Machine-readable diagnostic test devices and methods and apparatus for their manufacture and / or processing

Abstract

Methods, apparatus, systems, and articles of manufacture for the manufacture and / or processing of diagnostic test devices are disclosed. An exemplary device includes a porous medium including a first zone and a second zone, the first zone including an immobilized antigen corresponding to a target analyte or an immobilized antibody corresponding to the target analyte; a wireless chip for wirelessly acquiring a first voltage via a signal from an external device; outputting a second voltage, lower than the first voltage, to a first electrode in contact with at least one of the first zone or the second zone; and measuring an electrical signal from the first electrode corresponding to the presence or absence of the target analyte.

Description

[Technical Field]

[0001] This application claims the benefit of PCT Patent Application No. PCT / EP2021 / 064581, filed May 31, 2021; U.S. Provisional Patent Application No. 63 / 129,375, filed December 22, 2020; and U.S. Provisional Patent Application No. 63 / 284,513, filed November 30, 2021, which is related to U.S. Provisional Patent Application No. 63 / 129,375, filed May 29, 2020. U.S. Provisional Patent Application No. 63 / 284,513, PCT Patent Application No. PCT / EP2021 / 064581, U.S. Provisional Patent Application No. 63 / 129,375, and U.S. Provisional Patent Application No. 63 / 032,093, are each incorporated herein by reference in their entirety. Priority is claimed herein to U.S. Provisional Patent Application No. 63 / 284,513.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to biosensors, and more particularly to machine-readable diagnostic test devices and methods and apparatus for their manufacture and / or processing. [Background technology]

[0003] A biosensor (e.g., a lateral flow device such as a lateral flow assay (LFA)) is a device that can detect a condition, disease, etc. in a human or animal based on a sample (e.g., a blood sample, a saliva sample, a urine sample, etc.) from the human or animal. LFAs have been used to detect the presence of a target analyte to determine pregnancy, the presence or absence of HIV, the presence or absence of Ebola, the presence of various toxins, etc. [Brief explanation of the drawings]

[0004] [Figure 1A] FIG. 1 illustrates an exemplary environment including an exemplary machine-readable lateral flow immunoassay generator that generates the machine-readable lateral flow immunoassays described in connection with the examples disclosed herein. [Figure 1B] FIG. 1B is a side view of the exemplary machine-readable lateral flow immunoassay of FIG. 1A. [Figure 2A] FIG. 1B shows an exemplary implementation of a portion of the machine-readable lateral flow immunoassay of FIG. 1A. [Figure 2B] FIG. 1B shows an alternative exemplary implementation of a portion of the machine-readable lateral flow immunoassay of FIG. 1A. [Figure 2C] 1A, 1B, 2A, and / or 2B show exemplary designs of the potentiometric and / or bioelectrochemical cells. [Figure 2D] FIG. 1B is a top view of an alternative exemplary embodiment of the machine-readable lateral flow immunoassay of FIG. 1A. [Figure 2E] FIG. 2E is a side view of the machine-readable lateral flow immunoassay of FIG. 2D. [Figure 2F] 2D and 2E show exemplary conjugates that can be attached to immobilized antigens and / or antibodies on the test line of the machine-readable lateral flow immunoassay of FIG. 2D and FIG. 2E. [Figure 2G] FIG. 2C is an exploded view of the exemplary lateral flow immunoassay of FIGS. 2D and 2E in an exemplary housing. [Figure 2H] FIG. 1 shows an alternative exemplary machine-readable lateral flow immunoassay comprising quantum dots. [Figure 2I] FIG. 2B shows one embodiment of a front-end channel that can be used in the machine-readable lateral flow immunoassays of FIGS. 1-2H. [Figure 2J] FIG. 2B shows one embodiment of a front-end channel that can be used in the machine-readable lateral flow immunoassays of FIGS. 1-2H. [Figure 2K] FIG. 2B shows one embodiment of a front-end channel that can be used in the machine-readable lateral flow immunoassays of FIGS. 1-2H. [Figure 2L] FIG. 2C is a bottom view of the housing of the machine-readable lateral flow immunoassay of FIGS. 1-2H, including an exemplary housing lid and an exemplary switch in a first position. [Figure 2M]Bottom view of the housing of the machine-readable lateral flow immunoassay of FIG. 2L with an exemplary switch in the second position. [Figure 2N] Cross-sectional view of the housing of the machine-readable lateral flow immunoassay of FIG. 2L having a switch in the first position and an exemplary electrode board in the first position. [Figure 2O] Cross-sectional view of the housing of the machine-readable lateral flow immunoassay of FIG. 2L having a switch in the second position and an exemplary electrode board of FIG. 2N in the second position. [Figure 2P] Perspective view of the housing of the machine-readable lateral flow immunoassay of FIGS. 1-2H having another exemplary switch. [Figure 2Q] Partial cross-sectional view showing the interior of the housing of the machine-readable lateral flow immunoassay of FIG. 2P taken along the Q-Q line of FIG. 2P and having an exemplary switch in the first position. [Figure 2R] Partial cross-sectional view showing the interior of the housing of the machine-readable lateral flow immunoassay of FIG. 2P taken along the R-R line of FIG. 2P and having an exemplary switch in the second position. [Figure 3A] Figure showing an alternative exemplary machine-readable lateral flow immunoassay that can be generated by the exemplary machine-readable lateral flow immunoassay generator of FIG. 1A. [Figure 3B] Figure showing an exemplary circuit completion and silver amplification process that can occur in the exemplary machine-readable lateral flow immunoassay of FIG. 3A. [Figure 4] Block diagram of one embodiment of the machine-readable lateral flow immunoassay generator of FIG. 1A. [Figure 5] Block diagram of one embodiment of a wireless chip on the machine-readable lateral flow immunoassay of FIGS. 1A, 1B, 2A, 2B, 2I-2K, and / or 3A. [Figure 6] Block diagram of one embodiment of the machine-readable lateral flow immunoassay reader application of FIG. 1A. [Figure 7] 1A and / or 4. FIG. 1B is a flowchart representing machine-readable instructions that may be executed to implement the machine-readable lateral flow immunoassay generator of FIG. [Figure 8A] 1A, 2A, 2B, 2I-2K, 3A, and / or 5. FIG. 1A is a flowchart representing machine-readable instructions that may be executed to implement the wireless chip of FIG. [Figure 8B] 1A, 2A, 2B, 2I-2K, 3A, and / or 5. FIG. 1A is a flowchart representing machine-readable instructions that may be executed to implement the wireless chip of FIG. [Figure 9] 1A, 2A, 2B, 2I-2K, 3A, and / or 5. FIG. 1A is a flowchart representing machine-readable instructions that may be executed to implement the wireless chip of FIG. [Figure 10] 1A, 2A, 2B, 2I-2K, 3A, and / or 5. FIG. 1A is a flowchart representing machine-readable instructions that may be executed to implement the wireless chip of FIG. [Figure 11A] 1A and / or 6. FIG. 1B is a flowchart representing machine-readable instructions that may be executed to implement the machine-readable lateral flow immunoassay reader application of FIG. [Figure 11B] 1A and / or 6. FIG. 1B is a flowchart representing machine-readable instructions that may be executed to implement the machine-readable lateral flow immunoassay reader application of FIG. [Figure 12] FIG. 8 is a block diagram of an exemplary processing platform configured to execute the instructions of FIG. 7 to implement the lateral flow immunoassay generator of FIGS. 1A, 1B, and / or 4. [Figure 13] FIG. 10 is a block diagram of an exemplary processing platform configured to execute the instructions of FIGS. 8A-10 to realize the wireless chips of FIGS. 1A, 2A, 2B, 2I-2K, 3A, and / or 5. [Figure 14]FIG. 11B is a block diagram of an exemplary processing platform configured to execute the instructions of FIGS. 11A and 11B to implement the machine-readable lateral flow immunoassay reader application of FIGS. 1A and / or 6. [Figure 15] FIG. 11 is a block diagram of an exemplary software distribution platform that distributes software (e.g., software corresponding to the exemplary computer-readable instructions of FIGS. 11A and 11B) to client devices, such as consumers (e.g., for licensing, sale, and / or use), retailers (e.g., for sale, resale, licensing, and / or sublicensing), and / or original equipment manufacturers (OEMs) (e.g., for inclusion in products distributed to retailers and / or direct purchase customers). DETAILED DESCRIPTION OF THE INVENTION

[0005] The drawings are not drawn to scale. Instead, the thickness of layers or regions may be exaggerated in the drawings. Generally, the same reference numerals are used throughout the drawings and accompanying description to refer to the same or similar parts. As used in this patent, describing any part (e.g., layer, film, area, region, or plate) as being in any way over (e.g., positioned, arranged, disposed, formed, etc.) another part indicates that the referenced part is in contact with the other part or that the referenced part is over the other part via one or more intermediate parts. Connection references (e.g., attached, coupled, connected, and joined) should be interpreted broadly and may include intermediate members between sets of elements and relative movement between the elements, unless otherwise specified. Thus, connection references do not necessarily imply that two elements are directly connected and in a fixed relationship to each other. Describing any part as "in contact" with another part means that there are no intermediate parts between the two parts. Although the drawings show layers and regions with distinct lines and boundaries, some or all of these lines and / or boundaries may be idealized, and in fact the boundaries and / or lines may be unobservable, integrated, and / or irregular.

[0006] Rapid diagnostic tests include biosensors or test strip devices (e.g., lateral flow immunoassays (LFAs)), which are devices that include a first region where a sample (e.g., blood, urine, saliva, etc.) is acquired and a second region that changes (e.g., changes color and / or undergoes another change in physical property) when a target analyte corresponding to a particular disease or condition is present in the sample. For example, a user applies a sample to the sample pad of a test strip device or simply "test strip" (e.g., LFA, etc.). Once applied, the sample migrates along the test strip to a conjugate pad that contains a conjugate (e.g., a detectable label, tag, linker, antibody, antigen, etc.) specific to the target analyte. If the sample contains the target analyte, a reaction (e.g., a chemical reaction, a biochemical reaction, a physical reaction, etc.) occurs on the conjugate pad, causing the target analyte to bind to the conjugate. The test strip also includes a test line containing molecules (e.g., immobilized antibodies, antigens, analytes, aptamers, etc. specific to the target analyte) that bind to a first set of conjugate molecules (e.g., probe molecules) from the conjugate pad. For example, if the analyte of interest is an antibody, the positive test area contains an immobilized antigen. If the analyte of interest is an antigen, the positive test area contains an immobilized antibody. The labeling substance or conjugate includes a first binding moiety capable of binding the analyte of interest and, in some instances, a second visualization moiety. Thus, when a sample (e.g., containing a bound target analyte) flows to a test zone (e.g., a reaction zone), the antibody, analyte, or antigen at the test line binds to the bound target analyte, immobilizing it. In some test strips, the immobilized target analyte provides a visual output that identifies the presence of the target analyte in the sample. Thus, a scanner or user can identify whether a target analyte (e.g., corresponding to a condition or disease) is present in the sample based on the color of the test zone.

[0007] "Target analyte," "analyte," or "analyte of interest" refers to a compound or composition having at least one epitope or binding site and to be detected or measured in a sample. An analyte can be any substance for which a naturally occurring analyte-specific binding member exists, or any substance for which an analyte-specific binding member can be prepared. Analytes include, but are not limited to, toxins, organic compounds, proteins, peptides, microorganisms, amino acids, nucleic acids, hormones, steroids, vitamins, drugs (both therapeutically and illicitly administered), and / or metabolites or antibodies of any of these substances. The term "analyte" also includes any antigenic substance, hapten, antibody, macromolecule, and / or combinations thereof.

[0008] "Label" refers to any substance capable of producing a signal detectable by visual and / or instrumental means. Various labels suitable for use in the examples disclosed herein include labels that produce a signal through chemical and / or physical means. Examples include enzymes and substrates, chromagens, fluorescent compounds, chemiluminescent compounds, colored or colorable organic polymer latex particles, liposomes, and / or other vesicles containing directly visible substances. In some examples, radioactive labels, colloidal metal particles, and / or colloidal non-metallic particles are employed. In some examples, labels include colloidal gold and latex particles.

[0009] "Labeling agent" or "conjugate" refers to a substance comprising a detectable label attached to a specific binding member. Attachment can be covalent or non-covalent and can involve nucleic acid hybridization. The label enables the labeling agent to produce a detectable signal that is directly or indirectly related to the amount of analyte in a test sample. The specific binding member component of the labeling agent is selected to bind directly or indirectly to the analyte.

[0010] "Specific binding member" refers to a member of a specific binding pair (e.g., two different molecules, one of which specifically binds to the second molecule by chemical or physical means). If the specific binding member is an immunoreactive substance, it can be, for example, an antibody, an analyte, an antigen, a hapten, or a complex thereof; if an antibody is used, it can be a monoclonal or polyclonal antibody, a recombinant protein or antibody, a chimeric antibody, a mixture or fragment thereof, or a mixture of an antibody and another specific binding member. Examples of specific binding members include biotin and avidin, an antibody and its corresponding antigen (both independent of the sample being analyzed), a single-stranded nucleic acid and its complement, etc.

[0011] A "test strip" or "LFA" may include one or more bibulous or nonbibulous materials. When a test strip includes two or more materials, it is preferred that one or more materials be in fluid communication. One test strip material may be overlaid on another test strip material, such as filter paper overlaid on nitrocellulose. Additionally or alternatively, a test strip may have a region containing one or more materials (e.g., a medium) followed by a region containing one or more different materials. In this case, these regions are in fluid communication and may or may not overlap. Suitable test strip materials include, but are not limited to, cellulose-derived materials such as filter paper, chromatography paper, nitrocellulose, and cellulose acetate, as well as materials composed of glass fiber, nylon, Dacron, polyvinyl chloride (PVC), polyacrylamide, cross-linked dextran, agarose, polyacrylate, ceramic materials, and the like. One or more materials of a test strip may optionally be treated to modify their capillary flow characteristics or the properties of an applied sample. For example, buffer treatment of the sample application area of ​​the test strip may correct the pH or specific gravity of the applied urine sample to ensure optimal testing conditions.

[0012] The one or more materials can be a unitary structure, such as a sheet cut into strips, or multiple strips or particulate material attached to a support or solid surface, such as those found in thin-layer chromatography, and can have an absorbent pad as an integral part or in liquid contact. The material can also be a sheet with lanes thereon, definable to induce lane formation, with a separate assay performed in each lane. The material can be rectangular, circular, oval, triangular, or other shape, provided there is at least one directional traversal of the test solution by capillary migration. Other directional traversal may occur, such as in an oval or circular piece that contacts the test solution at its center. However, the primary consideration is that there is at least one directional flow to a predetermined location. In the following discussion, test strips are described as an example and not as a limitation.

[0013] The support of the test strip is typically water-insoluble, non-porous, and often rigid, although it can be elastic, typically hydrophobic, and porous, if desired or required, and typically the same length and width as the strip, although it can be larger or smaller. The support material can also be transparent, and when the test device disclosed herein is assembled, the transparent support material can be on the side of the test strip visible to the user, thereby forming a protective layer over the test strip and exposing it to the external environment, such as through an opening in the front of the test device. A wide variety of mobile and non-mobile materials (both natural and synthetic), as well as combinations thereof, can be employed, provided only that the support does not interfere with capillary action of one or more materials, nonspecific binding of assay components, or interference with the signal-producing system. Exemplary polymers include polyethylene, polypropylene, poly(4-methylbutene), polystyrene, polymethacrylate, poly(ethylene terephthalate), nylon, poly(vinyl butyrate), glass, ceramics, metals, and the like. The resilient support may be composed of polyurethane, neoprene, latex, silicone rubber, etc. Throughout this specification, LFAs are described with the understanding that discussion of LFAs also applies to other types of test strips.

[0014] In some conventional LFAs, test results appear as subtle color changes, leading to increased user error during reading. For example, an LFA may output a color corresponding to a positive result, but if the color is faint and / or lighting conditions are poor, a user may interpret the test as negative. Additionally, because some conventional LFAs rely on visual cues to determine the result, the test lines corresponding to the result must be sufficiently spaced and / or confined to avoid confusion or reading errors. Examples disclosed herein create an improved, machine-readable LFA that automatically generates objective results through algorithms that reduce and / or eliminate false positives and / or false negatives due to human error. Additionally, the use of an LFA that does not rely on visual cues allows for more test zones to be placed closer together without the risk of misreading the results.

[0015] Because resources may be limited in certain regions of the world, dedicated LFA readers may be prohibitively expensive in those regions. Therefore, examples disclosed herein provide improved LFAs that can be read using a smartphone application rather than a dedicated reader. While there are some smartphone applications that can read the results of LFA-based tests, such smartphone applications may output inaccurate results due to poor lighting conditions, LFAs with weak visual indicators, and / or low-quality sensors on the smartphone.

[0016] The examples disclosed herein create an improved LFA that addresses the errors of conventional smartphone applications and / or human error that correspond to the inaccurate results of conventional LFA readers. The examples disclosed herein provide a signal corresponding to a test result (e.g., one or more analog current and / or voltage values ​​corresponding to the test result, one or more digital current and / or voltage values ​​corresponding to the test result, one or more logic values ​​corresponding to the test result, etc.), which provides a more accurate measurement than analog systems. The examples disclosed herein correspond to a machine-readable LFA device that determines the results of a fluid sample-based test (e.g., an LFA-based test) without relying on traditional visual indicators. In the examples disclosed herein, the improved LFA provides machine-readable results to a smartphone application. Thus, the results are objective and can be read without human interpretation, eliminating operator subjectivity and improving the accuracy of the results. Additionally, there is no need to design and include a reading window on the LFA device. As disclosed elsewhere herein, the exemplary LFA device does not need to house a battery (e.g., an energy storage device). For example, LFA devices are battery-less, not wired to a power source, but are powered by an electromagnetic field generated by a user device such as a reader. Furthermore, accurate results can be easily transmitted to external databases and / or servers, such as remote databases and / or servers located at or associated with electronic medical records (EMRs), government agencies, non-governmental organizations (NGOs), doctors' offices, hospitals, hospital information systems, laboratory information management software (LIMS) systems, inventory consumption monitors, clinics and / or other medical facilities, medical device manufacturers, medical institutions, health information systems, and / or other external entities. In this manner, large-scale test results are generated, collected, and digitally integrated into other health management systems, eliminating human-based transcription errors. Examples disclosed herein also enable self-testing by, for example, non-medical personnel, since untrained self-testers do not need knowledge of how to interpret results.The self-test may be incorporated into a commercially available device, and examples disclosed herein may be incorporated into a disposable point-of-care device.

[0017] Examples disclosed herein include an LFA device including a wireless chip that acquires data corresponding to whether an analyte is present in a sample based on an electrical signal generated by the LFA device and transmits this data to a reader. The determination of a test result is based on a comparison of the electrical signal to one or more threshold values. This comparison can be made on the wireless chip of the LFA and / or in an external reader. In some examples, the wireless chip acquires analog current and / or voltage values ​​from electrodes placed in contact with the porous membrane of the LFA device and transmits the analog current and / or voltage values ​​via an antenna to the reader. The reader can then compare the analog values ​​to one or more threshold values ​​to determine whether the test result is positive or negative. For example, if the current and / or voltage values ​​exceed the threshold values, the reader determines that the test corresponding to the current and / or voltage values ​​is positive. Similarly, if the current and / or voltage values ​​are below the threshold values, the reader determines that the test corresponding to the current and / or voltage values ​​is negative. In some examples, the wireless chip acquires the analog current and / or voltage values, converts the analog values ​​to digital values, and transmits the digital values ​​to the reader. The reader can then compare the digital value to one or more thresholds to determine the test result. In some examples, the wireless chip takes the analog voltage and / or current value, compares the value (e.g., with or without conversion to a digital value) to one or more thresholds, generates a logic value (e.g., high or low) corresponding to a positive or negative test, and transmits the test result to the reader.

[0018] Examples disclosed herein include multiple techniques for generating an electrical signal on an LFA device that indicates the presence or absence of an analyte of interest. For example, examples disclosed herein may utilize a bioelectrochemical mechanism (e.g., an energy-generating device) in the test and / or control lines of the LFA device to obtain one or more electrical signals corresponding to one or more test results. As described elsewhere below, the bioelectrochemical mechanism includes a bioelectrochemical cell (e.g., a physical cell or a structure of a porous membrane acting as a physical cell) that generates an electrical signal in a porous membrane when a target analyte is present. Bioelectrochemical cells may be known as or include potentiometric cells, concentration cells, fuel cells, biofuel cells, etc. In some examples, the bioelectrochemical cell generates the electrical signal through one or more bioelectrochemical reactions occurring on the porous membrane. A wireless chip in the LFA device can measure the electrical signal by detecting the current and / or voltage drop between electrodes of the bioelectrochemical cell, which are placed in contact with the porous membrane. In another example, the LFA device may include a circuit completion mechanism in the test line and / or control line of the LFA device to generate an electrical signal. As described elsewhere below, the circuit completion mechanism creates a short circuit in the test zone when a target analyte is present in the sample. For example, the circuit completion mechanism may amplify a substance (e.g., silver) surrounding an immobilized molecule (e.g., gold) in the test zone when the target analyte is present. In this manner, the wireless chip can generate a voltage and measure whether current flows from one side of the test zone to the other (e.g., when a short circuit is created) to identify whether the target analyte is present.

[0019] In some examples of bioelectrochemical cells disclosed herein, one half of the bioelectrochemical cell is attached to a test zone (e.g., test line, test area, etc.) and / or control zone (control line) of a porous medium (e.g., membrane, paper, and / or other compartment-free or compartmentless substrate) of an LFA. In some examples, the bioelectrochemical cell is configured to detect glucose and a redox species (e.g., potassium ferricyanide K3 [Fe(CN)6]6). 3- The conjugate pad may be a paper impregnated with a solution of an enzyme (e.g., glucose oxidase (GOx)) and dried. In the examples disclosed herein, an enzyme (e.g., glucose oxidase (GOx)) is labeled (e.g., attached, bound, etc.) with the antibody, analyte, and / or antigen on the conjugate pad. When the antibody, analyte, and / or antigen bound to GOx attaches to the target analyte, the immobilized antibody, analyte, and / or antigen corresponding to the target analyte is attached to and immobilized on GOx in the test zone. With one half of the bioelectrochemical cell attached to the test zone, GOx reacts with the solution in the bioelectrochemical cell to oxidize glucose in the bioelectrochemical cell, as shown in Chemical Reaction Processes 1-3 below. Here, (Ox) and (Red) refer to the reduced and oxidized states of the enzyme, respectively. Glucose + GOx(Ox) ⇒ Gluconolactone + GOx(Red) (Process 1) GOx(Red) + O2 ⇒ GOx(Ox) + H2O2 (Process 2) Gluconolactone + H2O ⇒ gluconic acid (Process 3)

[0020] Also, the following processes 4-5 show the chemical reactions, where the cofactors flavin adenine dinucleotide (FAD) and FADH2 refer to the oxidized or reduced state of the enzyme active center, respectively. GOx(FADH2) + O2 ⇒ GOx(FAD) + H2O2 (Process 4) GOx(FAD) + glucose ⇒ GOx(FADH2) + gluconolactone (Process 5)

[0021] Although the examples disclosed herein refer to GOx as the enzyme used to generate a product (e.g., hydrogen peroxide (HO)) corresponding to current flow and / or electron release / transfer, the examples disclosed herein may be practiced using additional and / or alternative enzymes. The examples disclosed herein may utilize amino acid oxidase, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, alcohol oxidase, galactose oxidase, and / or any other oxidase as the enzyme used to generate a product (e.g., hydrogen peroxide) that facilitates electron release and / or transfer. In some examples, molecules other than glucose may be included to facilitate the reaction that produces hydrogen peroxide, depending on the enzyme used.

[0022] In some instances, an enzymatic reaction with a natural mediator (electron acceptor) (e.g., oxygen) can be used in a bioelectrochemical cell. In such instances, glucose is oxidized to gluconolactone and FADH2 is oxidized to FAD to yield a product (e.g., HO (hydrogen peroxide)). Additionally or alternatively, glucose can be oxidized by oxygen (e.g., oxygen is reduced) in the presence of glucose oxidase, thereby yielding CH 12 O6 and oxygen (O2) react to form CH 10 O6 and H2O2 (e.g., hydrogen peroxide). In some examples, the electrode may consist of a metal (e.g., copper, titanium, brass, silver, platinum, etc.), graphite, or a screen-printed carbon electrode doped with ferrocyanide. The product (e.g., H2O2) is then reduced, and the release of electrons causes oxidation of the electrode metal or ferrocyanide. In the latter case, ferrocyanide [Fe(CN)6] 4- reacts to form [Fe(CN)6] 3-The emitted electrons can be measured by a processor (e.g., using current and / or voltage measurements). Copper surfaces are typically oxidized in air to CuO (Cu(I)). CuO is oxidized by the reduction of HO to CuO (Cu(II)).

[0023] While the product (e.g., hydrogen peroxide) is generated at the test line and / or control line, it is not secured there and may begin to flow toward the wicking pad of the LFA device. Accordingly, some examples disclosed herein may include a mechanism to stop (e.g., slow or stop) the flow and maintain the product, or a portion of the product, in a test zone at or near the test line and / or control line until the test is read. A mechanism for stopping the flow may be used in any of the disclosed examples. Some examples disclosed herein stop the flow by slowing the flow through shearing, pinching, and / or cutting (e.g., of a portion or all of) the porous membrane. Such examples include mechanical devices that can be user-controlled (e.g., moved, slid, pivoted, twisted, rotated, etc.) to cut the porous membrane. Some examples disclosed herein apply a substance (e.g., a chemical, adhesive, gel, etc.) with a higher viscosity than the buffer to slow and / or stop the flow. In some instances, electrodes may be set in place after / during application of a flow-stopping mechanism to allow reaction of the product (e.g., hydrogen peroxide) with the electrode after the flow has stopped or slowed down, generating a strong electrical signal (e.g., corresponding to the flow of electrons caused by the reaction).

[0024] In other examples, alternative reactions can be performed in a bioelectrochemical cell. For example, a non-enzymatic amperometric redox reaction can be used in the bioelectrochemical cell. For example, the amperometric signal of an LFA can be measured without the GOx enzyme because the gold of the AuNPs can act as a catalyst (e.g., when the GOx in the conjugate is replaced with AuNPs). In such examples, thiosulfate can be used to improve the signal, as shown in Processes 6-8 below. In Process 11 below, thiosulfate, ferricyanide, and KBr or KCl react, and the AuNPs catalyze the reduction of ferrocyanide to produce an electronic signal. The KBr or KCl can be included in the buffer and / or dried onto a portion of the porous membrane and resuspended in the buffer. (Oxide)2S2O3 2- ⇒S4O6 2- +2e - (Process 6) (reduced) [Fe(CN)6] 3- +e - ⇒[Fe(CN)6] 4- (Process 7) 2[Fe(CN)6] 3- +2S2O3 2- ⇒2[Fe(CN)6] 4- +S4O6 2- (Process 8)

[0025] Alternatively, Processes 9-11 below show alternative chemical reactions for GOx-glucose oxidation. As shown in the previous process, oxygen can reactivate or reoxidize GOx to its active form. Processes 9-11 are described in connection with ferricyanide, but may also be adapted for use with other substances in oxidized form (e.g., quinones, ferrocene, osmium complexes, etc.). The quinones, ferrocene, osmium complexes, etc. can be included in a buffer and / or dried in a portion of the porous membrane and resuspended in a buffer. Glucose + GOx(Ox) ⇒ Gluconolactone + GOx(Red) (Process 9) GOx(Red)+2[Fe(CN)] 3- ⇒GOx(Ox)+2[Fe(CN)] 4- (Process 10) Gluconolactone + H2O ⇒ gluconic acid (Process 11)

[0026] Processes 4 and 11 result in a decrease in the pH level of the solution (e.g., into the acidic regime in the case of a low-buffer system) that corresponds to an electromotive force on an electrode placed adjacent to the test line of the LFA, but in this case, no GOx reaction occurs. In low-concentration buffer solutions, a change in pH level occurs, resulting in a measurable Nernst voltage and / or current.

[0027] In the redox cycle of GOx, electrons are transferred in one half of the bioelectrochemical cell, resulting in the formation of [Fe(CN)6] 3- [Fe(CN)6] 4- The ferricyanide molecule acts as an electron mediator and can eventually diffuse to the electrode. The concentration difference between the electrode at the top of the cell and the electrode at the bottom of the cell allows the Nernst equation to be satisfied:

number

number

[0028] In some examples disclosed herein, the medium (e.g., membrane, paper, and / or substrate) of a lateral flow immunoassay device can act as a bioelectrochemical cell. For example, instead of using paper dried with glucose and redox species to act as a bioelectrochemical cell, a liquid assay buffer may be applied to the lateral flow immunoassay device containing glucose and redox species. In some examples, the buffer can dilute the sample and, by containing glucose and redox species, promote a reaction that generates a current or voltage. In such examples, the membrane of the lateral flow immunoassay device acts as a salt bridge. Thus, when immobilized antibodies, analytes, and / or antigens corresponding to the target analyte are attached to and immobilized on GOx in the test zone, the GOx reacts with the glucose and redox species in the assay buffer to diffuse electrons into a zone of the medium outside the test zone, thereby creating a voltage and / or current. Thus, the bioelectrochemical cell is based on a target zone and a zone outside the target zone. Thus, a first electrode is placed in the test zone and a second electrode is placed in a zone outside the test zone, and a voltage and / or current can be measured between the two test zones to determine whether a target analyte is present. As used herein, a bioelectrochemical cell is a cell that converts chemical energy from a fuel and an agent (e.g., an oxidant) into electricity through a pair of oxidation-reduction reactions. A bioelectrochemical cell can also be a biofuel cell (e.g., a fuel cell that oxidizes a fuel using an enzyme as a catalyst), a concentration cell (e.g., an electrolysis cell containing two half-cells with identical electrodes that produces a voltage and / or current when the concentrations in the two half-cells are different (e.g., a GOx glucose reaction at one electrode and no reaction at the other electrode), a galvanic cell (e.g., containing two different metals immersed in an electrolyte connected by a salt bridge or porous medium), and / or any other cell that converts chemical energy into electricity.

[0029] As disclosed above, in some examples, an LFA device may use a circuit-completion mechanism in the test and / or control lines of the LFA device to generate or measure an electrical signal corresponding to a test result. For example, a machine-readable LFA device has a test zone that acts like an electrical switch. In such an example, a conjugate pad contains gold nanoparticles labeled with antibodies, analytes, and / or antigens corresponding to a target analyte. Thus, if the sample contains the target analyte, the target analyte will attach to the gold labeled with the antibody, analyte, and / or antigen and be immobilized in the test zone by the corresponding immobilized antigen, analyte, and / or antibody. Additionally, an autocatalytic silver enhancer (e.g., silver ions and a reducing agent such as hydroquinone, aminophenol, or ascorbic acid) is applied to the test zone, causing the silver to react with the gold and amplify its size. When the silver amplifies beyond a certain size, the amplified silver attached to each gold nanoparticle on the test zone comes into contact with each other, resulting in a connection between the electrodes, increased conductivity, reduced resistance, and / or a short circuit. In examples disclosed herein, electrical connections can be applied to both sides of the test zone, and a voltage can be applied to one side of the electrical connection. When a target analyte is present, the silver amplifies, creating a connection, increased conductivity, decreased resistance, and / or a short circuit, and application of the voltage causes current to flow from one electrical connection to the other. Thus, in examples disclosed herein, the presence of a target analyte in a sample is determined (e.g., corresponding to a positive test result) by measuring a signal (e.g., current flow and / or resistance between the electrical connections to the test line (e.g., a short circuit has a low resistance, and an open circuit has a high (infinite) resistance)). If the measured signal has a current above a current threshold or a corresponding resistance below a resistance threshold, the examples disclosed herein flag the test as positive for the corresponding target analyte; if the measured signal has a current below a current threshold or a corresponding resistance above a resistance threshold, the examples disclosed herein flag the test as negative for the corresponding target analyte, thereby eliminating the need for a visual indicator.

[0030] Alternatively, the reduction of silver by oxidation of the reducing agent results in electrons e - and recombines with H2O to form H3O + proton H + The silver amplification reaction (which releases H₃O) is initiated by changing the pH of the low-buffered reaction solution. + In one bioelectrochemical cell where silver amplification occurs at the top of the cell, the Nernst equation

number

[0031] Because an LFA device can accommodate one or more specific durations during which a user should perform a particular action (e.g., a duration for applying sample and / or buffer, a duration for obtaining results after applying sample, a duration for scanning the LFA device with a reader, a duration for moving a mechanical part of the LFA device, etc.), examples disclosed herein include mechanisms and processes for tracking time and / or guiding a user through one or more steps. For example, after sample and / or buffer are applied to the LFA, a user may be required to wait a first duration before obtaining results. Examples disclosed herein can include a timer in the LFA device and / or reader that tracks time to guide a user through the testing process. In some examples, the timer is powered by the current and / or voltage generated by the bioelectrochemical cell. In some examples, the LFA device may transmit timing information to the LFA reader, and the LFA reader may display and / or present the one or more durations to the user. In some examples, the LFA reader can track duration based on confirmation from the user and guide the user as to when to perform certain tasks to ensure that the task is not performed too early or too late (e.g., reading the result too early or too late, scanning the LFA too early or too late, or adjusting the LFA device too early or too late). By providing a reader to guide the user through the testing product, the LFA device can be operated by less trained and / or less educated users. The reader can also be implemented by the patient for self-testing by following the guides presented in the reader.

[0032] 1A illustrates an exemplary environment 100 including an exemplary machine-readable LFA generator 102 that generates an exemplary machine-readable LFA chip, strip, or LFA device 104 (shown in an overhead view). The exemplary machine-readable LFA device 104 includes an exemplary sample pad 106, an exemplary conjugate release pad 108, an exemplary porous medium 109, an exemplary test area 110, exemplary bioelectrochemical cells 111a-111n, an exemplary wicking pad 112, an exemplary inlet 113, an exemplary wireless chip 114, and an exemplary antenna 115. The environment 100 of FIG. 1A further includes an exemplary user device or reader 116 that determines test results (e.g., diagnostic test results) of a sample being applied to the exemplary machine-readable LFA device 104. The exemplary reader 116 includes an exemplary machine-readable LFA reader application 117, an exemplary antenna 118, and an exemplary user interface 120. Although the example of FIG. 1A determines test results based on bioelectrochemical cells 111a-111n, FIG. 1A may be described in conjunction with other techniques for determining test results based on electrical signals, as disclosed elsewhere herein.

[0033] 1A generates an exemplary machine-readable LFA device 104 (and / or an exemplary machine-readable LFA device 300 of FIG. 3A). For example, machine-readable LFA generator 102 generates machine-readable LFA device 104 to include an exemplary sample pad 106, an exemplary conjugate release pad 108, an exemplary porous medium 109, an exemplary test area 110, exemplary bioelectrochemical cells 111a-111n, an exemplary wicking pad 112, an exemplary inlet 113, an exemplary wireless chip 114, an exemplary antenna 115, and / or wires or etchings (not shown) included in the housing structure. The number of tests, the type of tests (e.g., pregnancy, Ebola, HIV, influenza, covid, cancer, sexually transmitted disease (STD), etc.), the number of control zones, the type of control zones (e.g., positive control, negative control, etc.), and / or the type of machine-readable LFA are based on instructions from a user and / or manufacturer. For example, if a user desires that the exemplary machine-readable LFA device 104 include a single test for pregnancy, the machine-readable LFA generator 102 generates an exemplary conjugate region including antibodies, analytes, and / or antigens corresponding to target analytes corresponding to pregnancy, antibodies, analytes, and / or antigens labeled with specific molecules (e.g., gold nanoparticles, GOx, etc.). In such an example, the machine-readable LFA generator 102 generates the test area 110 to include the antibodies, analytes, and / or antigens immobilized to bind to or attach to the target analytes, and a bioelectrochemical cell including a first half attached to the test area 110 (e.g., paper impregnated with an enzyme substrate (e.g., glucose), a reducing agent (e.g., hydroquinone, aminophenol, vitamin C (e.g., ascorbic acid found in vitamin C), etc.), and / or an electron mediator or redox species (e.g., potassium ferricyanide, ferrocene, oxygen, a ferrocene derivative, etc.)).The exemplary machine-readable LFA generator 102 also generates or otherwise attaches a wireless chip 114 for attachment to the bioelectrochemical cell to determine whether a sample (e.g., a biological sample) is positive or negative for a target analyte corresponding to pregnancy. An exemplary machine-readable LFA generator 102 is disclosed separately in connection with FIG. 4.

[0034] The exemplary machine-readable LFA device 104 of FIG. 1A is a bioelectrochemical cell-based LFA (e.g., a concentration cell with Nernst voltage detection) including exemplary bioelectrochemical cells 111a-111n. However, the machine-readable LFA device 104 may be another device capable of acquiring data associated with test results on the LFA 104. For example, as disclosed elsewhere below in connection with FIG. 3A, the exemplary machine-readable LFA device 104 may alternatively be a circuit completion (e.g., an electrical short circuit through a low resistance test line)-based LFA device. In some examples, the exemplary machine-readable LFA device 104 is a non-visual indicating biosensor device. For example, the LFA device 104 does not output a visual indication to a user (e.g., because gold nanoparticles are not present on the device) and / or the visual indication is not visible to a user (e.g., because the housing covers a porous medium in which the visual indication can be performed). In some examples, the LFA device 104 is a non-visual indicating circuit completion device. In some examples, LFA device 104 is a visual indicating circuit completed device and / or biosensor device that can provide a visual indication of a result and transmit the result wirelessly to a reader. LFA device 104 may also be a point-of-care device and / or a rapid diagnostic device that includes an application specific integrated circuit (e.g., exemplary wireless chip 114).

[0035] The exemplary machine-readable LFA device 104 of FIG. 1A is a device that includes a sample pad 106 (e.g., sample pad, sample region, sample area, sample zone, etc.). For example, the LFA device 104 may be a porous membrane device, a porous medium device, a fluid transport medium device, a test strip device, a lateral flow test strip device, and / or any fluid sample device. The sample pad 106 is structured to act as a sponge that holds a sample of fluid applied to the sample pad 106. In some examples, the sample pad 106 includes buffer components (e.g., salts, surfactants, etc.) to ensure that target analytes that may be present in the sample bind to components of the conjugate release pad 108. When the sample pad 106 is submerged, fluid retained in the sample pad 106 flows to the conjugate release pad 108. The conjugate pad 108 includes a labeling substance or conjugate configured to bind the target analyte. For example, the conjugate release pad 108 includes conjugates or probes (e.g., antibodies specific to one or more target analytes) labeled with a detectable label, tag, linker, antibody, analyte, antigen, GOx, gold nanoparticles, etc. Target analytes are components corresponding to a particular condition or disease. Thus, the presence of target analytes in a sample corresponds to the presence of a corresponding condition and / or disease in the patient providing the sample. If the sample contains one or more target analytes, the conjugates and / or probes labeled with GOx, gold nanoparticles, etc. will attach to the corresponding target analytes. The sample (e.g., including the probes if the corresponding target analytes are present in the sample) continues to flow through the exemplary porous medium 109 of the machine-readable LFA device 104 toward the wicking pad 112.

[0036] While flowing across the medium 109 of FIG. 1A, the sample flows across the test area 110. The medium 109 may be a porous membrane, a nitrocellulose membrane, paper, and / or other substrates, including non-compartmental substrates that propagate the flow of a biological sample and / or a liquid buffer. The test area 110 includes test zones (e.g., test lines, test areas, test regions, etc.) and / or control zones (e.g., control lines, control areas, control regions, etc.). The test zones contain specific immobilized antibodies, analytes, or antigens that react with corresponding target analytes attached with probes and / or conjugates. Thus, when the target analyte corresponding to a particular test zone is present in the sample, GOx and / or gold nanoparticles are immobilized in the particular test zone. In some examples, the test zones of the LFA 104 correspond to different conditions or diseases, a process known as multiplexing. Multiplexing involves constructing multiple test zones or test lines to detect multiple marks (e.g., multiple types of antibodies / antigens / analytes) in a given sample. Multiplexing has applications, for example, in a single diagnostic test that can test for multiple sexually transmitted diseases. In some examples, the test area 110 includes a control zone that immobilizes specific and / or excess conjugates that flow through the control zone. The control zone corresponds to a target that has dried into the porous medium 109 and indicates that the test is ready for reading (e.g., when the test is complete).

[0037] The test area 110 of FIG. 1A further includes exemplary bioelectrochemical cells 111a-111n (e.g., concentration cells). FIG. 1A shows portions of the bioelectrochemical cells 111a-111n. Other portions are shown in FIGS. 1B-2E and / or 2I-2K. In some examples, the potentiometric cells 111a-111n are paper or other substrates impregnated with an enzyme substrate (e.g., glucose) and / or a reducing agent (e.g., hydroquinone, aminophenol, ascorbic acid found in vitamin C, etc.), and / or an electron mediator or redox species (e.g., potassium ferricyanide, ferrocene, oxygen, ferrocene derivatives, etc.). However, the bioelectrochemical cells 111a-111n can be any type of bioelectrochemical cell, as described above in connection with processes 1-11 above. When GOx (which oxidizes glucose) or gold nanoparticles (autocatalytic silver nitrate reduction (e.g., vitamin C and / or other reducing agents)) are attached to the test zone and / or control zone, the corresponding bioelectrochemical cells 111 a-111 n are activated by generating a voltage according to the Nernst equation, which can be read via the wireless chip 114. Thus, the wireless chip 114 performs bioelectrochemical measurements using the exemplary bioelectrochemical cells 111 a-111 n, where the wireless chip 114 passively measures the potential between two different portions of the biofuel cells 111 a-111 n using two electrodes. In some examples, the bioelectrochemical cells 111 a-111 n are fluidly coupled (e.g., attached) to the test zone and / or control zone during manufacture. In some examples, the bioelectrochemical cells 111a-111n are separated from the test zones and / or control zones during manufacture, and the exemplary LFA device 104 includes a mechanical device that automatically and / or manually pushes the bioelectrochemical cells into contact (e.g., fluid contact) with the test zones and / or control zones when a test is performed (e.g., automatically and / or manually with user intervention pushes the bioelectrochemical cells into contact with the zones when a sample is applied to the LFA 104).

[0038] The test area 110 of FIG. 1A further includes an exemplary wicking pad 112. The exemplary wicking pad 112 of FIG. 1A is an absorbent material that wicks liquid through the LFA. In some examples, the wicking pad 112 includes a cellulose filter. The wicking pad 112 prevents backflow of liquid. In some examples, the wicking pad 112 also acts as a waste container.

[0039] 1A is structured to allow water or another buffer solution applied to the sample pad 106 to flow to the wicking pad 112. In some examples, the water and / or buffer is enclosed in a holding device (e.g., a frangible enclosure such as a bag), and the user presses and / or moves a component of the LFA device 104 (e.g., by breaking the bag) to release the buffer into the holding device. In some examples, the sample pad 106 may be two or more sample pads (e.g., one for the sample and another for water / buffer and / or additional reagents). As the water and / or buffer flows through the bioelectrochemical cells 111a-111n, it resuspends the dried reagents and allows a current to flow when the test zone and / or control zone are attached to GOx and / or gold nanoparticles (e.g., based on mixing of the conjugate with the enzyme substrate, reducing agent, and / or electron mediator of the bioelectrochemical cells 111a-111n). The central area (e.g., the constricted area in FIG. 2A ) between the first portion (e.g., the top portion in FIG. 2A ) and the second portion (e.g., the bottom portion in FIG. 2A ) of the bioelectrochemical cells 111 a-111 n acts as a salt bridge for diffusion-induced homogenization of the concentration gradient, allowing electrons lost in the first portion of the bioelectrochemical cells 111 a-111 n (e.g., by reactions occurring when the target analyte and corresponding conjugate are suspended in the test or control zone) to flow toward the second portion of the bioelectrochemical cells 111 a-111 n, which corresponds to a measurable voltage drop and / or current from the first portion of the bioelectrochemical cells 111 a-111 n to the second portion of the bioelectrochemical cells 111 a-111 n. Additionally or alternatively, the paper / membrane type may also reduce diffusion.

[0040] The exemplary machine-readable LFA device 104 further includes an exemplary wireless chip 114. The wireless chip 114 is a near-field communication (NFC) chip. As such, the wireless chip 114 can obtain power and / or communicate with the reader 116 via an NFC communication protocol. Alternatively, the exemplary wireless chip 114 may be a radio frequency identification (RFID) chip or any other type of wireless chip. The wireless chip 114 includes pins coupled to connectors (e.g., wires, etchings, etc.) that are coupled to electrodes (e.g., directly or via a front-end device, as described elsewhere below). The electrodes are coupled to two ends of each bioelectrochemical cell 111 a-111 n and / or different sections of the porous membrane 109. Thus, when a voltage and / or current is generated by the bioelectrochemical cells 111 a-111 n, the voltage drop and / or current between the two electrodes (e.g., located at opposite ends of the bioelectrochemical cells or at different locations on the porous membrane 109) is greater than a threshold value. In some examples, the generated voltage and / or current can be used to power the radio frequency chip 114 (e.g., to provide power for storing test results in the radio frequency chip 114). The exemplary radio frequency chip 114 includes hardware, software, and / or firmware that can measure current, electromotive force, or voltage drop and / or current to determine whether a target analyte is present in a sample. The radio frequency chip 114 may include an ASIC that encodes manufacturing and / or identification information. The radio frequency chip 114 is powered by the exemplary antenna 115. When the exemplary reader 116 generates a magnetic field within a threshold distance to the exemplary antenna 115, a current is generated in the antenna 115, and corresponding energy is used to power the radio frequency chip 114. This energy can be used to provide a voltage to power the radio frequency chip 114. In some examples, the voltage is, for example, 1.8 volts (V). In other examples, the voltage may be a different magnitude, including, for example, 3.3 V, 5 V, etc. The radio frequency chip 114 is operable when powered.For example, the wireless chip 114 can apply an electric potential during operation. In some examples, the wireless chip 114 operates to measure voltage, current, and / or resistance, etc. Additionally or alternatively, in some examples, the wireless chip 114 operates to transmit identification information (e.g., a device identifier, a test identifier, a serial number, a product code, etc.) to the example reader 116 and / or transmit measurements corresponding to test results (e.g., analog and / or digital values ​​corresponding to voltage and / or current measurements obtained by the LFA device 104). In some examples, communication between the wireless chip 114 and the reader 116 is encrypted using encryption techniques known by both the wireless chip 114 and the reader 116. In some examples, the wireless chip 114 may flag each test zone and / or control zone as positive or negative based on the measured current, electromotive force, and / or voltage drop. In some examples, the wireless chip 114 also stores the results corresponding to the flags and / or transmits the results using the antenna 115. The exemplary wireless chip 114 may also transmit identification information corresponding to the results, such as an LFA identifier, identifiers for the test zone and / or the control zone, etc. In some examples, the wireless chip 114 is coupled to a circuit-completion-based LFA. While the example of FIG. 1A includes the exemplary wireless chip 114 as part of the exemplary LFA 104, the wireless chip may be incorporated into an external device. In such examples, the LFA 104 may include components (e.g., an interface) that may connect electrodes of the LFA 104 to the wireless chip 114. In this manner, the design of the LFA 104 may be simplified to reduce its size and / or cost, and multiple LFAs may be connected to the wireless chip 114 to transmit test results to the exemplary reader 116. The operation of the wireless chip 114 in conjunction with a circuit-completion-based LFA is disclosed separately below in connection with FIG. 3A. The exemplary wireless chip 114 is disclosed separately below in connection with FIG. 5.

[0041] 1A is a smartphone that includes a machine-readable LFA reader application 117, an exemplary antenna 118, and an exemplary user interface 120. Alternatively, the exemplary reader 116 may be a tablet, a personal digital assistant, a laptop, a standalone LFA reader device, and / or any other processing device that includes or is in communication with the exemplary machine-readable LFA reader application 117, the exemplary antenna 118, and / or the exemplary user interface 120. The exemplary machine-readable LFA reader application 117 is an application that may be installed, downloaded, and / or encoded on the exemplary reader 116. In some examples, the exemplary machine-readable LFA reader application 117 may be provided via a near field communication tag or a Bluetooth device.

[0042] In some examples, reader 116 may be split into multiple readers. In such examples, a first reader 116 obtains information from LFA 104 and guides a user through a process with LFA 104, and a second reader 116 obtains test results from LFA 104. For example, in a hospital, hospital information system, LIMS system, inventory consumption monitor, clinic, testing site, etc., a first reader may guide a first user to obtain a sample using the first LFA reader, and once the sample is obtained, the first reader may communicate with a second reader to send LFA device information and start a timer on the second reader when the test is ready. In this manner, a first user can provide an LFA device to a second user, who can scan the LFA device using the second reader when ready.

[0043] 1A directs components of reader 116 to generate electromagnetic signals at various times to (a) obtain identification information from LFA device 104 at a first time, (b) obtain identification information from LFA device 104 at a second time before obtaining the results to verify that the correct device is being read, and (c) obtain results from LFA device 104 (e.g., one or more digital voltages and / or currents corresponding to the results). The example LFA reader application 117 causes electromagnetic fields to be generated at the second time to verify identification information and ensure that the user is reading the test from the correct LFA device (e.g., when reading multiple tests simultaneously). The example machine-readable LFA reader application 117 identifies the results of the LFA-based tests by interacting with wireless chip 114 (e.g., by receiving a wireless signal that identifies the results of the tests). For example, machine-readable LFA reader application 117 controls components of reader 116 to obtain identification information and / or test results corresponding to machine-readable LFA device 104 via NFC, RFID, etc. signals transmitted from wireless chip 114. In some examples, LFA reader application 117 determines information based on the obtained identification information. For example, LFA reader application 117 can determine whether a test has already been read, the type of test being performed, algorithms for identifying and / or classifying the results of the test, whether a test has expired or been recalled, etc. Algorithms (e.g., corresponding to how and when to read one or more electrical signals from a particular LFA device) can be stored locally at reader 116 and / or configured, reconfigured, updated, etc. remotely (e.g., via patches, updates, remote commands, etc.).Once test results are obtained (e.g., samples from LFA device 104), machine-readable LFA reader application 117 determines whether the test is ready (e.g., based on a flag corresponding to the control zone), and if so, determines the results of the test based on a corresponding algorithm (e.g., using voltage and / or current samples from the test line), displays the results using exemplary user interface 120, stores the results in a local database, and / or transmits the results to a monitoring entity for monitoring and / or statistical analysis. In this manner, a manufacturer or other party can process the results, perform diagnostics, and / or identify whether a particular LFA device is likely counterfeit (e.g., if more than a threshold number of results corresponding to the same identification information are determined). In some examples, LFA reader application 117 transmits the raw data. In some examples, the LFA reader application 117 obtains and / or determines (e.g., based on identification information from the wireless chip 114) various other contextual information, including lot number, expiration date, expiration date, test information, signal quality information, chain of custody, etc. Additionally or alternatively, in some examples, the LFA reader application 117 transmits processed data or data resulting from one or more levels of analysis. An exemplary machine-readable LFA reader application 117 is disclosed separately below in connection with FIG. 6.

[0044] 1A wirelessly powers and / or communicates with the example wireless chip 114 (e.g., via the example antenna 115). For example, based on instructions from the example machine-readable LFA reader application 117, the antenna 118 emits a magnetic field to power the example wireless chip 114 and receives wireless information (e.g., an identifier, test results, etc.) from the example wireless chip 114.

[0045] FIG. 1B is a side view of the LFA components of the LFA device 104 of FIG. 1A. FIG. 1B includes an exemplary sample pad 106 of FIG. 1A, an exemplary conjugate pad 108, an exemplary porous medium 109, a portion of exemplary bioelectrochemical cells 111a - 111n, and an exemplary waste pad 112. The exemplary bioelectrochemical cells 111a - 111n are connected via electrodes to the exemplary wireless chip 114 of FIG. 1A as described above in connection with FIG. 1A.

[0046] FIG. 2A shows an exemplary embodiment of each part of the machine - readable LFA device 104 of FIG. 1A when implementing the exemplary bioelectrochemical cells 111a - 111n of FIG. 1A to generate an electrical signal corresponding to a test analysis by an enzymatic reaction. The example of FIG. 2A includes the exemplary porous medium 109 of FIG. 1A, exemplary bioelectrochemical cells 111a - 111d (corresponding, for example, to the bioelectrochemical cells 111a - 111n of FIG. 1A), an exemplary inlet 113, an exemplary wireless chip 114, and an exemplary antenna 115. The exemplary porous medium 109 has two control lines, two test lines, and four bioelectrochemical cells 111a - 111d, but may have any number of test lines, control lines, and / or bioelectrochemical cells. Additionally or alternatively, as described separately below, other techniques (such as circuit - completion techniques that utilize the porous membrane 109 as a bioelectrochemical cell, etc.) may be used to obtain an electrical signal corresponding to the test result.

[0047] The exemplary porous medium 109 of FIG. 2A is structured with two test lines (e.g., T1 and T2) and two control lines (e.g., a positive control (PC) and a negative control (NC)). The negative control line contains immobilized antibodies and / or antigens that bind to the corresponding target analytes that bind to the immobilized antibodies when a sample is applied to the sample pad 106. The negative control line is included to verify that the current generated by the attached bioelectrochemical cell 111d is strong enough for a valid test measurement. For a test to be valid, the amount of voltage and / or current across the bioelectrochemical cell 111d on the negative control line must be less than a threshold value.

[0048] The positive control line contains immobilized antibodies, analytes, and / or antigens that bind to specific and / or excess conjugates labeled with GOx and / or gold nanoparticles and / or specific and / or excess probes labeled with GOx and / or gold nanoparticles, and flows from the conjugate pad 108 toward the wicking pad 112. As the sample flows toward the wicking pad 112, the positive control line is the last section to attach to the conjugates and / or probes, resulting in voltage and / or current generation by the bioelectrochemical cell 111a. Thus, the reader 116 determines whether the test is ready when the voltage and / or current measurement of the bioelectrochemical cell 111a is positive (e.g., greater than a threshold amount of voltage and / or current). Exemplary test lines T1 and T2 each have immobilized antibodies, analytes, and / or antigens corresponding to different target analytes. Thus, if a target analyte for T1 is present in the sample, the target analyte (attached to the GOx- and / or silver nitrate-labeled conjugated antibody, analyte, and / or antigen) will be immobilized on the T1 line.

[0049] The exemplary bioelectrochemical cells 111a-111d in FIG. 2A are paper impregnated with redox species (e.g., (i) potassium ferricyanide and (ii) (a) glucose or (b) ascorbic acid) and dried. In some examples, the bioelectrochemical cells 111a-111d are not initially attached to the porous medium 109, and the housing includes a mechanical device that automatically and / or manually presses the bioelectrochemical cells into contact with the porous medium 109 for testing. In other examples, the bioelectrochemical cells 111a-111d are initially attached to the porous medium 109. The bottom halves of the bioelectrochemical cells 111a-111d are coupled to the wireless chip 114 via a single pin, although they may be coupled to the wireless chip 114 via four separate pins.

[0050] The exemplary inlet 113 in FIG. 2A allows water or a buffer solution to resuspend the dried reagents in the bioelectrochemical cells for testing. Thus, before, during, and / or after adding a sample to the sample pad 106, a user applies water and / or a buffer solution to the sample pad 106 and / or a separate sample pad, which flows through the inlet and resuspends the dried reagents in the bioelectrochemical cells 111a-111d. Thus, the central sections of the bioelectrochemical cells 111a-111d act as salt bridges for diffusion-induced homogenization of the concentration gradient. This allows GOx (if immobilized on the test or control line) to oxidize glucose in the corresponding bioelectrochemical cell 111a-111d. Alternatively, this allows silver nitrate to oxidize ascorbic acid in the corresponding bioelectrochemical cell 111a-111d, and the reducing agent (e.g., ascorbic acid) to oxidize H. + (H3O + When one or more half cells of the bioelectrochemical cells 111a-111d are oxidized in the redox cycle of GOx, electrons are transferred in that half cell, resulting in the reduction of silver nitrate by the release of [Fe(CN)6]. 3- [Fe(CN)6] 4-The ferricyanide molecule acts as an electron mediator and can eventually diffuse to the electrode. The concentration difference between the upper and lower cells satisfies the Nernst equation:

number

[0051] 2A is structured around other components of the exemplary machine-readable LFA device 104. The connection between the bioelectrochemical cells 111a-111d, and / or the wireless chip 114, and the antenna 115 may be via wires or etchings.

[0052] 2B illustrates another implementation of the exemplary antenna 115 of FIG. 2A in the LFA device 104 of FIG. 1A. In the example of FIG. 2B, the antenna is structured in a dedicated space (rather than around components of the machine-readable LFA device 104). Additionally or alternatively, the exemplary antenna 115 may be structured in a different configuration.

[0053] FIG. 2C illustrates exemplary implementations 200a-200f of one or more of the bioelectrochemical cells 111a-111n of FIGS. 1A, 1B, 2A, and / or 2B in the LFA device 104 of FIG. 1A. While FIG. 2C illustrates six different implementations 200a-200f, other implementations of the bioelectrochemical cells 111a-111n may exist. One or more of the bioelectrochemical cells 111a-111n may be implemented as a combination or topological variation of one or more of the exemplary implementations 200a-200f. For example, implementation 200f may include any number of meanders between the first and second portions of implementation 200f. Alternatively, the porous membrane 109 may act as a bioelectrochemical cell, as described separately below in connection with FIG. 2D.

[0054] FIG. 2D shows another exemplary embodiment of a top view of the porous medium 109 of the machine-readable lateral flow immunoassay 104 of FIG. 1A, which generates an electrical signal corresponding to a test analysis via an enzymatic reaction. As shown in FIG. 2D, the porous medium 109 includes a positive control zone (PC), a test zone (T1), and a negative control zone (NC). Additionally or alternatively, the porous medium 109 may include any number and / or type of control and / or test zones. The exemplary porous medium 109 of FIG. 2D includes an exemplary membrane compression or cut 201, exemplary electrodes 202a-202f corresponding to the different zones. The exemplary electrodes 202a-202f of FIG. 2D have different widths, but can have the same width and / or be structured with any width. The width of electrodes 202a-202f may be based on, for example, the shape of porous membrane 109, the size of the salt bridge between the working electrode (e.g., electrode 202a) and the reference electrode (e.g., electrode 202b), whether they overlap a particular test zone, or whether they are outside the reference area. In some examples, electrodes 202a, 202c, 202e are wider than electrodes 102b, 102d, 102f (e.g., the reference electrodes), and electrodes 202a, 202c, 202e are wider than the test bands to allow for the most flexible positioning tolerances when assembling and manufacturing / printing the test bands. The spacing between the working and counter electrode pairs [electrode 202a, reference electrode 202b], [electrode 202c, reference electrode 202d], and [electrode 202e, reference electrode 202f] is as small as possible (e.g., 10 nanometers (nm) to 5 millimeters (mm), but can be as small as 1 nm). Exemplary electrodes 202a-202f may be silver-carbon electrodes, copper electrodes, graphite carbon electrodes, titanium electrodes, brass electrodes, platinum and palladium electrodes, screen-printed carbon electrodes doped with ferrocyanide, any other oxidizing material, or electron donor, and / or any other type of electrode. In some examples, electrodes 202a, 202c, and 202e are copper electrodes, and the reference electrode is a carbon electrode.By having a pair of electrodes (e.g., a working electrode and a reference electrode) for a single test and / or control line, a low-impedance salt bridge can be formed across the porous membrane 104 between the pair of electrodes. This facilitates generating a voltage and / or current by reading the voltage and / or current between the pair of electrodes without using an external power source. In some examples, the electrodes 202a-202f are not engaged with the porous medium 109 until it is time to read the result. Therefore, one or more mechanical devices may be used to keep the electrodes 202a-202f from engaging (e.g., contacting) the porous medium 109 until it is time to read the result. An example of one or more mechanical devices for engaging and / or disengaging the electrodes 202a-202f with the porous medium 109 is disclosed separately below in connection with Figures 2N-2R.

[0055] In some examples, a voltage regulator and / or driver of the wireless chip 114 may apply an electric potential (e.g., voltage, bias, etc.) across one or more of the electrodes 202a-202f to assist, promote, and / or improve one or more chemical reactions occurring in the porous membrane 104. In some examples, the applied electric potential is a poise potential or poise. Applying the electric potential to the electrodes promotes and / or induces a chemical reaction (oxidation and / or reduction) that results in a stronger signal corresponding to the presence of the target analyte. A stronger signal may include, for example, an increased current signal amplitude, a more stable polarity, reduced signal spread, a greater signal-to-noise ratio, and / or higher sensitivity (e.g., 0.001%-0.01%). For example, the poise or electric potential may affect the chemical reaction to allow more electrons to flow when the target analyte is present. For example, the penetration of electrons through the electrode surface of the analyte is related to the applied electric potential (e.g., leading to a quantitative analysis). Thus, applying a potential forces the reaction of the copper at the electrode from its oxidized form to its reduced form. In some instances, the amount of poise, bias, and / or voltage can force and / or support various parts of a chemical reaction. Thus, in some instances, one or more poises and / or voltages can be applied to support one or more of the chemical reactions that result in current flow when a target analyte is present. The application of a potential and / or poise results in increased sensitivity and / or signal robustness. As described elsewhere below, the driver and / or voltage regulator of the wireless chip 114 adjusts the voltage (e.g., 1.8V, 3.3V, 5V, etc.) generated by the antenna (e.g., via an electromagnetic field generated by the reader 116) to one or more lower voltages (e.g., 150mV, -100mV, -200mV, etc.) that can be used to apply one or more voltages (e.g., poise potentials) to the electrodes 202a-202f to increase the signal strength of the current / voltage measured when the target analyte is present during the test.For example, the wireless chip 114 may adjust a supply voltage (e.g., 1.8V, 3.3V, 5V, etc.) to 150mV and apply the 150mV to electrode 202a to generate a voltage of 150mV to promote and / or improve a chemical reaction in the test region in the presence of a target analyte. In this manner, more electrons flow from the test region to the region corresponding to electrode 202b (e.g., the non-test region) than if no potential were applied. The potential that improves one or more chemical reactions may correspond to a positive voltage or a negative voltage. The supply (e.g., application) of the potential may be applied via the working electrode or the counter electrode (e.g., depending on whether the voltage is positive or negative). The wireless chip 114 can apply the potential and / or poise without the use of a battery because it uses energy obtained from the antenna 115 via an electromagnetic field.

[0056] In the example of Figure 2D, the porous medium 109 itself acts as a salt bridge for the biofuel cell. The biofuel cell uses an additional enzyme (e.g., a reductase such as laccase) at the counter electrode (e.g., the cathode). In such an example, the laccase converts oxygen (O2) to 4e by a reaction at the anode. - +4H +The bioelectrochemical (e.g., biofuel) cells 111a-111d of FIGS. 2A and / or 2B are impregnated with glucose and redox species and generate a voltage and / or current when a target analyte reacts with the glucose of the biofuel cell (e.g., after a buffer resuspends the dried agent of the biofuel cells 111a-111d) with the redox species acting as an electron mediator. In the example of FIG. 2D, no chromatography paper (e.g., the impregnated paper of the biofuel cells 111a-111d described above) is included, and the glucose and redox agent are contained in a liquid assay buffer. Thus, the liquid assay buffer containing the glucose and redox agent saturates the porous medium 109 when applied to the sample pad 106. Thus, if the target analyte is present in the sample, the corresponding GOx / gold nanoparticle-labeled conjugate / probe will be immobilized in the corresponding test zone. After the liquid assay buffer is applied, the porous medium 109 is saturated with glucose and redox reagent, so that GOx reacts with (e.g., oxidizes) glucose on the test zones, while the redox reagent acts as an electron mediator to form [Fe(CN)6] at the corresponding test zones. 3- [Fe(CN)6] 4- This result corresponds to a measurable voltage drop and / or current between the test and non-test zones of the porous medium 109, which can be measured by the example wireless chip 114 via the example electrodes 202a-202f. Thus, the example of FIG. 2D is a bioelectrochemical cell integrated into an LFA.

[0057] As noted above, in some instances, an enzymatic reaction with a natural mediator (e.g., oxygen) can occur in the bioelectrochemical cells 111a-111d. In such instances, glucose is oxidized to gluconolactone, and FADH2 is oxidized to FAD to yield HO. Additionally or alternatively, glucose can be oxidized and reduced with oxygen in the presence of glucose oxidase to yield CH 12 O6 and oxygen (O2) react to form CH10 O6 and products (e.g., H2O2 (hydrogen peroxide)). In such an example, the electrode may consist of a screen-printed carbon electrode doped with a metal (e.g., copper) or ferrocyanide. H2O2 is then reduced, and the release of electrons results in oxidation of the metal or ferrocyanide at the electrode. In the latter case, ferrocyanide [Fe(CN)6] 4- reacts to form [Fe(CN)6] 3- The emitted electrons are measured by a sensor (e.g., using current and / or voltage measurements) and processed by a processor (e.g., locally in the wireless chip 114 and / or reader 116) to determine the test result. The surface of copper is typically oxidized in air to CuO (Cu(I)). CuO is oxidized by the reduction of HO to CuO (Cu(II)).

[0058] As described above, an intermediate reaction product (e.g., hydrogen peroxide) is generated by the enzyme glucose oxidase on the control line and / or test line of the porous membrane 109 in FIG. 2D , respectively. In some examples, glucose from the buffer reacts with glucose oxidase on the LFA (e.g., outside the control line or test line) to generate a small amount of product (e.g., hydrogen peroxide) on the test line where glucose oxidase is not immobilized (e.g., when the target analyte is not present in the sample). However, the concentration of the product in such an area is too low to generate enough electrons at the electrode on the target line when the target analyte is not present in the sample. Therefore, in such examples, the small amount of product does not generate a false-positive test result. The product (e.g., hydrogen peroxide) is diluted by the surrounding acetate buffer after it is generated. Therefore, without stopping the flow, the product may migrate toward the wicking pad 112 and not be able to fully or sufficiently react with the electrodes 202a-202f, resulting in a missing or reduced current signal. Also, without stopping the flow, the product (e.g., hydrogen peroxide) produced from the first test line may flow toward the second test line or the control line, thus causing the product (e.g., hydrogen peroxide) corresponding to the first test line to be detected at the second test line or the control line instead of at the first test line, leading to inaccurate results.

[0059] Additionally, electrochemical measurements are based on diffusion processes between the electrodes 202a-202f. Convection, along with diffusion, is an additional factor affecting the current outcome of biochemical reactions when using intact flow. Thus, products (e.g., hydrogen peroxide) that can react with the electrodes to generate an electrical current are created in the control and / or test lines of the porous medium 109 and then diluted with the surrounding buffer (e.g., acetate buffer). Thus, if the electrodes 202a-202f contact the porous medium 109 after the products have flowed to the wicking pad 112, there may not be enough product to react with the metal of the electrodes 202a-202f to generate an electrical signal (e.g., by releasing electrons). Therefore, in examples disclosed herein, the flow may be interrupted (e.g., slowed, stopped, etc.) (e.g., fully or partially) to prevent and / or slow the migration of products away from the test and / or control zones. In some examples, a mechanical device may be used to stop flow by cutting (e.g., fully or partially) the exemplary porous medium 109 at the exemplary membrane cut 201 to stop the product from flowing toward the exemplary wicking pad 112. Additionally or alternatively, flow may be stopped by applying a substance (e.g., adhesive, gel, chemical, etc.) to the porous membrane 109, activating a substance on the porous membrane 109, compressing the porous membrane 109, etc. Thus, the product (e.g., hydrogen peroxide) will remain at the corresponding test and / or control line and react with the metal of the electrodes 202a-202f. While the example of FIG. 2D includes two membrane cuts 201 (e.g., before the first test / control line and after the last test / control line), it is also possible for membrane cuts to exist between different test / control lines and / or for the membrane cut before the first test / control line to be removed. An example of one or more mechanical devices that cut through the porous medium 109 to stop, obstruct, or resist flow is described separately below in connection with Figures 2L-2R.

[0060] Additionally or alternatively, a mechanical device can apply compression to the porous medium 109 to create multiple barriers (e.g., along the lines shown by membrane cuts 201) that act as barriers to stop the product (e.g., hydrogen peroxide) from flowing toward the wicking pad 112. Additionally or alternatively, a chemical (e.g., adhesive, gel, oil, etc.) can be added to or contained on and / or in the porous membrane (e.g., along the lines shown by membrane cuts 201) that acts as a barrier to stop the product from flowing toward the wicking pad 112. Additionally or alternatively, any mechanism (e.g., mechanical, electrical, chemical, etc.) that stops the flow and prevents the product (e.g., hydrogen peroxide) from flowing away from the test and / or control zones can be used.

[0061] Also, as disclosed herein, in alternative examples, enzyme-free amperometric redox reactions can be used in the bioelectrochemical cells 111a-111d. For example, the amperometric signal of the LFA device 104 can be measured without the GOx enzyme because the gold of the AuNPs can act as a catalyst. In such examples, the use of thiosulfate can improve the signal, as shown in processes 6-8 above. Also, as shown in process 8 above, thiosulfate, ferricyanide, and KBr or KCl react, with the AuNPs catalyzing the reduction of ferrocyanide to generate an electronic signal.

[0062] 2D, electrode 202c contacts the T1 test zone, and electrode 202d contacts a non-test zone (e.g., the porous medium outside the PC, T1, and NC zones). In such an example, if a target analyte corresponding to T1 is present in the sample, the sample, when applied to sample pad 106, flows into conjugate pad 108, binds to the GOx-, gold nanoparticle-, and / or other label-labeled conjugates and / or probes, and continues through porous medium 109 to waste pad 112. Since the target analyte is present in the sample, it will attach to the GOx / gold nanoparticle-labeled conjugate / probe and become immobilized in test zone T1. Thus, after the porous medium 109 is saturated with the liquid buffer assay (e.g., after a threshold time after the liquid buffer assay containing glucose and redox species is applied to the sample pad 106), the GOx / gold nanoparticles in test zone T1 will oxidize the glucose in test zone T1, generating a voltage drop and / or current between test zone T1 and the area adjacent to the test zone where electrode 202d is located (shown as U2 in FIG. 2D ). The exemplary wireless chip 114 measures the voltage drop and / or current from electrode 202c to electrode 202d and determines that the target analyte is present when the voltage drop and / or current is above a threshold.

[0063] In operation, when the example of FIG. 2G is implemented in the LFA device 104 of FIG. 1A, a user or technician applies a sample (e.g., 25 microliters of urine, blood, etc.) to the exemplary sample pad 106. After applying the sample, the user or technician applies a biofuel-based buffer (e.g., six drops of a liquid assay buffer containing glucose and a redox agent) to the sample pad 106 and / or a dedicated buffer pad. After application, the user waits a threshold amount of time (e.g., 15 minutes) required to activate the fuel cell of the porous medium 109. In other examples, the threshold amount of time may be 20 minutes or some other value. In some examples, the threshold amount of time is monitored using a software / application-based timer or a timer powered by the voltage and / or current generated by the porous medium 109. After the threshold duration, the user and / or technician interacts with the LFA device using the reader 116 to obtain diagnostic test results (e.g., by generating an electromagnetic field), and within a duration (e.g., 1 minute), the wireless chip 114 of the LFA device 104 transmits the results to the reader 116 using the antenna 115. In some examples, the duration for reading the diagnostic test results may be other values, such as less than 1 minute or more than 1 minute (e.g., 2 minutes, 3 minutes, or more). In some examples, the reader 116 instructs the user to take action to stop the flow on the LFA device 104. In such examples, the reader 116 may instruct the user to take action within a second duration (e.g., 5 minutes) after the threshold amount of time (e.g., 15 minutes). In some examples, the reader 116 may prompt the user to confirm that the correct LFA device was selected for shearing prior to the second duration (e.g., 5 minutes) by scanning the LFA device 104. The amount of time the reader 116 needs to power the wireless chip 114 to measure and transmit the electrical signal may be 1-3 seconds. In some examples, the reader 116 prompts the user to confirm that action to stop the flow has been taken.The reader 116 then starts a clock, timer, and / or countdown of the duration (e.g., 1 minute) for which the diagnostic test will be read. In some examples, the reader 116 provides a display on the user interface 120 indicating the time and duration as disclosed herein.

[0064] FIG. 2E is a side view of the porous medium 109 of the machine-readable lateral flow immunoassay of FIG. 2D. In the example of FIG. 2E, the layer containing electrodes 202a-202f is in direct contact with the porous medium 109. In some examples, the electrodes are incorporated into a non-conductive layer, and the non-conductive layer containing electrodes 202a-202f is placed in contact with the porous medium (e.g., during manufacturing) so as to align with electrodes 202a-202f as shown in FIG. 2D. In some examples, electrodes 202a-202f are each placed in contact with the porous medium 109 (e.g., during manufacturing) and aligned as shown in FIG. 2D. In some examples, electrodes 202a-202f do not contact the porous membrane 109 until the device is ready to be read, as described separately below in connection with FIGS. 2L-2R.

[0065] Figure 2F shows exemplary conjugates that may be attached to immobilized antigens, analytes, and / or antibodies on the test zone on the porous medium 109 of the machine-readable lateral flow immunoassay of Figures 2A-2E for an exemplary HIV test. Figure 2F shows one exemplary embodiment 204. Figure 2F further includes an HIV-1 target analyte 206, a recombinant HIV-1 capture antigen 208, an HIV-2 capture antigen 210, an HIV-1 antibody, an HIV-1 antigen and glucose oxidase complex 211, a recombinant immobilized HIV-1 antigen 212, a recombinant immobilized HIV-2 antigen 214, and an antiserum 216.

[0066] During testing, a user and / or patient applies a patient biological sample and / or buffer solution via the sample pad 106. In the example of FIG. 2F, the sample includes an exemplary HIV-1 target analyte 206. The biological sample and / or buffer flows toward the exemplary wicking pad 112 of FIGS. 1A and 1B. The exemplary conjugate pad 108 has been pretreated with exemplary recombinant HIV-1 capture antigens 208 (e.g., gp41 and p24) and exemplary HIV-2 capture antigens 210 (e.g., gp36) linked (e.g., attached, tagged, etc.) to glucose oxidase. Because the biological sample includes the exemplary target analyte 206 of FIG. 2F, the exemplary target analyte 206 attaches to the exemplary HIV-1 capture antigen 208 and glucose (e.g., corresponding to the formation of an exemplary HIV-1 antibody, HIV-1 antigen, and glucose oxidase complex 211), which is transported toward the wicking pad 112. Test line 1 is coated with exemplary recombinant, immobilized HIV-1 antigens 212 (e.g., gp41 and p24), and test line 2 is coated with exemplary recombinant, immobilized HIV-2 antigens 214 (e.g., gp36). In the case of a positive patient sample with HIV-1 antibodies 206, antibody-antigen-glucose oxidase complex 211 binds to immobilized recombinant HIV-1 antigen 212 on test line 1. However, because the biological sample does not contain the HIV-2 target analyte, nothing binds to test line 2. As described above, antigen-antibody complex 211 linked to an enzyme (e.g., glucose oxidase) produces a product (e.g., hydrogen peroxide) on test line 1 when the enzyme reacts with a buffer (e.g., glucose). The control line in FIG. 2F contains an exemplary antiserum 216 (e.g., goat anti-recHIV antiserum), which binds to exemplary recombinant HIV-1 antigen 208.

[0067] 2D and 2E in an exemplary housing 222. The exemplary housing 222 houses the exemplary sample pad 106, exemplary conjugate pad 108, exemplary porous medium 109, exemplary waste pad 112, exemplary radio frequency chip 114, and exemplary antenna 115 of FIGS. 1A-2C. The exemplary housing 222 further houses the exemplary electrodes 202a-202f of FIGS. 2D and 2E. The exemplary housing 222 includes exemplary openings 223, 225 and exemplary layers 224, 226, 228.

[0068] The top layer 224 of the exemplary housing 222 in FIG. 2G includes exemplary openings 223, 225 that allow a user and / or technician to apply sample and / or liquid buffer. In some examples, the sample is applied through opening 225, while the liquid buffer is applied to opening 223 located near the edge of the housing 222. This allows the buffer to wash the sample from behind, as the lateral flow direction is left to right in the example shown in FIG. 2G. Alternatively, the housing 222 may include a single opening for both the sample and the liquid buffer. In some examples, openings 223, 225 include caps to protect against evaporation (e.g., of the sample and / or liquid buffer). Additionally or alternatively, the housing 222 may include physical structures (e.g., foam pads) on the underside of the top layer 224 and / or middle layer 226 for applying uniform pressure to the porous medium 109 (e.g., by user interaction with the housing 222). In this way, the sample and / or liquid buffer is spread evenly throughout the porous medium 109. The second / middle layer 226 includes the wireless chip 114, the antenna 115, and the electrodes 202a-202f. In some examples, the lower portion of the top layer 224 includes pads that press the electrodes 202a-202f into contact with the porous medium 109 to more fully connect the electrodes 202a-202f with sections of the porous medium 109.

[0069] In some examples, the intermediate layer 226 may further include additional electrodes to mitigate the risk of reading the LFA of the lower layer 228 too early and / or too late. For example, the exemplary intermediate layer 226 may include an electrode (e.g., an anode) in contact with the waste pad 112 and / or an electrode (e.g., a cathode) in the waste pad in contact with the waste pad 112. The waste pad 122 may be impregnated with ascorbic acid, which reacts with molecules in the waste pad 122 when saturated during testing to generate a voltage, current, and / or electromotive force (e.g., due to the various pH levels the electrodes are in contact with). In this way, the wireless chip 114 can read the voltage and / or current difference between the electrodes in the waste pad 112 to determine whether the LFA-based test is ready and / or whether the user has waited too long to receive accurate results. For example, before the test is ready to be read, the anode electrode will not measure voltage, current, and / or EMF because the dried citric acid has not been resuspended with buffer, indicating that the test is not ready to be read. When the test is ready to be read, the anode electrode will measure voltage, current, and / or EMF because the dried citric acid has been resuspended with buffer, indicating that the test is ready to be read. Also, if the test is read too slowly, the resuspended citric acid will diffuse to the cathode area and cancel the EMF, indicating that the test time has expired and there is no longer a consistent flow throughout the device to output an accurate result (e.g., the test is no longer possible to read). The lower layer 228 of the housing 222 includes an LFA material.

[0070] FIG. 2H illustrates another exemplary embodiment of the machine-readable lateral flow immunoassay 104 of FIG. 1A. As shown in FIG. 2H, the machine-readable lateral flow immunoassay 104 includes the porous medium 109 of FIG. 1 and exemplary quantum dots 230 positioned on an exemplary working electrode 232. The exemplary lateral flow immunoassay 104 further includes an exemplary working electrode 232, an exemplary counter electrode 234, and an exemplary reference electrode 236. The exemplary electrodes 232, 234, and 236 may be silver-carbon electrodes, copper electrodes, graphite carbon electrodes, titanium electrodes, brass electrodes, platinum and palladium electrodes, ferrocyanide-doped screen-printed carbon electrodes, and / or any other type of electrode or combination of electrodes. The machine-readable lateral flow immunoassay 104 of FIG. 2H may be adapted for use with the bioelectrochemical cell described above.

[0071] The exemplary quantum dots 230 in FIG. 2H act as conjugates on the exemplary LFA 104. Different quantum dots (e.g., zinc sulfide, lead sulfide, magnesium sulfide, copper sulfide, cadmium sulfide, etc.) may also be present as process controls, negative controls, and / or corresponding to one or more target analytes. During manufacturing, the exemplary machine-readable LFA generator 102 can dissolve the quantum dots 230 in a weak acid or suitable solvent to produce dissolved quantum dots that are added to the conjugate pad of the LFA 104. Thus, when a sample is applied to the LFA 104, the target analytes corresponding to a particular quantum dot attach to the quantum dot. As the quantum dots with attached target analytes flow toward the test zone of the porous medium, they are immobilized by antigens, analytes, and / or antibodies in the test areas corresponding to one or more target analytes.

[0072] The exemplary working electrode 232 in FIG. 2 is in contact with the porous medium of the LFA 104. Thus, the working electrode 232 is in contact with the test area and (e.g., if a target analyte is present) any immobilized quantum dots. To determine whether the target analyte is present, the wireless chip 114 or another device may perform a stripping voltammetry process. To set up the stripping voltammetry process, the wireless chip 114 or other voltage source applies a voltage to the working electrode 232 for a specific amount of time (e.g., 60-180 seconds) to deposit (e.g., coat) the immobilized quantum dots on the working electrode 232. After depositing the quantum dots on the working electrode 232, the wireless chip 114 can perform the stripping voltammetry process for a duration (e.g., 60-240 seconds). Stripping voltammetry involves changing the potential between the counter electrode 234 and the reference electrode 236, resulting in a change in current and / or voltage if quantum dots are deposited on the working electrode 232. The wireless chip 114 determines that the target analyte is present when the change in current and / or voltage is measured to be greater than a threshold amount.

[0073] 2I-2K illustrate example front-end channels 240, 250, 260 interfacing between the example bioelectrochemical cells 111a-111d of FIGS. 1A, 1B, 2A, and / or 2B and the wireless chip 114 of FIGS. 1A, 2A, and / or 2B. Additionally or alternatively, the example front-ends 240, 250, 260 may interface the electrodes 202a-202f, 234, 236 of FIGS. 2D, 2E, and / or 2H with the wireless chip 114. The example front-ends 240, 250, 260 may be implemented as components external to the wireless chip 114, but may also be implemented within the wireless chip 114 and / or as part of a separate device. If the exemplary wireless chip 114 is implemented in a standalone device (e.g., separate from the LFA 104), the exemplary front ends 240, 250, 260 may also be implemented in a device that includes the LFA 104 and / or the wireless chip 114.

[0074] The example front-end channel 240 of FIG. 2I acts as an electronic multiplexer, a bank of MOSFETs, and / or any other electronic circuitry to transmit signals received from each of the bioelectrochemical cells 111 a-111 d to four inputs of the radio chip 114. The example radio chip 114 outputs control signals to the example front-end 240 to control the bioelectrochemical cells being processed at different times. The radio chip 114 of FIG. 2I includes four inputs (e.g., very high, high, low, and very low) but may include any number of inputs corresponding to any number of levels. The four inputs of the radio chip 114 compare the magnitude of the acquired signals to preset thresholds to identify the amount of measured voltage or current. For example, if the output of bioelectrochemical cells 111a-111d is a voltage (e.g., in the case of potentiometric sensors), a first input may compare the magnitude of the acquired voltage to 80 mV, a second input may compare the magnitude of the acquired voltage to 60 mV, a third input may compare the magnitude of the acquired voltage to 40 mV, and a fourth input may compare the magnitude of the acquired voltage to 20 mV. Thus, if front end 240 outputs a 70 mV signal from first bioelectrochemical cell 111a, wireless chip 114 will determine, based on the comparison, that the acquired signal is high (e.g., greater than 60 mV) but not very high (e.g., greater than 80 mV). Wireless chip 114 may transmit the determined output strength (e.g., very high, high, low, or very low) for each measurement to exemplary LFA reader application 117. In this way, the results may be further analyzed (eg, in the reader 116 and / or another external device, database, server, or data center) to identify patterns, determine test accuracy, and / or for device monitoring.

[0075] 2J is an alternative implementation that acts as a multiplexer and / or demultiplexer that transmits signals received (e.g., accessed, acquired, etc.) from each of the bioelectrochemical cells 111 a-111 d to corresponding inputs of the wireless chip 114. For example, the front-end channel 250 ensures that the first bioelectrochemical cell 111 a is the output to a first input, the second bioelectrochemical cell 111 b is the output to a second input, etc. For example, the front-end channel 250 may be implemented with a multiplexer and demultiplexer, whose select lines are coupled together to transmit the first output of the bioelectrochemical cell 111 a to a first input of the wireless chip 114 and the second output of the bioelectrochemical cell 111 b to a second input of the wireless chip 114. The exemplary wireless chip 114 outputs one or more control signals to the exemplary front-end 240 to control the bioelectrochemical cells being processed at different times. In some examples, the front-end channel 250 may include a multiplexer controlled to sample / measure each of the electrodes at different times, with each measurement passed to a single comparator or analog-to-digital converter on the wireless chip 114. In this manner, all results may be obtained using a single component on the wireless chip 114. In some examples, the front-end 250 is controlled to obtain multiple measurements for each test line and multiple measurements for each control line. For example, the front-end 250 is controlled to obtain multiple measurements for the test and control lines, and the wireless chip 114 transmits the multiple results to the reader 116 and / or performs statistical processing of the multiple measurements before sending the data to the reader 116. The wireless chip 114 in FIG. 2J includes four inputs (e.g., for the four bioelectrochemical cells 111a-111d) but may include any number of inputs corresponding to any number of cells, controls, and / or electrodes. In the example of FIG. 2J, the input of the wireless chip 114 determines the amount of current and / or voltage (eg, as a digital value) corresponding to the first bioelectrochemical cell 111a-111d.The wireless chip 114 may transmit the determined output power for each measurement to an exemplary LFA reader application 117 .

[0076] The exemplary front-end channel 260 of FIG. 2K is an alternative implementation corresponding to a direct channel between each of the bioelectrochemical cells 111a-111d and a corresponding input of the wireless chip 114. For example, a first output of the bioelectrochemical cell 111a is directly coupled to a first input of the wireless chip 114 via a first channel, and a second output of the bioelectrochemical cell 111b is directly coupled to a second input of the wireless chip 114 via a second channel. The wireless chip 114 of FIG. 2K includes four inputs (e.g., for the four bioelectrochemical cells 111a-111d) but may include any number of inputs corresponding to any number of cells, controls, and / or electrodes. In the example of FIG. 2K, the inputs of the wireless chip 114 determine the amount of current and / or voltage (e.g., as a digital value) corresponding to the first bioelectrochemical cell 111a-111d. The wireless chip 114 may transmit the determined output intensity for each measurement to the exemplary LFA reader application 117.

[0077] The example wireless chip 114 of FIGS. 2I, 2J, and 2K includes a comparator that compares the acquired voltage and / or current magnitudes to a threshold value and transmits a result corresponding to the comparison, but may also include an analog-to-digital converter that converts the analog voltage and / or current readings to digital values ​​and transmits the digital values ​​to the example reader 116. The example reader 116 can then determine a result by comparing the digital values ​​to one or more threshold values. In some examples, the wireless chip 114 may acquire multiple voltage and / or current measurements (e.g., voltage samples, current samples, etc.) for each test line and control line, convert the measurements to digital values, and transmit all digital values ​​to the example reader 116. In some examples, the wireless chip 114 may process the values ​​(e.g., perform statistical analysis, such as determining the mean, median, mode, or standard deviation of the multiple measurements) and transmit one or more values ​​representing the multiple measurements to the reader 116.

[0078] 2L-2O illustrate examples of halting (e.g., stopping and / or slowing) the flow of liquid (e.g., including generated products, such as hydrogen peroxide) toward a wicking or waste pad. As described herein, halting the flow allows a certain amount of generated product (e.g., hydrogen peroxide) to accumulate or reside in the test line and react with an electrode in contact with the test line to generate a measurable electrical signal. In some examples, the electrode may react by contacting the test line after the flow is halted. In some examples, the electrode contacts the test line when the mechanism for halting the flow is deployed or activated. FIGS. 2L-2O include portions of the LFA device 104 in a flow position (e.g., FIGS. 2L and 2N) and a read position (e.g., FIGS. 2M and 2O). In the flow position of the LFA device 104, chemical mixing and reactions occur as disclosed herein, causing components and / or products to flow, for example, along the porous medium 109 of FIG. 1A. In the read position, electrodes 202a-202f of Figure 2D are applied to porous medium 109 to begin the read phase of the diagnostic test. The example of Figures 2L-2O includes an exemplary switch 278, one or more exemplary flow stops 280, and an exemplary electrode board or chip 282.

[0079] The example switch 278 in Figures 2L-2O is a component or device that moves between a first position (e.g., the flow position shown in Figures 2L and 2N) and a second position (e.g., the read position shown in Figures 2M and 2O). In some examples, the switch 278 slides within a groove or track 279 in the housing 222 of the LFA device 104. In some examples, the switch 278 slides, translates, or moves within the LFA device 104 between the first and second positions. For example, the switch 278 may be depressed downward to contact the porous media 109.

[0080] The switch 278 includes an exemplary positionable flow stop 280 (e.g., corresponding to the exemplary membrane cutter 201 in FIG. 2D ) that can be positioned to slice, cut, shear, and / or compress the exemplary porous medium 109 when moved from a first position to a second position. In some examples, the flow stop 280 includes one or more blades that cut (e.g., partially or completely) the porous medium 109. In some examples, to partially cut the porous medium 109, the blades cut partially through the depth of the porous medium. In some examples, a portion of the depth of the porous medium 109 (e.g., a lower portion) is left uncut. In some examples, the flow stop 280 includes one or more ridges that press into the porous medium 109. In some examples, the flow is stopped by applying a chemical (e.g., adhesive, gel, oil, etc.) to the porous medium 109 at one or more locations where the flow stop 280 contacts the porous medium 109. In some examples, the chemical may be structured to be released for a duration corresponding to when the liquid sample or buffer is applied (e.g., when the chemical is wetted by the liquid sample or buffer) and the flow is stopped to prevent the product (e.g., hydrogen peroxide) from flowing away from the test zone and / or control zone.

[0081] In the illustrated example, there are two flow stoppers 280. In some examples, there are other numbers of flow stoppers 280, such as one, three, etc. In some examples, if there is one flow stopper, it is positioned to compress, cut, or shear the porous medium 109 between where the electrodes 202a-202f contact the porous medium 109 and the wicking pad 112, separating the wicking pad 112 and preventing further wicking of the product (e.g., hydrogen peroxide) through the porous medium 109. In some examples, a second flow stopper 280 may be used to prevent liquid from flowing back toward the conjugate pad 108.

[0082] The switch 278 is initially placed in a first position (e.g., away from the porous medium 109). As described herein, when a sample is applied to the LFA device 104, the sample flows across the porous medium 109. If a target analyte is present in the sample, a chemical reaction occurs, releasing a product (e.g., hydrogen peroxide) at the target zone. After a duration of time after the sample is applied, the reader 116 may instruct (e.g., command, prompt, etc.) the user to move the switch 278 from the first position to the second position (e.g., over the porous medium 109), causing the exemplary flow stop 280 to cut, shear, and / or compress (e.g., squeeze) the porous medium 109 to stop or reduce the flow of the mixture, including any non-immobilized product (e.g., hydrogen peroxide) corresponding to the electron flow (if present). In some examples, the switch 278 may release a substance (e.g., oil, glue, gel, etc.) along a line on the porous membrane 109 corresponding to the membrane break 201 to act as a barrier to stop the flow of the product (e.g., hydrogen peroxide) that results in current flow. In some examples, the substance may be structured to be released for a duration corresponding to when the liquid sample or buffer is applied (e.g., when the liquid sample or buffer wets the substance) and the flow is stopped to prevent the product (e.g., hydrogen peroxide) from flowing away from the test zone and / or control zone. The product remains in the area of ​​the porous medium 109 between the flow stops 280. Thus, the product (e.g., hydrogen peroxide) may react with the metal of the electrodes 202a-202f present in this area of ​​the porous medium 109. The reaction of the product with the electrodes 202a-202f generates an electrical signal (e.g., by the emission of electrons), which can be read by the exemplary wireless chip 114 to determine that the target analyte is present in the sample. In some instances, if the electrode is in contact with the porous membrane 109 when a product (e.g., hydrogen peroxide) is being generated, reduced and / or inconsistent electron flow may occur, corresponding to a false negative or false positive test result.Thus, the electrodes may be placed in place (e.g., in contact with the porous membrane 109) after a period of time to allow a product (e.g., hydrogen peroxide) to be produced. For example, after sufficient time has passed for glucose oxidase and glucose to react, the switch 278 contacts the exemplary electrodes 202a-202f to produce the product hydrogen peroxide, sufficient to react with the electrodes 202a-202f after flow is stopped to generate an electrical signal of sufficient strength to measure without the need for an external power source. In other words, in some instances, an external power source is not required to provide a potential to facilitate reading of the electrical signal from the reaction at the electrodes because by allowing the electrodes to contact the porous membrane 109 at the appropriate time, a signal of sufficient strength is generated without the need for an external power source. In some instances, application of a potential to the electrodes can promote a chemical reaction that provides a signal of sufficient strength. Contacting the electrodes with the porous membrane 104 while the test glucose and glucose oxidase are reacting generates a smaller electrical signal, which is more difficult to detect. In some examples, the switch 278 may be structured to lock into two preset positions (e.g., a flow position and a read position). In this way, a user is less likely to accidentally move the switch 278 and / or more likely to perform a full shear when directed by the reader 116. For example, the switch 278 may include a mechanism that holds the switch 278 in the flow position and / or the read position until a threshold amount of force is applied or until it is adjusted from the locked position. In some examples, a click is emitted when the switch 278 is moved from the flow position and / or when the switch 278 is moved to the read position, providing an audio indication to the user that the position of the switch 278 has been moved and / or that the switch movement is complete.

[0083] The exemplary electrode plate 282 of Figure 2L is a circuit board including electrodes 202a-202f of Figure 2D. In a first position of switch 278, electrode plate 282 is positioned at an angle relative to porous media 109 and / or switch 278. LFA device 1045 includes an exemplary LFA support 283 in housing 222. Support 283 includes angled slots 284 that accommodate electrode plate 282 at an angle relative to the horizontal of porous media 109 when the LFA device is in the flow position. In this manner, electrodes 202a-202f on exemplary electrode plate 282 are not in contact with porous media 109. When a user moves switch 278 to a second position, movement of switch component 278 and ridge or fulcrum 286 of LFA support 283 changes the angle of electrode plate 282. For example, movement of switch 278 pushes electrode plate 282, rotating it about fulcrum 286 toward porous medium 109 until electrode plate 282 contacts porous medium 109 (e.g., in a second or read position). In the second position, electrode plate 282 is parallel to and / or in contact with porous medium 109 and / or switch 278. Thus, electrodes 202a-202f are present in the area of ​​porous medium 109 between flow stops 280 and can react with reactive products to generate electrons, and wireless chip 114 can measure the current and / or voltage difference corresponding to the electrons to determine whether the target analyte is present in the sample. If electrode plate 282 is not in contact with porous membrane 109 while reader 116 is attempting to read the results, there will be no indication from the electrode corresponding to the control zone or line. Thus, if the user fails to move switch 278 to the read position, electrodes 202a-202f will not contact porous membrane 109 and an error will be output to the user if reader 116 attempts to read the result. In some examples, electrode plate 282 is pivotable.In such an example, a user can move and / or pivot the switch to stop flow over the porous membrane 109 (e.g., by use of the exemplary flow stop 280) while pivoting the exemplary electrode plate 282 into position (e.g., contacting the porous membrane).

[0084] In some examples, instead of or in addition to the example flow stoppers 280 implemented in the example switch 278, one or more of the flow stoppers 280 may be implemented in the electrode plate 282. Thus, when the electrode plate 282 moves toward the porous medium 109, the flow stoppers 280 of the electrode plate 282 can compress, cut, and / or shear the porous medium 109 to stop or reduce the flow of the mixture toward the wicking pad 112. The example switch 278 holds the electrode plate 282 in place in the second position, thereby ensuring that the electrodes 202a-202f maintain contact with the porous medium 109. In some examples, a ridge or fulcrum 286 helps to secure the electrode plate 282 in the first or second position.

[0085] In some examples, the switch 278 is integrated into the electrode plate 282. For example, the side of the switch 278 that faces the porous medium 109 in the second or read position may include the electrode plate 282 such that the electrodes 202a-202f press into and / or contact the porous medium 109 when the switch 278 is moved to the second position. In some examples, the electrode plate 282 may be positioned on the switch laterally offset from the flow stop 280 such that the flow stop 280 contacts the porous medium 109 and stops the flow before the electrode plate 282 contacts the porous medium 109. In other examples, the electrode plate 282 and the flow stop 280 are aligned on the switch 278.

[0086] The example switch 278 compresses, cuts, and / or shears the porous medium 109 and the electrode plate 282 in contact with the porous medium 109 in response to being slid by a user, although the example switch 278 may be structured to compress, cut, and / or shear the porous medium 109 and / or move the electrode plate 282 in contact with the porous medium 109 in other manners including, for example, automatically, by pressing, and / or under any other user and / or processor control.

[0087] FIG. 2P is a perspective view of LFA device 104 including an alternative exemplary switch 292. FIG. 2Q is a partial cross-sectional view of the LFA device taken along line QQ of FIG. 2P. In FIG. 2Q, LFA device 104 is rotated 180 degrees compared to FIG. 2P, with a portion of the top plate shown in phantom and other portions removed along line QQ to reveal the interior of LFA device 104. FIG. 2R is a partial cross-sectional view of the LFA device taken along line RR of FIG. 2P. In FIG. 2R, LFA device 104 is oriented similarly to FIG. 2Q. Switch 292 includes an exemplary grip or actuator 293. Actuator 293 allows a user to move switch 292 between a first position (e.g., a flow position) and a second position (e.g., a read position). Exemplary switch 292 also includes flow detent 280 as disclosed above. In the illustrated example, flow detent 280 is coupled to or positioned on the opposite side of switch 292 from actuator 293.

[0088] FIG. 2Q shows the example switch 292 in a first position (e.g., a flow position) with the flow stop 280 positioned away from the porous medium 109. In this position, the example electrode 202a is not in contact with the test line of the porous medium 109. When ready to read the test, the user presses, translates, slides, or otherwise moves the actuator 293, which moves the switch 292 to the read position (e.g., over the porous medium 109). In this position, the flow stop 280 compresses, cuts, and / or shears the porous medium 109, reducing or stopping flow along the porous medium 109. Thus, any products (e.g., hydrogen peroxide) generated along the porous medium 109 in the area between where the flow stop 280 contacts the porous medium 109 remain in this area and at or near the corresponding test and / or control line. Moving the switch 292 also brings the electrode 202a into contact with the test line of the porous medium 109. Thus, the product at the test line (e.g., hydrogen peroxide) can react with electrode 202a to produce a measurable emission of electrons corresponding to a positive test result. In the example of Figures 2P-2R, a user moves actuator 293 in a sliding motion to operate switch 292 and flow stop 280. In other examples, other actuations may be used, including automatic operation, pressing, squeezing, and / or any other user and / or processor control.

[0089] In some examples, the LFA device 104 and / or housing 222 of FIGS. 2G, 2L-2R may include a compartment containing a holding device (e.g., a bag) that holds a liquid (e.g., a second liquid buffer). The holding device may be located near the porous medium 109. In such examples, a mechanical device (e.g., switch 278, one or more of flow stoppers 280, electrode plate 282, switch 292, and / or another device) may be used to break the holding device and / or release the liquid contained therein. In this way, the liquid may rebuffer the porous medium 109, changing the buffer conditions to optimal and / or improved conditions for antigen binding and providing a more reliable and / or effective electronic readout. The fluid stored in the holding device (e.g., a second liquid buffer different from the liquid buffer applied to the sample pad of the LFA) may be different from the liquid buffer applied after the sample is applied. For example, the second liquid buffer stored in the holding device may contain antibodies and / or antigens that facilitate the reaction of glucose and glucose oxidase to help optimize and / or improve the electrochemical readout (e.g., current and / or voltage output in the presence of the target analyte). Additionally or alternatively, the LFA reader 116 may instruct (e.g., command, prompt, etc.) the user to add additional buffer to the LFA device to increase the reliability and / or effectiveness of the electronic readout.

[0090] 3A shows another exemplary machine-readable LFA device 300 that can be generated by the exemplary LFA generator 102 and / or read by the exemplary machine-readable LFA reader application 117 of the reader 116. The exemplary LFA device 300 implements a circuit completion technique for determining a test result based on an electrical signal. The exemplary machine-readable LFA device 300 is a circuit completion LFA that includes the exemplary sample pad 106, exemplary conjugate pad 108, exemplary porous medium 109, exemplary test area 110, exemplary wicking pad 112, exemplary wireless chip 114, and exemplary antenna 115 of FIG. 1A. The exemplary machine-readable LFA device 300 further includes exemplary test / control lines 302, 304, 306, a first exemplary electrode 308a, and a second exemplary electrode 308b.

[0091] 3A, the exemplary conjugate pad 108 includes conjugates and / or probes (e.g., antigens and / or antibodies) labeled with gold nanoparticles. The conjugates and / or probes correspond to target analytes corresponding to one or more conditions or diseases. Thus, when a sample is applied to the sample pad 106, if the sample contains the target analyte, the corresponding gold-labeled conjugate will bind to the target analyte and flow toward the wicking pad 112.

[0092] The test and / or control zones 302, 304, 306 in Figure 3A extend from one side of the porous medium 109 to the other side of the porous medium 109. The test and / or control zones 302, 304, 306 contain immobilized antigens and / or antibodies corresponding to one or more target analytes. Thus, if a target analyte is present in the sample, the target analyte (bound to a gold-labeled conjugate) will bind to the corresponding test and / or control line 302, 304. After the sample is applied, the user applies a wash containing an autocatalytic silver component (e.g., a solution containing silver ions and a reducing agent such as hydroquinone, aminophenol, ascorbic acid, etc.) to the sample pad 106 or another sample pad. In some examples, the sample pad 106 (or another pad or inlet) may contain silver nitrate, and the reducing agent may be located on a separate paper / membrane that can be attached to the LFA medium after development (e.g., via a mechanical structure that separates the two membranes but can attach the two membranes with user intervention (e.g., a user and / or automated structure that applies force to the mechanical structure to push the two membranes into contact)).

[0093] As the cleaning agent flows toward the wicking pad 112 in FIG. 3A, the silver binds to the immobilized gold, thereby amplifying the size of the immobilized metal in the test and / or control lines 302, 304. When the silver is sufficiently amplified, the silver molecules attached to each immobilized gold nanoparticle come into contact and create a short circuit (e.g., closing an electrical switch and acting as a resistive element, such as a resistor). Thus, a voltage can be applied to exemplary electrode 308a at one end of the test and / or control lines 302, 304, 306, and if the target analyte is present, the amplification of the silver creates a resistive short circuit to a second electrode 308b at the other end of the test and / or control line 302, 304, 306, allowing current to flow from electrode 308a to electrode 308b through the silver-amplified gold nanoparticles, which act like a conduction facilitator (e.g., a small resistor). The exemplary wireless chip 114 measures current, voltage, electromotive force, and / or resistance to determine whether the target analyte is present (e.g., whether a current greater than a threshold or a resistance less than a threshold is detected between the electrodes 308a, 308b). The exemplary wireless chip 114 may test each of the lines 302, 304, 306 in series or in parallel. An exemplary silver amplification process is disclosed separately below in connection with FIG. 3B.

[0094] 3B illustrates an exemplary circuit completion process for the exemplary machine-readable LFA device 300 of FIG. 3A in conjunction with a target analyte attached to the exemplary test line 302 of FIG. 3A. The example of FIG. 3A includes the exemplary porous medium 109, exemplary test line 302, and exemplary electrodes 308a, 308b of FIG. 3A. The example of FIG. 3B further includes an exemplary immobilized antibody / antigen 310, exemplary gold nanoparticles 312, exemplary conjugated antibody / antigen 314, exemplary target analyte 316, and exemplary amplified silver 318. Alternatively, the example of FIG. 3B may be described in conjunction with any of lines 302, 304, 306 of FIG. 3A.

[0095] In step 1, the exemplary immobilized antibody 310 of the exemplary test line 302 is attached to the exemplary target analyte 316. As shown in FIG. 3B, the target analyte 316 is attached to the exemplary conjugated antibody and / or antigen 314 labeled with gold nanoparticles 312. However, the gold nanoparticles 312 are too small to touch each other. Therefore, when a voltage is applied to one of the electrodes 308a, 308b, no current flows (e.g., it acts as an open switch). Therefore, a cleaning agent containing a silver ion solution is applied to the porous medium 109. As shown in step 2, the silver in the cleaning agent amplifies (e.g., accumulates by autocatalysis) at the gold nanoparticles 312. When a sufficient amount of silver is amplified (e.g., by reduction of silver by a reducing agent (e.g., autocatalysis)), a short circuit is created from electrode 308a to electrode 308b (e.g., it acts as a closed switch with a certain resistance). Thus, when the wireless chip 114 applies a positive voltage to electrode 308b, a current flows to the exemplary electrode 308a (e.g., through the silver contacts). The exemplary wireless chip 114 detects the current and determines that the target analyte 316 is present in the sample.

[0096] 4 is a block diagram of an example implementation of the machine-readable LFA generator 102 of FIG. 1A. The example machine-readable LFA generator 102 includes an example user interface 400, an example part generator 402, and an example part applicator 404.

[0097] 4 interfaces with a user and / or manufacturer to obtain instructions regarding how to structure the machine-readable LFA device 104, 300. For example, the user interface 400 can receive (e.g., access, obtain, etc.) instructions regarding the type of machine-readable LFA device to produce, the number of test zones (e.g., in the case of a multiplexed LFA design) and / or types of tests the LFA device 104, 300 will perform, and / or the number of control zones and / or types to include in the LFA device 104, 300.

[0098] 4 produces and / or obtains components for the example LFA device 104, 300. For example, the component generator 402 may produce and / or obtain from storage the sample pad 106, the conjugate pad 108, the porous medium 109, antibodies, antigens, and / or molecules for application to the LFA device 104, 300, the wicking pad 112, the wireless chip 114, the antenna 115, connections, housings, and / or the bioelectrochemical cells 111 a-111 n. To produce a bioelectrochemical cell, the example component generator 403 may impregnate a paper or other substrate with an enzyme substrate (e.g., glucose) and / or a reducing agent (e.g., hydroquinone, aminophenol, ascorbic acid (e.g., vitamin C), etc.), and / or an electron mediator or redox species (e.g., potassium ferricyanide, ferrocene, oxygen, a ferrocene derivative, etc.) and allow the paper to dry, for example, by air drying.

[0099] The example component applicator 404 of FIG. 4 applies the acquired and / or generated components based on user and / or manufacturing instructions to generate the example machine-readable LFA device 104, 300 of FIG. 1A, FIG. 1B, FIG. 2A, FIG. 2B, FIG. 2D, FIG. 2E, FIG. 2H, FIG. 2L-FIG. 2R, and / or FIG. 3A. For example, the component applicator 404 may apply GOx, silver nitrate, a reducing agent, and / or antigens and / or antibodies attached to gold to the acquired and / or generated conjugate pad 108. In the case of gold nanoparticle amplification techniques, silver nitrate may be added to a second pad along with glucose (e.g., fuel and / or enzyme substrate), or a reducing agent may be impregnated into the cell paper / media. The component applicator 404 also structures the components of the machine-readable LFA device 104, 300 to apply antigens and / or antibodies corresponding to the number of tests, the type of tests, the number of controls, and / or the type of controls to the test zones and / or control zones of the test area 110 on the porous medium 109.

[0100] 5 is a block diagram of an example implementation of the radio chip 114 of Figures 1A, 2A, 2B, 2G, 2I-2K, and / or 3A. The example radio chip 114 includes an example antenna interface 500, an example driver / voltage regulator 502, an example sensor 504, an example comparator 506, example result storage 508, an example timer 510, and an example analog-to-digital converter 512.

[0101] The example antenna interface 500 of FIG. 5 interfaces with the example antenna 115. For example, when a magnetic field is present within a threshold range of the antenna 115, the antenna 115 generates a current from the magnetic field that is used to power the example wireless chip 114. Thus, in some examples, the LFA device 104 does not include a storage cell (e.g., a battery for storing energy) and / or does not use an external supply of one or more reactants to generate a voltage. In this manner, the example LFA device 104 is battery-less. For example, the LFA may be powered by one or more of the electromagnetic signals acquired by the antenna 115 (e.g., generating a voltage (e.g., 1.8 V, 3.3 V, 5 V, etc.) based on an electromagnetic signal generated by an external device or reader) or bioelectrochemical cells 111 a-111 d (e.g., generating a voltage based on a chemical reaction resulting from oxidation in a test zone caused by a target analyte attached to an antigen or antibody labeled with GOx and / or gold nanoparticles). In some examples, a voltage corresponding to the harvested power and / or energy used to power the wireless chip 114 is used to generate a potential, including, for example, a Poise potential, that supports one or more chemical reactions on the porous membrane 109. In this manner, the wireless chip 114 can operate satisfactorily without the need for a storage cell, such as a battery. In some examples, the wireless chip 114 may include a battery that provides power to the wireless chip 114. Additionally, once results (e.g., flags or logic values ​​for one or more tests and / or controls) are obtained, the antenna interface 500 may interface with the antenna 115 to transmit the results (e.g., flags) and / or any identification information (e.g., LFA identifier) ​​to the example reader 116.

[0102] The example driver / voltage regulator 502 of FIG. 5 is a voltage driver that outputs a voltage to the electrode 308a of FIG. 3A. As disclosed above, the wireless chip 114 outputs a voltage to determine whether the test zone has created a short circuit, indicating a positive result for the test analyte, by completing a circuit (e.g., silver amplification). Thus, the example driver / voltage regulator 502 outputs a voltage (e.g., in series or parallel) to the upper electrode 308a to ensure that the sensor 504 can measure a current and / or small resistance at the corresponding lower electrode 308b, which in turn corresponds to a short circuit and a positive result. In some examples, the driver / voltage regulator 502 can operate the wireless chip 114 without power from a power cell and / or battery by using energy provided by an electromagnetic field to output a voltage. In some examples, the driver / voltage regulator 502 controls the front-end channels 250, 260 to switch between the electrodes. In some examples, the driver / voltage regulator 502 applies an electric potential (e.g., voltage, poise potential, etc.) to one or more of the exemplary electrodes 202a-202f to promote, assist, and / or improve a chemical reaction at the electrodes that results in hydrogen peroxide flowing from the test area to the non-test area of ​​the porous membrane 109. For example, the driver / voltage regulator 502 may adjust a supply voltage (e.g., 1.8V, 3.3V, and / or 5V) corresponding to the energy of the electromagnetic field to a smaller voltage (e.g., 200mV, 150mV, 100mV, etc.) and apply the adjusted voltage to one or more of the electrodes 202a-202f. The electric potential that improves one or more chemical reactions may correspond to a positive voltage or a negative voltage. The supply (e.g., application) of the electric potential may be applied via a working electrode or a counter electrode (e.g., depending on whether the voltage is positive or negative). The poise, bias, and / or voltage may be derived from a generated voltage corresponding to an electromagnetic field that generates a current through the antenna 115 .

[0103] 5 may be a voltage sensor, a current sensor, an electromotive force sensor, or a resistance sensor. For example, in the case of the fuel-based LFA device 104 of FIGS. 1A, 2A, 2B, 2D, 2E, 2G, 2H, and / or 2L-2R, the example sensor 504 is a voltage and / or current sensor that measures the voltage drop and / or current across one or more of the bioelectrochemical cells 111 a-111 n by sensing the voltage drop and / or current from a first pin coupled to the top of the bioelectrochemical cell and a second pin coupled to the bottom of the bioelectrochemical cell. In another example, in the case of the circuit-completed LFA device 300 of FIG. 3A, the example sensor 504 is a current sensor that measures the amount of current through the test lines 302, 304 and / or the control zone 306 by sensing the current from a first pin coupled to the first electrode 308 a to a second pin coupled to the corresponding second electrode 308 b. In another example, the exemplary sensor 504 is an electromotive force sensor that measures the electromotive force between the first electrode 308 a and the second electrode 308 b and / or between a first pin coupled to a first portion of the bioelectrochemical cell and a second pin coupled to a second portion of the bioelectrochemical cell. If the exemplary sensor 504 is a resistance sensor, it measures the amount of resistance from a first pin coupled to the first electrode 308 a to a second pin coupled to the corresponding second electrode 308 b.

[0104] 5 compares the sensed resistance, current, and / or voltage of each test zone and / or control zone against a threshold amount of resistance, voltage, and / or current. The example comparator 506 may be a software-based comparator (e.g., comparing a digital and / or analog voltage and / or current value against a threshold value), a firmware-based comparator, and / or a hardware-based comparator (e.g., inputting a digital and / or analog voltage and / or current into a first input and a threshold voltage and / or current into a second input and outputting a logic value corresponding to whether the first input is high or low relative to the second input). For example, if the sensor 504 determines a voltage drop across a first bioelectrochemical cell (e.g., bioelectrochemical cell 111a), the example comparator 506 compares the voltage against a threshold value (e.g., 50 mV). If the comparator 506 determines that the voltage is above the threshold, it outputs a first logical value (e.g., "1") and / or flags the result as a positive result for the corresponding target analyte and / or control zone. If the example comparator 506 determines that the voltage is below the threshold, it outputs a second logical value (e.g., "0") and / or flags the result as a negative result for the corresponding target analyte and / or control zone.

[0105] 5 stores results (e.g., flags and / or logical values ​​corresponding to test zones and / or control zones). The result storage 508 may also store identifiers (e.g., device identifiers, machine-readable identifiers for the number and / or type of tests and / or controls used in the LFA device 104, 300, etc.). Thus, the antenna interface 500 can include the identifiers with the results when transmitting the results to the reader 116.

[0106] As disclosed herein, the results of the test are read at a specific time and / or within a specific time window to allow for the chemical reactions disclosed herein. To this end, in some examples, the wireless chip 114 includes a timer 510. The example timer 510 of FIG. 5 tracks the amount of time since one or more of the bioelectrochemical cells 111 a-111 n have been activated (e.g., since generating a voltage). For example, the bioelectrochemical cells 111 a-111 n may apply the voltage generated by the LFA-based test to the example wireless chip 114 to power the wireless chip 114 while the test is being performed. Upon being powered by the voltage generated by one or more of the bioelectrochemical cells 111 a-111 n, the timer 510 may start a wait timer to help identify when the LFA test is ready to be read. For example, the comparator 506 may compare the wait time against an assay time (e.g., a threshold value corresponding to when the LFA test is ready to be read). Thus, if the reader 116 attempts to read the LFA 104 before the LFA 104 is ready, the wireless chip 114 may transmit timing information to the exemplary reader 116 so that the reader 116 can determine that the test is not ready and / or when the test is ready to be read.

[0107] 5 converts analog voltage and / or current values ​​obtained (e.g., sensed) from the sensor 504 to digital voltage and / or current values. The example antenna interface 500 can then transmit the digital values ​​to the example reader 116.

[0108] Figure 6 is a block diagram of an example implementation of the machine-readable LFA reader application 117 of Figure 1A that reads the LFA devices of Figures 1A, 1B, 2A, 2B, 2D, 2E, 2G, 2H, 2L-2R, and / or 3. The example machine-readable LFA reader application 117 includes an example component interface 600, an example result determiner 602, an example test type storage 604, an example result storage 606, and an example timer / counter 608.

[0109] 6 interfaces with other components of the example reader 116. For example, the component interface 600 may send prompts, text, and / or images to the example user interface 120 for display to the user. The example component interface 600 also receives (e.g., accesses, retrieves, etc.) data entered by a user via the user interface 120. For example, if a user enters identification information, patient information, demographic information, etc. into the user interface 120, the example component interface 600 retrieves the input information from the user interface 120. The example component interface 600 also interfaces with the antenna 118 to output a magnetic field that may wirelessly power the example wireless chip 114 via the example antenna 115, and to control the antenna 118 to wirelessly receive (e.g., access, retrieve, detect, etc.) data (e.g., test results, identifiers, etc.) from the example wireless chip 114. In some examples, component interface 600 interfaces with a camera to capture identification information (e.g., a QR code, a barcode, etc.) by photographing and / or scanning LFA device 104. In some examples, component interface 600 interfaces with a transmitter (e.g., corresponding to example antenna 118 and / or another transmitting device) of reader 116 to transmit LFA-based test readings to an entity monitoring the results. For example, component interface 600 and transmitter can transmit results over a network to an external or remote location for inclusion in an EMR and / or to a medical facility, government agency, NGO, etc.The results may include which tests / controls were positive, which tests / controls were negative, the identity of the LFA device or test and / or control used, and / or context or supplemental information obtained from the reader 116 and / or the user (e.g., timestamp, location data from a global positioning system sensor on the reader 116, patient information and / or demographics, lot number, expiration date, expiry date, test information, signal quality information, chain of custody, operator information, etc.). Thus, if the entity monitoring the results determines that more than a threshold percentage of a particular LFA device is being used, the LFA device may be flagged as possibly counterfeit, and subsequent action may then be taken to prevent further counterfeits and / or reliance on test results from counterfeit devices. If network connectivity is unavailable after the test is performed, the component interface 600 may transmit the results after receiving an indication that network connectivity is available.

[0110] 6 determines test readiness and / or the result of the test based on the obtained results and / or identification information. For example, if the identification information is not known, the example result determiner 602 obtains the identification information from the wireless chip 114. Additionally or alternatively, the example result determiner 602 may obtain the identification information by using a camera to scan a QR code on the LFA device 104 or by prompting a user to manually enter a code into the LFA device 104. The result determiner 602 can then access the number of tests, test types, control numbers, and / or control types used on the LFA device 104, 300 from test type storage 604 (e.g., storing the identification information along with the corresponding number of tests, test types, control numbers, and / or control types used on the LFA device 104, 300).

[0111] In some examples, the result determiner 602 authenticates the LFA device 104 based on the obtained identification information. For example, if communication between the LFA device 104 and the wireless chip 114 is encrypted and the wireless chip 114 does not know the encryption protocol, the LFA device 104 will not be able to read the identification information. In this scenario, the result determiner 602 determines that the LFA device 104 is invalid or unauthorized.

[0112] Once the example result determiner 602 determines which flags and / or binary values ​​correspond to each test and / or control, it determines whether the test is ready by comparing the test of the control to the result corresponding to the completed test. For example, if the machine-readable LFA device 104, 300 has a positive control zone, the test is ready to be read when this positive control zone corresponds to a positive test result. If the example result determiner 602 determines that the value and / or flag corresponding to the positive control zone is not positive, it determines that the test is not ready to be read, and the example component interface 600 outputs a notification message, such as an error message, to the user via the user interface 120.

[0113] 6 determines whether a test is ready to be read, based on corresponding values ​​and / or flags in the received results. The example result determiner 602 instructs the component interface 600 to display the results to the user via the example user interface 120. The result determiner 602 may also store the results in the example result storage 606. The result determiner 602 may store the results along with the received identification information and / or any contextual or supplemental information (e.g., patient information, timestamp, demographics, location information, lot number, expiration date, expiry date, test information, signal quality information, chain of custody, operator information, etc.).

[0114] 6 stores information corresponding to the number and / or type of tests and the number and / or type of controls along with identification information (e.g., device identification, test structure identification, etc.) Thus, when the identification information of the example LFA device 104, 300 is obtained, the example result determiner 602 can identify which results correspond to different controls and / or tests.

[0115] The example result storage 606 of FIG. 6 stores the results of the LFA test (e.g., a test that showed a positive result, a negative result, or an intermediate result, and / or any corresponding information) along with any identifying information (e.g., a data matrix code, a test identifier, etc.). In some examples, a user can enter patient information via the user interface 120. In such examples, some or all of the patient information may be added to the result information (e.g., the result storage 606 stores a record of the test result along with the patient information). Additionally or alternatively, the example component interface 600 may collect contextual information about when the test was performed, which may be stored in the example result storage 606 along with the results (e.g., location information, time information, etc.).

[0116] The example timer / counter 608 of FIG. 6 tracks one or more durations (e.g., periods) to determine whether a test should be tagged as invalid or potentially invalid. For example, a test is considered invalid when a user performs an action after a specified duration. For example, after a user verifies that sample and / or buffer have been applied, the example timer / counter 608 tracks a first duration corresponding to when the test is ready to be read. The timer / counter 608 may also track a second duration corresponding to when the user rescans the LFA device 104 to verify that it is the correct LFA device to be read. The timer / counter 608 may also track a third duration corresponding to when the user stops the flow. Such durations may be based on a test algorithm corresponding to the type of test and / or the type of LFA device. In some examples, the timer / counter 608 outputs a timing window (e.g., a clock and / or countdown corresponding to one or more periods) to the user via the user interface 120.

[0117] An exemplary manner of implementing the exemplary machine-readable LFA generator 102 of FIG. 1A is shown in FIG. 4, an exemplary manner of implementing the exemplary wireless chip 114 of FIG. 1A, FIG. 2A, FIG. 2B, FIG. 2G, FIG. 2I-2K, and / or FIG. 3A is shown in FIG. 5, and an exemplary manner of implementing the exemplary machine-readable LFA reader application 117 of FIG. 1A is shown in FIG. 6, although one or more of the elements, processes, and / or devices shown in FIGS. 4-6 may be combined, divided, rearranged, omitted, deleted, and / or implemented in any other manner. Additionally, the example user interface 400, the example part generator 402, the example part applicator 404, the example antenna interface 500, the example driver / voltage regulator 502, the example sensor 504, the example comparator 506, the example result storage 508, the example component interface 600, the example result determiner 602, the example test type storage 604, the example result storage 606, and / or more generally the example machine-readable LFA generator 102, the example wireless chip 114, and / or the example machine-readable LFA reader application 117 of FIGS. 4-6 may be implemented by hardware, software, firmware, and / or any combination of hardware, software, and / or firmware.Thus, for example, the example user interface 400, the example part generator 402, the example part applicator 404, the example antenna interface 500, the example driver / voltage regulator 502, the example sensor 504, the example comparator 506, the example result storage 508, the example component interface 600, the example result determiner 602, the example test type storage 604, the example result storage 606, and / or more generally, any of the example machine-readable LFA generator 102, the example radio chip 114, and / or the example machine-readable LFA reader application 117 of FIGS. 4-6 may also be implemented using one or more analog or digital circuits, logic circuits, programmable processors, programmable controllers, graphics processing units (GPUs), digital signal processors (DSPs), application specific integrated circuits (ASICs), programmable logic devices (PLDs), and / or field programmable logic devices (FPLDs). When reading any of the apparatus or system claims of this patent covering purely software and / or firmware embodiments, at least one of the example user interface 400, example component generator 402, example component applicator 404, example antenna interface 500, example driver / voltage regulator 502, example sensor 504, example comparator 506, example result storage 508, example component interface 600, example result determiner 602, example test type storage 604, example result storage 606, and / or more generally, the example machine-readable LFA generator 102, example radio chip 114, and / or example machine-readable LFA reader application 117 of FIGS. 4-6 are expressly defined herein to include a non-transitory computer-readable storage device or storage disk, such as a memory, a digital versatile disk (DVD), a compact disk (CD), a Blu-ray disk, etc., including software and / or firmware.4, the example wireless chip 114 of FIG. 5, and the example machine-readable LFA reader application 117 of FIG. 6 can include one or more elements, processes, and / or devices in addition to or instead of those shown in FIG. 4-6, and / or can include two or more of any or all of the illustrated elements, processes, and devices. As used herein, the expression “in communication,” including variations thereof, includes direct communication and / or indirect communication through one or more intermediary components, and does not require direct physical (e.g., wired) communication and / or constant communication, but rather additionally includes selective communication at periodic intervals, scheduled intervals, aperiodic intervals, and / or one-time events.

[0118] Flowcharts representing example hardware logic, machine-readable instructions, hardware-implemented state machines, and / or any combination thereof for implementing the machine-readable LFA generator 102, example wireless chip 114, and / or machine-readable LFA reader application 117 of Figures 4-6 are shown in Figures 7-11B. The machine-readable instructions may be one or more executable programs or portions of executable programs for execution by a computer processor, such as the processors 1212, 1312, 1412 shown in example processor platforms 1200, 1300, 1410 discussed below in connection with Figures 12, 13, and / or 14. The programs may be embodied in software stored on a non-transitory computer-readable storage medium, such as a CD-ROM, floppy disk, hard drive, DVD, Blu-ray disk, or memory associated with the processors 1212, 1312, 1412; alternatively, the programs in their entirety and / or portions thereof may be executed by devices other than the processors 1212, 1312, 1412 and / or embodied in firmware or dedicated hardware. Furthermore, although the example programs are described with reference to the flowcharts shown in FIGS. 7-11B, many other ways of implementing the example machine-readable LFA generator 102, the example wireless chip 114, and / or the example machine-readable LFA reader application 117 may alternatively be used. For example, the order of execution of the blocks may be changed, and / or some of the described blocks may be changed, deleted, or combined. Additionally or alternatively, any or all of the blocks may be implemented by one or more hardware circuits (e.g., discrete and / or integrated analog and / or digital circuits, FPGAs, ASICs, comparators, operational amplifiers (op amps), logic circuits, etc.) structured to perform the corresponding operations without executing software or firmware.

[0119] The machine-readable instructions described herein may be stored in one or more of a compressed format, an encrypted format, a fragmented format, a compiled format, an executable format, a packaged format, etc. Machine-readable instructions as described herein may also be stored as data (e.g., portions of instructions, code, representations of code, etc.) that can be utilized to create, manufacture, and / or generate machine-executable instructions. For example, machine-readable instructions may be fragmented and stored on one or more storage devices and / or computing devices (e.g., servers). The machine-readable instructions may require one or more of installation, modification, adaptation, updating, combination, supplementation, configuration, decryption, decompression, deployment, distribution, reallocation, compilation, etc. to enable direct reading, interpretation, and / or execution by the computing device and / or other machines. For example, machine-readable instructions may be stored as multiple portions that are separately compressed, encrypted, and stored on separate computing devices that, when decrypted, decompressed, and combined, form a set of executable instructions that implement a program as described herein.

[0120] In another example, the machine-readable instructions may be stored in a computer-readable state, but may require the addition of a library (e.g., a dynamic link library (DLL)), a software development kit (SDK), an application programming interface (API), etc., to execute on a particular computing device or other device. In another example, the machine-readable instructions may require configuration (e.g., storing a configuration, inputting data, recording a network address, etc.) before all or a portion of the machine-readable instructions and / or corresponding program can be executed. Thus, disclosed machine-readable instructions and / or corresponding programs are intended to include such machine-readable instructions and / or programs, regardless of the particular format or state of the machine-readable instructions and / or programs when stored or installed or transported.

[0121] The machine-readable instructions described herein may be expressed in any past, present, or future command language, scripting language, programming language, etc. For example, the machine-readable instructions may be expressed using any of the following languages: C, C++, Java, C#, Perl, Python, JavaScript, Hypertext Markup Language (HTML), Structured Query Language (SQL), Swift, etc.

[0122] 7-11B may be implemented using executable instructions (e.g., computer- and / or machine-readable instructions) stored on a non-transitory computer- and / or machine-readable medium, such as a hard disk drive, flash memory, read-only memory, compact disk, digital versatile disk, cache, random access memory, and / or any other storage device or disk that stores information for any duration (e.g., long-term, permanent, short-term, temporary buffering, and / or caching of information). As used herein, the term non-transitory computer-readable medium is expressly defined to include any type of computer-readable storage device and / or disk, but not to include propagating signals and transmission media.

[0123] Figure 7 is an example flowchart representing machine-readable instructions 700 that may be executed to implement the example machine-readable LFA generator 102 of Figure 4 to generate one of the example machine-readable LFA devices 104, 300 of Figures 1A, 1B, 2A, 2B, 2D, 2E, 2H, 2L-2R, and / or 3A. The example instructions 700 of Figure 7 will be described in connection with one of the example machine-readable LFA devices 104, 300 of Figures 1A, 1B, 2A, 2B, 2D, 2E, 2H, 2L-2R, and / or 3A, but may be described and / or implemented in connection with any type of LFA device of any configuration.

[0124] In block 702, the example user interface 400 determines whether instructions have been obtained to generate the machine-readable LFA device 104, 300. If the example user interface 400 determines that instructions have not been obtained (block 702: no), control returns to block 702 until instructions are obtained. If the example user interface 400 determines that instructions have been obtained (block 702: yes), the example part generator 402 determines the number of tests, the type of tests, the number of control zones, and / or the type of control zones based on the user instructions (block 704). For example, a user may provide instructions to generate the LFA device 104, 300 to include three test zones corresponding to three target analytes and one positive control zone.

[0125] At block 706, the example component generator 402 designs and / or retrieves a conjugate pad based on the test type and / or LFA structure identified in the instructions. For example, the component generator 402 may generate (and / or retrieve from storage) a conjugate pad including antibodies and / or antigens that attach to target analytes corresponding to the test type identified in the instructions. In the case of the bioelectrochemical cell LFA device 104, the antigens and / or antibodies are attached to GOx or gold nanoparticles (e.g., depending on how the bioelectrochemical cells 111a-111n are structured). In the case of the circuit-complete LFA device 300, the antigens and / or antibodies are attached to gold nanoparticles.

[0126] In block 708, the example component generator 402 generates and / or acquires the example sample pad 106, the example porous medium 109, the example wicking pad 112, the example wireless chip 114, the example antenna 115, and / or the LFA housing. In block 710, the example component applicator 404 applies (e.g., immobilizes) antigens and / or antibodies corresponding to the target analytes and / or access target analytes to the test zone and / or control zone in the test area 110 of the porous medium 109. In block 712, the example component generator 402 determines whether the instructions correspond to the LFA being a bioelectrochemical cell LFA device 104 (e.g., rather than a circuit-completed LFA device 300). If the component generator 402 determines that the LFA does not correspond to a bioelectrochemical cell LFA device 104 (block 712: No), control continues to block 716. If the component generator 402 determines that the LFA corresponds to a bioelectrochemical cell LFA device 104 (block 712: Yes), the example component generator 402 generates and / or acquires a bioelectrochemical cell (block 714). The example component generator 402 generates the bioelectrochemical cell by impregnating paper or other material with an enzyme substrate (e.g., glucose) and / or a reducing agent (e.g., hydroquinone, aminophenol, vitamin C, other ascorbic acids, etc.), and / or an electron mediator or redox species (e.g., potassium ferricyanide, ferrocene, ferrocene derivatives, etc.). After impregnation, the example component generator 402 dries the bioelectrochemical cell prior to application to the LFA device 104.

[0127] In block 716, the example component applicator 404 creates (e.g., assembles and / or applies) one of the machine-readable LFAs 104, 300, including the sample pad 106, the example conjugate pad 108, the example porous medium 109, the example wicking pad 112, the example wireless chip 114, the example antenna 115, wiring or etching (e.g., connecting the wireless chip 114 to the test zone and / or cell), the electrodes 202a-202f, the switch 278, the flow stop 280, the electrode plate 282, the actuator 293, and / or the LFA housing. In block 718, the example component applicator 404 applies the example inlet 113 (e.g., by cutting away a portion of the LFA device 104, 300). In some examples, an inlet may not be included. For example, in the case of a circuit-completed LFA device 300, a silver amplification material may be applied to the example sample pad 106 and allowed to flow through the example lines 302, 304, 306.

[0128] FIG. 8A is an example flowchart representing machine-readable instructions 800 that may be executed to implement the example wireless chip 114 of FIG. 5 to determine results of a test from the example bioelectrochemical cell LFA device 104 of FIGS. 1A, 1B, 2A, 2B, 2D, 2E, 2G, 2H, and / or 2L-2R. The example instructions 800 of FIG. 8A are described in connection with one of the example machine-readable LFA devices 104 of FIGS. 1A, 1B, 2A, 2B, 2D, 2E, 2G, 2H, and / or 2L-2R. The example instructions 800 may be described in connection with any type of LFA device of any structure. The example instructions 800 may be described in connection with any type of LFA device of any structure, including, for example, the LFA devices of FIGS. 3A and 3B.

[0129] In block 801, the example antenna interface 500 harvests power via the antenna 115. For example, the example reader 116 generates a local electromagnetic field that induces a current in the example antenna 115 to power the example wireless chip 114. In block 802, the example driver / voltage regulator 502 reduces (e.g., limits, regulates, etc.) the supply voltage (e.g., 1.8 V, 3.3 V, and / or 5 V corresponding to the harvested power) to a smaller voltage (e.g., 100 mV, 150 mV, 200 mV, 250 mV, etc.) that is applied as a potential supporting a chemical reaction in the porous membrane 109. In block 803, the example driver / voltage regulator 502 uses the smaller voltage to apply a potential (e.g., voltage, poise potential, etc.) to one electrode of the electrode pair (e.g., the working electrode and / or the reference electrode, depending on whether the potential is positive or negative). As discussed above, a smaller voltage may assist and / or force one or more chemical reactions to occur by providing more optimal conditions for the reactions to occur, resulting in a stronger current measurement. In some examples, the driver / voltage regulator 502 may apply multiple potentials (e.g., voltages, poise potentials, etc.) to assist multiple different chemical reactions, thereby causing a current to flow in the presence of a target analyte. In block 804, the exemplary sensor 504 senses the voltage drop and / or current flow between corresponding pins coupled to the test zone and / or control zone via the exemplary electrodes 308a, 308b. The exemplary sensor 504 may sense the voltage drop and / or current flow across each zone in series or in parallel.

[0130] In block 806, the example comparator 506 determines whether the voltage drop and / or current flow is greater than a threshold value for one or more corresponding pins. For example, the comparator 506 may determine whether the detected voltage drop and / or current flow for each test and / or control is greater than 50 mV. In some examples, the comparator 506 determines whether the voltage drop and / or current flow is greater than multiple different threshold values. In this manner, the comparator 506 can determine the amount of the detected voltage drop and / or current flow, as described above in connection with FIGS. 2A-2K. If the example comparator 506 determines that the voltage drop and / or current flow is not greater than a threshold value for one or more corresponding pins (block 806: No), control continues to block 810. If the example comparator 506 determines that the voltage drop and / or current flow is greater than a threshold value for one or more corresponding pins (block 806: YES), the example comparator 506 flags (e.g., marks or outputs a logical value for) the corresponding test and / or control zone as corresponding to a positive result (block 808). The example results storage 508 stores the flag in conjunction with the corresponding zone, as disclosed separately in block 814 below.

[0131] In block 810, the example comparator 506 determines whether the voltage drop and / or current flow for one or more corresponding pins is less than a threshold value. For example, the comparator 506 may determine whether the detected voltage drop and / or current flow for each test and / or control is less than 50 mV. If the example comparator 506 determines that the voltage drop and / or current flow for one or more corresponding pins is not less than the threshold value (block 810: no), control continues to block 814. If the example comparator 506 determines that the voltage drop and / or current flow for one or more corresponding pins is less than the threshold value (block 810: yes), the example comparator 506 flags (e.g., marks or outputs a logic value for) the corresponding test zone and / or control zone as corresponding to a negative result (block 812). In block 814, the example results storage 508 stores the flag along with the corresponding zone and / or the example antenna interface 500 transmits the results corresponding to the flag (e.g., via antenna 115). Antenna 115 may also transmit identifying information (e.g., a device identifier, an identifier for the number and / or type of test, an identifier for the number and / or type of control) along with the results.

[0132] 8B is an example flowchart representing alternative machine-readable instructions 820 that may be executed to implement the example wireless chip 114 of FIG. 5 to determine results of a test from the example bioelectrochemical cell LFA device 104 of FIGS. 1A, 1B, 2A, 2B, 2D, 2E, 2G, 2H, and / or 2L-2R. Although the example instructions 820 of FIG. 8B are described in connection with one of the example machine-readable LFA devices 104 of FIGS. 1A, 1B, 2A, 2B, 2D, 2E, 2G, 2H, and / or 2L-2R. The example instructions 820 may be described and / or implemented in connection with any type of LFA device of any structure. The example instructions 800 may be described and / or implemented in connection with any type of LFA device of any structure, including, for example, the LFA devices of FIGS. 3A and 3B.

[0133] In block 821, the example antenna interface 500 acquires power via the antenna 115. For example, the example reader 116 generates a local electromagnetic field that induces a current in the example antenna 115 to power the example wireless chip 114. In block 822, the example driver / voltage regulator 502 reduces (e.g., limits, regulates, etc.) the supply voltage (e.g., 1.8 V, 3.3 V, and / or 5 V) corresponding to the acquired power to a smaller voltage (e.g., 100 mV, 150 mV, 200 mV, 250 mV, etc.) that is applied as a potential supporting a chemical reaction in the porous membrane 109. In block 823, the example driver / voltage regulator 502 uses the smaller voltage to apply a potential (e.g., voltage, poise potential, bias, etc.) to one electrode of the electrode pair (e.g., the working electrode and / or the reference electrode, depending on whether the potential is positive or negative). As discussed above, a lower voltage can assist and / or force a chemical reaction to occur by providing more optimal conditions for the chemical reaction to occur, resulting in a stronger current measurement. In some examples, the driver / voltage regulator 502 may apply multiple potentials (e.g., voltages, poise potentials, etc.) to assist multiple different chemical reactions, which will result in a current flow in the presence of the target analyte.

[0134] In block 824, the example driver / voltage regulator 502 switches electrode pairs so that the sensor 504 can acquire one or more voltage and / or current samples between corresponding pins coupled to the test zone and / or control zone. For example, the driver / voltage regulator 502 may switch select lines on one of the example front ends 240, 250 to enable the sensor 504 to sense the voltage drop and / or current flow between the corresponding electrodes. As described above, the driver / voltage regulator 502 may control the front ends 240, 250 to acquire multiple samples of each test and / or control line. In some examples, the sensor 504 may acquire voltage / current directly from a channel on the front end 260 without switching. Additionally or alternatively, the example LFA device 104 may acquire any data corresponding to the test results. In some examples, the driver / voltage regulator 502 may apply a single potential prior to switching. In some examples, the driver / voltage regulator 502 outputs a voltage potential prior to each voltage and / or current measurement during switching. At block 826, the example analog-to-digital converter 512 converts the analog voltage and / or current measurements to digital values. At block 828, the example antenna interface 500 transmits the digital voltage values ​​for each zone to the reader 116 (e.g., via the antenna 115) along with corresponding information (e.g., device identifier, test type identifier, product code, etc.). In some examples, block 826 may be omitted, and the example antenna interface 500 may transmit the analog voltage and / or current measurements to the example reader 116. In some examples, the wireless chip 114 may compare the measurements against one or more thresholds to generate a result, as described elsewhere above in connection with FIG. 8A .

[0135] 9 is an example flowchart representing machine-readable instructions 900 that may be executed to implement the example wireless chip 114 of FIG. 5 to determine the results of a test from the example bioelectrochemical cell LFA device 104 of FIGS. 1A, 1B, 2A, 2B, 2D, 2E, 2G, 2H, and / or 2L-2R that is powered by a voltage generated by one or more of the bioelectrochemical cells 111a-111n. The example instructions 900 of FIG. 9 are described in connection with one of the example machine-readable LFA devices 104 of FIGS. 1A, 1B, 2A, 2B, 2D, 2E, 2G, 2H, and / or 2L-2R, but may be described and / or implemented in connection with any type of LFA device of any configuration.

[0136] In block 902, the exemplary wireless chip 114 obtains power from one or more of the bioelectrochemical cells 111 a-111 n. As described above, when one or more of the test zones and / or control zones immobilize a target analyte, a voltage is generated in one or more of the bioelectrochemical cells 111 a-111 n. The generated voltage can be used to power the wireless chip 114. In block 904, the exemplary timer 510 starts a wait timer. When the wait timer reaches a threshold amount of time (e.g., assay time), the test is ready to be read. Thus, if the reader 116 attempts to read the LFA 104 before it is ready to be read, the wireless chip 114 can transmit the wait time and / or assay time, thereby allowing the reader 116 to indicate how much time remains until the LFA 104 is ready to be read.

[0137] In block 906, the example antenna interface 500 determines whether an electromagnetic field is detected via the example antenna 115. When the reader 116 is attempting to read the LFA 104, it generates an electromagnetic field to initiate communication with the wireless chip 114. If the example antenna interface 500 determines that an electromagnetic field is not detected (block 906: no), control returns until an electromagnetic field is detected. If the example antenna interface 500 determines that an electromagnetic field is detected (block 906: yes), the comparator 506 determines whether the wait time (e.g., from the example timer 510) is greater than the assay time (e.g., a threshold time corresponding to the test being ready to read) (block 908). If the example comparator 506 determines that the wait time is not greater than the assay time (block 908: no), the example antenna interface 500 interfaces with the antenna 115 to transmit timing information (e.g., the current wait time and / or assay time) to the example reader 116 (block 910). In this way, the reader 116 can determine how much more time is needed and / or display the amount of time to the user. Because the process 900 includes determining whether the wait time is longer than the assay time, premature reading of the results and / or other result reading errors are prevented.

[0138] If the example comparator 506 determines that the wait time is greater than the assay time (block 908: yes), the example sensor 504 detects a voltage drop across the corresponding pins coupled to the test zone and / or control zone via the example electrodes 308a, 308b (block 914). The example sensor 504 may detect the voltage drop across each zone in series or parallel. In block 916, the example comparator 506 determines whether the voltage drop across one or more corresponding pins is greater than a threshold value. For example, the comparator 506 may determine whether the detected voltage drop across each test and / or control is greater than 50 mV. If the example comparator 506 determines that the voltage drop across one or more corresponding pins is not greater than the threshold value (block 916: no), control continues to block 920. If the example comparator 506 determines that the voltage drop is greater than the threshold for one or more corresponding pins (block 916: YES), the example comparator 506 flags (e.g., marks or outputs a logical value for) the corresponding test and / or control zone as corresponding to a positive result (block 918). The example results storage 508 stores the flag in conjunction with the corresponding zone, as disclosed separately in block 924 below.

[0139] In block 920, the example comparator 506 determines whether the voltage drop for one or more corresponding pins is less than a threshold value. For example, the comparator 506 may determine whether the detected voltage drop for each or each test and / or control is less than 50 mV. If the example comparator 506 determines that the voltage drop for one or more corresponding pins is not less than the threshold value (block 920: no), control continues to block 924. If the example comparator 506 determines that the voltage drop for one or more corresponding pins is less than the threshold value (block 920: yes), the example comparator 506 flags (e.g., marks or outputs a logic value for) the corresponding test zone and / or control zone as corresponding to a negative result (block 922). In block 924, the example result storage 508 stores the flag in conjunction with the corresponding zone and / or the example antenna interface 500 transmits (e.g., via antenna 115) the result corresponding to the flag. Antenna 115 may also transmit identifying information (eg, device identifier, test number and / or type identifier, control number and / or type identifier) ​​along with the results.

[0140] Figure 10 is an example flowchart representing machine-readable instructions 1000 that may be executed to implement the example wireless chip 114 of Figure 5 to determine the results of tests from the example circuit-completed LFA device 300 of Figure 3A. The example instructions 1000 of Figure 10 are described in conjunction with the example machine-readable LFA device 300 of Figure 3A, but may be described and / or implemented in conjunction with any type of LFA device of any configuration.

[0141] In block 1002, the example antenna interface 500 obtains power through the antenna 115. For example, the example reader 116 generates a local electromagnetic field that induces a current in the example antenna 115 and powers the example wireless chip 114. In block 1004, the example driver / voltage regulator 502 outputs a voltage to a first pin coupled to the first electrode 308a of the test zone and / or control zone. The example driver / voltage regulator 502 may output a voltage to each of the first pins in parallel or series. In some examples, the voltage output by the driver / voltage regulator 502 corresponds to the power obtained through the electromagnetic field of the reader 116. In this way, the wireless chip 114 can output a voltage without the use of a storage cell and / or a battery cell. In block 1006, the example sensor 504 senses a current and / or resistance from a second pin coupled to the second electrode 308b of the test zone and / or control zone.

[0142] In block 1008, the example comparator 506 determines whether the current is greater than a threshold or the resistance is less than a threshold for one or more corresponding pins. For example, the comparator 506 may determine whether the sensed current for each test and / or control is within a specified range. In some examples, the comparator 506 determines whether the current / resistance is greater than multiple different thresholds. In this manner, the comparator 506 can determine the amount of sensed current / resistance, as described above in connection with FIGS. 2A-2K. If the example comparator 506 determines that the current is not greater than a threshold or the resistance is not less than a threshold for one or more corresponding pins (block 1008: No), control continues to block 1012. If the example comparator 506 determines that the current is greater than the threshold or the resistance is less than the threshold for one or more corresponding pins (block 1008: YES), the example comparator 506 flags (e.g., marks or outputs a logical value for) the corresponding test and / or control zone as corresponding to a positive result (block 1010). The example results storage 508 stores the flag in conjunction with the corresponding zone, as disclosed separately below in block 1016.

[0143] In block 1012, the example comparator 506 determines whether the current is less than a threshold or the resistance is greater than a threshold for one or more corresponding pins. For example, the comparator 506 may determine whether the sensed current for each test and / or control is within a specified range of current and / or resistance. In other examples, the comparator 506 performs a comparison metric against a particular value. For example, in one example embodiment, the comparator 506 may determine whether the sensed current for the test and / or control is less than 50 mA and / or whether the sensed resistance is greater than 100 ohms. In other examples, other values ​​may be used. If the example comparator 506 determines that the current is not less than a threshold or the resistance is not greater than a threshold for one or more corresponding pins (block 1012: No), control continues to block 1016. If the example comparator 506 determines that the current is less than the threshold or the resistance is greater than the threshold for one or more corresponding pins (block 1012: YES), the example comparator 506 flags (e.g., marks or outputs a logical value) the corresponding test zone and / or control zone as corresponding to a negative result (block 1014). In block 1016, the example result storage 508 stores the flag in conjunction with the corresponding zone and / or the example antenna interface 500 transmits (e.g., via the antenna 115) the result corresponding to the flag. The antenna 115 may also transmit identifying information (e.g., a device identifier, an identifier for the number and / or type of test, an identifier for the number and / or type of control) along with the result. In some examples, the result storage 606 may store a flag indicating that a result has been determined. The flag may be included in the results of subsequent reads. In this manner, the example reader 116 can identify that a test has already been read.

[0144] 11A and 11B are example flowcharts representing machine-readable instructions 1100 that may be executed to implement the example machine-readable LFA reader application 117 of FIG. 6 to read test results (e.g., diagnostic test results) of the example machine-readable LFA devices 104, 300 of FIGS. 1A, 1B, 2A, 2B, 2D, 2E, 2G, 2H, 2L-2R, and / or 3A. The example instructions 1100 of FIGS. 11A and 11B are described in connection with the example machine-readable LFA devices 104, 300 of FIGS. 1A, 1B, 2A, 2B, 2D, 2E, 2G, 2H, 2L-2R, and / or 3A, but may be described and / or implemented in connection with any type of LFA of any configuration.

[0145] The outcome determinator 602 instructs the component interface 600 to interface with the user of the reader 116 via the user interface 120. The outcome determinator 602 may send one or more prompts to the user and wait for an affirmative response from the user. For example, if the testing of the LFA 104 is not autonomous or semi-autonomous, the outcome determinator 602 may send instructions to the user of the reader 116 when the application 117 launches on the reader 116. For example, in block 1102, the example outcome determinator 602 outputs a prompt to the user of the reader 116 instructing the user to enter patient information (e.g., name, age, date of birth, gender, etc.). For example, the outcome determinator 602 instructs the component interface 600 to interface with the user via the user interface 120. The outcome determinator 602 may send one or more prompts to the user and wait for an affirmative response from the user. The patient information may be included in corresponding information that may be displayed, stored, and / or transmitted to an external database and / or server (e.g., tagged with the results or included as metadata for the results). In some examples, the external / remote database and / or server is located at or associated with an EMR, a government agency, an NGO, a doctor's office, a hospital, a hospital information system, a LIMS system, an inventory consumption monitor, a clinic and / or other medical facility, a medical device manufacturer, a medical institution, a health information system, and / or other external entity.

[0146] The result determiner 602 also sends a prompt to the user to register the LFA 104 and / or identify the type of LFA 104. At block 1014, the result determiner 602 instructs the example antenna 118, via the example component interface 600, to generate a magnetic field for a first scan to power the wireless chip 114 (e.g., to identify the LFA device 104). Thus, the wireless chip 114 can provide information to the reader 116 (e.g., wirelessly via the example antenna 115) while powered. In some examples, the reader 104 can obtain the identification information by using a camera to scan a QR code on the LFA device 104 or by having a user manually enter the code into the LFA device 104. The LFA reader application 117 presents instructions to the user to scan the LFA device 104 (e.g., bring the reader 116, running the reader application 117, close to the LFA device 104). At block 1106, the example result determiner 602 obtains a test identifier, an LFA device identifier, a product code, and / or any other coded or non-coded data from the wireless chip 114 (e.g., corresponding to one or more tests the LFA device is configured to obtain). The obtained information may be included in corresponding information (e.g., tagged with or included as metadata for the results) that may be displayed, stored, and / or transmitted to an external database and / or server. In some examples, the result determiner 602 uses the obtained information to determine the type of test and / or corresponding algorithm to use in obtaining data corresponding to the test results from the LFA device 104. In some examples, the result determiner 602 uses the obtained information to authenticate the LFA device 104 and / or prevent use of an invalid or unauthorized LFA device 104.

[0147] At block 1108, the example result determiner 602 determines the geolocation of the LFA device 104. In some examples, the component interface 600 accesses location information from other components of the reader 116 (e.g., if the reader 116 includes a GPS system). In some examples, the geolocation information is received (e.g., accessed, obtained, etc.) from the wireless chip 114. The geolocation information may be included in corresponding information (e.g., tagged with the result or included as metadata for the result) that may be displayed, stored, and / or transmitted to an external database and / or server.

[0148] In block 1110, the example result determinator 602 guides a user of the reader 116 through LFA reading instructions. For example, the result determinator 602 can send instructions such as (1) instructing the user to apply sample to the sample pad 106 and wait for a user acknowledgment, (2) instructing the user to apply an assay buffer and wait for a user acknowledgment, (3) instructing the user to wait for the LFA test, display the time, and / or wait for a user acknowledgment, (4) instructing the user to apply a reaction buffer and wait for an acknowledgment, (5) instructing the user to wait for a reaction to occur, display the time, and / or wait for a user acknowledgment, etc. In some examples, the result determinator 602 can display an error, for example, if an acknowledgment is not received within a threshold time range. In semi-autonomous or fully autonomous LFAs, some instructions can be eliminated because the LFA 104 can perform one or more of the steps automatically without the need for a user. The added information may be included in corresponding information that may be displayed, stored, and / or transmitted to an external database and / or server (e.g., tagged with the results or included as metadata for the results). In some examples, the external database and / or server is a hospital, a hospital information system, a LIMS system, an inventory consumption monitor, a medical facility, a medical device manufacturer, etc.

[0149] In block 1112, the example component interface 600 determines whether the user verified that the sample and / or buffer was applied to the example LFA 104 (e.g., by an acknowledgment on the user interface 120). If the example component interface 600 determines that the user did not verify that the sample and / or buffer was applied (block 1112: no), control returns to block 1112 until the user does. If the example component interface 600 determines that the user verified that the sample and / or buffer was applied (block 1112: yes), the example result determiner 602 determines whether the flow should be stopped (block 1114). In some examples, the result determiner 602 determines whether the flow should be stopped by tracking a time window based on the test and / or LFA identification information. For example, the LFA device 104 of Figures 2A-2E and / or 2L-2R prevents the product (e.g., hydrogen peroxide) created at the test or control line from flowing toward the wicking pad 112 by reducing or preventing flow over the porous membrane 109 using techniques such as shearing, cutting, compression, etc.

[0150] If the example component interface 600 determines that flow should not be stopped (block 1114: no), control proceeds to block 1114 until the time window expires. If the example component interface 600 determines that flow along the LFA device 104 should be stopped (block 1114: yes), the example component interface 600 prompts the user to scan the LFA device 104 (block 1116). Because multiple tests from multiple LFA devices can be run simultaneously in a short period of time, a user may become confused about which test is ready to be read. Therefore, the LFA reader application 117 scans the LFA device 104 and prompts the user to verify that the device the user scanned is the correct device, thereby preventing errors associated with running multiple tests simultaneously and / or in a short period of time.

[0151] At block 1118, the result determiner 602 instructs the example antenna 118 via the example component interface 600 to generate a magnetic field to power the wireless chip 114 and perform a second scan (e.g., to confirm the user read the correct LFA device 104). At block 1120, the example result determiner 602 determines whether the LFA device identification is verified (e.g., whether the identification from the first scan matches the identification from the second scan). If the example result determiner 602 determines that the LFA device identification is confirmed (block 1120: yes), control continues to block 1126 of FIG. 11B. If the example result determiner 602 determines that the LFA device identification is not verified (e.g., the identifier from the second scan does not match the identifier from the first scan) (block 1120: NO), the example result determiner 602 determines whether the scan window has expired (e.g., whether the amount of time corresponding to when the LFA device 104 should be verified has expired, based on the type of test and / or LFA device) (block 1122). If the scan window has expired, the results may be less accurate. In some examples, the component interface 600 displays a timer corresponding to the test window in the example user interface 120.

[0152] If the example result determiner 602 determines that the scan window has not ended (block 1122: no), control returns to block 1116. If the example result determiner 602 determines that the scan window has ended (block 1122: yes), the example result determiner 602 flags the test as potentially invalid (block 1124) and control returns to block 1116. In some examples, the test may continue, but the results will be flagged with a reading after the scan window (e.g., along with timing information corresponding to how long after the scan window until the result determination). In some examples, the test is marked invalid and the component interface 600 identifies the test as invalid.

[0153] In block 1126, the example component interface 600 sends a prompt to the user to stop the flow in the LFA device 104 (block 1114). For example, the component interface 600 may prompt the user to move the switches 278, 292 from a first position to a second position to cause the flow stop 280 to cut, shear, compress, and / or stop, obstruct, and / or resist the flow. In block 1128, the outcome determiner 602 (e.g., via a prompt on the user interface 120) determines whether the user verified that the flow has been stopped. If the example outcome determiner 602 determines that the user has verified that the flow has been stopped (block 1128: yes), control continues to block 1134. If the example outcome determiner 602 determines that the user has not verified that the flow has been stopped (block 1128: NO), the example outcome determiner 602 determines whether the flow stop window has expired (e.g., whether the amount of time corresponding to when the LFA device 104 should be sheared, based on the type of test and / or LFA device, has expired) (block 1130). If the flow stop window has expired, the results may be less accurate. In some examples, the component interface 600 displays a timer corresponding to the test window in the example user interface 120.

[0154] If the example result determiner 602 determines that the flow cessation window has not ended (block 1130: no), control returns to block 1126. If the example result determiner 602 determines that the scan window has ended (block 1130: yes), the example result determiner 602 flags the test as potentially invalid (block 1132) and control returns to block 1126. In some examples, the test may continue, but the results will be flagged with a reading after the flow cessation window (e.g., along with timing information corresponding to how long after the flow cessation window until the result determination). In some examples, the test is marked invalid and the component interface 600 identifies the test as invalid.

[0155] At block 1134, the example component interface 600 instructs the user to scan the LFA device 104. At block 1136, the result determiner 602, via the example component interface 600, instructs the example antenna 118 to generate a magnetic field to power the wireless chip 114 and perform a third scan (e.g., obtain digital values ​​from the LFA device 104). As described above, the digital values ​​may correspond to sensed voltages and / or currents from one or more test zones and / or control zones. At block 1138, the example result determiner 602 processes results based on an algorithm corresponding to the obtained test data (e.g., digital voltage and / or current values ​​tagged to the test zones and / or control zones) and the LFA identifier. Because the machine-readable LFA reader application 117 can scan different LFA devices and the algorithms for determining and / or classifying results based on the acquired data may differ for different devices and / or different diagnostic tests, the LFA reader application 117 determines which algorithm to apply based on the test identifier from the LFA device 104 and determines the test result using the acquired test data and the selected algorithm. The algorithm may define thresholds that identify voltage and / or current values ​​that result in a positive result and voltage and / or current values ​​that result in a negative result. The algorithm may also determine the number of samples that must be positive to result in a positive result (e.g., 5 out of 5 (i.e., all), 4 out of 5 (i.e., a percentage), etc.). In some examples, the wireless chip 114 determines the test result locally. In such examples, the result determiner 602 may display and / or store the results obtained based on the corresponding algorithm. In this manner, the result determiner 602 associates manufacturing data encoded on the wireless chip 114 (eg, the ASIC of the wireless chip 114) with test results without connecting to a secondary system.

[0156] In block 1140, the example result determiner 602 determines whether the results should be displayed on the example user interface 120. For example, for privacy reasons, a patient may want the results sent to a doctor rather than displayed to a technician. Thus, to protect the patient's privacy, a setting may be enabled or disabled corresponding to whether the results should be displayed. If the example result determiner 602 determines that the results should not be displayed (e.g., confidential to the user who administered the test) (block 1140: no), control continues to block 1144. If the example result determiner 602 determines that the results should be displayed (block 1140: yes), the example component interface 600 instructs the user interface 120 to display the results (block 1142). At block 1144, the example results storage 606 stores the results, corresponding information (e.g., device and / or test identification information), and / or contextual or supplemental information (e.g., time, date, patient information, location information, lot number, expiration date, expiration date, test information, signal quality information, chain of custody, operator information, etc.). In some examples, the results are tagged to the patient, and the corresponding information and / or contextual data is tagged to the results as metadata. Thus, the test data can be readily associated with the supplemental data set.

[0157] At block 1146, the example component interface 600 sends instructions to the transmitter of the reader 116 to transmit the results, corresponding information (e.g., device and / or test identification information), and / or context or supplemental information (e.g., time, date, patient information, location information, lot number, expiration date, expiration date, test information, signal quality information, chain of custody, operator information, etc.). The example component interface 600 may transmit the results, corresponding information, and / or context or supplemental information over a network to one or more remote databases and / or servers located at or associated with an EMR, government agency, NGO value proposition, doctor's office, hospital, hospital information system, LIMS system, inventory consumption monitor, clinic and / or other medical facility, medical device manufacturer, medical institution, health information system, and / or other external entity. In this manner, different actions may be taken based on receipt of the test data. For example, hospitals, clinics, manufacturers, institutions, etc. can automatically track the use of LFA devices, such as when scanned for reading, automatically reorder additional inventory from suppliers, and generate disease or pathogen outbreak alerts for specific areas. In some examples, results and / or other data are automatically uploaded. In some examples, results and / or other data are uploaded in real time or near real time. In some examples, reader 116 encrypts the information for transmission to an external database and / or server. When the results and corresponding information are transmitted to a monitoring entity, the monitoring entity can process the results and / or perform statistical analysis based on multiple received results from one or more improved LFA reader applications to determine if there is a disease outbreak, identify if the LFA is counterfeit, etc. In some examples, result determiner 602 prevents the transmission of duplicate results (e.g., when a device is flagged as having been read more than once).If a network connection does not currently exist, the example component interface 600 may delay instructing the transmitter until a network connection is established. Additionally or alternatively, the example component interface 600 may transmit results from the results storage 606 periodically, aperiodically, and / or based on a trigger (e.g., a results request from the measurement entity).

[0158] Figure 12 is a block diagram of an exemplary processor platform 1200 configured to execute the instructions of Figure 7 to implement the machine-readable LFA generator 102 of Figure 4. Processor platform 1200 can be, for example, a server, a personal computer, a workstation, a self-learning machine (e.g., neural network), an internet appliance, or any other type of computing device.

[0159] The processor platform 1200 of the illustrated example includes a processor 1212. The processor 1212 of the illustrated example is hardware. For example, the processor 1212 may be implemented by one or more integrated circuits, logic circuits, microprocessors, GPUs, DSPs, or controllers from any desired family or manufacturer. The hardware processor may be a semiconductor-based (e.g., silicon-based) device. In this example, the processor implements the example user interface 400, the example part generator 402, and the example part applier 404.

[0160] The processor 1212 of the illustrated example includes local memory 1213 (e.g., cache). The processor 1212 of the illustrated example communicates with main memory, including volatile memory 1214 and nonvolatile memory 1216, via bus 1218. The volatile memory 1214 may be implemented using synchronous dynamic random access memory (SDRAM), dynamic random access memory (DRAM), RAMBUS® dynamic random access memory (RDRAM®), and / or any other type of random access memory device. The nonvolatile memory 1216 may be implemented using flash memory and / or any other desired type of memory device. Access to the main memory 1214, 1216 is controlled by a memory controller.

[0161] The processor platform 1200 of the illustrated example also includes an interface circuit 1220. The interface circuit 1220 may be implemented using any type of interface standard, such as an Ethernet interface, a Universal Serial Bus (USB), a Bluetooth® interface, a Near Field Communication (NFC) interface, and / or a PCI Express interface.

[0162] In the depicted example, one or more input devices 1222 are coupled to the interface circuit 1220. The input devices 1222 allow a user to input data and / or commands to the processor 1212. The input devices 1222 may be implemented, for example, by audio sensors, microphones, cameras (still or video), keyboards, buttons, mice, touchscreens, trackpads, trackballs, isopoints, and / or voice recognition systems.

[0163] The interface circuitry 1220 of the illustrated example is also coupled to one or more output devices 1224. The output device(s) 1224 may be implemented by, for example, a display device (e.g., a light emitting diode (LED), an organic light emitting diode (OLED), a liquid crystal display (LCD), a cathode ray tube display (CRT), an in-place switching (IPS) display, a touch screen, etc.), a tactile output device, a printer, and / or a speaker. To this end, the interface circuitry 1220 of the illustrated example typically includes a graphics driver card, a graphics driver chip, and / or a graphics driver processor.

[0164] Additionally, the interface circuitry 1220 of the depicted example includes communications devices such as transmitters, receivers, transceivers, modems, residential gateways, wireless access points, and / or network interfaces that facilitate data exchange with external machines (e.g., any type of computing device) over a network 1226. Communications may be via, for example, an Ethernet connection, a digital subscriber line (DSL) connection, a telephone line connection, a coaxial cable system, a satellite system, a line-of-site wireless system, a cellular system, etc.

[0165] The processor platform 1200 of the depicted example also includes one or more mass storage devices 1228 for storing software and / or data. Examples of such mass storage devices 1228 include floppy disk drives, hard drive disks, compact disk drives, Blu-ray disk drives, redundant array of independent disks (RAID) systems, and digital versatile disk (DVD) drives.

[0166] The machine-executable instructions 1232 of FIG. 7 may be stored on the mass storage device 1228, the volatile memory 1214, the non-volatile memory 1216, and / or a removable non-transitory computer-readable storage medium such as a CD or DVD.

[0167] Figure 13 is a block diagram of an example processor platform 1300 configured to execute the instructions of Figures 8A-10 to implement the wireless chip 114 of Figure 5. The processor platform 1300 may be, for example, a machine-readable LFA device, a self-learning machine (e.g., a neural network), or any other type of computing device.

[0168] The processor platform 1300 of the illustrated example includes a processor 1312. The processor 1312 of the illustrated example is hardware. For example, the processor 1312 may be implemented with one or more integrated circuits, logic circuits, microprocessors, GPUs, DSPs, or controllers from any desired family or manufacturer. The hardware processor may be a semiconductor-based (e.g., silicon-based) device. In this example, the processor implements the example antenna interface 500, the example driver / voltage regulator 502, the example sensor 504, and the example comparator 506.

[0169] The processor 1312 of the illustrated example includes a local memory 1313 (e.g., a cache). The processor 1312 of the illustrated example communicates with a main memory, including a volatile memory 1314 and a non-volatile memory 1316, via a bus 1318. The volatile memory 1314 may be implemented using SDRAM, DRAM, RDRAM®, and / or any other type of random access memory device. The non-volatile memory 1316 may be implemented using flash memory and / or any other desired type of memory device. Access to the main memory 1314, 1316 is controlled by a memory controller. The exemplary local memory 1313 implements the results storage 508.

[0170] The processor platform 1300 of the illustrated example also includes an interface circuit 1320. The interface circuit 1320 may be implemented using any type of interface standard, such as an Ethernet interface, a USB, a Bluetooth® interface, an NFC interface, and / or a PCI Express interface.

[0171] In the depicted example, one or more input devices 1322 are connected to the interface circuit 1320. The input devices 1322 allow a user to input data and / or commands to the processor 1312. The input devices may be implemented, for example, by audio sensors, buttons, and / or any other type of input device.

[0172] The interface circuitry 1320 of the illustrated example is also coupled to one or more output devices 1324. The output device(s) 1324 may be realized, for example, by a display device (e.g., an LED, an OLED, an LCD, a CRT display, an IPS display, a touch screen, etc.) and / or a speaker. To this end, the interface circuitry 1320 of the illustrated example typically includes a graphics driver card, a graphics driver chip, and / or a graphics driver processor.

[0173] The interface circuitry 1320 of the depicted example also includes communications devices such as transmitters, receivers, transceivers, modems, residential gateways, wireless access points, and / or network interfaces that facilitate data exchange with external machines (e.g., any type of computing device) over a network 1326. Communications may be via, for example, an Ethernet connection, a DSL connection, a telephone line connection, a coaxial cable system, a satellite system, an in-site wireless system, a cellular phone system, etc.

[0174] The processor platform 1300 of the depicted example also includes one or more mass storage devices 1328 for storing software and / or data. Examples of such mass storage devices 1328 include floppy disk drives, hard drive disks, compact disk drives, Blu-ray disk drives, RAID systems, and DVD drives.

[0175] The machine-executable instructions 1332 of Figures 8A-10 may be stored on the mass storage device 1328, the volatile memory 1314, the non-volatile memory 1316, and / or a removable non-transitory computer-readable storage medium such as a CD or DVD.

[0176] Figure 14 is a block diagram of an exemplary processor platform 1400 configured to execute the instructions of Figures 11A and 11B to implement the machine-readable LFA reader application 117 of Figure 3. The processor platform 1400 may be, for example, a personal computer, a workstation, a self-learning machine (e.g., a neural network), a mobile device (e.g., a mobile phone, a smartphone, a tablet such as an iPad™), a personal digital assistant (PDA), a personal video recorder, or any other type of computing device.

[0177] The processor platform 1400 of the illustrated example includes a processor 1412. The processor 1412 of the illustrated example is hardware. For example, the processor 1412 may be implemented with one or more integrated circuits, logic circuits, microprocessors, GPUs, DSPs, or controllers from any desired family or manufacturer. A hardware processor may be a semiconductor-based (e.g., silicon-based) device. In this example, the processor implements the example component interface 600 and the example result determiner 602.

[0178] The processor 1412 of the illustrated example includes a local memory 1413 (e.g., a cache). The processor 1412 of the illustrated example communicates with a main memory, including a volatile memory 1414 and a non-volatile memory 1416, via a bus 1418. The volatile memory 1414 may be implemented using SDRAM, DRAM, RDRAM®, and / or any other type of random access memory device. The non-volatile memory 1416 may be implemented using flash memory and / or any other desired type of memory device. Access to the main memory 1414, 1416 is controlled by a memory controller. The example local memory 1413 implements the example test type storage 604 and the example results storage 606.

[0179] The processor platform 1400 of the illustrated example also includes an interface circuit 1420. The interface circuit 1420 may be implemented using any type of interface standard, such as an Ethernet interface, a USB, a Bluetooth® interface, an NFC interface, and / or a PCI Express interface.

[0180] In the depicted example, one or more input devices 1422 are coupled to the interface circuit 1420. The input devices 1422 allow a user to input data and / or commands to the processor 1412. The input devices 1422 may be realized by, for example, audio sensors, microphones, cameras (still or video), keyboards, buttons, mice, touchscreens, trackpads, trackballs, isopoints, and / or voice recognition systems.

[0181] The interface circuitry 1420 of the illustrated example is also coupled to one or more output devices 1424. The output device(s) 1424 may be implemented by, for example, a display device (e.g., an LED, OLED, LCD, CRT display, IPS display, touch screen, etc.), a tactile output device, a printer, and / or a speaker. To this end, the interface circuitry 1420 of the illustrated example typically includes a graphics driver card, a graphics driver chip, and / or a graphics driver processor.

[0182] Additionally, the interface circuitry 1420 of the depicted example includes transmitters, receivers, transceivers, modems, residential gateways, wireless access points, and / or network interfaces that facilitate data exchange with external machines (e.g., any type of computing device) over a network 1426. Communications may be via, for example, an Ethernet connection, a DSL connection, a telephone line connection, a coaxial cable system, a satellite system, an in-site wireless system, a cellular phone system, etc.

[0183] The processor platform 1400 of the depicted example also includes one or more mass storage devices 1428 for storing software and / or data. Examples of such mass storage devices 1428 include floppy disk drives, hard drive disks, compact disk drives, Blu-ray disk drives, RAID systems, and DVD drives.

[0184] The machine-executable instructions 1432 of Figures 11A and 11B may be stored on the mass storage device 1428, the volatile memory 1414, the non-volatile memory 1416, and / or a removable non-transitory computer-readable storage medium such as a CD or DVD.

[0185] A block diagram illustrating an example software distribution platform 1505 for distributing software, such as the example computer-readable instructions 1432 of FIG. 14, to third parties is shown in FIG. 15. The example software distribution platform 1505 may be implemented by any computer server, data facility, cloud service, etc. capable of storing software and transmitting it to other computing devices. The third party may be a customer of the entity that owns and / or operates the software distribution platform. The third party may be, for example, a developer, seller, and / or licensor of software, such as the example computer-readable instructions 1432 of FIG. 14. The third party may be a consumer, user, retailer, OEM, etc., that purchases and / or licenses the software for use, resale, and / or sublicensing. In the illustrated example, the software distribution platform 1505 includes one or more servers and one or more storage devices. The storage devices store computer-readable instructions 1432, which may correspond to the example computer-readable instructions 1100 of FIG. 11A and / or FIG. 11B, as described above. One or more servers of the example software distribution platform 1505 are in communication with a network 1510, which may correspond to the Internet and / or any one or more of any of the example networks described above. In some examples, the one or more servers respond to requests to transmit software to a requester as part of a commercial transaction. Payment for the distribution, sale, and / or license of the software may be handled by one or more servers of the software distribution platform and / or a third-party payment entity. The servers enable purchasers and / or licensors to download computer-readable instructions 1432 from the software distribution platform 1505.For example, software that may correspond to the example computer-readable instructions 1100 of Figures 11A and / or 11B may be downloaded to the example processor platform 1400, which may execute the computer-readable instructions 1432 to implement the machine-readable LFA reader application 117 of Figures 1 and / or 6. In some examples, one or more servers of the software distribution platform 1505 periodically provide, transmit, and / or force updates to the software (e.g., the example computer-readable instructions 1432 of Figure 14) to ensure that improvements, patches, updates, etc. are distributed and applied to the software on end-user devices.

[0186] Disclosed herein are exemplary methods, apparatus, systems, and articles of manufacture for the manufacture and / or processing of diagnostic test devices. Further examples and combinations thereof include the following: Example 1 includes a lateral flow assay device comprising: a porous medium including a first zone and a second zone, wherein the first zone includes an immobilized antigen corresponding to a target analyte or an immobilized antibody corresponding to the target analyte; a wireless chip that wirelessly acquires a first voltage via a signal from an external device, outputs a second voltage less than the first voltage to a first electrode in contact with at least one of the first zone or the second zone, and measures an electrical signal from the first electrode corresponding to the presence of the target analyte.

[0187] Example 2 includes the lateral flow assay device described in Example 1, wherein the signal is an electromagnetic signal and the first voltage corresponds to a current generated in the antenna when the electromagnetic signal is within a threshold distance to an external device.

[0188] Example 3 includes a lateral flow assay device as described in Example 1, in which the radio frequency chip outputs a second voltage to support a reaction in the porous medium that produces an electrical signal.

[0189] Example 4 includes the lateral flow assay device of Example 1, wherein the electrical signal is at least one of a voltage or a current.

[0190] Example 5 includes a lateral flow assay device as described in Example 1, in which the wireless chip transmits data to an external device based on an electrical signal.

[0191] Example 6 includes the lateral flow assay device of Example 1, wherein outputting the second voltage results in at least one of increased current amplitude or sensitivity of the electrical signal.

[0192] Example 7 includes the lateral flow assay device described in Example 1, where the first voltage powers the wireless chip.

[0193] Example 8 includes a battery-less lateral flow assay device comprising: a porous medium including a first zone and a second zone, the first zone including an immobilized antigen corresponding to a target analyte or an immobilized antibody corresponding to the target analyte; a wireless chip that outputs a voltage to the first electrode derived from a power signal acquired via the antenna when the first electrode is in contact with at least one of the first zone or the second zone; and measures an electrical signal from the first electrode corresponding to the presence of the target analyte.

[0194] Example 9 includes the battery-less lateral flow assay device of Example 8, wherein the power signal is an electromagnetic signal and the power signal corresponds to a current generated in the antenna when the electromagnetic signal is within a threshold distance to an external device that generates the electromagnetic signal.

[0195] Example 10 includes a battery-less lateral flow assay device as described in Example 8, in which the wireless chip outputs a voltage to support a reaction in the porous medium that generates an electrical signal.

[0196] Example 11 includes the battery-less lateral flow assay device of Example 8, wherein the electrical signal is at least one of a voltage or a current.

[0197] Example 12 includes the battery-less lateral flow assay device described in Example 8, in which the wireless chip transmits data to an external device based on an electrical signal.

[0198] Example 13 includes the battery-less lateral flow assay device of Example 8, wherein outputting a voltage results in at least one of increased current amplitude or sensitivity of the electrical signal.

[0199] Example 14 includes the battery-less lateral flow assay device described in Example 8, in which a power signal powers a wireless chip.

[0200] Example 15 includes a lateral flow assay device comprising: a porous medium including a first zone and a second zone, the first zone comprising an immobilized antigen corresponding to a target analyte or an immobilized antibody corresponding to the target analyte; a first electrode positionable in the first zone and a second electrode positionable in the second zone; an antenna in circuit with the first electrode and the second electrode, the antenna receiving a power signal from an external device; a voltage regulator adjusting a first voltage corresponding to the power signal to a second voltage different from the first voltage and outputting the second voltage to at least one of the first electrode or the second electrode; and a processor circuit detecting an electrical signal corresponding to at least one of the first electrode or the second electrode, the electrical signal corresponding to the presence of the target analyte.

[0201] Example 16 includes the lateral flow assay device of Example 15, wherein the power signal is an electromagnetic signal and the power signal corresponds to a current generated in the antenna when the electromagnetic signal is within a threshold distance to an external device.

[0202] Example 17 includes the lateral flow assay device of Example 15, wherein the voltage regulator outputs a second voltage to support a reaction in the porous medium that produces an electrical signal.

[0203] Example 18 includes the lateral flow assay device of Example 15, wherein the electrical signal is at least one of a voltage or a current.

[0204] Example 19 includes the lateral flow assay device of Example 15, wherein the antenna transmits data to an external device based on an electrical signal.

[0205] Example 20 includes the lateral flow assay device of Example 15, wherein outputting the second voltage results in at least one of increased current amplitude or sensitivity of the electrical signal.

[0206] Example 21 includes the lateral flow assay device of Example 15, wherein the power signal powers the processor circuit.

[0207] Example 22 includes a lateral flow assay device comprising an antenna that generates a first voltage based on an electromagnetic field generated by a reader, a voltage regulator that (A) reduces the first voltage to a second voltage and (B) applies the second voltage to an electrode when the electrode is in contact with a porous medium, and a processor circuit that determines the presence of a target analyte based on a signal corresponding to the electrode.

[0208] Example 23 includes the lateral flow assay device of Example 22, wherein the antenna generates a first voltage when a reader is within a threshold distance of the lateral flow assay device.

[0209] Example 24 includes the lateral flow assay device of Example 22, wherein the voltage regulator outputs a second voltage to support a reaction in the porous medium that generates a corresponding signal at the electrode.

[0210] Example 25 includes the lateral flow assay device of Example 22, wherein the signal corresponding to the electrode is at least one of a voltage or a current.

[0211] Example 26 includes the lateral flow assay device of Example 22, wherein the antenna transmits data to a reader based on the signal.

[0212] Example 27 includes the lateral flow assay device of Example 22, wherein outputting the second voltage results in at least one of an increased current amplitude or sensitivity of the signal.

[0213] Example 28 includes a lateral flow assay device as described in Example 22, wherein the first voltage powers the processor circuit. The disclosed methods, apparatus, and articles of manufacture improve the efficiency of determining the results of machine-readable diagnostic tests. To reduce and / or eliminate ambient light issues, examples disclosed herein provide machine-readable diagnostics that can be read with a smartphone rather than visually. Thus, the disclosed methods, apparatus, and articles of manufacture are directed to improving one or more of the functionality of diagnostic tests and diagnostic readers.

[0214] Also, as discussed above, visual interpretation of test results is prone to operator subjectivity and error. More accurate and objective results are obtained with the electrical-based examples disclosed herein. Examples disclosed herein include LFA devices that use various technologies (e.g., bioelectrochemical cell technology, circuit completion technology, etc.) to generate electrical signals (e.g., current, voltage, etc.) corresponding to test results. The electrical signals can be measured and wirelessly provided to a reader without including a battery device in the LFA device. In some examples, the LFA device can determine a test result based on the electrical signal and transmit the result to the reader. The reader can obtain the test result and / or process the electrical signal to determine the test result and deliver the test result (e.g., via the reader) to an external server or database to provide near real-time data corresponding to the disease and / or disease spread.

[0215] Additionally, the examples disclosed herein provide mechanisms for positioning electrodes on the flow stop and / or LFA device to obtain stronger electrical signals that can be measured over longer durations than other diagnostic tests. The examples disclosed herein also enable multiplexing, through the use of multiple lines, which can detect multiple marks (e.g., multiple types of antibodies / antigens) based on a single sample that are difficult or impossible to distinguish with the human eye. Multiplexing has applications, for example, in a single diagnostic test that can also test for multiple types of sexually transmitted diseases.

[0216] The example controls disclosed herein also control the execution time of diagnostic tests to ensure that the operator does not obtain results too early (i.e., before the test is completed) or too late, or stop the flow too early or too late. This provides error proofing in obtaining accurate test results. The example controls also facilitate multiple scans to (a) identify the LFA device, (b) verify that the test supposed to be read corresponds to the test that should be read (e.g., when running multiple tests in parallel on various LFAs using a single reader), and (c) obtain electrical signals corresponding to the test results. This provides error proofing to ensure that the wrong test is not read when obtaining multiple tests with overlapping reading windows.

[0217] Additionally, the disclosed examples include additional information along with the test results (lot number, expiration date, use by date, test information, signal quality information, chain of custody, etc.), all of which can be transmitted together using NFC technology. Traditional methods use additional readers, such as barcode readers, to read information about the test, which is in addition to the optical reader that determines / interprets the test results. Thus, the disclosed examples reduce the number of readers required to obtain more information.

[0218] Exemplary rapid diagnostic tests using electronic-based techniques are also more sensitive than traditional visually read tests. In the examples disclosed herein, the use of electronic-based techniques allows for a lower detection threshold than can be employed when results are based on the visual interpretation of an operator.

[0219] Examples disclosed herein may include an NFC chip capable of encoding and encryption. If adjustments are made to the product labeling data, including, for example, extending the shelf life, and / or other improvements are desired, the associated test and production-specific data may be later re-encoded. In some examples, the encoding and / or encryption may be updated and / or configured remotely.

[0220] Additionally, exemplary controls disclosed herein apply an electric potential (e.g., voltage, Poise potential, etc.) to electrodes in contact with the porous medium of a lateral flow assay. Applying an electric potential and / or voltage assists, promotes, and / or creates a more ideal environment for bioelectrochemical reactions to occur. In this manner, applying an electric potential and / or voltage increases signal robustness and sensitivity. In some examples, rather than using a conventional battery to apply the electric potential and / or voltage, examples disclosed herein utilize a voltage (e.g., corresponding to an electromagnetic field obtained via an antenna) used to power the wireless chip. In this way, a battery is not required to power the wireless chip and / or apply the electric potential and / or voltage.

[0221] As used herein, the descriptors "first," "second," "third," etc. are used to distinguish between multiple elements or components that may be referenced separately. Unless otherwise specified or understood based on the context of use, such descriptors are not intended to impart any sense of priority, physical order or placement in a list, or chronological order, but are merely used as labels to refer to multiple elements or components separately to facilitate understanding of the disclosed examples. In some instances, the descriptor "first" may be used to refer to an element in the detailed description, while in the claims, the same element may be referred to by a different descriptor, such as "second" or "third." In such instances, it is to be understood that such descriptors are used solely to facilitate reference to multiple elements or components.

[0222] As used herein, the terms "including" and "comprising" (and all forms and tenses thereof) are used as open-ended terms. Thus, in a preamble or any type of claim recitation, whenever a claim employs any form of "include" or "comprise" (e.g., comprises, includes, comprising, including, having, etc.), it is understood that additional elements, terms, etc. may be present without departing from the scope of the corresponding claim or recitation. As used herein, when the expression "at least" is used as a transitional term, for example in a claim preamble, it is open-ended in the same way that the terms "comprising" and "including" are open-ended. The term "and / or," when used in the form, for example, A, B, and / or C, refers to any combination or subset of A, B, and C, such as: (1) A alone; (2) B alone; (3) C alone; (4) A and B; (5) A and C; (6) B and C; and (7) A, B, and C. As used herein in the context of describing structures, components, items, objects, and / or things, the phrase "at least one of A and B" is intended to refer to embodiments including any of: (1) at least one A; (2) at least one B; and (3) at least one A and at least one B. Similarly, herein, when used in the context of describing structures, components, items, objects, and / or things, the phrase "at least one of A or B" is intended to refer to embodiments that include any of: (1) at least one A, (2) at least one B, and (3) at least one A and at least one B.As used herein, when used in the context of describing the performance or execution of a process, instruction, act, activity, and / or step, the phrase "at least one of A and B" is intended to refer to an embodiment that includes either (1) at least one A, (2) at least one B, and (3) at least one A and at least one B. Similarly, as used herein, when used in the context of describing the performance or execution of a process, instruction, act, activity, and / or step, the phrase "at least one of A or B" is intended to refer to an embodiment that includes either (1) at least one A, (2) at least one B, and (3) at least one A and at least one B.

[0223] As used herein, singular references (e.g., "a," "an," "first," "second," etc.) do not exclude a plurality. As used herein, the term "a" or "an" entity refers to one or more of that entity. As used herein, the terms "a" (or "an"), "one or more," and "at least one" may be used interchangeably. Furthermore, although individually listed, actions of a plurality of means, elements, or methods may be performed by, for example, a single unit or processor. Furthermore, although individual features may be included in different examples or claims, they may also be combined, and the inclusion of features in different examples or claims does not imply that a combination of features is not feasible and / or advantageous.

[0224] The following claims are incorporated by reference into this detailed description, with each claim standing on its own as a separate embodiment of this disclosure.

Claims

1. A lateral flow assay device comprising: a porous medium including a first zone and a second zone, the first zone containing an immobilized antigen corresponding to a target analyte or an immobilized antibody corresponding to the target analyte, and wherein an electric current is generated between the first zone and the second zone when an applied sample contains the target analyte; wirelessly obtaining a first voltage via a signal from an external device; adjusting the first voltage to a second voltage less than the first voltage; outputting a second voltage to a first electrode in contact with the first zone to amplify the current between the first zone and the second zone; Measuring the amplified current between the first electrode and a second electrode in contact with the second zone. Wireless chip and A lateral flow assay device comprising:

2. 10. The lateral flow assay device of claim 1, wherein the signal is an electromagnetic signal and the first voltage corresponds to a current generated in the antenna when the electromagnetic signal is within a threshold distance to an external device.

3. 10. The lateral flow assay device of claim 1, wherein the wireless chip outputs a second voltage to support a reaction in the porous medium that amplifies the current.

4. The lateral flow assay device of claim 1 , wherein the wireless chip transmits data to an external device based on the amplified current.

5. The lateral flow assay device of claim 1 , wherein the wireless chip outputs a second voltage to increase the sensitivity of the electrical signal corresponding to the current.

6. The lateral flow assay device of claim 1 , wherein the first voltage is used to power a wireless chip.

7. 1. A battery-less lateral flow assay device, comprising: a porous medium including a first zone and a second zone, the first zone containing an immobilized antigen corresponding to a target analyte or an immobilized antibody corresponding to the target analyte, and wherein an electric current is generated between the first zone and the second zone when an applied sample contains the target analyte; adjusting a first voltage derived from a power signal obtained via the antenna to a second voltage less than the first voltage; outputting a second voltage to the first electrode while the first electrode is in contact with the first zone to increase a current between the first zone and the second zone; Measuring the increased current between the first electrode and a second electrode in contact with the second zone. Wireless chip and A battery-less lateral flow assay device comprising:

8. 8. The battery-less lateral flow assay device of claim 7, wherein the power signal is an electromagnetic signal and the power signal corresponds to a current generated in the antenna when the electromagnetic signal is within a threshold distance to an external device that generates the electromagnetic signal.

9. 8. The battery-less lateral flow assay device of claim 7, wherein the wireless chip outputs a second voltage to support a reaction in the porous medium that increases the current.

10. 8. The battery-less lateral flow assay device of claim 7, wherein the wireless chip transmits data to an external device based on the increased current.

11. 8. The battery-less lateral flow assay device of claim 7, wherein the wireless chip outputs a second voltage to increase the sensitivity of the electrical signal corresponding to the increased current.

12. The battery-less lateral flow assay device of claim 7 , wherein the power signal powers the wireless chip.

13. A lateral flow assay device comprising: a porous medium including a first zone and a second zone, the first zone containing an immobilized antigen corresponding to a target analyte or an immobilized antibody corresponding to the target analyte, and wherein an electric current is generated between the first zone and the second zone when an applied sample contains the target analyte; a first electrode positionable in the first zone and a second electrode positionable in the second zone; an antenna in a circuit having a first electrode and a second electrode, the antenna receiving a power signal from an external device; adjusting a first voltage corresponding to the power signal to a second voltage different from the first voltage; A second voltage is applied to the first electrode to increase the current between the first zone and the second zone. A voltage regulator; a processor circuit for detecting an increased current corresponding to the first electrode and the second electrode; and A lateral flow assay device comprising:

14. 14. The lateral flow assay device of claim 13, wherein the power signal is an electromagnetic signal and the power signal corresponds to a current generated in the antenna when the electromagnetic signal is within a threshold distance to an external device.

15. 14. The lateral flow assay device of claim 13, wherein the voltage regulator outputs a second voltage to support a reaction in the porous medium that increases the current.

16. The lateral flow assay device of claim 13 , wherein the antenna transmits data to an external device based on the increased current.

17. 14. The lateral flow assay device of claim 13, wherein the voltage regulator outputs a second voltage to increase the sensitivity of the electrical signal corresponding to the increased current.

18. The lateral flow assay device of claim 13 , wherein the power signal powers the processor circuit.

19. A lateral flow assay device comprising: an antenna that generates a first voltage based on an electromagnetic field generated by the reader; a voltage regulator that (A) reduces the first voltage to a second voltage and (B) applies the second voltage to the first electrode when the first electrode is in contact with the porous medium, the application of the second voltage increasing the current generated on the porous medium; a processor circuit that determines the presence of a target analyte based on a signal corresponding to the amplified current between the first electrode and a second electrode in contact with the porous medium; A lateral flow assay device comprising:

20. 20. The lateral flow assay device of claim 19, wherein the antenna generates a first voltage when a reader is within a threshold distance of the lateral flow assay device.

21. 20. The lateral flow assay device of claim 19, wherein the voltage regulator outputs a second voltage to support a reaction in the porous medium that generates a signal corresponding to the first electrode.

22. 20. The lateral flow assay device of claim 19, wherein the voltage regulator applies a second voltage to increase at least one of the current amplitude or sensitivity of the signal.

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