Patent Publication Number: US-2020289766-A1

Title: Method and apparatus for applying an anesthetic and bactericide

Description:
PRIORITY CLAIM 
     In accordance with 37 C.F.R. 1.76, a claim of priority is included in an Application Data Sheet filed concurrently herewith. Accordingly, the present invention claims priority as a continuation of U.S. patent application Ser. No. 16/017,379, entitled “METHOD AND APPARATUS FOR APPLYING AN ANESTHETIC AND BACTERICIDE”, filed Jun. 25, 2018, which claims priority as a continuation-in-part of U.S. patent application Ser. No. 15/094,754, entitled “METHOD AND APPARATUS FOR APPLYING AN ANESTHETIC AND BACTERICIDE”, filed Apr. 8, 2016, now U.S. patent Ser. No. 10/004,855, issued Jun. 26, 2018, which claims priority to U.S. Provisional Patent Application No. 62/145,322, entitled “METHOD AND APPARATUS FOR APPLYING AN ANESTHETIC AND BACTERICIDE”, filed Apr. 9, 2015, which claims priority as a continuation-in-part of U.S. patent application Ser. No. 14/453,475, entitled “METHOD AND APPARATUS FOR APPLYING AN ANESTHETIC AND BACTERICIDE”, filed Aug. 6, 2014, now U.S. Pat. No. 9,656,028, Issued May 23, 2017, which is a continuation-in-part of U.S. Pat. No. 13,927,454, entitled “METHOD AND APPARATUS FOR APPLYING AN ANESTHETIC AND BACTERICIDE”, filed Jun. 26, 2013, now U.S. Pat. No. 9,561,334, issued Feb. 7, 2017, which is a continuation-in-part of U.S. patent application Ser. No. 12/557,753, entitled “METHOD AND APPARATUS FOR APPLYING AN ANESTHETIC”, filed Sep. 11, 2009, now U.S. Pat. No. 8,500,678, issued Aug. 6, 2013, which is a continuation-in-part of U.S. application Ser. No. 11/636,859, entitled “DENTAL SYRINGE”, filed on Dec. 11, 2006, now abandoned, which claims the priority to U.S. Provisional Patent Application No. 60/733,757, entitled “CRYO-SYRINGE”, filed on Mar. 7, 2006. The contents of which the above referenced applications are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     Generally, the invention relates to an apparatus for applying an anesthetic to a patient. In particular, the apparatus comprises a receptacle for a liquefied endothermic gas and system for dispensing the endothermic gas which is removably attached to a syringe barrel. 
     BACKGROUND 
     Syringes are employed millions of times daily all over the world to inject medicines into people as well as animals. Many times, injections are made in areas of the body that are somewhat less sensitive to pain. Other locations of the body where injections are contemplated are significantly more sensitive to pain and the patient feels a pinching sensation that may be quite painful as the syringe needle is inserted beneath the skin. Such areas include, for example, gums, areas of the face such as the forehead, as well as the lips. To minimize the pain that results when the injection needle penetrates, for example, a patient&#39;s gums, the dental practitioner will often apply a topical agent to the injection site using a cotton swab. Because the deadening agent is only applied topically, it is not effective, as it does not cross the skin/mucosal membranes and misleads the patient into a false expectation of a painless injection. As a result, injecting an anesthetic often causes significant pain at the injection site. In other cases, such as diabetics, patients may be required to self-medicate on a daily basis. The repeated injections often create sensitive areas where injections are painful to the patient. This pain may cause patients to delay or omit medication to avoid the pain associated therewith 
     SUMMARY 
     There is currently a need for a means of minimizing the pain associated with an injection. The present invention addresses this need by providing a syringe having a liquid anesthetic, or a liquid anesthetic cartridge and a compressed gas or vapor canister therein, or a receptacle for receiving a gas or vapor canister, wherein the receptacle comprises a clip for attaching a syringe, e.g. piggyback. One chamber within the syringe or syringe cartridge includes a conventional anesthetic, while the canister includes a compressed, endothermic gas or vapor that rapidly absorbs heat when released to the atmosphere; the endothermic gas or vapor is first applied to the injection site prior to the anesthetic injection to minimize the pain associated with conventional anesthesia techniques. Furthermore, the gas or vapor also blanches the mucosa (along with popping bubbles due to the boiling of the liquid phase), allowing a practitioner to readily identify the pretreated injection site so that the needle is not inserted into an unanesthetized area. 
     Embodiments of the invention are also directed to an apparatus comprising a syringe, a receptacle which is removably attached to the syringe barrel and which accommodates a canister comprising a gaseous (vaporous) anesthetizing composition. The receptacle further comprises an elongated nozzle or a short nozzle for attaching a tube. The apparatus comprises an actuating member which acts to dispense the contents of a container or canister containing the anesthetic composition. The actuating member comprises a lever and a spring biased means for the controlled release of the gaseous (vaporous) anesthetizing composition. 
     Embodiments of the invention are further directed to a gaseous anesthetizing canister assembly for attachment to a single use autoinjector type syringe. The anesthetizing canister assembly includes a collar that surrounds the autoinjector syringe for attachment. The canister assembly contains a high pressure canister filled with endothermic gas and a trigger mechanism for releasing the endothermic gas through a nozzle. The nozzle provides a predetermined spray pattern for directing the endothermic gas toward the skin to provide an anesthetized area. The autoinjector syringe can then be activated to insert the needle into the anesthetized area without pain to the user. 
     Other aspects are described infra. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of the dental syringe with the cartridge and canister removed therefrom; 
         FIG. 2  is a plan view of the dental syringe with the cartridge and canister installed in their corresponding chambers; 
         FIG. 3  is a perspective view illustrating an alternative embodiment of the present invention; 
         FIG. 4A  is an exploded view of one embodiment of a module of the present invention; 
         FIG. 4B  is a perspective view of the embodiment illustrated in  FIG. 4A  attached to a syringe; 
         FIG. 4C  is a perspective view of the module of  FIG. 4A ; 
         FIG. 4D  is an exploded view of the module of  FIG. 4A ; 
         FIG. 5A  is a perspective assembly view illustrating an alternative embodiment of the present invention having a remote tank for holding an endothermic gas or vapor; 
         FIG. 5B  is a perspective assembly view illustrating an alternative embodiment of the present invention having a remote tank for holding an endothermic gas or vapor; 
         FIG. 5C  is a perspective view of an alternative embodiment of the present invention; 
         FIG. 5D  is a partially exploded view of the embodiment illustrated in  FIG. 5C ; 
         FIG. 5E  is a perspective view of an alternative embodiment of the present invention; 
         FIG. 5F  is a partially exploded view of the embodiment illustrated in  FIG. 5E ; 
         FIG. 5G  is an exploded view of the embodiment illustrated in  FIG. 5E ; 
         FIG. 5H  is a section view taken along lines  5 H- 5 H of  FIG. 5D ; 
         FIG. 5I  is a partially exploded view of the embodiment illustrated in  FIG. 5H ; 
         FIG. 5J  is a perspective view of an alternative embodiment of the present invention; 
         FIG. 5K  is a partially exploded view of the embodiment illustrated in  FIG. 5J ; 
         FIG. 6  is a plan view of a syringe with the canister installed in the module or adjunctive chamber; 
         FIG. 7  is a perspective view of the embodiment illustrated in  FIG. 6 ; 
         FIG. 8  is a partially exploded front view of the embodiment illustrated in  FIG. 6 ; 
         FIG. 9A  is a perspective view of one embodiment of the dispenser cap of the present invention; 
         FIG. 9B  is a front view of the dispenser cap illustrated in  FIG. 9A ; 
         FIG. 9C  is a section view taken along lines  9 C- 9 C of  FIG. 9B ; 
         FIG. 10A  illustrates one embodiment of an adjunctive chamber suitable for use with the present device; 
         FIG. 10B  is a front view of the adjunctive chamber illustrated in  FIG. 10A ; 
         FIG. 10C  is a side view of the adjunctive chamber illustrated in  FIG. 10A ; 
         FIG. 10D  is a rear view of the adjunctive chamber illustrated in  FIG. 10A ; 
         FIG. 10E  is a top view of the adjunctive chamber illustrated in  FIG. 10A ; 
         FIG. 10F  is a section view of the adjunctive chamber taken along lines  10 F- 10 F of  FIG. 10E ; 
         FIG. 11A  is a perspective view of one embodiment of the sleeve of the present invention; 
         FIG. 11B  is a top view of the sleeve illustrated in  FIG. 11A ; 
         FIG. 11C  is a bottom view of the sleeve illustrated in  FIG. 11A  with portions illustrated in phantom; 
         FIG. 11D  is a front view of the sleeve illustrated in  FIG. 11A ; 
         FIG. 12A  is a perspective view of one embodiment of the lever of the present invention; 
         FIG. 12B  is a top view of the lever illustrated in  FIG. 12A ; 
         FIG. 12C  is a left side view of the lever illustrated in  FIG. 12A ; 
         FIG. 12D  is a right side view of the lever illustrated in  FIG. 12A ; 
         FIG. 12E  is a top view of the lever illustrated in  FIG. 12A ; 
         FIG. 13A  is a top isometric view of one embodiment of an autoinjector syringe suitable for use with the present invention; 
         FIG. 13B  is a top isometric view of one embodiment of an adjunctive chamber suitable for use with an autoinjector syringe; 
         FIG. 14  is a top isometric view illustrating the adjunctive chamber secured to the autoinjector syringe of  FIG. 13A ; 
         FIG. 15  is a top isometric view illustrating insertion of a gas canister into the autoinjector syringe; 
         FIG. 16  is a top isometric view illustrating the fully assembled adjunctive chamber and autoinjector syringe; 
         FIG. 17  is an isometric view of an adjunctive chamber; 
         FIG. 18  is an exploded view of the adjunctive chamber of  FIG. 17 ; 
         FIG. 19  is an exploded view of an autoinjector syringe; 
         FIG. 20A  is an assembled view of the autoinjector syringe and an adjunctive chamber illustrating a method of using the assembly; 
         FIG. 20B  is an assembled view of the autoinjector syringe and an adjunctive chamber illustrating a method of using the assembly; 
         FIG. 20C  is an assembled view of the autoinjector syringe and an adjunctive chamber illustrating a method of using the assembly; 
         FIG. 20D  is an assembled view of the autoinjector syringe and an adjunctive chamber illustrating a method of using the assembly; 
         FIG. 21  is a perspective view of an illustrative embodiment of an applicator for dispensing a fluid, such as an anesthetic, shown with a syringe attached thereto; 
         FIG. 22  illustrates the applicator for dispensing a fluid shown in  FIG. 21 , with a canister prior to be inserted therein, and shown without the attached syringe; 
         FIG. 23  illustrates the applicator for dispensing a fluid shown in  FIG. 21 , with the canister inserted therein, and shown without the attached syringe; 
         FIG. 24  is a side view of the applicator for dispensing a fluid shown in  FIG. 21 ; 
         FIG. 25  is an exploded view of the applicator for dispensing a fluid; 
         FIG. 26  is a perspective view of the module chamber frame; 
         FIG. 27  is a front view of the applicator for dispensing a fluid shown in  FIG. 21 , illustrated without the dispensing member or syringe barrel securing device; 
         FIG. 28  is a bottom view of the applicator for dispensing a fluid shown in  FIG. 21 , illustrated without an inserted canister; 
         FIG. 29  is an illustrative example of a dispensing member; 
         FIG. 30  is a front view of the dispensing member shown in  FIG. 29 ; 
         FIG. 31  is a cross sectional view taken along lines A-A of  FIG. 30 ; 
         FIG. 32  is an exploded view of the dispensing member shown in  FIG. 29 ; 
         FIG. 33  is a plane view of an illustrative example of the syringe barrel securing device, showing a front side; 
         FIG. 34  is a side view of the syringe barrel securing device shown in  FIG. 33 ; 
         FIG. 35  is a plane view of an illustrative example of the syringe barrel securing device, showing a back side; 
         FIG. 36  is an exploded view of the syringe barrel securing device shown in  FIG. 33 ; 
         FIG. 37  is a perspective view of the dispensing trigger and canister lift lever; 
         FIG. 38  is a plan view of the dispensing trigger and canister lift lever; 
         FIG. 39  illustrates the applicator for dispensing a fluid shown prior to insertion of a canister; 
         FIG. 40  illustrates the applicator for dispensing a fluid shown with insertion of a canister; 
         FIG. 41  illustrates the applicator for dispensing a fluid shown with the canister secured thereto; 
         FIG. 42  illustrates the applicator for dispensing a fluid shown prior to securing a syringe thereto; 
         FIG. 43  illustrates the applicator for dispensing a fluid, shown prior to securing the syringe thereto; 
         FIG. 44  is a perspective view of the applicator for dispensing a fluid with a modified canister; 
         FIG. 45  is a bottom view of the applicator for dispensing a fluid illustrated in  FIG. 44 , with the modified canister removed; 
         FIG. 46  is an exploded view of the modified canister; 
         FIG. 47  is a partial cross sectional view of the modified canister; 
         FIG. 48  is a partial cross-sectional view of the applicator, with the modified canister inserted therein; 
         FIG. 49  is a second partial cross-sectional view of the applicator, with the modified canister inserted therein; and 
         FIG. 50  is a partial cross-sectional view of the applicator, with a canister inserted therein. 
     
    
    
     DETAILED DESCRIPTION 
     It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein. 
     Referring to  FIGS. 1-20 , embodiments of the present invention relate to a method and apparatus of applying an anesthetic. In some embodiments, the apparatus comprises an elongated tubular housing  1  having an outer wall  2 , an upper end  3 , a substantially hollow interior, and a lower end  4  having an injection needle  5  extending therefrom. On the housing outer wall is an elongated opening  6  in communication with an anesthetic chamber  7  formed within the housing interior. The anesthetic chamber receives a cartridge  8  having a conventional dental anesthetic stored therein. 
     The outer wall also includes a smaller opening  9  that is in communication with an adjunctive chamber  10  for receiving a canister  11 . The canister includes an endothermic gas (vapor) or “freeze spray” solution that rapidly absorbs heat when dispersed into the atmosphere. 
     Coaxially received within the anesthetic chamber  7  is a plunger  12  having a thumb ring  13  at an upper end and a spear  14  at a lower end; the spear penetrates a membrane on the upper end of the anesthetic cartridge  8  to force fluid therein into the injection needle  5 . 
     Coaxially received within the adjunctive chamber  10  is a depressible trigger  15  having a handle  16  at an upper end that protrudes from the upper end of the housing. Depressing the trigger opens the valve assembly  17  of the canister  11 , propelling the gaseous or vaporous solution contained within canister  11  through an outlet nozzle  20  on the lower end of the housing. The nozzle  20  is oriented to project a stream of gas or vapor along a delivery axis  31  that intersect a delivery axis  30  of the needle, preferably at a point  40  immediately adjacent to the needle outlet. Accordingly, a practitioner can first deaden a proposed injection site and then immediately insert the needle with little movement or repositioning of the syringe. 
     The method of applying an anesthetic using the syringe described above includes initially dispersing the heat-absorbing, endothermic gas or vapor from the canister  11  onto a proposed injection site by depressing the trigger  15 . Because of its physical properties, the heat-absorbing substance constricts blood flow at the injection site, and temporary numbing occurs. The freeze spray stops the propagation of the painful nerve stimuli, and the patient feels the tactile or pressure as opposed to the pain sensation. The pressure nerve fibers supersede the painful nerve fibers so that the mechanical contraction of the muscles blocks the transmission of pain perception, according to the Gate theory. The use of the endothermic “freeze spray” also temporarily distracts the patient by creating a “popping” noise (due to the boiling of the liquid under pressure) that diverts the patient&#39;s attention away from any potential or anticipated pain. Finally, because the solution blanches the mucosa, a readily-visible target is created for insertion of the needle to assure that the deadened area is not bypassed. The aerosol propellants or gas (vapor) used as anesthetic herein avoid the drawbacks associated with traditional anesthetics. The gas or vapor freezes (blanches) the area of administration, allowing for the painless insertion of the needle to deliver the pharmaceutical drug, vaccine, BOTOX®, hair transplant and the like. 
     When the practitioner observes that the injection site mucosa has been blanched, the site is effectively deadened and a painless, concomitant injection is possible. The practitioner can then quickly inject the anesthetic into the blanched injection site by inserting the injection needle  5  and depressing the plunger  12 . Because of the positioning of the gas or vapor outlet nozzle  20  and needle outlet  21 , the dispersal of the gas or vapor and subsequent injection of anesthetic can be accomplished almost concurrently and with no pain to the patient. 
     Referring to  FIGS. 3, 4A -D,  9 A-C,  10 A-F,  11 A-D and  12 A-E, alternative embodiments of the present invention are illustrated. In these embodiments, an apparatus comprising a module  44  is removably attached to a syringe barrel  62  and accommodates a canister  11  comprising a gaseous (vapor) anesthetizing composition. The module  44  includes an elongated outlet nozzle  20  for directing the gaseous (vapor) anesthetizing composition to intersect with the delivery axis  30  ( FIG. 2 ) of the needle  5 . The module includes an adjunct chamber frame  56 , attachment means in the form of clips  23  or a sleeve  48 , a trigger  15  and an outlet nozzle  20 . The adjunct chamber frame  56  functions to contain the canister  11 , as well as providing support for the trigger  15 , clip(s)  23  and the dispenser cap  54 . The trigger member  15  ( FIG. 12A-E ) functions to dispense the contents of the canister  11  containing the anesthetic composition by forcing the canister to slide within the adjunctive chamber  10  of the adjunct chamber frame  56 . During the sliding action, the dispensing tube  58  of the canister  11  is pressed against the dispenser tube shoulder  55  to cause the canister valve  17  to open allowing compressed gas to escape through the dispenser tube  58 . The trigger  15  is secured to the adjunct chamber frame  56  via pivot pins  60 . The pivot pins  60  cooperate with pivot apertures  59  in the adjunct chamber frame  56 . The pivot pins are positioned to allow the trigger to rotate thereabout so that the handle  16  can be utilized to force the ram  66  against the base of the canister  11  to cause the movement within the adjunctive chamber  10  to allow the pressurized gas to be released. A biasing means in the form of a spring  68  may be utilized to return the trigger to its original position. In some embodiments, the module  44  is disposable. In other embodiments, the syringe  42  is disposable. In yet other embodiments, the canister  11  is disposable. In other embodiments, any one or combination of parts of the apparatus is disposable. 
     Still referring to  FIGS. 3, 4A -D,  9 A-C,  10 A-F,  11 A-D and  12 A-E, the module  44  includes an adjunctive chamber  10  for accepting a gas cartridge  8 . The outer diameter of the module includes an attachment means which may comprise a clip  23  ( FIG. 3 ) or sleeve  48  ( FIG. 4A ) which are adapted to cooperate with the outer diameter of a syringe barrel  62  for securing the module to the syringe. The clip  23  preferably includes a pair of arcuate members  24  made of a flexible resilient material so that the arcuate members may be temporarily enlarged by flexing to allow the arcuate members to snap over the outer diameter of the syringe barrel  62 . In this manner, the module may be attached to syringe barrels of differing diameters to provide versatility to the device. The sleeve member  48  is also constructed from a flexible resilient material, such as plastic, and includes a slot  49  extending between two barrels  45 ,  47 . In operation, the slot  49  may be expanded to allow the first and second barrels  45 ,  47  to be slipped over the outer diameter of the module  44  and the syringe  42 . A fastener  51  may be provided to compress the slot  49  in the sleeve member  48  to prevent slippage of the assembly during use. 
     Referring to  FIGS. 9A-C , the dispenser cap is illustrated. The dispenser cap is used to close the end of the adjunct chamber frame  56  and to cooperate with the valve assembly  17  to cause the pressurized gas to be dispensed. In the preferred embodiment, the first end of the dispenser cap includes threads  70  which secure the dispenser cap to the adjunct chamber frame  56 . Alternatively, adhesive, bayonet mount, friction fits or the like may be utilized to secure the dispenser cap to the adjunct chamber frame without departing from the scope of the invention. This is best seen in  FIGS. 9 and 10 , wherein the threaded cap  54  comprises an opening  27  and an engagement means, e.g. a valve aperture  55  to engage the canister and for delivery of metered doses of aerosol propellants. A restrictor jet  74  may be utilized to control the flow of gas through the outlet tube. The second end of the dispenser cap includes an outlet nozzle bore  72  sized to cooperate with the outlet nozzle  20  for positioning thereof. In the preferred embodiment, the outlet nozzle  20  is adhered or frictionally fit to the dispenser cap. The outlet nozzle  20  can be rigid, flexible or semi-flexible. The outlet nozzle  20  is tubular in construction, having a distal end  140  ( FIG. 8 ) with an opening  52  that may, if desired, be defined by an insert, e.g. nozzle, venturi or the like, inserted into the opening  52  and having a particularly configured passageway to cause the anesthetic sprayed therefrom to spray in a desired pattern. The distal end of the nozzle  20  can be flexible, and may be bent by a physician into a desired angulation so that the anesthetic is sprayed in a desired location with respect to the location where the syringe needle will be inserted beneath the skin of the patient. The needle  5  can be varied in length, for example, shortened or elongated, so it extends beyond the distal termination of the outlet nozzle  20  so that the nozzle  20  doesn&#39;t interfere with insertion of the needle subcutaneously. 
     As shown in  FIG. 3 , a disposable syringe  42  is illustrated in conjunction with the module  44  of the present invention. The disposable syringe includes an elongated barrel  62  that is typically cylindrical in outer configuration, a plunger  12  having a thumb pad  43  or ring  13  ( FIG. 1 ) that is engaged by the thumb or finger of the user, and a perpendicular tab  61  on the barrel  62  of the syringe  42  that is grasped by other fingers of the user while the ring or pad  13 ,  43  is being pushed to cause the plunger  12  to move in a direction toward the distal end  50  of the barrel  62 . The plunger  12  pushes the medicament or liquid in the chamber  7  through the needle. The needle  5  is attached to the distal end of the syringe via a locking taper, luer lock  46 , or the like, to allow fluid to flow into and through the needle  5 . As is well known, the needle is thin and hollow, permitting the medicament within the chamber  7  to be dispensed therethrough. The needle  5  can be of any length so long as its distal end extends beyond the end of outlet nozzle  20 . 
     In the various embodiments, the anesthetic comprises one or more gas, vapor or aerosol propellants. These propellants can be any type of aerosol propellants as long as they continue to decrease the temperature of the patient&#39;s skin or mucosal area targeted for an injection; examples are the aerosol propellants sold by DuPont Company, Wilmington, Del., under the trade names DYMEL™  134   a  and DYMEL™  227   a . In preferred embodiments the anesthetic comprises a blend of two aerosol propellants in varying percentages of weight/weight (w/w). The range of DYMEL™  134   a  can be from about 0.001% to 99.999% w/w and the weight of DYMEL™  227   a  can be from about 0.001% to 99.999% w/w. In other embodiments, one or more compounds, pharmaceutical grade compounds or compositions can be included, for example, compounds which alter the vapor pressure of the gas or vapor being emitted. Pharmaceutical compounds include, for example, antimicrobial, taste altering compounds or flavoring compounds, e.g. menthol, mint, etc., therapeutically effective compounds and the like. In preferred embodiments, the aerosol propellants (e.g. DYMEL™  134   a , DYMEL™  227   a ) are pharmaceutical grade and shown to be safe for inhalation, ingestion, and for use in sensitive areas of a patient, e.g. eyes, lips, nose etc. These pharmaceutical grade aerosol propellants can be obtained from DuPont Company, Wilmington, Del. 
     The anesthetic is preferably contained within a small or specialized canister of the type typically utilized for metered dose inhalers (e.g., asthma) and includes a deep drawn metal canister constructed from a metal such as aluminum or steel. The deep drawn canister  11  ( FIG. 4D ) includes a valve assembly  17  crimped and sealed within the open end of the metal canister to create a sealed pressure canister that is light weight and portable. The aerosol propellants are contained within the metal canister under pressure so that depression of the dispenser tube  58  releases the propellant through the valve assembly. In operation, the dispenser tube  58  of the valve assembly  17  may be operated in a variety of manners which may include, but should not be limited to, finger nozzles, levers, cams, solenoids or the like, which permit the valve to be depressed for release of the propellant. 
     The location on the surface area of the patient where an injection is to take place is determined, and the syringe  42  with the module  44  attached thereto is positioned at a desired location and angle of skin penetration approximately 1 to 2 centimeters above the skin. The lever  15  is depressed to engage the valve to permit flow of the anesthetic, e.g. an aerosol propellant (vapo-coolant), for a period of time, such as 1 to 3 seconds. The skin is then penetrated by the needle  5  of the syringe  42  to a desired depth and the medicament is injected to numb in a separate location either while the aerosol propellant is flowing, or just after the flow of the aerosol propellant is stopped. Injections may be first subcutaneous, then intramuscular or intradermal. The anesthetic can be administered at various depths in sequence of the dermal layers to make sure that the area is numb, such that a patient will not feel any pain when the needle, e.g. i.v. injection is inserted. In some embodiments, the first dermal or skin layer is numbed first, and then the next layer etc., in sequence. If desired, the needle may be retracted a desired distance, with additional injection occurring, or may be removed so that the next location can be chosen. During the step-wise process of injection including multiple injections at the same site of needle penetration, additional aerosol propellants may be dispensed as desired to maintain the numbness of the skin at that location. If, during the process of injection, the canister  11  runs out of anesthetic, e.g. an aerosol propellant, it may be removed from the adjunct chamber frame  56  and replaced with a replacement canister. In embodiments where a large area is targeted for numbing, a larger volume or quantity of aerosol propellant in a large canister  90  can be utilized so as not to contaminate the field or location and to prevent cross contamination ( FIGS. 5A, 5B ). In some embodiments, the apparatus comprises an assembly  200  ( FIGS. 5A, 5B ) which is attachable to a user&#39;s clothes or belt, or a back-pack carrying any further number of doses of propellant. In this manner, the user is not required to replace a spent canister. The assembly  200  is connected to the remote valve assembly  80  via a long flexible tube  91  which can be extended or retracted as needed by the user, and is actuated in a similar manner as with the smaller canister  11 , or the tube is connected to the canister, thereby providing a reservoir of aerosol propellant. The canister may also be refillable, and may additionally include regulators or the like known in the art for reducing pressure from large high pressure tanks. When the injection process is completed, the syringe  42  may be removed from the clip portion  23  and suitably discarded, and the module  44  may be re-used with other syringes or for single use per point to prevent cross-contamination. It should also be noted that while the preferred embodiment entails placing the large canister in a fixed position, the canister may optionally include an attachment means for securing the canister to the belt or back of the user to provide mobility to the user while still providing the added capacity of the larger canister. 
     As such, in this way the present invention provides an effective way of dispensing an anesthetic onto the skin of a patient where an injection is to take place so that the injection is painless. The present invention is not limited for use in association with injections in the face for aesthetic enhancement. Rather, it may be used as an attachment to any syringe or other injection device used to inject any medication for any purpose. For example, the inventive device may be used with injection devices associated with diabetes glucose monitors, BOTOX®, hair transplants, multiple needle allergy introducers and the like. 
     Referring to  FIGS. 1 and 2 , the apparatus comprises an elongated tubular housing  1  having an outer wall  2 , an upper end  3 , a substantially hollow interior, and a lower end  4  having an injection needle  5  extending therefrom. On the housing outer wall is an elongated opening  6  in communication with an anesthetic chamber  7  formed within the housing interior. The anesthetic chamber receives a cartridge  8  having a conventional dental anesthetic stored therein. 
     The outer wall  2  can also include a smaller opening  9  ( FIG. 1 ) which is utilized as the receptacle or adjunctive chamber  10  for receiving a canister  11  ( FIG. 2 ). The canister  11  includes an endothermic gas or vapor, or “freeze spray” solution that rapidly absorbs heat when dispersed into the atmosphere. Coaxially received within the anesthetic chamber is a plunger  12  having a thumb ring  13  or other means for pushing the plunger at an upper end. 
     Coaxially received within the adjunctive chamber  10  is a depressible trigger  15  having a handle  16  at an upper end that protrudes from the upper end of the housing. Depressing the trigger propels the gaseous or vapor propellant through an outlet nozzle  20  on the lower end of the housing. The nozzle  20  is oriented to project a stream of gas or vapor along a delivery axis that intersects a delivery axis of the needle, preferably at a point immediately adjacent to the needle outlet  21 . Accordingly, a practitioner can first deaden a proposed injection site and then immediately insert the needle with little movement or repositioning of the syringe. 
     Referring to  FIGS. 6-8 , an alternative embodiment of the present device is illustrated. This embodiment utilizes a reusable syringe in combination with the module  44  and the sleeve  48  for attaching the module to the syringe. This embodiment also illustrates that the module and the sleeve may be constructed from metal without departing from the scope of the invention. 
     In some embodiments, the module  44  may be constructed and arranged to accommodate two or more canisters  11 . The arrangement of the two or more canisters or modules can be arranged in any manner and can be of varying dimensions and shapes. For example, the modules can be attached together. In some embodiments, the modules  44  are arranged to be on either side of the syringe. One of ordinary skill in the art can envisage possible combinations, locations, patterns and designs for the receptacles. 
     Referring to  FIG. 8 , the container or canister  11  which contains one or more gases or vapors comprises a neck  111  having an end cap  112  and a dispenser tube  58  dimensioned for slidable insertion and engagement of the dispenser cap  54  of the module  44  ( FIG. 8 ). The canister contents can be any type of anesthetic. In some embodiments, the anesthetic comprises one or more gases (vapors); examples include, without limitation, aerosol propellants, endothermic gases (vapors) and refrigerants that rapidly absorb heat when released from pressure to the atmosphere and the like. Accordingly, a user can initially disperse the gas or vapor composition onto the injection site to minimize any pain and discomfort associated with an injection. Subsequently, the practitioner inserts the needle into the deadened site (blanched) and injects the contents of the syringe. As discussed above, the receptacle can be of any size and shape to accommodate canisters or containers of varying sizes and shapes. The size of the canisters used depends on the volume of the anesthetic, e.g. gas or vapor needed for the particular procedure. Different blends produce different temperatures; therefore, the doctor in charge can decide which of the blends to utilize for the necessary effect. In some embodiments, the temperature of the gas or vapor when administered is above freezing temperature to avoid necrosis, frost bite, pain, discomfort or any type of biological damage to the area of administration. Since the medical caregiver, e.g. doctor, controls the delivery of the anesthetic, e.g. gas or vapor, the doctor is in charge of the delivery of the gas or vapor to enhance the patient comfort, therefore, the doctor can add additional bursts if the patient informs the doctor that more is needed. 
     Referring to  FIGS. 5C-K , an alternative embodiment of the present invention is illustrated. In this embodiment, the module  144  is constructed and arranged to be secured to the syringe  42  in a perpendicular arrangement with respect to the syringe. The adjunct chamber frame  156  is still constructed to allow the insertion of a portion of the canister  11 . The distal end of the adjunct chamber frame  156  includes the dispenser tube shoulder  55  for accepting the dispenser tube  58 . In this embodiment, the trigger  115  is constructed and arranged to cooperate with the neck  111  of the canister  11  to provide controlled dispensing of the pressurized gas. The trigger  115  is provided with a pivot pin  160  which allows the ram  166  to catch under the neck to cause the canister to move within the adjunct chamber frame. Return spring  168  returns the trigger to its original position. An outlet tube  120  extends out of the adjunct chamber frame  156  at an angle that is substantially perpendicular with respect to the canister  11 . The outlet tube  120 , therefore, provides a body to cooperate with the sleeve  48  or clip  23  for ready attachment to reusable or disposable syringes. The outlet tube  120  also functions to secure and position the outlet nozzle  20 , which may be telescopingly engaged to the outlet tube to allow the length of the outlet nozzle to be adjusted. 
     It should also be noted that, while not shown, a small laser light or the like may be secured to the module  44 ,  144  to indicate the trajectory of the pressurized gas. In this manner, the user would be provided with a visual guide to where the gas will strike the patient&#39;s skin. 
     The above-described device is not limited to the exact details of construction and enumeration of parts provided herein. For example, the receptacle could comprise separate components, e.g. a separate clip that is attachable to the receptacle and to any conventional syringe. The endothermic gas or vapor should remove sufficient heat to function as described without causing necrosis. The concentration and volume of the propellant components can be varied to deliver small doses of highly-concentrated substances, or a prolonged, continuous dispersal of diluted substances. The canister can also be color coded for varying temperatures produced by the different blends or aerosol propellants. In addition, gas or vapor delivery can be automated with a laser mechanism that dispenses gas or vapor when the needle is within a minimal distance from the skin and automatically disables gas or vapor flow upon needle penetration. Accordingly, a practitioner can rapidly inject multiple sites. Finally, although the device has been primarily described and depicted as a syringe, the gas or vaporous canister could have other uses. For example, it could be attached to a scalpel blade to allow a quick, painless incision when performing certain procedures, such as removing moles. Furthermore, the size, shape and materials of construction of the various components can be varied. 
     Referring to  FIGS. 13A-B ,  14 - 19  and  20 A-D, alternative embodiments of the present invention are illustrated. In these embodiments, an apparatus comprising a module  44  is removably attached to an autoinjector syringe barrel  162 , and accommodates a canister  11  comprising a gaseous (vapor) anesthetizing composition. The module  44  includes an elongated outlet nozzle  20  for directing the gaseous (vapor) anesthetizing composition to intersect with the delivery axis  30  of the needle  5 . The module includes an adjunct chamber frame  56 , attachment means in the form of a securable clip  123  or a sleeve  48 , a latch  124 , an outlet nozzle  20  and a dispenser cap  54 . The adjunct chamber frame  56  functions to secure the adjunct chamber to the autoinjector syringe barrel  162 , and contains the canister  11  as well as the securable clip(s)  123  and the dispenser cap  54 . In this embodiment, the canister base  111  functions as the trigger member  15  ( FIG. 12A-E ) functions to dispense the contents of the canister  11  containing the anesthetic composition by forcing the canister to slide within the adjunctive chamber  10  of the adjunct chamber frame  56 . During the sliding action, the dispensing tube  58  of the canister  11  is pressed against the dispenser tube shoulder  55  to cause the canister valve  17  to open, allowing compressed gas to escape through the dispenser tube  58 . The canister  11  of the cartridge  8  is frictionally secured within the adjunct chamber frame  56  to allow the sliding action. Pressure and/or springs within the valve assembly  17  function to stop the flow of gas when pressure is released from the base of the canister  111  or the trigger  15 . Latch pivot pins  125  cooperate with latch pivot pin apertures  127  in the adjunct chamber frame  56  to allow the securable clip  123  to be pivoted between an open position  FIG. 13B  and a closed position around the autoinjector syringe  162   FIG. 14 . In some embodiments, the module  44  is disposable. In other embodiments, the autoinjector syringe  162  is disposable. In yet other embodiments, the canister  11  is disposable. In other embodiments, any one or combination of parts of the apparatus is disposable. 
     Still referring to  FIGS. 13A-B ,  14 - 19  and  20 A-D, the module  44  includes an adjunctive chamber  10  for accepting a gas cartridge  8  in the form of a canister  11 . The outer diameter of the module includes an attachment means which may comprise a securable clip  123  which is adapted to cooperate with the outer diameter of an autoinjector syringe barrel  162  for securing the module to the autoinjector syringe. The securable clip  123  preferably includes a pair of arcuate members  126  made of a resilient or rigid material so that the arcuate members may be closed around the outer diameter of the autoinjector syringe barrel  162  and latched in place via latch  124 . The latch  124  is rotatably secured to the adjunct chamber frame  56  to allow the latch pin  128  to engage the latch slot  130 . In this manner, the module may be securely attached to autoinjector syringe barrels to prevent slippage during use. In at least one embodiment, orientation tabs are provided to insure a preferred orientation between the autoinjector syringe  162  and the module  44 . 
     Referring to  FIG. 18 , one embodiment of the dispenser cap  54  is illustrated. The dispenser cap is used to close the end of the adjunct chamber frame  56  and to cooperate with the valve assembly  17  to cause the pressurized gas to be dispensed. In the preferred embodiment, the outlet nozzle  20  includes a pocket  134  sized to contain the dispenser cap. A pilot shaft  136  is utilized to align and secure the dispenser cap to the adjunct chamber frame  56  via fastener  138 . Alternatively, adhesive, bayonet mount, friction fits or the like may be utilized to secure the dispenser cap to the adjunct chamber frame without departing from the scope of the invention. A restrictor jet  74  ( FIG. 9C ) may be utilized to control the flow of gas through the outlet tube. The second end of the dispenser cap includes an outlet nozzle bore  52  sized to cooperate with the outlet nozzle  20  for directing the flow of gas. The outlet nozzle  20  of the preferred embodiment is rigid; however, flexible or semi-flexible outlet nozzles may be utilized without departing from the scope of the invention. The outlet nozzle  20  is tubular in construction, having a distal end  140  with an opening  52  ( FIG. 8 ) that may, if desired, be defined by an insert e.g. nozzle, venturi or the like, inserted into the opening  52  and have a particularly configured passageway to cause the anesthetic sprayed therefrom to spray in a desired pattern. The distal end of the nozzle  20  can be flexible, and may be bent by a physician into a desired angulation so that the anesthetic is sprayed in a desired location with respect to the location where the syringe needle will be inserted beneath the skin of the patient. The needle  5  can be varied in length, for example, shortened or elongated, so it extends beyond the distal termination of the outlet nozzle  20  so that the nozzle  20  doesn&#39;t interfere with insertion of the needle subcutaneously. 
     Referring to  FIG. 19 , an exploded view of an autoinjector syringe  142  is illustrated in conjunction with the module of the present invention. The autoinjector syringe  142  includes an elongated barrel  162  that is typically cylindrical in outer configuration, a plunger  12  having a thumb pad  43  or ring  13  ( FIG. 1 ) that is engaged by the thumb or finger of the user to cause the plunger  12  to move in a direction toward the distal end  50  of the barrel  162  via spring member  144 . The plunger  12  pushes the medicament or liquid in the chamber  7  through the needle. The needle  5  is attached to the distal end of the syringe via locking taper, press fit, luer lock  46  or the like, to allow fluid to flow into and through the needle  5 . As is well known, the needle is thin and hollow, permitting the medicament within the chamber  7  to be dispensed therethrough. The needle  5  can be of any length so long as its distal end extends beyond the end of outlet nozzle  20 . A top cap  146  and a needle cap  148  may be included with the autoinjector syringe to prevent inadvertent activation of the autoinjector syringe during shipping and travel. This construction permits the autoinjector syringe to be preloaded and carried for use as needed. 
     Referring to  FIGS. 20A-D , operation of the autoinjector syringe with the module secured thereto is illustrated. If included, the top cap  146  and needle cap  148  are removed prior to placing the autoinjector syringe above the injection area  9  ( FIG. 20A ). The base portion  111  of the canister  11  is pressed, causing the valve assembly  17  to be opened and allowing the pressurized gaseous anesthetic to be directed through the nozzle  20  to the skin, thereby numbing the injection site ( FIG. 20B ). The thumb pad  43  is pressed after the autoinjector syringe  142  is placed onto the injection area ( FIG. 20C ). Once the injection is complete, the autoinjector syringe and module assembly are lifted away from the injection site as normal ( FIG. 20D ). 
     Referring to  FIGS. 21-25 , an alternative embodiment of the present invention relating to the method and apparatus of applying an anesthetic is shown. In this embodiment, an apparatus, referred to generally as applicator  200 , comprises a module  202  configured to be secured or attached to a syringe  204 , with needles  206 , preferably secured or attached to the syringe barrel  208 , and is designed to accommodate a canister  11  comprising a gaseous (vapor) anesthetizing composition. The applicator  200  may further include a dispensing member  210 , a syringe barrel securing device  212 , a dispensing trigger  214 , and a canister lift lever  216 . The dispensing member  210  may be integrally formed from, or attached to, a portion of the module  202 . 
     Referring to  FIGS. 26 and 27 , an illustrative example of the module chamber frame  218  is shown with the dispensing member  210 , the syringe barrel securing device  212 , the dispensing trigger  214 , and the canister lift lever  216  removed. The module chamber frame  218  is shown assuming a generally tubular shape. However, such shape is illustrative only.  FIG. 26  illustrates the back end  220 , i.e. the end furthest away from a patient&#39;s skin, receiving the gaseous (vapor) anesthetizing composition. Running the length of the back end  220 , from the upper portion  222  of the module chamber frame  218  to the lower portion  224  is a channel  226 . The channel  226  is sized and shaped to receive and hold at least a portion of the canister lift lever  216 . A canister lift stop, illustrated herein as a canister lift stop elongated body or wall  227  prevents the at least one portion of the canister lift from being moved or pushed into the center of the module chamber frame  218 . The channel  226  terminates at the bottom end in an opening. The opening  228  is sized and shaped to receive a canister  11  when inserted therein and remain within the interior portion  232  ( FIG. 28 ) of the module chamber frame  218 . The opening  228  is shown having an elongated shape defined by curved surfaces  234  and  236 , thus forming a module chamber frame tail end  238  that ends below the end of the channel  226 . 
       FIG. 27  illustrates the front end  240 , i.e. the end closest to the patient&#39;s skin receiving the gaseous (vapor) anesthetizing composition, of the module chamber frame  218 . At or near the upper portion  222  is a dispensing member receiving area  242 , illustrated herein as an opening  244  with an internal passageway  246  that terminates in an end wall  248 . An outer module chamber frame fluid dispensing opening  250  positioned in the end wall  248  allows for fluid contained in canister  11  to dispense into the dispensing member  210  when secured to the dispensing member receiving area  242  and activated by triggering or pressing down on dispensing trigger  214 . When canister  11  is inserted into the interior portion  232  ( FIG. 28 ) of the module chamber frame  218 , the dispensing tube  58  of the canister  11  (see  FIG. 22 ) is pressed against the dispenser tube shoulder  55  to cause the canister valve  17  to open, allowing compressed gas to escape through the dispenser tube  58 . Since the dispensing tube  58  is aligned with and inserted into the inner module chamber frame fluid dispensing opening  252 , the compressed gas is directed to the dispensing member  210  via the inner module chamber frame fluid dispensing opening  252  and through the outer module chamber frame fluid dispensing opening  250 . 
     The dispensing member  210  is designed to deliver a treatment fluid, i.e. pressurized gaseous (vapor) anesthetizing composition to a patient&#39;s skin. The dispensing member  210  may comprise a first fluid dispensing end  254 , a second, opposing module connecting end  256 , and a dispensing member main body  258 , which may also be referred to as a nozzle, therebetween. 
     The dispensing member  210  is sized, shaped, or orientated to direct said gaseous anesthetizing composition to intersect with a delivery axis  30  (see  FIG. 2 ) of a needle connected to said module  202 . The first fluid dispensing end  254  is shown having a cap  260  attached thereto via threading  262 . The second, opposing module connecting end  256 , via threading, connects or secures to the module  202  at threading  266  (see  FIG. 27 ) within the dispensing member receiving area  242 . The dispensing member main body  258  has an inner lumen  268  sized and shaped to receive and hold therein an inner fluid dispensing tube  270 . The inner fluid dispensing tube  270  is preferably sized to traverse the length of the dispensing member main body  258  and has an opening at a first end  272 . The second end may contain a shoulder  276 , with a portion of the dispensing tube  270  extending through. The extended portion  280  is in contact with the opening  250  when the dispensing member  210  is connected to the module  202 . Washers  282  help create a tight seal and prevent fluid escape. An indicator ring  284 , which may be colored, may be used to help the user identify the size of the dispensing member  210 , i.e. a red ring to indicate a short dispensing member  210 , a white ring to indicate a medium dispensing member  210 , or a blue ring to indicate a long dispensing member  210 . 
     At least a portion of the dispensing member  210  may be used to support the syringe barrel securing device  212 . The syringe barrel securing device  212  is designed to securely hold a syringe, particularly at the orientation and distance so as not to interfere with the dispensing of the pressurized gaseous (vapor) anesthetizing composition from the dispensing member  210 . The syringe barrel securing device  212  contains two spring loaded clamping bodies  286  and  288  placed within the barrel securing device housing structure  290 . The securing device housing structure  290  comprises an upper portion  292  secured to a lower portion  294  via screws  297 . The clamping bodies  286  and  288  each have openings  296  (see  FIG. 36 , shown for clamp body  286  only) which secure the springs  298 . The clamping bodies  286  and  288  are sized and shaped to fit and move, by sliding linearly, within the cut-out portion or channels  300  and  302  in the upper portion  292 . The syringe barrel securing device  212  attaches to the dispensing member  210  via a securing member in the form of a generally circular shaped sleeve  304 . The sleeve  304  secures to the module chamber frame  218  via shaped prongs, tabs or appendages  306 . The shaped prongs, tabs, or appendages  306  are sized and shaped to engage and fit within the slotted recesses  308  and  310  ( FIG. 27 ) formed within the dispensing member receiving area  242 . The shaped prongs or appendages  306  may also act as orientation tabs to insure a preferred orientation between said syringe barrel securing device and said at least one portion of said modular chamber frame. The clamping body  286  may be configured so that the end which interacts with an inserted syringe has terminal end, shown as a pointed terminal end  312  that rises above a generally planar surface  314 . The clamping body  288  may be configured to have a terminal end which interacts with an inserted syringe, shown as pointed terminal end  316  that rises above a generally planar surface  318 , see  FIGS. 24 and 36 . The terminal ends  312  and  316  are arranged in a opposite orientation relative to each other so that when there is no body acting upon the clamps  286  and  288 , the pointed terminal end  312  of clamp  286  rests against the planar surface  318  of clamp  288  and the pointed terminal end  316  of clamp  288  rests on the generally planar surface  314  of clamp  286 . 
       FIGS. 37 and 38  illustrate the dispensing trigger  214  secured to the canister lift lever  216 , (which connect to the dispensing member main body  258 , not shown in the figures), through pins  320  and  322 . The canister lift lever  216  may comprise a first elongated portion  322  sized and shaped to fit within the channel  226 , a second curved or concave portion  324 , and a second elongated portion  326 , extending downwardly from the curved or concave portion  324 . The second elongated portion  326  is positioned inwardly relative to the first elongated portion  322 . The second elongated portion  326  ends in a hooked end portion  328 . The hooked end portion  328  forms a seat  330  which can secure against a bottom surface of the canister  11  to secure it in place. Since the dispensing trigger  214  is secured to the canister lift lever  216 , pressing the dispensing trigger causes the canister lift lever  216  to push the canister in an upward movement, thus providing a mechanism to deliver a metered amount of the gaseous (vaporous) anesthetizing composition.  FIGS. 39-41  illustrate the steps of securing the canister  11  to the module chamber frame  218 . In  FIG. 39 , the canister  11  is show prior to insertion into opening  228  of the module chamber frame  218 .  FIG. 40  illustrates the canister  11  inserted into the module chamber frame  218 .  FIG. 41  illustrates the canister  11  secured within the module chamber frame  218  via securing of the canister lift lever  216  to the canister  11 . In this position, the first elongated portion  322  rests within channel  226 . The second elongated portion  326  rests against a portion of the canister  11  outer surface  332  and the seat  330  of the hooked end portion  328  rests against and secures the bottom surface  334  of canister  11 . 
       FIGS. 42 and 43  illustrate the attachment of a syringe to the applicator  200 . As shown, the canister  11  is inserted into the module chamber frame  218  and secured with the canister lift lever  216  locked in place. Syringe barrel  208  of syringe  204  is secured to the applicator  200  by placing the syringe barrel  208  into the syringe barrel securing device  212 , see arrow  336 . The syringe barrel  208  of syringe  204  secures between clamps  286  and  288  as the force exerted causes the spring-loaded clamps  286  and  288  to move or open up from their original resting state. In this position, the user can dispense metered amounts of the gaseous (vaporous) anesthetizing composition by pressing on the dispensing trigger  214 . Such action causes the canister lift lever  216  to move upwardly, i.e. towards the inserted syringe barrel  208  of syringe  204 , causing the gaseous (vaporous) anesthetizing composition to be dispensed from the canister  11 , out from the dispensing member  210 , and delivered to the patient&#39;s skin. The user can then dispense the contents of the syringe  204  to the skin thereafter. 
     Referring to  FIG. 44 , the embodiment of the applicator  200  illustrated is configured to secure and engage a modified canister  311 . The applicator  200  shown may include all or some of the features as previously described, with several additional components to be used to engage and secure the modified canister  311 . Positioned within the interior portion  232  of the module chamber frame  218  are one or more ribs  338 , see  FIG. 45 . The one or more ribs  338  may be integrally formed or separately attached and secured to the inner wall  340  of the module chamber frame  218 , and extend outwardly from the inner wall  340  towards the center.  FIG. 45  illustrates four ribs  338 , a first pair  338 A, arranged oppositely about opening  252  and arranged in the same first plane (see dashed lines  340 ), and a second pair,  338 B, arranged oppositely about opening  252  and arranged in the same second plane (see dashed line  342 ), with the second plane  342  being different than the first plane  340 . The ribs  338  are sized, shaped, and spaced apart to engage with a modified canister cap  344 . 
     Referring to  FIG. 46 , the modified canister  311  is shown having a main body  346 , which is sized and shaped to store the gaseous (vaporous) anesthetizing composition therein, a metering valve  348 , and a valve stem  350 . The modified canister cap  344  may comprise an open bottom end  352  to allow securing to a portion of the main body  346 , and a top end  354  having an opening  356  sized and shaped to allow passage of the valve stem  350  therethrough. The modified canister cap  344  comprises a plurality of applicator receiving members  358 , illustrated herein as shaped openings. The applicator receiving members  358  are sized and shaped to correspond to fit with and engage ribs  338  so that the applicator receiving members  358  and the ribs  338  engage, they are locked or remain in place, preferably by a frictional fit. A sufficient force can be applied to pull off or disengage the ribs  338 -applicator receiving members  358  bond. Each applicator receiving member  358  may be defined by two generally parallel arranged side walls  360 ,  362 , a back wall  364 , and a bottom wall or seat  366 , each shaped to provide a secure fit with the ribs  338 . Once the modified canister  311  is inserted into the applicator  200 , see  FIGS. 48 and 49 , and secured by manipulation of the canister lift lever  216 , the canister is secured by engagement of the ribs  338  with the applicator receiving members  358 , thus aligning a metering valve  348  and a valve stem  350  in position to disperse the gaseous (vaporous) anesthetizing composition into the spray orifice  368  and through the dispensing member  210 . A pivoting block member  370  may be used to maintain the modified canister  311  (or canister  11 ) in place. Referring to  FIG. 50 , the applicator  200  having ribs  338  is shown engaging with a canister  11  that does not include the modified canister cap  344 . In this case, the ribs  338  rest against a shoulder  370  of the canister  11 . 
     One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary, and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.