Blood coagulometer and method

Patent metadata

Field	Value
Publication number	US-9753024-B2
Application number	US-201314427235-A
Country	US
Kind code	B2
Filing date	Sep 11, 2013
Priority date	Sep 11, 2012
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

An apparatus for determining blood clotting capacity comprises an actuator to cyclically move a member within a sample of blood received in a well in a tray and one of a deflection sensor and a position sensor to determine the position of the wetted member upon being acted upon by the actuator. The theoretical position of the wetted member, as determined using a known actuator force and wetted member physical data, is compared to the sensed deflection or position of the wetted member, and the resistance to movement of the wetted member caused by the blood is determined and correlated to a clotting capacity.

First claim

We claim:

1. An apparatus to measure clotting in a blood sample, comprising:
a tray;
a well in the tray to receive a sample of the blood;
a support beam connected at a first end to the tray and connected at a second end to a wetted member to support the wetted member at least partially within the well;
a linear motor connected between the tray and the support beam and activatable by application of an electrical current to impart a force, corresponding in magnitude to the applied current, on the support beam to move the support beam relative to the tray and to thereby move the wetted member within the well; and
a deflection sensor coupled to the tray to measure the deflection of the support beam resulting from resistance to movement of the wetted member imparted by the sample of blood received in the well;
wherein the measured deflection of the support beam resulting from the resistance to movement of the wetted member within the sample of blood in the well is correlated to a capacity of the blood to clot.

2. The apparatus of claim 1 , wherein the linear motor comprises:
an electrically-powered linear motor having at least one conductive coil through which the electrical current flows; and
at least one magnet disposed on a connecting rod movable within the at least one conductive coil;
wherein the application of a current having a first polarity to the linear motor causes the connecting rod to be moved in a first direction against the support beam; and
wherein the application of a current having a second polarity, opposite to the first current, causes the connecting rod to be moved in a direction opposite to the first direction.

3. The apparatus of claim 1 , wherein the support beam is an elastically flexible elongate shaft.

4. The apparatus of claim 1 , wherein the electrically-powered linear motor is connectable to a battery.

5. The apparatus of claim 4 , wherein the tray comprises a battery portion to receive and secure a battery to the tray.

6. The apparatus of claim 1 , wherein the deflection sensor comprises:
a laser element coupled to the tray to generate an incident beam;
a reflective member on the support beam; and
a photo-detector array coupled to the tray and connectable to a controller;
wherein the photo-detector array generates a signal to the controller indicating the location of impingement on the photo-detector array of a reflected beam, and the signal enables the determination of the angle between the incident beam and the reflected beam;
wherein the angle between the incident beam and the reflected beam indicates the deflection of the support beam resulting from the resistance to movement of the wetted member within the well as force is imparted by the linear motor to the support beam; and
wherein the angle between the incident beam and the reflected beam can be correlated to the clotting capacity of the blood.

7. The apparatus of claim 1 , wherein the deflection sensor comprises:
a strain gauge coupled to the support beam to generate a signal to a processor corresponding to the stress imparted to the support beam as a result of the resistance to movement of the wetted member within the well as force is imparted by the linear motor to the support beam;
wherein the signal generated by the strain gauge can be correlated to the clotting capacity of the blood.

8. The apparatus of claim 1 , further comprising:
a controller to receive a signal corresponding to the measured deflection and generated by the deflection sensor and to generate a display signal; and
a display device coupled to the tray and connected to receive the display signal from the controller.

9. The apparatus of claim 8 , wherein the display device is one of a light emitting diode display device, a liquid crystal display device or a gauge.

10. An apparatus to measure clotting in a blood sample, comprising:
a tray;
a well in the tray to receive a sample of the blood;
a carriage, having a first end, a second end, a magnetic material and a wetted member movably supported on the tray to support at least a portion of the wetted member within the well;
an electrically-powered motor comprising:
at least a first electromagnet connectable to an electrical current source;
wherein energizing the first electromagnet creates a magnetic field that imparts a corresponding force on the magnetic material of the carriage to move the carriage and to thereby move the wetted member within the well, and

a deflection sensor coupled to the tray to measure the deflection of the carriage resulting from resistance to movement of the wetted member imparted by the sample of blood received in the well;
wherein the measured deflection of the carriage resulting from the resistance to movement of the wetted member within the sample of blood in the well is correlated to a capacity of the blood to clot.

11. The apparatus of claim 10 , wherein the motor further comprises:
a second electromagnet connectable to an electrical current source;
wherein energizing the first and second electromagnets creates a magnetic field that imparts a corresponding force on the magnetic material of the carriage to move the carriage and to move the wetted member within the well.

12. The apparatus of claim 10 , wherein the deflection sensor comprises:
a laser emitting element coupled to the tray to generate an incident beam;
a photo-detector array connected to a controller; and
a reflecting member coupled to the carriage to reflect the incident beam to provide a reflected beam of laser light onto the photo-detector array;
wherein the controller senses the location of impingement of the reflected beam on the photo-detector array, determines an angle between the incident beam and the reflected beam, and calculates the position of the carriage resulting from the force applied to the magnetic material of the carriage; and
wherein the controller compares the calculated position of the carriage to a theoretical position of the carriage determined based on the carriage mass and the known force applied to the magnetic material by the first electromagnet.

13. The apparatus of claim 12 , wherein the theoretical position of the carriage and the detected position of the carriage are compared to indicate the clotting capacity of the sample of blood received in the well.

14. The apparatus of claim 12 ,
wherein the controller receives a signal corresponding to the measured deflection and generated by the deflection sensor and generates a display signal; and further comprising
a display device connected to receive the display signal from the controller.

15. The apparatus of claim 14 , wherein the display device is one of a light emitting diode display device, a liquid crystal display device or a gauge.

16. A method of testing a sample of blood to determine the clotting capacity of the blood, comprising:
providing a tray having a well;
receiving, into the well, a sample of the blood to be analyzed;
connecting, a wetted member to a first portion of a support member;
movably supporting the support member on the tray and above an interface between the sample of blood and air to dispose at least a portion of the wetted member within the sample of blood and below the interface;
imparting a known force to the support member to substantially linearly displace the portion of the support member, and the wetted member connected thereto, relative to the well to move the wetted member within the sample of blood;
determining a theoretical displacement of the wetted member corresponding to the known force imparted to the support member;
measu

Assignees

• Univ Texas
• Board Of Regents Of The Univ Of Texas Systems

Inventors

• Gill Brijesh S
• Aroom Kevin
• Cox Jr Charles

Classifications

• G01N11/16

  by measuring damping effect upon oscillatory body · CPC title

• G01N33/4905 Primary

  Determining clotting time of blood (by chemical methods G01N33/86, C12Q1/56) · CPC title

• G01N11/10

  by moving a body within the material · CPC title

• G01N33/49 Primary

  Blood {(chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80)} · CPC title