 mm elongation represents the length of the drive cable when the impeller is stationary. Note that the graph begins at a pressure gradient of 65 mmHg, and at this pressure, the elongation is negative (at approximately -0.25 mm), meaning the drive cable is shortened relative to its length before the impeller begins to rotate. This is because the drive cable is configured such that when the impeller first begins pumping, the drive cable is shortened (relative to its length before the impeller is activated) due to the unwinding of the coils within the drive cable, as described in further detail below. Figure 9 As seen in the portion of the curve shown, after the initial shortening of the drive cable caused by the aforementioned effects, the drive cable then gradually elongates as the pressure gradient increases.

[0605] As by Figure 9 As indicated by the results shown and as described above, typically, in response to changes in pressure resisted by the impeller pumping blood (e.g., the pressure difference between the left ventricle and the aorta), the impeller moves back and forth relative to the frame 34. In turn, the movement of the impeller causes the drive cable 130 to stretch more or less.

[0606] For some applications, during the operation of the ventricular assist device, console 21 ( Figure 1A The computer processor 25 is configured to measure an indication of the pressure applied to the impeller (which indicates the pressure difference between the left ventricle and the aorta) by measuring the tension in the drive cable 130 and / or an indication of the axial movement of the drive cable. For some applications, based on the measured indication, the computer processor detects events in the subject's cardiac cycle, determines the subject's left ventricular pressure, and / or determines the subject's cardiac afterload. For some applications, the computer processor controls the rotation of the impeller and / or the axial reciprocating motion of the axial shaft in response.

[0607] For some applications, substantially similar technology is used in right ventricular assist devices configured to pump blood from the right ventricle to the pulmonary artery, and a computer processor configured to determine the pressure difference between the right ventricle and the pulmonary artery after making necessary modifications in a substantially similar manner. For some applications, substantially similar technology is used in cardiac assist devices configured to pump blood from a first position to a second position (e.g., from the vena cava to the right ventricle, from the right atrium to the right ventricle, from the vena cava to the pulmonary artery, and / or from the right atrium to the pulmonary artery), and a computer processor configured to determine the pressure difference between the first and second positions after making necessary modifications in a substantially similar manner.

[0608] Refer again Figure 7 For some applications, the ventricular assist device 20 includes a sensor 84. For example, the sensor may include a Hall sensor disposed within the motor unit 23, such as... Figure 7 As shown in the diagram. For some applications, the Hall sensor measures changes in the magnetic field generated by one of the magnets to measure the axial movement of the drive cable 130 and, consequently, to determine the pressure resisted by the impeller pump. For example, the internal driven magnet 82 may be axially longer than the external drive magnet 77. Because the internal magnet is longer than the external magnet, magnetic field lines emanating from the internal magnet do not travel to the external magnet, and the magnetic flux generated by these magnetic field lines (as measured by the Hall sensor) varies with the axial movement of the drive cable and, consequently, the axial movement of the internal magnet. During operation, the motor 74 rotates, thereby generating an AC signal in the Hall sensor, which typically has a frequency between 200 Hz and 800 Hz. Typically, when the tension in the drive cable changes due to the subject's cardiac cycle, this generates a low-frequency envelope in the signal measured by the Hall sensor, which typically has a frequency of 0.5 Hz to 2 Hz. For some applications, a computer processor measures the low-frequency envelope and derives the subject's cardiac cycle from the measured envelope. It should be noted that, generally, the axial motion of the magnet is much smaller than the axial motion of the impeller, because the entire range of motion of the impeller is not transmitted along the length of the drive cable. However, typically, the axial reciprocating motion of the impeller produces the measurable reciprocating motion of the magnet.

[0609] For some applications, the Hall sensor measurements are initially calibrated such that the change in magnetic flux per unit pressure change (i.e., per unit change in the pressure difference between the left ventricle and the aorta) resisted by the impeller pump is known. It is known that, in most subjects, the left ventricular pressure equals the aortic pressure during systole. Therefore, for some applications, the subject's aortic pressure is measured, and then the subject's left ventricular pressure at a given time is calculated by a computer processor based on: (a) the measured aortic pressure, and (b) the difference between the magnetic flux measured by the Hall sensor at that time and the magnetic flux measured by the Hall sensor during systole (when the pressure in the left ventricle is assumed to be equal to the pressure in the aorta).

[0610] Now for reference Figure 10A , Figure 10B and Figure 10C ,Should Figure 10A , Figure 10B and Figure 10C This is a schematic diagram of the drive cable 130 of a ventricular assist device 20 according to some applications of the present invention. Typically, as described above, the rotational motion of the impeller (transmitted via an axial shaft) and the axial reciprocating motion of the axial shaft, as described above, are transmitted to the axial shaft via the drive cable. Typically, the drive cable extends from the motor unit 23 (which is usually disposed outside the subject's body) to the proximal end of the axial shaft 92 (e.g., Figure 10C As shown in the diagram, it illustrates the connection between the distal end of the drive cable and the proximal end of the axial shaft. For some applications, the drive cable comprises multiple wires 134 arranged in a tightly coiled configuration to provide sufficient strength and flexibility to allow a portion of the cable to remain within the aortic arch (corresponding to...). Figure 10A (See arrow 145 in the image), while the cable rotates and moves in an axial reciprocating motion. The drive cable is typically housed within a first outer tube 140, which is configured to remain stationary while the drive cable rotates and / or reciprocates axially. The first outer tube is configured to effectively act as a bearing along the length of the drive cable. Typically, the first outer tube is made of a polymer (such as polyetheretherketone) configured to be highly fatigue-resistant even under frictional forces generated by the relative motion between the drive cable and the first outer tube. However, since such polymers are typically relatively rigid, only a thin layer of the polymer is usually used in the first outer tube. For some applications, the first outer tube is housed within a second outer tube 142, which is made of a material with greater flexibility than the material of the first outer tube (e.g., nylon and / or polyether block amide), and the thickness of the second outer tube is greater than that of the first outer tube.

[0611] Typically, during insertion of the impeller and cage into the left ventricle, the impeller 50 and frame 34 are held in a radially constrained configuration via the delivery conduit 143. As described above, to present the impeller and frame in a non-radially constrained configuration, the delivery conduit is retracted. For some applications, such as Figure 10A As shown, during operation of the left ventricular device, the delivery catheter remains in the subject's aorta, and an outer tube 142 is disposed within the delivery catheter. To retract the left ventricular device from the subject's body, the delivery catheter is advanced over an impeller and frame such that the impeller and frame exhibit their radially constrained configuration. The catheter is then withdrawn from the subject's body.

[0612] refer to Figure 10C Typically, the axial shaft and cable define a continuous lumen 132 through which they pass. For some applications, the left ventricular assist device is guided to the aorta and then to the left ventricle by placing the axial shaft and cable on the guide wire 10 (described above) such that the guide wire is positioned within the lumen 132. For some applications, by using the lumen of the axial shaft and cable in this manner, no additional guide wire guide is required for use during insertion of the left ventricular assist device 20. For some applications, the axial shaft and cable each have an outer diameter greater than 0.6 mm (e.g., greater than 0.8 mm) and / or less than 1.2 mm (e.g., less than 1 mm), such as 0.6 mm–1.2 mm or 0.8 mm–1 mm. For some applications, the diameter of the lumen 132 defined by the shaft and cable is greater than 0.3 mm (e.g., greater than 0.4 mm) and / or less than 0.7 mm (e.g., less than 0.6 mm), such as 0.3 mm–0.7 mm or 0.4 mm–0.6 mm. For some applications, the drive cable 130 has a total length greater than 1 m (e.g., greater than 1.1 m) and / or less than 1.4 m (e.g., less than 1.3 m), such as a total length of 1 m–1.4 m or 1.1 m–1.3 m. As described above, for some applications, the guide cable additionally passes through the cavity 122 of the distal end portion 120. Typically, the diameter of the cavity 122 is approximately similar to the diameter of the cavity 132.

[0613] refer to Figure 10BFor some applications, the drive cable 130 consists of multiple coiled wires 134. Typically, because the impeller must resist pressure gradient pumping during diastole, the impeller is pushed distally relative to the frame 34 relative to its position relative to the frame during systole, as described above. When rotation of the impeller begins, if the direction of rotation of the impeller causes the rotation of the drive cable in that direction to at least partially tighten the coiled wires of the drive cable, this will also cause the impeller to advance relative to the frame due to the tightening of the coiled wires (i.e., becoming wound so that the radius of the coil decreases) and thus axial elongation. For some applications, at least a portion of the drive cable is configured such that (a) in response to the impeller rotating in a predetermined direction of rotation to pump blood from the left ventricle to the aorta, (b) rotation of the drive cable in that direction causes the coiled wires of the drive cable to at least partially unwind along a portion of the drive cable, causing that portion of the drive cable to shorten axially. By constructing the drive cable as described above, the length of the frame 34 need not accommodate the distal movement of the impeller within the frame due to pressure changes caused by the subject's cardiac cycle (as described above). For some applications, the extent to which the drive cable can be unwound and thus axially shortened is limited by an outer tube containing the drive cable to prevent radial expansion. Therefore, for some applications, the axial shortening of the drive cable is relatively small. For some applications, the drive cable does not shorten because the outer tube limits the extent to which it can be unwound and thus limits the axial shortening. However, even in such applications, the drive cable is typically configured not to elongate because the coil winding is constructed as described above.

[0614] Optionally or additionally, the impeller is inserted into frame 34 such that the drive cable is already preloaded (i.e., the impeller applies tension to the drive cable, causing the drive cable to be axially elongated relative to its rest state). Due to the preload of the drive cable, this does not cause axial elongation of the drive cable when the impeller begins to rotate, as the drive cable is already axially elongated relative to its rest state. For some such applications, the impeller is still configured to perform axial reciprocating motion due to pressure changes caused by the subject's cardiac cycle (as described above).

[0615] In some applications, debris is generated by friction between the drive cable and the outer tube 140. Optionally or additionally, fluid (e.g., a purification fluid) is disposed between the drive cable and the outer tube. Typically, the drive cable acts as an impeller and pumps debris and / or fluid axially relative to the outer tube 140 due to the winding portion of the drive cable. In some applications, the winding portion of the drive cable is oriented such that the drive cable is configured to pump debris and / or fluid toward the proximal end of the ventricular assist device by rotating in a predetermined rotational direction, and not to pump debris and / or fluid toward the distal end of the ventricular assist device toward the patient's left ventricle.

[0616] Now for reference Figure 11A and Figure 11B ,Should Figure 11A and Figure 11B This is a schematic diagram of an interface component 154 according to some applications of the invention, which forms an interface between corresponding portions of the drive cable 130 of the ventricular assist device 20. For some applications, the drive cable includes a first portion and a second portion. Also refer to... Figure 10A Typically, a first portion is configured to be disposed within the aortic arch of the subject (i.e., the portion of the aorta corresponding to arrow 145), and a second portion is configured to be disposed along the descending aorta (the portion of the aorta corresponding to arrow 147), and the second portion is typically configured to extend to the motor unit 23, to the outside of the subject's body. Generally, where the drive cable 130 bends significantly, such as at the aortic arch, it is desirable that the drive cable be relatively flexible. However, a drive cable with greater flexibility is generally also more capable of axial stretching than a drive cable with less flexibility. Therefore, for some applications, there is a trade-off between wanting the drive cable to be flexible enough to conform to the curvature of the aortic arch, but on the other hand, not wanting the drive cable to be subjected to significant axial stretching (which could lead to loss of control over the axial position of the impeller). For some applications, the corresponding portions of the drive cable have a corresponding degree of flexibility. For example, the first portion of the drive cable configured to be disposed within the aortic arch may have a first degree of flexibility, while the second portion of the drive cable configured to be disposed within the descending aorta may have a second degree of flexibility, with the first flexibility being greater than the second flexibility.

[0617] For some applications, the coil via line 134 in the first section includes fewer wires than that in the second section, and the first section is configured to have greater flexibility than the second section. For example, as... Figures 11A-11BAs shown, the first portion may include more than 4 wires and less than 8 wires (e.g., 4-8 wires, or 5-7 wires, e.g., 6 wires), and the second portion may include more than 8 wires and less than 12 wires (e.g., 8-12 wires, or 9-11 wires, e.g., 10 wires). For some applications, the length of the first portion of the drive cable is greater than 20cm (e.g., greater than 25cm) and less than 40cm (e.g., less than 35cm), such as 20cm-40cm or 25cm-35cm. For some applications, the length of the second portion of the drive cable is greater than 60cm (e.g., greater than 70cm) and less than 100cm (e.g., less than 90cm), such as 60cm-100cm or 70cm-90cm.

[0618] For some applications, the two sections of the drive cable are joined together via an interface component 154. Typically, the wires of both sections are soldered to the interface component. For some applications, a groove 157 is cut into the interface component. The groove is configured such that stress generated by the wires at the junction is distributed over the radius of the groove, rather than concentrated at the point where the wires are soldered to the interface component. For some such applications, the interface component further includes a protrusion 158 that holds the wires in place during soldering to the interface component.

[0619] Now for reference Figure 11C , Figure 11D and Figure 11E , Figure 11C , Figure 11D and Figure 11E This is a schematic diagram of the junction 156 between the drive cable and the axial shaft 92 of a ventricular assist device according to some applications of the present invention. For some applications, use with reference to Figures 11A-11B The described technology is substantially similar to that used to connect the drive cable to the axial shaft. For some applications, the proximal end of the axial shaft (its defining junction 156) includes a groove 157 and / or a protrusion 158, which are substantially as described above, and... Figure 11C As shown in the image.

[0620] refer to Figure 11D For some applications, as the coiled wire approaches the junction 156, it is at least partially straightened (i.e., the wire pitch increases), making the angle between the wire and the junction less sharp than it would be if the wire were not straightened. By making the angle less sharp, stress is reduced at the point where the wire is welded to the interface component. (Reference) Figure 11EFor some applications, as the wire approaches the junction 156, it is flattened and pushed radially inward, in addition to being straightened. For some applications, the wire is flattened enough that each wire in the coil contacts the adjacent wire to form a cylinder, as shown. For example, the shape of the wire can be changed from a circular cross-section with a radius of approximately 0.2 mm to an elliptical cross-section with a minor axis of 0.12 mm. For some applications, flattening is performed along a length between 1 mm and 3 mm. For some applications, the wire is flattened by placing an overtube 159 around the wire, placing the overtube and wire on a mandrel, and pressing the overtube and wire radially inward. Subsequently, the overtube and the flattened wire are welded to the axial shaft 92 at the junction.

[0621] For some applications, use and reference Figure 11D and Figure 11E The described techniques are broadly similar to those used for joining two parts of a drive cable together. For some applications, as the coiled wire approaches the interface component 154, the coiled wire is at least partially straightened (i.e., the wire pitch is increased) so that the angle formed by the wire and the interface is less sharp than the angle would be formed if the wire were not straightened. By making the angle less sharp, stress is reduced at the point where the wire is soldered to the interface component. For some applications, as the wire approaches the interface component 154, in addition to being straightened, the wire is flattened and pushed radially inward. For some applications, the wire is flattened sufficiently such that each wire in the coil contacts the adjacent wire to form a cylinder. For example, the shape of the wire can be changed from a circular cross-section with a radius of approximately 0.2 mm to an elliptical cross-section with a minor axis of 0.12 mm. For some applications, flattening is performed along a length between 1 mm and 3 mm. For some applications, the wire is flattened by placing an outer sheath (not shown, but similar to outer sheath 159) around the wire, placing the sheath and wire on a mandrel, and pressing the sheath and wire radially inward. Subsequently, the outer sheath and flat wire are soldered to the interface component 154.

[0622] For some applications, a swaging technique is used to join two parts of a drive cable together. In some such applications, the ends of an inner tube and an outer tube are placed inside and outside the ends of the two parts of the drive cable, respectively, to form the junction between the parts. The inner tube is then placed on a rigid mandrel, and the inner and outer tubes, as well as the ends of the drive cable, are forged together by applying pressure around the outside of the outer tube. Once the ends of the drive cable parts and the inner and outer tubes have been forged together, the junction between the parts of the drive cable is formed. For some applications, a similar swaging technique is performed to connect the drive cable to an axial shaft at the junction 156.

[0623] Now for reference Figure 12 , Figure 12 This is a schematic diagram of a drive cable 130 of a ventricular assist device 20 according to some applications of the present invention, the drive cable 130 including a friction-reducing element 170 disposed around at least a portion of the drive cable. For some applications, the friction-reducing element 170 is used to reduce friction between the drive cable 130 (which rotates during operation of the ventricular assist device) and the outer tube 142 (which remains stationary during the rotation of the drive cable). In the example shown, the friction-reducing element 170 is a ball bearing. However, the scope of the invention includes the use of other friction-reducing elements to reduce friction between the drive cable and the outer tube. For example, other rolling element bearings, such as cylindrical rollers, spherical rollers, gear bearings, tapered rollers, needle rollers, and / or annular roller bearings, can be used. For some applications, the friction-reducing element is used as an alternative to including a first outer tube 140 in addition to a second outer tube 142. Figure 12 In the example shown, the friction reduction element is disposed between the drive cable and the second outer tube, and the ventricular assist device does not include the first and second outer tubes.

[0624] Typically, the ventricular assist device traverses the subject's aortic arch and / or other generally tortuous sections of the subject's vascular system. Without a friction-reducing element, the drive cable 130 and tube 142 will generally be in contact with each other, particularly at the tortuous sections of the vascular system. As described above, the drive cable 130 typically rotates relative to the tube 142, and in some applications, also moves axially back and forth relative to the tube 142. Therefore, without a friction-reducing element (or the first outer tube 140, as described above), considerable frictional forces will be generated at the points where the drive cable and outer tube 142 are in contact. Therefore, for some applications, a friction-reducing element is disposed between the drive cable 130 and the outer tube 142 to reduce the frictional forces generated at the points where the drive cable 130 and outer tube 142 are in contact. For some applications, the friction-reducing element is disposed substantially along the entire length of the drive cable 130 and outer tube 142. Alternatively, during operation of the ventricular assist device, a friction reduction element is disposed between the drive cable 130 and the outer tube 142 at a location where the drive cable 130 and the outer tube 142 are configured to be substantially bent (e.g., where the drive cable 130 and the outer tube 142 are disposed within the aortic arch).

[0625] Now for reference Figure 13 , Figure 13This is a schematic diagram of the procedure for a drive cable 130 of a ventricular assist device 20 for some applications according to the present invention. For some applications, near the proximal bearing 116, the axial shaft 92 and the cable 130 are surrounded by a first outer tube 140 and a second outer tube 142, as described above. Typically, both the first and second outer tubes remain stationary during rotation of the drive cable. For some applications, a purification fluid (e.g., a fluid containing glucose or dextrose) is pumped between the first and second outer tubes, and an opening 146 is present in the first outer tube near the proximal bearing. As described above, typically, the purification system 29 ( Figure 1A (As shown in the diagram) Control the purified fluid through inlet 86 and outlet 88 ( Figure 7 , Figure 8A and Figure 8B (as shown in the diagram). For some applications, the purifying fluid flows between the drive cable 130 and the first outer tube 140, such as by... Figure 13 The flow of the purified fluid is indicated by arrow 148. In this way, the interface between the drive cable 130 (which rotates) and the outer tube 140 (which remains stationary during the rotation of the drive cable) is purified. For some applications, some purified fluid additionally flows to the interface between the axial shaft and the proximal bearing 116, thereby purifying that interface, as indicated by... Figure 13 The purified fluid flow is indicated by arrow 149.

[0626] In some applications, the purifying fluid is pumped through the cavity 132 defined by the drive cable 130 and the axial shaft 92, such that at least some fluid flows all the way to the distal end of the axial shaft. In some applications, in this way, some purifying fluid flows to the interface between the axial shaft and the distal bearing 118, thereby purifying that interface, as described by... Figure 13 The purified fluid flow is indicated by arrow 150.

[0627] For some applications, a hemostatic valve 152 is disposed at the distal end of the lumen 122 of the distal distal portion 120, as described above. Optionally or additionally, a plug (not shown) is disposed at the distal end of the lumen 122 of the distal portion 120. Typically, the hemostatic valve and / or plug prevents blood from flowing into the lumen 122 and / or the lumen 132. Further typically, by preventing the discharge fluid from flowing out of the distal end of the lumen 122, the plug causes the discharge fluid to flow toward the interface between the axial shaft 92 and the distal bearing 118, as described above. Figure 13 The purified fluid flow is indicated by arrow 150.

[0628] For some applications, the alternative techniques described above are used to direct fluids (e.g., fluids containing glucose) to ventricular assist devices. Figure 13In the application shown, fluid is allowed to flow distally after passing through opening 146, as indicated by arrow 149, and as described above. However, for some applications, fluid flow in the distal direction is blocked (i.e., the fluid flow indicated by arrow 149 is absent). For some such applications, fluid is initially released into the space between drive cable 130 (which rotates) and outer tube 140 (which remains stationary during the rotation of drive cable), such that fluid fills the space between drive cable and outer tube 140 near opening 146. For example, as shown, fluid can be pumped into this space via the gap between first outer tube 140 and second outer tube 142. Then, typically throughout the operation of the ventricular assist device, fluid is held in place between drive cable and outer tube 140 near opening 146. The fluid is configured to remove air from the space between the drive cable and the outer tube, and / or to reduce the friction between the drive cable 130 (which rotates) and the outer tube 140 (which remains stationary during the rotation of the drive cable).

[0629] For some applications, a broadly similar technique is employed, but during operation of the ventricular assist device, fluid is pumped between the drive cable 130 (which rotates) and the outer tube 140 (which remains stationary during the rotation of the drive cable). For example, as shown, fluid can be pumped into the space via the gap between the first outer tube 140 and the second outer tube 142. For some applications, fluid is continuously pumped between the drive cable and the outer tube during operation of the ventricular assist device, or periodically pumped between the drive cable and the outer tube during operation of the ventricular assist device. Note that even for such applications, fluid is pumped between the drive cable and the outer tube, but does not flow into the subject's bloodstream because the flow of fluid in the distal direction is blocked, as described above. The pumping of fluid is configured to remove air from the space between the drive cable and the outer tube to reduce friction between the drive cable 130 (which rotates) and the outer tube 140 (which remains stationary during the rotation of the drive cable), and / or is configured to remove debris generated by the ventricular assist device from the junction between the drive cable and the outer tube.

[0630] Now for reference Figure 14A and Figure 14B , Figure 14A and Figure 14BThis is a schematic diagram of a frame 34 of a ventricular assist device 20 according to some applications of the present invention, to which a stator 182 is coupled proximal to. For some applications, the stator is integrally formed with the frame 34, as described in further detail below. Typically, the stator includes a plurality of curved protrusions 66 (e.g., more than two and / or fewer than eight curved protrusions 66) extending from the frame 34 when the device 20 is in a non-radially constrained configuration, and is made of a flexible material (e.g., a polymer, such as polyurethane and / or silicone). Typically, the curvature of the curved protrusions is such that it is opposite to the direction of rotation of the impeller, as described in further detail below. For some applications, by means of the use of curved protrusions (e.g., curved such that they are opposite to the direction of rotation of the impeller of the ventricular assist device, as described in further detail below), the stator 182 is configured to reduce the swirling component of the blood flow before blood flows out from the proximal end of the frame of the ventricular assist device.

[0631] As described above, typically, device 20 is inserted into the subject's ventricle via a catheter while frame 34 is in a radially constrained state. Upon release from the catheter, the frame automatically assumes its unconstrained shape due to self-expansion of frame 34. Typically, during frame insertion into the left ventricle, the stator's curved protrusions are in a folded state, and the minimum diameter at which the frame can be radially constrained is not significantly increased compared to if the tube did not contain the curved protrusions. As frame 34 expands, the curved protrusions are configured to automatically assume their curved configuration due to their engagement with frame 34.

[0632] For some applications, the curved protrusion 66 is made of a flexible material (e.g., a polymer, such as polyurethane and / or silicone). The curved protrusion is typically coupled to a curved strut 186 of the frame 34, the curvature of which defines the curvature of the curved protrusion. Typically, the flexible material is coupled to the frame 34 such that it defines an inner cavity 188 passing through it. Figure 14B The cavity 188 is aligned with the longitudinal axis of the frame. The axial shaft 92 of the ventricular assist device typically enters the proximal end of the frame via the cavity 188.

[0633] For some applications, to facilitate the attachment of flexible material to the frame, to shape the flexible material into a desired form, and / or to facilitate the formation of the cavity 188, multiple elongated elements 190 (e.g., ropes and / or lines, typically made of a material similar to elongated element 67) are attached to the proximal end of the frame. For some applications, a curved strut 186 defines a ring 192 or other connecting element at its distal end, to which the elongated element 190 is attached. The flexible material is typically attached to the frame such that a curved membrane of the material is supported by the curved strut and the elongated elements, each membrane defining a corresponding curved protrusion. For some applications, the ropes and / or lines attached to the proximal end of the frame are tied together to define a circle 191, which defines one of the ends of the cavity 188. For example, during the formation of the stator, a mandrel can be placed through a proximal bearing 116, and the elongated element can be attached to the ring 192 and made to surround the mandrel to define... Figure 14B The pattern of the elongated element is shown in the diagram. The proximal end of the frame having the elongated element and the mandrel is then immersed in a material (which is typically a polymer, such as silicone) while the material is in an uncured liquid state. Subsequently, the material is cured, causing it to solidify, for example, by allowing it to dry. Once the material has dried, the mandrel is typically removed. For some applications, the other end of the cavity 188 is defined by a proximal bearing 116 located at the proximal end of the frame 34. Typically, a flexible material extends from a circle 191 defined by a cord and / or thread to the proximal bearing 116 to define the cavity 188. For some applications, a suture 189 is tied around the curved support 186 to facilitate a connection between the material and the support, for example, as described above with reference to the suture 53 of the impeller 50.

[0634] Now for reference Figure 15A , Figure 15A This is a schematic diagram of the flat outline of the frame 34 of a ventricular assist device 20 according to some applications of the present invention. As shown, the frame includes curved struts 186 at its proximal ends, with rings 192 disposed toward the ends of each strut. Also refer to Figure 15B , Figure 15B This is a schematic diagram showing an enlarged view of the proximal end of a frame 34 according to some applications of the invention. Once the flexible material is attached to the curved strut, the end 194 of the curved strut 186 typically defines the orientation of the leading edge of the corresponding blade (i.e., curved protrusion) of the stator. Also refer to... Figure 15C , Figure 15C This is a schematic diagram of a frame 34 according to some applications of the invention, showing a frame in which the material defining the curved protrusion 66 is attached to the frame. It can be observed that the orientation of the leading edge of the curved protrusion is defined by the orientation of the corresponding end of the curved strut.

[0635] like Figure 15BAs shown, the end 194 of the curved strut 186 is shaped to define an angle α relative to the axial component of the blood flow through the frame, indicated by arrow 196, and parallel to the longitudinal axis of the frame, and toward the proximal end of the frame. Figure 15C As indicated in the diagram, the leading edge of the corresponding curved protrusion, relative to the approximate direction of blood flow, is typically defined at an angle approximately equal to angle α. (For some applications, when the strut 186 is radially expanded, the angle of the leading edge of the curved protrusion becomes slightly less than α.) For some applications, angle α is greater than 45 degrees (e.g., greater than 60 degrees), and / or less than 85 degrees (e.g., less than 80 degrees), for example, 45 degrees–85 degrees, or 60 degrees–80 degrees.

[0636] The impeller rotates in the direction of... Figure 15C Arrow 198 indicates this. (As shown in...) Figure 15C As can be observed, the curvature of the curved protrusion typically results in a direction opposite to the rotation of the impeller (which is the direction of rotation of the swirling component of the blood flow, as imparted by the impeller to the blood flow). From its distal end to its proximal end, the curved protrusion gradually bends to become nearly parallel to the longitudinal axis of the frame. The curvature of the curved protrusion reduces the swirling component of the blood flow before it flows out from the proximal end of the frame of the ventricular assist device.

[0637] Now for reference Figure 16A , Figure 16B , Figure 16C and Figure 16D , Figure 16A , Figure 16B , Figure 16C and Figure 16D This is a schematic diagram of a ventricular assist device 20 according to some applications of the present invention, the ventricular assist device including one or more blood pressure measuring tubes 210. As described above, typically, the ventricular assist device includes a tube 24 that passes through the aortic valve of a subject, such that the proximal end of the tube is disposed within the subject's aorta and the distal end of the tube is disposed within the subject's left ventricle. Typically, a blood pump, typically including an impeller 50, is disposed within the tube 24, within the subject's left ventricle, and is configured to pump blood from the left ventricle into the subject's aorta through the tube 24. For some applications, the blood pressure measuring tubes 210 are configured to extend at least to the outer surface 212 of the tube 24, such that an opening 214 at the distal end of the blood pressure measuring tube is in direct fluid communication with the patient's blood flow outside the tube 24. Pressure sensor 216 (in Figure 1A(Schematic illustration) Blood pressure is measured inside the blood pressure measuring tube. Typically, a pressure sensor measures the blood pressure of a subject outside the tube 24 by measuring the blood pressure inside the tube. Typically, the blood pressure measuring tube 210 extends from outside the subject's body to an opening 214 at the distal end of the tube, and the pressure sensor 216 is positioned towards the proximal end of the tube, for example, outside the subject's body. For some applications, a computer processor 25 (… Figure 1A It receives the indication of the measured blood pressure and, in response to the measured blood pressure, controls the pumping of blood through the impeller.

[0638] refer to Figure 16A and Figure 16B For some applications, one or more blood pressure measuring tubes include one or more left ventricular blood pressure measuring tubes 220, which are configured to extend to the outer surface of a blood pump tube 24 at a location along a tube configured to be located within the left ventricle of the subject, near the blood pump (e.g., near the impeller 50). For such applications, a pressure sensor is configured to measure the subject's left ventricular pressure by measuring blood pressure within the left ventricular blood pressure measuring tube. For some applications, ventricular assist devices include two or more such left ventricular blood pressure measuring tubes, for example, such as... Figure 16A and Figure 16B As shown in the diagram. For some applications, based on the blood pressure measured in each left ventricular blood pressure measuring tube, the computer processor 25 determines whether the opening of one of the two or more left ventricular blood pressure measuring tubes is blocked. This can happen, for example, due to the opening contacting the wall of the interventricular septum and / or portions of different ventricles. Typically, in response to determining that the opening of one of the two or more left ventricular blood pressure measuring tubes is blocked, the computer processor determines the subject's left ventricular pressure based on the blood pressure measured in a different left ventricular blood pressure measuring tube among the two or more left ventricular blood pressure measuring tubes.

[0639] For some applications, one or more blood pressure measuring tubes include one or more aortic blood pressure measuring tubes 222, which are configured to extend to the outer surface of the tube at a location along a tube configured to be within the aorta of the subject, such as Figure 16C As shown in the diagram. For this application, the pressure sensor is configured to determine the subject's aortic pressure by measuring the blood pressure within the aortic blood pressure measuring tube. For some applications, the ventricular assist device includes two or more such aortic blood pressure measuring tubes, for example, as... Figure 16CAs shown in the diagram. For some applications, based on the blood pressure measured in each aortic blood pressure measuring tube, the computer processor 25 determines whether the opening of one of the two or more aortic blood pressure measuring tubes is blocked. This can happen, for example, due to the opening coming into contact with the wall of the aorta. Typically, in response to determining that the opening of one of the two or more aortic blood pressure measuring tubes is blocked, the computer processor determines the subject's aortic pressure based on the blood pressure measured in a different aortic blood pressure measuring tube among the two or more aortic blood pressure measuring tubes.

[0640] For some applications, the ventricular assist device includes both a left ventricular blood pressure measuring tube and an aortic blood pressure measuring tube, both of which extend to the outer surface of tube 24, for example, as... Figure 16C As shown in the image.

[0641] Still referencing Figure 16C As described above, for some applications, the drive cable 130 extends from a motor outside the subject's body to an axial shaft 92 on which the impeller 50 is disposed. Typically, the drive cable is disposed within an outer tube 142. For some applications, the drive cable is disposed within a first outer tube 140 and a second outer tube 142, as described above. For some applications, one or more blood pressure measuring tubes are disposed within the outer tube 142, surrounding the drive cable. For some applications, as shown, portions of one or more blood pressure measuring tubes are defined by the wall of the outer tube 142. For some applications, within the outer tube 142, the blood pressure measuring tubes have an elliptical cross-section (as shown). Typically, this increases the cross-sectional area of ​​the tube compared to if the tube had a circular cross-section. Typically, the tube has a circular cross-section in the distal portion (which extends to the opening 214) of each of the blood pressure measuring tubes. For some applications, the diameter of the distal portion of the tube is greater than 0.2 mm and / or less than 0.5 mm (e.g., 0.2 mm–0.5 mm).

[0642] like Figure 16A As shown, for some applications, at least one aortic blood pressure measuring tube 222 is used to measure aortic blood pressure, the aortic blood pressure measuring tube 222 defining an opening 219 at the distal end of the outer tube 142. The aortic blood pressure measuring tube is configured to extend from the outside of the subject's body to the outer surface of the outer tube 142 within the subject's aorta, such that the opening at the distal end of the aortic blood pressure measuring tube is in direct fluid communication with the subject's aortic blood flow. Note that for such applications, the aortic blood pressure measuring tube does not extend to the outer surface of the tube 24. The blood pressure sensor 216 is configured to measure the subject's aortic blood pressure by measuring the blood pressure within the aortic blood pressure measuring tube. For some applications, the opening 219 in the outer tube 142 is located within the tube 24, such as... Figure 16DAs shown in the diagram. Aortic pressure is measured via opening 219 because the pressure within tube 24, located downstream of the impeller, is typically equal to the aortic pressure.

[0643] like Figure 16A and Figure 16B As shown, for some applications, the outer tube 142 defines a groove 215 in a portion of the outer surface of the outer tube, which is configured to be disposed within the tube 24. Typically, during insertion of the ventricular assist device into the body of a subject, a portion of the blood pressure measuring tube 210 extending from within the tube 24 to at least the outer surface of the tube 24 is configured to be disposed within the groove, such that this portion of the blood pressure measuring tube does not protrude from the outer surface of the outer tube.

[0644] Now for reference Figure 16D For some applications, the distal portion of the blood pressure measuring tube 210 is disposed on the exterior of the tube 24. For example, as shown, the blood pressure measuring tube 210 can extend from the outer tube 142 to the proximal end of the tube 24, and thereafter the blood pressure measuring tube can be embedded in the outer surface of the tube 24. For some applications, one or more tubes are used in combination. Figure 16D The tubes extend along the outer surface of the tube 24 as shown, but these tubes extend all the way to the distal end of the tube 24, up to the distal portion 120 of the ventricular assist device. The tubes are used to expand the expandable portion of the distal portion, as referenced below. Figure 21C Further detailed description.

[0645] Although reference Figures 16A-16D The described ventricular assist devices have been described as including a blood pump configured to be positioned within the left ventricle of a subject; however, for some applications, the blood pressure measuring tube 210 and the techniques described herein for use with the blood pressure measuring tube 210 are used with ventricular assist devices that include a blood pump located elsewhere (e.g., within the subject's aorta). For some applications, substantially similar techniques are used with right ventricular assist devices. For example, device 20 can be inserted into the right ventricle and used to pump blood from the right ventricle to the pulmonary artery. For some such applications, the blood pressure measuring tube is used to measure pressure in the right ventricle and / or the pulmonary artery. For some applications, devices substantially similar to device 20 are used as cardiac assist devices by pumping blood from the right atrium to the right ventricle, from the vena cava to the right ventricle, from the right atrium to the pulmonary artery, and / or from the vena cava to the pulmonary artery in an antegrade direction. For some such applications, the blood pressure measuring tube is used to measure pressure in the right ventricle, vena cava, right atrium, and / or pulmonary artery.

[0646] Generally, the scope of this invention includes applying any of the devices and methods described herein to a right ventricular assist device, making necessary modifications. Right ventricular assist devices typically have a configuration substantially similar to that described herein and are used to pump blood from the right ventricle to the pulmonary artery, wherein tube 24 passes through the pulmonary artery semilunar valve. For some applications, components of device 20 may be adapted to different types of blood pumps. For example, aspects of the invention may be applicable to pumps for pumping blood from the vena cava and / or right atrium into the right ventricle, from the vena cava and / or right atrium into the pulmonary artery, and / or from the renal vein into the vena cava. Such aspects may include features of pump section 27, impeller 50, drive cable 130, devices and methods for measuring blood pressure, devices and methods for measuring flow rate, etc.

[0647] For some applications, a technique substantially similar to that described for the reference blood pressure measuring tube 210 is performed using a wire extending from within the blood pump tube 24 (and typically from outside the subject's body) to the outer surface of the tube 24, such that at least one end of the wire is electrically connected to the blood flow of the subject outside the tube 24. The subject's blood pressure (e.g., the subject's ventricular blood pressure and / or the subject's aortic blood pressure) is measured outside the tube 24 by detecting electrical parameters using a portion of the wire electrically connected to the subject's blood flow outside the tube 24.

[0648] Now for reference Figure 17A , Figure 17B and Figure 17C , Figure 17A , Figure 17B and Figure 17C This is a schematic diagram of the outer tube 142 of a ventricular assist device 20 according to some applications of the present invention, the outer tube including a pitot tube 225 configured to measure blood flow through the tube 24 of the device. Figures 17A-17C The portion of the outer tube 142 shown is typically disposed within the tube 24. For some applications, the flow obstruction 226 (which is typically funnel-shaped) is configured to create a stagnation region near the stagnation pressure measuring port 227. For some applications, such as... Figure 17A As shown, a flow straightener 228 is added to the outer surface of the pipe 142 to remove any swirling component of the flow (which does not contribute to the axial flow rate). Alternatively, as... Figure 17BAs shown, the stagnation pressure measuring port is positioned sufficiently close within the funnel-shaped flow barrier 226 such that the flow barrier itself removes eddy current components of the flow before blood reaches the stagnation pressure measuring port. For some applications, the stagnation pressure measuring port includes a short tube 233 extending from an outer tube 142 within the funnel-shaped flow barrier 226, such that the opening of the short tube 233 faces the direction of axial blood flow through the tube 24. The outer tube 142 further defines an opening 219, which is generally as described above, and this opening 219 serves as a static pressure measuring port 229. The pressures within the stagnation pressure measuring port 227 and the static pressure measuring port 229 are measured using pressure sensors, for example, as referenced above. Figures 16A-16D The pressure sensor described is placed outside the subject's body.

[0649] In some applications, the flow rate through pipe 24 is calculated based on pressure measurements. For example, the flow rate through pipe 24 can be calculated using the following equation:

[0650]

[0651] in:

[0652] Q is the flow rate through pipe 24.

[0653] C is a calibration constant, which is determined empirically and takes into account factors such as the geometry of the impeller speed and pressure measuring ports 227 and 229.

[0654] A is the cross-sectional area of ​​pipe 24 (excluding the area occupied by outer pipe 142).

[0655] △P is the difference between the stagnation pressure (measured via pressure measuring port 227) and the static pressure (measured via pressure measuring port 229).

[0656] p is the fluid density of blood.

[0657] Now for reference Figure 18 , Figure 18This is a schematic diagram of a ventricular assist device 20 according to some applications of the present invention, wherein the distal end portion 120 of the device is a radially expandable, non-invasive distal end portion. As described above, the ventricular assist device typically includes a tube 24 that passes through the aortic valve of a subject, such that the proximal portion of the tube is disposed within the subject's aorta, and the distal portion of the tube is disposed within the subject's left ventricle. The tube 24 defines one or more blood inlet openings 108 within the distal portion of the tube and one or more blood outlet openings 109 within the proximal portion of the tube. A blood pump of the ventricular assist device configured to be disposed within the tube 24 pumps blood from the left ventricle into the tube 24 through one or more blood inlet openings and pumps blood out of the tube 24 into the aorta through one or more blood outlet openings. Typically, the radially expandable, non-invasive distal end portion 120 is disposed distally within the subject's left ventricle relative to one or more blood inlet openings. The distal end portion is configured to be inserted into the left ventricle with a radially constrained configuration. Typically, during insertion of the distal portion into the left ventricle, at least a portion of the distal portion is positioned within the delivery catheter 143 (e.g., in...). Figure 1B (as shown in the diagram) and the delivery catheter holds the distal end portion within the radial constraint configuration. The distal end portion is configured to present a non-radial constraint configuration within the left ventricle of the subject, wherein at least a portion 232 of the distal end portion expands radially relative to the radial constraint configuration of the distal end.

[0658] For some applications, the radially expandable, non-invasive distal end portion 120 includes a frame 234 made of a shape memory material, such as nitinol, which is shaped such that it expands radially upon release from the delivery catheter. Typically, the frame is covered with a biocompatible, blood-impermeable material 236, such as polyurethane, polyester, and / or silicone, which is usually configured to form a continuous surface covering the frame. For some applications, the distal end portion additionally includes a non-invasive distal end 238, which may have a similar shape to the distal end portion 120, as referenced above. Figure 6C and / or refer to the following: Figure 21B As described.

[0659] The radially expandable, non-invasive distal portion 120 is typically configured such that, in a non-radially constrained configuration of the distal portion, the radially expandable portion 232 of the distal portion three-dimensionally separates one or more blood inlet openings 108 from the internal structures of the left ventricle. In this way, the radially expandable portion 232 of the distal portion separates one or more blood inlet openings 108 from the interventricular septum, chordae tendineae, papillary muscles, and / or the apex of the left ventricle. For some applications, the radially expandable portion 232 of the distal portion is shaped to guide blood flow from the left ventricle into one or more blood inlet openings, such as by… Figure 18As indicated by arrow 240 in the image.

[0660] Now for reference Figures 19A-19B ,Should Figures 19A-19B This is a schematic diagram of a ventricular assist device 20 according to some applications of the present invention, wherein the distal end portion 120 of the ventricular assist device is a radially expandable, non-invasive distal end portion. Also refer to... Figures 20A-20B ,Should Figures 20A-20B This is a schematic diagram of a ventricular assist device 20 according to some alternative applications of the present invention, wherein the distal end portion 120 of the ventricular assist device is a radially expandable, non-invasive distal end portion. Figure 19A and Figure 20A The distal end portion is shown in its radially constrained configuration, and this distal end portion is at least partially disposed within the delivery conduit 143, and Figure 19B and Figure 20B The distal end portion in its non-radial constrained configuration is shown. Generally, as... Figures 19A-19B and Figures 20A-20B The distal end portion 120 shown in the figure has the same characteristics as described above. Figure 18 The function described in the distal end portion 120 shown in the figure is substantially similar to that of the function described in the figure.

[0661] As described above, typically, during insertion of the distal end into the left ventricle, at least a portion of the distal distal portion 120 is disposed within the delivery catheter 143, and the delivery catheter holds the distal distal portion within a radially constrained configuration, such as... Figure 19A and Figure 20AAs shown in the diagram. For some applications, the distal distal portion is configured such that the distal region 244 of the distal distal portion protrudes from the distal end of the delivery catheter when the delivery catheter holds the distal distal portion in a radially constrained configuration. Typically, at least in the radially constrained configuration of the distal distal portion, the distal region is at least semi-rigid and shaped to converge radially in the longitudinal direction toward the distal end 246 of the distal distal portion. Typically, the delivery catheter is inserted into the subject's vascular system via a perforation. For some applications, the radially converging semi-rigid distal region of the distal distal portion is configured to act as a dilator by widening the perforation during insertion of the delivery catheter via the perforation. In this way, the delivery catheter and components of a ventricular assist device disposed within the delivery catheter can be inserted into the perforation without prior widening of the perforation and without the need for a separate inserter device for facilitating insertion of the delivery catheter through the perforation. For some applications, the distal region is configured to allow percutaneous insertion of the catheter into the punctured vessel by placing a first guide wire through the distal region of the distal distal portion. Subsequently, by tracing the route and shape of a second guide wire, which has less stiffness than the first guide wire, the distal region is used to guide the catheter along an arcuate anatomical structure (e.g., the aortic arch). For some such applications, the delivery catheter 143 itself acts as an inserter. Typically, the delivery catheter has an inner diameter of less than 9 mm. For example, the delivery catheter may be an 8-French catheter. For some applications, the delivery catheter is inserted through a perforation via a short inserter device.

[0662] For some applications, the distal end portion 120 is configured such that, in a non-radial constraint configuration of the distal end portion, the distal end 246 of the distal end portion is enclosed within the radially expandable portion 232 of the distal end portion. For some applications, the distal end retracts proximally such that the distal end is enclosed within the radially expandable portion. For example, the distal end portion may include a spring 249 and / or an elastic material configured to retract the distal end of the distal end portion, such as from... Figures 19A to 19B As shown in the transition. For some applications, the distal end is flipped so that the distal end becomes enclosed within the radially expandable portion of the distal end portion. For example, from Figures 20A to 20B The transition shows the distal end 246 of the distal distal portion 120 flipped over, as indicated by arrow 264. For some applications, by making the distal end enclosed within a radially expandable portion, the distal end is prevented from becoming entangled within the chordae tendineae, and / or is prevented from causing damage to the internal structures of the left ventricle.

[0663] refer to Figure 19BFor some applications, the distal end portion includes multiple longitudinal struts 248 shaped to bend radially outward. Typically, the struts are made of shape memory materials, such as nitinol. For some applications, the struts are covered with a biocompatible, blood-impermeable material 250, such as polyurethane, polyester, and / or silicone, which is typically configured to form a continuous surface covering the struts. Reference Figure 20B For some applications, the distal end portion includes a braided shape memory material 260. For some applications, the braided shape memory material is at least partially covered with a biocompatible, blood-impermeable material 262, such as polyurethane, polyester, and / or silicone, which is typically configured to form a continuous surface covering the braided shape memory material. Alternatively, the braided shape memory material may not be covered.

[0664] Now for reference Figure 21A , Figure 21B , Figure 21C and Figure 21D , Figure 21A , Figure 21B , Figure 21C and Figure 21D This is a schematic diagram of the distal end portion 120 of a ventricular assist device 20 according to some applications of the present invention, which is configured to be non-invasive. For example... Figure 21A As shown, for some applications, the distal end portion includes a J-shaped end 270 at its distal end. For example... Figure 21B As shown, for some applications, the distal end portion includes a spherical end 272 at its distal end. For example... Figure 21A and Figure 21B As shown, for some applications, the distal end portion is externally shaped to define a truncated cone 274 near the J-shaped or spherical end. Typically, the proximal end 276 of the truncated cone serves as a stopper for use with reference to... Figure 6C The delivery conduit 143 is prevented from advancing past the proximal end in a manner substantially similar to that described for the flared portion 124.

[0665] For some applications, the end portion has a straightening configuration, wherein the end portion is shaped to define a truncated cone that extends from the proximal end of the truncated cone to the distal end of the distal end portion. For example, through the cavity 122 defined by the end portion ( Figures 6A-6C (As shown in the diagram) An inserted guide wire (such as guide wire 10) can hold the distal portion in its straightened configuration. For some such applications, the distal portion has an unconstrained configuration (the distal portion is configured to present this configuration within the ventricle (e.g., due to the removal of the guide wire from the distal portion)), wherein the distal portion of the truncated cone is shaped into a J-shaped end, such as... Figure 21A As shown in the image.

[0666] like Figure 21C As shown, for some applications, the outer surface of the distal distal portion includes an inflatable portion 278 (e.g., a sac) configured to inflate when the distal distal portion is placed in the left ventricle of a subject. For some such applications, an inflatable lumen for inflating the inflatable portion is configured to pass through the outer tube 142 and then along the outer surface of the tube 24 to reach the inflatable portion of the distal distal portion. For example, the inflatable lumen can be configured to... Figure 16D The blood pressure measuring tube 210 shown is constructed in a generally similar manner, but may continue to extend along the outer surface of the tube 24 to the distal end of the tube, and then continue to the expandable portion of the distal end portion. For some applications, the distal end of the distal end portion includes an arched portion 280. As described above, typically, the distal end portion includes a hemostatic valve 152 at its distal end.

[0667] like Figure 21D As shown, for some applications, the outer surface of the distal end portion includes a radially expandable portion 282 (e.g., a radially expandable mesh and / or a radially expandable frame as shown), which is configured to self-expand when the distal end portion is placed in the left ventricle of the subject.

[0668] like Figure 21C and Figure 21D As shown, the undamaged distal portion 120 is typically configured such that, in an expanded or radially expanded configuration of the distal portion, the expanded or radially expanded portion separates one or more blood inlet openings 108 from the internal structures of the left ventricle in three dimensions. In this way, the expanded or radially expanded portion of the distal portion separates one or more blood inlet openings 108 from the interventricular septum, chordae tendineae, papillary muscles, and / or the apex of the left ventricle. For some applications, the expanded or radially expanded portion of the distal portion is shaped to guide blood flow from the left ventricle into one or more blood inlet openings, as referenced above. Figure 18 The distal end portion 120 shown in the figure is described.

[0669] Now for reference Figure 22A and Figure 22B , Figure 22A and Figure 22BThis is a schematic diagram of the distal end portion 120 of a ventricular assist device 20 in axially reinforced and non-axially reinforced configurations, respectively, according to some applications of the invention. As described above, for some applications, the distal end portion is configured such that a distal region 244 of the distal end portion protrudes from the distal end of the delivery catheter when the delivery catheter holds the distal end portion in a radially constrained configuration. Typically, at least in the axially reinforced configuration of the distal end portion, the distal region is at least semi-rigid and shaped to converge radially in the longitudinal direction toward the distal end 246 of the distal end portion. Typically, the delivery catheter is inserted into the subject's vascular system via a perforation. Additionally, typically, the distal end portion defines a lumen 122 through which the guide wire 10 is inserted, as described above. For some applications, the radially converging semi-rigid distal region of the distal end portion is configured to act as a dilator by widening the perforation during insertion of the delivery catheter via the perforation. In this way, the delivery catheter and components of the ventricular assist device disposed within the delivery catheter can be inserted into the perforation without prior perforation enlargement and without the need for a separate introducer device to facilitate insertion of the delivery catheter through the perforation. For some applications, the distal region is configured to allow percutaneous insertion of the catheter into the punctured vessel by positioning a first guide wire through the distal region of the distal distal portion. Subsequently, the distal region is used to guide the catheter along an arcuate anatomy (e.g., the aortic arch) by tracing the route and shape of a second guide wire, which is less stiff than the first guide wire. For some such applications, the delivery catheter 143 itself acts as the introducer. Typically, the delivery catheter has an inner diameter of less than 9 mm. For example, the delivery catheter may be an 8-French catheter. For some applications, the delivery catheter is inserted through the perforation via a short introducer device.

[0670] For some applications, the distal end portion is made of a flexible material (such as silicone), with a spring 290 disposed around the lumen 122. During insertion of the ventricular assist device into the subject's body, a rigid or semi-rigid reinforcing element 292 (e.g., a rigid or semi-rigid tube) is placed within the distal region 244 of the distal end portion to reinforce the distal region. This configuration in Figure 22A As shown in the diagram. Subsequently, the reinforcing element retracts, leaving the distal region of the distal end portion undamaged (e.g., elastic and flexible), as... Figure 22B As shown in the image.

[0671] Now for reference Figure 23A and Figure 23B , Figure 23A and Figure 23BThis is a schematic diagram of the distal end portion 120 of a ventricular assist device 20 in radially constrained and non-radially constrained configurations, respectively, according to some applications of the invention. For some applications, the distal region 144 of the distal end portion is shaped as a cone with slits 294 (e.g., two slits) within it. During insertion of the ventricular assist device into the subject's body, the distal region maintains its conical shape via a delivery catheter 143. This configuration in… Figure 23A As shown in the diagram. Subsequently, when the delivery conduit retracts, the distal region is configured to form a two-dimensional circular or elliptical shape by splitting into two semicircles 296 or semi-ellipses around the slit, as... Figure 23B As shown in [the image]. Figure 23B In the configuration shown, the distal terminal portion is typically configured to be undamaged and is configured to separate one or more blood inlet openings 108 from the internal structures of the left ventricle in two dimensions. In this way, the distal terminal portion separates one or more blood inlet openings 108 from the interventricular septum, chordae tendineae, papillary muscles, and / or the apex of the left ventricle.

[0672] Now for reference Figure 24A and Figure 24B , Figure 24A and Figure 24B This is a schematic diagram of the distal end portion 120 of a ventricular assist device 20 in radially constrained and non-radially constrained configurations, respectively, according to some applications of the invention. For some applications, the distal region 244 of the distal end portion is shaped as a cone with slits 294 (e.g., four slits) within it. During insertion of the ventricular assist device into the subject's body, the distal region maintains its conical shape via a delivery catheter 143. This configuration in… Figure 24A As shown in the diagram. Subsequently, as the delivery conduit retracts, the distal region is configured to form a three-dimensional basket shape by splitting into four arms 298 around the slit, as... Figure 24B As shown in the image. (Note that the fourth arm is in...) Figure 24B (Hidden from view.) Figure 24B In the configuration shown, the distal terminal portion is typically configured to be non-invasive and is configured to separate one or more blood inlet openings 108 from the internal structures of the left ventricle in three dimensions. In this way, the distal terminal portion separates one or more blood inlet openings 108 from the interventricular septum, chordae tendineae, papillary muscles, and / or the apex of the left ventricle.

[0673] For some applications, the distal distal portion 120 has a pointed distal region 244, the diameter of which at the proximal end of the distal distal portion is approximately equal to the diameter of the delivery conduit 143. Typically, the pointed distal region 244 has a length less than half the total length of the distal distal portion (e.g., less than one-quarter of the total length of the distal distal portion). Additionally, the distal distal region is typically more flexible than the proximal region of the distal distal portion. Typically, the distal region is configured to be straightened into a generally conical shape when a sufficiently rigid guide wire is inserted therein. For some applications, the distal region is configured to curl into a J-shape (e.g., as shown in the image) without any external force acting on the distal region. Figure 21A (As shown in the image).

[0674] Typically, the distal region of the distal terminal portion acts as a dilator for delivering catheter 143, allowing percutaneous insertion of the catheter into the punctured blood vessel by positioning a first guide wire through the distal region of the distal terminal portion. Subsequently, the distal terminal portion is used to guide the catheter along arched anatomy structures (e.g., the aortic arch) by tracing the route and shape of a second guide wire, which is less stiff than the first guide wire. For some applications, as described above, the distal region of the distal terminal portion is configured to curl when the second guide wire is withdrawn.

[0675] For some applications, refer to Figures 18-24B The features of the distal end portion 120 described above, as well as the techniques and references for practicing it, are mentioned in the preceding text. Figures 6A-6C and / or Figure 13 The described end portion 120 combines the features described therein with the techniques used to practice it.

[0676] Now for reference Figure 25A , Figure 25A This is a schematic diagram of a first portion 160A and a second portion 160B of a connecting element according to some applications of the invention, the connecting element being configured to facilitate radial contraction (e.g., during collapse) of an impeller (e.g., impeller 50 described above) independently of other components of the ventricular assist device. The first portion 160A and the second portion 160B are configured to engage with each other. The first portion is disposed on the impeller, and the second portion is disposed on a frame 34, for example on the distal bearing 118 of the frame 34. Note that, for illustrative purposes, in Figure 25A Only some parts of the impeller are shown in the image.

[0677] Also refer to Figure 25B and Figure 25C , Figure 25B and Figure 25CThis is a schematic diagram of the various stages of impeller collapse according to some applications of the invention. In some applications, before collapsing the outer portion of the ventricular assist device (e.g., the frame 34 of the left ventricular assist device 20, as shown), the impeller is radially contracted by engaging portions 160A and 160B together and axially elongating the impeller to radially contract it. Subsequently, the outer portion of the left ventricular assist device is radially contracted. In some applications, collapsing the impeller in this manner reduces the likelihood of the impeller becoming damaged during the collapse of the outer portion of the left ventricular assist device. Subsequently, when the impeller and frame are positioned in the left ventricle of the subject, the first and second portions of the connecting elements separate from each other, allowing the impeller to move relative to the frame 34.

[0678] for Figures 25A-25C The collapse technique shown can optionally or additionally, as described above, involve the impeller being configured to be coupled to an axial shaft by means of only one of the ends of the impeller (e.g., the proximal end of the impeller) and the other end (e.g., the distal end) becoming collapsible relative to the axial shaft. Sliding the impeller along the shaft via the other end of the impeller causes the impeller to become axially elongated and thus collapse.

[0679] Now for reference Figure 26 , Figure 26 This is a schematic diagram of a stopper 300 according to some applications of the invention, configured to prevent distal advance of the impeller 50 of the ventricular assist device 20 during withdrawal of the device from the subject's body. As described above, typically, to withdraw the ventricular assist device from the subject's body, the delivery conduit 143 is advanced distally over the frame 34 and the impeller 50, causing the frame and impeller to exhibit their radially constrained configuration. In some cases, there is a risk that the drive cable 130 may break when the impeller is pushed distally by the delivery conduit. In some applications, in the event of a drive cable breakage, the distal advance of the proximal end of the impeller then causes the stopper 300 to engage with the shoulder 302, thereby preventing further advance of the proximal end of the impeller. It should be noted that the stopper is configured such that it does not engage with the shoulder 302 during normal operation of the ventricular assist device (and throughout the entire axial reciprocating cycle described above).

[0680] For some applications (not shown), multiple electrodes are positioned on the distal portion of the left ventricular assist device. Computer processor 25 ( Figure 1AA current is applied between the distal and proximal electrodes, with the distal electrode typically positioned near the apex of the heart and the proximal electrode typically positioned above the aortic valve. The conductance of the current between each pair of electrodes is then measured by a computer processor. For some applications, the application of current and conductance measurement are performed using a technique substantially similar to that described in Cassidy et al.’s article, “The Conductance Volume Catheter Technique for Measurement of Left Ventricular Volume in Young Piglets” (Pediatric Research, Vol. 31, No. 1, 1992, pp. 85-90). For some applications, the computer processor is configured to derive the subject’s real-time left-ventricular pressure-volume loop based on the conductance measurement. For some applications, the computer processor controls the impeller rotation rate in response to the derived pressure-volume loop.

[0681] Regarding references Figures 1A-26 All aspects of the ventricular assist device 20 described herein, note, although Figure 1A and Figure 1BA ventricular assist device 20 is shown in the left ventricle of a subject; however, for some applications, device 20 is placed in the right ventricle of the subject, such that the device passes through the pulmonary valve, and the techniques described herein are applied with necessary modifications. For some applications, components of device 20 can be adapted to different types of blood pumps. For example, aspects of the invention can be adapted to pumps for pumping blood from the vena cava and / or right atrium into the right ventricle, from the vena cava and / or right atrium into the pulmonary artery, and / or from the renal vein into the vena cava. Such aspects may include features of impeller 50, pump portion 27, features of drive cable 130, devices and methods for measuring blood pressure, etc. Optionally or additionally, device 20 and / or a portion thereof (e.g., impeller 50, even without tube 24) may be placed within different parts of the subject's body to assist in pumping blood from those parts. For example, device 20 and / or a portion thereof (e.g., impeller 50, even without tube 24) may be placed in a blood vessel and may be used to pump blood through the blood vessel. For some applications, with necessary modifications, device 20 and / or a portion thereof (e.g., impeller 50, even without tube 24) are configured to be placed within the subclavian vein or jugular vein at the junction of a vein and a lymphatic duct, and to increase the flow of lymphatic fluid from the lymphatic vessels to the vein. Because the scope of the invention includes the use of the devices and methods described herein in anatomical locations other than the left ventricle and aorta, ventricular assist devices and / or portions thereof are sometimes referred to herein (in the specification and claims) as blood pumps.

[0682] Now for reference Figure 27A and 27B ,Should Figure 27A and 27B This is a schematic diagram of a ventricular assist device 308 according to some applications of the present invention, which includes a valve 70 to prevent backflow of blood, for example, in the event of a malfunction of the impeller 50 of the ventricular assist device. (Refer to the foregoing text) Figures 1A-26 Unlike the described ventricular assist device 20, the ventricular assist device 308 includes an impeller disposed within the aorta and not in the left ventricle (e.g., as described in Tuval WO 18 / 078615, which is incorporated herein by reference). For some applications, the impeller is constructed in a manner substantially similar to the impeller 50 described above. The impeller is disposed at the proximal end of a tube 312 (e.g., a polyester tube) that passes through the aortic valve, and a frame 310 is used to open and support the tube. Figure 27A The diagram shows a ventricular assist device configured when the impeller of the ventricular assist device is operating normally, such that there is blood flow from the left ventricle 22 through tube 312 (which passes through the aortic valve 26) to the aorta 30, as indicated by arrow 72.

[0683] For some applications, tube 312 includes a valve 70 located in a region of the tube, the valve 70 being configured to be positioned distal to the impeller 50 and near the aortic valve, such as... Figure 27B As shown in the diagram. For example, a malfunction in impeller 50 can cause backflow of blood via pipe 312 (as shown by...). Figure 27B In the case indicated by blood flow arrow 73 in the diagram, the leaflet of valve 70 is configured to close, so that there is substantially no retrograde blood flow from the aorta to the left ventricle. For some applications (not shown), tube 312 includes valve 70 at its proximal end, and valve 70 is configured to be disposed in the aorta.

[0684] Now for reference Figure 28A , Figure 28B and Figure 28C , Figure 28A , Figure 28B and Figure 28C This is a schematic diagram of a ventricular assist device 308 according to some applications of the present invention, which includes a safety bladder 80 to prevent backflow of blood, for example, in the event of a malfunction in the impeller of the ventricular assist device. (Refer to the foregoing) Figures 1A-26 Unlike the described ventricular assist device 20, the ventricular assist device 308 includes an impeller disposed within the aorta and not in the left ventricle (e.g., as described in Tuval WO18 / 078615, which is incorporated herein by reference). For some applications, the impeller is constructed in a manner substantially similar to the impeller 50 described above. The impeller is positioned at the proximal end of a tube 312 (e.g., a polyester tube) that passes through the aortic valve, and a frame 310 is used to open and support the tube. Figure 28A The diagram illustrates a ventricular assist device configured when the impeller is operating normally, such that blood flow exists from the left ventricle 22 via tube 312 (which passes through the aortic valve 26) to the aorta 30, indicated by arrow 72. For some applications, the ventricular assist device 308 includes a bladder 80 located in the region of the tube, configured distally relative to the impeller 50 and near the aortic valve, such as... Figure 28B As shown in the diagram. For example, a malfunction in impeller 50 can cause backflow of blood via pipe 312 (as shown by...). Figure 28B In the case indicated by blood flow arrow 73, the computer processor 25 is configured to inflate the sac, causing the tube 312 to become blocked, and there is essentially no retrograde blood flow from the aorta to the left ventricle.

[0685] For some applications, the ventricular assist device 308 includes a capsule 80 located at the distal end of the tube 312, the capsule 80 being configured to be positioned in the left ventricle, such as... Figure 28C As shown in the diagram. For example, a malfunction in impeller 50 can cause backflow of blood via pipe 312 (as shown by...). Figure 28CIn the case indicated by blood flow arrow 73, the computer processor 25 is configured to inflate the sac, causing the tube 312 to become blocked, and there is essentially no retrograde blood flow from the aorta to the left ventricle.

[0686] The scope of this invention includes combining any device and method described herein with any device and method described in one or more of the following applications, all of which are incorporated herein by reference:

[0687] Tuval’s international patent application PCT / IL2017 / 051273 entitled “Blood pumps”, filed November 21, 2017 (published as WO 18 / 096531), claims priority to Tuval’s U.S. provisional patent application 62 / 425,814 filed November 23, 2016.

[0688] Tuval's international application PCT / IL2017 / 051158 (published as WO 18 / 078615), entitled "Ventricular assist device," filed on October 23, 2017, claims priority to Tuval's US 62 / 412,631, filed on October 25, 2016, and US 62 / 543,540, filed on August 10, 2017.

[0689] Tuval’s international patent application PCT / IL2017 / 051092 entitled “Blood vessel tube”, filed on September 28, 2017 (published as WO 18-061002), claims priority to Tuval’s U.S. provisional patent application 62 / 401,403, filed on September 29, 2016.

[0690] Schwammenthal's US 2018 / 0169313 is the U.S. national phase of Schwammenthal's international patent application PCT / IL2016 / 050525 (published as WO 16 / 185473) entitled "Blood pump," filed May 18, 2016. This application claims priority to Schwammenthal's U.S. provisional patent application 62 / 162,881 entitled "Blood pump," filed May 18, 2015.

[0691] Schwammenthal's US 2017 / 0100527 is the U.S. national phase of Schwammenthal's international patent application PCT / IL2015 / 050532 (published as WO 15 / 177793) entitled "Blood pump," filed May 19, 2015. This application claims priority to Schwammenthal's U.S. provisional patent application 62 / 000,192 entitled "Blood pump," filed May 19, 2014.

[0692] Schwammenthal's U.S. Patent 10,039,874, which is the U.S. national phase of Schwammenthal's international patent application PCT / IL2014 / 050289 (published as WO 14 / 141284) entitled "Renal pump," filed March 13, 2014, claims priority to the following patent applications: (a) Schwammenthal's U.S. Provisional Patent Application 61 / 779,803 entitled "Renal pump," filed March 13, 2013, and (b) Schwammenthal's U.S. Provisional Patent Application 61 / 914,475 entitled "Renal pump," filed December 11, 2013;

[0693] Tuval's U.S. Patent 9,764,113, entitled "Curved catheter," issued September 19, 2017, claims priority to Tuval's U.S. Provisional Patent Application 61 / 914,470, also entitled "Curved catheter," filed December 11, 2013.

[0694] Tuval's U.S. Patent 9,597,205 is the U.S. national phase of Tuval's international patent application PCT / IL2013 / 050495 (published as WO 13 / 183060), filed June 6, 2013, entitled "Prosthetic renal valve," which claims priority to Tuval's U.S. provisional patent application 61 / 656,244, filed June 6, 2012, entitled "Prosthetic renal valve."

[0695] Those skilled in the art will recognize that the present invention is not limited to what has been specifically shown and described above. Rather, the scope of protection of the present invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications of the invention that may be conceived by those skilled in the art upon reading the foregoing description and which are not found in the prior art.

Claims

1. An apparatus, the apparatus comprising: Blood pump tubing; A blood pump, the blood pump being configured to be disposed within the blood pump tube and configured to pump blood through the blood pump tube; At least one blood pressure measuring tube, the at least one blood pressure measuring tube defining an opening at its distal end, and configured to extend from outside the subject's body to the opening at the distal end at least on the outer surface of the blood pump tube, such that the opening at the distal end of the at least one blood pressure measuring tube is in direct fluid communication with the blood flow of the subject outside the blood pump tube; as well as At least one pressure sensor is configured to be disposed outside the subject's body and configured to measure the pressure of blood flow to the subject outside the blood pump tube by measuring blood pressure inside the at least one blood pressure measuring tube.

2. The device according to claim 1, wherein, The blood pump includes an impeller configured to pump blood through the blood pump tubing by rotation.

3. The device according to claim 1, wherein, The at least one blood pressure measuring tube is configured to extend from the proximal end of the blood pump tube along the outer surface of the blood pump tube to the opening at the distal end of the at least one blood pressure measuring tube.

4. The device of claim 1, further comprising at least one computer processor configured to receive an indication of blood pressure measured in the at least one blood pressure measuring tube, and configured to control blood pumping through the blood pump in response to the blood pressure measured in the at least one blood pressure measuring tube.

5. The device according to any one of claims 1-4, wherein, The at least one blood pressure measuring tube includes at least one left ventricular blood pressure measuring tube, the at least one left ventricular blood pressure measuring tube being configured to extend along the outer surface of the blood pump tube near the blood pump, which is configured to be in the left ventricle of the subject, and wherein the pressure sensor is configured to measure the subject's left ventricular pressure by measuring the blood pressure within the at least one left ventricular blood pressure measuring tube.

6. The device according to claim 5, wherein, The at least one blood pressure measuring tube includes two or more left ventricular blood pressure measuring tubes, the two or more left ventricular blood pressure measuring tubes being configured to extend along the outer surface of the blood pump tube near the blood pump, which is configured to be in the left ventricle of the subject, and wherein the at least one pressure sensor is configured to measure the subject's left ventricular pressure by measuring blood pressure within at least one of the two or more left ventricular blood pressure measuring tubes.

7. The device according to claim 6, in, The at least one pressure sensor is configured to measure blood pressure in each of the two or more left ventricular blood pressure measuring tubes. The device further includes at least one computer processor, the computer processor being configured to: Receives an indication of the blood pressure measured in each of the two or more left ventricular blood pressure measuring tubes. In response, it is determined that the opening of one of the two or more left ventricular blood pressure measuring tubes is blocked, and In response, the subject's left ventricular pressure is determined based on the blood pressure measured in one of the two or more left ventricular blood pressure measuring tubes.

8. The device according to any one of claims 1-4, wherein, The at least one blood pressure measuring tube includes at least one aortic blood pressure measuring tube, the aortic blood pressure measuring tube being configured to extend along the outer surface of the blood pump tube at a location configured to be within the aorta of the subject, and wherein the pressure sensor is configured to measure the subject's aortic pressure by measuring blood pressure within the aortic blood pressure measuring tube.

9. The device according to claim 1, wherein, The blood pump includes an impeller disposed on an axial shaft, the impeller being configured to pump blood from the left ventricle to the aorta by rotation, wherein the device further includes: A motor, which is disposed outside the subject's body and configured to drive the impeller to rotate; A drive cable extending from outside the subject's body to the axial axis and configured to transmit rotational motion from the motor to the impeller by rotation; and An outer tube, configured to extend from outside the subject's body into the blood pump tubing, The drive cable and the at least one blood pressure measuring tube are configured to be disposed inside the outer tube.

10. The device according to claim 9, in, The at least one blood pressure measuring tube includes at least one left ventricular blood pressure measuring tube, the left ventricular blood pressure measuring tube being configured to extend to the outer surface of the blood pump tube along a position near the blood pump that is configured to be in the left ventricle of the subject, and wherein the at least one pressure sensor is configured to measure the left ventricular pressure of the subject by measuring the blood pressure within the left ventricular blood pressure measuring tube; The device also includes an aortic blood pressure measuring tube, which defines an opening at its distal end and is configured to extend from the outside of the subject's body into the subject's aorta, such that the opening at the distal end of the aortic blood pressure measuring tube is in direct fluid communication with the subject's aortic blood flow. The at least one pressure sensor is also configured to measure the subject's aortic pressure by measuring the blood pressure within the aortic blood pressure measuring tube.

11. The device according to claim 9, in, The at least one blood pressure measuring tube includes at least one left ventricular blood pressure measuring tube, the left ventricular blood pressure measuring tube being configured to extend to the outer surface of the blood pump tube along a position near the blood pump configured to be in the left ventricle of the subject, and wherein the at least one pressure sensor is configured to measure the subject's left ventricular pressure by measuring blood pressure within the left ventricular blood pressure measuring tube; The device also includes an aortic blood pressure measuring tube that defines an opening at its distal end and is configured to extend from outside the subject's body to a portion of the outer surface of the outer tube disposed within the blood pump tube, such that the opening at the distal end of the aortic blood pressure measuring tube is in direct fluid communication with the subject's aortic blood flow. The at least one pressure sensor is also configured to measure the subject's aortic pressure by measuring the blood pressure within the aortic blood pressure measuring tube.

12. The device according to claim 9, wherein, The outer tube defines a groove in a portion of the outer surface of the outer tube configured to be disposed within the blood pump tube, and wherein, during insertion of the blood pump into the body of the subject, a portion of the at least one blood pressure measuring tube configured to extend from within the blood pump tube to the outer surface of the blood pump tube is configured to be disposed within the groove, such that the portion of the at least one blood pressure measuring tube does not protrude from the outer surface of the outer tube.

13. The device according to claim 8, wherein, The diameter of at least one blood pressure measuring tube, at least in the distal portion of the at least one blood pressure measuring tube, is less than 0.5 mm.

14. The device according to claim 13, wherein, The diameter of the at least one blood pressure measuring tube, at least in the distal portion of the at least one blood pressure measuring tube, is greater than 0.2 mm.

15. The device according to claim 1, wherein, The at least one blood pressure measuring tube is configured to extend from inside the blood pump tube to the opening at the distal end of the at least one blood pressure measuring tube.

Images