Patent Publication Number: US-2022226009-A1

Title: Lithotriptor spacers and method

Description:
CLAIM OF PRIORITY 
     This patent application claims the benefit of priority, under 35 U.S.C. § 119(e), to U.S. Provisional Patent Application Ser. No. 63/138,973, entitled “LITHOTRIPTOR SPACERS AND METHOD,” filed on Jan. 19, 2021, which is hereby incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments described herein generally relate to medical devices. A specific example of a medical device includes lithotriptors. 
     BACKGROUND 
     Lithotriptors are used to break up and remove unwanted objects from locations within a subject. For example, kidney stones are impacted with a vibrating probed and broken up pieces are removed. The vibrational energy may cause unwanted wear on components due to friction or other contact between components. Improved lithotriptors and methods are desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
         FIG. 1  shows a lithotriptor in accordance with some example embodiments. 
         FIG. 2  shows an end view of a portion of a lithotriptor in accordance with some example embodiments. 
         FIG. 3  shows an end view of a portion of a lithotriptor in accordance with some example embodiments. 
         FIG. 4  shows an end view of a portion of a lithotriptor in accordance with some example embodiments. 
         FIG. 5  shows an end view of a portion of a lithotriptor in accordance with some example embodiments. 
         FIG. 6  shows a portion of a lithotriptor in operation in accordance with some example embodiments. 
         FIG. 7  shows a flow diagram of a method of using a lithotriptor in accordance with some example embodiments. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims. 
       FIG. 1  shows a lithotriptor  100  according to one example. In  FIG. 1 , a hollow shaft  102  extends from a handpiece  104 . A controller  120  is used in conjunction with the shaft  102  and handpiece  104  through connecting lines not shown. In one example, the handpiece  104  includes a transducer that is in communication with the controller, for example, through connecting lines. The transducer is configured to receive signals from the controller  120  and generate cyclic motion along the hollow shaft  102 . Examples of signals include, but are not limited to sine wave, square wave, combinations of waves, or other electronic signals. In one example, frequencies and amplitudes of signals are varied to provide varying cyclic motion in a distal end  106  of the hollow shaft  102 . 
     In one example procedure, the hollow shaft  102  is inserted into a lumen that leads to a target location, such as a location to break up a stone. The cyclic motion of the hollow shaft  102  and distal end  106  is used to impact and break up the stone. Factors such as friction and vibration between the hollow shaft  102  and the lumen may yield undesirable loss of performance and/or undesirable wear on either the hollow shaft  102  or the lumen. 
     Although a hollow shaft  102  is described, the invention is not so limited. In selected examples, a solid shaft may be used in place of the hollow shaft  102 . In such an example with a solid shaft, broken up fragments of a stone may be removed through suction along one or more longitudinal pathways as described in examples below. Although the longitudinal pathway shaft  102  and/or a solid shaft are shown in various examples with a round cross section geometry the invention is not so limited. Other cross section geometries, such as square, oval, etc. may also be used. Lateral spacers as described in examples below may be attached to a solid shaft example, similar to the hollow shaft examples described. 
       FIG. 2  shows an assembly  200  that illustrates the distal end  106  of the hollow shaft  102  as inserted within a lumen  110 . In the example shown in  FIG. 2 , a space  112  is provided between the hollow shaft  102  and the lumen  110 . In one example, one or more lateral spacers are included to control dimensions of the space  112 . 
       FIGS. 3-5  provide selected examples of lateral spacers. In  FIG. 3 , an assembly  300  is shown with a distal end  306  of a hollow shaft  302  similar to hollow shaft  102  from  FIGS. 1 and 2 . A spacer assembly  310  is shown extending from an outside surface  308  of the hollow shaft  302 . In one example the spacer assembly  310  includes one or more fins  312  that form a finned cross section spacer assembly  310 . In the example of  FIG. 3 , the one or more fins  312  are coupled to a hub  314  that fits over the outside surface  308  of the hollow shaft  302 . 
     In one example, the spacer assembly  310  includes at least one longitudinal pathway through the spacer assembly  310 . Arrow  320  shows a longitudinal pathway through the spacer assembly  310 , while arrow  322  shows how fin  312  blocks longitudinal passage, or otherwise re-channels flow into a longitudinal pathway. As such, the fins  312  define one or more longitudinal pathways  320  through the spacer assembly  310 . In one operation, as discussed in more detail below, liquid or other media is passed through the one or more longitudinal pathways  320  in the space (such as space  112  from  FIG. 2 ) between the hollow shaft  302  and a lumen (such as lumen  110  from  FIG. 2 ). The inclusion of spacer assembly  310  keeps the lumen  110  separated from the hollow shaft  302 , while the longitudinal pathway  320  concurrently allows passage of liquid or media. 
     In the example shown, fins  312  are longitudinally aligned with an axis of the hollow shaft  302 , although the invention is not so limited. In one example one or more of the fins  312  are angled to direct flow of the liquid or media. In select examples directing or concentrating flow with fins may improve flushing in an operation described in more detail in  FIG. 6 . In one example, angling fins  312  provides more consistent distributed support against the lumen  110  while minimizing any reduction in flow through the longitudinal pathways  320 . In one example, only some of the fins  312  are angled. In one example, the fins  312  form a spiral finned cross section spacer. 
       FIG. 4  shows another assembly  400 . The assembly  400  is shown with a distal end  406  of a hollow shaft  402  similar to hollow shaft  102  from  FIGS. 1 and 2 . A spacer assembly  410  is shown extending from an outside surface  408  of the hollow shaft  402 . In one example the spacer assembly  410  includes an oval cross section spacer assembly  410  that includes a pair of opposed lobes  411 . In other examples, one lobe  411  or more than two lobes  411  are included on a spacer assembly  410 . In the example of  FIG. 4 , the spacer assembly  410  includes a center hole that fits over the outside surface  408  of the hollow shaft  402 . 
     Similar to the example of  FIG. 3 , in one example, the spacer assembly  410  includes at least one longitudinal pathway through the spacer assembly  410 . Arrow  420  shows a longitudinal pathway through the spacer assembly  410 , while arrow  422  shows how lobe  411  blocks longitudinal passage, or otherwise re-channels flow into a longitudinal pathway. As such, the lobes  411  define one or more longitudinal pathways  420  through the spacer assembly  410 . The inclusion of spacer assembly  410  keeps the lumen  110  separated from the hollow shaft  402 , while the longitudinal pathway  420  concurrently allows passage of liquid or media. 
       FIG. 5  shows another assembly  500 . The assembly  500  is shown with a distal end  506  of a hollow shaft  502  similar to hollow shaft  102  from  FIGS. 1 and 2 . A plurality of protrusions  510  are shown extending radially outward from an outside surface  508  of the hollow shaft  502 . In one example the plurality of protrusions  510  include rounded bumps. Although rounded bumps are shown, the invention is not so limited. Other protrusion geometries include, but are not limited to, cylinders, ovals, rounded ovals, rectangles, squares, etc. In selected examples, rounded bumps minimizes contact area and friction with an inner surface of the lumen  110 , while maintaining spacing such as space  112 . 
     Similar to the examples of  FIGS. 3 and 4 , in one example, the plurality of protrusions  510  include at least one longitudinal pathway through the spacer assembly  510 . Arrow  520  shows a longitudinal pathway through the spacer assembly  410 , while arrow  522  shows how the plurality of protrusions  510  re-channel flow into a longitudinal pathway. As such, the plurality of protrusions  510  define one or more longitudinal pathways  520 . The inclusion of the plurality of protrusions  510  keeps the lumen  110  separated from the hollow shaft  502 , while the longitudinal pathway  520  concurrently allows passage of liquid or media. In one example the plurality of protrusions  510  allow for more open space along the outside surface  508  of the hollow shaft  502  to form larger, better flowing longitudinal pathways  520  compared to fins or lobes as described above. 
     In one example the plurality of protrusions  510  are adhered to the hollow shaft  502  with a separate adhesive layer. In one example the plurality of protrusions  510  are directly attached to the hollow shaft  502 , for example deposited in a viscous state, and cooled on a surface of the hollow shaft  502 . 
     In the example shown in  FIG. 5 , the plurality of protrusions  510  are adhered to the hollow shaft  502 . In one example, the plurality of protrusions  510  are instead adhered to an inside surface of the lumen  110 . Both configurations provide the space  112  shown in  FIG. 2 , as well as a longitudinal pathway. Likewise, other configurations of spacer assemblies described in the present disclosure may be coupled to an inside surface of the lumen  110  instead of an outside surface of the hollow shaft  502 . 
     In examples described in the present disclosure, protrusions  510 , fins  312 , and lobes  411  are all examples of spacers. Although three examples of spacers are shown, the invention is not so limited. One of ordinary skill in the art, having the benefit of the present disclosure, will recognize that other shapes and sizes of spacers are also included. 
     The examples of  FIGS. 3 and 4  illustrate singular examples of spacer assemblies. In other examples, the invention is not so limited. In selected examples, multiple spacer assemblies (i.e.  310 ,  410 ) are utilized on a single hollow shaft, and spaced apart along a length of the hollow shaft. By spacing out a number of spacer assemblies, a large unobstructed space between spacer assemblies will increase flow. 
     In examples with hubs, such as spacer assembly  310  and  410 , the hubs may be adhered to the hollow shaft ( 302 ,  402 ) to fix them in place longitudinally along the hollow shaft ( 302 ,  402 ). In one example, an adhesive may be used. In one example, a mechanical interference fit may be used. In one example, the hubs of spacer assemblies  310  and  410  may be free sliding along a longitudinal axis of the hollow shaft ( 302 ,  402 ). The ability of the spacer assemblies  310  and  410  to move relative to the hollow shaft ( 302 ,  402 ) may reduce friction and/or wear. In one example, it is desirable to have spacer assemblies removable for cleaning/sterilization of reusable devices. In one example a stopper is included at a distal end of the hollow shaft ( 302 ,  402 ) to prevent one or more spacer assemblies from falling off the distal end. One example of a suitable stopper includes a polymer o-ring. In one example, multiple polymer o-rings may be used to hold free sliding spacer assemblies in place. The o-rings may later be removed in order to remove the spacer assemblies for cleaning/sterilization. In one example, the spacer assemblies are disposable, while the lithotriptor (hollow shaft, transducer, etc.) is reusable. 
     In one example all or a portion of a spacer assembly includes an elastomer material. In contrast to hard polymers, an elastomer provides a level of dampening of vibrations in a device system, such as a hollow shaft of a lithotriptor inside a lumen. In selected examples, a hard material may chatter or wear when cyclic motion is introduced, which may produce unwanted material shavings. In one example, by using an elastomer between a hollow shaft and a lumen as described, friction and/or wear is reduced or eliminated. 
     Any number of elastomer materials or combination of elastomer materials may be used. In one example, an elastomer material includes silicone. In one example, an elastomer material includes rubber. In one example, an elastomer material includes a polyether block amide. In one example, an elastomer material includes a polyurethane. In one example, an elastomer material includes a polyester. In one example the elastomer is biodegradable. A biodegradable elastomer provides an added level of safety in the event of any shavings coming off a spacer due to vibration. 
       FIG. 6  shows one example of a procedure performed using devices and components described in examples above. A lithotriptor system  600  is shown, including a hollow shaft  602  and a lumen  110 . A spacer assembly  610  is shown separating the hollow shaft  602  from the lumen  110 , and providing a space  612 . As described in examples above, in one example, spacer assembly  610  includes one or more longitudinal pathway through the spacer  610 . In the example shown, one or more o-rings  612  may be included to hold the spacer assembly  610  in place along a longitudinal axis of the hollow shaft  602 . 
     The hollow shaft  602  is shown with a distal end  606  adjacent to a stone  601  to be broken up and removed in small pieces  604 . In operation, cyclic motion is generated in the hollow shaft  602 , for example by a transducer in a handpiece as described above. The cyclic motion impacts the stone  601  and breaks off small pieces  604 . 
     In one example, concurrently to the breaking operation, a media such as a liquid is passed through the space  612  along arrow  620 . The media is allowed to pass each spacer assembly  610  through the longitudinal pathways as described in examples above. The media then flushes the small pieces  604  from the distal end  606  into an interior of the hollow shaft  602 . The media and small pieces  604  are drawn along arrow  624  and are removed. 
     As discussed above, in one example, the spacer assembly  610  includes an elastomer material that provides a level of damping to one or more components in the lithotriptor system  600 . The damping reduces or eliminates wear of components such as the hollow shaft  602  or the lumen  110 . 
       FIG. 7  shows a flow diagram of an example method that may be performed using one or more of the devices described in the present disclosure. In operation  702 , a hollow shaft is inserted into a lumen. A plurality of spacers are located between the hollow shaft and the lumen to define an infusion pathway between an outer surface of the hollow shaft and an inner surface of the lumen. In operation  704 , cyclic motion is generated along the hollow shaft. In operation  706 , a target object is broken up at a distal end of the hollow shaft with impacts from the cyclic motion. In operation  708 , fluid is infused from a proximal end of the hollow shaft to a distal end of the hollow shaft through the infusion pathway and past the plurality of lateral spacers. In operation  710 , at least some of the fluid and portions of the target object are removed through an interior of the hollow shaft. 
     To better illustrate the method and apparatuses disclosed herein, a non-limiting list of embodiments is provided here: 
     Example 1 includes a method of operating a lithotriptor. The method includes inserting a hollow shaft into a lumen, wherein a plurality of spacers are located between the hollow shaft and the lumen to define an infusion pathway between an outer surface of the hollow shaft and an inner surface of the lumen, generating cyclic motion along the hollow shaft, breaking a target object at a distal end of the hollow shaft with impacts from the cyclic motion, infusing fluid from a proximal end of the hollow shaft to a distal end of the hollow shaft through the infusion pathway and past the plurality of lateral spacers, and removing at least some of the fluid and portions of the target object through an interior of the hollow shaft. 
     Example 2 includes the method of example 1, wherein generating cyclic motion includes coupling a transducer to the hollow shaft to provide a wave signal. 
     Example 3 includes the method of any one of examples 1-2, wherein inserting the hollow shaft into the lumen includes inserting a hollow shaft into a lumen, wherein a plurality of elastomer spacers are located between the hollow shaft and the lumen with the plurality of elastomer spacers coupled to the hollow shaft. 
     Example 4 includes the method of any one of examples 1-3, further including damping at least a portion of the cyclic motion with the elastomer spacers. 
     Example 5 includes the method of any one of examples 1-4, wherein the plurality of lateral spacers includes a plurality of protruding bumps located between the hollow shaft and the lumen. 
     Example 6 includes the method of any one of examples 1-5, wherein the plurality of protruding bumps protrude from the outer surface of the hollow shaft. 
     Example 7 includes the method of any one of examples 1-6, wherein the plurality of protruding bumps protrude from the inner surface of the lumen. 
     Example 8 include a lithotriptor. The lithotriptor includes a transducer located in a handpiece, a hollow shaft extending from the handpiece and coupled to the transducer, an impact surface located at a distal end of the hollow shaft, one or more lateral elastomer spacers extending from an outside surface of the hollow shaft, and at least one longitudinal pathway through the one or more lateral spacers. 
     Example 9 includes the lithotriptor of example 8, wherein the one or more lateral elastomer spacers includes an oval cross section spacer. 
     Example 10 includes the lithotriptor of any one of examples 8-9, wherein the one or more lateral elastomer spacers includes a finned cross section spacer. 
     Example 11 includes the lithotriptor of any one of examples 8-10 wherein the finned cross section spacer includes a spiral finned cross section spacer. 
     Example 12 includes the lithotriptor of any one of examples 8-11, wherein the one or more lateral elastomer spacers are free sliding along a longitudinal axis of the hollow shaft. 
     Example 13 includes the lithotriptor of any one of examples 8-12, further including at least one o-ring retainer to hold at least one of the free sliding lateral elastomer spacers in place. 
     Example 14 includes the lithotriptor of any one of examples 8-13, wherein the one or more lateral elastomer spacers are fixed at a selected axial location along a longitudinal axis of the hollow shaft. 
     Example 15 includes the lithotriptor of any one of examples 8-14, wherein the one or more lateral elastomer spacers include silicone spacers. 
     Example 16 includes the lithotriptor of any one of examples 8-15, wherein the one or more lateral elastomer spacers include a biodegradable elastomer spacer. 
     Example 17 includes a lithotriptor. The lithotriptor includes a transducer located in a handpiece, a hollow shaft extending from the handpiece and coupled to the transducer, an impact surface located at a distal end of the hollow shaft, and a plurality of protrusions extending radially outward from an outside surface of the hollow shaft. 
     Example 18 includes the lithotriptor of example 17, wherein the plurality of protrusions includes elastomer protrusions. 
     Example 19 includes the lithotriptor of any one of examples 17-18, wherein the elastomer protrusions include silicone protrusions. 
     Example 20 includes the lithotriptor of any one of examples 17-19, wherein the plurality of protrusions includes rounded bumps. 
     Example 21 includes the lithotriptor of any one of examples 17-20, wherein the plurality of protrusions includes a biodegradable elastomer. 
     Throughout this specification, plural instances may implement components, operations, or structures described as a single instance. Although individual operations of one or more methods are illustrated and described as separate operations, one or more of the individual operations may be performed concurrently, and nothing requires that the operations be performed in the order illustrated. Structures and functionality presented as separate components in example configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements fall within the scope of the subject matter herein. 
     Although an overview of the inventive subject matter has been described with reference to specific example embodiments, various modifications and changes may be made to these embodiments without departing from the broader scope of embodiments of the present disclosure. Such embodiments of the inventive subject matter may be referred to herein, individually or collectively, by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single disclosure or inventive concept if more than one is, in fact, disclosed. 
     The embodiments illustrated herein are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed. Other embodiments may be used and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. The Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. 
     As used herein, the term “or” may be construed in either an inclusive or exclusive sense. Moreover, plural instances may be provided for resources, operations, or structures described herein as a single instance. Additionally, boundaries between various resources, operations, modules, engines, and data stores are somewhat arbitrary, and particular operations are illustrated in a context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within a scope of various embodiments of the present disclosure. In general, structures and functionality presented as separate resources in the example configurations may be implemented as a combined structure or resource. Similarly, structures and functionality presented as a single resource may be implemented as separate resources. These and other variations, modifications, additions, and improvements fall within a scope of embodiments of the present disclosure as represented by the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. 
     The foregoing description, for the purpose of explanation, has been described with reference to specific example embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the possible example embodiments to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The example embodiments were chosen and described in order to best explain the principles involved and their practical applications, to thereby enable others skilled in the art to best utilize the various example embodiments with various modifications as are suited to the particular use contemplated. 
     It will also be understood that, although the terms “first,” “second,” and so forth may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first contact could be termed a second contact, and, similarly, a second contact could be termed a first contact, without departing from the scope of the present example embodiments. The first contact and the second contact are both contacts, but they are not the same contact. 
     The terminology used in the description of the example embodiments herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used in the description of the example embodiments and the appended examples, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     As used herein, the term “if” may be construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context. Similarly, the phrase “if it is determined” or “if [a stated condition or event] is detected” may be construed to mean “upon determining” or “in response to determining” or “upon detecting [the stated condition or event]” or “in response to detecting [the stated condition or event],” depending on the context.