Sample analyzer system and method for determining sample integrity

Abstract

Configurations for a system, method, and device for determining test card status and / or sample integrity are disclosed. Determining test card status and / or sample integrity includes assessing the pressure measurements of a pumping system in a sample analyzer to determine a threshold. The sample integrity may be determined by comparing pressure measurements of the pumping system attached to a test card to a threshold, which may be related to whether the test card is an empty test card or a prefilled test card. The sample integrity may be determined to be intact when the test card is determined to be an empty test card, and the user may be prompted to inject a sample into the test card. The sample integrity may be determined to be compromised when the test card is determined to be a prefilled test card, and the user may be prompted to discard the test card.

Description

SAMPLE ANALYZER SYSTEM AND METHOD FOR DETERMINING SAMPLE INTEGRITY

[0001] This application claims benefit under 35 USC § 119(e) of U.S. Provisional Application No. 63 / 846,612, filed July 18, 2025; U.S. Provisional Application No. 63 / 675,844, filed July 26. 2024; and U.S. Provisional Application No. 63 / 675.827, filed July 26, 2024. The entire contents of the above-referenced patent applications are hereby expressly incorporated herein by reference.FIELD

[0002] The present invention relates to systems, devices, and methods for determining sample integrity for a sample analyzer employing test cards. More particularly, this disclosure relates to characterizing the nature of a test card by measuring the pressure within portions of the test card.BACKGROUND

[0003] Samples collected for laboratory analysis are susceptible to degradation when the sample is in a different environment than its native environment and / or prematurely exposed to an open environment. Analyses may include gas analysis, liquid analysis, urinalysis, and / or blood or other bodily fluid analysis. One system for such analyses uses fluid sample holders which contain channels capable of holding samples with limited exposure to an open environment. Such analyzers may be used in an on-site laboratory, hospitals or in an off-site sample testing facility such as point-of-care settings. Alternatively, in the case of water or other liquid samples containing gases to be measured, such analyzers may be used in the field, at a manufacturing facility, or other research or factory setting. One such sample holder is a test card which may include channels for holding samples. Test cards may be placed into analyzers, such as handheld or benchtop biological sample analyzers. Such sample analyzers may include pumping systems which apply pressure to a sample thereby moving the liquid through the test card for analysis and measurement within the test card. Sample analyzers may have sensors that are capable of reading information about the sample within a test card. A sample analyzer may utilize a pump to facilitate movement or other application of the sample wi thin or to test cards while the test card itself is w ithin the sample analyzer.

[0004] Injecting a sample into a test card prior to inserting the test card into the sample analyzer can lead to the sample characteristics changing before being analyzed by the sample analyzer. This can lead to inaccurate results. Current sample analyzers may use optical sensors to detect sample within a test card. Optical sensors can detect optical level responses of fluids (e.g. samples). However, the optical sensors may not be reliable because the difference in optical level responses of a sample within a test card may be indistinguishable from an empty test card. Accordingly, a cost-effective system, device, and method that can detect whether a sample has been inj ected into a test card prior to the test card being inserted into a sample analyzer is desirable.SUMMARY

[0005] The present invention relates to a systems, devices, and methods to assess test card status and / or sample integrity7. Methods and systems are disclosed to assess test card status by utilizing pressure measurements. The present invention also discloses systems to sense pressure in a test card thereby assessing test card status and / or sample integrity.

[0006] The embodiments described herein relate to methods and systems of using pressure measurements to determine the status of a test card in a sample analyzer to reduce and / or eliminate inaccurate results and / or misidentification of sample status or integrity.

[0007] Embodiments of the invention provide detection of prefilled test cards for prevention of their use in sample analyzers. One embodiment is directed to a sample analyzer having an insertion slot operable to accept a test card having a channel capable of holding a sample, a pumping system with a pump and sensor capable of measuring pressure, and a programmable processor capable of operating a pumping system, receiving pressure measurements, determining a threshold, and determining the test card status and / or sample integrity7. The pumping system may further comprise a valve. The pumping system may be operable to facilitate a plurality7of pressure measurements when the valve is in different positions, and / or when the test card is present or absent from the insertion slot of the sample analyzer. In some embodiments, the programmable processor determines the threshold from pressure measurement(s) from the closed pumping system and pressure measurement(s) from the pumping system open to an external environment. The programmable processor may also compare pressure measurement(s) when the pumping system is operatively attached to a test card to the threshold. Based on these measurements, the processor determines whether the testcard is an empty test card or a prefilled test card. In other embodiments, the programmable processor can prompt a user to insert a sample into an empty test card and / or prompt a user to discard a prefilled test card.

[0008] Another embodiment of the invention is directed to a method of determining sample integrity utilizing a sample analyzer with an insertion slot capable of accepting a test card with a channel capable of holding a sample, comprising a pumping system having a pump and a valve, and a pressure sensor, and a programmable processor. Here, methods implemented by the programmable processor are provided for initiating the operation of the pumping system, receiving a first pressure measurement, a second pressure measurement and a third pressure measurement, determining a threshold, and determining test card status which may be indicative of sample integnty. In other embodiments, the programmable processor is further capable of receiving a plurality of pressure measurements when the valve is in various positions and / or in the presence or absence of a test card. In some examples, the programmable processor is capable of utilizing received pressure measurements to determine one or more threshold values and determining whether the test card status is an empty test card or a prefilled test card. In other examples, methods implemented by a programmable processor are provided for prompting a user to discard a prefilled test card and / or insert a sample into an empty test card.

[0009] In addition to the various aspects and embodiments described above, further aspects of the invention will become apparent by reference to the drawings and by study of the following description. Reference is made to the accompanying drawings which illustrate how the invention can be practiced through specific, non-limiting examples. It is understood that other examples can be used, and structural changes can be made without departing from the scope of the invention.BRIEF DESCRIPTION OF DRAWINGS

[0010] FIG. 1 illustrates a block diagram of one example of a sample analyzer;

[0011] FIGs. 2A and 2B illustrate a block diagram of a first side and a second side, respectively, of an example test card;

[0012] FIG. 3 illustrates a block diagram of an example pumping system;

[0013] FIG. 4 illustrates an exemplary test card and an insertion slot of a sample analyzer;

[0014] FIG. 5 illustrates a flowchart of an exemplary method for determining test card status and / or sample integrity;

[0015] FIG. 6 illustrates a graphical representation of an example of a threshold determination;

[0016] FIG. 7 illustrates an exemplary graphical representation of a determination of test card status using pressure measurements;

[0017] FIG. 8 illustrates a block diagram of a second side of an example test card with optical sensors; and

[0018] FIGs. 9-11 illustrate using optical sensors as an additional check for determining test card status and / or sample integrity.

[0019] The proportions and dimensions (either relative or absolute) of the various features and elements (and collections and groupings thereof) and the boundaries, separations, and positional relationships presented between them are provided in the accompanying figures merely to facilitate an understanding of the various embodiments described herein and, accordingly, may not necessarily be presented or illustrated to scale, and are not intended to indicate any preference or requirement for an illustrated embodiment to the exclusion of embodiments described with reference thereto.DETAILED DESCRIPTION

[0020] Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. The following description is not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to disclose alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.

[0021] Disclosed herein are devices, methods, and systems for measuring test card status and / or sample integrity. The present invention relates to a sample analyzer capable of determining whether a test card is filled or empty7, or in other words detecting presence or absence of a sample in the test card. In one example, the analyzer contains a pumping system having a pump which can manipulate fluids (i.e. liquids or gases) thereby effectuating a measurable change in measured pressure. Samples may7comprise fluids including, but not limited to, liquid fluids, bodily or biological fluids, non-biologic fluids, or gaseous fluids.(Fluids include both liquids and gases as that term is used herein.) The pump may also act on an external device, system, or object (i.e. a test card) in a similar manner. In particular, the pump may manipulate a fluid within the pumping system and any external object connected to the pumping system which, in turn, may result in a change in the pressure within the pumping system and the external object connected to the pumping system. The pumping system includes a pump, a valve, and may also include a pressure sensor for measuring pressure. The pressure measurements may be used to determine test card status and / or sample integrity. In one embodiment, pressure measurements taken when the valve of the pumping system is open to an external environment and when the valve of the pumping system is closed are used to determine a threshold. The pressure measurements when the valve is operatively connected to a test card are then compared to the threshold to determine the test card status.

[0022] The test card status and / or sample integrity refers to a determination as to whether the test card is empty or was filled with a sample prior to the test card insertion into the sample analyzer. (The terms test card status and sample integrity are used interchangeably herein where the test card status refers to the usefulness of the test card whereas the sample integrity refers to the sample contained in the test card.) Sample integrity’ is intact when the properties of the sample when measured have not changed substantially from the time the sample was originally collected, and sample integrity is compromised when the properties of the sample when measured are substantially different from the time the sample was originally collected. Certain samples may undergo changes during or after sample collection such as, but not limited to, coagulation, loss of dissolved gases (i.e. degassing), metabolism of various components dissolved or suspended in the sample, degradation of various components dissolved in or suspended in the sample, oxidation of various components dissolved in or suspended in the sample, and / or lysis of cells within the sample or similar other changes in the components of a sample. Sample integrity is important for having a correct analysis of a sample and therefore it is important to minimize the time the sample is awaiting or present in a test card before sample analysis by an analyte sensor(s) is initiated. In preparing a test card, it is important to understand if a test card has been prefilled and therefore contains a potentially compromised sample. As such, sample integrity’ correlates to test card status. Sample integrity may include whether the test card is an empty test card or a prefilled test card, wherein sample integrity’ is likely intact when the test card is empty and sample integrity is compromised when the test card was prefilled. An empty test card is a test card with no sample injected in the test card. A prefilled test card is a test card that has sample inj ected in the test card. Sample integrityis determined based on a pressure measurement of the test card and its comparison to a threshold, wherein the sample integrity is intact when this pressure measurement is above the threshold and the sample integrity is compromised when this pressure measurement is below the threshold

[0023] FIG. 1 illustrates a perspective view of an exemplary sample analyzer 100. Here, the sample analyzer 100 includes a sample analyzer body 130 with a housing 135, an insertion slot 1 10, and a display 120 with a display housing 136. The sample analyzer 100 may be used as a point of care biologic sample analyzer which provides feedback for a patient sample within minutes and may be a handheld or benchtop sample analyzer. Here, the sample analyzer body 130 includes the insertion slot 110 and a detachable display 120. The display 120 may be a graphical user interface which may include a touch screen interface. The insertion slot 110 is operable to receive a test card (not shown). The housing 135 of the sample analyzer 100 (e.g., as show n in Figure 1) may surround the sample analyzer body 130 and the display housing 136 may surround the display 120. In some examples, the housings 135 and 136 are the same housing when the sample analyzer body 130 and the display 120 are one component.

[0024] The sample analyzer may be any tester, system, or analyzer compatible with a test card where a sample is injected, inserted, or placed into a test card. In one example, sample analyzers are used to test biological samples to diagnose and / or generate a treatment plan, including but not limited to a treatment plan related to blood-gas, diabetes, urinalysis or cardiac measurement(s). Such devices include those sold by Siemens Healthineers, for example, EPOC® blood analysis systems, RAPIDPoint® 500e blood gas systems, RAPIDLab® 1200 systems, DCA Vantage® analyzers, Atellica® VTLi patient-side immunoassay analyzers, and CLINITEK systems and analyzers. In another embodiment, the sample analyzer tests other types of samples, such as fluids in a manufacturing and / or industrial system, in a plant, facility, store, or other setting where a sample requires accurate reading and / or identification.

[0025] FIG. 2A and FIG. 2B illustrate a first side of a test card 205 and a second side of a test card 205, respectively. The first side of the test card, as shown in FIG. 2A, includes a barcode 21 , test information 220, an expiration date 230, a lot number 240, an analyte sensor or sensor panel 250, and other information such as, but not limited to company identification, a QR code, manufacturing date, card type, and the like. In some examples, the test card is a single use, credit card sized device designed fortesting of samples, for example for bodily fluid or other fluid testing. The test card frame may be made of polyester, polypropylene,polyethylene, other plastics, or other materials as is known in the art. The test card may comprise a sample entry port and channels capable of holding fluids (e.g. samples). The test card may be used to perform various tests, providing results by measuring various signals and / or components in the samples and transmitting results to the user. Generally, different types of test cards for testing different samples may be used to test samples including, but not limited to, biological samples, such as from a plant or animal sample, a human sample, and various types of biological samples may include urine, whole blood, blood serum, blood plasma, saliva, cerebrospinal fluid, pleural fluid, dialysate fluid, nasopharyngeal fluid, vaginal fluid, tears, veinous samples, arterial samples, control fluids, any combination thereof, and the like. Similarly, test cards may carry non-biological samples that are compatible with the pumping system of the sample analyzer.

[0026] As shown in Fig. 2A, the test card may include a panel of sensors 250 that may indicate which analyses may be performed on the sample. For example, a blood test card includes sensors for reporting pH, pCO2, pO2, lactate, Na+, K+, iCa, glucose, creatinine, blood urea nitrogen, hematocrit, and TCO2 analytes. Alternatively or in addition, the test card may support other measurements, for example COOX measurements to report tHb, O2Hb, HHb, COHb, MetHb analytes. A different test card may include sensors that are some combination of the two previous test cards or entirely different test cards.

[0027] In FIG. 2B, the second side of the test card 205 includes a sample channel 255, a sample port 260, and a connecting port 265 for connecting the test card to the pumping system. The sample channel 255 may include a channel portion or a tube capable of holding fluids received by the test card 205 prior to sample positioning at and measurement by the sensor panel 250. For example, when using a sample transfer device, the user may transfer a sample from the sample transfer device to the sample channel 255 (or portion thereof) on the second side of the test card 205 via the sample port 260. The tip of the sample transfer device may be inserted into the sample port 260 to transfer the sample to the sample channel 255 (or portion thereof). Exemplary sample transfer devices include, but are not limited to, a syringe, capillary tube, vacuum tube, or the like. The connecting port 265 may or may not operably connect the pumping system of the sample analyzer to the test card while the test card 205 is inserted into the sample analyzer. For example, a valve(s) of the pumping system may be configured to open and close the connecting port 265 such that the pumping system is operatively connected to the test card 205 (e.g., at the sample channel 255 or portion thereof)when the valve(s) is open thereby permitting fluid communication (e.g., positive or negative gas / air pressure) between the pumping system and the sample channel 255, and the pumping system is not operatively connected to the test card when the valve(s) is closed thereby preventing fluid communication (e.g., positive or negative gas / air pressure) between the pumping system and the sample channel 255. It should be noted that the valve(s) may also be configured to open and close when the test card 205 is not inserted into the sample analyzer such that the pumping system may operably connect and disconnect from an external environment (e.g., the environment of the insertion slot without a test card therein and thereby having an ambient pressure).

[0028] As shown in FIG. 2B, the second side of the test card 205 also includes disposal or waste fluid chamber 270. calibration fluid chamber 280. and measurement or assay region 290 for measuring analyte parameters of the sample. In some examples, the measurement region 290 includes a tube or channel where sample can flow through the sample channel 255 and into the measurement region 290. The measurement region 290 may also include sensors or a panel of sensors 250 as seen on the first side of the test card (see FIG. 2A). In certain embodiments, the disposal chamber 270 includes a tube or channel that functions to prevent sample from flowing past the measurement region 290 and into the connecting port 265. In some examples, the calibration fluid chamber 280 stores a calibration fluid. In these examples, the calibration fluid may be a water-based fluid, an oil-based fluid, gaseous fluid or another fluid. In other examples, the calibration fluid may comprise a semi-solid or solid material or a combination of any of the aforementioned fluids. Other test cards may be used, where the channels have different configurations and / or may not include calibration fluid chambers or disposal chambers. The skilled person will recognize that known variations in test card configurations are known and can be used in the present invention.

[0029] FIG. 3 illustrates a block diagram of an exemplary pumping system 300 which includes a pump 320 and a pressure sensor 310. A pressure sensor is a device capable of measuring pressure and may also be able to relay pressure measurements through electrical signals as is known in the art. The pressure measurements may be absolute pressure measurements, differential pressure measurements, gauge pressure measurements, or other pressure measurements as is known in the art. In some embodiments, the pump 320 is a vacuum or negative pressure pump and the pressure sensor 310 is configured to detect or measure the presence or absence of fluid within an open or closed pumping system 300 with and withoutthe test card 205 inserted. In another embodiment, the pump 320 is a positive pressure pump. The pumping system 300 illustrated in FIG. 3 further includes a valve 340 connected to the pressure sensor 310 and pump 320 by a pumping tube or channel 330. The valve 340 is capable of controlling the flow of fluids (e.g., gas / air within the pumping system 300, or gas / air or liquid within the test card 205) by closing, partially blocking, and / or opening at least one passageway, for example, a passageway between the pumping tube 330 and a common tube 350. The pumping system 300 also includes tubing connecting the pump, the valve, and the pressure sensor. In some examples, the tubing extends from the valve 340 and is operable to be connected to the vent 365, the external environment, a test card, and / or another valve. In some embodiments, the tubing is a single tube and in other embodiments the tubing is comprised of multiple tubes that are capable of disconnecting and connecting to each other in a seemingly continuous way. The term “tube” used herein is not limited to a particular geometry or shape and can be used interchangeably with the term “channel.”

[0030] Illustrated in FIG. 3, the pumping system includes a common tube 350 capable of being connected to the connecting port of a test card or another external device. In other embodiments, the common tube 350 may be open to an external environment (via an open insertion slot 110) when the common tube 350 is not connected to the test card or another external device. In FIG. 3, the pumping system includes a venting tube 360 connecting the valve 340 and vent 365. In certain embodiments, vent 365 may be connected to an external device or open to the external environment. In some embodiments pumping tube 330, common tube 350, and venting tube 360 are a single entity while in other embodiments the tubes are separate entities that are capable of disconnecting and connecting to each other in a continuous but separable manner. Pumping tube 330, common tube 350, and venting tube 360 are capable of holding fluid (e.g., gas / air) and function to connect the various components of the pumping system to itself, to the external environment, and to external devices (e.g. test cards). In some embodiments the pumping tube 330, common tube 350, and venting tube 360 can be made of various plastics, rubbers, metals, or a combination thereof. In some embodiments, the various components of the pumping system are operated in unison, while in other embodiments the components are operated independently. The pumping system may further comprise multiple pumps, valves, and / or pressure sensors. Generally, the pumping system of a sample analyzer may be able to act in the presence or absence of a test card. Pumping systems can be handheld, mobile, or stationary and are widely used in vacuum cleaners, manufacturing plants, commercial buildings, and agricultural systems, as is known in the art.

[0031] The valve 340 illustrated in FIG. 3 may be operable to control the flow of fluids (e.g., gas / air or liquid) by closing, partially blocking, and / or opening at least one tube passageway (e.g., reference numerals 360, 350, and / or 330 shown in FIG. 3). In FIG. 3, the valve 340 is a three-way valve comprising a pump port 342, a common port 344, and a vent port 346. The three-way valve functions to connect the common tube 350 to the venting tube 360 through the common port 344 and the vent port 346, z.e., when connected, this position may be referred to as closed (i.e. the valve 340 is closed and the pumping system 300 is closed). The pumping system being closed refers to the pump being operatively disconnected from or closed to the insertion slot (when a test card is absent or when the test card is present). The three-way valve may also function to connect the common tube 350 to the pumping tube 330 through the common port 344 and the pump port 342. This position may be referred to as open (i.e. the valve 340 is open and the pumping system 300 is open). The pumping system being open refers to the pump being operatively connected and open to an external environment via an empty insertion slot (no test card inserted / present), or, if a test card is inserted / present, refers to the pump being operatively connected and open to the sample channel 255 of the inserted test card. The valve 340 may be operable to open or close with or without the test card in the insertion slot of the sample analyzer. In the open valve position, the valve may be open to an external environment and / or operatively connected to the test card. In other embodiments, the valve may be a two-way valve, a four-way valve, a ball valve, a check valve, a butterfly valve, a needle valve, a combination of types of valves, or an entirely different valve, as is know n in the art.

[0032] The pressure sensor 310 is operable to measure pressure. In one aspect of the invention, the pressure sensor measures pressure when the valve 340 is closed (i.e., pumping system 300 is closed) and the resulting measurement may be referred herein as a closed system measurement (which can be taken with or without the test card inserted). In another aspect of the invention, the pressure sensor measures pressure when the valve is open to the external environment, where the external environment may be the air outside of the pumping system. In this aspect, the resulting measurement may be referred as an open system measurement with no test card present. In yet another aspect of the invention, the pressure sensor measures pressure when the pump is operatively connected to the test card, where common tube 350 is connected to the connecting port 265 of a test card. In this aspect, the valve is open to the test card (e.g., to the sample channel 255) and the resulting measurement may be referred herein as an open system measurement with test card present. The pressure sensor can also continuouslycommunicate a pressure measurement as a pressure waveform or another graphical or nongraphical representation of pressure. The pressure sensor may be an absolute pressure sensor, a gauge pressure sensor, a differential pressure sensor, a capacitive pressure sensor, or another type of pressure sensor, as is known in the art. The pressure sensor may relay pressure measurements to at least one programmable processor (not shown) operable to receive pressure measurements and make determinations or calculations by utilizing pressure measurements.

[0033] The pump 320 can manipulate fluids, which, if the fluid is resistant to flow, can result in a change in pressure. The pump may be a centrifugal pump, a diaphragm pump, a gear pump, a piston pump, a reciprocating pump, or another type of pump, as is known in the art. The pump may be a vacuum pump or a positive pressure pump. The fluid manipulated by pump 320 may be resistant to flow and cause a change in pressure that may be measured by pressure sensor 310. In some examples, the pump manipulates gaseous fluids, such as, air, oxygen, nitrogen, argon, water vapor, and other gases. In other examples, the pump manipulates liquid fluids such as non-biological or biological samples including but not limited to: urine, whole blood, blood serum, blood plasma, saliva, cerebrospinal fluid, pleural fluid, dialysate fluid, nasopharyngeal fluid, vaginal fluid, tears, veinous samples, arterial samples, control fluids, water, any combination thereof, and the like. In some embodiments, the pump is operatively connected to an external device such as a test card through common tube 350. In these embodiments, the pump can manipulate fluids to flow through an external device such as a test card to have the fluid properties measured by the pressure sensor. The pump 320 builds negative pressure which can then act on the sample when the pump 320 is operatively connected to the test card after the sample has been transferred to the test card, effectively pulling the sample through the test card. Furthermore, when the pump 320 acts on a test card pre-filled with sample, the negative pressure builds faster than when the pump 320 acts on an empty test card. As a result, the pre-filled test card pressure profile can be correlated to the pressure profile of the closed pumping system and the empty test card pressure profile can be correlated to the pressure profile of the pumping system open to the external environment.

[0034] FIG. 4 illustrates an exemplary test card 405, and an insertion slot 410 included in a sample analyzer body 430. As previously described with reference to FIG. 1, the sample analyzer 400 may include a sample analyzer body 430. and a display 420. To begin a sample testing process, a user may power on each of the sample analyzer body 430 and the display 420. The display 420 may be a “host’' and the sample analyzer body 430 and the display 420may fixedly or detachably couple to one another. In one example, the display 420 couples directly to the sample analyzer body 430. The sample analyzer 400 may prompt a user to enter user credentials and to insert a test card 405 thereby allowing the sample analyzer 400 to carry out the process to determine whether the test card is an empty test card or a prefilled test card.

[0035] Depending on the status of test card, i. e. , empty or prefilled, the user may be prompted to inject the sample into the empty test card or to discard a prefilled test card. The display 420 may prompt the user to transfer the sample from the syringe to the test card 405. As previously described with reference to FIGs. 2A and 2B, the sample transfer device may be inserted into the sample port and the sample may be transferred from the sample transfer device to the test card 405 for testing by the sample analyzer.

[0036] The sample analyzer 400 includes a programmable processor, memory, and a graphical processor. The programmable processor stores data locally in the memory or may be connected to a server (not shown) via a network (not shown), for example, local area network (LAN), wide area network (WAN), WiFi, etc. In one example, the server is deployed in a cloud computing environment. As used herein, “cloud computing environment” refers to a processing environment comprising configurable computing physical and logical resources, for example, networks, servers, storage, applications, services, etc., and data distributed over the network, for example, the internet. The cloud computing environment provides on-demand network access to a shared pool of the configurable computing physical and logical resources. Additionally, the server may include a network interface for communicating with more than one sample analyzer and / or other types of devices via the network.

[0037] The programmable processor is capable of one or more of the following functions: operating the pumping system, receiving pressure measurements, determining thresholds, and determining test card status and / or sample integrity. Test card status may refer to whether the test card is empty7, prefilled, broken, damaged, and / or incompatible with the sample analyzer. Sample integrity may refer to various properties of the sample being substantially the same as they were when the sample was originally collected. These properties of the sample may include pH, or concentrations of various gases, such as, for example, CO2, O2, CO, and N2 or concentration of solutes such as Na+, K+, glucose, lactate, creatinine, blood urea nitrogen, hematocrit, or concentration of analytes such as TCO2, tHb, OzHb. HHb, COHb, and MetHb analytes. The test card status may be indicative or be correlated to the sample integrity, where an empty7test card status is indicative / correlated to acceptable sample integrity,while a prefilled test card status is indicative / correlated to unacceptable sample integrity. The programmable processor may be configured to provide an indication to the user of the determined test card status and / or correlated sample integrity. Such indication may be, for example, a visual and / or auditory alert indicating to the user an error state (e g., to discard the test card) or non-error state (e.g., insert sample into test card).

[0038] The programmable processor may be configured to perform the processes described herein. The programmable processor, as used herein, means any type of computational circuit, such as, but not limited to, a microprocessor, microcontroller, complex instruction set computing microprocessor, reduced instruction set computing microprocessor, very long instruction word microprocessor, explicitly parallel instruction computing microprocessor, graphics processor, digital signal processor, or any other type of processing circuit, as is known in the art. The programmable processor may also include embedded controllers, such as generic or programmable logic devices or arrays, application specific integrated circuits, single-chip computers, and the like. In general, a programmable processor can include hardware elements and software elements. The programmable processor can be configured for multi -threading, for example. The programmable processor can host different calculation processes at the same time, executing them either in parallel or switching between active and passive calculation processes.

[0039] The memory7may be transitory' memory' and non-transitory memory7. The memory may be coupled for communication with the programmable processor. The programmable processor may execute instructions and / or code stored in the memory. Embodiments of the present disclosure may comprise a special purpose computer or processor including a variety' of computer hardware. Computer-executable instructions comprise, for example, instructions and data which cause a general purpose computer to transform into a special purpose computer to perform a certain specific function or group of functions as described in further detail herein. A variety of computer-readable storage media may be stored in and accessed from the memory. The memory' may include any suitable elements for storing data and machine-readable instructions, such as read only memory7, random access memory7, erasable programmable read only memory7, electrically erasable programmable read only memory, a hard drive, a removable media drive for handling compact disks, digital video disks, diskettes, magnetic tape cartridges, memory cards, and the like. In the present embodiment, the memory' includes a graphical processor stored in the form of machine-readable instructions onany of the above-mentioned storage media and may be in communication to and executed by the programmable processor. When executed by the programmable processor, the processing and / or calculations described in further detail herein may be executed. The memory may also include a set of historical data. The set of historical data may include previously collected pressure measurements and previously determined thresholds. In some embodiments, the historical data may be used to determine the threshold of a test card. In particular, in one embodiment, a first pressure measurement and / or second pressure measurement can be reused for determining the threshold for a subsequent determination of test card status.

[0040] In some examples, the programmable processor is included in either one or both of the sample analyzer body, and / or the display. In the example in which the programmable processor is included in the display, the display is operably, communicatively, and / or physically coupled to the sample analyzer body. The display may synchronize to the sample analyzer body when both of the components are powered on so that the memory' is available to either one or both of the components. Additionally, the memory may be included in either one or both of the sample analyzer body, and / or the display. In the example in which the memory is included in the display, the display is operably, communicatively, and / or physically coupled to the sample analyzer body. As previously described, the display may synchronize to the sample analyzer body when both of the components are powered on so that the memory' is available to either one or both of the components.

[0041] FIG. 5 illustrates a flowchart of an exemplary method 500 for determining test card status and / or sample integrity. Test card status relates to whether a pressure measurement taken at a time when the pump is operatively connected to the test card is above or below a predetermined threshold. As explained herein, the time when the pump is operatively connected to the test card for the threshold comparison is when the test card is present in the insertion slot 410 and the valve 340 is open. Test card status indicates when the test card is empty and therefore acceptable to use for testing (i.e., acceptable sample integrity), and when the test card has been prefilled and is therefore compromised (i.e., compromised sample integrity).

[0042] In particular, in step 510 of FIG. 5, the sample analyzer is powered on. The pow ering on step may be carried out manually or through a processor.

[0043] The next step 520 illustrated in FIG. 5 describes receiving a first pressure measurement at a preselected time and when the valve 340 is open to an external environment.The first pressure measurement may be referred to as the open system measurement with no test card present, as discussed above, and as such may be obtained at a preselected time during which the pumping system 300 is open via an empty insertion slot (test card not present).

[0044] The preselected time or time range may be within 10 or more seconds from the start of activation of the pump, or within 5 seconds from the start of activation of the pump, or within 3 seconds from the start of activation of the pump, or within 1 second from the start of activation of the pump, or within 0.5 seconds from the start of activation of the pump, or between 0.4 and 0.5 seconds from the start of activation of the pump, for example. The first pressure measurement (step 520), the second pressure measurement (step 530), and the third pressure measurement (step 550) may be taken at the same preselected time or at different preselected times relative to the start of activation. For example, in one embodiment, the pump is driven in the same fashion for each of the pressure measurements and thus each of the pressure measurements are taken at the same preselected time. In other embodiments, each of the pressure measurements are taken at different preselected times.

[0045] The next step 530 illustrated in FIG. 5 describes receiving a second pressure measurement at a preselected time when the valve is closed. In this step, the second pressure measurement is received by the sample analyzer either with or without the presence of the test card. The second pressure measurement is received by the programmable processor. In examples where the second pressure measurement is obtained in the presence of the test card, prior to the second pressure measurement, the test card is inserted into the insertion slot. The second pressure measurement may be referred to as the closed system measurement, as discussed above, and as such may be obtained at a preselected time during when the pump is operatively disconnected from or closed to the insertion slot or test card (if present).

[0046] The method of FIG. 5 next describes step 540, that is, utilizing the first pressure measurement and the second pressure measurement to determine the threshold. The threshold is determined or calculated by the programmable processor of the sample analyzer. The threshold may be a value between 10 and 90 percent of a standard deviation between the first pressure measurement and the second pressure measurement. In another embodiment, the threshold may be defined as fifty percent of a standard deviation between the first pressure measurement and the second pressure measurement. In some embodiments, the threshold is determined every time after step 530 is executed (such as, every time a new test card is inserted into the sample analyzer). In other embodiments, the threshold is stored in the memory and thestored threshold is used for comparison with the third pressure measurement (of step 550). In these examples, the stored threshold in the memory may be determined between 1 and 10 times per month, or between 1 and 10 times per week, or between 1 and 10 times per day. In these examples, the programmable processor keeps record of how many tests or how many days have passed since the threshold was updated and prompts the user to update the threshold on the display, or automatically updates the threshold without user interaction.

[0047] The method of FIG. 5 includes step 550, that is, receiving a third pressure measurement at a preselected time when the pump is operatively connected to the test card. In this example, the third pressure measurement is received by the processor of the sample analyzer and is compared to the threshold. In examples where the test card is not present in the sample analyzer prior to the third pressure measurement, the test card may be manually inserted by a user, wherein the user may align the test card with the insertion slot and push the test card into the insertion slot before the third pressure measurement is executed. The third pressure measurement may be referred to as the open system measurement with test card present, as discussed above, and as such may be obtained at a preselected time during when the pump is operatively connected and open to the inserted test card.

[0048] The pumping system may vent to return to ambient pressure prior to measuring another pressure measurement. The venting of the pumping system may occur through the pump, the valve, and / or through another valve. The start of activation of the pump may refer to the moment after the pumping system has returned to ambient pressure and the pumping system is no longer venting, while the pump is on. In other examples, the start of activation of the pump refers to the moment that the pump is turned on.

[0049] The pressure sensor may continuously or intermittently measure pressure. When measured continuously during the preselected time, the received pressure measurements are pressure measurements communicated as a pressure waveform, wherein the pressure w aveform is a continuous measurement of pressure graphed over time. The pressure measurement may be communicated as a representative pressure measurement. The representative pressure measurement may be a single point taken from the pressure waveform or an average of points taken from the pressure waveform. The representative pressure measurement may be determined from a calculated average of at least 2 points, or between an average of 2 and 100,000 points, or between an average of 2 and 10,000 points, or between an average of 2 and 1,000 points, or between an average of 2 and 100 points, or between an average of 2 and 10points or a calculated average of 3 points from the pressure waveform within the preselected time, for example. The first pressure measurement, the second pressure measurement, the third pressure measurement, and / or other pressure measurements may be communicated as a pressure waveform and / or as a representative pressure measurement.

[0050] The method in FIG. 5 includes step 560. that is, determining whether the third pressure measurement is above or below the threshold. Here, the determination of whether the third pressure measurement is above or below the threshold is carried out by the processor. In one embodiment, the determination compares the third pressure measurement waveform to the threshold, wherein the waveform is either above or below the threshold compared within the same preselected time used to determine the threshold. In another embodiment, the determination compares the representative third pressure measurement to the threshold. The determination of whether the third pressure measurement is above or below the threshold is used to determine test card status and / or sample integrity, where the sample integrity is intact when the third pressure measurement is above the threshold and the sample integrity is compromised when the third pressure measurement is below the threshold.

[0051] The method in FIG. 5 includes step 570. that is, determining whether the third pressure measurement is indicative of an empty test card or a prefilled test card, thereby determining test card status and / or sample integrity. The determination of whether the third pressure measurement is indicative of an empty test card or a prefilled test card is carried out by the programmable processor. The determination of whether the third pressure measurement is indicative of an empty test card or a prefilled test card is used to determine sample integrity, wherein the sample integrity is intact when the test card is determined to be an empty test card, i.e., above the threshold, and the sample integrity is compromised when the test card is determined to be a prefilled test card, i.e., below the threshold. An empty' test card is a test card that has not had any sample injected into the sample port and does not have sample in the sample channel (prior to insertion within the insertion slot and / or prior to completion of step 570). A prefilled test card is a test card that has had sample injected into the sample port and may also have sample in the sample channel (prior to insertion within the insertion slot and / or prior to completion of step 570). The sample may comprise a blood sample, which may be a whole blood sample comprising plasma and whole blood cells, a plasma sample, or a serum sample. A whole blood sample may comprise red blood cells, platelets and the like. In the case of a determination of an empty test card, the sample analyzer may prompt the user to inject thesample into the test card. In the case of a determination of a prefilled test card, the sample analyzer may prompt the user to discard the test card. The prompt may be visual, auditory, tactile or the like.

[0052] FIG. 6 illustrates an exemplary graphical representation 600 of a threshold determination (of step 540). A graphical representation of a threshold illustrates the values used to determine a threshold. It is not necessary for such a representation to be provided (visually on a display) by the processor but rather the determination may be a simple prompt to begin further analysis (i.e. steps 550-570). In other embodiments, the processor provides a graphical representation of the threshold on a display. The graphical representation of a threshold determination 600 may include the open valve pressure waveform 610, the closed valve pressure waveform 620, and the threshold 630. The open valve pressure waveform 610 and the closed valve pressure waveform 620 are measured by a pressure sensor in the pumping system of the sample analyzer and communicated to the programmable processor.

[0053] The open valve pressure waveform 610 is communicated by the pressure sensor to the programmable processor. In some examples, the open valve pressure waveform 610 is or represents the first pressure measurement of step 520, when the valve of the pumping system is open to the external environment. The first pressure measurement may be communicated to the programmable processor in the absence of a test card in the insertion slot of the sample analyzer. In other embodiments, the first pressure measurement may be communicated to the programmable processor in the presence of a test card in the insertion slot of the sample analyzer. The first pressure measurement is used in a determination of the threshold 630.

[0054] The closed valve pressure waveform 620 is communicated by the pressure sensor of the pumping system to the programmable processor. In some examples, the closed valve pressure waveform 620 is or represents the second pressure measurement of step 530, when the valve of the pumping system is closed. The second pressure measurement can be communicated to the programmable processor with or without the presence of a test card in the insertion slot of the sample analyzer. The second pressure measurement is used in a determination of the threshold 630.

[0055] The threshold 630 is determined from the first and the second pressure measurements taken within the preselected time 640, wherein the preselected time 640 is the time frame whose start point is relative to the start of activation of the pump, and whose duration varies depending on the number of pressure measurements that are used for calculatingthe threshold (for example, that number may be 3 as illustrated by the 3 dots on lines 610 and 620, that are within the preselected time 640). In this example, the threshold 630 is determined by the programmable processor to be fifty percent of a standard deviation between the open valve pressure waveform 610 and the closed valve pressure waveform 620. When determining the threshold 630, the first pressure measurement and the second pressure measurement may be communicated as their representative pressure measurements or as a pressure waveform.

[0056] FIG. 7 illustrates an exemplary graphical representation 700 of a determination of test card status and / or sample integrity using pressure measurements. The graphical representation 700 includes three exemplary pressure waveforms obtained from step 550 being performed on three separate / different test cards. The exemplary pressure waveforms shown are an empty test card pressure waveform 710. a first prefilled test card pressure waveform 720. and a second prefilled test card pressure waveform 730. The threshold 740 and the preselected time 750 are also shown. The pressure waveforms are measured by a pressure sensor in the pumping system of the sample analyzer and communicated to the programmable processor. In certain embodiments, the programmable processor can make a graphical representation and determine therefrom whether pressure measurements when the pumping system is connected to a test card are above or below the threshold 740, which is then used to determine the test card status (i.e., an empty test card or a prefilled test card). The programmable processor may or may not display the graphical representation on a display or user interface of the sample analyzer or externally wired or non-wired connected device.

[0057] The empty test card pressure waveform 710 illustrates an example pressure waveform of an empty test card compared to the threshold 740. As shown, pressure waveform 710 in the preselected time 750 is above the threshold 740, and therefore indicative of an empty test card status and acceptable sample integrity. The first prefilled test card pressure waveform 720 and the second prefilled test card pressure waveform 730 illustrate example pressure waveforms of prefilled test cards compared to the threshold 740. As shown, pressure waveforms 720, 730 in the preselected time 750 are below the threshold 740, and therefore indicative of a prefilled test card status and unacceptable sample integrity. As explained above, such threshold comparison and indication(s) may be performed by the programmable processor which may be configured to output the indication(s) to a display or user interface of the sample analyzer or externally wired or non -wired connected device. As explain above, such indication(s) may be auditory, visual and / or tactile and the like.

[0058] The time required for the pumping system to reach a required pressure is different for empty cards and prefilled cards. Measuring the level of pressure when the pumping system is operatively connected to the test card (within the preselected time) and comparing it to the threshold allows the determination of whether the card contains fluid. It should be understood that, in the graphical representations 600 and 700, if the pump is activated for an extended period of time and the pressure waveforms are profiled / represented over that extended time, the pressure waveforms of 610 and 620 will eventually be the same (i.e., the final pressure values will be the same), and similarly the pressure waveforms of an empty card 710 and a prefilled card 720, 730 will eventually be the same (i.e., the final pressure values will be the same). It is understood that the preselected time as discussed herein is a preselected time before reaching the extended terminal time and pressure value.

[0059] FIG. 8 illustrates a diagram of a second side of an example test card with optical sensors. The second side of an example test card includes all the elements described in FIG. 2B as well as first optical sensor 801, second optical sensor 802, and third optical sensor 803. In some embodiments, these optical sensors are optical level sensors that are capable of using light beams to detect the presence of a fluid by measuring the reflection or refraction of the light, as is known in the art. As shown in FIG. 8, the first optical sensor 801 and the second optical sensor 802 are both located in sample channel 255 and the third optical sensor 803 is located near measurement region 290. These three optical sensors may be used to determine sample integrity and / or test card status. It should be noted that the location and number of optical sensors may be different than that shown.

[0060] FIGs. 9-11 illustrate using optical sensors as an additional or optional check for determining test card status and / or sample integrity. In some embodiments, the third pressure measurement may be in a grey area such that the determination of sample integrity / test card status is uncertain or not statistically reliable. For example, the third pressure measurement may be between forty and sixty percent of a standard deviation between the first pressure measurement and the second pressure measurement (referred to as the “grey area”). In these embodiments, an additional check may be desired to determine the sample integrity and / or test card status. The additional check includes activating the pump for a preselected period in response to the grey area determination, receiving at least one optical level measurement from at least one optical sensor, and then determining the sample integrity and / or test card status. This additional check occurs w hen the test card is inserted into the insertion slot of the sampleanalyzer and the test card is operably connected to the pumping system. A detection of a change in an optical level measurement by any of the optical sensor(s) within the preselected period indicates that the test card was prefdled, and no detection of a change indicates that the test card is empty. In some embodiments, the preselected period is within 10 seconds from start of activation of the pump.

[0061] In examples where there is prefilled sample in the test card, the volume of prefdled sample will define which optical sensor, or combination of optical sensors, will detect the presence of the sample in the test card. FIG. 9, for example, shows a situation where the sample channel 255 has been fully prefdled with sample 810. In this example, as the pump acts on test card, the sample moves and a change in level is detected by the third optical sensor 803. FIG. 10, for example, illustrates a situation where the sample channel 255 has been prefdled with the minimum required amount of sample 810. In this example, as the pump acts on the test card, the sample moves and a change in level is detected by the second optical sensor 802. FIG. 11, for example, shows a situation where the sample channel 255 has been prefdled with less than the minimum required amount of sample 810. In this example, as the pump acts on the test card, the sample moves and a change in level is detected by the first optical sensor 801. This additional check is only carried out in response to the grey area determination. In another embodiment, the optical sensor sample integrity / test card status check may be performed alternatively or in addition to the sample integrity / test card status check using pump pressure profiles as discussed herein above. In another embodiment, the optical sensor sample integrity / test card status check may be performed in response to user selection or input (e.g., selection or input via a user interface or display of the sample analyzer or externally wired or non-wired connected device). In yet another embodiment, in response to a grey area determination, the processor may provide an indication or alert to a user of said grey area determination, and / or prompt a user to optionally select performance of the additional optical sensor sample integrity / test card status check.ILLUSTRATIVE EXAMPLES

[0062] The following provides a non-limiting listing of exemplary embodiments as disclosed and described herein.

[0063] Example 1 : A sample analyzer capable of determining status of a test card, comprising an insertion slot operable to accept the test card having a channel capable of holding a sample, a sensor operable to measure pressure, a pump operatively coupled to the sensor, and a programmable processor. The programmable processor being capable of operating the pump, receiving, via the sensor, a plurality of pressure measurements, determining a threshold based on the plurality of pressure measurements, and determining the status of the test card based on the threshold.

[0064] Example 2: The sample analyzer of Example 1, wherein the status of the test card includes a first status indicative of a prefilled test card prefilled with sample in the channel and a second status indicative of an empty test card without sample in the channel.

[0065] Example 3: The sample analyzer of any of Examples 1 or 2, further having a valve operable to open and connect the pump to the insertion slot, and operable to close and disconnect the pump from the insertion slot.

[0066] Example 4: The sample analyzer of any of Examples 1-3, wherein the programmable processor is further capable of receiving a first pressure measurement at a first preselected time when the valve is open to an external environment, receiving a second pressure measurement at a second preselected time when the valve is closed, utilizing the first pressure measurement and the second pressure measurement to determine the threshold, receiving a third pressure measurement at a third preselected time when the pump is operatively connected to the test card, and determining the status based on whether the third pressure measurement is above or below the threshold.

[0067] Example 5: The sample analyzer of any of Examples 1-4, wherein the first pressure measurement is obtained with no test card in the insertion slot.

[0068] Example 6: The sample analyzer of any of Examples 1-5, where the second pressure measurement is obtained with the test card in the insertion slot and the valve is closed.

[0069] Example 7: The sample analyzer of any of Examples 1-6, where the second pressure measurement is obtained with no test card in the insertion slot and the valve is closed.

[0070] Example 8: The sample analyzer of any of Examples 1-7, where the third pressure measurement is obtained with the test card in the insertion slot and the valve open and connected to the test card.

[0071] Example 9: The sample analyzer of any of Examples 1-8, where the first preselected time, the second preselected time, and the third preselected time are the same.

[0072] Example 10: The sample analyzer of any of Examples 1-9, where the first preselected time, the second preselected time, and the third preselected time are different times.

[0073] Example 11 : The sample analyzer of any of Examples 1-10, wherein each of the preselected times are within 10 seconds from start of activation of the pump.

[0074] Example 12: The sample analyzer of any of Examples 1-11, wherein each of the preselected times are within 5 seconds from start of activation of the pump.

[0075] Example 13: The sample analyzer of any of Examples 1-12, wherein each of the preselected times are within 3 seconds from start of activation of the pump.

[0076] Example 14: The sample analyzer of any of Examples 1-13, wherein each of the preselected times are within 1.0 second from start of activation of the pump.

[0077] Example 15: The sample analyzer of any ofExamples 1-14, wherein each of the preselected times are within 0.5 seconds from start of activation of the pump.

[0078] Example 16: The sample analyzer of any ofExamples 1-15, wherein each of the preselected times are between 0.4 and 0.5 seconds from start of activation of the pump.

[0079] Example 17: The sample analyzer of any of Examples 1-16, wherein the programmable processor determines the threshold as anywhere between ten and ninety percent of a standard deviation between the first pressure measurement and the second pressure measurement.

[0080] Example 18: The sample analyzer of any of Examples 1-17, wherein the programmable processor determines the threshold as fifty' percent of a standard deviation between the first pressure measurement and the second pressure measurement.

[0081] Example 19: The sample analyzer of any of Examples 1-18, wherein the programmable processor determines sample integrity based on the status determined from the third pressure measurement, wherein the status is indicative of an empty' test card or a prefilled test card.

[0082] Example 20: The sample analyzer of any of Examples 1-19, wherein the programmable processor is operable to alert a user of an error when the third pressure measurement is indicative of the prefilled test card.

[0083] Example 21: The sample analyzer of any of Examples 1-20, wherein the error provides an indication to the user to discard the test card.

[0084] Example 22: The sample analyzer of any of Examples 1-21, wherein the programmable processor is operable to determine that the third pressure measurement is indicative of the empty test card and alert the user to insert the sample into the test card.

[0085] Example 23: The sample analyzer of any of Examples 1-22, wherein the programmable processor is further capable of storing historical data to memory.

[0086] Example 24: The sample analyzer of any of Examples 1-23, wherein the historical data can be one or more previous pressure measurements and / or one or more previous thresholds.

[0087] Example 25: The sample analyzer of any of Examples 1-24, wherein the historical data is used to determine the threshold of the test card.

[0088] Example 26: The sample analyzer of any of Examples 1-25, wherein the programmable processor is further capable of determining that the third pressure measurement is in a grey area, activating the pump for a preselected period in response to the grey area determination, receiving at least one level measurement from at least one optical sensor, and determining the status of the test card based on the at least one level measurement.

[0089] Example 27: The sample analyzer of any of Examples 1-26, wherein the preselected period is within 10 seconds from start of activation of the pump.

[0090] Example 28: A sample analyzer capable of determining sample integrity, having an insertion slot operable to accept a test card having a channel capable of holding a sample, a sensor operable to measure pressure, a valve operable to open and close, a pump operatively coupled to the valve and the sensor, and a programmable processor. The programmable processor being capable of initiating the operation of the pump, receiving a first pressure measurement when the valve is open to an external environment, receiving a second pressure measurement when the valve is closed, utilizing the first pressure measurement and the second pressure measurement to determine a threshold, receiving a third pressure measurement when the pump is operatively connected to the test card, determining whether the third pressure measurement is above or below the threshold, and determining that when the third pressure measurement is above the threshold the sample integrity is intact and when the third pressure measurement is below the threshold the sample integrity' is compromised.

[0091] Example 29: The sample analyzer of any of Examples 1-28, wherein a third pressure measurement above the threshold is indicative of an empty sample card and intact sample integrity and a third pressure measurement below the threshold is indicative of a prefilled test card and compromised sample integrity.

[0092] Example 30: A method for determining sample integrity using a sample analyzer with an insertion slot operable to accept a test card with a channel capable of holding a sample, a pump, a valve, a pressure sensor, and a programmable processor. The programmable processor being capable of initiating operation of the pump, receiving a plurality of pressure measurements from the pressure sensor, determining a threshold based on the plurality of pressure measurements, and determining status of the test card based on the threshold, wherein the status is indicative of the sample integrity.

[0093] Example 31 : The method of any of Examples 1-30, wherein the programmable processor is further capable of receiving a first pressure measurement at a preselected time when the valve is open to an external environment, receiving a second pressure measurement at a preselected time when the valve is closed, utilizing the first pressure measurement and the second pressure measurement to determine the threshold, receiving a third pressure measurement at a preselected time when the pump is operatively connected to the test card, and determining the status based on whether the third pressure measurement is above or below the threshold, wherein sample integrity is intact when the third pressure measurement is above the threshold and sample integrity is compromised when the third pressure measurement is below the threshold.

[0094] Example 32: The method of any of Examples 1-31, wherein the preselected time is within 10 seconds from start of activation of the pump.

[0095] Example 33: The method of any of Examples 1-32. wherein the preselected time is within 5 seconds from start of activation of the pump.

[0096] Example 34: The method of any of Examples 1-33. wherein the preselected time is within 3 seconds from start of activation of the pump.

[0097] Example 35 : The method of any of Examples 1 -34, wherein the preselected time is within 1.0 second from start of activation of the pump.

[0098] Example 36: The method of any of Examples 1 -35, wherein the preselected time is within 0.5 seconds from start of activation of the pump.

[0099] Example 37 : The method of any of Examples 1 -36, wherein the preselected time is between 0.4 and 0.5 seconds from start of activation of the pump.

[0100] Example 38: The method of any of Examples 1-37, wherein the threshold determination step determines the threshold as anywhere between ten and ninety percent of a standard deviation between the first pressure measurement and the second pressure measurement.

[0101] Example 39: The method of any of Examples 1-38, wherein the threshold determination step determines the threshold as fifty percent of a standard deviation between the first pressure measurement and the second pressure measurement.

[0102] Example 40: The method of any of Examples 1 -39, w herein the sample integrity step utilizes the programmable processor to determine whether the sample integrity is indicative of an empty test card or a prefilled test card.

[0103] Example 41: The method of any of Examples 1 -40, wherein the sample integrity step further utilizes the programmable processor to alert a user of an error when the third pressure measurement is indicative of the prefilled test card and alert the user to discard the test card.

[0104] Example 42: The method of any of Examples 1-41. w herein the sample integrity step further utilizes the programmable processor to determine that the third pressure measurement is indicative of the empty test card and alert the user to insert the sample into the test card.

[0105] Example 43: The method of any of Examples 1-42, wherein the programmable processor is further capable of determining that the third pressure measurement is in a grey area, wherein the grey area is betw een forty and sixty percent of a standard deviation between the first pressure measurement and the second pressure measurement, activating the pump for a preselected period in response to the grey area determination, receiving a plurality of level measurements from a plurality of optical sensors, and determining the status of the test card based on the plurality of level measurements from the plurality of optical sensors.

[0106] Example 44: The method of any of Examples 1-43, wherein the preselected period is within 10 seconds from start of activation of the pump.

Claims

CLAIMSWhat is claimed is:

1. A sample analyzer capable of determining status of a test card, comprising:- an insertion slot operable to accept the test card having a channel capable of holding a sample;- a sensor operable to measure pressure;- a pump operatively coupled to the sensor; and- a programmable processor capable of:- operating the pump;- receiving, via the sensor, a plurality of pressure measurements;- determining a threshold based on the plurality of pressure measurements; and- determining the status of the test card based on the threshold.

2. The sample analyzer of claim 1, wherein the status of the test card includes a first status indicative of a prefilled test card prefilled with sample in the channel and a second status indicative of an empty test card without sample in the channel.

3. The sample analyzer of claim 1, further comprising a valve operable to open and connect the pump to the insertion slot, and operable to close and disconnect the pump from the insertion slot.

4. The sample analyzer of claim 3, wherein the programmable processor is further capable of:- receiving a first pressure measurement at a first preselected time when the valve is open to an external environment;- receiving a second pressure measurement at a second preselected time when the valve is closed;- utilizing the first pressure measurement and the second pressure measurement to determine the threshold;- receiving a third pressure measurement at a third preselected time when the pump is operatively connected to the test card; and- determining the status based on whether the third pressure measurement is above or below the threshold.

5. The sample analyzer of claim 4, wherein the first pressure measurement is obtained with no test card in the insertion slot.

6. The sample analyzer of claim 4, wherein the second pressure measurement is obtained with the test card in the insertion slot and the valve is closed.

7. The sample analyzer of claim 4, wherein the second pressure measurement is obtained with no test card in the insertion slot and the valve is closed.

8. The sample analyzer of claim 4, wherein the third pressure measurement is obtained with the test card in the insertion slot and the valve open and connected to the test card.

9. The sample analyzer of claim 4, wherein the first preselected time, the second preselected time, and the third preselected time are the same.

10. The sample analyzer of claim 4, wherein the first preselected time, the second preselected time, and the third preselected time are different times.

11. The sample analyzer of claim 4, wherein each of the preselected times are within 1.0 second from start of activation of the pump.

12. The sample analyzer of claim 4, wherein the programmable processor determines the threshold as fifty percent of a standard deviation between the first pressure measurement and the second pressure measurement.

13. The sample analy zer of claim 4, wherein the programmable processor determines sample integrity based on the status determined from the third pressure measurement, wherein the status is indicative of an empty test card or a prefilled test card.

14. The sample analyzer of claim 13, wherein the programmable processor is operable to alert a user of an error when the third pressure measurement is indicative of the prefilled test card.

15. The sample analyzer of claim 14, wherein the error provides an indication to the user to discard the test card.

16. The sample analy zer of claim 13, wherein the programmable processor is operable to determine that the third pressure measurement is indicative of the empty test card and alert the user to insert the sample into the test card.

17. The sample analy zer of claim 1, wherein the programmable processor is further capable of storing historical data to memory, and wherein the historical data is selected from the group consisting of:- said first pressure measurement and said second pressure measurement determined from a previous test card; and- said threshold determined from the previous test card.

18. The sample analyzer of claim 4, wherein the programmable processor is further capable of:- determining that the third pressure measurement is between forty and sixty percent of a standard deviation between the first pressure measurement and the second pressure measurement;- activating the pump for a preselected period;- receiving a plurality of optical level measurements from a plurality of optical sensors; and- determining the status of the test card based on a change in any of the received optical level measurements.

19. A sample analyzer capable of determining sample integrity, comprising:- an insertion slot operable to accept a test card having a channel capable of holding a sample;- a sensor operable to measure pressure;- a valve operable to open and close;- a pump operatively coupled to the valve and the sensor; and- a programmable processor capable of:- initiating the operation of the pump;- receiving a first pressure measurement when the valve is open to an external environment;- receiving a second pressure measurement when the valve is closed;- utilizing the first pressure measurement and the second pressure measurement to determine a threshold;- receiving a third pressure measurement when the pump is operatively connected to the test card;- determining whether the third pressure measurement is above or below the threshold; and- determining that when the third pressure measurement is above the threshold the sample integrity is intact and when the third pressure measurement is below the threshold the sample integrity is compromised.

20. The sample analyzer capable of determining sample integrity of claim 19, wherein a third pressure measurement above the threshold is indicative of an empty' test card and intact sample integrity and a third pressure measurement below the threshold is indicative of a prefilled test card and compromised sample integrity.

21. A method for determining sample integrity using a sample analyzer with an insertion slot operable to accept a test card with a channel capable of holding a sample, a pump, a valve, a pressure sensor, and a programmable processor capable of executing the following steps:- initiating operation of the pump;- receiving a plurality' of pressure measurements from the pressure sensor;- determining a threshold based on the plurality of pressure measurements; and- determining status of the test card based on the threshold, wherein the status is indicative of the sample integrity’.

22. The method for determining sample integrity of claim 21, wherein the programmable processor is further capable of:- receiving a first pressure measurement at a preselected time when the valve is open to an external environment;- receiving a second pressure measurement at a preselected time when the valve is closed;- utilizing the first pressure measurement and the second pressure measurement to determine the threshold;- receiving a third pressure measurement at a preselected time when the pump is operatively connected to the test card; and- determining the status based on whether the third pressure measurement is above or below the threshold, wherein sample integrity is intact when the third pressure measurement is above the threshold and sample integrity is compromised when the third pressure measurement is below the threshold.

23. The method of claim 22, wherein the preselected time is within 1.0 second from start of activation of the pump.

24. The method of claim 22, wherein the threshold determination step determines the threshold as fifty percent of a standard deviation between the first pressure measurement and the second pressure measurement.

25. The method of claim 22, wherein the sample integrity step utilizes the programmable processor to determine whether the sample integrity is indicative of an empty test card or a prefilled test card.

26. The method of claim 25, w herein the sample integrity step further utilizes the programmable processor to alert a user of an error w hen the third pressure measurement is indicative of the prefilled test card and alert the user to discard the test card.

27. The method of claim 25, wherein the sample integrity step further utilizes the programmable processor to determine that the third pressure measurement is indicative of the empty test card and alert the user to insert the sample into the test card.

8. The method of claim 22, wherein the programmable processor is further capable of- determining that the third pressure measurement is between forty and sixty percent of a standard deviation between the first pressure measurement and the second pressure measurement;- activating the pump for a preselected period;- receiving at least one optical level measurement from at least one optical sensor; and- determining the status of the test card based on a change in the received optical level measurement.

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