Automatic Balloon Inflation Device for Transcatheter Heart Valve Implantation

Abstract

A method of implanting an artificial heart valve includes delivering the artificial heart valve to its native valve annulus while the artificial heart valve is crimped onto a deflated balloon of a delivery device. The method can include advancing fluid into the balloon through the delivery device to inflate the balloon and expand the artificial heart valve within its native valve annulus. The method can include monitoring the pressure within the delivery device while advancing fluid through the delivery device. The method can also include displaying the monitored pressure in real time on a display device while monitoring the pressure.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 343,479, filed on May 18, 2022, the disclosure of which is incorporated herein by reference.

Background Art

[0002] Cardiac valve diseases, particularly aortic valve disease and mitral valve disease, are significant health problems in the United States. Valve replacement is one option for treating cardiac valve diseases. In the patent literature, artificial heart valves are well - known, including surgical heart valves and foldable / expandable heart valves intended for transcatheter aortic valve replacement (“TAVR”) or transcatheter mitral valve replacement (“TMVR”). Surgical or mechanical heart valves can be sutured, for example, to a patient's native annulus (natural annulus) during an open - heart procedure. Foldable / expandable heart valves can be delivered into a patient's body via a tubular delivery device such as a catheter, trocar, laparoscopic instrument, etc., and can avoid more invasive procedures such as full - thoracotomy and open - heart surgery. As used herein, references to “foldable / expandable” heart valves include heart valves that are formed with a small cross - section so as to be deliverable to a patient via a tubular delivery device in a minimally invasive procedure and expand to an operable state when placed in place, and heart valves that are folded to a small cross - section for initial delivery to a patient and then expand to an operable size when placed in place within the annulus.

[0003] Foldable / expandable artificial heart valves typically take the form of a one-way valve structure (often referred to herein as a valve assembly) attached to or within an expandable stent. Generally, these foldable / expandable artificial heart valves include a self-expanding stent or a balloon-expandable stent, which is often made of nitinol or another shape memory metal or metal alloy (in the case of a self-expanding stent), or steel or cobalt chrome (in the case of a balloon-expandable stent). Existing foldable / expandable TAVR devices use stent configurations of various arrangements, including straight vertical struts connected by a "V-shaped portion" as shown in U.S. Patent No. 8,454,685, or a diamond-shaped cell layout as shown in U.S. Patent No. 9,326,856, both of which patents are hereby incorporated by reference herein. The one-way valve assembly attached to or within the stent includes one or more valve leaflets and may also include a cuff or skirt. The cuff can be disposed on the inner or lumen surface of the stent, the outer or outer lumen surface of the stent, and / or both surfaces. The cuff serves to prevent blood from simply flowing around the valve leaflets when the valve or valve assembly is not optimally seated in the valve annulus. The cuff, or a portion of the cuff disposed outside the stent, helps to prevent leakage around the outside of the valve, which is known as paravalvular regurgitation or "PV" regurgitation.

[0004] Balloon-expandable valves are typically delivered to the native valve annulus in a collapsed (or "crimped") state over a collapsed balloon of a balloon catheter, with the collapsed valve being either covered or not covered by a sheath thereover. When the crimped prosthetic heart valve is positioned within the valve annulus of the native heart valve being replaced, the balloon is inflated to force the balloon-expandable valve to transition from a collapsed or crimped state to an expanded or deployed state, and the prosthetic heart valve tends to remain in the shape expanded by the balloon. Typically, when the position of the collapsed prosthetic heart valve is determined to be at a desired position relative to the native valve annulus (e.g., by visualization under fluoroscopy), a fluid such as saline (gases can be used as well, but typically a liquid) is pushed through the balloon catheter via a manual syringe to initiate filling and expansion of the balloon, and thus the prosthetic heart valve thereabove expands within the native valve annulus. Relying solely on fully manual balloon inflation may not be optimal, and partial or full automation of the balloon inflation process may be desirable, for example, to provide more consistent and predictable results of balloon expansion. For example, the predictability of how a balloon-expandable prosthetic heart valve expands can vary significantly depending on how rapidly the user inflates the balloon. Also, such a system can be useful for providing data that can be used during a procedure and for learning information related to data that can be collected over multiple procedures regarding important parameters of balloon inflation that may not otherwise be readily determinable from a typical manual process. Such information can be collected and used to refine a partially or fully automated balloon inflation process for future procedures. Also, the balloon inflation system (or its ancillary components) preferably can reliably degas the balloon catheter system prior to use using an objective mechanism (e.g., not just by visual inspection) to ensure that no air remains in the catheter in an unacceptable amount prior to delivery. SUMMARY OF THE INVENTION

[0005] According to one aspect of the present disclosure, a method of implanting an artificial heart valve includes delivering the artificial heart valve to the native valve annulus while the artificial heart valve is crimped onto a deflated balloon of a delivery device. The method can include advancing fluid into the balloon through the delivery device to inflate the balloon and expand the artificial heart valve within the native valve annulus. The method can include monitoring the pressure within the delivery device while advancing fluid through the delivery device. The method can also include, while monitoring the pressure, displaying the monitored pressure in real time on a display device.

[0006] According to another aspect of the present disclosure, an artificial heart valve delivery system can include a handle, a balloon catheter extending from the handle, and a balloon positioned at a distal end portion of the balloon catheter. A fluid reservoir can be in fluid communication with a lumen, and the lumen is in fluid communication with an internal volume of the balloon. A motor can be operably coupled to the fluid reservoir. An actuator can be provided on the handle, and the actuator is operably coupled to the motor such that when the actuator is actuated in a first direction, the motor extrudes fluid from the fluid reservoir through the lumen and into the internal volume of the balloon, and when the actuator is actuated in a second direction opposite the first direction, the motor withdraws fluid from the internal volume of the balloon and into the fluid reservoir.

[0007] According to another embodiment of the present disclosure, a method of degassing a balloon of a balloon catheter can include (i) pulling out a plunger of a purge syringe while the purge syringe is in fluid communication with the balloon of the balloon catheter and while the purge syringe is not in fluid communication with a filling syringe containing fluid, and monitoring a vacuum pressure as a function of plunger displacement as the plunger of the purge syringe is pulled out to create a pressure-displacement line having a slope. The method can further include (ii) advancing a plunger of the filling syringe while the filling syringe is in fluid communication with the balloon of the balloon catheter and while the filling syringe is not in fluid communication with the purge syringe. The method can further include (iii) advancing the plunger of the filling syringe while the filling syringe is in fluid communication with the purge syringe and while the filling syringe is not in fluid communication with the balloon catheter to push out the remaining air through a one-way valve in fluid communication with the purge syringe. Steps (i) through (iii) can be repeated until the slope of the pressure-displacement line exceeds a threshold slope of a reference pressure-displacement line. BRIEF DESCRIPTION OF THE DRAWINGS

[0008]

Figure 1A

Figure 1B

Figure 1C

Figure 1D

Figure 1E

Figure 1F

Figure 1G

Figure 1H

Figure 1I

Figure 1J

Figure 2A

Figure 2B

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 3E

Figure 3F

Figure 3G

Figure 3H

Figure 3I

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0009] As used herein, the term "inflow end" when used in connection with an artificial heart valve refers to the end of the artificial heart valve where blood first enters when the artificial heart valve is implanted in its intended position and orientation, and the term "outflow end" refers to the end of the artificial heart valve where blood exits when the artificial heart valve is implanted in its intended position and orientation. Thus, in the case of an artificial aortic valve, the inflow end is the end closer to the left ventricle, and the outflow end is the end closer to the aorta. The intended position and orientation are used for convenience in describing the valves disclosed herein, but it should be noted that the use of the valve is not limited to its intended position and orientation and can be deployed in any type of lumen or passage. For example, although an artificial heart valve is described herein as an artificial aortic valve, the same or similar structures and functions can be employed in other heart valves such as pulmonary valves, mitral valves, or tricuspid valves. Further, the term "proximal" when used in connection with a delivery device or system refers to the direction that is relatively closer to the user of that device or system when it is used as intended, and the term "distal" refers to the direction that is relatively farther from the user of the device. In other words, the front end of a delivery device or system is positioned distally relative to the rear end of the delivery device or system when it is used as intended. As used herein, the terms "substantially", "generally", "approximately", and "about" are intended to mean that a slight deviation from the absolute is included within the scope of the term so modified. A stent as used herein may exhibit an "expanded state" and a "folded state", which refers to the overall radial size of the stent.

[0010] FIG. 1A shows a perspective view of a stent 100 of an artificial heart valve according to an embodiment of the present disclosure. The stent 100 can include a frame that extends axially between an inflow end 101 and an outflow end 103. The stent 100 includes three generally symmetric sections, each section extending approximately 120 degrees around the circumference of the stent 100. The stent 100 includes three vertical struts 110a, 110b, 110c that extend in a substantially parallel axial direction with respect to the direction of blood flow through the stent, which can also be referred to as the central longitudinal axis. Each vertical strut 110a, 110b, 110c can extend substantially over the entire axial length between the inflow end 101 and the outflow end 103 of the stent 100, and each vertical strut 110a, 110b, 110c can be disposed between two sections and shared by those two sections. In other words, each section is defined by the portion between two vertical struts of the stent 100. Thus, each vertical strut 110a, 110b, 110c is also spaced approximately 120 degrees around the circumference of the stent 100. It should be understood that the stent 100 can include three sections as shown if it is used in an artificial heart valve having three valve leaflets. However, in other embodiments, if the artificial heart valve has two valve leaflets, the stent can include only two sections.

[0011] Figure 1B shows a schematic view of the stent section 107 of the stent 100, which will be described in more detail herein and represents all three sections. The stent section 107 shown in Figure 1B includes a first vertical strut 110a and a second vertical strut 110b. The first vertical strut 110a extends axially between a first inflow node 102a and a first outer node 135a. The second vertical strut 110b extends axially between a second inflow node 102b and a second outer node 135b. As shown, the vertical struts 110a, 110b can extend over substantially the entire axial length of the stent 100. In some embodiments, the stent 100 can be formed as a one-piece unit, for example, by laser cutting the stent from a tube. The term "node" can refer to the location where two or more struts of the stent 100 contact each other. A pair of continuous inverted V-shaped portions extend between the inflow nodes 102a, 102b, and this inverted V-shaped portion includes a first inflow inverted V-shaped portion 120a and a second inflow inverted V-shaped portion 120b that are connected to each other at the inflow node 105. The first inflow inverted V-shaped portion 120a includes a first outer lower strut 122a that extends between the first inflow node 102a and the first central node 125a. The first inflow inverted V-shaped portion 120a further includes a first inner lower strut 124a that extends between the first central node 125a and the inflow node 105. The second inflow inverted V-shaped portion 120b includes a second inner lower strut 124b that extends between the inflow node 105 and the second central node 125b. The second inflow inverted V-shaped 120b further includes a second outer lower strut 122b that extends between the second central node 125b and the second inflow node 102b. Although described as inverted V-shaped portions, these structures can also be described as half-cells, and each half-cell is a semi-rhombic cell with the open portion of the half-cell at the inflow end 101 of the stent 100.

[0012] The stent section 107 further includes a first central strut 130a that extends between the first central node 125a and the upper node 145. The stent section 107 also includes a second central strut 130b that extends between the second central node 125b and the upper node 145. The first central strut 130a, the second central strut 130b, the first inner lower strut 124a, and the second inner lower strut 124b form a diamond cell 128. The stent section 107 includes a first outer upper strut 140a that extends between the first outer node 135 and the first outflow node 104a. The stent section 107 further includes a second outer upper strut 140b that extends between the second outer node 135b and the second outflow node 104b. The stent section 107 includes a first inner upper strut 142a that extends between the first outflow node 104a and the upper node 145. The stent section 107 further includes a second inner upper strut 142b that extends between the upper node 145 and the second outflow node 104b. The stent section 107 includes an outflow inverted V-shaped portion 114 that extends between the first outflow node 104a and the second outflow node 104b. The first vertical strut 110a, the first outer upper strut 140a, the first inner upper strut 142a, the first central strut 130a, and the first outer lower strut 122a form a first generally kite-shaped cell 133a. The second vertical strut 110b, the second outer upper strut 140b, the second inner upper strut 142b, the second central strut 130b, and the second outer lower strut 122b form a second generally kite-shaped cell 133b. The first kite-shaped cell 133a and the second kite-shaped cell 133b are symmetric and face each other in the stent section 107. Although the term "kite-shaped" is used above, it should be understood that such a shape is not limited to the exact geometric definition of a kite shape. The outflow inverted V-shaped portion 114, the first inner upper strut 142a, and the second inner upper strut 142b form an upper cell 134.The upper cell 134 is generally kite-shaped and is axially aligned with the diamond cell 128 in the stent section 107. Although designated as separate struts, it should be understood that the various struts described herein may be part of a single integral structure as described above. However, in other embodiments, the stent 100 need not be formed as an integral structure, and thus the struts may be different structures (or parts of different structures) that are connected to each other.

[0013] Figure 1C shows a schematic view of a stent section 207 according to an alternative embodiment of the present disclosure. Unless otherwise noted, like reference numbers refer to like elements of the stent 100 described above, but within the range of numbers in the 200s. The stent section 207 is substantially similar to the stent section 107 and includes inflow nodes 202a, 202b, vertical struts 210a, 210b, a first inflow reverse V-shaped portion 220a and a second inflow reverse V-shaped portion 220b, and outflow nodes 204a, 204b. The structure of the stent section 207 differs from the stent section 107 in that it does not include an outflow reverse V-shaped portion. The purpose of an embodiment having such a structure of the stent section 207 shown in Figure 1C is to reduce the force required to expand the outflow end 203 of the stent 200 compared to the stent 100 and to promote uniform expansion with respect to the inflow end 201. The outflow nodes 204a, 204b are connected by a properly oriented V-shaped portion formed by a first inner upper strut 242a, an upper node 245, and a second inner upper strut 242b. In other words, the struts 242a, 242b can form a semi-rhombic cell 234, and the open end of the half cell is directed towards the outflow end 203. The semi-rhombic cell 234 is axially positioned with respect to the rhombic cell 228. Adding an outflow reverse V-shaped portion connected between the outflow nodes 204a, 204b contributes to the addition of material, which in turn increases the resistance to changes in the stent shape and requires additional force to expand the stent. By removing material from the outflow end 203, the resistance to expansion of the outflow end 203 can be reduced, and uniform expansion of the inflow end 201 and the outflow end 203 can be promoted. In other words, the inflow end 201 of the stent 200 does not include a continuous circumferential structure, but rather has a half cell that is mostly or completely open, with the open portion of the half cell directed towards the inflow end 201, while most of the outflow end 203 includes a substantially continuous circumferential structure via struts corresponding to the struts 140a, 140b. All other conditions being the same, a substantially continuous circumferential structure may require more force to expand compared to a similar but open structure.Therefore, the inflow end 101 of the stent 100 may require a greater force to expand radially compared to the outflow end 103. By omitting the inverted V-shaped portion 114, the stent 200 is formed, and the force required to expand the outflow end 203 of the stent 200 can be reduced to an amount closer to that of the inflow end 201.

[0014] FIG. 1D shows a front view of the stent section 207 in the folded state, and FIG. 1E shows a front view of the stent section 207 in the expanded state. The stent 200 in FIGS. 1D and 1E is shown as having an opaque tube extending through the interior of the stent for the sole purpose of aiding in the explanation of the stent, and it should be understood that this tube may represent a balloon by which the stent section 207 is crimped. As described above, the stent includes three symmetric sections, each section extending approximately 120 degrees around the circumference of the stent. The stent section 207 shown in FIGS. 1D and 1E is defined by the region between the vertical struts 210a, 210b. The stent section 207 is representative of all three sections of the stent. The stent section 207 has an arcuate structure such that when the three sections are connected, they form one complete cylindrical shape. FIGS. 1F and 1G show a portion of the stent as viewed from the side. In other words, the views of the stent 200 in FIGS. 1F and 1G are rotated approximately 60 degrees compared to the views in FIGS. 1D and 1E. The views of the stent shown in FIGS. 1F and 1G are centered on the vertical strut 210b and show approximately half of each of the two adjacent stent sections 207a, 207b on either side of the vertical strut 210b. The sections 207a, 207b surrounding the vertical strut 210b are mirror images of each other. FIG. 1F shows the stent sections 207a, 207b in the folded state, and FIG. 1G shows the stent sections 207a, 207b in the expanded state.

[0015] Figure 1H shows a flattened view of a stent 200 including three stent sections 207a, 207b, 207c, shown as if the stent were cut longitudinally and laid flat on a table. As shown, sections 207a, 207b, 207c are symmetric with respect to each other, and adjacent sections share a common vertical strut. As described above, stent 200 is shown in a flattened view, but each section 207a, 207b, 207c has an arcuate shape spanning 120 degrees and forms a complete cylinder. Figure 1H further shows valve leaflets 250a, 250b, 250c connected to stent 200. However, it should be understood that only the connection portions of valve leaflets 250a - 250c are shown in Figure 1H. In other words, each valve leaflet 250a - 250c typically includes a free end that acts to join with each other to prevent retrograde blood flow through stent 200, and the free end moves radially outward toward the inner surface of the stent to allow for antegrade blood flow through the stent. These free ends are not shown in Figure 1H. Rather, in Figure 1H, the attachment edges of valve leaflets 250a - 250c are shown as dashed lines. Attachment can be performed via any suitable means, but the attachment edge can preferably be sutured to stent 200 and / or to an intervening cuff or skirt between the stent and valve leaflets 250a - 250c. Each of the three valve leaflets 250a, 250b, 250c extends around the circumference of stent 200 for approximately 120 degrees from end to end, and each valve leaflet includes a belly that can extend toward the radial center of stent 200 when the valve leaflets are joined to each other. Each valve leaflet extends between the upper nodes of adjacent sections. The first valve leaflet 250a extends from the first upper node 245a of the first stent section 207a to the second upper node 245b of the second stent section 207b. The second valve leaflet 250b extends from the second upper node 245b to the third upper node 245c of the third stent section 207c. The third valve leaflet 250c extends from the third upper node 245c to the first upper node 245a. Thus, each upper node includes a first end of the first valve leaflet and a second end of the second valve leaflet connected thereto.In the illustrated embodiment, each end of each valve leaf is connected to its respective node by a suture. However, any connecting means can be used to attach the valve leaf to the stent. It is further contemplated that the stent can include any number of sections and / or valve leaves. For example, the stent can include two sections, each section extending 180 degrees around the circumference of the stent. Further, the stent can include two valve leaves to mimic a bicuspid valve. Further, it should be noted that each valve leaf can include a tab or other structure (not shown) at the junction between the free end and the attachment end of the valve leaf, and each tab of each valve leaf can be connected to the tab of an adjacent valve leaf to form a cross-link. In the illustrated embodiment, the valve leaf cross-link is shown as being attached to the node where the struts intersect. However, in other embodiments, the stent 200 may include a cross-link attachment feature incorporated into the stent to facilitate such attachment. For example, the cross-link attachment feature can be formed at nodes 245a - 245c of the stent 200, and the cross-link attachment feature includes one or more apertures to facilitate suturing the valve leaf cross-link to the stent. Further, the valve leaves 250a - 250c may be formed of a biological material such as an animal pericardium or a synthetic material such as ultra-high molecular weight polyethylene (UHMWPE).

[0016] Figures 1I and 1J show an artificial heart valve 206 that includes a stent 200, a cuff 260 coupled to the stent 200 (e.g., via suture), and leaflets 250a, 250b, 250c attached to the stent 200 and / or the cuff 260 (e.g., via suture). The artificial heart valve 206 is intended to be used to replace an aortic valve, but the same or similar structure may be used in artificial heart valves for replacing other heart valves. The cuff 260 is disposed on the luminal or inner surface of the stent 200, but the cuff can alternatively or additionally be disposed on the external luminal or outer surface of the stent. The cuff 250 can include an inflow end disposed substantially along the inflow end 201 of the stent 200. FIG. 1I shows a front view of the valve 206 showing one stent portion 207 between vertical struts 210a, 210b that include the cuff 260 and the outer profiles of two leaflets 250a, 250b sutured to the cuff 260. Various methods can be used to suture the leaflets not only to the cuff but also the leaflets and / or the cuff to the stent, many of which are described in U.S. Patent No. 9,326,856, which is incorporated herein by reference. In the illustrated embodiment, the upper (or outflow) edge of the cuff 260 is sutured to a first central node 225a, an upper node 245, and a second central node 225b that extend along a first central strut 230a and a second central strut 230b. The upper (or outflow) edge of the cuff 260 extends substantially continuously between a second central node of one section and a first central node of an adjacent section. The cuff 260 extends between the upper node 245 and the inflow end 201. Thus, the cuff 260 covers the cells of the stent portion 207 formed by the struts between the upper node 245 and the inflow end 201 that include the diamond cells 228. FIG. 1J shows a side view of the stent 200 that includes the cuff 260 and the outer profile of the leaflet 250b. In other words, the view of the valve 206 in FIG. 1J is rotated approximately 60 degrees compared to the view in FIG. 1I. The view shown in FIG. 1J is centered on the vertical strut 210b and shows approximately half of each of two adjacent stent sections 207a, 207b on either side of the vertical strut 210b.The sections 207a, 207b surrounding the vertical strut 210b are mirror images of each other. As described above, the cuff can be disposed on the inner or lumen surface, the outer or outer lumen surface, and / or both surfaces of the stent. The cuff ensures that when the valve or valve assembly is not optimally seated within the valve annulus, blood does not simply flow around the valve leaflets. The cuff, or the portion of the cuff disposed external to the stent, can help prevent leakage around the outside of the valve, which is known as paravalvular regurgitation or "PV" regurgitation. In the embodiments shown in FIGS. 1I and 1J, the cuff 260 covers only about half of the stent 200, and about half of the stent is not covered by the cuff. In this configuration, less cuff material is required compared to a cuff that covers more or all of the stent 200. With less cuff material, it may be possible to crimp the prosthetic heart valve 206 to a smaller outer profile when folded. It is contemplated that the cuff can cover any amount of the surface area of the cylinder formed by the stent. For example, the upper edge of the cuff can extend straight around the circumference of any cross-section of the cylinder formed by the stent. The cuff 260 can be formed of any suitable material, including biological materials such as animal pericardium or synthetic materials such as UHMWPE.

[0017] The stent can be formed from a biocompatible material including metals and metal alloys such as cobalt chromium (or cobalt chromium alloy) or stainless steel, but in some embodiments, the stent may be formed from a shape memory material such as nitinol. Thus, the stent is configured to collapse when crimped to a smaller diameter, for example, by inflation of a balloon within the stent, and / or to expand when forced open, and the stent substantially maintains its altered shape when in a stationary state. The stent can be crimped to reduce its profile at any given cross-section such that it collapses radially and (to some extent) elongates axially. The stent can also expand radially and (to some extent) shorten axially.

[0018] The prosthetic heart valve can be delivered via any suitable transvascular route, such as transapically or transfemorally. Generally, in transapical delivery, a relatively stiff catheter is utilized that penetrates the patient's chest and the apex of the left ventricle, imposing a relatively high trauma compared to transfemoral delivery. In transfemoral delivery, the delivery device containing the valve is inserted from the femoral artery and passed against the flow of blood into the left ventricle. In either delivery method, initially, the prosthetic valve can be folded onto the expandable balloon with the expandable balloon in a deflated state. The balloon can be coupled to or disposed within the delivery system, which can transport the valve through the body and heart to reach the aortic valve, and the valve is disposed on the balloon (and, depending on the situation, under the sheath on the balloon). Upon reaching the aortic valve or a position adjacent to the aortic valve, the surgeon or the operator of the delivery system can properly position the prosthetic valve within the native annulus with the prosthetic valve folded on the balloon. When the desired positioning is achieved, if a sheath is included thereon, the sheath can be withdrawn (or advanced) to expose the prosthetic valve, and then the balloon can be expanded such that the prosthetic valve expands radially and at least a portion of the prosthetic valve shortens axially.

[0019] Although some embodiments of the balloon-expandable prosthetic heart valve have been provided above, it should be understood that the systems, devices, and methods described below for use in inflating, deflating, and / or degassing the balloon of the balloon catheter can be used with other types of balloon-expandable prosthetic heart valves different from the embodiments described above.

[0020] Referring now to FIG. 2A, one embodiment of an automatic balloon inflation device 300 is illustrated. In the illustrated embodiment, the balloon inflation device can include a housing that securely receives a syringe 305 therein. The housing can be attached in a fixed relationship to the body of the syringe 305, where the plunger handle of the syringe 305 is received within a movable member that can be axially driven relative to the housing to advance or retract the plunger into or out of the body of the syringe 305. The movable member can be operably coupled to a carriage within the housing, and the carriage can include a screw that engages a mating screw of a screw mechanism within the housing, and the screw mechanism is operably coupled to a motor within the housing. The motor can be operably coupled to a power source (e.g., a replaceable or permanent battery within the housing, or an AC main power source). In this embodiment, the motor can be actuated to rotate the screw mechanism, thereby advancing or retracting the movable member, and thus the plunger handle, (depending on the direction of rotation of the screw mechanism) to extrude fluid from or inject fluid into the syringe. For example, the housing of the balloon inflation device 300 can include a shrink button 310 and an inflate button 315. These buttons 310, 315 can be configured such that by continuously pressing the corresponding button, the motor is actuated to rotate the screw mechanism in the corresponding direction of rotation, whereby the plunger handle advances or retracts at a constant speed (and thus the volume portion generally moves into or out of the syringe at a constant volume rate), and the movement stops as soon as the pressure on the button is released. In other embodiments, the motor can be actuated by pressing the shrink button 310 or the inflate button 315 once, and the motor can be stopped by pressing the button again. In some embodiments, a third button can be provided that can be actuated to stop the motor.During inflation or deflation, syringe 305 can be connected to balloon inflation port 1010 of balloon catheter 1000, and the lumen of balloon catheter 1000 extends from balloon inflation port 1010 through a delivery device that houses the prosthetic heart valve in a crimped state into the balloon in which the prosthetic heart valve is crimped. One advantage of using balloon inflation device 300 compared to a manually operated syringe is that the inflation / deflation speed is constant and controlled inflation and deflation are possible. However, with balloon inflation device 300, the user still has full responsibility for determining the appropriate volume amount to press against the balloon to inflate the prosthetic heart valve.

[0021] The balloon inflation device 300 can be modified to provide further automation. For example, in another embodiment, the balloon inflation device can include an interface where a user can input a target volume to which the balloon of the balloon catheter 1000 is to be inflated. When the user sets the target inflation volume and connects the syringe 305 to the housing of the balloon inflation device 300, the user can start the inflation process by simply pressing a single button. The screw mechanism that advances the movable member to push down the handle of the syringe may be the same as that described above, and inflation occurs at a steady rate over the time required to reach the target inflation volume. The balloon inflation device 300 can be programmed to maintain a steady state for a predetermined time when the target inflation volume is reached and then automatically move the plunger handle of the syringe 305 in the opposite direction to start deflating the balloon. In such a system, a manual override button may be available to stop the process at any desired point. In a similar embodiment, instead of using a commercially available syringe housed in an external housing, the balloon inflation device 300 may be incorporated into a delivery device having a fluid reservoir instead of a syringe. If such a system is pre-packaged with an artificial heart valve, the target volume can be set before packaging the system, thereby eliminating the need for user input and enabling the entire process described in this paragraph to be automated by pressing a button or other actuator of the delivery device. One of the advantages of these two alternative embodiments is that, in addition to eliminating the need for manual balloon inflation and deflation, they reach the target volume in a predictable and controlled manner. In other words, the system automatically stops inflation when the target volume is reached, thereby effectively eliminating the possibility that the balloon will inflate beyond the target volume, which could cause balloon rupture and / or damage to the patient's tissue.

[0022] In some embodiments, when the balloon expands and the prosthetic heart valve expands to a predetermined position within the native valve annulus, it may be desirable to rapidly contract the balloon to minimize the time during which the expanded balloon fills the valve annulus and blocks blood flow. It should be noted that during delivery of a transcatheter prosthetic heart valve, the heart may be rapidly paced while the prosthetic valve is being deployed. Thus, it may also be desirable or alternatively desirable to rapidly contract the balloon to minimize the time during which the heart is rapidly paced after the prosthetic heart valve has been deployed. For example, the balloon inflation device 300 (or a similar version thereof) can include a biasing member such as a compression spring 330 having a first end that abuts the plunger handle 320 of the syringe 305 and a second end that abuts a platform 325 that may be on the housing or coupled to the syringe 305. The motor-driven mechanism schematically illustrated as mechanism 335 in FIG. 2B can operate in a similar manner as described above to drive the plunger handle 320 distally to inflate the balloon. However, as the plunger handle 320 advances distally, the spring 330 begins to compress and applies a proximal force to the plunger handle 320. The proximal force on the plunger handle 320 is not strong enough to overcome the motor-driven mechanism 335 during inflation. However, when the balloon is inflated and the prosthetic heart valve is deployed, the motor-driven mechanism 335 can be disengaged from the plunger handle 320 and the spring 330 can be rapidly depressurized to bias the plunger handle 320 proximally and cause a rapid withdrawal of fluid from the balloon back into the body of the syringe 305. Any suitable mechanism can be provided to disengage the motor-driven mechanism 335 from the plunger handle 320. For example, if the plunger handle 320 is received within (or coupled to) a movable member that is operably coupled to a carriage that engages a threaded screw mechanism, the connection between the movable member and the carriage or the connection between the carriage and the threaded screw can be separated to allow the compression spring 330 to be depressurized.In other embodiments, a split nut may be used, where the nut is formed as two or more members that can come together to engage the threads or separate to disengage from the threads so that the nut can quickly disengage the motor drive mechanism 335 from the plunger handle 320. In yet other embodiments, a single-sided thread may be provided that can translate or "rock" in place to engage or disengage the threads of the threaded screw mechanism. However, it should be understood that the compression spring 330 is optional. For example, the speed at which the plunger handle 320 is driven by the motor drive mechanism 335 may be such that when the plunger handle 320 is driven proximally to contract the balloon, the speed at which the balloon contracts is sufficient to avoid any significant patient negative outcome such as the duration of blood flow occlusion through the balloon (and / or the duration of rapid pacing of the heart).

[0023] Figures 3A and 3B illustrate another embodiment of the balloon inflation system 400. Similar to the balloon inflation device 300, the balloon inflation system 400 can include a housing 401 that houses one or more components, such as a motor, one or more batteries, electronics for communication with control and / or other components, etc. The housing 401 can include one or more fixed cradles for receiving the syringe 405. In the illustrated embodiment, the distal cradle 402a is provided with an open "C" or "U" shape such that the distal end of the syringe 405 can snap into or out of the distal cradle 402a. A proximal cradle 402b can also be provided, which can have a lower "C" or "U" shaped portion hingedly connected to an upper "C" or "U" shaped portion. This configuration can allow the proximal end of the outer body of the syringe 405 to snap into the bottom portion of the cradle 402b, closing the top portion of the cradle 402b and connecting it to the bottom portion to completely surround the outer body of the syringe 405 and lock the syringe 405 to the housing 401. It should be understood that more or fewer cradles of the same or different design can be included with the housing 401 to help secure the syringe 405 to the housing in any suitable manner.

[0024] The balloon inflation system 400 can include a movable member 406. In the illustrated embodiment, the movable member 406 includes a "C" or "U" shaped cradle for receiving a plunger handle 420 therein, and the cradle is attached to a carriage that extends at least partially within the housing 401. The carriage of the movable member 406 can generally be cylindrical and can include an internal thread that mates with an external thread of a screw mechanism (not shown) within the housing that is operably coupled to a motor. In some embodiments, the carriage can have the general shape of a "U" beam with a flat surface facing upward. The movable member 406 can be non-rotatably fixed to the housing 401 via any desired mechanism, such that when the screw mechanism is rotated by the motor, depending on the direction of rotation of the screw mechanism, the movable member 406 either further advances into the housing 401 or retracts further away from the housing 401. While the plunger handle 420 is coupled to the movable member 406, advancement of the movable member 406 causes fluid to be pushed from the syringe 405 towards the balloon, while retraction of the movable member 406 causes fluid to be withdrawn from the balloon towards the syringe. The motor or other drive mechanism can be located either inside or outside the housing 401, and it should be understood that any other suitable mechanism can be used to operably couple the motor or other drive mechanism to the movable member 406 to enable axial drive of the plunger handle 420.

[0025] As shown in FIGS. 3A - 3C, the distal end of the syringe 405 can be connected to a tube 407 that is in fluid communication with a lumen (e.g., of a balloon catheter) that leads to the balloon 480 at or near the distal end of the delivery device. The tube 407 can pass fluid (e.g., saline) from the syringe 405 towards the balloon 480 and vice versa, for example, through one or more fluid ports 485 (shown in FIG. 3F) within the shaft of the balloon catheter 490.

[0026] Although not separately numbered in FIGS. 3A and 3B, the housing 401 can include one or more cables extending from the housing to enable the transmission of power (e.g., from an AC main power source or another component to which a cable is connected), and / or the transmission of data, information, control commands, etc. For example, as will be described in more detail later, one cable can connect the housing 401 to the handle 450 of the delivery device, thereby enabling the use of the control unit of the handle 450 to operate the balloon inflation system 400 in a desired manner. As will be described in more detail later, another cable can be connected to a computer display or similar device to provide information regarding the inflation of the balloon 480. However, it should be understood that any transmission of data or information may be provided wirelessly via, for example, Bluetooth or other suitable connections instead of via a wired connection.

[0027] Referring now to FIGS. 3D and 3E, the handle 450 of the delivery device can include one or more knobs or actuators for operating different functions of the delivery device. For example, a rotary knob near the center of the handle 450 enables deflection of the catheter, and other knobs or actuators (e.g., near the proximal end of the handle 450) can enable rotation and / or axial adjustment of the balloon 480 (and the prosthetic heart valve PHV attached thereto), which can help obtain accurate positioning between the native valve annulus and the prosthetic heart valve PHV prior to deployment. A single shaft is shown as the balloon catheter 490 and is labeled, but it should also be understood that the delivery device can include two or more coaxial catheter shafts to provide desired functionality, including relative axial movement between catheter shafts within the stack.

[0028] Referring further to FIGS. 3D and 3E, the handle can include an actuator 410 for controlling the inflation and deflation of the balloon 480 via the control of the balloon inflation system 400. For example, the actuator 410 can be in the form of a slide button that has a neutral center position and can be advanced distally to inflate the balloon 480 and pulled proximally to deflate the balloon 480. In one example, the actuator 410 remains in a distal or proximal position after being moved from the neutral position. In another embodiment, the actuator 410 can be biased to the neutral position such that as soon as the force applied by the user to the actuator 410 is released, the actuator 410 automatically returns to the neutral position where neither fluid is passed to the balloon 480 nor withdrawn from the balloon 480. As should be understood, sliding the actuator 410 forward or backward transmits a control signal from the handle 450 to the balloon inflation system 400 (e.g., via a cable) such that the motor drives the movable member 406 forward or backward to either extrude fluid towards the balloon 480 or withdraw fluid from the balloon 480. FIGS. 3D and 3E show one example of the slide actuator 410, but it should be understood that other actuators, such as individual buttons, rotary knobs, etc., can be provided on the handle 450 to enable control of the balloon inflation system 400.

[0029] It should also be understood that the actuator 410 can provide a binary control mode where inflation (or deflation) occurs at a set rate or not at all. In other embodiments, the actuator 410 may have variable inflation rate control. For example, the user may be able to push the actuator 410 distally (or proximally), and the more the user pushes the actuator distally (or proximally), the faster the balloon inflation system 400 inflates (or deflates) the balloon 480. This variable volumetric flow rate may be desirable to allow the user to more finely control the inflation or deflation of the balloon 480, which may be particularly useful when the balloon is approaching the target size / volume.

[0030] Referring to FIG. 3F, an example of an artificial heart valve PHV that can include a stent similar to the stent 100 is shown crimped onto the balloon 480 of the balloon catheter 490 while the balloon 480 is in a deflated state. Sliding the actuator 410 distally causes the balloon inflation system 400 to pump fluid, for example, from the syringe 405 into the balloon 480 through the lumen within the balloon catheter 490 and into one or more ports 485 located inside the balloon 480. In a particular illustrated example of FIG. 3G in which the artificial heart valve PHV is omitted from the figure, the first port 485 can be one or more apertures in the sidewall of the balloon catheter 490, and the second port 485 can be the distal open end of the balloon catheter 490 that can terminate within the internal space of the balloon 480.

[0031] The balloon inflation system 400 can be used in a semi - manual manner where a pressure or other sensor does not provide real - time feedback to the user. In such an example, while the prosthetic heart valve PHV is crimped over the deflation balloon 480, the distal end of the delivery device can be delivered into the patient's body. For example, with or without using a steering mechanism (e.g., a pull - wire that connects the handle 450 to the distal end portion of the balloon catheter 490), the distal end of the delivery device can be advanced through the patient's femoral artery and ultimately redirected to traverse the aortic arch. Once the prosthetic heart valve PHV is positioned within the native aortic valve annulus, the balloon 480 can be inflated and the prosthetic heart valve PHV can be deployed within the native aortic valve annulus. This deployment can be performed while the patient's heart is being rapidly paced. To inflate the balloon 480, the user can slide the actuator 410 distally, which sends a signal to the balloon inflation system 400 to initiate driving the distal side of the movable member 406, thereby depressing the plunger handle 420 and forcing a fluid such as saline within the syringe 405 through the tube 407, through the balloon catheter 409 into the balloon 480, thereby inflating the balloon and expanding the prosthetic heart valve PHV within the native aortic valve annulus. The user can visualize this process, for example, under fluoroscopy, and when the user confirms that the prosthetic heart valve PHV is at the desired size and position, the user can slide the actuator 410 proximally to reverse the movement of the movable member 406 in a particular direction and draw the fluid back from the balloon 480 into the syringe 405 to deflate the balloon 480. With the balloon 480 deflated and the prosthetic heart valve PHV expanded in place, the rapid pacing of the heart can be stopped and the prosthetic heart valve PHV can regulate the blood flow between the left ventricle and the aorta, allowing the heart to begin beating normally again. In some embodiments, the user can input a target or maximum inflation volume directly into the balloon inflation system 400 (e.g., via a user interface provided thereon) or into a computer operatively coupled to the balloon inflation system 400.When such a target or maximum inflation volume is used, the motor of the balloon inflation system can be programmed to turn off when the balloon inflation system 400 has extruded the target inflation volume from the syringe 405. In some embodiments, for example, if the user determines that additional balloon inflation is necessary to properly expand the prosthetic heart valve PHV within the native aortic annulus, the target or maximum inflation volume can be manually overridden. It should be understood that the volume of fluid moving through the balloon inflation system 400 can be tracked by any suitable method. In one embodiment, since the inner diameter of the syringe 405 is known and the travel distance of the movable member 406 is known, the resulting volume exiting (or entering) the syringe 405 can be determined from a simple calculation. In other embodiments, a fluid sensor may be incorporated into the system to help track in real time the total amount of fluid entering or exiting the syringe 405.

[0032] By the above-described use of the balloon inflation system 400, significant advantages including control and precision can be provided compared to the known and completely manual balloon inflation for implanting an artificial heart valve. However, additional useful functions can also be provided using additional data in the balloon inflation system 400. For example, the pressure within the balloon catheter line can be actively monitored to provide additional data that can be used during the deployment of the prosthetic heart valve PHV. To obtain pressure data within the fluid line of the balloon catheter, one or more pressure sensors can be provided within the fluid path. Such locations can include, for example, within the balloon catheter lumen at a location inside the handle 450, within the syringe 405 or at a location adjacent to the syringe 405 (e.g., near the tip), or inside the balloon 480 (e.g., directly on the inner surface of the balloon or inside or outside a portion of the shaft of the balloon catheter 490 surrounded by the balloon 480). In some embodiments, a pressure wire can be provided within the balloon catheter. For example, the sensor housing can be positioned within the balloon 480. FIG. 3H shows one embodiment where the pressure sensor 482 is attached to a portion of the shaft of the balloon catheter 490 within the balloon 480 and a wire connection 484, such as an electrical or optical wire connection, connects the pressure sensor 482 to another component to read and / or transmit sensor information. The pressure sensor 482 can be a MEMS-based sensor, although other types of sensors may be suitable. By placing the pressure sensor 482 within the balloon 480, it may be possible to directly measure the pressure inside the balloon, thereby avoiding potential errors that may occur when making pressure measurements at locations further away from the balloon 480, such as at the inflation port or in the syringe 405. However, it should be understood that sufficient measurements may be provided using pressure sensors that are not directly installed within the balloon 480, and that the particular sensing mechanism for measuring the real-time pressure within the balloon catheter can take any other suitable form.

[0033] In some cases, it may be desirable to determine the area and / or diameter of the balloon 480 during inflation. One way to determine the area and / or diameter of the balloon 480 is based on a previously determined relationship between pressure or volume and diameter. For example, for a balloon 480 having a particular structure, a generally applicable correlation can be determined, whereby based on the calculated volume passed towards the balloon 480, the area and / or diameter of the balloon 480 can be estimated based on the known correlation between pressure or volume and size. Thus, if the final desired size of the artificial heart valve PHV is known, an algorithm based on that correlation can be applied to determine the total volume to be applied to the balloon 480 (or the pressure required to reach the desired size). In other embodiments, the balloon 480 may be provided with a sensor that provides information regarding the diameter of the balloon 480. For example, as shown in FIG. 3I, one or more strain gauges 486 can be attached to or otherwise affixed to the outer wall of the balloon 480 to provide a direct measurement of the diameter of the balloon 480. The strain gauge 486 may be attached radially to measure hoop strain or axially to measure the diameter. Generally, when the requirement is to measure the diameter, it may be desirable to attach it radially as compared to attaching it axially. The general formula for the radial strain of a cylindrical pressure vessel is that the radial strain is equal to the product of the pressure and the radius divided by the product of the modulus of elasticity and the wall thickness. Since the axial strain is half of the radial strain, it can be used as a less direct measure of the radial strain, but it may not be as preferred.

[0034] Figure 4 shows the balloon compliance curve of balloon 480 showing the relationship between balloon pressure and balloon volume. The solid line represents the baseline or "ambient air" pressure-volume curve 510 when balloon 480 is expanding without contacting other structures. However, when balloon 480 contacts the surface such as the aortic valve annulus, the pressure-volume curve shifts from the baseline (shown by dashed line 520). Curves 510, 520 are the same before balloon 480 expands and contacts the original aortic valve annulus. However, when contacting, the pressure-volume curve shifts by a certain amount from baseline 510, and this change or delta is represented by arrow 530. This delta 530 is the result of the compliance of the original tissue applying a compressive force to the expanded balloon. This information can be utilized to help determine when the prosthetic heart valve PHV is expanded by the desired amount. For example, the amount of a specific deviation 530 between the baseline pressure-volume curve 510 and the actual pressure-volume curve 520 during implantation can be determined as the amount of deviation 530 corresponding to optimal prosthetic heart valve PHV expansion within the aortic valve annulus. The value of this desired deviation 530 can be determined, for example, through testing across multiple patients or by analysis of data from a large number of actual implantations.

[0035] As described above, the volume of fluid entering balloon 480 from syringe 405 can be tracked in real time, and pressure can also be tracked in real time via one or more of the pressure sensors described above. Thus, during valve implantation using prosthetic heart valve PHV and balloon inflation system 400, the real-time pressure-volume curve 520 can be displayed for the user to reference along with the expected baseline pressure-volume curve 510, and the user can use the displayed data to confirm the desirability of the procedure or, alternatively, change the procedure based on that data.

[0036] For example, FIG. 5 is a schematic diagram of a treatment setup including a first user such as a physician 600, a second user such as a support staff 610, a treatment table 620 for a patient, one or more computers and / or displays 630, a balloon inflation system 400, and a delivery device including a handle 450. Before a more detailed explanation of specific examples of the intraoperative use of data obtained during the treatment for some of the various interactions within the setup, a brief explanation is provided below. As described above and repeated here, fluid can flow in either direction between the balloon inflation system 400 and the handle 450 of the delivery system, and an instruction signal for operating the balloon inflation system 400 can be transmitted from the handle 450 to the balloon inflation system 400. The physician 600 uses the handle 450 to implant an artificial heart valve PHV into the patient's body on the table 620, including by controlling the inflation and deflation of the balloon 450 via the actuator 410, and can manually control the delivery system. During the treatment, all data obtained from the treatment, such as the volume moved from the balloon inflation system 400 towards (or vice versa) the balloon 480, the current area of the balloon 480 (which can be calculated based on the fluid volume), and the current pressure within the system, can be transmitted and / or displayed on one or more computers and / or displays 630. As described above, the data transmission can be performed via a wired connection or a wireless connection. The physician 600 can view the display 630, which can include not only the data described above but also other information such as fluoroscopic images of the patient's anatomical structure. The support staff 610 can similarly view the data on the display 630, and either the physician 600 or the support staff 610 can input parameters such as the target volume for the inflation of the balloon 680 via the computer and / or display 630.Next, the computer and / or display 630 can communicate such parameters to the balloon inflation system 400, for example, by setting a target volume such that the balloon inflation system 400 does not inflate the balloon 480 beyond the target volume, unless either user 600 or 610 overrides the balloon inflation system 400.

[0037] FIG. 6A shows an exemplary screen that can be displayed on the computer and / or display 630 as part of a planning stage prior to implanting an artificial heart valve PHV in a patient. In this exemplary screen, one or more inputs can be made for use during the procedure. One exemplary input is the target annulus area, which represents the size of the patient's native annulus. In this particular example, the input value is 623 mm 2It is. Another exemplary input is the desired oversizing rate of the prosthetic heart valve PHV. In other words, for example, it is often desirable to target an area / size of the prosthetic heart valve PHV that is larger than the area / size of the patient's native annulus in order to generate sufficient friction to help maintain the prosthetic heart valve PHV in place during normal operation of the prosthetic heart valve PHV. In this particular example, the value entered for the oversizing rate is 5.3%. All numbers and values provided with respect to FIGS. 6A and 6B are merely exemplary and are not intended to be limiting, but rather are to be understood as showing one example of inputs and outputs for better explaining the related concepts. Based on the inputs during the planning phase, several outputs can be provided, such as the target area of the prosthetic heart valve PHV, which can be calculated by applying the oversizing rate to the patient's annulus area for the physician 600 and / or support staff 610 to consider and confirm. Depending on the output, a prosthetic heart valve PHV of a particular size may be proposed. For example, prosthetic heart valves PHV are typically offered in different size options, and the physician 600 selects the appropriate size option for a particular patient. In this example, a prosthetic heart valve PHV size of 29 mm is recommended based on the input. Another output that can be provided to the users 600, 610 is the proposed total inflation volume that should be extruded from the balloon inflation system 400 to achieve the desired expanded size of the prosthetic heart valve PHV. In this particular example, a total inflation volume of 33 mL is proposed. The proposed inflation volume can be provided based on a predetermined correlation derived from tests that relate the inflation volume to the valve area, for example, when the balloon 480 is inflated. Yet another output that can be provided is the target pressure of the balloon 480 to achieve the desired expanded size of the prosthetic heart valve PHV. In this particular example, the target pressure is provided as 6.3 atmospheres. It should be understood that although various recommended values are output based on the input data, the physician 600 can exercise control to override the recommended values based on his or her experience.

[0038] FIG. 6B shows an exemplary screen that can be displayed on a computer and / or display 630 as part of an intermediate stage of a procedure for implanting an artificial heart valve PHV into a patient following the planning stage shown in FIG. 6A. The intraoperative screen of FIG. 6B can display the current status of the procedure, such as "inflating" or "deflating", along with the patient's annulus area and the selected size of the artificial heart valve PHV from the planning stage of FIG. 6A. The intraoperative screen of FIG. 6B can display multiple sections that provide current treatment parameters versus target treatment parameters to help users 600, 610 understand the progress of the deployment of the artificial heart valve PHV. For example, the valve area section can provide the target inflation size / area of the artificial heart valve PHV compared to the current inflation size / area of the current artificial heart valve PHV during balloon 680 inflation. The illustrated screen 630 shows a previously selected target size of 656 mm 2 compared to the current inflation size of the artificial heart valve PHV of 326 mm 2 . In addition to providing values, a graph such as a progress bar can also be displayed showing the current expansion size as a percentage of the patient's annulus size compared to the desired expansion size as a percentage of the patient's annulus size. In this example, the target value from the planning stage, which is an oversize of 5.4% (e.g., 105.4% of the patient's annulus size), is shown on the progress bar along with the current status (e.g., the intraoperative size of the artificial heart valve PHV of 56.0% of the patient's annulus size). Similar information panels including progress bars can be provided for other parameters, such as the current balloon pressure (e.g., 6.0 atm) versus the planned target balloon pressure (e.g., 6.4 atm). Another information panel for the current inflation volume (e.g., 27.2 mL at the illustrated stage of the procedure) versus the target inflation volume (e.g., 33.2 mL from the planning stage) can be provided along with a graphical display via a progress bar that includes an indicator of the target inflation volume.

[0039] FIG. 6B also shows a graph plotting the pressure within balloon 480 against the area of balloon 480 as the treatment continues. Similar to the compliance curve of FIG. 4, the baseline pressure-area curve 510 can be provided as a static, known relationship expected when inflating balloon 480 in "atmospheric air". As balloon 480 inflates, the area is detected (e.g., using strain gauge 486) or calculated (e.g., based on a known correlation between the fluid volume and area of balloon 480), while the pressure is detected, so that an actual treatment pressure-area curve 520 can be plotted. As shown in FIG. 6B, a deviation 530 of the treatment pressure-area curve 520 from the baseline pressure-area curve 610 is produced. The large deviation 530 shown in FIG. 6B is for illustrative purposes only, and it should be understood that the deviation 530 of the size shown is not intended to represent the level of deviation actually expected. Nevertheless, the deviation 530 between the baseline curve 510 and the treatment curve 520 can provide important information to users 600, 610 that can be used to confirm that the treatment is proceeding as intended or, otherwise, that potential problems have occurred that need to be investigated and / or addressed. For example, as described above, a known target deviation 530 between the baseline curve 510 and the in-treatment curve 520 can be set or understood to be the desired deviation. If the illustrated deviation 530 is close to or equal to the target deviation 530 and all other target parameters (e.g., the size of the prosthetic heart valve PHV, the balloon pressure, and / or the inflation volume) are at or near their target values, physician 600 can determine that the treatment has achieved all of the goals and that the prosthetic heart valve PHV has been properly deployed. It should be understood that physician 600 can utilize fluoroscopic images or other information, including his or her general experience and knowledge, to assist in this determination. However, if the treatment pressure-area curve 520 deviates significantly more from the baseline curve 510 than expected, such a deviation 530 may indicate a potential problem.For example, in the example illustrated in FIG. 6B, the pressure of balloon 480 has risen much earlier than expected, which means that balloon 480 and the prosthetic heart valve PHV are subjected to a significantly greater force than expected, even though the prosthetic heart valve PHV has only been partially expanded towards the target size, which may be the result of the native tissue compressing the prosthetic heart valve PHV. Reasons for this deviation can include, for example, that the size of the patient's valve annulus has not been correctly measured and / or that the calcification of the native valve is significantly greater than expected. If the physician 600 continues to inflate balloon 480 despite the large deviation 530 being displayed, there is a risk that the valve annulus and / or balloon 480 will rupture. Therefore, the physician 600 can use the actuator 410 of the handle 450 to temporarily stop the inflation of balloon 480, evaluate the situation to determine the cause of the deviation 530, and adjust the treatment accordingly. In some embodiments, the physician 600 or the support staff 610 can interact with the computer and / or the display 630 to update the target parameters based on the information obtained from the evaluation after the inflation is temporarily stopped. In some embodiments, the physician 600 or the support staff 610 can rely on live fluoroscopic images for the expansion of the valve and, if the prosthetic heart valve is thought to be fixed, can deflate the balloon, for example, for further investigation using fluoroscopy and contrast agent injection.

[0040] In some embodiments, the computer and / or display 630 can be programmed to provide an alert to users 600, 610 when a parameter is approaching, at, and / or exceeding a target parameter. Such an alert may simply be informational or may cause a change in treatment. For example, when the detected pressure of balloon 480 reaches the target pressure (or, otherwise, exceeds the target pressure or exceeds the target pressure by a predetermined buffer value, such as 5%), the computer and / or display 630 may create an alert that simply conveys the information that the target pressure has been reached or exceeded (by either any amount or a predetermined buffer amount), or may create an alert that also sends a signal to balloon inflation system 400 to stop the inflation of balloon 480. If the alert causes such an action, users 600, 610 can override the alert by dismissing the alert, for example, via interaction with the computer and / or display 630, and then can continue the inflation of balloon 480 if it is deemed appropriate. Other similar types of alerts for other target values can be provided as well.

[0041] Information from a procedure can be not only potentially useful for that specific procedure, but can also be used to aggregate data from multiple procedures to inform a way to optimize subsequent procedures. For example, an information database (preferably with anonymized patient information) can be created that stores information related to the outcome of a procedure along with parameters that occurred during the specific procedure. As one specific example, the effectiveness of inflating balloon 480 to a specific pressure and specific size, taking into account the patient's native annulus size, can be stored in the database along with the effectiveness as a result of the implant. With sufficient data, desired target parameters for future patients can be determined based on previous procedure results. For example, if a patient of a specific age, gender, and with a native aortic annulus of a specific size is a candidate for an implant of an artificial heart valve PHV, the information of that patient can be compared to other similar patients who have received an implant of an artificial heart valve PHV, and the target parameters for the treatment of future patients can be based, at least in part, on the actual parameters seen in previous similar patients who have had a successful implant of an artificial heart valve PHV. As more data is accumulated, more accurate and sophisticated algorithms can be created to predict the target treatment parameters to optimize the patient outcome for an individual patient. For example, with sufficient data from previous procedures, the system can become very sensitive and potentially be able to determine subtle changes in the delivery and / or deployment of an artificial heart valve PHV based on recognizing patterns of detected pressure changes. For example, the system can warn the user of the first contact with tissue based on subtle changes in pressure readings while deploying the artificial heart valve PHV within the annulus. Also, characteristic pressure readings may be obtained in other situations, such as contact with highly calcified tissue, or any rupture of the native tissue due to the balloon's expansion force. The system can warn the user of each of these scenarios based on the detected characteristic pressure change readings.Also, it should be understood that the readings of these characteristic pressure changes are not necessarily limited to the deployment stage of the prosthetic heart valve PHV, and may be detected during delivery after the prosthetic heart valve PHV has been introduced into the vascular system. For example, during the delivery of the prosthetic heart valve PHV, the system may detect readings of characteristic pressure changes indicating several events, such as the movement of the position of the prosthetic heart valve PHV relative to the balloon, and the contact of the prosthetic heart valve PHV with the luminal tissue of the vascular system.

[0042] The balloon inflation system described above can provide significant utility when inflating balloon 480 during implantation of the prosthetic heart valve PHV. However, the balloon inflation system may also have utility when preparing the balloon catheter for subsequent use, such as degassing the system. During use of the balloon catheter 490 described above, the internal fluid line extending into syringe 405 within balloon catheter 490 is a closed system. Generally, it is important that the amount of air within that closed system is minimized. The presence of air within the system can cause problems or potential problems. For example, if balloon 480 ruptures and there is air within the system, the air can be released into the bloodstream and potentially cause an obstruction of the bloodstream, which can result in a stroke or another medical crisis. Additionally, the presence of air within the system can reduce the accuracy of pressure or other readings compared to when there is no air (or air is at a minimal acceptable level) within the system. Currently, to degas the balloon catheter prior to use, a manual process is performed where the interior of the balloon catheter is evacuated with a first syringe and then fluid is pushed into the balloon catheter with another syringe, repeating this cycle to fill the balloon catheter with fluid and purge any air remaining within the balloon catheter. However, a visual inspection is performed to confirm that there is no air (or air is at a minimal acceptable level) within the balloon catheter, but this is a relatively subjective analysis and there can potentially be a high risk of error when human factors are involved. Using the balloon inflation system described herein, it is possible to automate the degassing process while also providing a more objective, data-based confirmation of the amount of air remaining within the balloon catheter following the degassing procedure.

[0043] FIG. 7 is a schematic diagram of a degassing system including a filling syringe 405 and a purge syringe 705. The filling syringe 405 and the purge syringe 705 may be substantially identical and each may be part of a balloon inflation system similar to the system 400 described above. Each syringe 405, 705 can be fluidly connected to a balloon catheter 490 via a three-way stopcock valve 730, and the stopcock valve 730 enables any component of the system to be fluidly isolated from the other two components. An air intake portion 710 can be positioned between the purge syringe 604 and the valve 730, and a one-way check valve 720 is positioned downstream of the air intake portion 710.

[0044] In an exemplary usage of the degassing system of FIG. 7, initially, there is no fluid in the balloon catheter 490. The inflation syringe 405 is pre-filled with a desired fluid (typically saline) with the inflation syringe plunger 408 positioned proximally, and the plunger 708 of the purge syringe 705 is fully advanced distally. While the syringes 405, 705 are in this position, they are connected to the balloon catheter 490 via the three-way valve 730. The three-way valve 730 is positioned such that the syringes 405, 705 are in fluid communication with each other but isolated from the balloon catheter 490. While the three-way valve 730 is in this position, the plunger 408 of the inflation syringe 405 is pushed down and fluid is extruded towards the purge syringe 705. During this step, air in the line is purged through the air intake 710 and the check valve 720. It should be understood that a relatively small proportion of the fluid in the inflation syringe 405 may exit the inflation syringe 405 during this step. Next, the three-way valve 730 is positioned to fluidly connect the purge syringe 705 and the balloon catheter 490 and isolate the inflation syringe 405. The plunger 708 of the purge syringe 705 is withdrawn to create a vacuum within the balloon catheter 490. During this step, which may also be referred to as the first step, the pressure within the balloon catheter 490 can be measured and recorded as a function of the displacement of the purge syringe plunger 708 using any suitable pressure sensor device including those described above. While the vacuum is maintained, the three-way valve 730 can be positioned to fluidly connect the balloon catheter 490 and the inflation syringe 405 and isolate the purge syringe 705. During this step, which may also be referred to as the second step, the plunger 408 is advanced distally to push fluid into (or cause fluid to be drawn in by the vacuum) the balloon catheter 490. Then, the three-way valve is positioned to fluidly connect the syringes 405, 705 and isolate the balloon catheter 490.In this step, which may also be referred to as the third step, the plunger 408 can be pushed down to extrude the air captured in the air intake portion 710 from the check valve 720. The processes of the steps referred to as the first step, the second step, and the third step can be repeated in order while the pressure versus displacement of the plunger 708 is measured and recorded during the first step of each cycle.

[0045] As described above, during each cycle of the degassing process, pressure-versus-displacement measurements are recorded when the purge syringe 705 draws a vacuum while in fluid communication with the balloon catheter 490. If there is air in the balloon catheter 490, the vacuum pressure achieved during this first step is relatively low because the air in the system spreads into the purge syringe 705. However, during each cycle of the steps referred to as the first step, the second step, and the third step above, that air is purged from the system. Thus, on the second time the purge syringe 705 draws a vacuum, there is less air in the system than in the previous cycle, but the vacuum pressure achieved is greater than in the first cycle. As the cycles are repeated and more air is purged from the system, the vacuum pressure generated by a given displacement of the purge syringe plunger 708 increases. As shown in FIG. 8, the slope of the vacuum pressure-versus-displacement relationship increases as more air is removed from the system between each purge cycle. Since these slopes generally follow a mathematical model, a threshold slope can be determined that represents when the amount of air remaining in the balloon catheter 490 is at an acceptable level. Thus, the purge cycle can be continued until the slope of the vacuum pressure-versus-syringe displacement is greater than or equal to the minimum threshold slope. When the slope of the vacuum pressure-versus-syringe displacement is greater than or equal to the minimum threshold slope, the balloon catheter 490 is sufficiently purged, and thus no air in excess of an acceptable amount remains in the balloon catheter 490. In a similar but alternative embodiment, a minimum vacuum level for a given syringe displacement can be set as a threshold level that, when exceeded, indicates that no air in excess of an acceptable level remains in the balloon catheter 490.

[0046] The use of an electric syringe system for performing degassing, and the measurement of the relationship of the vacuum pressure to the displacement of the purge syringe, have advantages obtained from each method and should be understood to be usable separately or in combination. For example, by automating the degassing system, the preparation of the balloon catheter 490 is simplified even when the final check of the air in the system is manually performed by visual inspection. Similarly, even when degassing is performed manually using a syringe, it is still possible to eliminate the need to rely on visual inspection to confirm that the balloon catheter 490 has been properly degassed by utilizing the pressure-displacement measurement values. Most preferably, by combining automation with pressure measurement, a simple and rapid degassing process is provided that relies on objective measurements to determine when the balloon catheter 490 has been properly degassed. Finally, although the degassing system described in connection with FIG. 7 is shown as a separate component, it should be understood that this system can be incorporated into the handle 450 of the delivery system so as not to require a physically separate system to perform the degassing procedure.

[0047] According to one aspect of the present disclosure, a method of implanting an artificial heart valve comprises delivering the artificial heart valve to the native valve annulus while the artificial heart valve is crimped onto the deflated balloon of the delivery device; advancing fluid into the balloon through the delivery device to inflate the balloon and expand the artificial heart valve within the native valve annulus; monitoring the pressure within the delivery device while advancing fluid through the delivery device; displaying the monitored pressure in real time on a display device while monitoring the pressure; and / or displaying the monitored pressure in real time on a display device comprises displaying the monitored pressure as a treatment curve as a function of the area of the balloon, and / or The area of the balloon is determined based on the monitored pressure, and the monitored pressure is determined by measuring the pressure in the fluid line through which the fluid advances, and / or The area of the balloon is estimated based on the volume of the fluid advancing through the delivery device, and / or The area of the balloon is determined based on a strain gauge attached to the balloon, and / or The method includes displaying on the display device a reference curve of pressure as a function of balloon area, and / or The reference curve is based on the expected relationship of the pressure of the balloon to the area of the balloon when the balloon is inflated in free space, and / or The method includes monitoring the difference between the treatment curve and the reference curve while advancing fluid through the delivery device to expand the artificial heart valve, and / or Advancing fluid through the delivery device includes actuating an actuator at the handle of the delivery device, and / or Actuating the actuator at the handle of the delivery device includes sending a signal to an electric housing having a syringe containing the fluid, and in response to this signal, the electric housing pushes down on the plunger of the syringe.

[0048] According to another aspect of the present disclosure, an artificial heart valve delivery system includes a handle, a balloon catheter extending from the handle, a balloon positioned at the distal end portion of the balloon catheter, a fluid reservoir in fluid communication with the lumen, the lumen being in fluid communication with the internal volume of the balloon, a motor operably coupled to the fluid reservoir, An actuator in a handle, operably connected to a motor, such that when the actuator is actuated in a first direction, the motor extrudes fluid from a fluid reservoir through a lumen towards an internal volume of a balloon, and when the actuator is actuated in a second direction opposite the first direction, the motor withdraws fluid from the internal volume of the balloon towards the fluid reservoir. An actuator, comprising, and / or The fluid reservoir and the motor are housed within the handle, and / or The fluid reservoir is within a syringe, the syringe is connected to a housing that receives the syringe, the motor is positioned within the housing, and / or The system comprises a pressure sensor configured to determine the pressure within the balloon, and / or The pressure sensor is positioned directly within the balloon, and / or The system comprises a strain gauge attached to the balloon.

[0049] According to yet another aspect of the present disclosure, a method of degassing a balloon of a balloon catheter is (i) Withdraw the plunger of a purge syringe while the purge syringe is in fluid communication with the balloon of the balloon catheter and while the purge syringe is not in fluid communication with a filling syringe containing fluid, and monitor a vacuum pressure as a function of plunger displacement as the plunger of the purge syringe is withdrawn to create a pressure-displacement line having a slope. (ii) Advance the plunger of the filling syringe while the filling syringe is in fluid communication with the balloon of the balloon catheter and while the filling syringe is not in fluid communication with the purge syringe. (iii) Advance the plunger of the filling syringe while the filling syringe is in fluid communication with the purge syringe and while the filling syringe is not in fluid communication with the balloon catheter to expel any remaining air through a one-way valve in fluid communication with the purge syringe. Repeat steps (i) through (iii) until the slope of the pressure-displacement line exceeds the slope threshold of the reference pressure-displacement line, and comprises and / or the vacuum pressure is monitored using a pressure sensor in fluid communication with the purge syringe, and / or the plunger of the filling syringe and the plunger of the purge syringe are each operably coupled to a motor system, and / or the step of withdrawing the plunger of the purge syringe and the step of advancing the plunger of the filling syringe are automatically performed via the motor system, and / or a three-way valve is positioned between the filling syringe, the purge syringe, and the balloon catheter, and the three-way valve is operable to fluidly connect any two of the filling syringe, the purge syringe, and the balloon catheter at a given instant.

[0050] Although the invention has been described herein in connection with specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. Accordingly, it should be understood that numerous changes may be made to the exemplary embodiments without departing from the spirit and scope of the invention as defined by the appended claims, and other arrangements may be devised.

Claims

1. A method of implanting an artificial heart valve, comprising: delivering the artificial heart valve to the native valve annulus while the artificial heart valve is crimped on a deflated balloon of a delivery device; advancing fluid into the balloon through the delivery device to inflate the balloon and expand the artificial heart valve within the native valve annulus; monitoring the pressure within the delivery device while advancing fluid through the delivery device; displaying the monitored pressure in real time on a display device while monitoring the pressure. A method of implanting an artificial heart valve, comprising the steps above.

2. Displaying the monitored pressure in real time on the display device includes displaying the monitored pressure as a treatment curve as a function of the area of the balloon, according to the method of Claim 1.

3. The area of the balloon is determined based on the monitored pressure, and the monitored pressure is determined by measuring the pressure in the fluid line through which the fluid advances, according to the method of Claim 2.

4. The area of the balloon is estimated based on the volume of fluid advancing through the delivery device, according to the method of Claim 2.

5. The area of the balloon is determined based on a strain gauge attached to the balloon, according to the method of Claim 2.

6. The method of Claim 2 further includes displaying a reference curve of pressure as a function of balloon area on the display device.

7. The reference curve is based on the expected relationship of the pressure of the balloon to the area of the balloon when the balloon is expanding in free space, according to the method of Claim 6.

8. The method according to claim 7, further comprising monitoring a difference between the treatment curve and the reference curve while advancing fluid through the delivery device to expand the artificial heart valve. **Claim 9** Advancing fluid through the delivery device includes actuating an actuator at a handle of the delivery device, the method according to claim 1. **Claim 10** Actuating the actuator at the handle of the delivery device includes transmitting a signal to an electric housing having a syringe containing the fluid, and in response to the signal, the electric housing depressing a plunger of the syringe, the method according to claim 9. **Claim 11** A handle, A balloon catheter extending from the handle, A balloon positioned at a distal end portion of the balloon catheter, A fluid reservoir in fluid communication with a lumen, the lumen being in fluid communication with an internal volume of the balloon, the fluid reservoir, A motor operably coupled to the fluid reservoir, An actuator at the handle, operably coupled to the motor, such that when the actuator is actuated in a first direction, the motor extrudes fluid from the fluid reservoir through the lumen toward the internal volume of the balloon, and when the actuator is actuated in a second direction opposite the first direction, the motor withdraws fluid from the internal volume of the balloon toward the fluid reservoir, the actuator, An artificial heart valve delivery system comprising. **Claim 12** The artificial heart valve delivery system according to claim 11, wherein the fluid reservoir and the motor are housed within the handle. **Claim 13** The fluid reservoir is within the syringe, the syringe is connected to a housing that receives the syringe, and the motor is positioned within the housing, the artificial heart valve delivery system of claim 11.

14. The artificial heart valve delivery system of claim 11, further comprising a pressure sensor configured to determine the pressure within the balloon.

15. The pressure sensor is positioned directly within the balloon, the artificial heart valve delivery system of claim 14.

16. The artificial heart valve delivery system of claim 14, further comprising a strain gauge attached to the balloon.

17. A method of degassing the balloon of a balloon catheter, comprising: (i): withdrawing the plunger of the purge syringe while the purge syringe is in fluid communication with the balloon of the balloon catheter and while the purge syringe is not in fluid communication with a filling syringe containing fluid, monitoring a vacuum pressure as a function of plunger displacement as the plunger of the purge syringe is withdrawn to create a pressure-displacement line having a slope; (ii): advancing the plunger of the filling syringe while the filling syringe is in fluid communication with the balloon of the balloon catheter and while the filling syringe is not in fluid communication with the purge syringe; (iii): advancing the plunger of the filling syringe while the filling syringe is in fluid communication with the purge syringe and while the filling syringe is not in fluid communication with the balloon catheter to push out the remaining air through a one-way valve in fluid communication with the purge syringe; repeating steps (i) through (iii) until the slope of the pressure-displacement line exceeds a threshold slope of a reference pressure-displacement line; A method of degassing the balloon of a balloon catheter, comprising the above steps.

18. The method according to claim 17, wherein the vacuum pressure is monitored using a pressure sensor in fluid communication with the purge syringe.

19. The method according to claim 18, wherein the plunger of the filling syringe and the plunger of the purge syringe are each operably coupled to a motor system.

20. The method according to claim 19, wherein the step of withdrawing the plunger of the purge syringe and the step of advancing the plunger of the filling syringe are automatically performed via the motor system.

21. A three-way valve is positioned between the filling syringe, the purge syringe, and the balloon catheter, and the three-way valve is operable to fluidly connect any two of the filling syringe, the purge syringe, and the balloon catheter at a given instant. The method according to claim 17.

Images