Patent Publication Number: US-2022233788-A1

Title: Atomizer for nasal therapy

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 13/884,576, filed Aug. 2, 2013, which claims priority of International Application No. PCT/IB2011/002809, filed Nov. 11, 2011, which claims the benefit of U.S. Provisional Patent Application 61/456,780, filed Nov. 12, 2010, the disclosures of which are incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The invention relates to atomizing nozzles and devices which dispense treatment fluids in a misted or dispersed, small particle size, form and to methods of their manufacture and use. Certain devices constructed according to the invention are particularly suitable for use in nasal therapy. 
     BACKGROUND 
     Details of the principles of operation and construction of certain operable atomizing nozzles are disclosed in U.S. Pat. No. 6,698,429, titled “MEDICAL ATOMIZER”, issued Mar. 2, 2004, to Perry W. Croll, et aL the entire disclosure of which is hereby incorporated as though set forth herein in its entirety. The principal focus of the &#39;429 patent provides atomizing nozzles that may be inserted into, and advanced along the length of, conduit passages having cross-section areas of relatively small size. 
     One commercially available device commonly used for dispensing treatment fluid in substantially misted form includes the widely used white polypropylene actuator  50  illustrated in  FIG. 1 . Such actuator is manufactured by a company known as Valois or Aptar and having a worldwide presence. The actuator is typically provided as an OEM component and is ubiquitously available in an assortment of spray-bottle, or pump-bottle applications. Although certain atomizing details are approximated or not illustrated, relevant external structure of the actuator  50  is illustrated substantially true to scale. 
     Actuator  50  is exemplary of a discharge nozzle that is expressly not structured to resist over-insertion of the distal end into a nostril when applying topical therapy to nasal passages. In fact, the gradual taper and relatively small diameter of the extended discharge nozzle can easily permit over-insertion in an adult nostril. The conic angle γ calculated using direct measurements of a purchased actuator is about 3-½ degrees, and the nozzle tip is located more than 1 inch from the oblong cantilevered trigger structure  52  on which a user&#39;s fingers rest to actuate a fluid-dispensing pump bottle. The tip diameter  54  is about 0.3 inches, and the diameter  56  at the interference ring is about 0.41 inches. The interference ring is spaced apart from the tip by about 0.9 inches. Such slender, and small diameter, protruding structure can easily be over-inserted into an adult nostril, and cause damage to sensitive nasal tissue. 
     Actuator  50  is also exemplary of a commercially available 2-piece atomizing nozzle. The internal distal surface of bore  58  is believed to carry turbine structure effective to apply a spin to fluid prior to expelling the fluid through a discharge orifice. A core element (not illustrated) forms a proximal surface for a turbine chamber. The core element is installed in a press-fit inside bore  58 . Fluid is believed to flow distally along the side of the solid core element to the turbine chamber. A fluid supply conduit from a pump bottle can be placed in fluid communication with the proximal end of bore  58  (typically with a press-fit installation), to introduce treatment fluid to bore  58 . 
     An exemplary 6-piece atomizer assembly adapted for use in nasal therapy is generally indicated at  60  in  FIG. 1A . Such atomizer assembly is commercially available under part name MAD Nasal, MAD 300 from Wolfe Tory Medical, Inc., having a place of business located at  79  West 4500 South, Suite 18, Salt Lake City, Utah 84107. Atomizer assembly  60  includes atomizing nozzle, generally  62 , affixed to a short extension conduit  64 . A malleable wire is installed in one of two lumen that extend lengthwise through the conduit. A separate fluid guidance structure (not illustrated) is trapped inside the nozzle tip shell upon assembly of the nozzle tip shell and extension conduit. Luer-locking structure, generally  66 , including torsion wings  68  and thread  70 , is affixed to the proximal end of conduit  64 . The nozzle  62  and extension conduit  64  are forced into a soft rubber nasal stopper  72 . 
     It would be an improvement to provide a 2-piece atomizer having integral structure of a discharge tip configured to permit insertion of a distal tip end into even a child&#39;s nostril, and to resist over-insertion of the tip end into other nostrils having a range in larger size. A further advance would provide a 2-piece atomizer including integral threaded luer connection structure. 
     Another advance would provide an atomizing nozzle having a minimized dead volume to promote efficient use, and reduce waste, of treatment fluids. 
     SUMMARY 
     Provided is an operable atomizing nozzle that can be formed from only two pieces: a nasal stopper, and a stem. That is, a combination consisting of only the stem and the nasal stopper is operable as an atomizing nozzle. The atomizing nozzle is typically structured for use in combination with a syringe. 
     Desirably, a distal end of the nasal stopper includes a protruding tip that carries a discharge orifice for dispensing treatment fluids in misted, or atomized, form. A preferred such tip is sufficiently small in cross-section as to permit entrance of the tip into a nostril opening of a human child. Desirably, the leading end of the tip is structured to be blunt to avoid causing tissue damage inside a nostril. Also, the trailing end of a tip is typically structured to suggest a cylindrical section, a length of the cylindrical section being sized to form an interference with structure of a nostril to resist transverse displacement of the tip from an inserted position inside the nostril. 
     A proximal portion of the nasal stopper is typically configured to resist over-insertion of the protruding tip into a child&#39;s nostril opening. A currently preferred nasal stopper consists of a single unitary element. A currently preferred proximal portion may be characterized as a shield affixed to the protruding tip and arranged to define a flaring wall providing a variable diameter sized to contact skin around the opening of a plurality of different-sized nostrils effective to resist over-insertion of the distal portion of the nasal stopper. One workable shield includes a substantially conic surface, the conic angle being selected from a range between about 20 degrees and about 60 degrees. The currently preferred conic angle is about 30 degrees. A desirable shield comprises a substantially conic distally facing surface devoid of radial protrusions, with the proximal end of the conic surface being configured as a cantilevered free end. 
     A workable stem extends in a length direction between a proximal end and a distal end and is configured to couple directly to the nasal stopper. The stem provides a lumen to conduct treatment fluid to the atomizing structure. A preferred stem consists of a single unitary element. Integral thread structure carried at the proximal end of the stem is typically configured to couple with a lure-locking portion of a syringe. Sometimes, the stem is sized in length such that, upon assembly of the atomizer, that thread structure is disposed inside a volume defined by the nasal stopper. A preferred stem is structured to require fluid to discharge in a radial direction from at least one side discharge opening disposed at a location proximal to the distal end of the stem. 
     A workable connection may be formed between a stem and a nasal stopper between first cooperating coupling structure configured to form a primary distal fluid seal to resist leakage of fluid from the lumen. A workable connection between a stem and nasal stopper may also include a second cooperating coupling structure configured to form a primary torsion-carrying connection. 
     The combination formed by the nasal stopper and stem forms an atomizer including the aforementioned discharge orifice. That is, the discharge orifice is disposed in a wetted fluid path to conduct fluid from a turbine chamber of the atomizer. The stem is structured to provide a lumen for communication of treatment fluid to the turbine chamber for discharge of treatment fluid substantially as a mist from the discharge opening. A portion of the proximal wall of the turbine chamber is defined by structure disposed at a distal end of the stem. 
     Sometimes, a filler piece may be installed within the lumen of the stem. A workable filler piece is structured to reduce dead volume inside the working portion of the atomizer, itself, to less than about 0.02 ml. An alternative workable filler piece is further structured to reduce dead volume inside a syringe that is connected to the atomizer assembly to the extent that the dead volume of the combination including the syringe and atomizer is less than about 0.03 ml. In more preferred embodiments, the dead volume in a combination including a syringe and atomizer is less than 0.02 ml. In even more highly preferred embodiments, the dead volume in a combination including a syringe and atomizer is less than about 0.01 ml. 
     The inventions includes a method of, e.g., nasal or other delivery comprising utilizing the described atomizing nozzle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which illustrate what are currently regarded as the best modes for carrying out the invention: 
         FIG. 1  is a side view, partially in section, of a commercially available actuator; 
         FIG. 1A  is a side view, partially in section, of a commercially available atomizing nozzle assembly adapted for nasal therapy; 
         FIG. 2  is a side view, substantially to scale, of a first assembly structured according to certain principles of the invention; 
         FIG. 3  is a side view, substantially to scale, of a second assembly structured according to certain principles of the invention; 
         FIG. 4  is a side view, substantially to scale, of a third assembly structured according to certain principles of the invention; 
         FIG. 5  is a side view, partially in section, of a superposition of a plurality of atomizing nozzles; 
         FIG. 6  is a top view of the atomizer assembly illustrated in  FIG. 2 ; 
         FIG. 7  is a bottom view of the atomizer assembly illustrated in  FIG. 2 ; 
         FIG. 8  is a view in perspective from above of the atomizer assembly illustrated in  FIG. 2 ; 
         FIG. 9  is a view in perspective from below of the atomizer assembly illustrated in  FIG. 2 ; 
         FIG. 10  is a front view of the atomizer assembly illustrated in  FIG. 2 ; 
         FIG. 11  is a side view of the atomizer assembly illustrated in  FIG. 2 ; 
         FIG. 12  is a bottom view of a stem portion of the atomizer assembly illustrated in  FIG. 2 ; 
         FIG. 13  is a bottom view of a nasal stopper portion of the atomizer assembly illustrated in  FIG. 2 ; 
         FIG. 14  is a top view of the stem illustrated in  FIG. 12 ; 
         FIG. 15  is a top view of the nasal stopper illustrated in  FIG. 13 ; 
         FIG. 16  is an exploded front view in cross-section of a workable 2-piece atomizer assembly structured according to certain principles of the invention; 
         FIG. 17  is an exploded side view in cross-section of the assembly of  FIG. 16 ; 
         FIG. 18  is an assembled view of the structure illustrated in  FIG. 17 , installed on a syringe; 
         FIG. 19  is a view similar to  FIG. 18 , including alternative spacing structure to reduce dead volume inside the atomizer assembly; 
         FIG. 20  is a view similar to  FIG. 19 , including alternative spacing structure to reduce dead volume inside the atomizer assembly and syringe; 
         FIG. 21  is a side view in cross-section of a workable 2-piece atomizer structured according to certain principles of the invention; and 
         FIG. 22  is a cross-section view of the fluid guidance structure illustrated in  FIG. 21 . 
     
    
    
     DETAILED DESCRIPTION 
     The present invention provides an apparatus and method for applying treatment fluid to facilitate certain medical procedures. Preferred embodiments are used to apply topical treatment fluid in misted form to nasal passageways. 
     Currently preferred fluid dispensing devices are adapted to atomize expelled treatment fluid. By “atomize expelled fluid”, it is meant that the discharged fluid is dispersed substantially as a mist or cloud composed of very small droplets. Design variables incorporated in an atomizing nozzle include characteristic size of the discharge orifice, amount of pressure applied to the fluid upstream of the discharge orifice, and any turbine chamber structural arrangement to induce fluid spin. Effective atomization requires an expelled fluid to pass through a sufficient pressure drop at a discharge orifice. Further, the expelled fluid must have a rotational component of motion, (spin) about the discharge axis. Radial spread of the ejected cloud increases in correspondence with increases in the fluid spin rate at the discharge orifice. 
     As used in this disclosure, the term “integral” is used to mean referenced elements are formed from a single continuous piece of material. In contrast, an assembly may provide the same functionality, or even include the same elements, but is formed from more than one piece of material. 
     A first currently preferred assembly for dispensing a treatment fluid is illustrated generally at  100  in  FIG. 2 . Second and third currently preferred embodiments are indicated generally at  100 ′ and  100 ″, respectively, in  FIGS. 3 and 4 . All three embodiments illustrated in  FIGS. 2-4  are illustrated substantially at true scale with the attached syringes, and therefore convey a realistic sense of the visual appearance produced by such embodiments. 
     The first embodiment  100  includes a fluid motive source  102 , in combination with a dispensing nozzle, generally  104 . The illustrated fluid motive source  102  in  FIG. 2  is a 1 ml syringe, although other arrangements effective to cause pressure on a fluid are workable, including syringes having different fluid capacities. A workable 1 ml syringe may currently be obtained from Becton Dickinson at WorldWideWeb://catalog.bd.com/bdCat/viewProduct.doCustomer?productNumber=309628. It is within contemplation alternatively to supply fluid from a pressurized or pre-pressurized canister, or pump bottle, and the like. 
     The illustrated dispensing nozzle  104  is a 2-piece fluid atomizing nozzle operable to eject treatment fluid as a mist or cloud. Such atomizing nozzles apply spin (about an ejection axis) to a fluid just prior to ejecting the fluid through a small diameter orifice. The discharged spinning fluid experiences a significant pressure drop across the exit orifice, and is thereby effectively atomized. Dispensing nozzle  104  includes a shield  106  structured to resist over-insertion of the distal end, generally  108 , into nostril openings that may have different sizes. 
     First and second alternative shields  106 ′ and  106 ″, respectively, constitute the principal differences in structure illustrated in  FIGS. 3 and 4 . As illustrated, maximum sizes may be varied, as well as shape of the shields, including their trailing ends. The maximum diameter of shield  106  is 0.66 inches. The maximum diameter of shield  106 ′ is about 0.8 inches, and the maximum diameter for shield  106 ″ is about 0.75 inches. Currently preferred shield embodiments generally fall within such a range in maximum diameter. The trailing end of shield  106 ″ is rounded by including a rearward projecting dogleg section. Such contouring can be more comfortable when pressed against the lip of a patient during administration of therapeutic fluids. 
     With reference now to  FIG. 5 , currently preferred atomizers include a nasal stopper, generally  110 , and a stem, generally  112 . An exemplary stem cooperates with an exemplary nasal stopper to form an operational 2-piece atomizing nozzle. A currently preferred stem  112  carries integrated thread structure  113 . 
     Desirably, a nasal stopper  110  includes a distally projecting tip  114 , and a shield  116 . The distally projecting tip  114  carries a discharge orifice, generally indicated at  118 . The leading end  120  of tip  114  is desirably blunt, as illustrated, to avoid causing tissue damage inside a child&#39;s nostril. It is currently preferred for the trailing end  122  of tip  114  to be structured to suggest a cylindrical section. Furthermore, it is desirable for the cylindrical section to provide a length “L” sufficient to form a structural interference with the opening of a nostril to resist accidental transverse displacement of tip  114  from an inserted position inside that nostril. A workable length “L” is about 0.1 inches, or so. The currently preferred distally protruding tip has a length “L” of 5 mm, or about 0.13 inches. Desirably, the tip  114  is structured and sized to permit its insertion into a nostril opening of a child. That means, the diameter of the cylindrical portion of tip  114  is typically less than about 0.3 inches, with a currently preferred diameter being about 0.18 inches. 
     With continued reference to  FIG. 5 , it is preferred for a shield  116  to provide a proximal portion configured to resist over-insertion of discharge orifice  118  into a nasal opening. As illustrated, shield  116  defines a flaring wall providing a variable diameter sized to contact skin around the opening of a plurality of different-sized nostrils. Although other shapes are workable, illustrated shield  11  presents a substantially conic surface for contact with a nostril opening area. Desirably, a shield is structured to provide a measure of centering and orienting to facilitate positioning discharge orifice  118  in a nasal cavity. While even a flat washer is workable, it should be realized that a too shallow conic angle permits over-insertion, and a too steep conic angle starts to loose self-centering ability. A workable conic angle may be selected from a range between a minimum value  128  of about 20 degrees (see shield  116 ′), and a maximum value  126  of about 60 degrees (see shield  116 ″). The currently preferred shield  116  in  FIG. 5  has a conic angle of 30 degrees and a maximum diameter “D” at proximal end  130  of about 0.66 inches.  100511  preferred shield, such as shield  116  in  FIG. 5 , presents a smooth contact surface, which is devoid of radial protrusions, to the nostril and lip areas of a patient. Desirably, the contact surface is structured to make a seal against skin at the nostril opening. Also, it is preferred to structure a shield to provide a self-centering capability to urge a discharge orifice away from a nasal wall. The illustrated contact surface is formed by revolving a shape about a centerline. Such a smooth contact surface is in contrast to the oblong transverse trigger structure illustrated in  FIG. 1 . Further, the proximal end of a preferred contact surface is structured as a shell to provide an open cantilevered free end  132 . Such cantilevered structure  132  is in contrast to the solid proximal surface of stopper  72  illustrated in  FIG. 1A . 
     It is realized that humans are variable in their sizes and conformation. For purpose of this disclosure, it will be assumed that a nostril opening of a human child is less than 0.3 inches in diameter. The dispensing tip of the atomizer illustrated in  FIG. 1  simply cannot fit into a nostril of that child. In practice, a clinician places the dispensing end against the child&#39;s nasal opening, and hopes for sufficient alignment of the discharge orifice and nostril opening. One aspect of certain preferred embodiments of a nasal stopper  110  provides a protruding distal tip sized for reception inside the nostril of a child. Desirably, proximal shield structure of the nasal stopper is configured to resist over-insertion of the protruding tip in the nostril of a child, as well as a large number of adults. It is recognized that certain adult nostrils may be sufficiently large that preferred nasal stoppers may not provide self-centering or seal against skin at the nasal opening. However, the currently preferred nasal stoppers are believed to work well with the vast majority of human nostrils. 
       FIGS. 6-1   1  illustrate externally visible details of the atomizing nozzle assembly  104  illustrated in  FIG. 2 . Such FIGS. are illustrated in true scale, and therefore convey a realistic sense of the visual appearance produced by a currently preferred atomizer for nasal therapy. Nasal stopper  138  includes shield  106  with contact surface  140  configured to form a seal against skin at the nostril opening of a nostril selected from a plurality of nostrils having different sizes. Stem  142  couples with nasal stopper  138  to form a workable 2-piece atomizer assembly. As best illustrated in  FIG. 9 , stem  142  is received in standoff  144 . Integral thread structure, such as a plurality of thread lugs  146 , is carried at a proximal end of stem  142 . It is within contemplation to extend alternative thread structure around a circumference of stem  142 . A 6% bore  148  is provided inside stem  142  to couple with the dispensing tip of a syringe and to conduct treatment fluid toward throat  150  for eventual discharge through discharge orifice  118 . A volume  152  is defined by proximally open-ended skirt-like cantilevered shell structure of shield  106 . One boundary of such volume is provided by plane  154  defined by structure at the proximal end of shield  106 . 
       FIGS. 12-15  illustrate certain cooperating internal structure of atomizing assembly  104 . With reference to  FIG. 12 , a distal end of stem  142  is configured to form anvil surface  156 . With reference to  FIG. 15 , anvil surface  156  is assembled to press against standoff surfaces  158 , thereby defining a plurality of substantially fluid-tight turbine blades  160 . Thus, fluid introduced through throat  150  is caused to pass through turbine blades  160  and subsequently enter turbine chamber  162 . Fluid in turbine chamber  162  acquires a spin prior to being expelled through discharge orifice  118 . 
     With reference to  FIG. 16 . it can be visualized that anvil surfaces  156  is advanced along central axis  164  until that distal surface  156  encounters the cooperating proximal surface(s) of turbine structure, generally indicated at  166 , disposed around a perimeter of conic turbine chamber  162 . Turbine structure  166  includes a plurality of standoff surfaces  158  and turbine blades  160  best illustrated in  FIG. 15 . Therefore, anvil surface  156  forms a portion of a proximal wall of turbine chamber  162 . 
     In the embodiment illustrated in  FIGS. 16-18 , a primary fluid seal is formed between internal surface  170  of nasal stopper  138  and cooperating external surface  172  of stem  142 . Desirably, the primary fluid seal is disposed in close proximity to the one or more (two are illustrated) side discharge opening  174  disposed near the distal end of stem  142 . A side discharge opening  174  provides a portion of the fluid path extending through stem  142  and causes a transverse component of velocity in fluid flowing there-through. Of note, the transverse component of travel is enforced at a location inside the fluid supply lumen and proximal to the distal end of stem  142 . In other words, a preferred stem is structured to require fluid to discharge in a radial direction from at least one side discharge opening disposed at a location proximal to the distal end of that stem. 
     A primary torsion-transfer coupling is created between internal surface  176  of nasal stopper  138  and a cooperating external surface  178  of stem  142 . The contact area of the illustrated torsion-transfer coupling is larger than the contact area of the primary fluid seal. Further, the radius extending to the torsion-carrying coupling is larger than the radius extending to the primary fluid seal surface. Therefore, the primary torsion-transfer coupling carries more torsion loading than the primary fluid seal surface. The cooperating elements that form a workable torsion-transfer coupling permit a user to grasp the contact surface  140  and impart twist to a nasal stopper  138  effective to install, and to remove, an atomizer onto luer-locking structure of a syringe, such as included at the distal end of syringe  102  in  FIG. 18 . 
     The primary fluid seal can operate as a secondary torsion-transfer coupling. Also, the primary torsion-transfer coupling may function as a secondary fluid seal. It is currently preferred for both of the primary fluid seal and the primary torsion-coupling to be caused by an interference, or press-fit, between the cooperating elements. However, it is within contemplation that one or more such junction may be formed by alternative means, including adhesive joints, and the like. Also, it is within contemplation alternatively to provide a single surface at which to form a combined fluid seal and torsion-carrying coupling. 
     With reference now to  FIG. 18  (in which the syringe is not entirely to scale), the discharge end of a syringe  102  is conventionally jammed into compression against surface  180  of 6% bore  148  during engagement of cooperating luer-locking structure of syringe  102  and stem  142 . Such an arrangement forms a fluid-tight coupling between the syringe  102  and stem  142 . 
     Treatment fluid flows from discharge bore  182 , along unoccupied portion of the 6% bore  148 , through throat  150 , exits stem  142  through one or more side discharge opening  174 , and then flows into liquid zone  184 . The illustrated liquid zone  184  is essentially a cylindrical annulus about 0.015 inches in thickness and extending along axis  164  for a distance of about 0.1 inches. Fluid in liquid zone  184  is already displaced in a radial direction from the centerline axis  164  and enters openings of one or more turbine blade  160  (see  FIG. 15 ). Fluid exits a turbine blade  160  into turbine chamber  162  with a spin. If sufficiently pressurized, fluid is then ejected through discharge orifice  118  as a mist. 
     With continued reference to  FIG. 18 , a dead volume may be defined as the volume of fluid remaining in a fluid transporting device subsequent to exhaustion of operable fluid pumping. Such dead volume for atomizer  104  includes the working portion (or portion unoccupied by syringe or other pumping device) of the 6% bore  148 , throat  150 , any side discharge openings  174 , liquid zone  184 , turbine blade(s)  160 , and turbine chamber  162 . The dead volume for a syringe  102  having a conventional plunger includes primarily the bore  182 . The dead volume for the exemplary assembly  102 / 104  illustrated in  FIG. 18  has been calculated to be about 0.102 ml, about half of which is contained in the syringe  102 , and half in the atomizer  104 . It is often desirable to minimize the dead volume, e.g. to reduce waste of treatment fluid when dispensing a single dose and subsequently discarding the dispensing device. 
     One way to reduce dead volume in an atomizer assembly similar to assembly  104  is to reduce the length of the primary torsion-transfer coupling area, and neck down the distal portion of the 6% bore  148 . However, because it is possible to generate 600 psi with a 1 ml syringe  102 , there is some danger of separation of a press-fit stem  142  from a nasal stopper  138  if the contact area is excessively reduced. 
     An alternative approach to reduce dead volume in an atomizer, such as atomizer assembly  104 , is illustrated in  FIG. 19 . A volume-reducing insert  190  may be installed in bore  148  and throat  150  to displace a substantial portion of dead volume within the atomizer  104 . The lumen  148 ′ essentially replaces the fluid conducting path previously provided by the unoccupied portion of the 6% bore  148  and throat  150 , which constitutes the majority of the dead volume of an atomizer assembly  104 . The remaining dead volume in the combination illustrated in  FIG. 19  is less than about 0.07 ml. Preferred embodiments of the atomizer nozzle assembly, itself, provide a small dead volume; including a dead volume of less than about 0.03 ml, less than about 0.02 ml, and even less than about 0.01 ml. The illustrated atomizer assembly  104  and insert  190  would have a dead volume of easily less than about 0.02 ml when used in combination with a syringe having a plunger configured to cause essentially zero dead volume within the syringe. 
     A further reduction in dead volume of an assembly including a syringe  102  and atomizer assembly  104  may be effected by an arrangement such as illustrated in  FIG. 20 . Volume-reducing insert  194  is installed in bore  148  and throat  150 , and also projects proximally into bore  182  to displace a substantial portion of dead volume in the assembly formed by syringe  102  and atomizer  104 . The lumen  148 ″ essentially replaces the fluid conducting path previously provided by bore  182 , the unoccupied portion of the 6% bore  148 , and throat  150 , which cause the majority of the dead volume of an assembly including syringe  102  and atomizer  104 . The remaining dead volume in the illustrated embodiment in  FIG. 20  is in the ballpark of about 0.02 ml. Preferred embodiments of an assembled combination of a nasal atomizing nozzle and syringe provide a small dead volume; including a dead volume of less than about 0.03 ml, less than about 0.02 ml, and even less than about 0.01 ml. 
       FIG. 21  illustrates another embodiment of a 2-piece atomizer, generally indicated at  200 , structured according to certain principles of the invention. Atomizer  200  includes an integral protruding distal tip  202 ′, integral stem  204 , and integral shield  206 . The integrated structure of the atomizer can require rather specialized tooling to manufacture by way of currently preferred injection molding. However, certain of such tooling permits integrated thread structure  113  to even be disposed within the volume defined by distally open-ended shield  206 , as illustrated. 
     Workable turbine structure carried internal to distal tip  202 ′ is equivalent to the turbine structure  166  in  FIG. 15 . Fluid guidance structure  208  provides the same functionality as the distal end of a stem  142 , and distributes treatment fluid toward a liquid zone  184  (e.g. see  FIG. 18 ). One workable fluid guidance structure  208  is shown in cross-section in  FIG. 22 . The illustrated fluid guidance structure  208  may be manufactured by cutting a length of extruded material to a desired length. The guidance structure  208  may then be installed by press-fitting the cut length into an installed position. In such case, an outer radial dimension of ribs  210  is sized to cause a suitable press-fit engagement within the distal end of bore  180 . Treatment fluid can then flow in the direction of central axis  164  between adjacent ribs  210  of an installed fluid guidance structure  208  and enter turbine chamber  162  by way of one or more turbine blade. The distal surface of guidance structure  208  forms an anvil surface equivalent to the anvil surface  156  of stem  142 . If desired, a volume-reducing insert (e.g. structured similar to insert  190  in  FIG. 19 ), may be installed to reduce dead volume inside an atomizer  200 . 
     It is currently preferred to manufacture elements such as a stem, stopper, and spacer, by injection molding. A workable stem and/or stopper element is typically made from medical grade plastics, such as ABS, polypropylene, and polycarbonate. A workable spacer may be made from similar materials, or more compliant materials, such as rubber, urethane, and the like. Preferred assembly of a separate, or non-integral, stem to a stopper is accomplished with a press-fit joint between the elements. A radial interference of about 0.001 or 0.002 inches is workable to form a torsion-transfer coupling in polycarbonate elements structured similar to the embodiment illustrated in  FIG. 18 . For similar elements made from polypropylene, the radial interference should be increased to about 0.004 inches. In alternative construction, an adhesive joint may be used to joint a stem to a stopper. Workable adhesives are well known, and may be selected as appropriate for the material of composition of respective elements. For example, polycarbonate materials may be bonded with cyclohexanone solvent adhesive. UV-curing adhesives may be used in some cases. Preferably, a spacer is installed in a bore of an atomizer using a press-fit. 
     After having been apprised of the instant disclosure, one of ordinary skill in the art will be readily able to make the disclosed structure using commercially available materials and tools.