Patent Publication Number: US-2013245576-A1

Title: Applicator spray nozzles with pressure relief

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority of U.S. Provisional Patent Application Ser. Nos. 61/610,239, filed on Mar. 13, 2012 (pending) and 61/729,839, filed Nov. 26, 2012 (pending), the disclosures of which are incorporated by reference herein in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to spray applicators and, more particularly, to applicators configured to deliver therapeutic aerosols to a surgical site of a patient. 
     BACKGROUND 
     Intra-operative problems encountered by physicians often include management and prevention of post-operative pain, infection, tissue adhesion, and tumor formation. Numerous products exist on the market to address these problems by improving the surgical experience and patient outcomes. Among these products are suction and irrigation wands that are used for flushing tissue sites with sterile water or saline and removing blood and other fluids from the surgical site. Spray applicators may be used to deliver therapeutic aerosols, fluidized powder products, and/or gas streams to anatomical surfaces within a surgical site of a patient. The therapeutic aerosols may be applied to an open anatomical surface or within an artificially created surgical site, such as during minimally invasive surgery. The aerosol formulations may be delivered at any time before, during, or after a surgical procedure. 
     However, while applying the therapeutic aerosol by the spray applicator during a topical or laparoscopic procedure, there exists a risk that the applicator tip may come into contact with patient tissue comprising the surgical site. If tissue contact closes off the tip from which the medicine is dispensed, then pressure may build up within the applicator. Still worse, the force of the pressurized gas, applied at extremely close proximity, may drive fluids (including gases) into a cut blood vessel, causing pressure injury or embolism, or otherwise damage tissues already inflamed and distressed by the surgical procedure. Therefore, there exists a need for spray applicators and methods of use that reduce the adverse affects of inadvertent contact between the applicator tip and the surgical site. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment of the present invention a spray nozzle for applying a medicinal agent to a tissue includes a tip housing and a valve. The tip housing is positioned on a distal end of a tubing and the valve is movably positioned within the tip housing. The valve is configured to move from an extended position, in which the medicinal agent is directed away from the tip housing toward the tissue, and a retracted position, in which the medicinal agent is vented away from the tissue. 
     According to one embodiment of the present invention, a spray nozzle for applying a medicinal agent to a tissue includes a tip housing and a valve. The tip housing has a distal end, a proximal end, and a lumen that extends between the ends and defines a lengthwise central axis. The valve has an elongated body that extends through the lumen of the tip housing, along the lengthwise central axis, and slides with respect thereto between an extended position and a retracted position. A spin chamber at the distal end of the elongated body of the valve is configured to mix the medicinal agent. An insert, positioned within the lumen of the valve and proximate to the spin chamber, includes a gas bubble that receives the mixed medicinal agent and disperses the same. A plurality of relief vents, which are formed on an outer surface of the elongated body of the valve, is configured to be in fluid communication with the lumen of the tip housing when the valve is in the retracted position. When the valve is in the extended position with respect to the tip housing, the spray nozzle is configured to disperse the medicinal agent via the spin chamber and the insert toward the tissue; when the valve is in the retracted position with respect to the tip housing, the spray nozzle is configured to vent the medicinal agent away from the tissue via the plurality of relief vents. An additional feature is provided for mixing the medicinal agent at the tip. In this regard, mixing structure such as one or more generally spiral fins are provided in the tip housing. These may be used, for example, to mix a powder agent with a gas prior to dispersion. In another aspect, the tip housing may include a connector element, and the distal end of the applicator tubing may include a mating connector element for allowing a user to selectively couple the tip housing and valve to the applicator tubing. For example, these connector elements may be mating threads. 
     Still other embodiments of the present invention are directed to a spray applicator comprising a spray nozzle and a tubing. The spray nozzle tissue includes a tip housing and a valve. The tip housing is positioned on a distal end of a tubing and the valve is movably positioned within the tip housing. The valve is configured to move with respect to the tip housing between an extended position and a retracted position. The tubing is operably coupled to the proximal end of the tip housing. When the valve is in the extended position with respect to the tip housing, the spray nozzle is configured to disperse the medicinal agent toward the tissue; when the valve is in the retracted position with respect to the tip housing, the spray nozzle is configured to vent the medicinal agent away from the tissue. 
     According to embodiments of the present invention, methods of applying one or more medicinal agents to a tissue using a spray nozzle include directing a medicinal agent toward the tissue while the valve is in the extended position and venting the medicinal agent when the valve is in the retracted position. 
     Another embodiment of the present invention is directed to a removal tool that is configured to remove a spray nozzle from a tubing. The removal tool includes a cover portion and a disengagement portion. The cover portion operably engages and supports the tip housing of the spray nozzle. While the disengagement portion releases the tip housing from the tubing, the cover portion is configured to move with respect to the disengagement portion such that the spray nozzle is withdrawn from the tubing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational view of a spray applicator having a spray nozzle in accordance with one embodiment of the present invention. 
         FIG. 2  is an exploded, perspective view of the spray nozzle of  FIG. 1  having a tip housing and a valve in accordance with one embodiment of the present invention. 
         FIGS. 3A and 3B  are cross-sectional views of the assembled spray nozzle of  FIG. 2 , the valve shown in an extended position and a retracted position, respectively, with respect to the tip housing. 
         FIG. 4A  is a cross-sectional view of the assembled spray nozzle of  FIG. 2  illustrating the valve in the extended position such that medicinal agent is directed away from the tip housing and toward a tissue. 
         FIG. 4B  is a cross-sectional view of the assembled spray nozzle of  FIG. 2  illustrating the valve in the retracted position such that the medicinal agent is vented away from the tissue. 
         FIGS. 5A-5C  are cross-sectional views of the tip housing of  FIG. 2  with valves of varying length and in accordance with other embodiments of the present invention. 
         FIG. 6A  is an exploded, perspective view of a spray nozzle having the tip housing of  FIG. 2  and a valve in accordance with another embodiment of the present invention. 
         FIG. 6B  is a cross-sectional view of the assembled spray nozzle of  FIG. 6A . 
         FIG. 7  is a perspective view of a tip housing in accordance with another embodiment of the present invention. 
         FIG. 8  is an exploded, side elevational view of a spray nozzle having a tip housing and a valve in accordance with another embodiment of the present invention. 
         FIGS. 9A and 9B  are exploded, side elevational views of spray nozzles having tip housings and valves according to other embodiments of the present invention. 
         FIG. 10  is an assembled, side elevational view of the spray nozzle of  FIG. 9B . 
         FIG. 11  is a cross-sectional view of the assembled spray nozzle of  FIG. 10 . 
         FIG. 12  is a cross-sectional view through a spin chamber of the spray nozzle and taken along the line  12 - 12  of  FIG. 11 . 
         FIG. 13A  is a side elevational view of a spray chamber insert configured to be positioned within the valve and in accordance with one embodiment of the present invention. 
         FIG. 13B  is a front end view of the insert shown in  FIG. 13A . 
         FIG. 14  is a cross-sectional view of the spray nozzle of  FIG. 10  with the valve in an extended position with respect to the tip housing such that the medicinal agent is directed away from the tip housing and toward a tissue. 
         FIG. 14A  is an enlarged cross-sectional view of the spray nozzle of  FIG. 14 . 
         FIG. 14B  is a cross-sectional view through the spin chamber of the spray nozzle and taken along the line  14 B- 14 B of  FIG. 14A . 
         FIG. 15  is a cross-sectional view of the spray nozzle of  FIG. 10  with the valve in a retracted position with respect to the tip housing such that the medicinal agent is vented away from the tissue. 
         FIG. 15A  is an enlarged cross-sectional view of the spray nozzle of  FIG. 15 . 
         FIG. 16A  is a side elevational view of a spray chamber insert in accordance with another embodiment of the present invention. 
         FIG. 16B  is a front end view of the insert shown in  FIG. 16A . 
         FIG. 17  is a cross-sectional view of a spray nozzle in accordance with another embodiment of the present invention, in use with the insert of  FIG. 16A , and in which the valve is in an extended position with respect to the tip housing such that the medicinal agent is directed away from the tip housing toward a tissue. 
         FIG. 17A  is an enlarged cross-sectional view of the spray nozzle shown in  FIG. 17 . 
         FIG. 18A  is a side-elevational view, in partial cross-section, of the spray nozzle of  FIG. 10  and a spray nozzle removal tool according to one embodiment of the present invention coupled to the spray nozzle. 
         FIG. 18B  is a side elevational view similar to  FIG. 18A  but with the spray nozzle removed from the tubing via the spay nozzle removal tool. 
         FIG. 19  is an exploded, perspective view of a spray nozzle having a tip housing and a valve in accordance with another embodiment of the present invention. 
         FIG. 20A  is a cross-sectional view of the assembled spray nozzle of  FIG. 19 , with the valve shown in an extended position with respect to the tip housing. 
         FIG. 20B  is a cross-sectional view of the assembled spray nozzle of  FIG. 19 , similar to  FIG. 20A  but the section being taken with the spray nozzle rotated 90° relative to  FIG. 20A , and with the valve shown in a retracted position with respect to the tip housing. 
         FIGS. 21A and 21B  are respective cross sectional views of the proximal end of a spray applicator constructed in accordance with another embodiment of the invention. 
         FIG. 22  is a cross sectional view similar to  FIGS. 21A and 21B , but illustrating an alternative spacer design used between the inner and outer tubings. 
         FIG. 23  is a disassembled perspective view illustrating an alternative spray nozzle combining a valve feature with mixing structure. 
         FIG. 24A  is a cross sectional view of the assembled spray nozzle of  FIG. 23 , and illustrating the valve in an extended or open position. 
         FIG. 24B  is a cross sectional view similar to  FIG. 24A , but illustrating the valve in a retracted or closed and venting position. 
         FIG. 25A  is a disassembled cross sectional view showing an alternative spray nozzle and tip design. 
         FIG. 25B  is a cross sectional view similar to  FIG. 25A , but illustrating the spray nozzle assembled with a distal end of the spray applicator. 
     
    
    
     DETAILED DESCRIPTION 
     It will be appreciated that when referring to the drawings of the various embodiments illustrated and described herein, like reference numerals refer to like structure or elements shown in the figures. Therefore, with regard to various common features shown in different drawings, repeated discussion is not necessary, but the structure and function will be understood based on an earlier discussion of the structure or element. Turning now to the figures, and in particular to  FIG. 1 , a spray applicator  20  configured to apply a therapeutic aerosol spray onto a surgical site (represented by dashed line  21  of  FIG. 4A ) and in accordance with one embodiment of the present invention is shown. In the particular illustrative embodiment, the spray applicator  20  includes a proximal hub  22  having two parallel ports  26  for receiving a dual chamber syringe (not shown) and that may be utilized to transport one or more fluids into a multi-lumen tube  24 ; however, it would be readily understood that any number of ports may be included if so desired. The hub  22  includes passages (not shown) extending from the ports  26  and in fluid communication with the lumens  28 ,  30  ( FIG. 3A ) of the multi-lumen tube  24 . 
     The multi-lumen tube  24 , as shown in  FIG. 3A , may comprise an outer tubing  32  providing the first lumen  28  extending from the hub  22  ( FIG. 1 ), proximally, to a distally-positioned spray nozzle  34  and an inner tubing  36  providing the second lumen  30  extending from hub  22  ( FIG. 1 ), proximally, to a distal position that is proximate to the spray nozzle  34 . The outer tubing  32  may be constructed from rigid or compliant material, depending on the desired function of the application. The inner tubing  36  may be constructed from a hypotube or a flexible catheter material as would be known to those of ordinary skill in the art. 
     In use, the first lumen  28  may be configured to transfer a pressurized gas to the spray nozzle  34  from a pressurized container or a sterilized air system, which are commonly available at medical treatment facilities. This will provide a protective envelope of gas for the nozzle  34 . A continuous flow of gas through the first lumen  28  will protect against condensation or other moisture building at the distal end of the nozzle  34  which would have negative effects on powder discharge. The air system may be coupled to the first lumen  28  via a side port  35  of the hub  22 . Use of the air system may provide a constant overpressure to prevent contamination and/or plugging of the spray nozzle  34  between uses. The second lumen  30  may be configured to transfer a medicinal agent to the spray nozzle  34  from the dual chamber syringe (not shown) secured to the parallel ports  26  of the hub  22 . 
     In  FIGS. 2-3B , the spray nozzle  34  is shown in greater detail to include a valve  40  that is inserted into and in slidable relation with a tip housing  42 . The valve  40  has an elongated body  41  that may be oblong- or harpoon-shaped with one or more blades  44  positioned near a proximal end  46  thereof. The distal end  54  is shaped to have a maximum width dimension, d v , shown in  FIG. 3A  as a diameter offset from the distal edge of the valve  40 , with a shape (i.e., radius of curvature, smoothness, and so forth) tapering longitudinally away from the maximum width dimension. The shape of the distal end  54  may be selected to provide a particular pattern of spray, e.g., the shape of the distal end  54  of the valve  40  may be used to direct the expelled aerosol to fill a wide conical shape or to focus centrally as the aerosol extends away from the spray nozzle  34 . 
     The tip housing  42  may include a generally cylindrical outer surface  48  and, as shown in the instant embodiment, having an annular groove  50  such that the outer tubing  32  may be secured onto the tip housing  42 , such as by crimping; although other methods may be used, some of which are described in detail below. The proximal end of the tip housing  42  may be configured to facilitate assembly to the outer tubing  32 . Additionally, and as shown in  FIG. 2 , the distal end of the tip housing  42  may include an opening  64  having a width dimension (such as a diameter), d t , shape, and configuration to further direct the aerosol into a particular flow pattern. Generally, the width dimension of the opening  64  is approximately similar to, or slightly larger than, the maximum width dimension of the valve  40  such that d t ≧d v  and to create a small clearance provided between the elongated body  41  of the valve  40  and the distal opening  64  of the tip housing  42 . 
     Referring specifically now to  FIGS. 3A and 3B , a lumen  56  extends through the tip housing  42  and is configured to receive the valve  40  therein such that the valve  40  is configured to slide with respect thereto. A portion of the inner wall comprising the lumen  56  may include a tapered guide portion  58  configured to receive the blades  44  of the valve  40  such that the blades  44  may rotate with respect to, and slide within, the tip housing  42 . In that regard, the valve  40  slides between a distal taper edge  59  of the guide portion  58  and a positive stop  60 , shown as the distal edge of the inner tubing  36 . Therefore, the valve  40  may slide along a lengthwise central axis  62  of the multi-lumen tube  24  and the tip housing  42 , between an extended position, shown in  FIG. 3A , and a retracted position, shown in  FIG. 3B . 
     In some embodiments, the blades  44  and the guide portion  58  may additionally or alternatively be configured to facilitate proper alignment of the valve  40  within the tip housing  42 . 
     In use and with reference now to  FIGS. 4A and 4B , the liquid or fluidized dry powdered product (such as with a medicinal agent) may be directed from the hub  22  ( FIG. 1 ), through the inner and/or outer tubing  36 ,  32  to the spray nozzle  34 . The fluids enter the lumen  56  of the tip housing  42  and flow between the blades  44  of the valve  40  toward the opening  64 . The fluid flow between the blades  44  may be operable to cause the valve  40  to spin within the guide portion  58 , which evens out the spray pattern and to mix the fluids so as to be effective for a selected purpose, such as stopping unwanted bleeding within the surgical site  21 . 
     At the distal opening  64 , and with the valve  40  being in the extended position as shown in  FIG. 4A , the fluids are ejected as a dispersion  59  toward the tissue  21 . The dispersion  59  expands as the fluid moves through the constricted area of the small clearance provided between the elongated body  41  of the valve  40  and the distal opening  64 , e.g., from an area of higher pressure to an area of lower pressure, to cover a large surface area. 
     In  FIG. 4B , if or when the spray nozzle  34  makes contact with the tissue  21 , this contact creates a proximally-directed force that causes the valve  40  to move proximally within the tip housing  42  from the extended position, shown in  FIG. 4A , to the retracted position as shown. With the valve  40  in the retracted position, the proximal end  46  of the valve  40  will be proximate to, or will at least partially enter into, the lumen  30  of the inner tube  36 , thereby blocking and reducing fluid flow that may otherwise cause pressure injury or embolism. Furthermore, movement of the valve  40  into this retracted position brings the maximum width dimension, d v  ( FIG. 3A ), of the distal end  54  in closer proximity to the width dimension, d t  ( FIG. 2 ) of the tip housing  42 . As d v  converges toward d t  (d v →d t ), the small clearance provided between the elongated body  41  of the valve  40  and the distal opening  64  is reduced or closed. Fluid flow from the tip housing  42  is reduced, which causes pressure to build within the tip housing  42 . Release of this increased pressure (as a vented powder  61 ) may be provided by one or more openings  66  within the outer tubing  32  and positioned proximal to the proximal end of the tip housing  42 . Depending on the particular use of the spray nozzle  34 , the vented powder  61  may be released into the abdomen cavity or surrounding atmosphere or, alternatively, may enter a surrounding tubing (not shown) in fluid communication with a vacuum line for disposal. The use of a vacuum line may be particularly useful when vented powder  61  may obscure the view through a laparoscopic camera or otherwise contaminate the surgical site  21 . 
     It would be thus appreciated from the teachings provided herein that selection of a shape for the valve  40  may be based, at least in part, on physician preference, the medical procedure, the medicinal agent being applied, and so forth. In that regard, the valve  40  may vary in length for use in particular procedures. As shown in  FIGS. 5A-5C , spray nozzles  34   a,    34   b,    34   c  have the same tip housing  42  as  FIG. 2 , but with the elongated bodies  41   a ,  41   b,    41   c  of the valves  40   a,    40   b,    40   c  vary in length, such as 10 mm, 5 mm, and 3 mm, respectively. However, these lengths are only exemplary in nature and these dimensions shall not be considered to be limiting. 
     Yet, length of the valve  40  need not be the only variable feature. In  FIGS. 6A and 6B , a valve  78  in accordance with another embodiment of the present invention is shown and includes a plurality of vanes  77  extending into a surface of the valve  78  and decrease in depth proximally from the distal end  75  toward the blades  79  at the proximal end  81 . The depth, angle, shape, and number of the vanes  77  may vary to provide a particular shape to the expelled dispersion  59  ( FIG. 4A ). 
     In still other embodiments, such as is shown in  FIG. 7 , the tip housing  68  may also be altered to provide a particular shape of the dispersion  59  ( FIG. 4A ). According to the illustrative embodiment shown in  FIG. 7 , the tip housing  68  includes a body  70  with an outer groove  72  to receive the outer tubing  32  ( FIG. 3A ), and a textured lumen  76  extending therethrough from the distal opening  74 . The texture of the lumen  76  may include grooves, as shown, or other patterns as desired to effectuate a particular fluid mixing pattern within the tip housing  68  and/or expulsion of the fluid therefrom. 
     In still other embodiments, for example, as shown in  FIGS. 8-9B , the outer groove  50  ( FIG. 2 ) of the tip housing  82  may be replaced, or otherwise incorporated with, one or more snaps  100 , as shown in  FIG. 9B , or tabs  102 , as shown in  FIGS. 8 and 9A . The snaps  100  and/or tabs  102  are configured to be received by a space or recess  101  ( FIG. 11 ) within the outer tubing  32  ( FIG. 11 ). 
       FIG. 8  also illustrates a spray nozzle  80  in accordance with another embodiment of the present invention. The spray nozzle  80  includes a tip housing  82  and a valve  84  configured to be in slidable relation to the tip housing  82 . 
       FIG. 11  illustrates the details of the valve  84  in greater detail as including a lumen  86  extending therethrough to a distal opening  88  and a plurality of relief vents  90  on an outer surface thereof. The relief vents  90 , being positioned proximal to the distal opening  88  and arranged circumferentially about the valve  84 , are tapered proximally in width and/or depth without forming fluid communication with the lumen  86  of the valve  84 . 
     With reference to  FIGS. 11-13B , the distal end of the valve  84  turns radially inwardly to form an inner wall  109  defining a spin chamber  92  between inner and outer walls  109 ,  111 . The inner wall  109  includes a plurality of vanes  108  therethrough, which may be curved, arcuate, or otherwise angled for mixing the fluids during expulsion. A spin chamber insert  98  resides within the lumen  86  of the valve  84 , proximate the spin chamber  92 . A concave recess  96 , in the form of a domed-shaped reflector, may be formed in a distal surface  106  of the spin chamber insert  98  to provide low friction relief for spinning fluids and powders entering from the plurality of vanes  108  prior to expulsion from the spray nozzle  80 . The recess  96  will trap particles of powder to prevent blockage at the distal end of the valve  84 . The size and concavity of the bubble  96  may be controlled to prevent collapse of the liquid or powdered vortex formed within the spin chamber  92 . The spin chamber insert  98 , while residing within a shelf  94  adjacent the lumen  86  of the valve  84 , includes one or more cutouts  107  to allow fluid flow into the spin chamber  92  as described in detail below. 
     Use of the spray nozzle  80  is shown in  FIGS. 14-15A . That is, during normal operation of the spray nozzle  80 , shown in  FIGS. 14 and 14A , the valve  84  is in an extended position with respect to the tip housing  82  such that fluid moves (indicated with arrows in  FIG. 4A ) along a first fluid path from the inner and/or outer tubes  36 ,  32 , into the tip housing  82 , into the lumen  86  of the valve  84 , and outwardly from the distal opening  88 . At the spin chamber  92 , shown in  FIG. 14B , the fluid flow (indicated with arrows) moves from the lumen  86  of the valve  84 , between the inner and outer walls  109 ,  111  by way of the cutouts  107  of the insert  98 . The fluid then flows through the vanes  108  of the inner surface  106  and into the bubble  96  where the fluid turns and is reflected to be expelled from the spray nozzle  80  as the dispersion  59 . 
     When the valve  84  contacts tissue of the surgical site  21 , as shown in  FIGS. 15 and 15A , the valve  84  is directed proximally into the tip housing  82  to the retracted position. With sufficient retraction of the valve  84 , the release vents  90  enter into and form a fluid communication with the lumen  104  of the tip housing  82 . Accordingly, fluid may flow along the first fluid path, as described above, or a second fluid path that extends from the inner and/or outer tubes  36 ,  32 , into the lumen  104  of the tip housing  82 , between the blades  85  of the valve  84 , into a space between the tip housing  82  and the valve  84 , and outwardly from the relief vents  90 . Fluid flow along this second fluid path reduces the flow along the first fluid path. Yet, as was shown in  FIG. 14A , when the valve  84  is in the extended position, the release vents  90  are positioned distal to the tip housing  82  and are not in fluid communication with the lumen  104  of the tip housing  82 . Thus, when the valve  84  is in the extended position, only the first fluid path exists and all fluid flow is directed onto the surgical site  21   
       FIG. 16  illustrates a spin chamber insert  124  in accordance with another embodiment of the present invention. Similar to the insert  98  of  FIG. 13A , this spin chamber insert  124  includes a gas bubble  125  extending into a distal surface  126  and a plurality of cutouts  127  along the circumferential edge of the distal surface  126 . This particular spin chamber insert  124  further includes an elongated proximal end having a stopper  128  thereon that is configured to at least partially block the inner tubing  36  ( FIG. 3A ). 
     More particularly,  FIGS. 17 and 17A  illustrate a spray nozzle  114  having a tip housing  120  and a valve  112  with the spin chamber insert  124  of  FIG. 16  incorporated therein. The tip housing  120 , as shown, is similar to the tip housing  82  described in detail above with reference to  FIG. 11 . The valve  112  is similar to the valve  84  of  FIG. 11 ; however, the lumen  110  of the valve  112  is extended such that it is directly and fluidically coupled to the inner tubing  36 . Accordingly, the proximally-positioned stopper  128  is positioned proximate to, or may slightly enter into, the lumen  30  of the inner tubing  36 . In this way, the inner tubing  36  may be operable as a spring that biases the spray nozzle  114  toward the extended position. 
     This particular, illustrative embodiment of the present invention, as shown in  FIGS. 17 and 17A  may be used in wet or dry applications. For example, when the valve  124  is in the extended position, a wet medicinal agent may be applied to the surgical site  21  via the first fluid path, which extends from the inner tubing  36 , into the lumen  110  of the valve  112 , between the inner and outer walls  116 ,  118  of the valve  112  by way of the cutouts  127  of the insert  124 . The fluid then flows through the vanes  119  of the valve surface  126 , into the bubble  125 , and turns to be expelled from the spray nozzle  114  as the dispersion  59 . In dry applications, the valve  124  moves into the retracted position such that the dry medicinal agent may be applied to the surgical site  21  via the second fluid path. As was described above, the second fluid path extends from the lumen  28  of the outer tubing  32 , enters the lumen  110  of the tip housing  120  between the blades  113 , between the outer surface of the valve  112  and the inner wall of the lumen  110 , and is vented via the relief vents  122 , which are in fluid communication with the lumen  110  of the tip housing  120 . 
     Turning now to  FIG. 18 , a tool  130  configured to remove the spray nozzle  80  from the multi-lumen tube  24  is shown in accordance with one embodiment of the present invention. Although the removal tool  130  is shown in use with the particular embodiment  FIG. 8 , it would be understood that this is for exemplary illustration only, and the tool  130  may be used with a spray nozzle in accordance with any embodiment of the present invention. The tool  130  includes a cover portion  132  configured to threadably engage a disengagement portion  134 , which is configured to release the spray nozzle  80  from the multi-lumen tube  24 . In that regard, the cover portion  132  may include a support  136  configured to engage and support the tip housing  82  during removal. The disengagement portion  134  includes arms  138  (two of which are shown) operably coupled to one or more finger pads  140  and in alignment with the snaps  100  provided on the outer surface of the tip housing  82 . The user may actuate the arms  138 , such as by pressing simultaneously and inwardly on the finger pads  140 , e.g., with the forefinger and thumb, to direct the arms  138  inwardly. Because of the alignment between the arms  138  and the snaps  100 , the snaps  100  are also compressed inwardly and released from the openings  101  of the multi-lumen tube  24 . With the snaps  100  released, the cover portion  132  may be rotated, with respect to the disengagement portion  134 , to uncouple the cover portion  132  from the disengagement portion  134 . Further decoupling draws the spray nozzle  80  away from the multi-lumen tube  24 . Still further rotation causes the spray nozzle  80  to be completely withdrawn from the multi-lumen tube  24  such that the spray nozzle  80  may be washed, sterilized, and/or disinfected, such as by ultrasonic cleaner or by an autoclave, for further use or otherwise disposed. 
       FIGS. 19 ,  20 A and  20 B illustrate an alternative spray nozzle  150  comprised of a valve  152  received in a tip housing  154 , and operating similar to previously described embodiments. The tip housing  154  is secured within the distal end  156  of a multi-lumen tube  158  constructed generally similar to previously described embodiments, with differences to be described below. The multi-lumen tube  158  includes an outer tubing  160  and an inner tubing  162  spaced from the outer tubing  160  to create a gas lumen  164  and a powder lumen  166  which generally operate as previously described. In this embodiment, the valve  152  only includes two fins  168 ,  170  at its proximal end. The use of only two fins  168 ,  170  allows free flow of powder past the fins  168 ,  170  and out from the outlet  172  when the valve  152  is open ( FIG. 20A ). The valve  152  further includes two central locating members  174  to help center the valve  152  within the tip housing  154  as the valve  152  moves between the open position shown in  FIG. 20A  and the closed position shown in  FIG. 20B . The tip housing  154  is crimped within the outer tubing  160 . 
     As further shown in  FIGS. 21A and 21B , the inner tubing  162  may be secured in the outer tubing  160  using spacers  176 , and adhesive, at a desired position to create a fluidizing chamber  178  at the proximal end of the applicator  180 . The proximal end of the applicator  180  includes a hub  182  with a powder inlet  184  and a gas inlet  186 . The inner tubing  162  is shown in two different positions in  FIGS. 21A and 21B . The inner tubing  162  is secured in the desired position, such as by adhering the spacer  176 , which is rigidly fastened to the inner tubing  162 , to the inner wall of the outer tubing  160 . The spacer  176  ( FIG. 20A ) at the distal end is similarly secured. In each position, a fluidizing chamber  178  is created proximal to the inner tubing  162 . The fluidization chamber  178  in  FIG. 21B  is larger than that of  FIG. 21A  such that more fluidizing of the powder will occur prior to the powder entering the proximal end of the inner tubing  162 . This feature allows the applicator  180  to be tailored to the density of the desired plume, and type(s) of powder to be used. The inlet lines  184 ,  186  have respective check valves  188 ,  190  which prevent backflow. The distal end of the applicator  180  will often be inserted into a gas insufflated area of a patient, such as the abdomen. The check valves  188 ,  190  will prevent insufflation gas from backing up into gas and powder supplies associated with the applicator  180 . The moisture carried within the insufflation gas could create significant problems if it reached the powder supply, for example. The check valve  190  in the gas line further prevents back up of powder into the gas inlet  186 . 
       FIG. 22  illustrates an alternative hub configuration which is the same as shown in  FIGS. 21A and 21B  except that the spacers  176  have been replaced by a cylindrical centering spacer  200 . Cylindrical spacer  200  is affixed between outer tubing  160  and inner tubing  162 , such as by using adhesive. The spacer  200  includes a bevel or converging portion  200   a  which is located adjacent the proximal end  162   a  of the inner tubing  162 . This centering spacer  200  and particularly the bevel  200   a  is designed to help prevent the accumulation of powder at the proximal end of the inner tubing  162  and also help direct the powder into the powder lumen  166 . 
       FIGS. 23 ,  24 A and  24 B illustrate another alternative feature of the multi-lumen tube  158 . In particular, a valve  210  is received in a tip housing  212  and operates similar to previously described embodiments. The difference is that the tip housing  212  incorporates mixing structure, such as in the form of generally spiral-shaped internal fins  214 . The fin or other mixing structure  214  may be configured as shown and described in U.S. patent application Ser. No. ______ (Atty. Ref.: NOR-1529US), filed on even date herewith and the disclosure of which is hereby incorporated by reference herein. The tip housing  212  includes internal stops  216  at the proximal end of the mixing structure  214 . These stops  216  respectively engage two fins  218 ,  220  which act and serve generally the same purpose as the previously described fins  168 ,  170 . The valve  210  moves between two positions as respectively shown in  FIGS. 24A and 24B  for the same purposes as previously described. The stops  216  limit the distal travel of the valve  210 . The distal end of the inner tubing  162  limits the proximal movement or travel of the valve  210 . The valve  210  is in the open position as shown in  FIG. 24A  and in the closed and venting position as shown in  FIG. 24B , generally as previously described with regard to earlier embodiments. When in the open position shown in  FIG. 24A , powder and gas travel through the central powder lumen  166  and toward the distal end  156  of the multi-lumen tube  158 . When the powder and gas travel through the section of the tube  158  that includes the mixing structure  214 , the powder and gas are further mixed in a manner generally as described in the above-incorporated U.S. patent application Ser. No. ______ (Atty. Ref.: NOR-1529US). Thus, the powder and gas travel generally between the stem  210   a  of the valve  210  and the generally spiral-shaped fins or other mixing structure  214  before exiting at the distal opening  222 . 
       FIGS. 25A and 25B  illustrate another alternative feature incorporated generally at the distal end  156 . In this embodiment, the distal end includes a replaceable tip  230  which may be designed and configured generally similar to embodiments as previously described such as by including a valve  152 . The replaceable tip  230  includes a proximal end with a threaded element  232 . An adapter  234  is provided with a mating threaded element  236 . The adapter  234  includes a coupling portion  238  that is rigidly secured between the inner tubing  162  and the outer tubing  160 , such as by using adhesive or welding techniques. Once the adapter  234  is secured in place, the distal end  156  effectively includes a threaded or other type of coupling element that may be selectively coupled with a mating element of the replaceable tip  230 . In this embodiment, the distal end  156  will therefore include an internally threaded element  236  and the replaceable tip  230  includes a mating externally threaded element  232  allowing the replaceable tip  230  to be selectively coupled to and uncoupled from the distal end  156 . This will, for example, allow different types of tips to be used on the same device and allow a tip to be replaced with a new tip for various purposes, such as if the tip becomes clogged with powder and/or other material such as biomaterials. 
     While the invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broadest aspects is not limited to the specific details shown and described. The various features and embodiments disclosed herein may be used in any combination necessary or desired for a particular application. Consequently, departures may be made from the details described herein without departing from the spirit and scope of the claims which follow. What is claimed is: