Intravascular blood pump with outflow hose

Abstract

The invention relates to an intravascular blood pump with an outflow hose. An intravascular blood pump (200) includes a pump housing (211) having an input port (214) and an output port (216). A relatively short access cannula (226) may draw blood through the access port (230) and deliver blood to the input port (214) of the pump housing (211). The inlet cannula (226) is relatively short to prevent excessive loss of hydraulic pressure. The outflow hose (234) is connected to the output port (216) of the pump housing (211) to deliver blood exiting the output port (216) in a downstream direction through the outflow hose (234) to a discharge port (238), such as into the aorta or other blood vessel (205). Although the inlet cannula (226) is short, the outlet hose (234) sufficiently separates the inlet port (230) from the outlet port (238) in the longitudinal direction so that the inlet port (230) and the outlet port (238) remain on opposite sides of the heart valve even if the intravascular heart pump (200) is unintentionally displaced longitudinally.

Description

[0001] This application is a divisional application. The original application was filed on January 13, 2021, with application number 2021800167686 and invention title "Intravascular Blood Pump with Outflow Tube".

[0002] Cross-reference to related applications This application claims priority to U.S. Provisional Patent Application No. 62 / 961,017, filed January 14, 2020, entitled “Intravascular Blood Pump with Outflow Hose,” the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] This invention relates to intravascular blood pumps, and more particularly to intravascular blood pumps having an outflow tubing that increases the longitudinal spacing between the blood inlet port and the blood outlet port. Background Technology

[0004] An intravascular blood pump is a pump that can be propelled through a patient's circulatory system (i.e., veins and / or arteries) to the patient's heart or other locations within the circulatory system. For example, an intravascular blood pump can be inserted via a catheter and positioned across the heart valves. The intravascular blood pump is typically placed at the end of the catheter. Once in place, the pump can be used to pump blood through the circulatory system, thus temporarily reducing the workload on the patient's heart, such as enabling cardiac recovery after a heart attack.

[0005] Well-known types of intravascular blood pumps include axial pumps, centrifugal (i.e., radial) pumps, and hybrid pumps, in which blood flow is created by a combination of axial and radial forces. A blood pump generally includes a pump housing defining an inlet and an outlet port. An inlet cannula extends from the inlet port of the pump housing to a blood inlet port distal to the inlet cannula. An impeller is disposed within the pump housing. The impeller can be driven by an electric motor also disposed within the pump housing. Alternatively, the impeller can be driven by an external motor via a flexible drive shaft that extends through a catheter to the outside of the patient's body. In either case, rotation of the impeller causes blood to be drawn into the blood inlet port, flow through the cannula, and exit through the outlet port of the pump housing.

[0006] Some intravascular blood pumps have a diameter-expandable pump housing and a diameter-expandable impeller, while others have a fixed-diameter, non-expandable pump housing and a fixed-diameter, non-expandable impeller. When the pump and impeller are in a compressed (unexpanded) state, the expandable-housing pump is inserted into the patient, and then, after proper positioning, the pump housing and impeller are expanded in diameter. Compared to fixed-diameter pumps, the compressed state generally makes expandable-housing pumps easier to insert and guide through the patient's vascular system.

[0007] Typically, in expandable-cased blood pumps, the impeller expands to a larger diameter, allowing it to operate at a lower rotational speed while pumping at the same flow rate compared to fixed-diameter pumps. These lower speeds enable expandable-cased pumps to be driven by a flexible drive shaft and an external motor. In contrast, fixed-diameter pumps currently require a motor located close to the impeller. This internal motor is powered by wires extending through conduits to an external power source. Internal motors must be smaller and rotate faster than external motors, making them more complex and expensive. However, most intravascular blood pumps in use today are non-expandable pumps with internal motors.

[0008] An exemplary expandable-shell blood pump is described in U.S. Patent No. 8,439,859, and an exemplary fixed-diameter blood pump is described in U.S. Patent Publication No. 2019 / 0046702. The entire contents of each of the foregoing patents are incorporated herein by reference for all purposes.

[0009] When positioned in the operating position, the blood inlet of the intravascular blood pump is generally upstream of the blood outlet. When the blood pump is positioned across the heart valve, the leaflets of the heart valve open and close above the blood pump. That is, the leaflets close around the blood pump. Therefore, in use, with the pump body extending across the heart valve and in the closed position, the leaflets of the heart valve physically capture and seal around the pump body.

[0010] Catheters and blood pumps can be unintentionally displaced for various reasons, such as patient movement or cardiac action. However, for blood pumps positioned across heart valves, it is important that the blood inlet port remain on one side of the heart valve and the blood outlet port on the other. If the blood pump is displaced along the longitudinal axis of the catheter, such that both the blood inlet and outlet ports are on the same side of the heart valve, the pump's efficiency will be severely negatively affected. Even a relatively small displacement of the blood pump within the heart valve will be challenging, as the heart valve will then close at the outlet port. Although the pump may remain effective and continue to pump blood, the pumped blood will suffer from hemolysis.

[0011] Increasing the length of the insertion cannula further separates the blood inlet from the blood outlet, and thus allows for greater longitudinal displacement of the blood pump, thereby reducing the risk of the aforementioned negative consequences. However, a longer insertion cannula will result in increased hydraulic losses. To mitigate this increased hydraulic loss, the insertion portion of the cannula can be configured to expand in diameter after the blood pump has been positioned. Such expandable insertion cannulas are described in U.S. Patent Publication No. 2004 / 044266A1, the entire contents of which are incorporated herein by reference for all purposes. However, such expandable insertion cannulas increase the complexity and cost of the blood pump and its insertion process. Furthermore, as stated, most vascular blood pumps used today are non-expandable. Therefore, there is a need for fixed-diameter endovascular blood pumps that allow for greater longitudinal displacement than prior art pumps. Therefore, the technical problem is to increase the allowable amount of longitudinal displacement for a fixed-diameter endovascular blood pump without increasing the length of the insertion cannula. Summary of the Invention

[0012] Embodiments of the present invention provide an intravascular blood pump 200, comprising a conduit 204, a pump housing 211, an impeller 212, and an outlet hose 234. The conduit 204 is configured for insertion into a blood vessel 205. The blood vessel 205 defines an internal volume 207 through which blood flows in a blood flow direction 208. The pump housing 211 is attached to the conduit 204. The pump housing 211 defines an inlet port 214 and an outlet port 216. The impeller 212 is disposed within the pump housing 211. The impeller 212 is configured to pump blood from the inlet port 214 to the outlet port 216 when rotated. The outlet hose 234 is in fluid communication with the outlet port 216 of the pump housing 211. The outlet hose 234 defines a discharge port 238. The discharge port 238 is longitudinally spaced 240 from the outlet port 216 of the pump housing 211 in a downstream direction relative to the blood flow direction 208. The discharge port 238 is in fluid communication with the internal volume 207 of the blood vessel 205.

[0013] Optionally, in any embodiment, the outflow hose 234 may be coaxial with the conduit 204.

[0014] Optionally, in any embodiment, the effective inner cross-sectional area 502 of the outflow hose 234 may be at least as large as the effective inner cross-sectional area 700 of the inflow port 214 of the pump housing 211.

[0015] Optionally, in any embodiment, the effective inner cross-sectional area 502 of the outflow hose 234 may be greater than the effective inner cross-sectional area 700 of the inflow port 214 of the pump housing 211.

[0016] Optionally, in any embodiment, the effective inner cross-sectional area 502 of the outflow hose 234 may be at least twice the effective inner cross-sectional area 700 of the inflow port 214 of the pump housing 211.

[0017] Optionally, in any embodiment, the effective inner cross-sectional area 502 of the outflow hose 234 may be greater than the effective inner cross-sectional area 502 of the pump housing 211.

[0018] Optionally, in any embodiment, the discharge port 238 of the outflow hose 234 may be longitudinally spaced 240 from the output port 216 of the pump housing 211 by at least about 50 mm in a downstream direction relative to the blood flow direction 208.

[0019] Optionally, in any embodiment, the discharge port 238 of the outflow hose 234 may be longitudinally spaced 240 from the output port 216 of the pump housing 211 in a downstream direction relative to the blood flow direction 208 by at least about 80 mm.

[0020] Optionally, in any embodiment, the discharge port 238 of the outflow hose 234 may be longitudinally spaced 240 from the output port 216 of the pump housing 211 by at least about 100 mm in a downstream direction relative to the blood flow direction 208.

[0021] Optionally, in any embodiment, the discharge port 238 of the outflow hose 234 may be longitudinally spaced 240 about 50-150 mm from the output port 216 of the pump housing 211 in a downstream direction relative to the blood flow direction 208.

[0022] Optionally, in any embodiment, the discharge port 238 of the outflow hose 234 may be longitudinally spaced 240 approximately 80-120 mm from the output port 216 of the pump housing 211 in a downstream direction relative to the blood flow direction 208.

[0023] Optionally, in any embodiment, the outflow hose 234 may be at least about 50 mm long.

[0024] Optionally, in any embodiment, the outflow hose 234 may be at least about 80 mm long.

[0025] Optionally, in any embodiment, the outflow hose 234 may be at least about 100 mm long.

[0026] Optionally, in any embodiment, the outflow hose 234 may be between about 50 mm and about 150 mm in length.

[0027] Optionally, in any embodiment, the outflow hose 234 may be between about 80 mm and about 120 mm in length.

[0028] Optionally, in any embodiment, the outflow tubing 234 may be radially constricted by 600 and / or radially expanded by 500. The outflow tubing 234 may be configured to increase its radius from an initial radius by at least about 25% in response to blood pressure generated by the impeller 212 when it pumps blood. When the impeller 212 is not pumping blood, the outflow tubing 234 may be configured to be at least partially constricted by 600 due to insufficient blood pressure.

[0029] Optionally, any implementation may include a first pressure sensor 300 disposed on a pump housing 211 outside the outflow hose 234.

[0030] Optionally, any implementation may include a second pressure sensor 302 disposed inside the outflow hose 234.

[0031] Optionally, in any embodiment, the output port 216 of the pump housing 211 may include a plurality of orifices defined circumferentially around the pump housing 211.

[0032] Optionally, in any embodiment, the output port 216 of the pump housing 211 may include a plurality of orifices. A plurality of orifices may be defined along a plurality of rows 1600-1604. The rows (1600-1604) may be longitudinally spaced along the outflow hose 234.

[0033] Optionally, in any embodiment, the inlet port 214 of the pump housing 211 may include a cannula 226. The cannula 226 may extend longitudinally in an upstream direction relative to the blood flow direction 208 to an inlet port 228 defined by the cannula 226. The inlet port 228 may be in fluid communication with the internal volume 207 of the blood vessel 205.

[0034] Optionally, in any embodiment, the portion 400 of the defined inlet port 228 of the cannula 226 may be radially expanded to a diameter greater than the outer diameter of the pump housing 211.

[0035] Optionally, in any embodiment, the cannula (226) may define an inlet port (230), and the outlet port 238 of the outflow tubing 234 may be longitudinally spaced 236 from the inlet port 230 of the cannula 226 by at least about 90 mm or at least about 100 mm in a downstream direction relative to the blood flow direction 208.

[0036] Optionally, any implementation may include an electric motor 220 disposed in the pump housing 211. The electric motor 220 may be mechanically coupled to the impeller 212 and configured to rotate the impeller 212.

[0037] Optionally, any implementation may include a drive shaft 224 disposed in the catheter 204. The drive shaft 224 may be mechanically coupled to the impeller 212 and configured to transmit rotational energy to the impeller 212 by a motor external to the intravascular blood pump 200. Attached Figure Description

[0038] The foregoing description and the present invention will be more fully understood by referring to the following specific embodiments in conjunction with the accompanying drawings. However, the scope of this disclosure is not limited to the specific embodiments disclosed herein. In the drawings: Figure 1 This shows a conventional intravascular blood pump placed in the left ventricle of a human heart according to existing technology.

[0039] Figure 2 This illustrates an intravascular blood pump placed in the left ventricle of a human heart according to an embodiment of the present invention.

[0040] Figure 3a yes Figure 2 A magnified view of the portion.

[0041] Figure 3b This is an optional embodiment of the present invention. Figure 2 A magnified view of the portion.

[0042] Figure 4 Showing an optional embodiment according to the present invention Figure 2 The blood pump enters the distal portion of the enlarged cannula through the intravascular blood pump.

[0043] Figure 5 It is according to an embodiment of the present invention. Figures 2 to 4 A cross-sectional view of the outflow tubing and catheter of an intravascular blood pump, wherein the outflow tubing is expanded.

[0044] Figure 6 It is according to an embodiment of the present invention. Figure 5 A cross-sectional view of the outflow hose and conduit, in which the outflow hose is collapsed.

[0045] Figure 7 It is according to an embodiment of the present invention. Figures 2 to 4 A cross-sectional view of the pump housing and the input port of the intravascular blood pump.

[0046] Figure 8 It's a 3D image. Figure 9 It is a horizontal cross-sectional view, and Figure 10 It is according to an embodiment of the present invention. Figure 2 Figure 3 shows a longitudinal cross-sectional view of the end of the intravascular blood pump.

[0047] Figure 11 It is a 3D image, and Figure 12This is according to another embodiment of the present invention. Figure 2 Figure 3 shows a transverse cross-sectional view of the end of the intravascular blood pump.

[0048] Figure 13 It is a 3D image, and Figure 14 This is according to yet another embodiment of the present invention. Figure 2 Figure 3 shows a transverse cross-sectional view of the end of the intravascular blood pump.

[0049] Figure 15 This invention illustrates an intravascular blood pump according to another embodiment of the invention, which includes an optional access cannula placed in the left ventricle of a human heart.

[0050] Figure 16 It is a 3D image, and Figure 17 and Figure 18 These are respective side views of an intravascular blood pump according to an optional embodiment of the invention (one view rotated 90 degrees about the longitudinal axis).

[0051] Figure 19 Example from Figures 16 to 18 An exemplary blood flow at the discharge port of an intravascular blood pump, as simulated by a computer program. Detailed Implementation

[0052] Embodiments of the present invention provide intravascular blood pumps of a fixed diameter (non-expandable) that allow longitudinal displacement along their respective catheters without lengthening the insertion cannula or resulting in increased hydraulic losses. The intravascular blood pumps according to the invention reduce the risk of unintentionally displacing both the blood inlet and blood outlet ports to the same side of a heart valve. Furthermore, the intravascular blood pumps according to the invention reduce the risk of unintentionally displacing the blood outlet port to a position within the heart valve. Each such intravascular blood pump includes an outflow tubing. The outflow tubing provides a blood discharge port longitudinally separated from the pump output port in the downstream direction. Compared to prior art blood pumps, the outflow tubing longitudinally separates the blood discharge port and the blood inlet port without lengthening the insertion cannula. In some embodiments, the insertion cannula is shorter than that of the prior art.

[0053] Existing intravascular blood pump technology Figure 1 This illustrates a conventional, fixed-diameter (non-expandable) intravascular blood pump 100 placed in the left ventricle 102 of a human patient's heart 104. The blood pump 100 is positioned at one end of a catheter 106, through which it is inserted into the left ventricle 102 via the aorta 108. The blood pump 100 is positioned to extend through an aortic valve 110. The leaflets of the aortic valve 110 close around the blood pump 100.

[0054] The blood pump 100 includes a pump housing 112 that houses an impeller and a motor (not visible). The pump housing 112 defines an axial pump housing inlet port 114 and a radial pump housing outlet port 116. The radial pump housing outlet port 116 may include a plurality of orifices (windows) circumferentially defined around the pump housing 112. The impeller draws blood into the pump housing 112 through the axial pump housing inlet port 114 and exits through the radial pump housing outlet port 116, as indicated by the arrows.

[0055] The blood pump 100 includes an inlet cannula 118, one end of which is fluidly attached to an axial pump housing inlet port 114. The opposite end of the inlet cannula 118 defines an inlet port 120. The inlet port 120 may include a plurality of orifices (windows) circumferentially defined around the inlet cannula 118. Therefore, blood is drawn from the left ventricle 102 into the inlet cannula 118 through the inlet port 120 for delivery to the axial pump housing inlet port 114.

[0056] The inlet port 120 and the pump housing outlet port 116 are separated by a distance 122, such that after the blood pump 100 is placed in the heart 104, the inlet port 120 and the pump housing outlet port 116 are positioned on opposite sides of the aortic valve 110, and the anticipated longitudinal displacement of the blood pump 100 cannot move the inlet port 120 and the pump housing outlet port 116 to the same side of the aortic valve 110, or move the pump housing outlet port 116 into the aortic valve 110. As described, the distance 122 requires a considerably long inlet cannula 118, which results in a considerably high hydraulic loss, especially since the inlet cannula 116 is connected to the input (inhalation) end of the pump housing 112.

[0057] Any pump pushes or ejects fluid from the pump, rather than actually mechanically forcing fluid into it. The fluid discharged from the pump creates a partial vacuum within the pump. The surrounding pressure of the fluid at the pump's inlet (suction) port, such as the pressure of the blood in the left ventricle 102, pushes the fluid into the pump. The effectiveness of this pushing depends at least in part on the pressure difference between the surrounding pressure and the partial vacuum. Without sufficient inlet pressure, the pump will not operate properly. The available net positive suction head (NPSH) must be sufficient to meet the pump's net positive suction head requirement (NPSHr), otherwise the pump may become cavitary. The blood pressure in the left ventricle 102 is relatively low. Therefore, the blood pump 100 is particularly sensitive to frictional losses caused by the inlet cannula 118.

[0058] Intravascular blood pump with outflow tubing Figure 2This illustrates a fixed-diameter (non-expandable) intravascular blood pump 200 according to an embodiment of the present invention. The intravascular blood pump 200 is shown positioned in the left ventricle 102 of a human patient's heart 104. Figure 3a and Figure 3b It is based on two separate implementation methods. Figure 2 A magnified view of part 202.

[0059] The blood pump 200 includes a catheter 204 through which it is inserted into the left ventricle 102 via an aorta 108 comprising a descending aorta 205 and an aortic arch 206. The catheter 204 is configured for insertion into a vessel such as the aorta 206 that defines an internal volume 207 through which blood flows in the blood flow direction (e.g., as indicated by arrow 208). The catheter 204 extends to a controller (not shown), such as the Automatic Impella Controller (“AIC”) available from Abiomed, Inc., Danvers, MA01923. The controller provides a user interface for controlling and monitoring the intravascular blood pump 200.

[0060] As used herein, the term “distal” refers to the direction or location along conduit 204 away from the controller or user, and the term “proximal” refers to the direction or location along conduit 204 toward the controller or user.

[0061] like Figure 2 As shown, during insertion, the intravascular blood pump 200 is positioned to extend through the aortic valve 110; however, in other uses, the intravascular blood pump 200 can be positioned elsewhere in the patient's vascular system, without needing to be positioned within the heart. Furthermore, although... Figure 2 The inserted intravascular blood pump 200 is depicted with blood flow direction 208 away from the distal end of catheter 204; however, in other applications, the intravascular blood pump 200 may be inserted with blood flow direction 208 towards the distal end of catheter 204. For example, the intravascular blood pump 200 may be inserted into the left ventricle 102 from the left atrium 209 through the mitral valve 210. Figure 2 In the application described, the leaflets of the aortic valve 110 surround the blood pump 200 for closure.

[0062] Intravascular blood pump 200 includes pump housing 211 (in) Figure 3a and Figure 3bThe impeller (not visible, but indicated by reference numeral 212) is located within the pump housing 211. The pump housing 211 defines an axial pump housing inlet port 214 and a radial pump housing outlet port 216. The radial pump housing outlet port 216 may include a plurality of orifices (windows) circumferentially defined around the pump housing 211. The impeller 212 is configured to pump blood from the pump housing inlet port 214 to the pump housing outlet port 216 when rotating. The impeller 212 draws blood into the pump housing 212 through the axial pump housing inlet port 214 and exits from the radial pump housing outlet port 216, as indicated by arrow 218.

[0063] In some embodiments, an electric motor (not visible, but indicated by reference numeral 220) is arranged in or near the pump housing 211. The electric motor 220 is mechanically coupled to and configured to rotate the impeller 212. A wire 222 extends from the electric motor 220 through a conduit 204 to a controller to power the electric motor 220. In other embodiments, the impeller 212 is driven by a flexible drive shaft 224 (partially shown in dashed lines), which extends through the conduit 204 to an external motor (not shown), such as a motor in the controller.

[0064] The inlet port 214 of the pump housing 211 includes an inlet cannula 226. One end of the inlet cannula 226 is fluidly attached to the axial pump housing inlet port 214. The cannula 226 extends longitudinally in an upstream direction relative to the blood flow direction 208. The opposite end of the inlet cannula 226 defines an inlet port 228. The cannula inlet port 228 may include a plurality of orifices (windows) circumferentially defined around the inlet cannula 226, represented by orifice 230.

[0065] The insertion cannula 226 is relatively short, resulting in relatively small hydraulic losses. In some embodiments, the insertion cannula 226 is approximately 5-60 mm long, or approximately 10-25 mm long. Experiments and / or simulations show that this relatively short insertion cannula 226 can increase blood flow by approximately 0.2 l / min or more compared to conventional, other comparable intravascular blood pumps. Other suitable lengths of insertion cannula 226 can be used alternatively.

[0066] Optional, such as Figure 4 As shown, the enlarged distal portion 400 of the insertion cannula 226 has a larger diameter than the rest of the insertion cannula 226 and is larger than the inner and outer diameters of the pump housing 211. The enlarged distal portion 400 of the insertion cannula 226 may define a plurality of orifices 402 circumferentially around the insertion cannula 226, for example as the space between adjacent supports represented by the support 404.

[0067] Return to Figure 2Blood is drawn from the left ventricle 102 through multiple orifices 230 into the cannula inlet port 228, and then through the inlet cannula 226 to be delivered to the axial pump housing inlet port 214. As discussed in more detail herein, with Figure 1 Compared to the much longer access cannula 118 in the prior art intravascular heart pump 100 shown, the access cannula 226 is much shorter and therefore results in much less hydraulic loss.

[0068] The intravascular blood pump 200 includes a flexible pigtail or J-shaped tip 232 at its distal end, configured to facilitate insertion of the intravascular blood pump 200 into the patient's heart 104 without damaging surrounding tissue. The flexible tip 232 also helps to keep soft tissue away from the blood flow inlet opening 230 into the cannula 226. The flexible tip 232 may be, for example, about 10-60 mm long, or about 20-35 mm long.

[0069] Outflow hose As described so far, the inlet cannula 226, inlet port 228, and radial pump housing outlet port 216 are all located within the left ventricle 102. However, the intravascular blood pump 200 also includes an outlet hose 234 that extends from the radial pump housing outlet port 216 through the aortic valve 110 into the aorta 108. The outlet hose 234 separates the point where blood is discharged from the intravascular blood pump 200 from the inlet port 230 by a distance 236, which is at least as large as in the prior art, but does not require a long inlet cannula 118. Figure 1 ).

[0070] like Figure 5 As shown in the cross-section, the outflow hose 234 may be generally cylindrical and coaxial with the conduit 204. Alternatively, the outflow hose 234 may have another suitable cross-sectional shape (not shown). Figure 5 As shown, an outflow hose 234 may be arranged to surround a conduit 204 of a length for which the outflow hose 234 is located. Optionally (not shown), the outflow hose 234 may be parallel to the conduit 204, but not extend coaxially with the conduit 204.

[0071] The outflow tubing 234 is in fluid communication with the output port 216 of the pump housing 211. The proximal end 237 of the outflow tubing 234 should be mechanically attached to the catheter 204 to prevent the proximal end 237 from sliding along the catheter 204 into the left ventricle 102. Similarly, the distal end 304 of the outflow tubing 234 should be mechanically attached to the cannula 204, the pump housing 211, or the intubation cannula 226.

[0072] like Figure 3aAs shown, the distal end 304 of the outflow tubing 234 may be further than the furthest portion of the orifice of the output port 216. However, this configuration can create an undesirable blood recirculation zone 306 between the distal end 304 of the outflow tubing 234 and the furthest portion of the orifice of the output port 216. Figure 3b As shown, to avoid this potential problem, the farthest end 304 of the outflow hose 234 should be attached to the insertion tube 204, the pump housing 211, or the inlet tube 226, as close as possible to the farthest part of the orifice of the output port 216.

[0073] To facilitate insertion and retrieval of the intravascular blood pump 200, the outer diameter of the portion of the outflow tubing 234 near the proximal end 237 may taper radially inward in the proximal direction, i.e., in the downstream direction. However, in other embodiments, the outer diameter of the proximal portion of the outflow tubing 234 does not taper.

[0074] The outflow hose 234 defines an outlet port 238 near its proximal end 237, which may include a plurality of orifices circumferentially defined around the outflow hose 234. The outlet port 238 is in fluid communication with the internal volume 207 of a blood vessel (in this case, the aorta 205).

[0075] As shown in Figure 3, all orifices can be defined along a single circumferential row surrounding the outflow hose 234. Alternatively, as... Figures 16 to 19 As shown, orifices can be defined along two or more circumferential rows. Figure 16 The pump housing 211 and the output port 216 of the pump housing 211 are shown in dashed lines. Figures 16 to 19 The illustrated embodiment has three rows of orifices 1600, 1602, and 1604; however, other embodiments may have other numbers of rows, such as two, four, five, six, or more rows of orifices. Rows 1600-1604 may be longitudinally spaced along the outflow hose 234, as illustrated by longitudinal spacing 1606. Each row 1600-1604 may contain one or more orifices.

[0076] Figures 16 to 19 The implementation shown in the figure has two openings in each row 1600-1604, as... Figures 17 to 18This is most clearly visible in the center. However, other embodiments may have a different number of orifices per row 1600-1604, such as one, three, four, five, six or more orifices per row. All rows 1600-1604 may, but do not necessarily have, the same number of orifices. The orifices of each row 1600-1604 may be offset from the orifices of adjacent rows 1600-1604 (one or more) by a certain angle 1606, such as about 90° or another suitable angle. The orifices of multiple rows 1600-1604 and the angle offset 1606 reduce the vibration of the intravascular blood pump 200 and help stabilize the intravascular blood pump 200. Figure 19 The example, simulated by a computer program, shows an exemplary spiral blood flow 1900 from the discharge port 238 due to the orifices and angular offset 1606 of the multiple rows 1600-1603. Advantageously, the orifices and angular offset 1606 of the multiple rows 1600-1603 can prevent or limit blood backflow during cardiac diastole.

[0077] The discharge port 238 is longitudinally spaced from the output port 216 of the pump housing 211 in a downstream direction relative to the blood flow direction 208. This longitudinal separation is indicated by a distance 240. In various embodiments, the distance 240 may be at least about 50 mm, at least about 80 mm, at least about 100 mm, about 50-150 mm, about 80-120 mm, or another distance suitable for reducing the risk of unintentional displacement of the discharge port 238 and the inlet port 230 to the same side of the aortic valve 110, and / or reducing the risk of unintentional displacement of the discharge port 238 to the aortic valve 110, even if the intravascular blood pump 200 is longitudinally displaced further into the left ventricle 102 by the expected distance.

[0078] The distance 240 can be selected based on several considerations, such as: the expected size of the patient's heart chambers and / or heart valves, taking into account the patient's age and / or cardiac condition; the size of the pump housing 211 and / or the size of other components of the intravascular cardiac pump 200; and the desired length of the insertion cannula 226 to achieve the desired low hydraulic loss in the insertion cannula 226. However, positioning the discharge port 238 too high in the aorta 108 can lead to undesirable blood flow patterns, such as backflow during cardiac ejection.

[0079] In some embodiments, the length of the outflow tubing 234 is at least about 50 mm, at least about 80 mm, about 100 mm, at least about 100 mm, between about 50 and 150 mm, between about 80 and 120 mm, or another length, which is suitable for reducing the risk of unintentional displacement of the outflow port 238 and the inflow port 230 to the same side of the aortic valve 110, and / or reducing the risk of unintentional displacement of the outflow port 238 to the aortic valve 110, even if the intravascular blood pump 200 is longitudinally displaced a further distance into the left ventricle 102.

[0080] The length of the outflow tubing 234 can be selected based on several considerations, such as: the expected size of the patient's heart, taking into account the patient's age and / or cardiac condition; the size of the pump housing 211 and / or the size of other components of the intravascular cardiac pump 200; and the desired length of the inflow cannula 226 to achieve the desired low hydraulic loss during inflow to the cannula 226.

[0081] The discharge port 238 is longitudinally spaced from the inlet port 230 of the cannula 226 in a downstream direction relative to the blood flow direction 208, this longitudinal separation being indicated by a distance 236. In some embodiments, the distance 236 is at least about 90 mm. In other embodiments, the distance 236 is at least about 100 mm. In still other embodiments, the distance 236 is another distance suitable for reducing the risk of unintentional displacement of the discharge port 238 and the inlet port 230 to the same side of the aortic valve 110, and / or reducing the risk of unintentional displacement of the discharge port 238 to the aortic valve 110, even if the intravascular blood pump 200 is longitudinally displaced the expected distance further into the left ventricle 102.

[0082] The distance 236 can be selected based on several considerations, such as: the expected size of the patient's heart chambers and / or heart valves, taking into account the patient's age and / or cardiac condition; the size of the pump housing 211 and / or the size of other components of the intravascular cardiac pump 200; and the desired length of the insertion cannula 226 to achieve the desired low hydraulic loss during insertion into the cannula 226.

[0083] Some prior art expandable intravascular cardiac pumps (not shown) have impellers arranged relatively close to their inlet port. Due to the proximity of the impeller to the inlet port, i.e., due to the relatively short inlet cannula, such intravascular cardiac pumps advantageously result in relatively small hydraulic losses within the inlet cannula. However, in this configuration, the inlet port is arranged relatively close to the distal end of the catheter, near the pigtail or J-shaped tip. This location of the inlet port is relatively close to the inner wall of the heart chamber. Therefore, there is a relatively high risk that the rotating impeller may draw cardiac tissue (such as a column of flesh) into the inlet port and potentially damage the cardiac tissue. Ideally, the impeller 212 should be spaced at least about 2 cm from the inlet port 230 to prevent the impeller 212 from damaging the drawn-in column of flesh.

[0084] On the other hand, the existing intravascular cardiac pump 100 arranges the impeller relatively far from the inlet port 114, thereby advantageously reducing the risk of damage to cardiac tissue. However, as described, this arrangement of the impeller requires a fairly long inlet cannula 118, which in turn results in relatively high hydraulic losses.

[0085] The embodiments of the present invention solve this problem and provide two advantages: low risk or damage to cardiac tissue and low hydraulic loss.

[0086] The outflow tubing 234 may be made of a suitable biocompatible material, such as a suitable polymer, like polyurethane, polyamide, nylon, or silicone. In some embodiments, the outflow tubing 234 may be radially corrugated, as by... Figure 6 Arrow 600 in the diagram indicates, and / or may expand radially, as through Figure 5 Arrow 500 indicates this. In this embodiment, the outflow tubing 234 may be configured to increase its radius in response to blood pressure generated by the impeller 212 when the impeller pumps blood, for example, by at least about 25%, or at least about 50%, or at least about 75%, or at least about 100%, or at least about 133%, or at least about 150% of its initial radius. Essentially, blood pressure causes the outflow tubing 234 to expand. Figure 5 The outflow hose 234 and conduit 204 are shown, wherein the outflow hose 234 is expanded. In some embodiments, the outflow hose 234 may elastically constrict radially and / or elastically expand radially. In other embodiments, the expandability and / or constrictibility of the outflow hose 234 need not be elastic. In other words, the outflow hose 234 may be “soft” when not expanded, and the outflow hose 234 may be inherently folded or wrinkled to constrict and unfold to expand. As used herein, the term “expansion” does not necessarily require stretching the material of the outflow hose 234, and the term “constriction” does not necessarily require relatively stretching the material of the outflow hose 234.

[0087] like Figure 6As shown, when the impeller 212 is not pumping blood, the outflow hose 234 can be configured to constrict radially due to lack of blood pressure. Figure 6 The outflow tubing 234 and catheter 204 are shown, with the outflow tubing 234 deflated. This radially expandable outflow tubing 234 facilitates the insertion and removal of the intravascular blood pump 200 by reducing the outer diameter of the outflow tubing 234 during insertion and removal. For example, in some embodiments, the catheter 204 may have a size of about 9 Fr, and the outflow tubing 234 may have essentially the same size (9 Fr) or slightly larger when deflated or not expanded, however, the outflow tubing 234 may have a size of about 18-21 Fr when expanded.

[0088] The outflow hose 234 has an effective inner cross-sectional area of ​​502 ( Figure 5 This is equal to the inner cross-sectional area of ​​the outflow hose 234 minus the outer cross-sectional area of ​​the conduit 204 that obstructs blood flow between the pump housing output port 216 and the discharge port 238, and the outer cross-sectional area of ​​any other structures (one or more) inside the outflow hose 234. Figure 5 In the embodiment shown, the effective inner cross-sectional area 502 has an annular shape. In other embodiments, the effective inner cross-sectional area 502 may have another shape.

[0089] The effective inner cross-sectional area 502 of the outlet hose 234 should be at least equal to the inner cross-sectional area 700 of the inlet port 214 of the pump housing 211. Figure 7 The effective inner cross-sectional area 502 of the outlet hose 234 is larger than the inner cross-sectional area of ​​the inlet port 214 of the pump housing 211. In some embodiments, the effective inner cross-sectional area 502 of the outlet hose 234 is at least twice the size of the inner cross-sectional area of ​​the inlet port 214 of the pump housing 211. The effective inner cross-sectional area 502 of the outlet hose 234 should be larger than the inner cross-sectional area of ​​the pump housing 211.

[0090] The effective inner cross-sectional area 502 of the outflow hose 234 should be at least as large as the inner cross-sectional area of ​​the inflow cannula 226. Preferably, the effective inner cross-sectional area 502 of the outflow hose 234 is larger than the inner cross-sectional area of ​​the inflow cannula 226. In some embodiments, the effective inner cross-sectional area 502 of the outflow hose 234 is at least twice the inner cross-sectional area of ​​the inflow cannula 226.

[0091] Compared to other comparable conventional intravascular blood pumps, this outflow tubing 234 can generate an increase in blood flow of up to approximately 0.2 l / min. For the 14 F intravascular blood pump 200, i.e., an intravascular blood pump 200 with a maximum outer diameter of almost 5 mm, the total blood flow achievable under normal conditions is approximately 4 l / min.

[0092] pressure sensor The flow rate of the intravascular blood pump 200 can be estimated based on the size of the intravascular blood pump 200 and the difference between pressure measurements obtained at two or more points. To facilitate the measurement of these pressures, a first pressure sensor 300 (FIG. 3) can be disposed on the pump housing 211 upstream of the distal end of the outflow tubing 234. Alternatively, the first pressure sensor 300 can be positioned proximally to or near the inlet cannula 226, adjacent to the pump housing inlet port 214, or elsewhere along the inlet cannula 226, such as near the orifice 230 of the inlet port 228, as in 242 ( Figure 2 As indicated herein, the first pressure sensor 300 should be in direct contact with the blood in the left ventricle 102, i.e., not through the interior of the intravascular blood pump 200. In other words, the first pressure sensor 300 should be located on the outside of the intravascular blood pump 200. The first pressure sensor 300 should be positioned during operation of the intravascular blood pump 200 in a location where it is unlikely to be moved out of the left ventricle 102 under any possible use, such that the first pressure sensor 300 can depend on the reporting pressure in the left ventricle 102. The location described herein satisfies this criterion.

[0093] In the prior art, an intravascular blood pump 100 typically includes an insertion cannula 118 attached to the pump housing 112. Figure 1 The pump housing 112 is positioned such that it spans the heart valve 110. Because the intravascular blood pump 100 can be longitudinally displaced during use, entering the cannula 118 instead of the pump housing 112, it can be positioned within the heart valve 110. Therefore, this prior art intravascular blood pump 100 is unsuitable for including a pressure sensor near its pump housing 112. Such a pressure sensor can be moved away from the left ventricle 102 and thus provide an inaccurate pressure measurement. Therefore, in prior art intravascular blood pumps 100, the pressure sensor is generally located distal to the cannula 118. The embodiments of the present invention do not have this disadvantage.

[0094] The second pressure sensor 302 (FIG. 3) may be disposed inside the outflow tubing 234 to measure blood pressure in the outflowing blood, as produced by the intravascular blood pump 200. Because blood flows from the outflow tubing 234 into the aorta 205 without substantial pressure loss, the blood pressure inside the outflow tubing 234 is substantially the same as the blood pressure in the aorta 205. The outflow tubing 234 and the discharge port 238, comprising a plurality of orifices circumferentially defined around the outflow tubing 234, are configured to provide substantially unobstructed blood flow therethrough so as not to create any substantial pressure differential. Optionally, the second pressure sensor may be disposed on the conduit 204 inside or outside the outflow tubing 234. However, it is preferably placed on the motor housing 211 to facilitate connection of the second pressure sensor 302 to wires extending through the conduit 204 to the controller. These wires transmit signals from the first pressure sensor 300 and the second pressure sensor 302 to the controller.

[0095] The controller can be configured to estimate the flow rate of the intravascular blood pump 200 using blood pressure measurements provided by the first pressure sensor 300 and the second pressure sensor 302, i.e., blood pressure from inside the left ventricle 102 and inside the outflow tubing 234.

[0096] Blood flow inlet orifice As indicated, the enlarged distal portion 400 entering the cannula 226 may have an enlarged diameter portion 400 ( Figure 4 ), which defines multiple orifices 402. Figures 8 to 10 These are perspective views, transverse cross-sectional views, and longitudinal cross-sectional views of the enlarged diameter portion 400 of the insertion cannula 226 according to embodiments of the present invention. Figures 8 to 10 The enlarged diameter portion 400 of the insertion cannula 226 is shown under normal operating conditions of the intravascular blood pump 200 (including normal blood pressure and a flow rate of about 4 liters per minute (L / min)).

[0097] Multiple orifices 402 are defined by a frame structure, such as a cage 802 including struts 804. Each strut 804 separates a pair of adjacent orifices 402 from each other. In this embodiment, the struts 804 extend substantially axially parallel to the longitudinal axis 806 of the insertion cannula 226. However, in other embodiments, the struts 804 may extend radially or helically, or the struts 804 may be formed in any other suitable shape to define the orifices 402 between them. Figures 8 to 10 In the illustrated embodiment, five supports 804 form a cage 802. However, other embodiments may include more or fewer supports 804. For example, some embodiments (not shown) include three, four, six, seven, eight or more supports 804.

[0098] Optionally, in any embodiment, the struts 804 may be interconnected by components represented by components 808, shown in dashed lines, which extend between pairs of struts 804. Components 808 are configured to reinforce the cage 802 to resist shrinkage or other deformation.

[0099] The cannula 810 covers a portion of the enlarged distal portion 400 of the insertion cannula 226 to reduce the likelihood of tissue being aspirated into the orifice 402. The cannula 810 overlaps with the portion of the insertion cannula 226 and extends over the proximal portion of the cage 802.

[0100] The cannula 810 may have a funnel shape to increase the blood flow rate of the intravascular blood pump 200. The funnel shape has a decreasing cross-sectional diameter in the direction from the distal end 812 of the cannula 810 toward the proximal end 814 of the cannula 810. The cross-sectional diameter of the cannula 810 in the direction from the distal end 812 toward the proximal end 814 should monotonically narrow. In particular, the cross-sectional diameter of the distal end 812 of the cannula 810 should not decrease in the upstream direction.

[0101] If available Figure 9 As can be clearly seen most clearly, at least when no blood is being pumped, the cross-sectional shape of the cannula 810 can be substantially circular, and the cannula 810 can be supported by the support post 804 of the cage 802. That is, the inner wall surface of the cannula 810 can contact the support post 804 and can be held in place radially outward by the support post 804.

[0102] However, in some embodiments (not shown), the inner diameter of the cannula 810 may be larger than the outer diameter of the circle circumscribed to the strut 804. Under certain conditions, the cannula 810 may be kept radially open by the blood flowing into it. In this case, the flowing blood exerts pressure on the inner surface 900 of the cannula 810 to maintain its funnel shape and thus prevent it from wrinkling during operation of the intravascular blood pump 200. Optionally, the cannula 810 may be made of a suitable material that is strong enough to prevent it from wrinkling, or it may be reinforced by a suitable structure as described herein.

[0103] In some embodiments, or in certain circumstances, the sleeve 810 may take a cross-sectional shape other than substantially circular, for example... Figures 11 to 12 As shown in the diagram. The sleeve 810 can be tightly fitted around the support 804. For example, as... Figure 12 As shown, if the cage 802 includes five supports 804, the sleeve 810 may have a pentagonal cross-sectional shape.

[0104] Due to the inward pressure exerted by the blood at the distal end 812 of the cannula 810, as indicated by arrow 1400 ( Figure 14As indicated, the cannula 810 can be deflected inward by the support 804 into the orifice 402. However, the cannula 810, support 804, etc., should be configured to limit the deflection to no more than about 0.2 mm radially inward on each side to avoid adversely affecting blood flow under the intended pressure and flow rate. In particular, the cannula 810 should have sufficient rigidity to prevent the cannula 810 from being sucked into the orifice 402, which could block the orifice 402.

[0105] Expandable cage Optionally, in any embodiment, the cage 802, as well as the sheath 810 and optionally the insertion cannula 226, can expand diametrically. That is, these parts can be configured such that, before insertion into the operating position, they present a compressed configuration with a relatively small diameter, and after insertion into the operating position, they can expand diametrically to a larger diameter. In particular, in the compressed configuration (not shown), the outer diameter of the expanded diameter portion 400 can be substantially the same as or smaller than the outer diameter of the remainder of the insertion cannula 226 to facilitate delivery of the intravascular blood pump 200 through the guide sheath. Then, after the intravascular blood pump 200 has been positioned for operation, the outer diameter of the expanded diameter portion 400 can expand to a size greater than the outer diameter of the remainder of the insertion cannula 226, as shown in the figures.

[0106] While the cannula 810 may have a structure that provides sufficient radial rigidity to prevent it from wrinkling during normal operation of the intravascular pump 200, such as a membrane structure comprising a suitable material like polyurethane, additional reinforcing structures can be provided to attach to or embed in the cannula 810. The reinforcing structure provides radial rigidity during operation of the intravascular pump 200, but also provides expansion and compression properties to allow the component to be elastically: (a) compressed to facilitate insertion of the intravascular pump 200; (b) expanded—after the pump is in place; and (c) subsequently compressed again to facilitate removal of the intravascular pump 200 from the patient. In some embodiments, the access cannula 266 may expand to an outer diameter greater than the outer diameter of the pump housing 211 over most or all of its axial length. The expandable cage 802 and the cannula 810 may be made using the information provided in the aforementioned U.S. Patent Nos. 8,439,859 and / or U.S. Patent Publication No. 2019 / 0046702.

[0107] Compared to other conventional comparable intravascular blood pumps, this expandable cage 802 and cannula 810 can generate an increase in blood flow of up to about 0.2 1 / min without increasing the risk of hemolysis. Compared to other conventional comparable intravascular blood pumps 100, the expandable access cannula 226, which expands along most of its axial length, can generate a further increase in blood flow of up to about 0.2 1 / min. The expandable pump housing as described in the aforementioned U.S. Patent No. 8,439,859 can be used as the access cannula 226 for the intravascular blood pump 200 described herein.

[0108] Optional intubation Figure 15 This illustrates another embodiment of the blood pump 200, which, in comparison to the reference... Figure 2 The embodiments described in Figure 3 differ only in the configuration of the insertion cannula 226. Figure 15 In the illustrated embodiment, the enlarged diameter portion 400 of the access cannula 226 extends over its entire length. Thus, orifices 402 are arranged at the distal segment of the cage structure 802. However, the remainder of the cage structure 802 is covered by a sleeve 810, and the proximal end of the cage structure 802 is attached to the inlet port 214 of the pump housing 211. The access cannula 226 can be manufactured in the same manner as the pump housing of the expandable intravascular blood pump discussed herein. For example, the cage structure 802 can be manufactured using well-known laser cutting techniques. Advantageously, the pump housing 211 and the cage structure 802 of the access cannula 266 can be made from a single tube, thus forming them as an integral assembly.

[0109] The multiple access cannulas 266 and orifice 402 described herein prevent, or at least reduce, the risk of soft tissue such as filaments in the left ventricle 102 being aspirated into the orifice 402. Furthermore, when the intravascular blood pump 200 is in use, the access cannulas 226 described herein prevent, or at least reduce, the risk of the orifice 402 being displaced from the left ventricle 102, even due to slight longitudinal movement of the intravascular blood pump 200.

[0110] Although the invention has been described with reference to the exemplary embodiments described above, modifications and variations may be made to the exemplary embodiments without departing from the inventive concept disclosed herein. For example, while specific parameter values ​​such as dimensions and materials may be stated with respect to the disclosed embodiments, within the scope of the invention, the values ​​of all parameters may vary within a wide range to suit different applications. Unless otherwise indicated in the context or understood by those skilled in the art, terms such as “about” mean within ±20%.

[0111] As used herein, including in the claims, the term “and / or” used in conjunction with the list of terms means one or more of the terms in the list, i.e., at least one of the terms in the list, but not necessarily all of the terms in the list. The term “or” as used herein, including in the claims, used in conjunction with the list of terms, means one or more of the terms in the list, i.e., at least one of the terms in the list, but not necessarily all of the terms in the list. “Or” does not mean “exclusive or”.

[0112] The disclosed aspects or portions thereof can be combined in ways not listed above and / or not expressly claimed. Furthermore, embodiments disclosed herein may be suitably practiced in the absence of any elements not expressly disclosed herein. Therefore, the invention should not be considered limited to the disclosed embodiments.

[0113] As used herein, numerical terms such as “first,” “second,” and “third” are used to distinguish the respective pressure sensors or other elements from one another and are not intended to indicate any particular order or total number of pressure sensors or other elements in any particular embodiment. Thus, for example, a given embodiment may include only a second pressure sensor and a third pressure sensor.

Claims

1. Intravascular blood pump (200), which includes: A catheter (204) is configured to be inserted into a blood vessel (205) that defines an internal volume (207), through which blood flows in a blood flow direction (208). Pump housing (211), which is attached to the conduit (204) and defines an input port (214) and an output port (216). An impeller (212) is disposed within the pump housing (211) and configured to pump blood from the inlet port (214) to the outlet port (216) when rotating; and An outflow hose (234) is in fluid communication with the output port (216) of the pump housing (211), the outflow hose (234) defines an outlet port (238), the outlet port (238) is longitudinally spaced (240) from the output port (216) of the pump housing (211) in a downstream direction relative to the blood flow direction (208), and is in fluid communication with the internal volume (207) of the blood vessel (205).

2. The intravascular blood pump (200) according to claim 1, wherein the outflow tubing (234) is coaxial with the catheter (204).

3. The intravascular blood pump (200) according to any of the preceding claims, wherein the effective inner cross-sectional area (502) of the outflow tubing (234) is at least as large as the effective inner cross-sectional area (700) of the inflow port (214) of the pump housing (211).

4. The intravascular blood pump (200) according to any of the preceding claims, wherein the effective inner cross-sectional area (502) of the outflow tubing (234) is greater than the effective inner cross-sectional area (700) of the inflow port (214) of the pump housing (211).

5. The intravascular blood pump (200) according to any of the preceding claims, wherein the effective inner cross-sectional area (502) of the outflow tubing (234) is at least twice the effective inner cross-sectional area (700) of the inflow port (214) of the pump housing (211).

6. The intravascular blood pump (200) according to any of the preceding claims, wherein the effective inner cross-sectional area (502) of the outflow tubing (234) is greater than the effective inner cross-sectional area (502) of the pump housing (211).

7. The intravascular blood pump (200) according to any of the preceding claims, wherein the discharge port (238) of the outflow tubing (234) is longitudinally (240) spaced (200 mm) from the output port (216) of the pump housing (211) in a downstream direction relative to the blood flow direction (208).

8. The intravascular blood pump (200) according to any of the preceding claims, wherein the discharge port (238) of the outflow tubing (234) is longitudinally (240) spaced (240) from the output port (216) of the pump housing (211) by at least about 80 mm in a downstream direction relative to the blood flow direction (208).

9. The intravascular blood pump (200) according to any of the preceding claims, wherein the discharge port (238) of the outflow hose (234) is longitudinally (240) spaced (200 mm) from the output port (216) of the pump housing (211) in a downstream direction relative to the blood flow direction (208).

10. The intravascular blood pump (200) according to any one of claims 1 to 6, wherein the discharge port (238) of the outflow hose (234) is longitudinally (240) spaced (240) from the output port (216) of the pump housing (211) by about 50-150 mm in a downstream direction relative to the blood flow direction (208).

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