Abstract:
A system for collecting cannabis and the psychoactive component tetrahydrocannabinol from a sample of exhaled breath is disclosed. Single or multiple exhaled breaths are conditioned by removing contaminants, and regulating flow rate and/or pressure to collect a sample of tetrahydrocannabinol for timely local or remote analysis. The cannabis detection system comprises a containment trap for removing interfering materials from the breath of the subject and a collection component for sampling components of breath introduced into the system through the containment trap for analysis to determine a presence of THC in the breath.

Description:
RELATED APPLICATION 
       [0001]    This application claims benefit of U.S. Provisional Application Ser. No. 61/981,650 filed Apr. 18, 2014, currently pending, which is incorporated by reference herein in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention is directed to a portable or fixed device for the detection of cannabis, specifically tetrahydrocannabinol (THC), from the exhaled breath of a subject. 
       RELATED ART 
       [0003]    Detection of cannabis is commonly performed by urine, blood, or oral specimen sampling. These methods are frequently invasive and require complicated devices for analysis. Alcohol is a simple molecule which can be examined directly by an exhaled breath exam, most commonly by exhaling into an ion spectroscopy chamber. This method has proven reliable and is accepted by legal systems as a noninvasive method to quantify alcohol levels. 
         [0004]    Detection of drugs by an exhaled breath method has been proposed; however, the technique proposed is generic for multiple different illicit drugs. The proposed devices have been described for detection of drugs within the exhaled breath using a fluid collection or filtration system. Most of these devices describe a tube into which the subject exhales, which indiscriminately collects molecules of interest in either a liquid or filtration device. This liquid or fluid trapped within a filter is then sent to a laboratory for analysis, which may take several days. These devices lack methods for measurement of exhaled breath volumetric flowrate and for regulating pressure. With exhaled breath, each individual has the capability to exhale to different pressures, and if, for example, a filter based system is utilized to measure cannabis, an unregulated high pressure provided by a subject can tear apart the filter. Also, as each subject has a different amount of exhaled breath, it is important to be able to quantify the flowrate, or total volumetric flow, that has been breathed into the device. 
         [0005]    The prior art devices which are designed to measure exhaled breath describe a mouthpiece which comprises a tube into which the subject exhales. This tube, without a rebreather valve, requires that the subject inhale through their nose, or remove the device from their lips to inhale. 
         [0006]    Prior devices designed for exhaled breath do not describe a method of removal of fluid or solid contaminants, such as by way of a spit trap to collect or remove oral fluids, which prevents oral fluid contaminants from reaching a gas material detection chamber. 
       SUMMARY 
       [0007]    The present invention comprises a system which is designed to measure a subject&#39;s breath, remove fluid and/or contaminants, and collect a tetrahydrocannabinol (THC) sample in an entrapment container for detection of cannabis use. 
         [0008]    The invention includes a breathing tube with a rebreather valve, and a fluid and solid contaminant removal device. A pressure or volumetric flow measurement and regulating device is placed along the path of the exhaled breath pathway before or after a fixed or removable THC sample collecting chamber. 
         [0009]    The THC collecting chamber may contain a port for cannabis sample detection, preparation or collection. 
         [0010]    The described device is designed to permit detection of cannabis use relatively quickly, thus allowing it to be used, for example, by police officers in the field, etc. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a schematic illustration showing an embodiment of the system to collect a cannabis sample from a breathing subject. 
           [0012]      FIG. 2  is a flowchart illustrating a method for collecting a sample of cannabis. 
       
    
    
       [0013]    Reference numerals in the drawings: 
         [0014]      20  device for cannabis detection ( 10 ) 
         [0015]      22  Method of materials movement for detection of THC and cannabis ( 20 ) 
         [0016]      24  Subject 
         [0017]      30  mouthpiece ( 11 ) 
         [0018]      32  intake nonrebreather valve ( 12 ) 
         [0019]      34  contaminant trap ( 13 ) 
         [0020]      36  THC collection and housing component ( 16 ) 
         [0021]      38  pressure measurement and/or regulator ( 14 ) 
         [0022]      40  liquid injection and or sampling port ( 15 ) 
         [0023]      42  volumetric flow measuring device ( 17 ) 
         [0024]      50  breathing device ( 21 ) 
         [0025]      52  contaminant removal ( 22 ) 
         [0026]      54  exhaled breath flow conditioner ( 23 ) 
         [0027]      60  THC collection device ( 24 ) 
         [0028]      62  volume, flow and pressure measurement device ( 25 ) 
         [0029]      64  sample preparation or collection device ( 26 ) 
       DETAILED DESCRIPTION 
       [0030]    While this invention is susceptible of embodiments in many different forms, there are shown in the drawings and will herein be described in detail, preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspects of the invention to the embodiments illustrated. 
         [0031]    Cannabis detection by breath requires many components to separate raw cannabis and its metabolized forms from the psychoactive component tetrahydrocannabinol (THC). 
         [0032]    The embodiment of the invention described in  FIG. 1  consists of a portable cannabis detection system  20 , where the psychoactive component of cannabis, tetrahydrocannabinol, is detected from the breath of a subject  24 .  FIG. 2  is the block diagram illustrating a method  22  for detecting and/or measuring THC in the breath of the subject  24 . The method  22  depicted in the block diagram of  FIG. 2  may be implemented by the portable cannabis detection system  20  of  FIG. 1  or by any device or system capable of performing at least some combination of the steps described in  FIG. 1 . 
         [0033]    The example portable cannabis detection system  20  comprises a mouthpiece  30 , an intake non-rebreather valve  32 , a contaminant trap  34 , a THC collection and housing component  36 , a pressure measurement and/or regulator component  38 , a liquid injection/sampling port  40 , and a volumetric flow measuring component  42 . The cannabis detection system  20  is comprised of either disposable, or aseptic cleanable reusable components or as a single whole device. 
         [0034]    The flowchart of  FIG. 2  outlines the method for detection  22  of THC by outlining the direction materials pass through a device for cannabis detection such as the portable cannabis detection system  20  as generally described above. The detection method  22  depicted in  FIG. 2  comprises the steps of providing a breathing device at block  50 , removing contaminant material at block  52 , conditioning the exhaled breath flow at block  54 , collecting the THC at the block  60 , measuring at least one and typically all of volume, flow, and pressure at block  62 , and collecting or preparing a sample at block  64 . The components and materials used by the steps in the flowchart of  FIG. 2  are designed to provide to a THC collection device such as the THC collection component  36  of the example portable cannabis detection system  20  described above, at block  60 , an appropriate sample of exhaled breath from which THC content may be detected and/or measured. 
         [0035]    Referring now more specifically to  FIG. 1  of the drawing, it can be seen that the example cannabis detection system  20  is coupled to the subject  24  via the mouthpiece  30 . This mouthpiece  30  is directly connected to a non-rebreather valve  32  which allows the subject  24  to both inhale and exhale through the mouthpiece  30  without the subject  24  removing his lips from the mouthpiece  30  to inhale and without requiring the subject  24  to breathe through his nose to inhale. The air exchange step performed by the example mouthpiece  30  and non-rebreather valve  32  is described at the block  50  in the flowchart of  FIG. 2 . Arrows A and B in  FIGS. 1 and 2  show air entering and exiting the system, respectively, thereby allowing the subject  24  to inhale and exhale through the mouthpiece  30 , with the exhaled breath being redirected into the contaminant trap  34 . 
         [0036]    The example contaminant trap  34  consists of a device that allows interfering materials, such as vapor, fluid, and/or solids, to be removed from the exhaled breath from the subject  24  and allows exhaled THC-containing breath to pass through unrestricted. The example trap  34  thus removes contaminants from the exhaled breath as performed by the removing contaminant material step shown at block  52  in  FIG. 2 . The containment trap  34  can be removed to access liquid contaminants which may include metabolized or unmetabolized components of cannabis or to remove components of exhaled breath that would interfere with the detection of THC in the collection device  36 . The example containment trap  34  may be a contaminant removal component comprising a flap valve covering holes that allows oral fluid to pass out of the device or to be collected in another chamber. 
         [0037]    The degree of effort of exhalation by subjects such as the subject  24  is variable, which results in the exhaled breath occurring at various pressures. To provide the THC collection component  36  with a suitable pressure or flow rate, a pressure regulator and or measuring device  38  is placed in line with the exhaled breath. The example THC collection component  36  prepares the exhaled breath to be appropriately collected as shown at the step corresponding to block  54  in the flowchart of  FIG. 2 . The pressure measuring and/or regulating component  38  can be placed anywhere beyond the mouthpiece to control pressure input into or from the device. A wide variety of pressure regulating or measuring devices can be utilized, and an example may consist of a balloon which expands with high pressure exhaled breath, and collapses to deliver exhaled breath to the detection component of the device at a controlled pressure. 
         [0038]    The THC collection component  36  may consist of a vacuum, gas and/or liquid filled chamber with a filter or sensor that is capable of collecting or detecting THC. The example THC collection device  36  may be directly accessed by a sampling port  40  for either sampling or filling with gas or liquid materials as shown by block  64  in  FIG. 2 . The THC collection component  36  in whole or in part may be removed from the cannabis detection system  20 . An embodiment of the THC collection component  36  would be a filter or cartridge that can be removed for sampling via high performance liquid chromatography and/or mass spectrometry. Other potential embodiments include an ion or magnetic resonance chamber, color detection, light spectroscopy, and/or nanoparticle filter. In another embodiment, the THC collection component  36  may consist of a chemical that forms an appearance change material which reacts with THC. This would result in a reaction or change in chemical or physical properties of such chemical so that the alteration would be detectable. For example, a chemical coming into contact with THC could result in a changing of color of the chemical. This color change can then be visualized by detection/looking through the access port  40 . The port  40  can be used to prepare the filtered sample for any of these methods. 
         [0039]    In line with the exhaled breath flowchart as outlined in  FIG. 1 , a volumetric flow measuring device  42  is placed to quantify the amount of exhaled breath provided by the subject  24 . The location of this measurement device  62  as shown in the flowchart of  FIG. 2  can be placed anywhere along the pathway of the exhaled breath, or may be coupled with the step of conditioning the exhaled breath flow shown by block  54  and/or the pressure measurement or regulator device  38 . The purpose for recording the volume of breath passing through the device is to enable a way to measure how much exhaled breath has been input into the system  20 . Each individual, based on their lung capacity and/or effort, can exhale different volumes. A volumetric flow rate measurement device incorporated into the system for cannabis detection provides a means to quantify this amount per breath, and/or as a total sum during use of the device. This ensures that sufficient exhaled breath is delivered to the THC collection component  36  to allow detection of cannabis or THC use. A variety of different flow meters can be used as the volumetric flow measuring device  42 . One example is a rotating blade which spins with exhaled breath and records the volume of flow that is exhaled. A second example would be a diaphragm that detects air pressure and converts air pressure to flow volume. 
         [0040]    In one embodiment, the device can provide results of THC detection in seconds or minutes based on how the cannabis detection device  20  and/or THC collection analysis method  22  are implemented. 
         [0041]    In another embodiment, the device can be implemented or equipped to correlate a measured or detected THC sample to a specific subject. For example, a DNA fingerprint method can be added to the contaminant trap  34 , or elsewhere inline, to detect and/or monitor who is utilizing the device (e.g., through use of the subject&#39;s saliva or other DNA sample). In this case, the THC sample measurement and the DNA sample are stored together and/or cross-reference in a way that ensures that a particular THC sample measurement and DNA sample are positively associated with each other for evidentiary purposes if necessary. 
         [0042]    Several embodiments of the invention have been described. It should be understood that the concepts described in connection with one embodiment of the invention may be combined with the concepts described in connection with another embodiment (or other embodiments) of the invention. 
         [0043]    While an effort has been made to describe some alternatives to the preferred embodiment, other alternatives will readily come to mind to those skilled in the art. Therefore, it should be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not intended to be limited to the details given herein.