Patent Application
20240245903
Some applications of the present invention generally relate to medical apparatus. Specifically, some applications of the present invention relate to a ventricular assist device and methods of use thereof.
Ventricular assist devices are mechanical circulatory support devices designed to assist and unload cardiac chambers in order to maintain or augment cardiac output. They are used in patients suffering from a failing heart and in patients at risk for deterioration of cardiac function during percutaneous coronary interventions. Most commonly, a left-ventricular assist device is applied to a defective heart in order to assist left-ventricular functioning. In some cases, a right-ventricular assist device is used in order to assist right-ventricular functioning. Such ventricular assist devices are either designed to be permanently implanted or mounted on a catheter for temporary placement.
In accordance with some applications of the present invention, a ventricular assist device includes a motion-cushioning spring. As described in further detail hereinbelow, typically, during operation of the ventricular assist device, i.e., as an impeller of the ventricular assist device is rotating, the impeller of the ventricular assist device undergoes axial back-and-forth motion. For some applications, as the impeller undergoes the axial back-and-forth motion, the motion-cushioning spring is configured to act as a shock absorber, to provide cushioning to the motion. As the impeller moves distally from a systolic position to a diastolic position, the motion-cushioning spring becomes more compressed. For some applications, the impeller is configured to be radially constrained (i.e., crimped) by becoming axially elongated, and the motion-cushioning spring is configured to become compressed such as to accommodate the axial elongation of the impeller.
For some applications, the motion-cushioning spring is coupled to an elastomeric material (such as polyurethane, and/or silicone), such that at least a portion of an axial shaft of the ventricular assist device that is between a distal end of the impeller and a distal radial bearing is covered by the elastomeric material. For some applications, coupling the elastomeric material to the spring reduces a risk of the generation of thrombi and/or hemolysis by the spring, relative to if the spring is not coupled to the elastomeric material. It is noted that the scope of the present disclosure includes providing the motion-cushioning spring in the absence of elastomeric material, as may be desirable in some cases. For some applications, the spring is coated with the elastomeric material with the elastomeric material extending between adjacent windings of the spring. Alternatively, the spring is embedded within the elastomeric material. Typically, the elastomeric material is coupled to the motion-cushioning spring in such a manner that the elastomeric material changes shape (e.g., by stretching and compressing) to conform to shape changes that the motion-cushioning spring undergoes (e.g., when the motion-cushioning spring undergoes elongation and compression). Further typically, the elastomeric material is configured to undergo the above-described shape changes without the elastomeric material becoming broken or collapsing, and without the elastomeric material becoming creased when the spring is compressed.
For some applications, a proximal motion-cushioning spring is disposed on the proximal side of the impeller. For some such applications, the proximal motion-cushioning spring is disposed around the axial shaft between the proximal end of the impeller and a proximal bearing. For some applications, the pump head includes both a proximal motion-cushioning spring (disposed on a proximal side of the impeller) and a distal motion-cushioning spring disposed on a distal side of the impeller, such that axial movement of the impeller in either the distal or the proximal direction is cushioned by the motion-cushioning springs.
For some applications, a ventricular assist device includes a distal thrust bearing that is configured to prevent an axial shaft of the device from undergoing axial motion in response to variations in the pressure gradient against which the impeller is pumping (and, typically, to thereby prevent the impeller from undergoing axial motion in response to variations in the pressure gradient against which the impeller is pumping). For some applications, the thrust bearing is disposed within a frame of the device. Typically, the thrust bearing is coupled to the frame via connecting struts, which extend radially inwardly from the frame to the thrust bearing. Typically, in order to manufacture the frame, the frame is cut from a tube of a shape-memory alloy, such as nitinol. For some applications, the connecting struts are cut from the tube from which the frame is cut, such that the frame and the connecting struts form a single integral body, without requiring coupling to each other (e.g., via adhesive, welding, etc.). For some applications, the frame and the connecting struts are cut from a single piece of a material such as to form a single integral body. For some applications, the connecting struts as well as the thrust bearing itself are cut from the tube from which the frame is cut, such that the frame, the connecting struts, and the thrust bearing form a single integral body, without requiring coupling to each other (e.g., via adhesive, welding, etc.). In general, for some applications, the frame, the connecting struts, and the thrust bearing itself are cut from a single piece of a material such as to form a single integral body.
For some applications, a spring that is generally similar to the above-described motion-cushioning spring is used in combination with the thrust bearing (or with a differently designed thrust bearing that is disposed distally of the impeller). For some applications, the spring assists in stabilizing the impeller (e.g., the distal end of the impeller) with respect to the thrust bearing, subsequent to the radial expansion of the impeller. Thus, the spring functions as an impeller-stabilizing spring. For some applications, the impeller is configured to be radially constrained (i.e., crimped) by becoming axially elongated, and the spring is configured to become compressed such as to accommodate the axial elongation of the impeller. Typically, when the impeller is in a radially-constrained configuration during insertion of the pump head into the left ventricle, the impeller is axially elongated such that the distal end of the impeller is disposed distally within the and the impeller-stabilizing spring is compressed in order to accommodate the movement of the distal end of the impeller. Typically, the impeller-stabilizing spring is disposed around the axial shaft between the distal end of the impeller and the thrust bearing.
There is therefore provided, in accordance with some applications of the present invention, an apparatus including:
In some applications, the impeller is configured to undergo axial back-and-forth motion while the impeller is rotating, and the motion-cushioning spring is configured to provide cushioning to the axial back-and-forth motion.
In some applications, the impeller is configured to be radially constrained by becoming axially elongated and the motion-cushioning spring is configured to become compressed such as to accommodate the axial elongation of the impeller.
In some applications, the motion-cushioning spring is coupled to a distal end of the impeller.
In some applications, the ventricular assist device further includes a proximal motion-cushioning spring disposed around the axial shaft between a proximal end of the impeller and the proximal bearing, the motion-cushioning spring being configured to cushion axial motion that the impeller undergoes in a proximal direction.
In some applications, the motion-cushioning spring is coupled to the distal bearing. In some applications, the apparatus further includes a distal bearing housing disposed around the distal bearing, the motion-cushioning spring being coupled to the distal bearing via the distal bearing housing.
In some applications, the apparatus further includes an elastomeric material that is coupled to the motion-cushioning spring, such that at least a portion of the axial shaft between a distal end of the impeller and the distal bearing is covered by the elastomeric material. In some applications, the motion-cushioning spring is coated with the elastomeric material. In some applications, the motion-cushioning spring is embedded within the elastomeric material. In some applications, the elastomeric material includes at least one of silicone and polyurethane.
In some applications, the ventricular assist device includes a purging system that is configured to pump a purging fluid through a lumen defined by the axial shaft, such that at least a portion of the purging fluid flows proximally through an interface between the axial shaft and the elastomeric material.
In some applications, the elastomeric material is coupled to the motion-cushioning spring in such a manner that the elastomeric material changes shape to conform to shape changes that the motion-cushioning spring undergoes. In some applications, the elastomeric material is configured to undergo the changes in shape without the elastomeric material becoming broken or collapsing. In some applications, the elastomeric material is configured not to become creased as a result of the motion-cushioning spring being compressed.
In some applications, the ventricular assist device further includes a pump-outlet tube configured to traverse an aortic valve of the subject, such that a proximal portion of the pump-outlet tube is disposed within an aorta of the subject and a distal portion of the pump-outlet tube is disposed within the subject's left ventricle, the distal portion of the pump-outlet tube extending to the distal end of the frame and defining one or more lateral blood inlet openings that are configured to allow blood to flow from the subject's left ventricle into the pump-outlet tube.
In some applications, a porosity of the distal portion of the pump-outlet tube, which defines the blood-inlet openings, is lower within a proximal region of the distal portion of the pump-outlet tube than within a distal region of the distal portion of the pump-outlet tube that is distal to the proximal region. In some applications, the distal portion of the pump-outlet tube has a porosity of more than 40 percent. In some applications, the distal portion of the pump-outlet tube defines more than 10 blood-inlet openings that are sized such as (a) to allow blood to flow from the subject's left ventricle into the tube and (b) to block structures from the subject's left ventricle from entering into the frame. In some applications, the distal portion of the pump-outlet tube defines more than 50 blood-inlet openings that are sized such as (a) to allow blood to flow from the subject's left ventricle into the tube and (b) to block structures from the subject's left ventricle from entering into the frame.
There is further provided, in accordance with some applications of the present invention, an apparatus including:
In some applications, the apparatus further includes a light source and a light detector disposed at a proximal end of the optical fiber, and configured to detect blood pressure at the distal end of the optical fiber by directing light via the optical fiber and detecting reflected light.
In some applications, the apparatus further includes a computer processor that is configured to receive the blood pressure detected at the distal end of the optical fiber and to control pumping of blood by the impeller in response to the blood pressure detected at the distal end of the optical fiber.
In some applications, the apparatus further includes a computer processor that is configured to receive the blood pressure detected at the distal end of the optical fiber, and the computer processor is configured to derive at least one physiological parameter of the subject, at least partially based upon the blood pressure detected at the distal end of the optical fiber, the at least one physiological parameter of the subject being selected from the group consisting of: native cardiac output, total cardiac output, arterial compliance, and peripheral resistance.
In some applications, the pump-outlet tube defines one or more blood-inlet openings via which blood is pumped into the pump-outlet tube, and the distal end of the optical fiber is configured to be in direct fluid communication with left-ventricular bloodstream of the subject at a location that is proximal to a proximal-most portion of the one or more blood-inlet openings.
In some applications, the distal end of the fiber is exposed to blood that has a pressure that reflects the blood pressure of the left ventricle itself and that is not affected by pressure variations that are generated in the vicinity of the one or more blood-inlet openings as a result of fluid flow dynamics generated at the one or more blood-inlet openings.
In some applications, the distal end of the optical fiber is configured to be in direct fluid communication with left-ventricular bloodstream of the subject at a location that is at least 1 cm proximal to the proximal-most portion of the one or more blood-inlet openings.
In some applications, the at least one optical fiber includes two or more optical fibers, and the apparatus further includes a computer processor that is configured to receive the blood pressure detected at the distal end of each of the optical fibers and to thereby determine whether the distal end of one of the optical fibers is not exposed to the left-ventricular bloodstream. In some applications, in response to determining that the distal end of one of the optical fibers is not exposed to the left ventricular bloodstream, the computer processor determines the subject's left-ventricular pressure based upon blood pressure measured using a different one of the two or more optical fibers.
There is further provided, in accordance with some applications of the present invention, a method for determining native cardiac output of a subject who is receiving treatment with a percutaneous left ventricular assist device, the method including:
There is further provided, in accordance with some applications of the present invention, an apparatus for determining native cardiac output of a subject, the apparatus including:
In some applications, the computer processor is configured to generate an output indicating the subject's native cardiac output.
In some applications, the computer processor is configured to apply the mathematical model representing a dynamic vascular system of the subject by applying the Windkessel model of the aorta.
In some applications, the computer processor is configured to estimate the subject's vascular parameters by estimating one or more of the subject's aortic compliance, characteristic impedance, and peripheral resistance.
In some applications, the computer processor is configured to detect the one or more pressure-related parameters and/or flow-related parameters by detecting aortic pressure of the subject. In some applications, the computer processor is further configured to detect one or more pressure-related parameters and/or flow-related parameters by detecting aortic flow of the subject by detecting flow via the percutaneous left ventricular assist device.
In some applications, the percutaneous left ventricular assist device includes a pump-outlet tube that has a known cross-sectional area and a pump, and the computer processor is configured to detect flow via the percutaneous left ventricular assist device by calculating flow via the pump-outlet tube of the percutaneous left ventricular assist device based on the known cross-sectional area of the tube and a pressure difference that is generated by the pump of the percutaneous left ventricular assist device.
In some applications:
In some applications, the computer processor is configured to determine the pressure difference that is generated by a pump of the percutaneous left ventricular assist device by measuring left ventricular pressure and aortic pressure of the subject.
There is further provided, in accordance with some applications of the present invention, an apparatus including:
In some applications, the frame, the connecting struts, and the thrust bearing are all formed as a single integral body.
In some applications, the ventricular assist device further includes an impeller-stabilizing spring disposed around the axial shaft between a distal end of the impeller and the thrust bearing, the impeller-stabilizing spring being configured to stabilize the distal end of the impeller. In some applications, the impeller is configured to be radially constrained by becoming axially elongated and the impeller-stabilizing spring is configured to become compressed such as to accommodate the axial elongation of the impeller. In some applications, the impeller-stabilizing spring is coupled to a distal end of the impeller.
In some applications, the ventricular assist device further includes a proximal bearing and a proximal impeller-stabilizing spring disposed around the axial shaft between a proximal end of the impeller and the proximal bearing.
In some applications, the impeller-stabilizing spring is coupled to the thrust bearing.
In some applications, the apparatus further includes an elastomeric material that is coupled to the impeller-stabilizing spring, such that at least a portion of the axial shaft between a distal end of the impeller and the thrust bearing is covered by the elastomeric material. In some applications, the impeller-stabilizing spring is coated with the elastomeric material. In some applications, the impeller-stabilizing spring is embedded within the elastomeric material. In some applications, the elastomeric material includes at least one of silicone and polyurethane. In some applications, the ventricular assist device includes a purging system that is configured to pump a purging fluid through a lumen defined by the axial shaft, such that at least a portion of the purging fluid flows proximally through an interface between the axial shaft and the elastomeric material.
In some applications, the elastomeric material is coupled to the impeller-stabilizing spring in such a manner that the elastomeric material changes shape to conform to shape changes that the impeller-stabilizing spring undergoes. In some applications, the elastomeric material is configured to undergo the changes in shape without the elastomeric material becoming broken or collapsing. In some applications, the elastomeric material is configured not to become creased as a result of the impeller-stabilizing spring being compressed.
In some applications, the ventricular assist device further includes a pump-outlet tube configured to traverse an aortic valve of the subject, such that a proximal portion of the pump-outlet tube is disposed within an aorta of the subject and a distal portion of the pump-outlet tube is disposed within the subject's left ventricle, the distal portion of the pump-outlet tube extending to the distal end of the frame and defining one or more lateral blood inlet openings that are configured to allow blood to flow from the subject's left ventricle into the pump-outlet tube.
In some applications, a porosity of the distal portion of the pump-outlet tube, which defines the blood-inlet openings, is lower within a proximal region of the distal portion of the pump-outlet tube than within a distal region of the distal portion of the pump-outlet tube that is distal to the proximal region.
In some applications, the distal portion of the pump-outlet tube has a porosity of more than 40 percent. In some applications, the distal portion of the pump-outlet tube defines more than 10 blood-inlet openings that are sized such as (a) to allow blood to flow from the subject's left ventricle into the tube and (b) to block structures from the subject's left ventricle from entering into the frame. In some applications, the distal portion of the pump-outlet tube defines more than 50 blood-inlet openings that are sized such as (a) to allow blood to flow from the subject's left ventricle into the tube and (b) to block structures from the subject's left ventricle from entering into the frame.
There is further provided, in accordance with some applications of the present invention, an apparatus including:
In some applications, the impeller is configured to be radially constrained by becoming axially elongated and the impeller-stabilizing spring is configured to become compressed such as to accommodate the axial elongation of the impeller.
In some applications, the impeller-stabilizing spring is coupled to a distal end of the impeller.
In some applications, the ventricular assist device further includes a proximal bearing and a proximal impeller-stabilizing spring disposed around the axial shaft between a proximal end of the impeller and the proximal bearing.
In some applications, the impeller-stabilizing spring is coupled to the thrust bearing.
In some applications, the apparatus further includes an elastomeric material that is coupled to the impeller-stabilizing spring, such that at least a portion of the axial shaft between a distal end of the impeller and the thrust bearing is covered by the elastomeric material. In some applications, the impeller-stabilizing spring is coated with the elastomeric material. In some applications, the impeller-stabilizing spring is embedded within the elastomeric material. In some applications, the elastomeric material includes at least one of silicone and polyurethane.
In some applications, the ventricular assist device includes a purging system that is configured to pump a purging fluid through a lumen defined by the axial shaft, such that at least a portion of the purging fluid flows proximally through an interface between the axial shaft and the elastomeric material.
In some applications, the elastomeric material is coupled to the impeller-stabilizing spring in such a manner that the elastomeric material changes shape to conform to shape changes that the impeller-stabilizing spring undergoes. In some applications, the elastomeric material is configured to undergo the changes in shape without the elastomeric material becoming broken or collapsing. In some applications, the elastomeric material is configured not to become creased as a result of the impeller-stabilizing spring being compressed.
There is further provided, in accordance with some applications of the present invention, apparatus for use with a percutaneous ventricular assist device that includes a self-expandable pump head and that is configured to be delivered to a subject's left ventricle using a delivery catheter, while the pump head is disposed in a radially-constrained configuration within the delivery catheter, the apparatus including:
In some applications, the pump-head chamber is configured to be filled with a solution prior to the pump head being retracted into the distal end of the delivery catheter. In some applications, the catheter securement piece is configured to secure the distal end of the delivery catheter to a surface that is slanted downwards, such that the distal end of the catheter is oriented in a downwards slant. In some applications, a slant of the surface is configured to reduce a likelihood of air bubbles entering the distal end of the delivery catheter as the pump head is retracted into the distal end of delivery catheter, relative to if the distal end of the catheter were to be secured to a horizontal surface.
In general, in the specification and in the claims of the present application, the term “proximal” and related terms, when used with reference to a device or a portion thereof, should be interpreted to mean an end of the device or the portion thereof that, when inserted into a subject's body, is typically closer to a location through which the device is inserted into the subject's body. The term “distal” and related terms, when used with reference to a device or a portion thereof, should be interpreted to mean an end of the device or the portion thereof that, when inserted into a subject's body, is typically further from the location through which the device is inserted into the subject's body.
The present invention will be more fully understood from the following detailed description of embodiments thereof, taken together with the drawings, in which:
Reference is now made to
For some applications, the ventricular assist device is used to assist the functioning of a subject's left ventricle during a percutaneous coronary intervention. In such cases, the ventricular assist device is typically used for a period of up to six hours (e.g., up to ten hours), during a period in which there is risk of developing hemodynamic instability (e.g., during or immediately following the percutaneous coronary intervention). Alternatively or additionally, the ventricular assist device is used to assist the functioning of a subject's left ventricle for a longer period (e.g., for example, 2-20 days, e.g., 4-14 days) upon a patient suffering from cardiogenic shock, which may include any low-cardiac-output state (e.g., acute myocardial infarction, myocarditis, cardiomyopathy, post-partum, etc.). For some applications, the ventricular assist device is used to assist the functioning of a subject's left ventricle for yet a longer period (e.g., several weeks or months), e.g., in a “bridge to recovery” treatment. For some such applications, the ventricular assist device is permanently or semi-permanently implanted, and the impeller of the ventricular assist device is powered transcutaneously, e.g., using an external antenna that is magnetically coupled to the impeller.
As shown in
For some applications (not shown), the ventricular assist device and/or delivery catheter 143 includes an ultrasound transducer at its distal end and the ventricular assist device is advanced toward the subject's ventricle under ultrasound guidance.
Reference is made to
For some applications, control console 21 (shown in
For some applications, a purging system 29 (shown in
Typically, along distal portion 102 of pump-outlet tube 24, a frame 34 is disposed within the pump-outlet tube around impeller 50. The frame is typically made of a shape-memory alloy, such as nitinol. For some applications, the shape-memory alloy of the frame is shape set such that at least a portion of the frame (and thereby distal portion 102 of tube 24) assumes a generally circular, elliptical, or polygonal cross-sectional shape in the absence of any forces being applied to distal portion 102 of tube 24. By assuming its generally circular, elliptical, or polygonal cross-sectional shape, the frame is configured to hold the distal portion of the pump-outlet tube in an open state. Typically, during operation of the ventricular assist device, the distal portion of the pump-outlet tube is configured to be placed within the subject's body, such that the distal portion of the pump-outlet tube is disposed at least partially within the left ventricle.
For some applications, along proximal portion 106 of pump-outlet tube 24, the frame is not disposed within the pump-outlet tube, and the pump-outlet tube is therefore not supported in an open state by frame 34. Pump-outlet tube 24 is typically made of a blood-impermeable collapsible material. For example, pump-outlet tube 24 may include polyurethane, polyester, and/or silicone. Alternatively or additionally, the pump-outlet tube is made of polyethylene terephthalate (PET) and/or polyether block amide (e.g., PEBAX®). For some applications (not shown), the pump-outlet tube is reinforced with a reinforcement structure, e.g., a braided reinforcement structure, such as a braided nitinol tube. Typically, the proximal portion of the pump-outlet tube is configured to be placed such that it is at least partially disposed within the subject's ascending aorta. For some applications, the proximal portion of the pump-outlet tube traverses the subject's aortic valve, passing from the subject's left ventricle into the subject's ascending aorta, as shown in
As described hereinabove, the pump-outlet tube typically defines one or more blood-inlet openings 108 at the distal end of the pump-outlet tube, via which blood flows into the pump-outlet tube from the left ventricle, during operation of the impeller. For some applications, the proximal portion of the pump-outlet tube defines one or more blood-outlet openings 109, via which blood flows from the pump-outlet tube into the ascending aorta, during operation of the impeller. Typically, the pump-outlet tube defines a plurality of blood-outlet openings 109, for example, between two and eight blood-outlet openings (e.g., between two and four blood-outlet openings). During operation of the impeller, the pressure of the blood flow through the pump-outlet tube typically maintains the proximal portion of the tube in an open state. For some applications, in the event that, for example, the impeller malfunctions, the proximal portion of the pump-outlet tube is configured to collapse inwardly, in response to pressure outside of the proximal portion of the pump-outlet tube exceeding pressure inside the proximal portion of the pump-outlet tube. In this manner, the proximal portion of the pump-outlet tube acts as a safety valve, preventing retrograde blood flow into the left ventricle from the aorta.
Referring again to
Typically, pump-outlet tube 24 includes a conical proximal portion 42 and a cylindrical central portion 44. The proximal conical portion is typically proximally-facing, i.e., facing such that the narrow end of the cone is proximal with respect to the wide end of the cone. Typically, blood-outlet openings 109 are defined by pump-outlet tube 24, such that the openings extend at least partially along the proximal conical section of tube 24. For some such applications, the blood-outlet openings are teardrop-shaped, as shown in
For some applications (not shown), the diameter of pump-outlet tube 24 changes along the length of the central portion of the pump-outlet tube, such that the central portion of the pump-outlet tube has a frustoconical shape. For example, the central portion of the pump-outlet tube may widen from its proximal end to is distal end, or may narrow from its proximal end to its distal end. For some applications, at its proximal end, the central portion of the pump-outlet tube has a diameter of between 5 and 7 mm, and at its distal end, the central portion of the pump-outlet tube has a diameter of between 8 and 12 mm.
Again referring to
As shown in the enlarged portion of
Reference is now made to
Typically, the frame is a stent-like frame, in that it comprises struts that, in turn, define cells. Further typically, the frame is covered with pump-outlet tube 24, and/or covered with an inner lining 39, described hereinbelow, with reference to
Referring to
Still referring to
Still referring to
Typically, when disposed in its non-radially constrained configuration, frame 34 has a total length of more than 25 mm (e.g., more than 30 mm), and/or less than 50 mm (e.g., less than 45 mm), e.g., 25-50 mm, or 30-45 mm. Typically, when disposed in its radially-constrained configuration (within delivery catheter 143), the length of the frame increases by between 2 and 5 mm. Typically, when disposed in its non-radially constrained configuration, the central cylindrical portion of frame 34 has a length of more than 10 mm (e.g., more than 12 mm), and/or less than 25 mm (e.g., less than 20 mm), e.g., 10-25 mm, or 12-20 mm. For some applications, a ratio of the length of the central cylindrical portion of the frame to the total length of the frame is more than 1:4 and/or less than 1:2, e.g., between 1:4 and 1:2.
Reference is now made to
Each of the helical elongate elements, together with the film extending from the helical elongate element to the spring, defines a respective impeller blade, with the helical elongate elements defining the outer edges of the blades, and the axial spring defining the axis of the impeller. Typically, the film of material extends along and coats the spring. For some applications, sutures 53 (e.g., polyester sutures, shown in
Typically, proximal ends of spring 54 and helical elongate elements 52 extend from a proximal bushing (i.e., sleeve bearing) 64 of the impeller, such that the proximal ends of spring 54 and helical elongate elements 52 are disposed at a similar radial distance from the longitudinal axis of the impeller, as each other. Similarly, typically, distal ends of spring 54 and helical elongate elements 52 extend from a distal bushing 58 of the impeller, such that the distal ends of spring 54 and helical elongate elements 52 are disposed at a similar radial distance from the longitudinal axis of the impeller, as each other. The helical elongate elements typically rise gradually from the proximal bushing before reaching a maximum span and then falling gradually toward the distal bushing. Typically, the helical elongate elements are symmetrical along their lengths, such that the rising portions of their lengths are symmetrical with respect to the falling portions of their lengths. Typically, the impeller defines a lumen 62 therethrough (shown in
Reference is now made to
As shown in
For some applications, when impeller 50 and frame 34 are both disposed in non-radially-constrained configurations and prior to operation of the impeller, gap G between the outer edge of the impeller and the inner lining 39, at the location at which the span of the impeller is at its maximum, is greater than 0.05 mm (e.g., greater than 0.1 mm), and/or less than 1 mm (e.g., less than 0.4 mm), e.g., 0.05-1 mm, or 0.1-0.4 mm. For some applications, when the impeller is disposed in its non-radially-constrained configurations and prior to operation of the impeller, the outer diameter of the impeller at the location at which the outer diameter of the impeller is at its maximum is more than 7 mm (e.g., more than 8 mm), and/or less than 10 mm (e.g., less than 9 mm), e.g., 7-10 mm, or 8-9 mm. For some applications, when frame 34 is disposed in its non-radially-constrained configuration, the inner diameter of frame 34 (as measured from the inside of inner lining 39 on one side of the frame to the inside of inner lining on the opposite side of the frame) is greater than 7.5 mm (e.g., greater than 8.5 mm), and/or less than 10.5 mm (e.g., less than 9.5 mm), e.g., 7.5-10.5 mm, or 8.5-9.5 mm. For some applications, when the frame is disposed in its non-radially-constrained configuration, the outer diameter of frame 34 is greater than 8 mm (e.g., greater than 9 mm), and/or less than 13 mm (e.g., less than 12 mm), e.g., 8-13 mm, or 9-12 mm.
Typically, an axial shaft 92 passes through the axis of impeller 50, via lumen 62 of the impeller. Further typically, the axial shaft is rigid, e.g., a rigid tube. For some applications, proximal bushing 64 of the impeller is coupled to the shaft such that the axial position of the proximal bushing with respect to the shaft is fixed, and distal bushing 58 of the impeller is slidable with respect to the shaft. For example, the proximal bushing may be coupled to a coupling element 65 disposed on the axial shaft (shown in
Referring again to
For some applications, the elongate elements 67 maintain helical elongate element 52 (which defines the outer edge of the impeller blade) within a given distance with respect to the central axial spring. In this manner, the elongate elements are configured to prevent the outer edge of the impeller from being forced radially outward due to forces exerted upon the impeller during the rotation of the impeller. The elongate elements are thereby configured to maintain the gap between the outer edge of the blade of the impeller and the inner surface of frame 34, during rotation of the impeller. Typically, more than one (e.g., more than two) and/or fewer than eight (e.g., fewer than four) elongate elements 67 are used in the impeller, with each of the elongate elements typically being doubled (i.e., extending radially from central axial spring 54 to an outer helical elongate element 52, and then returning from the helical elongate element back to the central axial spring). For some applications, a plurality of elongate elements, each of which extends from the spring to a respective helical elongate element and back to the spring, are formed from a single piece of string or a single wire.
Reference is now made to
It is noted that the scope of the present application includes using single integrated impeller-overexpansion-prevention element 72 with an impeller having a different construction from that shown in
For some applications, the material from which the film is made is an elastomer having an ultimate elongation of more than 300 percent, e.g., more than 400 percent. Typically, the material has a relatively low molecular weight. For some applications, the material has a melt flow index (which is an indirect measure of molecular weight) of at least 4, e.g., at least 4.3. For some applications, the material has an ultimate tensile strength of more than 6000 psi, e.g., more than 7000 psi, or more than 7500 psi. For some applications, the material is a polycarbonate-based thermoplastic polyurethane, e.g., a Carbothane™. For some applications, Aromatic Carbothane™ (e.g., Aromatic Carbothane™ 75A) is used. Typically, such materials combine one or more of the following properties: no outer diameter loss caused during the dip process, resistance to fatigue, resistance to becoming misshaped by being crimped, and low outer diameter loss during crimping. Subsequently, the material is cured such that it solidifies, e.g., by being left to dry.
Typically, impeller 50 is inserted into the left ventricle transcatheterally, while impeller 50 is in a radially-constrained configuration. In the radially-constrained configuration, both helical elongate elements 52 and central axial spring 54 become axially elongated, and radially constrained. Typically film 56 of the material (e.g., silicone and/or polyurethane) changes shape to conform to the shape changes of the helical elongate elements and the axial support spring, both of which support the film of material. Typically, using a spring to support the inner edge of the film allows the film to change shape without the film becoming broken or collapsing, due to the spring providing a large surface area to which the inner edge of the film bonds. For some applications, using a spring to support the inner edge of the film reduces a diameter to which the impeller can be radially constrained, relative to if, for example, a rigid shaft were to be used to support the inner edge of the film, since the diameter of the spring itself can be reduced by axially elongating the spring.
As described hereinabove, for some applications, proximal bushing 64 of impeller 50 is coupled to axial shaft 92 such that the axial position of the proximal bushing with respect to the shaft is fixed, and distal bushing 58 of the impeller is slidable with respect to the shaft. For example, the proximal bushing may be coupled to coupling element 65 disposed on the axial shaft (shown in
Reference is now made to
As indicated in
As described hereinabove, typically, axial shaft 92 passes through the axis of impeller 50, via lumen 62 of the impeller. Typically, proximal bushing 64 of the impeller is coupled to the shaft via a coupling element 65 such that the axial position of the proximal bushing with respect to the shaft is fixed, and distal bushing 58 of the impeller is slidable with respect to the shaft. (Alternatively, distal bushing 58 of the impeller is coupled to the shaft such that the axial position of the distal bushing with respect to the shaft is fixed, and proximal bushing 64 of the impeller is slidable with respect to the shaft.) The axial shaft itself is radially stabilized via a proximal radial bearing 116 and a distal radial bearing 118. Typically, proximal bearing housing 116H is disposed around, and houses, the proximal bearing, and distal bearing housing 118H is disposed around, and houses, the distal bearing. For some such applications, the radial bearings and the bearing housings are made of respective, different materials from each other. For example, the radial bearings may be made of a first material that has a relatively high hardness, such as ceramic (e.g., zirconia), and the bearing housings may be made of a second material that is moldable into a desired shape, such as a metal or an alloy (e.g., stainless steel, cobalt chromium, and/or nitinol).
For some applications, axial shaft 92 is made of a metal or an alloy, such as stainless steel. For some such applications, the axial shaft is covered with ceramic sleeves 240 (e.g., zirconia sleeves) along regions of the axial shaft that come into contact with either of the proximal and distal bearings 116, 118 during operation of the ventricular assist device. In this manner, the radial interfaces between the axial shaft and the proximal and distal bearings are ceramic-ceramic interfaces. As described in further detail herein, typically, the impeller and the axial shaft are configured to undergo axial back-and-forth motion during operation of the ventricular assist device. Therefore, for some applications, at locations along the axial shaft corresponding to each of the proximal and distal bearing, the axial shaft is covered with the ceramic sleeve along a length of more than 5 mm, e.g., more than 7 mm. In this manner, over the course of the axial back-and-forth motion of the axial shaft, the regions of the axial shaft that are in contact with the radial bearings are covered with the ceramic sleeves.
For some applications, along the portion of the axial shaft that is covered with the ceramic sleeve, the shaft is shaped (e.g., via milling, molding, or a different shaping process) to define one or more grooves or indents 95, as shown in the transverse cross-sectional view of
For some applications, the proximal bearing housing 116H and distal bearing housing 118H perform additional functions. Referring first to the proximal bearing housing, as described hereinabove, for some applications, proximal strut junctions 33 of frame 34 are closed around the outside of the proximal bearing housing. For some applications, the outer surface of the proximal bearing housing defines groves that are shaped such as to receive the proximal strut junctions. For example, as shown, the proximal strut junctions have widened heads, and the outer surface of the proximal bearing housing defines groves that are shaped to conform with the widened heads of the proximal strut junctions. Typically, securing element 117 (which typically includes a ring) holds the strut junctions in their closed configurations around the outside of proximal bearing housing 116H. For some applications, additional portions of the ventricular assist device are coupled to the proximal bearing housing. For some applications, a drive cable 130 extends from outside the subject's body to axial shaft 92, and is coupled to the axial shaft. Typically, the drive cable rotates within a first outer tube 140, which functions as a drive-cable bearing tube, and which extends from outside the subject's body to the proximal bearing housing. For some applications, the first outer tube is disposed within a second outer tube 142, which also extends from outside the subject's body to the proximal bearing housing. For some applications, first outer tube 140 and/or second outer tube 142 is coupled to the proximal bearing housing (e.g., using an adhesive). For example, first outer tube 140 may be coupled to an inner surface of the proximal bearing housing, and second outer tube 142 may be coupled to an outer surface of the proximal bearing housing.
Referring now to distal bearing housing 118H, for some applications, distal coupling portion 31 of frame 34 is coupled to an outer surface of distal bearing housing 118H, e.g., via a snap-fit mechanism. For example, the outer surface of a proximal-most portion 119 of the distal bearing housing may include a snap-fit mechanism to which distal coupling portion 31 of frame 34 is coupled. For some applications, distal bearing 118 is disposed within the proximal-most portion 119 of the distal bearing housing, as shown in
As described above, axial shaft 92 is radially stabilized via proximal radial bearing 116 and distal radial bearing 118. In turn, the axial shaft, by passing through lumen 62 defined by the impeller, radially stabilizes the impeller with respect to the inner surface of frame 34 and inner lining 39, such that even a relatively small gap between the outer edge of the blade of the impeller and inner lining 39 (e.g., a gap that is as described above) is maintained, during rotation of the impeller, as described hereinabove. Typically, the impeller itself is not directly disposed within any radial bearings or thrust bearings. Rather, bearings 116 and 118 act as radial bearings with respect to the axial shaft. Typically, pump-head portion 27 (and more generally ventricular assist device 20) does not include any thrust bearing that is configured to be disposed within the subject's body and that is configured to oppose thrust generated by the rotation of the impeller. For some applications, one or more thrust bearings are disposed outside the subject's body (e.g., within motor unit 23, shown in
Reference is now made to
For some applications, by moving in the axial back-and-forth motion, the portions of the axial shaft that are in contact with proximal bearing 116 and distal bearing 118 are constantly changing. For some such applications, in this manner, the frictional force that is exerted upon the axial shaft by the bearings is spread over a larger area of the axial shaft than if the axial shaft were not to move relative to the bearings, thereby reducing wear upon the axial shaft, ceteris paribus. Alternatively or additionally, by moving in the back-and-forth motion with respect to the bearing, the axial shaft cleans the interface between the axial shaft and the bearings from any residues, such as blood residues.
For some applications, at the proximal-most position of the impeller during its motion cycle, the proximal end of the impeller is disposed within the proximal conical section of frame 34, as shown in
Reference is again made to
Typically, during the insertion of the ventricular assist device into the subject's ventricle, delivery catheter 143 is placed over impeller 50 and frame 34 and maintains the impeller and the frame in their radially-constrained configurations. For some applications, distal-tip element 107 extends distally from the delivery catheter during the insertion of the delivery catheter into the subject's ventricle, as shown in
For some applications, distal-tip element 107 defines an overall curvature that is similar to that of a question mark or a tennis-racket, with the distal-tip element defining a straight proximal portion and a bulge on one side of the longitudinal axis of the straight proximal portion. Typically, the ventricular assist device is introduced into the subject's ventricle over a guidewire, as described hereinabove. Distal-tip portion 120 defines lumen 122, such that the distal-tip portion is held in a straightened configuration during the introduction of the ventricular assist device into the subject's ventricle (e.g., as shown in the left frame of
Referring again to
Typically, during normal operation of the impeller, the axial shaft does not come into contact with stopper 128, even when drive cable 130 (shown in
It is noted that, at the proximal end of frame 34, proximal radial bearing 116 also functions as a stopper, by preventing coupling element 65 and/or proximal bushing 64 of impeller 50 from being able to move beyond the proximal radial bearing. Typically, during normal operation of the impeller, coupling element 65 and proximal bushing 64 do not come into contact with proximal radial bearing 116. However, proximal radial bearing 116 is configured to prevent coupling element 65 and/or proximal bushing 64 of impeller 50 from migrating proximally from inside the frame, for example, when the impeller and the frame are held in radially-constrained (i.e., crimped) configurations inside delivery catheter 143. Typically, the coupling element and/or the proximal bushing is proximally-extended such as to prevent a central region of the impeller (at which the span of the impeller is at its maximum) from sliding proximally into the proximal conical portion of frame 34. For example, in the systolic phase of the impeller's motion cycle (shown in
Typically, during operation of the ventricular assist device, and throughout the axial back-and-forth motion cycle of the impeller, the impeller is disposed in relatively close proximity to the distal-tip portion. For example, the distance of the impeller to the distal-tip portion may be within the distal-most 50 percent, e.g., the distal-most 30 percent (or the distal-most 20 percent) of tube 24, throughout the axial back-and-forth motion cycle of the impeller.
Reference is now made to
Typically, the motion-cushioning spring is disposed around axial shaft 92 between the distal end of the impeller (e.g., distal bushing 58 of the impeller) and distal bearing 118. For some applications, the motion-cushioning spring is coupled to distal bearing 118 or the distal bearing housing 118H and extends proximally over axial shaft 92 from the distal bearing or the distal bearing housing 118H. Typically, in such cases, the motion-cushioning spring remains rotationally stationary as the impeller rotates, and the impeller is configured to rotate with respect to the motion-cushioning spring. Alternatively or additionally, the motion-cushioning spring is coupled to the distal end of the impeller (e.g., distal bushing 58 of the impeller) and/or extends distally over axial shaft 92 from the distal end of the impeller (e.g., distal bushing 58 of the impeller). For some such applications, the motion-cushioning spring is configured to rotate together with the impeller. Alternatively, the motion-cushioning spring extends from a radial bearing that is disposed around the distal end of the impeller (e.g., distal bushing 58 of the impeller), such that motion-cushioning spring remains rotationally stationary as the impeller rotates, and the impeller is configured to rotate with respect to the motion-cushioning spring.
For some applications, the motion-cushioning spring is coupled to an elastomeric material 69 (such as polyurethane, and/or silicone), such that at least a portion of axial shaft 92 that is between the distal end of the impeller and the distal radial bearing is covered by the elastomeric material. For some applications, coupling the elastomeric material to the spring reduces a risk of the generation of thrombi and/or hemolysis by the spring, relative to if the spring is not coupled to the elastomeric material. It is noted that the scope of the present disclosure includes providing the motion-cushioning spring in the absence of elastomeric material, as may be desirable in some cases.
As described hereinabove, typically purging fluid is pumped between outer tube 140 and outer tube 142. Typically, within the pump head, a portion of the purging fluid flows through the lumen defined by axial shaft 92 and then exits the axial shaft in the vicinity of distal bearing 118, in order to purge the interface between the axial shaft and the distal bearing. For some applications, the purging system is configured such that purging fluid flows proximally from the distal bearing along an interface between the axial shaft and the elastomeric material. In this manner, the interface between the axial shaft and the elastomeric material is purged and/or lubricated.
For some applications (not shown), a proximal motion-cushioning spring is disposed on the proximal side of the impeller. For some such applications, the proximal motion-cushioning spring is disposed around axial shaft 92 between the proximal end of the impeller (e.g., proximal bushing 64 of the impeller) and proximal bearing 116. For some applications, the proximal motion-cushioning spring is coupled to proximal bearing 116 or proximal bearing housing 116H and extends distally over axial shaft 92 from the proximal bearing or the proximal bearing housing. Typically, in such cases, the proximal motion-cushioning spring remains rotationally stationary as the impeller rotates, and the impeller is configured to rotate with respect to the motion-cushioning spring. Alternatively or additionally, the proximal motion-cushioning spring is coupled to the proximal end of the impeller (e.g., proximal bushing 64 of the impeller) and/or extends distally over axial shaft 92 from the proximal end of the impeller (e.g., proximal bushing 64 of the impeller). For some such applications, the motion-cushioning spring is configured to rotate together with the impeller. Alternatively, the proximal motion-cushioning spring extends from a radial bearing that is disposed around the proximal end of the impeller (e.g., proximal bushing 64 of the impeller), such that motion-cushioning spring remains rotationally stationary as the impeller rotates, and the impeller is configured to rotate with respect to the motion-cushioning spring.
For some applications, the pump head includes both a proximal motion-cushioning spring (disposed on a proximal side of the impeller) and a distal motion-cushioning spring disposed on a distal side of the impeller, such that axial movement of the impeller in either the distal or the proximal direction is cushioned by the motion-cushioning springs.
Reference is now made to
Typically, motor unit 23 includes a motor 74 that is configured to impart rotational motion to impeller 50, via drive cable 130. As described in further detail hereinbelow, typically, the motor is magnetically coupled to the drive cable. For some applications, an axial motion driver 76 is configured to drive the motor to move in an axial back-and-forth motion, as indicated by double-headed arrow 79. Typically, by virtue of the magnetic coupling of the motor to the drive cable, the motor imparts the back-and-forth motion to the drive cable, which it turn imparts this motion to the impeller. As described hereinabove and hereinbelow, for some applications, the drive cable, the impeller, and/or the axial shaft undergo axial back-and-forth motion in a passive manner, e.g., due to cyclical changes in the pressure gradient against which the impeller is pumping blood. Typically, for such applications, motor unit 23 does not include axial motion driver 76.
For some applications, the magnetic coupling of the motor to the drive cable is as shown in
It is noted that in the application shown in
As described hereinabove, typically purging system 29 (shown in
Typically, magnet 82 and pin 131 are held in axially fixed positions within motor unit 23. The proximal end of the drive cable is typically coupled to pin 131 and is thereby held in an axially fixed position by the pin. Typically, drive cable 130 extends from pin 131 to axial shaft 92 and thereby at least partially fixes the axial position of the axial shaft, and in turn impeller 50. For some applications, the drive cable is somewhat stretchable. For example, the drive cable may be made of coiled wires that are stretchable. The drive cable typically allows the axial shaft (and in turn the impeller) to assume a range of axial positions (by the drive cable becoming more or less stretched), but limits the axial motion of the axial shaft and the impeller to being within a certain range of motion (by virtue of the proximal end of the drive cable being held in an axially fixed position, and the stretchability of the drive cable being limited).
As described hereinabove, for some applications, impeller 50 and axial shaft 92 are configured to move axially back-and-forth within frame 34 in response to forces that act upon the impeller, and without requiring the axial shaft to be actively driven to move in the axial back-and-forth motion. Typically, over the course of the subject's cardiac cycle, the pressure difference between the left ventricle and the aorta varies from being approximately zero during systole to a relatively large pressure difference (e.g., 50-70 mmHg) during diastole. For some applications, due to the increased pressure difference that the impeller is pumping against during diastole (and due to the drive cable being stretchable), the impeller is pushed distally with respect to frame 34 during diastole, relative to the location of the impeller with respect to frame 34 during systole. In turn, since the impeller is connected to the axial shaft, the axial shaft is moved forward. During systole, the impeller (and, in turn, the axial shaft) move back to their systolic positions. In this manner, the axial back-and-forth motion of the impeller and the axial shaft is generated in a passive manner, i.e., without requiring active driving of the axial shaft and the impeller, in order to cause them to undergo this motion.
Reference is now made to
Reference is now made to
For some applications, during operation of the ventricular assist device, computer processor 25 of control console 21 (
Referring again to
For some applications, the magnetometer measurements are initially calibrated, such that the change in magnetic flux per unit change in pressure against which the impeller is pumping (i.e., per unit change in the pressure difference between the left ventricle and the aorta, or per unit change in the pressure gradient) is known. It is known that, in most subjects, at systole, the left-ventricular pressure is equal to the aortic pressure. Therefore, for some applications, the subject's aortic pressure is measured, and the subject's left-ventricular pressure at a given time is then calculated by the computer processor, based upon (a) the measured aortic pressure, and (b) the difference between the magnetic flux measured by the magnetometer at that time, and the magnetic flux measured by the magnetometer during systole (when the pressure in the left ventricle is assumed to be equal to that of the aorta). For example, the subject's aortic pressure may be measured by measuring pressure in a channel 224 defined by delivery catheter 143, as described in further detail hereinbelow. For some applications, alternative or additional physiological parameters are determined using the above-described technique. For example, events in the subject's cardiac cycle and/or the subject's cardiac afterload may be determined.
For some applications, generally similar techniques to those described in the above paragraph are used, but as an alternative to or in addition to utilizing magnetometer measurements, a different parameter is measured in order to determine left ventricular blood pressure (and/or a different physiological parameter, e.g., events in the subject's cardiac cycle and/or the subject's cardiac afterload) at a given time. For example, it is typically the case that there is a relationship between the amount of power (and/or current) that is required to power the rotation of the impeller at a given rotation rate and the pressure difference that is generated by the impeller. (It is noted that some of the pressure difference that is generated by the impeller is used to overcome the pressure gradient against which the impeller is pumping, and some of the pressure difference that is generated by the impeller is used to actively pump the blood from the left ventricle to the aorta, by generating a positive pressure difference between the left ventricle and the aorta. Moreover, the relationship between the aforementioned components typically varies over the course of the cardiac cycle.) For some applications, calibration measurements are performed, such that the relationship between (a) power (and/or current) consumption by the motor that is required to rotate the impeller at a given rotation rate and (b) the pressure difference that is generated by the impeller, is known. For some applications, the subject's aortic pressure is measured, and the subject's left-ventricular pressure at a given time is then calculated by the computer processor, based upon (a) the measured aortic pressure, (b) the power (and/or current) consumption by the motor that is required to rotate the impeller at a given rotation rate at that time, and (c) the predetermined relationship between power (and/or current) consumption by the motor that is required to rotate the impeller at a given rotation rate and the pressure difference that is generated by the impeller. For some applications, the above-described technique is performed while maintaining the rotation rate of the impeller at a constant rate. Alternatively or additionally, the rotation rate of the impeller is varied, and the variation of the rotation rate of the impeller is accounted for in the above-described calculations. For some applications, alternative or additional physiological parameters are determined using the above-described technique. For example, events in the subject's cardiac cycle and/or the subject's cardiac afterload may be determined.
Typically, tube 24 has a known cross-sectional area (when the tube is in an open state due to blood flow through the tube). For some applications, the flow through tube 24 that is generated by the impeller is determined based on the determined pressure difference that is generated by the impeller, and the known cross-sectional area of the tube. For some applications, such flow calculations incorporate calibration parameters in order to account for factors such as flow resistance that are specific to the ventricular assist device (or type of ventricular assist device) upon which the calculations are performed. For some applications, the ventricular pressure-volume loop is derived, based upon the determined ventricular pressure.
Referring again to
The torque that is transmitted to the driven magnet typically gives rise to a phase difference between the signal that is measured by magnetometer 84 (which measures magnetic flux density of the driven magnet) and the signal that is measured by second magnetometer 84A (which measures magnetic flux density of the motor and/or the driving magnet). For some applications, as the torque upon the impeller varies, this gives rise to a variation in the phase difference between the signal that is measured by magnetometer 84 and the signal that is measured by second magnetometer 84A. For some applications, the computer processor detects the variation in the aforementioned phase difference, and determines a physiological parameter of the subject, at least partially in response thereto. For example, at least partially based upon variations in the phase difference, the computer processor may determine the difference between the subject's left-ventricular pressure and the subject's aortic pressure, the subject's left ventricular pressure, an event in the subject's cardiac cycle, the subject's cardiac afterload, and/or a different physiological parameter. For some applications, the technique described in the present paragraph is used as an alternative to the above-described technique for using magnetic flux density measurements and/or power consumption measurements to determine physiological parameters. Alternatively, two or more of these techniques are used in combination with each other. For example, the subject's physiological parameters may be determined based upon a mathematical model that incorporates two or more measurements, and/or one of the techniques may be used to validate estimations of the subject's physiological parameters that are made using another one of the techniques.
Reference is now made to
The graph shown in
The graph shown in
In accordance with the above, and in accordance with some applications of the invention, a magnetic phase difference between the one or more driven magnets and the one or more drive magnets is measured, and a physiological parameter of the subject is determined, at least partially in response thereto. For example, at least partially based upon variations in the phase difference, the computer processor may determine the difference between the subject's left-ventricular pressure and the subject's aortic pressure, the subject's left ventricular pressure, an event in the subject's cardiac cycle, the subject's cardiac afterload, and/or a different physiological parameter. For some applications, the physiological parameter is determined based upon the phase difference measurements in combination with one or more additional measurements, such as magnetic flux amplitude measurements, power consumed by the motor, and/or current consumed by the motor. Typically, such measurements are combined into a mathematical model, such as a linear regression model, and/or a space state model.
Reference is now made to
For some applications, the ventricular assist device includes two or more such ventricular blood-pressure-measurement tubes 222, e.g., as shown in
For some applications, outer tube 142 defines a groove 215 in a portion of the outer surface of the outer tube that is configured to be disposed within tube 24. Typically, during insertion of the ventricular assist device into the subject's body, the portion of ventricular blood-pressure-measurement tube 222 that extends from within tube 24 to at least an outer surface of tube 24, is configured to be disposed within the groove, such that the portion of the ventricular blood-pressure-measurement tube does not protrude from the outer surface of the outer tube.
For some applications (not shown), distal portions of blood-pressure-measurement tubes 222 are disposed on the outside of pump-outlet tube 24. For example, blood-pressure-measurement tubes 222 may extend from outer tube 142 to the proximal end of pump-outlet tube 24, and thereafter the blood pressure measurement tubes may be built into the outer surface of tube pump-outlet tube 24, as shown in FIG. 16D of U.S. Pat. No. 10,881,770 to Tuval, which is incorporated herein by reference, for example.
As described hereinabove, for some applications, drive cable 130 extends from a motor outside the subject's body to axial shaft 92 upon which impeller 50 is disposed. Typically, the drive cable is disposed within first outer tube 140 and second outer tube 142, as described hereinabove. For some applications, a proximal portion of blood-pressure-measurement tube 222 comprises a channel between first outer tube 140 and second outer tube 142, as shown in the cross-section of
Referring to
Typically, distal end 230 of optical fiber 228 is configured to be within the subject's left ventricle proximal to the blood pump (e.g., proximal to impeller 50). Typically, by measuring pressure of blood at distal end 230 of optical fiber 228, the pressure sensor thereby measures the subject's blood pressure outside tube 24 (i.e., left ventricular blood pressure). For some applications, computer processor 25 (
For some applications, the ventricular assist device includes two or more such optical fibers 228, e.g., as shown in
For some applications, along the length of outer tube 142, the optical fibers are disposed within the outer tube. Typically, at the distal end of outer tube, the optical fibers are coupled to proximal conical portion 36 of frame 34, such that the optical fibers extend radially to the outer surface of pump-outlet tube 24. For example, as shown in
Referring to both blood-pressure measurement tube 222 and optical fiber 228, it is noted that the distal end of the tube or the fiber is typically in direct fluid communication with left-ventricular bloodstream of the subject at a location that is proximal to the proximal-most portion of blood-inlet opening(s) 108 (e.g., at least 1 cm, or at least 1.5 cm proximal to the proximal-most portion of blood-inlet opening(s) 108). Thus, the distal end of the tube or the fiber is typically exposed to blood that has a pressure that reflects the blood pressure of the left ventricle itself and that is not affected by any pressure variations that are generated in the vicinity of the blood-inlet openings as a result of fluid flow dynamics generated at the blood-inlet openings.
In accordance with the techniques described hereinabove, typically computer processor 25 is configured to determine the pressure and flow related parameters of the subject's left ventricle, e.g., using any one of the techniques described herein for determining flow through the ventricular assist device in combination with any one of the techniques described herein for determining left-ventricular pressure. For some applications, using the aforementioned parameters, the computer processor is configured to estimate the subject's native cardiac output (i.e., stroke volume), total cardiac output, arterial compliance, and/or peripheral resistance. For some applications, the aforementioned parameters are determined using a mathematical model that represents the aorta and/or the left ventricle as a dynamic vascular system.
For example, in accordance with the Windkessel model of the aorta, the relationship between flow and pressure in the aorta may be described by the following equation:
During operation of ventricular assist-device 20, Equation 1 can be rewritten as follows:
For some applications, in a first step, the vascular parameters (C, Zc, R) of the subject are estimated. In order to this, the speed at which the impeller is rotated is varied during one or more vascular-parameter determination period(s). Typically, the vascular-parameter determination period(s) is for the duration of a few cardiac cycles (e.g., 1-10, or 2-6 cardiac cycles), or during diastole only for a few cardiac cycles (e.g., 1-10, or 2-6 cardiac cycles). It is assumed that during the vascular-parameter determination period(s), the subject's parameters remain substantially unchanged. (Alternatively, any changes in the subject's vascular parameters resulting from the change in speed at which the impeller is rotated are accounted for, using a mathematical model that models such changes.)
For the two operational conditions of the ventricular assist device (i.e., when the impeller is operating at its regular operational speed, and when the impeller is rotating at the varied speed during the vascular-parameter determination period(s)), Equation 2 may be rewritten as Equations 3 and 4 respectively, where the 1 and 2 notations included in the subscript represent the first and second operational conditions.
By subtracting Equation 4 from Equation 3, the effect of the ventricular assist device on the vascular system may be characterized, as in Equation 5.
In accordance with the techniques described hereinabove, typically computer processor 25 is configured to determine the pressure and flow related parameters of the subject's left ventricle, e.g., using any one of the techniques described herein for determining flow through the ventricular assist device in combination with any one of the techniques described herein for determining left-ventricular pressure. Therefore, only the vascular parameters (aortic compliance, characteristic impedance, and peripheral resistance) are unknown. Typically, using the known values of the pressure and flow related parameters of the subject's left ventricle, the subject's vascular parameters (aortic compliance, characteristic impedance, and peripheral resistance) are estimated, e.g., using model identification techniques (such as linear regression).
For some application, subsequent to the subject's vascular parameters being estimated, the total cardiac output and the subject's native cardiac output are estimated based upon Equation 3, using the pressure and flow related parameters of the subject's left ventricle (which are typically determined in real time using the sensors described herein), as well as the subject's vascular parameters (which are determined by varying the speed at which the impeller is rotated, as described hereinabove).
For some applications, generally similar techniques to those described above are used, but using a different mathematical model to represent a dynamic vascular system of the subject (e.g., the subject's aorta, and/or the subject's left ventricle), such as to determine vascular parameters, native cardiac output, and/or alternative or additional physiological parameters. Typically, the mathematical model is of the same type as the Windkessel model, in that it accounts for the shape of the aortic waveform in terms of the interaction between the stroke volume and the compliance of the aorta.
In general, the scope of the present application includes a method in which:
More generally, the above steps may be summarized as follows:
The above-described steps are typically repeated during the operation of the ventricular assist device as often as needed.
Reference is now made to
Typically, the inner lining is disposed over the inner surface of at least a portion of central cylindrical portion 38 of frame 34. For some applications, pump-outlet tube 24 also covers central cylindrical portion 38 of frame 34 around the outside of the frame, for example, such that pump-outlet tube 24 and inner lining 39 overlap over at least 50 percent of the length of the inner lining, for example, over the entire length of the cylindrical portion of frame 34, e.g., as shown in
Typically, over the area of overlap between inner lining 39 and pump-outlet tube 24, the inner lining is shaped to form a smooth surface (e.g., in order to reduce hemolysis, as described hereinabove), and pump-outlet tube 24 is shaped to conform with the struts of frame 34 (e.g., as shown in the cross-section in
For some applications, inner lining 39 and pump-outlet tube 24 are made of different materials from each other. For example, the inner lining may be made of polyurethane, and the pump-outlet tube may be made of polyether block amide (PEBAX®). Typically, for such applications, the material from which the inner lining is made has a higher thermoforming temperature than that of the material from which the pump-outlet tube is made. Alternatively, inner lining 39 and pump-outlet tube 24 are made of the same material as each other. For example, the both the inner lining and the pump-outlet tube may be made of may be made of polyurethane or polyether block amide (PEBAX®).
For some applications, the pump-outlet tube and the inner lining are bonded to each other and/or the frame in the following manner. For some applications, the inner lining is directly bonded to the inner surface of the frame, before the pump-outlet tube is bonded to the outside of the frame. It is noted that, by bonding the inner lining directly to the inner surface of the frame, (rather than simply bonding the inner lining to the pump-outlet tube and thereby sandwiching the frame between the inner lining to the pump-outlet tube), any air bubbles, folds, and other discontinuities in the smoothness of the surface provided by the inner lining are typically avoided. For some applications, similar techniques to those described hereinabove, for enhancing bonding between the elastomeric film and the helical elongate elements of the impeller, are used to enhance bonding between the inner lining and the inner surface of the frame. For some applications, initially, the frame is treated so as to enhance bonding between the inner lining and the inner surface of the frame. For some applications, the treatment of the frame includes applying a plasma treatment to the frame (e.g., to the inner surface of the frame), dipping the frame in a coupling agent that has at least two functional groups that are configured to bond respectively with the frame and with the material form which the inner lining is made (e.g., silane solution), and/or dipping the frame in a solution that contains the material from which the inner lining is made (e.g., polyurethane solution). For some applications, the inner lining is made of an elastomeric material (e.g., polyurethane) and the coupling agent is a silane solution, such as a solution of n-(2-aminoethyl)-3-aminopropyltrimethoxysilane, with the silane containing a first functional group (e.g., (OH)) which is configured to bond with the frame (which is typically made of an alloy, such a nitinol), and the silane containing a second functional group (e.g., (NH2)) which is configured to bond with the elastomeric material.
For some applications, subsequently, a solution that contains the material from which the inner lining is made (e.g., polyurethane solution) is sprayed over the central cylindrical portion of the frame. Once the inner surface of the frame has been treated, the inner lining is bonded to the inner surface of the central cylindrical portion of the frame (e.g., to the inner surface of a central cylindrical portion of the frame). Typically, the inner lining (which is shaped as a tube), is placed over a mandrel, the frame is placed over the inner lining, and pressure is applied by a heat shrinking process. Further typically, the assembly of the inner lining and the frame is heated in an oven.
Subsequent to the inner lining having been bonded to the frame, a portion of pump-outlet tube 24 is placed around the outside of the frame. As described above, for some applications, inner lining 39 and pump-outlet tube 24 are made of different materials from each other. For example, the inner lining may be made of polyurethane, and the pump-outlet tube may be made of polyether block amide (PEBAX®). Typically, for such applications, the material from which the inner lining is made has a higher thermoforming temperature than that of the material from which the pump-outlet tube is made. For some applications, in order to mold pump-outlet tube 24 to conform with the struts of frame 34, without causing the inner lining to deform, the frame is heated to a temperature that is above the thermoforming temperature of pump-outlet tube 24 but below the thermoforming temperature of inner lining 39.
Typically, the frame is heated from inside the frame, using the mandrel. Typically, while the frame is heated to the aforementioned temperature, an outer tube (which is typically made from silicone) applies pressure to pump-outlet tube 24 that causes pump-outlet tube 24 to be pushed radially inwardly, in order to cause the pump-outlet tube to conform with the shapes of the struts of the frame, as shown in the cross-section of
Reference is now made to
For some applications (not shown), the pump-outlet tube defines two to four lateral blood-inlet openings. Typically, for such applications, each of the blood-inlet openings defines an area of more than 20 square mm (e.g., more than 30 square mm), and/or less than 60 square mm (e.g., less than 50 square mm), e.g., 20-60 square mm, or 30-50 square mm. Alternatively or additionally, the outlet tube defines a greater number of smaller blood-inlet openings 108, e.g., more than 10 blood-inlet openings, more than 50 blood-inlet openings, more than 100 blood-inlet openings, or more than 150 blood-inlet openings, e.g., 50-100 blood-inlet openings, 100-150 blood-inlet openings, or 150-200 blood-inlet openings. For some applications, the blood-inlet openings are sized such as (a) to allow blood to flow from the subject's left ventricle into the tube and (b) to block structures from the subject's left ventricle from entering into the frame. Typically, for such applications, the distal conical portion 46 of pump-outlet tube 24 is configured to reduce a risk of structures from the left ventricle (such as chordae tendineae, trabeculae carneae, and/or papillary muscles) entering into frame 34 and potentially being damaged by the impeller and/or the axial shaft, and/or causing damage to the left ventricular assist device. Therefore, for some applications, the blood-inlet openings are shaped such that, in at least one direction, the widths (or spans) of the openings are less than 1 mm, e.g., 0.1-1 mm, or 0.3-0.8 mm. By defining such a small width (or span), it is typically the case that structures from the left ventricle (such as chordae tendineae, trabeculae carneae, and/or papillary muscles) are blocked from entering into frame 34. For some such applications, each of the blood-inlet openings defines an area of more than 0.05 square mm (e.g., more than 0.1 square mm), and/or less than 3 square mm (e.g., less than 1 square mm), e.g., 0.05-3 square mm, or 0.1-1 square mm. Alternatively, each of the blood-inlet openings defines an area of more than 0.1 square mm (e.g., more than 0.3 square mm), and/or less than 5 square mm (e.g., less than 1 square mm), e.g., 0.1-5 square mm, or 0.3-1 square mm.
Typically, the portion of the pump-outlet tube that defines the blood-inlet openings has a porosity of more than 40 percent, e.g., more than 50 percent, or more than 60 percent (where porosity is defined as the percentage of the area of this portion that is porous to blood flow). Thus, on the one hand, the blood-inlet openings are relatively small (in order to prevent structures of the left ventricular from entering the frame), but on the other hand, the porosity of the portion of the pump-outlet tube that defines the blood-inlet openings is relatively high, such as to allow sufficient blood flow into the pump-outlet tube.
For some applications, each of the blood-inlet openings has a circular or a polygonal shape. For some applications, each of the blood-inlet openings has a hexagonal shape, as shown in
As described hereinabove with reference to
Typically, width W of the gaps between the hexagonal (or other type of polygonal) holes and distance D between opposing sides of each of the hexagons (or other type of polygons) within distal region 46D of distal conical portion 46 of the pump-outlet tube are as described hereinabove. For some applications, width WI of gaps between adjacent hexagonal (or other polygonal) holes within proximal region 46P of distal conical portion 46 of pump-outlet tube 24 is more than 0.05 mm (e.g., more than 0.07 mm), and/or less than 0.2 mm (e.g., less than 0.15 mm), for example, 0.05-0.2 mm, or 0.07-0.15 mm. For some applications, distance D1 between opposing sides of each of the hexagons (or other types of polygons) within proximal region 46P of distal conical portion 46 of pump-outlet tube 24 is more than 0.1 mm (e.g., more than 0.3 mm) and/or less than 0.6 mm (e.g., less than 0.5 mm), e.g., 0.1-0.6 mm, or 0.3-0.5 mm.
The scope of the present disclosure includes having non-uniformly sized and/or shaped lateral blood-inlet openings (e.g., circular, rectangular, polygonal, and/or hexagonal lateral blood-inlet openings), disposed in any arrangement along the distal conical portion 46 of the pump-outlet tube. Similarly, the scope of the present disclosure includes a distal conical portion 46 of the pump-outlet tube that defines lateral blood-inlet openings being arranged such that the distal conical portion has a non-uniform porosity, with the porosity varying over different regions of the distal conical portion. For some applications, the shapes and/or sizes of the lateral blood-inlet openings, and/or the porosity of the distal conical portion, is varied such as to account for varying blood flow dynamics at different regions of the distal conical portion. Alternatively or additionally, the shapes and/or sizes of the lateral blood-inlet openings, and/or the porosity of the distal conical portion, is varied such as to account for changes in the shape of the distal conical portion along its length.
Reference is now made to
As described hereinabove, for some applications, coupling portion 41 is coupled to the outer surface of portion 123 of distal bearing housing 118H. For some applications, coupling portion 41 defines a hole 111 (e.g., toward the distal end of the coupling portion), as shown in
Reference is now made to
The drive cable is typically disposed within a first outer tube 140, which is configured to remain stationary while the drive cable undergoes rotational and/or axial back-and-forth motion. The first outer tube is configured to effectively act as a bearing tube for the drive cable, along the length of the drive cable. As such, first outer tube is also referred to herein as the drive-cable bearing tube. The drive-cable bearing tube is described in further detail hereinbelow with reference to
Typically, during insertion of the impeller and the frame into the left ventricle, impeller 50 and frame 34 are maintained in radially-constrained configurations by delivery catheter 143. As described hereinabove, in order for the impeller and the frame to assume non-radially-constrained configurations, the delivery catheter is retracted. For some applications, as shown in
Reference is now made to
Reference is now made to
Reference is now made to
Subsequent to the distal end of the ventricular assist device being guided to the left ventricle, impeller 50 and frame 34 of the ventricular assist device are deployed, by retracting the delivery catheter, which typically causes the impeller and frame to assume non-radially-constrained configurations. Typically, at this stage, the tip of the guidewire is retracted proximally through the distal tip portion 120 and is retracted proximally from the pump portion. In some cases, after the guidewire has been retracted in the above-described manner, it is desirable to reinsert the guidewire through distal tip portion 120, and out of duckbill valve 160, which is disposed toward a distal end of the distal tip portion. For example, this may be desirable if the pump portion migrates from its correct position and requires repositioning within the left ventricle. However, if the tip of the guidewire is still flexible (as described above), it is not possible to advance the tip of the guidewire through the narrow tip of the proximally-facing duckbill valve 160. Therefore, for some applications, the guidewire is configured such that its tip can define two states: a flexible state, and a stiff state.
For some applications, guidewire 10 includes an outer coil 250 and an inner stiffening wire 252. When the distal end of the guidewire should be in a flexible state, the inner stiffening wire is retracted from the distal end of the guidewire, such that there is a distal portion of the outer coil that does not have the stiffening wire disposed therein. For some applications, the guidewire is releasably locked into this state, in order to prevent the distal end of the guidewire from becoming rigid and damaging the subject's vasculature and/or left ventricle. For example, as shown in FIG. 14A, for some applications, one or more locking elements 254 extend radially from a proximal portion of the stiffening wire and protrude between windings of the outer coil, such as to prevent the stiffening wire from being advanced. For some applications, at the proximal end 256 of the outer coil, there are larger gaps between the windings of the coil than at portions of the outer coil that are more distal, such that the locking elements protrude between windings of the outer coil at the proximal end. For some applications, in order to convert the distal end of the guidewire to a rigid state, locking elements 254 are pushed radially inwardly such that they are disposed within the outer coil, and the stiffening wire is advanced distally, such that the stiffening wire becomes disposed within the outer coil even at the distal end of the guidewire. For some applications, the locking elements remain disposed within the outer coil as the stiffening wire is advanced distally because the locking elements are now disposed within a portion of the outer coil at which the windings of the coil are disposed sufficiently close to each other that they block the locking elements from protruding from between them.
Reference is now made to
For some applications, thrust bearing 260 is disposed within frame 34 as shown. For example, the thrust bearing may be disposed within the cylindrical portion of the frame or within the distal conical portion of the frame. For some applications at a distal end of axial shaft, the axial shaft defines a widened portion 262 that is configured to engage the thrust bearing and to prevent the axial shaft (and thereby prevent the impeller) from undergoing axial motion. (In addition, the widened portion of the axial shaft is constrained radially by bearing 260, such that the bearing also functions as a distal radial bearing.) Typically, the thrust bearing is coupled to the frame via connecting struts 264, which extend radially inwardly from the frame to the thrust bearing. Typically, in order to manufacture frame 34, the frame is cut from a tube of a shape-memory alloy, such as nitinol. For some applications, connecting struts 264 are cut from the tube from which the frame is cut, such that the frame and the connecting struts form a single integral body, without requiring coupling to each other (e.g., via adhesive, welding, etc.). In general, for some applications, the frame and the connecting struts are cut from a single piece of a material such as to form a single integral body. For some applications, connecting struts 264 as well as thrust bearing 260 itself are cut from the tube from which the frame is cut, such that the frame, the connecting struts, and the thrust bearing form a single integral body, without requiring coupling to each other (e.g., via adhesive, welding, etc.). In general, for some applications, the frame, the connecting struts, and thrust bearing 260 itself are cut from a single piece of a material such as to form a single integral body.
For some applications, a spring that is generally similar to motion-cushioning spring 68 (shown in
Typically, the impeller-stabilizing spring is disposed around axial shaft 92 between the distal end of the impeller (e.g., distal bushing 58 of the impeller) and thrust bearing 260. For some applications, the impeller-stabilizing spring is coupled to thrust bearing 260 and extends proximally over axial shaft 92 from thrust bearing 260. Typically, in such cases, the impeller-stabilizing spring remains rotationally stationary as the impeller rotates, and the impeller is configured to rotate with respect to the impeller-stabilizing spring. Alternatively or additionally, the impeller-stabilizing spring is coupled to the distal end of the impeller (e.g., distal bushing 58 of the impeller) and/or extends distally over axial shaft 92 from the distal end of the impeller (e.g., distal bushing 58 of the impeller). For some such applications, the impeller-stabilizing spring is configured to rotate together with the impeller. Alternatively, the impeller-stabilizing spring extends from a radial bearing that is disposed around the distal end of the impeller (e.g., distal bushing 58 of the impeller), such that impeller-stabilizing spring remains rotationally stationary as the impeller rotates, and the impeller is configured to rotate with respect to the impeller-stabilizing spring. For some applications, the impeller-stabilizing spring is coupled to (e.g., coated with or embedded within) elastomeric material 69 (also shown in
For some applications, an impeller-stabilizing spring is disposed around the axial shaft on a proximal side of the impeller, e.g., as described hereinabove with reference to
For some applications, thrust bearing 260 is used in combination with a pump-outlet tube 24 that is configured as shown in, and described with reference to,
As shown in
Reference is now made to
For some applications, in order to unpackage the ventricular assist device and prepare it for use, a top cover 271 of the packaging is removed, such as to expose pump-head chamber 274. For some applications, the pump-head chamber is then filled within a solution 282, such as saline, as indicated in
With regards to all aspects of ventricular assist device 20 described with reference to
The scope of the present invention includes combining any of the apparatus and methods described herein with any of the apparatus and methods described in one or more of the following applications, all of which are incorporated herein by reference:
International Application No. PCT/IB2022/051990 to Tuval, entitled “Ventricular assist device,” filed Mar. 7, 2022, which claims priority from:
U.S. Provisional Patent Application 63/158,708 to Tuval, entitled “Ventricular assist device,” filed Mar. 9, 2021, and
U.S. Provisional Patent Application 63/254,321 to Tuval, entitled “Ventricular assist device,” filed Oct. 11, 2021.
International Application No. PCT/IB2021/052590 to Zipory (published as WO 21/198881), entitled “Centrifugal and mixed-flow impellers for use with a blood pump,” filed Mar. 29, 2021, which claims priority from U.S. 63/003,955 to Zipory, entitled “Ventricular assist device,” filed Apr. 2, 2020.
US 2022/0226632 to Tuval, entitled “Ventricular assist device,” which is the US national phase of PCT Application No. PCT/IB2021/052857 (published as WO 21/205346), filed Apr. 6, 2021, which claims priority from:
U.S. Provisional Patent Application 63/006,122 to Tuval, entitled “Ventricular assist device,” filed Apr. 7, 2020;
U.S. Provisional Patent Application 63/114,136 to Tuval, entitled “Ventricular assist device,” filed Nov. 16, 2020; and
U.S. Provisional Patent Application 63/129,983 to Tuval, entitled “Ventricular assist device,” filed Dec. 23, 2020.
US 2020/0237981 to Tuval, entitled “Distal tip element for a ventricular assist device,” filed Jan. 23, 2020, which claims priority from:
U.S. Provisional Patent Application 62/796,138 to Tuval, entitled “Ventricular assist device,” filed Jan. 24, 2019;
U.S. Provisional Patent Application 62/851,716 to Tuval, entitled “Ventricular assist device,” filed May 23, 2019;
U.S. Provisional Patent Application 62/870,821 to Tuval, entitled “Ventricular assist device,” filed Jul. 5, 2019; and
U.S. Provisional Patent Application 62/896,026 to Tuval, entitled “Ventricular assist device,” filed Sep. 5, 2019.
US 2019/0209758 to Tuval, which is a continuation of International Application No. PCT/IB2019/050186 to Tuval (published as WO 19/138350), entitled “Ventricular assist device,” filed Jan. 10, 2019, which claims priority from:
US 2019/0269840 to Tuval, which is the US national phase of International Patent Application PCT/IL2017/051273 to Tuval (published as WO 18/096531), filed Nov. 21, 2017, entitled “Blood pumps,” which claims priority from U.S. Provisional Patent Application 62/425,814 to Tuval, filed Nov. 23, 2016;
US 2019/0175806 to Tuval, which is a continuation of International Application No. PCT/IL2017/051158 to Tuval (published as WO 18/078615), entitled “Ventricular assist device,” filed Oct. 23, 2017, which claims priority from U.S. 62/412,631 to Tuval filed Oct. 25, 2016, and U.S. 62/543,540 to Tuval, filed Aug. 10, 2017;
US 2019/0239998 to Tuval, which is the US national phase of International Patent Application PCT/IL2017/051092 to Tuval (published as WO 18/061002), filed Sep. 28, 2017, entitled “Blood vessel tube,” which claims priority from U.S. Provisional Patent Application 62/401,403 to Tuval, filed Sep. 29, 2016;
US 2018/0169313 to Schwammenthal, which is the US national phase of International Patent Application PCT/IL2016/050525 to Schwammenthal (published as WO 16/185473), filed May 18, 2016, entitled “Blood pump,” which claims priority from U.S. Provisional Patent Application 62/162,881 to Schwammenthal, filed May 18, 2015, entitled “Blood pump;”
US 2017/0100527 to Schwammenthal, which is the US national phase of International Patent Application PCT/IL2015/050532 to Schwammenthal (published as WO 15/177793), filed May 19, 2015, entitled “Blood pump,” which claims priority from U.S. Provisional Patent Application 62/000,192 to Schwammenthal, filed May 19, 2014, entitled “Blood pump;”
U.S. Pat. No. 10,039,874 to Schwammenthal, which is the US national phase of International Patent Application PCT/IL2014/050289 to Schwammenthal (published as WO 14/141284), filed Mar. 13, 2014, entitled “Renal pump,” which claims priority from (a) U.S. Provisional Patent Application 61/779,803 to Schwammenthal, filed Mar. 13, 2013, entitled “Renal pump,” and (b) U.S. Provisional Patent Application 61/914,475 to Schwammenthal, filed Dec. 11, 2013, entitled “Renal pump;”
U.S. Pat. No. 9,764,113 to Tuval, issued Sep. 19, 2017, entitled “Curved catheter,” which claims priority from U.S. Provisional Patent Application 61/914,470 to Tuval, filed Dec. 11, 2013, entitled “Curved catheter;” and
U.S. Pat. No. 9,597,205 to Tuval, which is the US national phase of International Patent Application PCT/IL2013/050495 to Tuval (published as WO 13/183060), filed Jun. 6, 2013, entitled “Prosthetic renal valve,” which claims priority from U.S. Provisional Patent Application 61/656,244 to Tuval, filed Jun. 6, 2012, entitled “Prosthetic renal valve.”
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.
The present application is a continuation of International Application PCT/IB2022/058101 to Tuval (published as WO 23/062453), entitled “Ventricular assist device,” filed Aug. 30, 2022, which claims priority from: U.S. Provisional Patent Application 63/254,321 to Tuval, entitled “Ventricular assist device,” filed Oct. 11, 2021; andU.S. Provisional Patent Application 63/317,199 to Tuval, entitled “Ventricular assist device,” filed Mar. 7, 2022. Both of the above-referenced US Provisional applications are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2022/058101 | 8/30/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63254321 | Oct 2021 | US | |
| 63317199 | Mar 2022 | US |
