This application claims the benefit of priority from U.S. Provisional Application No. 63/156,079, filed on Mar. 3, 2021, which is incorporated by reference herein in its entirety.
The present disclosure relates generally to devices, systems, and methods for vapor generation and, in particular, vapor generators for vapor ablation devices.
Certain medical conditions, such as conditions of the prostate, may be treated by ablation, including by vapor ablation. Such ablation may be performed using a device having a sheath that is inserted into a body lumen or otherwise into a body of a patient. Vapor (e.g., water vapor) may be released from the device in order to ablate tissue, such as prostate tissue, or otherwise treat tissue. The vapor may be generated by a vapor generator of the device. It may be desirable for the generator to occupy a smaller footprint than current generators and to efficiently produce high-quality vapor.
The systems, devices, and methods of the current disclosure may rectify some of the deficiencies described above, and/or address other aspects of the prior art.
In an exemplary arrangement, a vapor generator for use in a medical device may include a heating core in fluid communication with a source of fluid and defining at least one fluid pathway along which fluid from the source of fluid travels. The at least one fluid pathway may include one or more surfaces that generate turbulence in the fluid. The vapor generator may also include a coil disposed about the heating core, wherein the coil is configured to receive a current so as to heat the fluid traveling along the at least one fluid pathway, thereby generating a vapor.
The coil may be configured to inductively heat the fluid.
The heating core may include a latticed body, and one or more struts of the latticed body may define the one or more surfaces that generate the turbulence in the fluid.
The heating core may further include a sheath disposed about the latticed body.
The latticed body may include Inconel.
The latticed body may have an approximately cylindrical shape.
The latticed body may define a plurality of openings defined by a plurality of struts.
All of the openings may be in fluid communication with one another.
The at least one fluid pathway may define a plurality of routes of fluid travel along (a) a path approximately parallel to a longitudinal axis of the latticed body and (b) a path transverse to the longitudinal axis of the latticed body.
At least a portion of the heating core may be disposed within a needle of the medical device.
A portion of the needle having the heating core may be disposed within a shaft insertable into a body lumen of a subject.
The heating core may include a tube, and the tube may define a lumen having a textured wall surface. The textured wall surface may generate the turbulence in the fluid.
The tube may form a coil.
The heating core may include two or more coils.
The tube may have a non-circular cross-section.
In another exemplary arrangement, a vapor generator for use in a medical device may include a latticed body in fluid communication with a source of fluid and defining a plurality of fluid pathways along which fluid from the source of fluid travels. The latticed body may include a plurality of struts defining a plurality of openings. The vapor generator may further include a coil disposed about the latticed body. The coil may be configured to receive a current so as to heat the fluid traveling along the plurality of fluid pathways, thereby generating a vapor.
The plurality of fluid pathways define routes of fluid travel along (a) a path approximately parallel to a longitudinal axis of the latticed body and (b) a path transverse to the longitudinal axis of the latticed body.
At least a portion of the latticed body may be disposed within a needle of the medical device.
The latticed body may have an approximately cylindrical shape.
In a further exemplary arrangement, a vapor generator for use in a medical device may include a latticed body in fluid communication with a source of fluid and defining a plurality of fluid pathway along which fluid from the source of fluid travels. The plurality of fluid pathways may define routes of fluid travel along (a) a path approximately parallel to a longitudinal axis of the latticed body and (b) a path transverse to the longitudinal axis of the latticed body. The vapor generator may further include a coil disposed about the latticed body. The coil may be configured to receive a current so as to heat the fluid traveling along the plurality of fluid pathways, thereby generating a vapor.
It may be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. The term “exemplary” is used in the sense of “example,” rather than “ideal.” As used herein, the term “proximal” means a direction closer to an operator and the term “distal” means a direction further from an operator. Although vapor ablation is referenced herein, such references should not be construed as limiting. The examples disclosed herein may also be used with other types of ablation mechanisms (e.g., cryoablation, RF ablation, or other types of ablation) or with other devices not relating to ablation.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate examples of the present disclosure and together with the description, serve to explain the principles of the disclosure.
A vapor generator for a vapor ablation device may include a radio frequency (“RF”) coil surrounding a conductive body that defines a pathway through which fluid (e.g., water) may pass. The conductive body may be formed via additive manufacturing, such as three-dimensional (“3D”) metal printing. A current through the RF coil may produce an electromagnetic flux, causing current(s) (e.g., eddy currents) in the conductive body, and heating of the conductive body. The heating of the conductive body may cause heating of water passing therethrough, thereby generating water vapor. The conductive body may include, for example, a conductive mesh, lattice, or one or more coils. The generator (RF coil and conductive body) may be disposed within a handle of the vapor ablation device or within a shaft of the vapor ablation device. The water vapor may be conveyed to a treatment site in order to therapeutically treat a tissue. For example, the vapor may ablate the tissue. In one example, the ablated tissue may be prostate tissue, and the ablation may treat benign prostatic hyperplasia (BPH).
A needle 24 may be extendable and/or retractable from distal tip 12. Needle 24 may be a member having a central lumen or channel extending from a proximal end of needle 24 toward a distal tip of needle 24, and a plurality of apertures near the distal tip of needle 24. The plurality of apertures may be configured to communicate the contents of the central lumen or channel (e.g., vapor, steam) to surrounding tissue into which needle 24 is positioned, received, or otherwise inserted. For example, the central lumen or channel of needle 24 may be configured to receive vapor therein (e.g., via a vapor generator) and to deliver the vapor to tissue via the apertures. Needle 24 may be configured to have a first, insertion configuration, in which needle 24 is contained, received, or otherwise positioned within shaft 11 (e.g., such that no portion of needle 24 extends radially outwardly of distal tip 12, relative to a longitudinal axis of distal tip 12). Needle 24 may have a second, treatment configuration (
Handle 50 may include cabling 52 extending proximally from a proximal end of handle 50. Cabling 52 may transmit power, fluids, signals, etc. to handle 50 or other portions of ablation device 10 (e.g., shaft 11). In an example, cabling 52 may transmit fluid, such as water, from a fluid source to ablation device 10. In some embodiments, a vapor generator (to be discussed in further detail, with respect to
Coil 162 may carry an RF current or other alternating current. Coil 162 may have any features that assist coil 162 in carrying current. Coil 162 may be made from any suitable material and may contain any suitable number of windings. For example, coil 162 may include a Litz wire (a type of wire that is particularly efficient at carrying RF energy). As alternating current passes through coil 162, the current may generate one or more magnetic fields. Coil 162 may be constructed from turned wire. Alternatively, coil 162 may be formed by additive manufacturing methods, including, for example, extrusion, binder jetting, powder bed fusion, or any other suitable form of additive manufacturing/3D metal printing. Coil 162 may include an insulating material to prevent current from coil 162 from passing to other structures or between turns of coil 162.
Core 170 may include a latticed body 172 and a sheath 174. Latticed body 172 may have an approximately cylindrical overall shape having a first end 176 and a second end 178. Latticed body may include a plurality of cells having a plurality of struts meeting at a plurality of nodes. Latticed body 172 may include one cell structure that is repeated a plurality of times in a pattern or a plurality of cell structures that may be repeated in a pattern. Each cell may include an opening defined by the struts. The openings of the plurality of cells may all be in fluid communication with one another. Fluid may flow from first end 176 to second end 178, via the fluidly connected openings. Alternatively, the openings may define a plurality of pathways that extend from first end 176 to second end 178 but are not in fluid communication with one another between first end 176 and second end 178. Latticed body 172 may be formed of one of more conductive materials and may be formed via any of the additive manufacturing techniques described above. For example, latticed body 172 may be formed of a printable material exhibiting high thermal conductivity such as copper. Additionally or alternatively, latticed body 172 may be formed of a printable material exhibiting a combination of high thermal conductivity and biocompatibility such as 17-4 stainless, Inconel, 316L stainless, Cobalt Chromium (CoCr), etc. A material of latticed body 172 may be uniform or may be varied in order to maximize efficiency of the energy transfer described below. In some arrangements, a material of latticed body 172 may be formed via powder bed fusion.
Sheath 174 may encase an outer surface of latticed body 172 between first end 176 and second end 178, such that fluid may not pass out of the side of latticed body 172 between first end 176 and second end 178. Sheath 174 may be formed of any suitable material, such as metal or non-metal. Sheath 174 may be formed by any suitable manufacturing method, such as from a sheet of material or via additive manufacturing. Sheath 174 may be formed of the same material as latticed body 172 or from a different material. Sheath 174 may be fixed to latticed body 172 via, for example, adhesive, welding, or by frictional fit. Together, sheath 174 and latticed body 172 may form a tube (sheath 174) having a lattice infill (latticed body 172).
Core 170 may be positioned in a center of coil 162. As shown in
As current flows through coil 162, a source of fluid (e.g., water) may cause fluid to flow into first end 176 of latticed body 172. Latticed body 172 may define a fluid pathway through which the fluid from the source of fluid may travel. The fluid pathway may include numerous branches, and a particular route the fluid follows may vary. For example, routes may facilitate movement of fluid approximately parallel to a longitudinal axis of latticed body 172 and transverse to the longitudinal axis of latticed body 172. As fluid passes the struts of the latticed body 172 and/or sheath 174, the heat may be transferred from latticed body 172 and/or sheath 174 to the fluid, thereby heating the fluid. Flow through latticed body 172 may be turbulent and provide a large amount of surface area to contact the fluid and heat it. The turbulence may promote an efficient heat flow. The fluid may be sufficiently heated such that a vapor is generated. For example, substantially all of the fluid may be transformed to vapor. The configuration of latticed body 172 may provide a large amount of surface area for the fluid to contact, providing efficient heating. As compared with a coil through which fluid flows through in order to be heated, latticed body 172 may provide the same heating (due to the large surface area of latticed body 172 that contacts the fluid) while occupying a smaller footprint. The smaller footprint may facilitate manufacturing efficiencies and/or a smaller size of ablation device 10. For example, vapor generator 160 may occupy a smaller amount of space in handle 50 of ablation device 10, allowing handle 50 to be manufactured with a smaller size, making room for additional components (e.g., control boards or other electronics), allowing alternative positions of vapor generator 160 within handle 50, or easing manufacturing of handle 50 due to a greater availability of space. Furthermore, as discussed above, a smaller profile of vapor generator 160 may allow placement of generator 160 in shaft 11.
As compared to a coil, for example, a length of a path of the fluid may be shorter through latticed body 172, providing for faster travel through vapor generator 160, thereby resulting in more efficient heat transfer. That is, an overall length of the path traveled by a fluid passing through the lattice may be shorter than an overall length of the path of fluid passing around the various turns of a coil. The efficient heat transfer from core 170 to the fluid produces a high-quality, uniform vapor. Vapor quality is the ratio of water to vapor in a mixture. For example, a mixture may start with 100% water and 0% vapor. However, as heat is added, a phase change occurs and the percentage amount of vapor increases. Eventually, all water is converted to vapor such the mixture includes 0% water and 100% vapor. Higher vapor quality (e.g., the higher the ratio) is ideal for treating tissue (e.g., prostate tissue) as vapor is a gas and may pass through interstitial space in the tissue easier (e.g., more freely) than a liquid.
Vapor generator 160 may have additional elements that are not shown in
Although latticed bodies 372, 472, 572 are separately described below, it will be appreciated that the properties described below may be combined with one another in any combination. Shapes and structures may be mixed and matched to generate a wide variety of patterns. The patterns of latticed bodies 372, 472, 572, below, are merely exemplary. A wide variety of structures/patterns may be used within the scope of this disclosure.
As shown in
The spaces between the clover/rounded “X” shaped struts and the struts connecting the various layers may form openings through which fluid may pass. All of the openings may be in fluid communication with one another. Water, or another fluid, may thus be passed from a first end of latticed body 372 to a second end of latticed body 372. The fluid may also pass laterally (perpendicularly to a longitudinal axis of latticed body 372) through latticed body 372. Fluid traveling through latticed body 372 may traverse a variety of paths, contacting the struts of latticed body 372 as it travels through latticed body 372. As discussed above, the struts of latticed body 372 may heat the fluid.
The layers of latticed body 472 may all be the same and have the same orientation, such that the openings are aligned with one another along the longitudinal axis of latticed body 472. Alternatively, the layers of latticed body 472 may be offset from one another such that the openings are not aligned. For example, layers of latticed body 472 may be rotated relative to one another or may be laterally offset from one another. The layers of latticed body 472 (and/or the other latticed bodies described herein) may also be angled such that planes defined by the layers are not normal to the longitudinal axis. The layers may have different angles relative to one another or the same angle.
As discussed above relative to latticed body 372, fluid may flow in a general longitudinal direction through latticed body 472. The fluid may take a variety of paths, traveling longitudinally and laterally as it moves in an overall longitudinal direction from a first end of latticed body 472 to a second end of latticed body 472. The struts of latticed body 472 may be heated, as described above relative to
While latticed bodies 372, 472 may have non-uniform cross-sections (discrete struts may join layers to one another), latticed body 572 may have uniform cross-sections. The pattern shown in
As discussed above relative to latticed bodies 372, 472, fluid may flow in a general longitudinal direction through latticed body 572. Where the channels are discrete, fluid may be retained within individual channels. Where the channels are in fluid communication, the fluid may take a variety of paths, traveling longitudinally and laterally as it moves in an overall longitudinal direction from a first end of latticed body 572 to a second end of latticed body 572. The struts of latticed body 572 may be heated, as described above relative to
A portion of needle 624 (e.g., approximately six inches of needle 624) proximal of a bendable portion may include (or form) at least a portion of vapor generator 660, which may be any suitable material (e.g., Inconel). Including vapor generator 660 at least partially within (or as a portion of) needle 624 may provide very pure vapor for delivery to a tissue as such a location minimizes the distance between the vapor generator and the target tissue, thereby minimizing any condensation that may occur along the vapor delivery path. As noted above, vapor delivered from vapor generator 660 may have a small distance to travel, as compared to other locations of a vapor generator. Such positioning of vapor generator 660 within (or as a part of) needle 624 may also reduce or eliminate a need to cool an outer jacket of needle 624. For example, as opposed to arrangements where the vapor generator is positioned elsewhere, such as a handle, thereby requiring temperatures of the handle and the entirety of the shaft to be controlled so as not to exceed an acceptable temperature threshold for handling, the positioning of vapor generator 660 along a distal end of shaft 611 (within or as part of needle 624) permits cooling of only this portion of shaft 611.
In one example, a sheath of needle 624 may surround vapor generator 660. In another example, generator 660 may form an outer surface of needle 624. Vapor generator 660 may include a coil 162, as described above, with respect to
The layers of latticed body 772 may all be the same and may be oriented the same, such that the openings are aligned with one another along the longitudinal axis of latticed body 772. Alternatively, the layers of latticed body 772 may be offset from one another such that the openings are not aligned. For example, layers of latticed body 772 may be rotated relative to one another or may be laterally offset from one another. The layers of latticed body 772 (and/or the other latticed bodies described herein) may also be angled such that planes defined by the layers are not normal to the longitudinal axis. The layers may have different angles relative to one another or the same angle.
As discussed above relative to latticed bodies 372, 472, and 572 fluid may flow in a general longitudinal direction through latticed body 772. The fluid may take a variety of paths, traveling longitudinally and laterally as it moves in an overall longitudinal direction from a first end of latticed body 772 to a second end of latticed body 772. The struts of latticed body 772 may be heated, as described above relative to
The layers of latticed body 872 may all be identical and may be oriented the same, such that the openings are aligned with one another along the longitudinal axis of latticed body 872. Alternatively, the layers of latticed body 872 may be offset from one another such that the openings are not aligned. For example, layers of latticed body 872 may be rotated relative to one another or may be laterally offset from one another. The layers of latticed body 872 (and/or the other latticed bodies described herein) may also be angled such that planes defined by the layers are not normal to the longitudinal axis. The layers may have different angles relative to one another or the same angle.
As discussed above relative to latticed bodies 372, 472, 572, 772, fluid may flow in a general longitudinal direction through latticed body 872. The fluid may take a variety of paths, traveling longitudinally and laterally as it moves in an overall longitudinal direction from a first end of latticed body 872 to a second end of latticed body 872. The struts of latticed body 872 may be heated, as described above relative to
The layers of latticed body 972 may all be the same and may be oriented the same, such that the openings are aligned with one another along the longitudinal axis of latticed body 972. Alternatively, the layers of latticed body 972 may be offset from one another such that the openings are not aligned. For example, layers of latticed body 972 may be rotated relative to one another or may be laterally offset from one another. The layers of latticed body 972 (and/or the other latticed bodies described herein) may also be angled such that planes defined by the layers are not normal to the longitudinal axis. The layers may have different angles relative to one another or the same angle.
As discussed above relative to latticed bodies 372, 472, 572, 772, and 872, fluid may flow in a general longitudinal direction through latticed body 972. The fluid may take a variety of paths, traveling longitudinally and laterally as it moves in an overall longitudinal direction from a first end of latticed body 972 to a second end of latticed body 972. The struts of latticed body 972 may be heated, as described above relative to
As discussed above relative to latticed bodies 372, 472, 572, 772, 872, and 972, fluid may flow in a general longitudinal direction through latticed body 1072. The fluid may take a variety of paths, traveling longitudinally and laterally as it moves in an overall longitudinal direction from a first end of latticed body 1072 to a second end of latticed body 1072. The struts of latticed body 1072 may be heated, as described above relative to
Fluid coils 1182, 1184 may define one of more fluid pathways through which fluid from a source of fluid may travel. Fluid coil 1182 may be encapsulated by a sheath 1164 which may insulate fluid coils 1182, 1184 from RF coil 1162, or vice versa. As such, sheath 1164 may be formed of a high temperature thermoplastic such as polyimide. Sheath 1164 may be insulative so as to prevent a direct flow of current from RF coil 1162 to fluid coil(s) 1182 and/or 1184. RF coil 1162 may heat fluid coils 1182, 1184, as described above with respect to RF coil 162 of vapor generator 160.
As noted above, first fluid coil 1182 and second fluid coil 1184 may be concentrically arranged. For example, second fluid coil 1184 may be disposed within first fluid coil 1182. A first lumen 1183 may extend through first fluid coil 1182, and a second lumen 1183 may extend through second fluid coil 1184. First lumen 1183 and second lumen 1185 may be in fluid communication with one another. Fluid may pass through first lumen 1183 and second lumen 1185 during heating. Fluid may first pass through one of fluid coils 1182, 1184, and then through the other of fluid coils 1182, 1184. For example, a fluid source may provide fluid to one end of one of fluid coils 1182, 1184. Fluid may travel through lumen 1183 or 1185 to the other end of the one of fluid coils 1182, 1184. Fluid may then pass into lumen 1183 or 1185 of the other of fluid coils 1182, 1184 and may flow through lumen 1183 or 1185 until it reaches an end of the other of fluid coils 1182, 1184. Lumens 1183 and 1185 may be directly joined together such that fluid enters and exits at the same end of vapor generator 1160. Alternatively, a piece of tubing (not shown) may span lumens 1183 and 1185. In such a configuration, fluid may flow in one end of vapor generator 1160 and out the other end of vapor generator 1160 or may flow into and out of the same end of vapor generator 1160. It is understood that fluid coils 1182, 1184 may be formed via 3D printing such that numerous configurations of coils 1182, 1184 may be realized. For example, in some arrangements, multiple independent fluid pathways may be formed, or one continuous winding pathway may be formed. In some arrangements, a fluid coil may start at one end, wind upwardly in a circular fashion toward a second end, then fold (e.g., invert, turn) in on itself to form an inner coil and wind downwardly back toward the first end. In another arrangement, a first coil layer of a fluid coil may wind in a first direction (e.g., clockwise) to form a circular or semi-circular shaped outer segment, and then turn in towards a center of the segment and wind in a second direction (e.g., counter-clockwise) to form an inner coil segment. This pattern may then be repeated forming numerous layers along a longitudinal length.
Fluid coils 1182 and 1184 may be formed of any suitable material, such as Inconel. Fluid coils 1182 and 1184 may be formed of the same material or from different materials. A material may also vary along a single coil. A thickness of walls of fluid coils 1182, 1184 may be uniform or may be varied in order to provide a desired heating profile. Fluid coils 1182 and/or 1184 may be formed by winding a tubing. Alternatively, fluid coils 1182 and/or 1184 may be formed via additive manufacturing, including any of the techniques described above with respect to vapor generator 160.
Generator 1160 may provide benefits over a generator that uses only one fluid coil. Generator 1160 may provide the same length of fluid travel within a smaller footprint, due to the concentric coils. The smaller footprint may have any of the benefits described above, with respect to generator 160. Indeed, generator 1160 may produce higher quality vapor than previously existing generators as a length of the heating pathway may be doubled or otherwise increased, thereby increasing the amount of time the fluid is positioned inside the heating coil.
Eliminating gaps that would otherwise exist with a coil having a rounded cross-section may provide for more efficient heat transfer along coil 1780. Heat may conduct through coil 1780 (and any of the cores, latticed bodies, and coils disclosed herein), and infill 1796, 1798 may improve such heat transfer and thereby provide higher quality vapor and may result in a shorter path of travel required for fluid, thereby allowing a length of coil 1780 to be decreased. A decrease in length of coil 1780 may provide for the space-saving efficiencies described above with respect to generator 160. Coil 1780 may be formed of any suitable material, such as Inconel and by any suitable method, such as any of the additive manufacturing techniques described herein. A material of coil 1780 may be uniform or non-uniform, in order to provide efficient heating. Widths of wall 1792 and/or infill 1796, 1798 may be uniform or may vary in order to efficiently heat fluid passing through the lumen of coil 1780.
Any of the devices described herein may have additional features to provide for more efficient heat and/or energy transfer. For example, the examples described herein may include features that are formed by any of the additive manufacturing methods described herein. For example, features such as thickened or flattened portions of any of the coils or cores disclosed herein may be formed to provide for improved connections between thermocouples and/or Litz wires and the coils/cores. The thickened or flattened portions may provide landing pads for the wires of thermocouples, Litz wires, or other structures, so as to improve welding of various structures by adding robust areas/thickened portions to which the thermocouples, Litz wires, or other structures adhere so as to avoid or reduce areas/welds susceptible to breaking or leaking.
While principles of the present disclosure are described herein with reference to illustrative examples for particular applications, it should be understood that the disclosure is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and substitution of equivalents all fall within the scope of the examples described herein. Accordingly, the invention is not to be considered as limited by the foregoing description.
Number | Date | Country | |
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63156079 | Mar 2021 | US |