Patent Publication Number: US-2023160480-A1

Title: Medical cleaning valve

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority from U.S. Provisional Application No. 62/859,537, filed Jun. 10, 2019, which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to valves for medical devices, for example endoscopes. 
     BACKGROUND 
     Endoscopes include functionality to deliver fluids (including air and water) and suction to a site of a procedure. Tubing for delivering fluids and/or suction extends from a handle of the endoscope, through a sheath of the endoscope, and to a distal tip of the endoscope. During a procedure, body fluids, tissues, or other material could migrate into the tubing and, in some cases, lead to clogging of the tubing. In order to aid in reprocessing of reusable endoscopes between procedures, pre-processing is performed in an endoscopy suite. For example, water or other fluids are flushed through the tubing after the endoscope is removed from a patient, in order to clear debris from the air/water and/or suction tubing. One option for accomplishing such pre-processing is a reusable cleaning valve. Such cleaning valves may include a number of components, including a valve stem (often made of metal) with one or more channels therein, a number of seals, and an actuation mechanism. The cleaning valve may be inserted into an air/water valve cylinder of an endoscope after the scope is removed from a patient. An operator may then depress a button of the cleaning valve for a predetermined amount of time (e.g., 30 seconds) to flush the air and/or water channels of the endoscope prior to further reprocessing of the endoscope. A reusable cleaning valve must be subject to cleaning, itself, in between uses, which can add to reprocessing cost. Therefore, a need exists for valves capable of performing cleaning functions with less operator interaction or single use valves that do not need to themselves be processed. 
     SUMMARY 
     Embodiments of the present disclosure relate to, among other things, valves for medical devices. Each of the embodiments disclosed herein may include one or more of the features described in connection with any of the other disclosed embodiments. 
     According to one aspect, a valve for use in a medical device having a fluid inlet and a fluid outlet. The valve may include a valve stem having a lumen extending from a first opening at a proximal portion of a radially-outer surface of the valve stem to a second opening at a distal end of the valve stem; and a plurality of seals positioned relative to the valve stem. The valve stem and the plurality of seals may be configured so that a fluid entering the fluid inlet is prevented from flowing to the fluid outlet in a first position of the valve stem and the plurality of seals relative to the fluid inlet and the fluid outlet. Also, the valve stem and the plurality of seals may be configured so that a fluid entering the fluid inlet is flowable to the fluid outlet in a second position of the valve stem and the plurality of seals relative to the fluid inlet and the fluid outlet, the second position being more distal than the first position relative to the fluid inlet and the fluid outlet. 
     In other aspects of the present disclosure, the valve may include one or more of the features below. A channel seal may be at the second opening of the lumen. The channel seal may form a fluid-tight barrier over the second opening in the first position and may permit the flow of fluid through the second opening in the second position. The plurality of seals may be configured to form a slidable interference fit with a valve cylinder of the medical device so that a fluid is prevented from flowing between each of the plurality of seals and the wall of the valve cylinder. The lumen may include a bend proximate to the first opening. The channel seal may be configured to receive a channel stem. When the channel stem is positioned within the channel seal, the valve may be in the second position and fluid may flow between an area exterior to the valve stem, the second opening of the lumen, and the lumen. The valve may further include an actuation mechanism including a button and at least one biasing member, wherein the actuation mechanism is configured to transition the valve between the first position and the second position, and the valve is biased towards the first position. The actuation mechanism may be configured to align the first opening of the lumen with the fluid outlet when the valve is in the first position. The fluid inlet may be a first fluid inlet and the fluid outlet may be a first fluid outlet. 
     In other aspects of the present disclosure, the valve may include one or more of the features below. The medical device may further comprise a second fluid inlet and a second fluid outlet. The plurality of seals may include a first seal, a second seal, a third seal, and a fourth seal. The first seal may be positioned proximal to the first opening and proximal to the first fluid outlet when the valve is in the first position and when the valve is in the second position. The second seal may be positioned distal to the first opening and proximal to the first fluid outlet when the valve is in the first position. The second seal may be positioned distal to the first opening and distal to the first fluid outlet when the valve is in the second position. The third seal may be positioned distal to the second fluid inlet and proximal to the second fluid outlet when the valve is in the first position and when the valve is in the second position. The fourth seal may be positioned distal to the second fluid outlet and proximal to the first fluid inlet when the valve is in the first position and when the valve is in the second position. The lumen may be a first lumen, and the valve stem may further comprise a second lumen extending from a third opening at a distal portion of the first lumen to a fourth opening at a distal portion of a radially-outer surface of the valve stem. The second lumen may be transverse to the first lumen, and fluidly connects the first lumen with an area exterior to the valve stem. The valve may further include a face seal at the fourth opening of the second lumen. The face seal may be annular and may be configured to form a slidable interference fit with a wall of the medical device so that a fluid is prevented from flowing between an area outside of the radially outer portion of the face seal and the fourth opening. The valve may also include an air seal coupled to a radially-outer surface of the valve stem. The air seal may be configured to align with a second fluid inlet of the medical device when the valve is in the second position. The first lumen may include a bend proximate to the proximal opening. The face seal and the air seal may be longitudinally-aligned on a radially-outer surface of the valve stem. A proximal portion of the first lumen may be parallel and longitudinally aligned with the second lumen. 
     In other aspects of the present disclosure, the valve may include one or more of the features below. The valve may further include one or more threads protruding from a proximal portion of the exterior surface of the valve stem, and wherein, when each of the at least one thread are received by at least one groove of the medical device, the first opening may be configured to align with the fluid outlet, the fourth opening may be configured to align with the first fluid inlet, the air seal may be configured to align with the second fluid inlet, and the valve may be configured to be in the second position. The plurality of seals may include a first seal, a second seal, a third seal, and a fourth seal. The first seal may be positioned proximal to the first opening; the second seal may be positioned distal to the first opening; the third seal may be positioned distal to the second seal and proximal to the fourth opening; and the fourth seal may be positioned distal to the fourth opening and proximal to the second opening. Each of the first seal, the second seal, the third seal, and the fourth seal may be positioned within a first recess, a second recess, a third recess, and a fourth recess, respectively. Each of the first recess, the second recess, the third recess, and the fourth recess may be in the exterior surface of the valve stem and extend circumferentially about the longitudinal axis of the valve stem. 
     In other aspects of the present disclosure, a method of delivering liquid to an air outlet of a medical device, the medical device including an air inlet, the air outlet, a liquid inlet, and a liquid outlet. The method may include moving a first seal of a valve distally relative to the air inlet, the air outlet, the liquid inlet, and the liquid outlet from proximal to the air outlet to distal to the air outlet. The method may also include moving a first opening of a lumen extending through the valve from out of alignment with the air outlet to in alignment with the air outlet. The first opening may be at a proximal portion of a radially-outer surface of the valve. The method may further include applying liquid to the liquid inlet; and delivering the liquid to the air outlet via a second opening in the valve and the first opening in the valve. 
     In other aspects, the method of delivering liquid to an air outlet of a medical device may further include one or more of the features below. The method may further include, via a stem, opening a channel seal positioned at the second opening to permit a flow of fluid through the second opening and fluidly connect the liquid inlet, the air outlet, and the lumen. The lumen may be a first lumen, and the method may further including moving a face seal at a third opening of a second lumen of the valve from out of alignment with the fluid inlet to in alignment with the fluid inlet; and moving an air seal coupled to a radially-outer surface of the valve from out of alignment with the air inlet to in alignment with the air inlet, wherein the air seal prevents air flow from the air inlet into a valve cylinder of the medical device; so that the liquid inlet, the air outlet, the first lumen, and the second lumen are fluidly connected. The method may further include rotating the valve about a central longitudinal axis of the valve. The method may also include moving a third seal of the valve distally relative to the air inlet, the air outlet, the liquid inlet, and the liquid outlet from proximal to the fluid outlet to distal to the fluid outlet and proximal to the fluid inlet; and moving a fourth seal of the valve distally relative to the air inlet, the air outlet, the liquid inlet, and the liquid outlet from proximal to the fluid outlet to distal to the fluid outlet and proximal to the fluid inlet. 
     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 a surface (e.g., a button) contacted by an operator for operating a valve, and the term “distal” means a direction away from the surface (e.g., a button) for operating the valve. Proximal and distal directions are labeled with arrows marked “P” and “D”, respectively, throughout the figures. Although endoscopes are referenced herein, reference to endoscopes or endoscopy should not be construed as limiting the possible applications of the disclosed aspects. For example, the disclosed aspects may be used with duodenoscopes, bronchoscopes, ureteroscopes, colonoscopes, catheters, diagnostic or therapeutic tools or devices, or other types of medical devices. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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. 
         FIGS.  1 A- 1 B  show cross-sectional views of a first exemplary valve. 
         FIGS.  2 A- 2 B  show cross-sectional views of a second exemplary valve. 
         FIG.  3    shows a side cross-sectional view of a channel and a protrusion of the first exemplary valve shown in  FIGS.  1 A- 1 B . 
     
    
    
     DETAILED DESCRIPTION 
     A valve may be configured to provide cleaning functionality to air channels of an endoscope. In at least some embodiments, the valve may be appropriate for a single-use and therefore be disposable, and in other embodiments, the valve may be appropriate for repeated use. In a first configuration, the valve may provide a continuous feed of air to an air channel in a handle and sheath of an endoscope, and through an air/water nozzle at the distal end of the endoscope. In a second configuration, the valve may feed water into the air channel in the handle and sheath and through an air/water nozzle. In some examples, the valve may be made from a limited number of parts and materials, to limit its cost, so that it is disposable. 
       FIG.  1    shows a cross-sectional view of an exemplary valve  100  in a valve cylinder  102 . Valve cylinder  102  may have surfaces  103  that define a cavity into which valve  100  may be inserted. Valve cylinder  102  may include connections to channels for inflow or outflow of air or water in a medical device, such as an endoscope. For example, valve cylinder  102  may have an air inlet  112  and an air outlet  114 . Valve cylinder  102  may also have a water inlet  108  and a water outlet  110 . From proximal to distal, the outlets may be ordered as follows: air outlet  114 , air inlet  112 , water outlet  110 , and water inlet  108 . Valve cylinder  102  may be incorporated in a handle of the medical device, for example an endoscope. 
     Valve  100  may have a valve stem  104 . Valve stem  104  may be cylindrical and may have a decreasing circumference around a longitudinal axis of valve stem  104  moving from a proximal portion to a distal portion of the valve stem  104 . Valve stem  104  may have an exterior surface configured to align with an interior surface  103  of valve cylinder  102 . Portions of valve stem  104  may be made from metal (e.g., stainless steel, titanium, aluminum, etc.), from a polymer (e.g. polycarbonate, ABS, HDPE, Nylon, PEEK, thermoplastic, plastic, etc.), or from any other suitable material, or combinations thereof. 
     Valve stem  104  may include a channel  124  extending from a distal end of valve stem  104  to a proximal portion of valve stem  104 . Channel  124  may include a proximal opening  125 , a distal opening  126 , and a turn or bend  127 . Channel  124  may fluidly connect an opening in a channel seal  122  to an area at a proximal portion of valve cylinder  102  external to valve stem  104 . Turn  127  may be a substantially ninety degree turn such that proximal opening  125  faces radially outward from a central longitudinal axis of valve stem  104  and distal opening  126  faces the direction of the central longitudinal axis of valve stem  104 . In some examples, turn  127  may be a curved portion of channel  124  (not shown). 
     Proximal portion of valve  100  may include a button  105  and an actuation mechanism  180 . Actuation mechanism  180  may be positioned between button  105  and valve cylinder  102 . Button  105  may be formed as one continuous structure with valve stem  104 , or button  105  may be a separate structure attached to valve stem  104 . Button  105  may have an outer circumference that is wider than a proximal opening  106  of valve cylinder  102 , so that when button  105  is depressed, button  105  cannot pass through the proximal opening of valve cylinder  102 . In some examples, button  105  may have an outer circumference that is narrower than a proximal opening  106  of valve cylinder  102 , and actuation mechanism  180  may prevent button  105  from passing through the proximal opening of valve cylinder  102 . 
     Valve stem  104  may be fitted with one or more seals. For example, valve stem  104  may include, in a direction from proximal to distal, a first seal  130 , a second seal  132 , a third seal  134 , and a fourth seal  136 . Seals  130 ,  132 ,  134 ,  136  may be, for example, O-rings. Seals  130 ,  132 ,  134 ,  136  may be formed from an elastomeric material. Valve stem  104  may also include a channel seal  122 , which may be made of the same or different material as seals  130 ,  132 ,  134 ,  136  (e.g., an elastomeric material), or any material to form a seal between the valve stem  104  and the valve cylinder  102  to prevent a fluid flow.. Channel seal  122  may prevent passage of fluid or other substance into channel  124  when in a closed position, and may permit passage of fluid or other substances proximally past channel seal  122  when in an open position. Channel seal  122  may be opened by a channel stem  120  positioned at a distal inner surface  121  of valve cylinder  102 . First seal  130  and second seal  132  may be disposed on a proximal portion of valve stem  104 . Third seal  134  and fourth seal  136  may be disposed on a distal portion of valve stem  104 . Channel seal  122  may be disposed at a distal end of valve stem  104 . Alternatively, seals  130 ,  132 ,  134 ,  136  and channel seal  122  may be disposed on alternative portions of valve stem  102  or in different orders. Proximal opening  125  of channel  124  may be disposed between first seal  130  and second seal  132 . Channel seal  122  may be disposed at distal opening  126  of channel  124  and close opening  126  when seal  122  is in a closed position. 
     Seals  132 ,  134 ,  136  may be configured so as to form a slidable interference fit between seals  132 ,  134 , and  136  and surface  103 . Thus, valve stem  104  can move relative to surface  103 , but fluids (e.g. water and air) cannot move between seals  130 ,  132 ,  134 , and  136  and surface  103 . Thus, seals  132 ,  134 , and  136  prevent movement of fluids in a proximal or distal direction past seals  132 ,  134 , and  136 . 
     Channel seal  122  may be biased toward a closed position such that fluid is prevented from flowing through channel seal  122  when channel seal  122  is in a closed position. Channel seal  122  may be opened by positioning an object within a radially-inner portion of channel seal  122 . Channel seal  122  may be, for example, a circular and plate-like shape with a slit, flap, or duck-bill seal at its radially-inner portion. Channel seal  122  may be configured to receive channel stem  120 . For example, stem  120  may protrude through a portion of a slit, flap, or other portion of seal  122 . Channel stem  120  may protrude from a distal inner surface  121  of valve cylinder  102 . Channel stem  120  may be cylindrical and may have a circumference smaller than the circumference of channel  124 . Distal opening  126  of channel  124  may be configured to received channel stem  120 . In some embodiments not shown, channel stem  120  may include a channel, lumen, or other configuration to allow fluid to move through an interior portion of channel stem  120  from an area proximate to a distal portion of channel stem  120  to an area proximal to channel stem  120 . Channel stem  120  may have a rounded or pointed proximal end configured to be pushed through channel seal  122 . Channel stem  120  may be resilient enough to maintain its shape when channel seal  122  contacts channel stem  120 . When valve  100  is translated distally towards distal interior surface  121  of valve cylinder  102 , channel seal  122  may move from a closed position to an open position once channel stem  120  is positioned within distal opening  126  of channel  124 . When channel stem  120  is positioned within distal opening  126 , channel seal  122  may be opened and fluid may flow around channel stem  120  and channel seal  122  into channel  124 . Channel stem  120  may be rigid, metal, plastic, or other suitable material. In some examples, channel stem  120  may be incorporated into valve cylinder  102 . In some examples, channel stem  120  may be cylindrical. 
     Valve  100  may also include an actuation mechanism  180 . Actuation mechanism  180  may include a biasing member, such as spring  184 , that biases valve  100  towards a first configuration shown in  FIG.  1 A . In some examples, spring  184  may be positioned around the longitudinal axis of valve  100  and may have a helical shape that wraps around a proximal portion of valve  100  distal to button  105 . In other examples, spring  184  may be a plurality of springs positioned between button  105  and collar  181 . When a user presses on button  105 , button  105  may compress a spring of actuation mechanism  180 , and valve stem  104  may translate distally. In some examples, when a user releases the user&#39;s finger from button  105 , valve  100  returns to the first configuration shown in  FIG.  1 A . In other examples, actuation mechanism  180  may provide a bistable system where in one stable position the valve  100  is retracted from the distal surface  121  of valve cylinder  102 , and in the other stable position valve  100  is extended such that a distal portion of valve stem  104  contacts distal surface  121  and/or channel stem  120 . In this latter position, valve  100  may include a locking mechanism to hold valve stem  104  in position. In some examples, actuation mechanism  180  may provide a means for a user to switch between operating configurations of valve  100 . 
     An exemplary actuation mechanism  180  is shown in  FIGS.  1 A and  1 B . Actuation mechanism  180  may include a collar  181 , a biasing member  184 , a seal  185  positioned at a proximal portion of the collar  181 , and a protrusion  183  extending from an exterior surface of valve  100 . 
     Collar  181  may be annular and may include a lumen  189  sized to receive valve  100 . Collar  181  may include an annular channel  186  at a distal portion of collar  181  configured to receive a proximal end of valve cylinder  102 . Channel  186  may include a protrusion  187  that is configured to extend into a recess of valve cylinder  102  to form a snap-fit and couple collar  181  to valve cylinder  102 . For example, channel  186  may receive an outer lip of valve cylinder  102  and protrusion  187  may extend within a recess of valve cylinder  102  to fixedly couple collar  181  to valve cylinder  102 . A seal  185  may be positioned at a radially-inner portion of channel  186  and may be configured to form a slidable interference fit between seal  185  and surface  103  of valve cylinder  102 . Seal  185  may have any of the characteristics previously described in relation to seals  132 ,  134 ,  136 . When collar  181  is coupled to valve cylinder  102 , seal  185  may prevent fluid from exiting valve cylinder  102 . 
     Seal  130  of valve  100  may also have any of the characteristics previously described in relation to seals  132 ,  134 ,  136 . When valve  100  is positioned within lumen  189  of collar, seal  130  may form a slidable interference fit between seal  130  and collar  181 . Seal  130  may prevent fluid from exiting from valve cylinder  102  through lumen  189 . 
     Collar  181  may include a second channel  182  extending circumferentially about a central longitudinal axis of collar  181  and positioned at a radially-inner surface of collar  181 . An exemplary embodiment of a side cross-sectional view of second channel  182  and protrusion  183  of valve  100  is shown in  FIG.  3   . Second channel  182  may be annular and may include proximal surfaces  301  and distal surfaces  302 , each of which may be transverse to the longitudinal axis of collar  181 . Channel  182  may be configured to receive protrusion  183  of valve  100 . Surfaces  301  may be angled and configured to guide protrusion  183  between a first configuration (shown in  FIG.  1 A ) and a second configuration (shown in  FIG.  1 B ). Biasing member  184  may bias protrusion  183  towards the proximal direction such that when a user releases button  105 , protrusion  183  will move proximally until protrusion  183  contacts one of proximal surfaces  301 . Protrusion  183  may include exterior surfaces configured to mate with proximal surfaces  301  and distal surfaces  302  of second channel  182 . As valve  100  is depressed, such as when a user presses on button  105  to move valve  100  distally, the proximal surfaces  301  may rotate valve  100  by the interaction between one or more of proximal surfaces  301  and protrusion  183  until protrusion  183  is positioned within an intermediate portion  312  in second channel  182  (such as shown in  FIG.  3   ). In other examples, collar  181  will rotate about longitudinal axis of valve  100 , due to forces applied by protrusion  183  on collar  181 . Once protrusion  183  is positioned in an intermediate portion  312  and a user then releases button  105 , protrusion  183  may be translated proximally via a force applied to valve  100  via biasing member  184 , thus moving protrusion  183  from intermediate portion  312  to one of the locking features  310 ,  311  of second channel  182 . For example, valve  100  may be in a first configuration shown in  FIG.  1 A  when protrusion  183  is positioned at locking feature  310 , and may be in a second configuration shown in  FIG.  1 B  when protrusion  183  is positioned at locking feature  311 . When a user presses down on button  105  and moves valve  100  distally, protrusion  183  may move to one of several intermediate portions  312 , and then, when a user releases button  105 , biasing member  184  may translate valve  100  proximally and position protrusion  183  at a locking feature  310 ,  311  that is adjacent to the locking feature  310 ,  311  in which protrusion  183  was previously positioned. Valve  100  may move circumferentially around collar  181  as a user transitions valve  100  between a first configuration (shown in  FIG.  1 A ) and second configuration (shown in  FIG.  1 B ), and protrusion  183  may slidably engage proximal surfaces  301  and/or distal surfaces  302  as valve  100  transitions between the first configuration (shown in  FIG.  1 A ) and second configuration (shown in  FIG.  1 B ), for example as protrusion  183  moves between locking features  310 ,  311 . Alternatively, collar  181  may move circumferentially around the longitudinal axis of valve  100  and valve  100  may not rotate. 
     In some examples, valve  100  including button  105  may be rotatable relative to biasing member  184 . In other examples, biasing member  184  may be fixedly coupled to valve  100  and may be rotatable relative to collar  181 . In some examples, biasing member  184  may be in an expanded state when valve  100  is in a first configuration shown in  FIG.  1 A  and may be in a compressed state when valve  100  is in a second configuration shown in  FIG.  1 B . 
     When actuation mechanism  180  provides a bistable system, valve  100  may be configured to move between a first stable configuration and a second stable configuration. In some examples, the user may press on button  105  to move valve  100  distally, compressing a biasing member, until actuation system  180  creates an audible “click” sound. Once the user hears the audible “click” sound, the user may release button  105  and valve  100  may be in and/or move to a second stable configuration that is distal relative to the first stable configuration. The audible “click” sound may be caused, in some examples, by the movement of protrusion  183  between locking features  310 ,  311  and intermediate portion  312  of second channel  182 . To transition valve  100  from the second stable configuration to the first stable configuration, the user may press on button  105  to move valve  100  distally until actuation system  180  creates an audible “click” sound, and then the user may release button  105  and valve  100  may move proximally to the first stable configuration via a force supplied by the biasing member. In some examples, the first stable configuration may be the configuration shown in  FIG.  1 A  and the second stable configuration may be the configuration shown in  FIG.  1 B . 
       FIG.  1 A  shows valve  100  in a first configuration. In the first configuration of valve  100 , neither air nor water may be delivered to either the proximal opening  125  or distal opening  126  of channel  124 . Air or other fluid may be delivered to an air channel of an endoscope via air inlet  112  and air outlet  114 , but water or other fluid is not delivered to any channel of the endoscope from water inlet  108 . Channel seal  122  is positioned proximal to channel stem  120 , and thus channel seal  122  seals distal opening  126  and prevents passage of fluid through distal opening  126 . Seal  136  prevents proximal fluid flow, such as fluid flow from water inlet  108  to water outlet port  110 . Seal  134  prevents fluid flow, such as air flow, from air inlet  112  to water outlet  110 . Seal  132  prevents fluid flow from air inlet  112  from flowing into proximal opening  125  of channel  124  and/or from exiting valve cylinder  102 . Seal  130  prevents fluid flow from exiting valve cylinder  102  at the proximal end, and may serve as a back-up seal to seal  132  for preventing fluid flow from air inlet  112  from exiting valve cylinder  102 . In this first configuration shown in  FIG.  1 A , air or other fluid may be supplied to air inlet  112  and may flow within an annular space  140  to outlet port  114  such that air inlet  112  is in fluid communication with air outlet  114 . Thus, in the first configuration, air may flow through air inlet  112  and out of air outlet  114 , and water may not flow to water outlet  110 , channel  124 , or air outlet  114 . The arrows in  FIG.  1 A  show this air flow path. 
     In the second configuration, shown in  FIG.  1 B , water is delivered to an air channel of the endoscope but air is not delivered to any endoscope channel. To transition from the first configuration to the second configuration, button  105  may be depressed. For example, button  105  may be depressed until a user hears an audible “click” sound created by actuation mechanism  180 . In some examples, actuation mechanism  180  may cause tactile feedback to a user to indicate that valve  100  is in the second configuration. 
     In transitioning from the first configuration to the second configuration, valve stem  104  may translate distally relative to valve cylinder  102 , as a result of button  105  being pressed downward. A force on button  105  to transition valve  100  from the first configuration to the second configuration may cause the distalmost end of valve stem  104 , which may include channel seal  122 , to contact channel stem  120 . Once channel stem  120  contacts channel seal  122 , channel seal  122  may open as valve  100  moves distally relative to valve cylinder  102  and channel stem  120  penetrates channel seal  122 . 
     In the second configuration, channel seal  122  may be open and proximal opening  125  may be aligned with air outlet  114 , such that water may flow from water inlet  108 , through annular space  142 , around channel stem  120 , and into channel  124 , to air outlet  114 . Fourth seal  136  may be proximal to water inlet  108  and distal to water outlet  110 . Thus, water from water inlet  108  may not move proximally past fourth seal  136  to water outlet  110 , but may move through channel  124  and air outlet  114  to flush an air channel of an endoscope. Third seal  134  may be proximal of water outlet  110  and distal to air inlet  112 . Second seal  132  may be proximal to air inlet  112  and distal to air outlet  114 , thus preventing air flow from air inlet  112  to air outlet  114 . Also, second seal  132  may prevent water flow from proximal opening  125  from entering air inlet  112 . First seal  130  may be proximal to air outlet  114  and distal to proximal opening  106 , and thus may prevent water flow from proximal opening  125  from exiting valve cylinder  102 . As a result, in the second configuration, the only fluid flow to the endoscope sheath is that of water through the air channel. The second configuration of valve  100  may provide a means for a user to flush the air channel of an endoscope with water. 
     In order to make use of valve  100 , an operator may insert valve  100  into valve cylinder  102  of an endoscope. For example, following an endoscopic procedure, the endoscope may be removed from the patient for reprocessing, a valve used during the endoscope procedure may be removed, and valve  100  may be inserted into valve cylinder  102 . Valve  100  may be inserted into valve cylinder  102  by pressing valve  100  into valve cylinder  102 . In some examples, valve  100  may be rotatable by the user to a selected position, e.g., a keying feature in order to rotate valve  100  into the correct position within valve cylinder  102 . The user may first apply air flow to air inlet  112  to allow air to flow through annular space  140  to air outlet  114 . Also, user may then transition valve  100  from a first configuration (shown in  FIG.  1 A ) to a second configuration (shown in  FIG.  1 B ). Specifically, button  105  may be fully depressed so that valve  100  transitions to the second configuration (shown in  FIG.  1 B ). Valve  100  may flush water through the air channel. After flushing is complete, a user may release button  105  to stop water flow to air outlet  114 . In other examples, a user may press button  105  until an actuation mechanism  180  creates a “click” sound. Then the user may then release button  105  and actuation mechanism  180  may transition valve  100  from the second configuration to the first configuration via a biasing member, and thus stop water flow to air outlet  114 . After flushing of the air channel is complete, valve  100  may be removed from valve cylinder  102 . Valve  100  may be removed from valve cylinder  102  by grasping the exposed portion of the proximal end of valve  100  and pulling proximally to remove valve  100  from valve cylinder  102 . Once removed from valve cylinder  102 , in some examples valve  100  would be disposed. 
       FIGS.  2 A and  2 B  depict configurations of another exemplary valve  200  within a valve cylinder  202 .  FIG.  2 A  shows valve  200  in a first configuration, and  FIG.  2 B  shows valve  200  in a second configuration. Valve  200  may have a valve stem  204 . Valve stem  204  may be substantially cylindrical extending along a longitudinal axis and may have a proximal end  209  and a distal end  211 . Proximal end  209  of valve stem  204  may include a button  205 , which may be configured to be contacted by one or more fingers of a user in operation of valve  200 . External screw/threads  270  may protrude radially from a proximal portion of valve stem  204  and may be configured to be received by thread grooves  260  in valve cylinder  202 . When valve  200  is inserted into valve cylinder  202 , threads  270  may engage grooves  260  and a user may rotate button  205  in order to couple valve  200  to valve cylinder  202 . 
     Valve stem  204  may include a channel  224  extending proximally from distal end  211  of valve stem  204  to a proximal portion of valve stem  204 . Channel  224  may include a proximal opening  225 , a distal opening  226 , a bend or turn  227 , and a side opening  229 . Turn  227  may be an approximately ninety degree turn such that proximal opening  225  faces radially outward from a central longitudinal axis of valve stem  204  and distal opening  226  faces the direction of the central longitudinal axis of valve stem  204 . Proximal opening  225  may be configured to align with air outlet  214  when valve  200  is fully inserted within valve cylinder  202  (shown in  FIG.  2 B ). In some examples, turn  227  may be a curved portion of channel  224  (not shown). Side opening  229  may be positioned at a distal portion of channel  224  and may connect a side channel  231  (shown in  FIG.  2 B ) to channel  224 . Side channel  231  may extend in a direction radially outward from the central longitudinal axis of valve stem  204  and may be transverse to channel  224 . In some examples, side channel  231  may be perpendicular to channel  224 . Side channel  231  may fluidly connect channel  224  to an area at a distal portion of valve cylinder  202  external to valve stem  204 . Side channel  231  may be configured to align with water inlet  208  when valve  200  is fully inserted within valve cylinder  202  (shown in  FIG.  2 B ). Channel  224  may fluidly connect an area at a distal portion of valve cylinder  202  external to valve stem  204  to an area at a proximal portion of valve cylinder  202  external to valve stem  204 . 
     Valve stem  204  may also be fitted with a plurality of seals. For example, valve stem  204  may include a first seal  230 , a second seal  232 , a third seal  234 , and a fourth seal  236 . Seals  230 ,  232 ,  234 , and  236  may be disposed in grooves of valve stem  204 . Seals  230 ,  232 ,  234 , and  236  may have any of the properties of seals  130 ,  132 ,  134 , or  136 , described above. Seals  230 ,  232 ,  234 , and  236  may have a slidable interference fit with a surface  203  of valve cylinder  202  so that fluids (e.g., air, water) cannot move proximally or distally between seal  230 ,  232 ,  234 , or  236  and the surface  203  of valve cylinder  202 . First seal  230  may be disposed proximally of proximal opening  225  of channel  224  and may be disposed distally of threads  270 . Second seal  232  may be disposed distally of proximal opening  225  of channel  224  and proximally of third seal  234 . Third seal  234  may be disposed distally of second seal  232  and proximally of side channel  231 . Fourth seal  236  may be disposed distally of side channel  231  and proximally of distal opening  226  of channel  224 . 
     Valve stem  204  may also include a face seal  235  positioned at the outlet  281  of side channel  231  and coupled to the radially outer surface of valve stem  204  (see  FIG.  2 B ). Face seal  235  may be annular and may be configured to surround the outlet  281 . Face seal  235  may have any of the properties of seals  130 ,  132 ,  134 ,  136 ,  230 ,  232 ,  234 , and  236 . Face seal  235  may have a slidable interference fit with a surface  203  of valve cylinder  202  so that fluids (e.g., air, water) cannot move between the outlet  281  and the area external to the radially-outer surface of face seal  235 . Face seal  235  may be configured to allow fluid flow between water inlet  208  and side channel  231  when outlet  281  is aligned with water inlet  208 . When inlet  208  is not overlapping with outlet  281  (such as the configuration shown in  FIG.  2 A ), face seal  235  may prevent flow of fluid from side channel  231  into an area outside the radially-outer surface of face seal  235  within valve cylinder  202 . 
     Valve stem  204  may further include a second face seal  237  or static seal coupled to an exterior surface of valve  200  between the second seal  232  and third seal  234 . Second face seal  237  may have any of the features described above with regard to face seal  235 . Second face seal  237  may be positioned such that when valve  200  is completely inserted within valve cylinder  202  (shown in  FIG.  2 B ), second face seal  237  aligns with air inlet  212 . When second face seal is aligned with air inlet  212 , second face seal  237  may prevent fluid flow between air inlet  212  and the interior portion of valve cylinder  202  outside the radially-outer surface of second face seal  237 . In some examples, second face seal  237  may be circular and disc-shaped (without a radially-inner opening) to completely cover inlet  212  and may prevent the flow of fluid into the interior portion of valve cylinder  202  when aligned with air inlet  212 . By preventing or blocking fluid flow into the interior portion of valve cylinder  202 , second face seal  237  may prevent complications associated with air flow within valve cylinder  202  while flushing an air channel of an endoscope with water, among other potential benefits. 
     Valve stem  204  may also include one or more threads  270 . Threads  270  may be on a circumferential outer surface of valve stem  204  and positioned proximal to button  205 . Threads  270  may couple valve  200  to valve cylinder  202  when positioned within one or more grooves  260  at a proximal portion of the interior surface  203  of valve cylinder  202 . In some examples, one or more threads  270  may be configured to couple valve  200  to valve cylinder  202  by a user rotating valve  200  ninety degrees. In some examples, a user may insert valve  200  into valve cylinder  202  and rotate valve  200  ninety degrees to position valve  200  within valve cylinder  202  in the configuration shown in  FIG.  2 B . In other examples, threads may be configured to rotate one hundred and eighty degrees, two hundred and seventy degrees, three hundred and sixty degrees, or any other amount of rotation to position threads  270  within grooves  260  and achieve the valve configuration shown in  FIG.  2 B . In some examples, valve  200  may transition between the configuration shown in  FIG.  2 A  and the configuration shown in  FIG.  2 B  by a user rotating button  205  ninety degrees. In some examples, valve  200  may transition between the configuration shown in  FIG.  2 A  and the configuration shown in  FIG.  2 B  by a user pressing on button  205  and rotating valve  200  simultaneously. 
       FIG.  2 A  shows valve  200  in a first configuration. In the first configuration, air may be delivered to an air channel of an endoscope via air inlet  212  and air outlet  214 , but water is not delivered to water outlet  210  or air outlet  214 . Seal  236  prevents proximal fluid flow, such as fluid flow from water inlet  208  to water outlet  210 . Seal  234  prevents fluid flow, such as air flow, from air inlet  212  to water outlet  210 . Water or other fluid may flow from water inlet  208  through channel  224  to proximal opening  225 . Seal  232  prevents fluid flow from air inlet  212  from flowing into proximal opening  225 , and prevents fluid flow from proximal opening  225  to air outlet  214  and air inlet  212 . Seal  230  prevents fluid flow from exiting valve cylinder  202 , and prevents fluid flow from proximal opening  225  from exiting valve cylinder  202 . Face seal  235  prevents fluid flow between side channel opening  281  and the exterior portion of valve stem  204  between seals  234  and  236 . In this first configuration shown in  FIG.  2 A , air or other fluid may be supplied to air inlet  212  and may flow within annular space  240  to air outlet  214  such that air inlet  212  is in fluid communication with air outlet  214 . Thus, in the first configuration, air may flow through air inlet  212  and out of air outlet  214 , and water may not flow to water outlet  210  or air outlet  214 . 
     In the second configuration, shown in  FIG.  2 B , water or other fluid from water inlet  208  is delivered to an air channel of the endoscope, but air or other fluid from air inlet  212  is not delivered to any endoscope channel. To transition from the first configuration to the second configuration, button  205  may be twisted/rotated. For example, button  205  may be rotated until at least one radially-outer portion or flange  291 ,  292  is flush or proximate to opening  206  of valve cylinder  202 . In some examples, distal end  211  of valve  200  may contact distal surface  221  of valve cylinder  202  when in the second configuration. 
     In the second configuration, proximal opening  225  of channel  224  may be aligned with air outlet  214 , and side channel  231  may be aligned with water inlet  208 , such that water may flow from water inlet  208 , through side channel  231  and channel  224 , to air outlet  214 . Fourth seal  236  may be distal to water inlet  208 . Third seal  234  may be proximal to water inlet  208  and distal to water outlet  210 . Face seal  235  may be positioned around water inlet  208  and side channel opening  281 , such that fluid flowing between water inlet  208  and side channel  231  does not flow to an area external to valve  200  within valve cylinder  202  exterior to face seal  235 . Channel  224  allows fluid to flow out of distal opening  226  to a distal portion of valve cylinder  202 . Seal  236  prevents fluid flowing out of distal opening  226  from flowing proximally beyond seal  236 . Second face seal  237  may be aligned with air inlet  212  and may prevent the flow of fluid (such as air) into an interior portion of valve cylinder  202 . Second seal  232  may be distal to air outlet  214  and proximal to air inlet  212 , and may prevent fluid flow between proximal opening  225  and air inlet  212 . First seal  230  may be proximal to air outlet  214  and distal to opening  206  of valve cylinder  202 , and may prevent fluid flow between proximal opening  225  and the exterior of valve cylinder  202 . Thus, water may move through water inlet  208 , side channel  231 , channel  224 , and air outlet  214  to flush an air channel of an endoscope. As a result, in the second configuration, the only fluid flow to the endoscope sheath is that of water through the air channel. The second configuration of valve  200  may provide a means for a user to flush the air channel of an endoscope with water. 
     In order to make use of valve  200 , an operator may insert valve  200  into valve cylinder  202  of an endoscope. For example, following an endoscopic procedure, the endoscope may be removed from the patient for reprocessing, a valve used during the endoscope procedure may be removed, and valve  200  may be inserted into valve cylinder  202 . Button  105  may be rotated so that valve  200  transitions to the second configuration (shown in  FIG.  2 B ). Valve  200  may flush water through the air channel. After flushing is complete, a user may rotate button  205  to stop water flow to air outlet  114 . In some examples, valve  200  may be configured to transition from the configuration shown in  FIG.  2 A  to the configuration shown in  FIG.  2 B  when a user rotates valve  200  a predetermined degree of rotation, and the predetermined degree of rotation may be between 60 degrees and 270 degrees. In some examples, a user may rotate button  205  to align valve  200  in the first configuration of  FIG.  2 A  to allow flow of air into air outlet  214 , and thus allow air flow into an air channel of an endoscope. After flushing and/or air flow application is complete, a user could either move button  205  to disable the flow of water or air or could simply remove valve  200  from valve cylinder  202  by continually rotating button  205  (such that one or more threads  270  translate out of grooves  260 ) and pulling proximally on valve  200 . The endoscope would be subject to further processing, and, in some examples, valve  200  may be disposed. 
     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.