Patent Publication Number: US-2023138253-A1

Title: Ultrasonic therapy catheter systems and wire connector assemblies

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     None. 
     FIELD OF THE DISCLOSURE 
     The devices and methods described herein generally relate to vascular catheter systems, such as catheter systems that deliver therapeutic energy to occlusive materials, such as thrombus. 
     BACKGROUND 
     Thrombosis is a medical condition that results from the formation of a blood clot, or thrombus, within a vessel. Thrombi often develop in the valves, legs, or other lower abdomen (that is, deep vein thrombosis), but may occur in other vessels. The clot is typically formed from a pooling of blood within the vein due to abnormally long periods of rest, for example, when an individual is bed ridden following surgery or suffering a debilitating illness. In addition, thrombi also often develop near atherosclerotic plaque. 
     Embolisms occur when obstructive materials, such as a thrombus, travels around the body and lodges itself in an organ. For example, a pulmonary embolism is a blockage of the blood supply to the lungs that may cause hypoxia and cardiac failure. The formation of thrombi can lead to an embolism that may lead to serious health issues, including death. As another example, strokes occur when an embolus blocks an artery supplying blood to the brain, thus depriving the brain tissue of oxygen. Without oxygen, brain cells begin to die. 
     A variety of interventional methods and catheter devices are available to treat thrombi. For example, some catheter systems deliver ultrasonic energy to pulverize obstructions and permit subsequent aspiration of pulverized materials. An example of a portion of such a catheter system is shown in  FIG.  1   . More specifically,  FIG.  1    illustrates a wire connector assembly  100  that couples to an ultrasound generator (not shown), commonly referred to as an ultrasonic “horn”, via a threaded surface  102 . The threaded surface  102  is a portion of a sonic connector  104  that couples the ultrasound generator to an elongated wire  106  that enters the vasculature of a subject, typically inside the lumen of a sheath (not shown). The wire  106  receives and transmits ultrasonic energy to pulverize obstructions within the subject. 
     However, ultrasonic therapy catheter systems, including those having the wire connector assembly  100  illustrated in  FIG.  1   , typically have one or more drawbacks. More specifically, the sonic connector  104  is typically provided as a relatively long component (more specifically, about 1.2 inches long) to facilitate resonance upon receiving ultrasonic energy. This length introduces several manufacturing challenges. For example, using a machining process to form the sonic connector  104 , which typically comprises titanium grade  5 , is relatively difficult and expensive. As another example, a simple manufacturing process for coupling the wire  106  to the sonic connector  104  includes forming a shallow blind hole  108  in the distal end  110  and crimping the wire  106  to the sonic connector  104  in the blind hole  108 . Such a connection is typically secure, but not necessarily uniform. As such, the crimped connection may create a stress concentration, which may lead to wire failure. As another example, the length of the sonic connector  104  may cause misalignment between the wire  106  and the threaded surface  102 . More specifically, the centers of the wire  106  and the threaded surface  102  may be misaligned due to tolerances and/or machining variations. This misalignment may cause transverse motion of the wire  106  and possible wire failure. As another example, the wire  106  is crimped to the sonic connector  104  proximally from the node of the ultrasonic horn, which is disposed at its distal end. This may cause relatively inefficient transmission of ultrasonic energy from the horn to the wire  106 . As another drawback, the sonic connector  104  includes several abrupt size transitions, which can create stress concentrations. 
     Accordingly, improved ultrasonic therapy catheter systems and wire connector assemblies are needed. 
     SUMMARY 
     The present disclosure presents a wire connector assembly for an ultrasonic therapy catheter system including an ultrasound generator. The wire connector assembly includes a sonic connector that is configured to couple to the ultrasound generator and receive ultrasonic energy therefrom. The sonic connector includes a body having a passageway that extends therethrough, and the passageway includes a tapered surface. The wire connector assembly further includes a wire that engages the tapered surface and extends outwardly from the passageway. The wire is configured to receive ultrasonic energy from the sonic connector. 
     The wire connector assembly according to the previous paragraph, wherein the wire includes a proximal end portion including an engagement feature, and the engagement feature engages the tapered surface of the passageway of the sonic connector. 
     The wire connector assembly according to any of the previous paragraphs, wherein the sonic connector further includes a longitudinal axis aligned with the passageway, and an ultrasound generator engagement surface that is configured to engage the ultrasound generator. The ultrasound generator engagement surface is aligned with the engagement feature relative to the longitudinal axis. 
     The wire connector assembly according to any of the previous paragraphs, wherein the engagement feature includes a ball. 
     The wire connector assembly according to any of the previous paragraphs, wherein the wire further includes an elongated portion coupled to the engagement feature, wherein the passageway includes a proximal passageway portion including the tapered surface and a distal passageway portion coupled to the proximal passageway portion, and the distal passageway portion slip fittingly receives the elongated portion of the wire. 
     The wire connector assembly according to any of the previous paragraphs, wherein the sonic connector includes a longitudinal axis aligned with the passageway, and the sonic connector has a length along the longitudinal axis of substantially 0.7 inches. 
     The present disclosure also presents a method of manufacturing a wire connector assembly for an ultrasonic therapy catheter system. The method includes providing a sonic connector, the sonic connector includes a body having a passageway extending therethrough, and the passageway includes a tapered surface. The method further includes providing a wire and coupling the wire to the sonic connector such that the wire engages the tapered surface and extends outwardly from the passageway. 
     The method according to the previous paragraph, wherein providing the wire includes providing an elongated portion; providing an engagement feature; and coupling the engagement feature to the elongated portion; and wherein and coupling the wire to the sonic connector includes engaging the engagement feature with the tapered surface. 
     The method according to any of the previous paragraphs, wherein coupling the engagement feature to the elongated portion includes at least one of welding, crimping, and bonding the engagement feature to the elongated portion. 
     The method according to any of the previous paragraphs, wherein coupling the engagement feature to the elongated portion includes melting a proximal end portion of the wire. 
     The method according to any of the previous paragraphs, wherein coupling the wire to the sonic connector includes moving the sonic connector relative to the wire such that the wire passes through a proximal opening of the passageway, extends outwardly from a distal opening of the passageway, and the engagement feature engages the tapered surface. 
     The method according to any of the previous paragraphs, wherein the sonic connector includes a longitudinal axis aligned with the passageway and an ultrasound generator engagement surface configured to engage an ultrasound generator of the ultrasonic therapy catheter system, and wherein engaging the engagement feature with the tapered surface includes aligning the engagement feature with the ultrasound generator engagement surface relative to the longitudinal axis. 
     The method according to any of the previous paragraphs, wherein coupling the wire to the sonic connector further includes positioning a joining material in a proximal portion of the passageway including the tapered surface. 
     The method according to any of the previous paragraphs, wherein the engagement feature includes a ball. 
     The method according to any of the previous paragraphs, wherein the sonic connector includes a longitudinal axis aligned with the passageway and a length along the longitudinal axis of substantially 0.7 inches. 
     The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. When each one of A, B, and C in the above expressions refers to an element, such as X, Y, and Z, or class of elements, such as X 1 -X n , Y 1 -Y m , and Z 1 -Z o , the phrase is intended to refer to a single element selected from X, Y, and Z, a combination of elements selected from the same class (for example, X 1  and X 2 ) as well as a combination of elements selected from two or more classes (for example, Y 1  and Z o ). 
     The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” may be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” may be used interchangeably. 
     The term “means” as used herein shall be given its broadest possible interpretation in accordance with 35 U.S.C. Section 112(f). Accordingly, a claim incorporating the term “means” shall cover all structures, materials, or acts set forth herein, and all of the equivalents thereof. Further, the structures, materials or acts and the equivalents thereof shall include all those described in the summary, brief description of the drawings, detailed description, abstract, and claims themselves. 
     It should be understood that every maximum numerical limitation given throughout this disclosure is deemed to include each and every lower numerical limitation as an alternative, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this disclosure is deemed to include each and every higher numerical limitation as an alternative, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this disclosure is deemed to include each and every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein. 
     The preceding is a simplified summary of the disclosure to provide an understanding of some aspects of the disclosure. This summary is neither an extensive nor exhaustive overview of the disclosure and its various aspects, embodiments, and configurations. It is intended neither to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure but to present selected concepts of the disclosure in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other aspects, embodiments, and configurations of the disclosure are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are incorporated into and form a part of the specification to illustrate several examples of the present disclosure. These drawings, together with the description, explain the principles of the disclosure. The drawings simply illustrate preferred and alternative examples of how the disclosure may be made and used and are not to be construed as limiting the disclosure to only the illustrated and described examples. Further features and advantages will become apparent from the following, more detailed, description of the various aspects, embodiments, and configurations of the disclosure, as illustrated by the drawings referenced below. 
         FIG.  1    is a perspective view of a wire connector assembly of an ultrasonic therapy catheter system according to the prior art. 
         FIG.  2    is a perspective, partial sectional view of an ultrasonic therapy catheter system according to an embodiment of the present disclosure. 
         FIG.  3    is another perspective, partial sectional view of the ultrasonic therapy catheter system of  FIG.  1   . 
         FIG.  4    is a perspective view of a sonic connector according to an embodiment of the present disclosure. 
         FIG.  5    is another perspective view of the sonic connector of  FIG.  4   . 
         FIG.  6    is a proximal end view of the sonic connector of  FIG.  4   . 
         FIG.  7    is a sectional view of the sonic connector along line  7 - 7  of  FIG.  6   . 
         FIG.  8    is a side view of the sonic connector of  FIG.  4   . 
         FIG.  9    is a side view of a wire according to an embodiment of the present disclosure. 
         FIG.  10    is a side view of a wire connector assembly including the sonic connector of  FIG.  4    and the wire of  FIG.  9   . 
         FIG.  11    is a flowchart illustrating a method of manufacturing a wire connector assembly according to an embodiment of the present disclosure. 
         FIG.  12    is a sectional view of the sonic connector of  FIG.  4    receiving the wire of  FIG.  9   . 
         FIG.  13    is a sectional view of the sonic connector of  FIG.  4    receiving the wire of  FIG.  9    and engaging the wire with an internal tapered surface of the sonic connector. 
     
    
    
     It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the disclosure or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the disclosure is not necessarily limited to the particular embodiments illustrated herein. 
     DETAILED DESCRIPTION 
     Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. 
     The present disclosure relates generally to vascular catheter systems, devices, and methods for delivering therapeutic energy to occlusive materials, such as thrombus. The present disclosure also generally relates to methods of manufacturing such systems and devices. 
     Referring to  FIGS.  2 - 3   , an ultrasonic therapy catheter system  200  according to an exemplary embodiment of the present disclosure is illustrated in partial section. The system  200  includes an ultrasound generator  202 , also referred to as an ultrasonic “horn,” that is received in a passageway  204  of a shroud  206 . At a distal end portion  208 , the ultrasonic horn  202  detachably couples to a wire connector assembly  210 . The wire connector assembly  210  generally includes a sonic connector  400 , which detachably couples to the ultrasonic horn  202  and receives ultrasonic energy therefrom, and an elongated wire  900 , which enters the vasculature of a subject, typically inside the lumen of a sheath (not shown), and receives and transmits ultrasonic energy to pulverize obstructions within a subject. 
     With continued reference to  FIGS.  2 - 3   , a distal end portion  216  of the shroud  206  detachably couples to a coupler  218 . The coupler  218  generally receives the wire connector assembly  210  in a coupler passageway  220 . The coupler  218  couples to a sheath (not shown) that receives the wire  900 . The coupler  218  also couples to an auxiliary port (not shown) in fluid communication with the coupler passageway  220 . As such, the auxiliary port facilitates delivering a fluid, such as saline, to the coupler passageway  220 . To inhibit proximal flow into the shroud passageway  204 , the distal end portion  208  of the shroud  206  carries a seal  222 . More specifically and as illustrated, the shroud  206  carries a diaphragm seal  222  that sealingly engages the shroud  206  at an outer end portion  224 . The outer end portion  224  couples to a proximally and inwardly extending flexible portion  226 , and the flexible portion  226  couples to an opposite inner end portion  228 . The inner end portion  228  sealingly engages the ultrasonic horn  202 . Additionally, the flexible portion  226  of the diaphragm seal  222  flexes as the ultrasonic horn  202  delivers ultrasonic energy to the wire connector assembly  210 . The seal  222  may comprise various flexible and medically-appropriate materials, such as polymers, and more specifically silicone. 
       FIGS.  4 - 8    illustrate a sonic connector  400  according to an exemplary embodiment of the present disclosure. The sonic connector  400  is generally similar to the sonic connector  212  described above, with the exception of including flat surfaces  402  as described below instead of a radially outwardly facing blind hole  230  (see  FIGS.  2 - 3   ). The sonic connector  400  may be used in the ultrasonic therapy catheter system  200  shown in  FIGS.  2 - 3    in lieu of the sonic connector  212 . The sonic connector  400  may comprise any of various medically-appropriate materials, such as metals, and more specifically titanium grade  5 . The sonic connector  400  generally includes a monolithic body  404  that defines an internal passageway  406 , and the internal passageway  406  carries the wire  900  (shown elsewhere). 
     The body  404  generally includes a proximal end portion  408 , an intermediate portion  410  coupled to the proximal end portion  408 , and an opposite distal end portion  412  coupled to the intermediate portion  410 . The proximal end portion  408  is configured to couple to the ultrasound generator  202  (shown elsewhere) via a threaded surface  414 . The intermediate portion  410  is radially larger than the proximal end portion  408 . The intermediate portion  410  includes a proximal ultrasound generator engagement surface  416  that is configured to engage the ultrasound generator  202 . The intermediate portion  410  also includes flat surfaces  402  that facilitate coupling the sonic connector  400  to the ultrasonic generator  202 . More specifically, the flat surfaces  402  facilitate grasping the sonic connector  400  with a tool, such as a spanner wrench. The intermediate portion  410  is illustrated as including two flat surfaces  402 . In other embodiments, the intermediate portion  410  may have a different number of flat surfaces  402 , such as three to eight flat surfaces  402 . The distal end portion  412  is radially smaller than the intermediate portion  410 . 
     With specific reference to  FIGS.  7 - 8   , the portions  408 ,  410 , and  412  of the body  404  are coupled by multiple radii  418 ,  420 , and  422 . In some embodiments, the radii  418 ,  420 , and  422  advantageously facilitate “funneling” ultrasonic waves relatively gradually and/or reduce or eliminate stress concentrations between the body portions  408 ,  410 , and  412  compared to previous connectors. In some embodiments, the radii  418 ,  420 , and  422  advantageously facilitate smooth ultrasonic wave transmission between the body portions  408 ,  410 , and  412  compared to previous connectors. 
     With specific reference to  FIG.  7    and as described briefly above, the body  404  of the sonic connector  400  defines an internal passageway  406 . The passageway  406  extends from a proximal opening  424  at the proximal end portion  408  of the body  404  to a distal opening  426  at the distal end portion  412  of the body  404 . The passageway  406  is also aligned with a longitudinal axis  428  of the body  404 . The passageway  406  includes a proximal passageway portion  430  and a distal passageway portion  432 . The proximal passageway portion  430  includes a tapered surface  434  that narrows proceeding proximally to distally. As described in further detail below, the tapered surface  434  engages and secures the sonic connector  400  to the wire  900  (shown elsewhere). In some embodiments, the tapered surface  434  tapers by substantially 6 percent (that is, 6 percent±1 percent). In some embodiments, the tapered surface  434  has dimensions consistent with a Morse taper. As described in further detail below, the distal passageway portion  432  is sized to slip fittingly receive the wire  900 . 
     The sonic connector  400  may include any of the following exemplary dimensions. The sonic connector  400  may have a length along the longitudinal axis  428  of substantially 0.7 inches (that is, 0.7 inches±10 percent). Such a length is relatively short compared to previous connectors. In some embodiments, this short length advantageously reduces machining costs compared to those of previous connectors. Similarly, in some embodiments this short length facilitates forming the passageway  406  in the sonic connector  400 . This in turn facilitates coupling the wire  900  to the sonic connector  400  near the proximal end portion  408 , as described in further detail below. The intermediate portion  410  may have a diameter of substantially 0.344 inches (that is, 0.344 inches±10 percent). The distal end portion  412  may have a diameter of substantially 0.134 inches (that is, 0.134 inches±10 percent). The proximal end portion  408  may have a thread size appropriate for coupling to the ultrasonic horn  202  (shown elsewhere). The radius  418  may be substantially 0.04 inches (that is, 0.04 inches±10 percent). The radius  420  may be substantially 0.063 inches (that is, 0.063 inches±10 percent). The radius  422  may be substantially 0.125 inches (that is, 0.125 inches±10 percent). 
       FIG.  9    illustrates a wire  900  according to an exemplary embodiment of the present disclosure. The wire  900  may be the same wire  214  as described above in connection with  FIGS.  2 - 3   . The wire  900  generally includes a proximal end portion  902  and a narrower, distally extending, elongated portion  904 . The proximal end portion  902  includes an engagement feature  906  that is configured to engage the tapered surface  434  of the sonic connector  400  (shown elsewhere) and thereby secure the wire  900  to the sonic connector  400 . The engagement feature  906  is illustrated as being a ball. In other embodiments, the engagement feature  906  may have a different shape, such as a frusto-conical shape. The elongated portion  904  may have a generally uniform cross-sectional shape and size. 
       FIG.  10    illustrates a wire connector assembly  1000  including the sonic connector  400  and the wire  900 . The wire connector assembly  1000  is generally similar to the wire connector assembly  210  described above, with the exception of the sonic connector  400  as described above. The wire connector assembly  1000  may be used in the ultrasonic therapy catheter system  200  shown in  FIGS.  2 - 3    in lieu of the wire connector assembly  210 . As illustrated, the engagement feature  906  of the wire  900  engages the tapered surface  434  of the passageway  406  of the sonic connector  400 . More specifically, the engagement feature  906  engages the tapered surface  434  such that the engagement feature  906  is longitudinally aligned with the ultrasound generator engagement surface  416  of the sonic connector  400 . In some embodiments, this advantageously facilitates relatively efficient transmission of ultrasonic energy from the ultrasonic horn  202  (shown elsewhere) to the wire  900  compared to previous systems. As described briefly above, the distal passageway portion  432  slip fittingly receives the elongated portion  904  of the wire  900 . In some embodiments, this facilitates maintaining alignment of the wire  900  with the longitudinal axis  428 , or stated another way, reducing or eliminating transverse motion of the wire  900  at the distal end portion  412  of the sonic connector  400 . The elongated portion  904  extends outwardly and distally from the distal opening  426  of the passageway  406 . 
     Referring to  FIGS.  11 - 13   , a method of manufacturing the wire connector assembly  1000  according to an exemplary embodiment of the present disclosure is illustrated.  FIG.  11    illustrates a flowchart including processes of the method of manufacturing the wire connector assembly  1000 , and  FIGS.  12 - 13    illustrate the wire connector assembly  1000  in partial cross section during several specific processes of the method. As shown in  FIG.  11   , the method includes providing the sonic connector  400  at block  1100 . In some embodiments, this may include machining a short section of rod stock (such as titanium grade  5 ) to form the portions and other features of the sonic connector  400 , such as the passageway  406  and the tapered surface  434 . At block  1102 , the wire  900  is provided. In some embodiments, this may include providing the elongated portion  904  and the engagement feature  906  and coupling them to each other. This may include, for example, coupling the engagement feature  906  to the elongated portion  904  via welding, crimping, and/or bonding. Alternatively, coupling the engagement feature  906  to the elongated portion  904  may include melting an end of the elongated portion  904  to form the engagement feature  906 , and thereby monolithically coupling the engagement feature  906  to the elongated portion  904 . At block  1104 , the sonic connector  400  is coupled to the wire  900  such that the engagement feature  906  engages the tapered surface  434  and the elongated portion  904  extends outwardly from the distal opening  426  of the passageway  406 . This may include, for example and as shown in  FIGS.  12 - 13   , moving the sonic connector  400  relative to the wire  900  such that the wire  900  passes through the proximal opening  424  of the passageway  406 , the elongated portion  904  extends outwardly from a distal opening  426  of the passageway  406 , and the engagement feature  906  engages the tapered surface  434 . In some embodiments and as shown in  FIGS.  12 - 13   , the proximal passageway portion  430  may carry joining material  1200  (for example, an epoxy or adhesive) to facilitate securing the engagement feature  906  to the tapered surface  434 . In some embodiments, the engagement feature  906  may be impacted (for example, by a pin) to facilitate securing the engagement feature  906  to the tapered surface  434 . In some embodiments, the wire  900  and the sonic connector  400  may be subjected to an ultrasonic welding process to facilitate securing the engagement feature  906  to the tapered surface  434 . In some embodiments, the sonic connector  400  may be subjected to a heating process prior to coupling to the wire  900  to facilitate securing the engagement feature  906  to the tapered surface  434  upon cooling. 
     The foregoing discussion has been presented for purposes of illustration and description. The foregoing is not intended to limit the disclosure to the form or forms disclosed herein. In the foregoing Summary for example, various features of the disclosure are grouped together in one or more aspects, embodiments, and/or configurations for the purpose of streamlining the disclosure. The features of the aspects, embodiments, and/or configurations of the disclosure may be combined in alternate aspects, embodiments, and/or configurations other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed aspect, embodiment, and/or configuration. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the disclosure. 
     Moreover, though the description has included description of one or more aspects, embodiments, and/or configurations and certain variations and modifications, other variations, combinations, and modifications are within the scope of the disclosure, for example, as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative aspects, embodiments, and/or configurations to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.