Patent Publication Number: US-2023149699-A1

Title: Percutaneous circulatory support device including proximal pressure sensor

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to Provisional Application No. 63/279,941, filed Nov. 16, 2021, and Provisional Application No. 63/390,054, filed Jul. 18, 2022, which are herein incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to percutaneous circulatory support systems. More specifically, the disclosure relates to percutaneous circulatory support devices that include one or more pressure sensors. 
     BACKGROUND 
     Percutaneous circulatory support devices can provide transient support for up to approximately several weeks in patients with compromised heart function or cardiac output. Some percutaneous circulatory support devices include one or more pressure sensors for measuring intravascular pressures. Measuring these pressures facilitates, for example, (1) detecting unintended device position changes within the heart, and (2) determining cardiac output, which in turn facilitates evaluation of potential treatment changes. However, devices including pressure sensors have several drawbacks. For example, the pressure sensors can be damaged during deployment. As another example, the sensed pressures may be inaccurate due to the operating speed of the device and other dynamic pressure effects. Accordingly, there is a need for improved devices that include pressure sensors. 
     SUMMARY 
     In an Example 1, a percutaneous circulatory support device comprises a housing; an impeller disposed within the housing, the impeller configured to rotate relative to the housing to cause blood to flow through the housing; a motor operably coupled to the impeller, the motor configured to rotate the impeller relative to the housing; a catheter coupled to the motor; and a pressure sensor coupled to the catheter and disposed proximally relative to the housing. 
     In an Example 2, the percutaneous circulatory support device of Example 1, further comprising a sensor housing comprising an internal chamber, the pressure sensor being disposed within the internal chamber. 
     In an Example 3, the percutaneous circulatory support device of Example 2, wherein the sensor housing comprises an aperture. 
     In an Example 4, the percutaneous circulatory support device of Example 3, wherein the aperture is a distally-facing aperture. 
     In an Example 5, the percutaneous circulatory support device of Example 3, wherein the aperture is a transversely-facing aperture. 
     In an Example 6, the percutaneous circulatory support device of Example 5, wherein the sensor housing further comprises a distally-facing aperture. 
     In an Example 7, the percutaneous circulatory support device of any of Examples 2-6, wherein the sensor housing comprises a ferrule. 
     In an Example 8, the percutaneous circulatory support device of any of Examples 2-7, further comprising an outer jacket securing the sensor housing and the pressure sensor to the catheter. 
     In an Example 9, the percutaneous circulatory support device of any of Examples 2-8, further comprising an adhesive securing the sensor housing and the pressure sensor to the catheter. 
     In an Example 10, the percutaneous circulatory support device of any of Examples 1-9, further comprising: a sensor cable coupled to the pressure sensor; and a cable lumen coupled to the catheter, the sensor cable being disposed in the cable lumen. 
     In an Example 11, the percutaneous circulatory support device of any of Examples 1-10, wherein the pressure sensor comprises one of an optical pressure sensor and an electrical pressure sensor. 
     In an Example 12, a percutaneous circulatory support system comprises: a support device, comprising: a housing; an impeller disposed within the housing, the impeller configured to rotate relative to the housing to cause blood to flow through the housing; a motor operably coupled to the impeller, the motor configured to rotate the impeller relative to the housing; a catheter coupled to the motor; a guidewire lumen coupled to the catheter; a sensing region; a guidewire, comprising: an elongated flexible body; and a pressure sensor coupled to the elongated flexible body; wherein the elongated flexible body is movable within the guidewire lumen to position the pressure sensor in the sensing region. 
     In an Example 13, the percutaneous circulatory support system of Example 12, further comprising a motor cable coupled to the motor, the motor cable being disposed within the catheter, and the guidewire lumen being disposed radially outwardly relative to the motor cable. 
     In an Example 14, the percutaneous circulatory support system of either of Examples 12-13, wherein the sensing region is disposed proximally relative to the motor. 
     In an Example 15, the percutaneous circulatory support system of any of Examples 12-14, further comprising an outer jacket coupling the guidewire lumen to the catheter. 
     In an Example 16, a percutaneous circulatory support device, comprises: a housing comprising an inlet and an outlet; an impeller disposed within the housing, the impeller configured to rotate relative to the housing to cause blood to flow into the inlet, through the housing, and out of the outlet; a motor operably coupled to the impeller, the motor configured to rotate the impeller relative to the housing; a catheter coupled to the motor; and a pressure sensor coupled to the catheter and disposed proximally relative to the housing. 
     In an Example 17, the percutaneous circulatory support device of Example 16, further comprising a sensor housing comprising an internal chamber, the pressure sensor being disposed within the internal chamber. 
     In an Example 18, the percutaneous circulatory support device of Example 17, wherein the sensor housing comprises an aperture. 
     In an Example 19, the percutaneous circulatory support device of Example 18, wherein the aperture is a distally-facing aperture. 
     In an Example 20, the percutaneous circulatory support device of Example 18, wherein the aperture is a transversely-facing aperture. 
     In an Example 21, the percutaneous circulatory support device of Example 20, wherein the sensor housing further comprises a distally-facing aperture. 
     In an Example 22, the percutaneous circulatory support device of Example 17, wherein the sensor housing comprises a ferrule. 
     In an Example 23, the percutaneous circulatory support device of Example 17, further comprising an outer jacket securing the sensor housing and the pressure sensor to the catheter. 
     In an Example 24, the percutaneous circulatory support device of Example 17, further comprising an adhesive securing the sensor housing and the pressure sensor to the catheter. 
     In an Example 25, the percutaneous circulatory support device of Example 16, further comprising: a sensor cable coupled to the pressure sensor; and a cable lumen coupled to the catheter, the sensor cable being disposed in the cable lumen. 
     In an Example 26, the percutaneous circulatory support device of Example 16, wherein the pressure sensor comprises one of an optical pressure sensor and an electrical pressure sensor. 
     In an Example 27, a percutaneous circulatory support system comprises: a support device, comprising: a housing comprising an inlet and an outlet; an impeller disposed within the housing, the impeller configured to rotate relative to the housing to cause blood to flow into the inlet, through the housing, and out of the outlet; a motor operably coupled to the impeller, the motor configured to rotate the impeller relative to the housing; a catheter coupled to the motor; a guidewire lumen coupled to the catheter; a sensing region; a guidewire, comprising: an elongated flexible body; and a pressure sensor coupled to the elongated flexible body; wherein the elongated flexible body is movable within the guidewire lumen to position the pressure sensor in the sensing region. 
     In an Example 28, the percutaneous circulatory support system of Example 27, further comprising a motor cable coupled to the motor, the motor cable being disposed within the catheter, and the guidewire lumen being disposed radially outwardly relative to the motor cable. 
     In an Example 29, the percutaneous circulatory support system of Example 27, wherein the sensing region is disposed proximally relative to the motor. 
     In an Example 30, the percutaneous circulatory support system of Example 27, further comprising an outer jacket coupling the guidewire lumen to the catheter. 
     In an Example 31, a method of manufacturing a percutaneous circulatory support device comprises: positioning an impeller within a housing such that the impeller is rotatable relative to the housing; operably coupling a motor to the impeller; coupling a catheter to the motor; and coupling a pressure sensor to the catheter proximally of the motor. 
     In an Example 32, the method of Example 31, wherein coupling the pressure sensor to the catheter comprises covering the catheter with an outer jacket. 
     In an Example 33, the method of Example 32, wherein covering the catheter with the outer jacket comprises forming the outer jacket on the catheter via a polymer reflow process. 
     In an Example 34, the method of Example 32, further comprising coupling a sensor cable to the pressure sensor. 
     In an Example 35, the method of Example 31, further comprising: positioning the pressure sensor within a sensor housing; and coupling the sensor housing to the catheter. 
     While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side sectional view of an illustrative percutaneous circulatory support device (also referred to herein, interchangeably, as a “blood pump”), in accordance with embodiments of the subject matter disclosed herein. 
         FIG.  2    is a detail view of the illustrative percutaneous circulatory support device within line  2 - 2  of  FIG.  1   . 
         FIG.  3    is a side view of an illustrative sensor assembly of a percutaneous circulatory support device, in accordance with embodiments of the subject matter disclosed herein. 
         FIG.  4    is a side sectional view of the sensor assembly along line  4 - 4  of  FIG.  3   . 
         FIG.  5    is a side sectional view of an illustrative percutaneous circulatory support system, in accordance with embodiments of the subject matter disclosed herein. 
         FIG.  6    is a side view of a pressure-sensing guidewire of the percutaneous circulatory support system of  FIG.  5   . 
         FIG.  7    is a side sectional view of an illustrative percutaneous circulatory support system, in accordance with embodiments of the subject matter disclosed herein. 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION 
       FIG.  1    depicts a partial side sectional view of an illustrative percutaneous circulatory support device  100  (also referred to herein, interchangeably, as a “blood pump”) in accordance with embodiments of the subject matter disclosed herein. The device  100  may form part of a percutaneous circulatory support system, together with a guidewire and an introducer sheath (not shown). More specifically, the guidewire and the introducer sheath may facilitate percutaneously delivering the device  100  to a target location within a patient, such as within the patient&#39;s heart. Alternatively, the device  100  may be delivered to a different target location within a patient. 
     With continued reference to  FIG.  1   , the device  100  generally includes a housing  101  that includes an impeller housing  102  and a motor housing  104 . In some embodiments, the impeller housing  102  and the motor housing  104  may be integrally or monolithically constructed. In other embodiments, the impeller housing  102  and the motor housing  104  may be separate components configured to be removably or permanently coupled. In some embodiments, the blood pump  100  may lack a separate motor housing  104  and the impeller housing  102  may be coupled directly to the motor  105  described below, or the motor housing  104  may be integrally constructed with the motor  105  described below. 
     The impeller housing  102  carries an impeller assembly  106  therein. The impeller assembly  106  includes an impeller shaft  108  that is rotatably supported by at least one bearing, such as a bearing  110 . The impeller assembly  106  also includes an impeller  112  that rotates relative to the impeller housing  102  to drive blood through the device  100 . More specifically, the impeller  112  causes blood to flow from a blood inlet  114  ( FIG.  1   ) formed on the impeller housing  102 , through the impeller housing  102 , and out of a blood outlet  116  formed on the impeller housing  102 . In some embodiments and as illustrated, the impeller shaft  108  and the impeller  112  may be separate components, and in other embodiments the impeller shaft  108  and the impeller  112  may be integrated. In some embodiment and as illustrated, the inlet  114  and/or the outlet  116  may each include multiple apertures. In other embodiments, the inlet  114  and/or the outlet  116  may each include a single aperture. In some embodiments and as illustrated, the inlet  114  may be formed on an end portion of the impeller housing  102  and the outlet  116  may be formed on a side portion of the impeller housing  102 . In other embodiments, the inlet  114  and/or the outlet  116  may be formed on other portions of the impeller housing  102 . In some embodiments, the impeller housing  102  may couple to a distally extending cannula (not shown), and the cannula may receive and deliver blood to the inlet  114 . 
     With continued reference to  FIG.  1   , the motor housing  104  carries a motor  105 , and the motor  105  is configured to rotatably drive the impeller  112  relative to the impeller housing  102 . In the illustrated embodiment, the motor  105  rotates a drive shaft  120 , which is coupled to a driving magnet  122 . Rotation of the driving magnet  122  causes rotation of a driven magnet  124 , which is connected to and rotates together with the impeller assembly  106 . More specifically, in embodiments incorporating the impeller shaft  108 , the impeller shaft  108  and the impeller  112  are configured to rotate with the driven magnet  124 . In other embodiments, the motor  105  may couple to the impeller assembly  106  via other components. 
     In some embodiments, a controller (not shown) may be operably coupled to the motor  105  and configured to control the motor  105 . In some embodiments, the controller may be disposed within the motor housing  104 . In other embodiments, the controller may be disposed outside of the motor housing  104  (for example, in an independent housing, etc.). In some embodiments, the controller may include multiple components, one or more of which may be disposed within the motor housing  104 . According to embodiments, the controller may be, may include, or may be included in one or more Field Programmable Gate Arrays (FPGAs), one or more Programmable Logic Devices (PLDs), one or more Complex PLDs (CPLDs), one or more custom Application Specific Integrated Circuits (ASICs), one or more dedicated processors (e.g., microprocessors), one or more Central Processing Units (CPUs), software, hardware, firmware, or any combination of these and/or other components. Although the controller is referred to herein in the singular, the controller may be implemented in multiple instances, distributed across multiple computing devices, instantiated within multiple virtual machines, and/or the like. In other embodiments, the motor  105  may be controlled in other manners. 
     With continued reference to  FIG.  1    and additional reference to  FIG.  2   , the motor housing  104  couples to a catheter  126  opposite the impeller housing  102 . The catheter  126  may couple to the motor housing  104  in various manners, such as laser welding, soldering, or the like. The catheter  126  extends proximally away from the motor housing  104 . The catheter  126  carries a motor cable  128  within a main lumen  130 , and the motor cable  128  may operably couple the motor  105  to the controller (not shown) and/or an external power source (not shown). Externally, the catheter  126  carries a sensor assembly  132  for measuring pressure within the vasculature of a patient, for example, within the aorta. Advantageously, the sensor assembly  132  is positioned, relative to the other components of the device  100 , in location for obtaining highly accurate pressure data. For example, the proximal position of the sensor assembly  132  relative to the motor housing  104  and the motor  105  reduces or eliminates the motor speed-related or dynamic pressure-related sensing inaccuracies. Such inaccuracies are typical of other percutaneous circulatory support devices that employ pressure sensors located more distally relative to the motor or impeller assembly, for example, devices that employ pressure sensors located near the outlet. 
     With specific reference to  FIG.  2   , the sensor assembly  132  includes a sensor housing  134  having a counterbore-shaped internal chamber  136 . A pressure sensor  138 , such as an optical or electrical pressure sensor, is disposed within the internal chamber  136 . As such, the sensor housing  134  protects the pressure sensor  138  during deployment of the device  100 . The sensor housing  134  also includes a distally-facing aperture  140  coupled to the internal chamber  136 . The aperture  140  permits blood to enter the internal chamber  136 , and the aperture  140  thereby permits the pressure sensor  138  to sense the pressure of the blood. 
     The sensor housing  134  may take various forms. For example, the sensor housing  134  may be a tube or ferrule manufactured from, for example, one or more metals, one or more plastics, composites, or the like. The sensor housing  134  may be coupled to the catheter  126  via one or more weldments (not shown), one or more adhesives  142 , and/or an outer jacket  144  surrounding the sensor housing  134  and the catheter  126 . The sensor housing  134  may also include a sensor mount  146  within the internal chamber  136 . The sensor mount  146  facilitates supporting the pressure sensor  138  apart from the walls of the sensor housing  134  (that is, the sensor mount  146  centers the pressure sensor  138  within the internal chamber  136 ), which in turn facilitates high-accuracy pressure sensing. 
     With continued reference to  FIG.  2   , the sensor assembly  132  further includes a sensor cable  148  coupled to the pressure sensor  138 . The sensor cable  148  may operably couple the pressure sensor to the controller (not shown). As illustrated, the sensor cable  148  may extend through the sensor mount  146  and support the pressure sensor  138  apart from the walls of the sensor housing  134 . The sensor cable  148  extends proximally, through the adhesive  142 , and through a cable lumen  150  coupled to the catheter  126 . The cable lumen  150  may be coupled to the catheter  126  via one or more weldments (not shown), an adhesive (not shown), and/or the outer jacket  144 . In other embodiments, the cable lumen  150  may be omitted, and the sensor cable  148  may extend through the main lumen  130  of the catheter  126  or lie directly under the outer jacket  144 . 
       FIGS.  3  and  4    depict another sensor assembly  200  in accordance with embodiments of the subject matter disclosed herein. The sensor assembly  200  may be used part of the percutaneous circulatory support device  100  in place of the sensor assembly  132  described above. The sensor assembly  200  is similar to the sensor assembly  132  described above. More specifically, the sensor assembly  200  includes a sensor housing  202  that has an internal chamber  204 ,a pressure sensor  206 , a sensor cable  208  ( FIG.  4   ), and an optional sensor mount  210  ( FIG.  4   ) which is disposed within the internal chamber  204 . The sensor housing  202  also includes a plurality of apertures coupled to the internal chamber  204 . More specifically, the sensor housing  202  includes a distally-facing aperture  212 , a first transversely-facing aperture  214 , and a second transversely-facing aperture  216  ( FIG.  4   ). The plurality of apertures facilitate blood flow through the sensor housing  202  and thereby reduce thrombi formation. Alternatively, the sensor housing  202  could include a different number of apertures. For example, the sensor housing  202  could include one or more transversely-facing apertures and omit a distally-facing aperture. In any case, each of the apertures may be sized to inhibit the sensor  206  from passing therethrough, for example, if the sensor  206  detaches from the sensor cable  208  in use. The apertures may also have an oval shape, as shown in  FIG.  3   , or various other shapes. 
     In some embodiments and as illustrated in  FIGS.  3  and  4   , the distally-facing aperture  212  is formed by a tapering portion  218  of the sensor housing  202 . The tapering portion  218  may be formed by crimping or coupling a separate piece of material to the remainder of the sensor housing  202 . In other embodiments, the distally-facing aperture  212  can be a flat feature perpendicular to the axis of the internal chamber  204 . 
     In some embodiments and as illustrated in  FIGS.  3  and  4   , the sensor  206  is at least partially aligned with the first transversely-facing aperture  214  and the second transversely-facing aperture  216 . This position of the sensor  206  provides relatively little space within sensor housing  202  in which bubbles could form, which could reduce sensing accuracy. Alternatively, the sensor  206  may be disposed in other positions within the sensor housing  202 . In some embodiments, the sensor  206  includes a surface energy-reducing coating (not shown), such as silicone, to inhibit bubble formation on the sensor  206  or within the sensor housing  202 . 
       FIG.  5    depicts a partial side sectional view of an illustrative percutaneous circulatory support system  300  in accordance with embodiments of the subject matter disclosed herein. The system  300  includes a percutaneous circulatory support device  302  that is similar to the device  100  described above. More specifically, a distal portion (not shown) of the device  302  generally includes an impeller housing and an impeller, such as the impeller housing  102  and the impeller  112 , respectively, described above and shown elsewhere. A proximal portion of the device  302  includes a motor housing  304  that carries a motor  306 , and the motor housing  304  couples to a catheter  308  opposite the motor  306 . The catheter  308  extends proximally away from the motor housing  304 . The catheter  308  carries a motor cable  310  within a main lumen  312 , and the motor cable  310  may operably couple the motor  306  to a controller (not shown) and/or an external power source (not shown). Externally, the catheter  308  carries a guidewire lumen  314  that receives a pressure-sensing guidewire  316 . The pressure-sensing guidewire  316  may operably couple to the controller, and the guidewire  316  may take various specific forms. However, and with additional reference to  FIG.  6   , the pressure-sensing guidewire  316  generally includes an elongated flexible body  318  that carries a pressure sensor  320 , such as an optical or electrical pressure sensor. The pressure-sensing guidewire  316  is advanced from a proximal end (not shown) of the guidewire lumen  314  to a distal end  322  of the guidewire lumen  314  (either before or after the device  302  is positioned in the vasculature of the patient). The sensor  320  extends distally from the guidewire lumen  314  and is positioned in a sensing region  324  of the catheter  308 . The sensing region  324  is located proximally from the motor housing  304  and the motor  306 , which, as described above, facilitates obtaining highly accurate pressure data. The guidewire  316  may additionally or alternatively sense pressure at various other locations relative to the catheter  308 . 
     In other embodiments, the system  300  may take other forms or include additional components. For example, the device  302  may include a sensor housing, such as the sensor housing  134  or the sensor housing  202  described above and shown elsewhere, for receiving and protecting the pressure sensor  320  of the guidewire  316 . Such a sensor housing may be coupled to the catheter  308  in various manners, including those described above in connection with the catheter  126  and the sensor housing  134  or the sensor housing  202 . As another example, the guidewire  316  may be fixed relative to the catheter  126 . 
       FIG.  7    depicts a partial side sectional view of an illustrative percutaneous circulatory support system  400  in accordance with embodiments of the subject matter disclosed herein. The system  400  includes a percutaneous circulatory support device  402  that is similar to the device  100  described above. More specifically, a distal portion (not shown) of the device  402  generally includes an impeller housing and an impeller, such as the impeller housing  102  and the impeller  112 , respectively, described above and shown elsewhere. A proximal portion of the device  402  includes a motor housing  404  that carries a motor  406 , and the motor housing  404  couples to a catheter  408  opposite the motor  406 . The catheter  408  extends proximally away from the motor housing  404 . The catheter  408  is a dual lumen catheter. That is, the catheter  408  carries a motor cable  410  within a main lumen  412 , and the motor cable  410  may operably couple the motor  406  to a controller (not shown) and/or an external power source (not shown). The catheter  408  also includes a guidewire lumen  414  that receives a pressure-sensing guidewire  416 . The pressure-sensing guidewire  416  may operably couple to the controller, and the guidewire  416  may be similar to the pressure-sensing guidewire  316  (shown elsewhere). The pressure-sensing guidewire  416  is advanced from a proximal end (not shown) of the guidewire lumen  414  to a distal end  420  of the guidewire lumen  414  (either before or after the device  402  is positioned in the vasculature of the patient). A sensor  422  of the guidewire  416  extends distally from the guidewire lumen  414 , through an opening at the distal end  420  of the guidewire lumen  414 , and is positioned in a sensing region  424  of the catheter  408 . The sensing region  424  is located proximally from the motor housing  404  and the motor  406 , which, as described above, facilitates obtaining highly accurate pressure data. The guidewire  416  may additionally or alternatively sense pressure at various other locations relative to the catheter  408 . 
     A method of manufacturing the percutaneous circulatory support device  100  may be as follows, and a method of manufacturing the device  302  may be similar. The impeller  112  is positioned within the impeller housing  102  such that the impeller  112  is rotatable relative to the impeller housing  102 . The impeller  112  is operably coupled to the motor  105 , and the catheter  126  is positioned adjacent to the motor housing  104 . The cable lumen  150  is positioned adjacent to the catheter  126  and coupled to the catheter  126  via a process which may include forming the outer jacket  144  via at least one polymer reflow process. The pressure sensor  138  and the sensor cable  148  are then coupled to the sensor housing  134  such that the sensor  138  is positioned within the internal chamber  136  of the sensor housing  134 . The sensor cable  148  is positioned in the cable lumen  150  and the sensor housing  134  and the pressure sensor within  138 are positioned adjacent to the catheter  126 . The sensor housing  134  and the pressure sensor  138  within the sensor housing  134  are coupled to the catheter  126 , for example, via one or more of welding, adhering, and covering the above components with the outer jacket  144 . Covering these components with the outer jacket  144  may include forming the outer jacket  144  via a polymer reflow process. 
     Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.