Infusion Module of an Electrosurgical Instrument

Abstract

It is a medical device that delivers liquid to an electrosurgical instrument. A plunger is movably disposed and biased within a fluid reservoir. The plunger includes a first colored portion and a second colored portion. The first colored portion is visible through a window when the fluid reservoir contains a first volume, and the movement of the plunger is configured to expose the second colored portion when the fluid reservoir discharges liquid. The housing of the medical device may include a first shell with a female snap and a second shell with a male snap. The female snap includes a female annular protrusion, a female snap undercut portion, and a central locking feature. The central locking feature is received within a male annular protrusion and extends from the first shell to an axial position closer to the distal end of the female annular protrusion than the female snap undercut portion.

Description

Technical Field

[0001] The present invention relates to an infusion module of an electrosurgical instrument.

[0002] [Claiming Priority] This application claims the priority and all benefits of U.S. Provisional Patent Application No. 63 / 352,686, filed on June 16, 2022, the entire content of which is incorporated herein by reference.

Background Art

[0003] High-frequency (RF) energy is generally utilized to ablate diseased tissue to treat pain or pathology. The tissue can be, among other anatomical structures, a sensory nerve, an intramedullary nerve, or an intramedullary tumor. Conventionally, an electrode is coupled to an electrosurgical console, and RF energy is conducted from the electrode to the tissue across the electrode-tissue interface, resulting in a lesion at the treatment site. In the case of an intramedullary tumor, RF energy often heats the tissue to at least 90°C (194°F) to destroy the tumor cells. Due to the high temperature at the treatment site, the infusion of a fluid such as saline into the treatment position can limit carbonization by improving the conductivity of the electrode-tissue interface. Thus, providing a continuous and consistent infusion of fluid into the treatment site can enhance the effectiveness of the ablation procedure while reducing the risks associated with such a procedure.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Although it is known to supply cooling or irrigation fluid using an electronically controlled fluid pump system, the structure can be complex and the operation can be cumbersome. One solution is the injection module disclosed in International Publication No. WO 2020 / 198150 of the same applicant, published on October 1, 2020, in which a spring is biased within a housing to provide consistent delivery of fluid to the treatment site. There remains room for further improvement to enhance the robustness and usability of the injection module.

Means for Solving the Problem

[0005] According to a first aspect of the present disclosure, a medical device for delivering a liquid to an electrosurgical instrument includes a housing defining a window. A fluid reservoir is disposed within the housing and configured to receive the liquid. At least a portion of the fluid reservoir is transparent. A plunger is movably disposed within the fluid reservoir and includes a first colored portion and a second colored portion, the second colored portion being a different color from the first colored portion. A spring is disposed within the housing and configured to bias the plunger to discharge the injection fluid to the electrosurgical instrument. The medical device is configured to be visible to a user such that the first colored portion of the plunger is visible through the window when the fluid reservoir contains a first volume of the liquid, while the plunger is configured to expose the second colored portion of the plunger within the window when the fluid reservoir discharges at least a portion of the liquid such that the fluid reservoir contains a second volume of the liquid that is less than the first volume.

[0006] According to a second aspect of the present disclosure, a medical device for delivering a liquid to an electrosurgical instrument comprises a housing defining a window. A fluid reservoir is disposed within the housing and configured to receive the liquid. At least a portion of the fluid reservoir is transparent. A plunger is movably disposed within the fluid reservoir and includes a first colored portion and a second colored portion, the second colored portion being of a color different from that of the first colored portion. A spring is disposed within the housing and configured to bias the plunger to discharge the infusion fluid to the electrosurgical instrument. The medical device is configured to be visible to a user such that the second colored portion of the plunger is visible through the window, indicating a small volume of infusion fluid, with less than about 20% of the filled volume (fill volume) of liquid remaining in the fluid reservoir.

[0007] According to a third aspect of the present disclosure, a method for monitoring the delivery of a liquid during an ablation procedure using a medical device is provided. With the fluid reservoir containing a first volume of liquid, the sealing head of the plunger is visible through the window. The medical device is operated to discharge a portion of the liquid from the fluid reservoir. With the fluid reservoir containing a second volume of liquid smaller than the first volume, the first colored portion of the plunger is visible through the window. The medical device can be further operated to discharge another portion of the liquid from the fluid reservoir. With the fluid reservoir containing a third volume of liquid smaller than the first volume and the second volume, the second colored portion of the plunger is visible through the window.

[0008] According to a fourth aspect of the present disclosure, a medical device housing is provided in which a first shell includes a female snap and a second shell includes a male snap. The female snap includes a female annular protrusion extending from a distal end of the first shell, a female snap undercut portion extending inwardly from the female annular protrusion, and a central locking feature disposed within the female annular protrusion. The male snap includes a male annular protrusion extending from a distal end of the second shell and received (inserted) within the female annular protrusion. The central locking feature is received within the male annular protrusion. A male snap undercut portion extends outwardly from the male annular protrusion and engages the female snap undercut portion. Additionally, the central locking feature extends from the first shell to an axial position closer to the distal end of the female annular protrusion than the female snap undercut portion.

[0009] According to a fifth aspect of the present disclosure, a medical device housing is provided in which a first shell includes a female snap and a second shell includes a male snap. The female snap includes a female protrusion extending from the first shell a first distance and defining a first void. A female snap undercut portion extends into the first void and is located a second distance from the first shell. A central locking feature is disposed within the first void. The male snap includes a male protrusion extending from the second shell and defining a second void. The male protrusion is received within the first void and the central locking feature is received within the second void. A male snap undercut portion extends away from (so as to be away from) the second void. The male snap undercut portion extends outwardly from the male protrusion and engages the female snap undercut portion. Additionally, the central locking feature extends from the first shell to a third distance greater than the second distance.

[0010] According to a sixth aspect of the present disclosure, there is provided a medical device housing in which a first shell includes a female snap and a second shell includes a male snap. The female snap includes a female protrusion extending from the first shell and defining a first void and at least one slot. A female snap undercut extends inwardly from the female protrusion. A central locking feature is disposed within the first void of the female protrusion. The male snap includes a male protrusion extending from the second shell and defining a second void and at least one slot. The male protrusion is received within the first void and the central locking feature is received within the second void. A male snap undercut extends outwardly from the male protrusion and engages the female snap undercut. In addition, these slots are configured to allow deflection (deformation) of at least one of the female protrusion and the male protrusion to enable the female snap to be mated with the male snap. The central locking feature extends from the first shell to an axially positioned state configured (set) to limit or prevent inward deflection of the male protrusion when the first snap is mated with the second snap.

[0011] Any of the above aspects may be combined, in part or in whole, with any other aspect. Regardless of whether any of the above aspects are combined in part or in whole, they may be further combined, in whole or in part, with any of the following embodiments.

[0012] In certain embodiments, with the fluid reservoir containing a first volume of liquid, the second colored portion is not visible through the window. With the fluid reservoir containing a first volume of liquid, the liquid may be visible through the window. The first colored portion and the second colored portion may extend across the length of the window, indicating that the fluid reservoir is substantially empty.

[0013] In certain embodiments, the plunger further comprises a sealing head that is a different color than the first and second colored portions, and the sealing head is visible through the window with the fluid reservoir containing a third volume of liquid that is greater than the first volume. The third volume may indicate that the fluid reservoir is substantially filled with liquid. The plunger may be coaxially disposed within the spring and include a support member that engages an internal shelf of the housing. The plunger can be formed from a material the same color as the first colored portion, with the second colored portion being coupled to the plunger. The window can be oblong (rectangular, oval, elliptical), and the length of the window can correspond to approximately 6 milliliters of liquid visible within the fluid reservoir. The fluid reservoir can be without volume markings.

[0014] In certain embodiments, the device includes a first inlet, a second inlet, and an outlet, and a port assembly that defines a valve. The valve can be configured to direct liquid injected from an external source into the fluid reservoir through the first inlet, and further to direct liquid discharged from the fluid reservoir through the second inlet and through the outlet. The port assembly can engage a second internal barrier of the housing to resist movement of the fluid reservoir by a force from a plunger biased by a spring. The outlet can be oriented (directed) orthogonal to each of the first and second inlets. The device can further include a collar coupled to the fluid reservoir and to the valve by a luer fitting. The collar can be configured to be adjusted to rotatably orient such that the second inlet is aligned with an opening during assembly of the housing.

[0015] In certain embodiments, the female snap undercut portion comprises a distal inclined surface and a proximal inclined surface that directly engages a complementary proximal inclined surface of the male snap undercut portion. In certain embodiments, the axial position of the central locking feature is closer to the distal end of the female annular protrusion than the transition between the distal inclined surface and the proximal inclined surface. In certain embodiments, the female snap undercut portion further comprises a transition surface between the distal inclined surface and the proximal inclined surface.

[0016] In certain embodiments, at least one of the female annular protrusion and the male annular protrusion defines at least one slot configured to permit flexure of at least one of the female annular protrusion and the male annular protrusion to allow the female snap to be mated with the male snap. Each of the female protrusion and the male protrusion can be of an annular shape, and the female snap undercut portion and / or the male snap undercut portion can be of a ring shape. The central locking feature is configured to limit or prevent inward flexure of the male annular protrusion in a state where the first snap is mated with the second snap. The central locking feature can be coaxially disposed within the female annular protrusion. The central locking feature can be tapered in a direction away from the first shell. The at least one slot can be two slots longitudinally extending from the respective distal ends of the female annular protrusion and the male annular protrusion. The two slots can be diametrically opposed to each other. A portion of the female snap undercut portion and a portion of the male snap undercut portion can be disposed on each side of the two slots of each of the female annular protrusion and the male annular protrusion.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Figure 7A - 7D

Figure 8A

Figure 8B

Modes for Carrying Out the Invention

[0018] During radio-frequency (RF) ablation procedures, it is often useful to deliver a conductive fluid to the treatment site to enhance the effectiveness of ablation while reducing the potential to carbonize the tissue located at the treatment site. Therefore, an electrosurgical system including an injection module is provided. Referring to FIG. 1, the electrosurgical system 100 includes an electrosurgical console 110, one or more electrosurgical instruments 120, and optionally a cable accessory 112. The cable accessory 112 is configured to be removably coupled to the electrosurgical console 110, and the electrosurgical instrument(s) 120 is configured to be removably coupled to the electrosurgical console 110 and / or the cable accessory 112. The electrosurgical instrument(s) 120 can be a bipolar electrode, such as a self-grounding bipolar electrode, provided by a proximal electrode 122 and a distal electrode 124 that provide a current path through the tissue to be ablated. Put simply, the electrosurgical instrument 120 can be an ablation probe. The ablation probe can include a thermocouple for providing a temperature measurement of the tissue near the electrode(s) 122, 124. Additional thermocouples can also be utilized to notify the user if ablation heat has migrated to an undesirable location, for example, by monitoring a point of interest such as the soft tissue of the spinal canal. In addition to this, the electrosurgical system 100 includes an injection module 200. The injection module(s) 200 can direct a fluid (e.g., a liquid) through (via) the electrosurgical instrument(s) 120 so as to be discharged near the proximal electrode 122 and the distal electrode 124. One preferred embodiment of the electrosurgical instrument(s) 120 is disclosed in International Publication No. WO 2020 / 198150 mentioned above.

[0019] The electrosurgical system 100 is configured to treat tissue, i.e., by RF ablation. The electrosurgical console 110 generates controlled high-frequency electrical energy and passes the energy through the electrosurgical instruments 120A, 120B and the tissue, thereby heating the tissue to a temperature sufficient to destroy the cells of the tissue. The ablation can be performed by a self-grounding bipolar configuration, which is detailed in International Publication No. WO 2018 / 200254 of the same applicant, published on November 1, 2018. The entire disclosure thereof is incorporated herein by reference. In certain embodiments, the electrosurgical system 100 is utilized to ablate nerves for pain management. In other embodiments, the electrosurgical system 100 is utilized to ablate lesions, particularly intraosseous tumors. An exemplary treatment of particular interest is the ablation of a tumor within a vertebral body. An introducer assembly is deployed through the pedicle of the vertebral body to facilitate access into the vertebral body, and the electrosurgical console 110 applies temperature-controlled RF energy into the tumor. Ablation of the nerves associated with or surrounding the tumor within the tumor can also provide pain relief. It should be understood that by using the electrosurgical system 100 of the present disclosure, intraosseous tumors such as long bones, skulls, mandibles, ileums, etc. can be treated.

[0020] As shown in FIG. 1, the electrosurgical console 110 includes a display 114 configured to display a graphical user interface (GUI) 116 that enables a user to select operating parameters provided by software on the electrosurgical console 110, among other actions. The display 114 is, in one example, a touch screen and uses touch locations capacitively sensed on the touch screen to enable selection of digital displays presented on the display 114. The electrosurgical console 110 generally includes a controller, one or more processors, and memory. Computer-executable instructions can be stored in the memory, for example, within a database of the memory. The instructions are accessible by the processor and are executable by the processor to implement the various functions of the electrosurgical console 110. An exemplary electrosurgical console 110 can be the one disclosed in International Publication No. WO 2018 / 200254 described above.

[0021] Referring to FIG. 2, the infusion module 200 is shown in more detail. The infusion module 200 can be releasably (detachably) coupled to the electrosurgical instrument 120A using a fluid coupling (fluid joint) 202 such as a Luer lock fitting. When coupled to the electrosurgical instrument 120A, the infusion module 200 is configured to be disposed in fluid communication with the electrosurgical instrument 120A. Although the infusion module 200 is shown with a single fluid coupling 202, it is also contemplated to couple the fluid coupling 202 to a split line to supply fluid to a plurality of electrosurgical instruments 120A. Regardless of the number of instruments 120A utilized, the infusion module 200 includes the fluid coupling 202 along with a flexible infusion line 204, a stop clamp 206, a filter and vent assembly 208, and a flow restrictor 210. The infusion module 200 also includes a housing 270 configured to house the other elements of the infusion module 200. The housing generally consists of a first shell 272 and a second shell 274, and at least one of the first shell 272 and the second shell 274 defines a window 280 through which a user can identify the amount of fluid remaining within the infusion module 200.

[0022] The infusion module 200 supplies fluid to the electrosurgical instrument 120A through the flexible infusion line 204. To ensure that only fluid is supplied to the instrument 120A, the filter and vent assembly 208 includes a gas-permeable and liquid-impermeable vent to allow gas to escape before it reaches the fluid junction 202. To control how much fluid is supplied, a stop clamp 206 and a flow restrictor 210 are disposed in the infusion line 204. The stop clamp 206 can completely stop the flow of fluid (e.g., in a clamped configuration), while the flow restrictor 210 can control the amount of fluid supplied when the stop clamp 206 is configured to allow the flow of fluid (e.g., in an unclamped configuration). The flow restrictor 210 can be configured to limit the flow of fluid to a flow rate of from about 0.5 milliliters per hour (mL / hr) to about 15 mL / hr. It should be understood that the flow rate of the fluid output of the infusion module 200 can be changed by using a particular example of the flow restrictor 210 to produce the desired flow rate. A variety of flow restrictors or flow limiters known to those of ordinary skill in the art can be used and, for the purposes of the present disclosure, can be described as any component shaped to limit the flow of fluid to a set flow rate. Some non-limiting examples of such flow restrictors are capillaries (e.g., tubes having a predetermined restriction in cross-section to control the flow therethrough), and other such flow restrictors use single-stage or multi-stage orifice plates to handle high and low flow rates. In many examples, the flow restrictor 210 limits the fluid output to a flow rate of from about 0.5 mL / hr to about 15 mL / hr, or from about 1 mL / hr to about 12 mL / hr.

[0023] Referring to FIG. 3, the infusion module 200 is shown in an exploded view. To couple the infusion module 200 to the infusion line 204, the infusion module 200 includes a port assembly 220 coupled to the infusion line 204 and a fluid reservoir 230. The port assembly 220 includes a port junction 222, a fill port 224, a port body 225, and a collar assembly 226. Generally, the port junction 222 defines an outlet through which fluid can flow from the fluid reservoir 230 out of the port assembly 220, while the fill port 224 and the collar assembly 226 each include an inlet through which fluid can flow into the port assembly 220. More specifically, fluid can be introduced through an inlet defined by the fill port 224 to fill the fluid reservoir 230. During use, the same fluid from the fluid reservoir 230 can flow through an inlet defined by the collar assembly 226 and out of the port assembly 220 through an outlet defined by the port junction 222 and into the infusion line 204. The port assembly 220 is partially housed within the housing 270 of the infusion module 200 and is located at the distal end of the fluid reservoir 230. As best shown in FIG. 2, the port junction 222 extends beyond the housing 270 of the infusion module 200 and is connected or releasably connected to the flexible infusion line 204. Similarly, as shown in FIG. 2, the fill port 224 extends through a second shell 274 of the housing 270 of the infusion module 200. Advantageously, the port assembly 220 allows for replenishment (filling) of the infusion module 200 through an inlet defined by the fill port 224 while the infusion module 200 is coupled to the electrosurgical instrument 120A. Further, the infusion module 200 can be refilled during use when the fluid is depleted. Nevertheless, the port assembly 220 also allows for replenishment (filling) of the infusion module 200 even when the infusion module 200 is not coupled to the instrument 120A.

[0024] The injection module 200 is configured to be releasably connected to a filling source, such as a syringe filled with a fluid such as physiological saline. Some non-limiting examples of suitable filling sources are 5 mL, 6 mL, 7 mL, 8 mL, 9 mL, or 10 mL syringes having a luer lock tip. The filling source may be filled with a fluid pre-withdrawn (removed) from a fluid supply source, such as an IV fluid bag, a sterilized fluid vial, etc. The injection module 200 of this example may have a total volume fluid capacity of about 1 mL to about 20 mL, more particularly about 2 mL to about 10 mL, and even more particularly about 2 mL to about 8 mL. In some examples, the fluid reservoir 230 has a capacity of 6 mL. In this example, the port assembly 220 includes a filling port 224 (e.g., a luer lock connection, a slip tip connection, an eccentric tip connection, a catheter tip connection, etc.) that releasably connects to a corresponding connector at the filling source, and a port coupling 222 that connects to or in some examples is releasably connected to the flexible injection line 204. To provide a secure connection between the fluid reservoir 230 and the injection line 204, the collar assembly 226 may include alignment means and / or length adjustment means. For example, as can be understood from FIG. 3, the collar assembly 226 may include at least one adjustment member 228 configured to couple to the port assembly 220 and the fluid reservoir 230 (e.g., by a luer lock joint), such that the adjustment member(s) 228 can complete the fluid connection between the fluid reservoir 230 and the port assembly 220. In the illustrated embodiment, the collar assembly 226 includes two adjustment members 228 that can each be rotated relative to the remainder of the port assembly 220 to change the length of the collar assembly 226. In addition to this, the adjustment member 228 enables the port assembly 220 to be rotated relative to the fluid reservoir 230, such that when assembled, the filling port 224 can exit from the outer surface of the injection module 200.

[0025] The fluid reservoir 230 is configured to hold fluid inside the void defined by the fluid reservoir 230. Although in this specification the fluid is used to denote a liquid, it should be understood that other suitable phases can also be assumed. As will be described in more detail below, the fluid reservoir 230 can be made of transparent plastic (e.g., polypropylene) such that a user can view the fluid reservoir 230 through one of the windows 280 and can determine the amount of fluid held inside the void defined by the fluid reservoir 230. To provide the pressure necessary to deliver fluid from the fluid reservoir 230 to the electrosurgical instrument 120A, the infusion module 200 also includes a plunger 240 configured to be pushed into the void of the fluid reservoir 230 by a biasing element 250. The plunger 240 can be at least partially hollow to accommodate the biasing element 250. In the illustrated embodiment, the biasing element 250 is a spring configured to store positional energy (potential energy) as it is compressed. A support member 260 can be disposed within the biasing element to prevent the biasing element from bending. For example, if the biasing element 250 is a spring, the support member 260 can be disposed within the spring to prevent the spring from bending when the spring is compressed. In such an embodiment, the biasing element 250 is disposed at least partially within the plunger 240 and around the support member 260. The first shell 272 of the housing 270 can include a shelf (shelf-like member) 290 configured to abut the biasing element 250 and the support member 260. The shelf 290 provides support for the biasing element 250 when the biasing element 250 is pushing the plunger 240 toward and / or into the void of the fluid reservoir 230. Alternatively, the support member 260 can abut the shelf 290 and the biasing element 250 can abut the support member 260. In either case, the shelf 290 provides a fixed surface against which the biasing element 250 can exert a force. It is further contemplated that the second shell 274 of the housing can include the shelf 290 instead of or in addition to the first shell 272.

[0026] The plunger 240 generally includes a sealing head 242, a first colored portion 244, and a second colored portion 246. When the fluid reservoir 230 is made of transparent plastic and the plunger 240 is disposed within the void defined by the fluid reservoir 230, the plunger 240 is visible through the transparent plastic. As an extension thereof, the sealing head 242, the first colored portion 244, and the second colored portion 246 may also be visible through the transparent plastic of the fluid reservoir 230 depending on how far the plunger 240 is pushed into the void of the fluid reservoir 230. For example, as detailed below, the user can determine the fluid volume of the fluid reservoir 230 based on the visibility of at least one of the sealing head 242, the first colored portion 244, and the second colored portion 246 through the window 280 by looking at the fluid reservoir 230 through the window 280 of the injection module 200. The plunger 240 can be formed of a colored material and the plunger 240 itself can be colored such that it includes at least one of the colored portions 244, 246. Alternatively, a component of a material such as a colored tape can be fixed to the outside of the plunger 240 so as to define at least one of the colored portions 244, 246. For example, the plunger 240 can be formed of a first colored material (e.g., colored plastic) so as to define the first colored portion 244, while the second colored portion 246 is created by fixing a component of the colored material to the outside of the plunger 240.

[0027] To hold the fluid reservoir 230 in place, the reservoir 230 may include a collar 232 shaped to abut a portion of the housing 270. For example, the first shell 272 may include a reservoir guide 292 shaped to receive (accommodate) the fluid reservoir 230. The reservoir guide 292 may include a support surface 294 shaped to abut the collar 232 of the fluid reservoir 230 such that the support surface 294 resists displacement of the fluid reservoir 230 by the forces exerted by the biasing element 250 and the plunger 240. Thereby, the collar 232 is pressed against the support surface 294, and the fluid reservoir 230 is held in place. In addition to this, the first shell 272 and / or the second shell 274 may include an internal barrier to resist the forces experienced by the port assembly (the forces received from the port assembly). For example, the internal barrier may include a port support 296 configured to support the port assembly 220. The port support 296 is generally shaped to receive the port assembly 220 and may include a wing portion 298 extending from one of the first shell 272 and the second shell 274 toward the other of the first shell 272 and the second shell 274. In the illustrated embodiment, a plurality of wing portions 298 extend from both the first shell 272 and the second shell 274 and are shaped to abut the port body 225. When the biasing element 250 applies a force to the plunger 240, the plunger 240 applies a force to the fluid reservoir 230, and the fluid reservoir 230 applies a force to the port assembly 220. The support by the port support 296 and the wing portions 298 resists this force on the port assembly 220 and is configured to keep the port assembly 220 in the same position relative to the housing 270.

[0028] As described above, the first shell 272 of the housing includes a shelf 290 for providing a fixed surface against which the biasing element 250 stores the potential energy necessary to push the plunger 240 into the void of the fluid reservoir 230. To ensure that the injection module 200 provides a consistent volume of fluid over time through the injection line 204, the biasing element 250 is configured to store a large amount of potential energy. Therefore, when the biasing element 250 is compressed between the shelf 290 and the plunger 240, the shelf 290, and thus the housing 270 itself, experiences (receives) a significant amount of force from the biasing element 250. To ensure that the first shell 272 is not separated from the second shell 274 by the force, the first shell 272 can be fixed to the second shell 274 by a snap that can resist the force.

[0029] Referring to FIG. 4, the housing 270 of the injection module 200 is shown with the first shell 272 separated from the second shell 274. The first shell 272 includes female snaps 300 and the second shell 274 includes male snaps 350. The female snaps 300 are configured to receive the male snaps 350 to fix the first shell 272 to the second shell 274. As can be understood from the figure, each shell 272, 274 can include two or more pairs of snaps 300, 350 (e.g., four pairs of snaps) to provide a stronger fastening relationship between the first shell 272 and the second shell 274. If the first shell 272 includes four female snaps 300 and / or the second shell 274 includes four male snaps 350, each male snap 350 is generally the same as the other male snaps 350 and each female snap 300 is generally the same as the other female snaps 300. It is also conceivable that one female snap 300 is different from the remaining female snaps 300 and one male snap 350 is different from the remaining male snaps 350. For example, a pair of snaps 300, 350 may be configured to provide a stronger fastening relationship compared to the remaining snaps 300, 350.

[0030] The female snap 300 includes a female annular protrusion 310, a female snap undercut 320, and a central locking feature 330. The female annular protrusion 310 extends from the first shell 272 to the distal end 312. In the illustrated embodiment, the female annular protrusion 310 defines slots 314 that are configured to allow flexure of the female annular protrusion 310 and that better enable the female snap 300 to receive the male snap 350. More specifically, the female annular protrusion 310 may define a pair of diametrically opposed slots 314, each slot 314 extending longitudinally from the distal end 312 of the female annular protrusion 310 such that the protrusion 310 is divided into two "sides". The female annular protrusion 310 also includes a female snap undercut 320 that extends inwardly from the female annular protrusion 310 such that the female snap 300 can better hold the male snap 350 as described below. The female snap undercut 320 can be located anywhere between the first shell 272 and the distal end 312 of the female annular protrusion 310.

[0031] Similar to the female snap 300, the male snap 350 includes a male annular protrusion 360 and a male snap undercut 370. The male annular protrusion 360 extends from the second shell 274 to the distal end 362. In the illustrated embodiment, the male annular protrusion 360 is configured to allow deflection of the male annular protrusion 360 and to better enable the male snap 350 to be received by the female snap 300, defining a slot 364. More specifically, the male annular protrusion 360 may define a pair of diametrically opposed slots 364, each slot 364 extending longitudinally from the distal end 362 of the male annular protrusion 360 such that the protrusion 360 is divided into two "sides". The male annular protrusion 360 also includes a male snap undercut 370 that extends outwardly from the male annular protrusion 360 and is located at the distal end 362 of the male annular protrusion 360. The male snap undercut 370 is configured to engage the female snap undercut 320 when the snaps 300, 350 are fitted together.

[0032] The female snap 300 further includes a central locking feature 330 coaxially disposed within the female annular protrusion 310. As will be described in more detail below, the central locking feature 330 is configured to be received by the male annular protrusion 360 and resist inward deformation of the male annular protrusion 360 when the snaps 300, 350 are mated with each other. The central locking feature 330 extends from the first shell 272 to an axial position closer to the distal end 312 of the female annular protrusion 310 than the female snap undercut 320. In other words, the central locking feature 330 generally terminates at an axial position between the distal end 312 of the female annular protrusion 310 and the snap undercut 320. It is also contemplated that the central locking feature 330 could be at least as long as the female annular protrusion 310 and terminate at an axial position substantially equal to or greater than that of the distal end 312 of the female annular protrusion 310. Regardless of the relative length of the central locking feature 330, the male annular protrusion 360 is configured to receive the central locking feature 330 and thus the protrusion 360 must be of sufficient length to accommodate the central locking feature 330 without inhibiting the mating ability of the snaps 300, 350. In the illustrated embodiment, the central locking feature 330 includes an inclined distal end 332 to assist in aligning the male snap 350 when it is pushed toward the female snap 300.

[0033] Referring to FIGS. 5A and 5B, snaps 300, 350 are shown in a mated configuration in FIG. 5A and in an unmated configuration in FIG. 5B. As can be understood from the figures, the female annular protrusion 310 includes a female snap undercut 320 configured to engage the male snap undercut 370 when the snaps 300, 350 are in the mated configuration of FIG. 5A. For that purpose, the female snap undercut 320 may include a proximal inclined surface 322, a distal inclined surface 324, and a transition surface 326, and the transition surface 326 extends between the proximal inclined surface 322 and the distal inclined surface 324 of the female snap undercut 320. Similarly, the male snap undercut 370 may include a proximal inclined surface 372, a distal inclined surface 374, and a transition surface 376, and the transition surface 376 extends between the proximal inclined surface 372 and the distal inclined surface 374 of the male snap undercut 370. In this way, the snap undercuts 320, 370 are substantially trapezoidal in shape. The illustrated embodiment shows transition surfaces 326, 376 extending between the inclined surfaces 322, 324 and between the inclined surfaces 372, 374, but the transition surfaces 326, 376 may not exist at all. Alternatively, the proximal inclined surfaces 322, 372 may be in direct contact with their respective distal inclined surfaces 324, 374 such that the snap undercuts 320, 370 are substantially triangular in shape. Regardless of the configuration, the snap undercuts 320, 370 generally extend radially from the annular protrusions 310, 360 such that the snap undercuts 320, 370 are ring-shaped.

[0034] When the female annular protrusion 310 is pushed toward the male annular protrusion 360 and fitted with the male annular protrusion 360, the distal inclined surface 374 of the male snap undercut portion 370 abuts at least one of the distal inclined surface 324 of the female snap undercut portion 320 and / or the inclined distal end 332 of the central lock feature 330. These two inclined surfaces 324, 374 form a V-shaped receiving channel (receiving channel) toward the distal end 312 of the female annular protrusion 310. This V-shaped receiving channel helps to align the male annular protrusion 360 into the female annular protrusion 310 when the male snap 350 is pushed toward the female snap 300.

[0035] When the snaps 300, 350 are in the fitting configuration of FIG. 5A, the proximal inclined surface 322 of the female snap undercut portion 320 abuts the proximal inclined surface 372 of the male snap undercut portion 370. Then, when trying to return the snaps 300, 350 to the non-fitting configuration and the snaps 300, 350 are subjected to a force in a direction away from each other, the contact between the female snap undercut portion 320 and the male snap undercut portion 370 substantially prevents the male annular protrusion 360 from being removed from the female annular protrusion 310. Thus, in order for the male annular protrusion 360 to be removed from the female annular protrusion 310, at least one of the annular protrusions 310, 360 must flex outwardly or inwardly, respectively. For example, when the male annular protrusion 360 flexes inwardly, the male snap undercut portion 370 no longer abuts the female snap undercut portion 320, and the male annular protrusion 360 can be removed from the female annular protrusion 310. Alternatively, when the female annular protrusion 310 flexes outwardly, the same result occurs.

[0036] With the above in mind, it is apparent that the fastening strength of the snaps 300, 350 depends on the amount of force required to deflect at least one of the female annular protrusion 310 and / or the male annular protrusion 360 outwardly and / or inwardly, respectively. Therefore, the fastening strength of the snaps 300, 350 can be affected by the material from which the snaps 300, 350 are made, the shape of the annular protrusions 310, 360 (e.g., the length of the slots 314, 364), the shape of the undercuts 320, 370, and / or a locking element that limits the deflection of at least one of the annular protrusions 310, 360. In the embodiments shown in FIGS. 3-5B, the locking element is a central locking feature 330 configured to limit the inward deflection of the male annular protrusion 360. Therefore, since the inward deflection of the male annular protrusion 360 is limited, the female annular protrusion 310 must deflect outwardly in order to allow the snaps 300, 350 to transition from the mated configuration to the unmated configuration.

[0037] In order for the central locking feature 330 to limit the inward deflection of the male annular protrusion 360, the male snap undercut 370 must be pressed against both the central locking feature 330 and the female snap undercut 320 simultaneously. More specifically, when the male snap 350 is subjected to a force to move away from the female snap 300, the proximal inclined surface 372 of the male snap undercut 370 moves and disengages from contact with the proximal inclined surface 322 of the female snap undercut 320 before the central locking feature 330 must resist the inward deflection of the male annular protrusion 360. Therefore, the central locking feature 330 generally extends from the first shell 272 to an axial height that is at least as high as (or higher than) the female snap undercut 320. In this way, the male snap undercut 370 contacts the central locking feature 330 before the proximal inclined surface 372 of the male snap undercut 370 moves and disengages from contact with the proximal inclined surface 322 of the female snap undercut 320. Further, the central locking feature 330 must have a sufficient radius so that the male annular protrusion 360 cannot deflect inwardly until the proximal inclined surface 372 of the male snap undercut 370 moves and disengages from contact with the proximal inclined surface 322 of the female snap undercut 320 at the point before the male annular protrusion 360 contacts the central locking feature 330.

[0038] Another way to explain the relationship between snap 300 and snap 350 is to use a series of heights with respect to the first shell 272, as shown in FIG. 5A. For example, the first height H1 represents the length of the female annular protrusion 310 from the first shell, the second height H2 represents the distance between the first shell 272 and the female snap undercut 320, the third height H3 represents the distance between the first shell 272 and the distal end 332 of the central locking feature 330, and the fourth height H4 may represent the distance between the first shell 272 and the male snap undercut 370 when the male snap 350 is mated with the female snap 300. In the figure, the second height H2 is aligned with the transition surface 326 of the female snap undercut 320, and the fourth height H4 is aligned with the transition surface 376 of the male snap undercut 370. Alternatively, if the proximal inclined surface 322 and the distal inclined surface 324 of the female snap undercut 320 are joined together without the transition surface 326 therebetween, the second height H2 may be aligned with the transition between the proximal inclined surface 322 and the distal inclined surface 324. Similarly, if the proximal inclined surface 372 and the distal inclined surface 374 of the male snap undercut 370 are joined together without the transition surface 376 therebetween, the fourth height H4 may be aligned with the transition between the proximal inclined surface 372 and the distal inclined surface 374. Generally, the first height H1 is the largest, followed by the third height H3, then the second height H2, and the fourth height H4 is the smallest among the heights H1, H2, H3, H4. However, the first height H1 may be substantially equal to the third height H3.

[0039] Referring to FIGS. 6A and 6B, an alternative snap embodiment including a female snap 400 and a male snap 450 is shown. These alternative snaps 400, 450 are quite similar to snaps 300, 350, but the central lock feature 330 has been replaced by an outer lock feature 430. Thus, most of the elements of snaps 300, 350 described above also exist in alternative snaps 400, 450, and similar elements are referenced by numbers with the last two digits the same and the first digit changed from 3 to 4 (e.g., from 300 to 400, from 350 to 450). The alternative snaps 400, 450 are shown in a mated configuration in FIG. 6A and an unmated configuration in FIG. 6B.

[0040] Similar to female snap 300, female snap 400 includes a female annular protrusion 410 and a female snap undercut 420. The female annular protrusion 410 extends from the first shell 272 to the distal end 412. Although not shown in the figure, the female annular protrusion 410 defines slots 414 configured to allow flexure of the female annular protrusion 410 and to better enable the female snap 400 to receive the male snap 450. More specifically, the female annular protrusion 410 may define a pair of diametrically opposed slots 414, each slot 414 extending longitudinally from the distal end 412 of the female annular protrusion 410. The female annular protrusion 410 also includes a female snap undercut 420 extending inwardly from the female annular protrusion 410 so that the female snap 400 can better hold the male snap 450. The female snap undercut 420 may be located anywhere between the first shell 272 and the distal end 412 of the female annular protrusion 410.

[0041] Similar to the male snap 350, the male snap 450 includes a male annular protrusion 460 and a male snap undercut 470. The male annular protrusion 460 extends from the second shell 274 to the distal end 462. Although not shown in the figure, the male annular protrusion 460 is configured to allow deflection of the male annular protrusion 460 and defines slots 464 configured to better enable the male snap 450 to be received by the female snap 400. More specifically, the male annular protrusion 460 may define a pair of diametrically opposed slots 464, each slot 464 extending longitudinally from the distal end 462 of the male annular protrusion 460. The male annular protrusion 460 also includes a male snap undercut 470 that extends outwardly from the male annular protrusion 460 and is located at the distal end 462 of the male annular protrusion 460. The male snap undercut 470 is configured to engage the female snap undercut 420 when the snaps 400, 450 are fitted together.

[0042] As an alternative to the central locking feature 330 of the snaps 300, 350 shown in FIGS. 5A and 5B, the male snap 450 of FIGS. 6A and 6B further includes an outer locking feature 430. As will be described in more detail below, the outer locking feature 430 is configured to cooperate with the male annular protrusion 460 to receive the female annular protrusion 410 and resist outward deformation of the female annular protrusion 410 when the snaps 400, 450 are fitted together. The outer locking feature 430 extends from the second shell 274 to an axial position that is at least substantially equal to the distal end 462 of the male annular protrusion 460. In the illustrated embodiment, the outer locking feature 430 includes an inclined distal end 432 to assist in aligning the female snap 400 when the female snap 400 is pushed toward the male snap 450.

[0043] Similar to the previous snaps 300, 350, the female annular protrusion 410 includes a female snap undercut 420 configured to engage with the male snap undercut 470 when the snaps 400, 450 are in the mating configuration of FIG. 6A. For that purpose, the female snap undercut 420 may include a proximal inclined surface 422, a distal inclined surface 424, and a transition surface 426, and the transition surface 426 extends between the proximal inclined surface 422 and the distal inclined surface 424 of the female snap undercut 420. Similarly, the male snap undercut 470 may include a proximal inclined surface 472, a distal inclined surface 474, and a transition surface 476, and the transition surface 476 extends between the proximal inclined surface 472 and the distal inclined surface 474 of the male snap undercut 470. When the female annular protrusion 410 is pressed toward the male annular protrusion 460 to be in a mating configuration with the male annular protrusion 460, the distal inclined surface 424 of the female snap undercut 420 abuts at least one of the distal inclined surface 474 of the male snap undercut 470 and the inclined distal end 432 of the outer lock feature 430. These two inclined surfaces 424, 474 form a V-shaped receiving channel toward the distal end 412 of the male annular protrusion 460. This V-shaped receiving channel helps to align the male annular protrusion 460 into the female annular protrusion 410 when the male snap 400 is pushed toward the female snap 450.

[0044] When the snaps 400, 450 are in the mating configuration of FIG. 6A, the proximal inclined surface 422 of the female snap undercut portion 420 abuts against the proximal inclined surface 472 of the male snap undercut portion 470. Then, when an attempt is made to return the snaps 400, 450 to the non-mating configuration and the snaps 400, 450 are subjected to a force in a direction away from each other, the contact between the female snap undercut portion 420 and the male snap undercut portion 470 substantially prevents the male annular protrusion 460 from being removed from the female annular protrusion 410. Thus, the only way for the male annular protrusion 460 to be removed from the female annular protrusion 410 is for at least one of the annular protrusions 410, 460 to flex either outwardly or inwardly. For example, when the male annular protrusion 460 flexes inwardly, the male snap undercut portion 470 no longer abuts against the female snap undercut portion 420, and the male annular protrusion 460 can be removed from the female annular protrusion 410. Alternatively, when the female annular protrusion 410 flexes outwardly, a similar result occurs.

[0045] In order for the outer lock feature 430 to limit the outward deflection of the female annular protrusion 410, the female snap undercut 420 must be pressed against the outer lock feature 430 and the male snap undercut 470 simultaneously. More specifically, when the male snap 450 is subjected to a force to move away from the female snap 400, before the proximal inclined surface 422 of the female snap undercut 420 moves out of contact with the proximal inclined surface 472 of the male snap undercut 470, the outer lock feature 430 must resist the outward deflection of the female annular protrusion 410. Therefore, the outer lock feature 430 generally extends from the second shell 272 to an axial height that is at least as high as (or higher than) the male snap undercut 420. In this way, before the proximal inclined surface 422 of the female snap undercut 420 moves out of contact with the proximal inclined surface 472 of the male snap undercut 470, the female snap undercut 420 contacts the outer lock feature 430. Further, the outer lock feature 430 must be sufficiently close to the male annular protrusion 460 so that the female annular protrusion 410 cannot deflect outwardly until the point where the proximal inclined surface 422 of the female snap undercut 420 moves out of contact with the proximal inclined surface 472 of the male snap undercut 470 before the female annular protrusion 410 contacts the outer lock feature 430.

[0046] The housing 270, and thus the snaps 300, 350, 400, 450, can be formed by various molding techniques such as injection molding. As an extension thereof, the housing 270 and the snaps 300, 350, 400, 450 can be formed of a plastic material adapted to the selected molding process. Two such classifications of materials that can be used are thermoplastic and thermosetting plastics. It is even further contemplated to form the snaps 300, 350, 400, 450 of a different material than the remainder of the housing 270, or even to form the female snaps 300, 400 of a different material than the male snaps 350, 450. For example, since the lock features 330, 430 prevent the male annular protrusions 360 from flexing inwardly and the female annular protrusions 410 from flexing outwardly, it can be assumed that these protrusions 360, 410 need not be formed of a plastic as strong as the complementary protrusions 310, 460.

[0047] Referring to FIGS. 7A - 7D, a partial view of the injection module 200 including the window 280 is shown. These figures focus on the elements of the injection module 200 that are visible through the window 280 while the fluid reservoir 230 is filled with various amounts of fluid, and these visible elements are the sealing head 242, the first colored portion 244, and the second colored portion 246. This effectively enables a user to look through the window 280 of the injection module 200 at the fluid reservoir 230 and determine the amount of fluid in the fluid reservoir 230 based on the visibility of at least one of the sealing head 242, the first colored portion 244, and the second colored portion 246 through the window 280. In addition to this, since the fluid reservoir 230 is substantially transparent as described above, the fluid contained therein may also be visible through the window 280. The fluid reservoir 230 is substantially transparent, but the reservoir 230 may also include graduations (incremental hash marks) indicating how much fluid remains. For example, the fluid reservoir 230 may include six large graduations indicating 1 mL units and four small graduations indicating 1 / 5 mL units.

[0048] Referring to FIG. 7A, the injection module 200 is shown with the fluid reservoir 230 substantially filled to its maximum capacity (e.g., filled with 6 mL of fluid for a total capacity of 6 mL). In this state, the sealing head 242 can be seen through the window 280, but the first colored portion 244 and the second colored portion 246 cannot be seen through the window 280. In one example, the injection module 200 can reach this state after the user has filled the fluid reservoir 230 to its maximum capacity and before the injection module 200 is used to provide fluid to the treatment site.

[0049] FIG. 7B shows the injection module 200 with the fluid reservoir 230 filled to a state where it is more than one-third and less than the maximum capacity (e.g., filled with 2 mL to 5.9 mL of fluid for a total capacity of 6 mL). In this state, both the sealing head 242 and the first colored portion 244 can be seen through the window 280, but the second colored portion 246 cannot be seen through the window 280. In one example, the injection module 200 can reach this state after injecting 0.1 mL to 3 mL of fluid from the injection module 200 to the treatment site.

[0050] Referring to FIG. 7C, the injection module 200 is shown with the fluid reservoir 230 filled to a state where it is less than one-third of the maximum capacity (e.g., filled with 2 mL or less of fluid for a total capacity of 6 mL). In this state, the sealing head 242, the first colored portion 244, and the second colored portion 246 can all be seen through the window 280. Additionally, only a small amount of the second colored portion 246 can be seen through the window 280. In one example, the injection module 200 can reach this state after providing at least 4 mL and less than 6 mL of fluid from the injection module 200 to the treatment site.

[0051] Finally, FIG. 7D shows the injection module 200 with the fluid reservoir 230 in a substantially empty state (e.g., a state in which approximately 0 mL of fluid is contained in a total volume of 6 mL). In this state, both the first colored portion 244 and the second colored portion 246 are visible through the window 280. When the fluid reservoir 230 is empty, a greater amount of the second colored portion 246 is visible through the window 280 as compared to when the fluid reservoir 230 is filled to less than one-third of its maximum capacity. In FIG. 7D, the sealing head 242 is no longer visible through the window, although it is contemplated that the sealing head 242 may (or may not) be visible when the fluid reservoir 230 is substantially empty. In one example, the injection module 200 may reach this state after providing 6 mL of fluid to the treatment site by the injection module 200. In addition to this, as described below, the injection module 200 may be shipped with an empty fluid reservoir 230, and the first colored portion 244 and the second colored portion 246 may be visible through the window 280 prior to use of the injection module 200.

[0052] Referring to FIGS. 8A and 8B, a packaging assembly 500 for the injection module 200 is shown. The packaging assembly 500 is configured to enable a manufacturer to ship the injection module 200 and other related elements in a safe and organized manner. For that purpose, the packaging assembly 500 generally includes a mounting surface 510 configured to removably couple the injection module 200 and other related elements to the packaging assembly 500, and an information surface 520 optionally coupled to the mounting surface 510 and configured to present information to a user. The packaging assembly 500 may be made of flexible paper and / or plastic material(s), and may consist of a single piece or multiple pieces. In the illustrated embodiment, the packaging assembly 500 is a single-piece material with the mounting surface 510 being substantially planar and connected to the information surface 520 by a fold of the material.

[0053] Referring specifically to FIG. 8A, the information surface 520 is shown as a folded-back part of the packaging assembly 500 and is formed of a part of the same material as the attachment surface 510. Therefore, the manufacturer does not need to separately include a supplementary information booklet or collection as is usually done when shipping products with information materials. Further, the information surface 520 is available in a sterile area for the user, in contrast to typical instructions that are not sterile and not easily accessible by the user. In FIG. 8A, the information surface 520 is shown folded over a part of the attachment surface 510 such that a part of the attachment surface 510 is hidden behind the information surface 520. In this way, the user can be directed to the information contained in the information surface 520 prior to removing an element (e.g., the infusion module 200) attached to the attachment surface 510. The information surface 520 generally includes instructions (operating instructions) intended to guide the user when using the infusion module 200 with the associated elements. For example, in the figure, the instructions include: (1) filling the infusion module 200 with fluid through the filling port 224; (2) connecting the infusion module 200 to the electrosurgical instrument 120A via the fluid coupling 202; and (3) priming the infusion module 200 by waiting for a certain length of time until fluid begins to flow out of the electrosurgical instrument 120A. It is further contemplated to include additional / different instructions and / or additional / different information on the information surface 520. The information surface 520 may further include instructions / information on the other side (back side) of the material such that the user is presented with more information when the information surface 520 is unfolded (spread out) with respect to the attachment surface 510. As an example, one side of the information surface 520 may include instructions (explanation) on how to read the information presented through the window 280 of the infusion module 200 as described above with reference to FIGS. 7A-7D. Other examples are also contemplated.

[0054] Referring specifically to FIG. 8B, the attachment surface 510 is shown in more detail, with the information surface 520 deployed so that the attachment surface 510 is no longer hidden behind the information surface 520. As shown, the attachment surface 510 includes a plurality of features configured to removably couple at least the injection module 200, the injection line 204, the fluid coupling 202, and the filling source 530 to the attachment surface 510. These features may include cutouts in the attachment surface 510 to form positioning features 512, securing features 514, and wrapping features 516 including tabs 518. Features 512, 514, 516 may be formed by cutting the material of the attachment surface 510 using a sharp object and then folding the material to form features 512, 514, 516. In the exemplary embodiment shown in the figure, the injection module 200 is removably coupled to the attachment surface 510 via the wrapping feature 516. The wrapping feature 516 is formed from material cut out from the attachment surface 510 (although still connected to at least a portion of the attachment surface 510 and the cutout) and is configured to wrap around the injection module 200. The wrapping feature 516 includes tabs 518 and receiving cutouts 519. When the wrapping feature 516 is wrapped around the injection module 200, the tabs 518 are oriented into the receiving cutouts 519. When the tabs 518 are received by the receiving cutouts 519, the wrapping feature 516 is securely held around the injection module 200. If desired, the wrapping feature 516 can be pulled away from the injection module 200 to allow the tabs 518 to be removed from the receiving cutouts 519, thereby allowing the injection module 200 to be removed from the attachment surface 510. The injection line 204 is removably coupled to the attachment surface 510 by positioning features 512 formed as cutout portions of the attachment surface 510. The injection line 204 is wrapped around the positioning features 512, and the fluid coupling 202 is then removably secured to the attachment surface by the securing features 514.The fixed feature portion 514 is also a part of the material cut out from the mounting surface 510, like the other feature portions 512, 516, but is still connected to the mounting surface 510 by at least some of the material. The filling source 530 is also removably fixed to the mounting surface 510 by the fixed feature portion 514. It is further contemplated that the elements 200, 202, 204, 530 can be fixed to the mounting surface 510 via other means. In addition to this, the filling source 530 can be an external filling source as described above.

[0055] To reduce the distortion (deformation) of the various components of the injection module 200, in many instances, the injection module 200 is assembled and provided with a minimum compression against the biasing element 250 and a minimum or zero fluid volume in the fluid reservoir 230. In this way, the injection module 200 is not packaged with fluid that can flow out of the fluid reservoir 230 and / or unnecessary distortion in the shelf 290 due to the biasing element 250. After the user removes the injection module 200 from the package, the user is instructed (explained) about how to use the injection module 200 by the information surface 520. For example, to replenish (fill) the injection module 200, the filling source 530 is connected to the filling port 224 via a luer lock or a similar connection mechanism, and fluid is injected into the injection module 200. During the injection, the fluid reservoir 230 is filled with fluid, and as the volume fluid capacity of the fluid reservoir 230 increases to accommodate the injected fluid, the biasing element 250 is further compressed. As the volume fluid capacity of the fluid reservoir 230 increases, the plunger 240 is moved out of the fluid reservoir 230 and towards the shelf 290. Further, as the volume fluid capacity of the fluid reservoir 230 increases, the biasing element 250 is further compressed. Briefly stated, replenishing (filling) the injection module 200 simultaneously fills the fluid reservoir 230 and stores the potential energy in the biasing element 250.

[0056] When the infusion module 200 is replenished (filled) and the infusion module 200 is connected to the electrosurgical instrument 120A via the fluid coupling 202, the fluid reservoir 230 is in fluid communication with the infusion line 204 and the fluid coupling 202, and the biasing element 250 releases potential energy and actuates the plunger 240 to cause fluid to be discharged from the fluid reservoir 230 into the infusion line 204, then further through the fluid coupling 202 into the electrosurgical instrument 120A, and finally to the treatment site.

[0057] Several embodiments have been discussed in the above description. However, the embodiments discussed herein are not intended to be exhaustive or to limit the invention to any particular form. The terms used are not limiting but are intended to be within the nature of explanatory language. Many changes and modifications are possible in light of the above teachings, and the invention may be practiced in ways other than specifically described. Certain aspects are disclosed by the following exemplary clauses.

[0058] A method of monitoring the delivery of liquid during an ablation procedure using a medical device comprising a housing defining a window, a fluid reservoir within the housing, and a plunger biased within the fluid reservoir to discharge liquid, the method comprising viewing a sealing head of the plunger through the window with the fluid reservoir containing a first volume of liquid, operating the medical device to discharge a portion of the liquid from the fluid reservoir, viewing a first colored portion of the plunger through the window with the fluid reservoir containing a second volume of liquid smaller than the first volume, operating the medical device further to discharge another portion of the liquid from the fluid reservoir, and viewing a second colored portion of the plunger through the window with the fluid reservoir containing a third volume of liquid smaller than the first volume and the second volume.

[0059] The method of clause 1, further comprising viewing the liquid through the window and through the fluid reservoir with the fluid reservoir containing a first volume of liquid.

[0060] The method according to claim 1 or 2, further comprising looking through a window to see only the sealing head, as indicating that the fluid reservoir is substantially filled with liquid.

[0061] The method according to claim 1 or 2, further comprising looking at each of the sealing head, the first colored portion, and the second colored portion, as indicating a small volume of liquid, where less than about 35% of the filled volume of liquid remains in the fluid reservoir.

[0062] The method of claim 1 or 2, further comprising looking at only the first colored portion and the second colored portion, as indicating that the fluid reservoir is substantially empty.

[0063] The method according to any one of claims 1 to 4, wherein the fluid reservoir is packaged as empty and the method further comprises filling the medical device by directing liquid from a filling source through a filling port into the fluid reservoir.

[0064] The method according to claim 5, further comprising priming the medical device by operating the device for a predetermined duration prior to initiating an ablation procedure.

[0065] The method according to claim 6, wherein the steps of filling the medical device and priming the device are printed on a package to which the device and an external supply source are coupled.

Claims

1. A medical device for delivering liquid to electrosurgical instruments, Housing that defines the window, A fluid reservoir disposed within the housing and configured to receive liquid, A plunger is movably disposed within the fluid reservoir, A spring disposed within the housing and configured to bias the plunger to drain fluid into the electrosurgical instrument, Equipped with, At least a portion of the fluid reservoir is transparent, The plunger comprises a first colored portion and a second colored portion, wherein the second colored portion is a different color from the first colored portion. With the fluid reservoir containing a first volume of liquid, the first colored portion of the plunger is visible through the window. A medical device wherein, when the fluid reservoir discharges at least a portion of the liquid so that it contains a second volume of liquid smaller than the first volume, the movement of the plunger is configured to expose the second colored portion of the plunger into the window.

2. The medical device according to claim 1, wherein the second colored portion is not visible through the window when the fluid reservoir contains the first volume of liquid.

3. The medical device according to claim 1, wherein the fluid reservoir contains the first volume of liquid and the liquid is visible through the window.

4. The plunger further comprises a sealing head which is a different color from the first colored portion and the second colored portion. The medical device according to claim 3, wherein the sealing head is visible through the window when the fluid reservoir contains a third volume of liquid that is larger than the first volume.

5. The medical device according to claim 4, wherein the third volume indicates that the fluid reservoir is substantially filled with liquid.

6. The medical device according to any one of claims 1 to 5, wherein the plunger further comprises a support member that is coaxially arranged within the spring and engages with an internal shelf of the housing.

7. A medical device for delivering liquid to electrosurgical instruments, Housing that defines the window, A fluid reservoir disposed within the housing and configured to receive liquid, A plunger is movably disposed within the fluid reservoir, A spring disposed within the housing and configured to bias the plunger to drain fluid into the electrosurgical instrument, Equipped with, At least a portion of the fluid reservoir is transparent, The plunger comprises a first colored portion and a second colored portion, wherein the second colored portion is a different color from the first colored portion. A medical device in which the second colored portion of the plunger, which indicates a small volume of liquid remaining in the fluid reservoir, less than approximately 35% of the filled volume, is visible through the window.

8. The medical device according to claim 7, wherein the second colored portion is not visible through the window when the fluid reservoir is substantially filled with liquid.

9. The medical device according to claim 7 or 8, wherein the fluid reservoir is substantially filled with liquid and the liquid is visible through the window.

10. A medical device for delivering liquid to an electrosurgical instrument, Housing that defines the window, A fluid reservoir disposed within the housing and configured to receive liquid, A plunger is movably disposed within the fluid reservoir, A spring disposed within the housing and configured to bias the plunger to discharge fluid into the electrosurgical instrument, Port assembly and Equipped with, At least a portion of the fluid reservoir is transparent, The port assembly comprises a collar assembly coupled to the outlet of the fluid reservoir, a filling port extending through the housing and configured to receive liquid from an external source for filling or refilling the fluid reservoir, and a port coupling configured to be coupled to an injection line and to discharge the liquid into the injection line. Medical device.

11. The medical device according to claim 10, wherein the filling port is perpendicular to the color assembly and the port coupling portion, respectively.

12. The medical device according to any one of claims 1, 7, and 10, wherein the first and second colored portions extending over the length of the window indicate that the fluid reservoir is substantially empty.

13. The medical device according to any one of claims 1, 7, and 10, wherein the window is oblong in shape.

14. The medical device according to any one of claims 1, 7, and 10, wherein the length of the window corresponds to approximately 6 milliliters of liquid being visible in the fluid reservoir.

15. The medical device according to any one of claims 1, 7, and 10, wherein the fluid reservoir does not have volume markings.

16. The medical device according to any one of claims 1, 7, and 10, wherein the plunger is formed from a material of the same color as the first colored portion, and the second colored portion is coupled to the plunger.

17. The medical device according to claim 1 or 7, further comprising a port assembly defining a first inlet, a second inlet, an outlet, and a valve, wherein the valve is configured to direct a liquid injected from an external source through the first inlet into the fluid reservoir, and further direct a liquid discharged from the fluid reservoir through the second inlet and the outlet.

18. The medical device according to claim 17, wherein the port assembly engages with a second internal barrier of the housing to resist movement of the fluid reservoir due to a force from the plunger biased by the spring.

19. The medical device according to claim 18, wherein the outlet is directed perpendicular to the first inlet and the second inlet, respectively, and the device further comprises a collar, which is coupled to the fluid reservoir by a Luer fitting and to the valve, and the collar is configured to be rotatably oriented during the assembly of the housing so that the second inlet aligns with the opening.

20. Further comprising a port assembly, The medical device according to claim 1 or 7, wherein the port assembly comprises a collar assembly coupled to the outlet of the fluid reservoir, a filling port extending through the housing and configured to receive liquid from an external source for filling or refilling the fluid reservoir, and a port coupling portion coupled to an injection line and configured to discharge the liquid into the injection line.

Images