Method of using disposable BioMEMS coagulation profiling cartridge

Abstract

A handheld medical analyzer works with different disposable application cartridges to perform a variety of interrogations on specimen samples. One application includes attaching a biological microelectromechanical systems (BioMEMS) cartridge that generates blood coagulation profiles indicative of particular forms of coagulation disorders. The device makes coagulopathy testing simpler for small hospitals, clinics, ambulances, remote locations and individuals and permits for a larger number of parallel or serial devices operating simultaneously. One insertion of a cartridge actuates an oscillating circular motion to generate a blood coagulation profile based on a change in rotational motion as blood coagulates in a sample. Change in rotational motion is analyzed through a video camera such as in a smartphone and is plotted to show an amplitude over time. Actuation of the BioMEMS can be achieved by magnetic actuation of a motor controlled by an iPhone or a smart phone to provide a specific rotational pattern.

Claims

1. A method comprising: turning a disc in a first direction and a second direction opposite the first direction in an oscillating motion within a liquid capable of coagulating with a magnetic coupling, the disc comprising a rotational center, wherein the disc is magnetic, wherein the disc comprises a first tracking point comprising a first color, the first tracking point proximate the rotational center of the disc, wherein the disc comprises a second tracking point comprising a second color, the second tracking point spaced apart from the rotational center of the disc, the first color different from the second color; and tracking the rotational motion of the first tracking point and the second tracking point of the disc over time with a video camera and processor to generate a coagulation profile.

2. The method of claim 1, further comprising recording motion before the onset of coagulation as a baseline trace.

3. The method of claim 1, wherein the coagulation profile is indicative of a coagulation disorder.

4. The method of claim 1, further comprising calculating the centroid of each tracking point.

5. The method of claim 1, further comprising calculating rotation motion in real-time.

6. The method of claim 1, further comprising displaying the coagulation profile continuously over time.

7. The method of claim 1, wherein the liquid is blood.

8. A method comprising: rotating a disc in a first direction and a second direction opposite the first direction in an oscillating motion in a liquid capable of coagulating, the disc comprising a first tracking point comprising a first color, the first tracking point located at a rotational center of the disc, the disc comprising a second tracking point comprising a second color, the second tracking point located at a distance from the rotational center of the disc, the first color different from the second color; tracking the first tracking point and the second tracking point of the disc with a video camera; and calculating changes in motion of the second tracking point with respect to the first tracking point of the disc with a processor to determine a coagulation profile.

9. The method of claim 8, wherein motion is calculated in real-time.

10. The method of claim 8, wherein the disc is rotated with a contactless magnetic coupling.

11. The method of claim 8, wherein a smartphone comprises the video camera.

12. The method of claim 11, further comprising displaying the coagulation profile on the smartphone.

13. The method of claim 8, further comprising rotating the disc in a magnetic field.

14. The method of claim 8, further comprising rotating the disc by a direct mechanical or electrostatic inducer of rotation.

15. The method of claim 8, further comprising measuring the coagulation profile for 30 minutes to 60 minutes.

16. The method of claim 8, further comprising displaying the coagulation profile.

17. The method of claim 8, wherein the coagulation profile is indicative of a particular form of a coagulation disorder.

18. A method for measuring coagulation, comprising: rotating a disc in a first direction and a second direction opposite the first direction in an oscillating motion in a liquid capable of coagulating, the disc comprising a first tracking point comprising a first color, the first tracking point at a rotational center of the disc, the disc comprising a second tracking point comprising a second color, the second tracking point spaced apart from the rotational center of the disc, the first color different from the second color; tracking the motion of the second tracking point of the disc; and calculating changes in motion of the second tracking point with a processor to determine a coagulation profile.

19. The method of claim 18, further comprising rotating the disc in a magnetic field.

20. The method of claim 18, wherein motion is calculated in real-time.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A is a CAD rendering of the new Coagulation Profiler and subsystems.

(2) FIG. 1B is a prototype showing blood placed on cartridge is loaded into the analysis slot.

(3) FIG. 1C is a conceptual rendering of cartridge actuation and sub system.

(4) FIG. 1D is a description of displayed profile, relative to cartridge actuation.

(5) FIG. 1E is a detailed description of BioMEMS coagulation profile cartridge.

(6) FIG. 1F is an image describing BioMEMS device marking relative to trading.

(7) FIG. 2A are images describing translation of device motion into zero amplitude profile.

(8) FIG. 2B are images describing translation of device motion into max amplitude (MA) profile.

(9) FIG. 3 shows an alternate embodiment with a fixed magnet.

(10) FIG. 4 shows an alternate embodiment with torsion springs.

(11) FIG. 5 is an image of a prototype showing accuracy of Level I control

(12) FIG. 6 is an age of a prototype showing accuracy of Level II control fluid.

(13) FIG. 7 is an image of a prototype showing repeatability of Level I profiles using two separate cartridges.

(14) FIG. 8 is an SEM image showing fibrin adhesion into surface of HDDA.

(15) FIG. 9 shows a forward surgical team attending a soldier.

(16) FIG. 10 shows TEG and ROTEM.

(17) FIGS. 11A and 11B are perspective and a schematic side view showing a cartridge, platform, well, extended lid, an abutment on the platform and a disk attached to the lid, all of which are inserted in a receiver before fluid is injected into the well.

(18) FIGS. 12A and 12B are perspective and a schematic side view showing a cartridge, platform, well, extended lid, an abutment on the platform and a disk attached to the lid, all of which are inserted in a receiver after fluid is injected into the well.

(19) FIGS. 13A and 13B are perspective and a schematic side view showing a cartridge, platform, well, lid, an abutment on the platform and a disk attached to the lid, fluid is injected into the well after the lid is pushed back and the disk is dropped from the lid into the well.

(20) FIG. 14 is a perspective view of a cartridge without a cover showing a fluid injection port at one end of a passageway to the well and a retaining clip for retaining the cartridge in the receiver.

(21) FIG. 15 shows a two-piece injection construction of the cartridge platform for compatibility with manufacture by injection molding.

DETAILED DESCRIPTION OF THE INVENTION

(22) The invention provides a handheld medical analyzer platform and biological microelectromechanical systems (BioMEMS) cartridges. This combined system uses microfluidics, optics, a mobile device (e.g. a smartphone or tablet) and video analysis software to create a handheld analyzer that produces data used in medical and biological diagnostics. In this embodiment two primary components are the handheld medical analyzer and the coagulation profile cartridge. The combination of the handheld analyzer and coagulation profile cartridge provide results equal to bench top systems used in hospitals, such as TEG and ROTEM. The handheld medical analyzer is a platform that is capable of analyzing a variety of cartridges. However the coagulation profile cartridge is specific to coagulopathy applications only. Although the cartridges are intended to be disposable, they also can be implemented in a permanent fashion when cleaned properly and constructed of the proper material. Combined, the handheld medical analyzer and coagulation profile cartridge produce a coagulation profile which is displayed and stored on the analyzer. In this embodiment of the invention, the cartridge provides data used in diagnosing different forms of coagulopathy.

(23) Although the combination of the handheld analyzer and coagulation profile cartridge is one part of the invention, the handheld analyzer is not limited to analyzing this specific cartridge.

(24) Other similar embodiments include profiling the coagulation of Limulus amebocyte lysate (LAL). In this case the extent of LAL coagulation would be representative of the presence of gram negative bacteria, since the LAL reacts with bacterial endotoxin or lipopolysaccharide (LPS).

(25) A similar cartridge would also apply to other assays that detect a physical change in the sample, such a viscosity, elasticity or viscoelasticity. Examples of these embodiments may include saliva, cervical mucus or other body fluids.

(26) Furthermore the handheld analyzer is also capable of using the same basic configuration to analyze a great many cartridges. These embodiments would also capture data using the video camera and interrogated using the CPU and CPU running proprietary software. These cartridges include, but are not limited to PaO.sub.2, pH and blood type.

(27) Likewise similar use of a smartphone for cartridge analysis is not limited to video input, but also could use many other sensors on the smartphone, including direct electrical signals, wireless signals, manometer, accelerometer, gyroscopes and compass. This includes combinations of the different methods of obtaining direct sensor information and indirect supplementary sensor information. An example of this would be using the combined system to provide a coagulation profile, while using the smartphone, wireless communication, accelerometers, gyroscopes, GPS, etc. to provide stabilization in rough environments such as a helicopter which is in motion and vibrating. These subsystems could also be used to send the coagulation profile, GPS coordinates to the ER providing an estimated time of arrival (ETA) and allowing for preparation of blood products, etc., in advanced for the patient's arrival.

(28) A primary embodiment of the combined inventions is shown in FIG. 1A. The coagulation profile cartridge 12 is inserted into the cartridge slot 7 where the BioMEMS device motion interfaces with the sample 15 and the motion is captured using the smartphone 1 video camera 11 and is analyzed using the smartphone central processing unit (CPU), graphics processor unit (GPU) running proprietary software. The resultant coagulation profile 3 is displayed 2 on smartphone 1 (e.g. iPhone) screen along with the measured parameters, similar to TEG/ROTEM, Table 1, Table 2. A custom enclosure 4 provides a docking point for the smartphone and attachment of peripheral components. In this embodiment the peripheral components consist of a motor 5, mechanical linkage 6 and compact microscope assembly 8, light source 9 and temperature control unit 10. The motor and linkage can be replaced with a servo and gearing, to provide the desired rotational actuation.

(29) The coagulation profile cartridge 12 is interrogated using the compact microscope 8 and video camera 11.

(30) The loading protocol for the simplest embodiment of the combined system is: place blood 15 into well 14 on cartridge 12 and load the cartridge into analysis slot 7, also shown in FIG. 1B. The disc 13 may be removed prior to filling the well 14, or the well may be filled with the disc in place. In this simple embodiment the well would be filled using a pipette.

(31) Upon loading the cartridge the measurement begins as the disk is actuated, as shown in FIG. 1C. Actuation in this embodiment is performed using a motor 5, mechanical linkage 6 in the form of reduction gears and magnet 16, which couples motion to the cartridge disc 13. Other embodiments would include electromagnetic induction or direct mechanical drive via a spring. By embedding ferrous metal into the cartridge disc 13, the magnetic field 17 couples the disc with the magnet. This coupling forms a link analogous to a torsion spring 18. Motion is thereby induced into the disc by rotating the magnet. In this embodiment the rotation is ±4°45′ degrees over 10 seconds. Other embodiments would include any number variations in the angular rotation over time.

(32) In the embodiment the degree to which the motion is decoupled is representative of the displayed 2 profile 3, as shown in FIG. 1D. Both processed profiles 3 and preprocessed traces are sinusoidal waveforms, e.g. 3a, that represent the motion or decoupled motion. The sinusoidal waveform is acquired using the video camera and the CPU and GPU running proprietary software.

(33) The alpha numeric displays: R: 31.329 sec K: 156.846 sec a: 2.834 deg/sec MA: 34.482 mm

(34) FIG. 1E shows a cartridge 12, an enlarged well top view, side cross section and an exploded side cross section. As shown in FIG. 1E, the cartridge has a well 14 and a disc 13. The disc is seated in the well via a spindle 19 and a bearing cup 20, at the bottom of the well. Both the well and the disc are sealed in the cartridge with a clear plastic lid 21. The lid can be hinged, sliding to allow sample insertion, or a microfluidic channel maybe used to load the sample into the well. This particular subcomponent of the cartridge may be realized in a number of different embodiments. These range from a simple hole in the lid to more complex automated microfluidics channels and chambers which meter the appropriate amount of blood or reagent into the well. Likewise the insertion of the sample may range from manually using a pipette to the use of automated microfluidics.

(35) The motion of the disc is captured by tracking two points overtime. FIG. 1F shows the pivot point 23 at the center of the disc 13 and a tracking point 22 at the outside edge of the disc. Each point is a unique color. In this embodiment the colors are florescent when illuminated using a UV LED light source 9. Both points are tracked by selecting the color to be tracked on the smartphone screen followed by selecting a threshold for the hues of the selected color to be included. The centroid of each of the prescribed points is then calculated to determine the exact location to be tracked. The angular motion is then calculated by comparing the centroid of the pivot point 23 to the centroid of the tracking point 22. This calculation is performed real-time and is used to calculate the displayed profile continuously over time.

(36) The detailed translation of the device motion is shown in FIG. 2A. At the beginning of the measurement the disc motion is uninhibited and rotates the full range of motion, plus 4′45′ 31 and minus 4′45′ 32, in the fluid tested. This initial motion, before the onset of coagulation, is recorded as the baseline trace 35. The baseline trace is then differenced with the subsequent motion trace 36 to detect coagulation, which inhibits the coupling of motion of the magnet with the motion of the disc. In this embodiment, the displayed trace 36 (coagulation profile) is the difference between the baseline trace 35 and the subsequent motion trace 36. Prior to coagulation the baseline trace 35 is the same as the pre coagulation subsequent motion trace 36, and the coagulation profile 37 is the difference between the two: zero. As the blood coagulates, the induced motion is decoupled, and the magnetic field is no longer strong enough to overcome the viscoelasticity of the blood, as shown in FIG. 2B. Initially the motion is uninhibited 31, 32 producing the baseline motion 35. When coagulation occurs, decoupling reduces the induced motion 38, 39. Upon coagulation the large baseline trace 35 is differenced with the small post coagulation subsequent motion trace 40, resulting in a large amplitude profile 41. The moment in time shown, is at maximum amplitude represented by the parameter similar to the TEG parameter MA. As shown at the right of FIG. 2B and in FIG. 1B, the “reaction time” is the calculated time in decimal fractions of a second for a clot to reach 2 mm, “22 mm time” is the time in decimal fractions of a second for a clot to reach 22 mm., and “angle” is the slope of the angle between “reaction time” and “22 mm time”. The “max clot” is maximum strength of a clot indicated in mm.

(37) A second embodiment of the BioMEMS device is shown in FIG. 3. In this embodiment a fixed magnet 51 is coupled to the disc. In this fixed magnet case, the rotation would be induced by rotating the cartridge 12 or well 14 within the cartridge. In this fixed magnet embodiment, the motion induced to the disc would be traced directly, with no differencing necessary. In this case the tracked motion could be directly used as the profile trace. Prior to the onset of coagulation there would be no motion coupled and the disc would oscillate uninhibited within the well. With no motion induced, the coagulation profile would be zero. In the fixed magnet case as the coagulation increases, the coupling would increase inducing more motion as coagulation continues. At MA the maximum amount of motion would be induced through the magnet.

(38) A third embodiment of a coagulation profiling BioMEMS device is shown FIG. 4. This device has a center disc 61 and an outer ring 62 that is suspended by torsion springs 63. As the blood begins to coagulate, the rotating inner disc 61, actuated via an oscillating magnet, couples to the outer ring 62. This couples a reciprocating motion to the outer ring 2. At MA the maximum amount of motion would be induced through the magnet.

(39) The BioMEMS embodiments shown are not all of the possible variations. For instance, one embodiment could use disc fixed to the center of the well and actuate a ferrous ring in the well. These variation of the described embodiments are apparent to one skilled in the art.

(40) The measurement provided by the invention is impervious to motion. Due to the extremely small dimensions of the BioMEMS device, compared to the conventional size of TEG and ROTEM, the measurement is highly impervious to motion. The small mass of the device and small volume residing in the well present less inertia when external motion is applied. The ability to produce a noise-free measurement in the presence of motion is further enhanced by the magnetic coupling, which fixes the disc and the well in the magnetic field.

(41) A prototype of the invention has provided concept validation. The image shown in FIG. 1B is an actual working prototype. The coagulation profile on the screen was taken using the prototype and shows the coagulation profile of using a quality control standard used and provided by Haemoscope, the makers of the TEG. The present prototype of the invention has accurately differentiated between the Haemoscope Level I control (normal profile) as shown in screen 75 in FIG. 5 and the Level II control (abnormal profile) as shown on screen in FIG. 6. In addition repeatability has been demonstrated with multiple cartridges accurately measuring the samples with nearly identical results, as shown on screens 77 and 78 in FIG. 7.

(42) The polymer selection provides improved fibrin adhesion.

(43) The use of polymers for the fabrication of the cartridges has also been demonstrated to work well. In addition to being disposable and inexpensive to manufacture, the polymers have demonstrated advantages for us in this invention. Specifically, the use of HDDA promotes fibrinogen to be embedded into the polymer surface prior to the formation of fibrinogen. As the fibrinogen polymerizes it forms an excellent bond to the surfaces. This provides an ideal surface for detecting the viscoelasticity of the coagulating blood between the two HDDA surfaces. FIG. 8 shows fibrin 81 embedded into the surface of a HDDA disc sidewall. FIG. 8 also shows fibrin on the surface of the glass substrate, where air pockets are forming due to a lack of adhesion with no apparent fibrin embedded into the glass surface.

(44) FIG. 9 shows a forward surgical team attending a soldier at a forward position where the present invention is needed. A similar case would be an EMT or paramedic attending a trauma victim.

(45) FIG. 10 shows prior art TEG and ROTEM.

(46) FIGS. 11A and 11B are perspective and a schematic side view showing additional features of the cartridge 100, a platform 102, a well 104, an extended lid 106, an abutment 108 on the platform and a disk 110 attached to the lid 108, all of which are inserted in a receiver before fluid is injected into the well 104. FIG. 11B is a schematic representation of the well 104 and the disk 110 which is still attached to a bottom of the lid 106.

(47) FIGS. 12A and 12B are perspective and a schematic side view showing disk loading technique of the cartridge 100, platform 102, the well 104, the extended lid 106, and an abutment 108 on the platform. Disk 110 is still attached to the lid 106.

(48) FIGS. 13A and 13B are perspective and a schematic side view showing a cartridge 100, the platform 102, well 104 and lid 106. An abutment 108 on the platform 102 has dislodged disk 110 from the lid after fluid is injected into the well and after lid 106 is pushed back and disk 110 is dislodged and dropped from the lid into the well.

(49) FIG. 14 is a perspective view of a cartridge 130, which shows additional features of an injection port and a retaining clip. In this case it is shown without a lid, showing a fluid injection port 132 at one end of a passageway to the well and retaining clip 134 for retaining the cartridge in the receiver. Upward and inward extending opposite guide rails 136 hold a lid 106.

(50) FIG. 15 shows a two-piece injection construction of a cartridge 140 platform 142 for compatibility with manufacture by injection molding. Inner part 143 holds the well 104, and outer part 145 has the retaining clip 134 and the guide rails 136.

(51) While the invention has been described with reference to specific embodiments, modifications and variations of the invention may be constructed without departing from the scope of the invention, which is defined in the following claims.