Patent Description:
The coagulation test device described herein requires little-to-no laboratory skills to operate and presents individualized, evidence-based results, which may aide in treatment decisions within <NUM> minutes from inserting the sample tube to obtaining results. Furthermore, there have been reported cases of treatment selection and administration, which have led to thromboembolic events. The device allows for the in-vitro testing of potential therapeutic agents, which can aid in determining the underlying cause of coagulopathy, and guard against the administration of agents that may induce thromboembolic events.

The coagulation test device described herein is an in vitro diagnostic point-of-care device for measuring clotting time and clot characteristics of a whole blood sample under different hemostatic conditions. Results of the test are used as an aid in management of patients with coagulopathy of unknown etiology in order to help the physician determine appropriate clinical action to arrest bleeding. Additionally, the device addresses a key problem in perioperative medicine and solves this problem by testing the effect of specific hemostatic therapeutic agents on whole blood clotting time in a bleeding patient.

In the existing state of clinical practice abnormal test results are typically addressed with an experience-based educated guess on the course of therapy to administer. The coagulation test device described herein provides personalized, clinical guidance to physicians regarding etiology of the patient's specific coagulopathy. The device simultaneously compares the effect of several hemostatic agents on whole blood clotting time and derives the underlying etiology, based on the measured responses across these hemostatic agents.

In one embodiment, a device is disclosed herein for processing a cartridge containing a whole blood sample. The device comprises a recess for receiving the cartridge, a vacuum source coupled to the cartridge, an actuator linked to the cartridge to agitate the cartridge; and a controller. The controller is configured to activate the vacuum source to move the whole blood sample from a container into a plurality of channels in the cartridge and subsequently into a plurality of reagent chambers where the blood mixes with a reagent, and then through a plurality of serpentine-shaped channels to a plurality of test chambers, activate the actuator to agitate the cartridge, receive signals from a plurality of sensors, each sensor associated with one of the test chambers, where the signals are based on the presence of a spherical member within a magnetic field generated by a magnet positioned adjacent to each of the test chambers, determine whether coagulopathy is present in the whole blood for each test chamber, and output an indicator whether coagulopathy is present in the whole blood for each test chamber on a display.

In another embodiment, a system is disclosed herein comprising a cartridge comprising a whole blood sample, the cartridge including a plurality of test chambers and a metal sphere in each test chamber and a device configured to receive the cartridge. The device includes a plurality of sensors, each sensor positioned adjacent to one of the test chambers, and a controller with the controller configured to activate a vacuum source to move a portion of the whole blood sample into each of the test chambers, move the cartridge, receive signals from each of the sensors while the cartridge is moving, determine whether the metal sphere is moving in the test chamber, determine whether the whole blood sample in each test chamber exhibits coagulopathy, and output an indicator whether coagulopathy is present in the whole blood for each test chamber on a display.

In a further embodiment, disclosed herein is a method of determining clotting characteristics of a whole blood sample. The method comprises introducing the whole blood sample into a cartridge having a plurality of test channels, wherein each test channel includes a reagent chamber, a test chamber, and a metal sphere in each test chamber; mixing the whole blood sample with a reagent in each of the reagent chambers; agitating the cartridge; detecting movement of the metal sphere in each of the test chambers with two sensors positioned adjacent to each of the test chambers; determining, with a controller, one or more clot characteristics of the whole blood sample based on detection of movement of the metal sphere; and generating an indicator of the clot characteristic for display to a user.

<CIT> discloses a blood coagulation test including multiple chambers that may contain blood clotting affecting reagents. A ferromagnetic washer which is movable within a blood sample is contained within each chamber. The chambers are configured to remain stationary during the testing process. The ferromagnetic object when moved against gravity the rate of movement of the object within the chamber as it falls through the blood sample may be detected by a sensor.

The invention is defined in the independent claims <NUM> and <NUM>, further embodiments are defined in the dependent claims. One or more embodiments are described and illustrated in the following description and accompanying drawings. Furthermore, some embodiments described herein may include one or more electronic processors configured to perform the described functionality by executing instructions stored in non-transitory, computer-readable medium. Similarly, embodiments described herein may be implemented as non-transitory, computer-readable medium storing instructions executable by one or more electronic processors to perform the described functionality. As used in the present application, "non-transitory computer-readable medium" comprises all computer-readable media but does not consist of a transitory, propagating signal. Accordingly, non-transitory computer-readable medium may include, for example, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (Read Only Memory), a RAM (Random Access Memory), SIM card, register memory, a processor cache, or any combination thereof.

In addition, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. For example, the use of "including," "containing," "comprising," "having," and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms "connected" and "coupled" are used broadly and encompass both direct and indirect connecting and coupling. Further, "connected" and "coupled" are not restricted to physical or mechanical connections or couplings and can include electrical connections or couplings, whether direct or indirect. In addition, electronic communications and notifications may be performed using wired connections, wireless connections, or a combination thereof and may be transmitted directly or through one or more intermediary devices over various types of networks, communication channels, and connections. Moreover, relational terms such as first and second, top and bottom, and the like may be used herein solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Articles "a" and "an" are used herein to refer to one or to more than one (at least one) of the grammatical object of the article. By way of example, "an element" means at least one element and can include more than one element. Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

Embodiments are described herein with reference to flowchart illustrations and/or block diagrams and/or figures. The flowchart, block diagrams and other illustrations in the present disclosure illustrate the architecture, functionality, and operation of possible implementations of systems, methods, computer program products (non-transitory computer-readable medium storing instructions executable one electronic processors, such as a microprocessor, to perform a set of functions), and the like according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram(s), or accompanying figures herein may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks or figures may occur out of the order noted in the figures. It will also be noted that each block of the block diagrams and/or flowchart illustration and/or figures and combinations of blocks in the block diagrams and/or flowchart illustration and/or figures can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.

Herein, various terms that are well understood by those of ordinary skill in the art are used. The intended meaning of these terms does not depart from the accepted meaning.

The terms anti-coagulant or anti-coagulating agent may be used interchangeably, and refer to compositions that are added to, or are present in biological specimens which inhibit natural or artificial coagulation, prolonging coagulation time. Examples of anti-coagulants include, but are not limited to, sodium citrate, hirudin, chelating agents, exemplified by ethylenediamine tetraacetic acid (EDTA), diethylenetriamine pentaacetic acid (DTPA), <NUM>,<NUM>-diaminocyclohexane tetraacetic acid (DCTA), ethylenebis(oxyethylenenitrilo) tetraacetic acid (EGTA), or by complexing agents, such as heparin, and heparin species, such as heparin Sulfate and low-molecular weight heparins, as well as coumarins and indandiones, factor Xa inhibitors, and thrombin inhibitors.

The term coagulopathy as used herein refers to any bleeding disorder that affects the way a patient's blood clots. The term hyper-coagulable as used herein refers to a state of abnormal increase towards blood clot formation. The term hypo-coagulable as used herein refers to a state of abnormal decrease away from blood clot formation.

Examples of excitation sources as used herein may be magnetic fields, electromagnetic fields, light, or ultrasonic energy. Excitation sensors as used herein are means capable of detecting the presence, absence, or changes in excitation source as affected or disrupted by the test element in the test sample.

The term blood clot lysis and fibrinolysis may be used interchangeably and as used herein refers to the breakdown of fibrin, usually by the enzymatic action of plasmin. The term clot integrity and clot strength may be used interchangeably and as used herein refers to the strength of a clot that has formed as a result of a fibrin and platelets mesh. The term premature thrombolysis as used herein refers to the premature dissolution of a clot after formation and is indicative of a defect in hemostasis.

<FIG> illustrate a coagulation test device <NUM> according to some embodiments. The coagulation test device <NUM> provides the ability to simultaneously evaluate clotting time and determine clot characteristics of whole blood under multiple hemostatic conditions according to some embodiments. As illustrated in <FIG>, the coagulation test device <NUM> includes a housing <NUM>, a recessed area <NUM> configured to receive a cartridge <NUM>, and a display <NUM>. As shown, the recessed area <NUM> and the display <NUM> are positioned adjacent to one another in the housing <NUM>; however other configurations and orientations between the recessed area <NUM> and display <NUM> are possible.

With reference to <FIG>, the coagulation test device <NUM> also includes a vacuum source <NUM> supported by the housing <NUM> and a heater <NUM> supported by the housing <NUM>. The coagulation test device <NUM> further includes a controller <NUM> including an electronic processor <NUM> and a computer-readable, non-transitory memory <NUM>. The memory <NUM> stores instructions that are executed by the electronic processor <NUM> to provide the functionality of the controller <NUM> as discussed herein. The controller <NUM> is also coupled to the display <NUM> and is configured to output graphical information and data. For example, in some implementations, the device <NUM> is configured to output on the display <NUM> specific data related to hemostatic reagents under test and whole blood clotting time for each channel while the test is in progress. Hemostatic agents may include fibrinogen, Factor VIII, Factor IX, cryoprecipitate, human plasma, Factor VIII and von Willebrand, <NUM> factor Prothrombin Complex Concentrate (PCC), <NUM> factor Prothrombin Complex Concentrate (PCC), Protamine Sulfate, platelets, Heparinase, Factor VII, Factor VIIa, and Factor XIII, however other suitable hemostatic agents may be employed. When the test is completed, the display <NUM> also can display a diagnosis and other testing characteristics derived from analysis of the test channel data. The controller <NUM> is also coupled to the vacuum source <NUM> and the heater <NUM> to control activation and deactivation.

With reference to <FIG>, the recessed area <NUM> is configured to receive the cartridge <NUM>, which allows for up to <NUM> channels of clotting time testing in a single cartridge <NUM>. In one configuration, the cartridge <NUM> is about the size of a microtiter plate (e.g., <NUM> by <NUM>) and conducts <NUM> individual coagulation tests. Additional or fewer channels may be utilized within the envelope of the cartridge <NUM>. For example, for purposes of illustration, <FIG> show <NUM> channels in the cartridge <NUM>, however the cartridge <NUM> may include more or fewer than <NUM> channels. In one embodiment, the device <NUM> accepts a sample tube containing <NUM> of whole blood. For <NUM> channels of coagulation testing, this embodiment creates <NUM> aliquots of approximately <NUM> microliters for testing. The construction and dimensions of the cartridge <NUM> may be altered to reduce the sample volume to <NUM> by reducing the size of the reagent chambers and subsequent test chambers.

With continued reference to <FIG>, the recessed area <NUM> is mechanically linked to a gear drive <NUM> for agitating the cartridge <NUM> and samples therein. The gear drive <NUM> is in communication with the controller <NUM> via an actuator <NUM> (e.g., motor, pump, etc.). In one example, the actuator provides an agitation/rocking speed between <NUM> degrees and <NUM> degrees per second with a rocking angle between <NUM> degrees and <NUM> degrees. One cycle duration is between <NUM> and <NUM> seconds. In other examples, the actuator can provide a suitable rocking speed and rocking angle that may be less than or greater than the parameters provided herein. Similarly, the cycle duration can be suitably adjusted within the scope of the operation of the device <NUM>.

The recessed area <NUM> also includes one or more vacuum ports <NUM> that interface with the cartridge <NUM>, one or more heater regions <NUM> for incubation and test regions, a plurality of magnets <NUM>, and a plurality of sensors <NUM> in communication with the controller <NUM>.

<FIG> illustrates an embodiment of the cartridge <NUM>. The cartridge <NUM> includes a housing <NUM>, a waste collection area <NUM>, and one or more vacuum ports <NUM> configured to interface with the one or more vacuum ports <NUM> on the recessed area <NUM>. The cartridge <NUM> also includes a reagent vacuum region <NUM>, a sample tube interface <NUM>, a sample tube housing <NUM> configured to receive a sample tube <NUM> (as shown in the sample tube housing <NUM> in <FIG>), and a test channel vacuum region <NUM>.

The cartridge <NUM> is designed for injection molding and secondary assembly operations. The cartridge <NUM> is sealed with a film that is compatible with blood and does not influence coagulation. The cartridge <NUM> includes a plurality of chambers that are isolated from each other. The blood sample is introduced into the cartridge <NUM> by the vacuum source <NUM>. Hydrophobic filters <NUM> (<FIG>) are used to stop the flow of blood when it has been fully aspirated. The vacuum ports <NUM> are at atmospheric pressure when the cartridge <NUM> is outside of the device <NUM>. Since no pressure is being applied to the sample, the sample remains in the sample tube <NUM> until it is loaded onto the device <NUM> and the sample sequence has begun.

The cartridge <NUM> includes a common feed channel X (shown in <FIG>) that connects the sample input to the chambers containing the individual hemostatic reagents. Each reagent chamber is connected to one of the vacuum ports <NUM> through a series of hydrophobic filters <NUM> for each channel. As the sample is aspirated into the cartridge <NUM>, each channel is filled sequentially at a rate established by a predetermined vacuum pressure of the vacuum source <NUM>. When an individual channel is filled completely, the hydrophobic filter <NUM> shown in <FIG> for that channel is blocked and the channel stops filling beyond its capacity. The remaining channels fill until each of the filters are blocked. The controller <NUM> monitors duration of applied vacuum and may also monitor the pressure drop across the filters to determine when all of the channels are filled.

The fluidics of the cartridge <NUM> are further described and illustrated in <FIG> according to some embodiments. The cartridge <NUM> includes a waste region <NUM>, a sample feed channel <NUM> in communication with the waste region <NUM>, and one or more hemostatic reagent chambers <NUM> in communication with the sample feed channel <NUM> via respective channels <NUM>. The cartridge <NUM> also includes one or more serpentine mixing channels <NUM> at an outlet of a respective hemostatic reagent chamber <NUM>. The serpentine mixing channels <NUM> are in fluid communication with one or more anticoagulant reversal chambers <NUM> (for if an anti-coagulant was used to anti-coagulate the whole blood sample), respectively, which are each then in respective communication with one or more clotting test chambers <NUM>. As noted above, and as illustrated herein, the cartridge <NUM> is shown with <NUM> individual test channels <NUM>, with each channel including a reagent chamber <NUM>, a serpentine fluid path <NUM>, and a test chamber <NUM>, however, the cartridge <NUM> may include more or fewer than <NUM> test channels <NUM> in other constructions.

<FIG> illustrates a system for determining clotting characteristics of a whole blood sample <NUM> including the device <NUM> and the cartridge <NUM>. In particular, the cartridge <NUM> is shown in position in the recessed area <NUM> of the device <NUM>. The vacuum ports <NUM> in the recessed area <NUM> are in communication with the vacuum ports <NUM> on the cartridge <NUM>.

Clot formation in whole blood or plasma can be measured in many different ways. Electrical conductivity requires contact with the whole blood. Capacitive measurements do not require contact and can be measured through barrier films; however, these techniques require some type of electrical connection to the testing device in order to bring signals in and out of the device. The coagulation test device <NUM> described herein utilizes a non-contact measurement method where a sphere <NUM>, comprised of a magnetic material, is within each of the <NUM> test chambers <NUM> and is used to determine the viscosity of the whole blood in each test chamber <NUM>. <FIG> illustrates a cross-section of an enlarged test chamber <NUM> and the spherical member <NUM> positioned therein. Agitating the test chamber <NUM> causes the spherical members <NUM> to roll through the whole blood in each test chamber <NUM>. The sensors <NUM> are positioned in close proximity to the test chamber <NUM> to measure the presence of the spherical member <NUM> in the test chamber <NUM> as it is agitated by the device <NUM>. In one construction, the test chambers <NUM> have a width of <NUM> and a length of <NUM> to accommodate a sample aliquot volume of approximately <NUM> microliters. In other constructions, the test chambers <NUM> could have a width of <NUM> and a length of <NUM> in order to reduce the sample aliquot volume to approximately <NUM> microliters. In one example construction, the test chambers <NUM> are spaced <NUM> apart which allows for <NUM> channels of clotting time testing to be incorporated into the envelope of the cartridge <NUM>. Other suitable dimensions are possible within the scope of the device described herein.

Sensing travel speed within a test chamber <NUM> is accomplished by measuring the change in magnetic flux as the spherical member <NUM> passes in proximity to the sensors <NUM> located along the path of each test chamber <NUM>. The sensor <NUM> does not require contact with the test chamber <NUM> and can be spaced up to <NUM> away from the test chamber surface. The sensors <NUM> sense the signals generated within the housing <NUM> of the cartridge <NUM> from their respective test chamber <NUM>. This non-contact method of measurement enables complete separation between the cartridge <NUM> and the device <NUM>, thereby eliminating the need for the device <NUM> to make contact with the whole blood sample. This configuration also eliminates any device cleaning or maintenance steps between test samples. It further eliminates the possibility of the device losing functionality due to a clot in the device fluid pathways.

Each test chamber <NUM> is associated with two sensors <NUM>, located linearly along the travel path of the spherical member <NUM> in the test chamber spaced apart by a distance (e.g., <NUM>). With reference to <FIG>, each sensor <NUM> is comprised of a magnetic member <NUM> (e.g., comprised of one or more rare earth metals) of sufficient magnetic field strength whereby the magnetic field extends into the test chamber region, and a Hall-Effect sensor <NUM>, which is located between the magnetic member <NUM> and the test chamber <NUM>. The Hall-Effect sensors <NUM> produce a voltage signal proportional to the magnetic field of between <NUM> and <NUM> millivolts per gauss. The controller <NUM> records a baseline, quiescent reading of the magnetic field for each sensor <NUM> at the beginning of an agitation cycle. This baseline measurement is used to establish the amount of disturbance of the field as the spherical member <NUM> passes over the sensors <NUM>. As the spherical member <NUM> passes over the sensors <NUM>, the spherical member <NUM> causes a disturbance in the quiescent magnetic field and is detected by the sensor <NUM>. This disturbance in magnetic flux is detected by the Hall-Effect sensor <NUM> and converted to a voltage. The voltage signal for each sensor <NUM> is then transmitted to the controller <NUM>. A signal threshold is established to remove signal artifacts. The voltage signal form the sensor <NUM> can be converted to a digital signal via a series of analog to digital converters. Since there are two sensors <NUM> located for each test chamber <NUM>, the time between the peak of the disturbances of the two sensors <NUM> relates directly to the travel time of the spherical member <NUM> within the test chamber <NUM>. By this method, the viscosity of the fluid in the test chamber <NUM> can be traced as the device <NUM> agitates the test chamber <NUM> over a period of time, causing the spherical member <NUM> to pass by the sensors <NUM>. <FIG> illustrates a magnetic field map showing the interaction with the test chamber <NUM> and the spherical member <NUM>. As shown in <FIG>, the map on the left shows how the spherical member causes more field lines than the map on the right, where no spherical member is present.

The test chambers <NUM>, sensors <NUM>, and controller <NUM> determine the travel time of the spherical member <NUM> in each test chamber at a predetermined and programmable agitation rate. The viscosity of the fluid in each test chamber <NUM> is proportional to the travel time within the chamber. As such, the progression of clotting can be viewed as an increase in fluid viscosity vs. time. The coagulation cascade is truly a cascade of events and is therefore non-linear. The traces of travel time for the device <NUM> can detect and monitor quiescent blood status as it approaches coagulation. Shortly after this initial onset of clotting, the fluid rapidly approaches a high viscosity by forming a clot as shown in <FIG>. The angle of trajectory from a fluid state to clot formation is also measured and used as a basis for diagnosis of apparent factor or platelet function deficiency.

In addition to clotting time, the device <NUM> is capable of determining the integrity or strength of the clots being formed. Each test chamber <NUM> within the device <NUM> has two independent sensors <NUM> (as described above), by which travel time is calculated. When the spherical member <NUM> fails to traverse both sensors <NUM> within a test chamber, a travel time cannot be calculated. This is indicative of a clot that is impeding the full travel of the spherical member <NUM> within a test chamber <NUM>. However, since the gravitational forces on the spherical member <NUM> within a test chamber are less than <NUM>, it is possible for a spherical member <NUM> to be held by a weak clot, where the spherical member <NUM> will continue to move over a limited range of the full chamber length. The device <NUM> monitors the signals from both sensors <NUM> and may detect that one of the two sensors <NUM> is continuing to provide a signal. This signal is indicative of a weak clot that is preventing the spherical member <NUM> from fully traveling the length of the test chamber <NUM>, yet is still allowing the spherical member <NUM> to move. As shown in <FIG>, only one of the two sensors continues to show movement of the spherical member <NUM>.

<FIG> shows a condition where the spherical member <NUM> is transitioning across only one of the sensors <NUM> with each agitation or duty cycle of the cartridge, indicating a weak clot. The frequency by which the spherical member <NUM> is detected by a single one of the two sensors <NUM> is indicative of clot integrity, where a high frequency of signal generation indicates a weak clot. As the number of single sensor signals decreases, this is indicative of increased clot strength. No movement of the spherical member <NUM> would indicate a strong clot after clot formation, yielding a frequency of zero or below a threshold set by the device <NUM>. The device <NUM> establishes a cut-off value for clot integrity.

In one example, the duty cycle of the spherical member <NUM> is proportional to the integrity of the clot where the duty cycle of greater that <NUM>% is indicative of a severely weak clot, the duty cycle of between <NUM>% and <NUM>% is indicative of a moderately weak clot, the duty cycle of between <NUM>% and <NUM>% is indicative of a moderately strong clot, and the duty cycle between <NUM>% and <NUM>% is indicative of a strong clot.

The relative size of the spherical member <NUM> within the test chamber and the test chamber diameter helps to induce coagulation in a manner similar to physiological clotting mechanisms. It is known that shear stress within the human vascular system promotes coagulation. Many coagulation test systems require the addition of a high surface area pro-coagulant such as Celite or Kaolin to reduce the normal clotting time to a level that meets the needs for a rapid clotting time. The method and apparatus described herein eliminates the need for pro-coagulants by inducing physiological shear rate and shear stress within each test channel of between <NUM> and <NUM>,<NUM> sec-<NUM> or <NUM> to <NUM>,<NUM> dynes per second. <FIG> illustrates the relationship between the travel speed of the spherical member <NUM> within the test chamber <NUM> and the resulting shear rate, based upon the diameter of the test chamber and the relative size of the spherical member <NUM> in the test chamber. The shear rate can be adjusted by altering the agitation angle, the test chamber diameter and the relative spherical member diameter. However, the system could also be used with the addition of a pro-coagulant, such as kaolin, citrate, tissue factor, phospholipid, or other appropriate activator, if a more rapid time to test results is desired.

With reference to <FIG>, sample processing begins with power up of the device <NUM> (at <NUM>). The device <NUM> undergoes quality control tests (at <NUM>). The device <NUM> performs a quality check to ensure that all electro-mechanical subsystems are in proper working order. Subsystems such as the vacuum system, the temperature elements and magnetic sensors are all checked prior to allowing a user to initiate a sample test. Additionally, the device is supplied with a re-usable QC cartridge which agitates the QC cartridge in a manner similar to a sample test to ensure that all electro-mechanical systems are working properly. The re-usable cartridge test results are recorded in the controller or memory. The QC cartridge is removed and the device is then ready to accept a patient sample. Next, the sample tube (filled with whole blood from a patient; the sample tube includes a unique barcode) is identified to the device <NUM> (at <NUM>). The device <NUM> allows for entry of all information required to run a test with no operator typing. The device <NUM> can include a barcode scanner <NUM> in communication with the controller <NUM>. The operator places the sample tube barcode in front of the scanner <NUM>. The scanner <NUM> records the barcode and sample information into the memory <NUM> or other storage device (e.g., database, local or remote from device <NUM>). The device <NUM> has an override function that can permit manual entry of patient information via the display <NUM> (e.g., touchscreen). The patient sample also must be associated with a test cartridge <NUM>. The operator places the barcode affixed to the cartridge in front of the scanner <NUM>. The scanner <NUM> records the cartridge <NUM> information into the memory <NUM> or other storage device (e.g., database, local or remote from device <NUM>). If the sample tube does not have a barcode, then the operator can be prompted to enter the information via an on-screen keyboard on the display <NUM>.

The sample and cartridge <NUM> are loaded onto the device <NUM> (at <NUM>) and the operator confirms (at <NUM>) the sample and cartridge <NUM> via a user interface on the display <NUM>. A cover <NUM> on the device is lowered onto the recessed area <NUM>. The cover <NUM> includes the vacuum connections that interface with the vacuum ports <NUM> on the cartridge <NUM> necessary for moving fluids through the cartridge <NUM> during sample processing and prior to initiating the clotting time tests. The vacuum ports <NUM> on the cartridge <NUM> are connected to the vacuum ports <NUM> in the device <NUM> through the action of closing the cover <NUM>. The cover <NUM> also applies pressure to the cartridge <NUM> to maintain a uniform distance between the cartridge <NUM> and the sensors <NUM> within the device <NUM>. The operator initiates the testing sequence via the user interface on the display <NUM>.

Samples presented to the device <NUM> are typically anti-coagulated in order to allow time between sample collection and sample testing. This is a common practice for most blood testing procedures. The device <NUM> also can test a sample that is not anti-coagulated with a cartridge that does not contain the anti-coagulant reversal agent (e.g., calcium); however, there are time constraints for placing a non-anticoagulated sample into the cartridge <NUM> and onto the device <NUM>.

The cartridge <NUM> is configured to receive a sample vacuum drawtube (e.g., an evacuated container with a flexible cap) as a sample input device in the sample tube housing <NUM>. This eliminates the need for the sample to be pipetted into the cartridge <NUM>, a process common to laboratory instruments, but not required for the device <NUM>. The operator inserts the sample drawtube directly into the cartridge <NUM> (in the sample tube housing <NUM>) and places the cartridge <NUM> onto the recessed area <NUM> in the device <NUM>. The cartridge <NUM> prevents the blood sample from moving into the cartridge by controlling any vent path from being opened prior to placement on the device <NUM>. The sample in the tube is accessed by one or more needles (e.g., two needles) that pierce the flexible cap. The operator inserts the sample tube into the sample tube receiver on the cartridge. Gentle insertion force causes the needle assembly to pierce the sample tube cap. One needle serves to aspirate the sample and the other serves as a vent to allow the blood to flow from the drawtube when the vacuum is applied.

The device <NUM> processes (at <NUM>) the sample with a known set of programmed parameters. The first step is to pierce the flexible cap to draw the blood from the sample tube and fill the sample feed channel <NUM> and the connected reagent-containing chambers <NUM>. The blood travels from the sample tube into the cartridge <NUM> at point X (shown in <FIG>) and fills the sample feed channel <NUM>, and begins to fill the reagent-containing chambers <NUM>. The controller <NUM> activates the vacuum source <NUM> in the housing <NUM> to apply vacuum to the blood sample in the cartridge. A pressure regulator that is in line with the vacuum pump is read by the device <NUM> so that the pressure is controlled to a preset value. Typical vacuum levels for sample aspiration are between <NUM> and <NUM> millibars (mb). In this sequence, the initial sample is now split into <NUM> equal and isolated aliquots of the blood sample.

The controller <NUM> selects certain valves in the vacuum ports <NUM> thereby controlling the direction of the vacuum. The blood sample continues to move through the various channels in the cartridge <NUM>. The reagent chambers <NUM> contain individual doses of a variety of hemostatic agents. These agents are dried and remain in the reagent chamber <NUM> as part of the manufacturing process. Drying methods may be lyophilization or air drying, depending upon the reagent properties. The design of the cartridge is such that the blood sample is drawn into the reagent chambers <NUM> from the bottom of the chamber and drawn to the upper portion of the chamber by the vacuum source <NUM>. The dried reagents are rehydrated by the entering sample volume of blood (at <NUM>). Each reagent chamber <NUM> contains a hydrophobic filter, which prevents the reagent chambers from overfilling. The device <NUM> applies vacuum for a pre-set time duration or monitors the pressure drop across the hydrophobic filters until all filters are blocked.

Each sample-reagent complex must be separated from its nearest neighboring sample-reagent complex in order to avoid cross contamination. After filling the individual reagent chambers <NUM>, the device <NUM> clears the sample feed channel <NUM> that connects the reagent chambers <NUM> by closing valves used to direct the sample to the reagent chambers <NUM> and opens valves to direct the sample feed channel <NUM> contents to the waste area <NUM> in the cartridge <NUM>. An absorbent material collects the waste from the feed channel <NUM>. Each sample aliquot is now isolated from its adjacent reagent chambers <NUM> by a large air gap created by the empty feed channel <NUM>.

Coagulation is a temperature dependent phenomenon. The controller <NUM> activates the heater <NUM> to provide thermal energy (via heater region <NUM> on the recessed area <NUM>) to the cartridge <NUM> and bring the sample aliquots within the reagent chambers <NUM> to a programmable temperature value of between <NUM> and <NUM> degrees Celsius with normal test temperature of <NUM> degrees Celsius. This range allows for testing samples under normal, hypo-thermic and hyperthermic conditions. The sample aliquots are incubated with the hemostatic agents for a programmable period of time, typically between <NUM> minute and <NUM> minutes. In other embodiments, the sample aliquots are incubated with the hemostatic agents between <NUM>-<NUM> minutes. This allows the temperature of the sample aliquots to equilibrate to the proper temperature as well as allowing the hemostatic agents to fully dissolve and diffuse into the sample aliquots.

Up until this point, the blood sample and the reagents are anti-coagulated to prevent the blood sample from starting to clot until all sample aliquots are ready to be tested. Prior to initiating the clotting time test for each test channel, the anti-coagulant must be reversed. The serpentine-shaped channel <NUM> connects the reagent chambers <NUM> with the test chambers <NUM>. The narrow diameter of the serpentine section increases the fluid velocity as it travels from the reagent region to the test region. In line with the flow of each channel is a precise amount of dried or lyophilized calcium. The traveling fluid rehydrates the calcium and mixes with the sample aliquots at the time of transfer. The cartridge <NUM> contains individual quantities of calcium in each channel, directly before the sample enters the test region. The calcium mixes with the aliquots as it proceeds to the test region. The anticoagulant in each aliquot has now been reversed and the clotting cascade can begin.

The controller <NUM> transmits a signal to change the direction of the vacuum source <NUM> via the valves and directs the flow of the sample aliquots from the reagent chambers <NUM> to the test chambers <NUM> (at <NUM>). Typical vacuum levels are between 50mb and 100mb. The cartridge <NUM> and test chambers <NUM> are placed at a predetermined angle between <NUM> and <NUM> degrees relative to the horizontal position of the cartridge when placed on the device so as to facilitate channel filling and to minimize the possibility of trapping an air bubble in the test chambers <NUM>. Each test chamber <NUM> has a hydrophobic filter in line with the vacuum source <NUM> to prevent overfilling of the test chamber and drawing blood into the device vacuum system.

With all (or some) of the test chambers <NUM> filled and the sample aliquots' anticoagulation state reversed, the controller <NUM> activates the actuator <NUM> to begin (at <NUM>) to agitate the cartridge <NUM> about a central axis, centered on the test channels <NUM> and to begin the clotting test. This action causes the spherical members <NUM> within the cartridge <NUM> to roll from one end of the test channel to the other end in a uniform manner. With each agitation cycle, the spherical members <NUM> in each test channel pass over the sensors <NUM> associated with each channel <NUM> to generate a signal that is proportional to the viscosity of the blood sample within each test channel <NUM>. The sensors <NUM> transmit the generated signals to the controller <NUM>.

As noted above, the device <NUM> utilizes a non-contact method of detecting the motion and travel time of the spherical members <NUM> within the cartridge channels. The current method utilizes the magnetic properties of the <NUM> series stainless steel ball; however, other non-contact detection methods may be used, such as ultrasonic, electromagnetic, optical, etc..

Each sensor <NUM> includes a pair of neodymium-iron-boron rare earth magnets <NUM> and two Hall-Effect sensors <NUM> for each channel <NUM>. Each magnet <NUM>, separated by approximately <NUM> along the linear path of each test channel creates a localized magnetic field through the Hall-Effect sensor <NUM> and into the specific region of the cartridge <NUM>. When the magnetic stainless steel ball passes through the magnetic field, the Hall-Effect sensor <NUM> detects the change in flux above a quiescent baseline signal caused by the presence of magnetic ball and generates a voltage. The device measures the baseline (quiescent) magnetic signal at the beginning of each cycle. The voltage from each sensor <NUM> (if there is a voltage detected) is transmitted to the controller <NUM> for further processing.

Other excitation sources and sensor technologies could be employed to measure the coagulation effect in each channel; however, they may be subject to channel-to-channel crosstalk. Ultrasonic sensors for each channel could also be used. In this case, the spherical members <NUM> in each channel would not be required to be magnetic, but of a density much greater than whole blood, so that the ultrasonic reflection would be large enough to receive a signal. Electromagnetic sensors, similar to miniature metal detectors, could also be used. In this case, the spherical members would need to be electrically conductive, but not magnetic. Optical detection of the spherical members could be used. In this case, reflective sensor elements that provide an excitation light source and an adjacent light detector would detect the reflection of the spherical members as they pass over the optical sensor. The advantage of the use of magnetic sensing is that the magnetic fields between channels are self-isolating, due to the fact that they are all of the same polarity and do not interfere with adjacent channels as close at <NUM> apart.

During the first minutes of the testing, the baseline or normal viscosity of the sample aliquots is established. As fibrin begins to form in each of the test channels, an increase in viscosity of between <NUM>% and <NUM>% is observed and recorded by the controller <NUM>. Shortly after this increase, the coagulation cascade progresses rapidly to the point where the viscosity of the sample in a given channel is greater than the spherical member's ability to travel through the sample. The sensors <NUM> in line with the specific channel <NUM> sense that there is no longer a voltage being generated. The controller <NUM> interprets this as clot formation and records the time of the clot. The test proceeds until all channels have clotted or the pre-programmed maximum test time has been achieved (e.g., the test is complete at <NUM>).

As described earlier, clot integrity or strength is also considered when considering clotting time and the determination of a complete clot. Only those clotting times that are associated with a firm clot are considered in determining the source of coagulopathy. Physical observation of weak clots show small fibers formed around the spherical member that inhibit the sphere from traversing the entire length of the test channel; however, the spherical member is able to move a short distance and across one of the two sensors in the test channel. By contrast, a high integrity clot captures the spherical member completely and allows for little or no travel after clot formation.

After clot formation, the sensor signals can assess clot integrity. Clot formation is determined when the sensors <NUM> no longer see the two sensor peaks in each device agitation cycle. In a clot of high integrity/strength, neither sensor <NUM> produces a signal after clot formation. In a weak clot of low integrity, one of the sensors <NUM> continues to produce a signal, indicating that the clot is allowing the spherical member <NUM> to travel over a limited distance. Clot integrity is quantified by looking at the average signal in the channel from the time the clot is initially formed, when at least one sensor reports no signal, until the end of the programmable testing period of between <NUM> and <NUM>,<NUM> seconds. The lower the number, the higher the clot integrity. A high integrity clot gives a value of between zero and <NUM>. A moderate integrity clot gives a value between <NUM> and <NUM>. Low integrity clots yield clot strength values greater than <NUM> and as high as <NUM>,<NUM>.

The device <NUM> compares the clotting times and clot integrity to two (<NUM>) untreated or reference channels within the cartridge <NUM> to the therapy containing channels. Other clotting tests determine clotting times in seconds and compare to an established range of clotting times. The device <NUM> looks at clotting times relative to the reference sample channels, in the form of a clotting time ratio, as a way of determining the response to the various hemostatic agents. A value of <NUM> indicates no difference between the hemostatic agent and reference sample channels. A value below <NUM> indicates a reduction in clotting time as compared to the reference channels and a value greater than <NUM> indicates a prolongation of clotting time. The coefficient of variation (CV) in clotting times may be as high as <NUM>%, so the threshold for a 'response' to a reagent is based on a reduction greater than the CV. A reduction in clotting time, normalized to the reference channels, of greater than <NUM>% with a clot of high integrity (equal to or less than <NUM>), is considered a valid response to the reagents within a specific channel. If the clotting time for a test chamber is below the lower limit of an established normal range (typically between <NUM> and <NUM> seconds), the chamber results are flagged as potentially hypercoagulable. If the clotting time is above the upper limit of the established normal range, the test chamber is flagged as hypocoagulable.

The etiology of coagulopathy is determined by the clotting time ratios described and clot strength of each test chamber <NUM> as compared to reference sample aliquots included within the cartridge <NUM>. Information for hemostatic agents that reduce clotting time as well as hemostatic agents that do not reduce clotting time are combined to isolate either a specific etiology or a probable group of factors that are deficient and thereby causing the coagulopathy. For example, with reference to the decision tree in <FIG>, if a cartridge <NUM> and sample responds with reduced clotting time (indicated by the <<NUM> ratio) in the cryoprecipitate channels, but does not respond in the Factor VIII channels (indicated by the ><NUM> ratio), then the deficiency is likely to be von Willebrand Factor or fibrinogen, since cryoprecipitate contains all three coagulation factors. Likewise, if the sample responds to the fibrinogen channels and the cryoprecipitate channels but does not respond to the Factor VIII or Factor VIII/vWF complex channels, then the determination is likely to be a fibrinogen deficiency.

These responses to the various hemostatic agents create patterns or signatures that are indicative of specific conditions that are reported at the end of the testing sequence. The display <NUM> can provide a visual indication of each channel's clotting time and the ratio to the untreated reference channels. The display <NUM> also can provide the resulting deficiencies or diagnosis, subject to interpretation by a physician, regarding the possible cause of the coagulopathy, based upon clotting times, clotting ratios and clot strength across all test channels. The analysis performed by the controller is multi-variate in nature, looking at all channel data in determining the etiology of coagulopathy. The device <NUM> may also include a printer to print the information and data provided on the display <NUM>. Response to therapy is established by a threshold of the ratios to the reference channels. Since there is inherent variation across channels of up to <NUM>%, the thresholds are established to take this into account. Response to a hemostatic reagent is defined as a ratio greater than a predetermined threshold (e.g., a change of <NUM>% or more as compared to a reference channel).

The device <NUM> may also be used in testing how a clot breaks up after clot formation has been established. Normally, there is a process called fibrinolysis where a blood clot dissolves naturally. In device <NUM> described herein, the cartridge <NUM> could continue to agitate for about <NUM>-<NUM> minutes while monitoring for the spherical members <NUM> to resume movement. While this should not occur in a normal sample, some patients, for example trauma patients may experience hyperfibrinolysis, where the clots dissolve too quickly and bleeding starts up again.

Initial agitation cycles of between <NUM> and <NUM> seconds allow sufficient time for the spherical members <NUM> to traverse from one end of the cartridge <NUM> to the other. As clot formation begins, the viscosity of the sample aliquot increases, causing the travel time to increase. The device has the ability to apply an adaptive approach to the agitation cycle parameters.

It is understood that the foregoing detailed description is merely illustrative and is not to be taken as limitations upon the scope of the invention, which is defined solely by the appended claims.

Claim 1:
A system comprising:
a cartridge (<NUM>) comprising a whole blood sample, the cartridge including a plurality of test chambers (<NUM>) and a metal sphere (<NUM>) in each test chamber;
a device (<NUM>) configured to receive the cartridge, the device including
a plurality of sensors (<NUM>), each sensor positioned adjacent to one of the test chambers, and
a controller (<NUM>) configured to
activate a vacuum source (<NUM>) to move a portion of the whole blood sample into each of the test chambers,
move the cartridge,
receive signals from each of the sensors while the cartridge is moving,
determine whether the metal sphere is moving in each test chamber, and
determine whether the whole blood sample in each test chamber exhibits coagulopathy, and
output an indicator whether coagulopathy is present in the whole blood for each test chamber on a display (<NUM>).