The present disclosure relates to a cartridge within a portable and handheld breath collection and analysis device, for analysis of a chemical present in a human body.
Existing portable systems exist for measuring a concentration of ethanol present in a person's body, via their breath. However, such portable systems do not presently exist for measuring other substances accurately in a human body. The present disclosure is directed to a replaceable cartridge that can be utilized in a portable system for collecting and determining a measurement of such other substances in a human body via a breath collection and analysis device.
This summary is provided to introduce a selection of concepts in a simplified form that are further described in the Detailed Description below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
In one embodiment, the present disclosure is directed to a single-use microfluidic cartridge for detection of a target chemical present in human breath via a breath collection and analysis device, the cartridge comprising: a breath collection module configured to collect a desired volume of air from the human subject, and extract a target chemical from the collected air; an evidence sample storage chamber configured to preserve a sample of the extracted target chemical from the collected air for later analysis; and a multi-channel reaction chamber configured to process a competitive immunoassay to generate a signal representing a concentration amount of the target chemical present in the collected air from the human subject.
In another embodiment, the present disclosure is directed to a method for detection of a target chemical present in human breath via a single-use microfluidic cartridge, the method comprising: receiving a desired volume of air from a human subject in a breath collection module of the single-use microfluidic cartridge; processing the received air in the breath collection module to solubilize and extract the target chemical present in the received air from a surface upon which particles in the breath are collected and concentrated; combining the extracted target chemical with an antibody; saving a portion of the extracted target chemical for evidence preservation; reacting a remainder portion of the extracted target chemical in a multi-channel reaction chamber with one or more chemical reagents; washing the reacted chemicals in the multi-channel reaction chamber with a wash solution; introducing a substrate to the washed chemicals in the multi-channel reaction chamber, the substrate configured to emit a low level light from the single-use microfluidic cartridge, communicating with a detector device to determine a concentration level of the target chemical from the emitted low level light.
Other features, examples, and embodiments are described below.
The accompanying drawings, where like reference numerals refer to identical or functionally similar elements throughout the separate views, together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate embodiments of concepts that include the claimed disclosure, and explain various principles and advantages of those embodiments.
The methods and systems disclosed herein have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosure. It will be apparent, however, to one skilled in the art, that the disclosure may be practiced without these specific details. In other instances, structures and devices are shown as block diagram form only in order to avoid obscuring the disclosure.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” or “according to one embodiment” (or other phrases having similar import) at various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Furthermore, depending on the context of discussion herein, a singular term may include its plural forms and a plural term may include its singular form. Similarly, a hyphenated term (e.g., “on-demand”) may be occasionally interchangeably used with its non-hyphenated version (e.g., “on demand”), a capitalized entry (e.g., “Device”) may be interchangeably used with its non-capitalized version (e.g., “device”), a plural term may be indicated with or without an apostrophe (e.g., PE's or PEs), and an italicized term (e.g., “N+1”) may be interchangeably used with its non-italicized version (e.g., “N+1”). Such occasional interchangeable uses shall not be considered inconsistent with each other.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/ or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It is further noted that various figures (including component diagrams) shown and discussed herein are for illustrative purpose only, and are not drawn to scale.
The present disclosure pertains to methods, systems, and apparatus for capturing human breath at a point of care, extracting certain chemical(s) from the captured breath, and measuring a concentration of the extracted chemicals. In one example, an amount of tetrahydrocannabinol (THC) level from a breath sample is determined by practicing embodiments of the present disclosure. While THC is discussed herein for simplicity, similar methods can be utilized to extract and measure a concentration of other chemicals in human breath as well, such as ethanol, other controlled substances, or airborne indicators of various disease states.
Embodiments of the present disclosure describe a proprietary microfluidic cartridge that is disposable, and used within a portable breath collection and analysis device. The cartridge is located within a portable handheld device and provides for mechanisms to capture and accurately measure an amount of a target chemical that is present in a person's breath.
In one example, the target chemical is THC. When THC is present in human breath, the bulk of it is contained within aerosol droplets. The present disclosure relates to mechanisms for capturing those aerosol droplets from human breath, such that a sufficient amount of THC can be captured from a human breath sample to accurately analyze. The THC is extracted from a physical surface of an impaction plate where it is collected and concentrated. The extracted THC is subjected to further analysis, such as to measure a concentration level. In addition to sample processing, the disposable cartridge also allows for processing on-board calibrators, positive controls, and negative controls. In addition, the disposable cartridge may contain a cryptographic computing chip with an RFID tag to attach personal information about the human subject's sample contained and analyzed within the cartridge.
In the exemplary figure of device 100, there is display 110 that may or may not be a touchscreen. From this display 110, an administrator utilizing device 100 to test a subject's breath can view information and results about the breath collection and sampling. As would be understood by persons of ordinary skill in the art, any information can be displayed on the display 110 for the administrator of device 100 and/or a subject whose breath is being tested.
Exemplary
Device 100 also contains a mouthpiece 115, which may be a disposable tube that is placed into a subject's mouth while the subject breathes air into device 100. In various embodiments, mouthpiece 115 may be constructed of PVC (polyvinyl chloride) or similar material. Mouthpiece 115 may be further connected to device 100. In this way, mouthpiece 115 may be a removable and disposable component of device 100.
In an exemplary embodiment, 18 liters of breath is desired to be captured within 2 minutes. For a typical human subject, this is approximately 3-10 breaths. In various embodiments, device 100 tracks an amount of volume of air collected with each breath of the subject, until the full desired volume is collected. Further, with each breath, pump 310 is activated and then turns off when the breath stops, as detected by pressure sensor 315. That is, if a human subject blows into mouthpiece 115 four times, pump 310 turns on and off with each breath (four times total), within the allotted time (2 minutes in this exemplary embodiment).
Further, device 100 can track an amount of volume of air collected via a timer. Pump 310 dictates a flow rate of air passing through breath collection module 305. Thus, a flow rate of air passing through breath collection module 305 is fixed, regardless of how fast or slow a subject blows through mouthpiece 115. Since the flow rate is dictated by pump 310, and is a known value, an amount of time needed to collect a fixed volume of air (such as 18 liters) can be determined. Device 100 may count down the time for each breath, until the requisite amount of time has elapsed and the desired volume of air is captured. This may help determine depth of sample volume from the subject's respiratory tract to minimize a potential for spoofing the system.
As would be understood by persons of ordinary skill in the art, although 18 liters is discussed herein as the desired volume of air to be captured, the present disclosure is equally applicable to other amounts of desired volume of air capture.
In various embodiments, breath collection module 305 may also filter out saliva from the subject's breath. Breath collection module contains a plurality of internal components that are discussed in greater detail in co-pending U.S. patent application Ser. No. NNN filed on DDD.
After breath capture via breath collection module 305, elution is used to extract the target chemical from the aerosol droplets in the captured breath. In analytical and organic chemistry, elution is the process of extracting one material from another by washing with a solvent.
The captured aerosol droplets are contacted with a fluid to solubilize the target chemical from the aerosol droplets into a solution. By minimizing the volume of solution used to extract the target chemical from the aerosol droplets, the concentration of the target chemical in the solution can be maximized. Further, by utilizing a circular geometry in the breath collection module 305 pieces, one can minimize the total volume of fluid present in the breath collection module 305. This enables one to maximize the concentration of the target chemical extracted.
An elution buffer serves to remove the target chemical from an impactor surface in the breath collection module 305, and is also utilized as a solvent for a reagent in an immunoassay utilized by a cartridge within device 100 to analyze the concentration of the target chemical present in the captured sample. Thus, the elution buffer is compatible to an antibody in the immunoassay utilized downstream in device 100, but also has properties that extract the target chemical from the impactor surface.
As depicted in
After breath sample capture, an elution fluid with antibody-enzyme conjugate is passed through breath collection module 305, as discussed above with reference to
The reaction chamber 710 is pre-coated with THC-BSA (Bovine Serum Albumin) conjugate. Within reaction chamber 710, a process occurs whereby, the sample incubates for a period of time to allow the antibody to competitively bind to target analyte in sample as well as the antigen coated on the surface. The reaction chamber 710 is then washed to remove any unbound species. Subsequently, a substrate is introduced, which generates a signal proportional to the number of antibody-enzyme molecules bound to the reaction surface.
Turning to
The fluid entering reaction chamber 710 has antibody mixed with the target chemical (THC in this example). This fluid enters the sample channel 810. In the calibrator channel, the fluid is just the antibody, which may or may not be mixed with a solution. In the positive control channel 815, there is a separate reservoir that contains a known amount of the target chemical. The positive control channel 815 and calibrator channel 805 are utilized to ensure that the workflow of the assay in the sample channel 810 processed correctly, and that the reagents of cartridge 500 are functioning properly.
Calibrator channel 805 allows for the correction of any small deviations in the response of the chemical reagents present in cartridge 500. It can act to compensate for small changes in environmental conditions as well (such as temperature), and/or small changes in the optical train from system to system or cartridge to cartridge. No target chemical is present in calibrator channel 805, and thus it functions as a negative control.
In exemplary embodiments, reaction chamber 710 provides a competitive immunoassay. That is, the generated signal decreases with an increase in concentration of the target chemical, as depicted in graph 820. For example, higher signal values indicate a lower concentration of THC, and vice versa.
Thus, since calibrator channel 805 has no target chemical, it should have a maximum signal value. This provides a baseline for normalization. While there may be some differences in reagent activity from cartridge to the next, calibrator channel 805 provides for the normalization of a signal within each cartridge, since the same reagent is used in all three reaction channels. Thus, the relative response of the reagent in all three channel is harmonized, and a target chemical concentration can be determined based on a relative response between the three reaction channels, rather than an absolute magnitude of a signal generated in any one particular reaction chamber. Thus, calibrator channel 805 creates a relative signal to a maximum signal possible.
Positive control chamber 815 contains the target chemical (THC), completely isolated from the sample. It is placed in a separate reservoir in the reaction chamber 710. Since the concentration of the target chemical in the positive control sample is known, the expected response of the reagent and the expected signal generated by positive control chamber 815 is known. By checking the response generated from positive control chamber 815 against the expected response, it can be objectively determined if the sample processed correctly through the reaction chamber 710. In this way, device 100 can provide a mechanism to verify its own accuracy of reaction chamber 710.
The negative control from calibrator channel 805 determines what the generated signal from reaction chamber 710 would be if there was no THC in the sample. The positive control chamber 815 determines what the generated signal from the reaction chamber 710 would be if there was pure THC in the sample. A cutoff point is determined from graph 820 for comparison with the generated signal from sample chamber 810.
In processing a sample, reaction area 830 of reaction chamber 710 undergoes a multi-step process. Fluid is introduced into reaction area 830 via all three reaction channels 805, 810, and 815. Subsequently, the antibody is introduced into reaction area 830. It competes with any THC present, whether that THC was introduced from the sample chamber 810 or the positive control chamber 815. It then binds to an antigen that is on reaction surface 825 and forms a THC-BSA conjugate.
By utilizing this competing immunoassay process, if there are no free THC molecules, all of the antibodies bind to reaction surface 825 and a maximum signal is generated. If there is a high amount of THC, all of the antibodies are tied up with the free THC and there is nothing to bind to reaction surface 825, yielding a low signal.
After the antibody introduction step, reaction area 830 is washed by sending a wash buffer solution through reaction area 830. The wash buffer solution clears away any unbound species from reaction area 830. In exemplary embodiments, the wash buffer solution may be introduced anywhere from 1-10 times.
After washing, a substrate is introduced into reaction area 830. In exemplary embodiments, the substrate may be a small molecule such as luminol. Luminol in the presence of an oxidizing agent and an enzyme such as Horseradish Peroxidase (HRP) emits light.
During the reaction process, a catalyst for the reaction may be used within reaction area 830. In one example, the catalyst is horseradish peroxidate enzyme (HRP). This enzyme catalyzes luminol and produces light. HRP enzyme has a high turnover rate and serves as an effective catalyst for reactions in reaction area 830.
After introduction of the substrate, the amount of light emitted from reaction chamber 710 is in the order of 0.1-10 pW.
Returning to
In exemplary embodiments, the detector 715 may be placed in physical proximity to reaction chamber 715, when cartridge 500 is removed from device 100. In other embodiments, cartridge 500 may have optical fibers with liquid light guides to assist with detection of light being emitted from reaction chamber 715. This allows for positional flexibility as to where the detector is placed relative to cartridge 500.
While not explicitly depicted in the figures, cartridge 500 may also have a cryptographic computing chip to store information on the single-use cartridge itself. The cryptographic computing chip ensures that cartridge 500 can only be utilized with an approved device 100, base station, and/or detector 715. Further, cryptographic computing chip may contain a read/write RFID tag to store information about the human subject whose sample is contained within cartridge 500. For example, information regarding the human subject such as any one or more of a unique identifier number, name, age, address, phone number, etc. may be stored on the RFID tag of the cryptographic computing chip on cartridge 500. In addition, objective information such as any one or more of date, time, location, identifier for person administering the test via device 100, etc. may also be stored in the cryptographic computing chip. Further, device information and measurement(s) may also be stored on the cryptographic computing chip such as any one or more of breath collection workflow (e.g., breath volume collected, flow rate, number/duration of breaths collected by device 100), assay workflow (e.g., reaction light levels of optical measurements from the reactions), system serial numbers, calibration dates, quantities of the one or more target chemicals, such as a THC level and/or BAC (Blood Alcohol Content) level.
As would be understood by persons of ordinary skill in the art, mechanisms other than an RFID tag may also be used to store information on the cryptographic computing chip. Further, any type of information other than that enumerated here may be stored on the chip.
When testing alcohol on a human subject's breath, there is a known behavior of how the concentration of alcohol in the breath changes over time. Thus, field testing can be used to generate one result, and later verified by testing the subject's breath again with more sophisticated equipment at a law enforcement facility. By measuring the concentration of alcohol in the subject's breath as detected by the more sophisticated equipment, the concentration of alcohol in the subject's breath at a time of a field test can be extrapolated using a known profile for alcohol kinetic behavior over time.
However, other chemicals, such as THC, do not have similar degradation profiles over time. In particular, THC levels in human breath degrade very quickly in time. Thus, a portion of sample collected from the subject via device 100 is physically preserved on single-use cartridge 500. In this way, when cartridge 500 is removed from device 100, the sample from evidence sample storage 705 can be independently tested using reference means (such as mass spectrometry) at a later time to verify a result generated on device 100 from a test conducted in a field location.
As shown in
Evidence sample storage 705 contains a filter with an absorbent material that absorbs the received sample. In a laboratory environment, the absorbent material containing the sample can be removed from cartridge 500, the contents extracted from the absorbent material into a solvent such as methanol, and then fluid can be processed using known methods such as mass spectrometry. In this way, the absorbent material retains an amount of the original sample before it is processed by reaction chamber 710 of cartridge 500, and preserves that sample for later testing.
THC is prone to oxidation and degradation of its molecules over time. A key driver of degradation is light exposure. To combat this, evidence sample storage 705 shields the sample within a compartment of cartridge 500 such that the sample is opaque on all sides.
In step 905 of the reaction process, a sample is received by the reaction chamber for analysis of a target chemical. The sample is received from a breath collection module. In step 910, the received sample is reacted with one or more chemical reagents, as discussed herein. The reacted chemicals are then washed with a wash solution in step 915. A substrate is introduced to the washed and reacted chemicals in step 920. Optionally, a result of the reaction process is generated and saved on a cryptographic computing chip of the cartridge, in step 925.
A remainder portion of the extracted target chemical is reacted in a reaction chamber with one or more chemical reagents in step 1025. The reacted chemicals are then washed in the reaction chamber with a wash solution in step 1030. A substrate is introduced to the washed chemicals in the reaction chamber in step 1035. Optionally, a result of the process is generated and saved on a cryptographic computing chip of the cartridge, in step 1040. Further, as discussed herein, a low level light may be generated by the reaction chamber of the cartridge, for detection by a detector device that is separate and apart from the cartridge.
The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the present technology in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the present disclosure. Exemplary embodiments were chosen and described in order to best explain the principles of the present disclosure and its practical application, and to enable others of ordinary skill in the art to understand the present disclosure for various embodiments with various modifications as are suited to the particular use contemplated.
Aspects of the present disclosure are described above with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) according to embodiments of the present disclosure.
The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and apparatus, according to various embodiments of the present disclosure.
Thus, systems and methods for a single-use microfluidic cartridge for detecting a presence of a target chemical in human breath are described herein. While various embodiments have been described, it should be understood that they have been presented by way of example only, and not limitation. The descriptions are not intended to limit the scope of the disclosure to the particular forms set forth herein. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above-described exemplary embodiments. It should be understood that the above description is illustrative and not restrictive. To the contrary, the present descriptions are intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the disclosure as defined by the appended claims and otherwise appreciated by one of ordinary skill in the art. The scope of the present disclosure should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.
The present application claims the priority benefit of U.S. Provisional Patent Application No. 62/799,675 filed on Jan. 31, 2019, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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62799675 | Jan 2019 | US |