Patent Publication Number: US-2022211256-A1

Title: Disposable air/water and suction valves for an endoscope

Description:
CROSS-REFERENCE 
     The present specification relies on, for priority, U.S. Patent Provisional Application No. 62/259,573, entitled “Disposable Air/Water and Suction Valves for An Endoscope”, and filed on Nov. 24, 2015. 
     In addition, the present specification relies on, for priority, U.S. Patent Provisional Application No. 62/375,359, entitled “Disposable Air/Water and Suction Valves for An Endoscope”, and filed on Aug. 15, 2016. 
     The above-mentioned applications are herein incorporated by reference in their entirety. 
    
    
     FIELD 
     The present specification relates generally to endoscopy systems and more particularly, to disposable air/water and suction valves for use with an endoscope. 
     BACKGROUND 
     Endoscopes have attained great acceptance within the medical community since they provide a means for performing procedures with minimal patient trauma while enabling the physician to view the internal anatomy of the patient. Over the years, numerous endoscopes have been developed and categorized according to specific applications, such as cystoscopy, colonoscopy, laparoscopy, and upper GI endoscopy and others. Endoscopes may be inserted into the body&#39;s natural orifices or through an incision in the skin. 
     An endoscope usually includes an elongated tubular shaft, rigid or flexible, having a video camera or a fiber optic lens assembly at its distal end. The shaft is connected to a handle which sometimes includes an ocular element for direct viewing. Viewing may also be possible via an external screen. Various surgical tools may be inserted through a working channel in the endoscope for performing different surgical procedures. Often, the endoscope also has fluid injectors (“jet”) for cleaning a body cavity, such as the colon, into which they are inserted. A control section of the endoscope may include a suction cylinder and an air/water cylinder. Valves may be inserted into these cylinders to control various functions of the endoscope. 
     For example, an air/water valve for an endoscope may be inserted into the air/water cylinder or channel of the endoscope to provide air and water to the endoscope. When the air/water valve is in a first, normal position, air escapes from a vent in the valve. When insufflation is desired, an operator places a finger over the vent, which redirects the air towards the distal end of the endoscope, thus insufflating the organ that is being examined. When the operator engages the air/water valve (e.g. by depressing the valve), air is redirected to a water bottle and creates pressure in the bottle that causes water to flow towards the distal end of the endoscope. 
     In addition, a suction valve for the endoscope may be inserted into the suction cylinder or channel of the endoscope to provide suction to the endoscope. When the suction valve is in a first, normal position, air flow from the distal tip of the endoscope is blocked by the valve. When suction is desired, an operator engages the suction valve (e.g. by depressing the valve) to open the suction channel to create negative pressure that draws air or fluid into the opening of the instrument channel of the endoscope. When the operator releases the suction valve, the valve returns to its normal position blocking air flow and stops the suctioning. 
     After each use, an endoscope must be cleaned, disinfected, and sterilized to prevent the spread of disease, germs, bacteria and illness. Many components of an endoscope may be reusable, such as the air/water valve and suction valve and thus, must also be cleaned, disinfected, and/or sterilized between uses. Unfortunately, there is usually a great expense associated with maintaining sterility of the equipment. In addition, since reusable air/water and suction valves may be assembled from a combination of several metal, plastic, and/or rubber components there are significant costs associated with the manufacturing of reusable air/water valves. 
     Accordingly, there is a need for single-use or disposable air/water and suction valves that can be easily manufactured and assembled using a variety of materials for various components of the valves. Additionally, disposable air/water and suction valves do not require expensive materials to fabricate the valves, thereby eliminating the high cost of manufacturing suction valves from expensive materials. 
     SUMMARY 
     The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods, which are meant to be exemplary and illustrative, not limiting in scope. The present application discloses numerous embodiments. 
     The present specification discloses a disposable air and water valve for an endoscope, comprising: a shaft having a passage from a first opening to a vent, wherein the shaft has at least one groove, at least one ridge, and at least one protrusion formed at the vent; at least one seal set within the at least one groove; an outer cap; an inner ring having a diaphragm that extends from an outer circumference of the inner ring to an internal circumference of the outer cap, wherein at least one hinge extends vertically downwards from said diaphragm and wherein at least one rib is positioned along the internal circumference of the outer cap; a button cap having an internal ring that securely attaches to the shaft by fitting into a notch near the vent of the shaft; and a resilient member securely disposed between the button cap and the diaphragm, wherein the outer cap, inner ring, and internal ring of the button cap define a central bore to accommodate said shaft. 
     Optionally, the disposable air/water valve further comprises at least one bushing set within the at least one groove or a second groove, wherein said at least one bushing is configured to center said valve within a channel of an endoscope. 
     The shaft, seals, outer cap, inner ring, and button cap may comprise at least one of polyurethane, polyurea, polyether(amide), PEBA, thermoplastic elastomeric olefin, copolyester, styrenic thermoplastic elastomer, carbon fiber, glass fiber, ceramics, methacrylates, poly (N-isopropylacrylamide), PEO-PPO-PEO, rubber, plastic, polycarbonate, ABS, MABS, and silicone. 
     The resilient member may comprise at least one of a corrosion resistant metal, polyurethane, polyurea, polyether(amide), PEBA, thermoplastic elastomeric olefin, copolyester, and styrenic thermoplastic elastomer, carbon fiber, glass fiber, ceramics, methacrylates, poly (N-isopropylacrylamide), PEO-PPO-PEO, rubber, and plastic. 
     Optionally, the shaft comprises machined steel and said button cap comprises plastic and said shaft is mechanically bonded to said button cap. 
     Optionally, the at least one hinge comprises a tine and barb wherein the barb has a width of less than 200 microns. 
     Optionally, the at least one hinge is configured to connect to a corresponding mount on an endoscope and prevent vertical displacement of said at least one seal. Optionally, said at least one hinge is configured to generate an audible and tactile snap when said at least one hinge is connected to said corresponding mount, thereby indicating that the valve has been seated correctly. 
     Optionally, the at least one rib is configured to act as an edge stop to ensure said valve is centered on the mount and prevent a side loading from breaking said at least one seal. 
     Optionally, the outer cap and said inner ring with said at least one hinge and said at least one rib are molded as a single component. 
     The present specification also discloses a disposable suction valve for an endoscope, comprising: a shaft having a passage from a first opening to a vent, wherein the shaft has a plurality of grooves, a plurality of ridges and a protrusion formed at the vent; an outer cap; an inner ring having a diaphragm that extends from an outer circumference of the inner ring to an internal circumference of the outer cap, wherein a plurality of vertical hinges extend downward from said diaphragm and wherein a plurality of vertical ribs are formed along the internal circumference of the outer cap; a button cap having an internal ring configured to securely attach to the shaft; and a resilient member securely disposed between the button cap and the diaphragm, wherein the outer cap, inner ring, and internal ring of the button cap define a central bore to accommodate the shaft. 
     Optionally, the internal ring securely attaches to the shaft by fitting into a tapered notch near the vent of the shaft. 
     Optionally, each of the plurality of hinges comprises a tine and a barb. Optionally, the barb is defined by a width of less than 200 microns. 
     Optionally, said plurality of hinges is configured to connect to a corresponding mount on an endoscope. Optionally, each of said plurality of hinges is configured to generate an audible and tactile snap when each of said plurality of hinges connects to said corresponding mount. 
     Optionally, each of said plurality of vertical ribs is configured to act as an edge stop to ensure said valve is centered on the mount. 
     Optionally, the outer cap and said inner ring with said plurality of hinges and said plurality of ribs are molded as a single component. 
     The present specification also discloses a method of operating a disposable air/water valve for an endoscope comprising an air channel and a water channel each connected to a water bottle, said method comprising: placing a disposable air and water valve in a port of an endoscope wherein said disposable air and water valve comprises: a shaft having a passage from a first opening to a vent, wherein the shaft has a plurality of grooves, a plurality of ridges, and a protrusion formed at the vent; a plurality of seals set within at least a portion of the plurality of grooves; an outer cap; an inner ring having a diaphragm that extends from an outer circumference of the inner ring to an internal circumference of the outer cap, wherein a plurality of hinges extend vertically downwards from said diaphragm and wherein a plurality of ribs are formed along the internal circumference of the outer cap; a button cap having an internal ring configured to securely attach to the shaft; and a member securely disposed between the button cap and the diaphragm, wherein the outer cap, inner ring, and internal ring of the button cap define a central bore to accommodate the shaft; allowing air to enter at said first opening and escape from said vent when valve is un-actuated; covering said vent to force air through said air channel in a distal direction to insufflate a body cavity; actuating said valve by depressing said button cap to compress said resilient member and move said first opening into said water channel, forcing air into said water bottle and resulting in water being forced through said water channel in a distal direction; and releasing said button cap to allow said resilient member to decompress, move said first opening out of alignment with said water channel, un-actuate said valve and stop said flow of water. 
     The present specification also discloses a method of operating a disposable suction valve for an endoscope connected to a suction pump, said method comprising: placing a disposable suction valve in a suction cylinder of an endoscope wherein said disposable suction valve comprises: a shaft having a passage from a first opening to a vent, wherein the shaft has a plurality of grooves, a plurality of ridges and a protrusion formed at the vent; an inner ring having a diaphragm that extends from an outer circumference of the inner ring, wherein at least one hinge extends downward from said diaphragm; a button cap with an internal ring configured to securely attach to the shaft; and a resilient member securely disposed between the button cap and the diaphragm; preventing the suction pump from preventing negative pressure in the suction channel by not actuating said suction valve; actuating said suction valve by depressing said button cap to compress said resilient member and move said first opening into alignment with said suction channel, allowing said suction pump to create negative pressure in said suction channel to suction air and/or fluid from a distal end of said endoscope; and releasing said button cap to allow said resilient member to decompress to thereby move said first opening out of alignment with said suction channel, un-actuate said valve and stop said suction. 
     The aforementioned and other embodiments of the present shall be described in greater depth in the drawings and detailed description provided below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the present invention will be appreciated, as they become better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
         FIG. 1A  is a perspective view of a single use, disposable air/water valve in accordance with an embodiment of the present specification; 
         FIG. 1B  is a cross-section view of the air/water valve of  FIG. 1A ; 
         FIG. 1C  is another cross-section view of the air/water valve of  FIG. 1A ; 
         FIG. 1D  is yet another cross-section view of the air/water valve of  FIG. 1A ; 
         FIG. 1E  is a bottom perspective view of the air/water valve of  FIG. 1A ; 
         FIG. 1F  is a bottom view of the air/water valve of  FIG. 1A ; 
         FIG. 1G  illustrates a first hinge or hook configured to enable a first amount of insertion/removal force, in accordance with an embodiment; 
         FIG. 1H  illustrates a second hinge or hook configured to enable a second amount of insertion/removal force, in accordance with an embodiment; 
         FIG. 1I  illustrates a third hinge or hook configured to enable a third amount of insertion/removal force, in accordance with an embodiment; 
         FIG. 1J  illustrates a fourth hinge or hook configured to enable a fourth amount of insertion/removal force, in accordance with an embodiment; 
         FIG. 2A  is a table showing an air/water valve insertion force for a 140 micron hook; 
         FIG. 2B  is a table showing an air/water valve insertion force for a 70 micron hook; 
         FIG. 2C  is a table showing an air/water valve insertion force for a 35 micron hook; 
         FIG. 2D  is a table showing an air/water valve removal force for a 140 micron hook; 
         FIG. 2E  is a table showing an air/water valve removal force for a 70 micron hook; 
         FIG. 2F  is a table showing an air/water valve removal force for a 35 micron hook; 
         FIG. 3A  is an illustration showing various dimensions of a 70 micron hook that is used in an air/water valve of the present specification; 
         FIG. 3B  is an illustration showing various dimensions of a 70 micron hook that is used in an air/water valve of the present specification; 
         FIG. 3C  is an illustration showing various dimensions of a 70 micron hook that is used in an air/water valve of the present specification; 
         FIG. 3D  is a table showing an air/water valve depression force for a 140 micron hook; 
         FIG. 3E  is a table showing an air/water valve depression force for a 70 micron hook; 
         FIG. 3F  is a table showing an air/water valve depression force for a 35 micron hook; 
         FIG. 4A  illustrates an embodiment of an exemplary outer cap with a hook size of 70 micros and a lead-in angle of 15 degrees on each side; 
         FIG. 4B  shows a bottom view (or attachment portion) of the outer cap of  FIG. 4A  that is used to attach the air/water valve to a corresponding mount of an endoscope; 
         FIG. 4C  is a diagram showing the location of cross-section A-A of an outer cap; 
         FIG. 4D  is a cross-sectional view of the outer cap of  FIG. 4C ; 
         FIG. 4E  is a diagram showing the location of cross-section A-A on an outer cap; 
         FIG. 4F  is a cross-sectional view of the outer cap of  FIG. 4E ; and 
         FIG. 4G  which represents an exploded view of cross section B-B of  FIG. 4F . 
         FIG. 5  is a flow chart illustrating a plurality of exemplary steps involved in operating an air/water valve of the present specification; 
         FIG. 6A  is a perspective view of a disposable suction valve in accordance with an embodiment of the present specification; 
         FIG. 6B  is a top view of the disposable suction valve of  FIG. 6A ; 
         FIG. 6C  is a vertical cross-section view along an axis F-F of the disposable suction valve of  FIG. 6A ; 
         FIG. 6D  is a horizontal cross-section view along an axis G-G of the disposable suction valve of  FIG. 6C ; 
         FIG. 6E  is a bottom perspective view of the disposable suction valve of  FIG. 6A ; 
         FIG. 6F  is a magnified view of the bottom of the disposable suction valve of  FIG. 62E ; and, 
         FIG. 7  is a flow chart illustrating a plurality of exemplary steps involved in operating a suction valve of the present specification; 
     
    
    
     DETAILED DESCRIPTION 
     The present specification is directed towards multiple embodiments. The following disclosure is provided in order to enable a person having ordinary skill in the art to practice the invention. Language used in this specification should not be interpreted as a general disavowal of any one specific embodiment or used to limit the claims beyond the meaning of the terms used therein. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention. In the description and claims of the application, each of the words “comprise” “include” and “have”, and forms thereof, are not necessarily limited to members in a list with which the words may be associated. 
     It should be noted herein that any feature or component described in association with a specific embodiment may be used and implemented with any other embodiment unless clearly indicated otherwise. 
     As used herein, the indefinite articles “a” and “an” mean “at least one” or “one or more” unless the context clearly dictates otherwise. 
     It is noted that the term “endoscope” as mentioned to herein may refer particularly to colonoscopes and gastroscopes, according to some embodiments, but is not limited only to colonoscopes and gastroscopes. The term “endoscope” may refer to any instrument used to examine the interior of a hollow organ or cavity of the body. 
       FIG. 1A  is a perspective view of a disposable air/water valve  100  in accordance with an embodiment of the present specification while  FIGS. 1B, 1C and 1D  are respectively first, second and third cross-section views of the air/water valve  100 . Referring now to  FIGS. 1A through 1D , the air/water valve  100  comprises a stem or shaft  105  having a plurality of grooves  109 ,  110 ,  111 ,  112 ,  113 ,  114 ,  115  and ridges  116 ,  117 ,  118 ,  119 ,  120 ,  121 ,  122 ,  123  that are molded or machined, in various embodiments, as part of the shaft  105 . A plurality of seals  125 ,  127 , and  129  may be set into the respective grooves  109 ,  112 ,  114  in accordance with some embodiments. A plurality of bushings  126 ,  128  may be set into respective grooves  110 ,  113  in accordance with some embodiments. The bushings  126 ,  128  assist in centering the air/water valve  100  in a channel within an endoscope. In various embodiments, the bushings  126 ,  128  are rigid or semi-rigid. In some embodiments, the air/water valve includes two bushings  126 ,  128  positioned in grooves  110 ,  113  respectively. In other embodiments, the air/water valve  100  includes only bushing  126  positioned in groove  110 . In other embodiments, the device does not have bushings and, instead, rely on ribs to center the valve appropriately. In addition, air/water valve  100  may also comprise inner ring  135 , outer cap  140 , resilient member  145  ( FIG. 1C, 1D ) such as, but not limited to, spring, rubber, elastic, and a button cap  150 . 
     In accordance with aspects of the present specification, the ridge  116  prevents unintentional removal of the seal  125  by providing an additional interference between the seal  125  and the shaft  105 . In various embodiments, the shaft  105  has a preferred travel direction (from the ridge  116  toward the end  165 ) which enables an easier placement of the seal  125  than removal of the seal due to a direction of taper of the ridge  116 . 
     The components of air/water valve  100  may comprise at least one disposable material, including, but not limited to polyurethane, polyurea, polyether(amide), PEBA, thermoplastic elastomeric olefin, copolyester, styrenic thermoplastic elastomer, carbon fiber, glass fiber, ceramics, methacrylates, poly (N-isopropylacrylamide), PEO-PPO-PEO (pluronics), rubber, plastic (e.g., polycarbonates), ABS, MABS, silicone, or combinations thereof. The resilient member  145  may be formed from a suitable material, such as corrosion resistant metal, polyurethane, polyurea, polyether(amide), PEBA, thermoplastic elastomeric olefin, copolyester, and styrenic thermoplastic elastomer, carbon fiber, glass fiber, ceramics, methacrylates, poly (N-isopropylacrylamide), PEO-PPO-PEO (pluronics), rubber, plastic, or combinations thereof. 
     It should be understood that the plurality of seals  125 ,  127 , and  129  can be any member suitable for sealing a portion of the shaft  105 . The positioning of the seals corresponds to the water and air channels. The seals serve to prevent air from entering the water channel and to prevent air from exiting anywhere other than outside of the vent hold on the top of the shaft  105 . In some embodiments, the plurality of seals can be permanently attached to the shaft  105 , such as for example, by over-molding. In other embodiments, the plurality of seals can be removably attached to the shaft  105 , such as for example, by sliding the seal onto shaft  105 . Like other components of the air/water valve  100 , the plurality of seals can comprise polyurethane, polyurea, polyether(amide), PEBA, thermoplastic elastomeric olefin, copolyester, and styrenic thermoplastic elastomer, carbon fiber, glass fiber, ceramics, methacrylates, poly (N-isopropylacrylamide), PEO-PPO-PEO (pluronics), rubber, plastic (e.g., polycarbonates), ABS, MABS, silicone or combinations thereof. 
     In embodiments, the air/water valve  100 , when attached to or mounted onto an endoscope enables an air-flow rate of at least 800 cc/min from the tip section of the endoscope, wherein the tip section is capable of an overall output of about 1500 cc/min at a pressure of 0.05 MPa (mega pascal). In some embodiments, the seal  127  is fabricated from a TPE (Thermoplastic Elastomer) material having a wall thickness of 0.35 mm and a 50 shore A hardness which enables an air-flow rate of at least 800 cc/min. In a preferred embodiment, the seal  127  is fabricated from a TPE material having a wall thickness of 0.22 mm and a 50 shore A hardness which enables an air-flow rate in a range of 1250 to 1300 cc/min. It should be appreciated that the wall thickness for the seal  127  may vary, in other embodiments, depending upon at least the type of material, hardness, geometry, molding conditions and number of support ribs. In some embodiments, the seal  127  includes, along its sides, a plurality of ribs. One embodiment of the seal  127  comprises four ribs 90 degrees apart from one another—two fully spanning the cross-section of the seal and the other two acting as filling channels. In one embodiment, the air-flow rate is a minimum of 700 cc per minute. 
     The shaft  105  provides an opening  155  and a passage or bore  160  that runs upwards through the shaft  105 , substantially along a longitudinal axis  170 , from the opening  155  to an end or vent  165 . The opening  155  lies along an axis  172  that is substantially perpendicular to the longitudinal axis  170 . When the end or vent  165  is not covered by an operator, air may travel via the opening  155  and up the passage or bore  160  to escape from the vent  165 . 
     The inner ring  135  has a diaphragm or collar  136  extending from an outer circumference of the inner ring  135  to the internal circumference of the outer cap  140 . The resilient member  145  is installed to lie between the inner ring  135  and the button cap  150  such that one end of the resilient member  145  is secured to the diaphragm or collar  136  and the other end to the button cap  150 . In some embodiments, the inner ring  135  is a monolithic internally molded part of the outer cap  140  while in other embodiments these may be two separate components. In various embodiments, the outer cap  140  (along with the inner ring  135  when molded as a monolithic part of the outer cap  140 ) is molded using material of sufficient rigidity. In an embodiment, the outer cap  140  is molded from ABS having a Rockwell R hardness of 112 or hardness in the range of 70 to 90 shore D. The inner ring  135 , outer cap  140  and the button cap  150  respectively define internal bores for receiving the end or vent  165  of the shaft  105 . End  165  of the shaft  105  is placed through inner ring  135  and resilient member  145  and secured to the button cap  150  (as shown in  FIGS. 1C, 1D ). When assembled, the diaphragm or collar  136  of the inner ring  135  rests upon the ridge  123 . 
     In accordance with an aspect of the present specification and as shown in  FIG. 1D , an internal ring  180  of the button cap  150  is secured to the shaft  105 , at the end  165 , within a tapered notch, groove or recessed portion  175  (on the outer diameter of the shaft  105 ) defined between a detent or protrusion  178  (towards the end  165 ) and a ridge  179 . In an embodiment, the notch portion  175  is tapered at an angle ‘A’ with reference to a vertical line parallel to the longitudinal axis  170 . 
     Conventional valves typically use adhesive or welded joints to join or secure the button cap to the shaft. However, the securing mechanism of the present specification allows the use of dissimilar materials for the components such as the button cap  150  and the shaft  105 . For example, the shaft  105  may be of metal while the button cap  150  may be of plastic or the shaft  105  and the button cap  150  may both be of plastic yet of different melt temperatures. During a sterilization process, such as autoclaving, the plastic button cap  150  will melt and then become secured to shaft  105  as it dries post sterilization. Using dissimilar material for the button cap  150  and shaft  105  eliminates the need of matching material properties required in a gluing or welding process. Typically, materials must be selected so that they have similar melt temperatures (in the case of welding) or have surface properties conducive to adhesives. Eliminating such constraints allows the individual component materials of the button cap  150  and shaft  105  to be optimized for their specific purposes. For example, in some embodiments, the button cap is molded out of a lubricious plastic (ABS, Acetal, PTFE) that is cheap to manufacture. In some embodiments, the shaft  105  is machined out of steel and mechanically bonded to a plastic button. Use of a machined steel shaft allows for dimensional and geometric tolerances (diameter, straightness) that are difficult or impossible to meet with conventional molding. The shaft  105  and the button cap  150 , though manufactured of different materials or materials of different properties may be easily secured using the securing mechanism of the present specification. This further allows for optimization of materials for the shaft  105  and the button cap  150  and therefore the fabrication, manufacturing and assembly processes. 
     In accordance with another aspect of the present specification and as shown in  FIGS. 1C, 1E and 1F , a plurality of hinges or hooks  182  extend vertically downwards (substantially parallel to the longitudinal axis  170 ) from the diaphragm or collar  136 . The plurality of hinges  182  enables attachment of the air/water valve  100  to a corresponding mount of an endoscope. In various embodiments, the corresponding mount of an endoscope comprises a flange which is surrounded by ribs  185  of the outer cap  140 , as described further below, and onto which the hinges  182  of the outer cap  140  snap and connect. Thus, ribs  185  and hinges  182  contained within outer cap  140  are used to connect the air/water valve to the flange of an endoscope. In various embodiments, the flange is an integral part of the endoscope and not single use or disposable. Use of the hinges  182  for attachment prevents vertical displacement of the seals and provides an audible and tactile positive locking ‘snap’ indicating to a user that the valve  100  is properly seated. Conventionally, over-molded TPE/TPU/Silicone in a two-part design is used for attaching the valve to the endoscope mount. However, the attachment mechanism enabled by the plurality of hinges  182  of the present specification is easier to manufacture while also providing a more secure connection to the endoscope during use. Specifically, inclusion of the hinges  182  reduces the overall part count. A single component is molded for the device of the present specification, whereas, in the prior art, a two-step molding process must be used or manual assembly of a rubber boot with a rigid plastic collar is required. A single mold results in shorter molding times and lower tooling costs. Elimination of a manual assembly step reduces overall labor input into the device. 
     In accordance with aspects of the present specification, it is desirable to configure or design the hinges or hooks  182  so that it achieves both a tactile, locking feel while the valve  100  is attached to the endoscope mount (using the hinges  182 ) but is not so engaged that removing the valve  100  (such as for autoclaving, for example) poses a challenge. In other words, it is desired that the amount of insertion force required to engage the hinges or hooks  182  to the endoscope mount should be optimal that enables sufficient retention or attachment of the valve  100  to the endoscope mount without the retention being too strong to enable detachment of the valve  100  from the endoscope mount a challenge. 
       FIGS. 1G through 1J , respectively illustrate first, second, third and fourth hinges or hooks  182   g ,  182   h ,  182   i ,  182   j  configured in accordance with various embodiments. In various embodiments, each hinge or hook  182   g ,  182   h ,  182   i ,  182   j  respectively comprises a barb  191 ,  192 ,  193 ,  194  which is curved or angled (lead-in angle) on at least a portion and a tine  195 ,  196 ,  197 ,  198 , which is a straight portion. Together, the barb and tine form an opening that is used to attach the valve  100  to an endoscope mount  101 . In an embodiment, the barb faces an inner diameter of the valve and the tine faces the outer diameter of the valve. In embodiments, the amount of insertion force required to engage a valve with an endoscope mount, degree of retention of the mounted valve, amount of depression force required to actuate the mounted valve and the amount of removal force required to disengage the valve from the endoscope mount are determined by at least a width ‘w’ and a lead-in angle θ of the barb. 
     In one embodiment, as shown in  FIG. 1G , the barb  191  has a width w g =0.5 mm and a lead-in angle θ g =45 degrees enabling the hinge or hook  182   g  to require a first amount of insertion/removal force. 
     In another embodiment, as shown in  FIG. 1H , the barb  192  has a width w h =0.25 mm and a compound lead-in angle θ h =45/15 degrees (different lead-in angles for each side) enabling the hinge or hook  182   h  to require a second amount of insertion/removal force. 
     In another embodiment, as shown in  FIG. 1I , the barb  193  has a width w i =0.5 mm and a compound lead-in angle θ i =45/15 degrees (different lead-in angles for each side) enabling the hinge or hook  182   i  to require a third amount of insertion/removal force. 
     In yet another embodiment, as shown in  FIG. 1J , the barb  194  has a width w i =0.5 mm and a lead-in angle θ j =15 degrees enabling the hinge or hook  182   j  to require a fourth amount of insertion/removal force. 
     The amount of insertion/removal force corresponding to the hinges or hooks  182   g  through  182   j  varies as follows: first insertion/removal force&gt;second insertion/removal force&gt;third insertion/removal force&gt;fourth insertion/removal force. Accordingly, the corresponding retention is highest for hinge or hook  182   g  progressively reducing for hinges or hooks  182   h ,  182   i  and lowest for hinge or hook  182   j . Therefore, it can be generalized that the greater the width and the greater the compound lead-in angle, the greater the amount of force needed for insertion/removal. 
     As an example, air/water valve hinges or hooks having barb dimensions of 140 microns, 70 microns and 35 microns were tested to determine insertion force, removal force, and depression force. Note that a unit having 0 microns (or no barb) would have a very low retention force that would be insufficient for the purposes of the present invention. As shown in the table  205  in  FIG. 2A , for the 140 micron hooks, the insertion force varied from 8.1 to 12.2 N. As shown in table  210  in  FIG. 2B , for the 70 micron hooks, the insertion force varied from 7.4 to 13N. As shown in table  215  in  FIG. 2B , for the 35 micron hooks, the insertion force varied from 6.4 to 12N. While there is some overlap, the general trend shows that the thinner the barb, the less the insertion force required. 
     As shown in the table  220  in  FIG. 2D , for the 140 micron hooks, the removal force varied from 5.8 to 14.2 N. As shown in the table  225  in  FIG. 2E , for the 70 micron hooks, the removal force varied from 4.0 to 9.2 N. As shown in the table  230  in  FIG. 2F , for the 35 micron hooks, the removal force varied from 4.5 to 6.6 N. Again, while there is some overlap, the general trend shows that the thinner the barb, the less the removal force required. 
       FIGS. 3A, 3B and 3C  are partial diagrams of a molded and machined air/water outer cap  300 . In an embodiment, as shown in  FIG. 3A , an exemplary molded hook portion  320  has a width  321  of approximately 2.10 mm. Further, as shown in  FIG. 3B , the thickness  322  of the hook  320  at a base portion  323  is approximately 0.7 mm. In an embodiment, it should be noted that the thickness  322  of the base portion  323  of the hook  320  ranges from 0.5 mm to 1.0 mm, as too thick of a hook will lead to stiffness and too thin of a hook will lead to a part that is not moldable. 
     As shown in  FIG. 3C , the overall length or height  324  of the hook  320  is approximately 3.8 mm. Further, hook  320  travels a distance  325  of 0.504 mm when depressed or engaged. As shown in the table  314  in  FIG. 3D , for the 140 micron hooks, the depression force varied from 9.15 to 20.95 N. As shown in the table  316  in  FIG. 3E , for the 70 micron hooks, the depression force varied from 9.40 to 18.94 N. As shown in the table  318  in  FIG. 3F , for the 35 micron hooks, the depression force varied from 10.65 to 15.26 N. Again, while there is some overlap, the general trend shows that the thinner the barb, the less the depression force required. 
     In one embodiment, the hook, having a barb and tine, comprises a barb having a width of less than 200 micron. 
     In accordance with still another aspect of the present specification and as shown in  FIGS. 1E and 1F , a plurality of positioning ribs  185  are formed along the inner circumference of the outer cap  140 . The ribs  185  extend vertically downwards (substantially parallel to the longitudinal axis  170 ) along the inner circumference of the outer cap  140 . The ribs  185  enable the valve  100  to be centered on a valve well on the endoscope, aligning the shaft  105  with a center of the valve well and enabling precise vertical positioning of the plurality of seals within the valve well. The ribs  185  act as edge stops to ensure the valve  100  is centered on the mount and also prevent side loading from the user from breaking the seals on the valves. 
     In various embodiments, the shaft  105  of the disposable air/water valve  100  along with the plurality of ridges and grooves are of the same material as the shaft  105 . Similarly, the plurality of hinges or hooks  182  and ribs  185  may be molded as components of the inner ring  135  and the outer cap  140  (the inner ring  135  and outer cap  140  may also be molded as a single component) in accordance with various embodiments. It should be appreciated that the shaft  105 , the plurality of seals  125 ,  127 , and  129 , inner ring  135 , outer cap  140  and button cap  150  may all be manufactured from dissimilar materials and still be easily assembled or secured together in accordance with various aspects of the present specification. 
     As described with respect to  FIGS. 1C, 1E and 1F , a plurality of hinges or hooks  182  extend vertically downwards (substantially parallel to the longitudinal axis  170 ) from the diaphragm or collar  136 . The plurality of hinges or hooks  182  enables attachment of the air/water valve  100  to a corresponding mount of an endoscope.  FIGS. 4A, 4B, 4C, 4D, 4E, 4F, and 4G  illustrate an exemplary outer cap and associated components having a barb hook size of 70 microns with a lead-in angle of 15 degrees on each side. Outer cap  500  is shown in  FIG. 4A  and in an embodiment, has a height ‘h’ of approximately 12.20 mm.  FIG. 4B  shows the underside  405  or attachment portion of outer cap  400  that is used to attach the air/water valve to a corresponding mount of an endoscope. As shown in  FIG. 4B , the attachment portion  405  may have a diameter of approximately 18.33 mm.  FIG. 4C  is a diagram showing the cross-section A-A  410  of outer cap  400  which is described in greater detail in  FIG. 4D . As shown in  FIG. 4D , cross section A-A  410  of the outer cap  400  shows an approximate distance  415   a  of 13.30 mm between hooks  420 , at a proximal end  420   a , at the barbs  430  where the hook engages with a flange on the corresponding mount of an endoscope. At a distal end  420   b , the approximate distance  415   b  between hooks  420  is 14.50 mm. Further, the approximate length  425  of each hook  420  is 4.10 mm. 
       FIG. 4E  shows outer cap  400  with cross-section A-A  450  in a different view, as represented by  FIG. 4F . As shown in  FIG. 4F , the approximate distance  455  between barbs  430  of the hook  420  (where the hook engages with a flange on the corresponding mount of an endoscope) is 14.185±0.06 mm. In one embodiment, the barbs  430  are machined at an angle  435  of approximately 15±3 degrees with respect to a central longitudinal axis  460 . Further, a straight edge of barbs  430 , located just above the angular slanted portion, is machined at a distance of approximately 7.530 mm from the central longitudinal axis  460 . This detail is shown in  FIG. 4G  which represents an exploded view of cross section B-B of  FIG. 4F . Further, a straight portion or tine  440  of hook  420  extends approximately 0.320±0.1 farther than barbs  430 . 
       FIG. 5  is a flow chart illustrating a plurality of exemplary steps involved in operating an air/water valve of the present specification. Referring now to  FIGS. 1A through 1D  and  FIG. 5 , during operation the air/water valve  100  of the present specification may be positioned in an air/water cylinder of an endoscope. The endoscope provides an air channel for air and a water channel for water. The air and water channels are connected to a water bottle. The water channel extends into the fluid contained in the water bottle. When air/water valve  100  is placed in the air/water cylinder of the endoscope, the air/water valve  100  passes through both the air and water channels. 
     At step  505 , the air/water valve  100  is un-actuated, that is the button cap  150  is not depressed and the resilient member  145  is not compressed, and the vent  165  is open. As a result, at step  510  the air/water valve  100  allows air flow (provided by an air pump, for example) to enter the valve opening  155  and escape from the vent  165 . Note that disposable air/water valve  100  provides a plurality of seals ( 125 ,  127 , and  129 ) that prevent air or water from leaking from the air or water channels. Also, the opening  155  of the air-water valve  100  is not aligned with the water channel and therefore there is no movement of water away from the water bottle, as the water channel is blocked. 
     At step  515 , the air/water valve  100  is unactuated, that is the button cap  150  is not depressed and the resilient member  145  is not compressed, but the vent  165  is closed or covered by an operator (using his finger, for example). As before, from the previous step  510 , the water channel is still blocked by the air/water valve  100 . Since the air vent  165  is now blocked by the operator, air from the air pump flows, at step  520 , past the air/water valve  100  towards a distal end of an endoscope. This allows the operator to insufflate a body cavity by blocking the air vent  165  of air/water valve  100  without actuating the valve. 
     At step  525 , the air/water valve  100  is actuated, that is the button cap  150  is depressed and the resilient member  145  is compressed, and the vent  165  continues to remain obstructed, closed or covered by the operator. Depressing the button cap  150  causes a downward force to be applied to the shaft  105  via ridge  179  and therefore the shaft  105  moves or is displaced downwards. Also, depressing the button cap  150  causes the resilient member  145  to compress against the supporting collar or diaphragm  136 . 
     The collar  136  rests against the endoscope mount and is therefore prevented from moving downwards (due to the depression of the button cap  150 ). The downward movement or displacement of the shaft  105  causes the valve  100  to block the air channel and moves the opening  155  into the water channel, thereby creating a passageway for water to pass through the air/water valve  100 , at step  530 . Because the vent  165  is also blocked by the operator pressing down on the valve  100  (for depressing the button cap  150 ), air flows instead into the water bottle via an air branched-channel connected to the water bottle. As the air pressure in water bottle increases, fluid is forced from the water bottle into the water channel, at step  535 . Thus, by actuating the air/water valve  100 , the operator causes water to flow towards the distal end of the endoscope for rinsing or irrigation. 
     When the operator stops depressing the button cap  150 , the compressed resilient member  145  begins to recoil or get uncompressed. The recoiling resilient member  145  applies an upward force to the button cap  150  that in turn transfers the upward force to the shaft  105  via the detent or protrusion  178 . This causes both the shaft  105  and the button cap  150  to be displaced upwards and return to the un-actuated position of the valve  100  of step  505 . 
       FIG. 6A  is a perspective view of a disposable suction valve  600  in accordance with an embodiment of the present specification,  FIG. 6B  is a top view of the disposable suction valve  600 ,  FIG. 6C  is a vertical cross-section view along an axis F-F of the disposable suction valve  600  of  FIG. 6A  while  FIG. 6D  is a horizontal cross-section view along an axis G-G of the disposable suction valve  600  of  FIG. 6C . Referring now to  FIGS. 6A through 6D , the disposable suction valve  600  comprises a stem or shaft  605  of outer diameter ‘D’ and having a first groove or recess  610  (of a first diameter d 1 ) and a second groove or recess  612  (of a second diameter d 2 ) formed on the outer circumference of the shaft  605  and towards an end  615  of the shaft  605 ; the first and second grooves  610 ,  612  result in the formation of a first ridge  611  and a second ridge  613 ; an inner ring  620  having a bore of a first internal diameter b 1  along a first length l 1  (parallel to the longitudinal axis F-F) of the bore and a second internal diameter b 2  along a second length l 2  (parallel to the longitudinal axis F-F) of the bore, wherein b 1  is approximately equal to d 2  and b 2  is approximately equal to ‘D’; an outer cap  630 ; a resilient member  635  such as, but not limited to, spring, rubber, elastic; and a button cap  640  having a central bore (along the longitudinal axis F-F). 
     The components of the disposable suction valve  600  may comprise disposable material, including, but not limited to polyurethane, polyurea, polyether(amide), PEBA, thermoplastic elastomeric olefin, copolyester, styrenic thermoplastic elastomer, carbon fiber, glass fiber, ceramics, methacrylates, poly (N-isopropylacrylamide), PEO-PPO-PEO (pluronics), rubber, plastic (e.g., polycarbonates), ABS, MABS, silicone, or combinations thereof. The resilient member  635  may be formed from a suitable material, such as corrosion resistant metal, polyurethane, polyurea, polyether(amide), PEBA, thermoplastic elastomeric olefin, copolyester, and styrenic thermoplastic elastomer, carbon fiber, glass fiber, ceramics, methacrylates, poly (N-isopropylacrylamide), PEO-PPO-PEO (pluronics), rubber, plastic, or combinations thereof. 
     The shaft  605  provides an opening  655  and a passage or bore  660  that runs through the shaft  605 , substantially along the longitudinal axis F-F, from the opening  655  and vertically downwards to an end, opening or vent  665 . The opening  655  lies along an axis G-G that is substantially perpendicular to the longitudinal axis  670 . Fluid may pass horizontally through one side of the opening  655  and vertically downwards through the vent  665 . Opening  655  and vent  665  allow air or fluid to pass through a suction channel of the endoscope when the suction valve  600  is actuated. 
     The inner ring  620  has a diaphragm or collar  625  ( FIG. 6D ) extending from an outer circumference of the inner ring  620  to the internal circumference of the outer cap  630 . The resilient member  635  resides between the inner ring  620  and the button cap  640  such that one end of the resilient member  635  is secured to the diaphragm or collar  625  and the other end to the button cap  640 . In some embodiments, the inner ring  620  is a monolithic internally molded part of the outer cap  630  while in other embodiments these may be two separate components. The inner ring  620 , outer cap  630  and the button cap  640  respectively define internal bores for receiving the end  615  of the shaft  605 . End  615  of the shaft  605  is placed through inner ring  620  and resilient member  635  and secured to the button cap  640 . When assembled, the first length l 1  of the bore of the inner ring  620  fits over the second groove  612  (since, b 1  is approximately equal to d 2 ) to rest upon the second ridge  613 . 
     In accordance with an aspect of the present specification and as shown in  FIG. 6C , an internal ring  680  of the button cap  640  is secured to the shaft  605 , at the end  615 , within the first groove or recess  610  that has a taper defined between a detent or protrusion  678  (towards the end  615 ) and the first ridge  611 . In an embodiment, the first groove or recess  610  is tapered at an angle ‘N’ with reference to a vertical line parallel to the longitudinal axis F-F. Conventional designs typically join or secure the button cap to the shaft using adhesive or welded joints. For optimal performance, the suction valve shaft requires a high degree of dimensional precision, generally not available to molded components. The securing mechanism of the present specification allows for a higher degree of dimensional precision through the use of dissimilar materials for the components such as the button cap  640  and the shaft  605 . For example, the shaft  605  may be of metal while the button cap  640  may be of plastic or the shaft  605  and the button cap  640  may both be of plastic yet of different melt temperatures. During a sterilization process, such as autoclaving, the plastic button cap  640  will melt and then become secured to shaft  605  as it dries post sterilization. Using dissimilar material for the button cap  640  and shaft  605  eliminates the need of matching material properties required in a gluing or welding process. Typically, materials must be selected so that they have similar melt temperatures (in the case of welding) or have surface properties conducive to adhesives. Eliminating such constraints allows the individual component materials of the button cap  640  and shaft  605  to be optimized for their specific purposes. For example, in some embodiments, the button cap is molded out of a lubricious plastic (ABS, Acetal, PTFE) that is cheap to manufacture. In some embodiments, the shaft  605  is machined out of steel and mechanically bonded to a plastic button. Use of a machined steel shaft allows for dimensional and geometric tolerances (diameter, straightness) that are difficult or impossible to meet with conventional molding. The shaft  205  and the button cap  640  though manufactured of different materials or materials of different properties may be easily secured using the securing mechanism of the present specification. This further allows optimization of materials for the shaft  605  and the button cap  640  and therefore their manufacturing and assembling processes. 
     In accordance with another aspect of the present specification and as shown in  FIGS. 6D, 6E and 6F , a plurality of hinges or hooks  682  extend vertically downwards (substantially parallel to the longitudinal axis F-F) from the diaphragm or collar  625 . The plurality of hinges or hooks  682  enables attachment of the suction valve  600  to a corresponding mount of the endoscope. In various embodiments, the corresponding mount of an endoscope comprises a flange which ribs  685  of the outer cap  630  surround, as described further below, and on to which the hinges  682  of the outer cap  630  snap and connect. In various embodiments, the flange is an integral part of the endoscope and not single use or disposable. The hinges or hooks  682  allow the collar component to be a single molded part, rather than an over-molded component or an assembly. Use of the hinges or hooks  682 , for attachment, provides an audible and tactile positive locking ‘snap’ indicating to the user that the valve  600  is properly seated. Typically, a two-part over-molded TPE/TPU/Silicone design is used for attaching the valve to the endoscope mount. However, the attachment mechanism enabled by the plurality of hinges  682  of the present specification is easier to manufacture while also providing a more secure connection to the endoscope during use. Specifically, inclusion of the hinges  682  reduces the overall part count. A single component is molded for the device of the present specification, whereas, in the prior art, a two-step molding process must be used or manual assembly of a rubber boot with a rigid plastic collar is required. A single mold results in shorter molding times and lower tooling costs. Elimination of a manual assembly step reduces overall labor input into the device. 
     In accordance with still another aspect of the present specification and as shown in  FIGS. 6D, 6E and 6F , a plurality of positioning ribs  685  are formed along the inner circumference of the outer cap  630 . The ribs  685  extend vertically downwards (substantially parallel to the longitudinal axis F-F) along the inner circumference of the outer cap  630 . The ribs  685  enable the valve  600  to be centered on a valve well on the endoscope, aligning the shaft  605  with a center of the valve well. The ribs  685  act as edge stops to ensure the valve  600  is centered on the mount. 
     In various embodiments, the plurality of hinges or hooks  682  and ribs  685  may be molded as components of the inner ring  620  and the outer cap  630  (the inner ring  620  and outer cap  630  may also be molded as a single component) in accordance with some embodiments. It should be appreciated that the shaft  605 , inner ring  620 , outer cap  630  and button cap  640  may all be manufactured from dissimilar materials and still be easily assembled or secured together in accordance with various aspects of the present specification. 
       FIG. 7  is a flow chart illustrating a plurality of exemplary steps involved in operating a suction valve of the present specification. Referring now to  FIGS. 6A through 6F  and  FIG. 7 , during operation the disposable suction valve  600  of the present specification may be placed into a suction cylinder of the endoscope. A suction channel of the endoscope is linked to the opening  655  (of the suction valve  600 ) and leads to a distal end of an endoscope or leads toward the patient. The endoscope may be connected to a suction pump to create negative pressure in the suction channel when the suction valve  600  is actuated. 
     At step  705 , the suction valve  600  is unactuated, meaning that the button cap  640  is not depressed and the resilient member  635  is not compressed. As a result, at step  710 , the opening  655  remains out of position with the suction channel of the endoscope, thereby preventing the suction pump from creating negative pressure in the suction channel (that is, no suction is applied to the distal end of the endoscope). 
     At step  715 , the suction valve  600  is actuated—that is, the button cap  640  is depressed and the resilient member  635  is compressed. Depressing the button cap  640  causes a downward force to be applied to the shaft  605  via the first ridge  611  and therefore the shaft  605  moves or is displaced downwards. Also, depressing the button cap  640  causes compression of the resilient member  635  against the supporting collar or diaphragm  625 . The ring  620  rests against the second ridge  613  as a result of which the collar  625  is prevented from moving downwards (due to the depression of the button cap  640 ). The downward movement or displacement of the shaft  605  causes the opening  655  to move into position with the suction channel from the distal end of the endoscope or from the patient. At step  720 , by aligning the opening  655  with the suction channel of the endoscope, a negative pressure created by the suction pump cause flow from the distal end of the endoscope towards the opening  655  (that is, suction is applied to the distal end of the endoscope). As a result, air and/or fluid may be suctioned from the distal end of the endoscope when the disposable suction valve  600  is in an actuated position. 
     When the suction valve  600  is released—that is, button cap  640  is not depressed the resilient member  635  recoils and applies an upward force to the button cap  640  that in turn transfers the upward force to the shaft  605  via the detent or protrusion  678 . This causes both the shaft  605  and the button cap  640  to be displaced upwards and return to the un-actuated position of the valve  600  of step  705 . 
     The above examples are merely illustrative of the many applications of the system of present invention. Although only a few embodiments of the present invention have been described herein, it should be understood that the present invention might be embodied in many other specific forms without departing from the spirit or scope of the invention. Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive, and the invention may be modified within the scope of the appended claims.