Electrode assembly patch for conductance and admittance measurements

Abstract

Disclosed are electrode assembly patches configured for conductance and admittance measurements, and methods for their manufacture. The present technology provides designs and manufacturing methods that can enable conductance or admittance electrode assembly patches to be flexible, low-profile, and easily attached to intravascular blood pumps or other devices with little or no change in the overall diameter, profile, and functionality of the device. TIFF2023552946000002.tif84132

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63 / 088,784, filed October 7, 2020, U.S. Provisional Application No. 63 / 173,709, filed April 12, 2021, and U.S. Provisional Application No. 63 / 252,434, filed October 5, 2021, the entire disclosures of which are incorporated herein by reference.

[0002] Technical Field FIELD OF THE DISCLOSURE The present disclosure relates to electrode assemblies, such as electrode assemblies for intravascular blood pumps. [Background technology]

[0003] background Intravascular blood pumps can be introduced surgically or percutaneously into a patient and used to deliver blood from one location in the heart or circulatory system to another location in the heart or circulatory system. For example, when deployed in the left heart, an intravascular blood pump can pump blood from the left ventricle of the heart to the aorta. Similarly, when deployed in the right heart, an intravascular blood pump can pump blood from the inferior vena cava to the pulmonary artery. Intravascular blood pumps can be driven by a motor located outside the patient's body via an elongated drive shaft or by an internal motor located inside the patient's body. Some intravascular blood pumps can operate in parallel with the patient's own heart to supplement cardiac output and partially or completely relieve the heart's components of their workload. Summary of the Invention

[0004] Quick Overview The present technology relates to electrode assemblies configured for conductance and admittance measurements, and methods of manufacturing the same. In that regard, the present technology describes electrode assemblies adapted for use with intravascular blood pumps and other devices in which real-time ventricular volume measurements may be relevant.

[0005] In one aspect, an electrode assembly patch attachable to an intravascular device comprises: a strip extending from a proximal end to a distal end; a first electrode tab extending outwardly away from the strip, the first electrode tab configured to supply a current to the surrounding fluid; a second electrode tab spaced from the first electrode tab, the second electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a third electrode tab spaced from the second electrode tab, the third electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a fourth electrode tab spaced from the third tab, the fourth electrode tab extending outwardly away from the strip and configured to supply a current to the surrounding fluid; Equipped with.

[0006] In one embodiment, the first, second, third, and fourth electrode tabs extend outwardly away from the first side of the strip in a first direction.

[0007] In one aspect, the electrode assembly patch further comprises a first stabilizing tab extending outwardly away from the second side of the strip in a second direction opposite the first direction, and a second stabilizing tab spaced apart from the first stabilizing tab and extending outwardly away from the strip in the second direction.

[0008] In one aspect, the electrode assembly may further include a first non-conductive tab extending outwardly away from the strip and a second non-conductive tab extending outwardly away from the strip.

[0009] The first and second non-conductive tabs may be configured to ensure separation and / or proper alignment of the electrode tabs (when encased within the intravascular device).

[0010] Additionally or alternatively, the first and second non-conductive tabs may be configured to enhance adhesion of the electrode assembly patch and may be further configured to stabilize the electrode assembly patch when affixed to a portion of an intravascular blood pump or other device.

[0011] The first and second non-conductive tabs may be non-conductive stabilizer tabs.

[0012] In one embodiment, the first stabilizing tab is positioned laterally between the first electrode tab and the second electrode tab.

[0013] In one embodiment, the second stabilizing tab is positioned laterally between the third and fourth electrode tabs.

[0014] The second side may be opposite the first side.

[0015] In one aspect, the electrode assembly patch is configured to be flexible.

[0016] The electrode assembly patch may have a sandwich configuration.

[0017] The electrode assembly patch may include more than one layer, for example, the electrode patch may include four layers.

[0018] The electrode assembly patch may have a multi-layer construction.

[0019] The layers of the electrode patch assembly may be fused or welded together, for example by thermoforming, or may be glued together.

[0020] The electrode assembly patch may include a base layer, for example a non-conductive base layer.

[0021] The electrode assembly patch may include one or more non-conductive layers and one or more conductive layers.

[0022] The base layer may be a non-conductive layer.

[0023] The electrode assembly may include an outer layer.

[0024] The outer layer of the electrode assembly patch may include one or more exposed electrodes.

[0025] In one aspect, the electrode assembly patch is configured to have a two-dimensional configuration in the undeployed state, and the electrode assembly patch is further configured to have a three-dimensional configuration in the deployed state.

[0026] For example, the electrode assembly patch can be wrapped or rolled into a three-dimensional configuration.

[0027] In one embodiment, each of the first, second, third, and fourth electrode tabs includes an electrode extending within the tab.

[0028] In one embodiment, the electrodes comprise one or both of gold or platinum.

[0029] In one embodiment, the second tab is spaced a first distance from the first tab, the third tab is spaced a second distance from the second tab, and the fourth tab is spaced a first distance from the third tab.

[0030] In one embodiment, the second distance is greater than the first and third distances.

[0031] In one embodiment, each of the first, second, third, and fourth electrode tabs and each of the first and second stabilization tabs extend perpendicular to the strip.

[0032] In one aspect, the width of the first stabilizing tab is less than or equal to the first lateral distance between the first and second electrode tabs, and the width of the second stabilizing tab is less than or equal to the second lateral distance between the third and fourth electrode tabs.

[0033] In one embodiment, the electrode assembly patch comprises four layers, each layer having a thickness of 5 μm.

[0034] In one aspect, a system for determining admittance or conductance comprises: an intravascular device configured to be inserted into a patient's heart; a flexible electrode assembly patch attached to at least a portion of the intravascular device, the flexible electrode assembly patch including two or more electrodes configured to determine admittance and / or conductance; Equipped with.

[0035] In one aspect, the flexible electrode assembly patch comprises: a strip extending from a proximal end to a distal end; a first electrode tab extending outwardly away from the strip, the first electrode tab configured to supply a current to the surrounding fluid; a second electrode tab spaced from the first electrode tab, the second electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a third electrode tab spaced from the second electrode tab, the third electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a fourth electrode tab spaced from the third tab, the fourth electrode tab extending outwardly away from the strip and configured to supply a current to the surrounding fluid; Includes.

[0036] In one embodiment, the first, second, third, and fourth electrode tabs extend outwardly away from the first side of the strip in a first direction.

[0037] In one aspect, the system further includes a first stabilizing tab extending outwardly away from the second side of the strip in a second direction opposite the first direction, and a second stabilizing tab spaced apart from the first stabilizing tab and extending outwardly away from the strip in the second direction.

[0038] In one aspect, the flexible electrode assembly patch includes a strip having a proximal end and a distal end.

[0039] In one aspect, the system further comprises a controller electrically connected to the electrode assembly patch, the controller comprising: a current source; Memory and coupled to the memory, and supplying an alternating current to the electrodes of the first electrode tab and the fourth electrode tab; measuring the voltage across the electrodes of the second electrode tab and the third electrode tab; and Determine the admittance or conductance based on the measured voltages on the second and third tabs one or more processors configured to Equipped with.

[0040] In one aspect, a system for determining admittance or conductance comprises an intravascular device configured to be inserted into a patient's heart; and an electrode assembly patch attached to at least a portion of the intravascular device; The electrode assembly patch is a first non-conductive layer configured to adhere to a portion of an intravascular device; a second layer having one or more wires; a third non-conductive layer configured to electrically insulate the one or more wires; and a fourth layer including one or more electrodes. The multilayer structure includes:

[0041] In one aspect, the first non-conductive layer can be formed from a polymeric material configured to be adhered, bonded, and / or thermoformed to a portion of the intravascular device.

[0042] In one embodiment, each of the one or more wires is separated by a non-conductive material.

[0043] In one embodiment, the wire or wires are formed from an electrically conductive material.

[0044] In one embodiment, the conductive material comprises platinum, gold, silver, and / or copper.

[0045] In one embodiment, one or more electrodes in the fourth layer are at least partially exposed.

[0046] In one embodiment, the multi-layer structure comprises four sandwich layers.

[0047] In one embodiment, the layers are glued, bonded, and / or thermoformed together.

[0048] In one aspect, the electrode assembly patch comprises: a strip extending from a proximal end to a distal end; a first electrode tab extending outwardly away from the strip, the first electrode tab configured to supply a current to the surrounding fluid; a second electrode tab spaced from the first electrode tab, the second electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a third electrode tab spaced from the second electrode tab, the third electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a fourth electrode tab spaced from the third tab, the fourth electrode tab extending outwardly away from the strip and configured to supply a current to the surrounding fluid; Includes.

[0049] In one embodiment, the first, second, third, and fourth electrode tabs extend outwardly away from the first side of the strip in a first direction.

[0050] In one aspect, the system further includes a first stabilizing tab extending outwardly away from the second side of the strip in a second direction opposite the first direction, and a second stabilizing tab spaced apart from the first stabilizing tab and extending outwardly away from the strip in the second direction.

[0051] In one aspect, the electrode assembly patch includes a strip having a proximal end and a distal end.

[0052] In one aspect, the system further comprises a controller electrically connected to the electrode assembly patch, the controller comprising: a current source; Memory and coupled to the memory, and supplying an alternating current to the electrodes of the first electrode tab and the fourth electrode tab; measuring the voltage across the electrodes of the second electrode tab and the third electrode tab; and Determine the admittance or conductance based on the measured voltages on the second and third tabs one or more processors configured to Equipped with.

[0053] In one aspect, a method of forming a system for determining admittance or conductance includes wrapping and / or enveloping a flexible electrode assembly patch around at least a portion of an intravascular device configured to be inserted into a patient's heart; and attaching the flexible electrode assembly patch to the portion of the intravascular device.

[0054] For example, the cannula of an intravascular blood pump can be formed at least in part by the electrode assembly patch.

[0055] For example, the cannula may be at least partially formed by wrapping and / or enveloping the electrode assembly patch.

[0056] The cannula may include a support structure, and the electrode assembly patch may be wrapped around and / or encase the support structure.

[0057] The support structure may comprise one or more strands or coils of a shape memory material such as Nitinol.

[0058] The electrode assembly patch may form a fluid-tight outer shell for the cannula.

[0059] In one aspect, the attaching step includes thermoforming the flexible electrode assembly patch onto a portion of the intravascular device.

[0060] In one aspect, the flexible electrode assembly patch comprises a multi-layer structure.

[0061] In one aspect, the flexible electrode assembly patch comprises: a strip extending from a proximal end to a distal end; a first electrode tab extending outwardly away from the strip, the first electrode tab configured to supply a current to the surrounding fluid; a second electrode tab spaced from the first electrode tab, the second electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a third electrode tab spaced from the second electrode tab, the third electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a fourth electrode tab spaced from the third tab, the fourth electrode tab extending outwardly away from the strip and configured to supply a current to the surrounding fluid; Includes.

[0062] In one embodiment, the first, second, third, and fourth electrode tabs extend outwardly away from the first side of the strip in a first direction.

[0063] In one aspect, the flexible electrode assembly patch further comprises a first stabilizing tab extending outwardly away from the second side of the strip in a second direction opposite the first direction, and a second stabilizing tab spaced apart from the first stabilizing tab and extending outwardly away from the strip in the second direction.

[0064] In one aspect, the flexible electrode assembly patch comprises a two-dimensional configuration before the flexible electrode assembly patch is wrapped around and / or envelops the intravascular device. [Brief explanation of the drawings]

[0065] [Figure 1] FIG. 1 illustrates a schematic perspective view of an exemplary intravascular blood pump configured for left ventricular assist, according to aspects of the present disclosure. [Figure 2] FIG. 2 illustrates a schematic perspective view of an exemplary intravascular blood pump configured for right ventricular assist, according to aspects of the present disclosure. [Figure 3] FIG. 3 is a functional block diagram of an exemplary system according to an aspect of the present disclosure. [Figure 4A] FIG. 4A shows a schematic top view of an exemplary electrode assembly patch according to aspects of the present disclosure. [Figure 4B] FIG. 4B illustrates selected dimensions of the electrode assembly patch of FIG. 4A according to aspects of the present disclosure. [Figure 4C] FIG. 4C shows a schematic cross-sectional view of the electrode assembly patch of FIG. 4A along line XX, according to an aspect of the present disclosure. [Figure 4D] FIG. 4D shows a schematic cross-sectional view of the electrode assembly patch of FIG. 4A along line YY, according to an aspect of the present disclosure. [Figure 4E] 4B shows a schematic cross-sectional top view of the electrode assembly patch of FIG. 4A attached to the cannula of an intravascular pump. [Figure 5] 4B shows a schematic perspective view of an exemplary application of the electrode assembly patch of FIG. 4A to a portion of the exemplary intravascular blood pump of FIG. 1 according to aspects of the present disclosure. [Figure 6A]FIG. 6A shows a schematic top view of an exemplary electrode assembly patch according to aspects of the present disclosure. [Figure 6B] FIG. 6B illustrates selected dimensions of the electrode assembly patch of FIG. 6A according to aspects of the present disclosure. [Figure 7A] FIG. 7A shows a schematic top view of an exemplary electrode assembly patch according to aspects of the present disclosure. [Figure 7B] FIG. 7B illustrates selected dimensions of the electrode assembly patch of FIG. 7A according to aspects of the present disclosure. [Figure 8] FIG. 8 shows a schematic top view of an exemplary electrode assembly patch according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0066] Detailed Description Aspects of the present disclosure will be described in detail with reference to the figures, in which like numerals identify similar or identical elements. It should be understood that the disclosed aspects are merely examples of the present disclosure and may be embodied in various forms. To avoid obscuring the present disclosure in unnecessary detail, well-known functions or structures have not been described in detail. Therefore, specific structural and functional details disclosed herein should not be construed as limiting, but merely as a basis for the claims and as a representative basis for teaching those skilled in the art how to variously use the present disclosure in substantially any appropriately detailed structure.

[0067] Specific illustrative examples will be described to provide a general understanding of the systems, methods, and devices described herein. While various examples may be used to describe intravascular blood pumps, it will be understood that the improvements of the present technology may also be adapted and applied to other types of medical devices, such as electrophysiology study and catheter ablation devices, angioplasty and stent placement devices, angiography catheters, peripherally inserted central venous catheters, central venous catheters, midline catheters, peripheral catheters, inferior vena cava filters, abdominal aortic aneurysm treatment devices, thrombectomy devices, TAVR delivery systems, cardiac therapy and cardiac assist devices including balloon pumps, cardiac assist devices implanted using surgical incisions, and any other venous or arterial-based introducer catheters and devices. As is known, intravascular blood pumps can be surgically or percutaneously introduced into a patient to deliver blood from one location in the heart or circulatory system to another location in the heart or circulatory system. For example, when deployed in the left heart, an intravascular blood pump can pump blood from the left ventricle of the heart to the aorta. When deployed in the right heart, an intravascular blood pump can pump blood from the inferior vena cava to the pulmonary artery.

[0068] The inventors have recognized the advantages of allowing such an intravascular blood pump to perform continuous measurements while the pump is operating. Benefits may be realized, for example, by determining ventricular volume while the intravascular pump or other device remains within the patient's heart. In some cases, ventricular volume may be used to improve the functionality of intravascular blood pumps and other devices. Ventricular volume may also be used to assess cardiac function and cardiac unloading.

[0069] According to aspects described herein, ventricular volume can be determined using conductance or admittance methods. Such real-time ventricular volume measurements can then be used to generate pressure-volume loops from which cardiac function and levels of cardiac unloading can be assessed. In some aspects, ventricular volume can be assessed without the need to insert a dedicated conductance or admittance catheter.

[0070] In view of the above, the inventors have recognized the advantages of an electrode assembly patch (also referred to herein as a "patch") attached or attachable to an intravascular blood pump, for example, to the cannula of such a pump, for measuring ventricular volume. As will be appreciated, while shown and described as being attachable to an intravascular blood pump, such an electrode assembly patch may in other aspects be attachable to other suitable medical devices, such as a portion of a catheter device. As will be further appreciated, while shown and described for measuring ventricular volume, the electrode assembly patch may be configured to measure other suitable parameters. Alternatively, the electrode assembly patch may be configured for tissue ablation. For example, such an electrode assembly patch may be attached or attachable to a catheter ablation device.

[0071] As described herein, the electrode assembly patch can be configured to maintain proper alignment and separation of one or more electrodes thereon. For example, in some embodiments, the electrode assembly patch may include one or more internal electrodes for measuring voltage and one or more external electrodes configured to induce current (one of the electrodes is used as a ground). In such embodiments, the electrode assembly patch may allow the distance between the internal electrodes to be maintained fixed relative to one another, and maintained at a predetermined distance as large as possible. In some embodiments, the electrode assembly patch may also allow the distance between the internal and external electrodes to be fixed relative to one another. In some embodiments, the electrode assembly patch may allow the electrodes to be arranged in a series configuration. The electrode assembly patch may also be configured so that it does not completely surround the device (e.g., does not include a ring shape) when applied to the device.

[0072] In some embodiments, the electrode assembly patch comprises a flexible structure. For example, as disclosed herein, the electrode assembly patch may be wrapped around, folded (e.g., spirally wrapped), or otherwise positioned around the exterior of the device (e.g., cannula) to mount the electrode assembly patch on the device. In such embodiments, the electrode assembly patch may have a two-dimensional configuration when in the undeployed state and a three-dimensional configuration while in the deployed state.

[0073] In some embodiments, the electrode assembly patch may include a multi-layer structure. In such embodiments, the electrode assembly patch may allow wiring to be fully encased and routed through the multi-layer structure to a desired location on the device (e.g., to an outflow cage). In such embodiments, at least a portion of the electrode may be exposed. In some embodiments, the electrode assembly patch may also include a non-conductive layer.

[0074] In some embodiments, the electrode assembly patch is configured with a low profile such that there is little or no change in the outer diameter of the device (e.g., cannula) after attachment of the electrode assembly patch. In such embodiments, the low profile configuration may result in little or no change in the overall profile and functionality of the device.

[0075] In some aspects, the electrode assembly patch can be configured for easy application to the device (e.g., to the cannula). For example, as described herein, the electrode assembly patch can be thermoformed, glued, bonded, or otherwise suitably attached to the exterior surface of the device (e.g., to the cannula).

[0076] In some embodiments, the electrode assembly patch can include one or more tabs that allow for proper application of the electrode assembly patch on the device and proper spacing between the electrodes. In some embodiments, the tabs can also provide mechanical stability to the electrode assembly patch while it is attached to the device.

[0077] 1 illustrates an exemplary intravascular blood pump 100 adapted for left ventricular assist in accordance with aspects of the present disclosure. In that regard, intravascular blood pump 100 includes an elongate catheter 102, a motor 104, a cannula 110, a blood inflow cage 114 disposed at or near a distal end 112 of cannula 110, a blood outflow cage 106 disposed at or near a proximal end 108 of cannula 110, and an optional atraumatic extension 116 disposed at the distal end of blood inflow cage 114.

[0078] Motor 104 is configured to rotationally drive an impeller (not shown), thereby generating sufficient suction to draw blood into cannula 110 through blood inflow cage 114 and expel blood from cannula 110 through blood outflow cage 106. In that regard, the impeller may be positioned distal to blood outflow cage 106, for example, within proximal end 108 of cannula 110, or within a pump housing 107 coupled to proximal end 108 of cannula 110. In some aspects of the present technology, rather than the impeller being driven by an internal motor 104, the impeller may instead be coupled to an elongated drive shaft driven by a motor located external to the patient.

[0079] The catheter 102 may house electrical wires coupling the motor 104 to one or more electrical controllers or other sensors. Alternatively, if the impeller is driven by an external motor, an elongated drive shaft may pass through the catheter 102. The catheter 102 may also serve as a conduit for one or more wires (e.g., wire 502 in FIG. 5 , described below) connecting the electrodes described herein to one or more controllers (e.g., as included in controller 302 in FIG. 3 , described below) located outside the patient's body, a power source, or the like. The catheter 102 may also include a purge fluid conduit, a lumen configured to receive a guidewire, or the like.

[0080] Blood inflow cage 114 includes one or more openings or apertures configured to allow blood to be drawn into cannula 110 when motor 104 is operating. Similarly, blood outflow cage 106 includes one or more openings or apertures configured to allow blood to exit intravascular blood pump 100 and out cannula 110. Blood inflow cage 114 and blood outflow cage 106 may be constructed of any suitable biocompatible material(s). For example, blood inflow cage 114 and / or blood outflow cage 106 may be formed from a biocompatible metal such as stainless steel, titanium, or a biocompatible polymer such as polyurethane. Additionally, the surfaces of blood inflow cage 114 and / or blood outflow cage 106 may be treated in various ways, including, but not limited to, etching, texturing, or coating or plating with another material. For example, the surfaces of blood inflow cage 114 and / or blood outflow cage 106 may be laser textured.

[0081] Cannula 110 may include a flexible hose portion. For example, cannula 110 may be at least partially constructed of a polyurethane material. In addition, cannula 110 may include a shape-memory material. For example, cannula 110 may comprise a combination of a polyurethane material and one or more strands or coils of a shape-memory material, such as Nitinol. Cannula 110 may be formed to include one or more bends or curves in its relaxed state, or may be configured to straighten in its relaxed state. In that regard, in the exemplary arrangement shown in FIG. 1 , cannula 110 has a single preformed anatomical bend 118 based on the portion of the left heart in which it is intended to operate. Despite this bend 118, cannula 110 may still be flexible and thus may be able to straighten (e.g., during insertion over a guidewire) or further bend (e.g., in patients with narrower anatomy). Further in that regard, cannula 110 may include a shape memory material configured to allow cannula 110 to assume different shapes (e.g., straight or nearly straight) at room temperature and to form bend 118 when the shape memory material is exposed to the heat of the patient's body.

[0082] The atraumatic extension 116 may assist in stabilizing and positioning the intravascular blood pump 100 in the correct position within the patient's heart. The atraumatic extension 116 may be solid or tubular. If tubular, the atraumatic extension 116 may be configured to allow a guidewire to be threaded therethrough to further assist in positioning the intravascular blood pump 100. The atraumatic extension 116 may be of any suitable size. For example, the atraumatic extension 116 may have an outer diameter in the range of 4 to 8 Fr. The atraumatic extension 116 may be at least partially constructed of a flexible material and may be of any suitable shape or configuration, such as a straight configuration, a partially curved configuration, or a pigtail-shaped configuration as shown in the example of FIG. 1. The atraumatic extension 116 may also have sections with different stiffnesses. For example, the atraumatic extension 116 may include a proximal section that has sufficient stiffness to prevent buckling, thereby holding the blood inflow cage 114 in a desired position, and a distal section that is softer and has lower stiffness, thereby providing an atraumatic tip for contacting the wall of the patient's heart and allowing for guidewire loading. In such cases, the proximal and distal sections of the atraumatic extension 116 may be constructed from different materials or may be constructed from the same material that has been treated to provide different stiffnesses.

[0083] Notwithstanding the above, as previously mentioned, the atraumatic extension 116 is of optional construction. In that regard, the present technology may also be used with intravascular blood pumps and other intracardiac devices that include extensions of different types, shapes, materials, and qualities. Similarly, the present technology may be used with intravascular blood pumps and other intracardiac devices that do not have distal extensions of any kind.

[0084] The intravascular blood pump 100 may be inserted percutaneously. For example, when used for left ventricular assist, the intravascular blood pump 100 may be inserted by catheterization through the femoral or axillary artery into the aorta and across the aortic valve into the left ventricle. When positioned in this manner, the intravascular blood pump 100 can deliver blood from the blood inflow cage 114, which may be placed in the left ventricle, through the cannula 110 to the blood outflow cage 106, which may be placed in the ascending aorta. In some aspects of the present technology, the intravascular blood pump 100 can be configured so that the bent portion 118 abuts a predetermined portion of the patient's heart when the intravascular blood pump 100 is in a desired position. Similarly, the atraumatic extension 116 can be configured to abut a different predetermined portion of the patient's heart when the intravascular blood pump 100 is in a desired position.

[0085] 2 illustrates an exemplary intravascular blood pump 200 adapted for right heart assist in accordance with aspects of the present disclosure. In that regard, intravascular blood pump 200 includes an elongate catheter 202, a motor 204, a cannula 210, a blood inflow cage 214 disposed at or near a proximal end 208 of cannula 210, a blood outflow cage 206 disposed at or near a distal end 212 of cannula 210, and an optional atraumatic extension 216 disposed at the distal end of blood outflow cage 206.

[0086] 1 , motor 204 is configured to rotationally drive an impeller (not shown), thereby generating sufficient suction to draw blood into cannula 210 through blood inflow cage 214 and expel blood from cannula 210 through blood outflow cage 206. In that regard, the impeller may be located distal to blood inflow cage 214, for example, within proximal end 208 of cannula 210, or within pump housing 207 coupled to proximal end 208 of cannula 210. Again, in some aspects of the present technology, rather than the impeller being driven by an internal motor 204, the impeller may instead be coupled to an elongated drive shaft driven by a motor located external to the patient.

[0087] Cannula 210 of FIG. 2 may serve the same purpose and have the same properties and characteristics as described above with respect to cannula 110 of FIG. 1. However, in the exemplary arrangement shown in FIG. 2, cannula 210 has two preformed anatomical bends 218, 220 based on the portion of the right heart in which it is intended to operate. Again, despite the presence of bends 218, 220, cannula 210 may still be flexible and thus may be able to straighten (e.g., during insertion over a guidewire) or bend further (e.g., in patients with narrower anatomical dimensions). Further in that regard, cannula 210 may include a shape-memory material configured to allow cannula 210 to be in different shapes (e.g., straight or nearly straight) at room temperature and form bends 218 and / or 220 when the shape-memory material is exposed to the heat of the patient's body.

[0088] The catheter 202 and atraumatic extension 216 of Figure 2 may serve the same purpose and have the same properties and characteristics as described above with respect to the catheter 102 and atraumatic extension 116 of Figure 1. Similarly, the blood inflow cage 214 and blood outflow cage 206 of Figure 2 are similar to the blood inflow cage 114 and blood outflow cage 106 of Figure 1, except that they are located at opposite ends of the cannula from those of Figure 1, and therefore may have the same properties and characteristics as described above.

[0089] Like the exemplary blood pump of Figure 1, the intravascular blood pump 200 of Figure 2 may also be inserted percutaneously. For example, when used for right heart assist, the intravascular blood pump 200 may be inserted via catheterization through the femoral vein into the inferior vena cava, through the right atrium, across the tricuspid valve, into the right ventricle, and through the pulmonary valve into the pulmonary artery. When positioned in this manner, the intravascular blood pump 200 may deliver blood from a blood inflow cage 214, which may be mounted in the inferior vena cava, through a cannula 210, and to a blood outflow cage 206, which may be mounted in the pulmonary artery.

[0090] As described herein, an intravascular pump or other device may be configured to assess ventricular volume (and thus cardiac function and unloading) while residing within a patient's heart via one or more electrodes through which the intravascular blood pump or other device induces current and one or more electrodes that measure voltage. FIG. 3 is a functional block diagram of an exemplary system according to aspects of the present disclosure. In the example of FIG. 3, system 300 includes an intravascular blood pump 318 and a controller 302. The intravascular blood pump 318 may take any form, including those shown in the exemplary intravascular blood pumps 100 and 200 of FIGS. 1 or 2, respectively. As shown in the example of FIG. 3, the intravascular blood pump 318 of FIG. 3 may include one or more pressure sensors 322 and a motor 324. The intravascular blood pump 318 may include an attached electrode assembly patch 320, such as electrode assembly patches 400, 600, 700, 800 shown in FIGS. 4A, 4B, 6A, 6B, 7A, 7B, and 8.

[0091] As described herein, the electrode assembly patch 320 may include one or more electrodes. For example, as shown in FIG. 4D , the electrode assembly patch 400 may include at least two electrodes configured to supply (e.g., induce) a current (e.g., electrodes 454 a, 454 d of FIG. 4D , electrodes at electrode tabs 606 a, 606 d of FIG. 6 , electrodes at electrode tabs 706 a, 706 d of FIG. 7 , and electrodes 806 a, 806 d of FIG. 8 , as described further below) and at least two electrodes configured to measure a voltage (e.g., electrodes 454 b, 454 c of FIG. 4D , electrodes at electrode tabs 606 b, 606 c of FIG. 6 , electrodes at electrode tabs 706 b, 706 c of FIG. 7 , and electrodes 806 b, 806 c of FIG. 8 , as described further below).

[0092] In some embodiments, the one or more pressure sensors 322 may include any suitable type of pressure sensor or combination of pressure sensors configured to measure pressure at or near the electrodes of the electrode assembly patch 320. Thus, in some aspects of the present technology, the pressure sensor(s) 322 may be a single pressure sensor located at or near the distal end of a cannula (e.g., cannula 110 or 210). Similarly, in some aspects of the present technology, the pressure sensor(s) 322 may be a combination of pressure sensors whose readings may be combined to derive an estimated pressure near the electrode set of the electrode assembly patch 320.

[0093] 3 , the controller 302 may include one or more processors 304 coupled to a memory 306 storing instructions 308 and data 310, a device interface 312 with an intravascular blood pump 318, a current source 314, a power supply 316, and a voltage measurement unit 317. The device interface 312 may be any suitable type of interface between the controller 302 and the intravascular blood pump 318 capable of supplying current to the electrodes of the electrode assembly patch 320 from the current source 314, receiving voltage readings from the electrodes of the electrode assembly patch 320, receiving pressure readings from one or more pressure sensors 322, and providing power to the motor 324 from the power supply 316. The current source 314 may be any device capable of providing a suitable current for making conductance or admittance measurements. For example, the current source 314 may be configured to supply a substantially constant alternating current of 10 μA and 100 μA at 20 kHz. As will be appreciated, in some aspects of the present technology, the current source 314 and the power source 316 may be implemented as a single unit configured to both power the motor 324 and provide appropriate current to the electrodes of the electrode assembly patch 320.

[0094] Controller 302 may take any form. In that regard, controller 302 may comprise a single modular unit or its components may be distributed among two or more physical units. Controller 302 may further include any other components typically used in connection with a computing device, such as a user interface. In that regard, controller 302 may have a user interface that includes one or more user inputs (e.g., buttons, touchscreen, keypad, keyboard, mouse, microphone, etc.), one or more electronic displays (e.g., a monitor having a screen or any other electrical device operative to display information, one or more lights, etc.), one or more speakers, chimes, or other audio output devices, and / or one or more other output devices, such as vibrating, pulsing, or tactile elements.

[0095] The one or more processors 304 and memory 306 described herein may be implemented on any type of computing device(s), including customized hardware or any type of general-purpose computing device. The memory 306 may be of any non-transitory type capable of storing information accessible by the processor(s) 304, such as a hard drive, memory card, optical disk, solid-state drive, tape memory, or similar structure.

[0096] The instructions 308 may include programming configured to receive and process readings from the electrode set 320 and one or more pressure sensors 322 . In that regard, the instructions 308 may include programming necessary to calculate (e.g., using the voltage measurement unit 317) a voltage drop and / or a phase shift between voltage reading electrodes of the electrodes of the electrode assembly patch 320 (e.g., electrodes 454b, 454c of FIG. 4D , electrodes at electrode tabs 606b, 606c of FIG. 6 , electrodes at electrode tabs 706b, 706c of FIG. 7 , and electrodes 806b, 806c of FIG. 8 , as described further below), calculate a conductance or admittance based on readings received from the electrodes of the electrode assembly patch 320 and one or more pressure sensors 322, estimate a ventricular volume based on the conductance or admittance calculation, generate a pressure-volume loop based on the estimated ventricular volume, generate an estimate of cardiac function based on the generated pressure-volume loop, and / or generate an estimate of ventricular unloading provided by operation of the intravascular blood pump 318 based on the generated pressure-volume loop. Controller 302 may be further configured to store readings from electrode set 320 and one or more pressure sensors 322, as well as calculations based on the readings, in memory 306. In some embodiments, controller 302 may also be configured to transmit readings from the electrodes of electrode assembly patch 320 and / or generated estimates of ventricular unloading or cardiac function to an external device, such as, for example, a user interface (not shown) and / or a cloud-based storage device where the readings and / or generated estimates may be stored.

[0097] Data 310 may include any relevant data for operating intravascular blood pump 318. For example, data 310 may include lookup tables and other data related to interpreting signals from intravascular blood pump 318, calibrating and / or interpreting signals of electrodes of electrode assembly patch 320 or one or more pressure sensors 322, etc.

[0098] 4A illustrates an exemplary electrode assembly patch 400 according to aspects of the present disclosure. As shown in FIG. 4D, the exemplary electrode assembly patch 400 is configured as a multi-layered strip 404 extending longitudinally (e.g., in the direction of line YY) from a proximal end 402 to a distal end 410.

[0099] 4A and 4B, the electrode assembly patch 400 may include one or more tabs extending outwardly away from the strip. For example, one or more tabs may extend outwardly away from a first side of the strip in a first direction, and one or more tabs may extend outwardly away from a second, opposite side of the strip in a second, opposite direction. In some embodiments, the tabs may extend to the left and right of the strip.

[0100] As shown in Figures 4A and 4B, in some embodiments, the tabs may be perpendicular to the strip. In other embodiments, one or more tabs may extend at other suitable angles relative to the strip. For example, the tabs may extend ±45 degrees relative to the horizontal axis of the strip. In some embodiments, the tabs may be positioned parallel to one another, as shown in Figures 4A and 4B. As will be appreciated, in other embodiments, one or more tabs may extend in a non-parallel direction relative to another tab (or possibly multiple tabs).

[0101] As shown in FIG. 4A , the tabs labeled 406a, 406b, 406c, and 406d and extending to the right side of strip 404 are electrode tabs. For purposes herein, an electrode tab includes a tab into which an electrode extends at least partially. As described herein, an electrode may induce current in some embodiments and / or measure voltage in other embodiments. In some embodiments, the tabs labeled 408a and 408b and extending to the left side of the strip are non-conductive stabilizer tabs. In some embodiments, the non-conductive stabilizer tabs may be used to ensure separation and / or proper alignment of the electrode tabs (when encased within an intravascular device) as well as to enhance adhesiveness and stability of the electrode assembly patch when affixed to a portion of an intravascular blood pump or other device (e.g., using thermoforming, bonding, adhesive, etc.).

[0102] In some embodiments, as shown in FIG. 4E, when attached to an intravascular device, the electrode tabs (e.g., electrode tab 406a in FIG. 4E) are configured to encircle only a portion of the intravascular device 470. That is, in such embodiments, the electrode tabs do not encircle the entire circumference of the device. In other words, in such embodiments, the electrodes of the electrode assembly patch do not form a closed loop (e.g., the distal end of the electrode tab is spaced from the adjacent portion of the strip) when the electrode assembly patch is attached to the device.

[0103] 4A shows all electrode tabs extending to the right side of strip 404 and all stabilizer tabs extending to the left side of strip 404, it will be understood that any suitable arrangement may be used. For example, in some aspects of the present technology, the orientation of each tab may be reversed from that shown in FIG. 4A. Similarly, in some aspects of the present technology, tabs labeled 406a, 406b, and 408b may each extend to the left side of strip 404, and tabs labeled 408a, 406c, and 406d may each extend to the right side of strip 404.

[0104] 4A shows an electrode assembly patch having both electrode tabs and stabilizer tabs, in other embodiments, the electrode assembly patch may include only electrode tabs. As will be appreciated, in such examples, the electrode tabs may have any suitable arrangement relative to the strips.

[0105] As shown in FIG. 4A , strip 404 may have a tapered section at or near proximal end 402. In such embodiments, strip 404 may be wider at or near proximal end 402 than at distal end 410 (or another suitable portion of the strip). In some embodiments, the wider portion at or near proximal end 402 may be used to weld or bond an external wire (e.g., wire 504 in FIG. 5 ) to contacts (e.g., contacts 462a-462d in FIG. 5 ) located at or near proximal end 402. If one or more wires are welded to each contact, an additional layer of non-conductive material may be applied on top of the weld to electrically insulate the exposed wires and / or weld from the surrounding fluid.

[0106] 4A is shown with four electrode tabs, in some aspects of the present technology, the electrode assembly patch 400 may be implemented with additional or fewer electrode tabs (e.g., so that the total number of electrode tabs is 2, 6, 8, 10, 12, etc.). Additionally, although the exemplary electrode assembly patch 400 is shown in FIGS. 4C and 4D as having four layers, any other number of layers and conductor arrangements may be used.

[0107] It will be appreciated that the exemplary electrode assembly patch 400 of FIG. 4A may be adapted to any suitable intravascular blood pump, and its dimensions may be customized for whatever device the electrode assembly patch 400 is attached to. In that regard, FIG. 4B shows a copy of the exemplary electrode assembly patch 400 of FIG. 4A annotated to indicate various features and dimensions that may be modified to adapt the assembly to different intravascular blood pumps or other devices. For illustrative purposes, each of the features and dimensions shown in FIG. 4B is described below using the assumption that the electrode assembly patch will be affixed (e.g., thermoformed, glued, adhesive, etc.) to the exterior surface of a cannula (e.g., cannula 110 of FIG. 1) of an intravascular blood pump. It is further assumed that the cannula has a length of at least 70 mm and a diameter of approximately 14 Fr (4.67 mm). While FIGS. 4A and 4B show the same exemplary electrode assembly patch 400, for clarity, elements identified in FIG. 4A are not re-identified in FIG. 4B.

[0108] Using the above assumptions, the electrode assembly patch 400 of Figure 4B may have an overall length 428 of 70 mm. The proximal end 402 of the strip 404 may have a contact patch having a width 420 of 6 mm and a length 422 of 2.5 mm, then tapering to a width 442 of 3 mm. The tapered section may have a length 424 of 2.5 mm and a taper angle 426 of approximately 149°.

[0109] The four electrode tabs may each have a width 446 of 3 mm and may be arranged such that the first and second tabs (406a and 406b in FIG. 4A ) and the third and fourth tabs (406c and 406d in FIG. 4A ) are separated by a distance 436 of 3 mm, and the second and third tabs (406b and 406c in FIG. 4A ) are separated by a distance 430 of 10 mm. Thus, the set of four electrode tabs may span a total length 432 of 28 mm. In some aspects of the present technology, it may be desirable to maximize the distance 430 between the second and third tabs (406b and 406c in FIG. 4A ). Thus, if the dimensions of the intravascular blood pump and / or the patient's anatomy allow for increasing the distance 430, it may be advantageous to do so, provided all four electrode tabs can still fit within the volume to be measured (e.g., the patient's left ventricle).

[0110] The length 444 of each electrode tab can be configured so that when the tabs wrap around the outside of the cannula, the end of each tab approaches but does not overlap the left edge of the strip. In that regard, if a 14 Fr diameter cannula has a circumference of approximately 14.66 mm and the strip has a width 442 of 3 mm, each electrode tab can have a length 444 of 11.5 mm so that a gap of approximately 0.16 mm remains when the tabs wrap around the cannula. It will be appreciated that avoiding overlap is not essential to the present technology but may provide advantages in certain cases. For example, if the electrode assembly patch 400 is thermoformed to a portion of an intravascular blood pump, overlap could cause the end of the electrode tab to melt with a portion of the strip, which could create a short circuit between an electrode (e.g., electrode 454a in FIG. 4C ) and one of the conductors for another electrode (e.g., wires 456b, 456c, or 456d in FIG. 4C ). Similarly, the material of the electrode assembly patch 400 may not adhere to itself strongly enough to adhere to the cannula (or whatever other part of the intravascular blood pump it may be affixed to), so overlaps may create weak areas where tabs may begin to peel and delaminate. Additionally, avoiding overlaps may be desirable to minimize the overall diameter of the intravascular blood pump and / or to achieve a smoother outer profile when the electrode assembly patch 400 is affixed to the surface of the intravascular blood pump.

[0111] In the example of FIGS. 4A and 4B, the first stabilizer tab (408a in FIG. 4A) is positioned to fit between the distal ends of the first and second electrode tabs (406a and 406b in FIG. 4A) when the electrode assembly patch 400 is encased around an intravascular blood pump, and the second stabilizer tab (408b in FIG. 4A) is positioned to fit between the distal ends of the third and fourth electrode tabs (406c and 406d in FIG. 4A). Thus, in this example, the length 440 of each stabilizer tab may be 5 mm, and the width 434 may be 2.5 mm. Using a width 434 of 2.5 mm allows for a 0.25 mm space to be left between the edge of each stabilizer tab and its two adjacent electrode tabs. Again, leaving a space between the edge of the stabilizer tab and its adjacent electrode tab can be advantageous to prevent overlaps during manufacturing that could adversely affect the overall diameter and / or smoothness of the outer profile or create weak spots in the bond between the electrode assembly patch 400 and the cannula.

[0112] While each of the electrode tabs is shown in FIG. 4A as having the same width and length, it will be understood that the width and / or length of the tabs may vary from tab to tab (or among subsets of tabs). Similarly, while each of the stabilizer tabs is shown in FIG. 4A as having the same width and length, it will be understood that the width and / or length of the tabs may vary from tab to tab. Also, while each of the electrodes and each of the stabilizer tabs are shown as having a uniform width, in other embodiments, one or more tabs may have a width that varies between the proximal and distal ends (see, e.g., the electrode tabs in FIG. 6A). For purposes of this specification, the proximal end of a tab is the end of the tab closest to the strip.

[0113] Figures 4C and 4D show exemplary cross-sectional views of the electrode assembly patch of Figure 4A according to aspects of the present disclosure. More specifically, Figure 4C shows an exemplary cross-sectional view of the electrode assembly patch of Figure 4A along line XX, thereby showing a transverse cross-section extending from the left edge 450 of the strip 404 to the right edge 452 of the electrode tab 406a. Figure 4D shows an exemplary cross-sectional view of the electrode assembly patch of Figure 4A along line YY, thereby showing a longitudinal cross-section extending from the proximal end 402 to the distal end 410 of the electrode assembly patch of Figure 4A.

[0114] As shown in the example of FIG. 4C, the electrode assembly patch can include four sandwich layers (labeled 1-4 in FIGS. 4C and 4D). Layer 1 can be a non-conductive (dielectric) layer configured to adhere to a specific portion of an intravascular blood pump (or other device) and electrically insulate the second layer from whatever surface the electrode assembly patch is affixed to. For example, if the electrode assembly patch is to be affixed to a flexible cannula (e.g., cannula 110 in FIG. 1) of an intravascular blood pump (e.g., intravascular blood pump 100 in FIG. 1), layer 1 can be made from a polymer (e.g., polyamide film) suitable for adhering, bonding, or thermoforming to the cannula.

[0115] Layer 2 may include wires 456a-456d, each passing between a contact patch (e.g., contact patch 462a) near the proximal end 402 of the electrode assembly patch and a respective electrode (454a-454d). Wires 456a-456d may be formed from any suitable metal or other conductive material, such as platinum, gold, silver, copper, etc. As shown in FIG. 4C , each of wires 456a-456d may be spaced and separated by a non-conductive material (all white portions on layers 1-4 represent non-conductive material). In addition, a non-conductive material may also be used to fill the space between wire 456d and the left edge 450 of strip 404 and between 456a and the right edge of strip 404, so that wire 456a and wire 456d also remain insulated from the surrounding fluid.

[0116] In some aspects of the present technology, one or more of the portions of non-conductive material in Layer 2 may result from the insertion of a non-conductive strip prior to fusing the layers of the electrode assembly patch together (e.g., using thermoforming). Similarly, in some aspects of the present technology, when the layers of the electrode assembly patch are fused together using thermoforming, one or more of the portions of non-conductive material in Layer 2 may result from non-conductive material melting and flowing into Layer 2 from one or more adjacent layers (e.g., Layer 1 or Layer 3) during thermoforming. Again, the non-conductive material may be a polymer (e.g., polyamide) or other suitable non-conductive material, including any of the non-conductive materials used in the other layers.

[0117] Layer 3 may be another non-conductive layer configured to electrically insulate wires 456a-456d from layer 4, except that a conductive bridge is provided to connect a given one of the wires (e.g., wire 456a) to its respective contact patch (e.g., contact patch 462a) or its respective electrode (e.g., electrode 454a). For example, as shown in FIGS. 4C and 4D, a portion of layer 3 near electrode tab 406a is provided with conductive bridge 458a to electrically connect wire 456a to electrode 454a. Similarly, as shown in FIG. 4D, a portion of layer 3 near proximal end 402 is provided with conductive bridge 460a to electrically connect wire 456a to contact patch 462a. Again, the conductive bridges (e.g., 458a, 460a) may be formed from any suitable metal or other conductive material, such as platinum, gold, silver, copper, etc.

[0118] As noted above, one or more of the portions of non-conductive material in layer 3 may result from the insertion of a non-conductive strip prior to fusing the layers of the electrode assembly patch together (e.g., using thermoforming). Similarly, in some aspects of the present technology, when the layers of the electrode assembly patch are fused together using thermoforming, one or more of the portions of non-conductive material in layer 3 may result from non-conductive material melting and flowing into layer 3 from one or more adjacent layers (e.g., layer 2 or layer 4) during thermoforming. Again, the non-conductive material of layer 3 may be a polymer (e.g., polyamide) or other suitable non-conductive material, including any of the non-conductive materials used in the other layers.

[0119] Layer 4 may include electrodes 454a-454d, each of which may be positioned to coincide with a corresponding electrode tab (406a-406d). As shown in FIG. 4D, each of electrodes 454a-454d may be spaced apart and separated by non-conductive material. Similarly, FIG. 4C shows a small amount of non-conductive material between the left end of electrode 454a and the left edge 450 of strip 404, and another small amount of non-conductive material between the right end of electrode 454a and the right edge 452 of electrode tab 406a. However, in some aspects of the present technology, electrode 454a may run the entire length from the left edge 450 of strip 404 to the right edge 452 of electrode tab 406a.

[0120] The top surface of each electrode 454a-454d may be exposed so that it can be used to supply current to or sense voltage from the surrounding fluid (e.g., blood in the left ventricle of a patient). Again, any suitable metal or other conductive material may be used for electrodes 454a-454d, such as platinum, gold, silver, copper, etc. Additionally, electrodes 454a-454d may include a combination of conductive materials. For example, in some aspects of the present technology, electrodes 454a-454d may be formed from gold and then coated or plated with a thin (e.g., 100 nm) top layer of platinum.

[0121] As noted above, one or more of the portions of non-conductive material in layer 4 may result from the insertion of a non-conductive strip prior to fusing the layers of the electrode assembly patch together (e.g., using thermoforming). Similarly, in some aspects of the present technology, when the layers of the electrode assembly patch are fused together using thermoforming, one or more of the portions of non-conductive material in layer 4 may result from non-conductive material melting and flowing into layer 4 from an adjacent layer (e.g., layer 3) during thermoforming. Again, the non-conductive material of layer 4 may be a polymer (e.g., polyamide) or other suitable non-conductive material, including any of the non-conductive materials used in the other layers.

[0122] Each of layers 1-4 may be of any suitable thickness. For example, in some aspects of the present technology, each layer may have a thickness of 5 μm, such that the electrode assembly patch may have a total thickness of 20 μm. Similarly, in some aspects of the present technology, each layer may have a thickness of 1-10 μm. However, while FIGS. 4C and 4D show layers of equal thickness, in some aspects of the present technology, one or more of the layers may have a different thickness than the other layers. Similarly, while the examples in FIGS. 4C and 4D show layers of constant thickness, in some aspects of the present technology, the layer thickness may vary from left to right or proximal to distal. For example, in some aspects of the present technology, layers 1 and 2 may be formed using a first preformed sheet having a conductive film bonded to a non-conductive (dielectric) base that has been etched so that only selected patches of the conductive film remain, and layers 3 and 4 may similarly be formed from a second preformed sheet of similar composition. In such cases, when the two sheets are combined using thermoforming, the non-conductive material from layers 1 and 3 may flow into the adjacent layers 2 and 4, bonding the two sheets together and sealing against any remaining conductive material in layers 2 and 4, resulting in the electrode assembly patch having a slightly different thickness in areas with and without the conductive film.

[0123] Additionally, the thickness and materials of layers 1-4 may be selected to provide suitable material properties for a given application. For example, if the electrode assembly patch is to be attached to a flexible section of an intravascular blood pump, such as a cannula (e.g., cannula 110 in FIG. 1), a relatively thin layer (e.g., 5 μm) may be used for the non-conductive portion, and a relatively flexible material (e.g., polyamide) may be used to allow the entire electrode assembly patch to flex along with the section of the intravascular blood pump to which it is attached.

[0124] FIG. 5 illustrates an exemplary application of the electrode assembly patch of FIG. 4A to a portion of the exemplary blood pump of FIG. 1 in accordance with aspects of the present disclosure. In that regard, FIG. 5 illustrates a wire 502 routed along one of the struts of the blood outflow cage 106 and along the outside of the motor 104, with the wire 502 expanding into individual wires 504, each of which connects to a different one of the contacts 462a-462d. In some aspects of the present technology, the wire 502 may travel within the elongate catheter 102 (not visible in FIG. 5) and exit at a point near the proximal end of the motor 104. As noted above, a coating or layer of non-conductive material may be applied over the contact patches 462a-462d to insulate the contact patches 462a-462d from the surrounding fluid. Similarly, in some aspects of the present technology, a coating or layer of non-conductive material may also be applied over the wire 504. In some aspects of the present technology, the non-conductive material may be a polymer sleeve (eg, a polyamide sleeve) that is thermoformed over the wire 504 and / or contacts 462a-462d.

[0125] As will be appreciated, the electrode assembly patch may be joined to contacts located at other suitable locations on the intravascular pump. For example, in one embodiment, the electrode assembly patch may extend over at least a portion of the outflow cage 106 and into the catheter of the intravascular blood pump. In such an embodiment, the contacts and electrode assembly patch may be positioned within the catheter of the intravascular blood pump for connection.

[0126] In the example of FIG. 5, the electrode assembly patch of FIG. 4A is affixed to a flexible cannula 110. As can be appreciated, the proximal end 402 of the strip 404 may be positioned near the proximal end 108 of the cannula 110, and the distal end 410 of the strip 404 may be positioned near the distal end 112 of the cannula 110. For example, in some embodiments, the distal end may be positioned near an inlet inflow cage (not shown) attached to the distal end of the cannula. Additionally, the electrode tabs 406a-406d are positioned distal to a pre-formed anatomical bend 118 in the cannula 110. In some aspects of the present technology, the intravascular blood pump 100 may be configured such that the anatomical bend 118 is placed at or near the aortic valve. In such a case, by placing the electrode tabs 406a-406d distal to the preformed anatomical bend 118, the electrode tabs 406a-406d can be positioned within the patient's left ventricle when the pump is operating so that they can be used to measure left ventricular volume.

[0127] In some aspects of the present technology, the electrode assembly patch may be configured and / or applied such that the wires 456a-456d in the strip 404 run along the side of the cannula (as opposed to running outside or inside the anatomical bend 118). While the electrode assembly patch may be formed to be thin and flexible (as described above), applying it in this manner may reduce stress on the wires 456a-456d that could lead to breakage and / or reduce the likelihood of the electrode assembly patch delaminating due to bending of the cannula 110.

[0128] The electrode assembly patch may be affixed to the cannula 110 using any suitable bonding, adhesive, thermoforming, or other method. For example, in some aspects of the present technology, the electrode assembly patch of Figures 4A-4D may be formed using one or more polyamides as the non-conductive material and gold as the conductive material (with or without platinum plating on the top surfaces of the electrodes 454a-454d), and may be thermoformed onto the exterior surface of the cannula 110. In such a case, the electrode assembly patch may be placed over the cannula 110, covered with heat shrink tubing, and heated until the polyamide of layer 1 (and potentially some or all of the polyamide on the edges of the other layers) fuses with the material of the cannula 110 (e.g., polyurethane).

[0129] FIG. 6A illustrates another exemplary electrode assembly patch 600 according to aspects of the present disclosure. Again, the exemplary electrode assembly patch 600 may be configured as a multi-layer strip 604, which may have any suitable number and configuration of layers, including configurations based on those described above with respect to FIGS. 4C and 4D . Similar to the example of FIG. 4A , the strip 604 extends longitudinally from a proximal end 602 to a distal end 610, with a series of electrode tabs 606 a, 606 b, 606 c, and 606 d extending vertically to the right side and two stabilizer tabs 608 a, 608 b extending to the left side. In the example of FIG. 6A , the non-conductive stabilizer tabs are not positioned between the electrode tabs when encased around a medical device. In that regard, the stabilizer tabs may function to stabilize and enhance adhesion of the electrode assembly patch when the electrode assembly patch is affixed (e.g., using thermoforming, adhesive, bonding, etc.) to a portion of an intravascular blood pump or other device, but do not function as separator tabs. Similar to FIG. 4A, the strip 604 has a tapered section near its proximal end 602, resulting in the strip 604 having a wider portion at the proximal end 602 that can be used to weld or bond an external wire to a contact located thereon.

[0130] Again, while the example of FIG. 6A shows all of the electrode tabs extending to the right side of strip 604 and all of the stabilizer tabs extending to the left side of strip 604, it will be understood that any suitable arrangement may be used. For example, in some aspects of the present technology, the orientation of each tab may be reversed from that shown in FIG. 6A. Similarly, in some aspects of the present technology, tabs labeled 606a, 606b, and 608b may each extend to the left side of strip 604, and tabs labeled 608a, 606c, and 606d may each extend to the right side of strip 604. Furthermore, while the example electrode assembly patch 600 of FIG. 6A is shown with four electrode tabs, in some aspects of the present technology, electrode assembly patch 600 may be implemented with more or fewer additional electrode tab sets (e.g., so that the total number of electrode tabs is 2, 6, 8, 10, 12, etc.). Again, as above, while the electrode assembly patch is shown with two stabilizer tabs, it will be understood that the electrode assembly patch may include no stabilizer tabs or may have more or fewer tabs, and the location of the tabs along the longitudinal axis of the strip may vary in other embodiments.

[0131] It will be appreciated that the exemplary electrode assembly patch 600 of FIG. 6A may be adapted to any suitable intravascular blood pump, and its dimensions may be customized for whatever device the electrode assembly patch 600 is attached to. In that regard, FIG. 6B shows a copy of the exemplary electrode assembly patch 600 of FIG. 6A annotated to indicate various features and dimensions that may be modified to adapt the assembly to different intravascular blood pumps or other devices. For illustrative purposes, each of the features and dimensions shown in FIG. 6B is described below using the assumption that the electrode assembly patch will be affixed (e.g., thermoformed, glued, adhesive, etc.) to the exterior surface of a cannula (e.g., cannula 110 of FIG. 1) of an intravascular blood pump. It is further assumed that the cannula has a length of at least 55 mm and a diameter of approximately 14 Fr (4.67 mm). While FIGS. 6A and 6B show the same exemplary electrode assembly patch 600, for clarity, elements identified in FIG. 6A are not re-identified in FIG. 6B.

[0132] Using the above assumptions, the electrode assembly patch 600 of Figure 6B may have an overall length 628 of 55 mm. The proximal end of the strip may have a contact patch having a width 620 of 6 mm and a length 622 of 2.5 mm, then tapering to a width 638 of 3 mm. The tapered section may have a length 624 of 2.5 mm and a taper angle 626 of approximately 149°.

[0133] The four electrode tabs may each have a width 642 of 3 mm and may be arranged such that the first and second tabs (606a and 606b in FIG. 6A ) and the third and fourth tabs (606c and 606d in FIG. 6A ) are separated by a distance 644 of 3 mm, and the second and third tabs (606b and 606c in FIG. 6A ) are separated by a distance 632 of 10 mm. Thus, the set of four electrode tabs may span a total length 634 of 28 mm. Again, in some aspects of the present technology, it may be desirable to maximize the distance 632 between the second and third tabs (606b and 606c in FIG. 6A ). Thus, if the dimensions of the pump and / or patient anatomy allow for increasing the distance 632, it may be advantageous to do so, provided all four electrode tabs can still fit within the volume to be measured (e.g., the patient's left ventricle).

[0134] 4B, the length 640 of each electrode tab can be configured so that the end of each tab approaches but does not overlap the left edge of the strip when the tabs wrap around the outside of the cannula. In that regard, assuming a 14 Fr diameter cannula has a circumference of approximately 14.66 mm and the strip has a width 638 of 3 mm, each electrode tab can have a length 640 of 11.5 mm so that a gap of approximately 0.16 mm remains when the tabs wrap around the cannula. Again, as noted above, it will be appreciated that avoiding overlap is not essential to the present technology, but may provide advantages in certain cases.

[0135] In the example of FIGS. 6A and 6B, the first stabilizer tab (608a in FIG. 6A) is positioned proximal to the first electrode tab (606a in FIG. 6A), and the second stabilizer tab (608b in FIG. 6A) is positioned between the second and third electrode tabs (606b and 606c in FIG. 6A) to stabilize and enhance adhesion of the electrode assembly patch in the region between the second and third electrode tabs. The stabilizer tabs in FIGS. 6A and 6B can have a wider range of dimensions than those in FIGS. 4A and 4B because they do not need to fit within the distance 644 between the first and second electrode tabs or the third and fourth electrode tabs. In this example, each stabilizer tab is assumed to have a length 636 of 5 mm and a width 630 of 3 mm.

[0136] As shown in FIGS. 6A and 6B, each of the stabilizer tabs 608a, 608b and each of the electrode tabs 606a-606d have curved sections (e.g., 646) where they join with the strip 604. In some embodiments, rounding the corners in this manner may reduce the likelihood of tearing and / or delamination of the electrode assembly patch at these joints. Any suitable profile may be used for these curved sections. For example, in some aspects of the present technology, the curved sections may have a constant radius (e.g., 1 mm).

[0137] FIG. 7A illustrates a further exemplary electrode assembly patch 700 according to aspects of the present disclosure. Again, the exemplary electrode assembly patch 700 may be configured as a multi-layer strip 704, which may have any suitable number and configuration of layers, including configurations based on those described above with respect to FIGS. 4C and 4D . In the example of FIG. 7A , the strip 704 extends longitudinally from a proximal end 702 to a distal end 708 and has a series of electrode tabs 706 a, 706 b, 706 c, and 706 d, each extending perpendicularly both left and right relative to the strip 704. As above, in other embodiments, the tabs may extend at other suitable angles relative to the strip and each other. As shown in the example of FIG. 7A , the strip 704 may be wider in a section at or near the proximal end of the strip (e.g., proximal to the first electrode strip 706 a), which may be useful for welding or bonding an external wire to a contact patch disposed thereon.

[0138] 4A and 6A, a wider portion of strip 704 at proximal end 702 directly abuts first electrode strip 706a. As a result, exemplary electrode assembly patch 700 can be shorter overall than exemplary electrode assemblies 400 and 600 of FIGS. 4A and 6A, which can be advantageous when the electrode assembly patch needs to be applied to a shorter portion of an intravascular blood pump or other device, such as where wires connected to each contact patch are routed within the lumen or wall of a cannula (e.g., cannula 110 of FIG. 1). In contrast, the exemplary electrode assemblies 400 and 600 of FIGS. 4A and 6A may be advantageous when the electrode tabs (e.g., tabs 406a-406d of FIG. 4A, tabs 606a-606d of FIG. 6A) need to be positioned a greater distance from where the wires connected to each contact patch protrude from the catheter (e.g., catheter 102 of FIG. 1) because the portion of the strip (e.g., strip 404 of FIG. 4A, strip 604 of FIG. 6A) between the proximal end (e.g., proximal end 402 of FIG. 4A, proximal end 602 of FIG. 6A) and the first electrode tab (e.g., electrode tab 406a of FIG. 4A, electrode tab 606a of FIG. 6A) may be thinner, more flexible, more durable, and / or easier to attach to the cannula than if a standard wire (e.g., wire 502) were secured to the cannula (e.g., cannula 110 of FIG. 1).

[0139] 7A shows all of the electrode tabs extending to both the left and right sides of the strip 704, any suitable arrangement may be used. For example, in some aspects of the present technology, all of the tabs may extend only to the right side or only to the left side. Similarly, in some aspects of the present technology, the tabs labeled 706a and 706b may each extend to the right side of the strip 704, and the tabs labeled 706c and 706d may each extend to the left side of the strip 704, or vice versa. Furthermore, while the example electrode assembly patch 700 of FIG. 7A is shown with four electrode tabs, in some aspects of the present technology, the electrode assembly patch 700 may be implemented with more or fewer electrode tab sets (e.g., so that the total number of electrode tabs is 2, 6, 8, 10, 12, etc.).

[0140] It will be appreciated that the exemplary electrode assembly patch 700 of FIG. 7A may be adapted to any suitable intravascular blood pump, and its dimensions may be customized for whatever device the electrode assembly patch 700 is attached to. In that regard, FIG. 7B shows a copy of the exemplary electrode assembly patch 700 of FIG. 7A annotated to indicate various features and dimensions that may be modified to adapt the assembly to different intravascular blood pumps or other devices. For illustrative purposes, each of the features and dimensions shown in FIG. 7B is described below using the assumption that the electrode assembly patch is configured to be affixed (e.g., thermoformed, glued, adhesive, etc.) to the exterior surface of a cannula (e.g., cannula 110 of FIG. 1) of an intravascular blood pump. It is further assumed that the cannula has a length of at least 30 mm and a diameter of approximately 14 Fr (4.67 mm). While FIGS. 7A and 7B show the same exemplary electrode assembly patch 700, for clarity, elements identified in FIG. 7A are not re-identified in FIG. 7B.

[0141] Using the above assumptions, the electrode assembly patch 700 of Figure 7B may have an overall length 730 of 30 mm. The proximal end of the strip may have a contact patch with a width 720 of 4 mm and a length 722 of 2 mm.

[0142] The four electrode tabs may each have a width 726 of 3 mm and may be arranged such that the first and second tabs (706a and 706b in FIG. 7A ) and the third and fourth tabs (706c and 706d in FIG. 7A ) are separated by a distance 724 of 3 mm, and the second and third tabs (706b and 706c in FIG. 7A ) are separated by a distance 728 of 10 mm. Again, in some aspects of the present technology, it may be desirable to maximize the distance 728 between the second and third tabs (706b and 706c in FIG. 7A ). Thus, if the dimensions of the pump and / or patient anatomy allow for increasing the distance 728, it may be advantageous to do so, provided all four electrode tabs can still fit within the volume to be measured (e.g., the patient's left ventricle).

[0143] Each electrode tab may extend a distance 732 of 5.5 mm to the left and right sides of the strip. Again, this distance 732 may be selected so that the ends of each tab are close to one another but do not overlap. In that regard, assuming a cannula having a diameter of 14 Fr has a circumference of approximately 14.66 mm and the strip has a width 734 of 3 mm, each electrode tab may extend a distance 732 of 5.5 mm to the left and right sides so that a gap of approximately 0.66 mm remains when the tabs wrap around the cannula. Again, as noted above, it will be appreciated that avoiding overlap is not essential to the present technology, but may provide advantages in certain cases.

[0144] Although the patch is illustrated and described as having tabs into which the electrodes can extend, it will be understood that the electrode assembly patch may include only a strip with the electrodes extending into different regions of the strip, as shown in FIG. 8 . For example, as shown in FIG. 8 , the electrode assembly patch 800 may include four electrodes (806a-806d). In some embodiments, the strip 804 may have a uniform thickness between the proximal end 802 and the distal end 808 that is greater than the thickness of the strip shown in other exemplary patches (see, e.g., FIGS. 4A and 6A ). As above, the distance between the electrodes may be maintained relative to one another through the electrode assembly patch 800 and may be similar to the distances described above with respect to electrode assembly patches having tabs. The length of the electrodes may also be the same as the electrodes extending into the electrode tabs shown in the exemplary patches above.

[0145] From the foregoing and with reference to the various figures, those skilled in the art will understand that certain modifications can be made to the present disclosure without departing from the scope of the present disclosure. While the figures illustrate certain aspects of the present disclosure, it is not intended to limit the present disclosure thereto, and it is intended that the present disclosure have the same breadth of scope as permitted in the art, and that the specification be read in the same manner. Therefore, the above description should not be construed as limiting, but merely as an illustration of certain aspects of the present technology.

[0146] In some embodiments, the electrode assembly patch may be configured to form at least a portion of a cannula of an intravascular blood pump. For example, in some embodiments, the electrode assembly patch may form the outer layer of the cannula of the intravascular blood pump. In such embodiments, the electrode assembly patch may encase, be wrapped around, or otherwise disposed on a support structure. In one embodiment, the support structure may include one or more strands or coils of a shape memory material such as nitinol. In some embodiments, the cannula may include a multi-layer structure including a polyurethane inner layer, a layer formed from the support structure (e.g., a nitinol coil), and an outer layer formed from the electrode assembly patch. In some embodiments, the non-conductive layer of the electrode assembly patch may also include polyurethane as the non-conductive material.

[0147] Exemplary Implementation As previously mentioned, the techniques described herein may be implemented in a variety of ways, and in that regard, the above disclosure is intended to include, but not be limited to, the systems, methods, and combinations and subcombinations thereof set forth in the following categories of exemplary implementations.

[0148] Category A: A1. a strip extending from a proximal end to a distal end; a first electrode tab extending outwardly away from the strip, the first electrode tab configured to supply a current to a surrounding fluid; a second electrode tab spaced from the first electrode tab, the second electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a third electrode tab spaced from the second electrode tab, the third electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a fourth electrode tab spaced from the third tab, the fourth electrode tab extending outwardly away from the strip and configured to supply a current to the ambient fluid; An electrode assembly patch attachable to an intravascular device, comprising: A2. The electrode assembly patch of A1, wherein the first electrode tab, the second electrode tab, the third electrode tab, and the fourth electrode tab extend outwardly away from the first side of the strip in a first direction. A3. a first stabilizing tab extending outwardly away from the second side of the strip in a second direction opposite the first direction; a second stabilizing tab spaced from the first stabilizing tab and extending outwardly away from the strip in the second direction; and The electrode assembly patch of A2, further comprising: A4. The electrode assembly patch of A3, wherein the first stabilization tab is positioned laterally between the first electrode tab and the second electrode tab. A5. An A4 electrode assembly patch, wherein the second stabilization tab is positioned laterally between the third electrode tab and the fourth electrode tab. A6. An electrode assembly patch of any of A1 to A5 configured to be flexible. A7. The electrode assembly patch of any of A1 to A6, configured to have a two-dimensional configuration in an undeployed state and further configured to have a three-dimensional configuration in an undeployed state. A8. The electrode assembly patch of A1 to A7, wherein each of the first electrode tab, the second electrode tab, the third electrode tab, and the fourth electrode tab includes an electrode extending into the tab. A9. The electrode assembly patch of A8, wherein the electrodes comprise one or both of gold and platinum. A10. The electrode assembly patch of any of A1 to A8, wherein the second tab is spaced apart from the first tab by a first distance, the third tab is spaced apart from the second tab by a second distance, and the fourth tab is spaced apart from the third tab by the first distance. A11. The electrode assembly patch of A10, wherein the second distance is greater than the first distance and the third distance. A12. The electrode assembly patch of any of A3 to A11, wherein each of the first electrode tab, the second electrode tab, the third electrode tab, and the fourth electrode tab, and each of the first stabilizing tab and the second stabilizing tab, extend perpendicular to the strip. A13. The electrode assembly patch of any of A3 to A12, wherein the width of the first stabilizing tab is less than or equal to a first lateral distance between the first electrode tab and the second electrode tab, and the width of the second stabilizing tab is less than or equal to a second lateral distance between the third electrode tab and the fourth electrode tab. A14. The electrode assembly patch of any of A1 to A13, wherein the patch comprises four layers, each layer having a thickness of 5 μm.

[0149] Category B: B15. an intravascular device configured to be inserted into a patient's heart; a flexible electrode assembly patch attached to at least a portion of the intravascular device, the flexible electrode assembly patch including two or more electrodes configured to determine admittance and / or conductance; 1. A system for determining admittance or conductance, comprising: B16. The flexible electrode assembly patch comprises: a strip extending from a proximal end to a distal end; a first electrode tab extending outwardly away from the strip, the first electrode tab configured to supply a current to a surrounding fluid; a second electrode tab spaced from the first electrode tab, the second electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a third electrode tab spaced from the second electrode tab, the third electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a fourth electrode tab spaced from the third tab, the fourth electrode tab extending outwardly away from the strip and configured to supply a current to the ambient fluid; Including the B15 system. B17. The system of B16, wherein the first electrode tab, the second electrode tab, the third electrode tab, and the fourth electrode tab extend outwardly away from a first side of the strip in a first direction. B18. a first stabilizing tab extending outwardly away from the second side of the strip in a second direction opposite the first direction; a second stabilizing tab spaced from the first stabilizing tab and extending outwardly away from the strip in the second direction; and The B17 system also includes: B19. The system of B15-B18, wherein the flexible electrode assembly patch comprises a strip having a proximal end and a distal end. B20. a controller electrically connected to the electrode assembly patch, a current source; Memory and coupled to the memory; and supplying an alternating current to the electrodes of the first electrode tab and the fourth electrode tab; measuring a voltage across the electrodes of the second electrode tab and the third electrode tab; and determining an admittance or conductance based on the measured voltages at the second tab and the third tab; one or more processors configured to a controller Any of the systems B15 to B19 further comprising:

[0150] Category C: C21. an intravascular device configured to be inserted into a patient's heart; and an electrode assembly patch attached to at least a portion of the intravascular device, a first non-conductive layer configured to adhere to the portion of the intravascular device; a second layer having one or more wires; a third non-conductive layer configured to electrically insulate the one or more wires; a fourth layer including one or more electrodes; an electrode assembly patch comprising a multi-layer structure comprising: 1. A system for determining admittance or conductance, comprising: C22. the first non-conductive layer: a polymeric material configured to be adhered, bonded, and / or thermoformed to the portion of the intravascular device; The C21 system can be formed from C23. The system of C21 or C22, wherein each of the one or more wires is separated by a non-conductive material. C24. The system of any of C21 to C23, wherein the one or more wires are formed from a conductive material. C25. The system of C24, wherein the conductive material comprises platinum, gold, silver, and / or copper. C26. The system of any of C21 to C25, wherein the one or more electrodes in the fourth layer are at least partially exposed. C27. Any of the systems of C21 to C26, wherein the multilayer structure comprises four sandwich layers. C28. The system of any of C21 to C27, wherein the layers are glued, bonded, and / or thermoformed together. C29. The electrode assembly patch comprises: a strip extending from a proximal end to a distal end; a first electrode tab extending outwardly away from the strip, the first electrode tab configured to supply a current to a surrounding fluid; a second electrode tab spaced from the first electrode tab, the second electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a third electrode tab spaced from the second electrode tab, the third electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a fourth electrode tab spaced from the third tab, the fourth electrode tab extending outwardly away from the strip and configured to supply a current to the ambient fluid; Any of the systems C21 to C28, including: C30. The system of C29, wherein the first electrode tab, the second electrode tab, the third electrode tab, and the fourth electrode tab extend outwardly away from a first side of the strip in a first direction. C31. a first stabilizing tab extending outwardly away from the second side of the strip in a second direction opposite the first direction; a second stabilizing tab spaced from the first stabilizing tab and extending outwardly away from the strip in the second direction; and The C30 system also includes: C32. The system of any of C31 to C31, wherein the electrode assembly patch includes a strip having a proximal end and a distal end. C33. a controller electrically connected to the electrode assembly patch, a current source; Memory and coupled to the memory; and supplying an alternating current to the electrodes of the first electrode tab and the fourth electrode tab; measuring a voltage across the electrodes of the second electrode tab and the third electrode tab; and determining an admittance or conductance based on the measured voltages at the second tab and the third tab; one or more processors configured to a controller The C16 system also includes:

[0151] Category D: D34. 1. A method of forming a system for determining admittance or conductance, comprising: wrapping and / or encasing a flexible electrode assembly patch around at least a portion of an intravascular device configured to be inserted into a patient's heart; and Attaching the flexible electrode assembly patch to the portion of the intravascular device. A method comprising: D35. The method of D34, wherein the attaching step includes thermoforming the flexible electrode assembly patch to the portion of the intravascular device. D36. The method of D34 or D35, wherein said flexible electrode assembly patch comprises a multi-layer structure. D37. The flexible electrode assembly patch comprises: a strip extending from a proximal end to a distal end; a first electrode tab extending outwardly away from the strip, the first electrode tab configured to supply a current to a surrounding fluid; a second electrode tab spaced from the first electrode tab, the second electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a third electrode tab spaced from the second electrode tab, the third electrode tab extending outwardly away from the strip and configured to measure a voltage in the ambient fluid; a fourth electrode tab spaced from the third tab, the fourth electrode tab extending outwardly away from the strip and configured to supply a current to the ambient fluid; Any of the methods D34 to D36, including: D38. The method of D37, wherein the first electrode tab, the second electrode tab, the third electrode tab, and the fourth electrode tab extend outwardly away from a first side of the strip in a first direction. D39. The flexible electrode assembly patch comprises: a first stabilizing tab extending outwardly away from the second side of the strip in a second direction opposite the first direction; a second stabilizing tab spaced from the first stabilizing tab and extending outwardly away from the strip in the second direction; and The method of D38, further comprising: D40. The method of any of D34-D39, wherein the flexible electrode assembly patch comprises a two-dimensional configuration prior to being wrapped around and / or enveloping the intravascular device.

[0152] Category E: E41. an intravascular blood pump configured to pump blood from a blood inlet to a blood outlet through a cannula; an electrode assembly coupled to at least a portion of the cannula, a strip extending from a proximal end to a distal end; a first tab extending perpendicularly away from the strip, the first tab having an electrode configured to supply a current to the surrounding fluid; a second tab positioned distally of the first tab and extending perpendicularly away from the strip, the second tab configured to measure a voltage in the ambient fluid; a third tab positioned distally of the second tab and extending perpendicularly away from the strip, the third tab configured to measure a voltage in the ambient fluid; a fourth tab positioned distally of the third tab and extending perpendicularly away from the strip, the fourth tab configured to supply an electric current to the ambient fluid; an electrode assembly; a controller electrically connected to the electrode assembly, a current source; Memory and coupled to the memory; and supplying an alternating current to the electrodes of the first tab and the fourth tab; measuring a voltage across the electrodes of the second tab and the third tab; and determining an admittance or conductance based on the measured voltages at the second tab and the third tab; one or more processors configured to a controller An intravascular blood pump system comprising: E42. The system of E41, wherein the second tab is spaced distally from the first tab by a first distance, the third tab is spaced distally from the second tab by a second distance, and the fourth tab is spaced distally from the third tab by the first distance. E43. The electrode assembly a fifth tab positioned distal to the first tab and proximal to the second tab and extending perpendicularly away from the strip in an opposite direction from the first and second tabs; a sixth tab positioned distal to the third tab and proximal to the fourth tab and extending perpendicularly away from the strip in an opposite direction from the third and fourth tabs; and The E42 system also includes: E44. The system of E43, wherein the width of the fifth tab and the width of the sixth tab are configured to be less than or equal to the first distance. E45. The system of E44, wherein the first distance is 3 mm. E46. The system of E45, wherein the width of the fifth tab and the width of the sixth tab are 2.5 mm. E47. The system of E45, wherein the second distance is 10 mm. E48. The electrode assembly a fifth tab positioned proximal to the first tab and extending perpendicularly away from the strip in an opposite direction from the first and second tabs; a sixth tab positioned distal to the second tab and proximal to the third tab and extending perpendicularly away from the strip in an opposite direction from the third and fourth tabs; The E42 system also includes: E49. The system of E48, wherein the first distance is 3 mm. E50. The system of E49, wherein the width of the fifth tab and the width of the sixth tab are 3 mm. E51. The system of E49, wherein the second distance is 10 mm. E52. The system of E41, wherein the electrode assembly is configured to be flexible. E53. The system of E41, wherein the electrodes of the first tab, the second tab, the third tab, and the fourth tab comprise one or both of gold or platinum. E54. The system of E41, wherein the electrode assembly comprises four layers, each layer having a thickness of 5 μm. E55. The system of E41, wherein the current source is configured to provide a substantially constant alternating current of 10 μA and 100 μA at 20 kHz.

[0153] Category F: F56. an intravascular device configured to be inserted into a patient's heart; an electrode assembly coupled to at least a portion of the intravascular device, a strip extending from a proximal end to a distal end; a first tab extending perpendicularly away from the strip, the first tab having an electrode configured to supply a current to the surrounding fluid; a second tab positioned distally of the first tab and extending perpendicularly away from the strip, the second tab configured to measure a voltage in the ambient fluid; a third tab positioned distally of the second tab and extending perpendicularly away from the strip, the third tab configured to measure a voltage in the ambient fluid; a fourth tab positioned distally of the third tab and extending perpendicularly away from the strip, the fourth tab configured to supply an electric current to the ambient fluid; an electrode assembly; a controller electrically connected to the electrode assembly, a current source; Memory and coupled to the memory; and supplying an alternating current to the electrodes of the first tab and the fourth tab; measuring a voltage across the electrodes of the second tab and the third tab; and determining an admittance or conductance based on the measured voltages at the second tab and the third tab; one or more processors configured to a controller 1. A system for determining admittance or conductance, comprising: F57. The system of F56, wherein the second tab is spaced distally from the first tab by a first distance, the third tab is spaced distally from the second tab by a second distance, and the fourth tab is spaced distally from the third tab by the first distance. F58. The electrode assembly a fifth tab positioned distal to the first tab and proximal to the second tab and extending perpendicularly away from the strip in an opposite direction from the first and second tabs; a sixth tab positioned distal to the third tab and proximal to the fourth tab and extending perpendicularly away from the strip in an opposite direction from the third and fourth tabs; and The F57 system also includes: F59. The system of F58, wherein the width of the fifth tab and the width of the sixth tab are configured to be less than or equal to the first distance. F60. The system of F59, wherein the first distance is 3 mm. F61. The system of F60, wherein the width of the fifth tab and the width of the sixth tab are 2.5 mm. F62. The system of F60, wherein the second distance is 10 mm. F63. The electrode assembly a fifth tab positioned proximal to the first tab and extending perpendicularly away from the strip in an opposite direction from the first and second tabs; a sixth tab positioned distal to the second tab and proximal to the third tab and extending perpendicularly away from the strip in an opposite direction from the third and fourth tabs; The F57 system also includes: F64. The system of F63, wherein the first distance is 3 mm. F65. The system of F64, wherein the width of the fifth tab and the width of the sixth tab are 3 mm. F66. The system of F64, wherein the second distance is 10 mm. F67. The system of F56, wherein the electrode assembly is configured to be flexible. F68. The system of F56, wherein the electrodes of the first tab, the second tab, the third tab, and the fourth tab comprise one or both of gold or platinum. F69. The system of F56, wherein the electrode assembly comprises four layers, each layer having a thickness of 5 μm. F70. The system of F56, wherein the current source is configured to provide a substantially constant alternating current of 10 μA and 100 μA at 20 kHz.

Claims

1. an intravascular device (318) configured to be inserted into the patient's heart; and an electrode assembly patch (320, 400, 600, 700, 800) attached to at least a portion of the intravascular device (318), a first non-conductive layer configured to adhere to the portion of the intravascular device; a second layer having one or more wires (456a-456d); a third non-conductive layer configured to electrically insulate the one or more wires (456a-456d); a fourth layer including one or more electrodes (454a-454d); an electrode assembly patch comprising a multi-layer structure comprising:

1. A system (300) for determining admittance or conductance, comprising:

2. the first non-conductive layer comprising: a polymeric material configured to be adhered, bonded, and / or thermoformed to the portion of the intravascular device (318); The system (300) of claim 1, wherein the system (300) can be formed from:

3. The system (300) of claim 1 or 2, wherein each of the one or more wires (456a-456d) is separated by a non-conductive material.

4. The system (300) of any one of claims 1 to 3, wherein the one or more wires (456a-456d) are formed from an electrically conductive material.

5. The system (300) of claim 4, wherein the conductive material comprises platinum, gold, silver, and / or copper.

6. The system (300) of any one of claims 1 to 5, wherein the one or more electrodes (454a-454d) in the fourth layer are at least partially exposed.

7. The system (300) of any one of claims 1 to 6, wherein the multi-layer structure comprises four sandwich layers.

8. The system (300) of any one of claims 1 to 7, wherein the layers are glued, bonded and / or thermoformed together.

9. The electrode assembly patch (320, 400, 600, 700, 800) a strip (404, 604, 704, 804) extending from a proximal end (402, 602, 702, 802) to a distal end (408, 608, 708, 808); a first electrode tab (406 a, 606 a, 706 a, 806 a) extending outwardly away from the strip (404, 604, 704, 804), the first electrode tab (406 a, 606 a, 706 a, 806 a) configured to supply a current to a surrounding fluid; a second electrode tab (406b, 606b, 706b, 806b) spaced apart from the first electrode tab (406a, 606a, 706a, 806a), the second electrode tab (406b, 606b, 706b, 806b) extending outwardly away from the strip (404, 604, 704, 804) and configured to measure a voltage in the ambient fluid; a third electrode tab (406c, 606c, 706c, 806c) spaced from the second electrode tab (406b, 606b, 706b, 806b), the third electrode tab (406c, 606c, 706c, 806c) extending outwardly away from the strip (404, 604, 704, 804) and configured to measure a voltage in the ambient fluid; a fourth electrode tab (406d, 606d, 706d, 806d) spaced apart from the third electrode tab (406c, 606c, 706c, 806c), the fourth electrode tab (406d, 606d, 706d, 806d) extending outwardly away from the strip (404, 604, 704, 804) and configured to supply a current to the surrounding fluid; The system (300) of any one of claims 1 to 8, comprising:

10. 10. The system of claim 9, wherein the first electrode tab, the second electrode tab, the third electrode tab, and the fourth electrode tab extend outwardly away from a first side of the strip in a first direction.

11. a first stabilizing tab (408a, 608a) extending outwardly away from the second side of the strip (404, 604) in a second direction opposite the first direction; a second stabilizing tab (408b, 608b) spaced from the first stabilizing tab (408a, 608a) and extending outwardly away from the strip (404, 604) in the second direction; The system (300) of claim 10, further comprising:

12. 12. The system (300) of claim 11, wherein a width of the first stabilizing tab (408a, 608a) is less than or equal to a first lateral distance between the first electrode tab (406a, 606a) and the second electrode tab (406b, 606b), and a width of the second stabilizing tab (408b, 608b) is less than or equal to a second lateral distance between the third electrode tab (406c, 606c) and the fourth electrode tab (406d, 606d).

13. a controller (302) electrically connected to the electrode assembly patch (320, 400, 600, 700, 800), a current source (314); A memory (302); coupled to the memory (302); and supplying an alternating current to the electrodes (454a-454d) of the first electrode tab (406a) and the fourth electrode tab (406d); measuring the voltage across the second electrode tab (406b) and the third electrode tab (406c); and determining an admittance or conductance based on the measured voltages of the second electrode tab (406b) and the third electrode tab (406c); one or more processors (304) configured to a controller (302) comprising: The system (300) of any one of claims 9 to 12, further comprising:

14. The system (300) of any one of claims 9 to 13, wherein the electrode assembly patch (320, 400, 600, 700, 800) is configured to have a three-dimensional configuration in a deployed state that wraps around and / or encases at least a portion of the intravascular device (318), and is further configured to have a two-dimensional configuration in a non-deployed state that is not in the deployed state.

15. The system (300) of any one of claims 1 to 14, wherein each layer has a thickness of 1 μm to 10 μm.

16. A system (300) described in any one of claims 1 to 15, wherein each layer has a thickness of 5 μm.

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