Abstract:
The present invention is a vaporizer apparatus ( 1 ) and method for uniformly extracting active ingredients of specimen of crude natural product, or inert particulate matrix impregnated with volatile substances without pyrolysis which uses hot air ( 2 ), or a heated inert gas stream to volatilize the specimen. The heated air or gas in introduced from below (from either a hot air gun or a high-pressure tank connected to a heat exchanger), and ascends through in most embodiments through a permeable support structure ( 4 ) (e.g., fritted glass disk, etc.) subsequently causing specimen particules disposed on the permeable support structure to be suspended within the confines of an isolation chamber ( 5 ).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of application Ser. No. 08/919,317, filed Aug. 28, 1997, now U.S. Pat. No. 6,250,301, the entirety of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a vaporizer for inhalation and a method for extraction of active ingredients from a crude natural product or other matrix, by means of an ascending airstream heated to the temperature appropriate to volatilize the molecules. 
     The use of plants as medicinal agents has a long and successful history. The majority of medicines used today are either derived directly from plants or synthesized as variations on natural molecules. However, modern medical practice has, for the most part, abandoned the use of whole plant products because of objections concerning variability in concentration of active ingredients, and unpredictable rates of active drug release from orally ingested crude drugs. Even teas made from medicinal plants cannot fully overcome the latter objection, as the dose provided depends on compound solubility and the conditions of extraction. In addition, accurate self-titration of this dose cannot be expected to overcome either objection, considering the excessive time-lag between oral ingestion and the onset of action. 
     The best resolution of these problems is through pulmonary ingestion of vaporized compounds, if they are sufficiently volatile. This provides a more immediate means of relief and a more accurate method for dose self-titration, as well as allowing a means for applying compounds to the pulmonary tract itself, as is necessary with diseases such as bronchial asthma, etc. Pulmonary ingestion of drugs also circumvents the “first-pass effect” by which oral drugs are transferred from the intestines and then partially or entirely metabolized by the liver, before entering the blood stream. 
     Unfortunately, the only technique available to accomplish pulmonary application of crude natural drugs has been via the method of smoking. This is objectionable from the medical perspective because pyrolysis products are irritating and long-term ingestion of smoke has been implicated in the etiology of various pulmonary disease states (e.g., emphysema, cancer, etc.). 
     Other objections to inhalers such as U.S. Pat. No. 87,603 (Tichenot) which continuously heats or pyrolizes a substance on a grating, and U.S. Pat. No. 1,858,580 (Collins) which steam heats a carrying agent permeated with a medicated substance, involve the lack of ability to either maximize the extraction exposure of the specimen particles, or to promote a uniform extraction of the aggregate charge through its periodic mixing. Additionally, prevention of large particle inhalation which may prove irritating to the pulmonary system of the user, and providing a demand-only flow of heated gas upon each inhalation, which spares wasteful loss of active ingredient during periods of device disuse, is not achieved. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a vaporizer and a method by which a hot gas stream vaporizes and uniformly extracts the active ingredients of a crude natural product or other specimen without pyrolysis, thereby avoiding the potentially detrimental effects of smoking. 
     A further object of the present invention is to spare the wasteful loss of active ingredients extracted by the vaporizer due to a continuous gas flow instead of a demand-only gas flow, and also to prevent the inhalation of large particles by the user due to a lack of a filtering mechanism. 
     A still further object of the present invention is to prevent clogging of the vaporizer apparatus due to evaporated compounds condensing on the permeable support structure of the vaporizer apparatus. 
     Yet another object of the present invention is to initiate a high speed of air flow through the vaporizer, such that lofting of the crude natural product is more easily achieved, in order to maximize the extraction of the active ingredients, without excessive inhalation force. 
     The present invention extracts volatile active ingredients from a crude natural product, as well as other volatile substances (e.g., essential oils) impregnated into an inert matrix (e.g., paper), by means of a moving airstream heated to the temperature appropriate to volatilize the molecules of the product or substance. Transfer of these agents or ingredients as a water-free aerosol is simultaneously accomplished by this same airstream. In addition, the means of introducing the heated gas into the pulverized crude drug from below provides for the solid particulates to be suspended in the airstream, completely exposing them to the extractive gases, as well as causing a mixing of the aggregate charge upon each inhalation. 
     In cases where prevention of labile active compound denaturation (e.g., oxidation) is required, the substitution of a stream of hot inert gas (e.g., helium, argon) for the stream of hot air can be implemented. The use of helium carries the additional advantage of raising the voice pitch of the inhaler, reminding the user that air has not been inhaled. 
     Upon each inhalation, the heated gas is introduced from below and ascends through, in most embodiments, a permeable support structure (e.g., fritted glass disk, etc.), subsequently causing specimen particles to be suspended within the confines of the isolation chamber. This allows a maximized gas extraction exposure for each suspended particle and promotes a uniform extraction of the aggregate charge through its periodic mixing. In addition, this method ensures that the support structure is kept clean and unclogged, since evaporated compounds are constantly swept away from its upper surface. A filter provided downstream from the permeable support structure prevents large particles from being inhaled by the user. 
     During device disuse in one embodiment, the heated airstream flows through a side-arm of the vaporizer apparatus, preventing wasteful loss of active ingredients. In another embodiment, the side arm can also be used to divert mixed purge gases from the specimen, when the specimen is required to be under the flow of inert gas during its extraction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings, wherein: 
     FIG. 1 shows an exploded view of the completed assembly of the vaporizer apparatus according to a first embodiment of the invention. 
     FIG. 2 shows the completed assembly of the vaporizer apparatus according to a first embodiment of the invention. 
     FIG. 3A shows the isolation chamber of the vaporizer apparatus with the specimen particles in their normal state. 
     FIG. 3B shows the isolation chamber of the vaporizer apparatus with the specimen particles suspended by the ascending heated gas flow through the isolation chamber. 
     FIG. 4 shows the disk filter screen retention assembly of the vaporizer apparatus and a metal clip removal tool. 
     FIG. 5 shows the hollow cylindrical filter screen of the invention. 
     FIG. 6 shows the assembly of the hollow cylindrical filter screen of the vaporizer apparatus and a metal clip removal tool. 
     FIGS. 7A and 7B show the hot air gun with cradle and rod assembly of the vaporizer apparatus. 
     FIGS. 8,  9 , and  10 , show a more detailed view of the cradle and rod assembly of the vaporizer apparatus. 
     FIG. 11 shows the completed assembly of the vaporizer apparatus according to a second embodiment of the invention. 
     FIG. 12 shows a conical fritted disk and the isolation chamber of the vaporizer apparatus according to a third embodiment of the invention. 
     FIG. 13 shows a bottom view of the integral baffle in the tubing of the vaporizer apparatus according to a third embodiment of the invention. 
     FIG. 14 shows a cap in the isolation chamber of the vaporizer apparatus according to a fourth embodiment of the invention. 
     FIG. 15 shows a top view of the cap in the isolation chamber of the vaporizer apparatus according to a fourth embodiment of the invention. 
     FIG. 16 shows the specimen particles lofted in the isolation chamber of the vaporizer apparatus according to a fourth embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A completed assembly of the first embodiment of the vaporizer apparatus  1  of the present invention is shown in FIG. 2, with an exploded view shown in FIG.  1 . The vaporizer apparatus  1  is mounted on a source of hot air  2  (e.g., Bosch Model 1943 or Model PHG 630-2 LCE hot air gun), and includes an optional internal diverter  3 , which acts as a baffle-cum-brace within a glass tubing  4  which connects the source of hot air  2  to an isolation chamber  5  containing a permeable support structure  6  (e.g., fritted glass disk), and to a side-arm  7 . The optional internal diverter  3 , which increases efficiency if used, is fitted on the source of hot air  2  in order to secure the vaporizer apparatus  1  to the hot air source  2 . 
     When the user inhales, the partial vacuum created allows hot air to stream past the curved section of the upper portion of the diverter  3  through the permeable support structure  6 . Between inhalations, the diverter  3  acts as a baffle, encouraging hot air to stream out through the side-arm  7  rather than flowing upward through the permeable support structure  6 . 
     The isolation chamber  5  holds the specimen particles  8  (see FIGS. 3A and 3B) on the surface  9  of the permeable support structure  6 . The permeable support structure  6  is fixed to the walls of the glass tubing  4 . A disk filter screen  10  is disposed above, or downstream of the isolation chamber  5 , and a tubing  11  (see FIG. 2) leads from the disk filter screen  10  to a mouthpiece  12  or a mask (not shown) through which the user inhales. The tubing  11  may be corrugated which allows flexing of the tube without kinking (not shown). 
     The side arm  7  (see FIGS. 1 and 2) provides means to duct the heated air stream away from the permeable support structure  6  when the vaporizer apparatus  1  is not in use (e.g., when the user is resting between inhalations). The side arm  7  can be equipped with a valve  24  to manually re-route the entire heated airstream through the permeable support structure  6  for ancillary purposes such as device cleaning, or as a room vaporizer upon removal of the tubing  11 . As an example, the valve  24  could be provided with either a silicone stopper or, alternatively, could be manually clamped by a hemostat, pinchcock or other similar compression device (not shown). The wall thickness of this short piece of silicone tubing also provides the user insulation from the hot glass side arm  7  underneath it. 
     FIG. 4 shows the disk filter screen retention assembly. In order to assemble the disk filter screen retention assembly, the disk filter screen  10 , which is made of a finely meshed material (e.g., stainless steel), is first seated in an outer filter retention ring  13 . Then, the arms  20  of a metal clip tool  21  are inserted into holes  19  which are located in the inner peripheral surface of inner filter retention ring  14 , and disposed directly across from one another. The inner filter retention ring  14  is then threaded into the outer filter retention ring  13  by turning the tool  21  to tighten the inner filter retention ring  14  within the outer filter retention ring  13  and keep the disk filter screen  10  stable between the two structures  13 ,  14 . 
     Next, the outer filter retention ring  13  is inserted into an interface ring  15  made of a heat-resistant synthetic material (e.g., fluorocarbon). The interface ring  15  is provided in the lower portion of a glass headpiece  16 , which fits onto the upper portion of the glass tubing  4 . The interface ring  15  is laterally compressed into an ovoid shape and is inserted through the bottom of the glass headpiece  16 . Interface ring  15  includes an upper lip  18   d,  a lower lip  18   c,  a groove  18   a,  and gap  18   b  within the lower lip  18   c  of the groove  18   a,  all within its inner periphery, which are operative to provide a locking fit to the outer filter retention ring  13 . 
     Namely, pins  17   a,    17   b,  which are disposed on the outer peripheral surface of the outer filter retention ring  13 , are aligned with gap  18   b  of groove  18   a  of the interface ring  15 , and are inserted through the gap  18   b  into the groove  18   a.  The subassembly of the outer filter retention ring  13 , inner filter retention ring  14  and disk filter screen  10 , is then turned using the tool  21 , to provide a locking fit of the subassembly within the interface ring  15  (bayonet-type coupling). 
     To remove the disk filter screen retention assembly, the steps above are conducted in reverse order. 
     A hollow cylindrical filter screen  22 , shown in FIG. 5, can be used as an alternative to the disk filter screen  10 , in order to increase the surface area of the filtering means and provide additional height for specimen particles  8  to ascend from their origin on the surface  9  of the permeable support structure  6 . The cylindrical filter screen  22  is made of a meshed material (e.g., stainless steel), and is assembled within the inner filter retention ring  14  and outer filter retention ring  13  as shown in FIG. 6 (like elements being denoted by like reference numerals), in the same manner as the disk filter screen  10 , discussed above. The closed top portion  23  of the hollow cylindrical filter screen  22  can have any shape, including a domed, conical or flat surface. 
     The vaporizer apparatus  1  (see FIGS. 7A-10) is supported by a support cradle  25 , which can be semi-permanently attached by screws or the like, mounted in threaded holes  30  and fixed to the handle  26  of a hot air gun  2 . The support cradle  25  accommodates an easily mountable/demountable rod  27  via a rod receiving channel  28  disposed in the lower portion of the support cradle  25 . A receiving groove  29  fixes rod  27  via a spring-ball screw or the like, mounted in threaded hole  31 . Accordingly, by using the support cradle  25  and rod  27  apparatus, the entire vaporizer apparatus  1  can be laterally stabilized. Removal of the rod  27  allows flat storage of the vaporizing apparatus  1  or alternative uses of the hot air gun  2  itself in a variety of unrelated hand-held applications. 
     The operation of the present invention, with respect to the first embodiment shown in FIGS. 1 and 2, begins when the glass headpiece  16  of the isolation chamber  5  is removed and a small charge of specimen particles  8  (crude natural product or inert particulate matrix impregnated with the desired compounds) is placed in the isolation chamber  5 , and the glass headpiece  16  replaced to close the isolation chamber  5 . 
     The source of hot air (e.g., hot air gun)  2  is then turned on to bring the air-stream to the proper predetermined temperature. The source of hot air  2  provides a heated gas flow, which the internal diverter  3 , acting as a baffle, routes through the side-arm  7 . Inhalation provides the drop in pressure necessary to re-route a portion of the heated gas stream past the internal diverter  3  and through the permeable support structure  6 . The proper predetermined working temperature of the air stream through the vaporizer apparatus  1  will vary according to the nature of the materials being volatilized, from approximately 50 to 250 degrees Celsius, but it is generally in the 100 to 200 degree Celsius range. 
     Inhalation draws a portion of the diverted hot airstream upwards through the permeable support structure (e.g., fritted glass disk)  6 , to enter the isolation chamber  5  under the specimen charge. 
     The aggregate charge is suspended as a cloud of particles  8 , completely exposing each component particle to the extractive stream of hot air (see FIG.  3 B). Accordingly, volatile components of the specimen are vaporized from the suspended specimen particles  8  by the hot air and this vapor is drawn into the pulmonary tract by inhaling, via the tubing  11  through the mouthpiece  12  or a mask (not shown). 
     Cessation of inhalation stops the upward flow of heated air through the chamber and allows gravity to collapse the cloud of suspended particles  8  back into its original state as a layer on the surface  9  of the permeable support structure  6  (see FIGS. 3A and 3B) 
     Backflow of outside unheated air through the side arm  7  during inhalation is avoided due to an overpressure maintained by the source of hot air  2  that is in excess of the pressure removed by the inhalation. 
     Inhalation of large particles  8  is prevented by the filter screen  10  disposed above the isolation chamber  5 . 
     When not in active use, the system functions to allow the air and, therefore, the entire vaporizer apparatus  1 , to maintain its optimal temperature, while avoiding a constant flow of heated gas through the specimen particles  8  whose active ingredients are to be extracted. This bypass effect is interrupted only on demand by inhalation, thereby sparing wasteful loss of active ingredients during periods of device disuse. 
     The disk filter screen  10  is self-cleaned at the end of each inhalation, of most specimen particles  8  by this same gravitational action. However, a sharp momentary exhalation into the tubing  11  also helps to force most residual specimen particles  8  away from the disk filter screen  10 . 
     The exhausted charge of specimen particles  8  is emptied from the vaporizer apparatus  1  by turning off the heat source air flow, removing the glass headpiece  16  from the top of the isolation chamber  5  and then either scooping or vacuuming out the contents, or by lifting the cooled glass tubing  4  from the source of hot air  2  and inverting the vaporizer apparatus  1  to empty the contents of the isolation chamber  4 . The specimen particles  8  may also be removed by simply lifting the glass headpiece  16  while sharply inhaling, thereby ensuring particles are adherent on the disk filter screen  10 . 
     In a second embodiment of the present invention as shown in FIG. 11, a heated inert gas (i.e., helium, argon) is used instead of heated air. The heated inert gas is used to evaporate volatile compounds from their matrix in order to prevent their decomposition due to exposure to atmospheric gases (e.g., oxygen). Again, like elements are denoted by like reference numerals. 
     The second embodiment of the vaporizer apparatus  1  (see FIG. 11) includes a high pressure tank  32  of inert gas equipped with a demand-type SCUBA regulator  33  equipped with a refill port  34 . A hose or tubing  35  from this regulator  33  is routed to a heat-exchange device  36 . The heat exchange device  36  includes a heating band  37  or other resistance heating device made of metal, silicone, or other material, that generates heat from electrical input. A thermostatic control  38  regulates the electrical input to the heating band  37  so that the chamber or vessel  39  contained within the heat exchange device  36  is limited to a desired predetermined range of temperatures. A thermostatic sensor  40  acts as a heat detection device that determines the temperature of the heated vessel  39 , and transmits the data to the thermostatic control  38 . A thermometer  41  measures the internal temperature status of the contents of the vessel  39 , and provides visual feedback to the user. 
     The heating band  37  heats the heat exchange spheres  42 , which are made of metal, glass, ceramic, or other suitable material. The heat exchange spheres  42  provide a large surface area upon which the percolating gases can be instantaneously heated. 
     The insulation  43  surrounding the vessel  39  of the heat exchange device  36  is made of glass, ceramic, or other suitable material, and traps the heat generated by the heating band  37  to ensure temperature stability for the heat exchange spheres  42 . The insulation  43  is normally contained within an outer protective casing  44  made of metal or other material. 
     A vertical pipe  45  disposed within the vessel  39  amongst the heat exchange spheres  42 , and which has an upper portion which projects upwardly out of the heat exchange device  36 , has a glass tubing  46  fitted over its upper portion. The glass tubing  46  contains an isolation chamber  5 , the lower portion of which seats a permeable support structure  6 . A glass headpiece  16  is fitted into the isolation chamber  5 . 
     As with the first embodiment, the isolation chamber  5  holds the specimen particles  8  (see FIGS. 3A and 3B) on the surface  9  of the permeable support structure  6 . The permeable support structure  6  is fixed to the walls of the glass tubing  46 . A filter screen  10  is disposed above, or downstream of the isolation chamber  5 , and a tubing  11  leads from the filter screen  10  to a mouthpiece  12  or a mask (not shown) through which the user inhales. As with the first embodiment, the tubing  11  may be corrugated (not shown) which allows flexing of the tube without kinking. A hollow cylindrical filter screen  22  can be used instead of the disk filter screen  10 . 
     In initial operation of the invention with respect to the second embodiment, the demand-type pressure regulator  33  of the tank  32  of inert gas, is first opened via its purge valve  47  so that the gas flows through the tubing  35  into the heat exchange vessel  39  and then out via tube opening  7 , purging residual air in the vaporizer apparatus. Tube  7  is then blocked by using a stopper or suitably clamping the attached silicone tubing  24  (not shown) (see FIG.  2 ). 
     Once in the heat exchange device  36 , the inert gas is heated by heat exchange spheres  42  in the heat exchange vessel  39  to the proper predetermined temperature. After charging the isolation chamber  5  with a specimen to be extracted (e.g., crude natural product or inert particulate matrix impregnated with the desired compounds), inhalation draws additional inert gas from the pressure tank  32  via the heat exchange device  36 . The heated inert gas proceeds upwards through the vertical pipe  45  and through the permeable support structure  6 , entering the isolation chamber  5  which contains the charge of specimen particles  8 . The remaining structure and steps in the procedure are the same as that described above with the first embodiment. 
     In the second embodiment of the invention, side-arm  7  venting of gas is not absolutely necessary. However, if the isolation chamber  5  is to be charged with specimen particles  8  before the purging of residual air from the heat exchange vessel  39 , a manually valved side-arm  7  venting feature is useful to prevent heated mixed gases from sweeping over the specimen particles  8  until the system is free of air. 
     Removal of the exhausted charge of specimen particles  8  is initiated by removing the glass headpiece  16  from the top of the isolation chamber  5 . The cooled glass tubing  46  that houses the permeable support structure  6  can then be removed from the glass tubing  45  and inverted to empty its contents resting on the surface  9 . All the other removal techniques discussed above with respect to the first embodiment, can also be used. 
     In a third embodiment of the present invention, the baffle  103  (see FIGS. 12 and 13) of the vaporizer apparatus  101  is formed integrally with the vertical tubing  104 , the latter of which can be made from glass, plastic material (e.g., polysulfone, Torlon®, PEEK, Liquid Crystal, etc.) or other suitable material (see FIG.  12 ). Radial air-cooling fins, to prevent finger burns, may optionally be provided on the outside of side-arm  102  and tubing  104  of the vaporizer apparatus  101 . The side-arm  102  has a bevel (e.g., 70°) for more diffuse air dispersal. 
     A Venturi restriction  105  is provided in the upper portion of tubing  104 , which has an optional cylindrical flotation chamber  106  provided above the Venturi restriction (see FIG.  12 ). A permeable support structure made from fritted glass or other appropriate porous material, which is a conical disk  107 , is provided immediately below the Venturi restriction  105  and above baffle  103 . The tubing  104  has a waisted portion  108  below the Venturi restriction  105 , which parallels the shape of the conical fritted disk  107 . A headpiece  116  is provided above the tubing  104  at the point where tubing  104  regains its full diameter above the Venturi restriction  105 , and includes a cylindrical filter screen  110 , made of a meshed material (e.g., stainless steel), similar to that of the filter screen  22  or  10  of the first embodiment of the invention. 
     In operation of the third embodiment of the present invention, the specimen particles  118  (crude natural product or inert particulate matrix impregnated with the desired compounds) are placed in the top of the tubing  104  and settle on the surface of the conical fritted disk  106 . As with the first embodiment, the source of hot air (e.g., hot air gun) (not shown in FIG. 12) is then turned on to bring the air-stream to the proper predetermined temperature, to provide a heated gas flow. Inhalation provides the drop in pressure needed to re-route a portion of the heated gas stream past the baffle  103  and through the conical permeable disk  107  to loft the specimen particles  118 . However, due to the shape of the conical fritted disk  107 , more surface area is provided which makes it easier to draw air through for the user. Further, the narrow gap between the conical fritted disk  107  and the parallel wall  108  of the waisted section of tubing  104 , maintains a high speed air flow induced by the Venturi restriction  105 , to make it easier for the user to loft the material while inhaling more normally. 
     As described in the first embodiment, upon inhalation, the aggregate charge is suspended as a cloud of particles, completely exposing each component particle to the extractive stream of hot air, and volatile components are vaporized. The vapor is drawn through the headpiece and via tubing, to the user. The filter screen  110  prevents the inhalation of large particles. 
     The fourth embodiment of the present invention is similar to the third embodiment of the invention, with the exception that the hourglass-like Venturi restriction  105  in the cylindrical tubing  104  in the third embodiment, is replaced with that of spherical tubing  201  containing a cap  202  atop cylindrical neck or support tube  203  (see FIG.  14 ). The spherical tubing  201  is made from glass, plastic or other suitable material as described above in the third embodiment. The cap  202  is a conical disk made of glass, plastic or other suitable material as described in the third embodiment, which is welded or molded onto tube  203  in the base of the tubing  201 . The cap  202  has support struts  204  (see FIG. 15) at the base which is used for attachment (welding or molding) onto the cylindrical tube  203 . Other than the support struts  204 , the cap  202  is open at its base, and forms an internal Venturi that accelerates airflow in a manner similar to that of the Venturi restriction  105  of tube  104  of the third embodiment. This arrangement also serves to momentarily divert the flow of air in a reversed direction. In the fourth embodiment, the air diverter baffle  206  also deflects particles, which may fall down cylindrical tube  203 , away from the opening of the hot air source (not shown). 
     In operation of the fourth embodiment, the specimen particles  207  are placed in the top of the tubing  201 , and settle around the cylindrical support  203 . Due to the small orifice provided by the gap between the vertical cylindrical support  203 , and the cap  202 , when the user inhales, there is a localized increase in airspeed through this gap which then flows between the cylindrical support  203  and cap  202  (see FIG. 16) The specimen particles  207  are then lofted by the high speed airflow more easily, and the user can inhale more normally. 
     It is contemplated that numerous modifications may be made to the apparatus and procedure of the invention without departing from the spirit and scope of the invention as defined in the following claims.