Patent Publication Number: US-2023143118-A1

Title: Point of need diagnostic with thermal control

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. provisional patent application No. 63/039,208, titled Point of Need Diagnostic with Thermal Control and filed Jun. 15, 2020, the entirety of which is incorporated herein by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     Not applicable. 
     BACKGROUND 
     Centralized clinical testing of diagnostics is expensive and time consuming, causing delays in health care delivery. Often point of need testing and diagnostic assays lack the ability to provide quantitative and diagnostic information. In some cases, it may be useful in both clinical and non-clinical settings to provide a point of need testing system to address these and other issues. 
     BRIEF SUMMARY 
     The present disclosure provides, by way of various example embodiments, systems and methods for a point of need testing system. The point of need testing system includes a first collector and a sample amplifier. The first collector is configured to collect a first biofluid sample. The sample amplifier is configured for performing an amplification reaction to generate amplification products of a target nucleic acid to produce a second biofluid sample. The sample amplifier may comprise a reagent reservoir containing one or more reagents for performing the amplification reaction to generate amplification products of the target nucleic acid and, optionally, a control nucleic acid. The sample amplifier may further includes an inlet dimensioned to receive the first biofluid sample from the first collector, a filter, a heater, a second collector, or any combination thereof. In some embodiments, the sample amplifier further includes an indicator configured to produce an indication that the second biofluid sample has been produced from the first biofluid sample. In some embodiments, a reader can be used with the sample amplifier to read a second biofluid produced by the sample amplifier. 
     In some embodiments, a point of need testing system can include a reader. The ready may be configured to accept the second biofluid sample and produce an output. The reader can include a heater configured to heat the second biofluid sample, a lateral flow test strip, a detection site, an excitation array, a photodetector, or any combination thereof. In some embodiments, a photodetector can be configured to communicate a signal wirelessly. 
     In some embodiments, a point of need testing system includes a sample amplifier that is separate from the reader. The sample amplifier can be configured as a portable sample amplifier and the reader can be configured as a stationary reader so that the portable sample amplifier can be brought into contact with the stationary reader to accept the biofluid sample. 
     In some embodiments, a method of testing a biofluid sample is disclosed. The method includes collecting a first biofluid sample, filtering the first biofluid sample to remove particulate, heating the first biofluid sample in the presence of one or more reagents for performing an amplification reaction to generate amplification products of a target nucleic acid to produce a second biofluid sample; collecting the second biofluid sample, transporting the second biofluid sample to a detection site, irradiating the second biofluid sample at the detection site, and detecting emitted electromagnetic radiation indicative of the presence or absence of the target nucleic acid and, optionally, a control nucleic acid. The method may be performed with any of the point of need testing systems described herein. 
     In some embodiments, a method of testing a biofluid sample can include obtaining a first biofluid sample by inserting the biofluid into a biofluid collector. The method can include inserting the biofluid sample into a sample amplifier by rotating the biofluid collector and employing gravity to move the biofluid from the biofluid collector to the sample amplifier. 
     In some embodiments, a method of testing a biofluid sample can including transmitting a result to a processor. The method can also include decoding electromagnetic radiation intensity detected by a photodetector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and form a part of this specification, illustrate example embodiments of the invention and, together with the description, serve to explain the principles of certain embodiments. 
         FIG.  1    is a schematic illustration of a point of need testing system including a biofluid collector, a sample amplifier, and a reader according to one embodiment of the invention. 
         FIG.  2    is a schematic illustration of the biofluid collector of  FIG.  1   . 
         FIG.  3    is a schematic illustration of the biofluid collector and the sample amplifier of  FIG.  1   . 
         FIG.  4    is a schematic illustration of the biofluid collector coupled to the sample amplifier of  FIG.  3   . 
         FIG.  5    is a detailed schematic illustration of the sample amplifier of  FIG.  1   . 
         FIG.  6    is a detailed schematic illustration of the reader of  FIG.  1   . 
         FIG.  7    is a flowchart illustrating an example of a method of a point of need testing system according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art after having studied the teachings in this disclosure, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans, after having studied the teachings in this disclosure, will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention. 
     A point of need (or point-of-care) testing system for use in clinical and non-clinical settings is described below. It can be generally useful to quantitatively test a biological fluid (“biofluid”) sample. In some embodiments, the biofluid can include, without limitation, saliva, blood, serum, urine, cerebrospinal fluid, interstitial fluid, and other fluid samples. The point of need testing systems generally operate by detecting the presence or absence of a target nucleic acid. This may be accomplished by amplifying a target nucleic acid to prepare an amplification products that can be detected with a reader. 
     In particular embodiments, the testing system can be used to test a biofluid sample that has been allotted appropriate reaction time to amplify one or more target nucleic acids, including target nucleic acids indicative of potential pathogens, or control nucleic acids within the biofluid sample to generate amplification products. An “amplification product” or “amplicon” is a piece of nucleic acid that is the product of amplification or replication events. The amplification product may also be a source of further amplification or replication events. The “amplification” refers to production of one or more copies of nucleic acid sequence. Amplification of the nucleic acid sequence may be accomplished by various amplification methods known in the art including isothermal and non-isothermal amplification methods. 
     As used herein, “subject” or “patient” refers to mammals and non-mammals. A “mammal” may be any member of the class Mammalia including, but not limited to, humans, non-human primates (e.g., chimpanzees, other apes, and monkey species), farm animals (e.g., cattle, horses, sheep, goats, and swine), domestic animals (e.g., rabbits, dogs, and cats), or laboratory animals including rodents (e.g., rats, mice, and guinea pigs). Examples of non-mammals include, but are not limited to, birds, and the like. The term “subject” does not denote a particular age or sex. In one specific embodiment, a subject is a mammal, preferably a human. The subject may have or suffer from, or be suspected of having or suffering from, a disease, condition, or disorder. 
     In some embodiments, the subject may have or suffer from, or be suspected of having or suffering from, an infection by a pathogen. “Pathogen” means an organism that can produce disease in a subject. Examples of pathogens include, without limitation, viruses, bacteria, fungi, and parasites. 
     The target nucleic acid and the control nucleic acid can, but need not, originate from the same source. For example, the target nucleic acid may originate from a pathogen and the control nucleic acid may originate from the subject. In other embodiments, the both the target and control nucleic acids may originate from the subject. In yet other embodiments, the both the target and control nucleic acids may originate from a pathogen. 
     Some nucleic acid amplification processes can take close to an hour (e.g., approximately 45 minutes to 75 minutes) for target nucleic acids in a biofluid to be properly amplified into a detection sample. In some cases, it may be useful for a user to start the amplification process prior to arriving at a sample reader that reads the detection sample. 
     In some embodiments, the systems and devices of this disclosure are capable of analyzing samples at the point-of-need rather than in a laboratory. As used herein, the term “point of need” or “point of care” can be defined to mean a location on or near a site of patient care where medical or medically related services such as medical testing and/or treatment are provided, including but not limited to hospitals, emergency departments, intensive care units, primary care setting, medical centers, patient homes, physician offices, pharmacies, or sites of an emergency. 
     In some embodiments, the systems and devices of this disclosure are capable of analyzing samples to provide point-of-entry style testing. As used herein, the term “point of entry” can be defined as an entry point to a variety of workplaces or gathering locations, such as, for example, airports, train stations, nursing homes, schools, etc. Allowing for the testing of samples collected at or brought to the entry point aids in restricting access to the workplace or gathering location for those who test positive. Further, in some embodiments, the systems and devices of this disclosure are capable of analyzing samples at home to provide regular checks of individuals in a multi-family environment, such as assisted living facilities, dormitories, etc. In some embodiments, systems and devices of this disclosure include software that permits wirelessly transmitting test results to trusted parties including the individual being tested, the location allowing (or denying) entry, and healthcare entities. 
     The advantages of the systems and devices of this disclosure are multifold and include, for example, the benefit of shortening the time between sample collection and analysis, thereby identifying subjects having particular test results and, if appropriate, providing medical treatment sooner than traditionally possible with conventional diagnostic systems. 
       FIG.  1    illustrates a point of need testing system  100  according to one example embodiment of the invention. As illustrated in the example embodiment of  FIG.  1   , the point of need testing system  100  includes a biofluid collector  104 , a sample amplifier  108 , and a reader  112 . In some embodiments, the sample amplifier  108  may be separate from the reader  112 . In particular, the sample amplifier  108  may be portable, and can be transported to a final destination where the reader  112  resides. For example, a user may possess and travel with the sample amplifier  108  to a clinical or non-clinical destination, such as a hospital or an office, that has the reader  112 . In other embodiments, the sample amplifier  108  can be fixed or removably coupled to the reader  112 . 
       FIG.  2    illustrates the biofluid collector  104  of  FIG.  1   . The biofluid collector  104  can be fluidly coupled to a receiver  116  that provides a pathway between a user and the biofluid collector  104  for the biofluid to travel. In some embodiments, the receiver  116  may be dimensioned to facilitate the collection of particular biofluids, such as saliva. However, other configurations and biofluids are possible. For example, the receiver  116  may be configured as a cannulated needle configured to sample a biofluid from a user, including, without limitation, blood, serum, urine, cerebrospinal fluid, interstitial fluid, and other fluid samples, which may then be collected in the biofluid collector  104 . 
       FIG.  3    illustrates the biofluid collector  104  and the sample amplifier  108  of  FIG.  1   . The sample amplifier includes an inlet  120  that is dimensioned to receive the biofluid collector  104 , thereby fluidly coupling the biofluid collector  104  to the sample amplifier  108 . In some embodiments, the biofluid collector  104  may include threads configured to engage threads of the sample amplifier  108  to secure the biofluid collector  104  to the sample amplifier  108 . In other embodiments, the biofluid collector  104  may be secured to the sample amplifier  108  via additional (or alternative) coupling mechanisms such as press fit, snaps, and other latch and securement mechanisms. In some embodiments, the securement of the biofluid collector  104  to the sample amplifier  108  may permit and initiate the biofluid transfer from the biofluid collector  104  to the sample amplifier  108 . 
     Further illustrated in  FIG.  3   , in some embodiments the biofluid collector  104  is positioned, relatively speaking, below the sample amplifier  108  when in use by a user. As illustrated in  FIG.  4   , in use, once the biofluid collector  104  is secured to the sample amplifier  108 , the sample amplifier  108  may be rotated  180  degrees relative to the orientation shown in  FIG.  3   . For example, as illustrated in  FIG.  4   , the biofluid collector  104  can be positioned above the sample amplifier  108  and gravity can be used to move biofluid from inside the biofluid collector  104  into the sample amplifier  108 . 
     In other embodiments, sonication can be used to apply sound energy to agitate particles in the biofluid sample to move the biofluid sample from the biofluid collector  104  into the sample amplifier  108 . In other embodiments, capillary flow may be used to induce a flow of the biofluid sample from the biofluid collector  104  to the sample amplifier  108 . In other embodiments, a pressure difference created between the biofluid collector  104  and the sample amplifier  108  when the biofluid collector  104  is secured to the sample amplifier  108  can force the biofluid from the biofluid collector  104  to the sample amplifier  108 . 
       FIG.  5    illustrates the sample amplifier  108  with the biofluid collector  104  secured thereto. In general, the sample amplifier  108  can provide reagents for performing an amplification technique therein. Suitably, the amplification technique is an isothermal amplification technique. In some cases, the isothermal amplification technique is loop-mediated isothermal amplification (LAMP). Other isothermal amplification techniques may alternatively be used, and include, without limitation, strand displacement amplification (SDA), helicase-dependent amplification (HDA), nicking enzyme amplification reaction (NEAR), signal mediated amplification of RNA technology (SMART), rolling circle amplification (RCA), isothermal multiple displacement amplification (IMDA), single primer isothermal amplification (SPIA), recombinase polymerase amplification (RPA), polymerase spiral reaction (PSR), and reverse transcription polymerase chain reaction (RT-PCR). In some cases, reagents for isothermal amplification will vary based on the isothermal amplification technique employed and generally comprise primers and a strand-displacing DNA polymerase, a reverse transcriptase (for detection of RNA species), and/or a DNA helicase. In some cases, the reagents further comprise synthetic nucleic acids (e.g., riboregulators) configured to detect natural nucleic acids from one or more pathogens such as viruses, bacteria, fungi, and parasites. 
     In some embodiments, sample amplifier  108  may provide compounds or compositions suitable for use with point of need diagnostic devices or other biological assays. Suitably, the sample amplifier  108  may include, without limitation, buffers, surfactants, chaotropic salts, proteases such as poteninase K, chelating agents such as EDTA, co-factors, salts such as chaotropic salts, carrier RNA, or any combination thereof. 
     In the illustrated embodiment, the sample amplifier includes a housing  124  that houses a filter  128 , a heater  132 , a reagent reservoir  136 , and a second biofluid collector  140 . The housing  124  may selectively provide access to an interior of the housing  124  from an exterior of the housing  124 . In some embodiments, access to the interior of the housing  124  can allow the user to remove, replace, dispose, and/or recharge certain components within the housing  124 , as will be described in greater detail below. 
     The filter  128  in the illustrated embodiment is a filter configured to remove particulates from biofluid. In some embodiments, the filter is a mechanical, affinity, adsorption, or chemical bonding filter. As those of ordinary skill in the art will readily recognize and appreciate after having studied and benefited from the teachings in this disclosure, a variety of mechanical filters may be used, such as filter employing mesh membranes, beads, pores, or other filtering apparatuses. In some embodiments, particulates can include unwanted particles in the biofluid that are not useful to (or may hinder) amplifying nucleic acids in the biofluid. Such particles can include residual food particles from saliva, for example. The filter  128  may be disposable and replaceable within the sample amplifier  108  such that a user can remove the filter  128  after use and replace the filter  128  with an unused filter. 
     The heater  132  in the illustrated embodiment is configured to heat the biofluid sample within the sample amplifier  108 . In some embodiments, the heater  132  may be reusable between biofluid samples within the housing  124 . The heat provided by the heater  132  can accelerate the reaction kinetics of an amplification reaction of the target nucleic acid within the biofluid sample with reagents in the reagent reservoir  136 . 
     The reagent reservoir  136  contains one or more reagents for performing an amplification technique therein to generate amplification products or amplicons of the target or control nucleic acid. Suitably, the reagent reservoir may contain a primer, a strand-displacing DNA polymerase, a reverse transcriptase, a DNA helicase, or any combination thereof. Like the filter  128 , the reagent reservoir  136  may be disposable and replaceable within the sample amplifier  108  such that the user can remove the reagent reservoir  136  after use and replace the reagent reservoir  136  with an unused reservoir. 
     After a predetermined amount of time, the sample amplifier  108  can convert the biofluid sample into a second, processed biofluid sample which can be used as a detection sample as will be described below. The processed biofluid sample may contain amplification products or amplicons suitable for detection, thereby providing qualitative or quantitative information on the presence or absence of the target nucleic acid in the biofluid. The second biofluid collector  140  can collect (or receive) and retain the detection sample. 
     In some embodiments, the heater  132  may include a first heater and a second heater. The first heater may be placed proximate to a top of the biofluid sample and the second heater may be placed proximate to a bottom of the biofluid sample in the device. In an area that is proximate to the reagent reservoir  136 , the biofluid sample may be surrounded by a thermally conductive material, such as copper, for example, to promote even heating provided by the heater  132  at the area proximate to the reagent reservoir  136 . 
     In some embodiments, the sample amplifier  108  can further include an indicator (not shown). The indicator can include one or more of an audio, visual, or tactile indication. For example, the indicator may output a light (e.g., a green light) when a predetermined amount of time has passed from when the biofluid first entered the sample amplifier  108 . In some embodiments, a user may initiate the sample amplifier via a start actuator, such as a button or a switch, for example, which begins the countdown from the predetermined amount of time. In other embodiments, a timer armed with the predetermined amount of time may be started once the biofluid collector  104  is secured to the sample amplifier  108 . In some embodiments, the predetermined amount of time may be between approximately 15 minutes and 90 minutes. In other embodiments, the predetermined amount of time may be between approximately 30 minutes and 60 minutes. In general, the predetermined amount of time is the time required for the biofluid to be reacted and amplified such that the detection sample can be read by the reader  112 . 
       FIG.  6    illustrates the reader  112  of  FIG.  1   . In general, the reader is configured to accept (or receive) the detection sample and produce a qualitative or quantitative output. In the embodiment shown, the reader  112  includes a housing  144  that houses a lateral flow strip  148 , a heater  152 , and a detection site  156 . The housing  144  may selectively provide access to an interior of the housing  144  from an exterior of the housing  144 . In some embodiments, access to the interior of the housing  144  can allow the user to remove, replace, dispose, and/or recharge certain components within the housing  144 , as will be described in greater detail below. The reader  112  further includes an inlet  160  that is dimensioned to receive the detection sample from the second biofluid collector  140 . 
     The lateral flow strip  148  is proximate to the inlet  160  and can transport the detection sample from the second biofluid collector  140  to the detection site  156 . The lateral flow strip  148  enables flow through capillary forces. In alternative embodiments, a channel that allows for flow driven by pressure may substitute for the lateral flow strop. Suitably, the lateral flow strip  148  or channel may include reagents, such as reagents for performing an amplification technique or compounds or compositions suitable for use with point of need diagnostic devices or other biological assays. The second biofluid collector  140  may include a paper-based membrane or microfluidic channel that is configured to induce capillary flow from the second biofluid collector  140  to the lateral flow strip  148 . In some embodiments, the heater  152  may heat the detection sample as the detection sample is transported along the lateral flow strip  148  and is received at the detection site  156 . Heating the lateral flow strip  148  or detection site  156  allows for the amplification reaction to be accomplished in whole or in part within the lateral flow strip  148  or detection site  156 . 
     The detection site  156  can be positioned between an excitation array  164  and a photodetector  168 . Optionally, an optical filter (not shown) may be positioned between the excitation array  164  and the detection site  156  or an optical filter (not shown) may be positioned between the detection site  156  and the photodetector  168 . In some embodiments, optical filters are positioned between excitation array  164  and the detection site  156  and the detection site  156  and the photodetector  168 . 
     The excitation array  164  provides electromagnetic radiation that may be absorbed by the detection sample. The electromagnetic radiation may be of any suitable wavelength that can provide a detectable signal indicating the presence or absence of an amplification product of a target nucleic acid. In some embodiments, the electromagnetic radiation may be of any suitable wavelength that can provide a detectable signal indicating the presence or absence of an amplification product of a control nucleic acid. In some embodiments, the excitation array  164  provides electromagnetic radiation in the infrared, visible, or ultraviolet spectrums. The excitation array  164  may emit broadband or narrowband electromagnetic spectrums. An optical filter provided between the excitation array  164  and the detection site  156  may be used to selectively provide the wavelengths within a desired spectral window to the detection site  156 . 
     The photodetector  168  may detect any suitable wavelength or electromagnetic radiation. In some embodiments, the photodetector  168  detects electromagnetic radiation in the infrared, visible, or ultraviolet spectrums. The photodetector  168  may include an array connected to a readout circuit, which can include a microchip. The photodetector  168  can wirelessly or wiredly communicate to a processor (not shown) that can decode and translate intensities sent via a digital signal that originate from a current signal. The detection sample may include biomarkers, chromophores, fluorophores, dyes, and other compounds or substances capable of emit light of a second wavelength or color when stimulated by a first light of a first wavelength or color. The presence of amplification products of the target and/or control nucleic acid sequence in the second biofluid sample may alter electromagnetic radiation intensity emitted at the second wavelength relative to an amplification product free second biofluid sample. The photodetector  168  can detect the light of the second color and output the current which is then transmitted to the processor. The intensity of the detected light allows for determination of the presence or absence of the target nucleic acid and/or control nucleic acid target. The processor can output qualitative or quantitative results that can be used for epidemiological data collection and studies. 
     An optical filter provided between the detection site  156  and the photodetector  168  may be used to select selectively provide wavelengths within a desired spectral window to the photodetector  168 . When optical filters are positioned between excitation array  164  and the detection site  156  and the detection site  156  and the photodetector  168 , the optical filter positioned between excitation array  164  and the detection site  156  may selectively provide the wavelength of the first color and the optical filter positioned between the detection site  156  and the photodetector  168  may selectively provide the wavelength of the second color. Such an embodiment may minimize the electromagnetic radiation provided by the excitation array  164  being provided directly to the photodetector  168 . 
     In some embodiments, the reader  112  can further include an indicator (not shown). The indicator can include one or more of an audio, visual, or tactile indication. For example, the indicator may output a light (e.g., a green light or a red light) if a specific pathogen at a predetermined level is found (or not found) in the detection sample. Similar to the sample amplifier  108 , elements of the reader  112  may be reusable. For example, the heater and components of the detection site  156  such as the photodetector, excitation array, and the microchip. Correspondingly, the lateral flow strip  148  may be replaceable within the housing  144  which can be selectively accessible from the outside. 
       FIG.  7    illustrates a flowchart  200  of an example method of use of a point of need testing system, similar to the point of need testing system  100  described above. In use, a user may collect a biofluid sample in a sample collector, as indicated in  210 . The biofluid may then be separated via a first device to form a second biofluid, as indicated in step  220 . The second biofluid may be an amplified version of the first biofluid that has undergone a reaction with heat and/or reagents. After a predetermined amount of time has passed, an indicator may indicate that the biofluid sample is successfully separated into the second biofluid, as indicated in step  230 . A plug or second sample collector that contains the second biofluid may be removed from the first device as indicated in step  240 . In some embodiments, the plug or second sample collector may be removed from the first device via a Leur or compression-style system. The plug or second sample collector may then be mated to a second device as indicated in step  250 . The second device may be a reader with a photodetector configured to detect pathogens in the biofluid sample and provide an output to an indicator on the reader and/or send the output wirelessly to a processor that includes quantitative data. 
     In some embodiments, the first device of the method  200  may be separate from the second device. However, in other embodiments, the first device may be fluidly coupled to the second device such that steps  240  and  250  of the method  200  are unnecessary. 
     The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.