Patent Publication Number: US-2023158286-A1

Title: Percutaneous circulatory support device facilitating reduced hemolysis

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to Provisional Application No. 63/282,207, filed Nov. 23, 2021, which is herein incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to percutaneous circulatory support systems. More specifically, the disclosure relates to percutaneous circulatory support devices that facilitate reduced hemolysis and/or related complications. 
     BACKGROUND 
     Percutaneous circulatory support devices such as devices can provide transient support for up to approximately several weeks in patients with compromised heart function or cardiac output. Operation of such devices, however, may cause some amount of hemolysis (that is, the rupture or destroying of blood cells) or other complications. Hemolysis can in turn cause thrombi formation or other complications. Accordingly, there is a need for improved devices that facilitate reduced hemolysis and/or related complications. 
     SUMMARY 
     In an Example 1, a percutaneous circulatory support device comprises a housing comprising a proximal end portion; a motor carried by the housing; a driving magnet operatively coupled to the motor; a driven magnet operatively coupled to the driving magnet; the driven magnet comprising a frustoconical shape; and an impeller disposed within the housing, the impeller being operatively coupled to the driven magnet. 
     In an Example 2, the percutaneous circulatory support device of Example 1, further comprising an outlet, and wherein the driven magnet is disposed apart from the outlet to define an inverse frustoconical chamber in the housing. 
     In an Example 3, the percutaneous circulatory support device of either of Examples 1 or 2, further comprising an impeller shaft being fixed relative to the impeller and the driven magnet. 
     In an Example 4, the percutaneous circulatory support device of any of Examples 1 to 3, further comprising a bearing disposed between the driving magnet and the driven magnet. 
     In an Example 5, the percutaneous circulatory support device of any of Examples 1 to 4, wherein the driven magnet tapers radially inwardly proceeding in a proximal direction. 
     In an Example 6, the percutaneous circulatory support device of any of Examples 1 to 4, wherein the driven magnet tapers radially inwardly proceeding in a distal direction. 
     In an Example 7, the percutaneous circulatory support device of any of Examples 1 to 6, wherein the housing comprises a plurality of outlet apertures each extending to a proximal end of the driven magnet. 
     In an Example 8, the percutaneous circulatory support device of any of Examples 1 to 7, wherein a proximal portion of the impeller comprises a flattened shape. 
     In an Example 9, a percutaneous circulatory support device comprises a housing comprising a proximal end portion, an inlet, and an outlet; a motor carried by the housing; a driving magnet operatively coupled to the motor; a driven magnet operatively coupled to the driving magnet; the driven magnet comprising a frustoconical shape and being disposed apart from the outlet to define an inverse frustoconical chamber in the proximal end portion of the housing; and an impeller disposed within the housing, the impeller being operatively coupled to the driven magnet. 
     In an Example 10, the percutaneous circulatory support device of Example 9, further comprising an impeller shaft being fixed relative to the impeller and the driven magnet. 
     In an Example 11, the percutaneous circulatory support device of either of Examples 9 or 10, wherein the driven magnet tapers radially inwardly proceeding in a proximal direction. 
     In an Example 12, the percutaneous circulatory support device of either of Examples 9 or 10, wherein the driven magnet tapers radially inwardly proceeding in a distal direction. 
     In an Example 13, the percutaneous circulatory support device of any of Examples 9 to 12, wherein the outlet comprises a plurality of outlet apertures each extending to a proximal end of the driven magnet. 
     In an Example 14, the percutaneous circulatory support device of any of Examples 9 to 13, wherein a proximal portion of the impeller comprises a flattened shape. 
     In an Example 15, the percutaneous circulatory support device of any of Examples 9 to 14, wherein the housing comprises a motor housing carrying the motor and an impeller housing carrying the impeller. 
     In an Example 16, a percutaneous circulatory support device comprises an impeller housing comprising a proximal end portion; a motor housing coupled to the impeller housing; a motor carried by the motor housing; a driving magnet operatively coupled to the motor; a driven magnet operatively coupled to the driving magnet; the driven magnet comprising a frustoconical shape; and an impeller disposed within the impeller housing, the impeller being operatively coupled to the driven magnet; wherein the motor rotates the impeller, via the driving magnet and the driven magnet, relative to the impeller housing to cause blood to flow through the percutaneous circulatory support device and blood is inhibited from pooling in the proximal end portion of the impeller housing. 
     In an Example 17, the percutaneous circulatory support device of Example 16, further comprising an outlet, and wherein the driven magnet is disposed apart from the outlet to define an inverse frustoconical chamber in the impeller housing. 
     In an Example 18, the percutaneous circulatory support device of Example 16, further comprising an impeller shaft being fixed relative to the impeller and the driven magnet. 
     In an Example 19, the percutaneous circulatory support device of Example 16, wherein the driving magnet is disposed within the motor housing and the driven magnet is disposed within the impeller housing. 
     In an Example 20, the percutaneous circulatory support device of Example 16, further comprising a bearing disposed between the driving magnet and the driven magnet. 
     In an Example 21, the percutaneous circulatory support device of Example 16, wherein the driven magnet tapers radially inwardly proceeding in a proximal direction. 
     In an Example 22, the percutaneous circulatory support device of Example 16, wherein the driven magnet tapers radially inwardly proceeding in a distal direction. 
     In an Example 23, the percutaneous circulatory support device of Example 16, wherein the impeller housing comprises a plurality of outlet apertures each extending to a proximal end of the driven magnet. 
     In an Example 24, the percutaneous circulatory support device of Example 16, wherein a proximal portion of the impeller comprises a flattened shape. 
     In an Example 25, a percutaneous circulatory support device comprises an impeller housing comprising a proximal end portion, an inlet, and an outlet; a motor housing coupled to the impeller housing; a motor carried by the motor housing; a driving magnet operatively coupled to the motor; a driven magnet operatively coupled to the driving magnet; the driven magnet comprising a frustoconical shape and being disposed apart from the outlet to define an inverse frustoconical chamber in the proximal end portion of the impeller housing; and an impeller disposed within the impeller housing, the impeller being operatively coupled to the driven magnet; wherein the motor rotates the impeller, via the driving magnet and the driven magnet, relative to the impeller housing to cause blood to flow through the percutaneous circulatory support device and blood is inhibited from pooling in the proximal end portion of the impeller housing. 
     In an Example 26, the percutaneous circulatory support device of Example 25, further comprising an impeller shaft being fixed relative to the impeller and the driven magnet. 
     In an Example 27, the percutaneous circulatory support device of Example 25, wherein the driven magnet tapers radially inwardly proceeding in a proximal direction. 
     In an Example 28, the percutaneous circulatory support device of Example 25, wherein the driven magnet tapers radially inwardly proceeding in a distal direction. 
     In an Example 29, the percutaneous circulatory support device of Example 25, wherein the outlet comprises a plurality of outlet apertures each extending to a proximal end of the driven magnet. 
     In an Example 30, the percutaneous circulatory support device of Example 25, wherein a proximal portion of the impeller comprises a flattened shape. 
     In an Example 31, a method for using a percutaneous circulatory support device comprises positioning the percutaneous circulatory support device at a target location within a patient; rotating an impeller of the percutaneous circulatory support device, via a motor, a driving magnet, and a driven magnet comprising a frustoconical shape, to cause blood to flow through the percutaneous circulatory support device, wherein blood is inhibited from pooling in a proximal end portion of an impeller housing of the percutaneous circulatory support device. 
     In an Example 32, the method of Example 31, wherein rotating the impeller and rotating the driven magnet comprise rotating the impeller and the driven magnet together relative to the impeller housing. 
     In an Example 33, the method of Example 31, wherein the driven magnet tapers radially inwardly proceeding in a proximal direction. 
     In an Example 34, the method of Example 31, wherein the driven magnet tapers radially inwardly proceeding in a proximal direction. 
     In an Example 35, the method of Example 31, wherein the percutaneous circulatory support device further comprises an outlet, and the outlet comprises a plurality of outlet apertures each extending to a proximal end of the driven magnet. 
     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 mechanical 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 perspective view of the mechanical circulatory support device of  FIG.  1   , with housing components of the device shown in phantom lines, in accordance with embodiments of the subject matter disclosed herein. 
         FIG.  3    is a side sectional view of another illustrative mechanical circulatory support device, in accordance with embodiments of the subject matter disclosed herein. 
         FIG.  4    is a perspective view of the mechanical circulatory support device of  FIG.  3   , with housing components of the device shown in phantom lines, 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 mechanical 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    and additional reference to  FIG.  2   , the device  100  generally 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. 
     The impeller housing  102  carries an impeller assembly  106  therein. The impeller assembly  106  includes an impeller shaft  108  ( FIG.  1   ) 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  FIGS.  1  and  2   , the motor housing  104  carries a motor  118 , and the motor  118  is configured to rotatably drive the impeller  112  relative to the impeller housing  102 . In the illustrated embodiment, the motor  118  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  118  may couple to the impeller assembly  106  via other components. 
     In some embodiments, a controller (not shown) may be operably coupled to the motor  118  and configured to control the motor  118 . 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 a catheter handle, 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  118  may be controlled in other manners. 
     With further reference to  FIGS.  1  and  2   , the device  100  facilitates reduced device-induced hemolysis compared to conventional devices. More specifically, the driven magnet  124  includes an outer surface  126  that has a frustoconical shape. The frustoconical outer surface  126  is disposed apart from the outlet  116  and thereby defines an inverse frustoconical chamber  128  in a proximal end portion  130  of the impeller housing  102 . The chamber  128  is relatively large compared to the small spaces between the driven magnet and the impeller housing in a conventional device. As a result, rotation of the driven magnet  124  inhibits blood from pooling in the inverse frustoconical chamber  128 , which reduces hemolysis and/or thrombosis. In some embodiments, the frustoconical outer surface  126  of the driven magnet  124  tapers radially inwardly proceeding in a proximal direction. In other embodiments and as shown elsewhere, the frustoconical outer surface  126  of the driven magnet  124  tapers radially inwardly proceeding in a distal direction. 
     The device  100  may also include one or more additional features that facilitate reduced device-induced hemolysis compared to conventional devices. For example, the apertures of the outlet  116  may be relatively long compared to those of conventional devices. More specifically, the apertures of the outlet  116  may each extend to a proximal end  132  ( FIG.  1   ) of the driven magnet  124 . Such apertures further inhibit blood from pooling in the proximal end portion  130  of the impeller housing  102 , which reduces hemolysis and/or thrombosis. As another example, a proximal end portion  134  of the impeller  112  may have a flattened shape, in contrast to lips or peaks of the impellers of conventional devices. Such a shape inhibits blood from forming and pooling in vortices adjacent to the impeller  112 . 
       FIGS.  3  and  4    depict another illustrative mechanical circulatory support device  200  in accordance with embodiments of the subject matter disclosed herein. The device  200  includes the same features and components as the device  100 , except that the frustoconical outer surface  226  of the driven magnet  224  tapers radially inwardly proceeding in a distal direction. 
     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.