METHODS AND SYSTEMS FOR MEASURING AND USING THE OXIDATION-REDUCTION POTENTIAL OF A BIOLOGICAL SAMPLE

• US 20140110273A1
• Filed: 10/23/2013
• Published: 04/24/2014
• Est. Priority Date: 10/23/2012
• Status: Active Grant

• Current Assignee: Caerus Biotechnologies
• Original Assignee: Luoxis Diagnostics, Inc. (Aytu Biopharma, Inc.)
• Inventors: Bar-Or, Raphael, Bar-Or, David, Rael, Leonard T.
• Granted Patent: US 9,410,913 B2
• Time in Patent Office: Days
• US Class Current: 205/792
• CPC Class Codes: A61K 35/16 Blood plasma; Blood serum umbilical cord blood A61K35/51
• CPC Class Codes: G01N 27/26 by investigating electrochemical variables; by using electrolysis or electrophoresis
• CPC Class Codes: G01N 27/4161 measuring the voltage and using a constant current supply, e.g. chronopotentiometry
• CPC Class Codes: G01N 27/4168 Oxidation-reduction potential, e.g. for chlorination of water water analysis G01N33/18
• CPC Class Codes: G01N 2800/7009 Oxidative stress
• CPC Class Codes: G01N 33/48 Biological material, e.g. blood, urine G01N33/02, G01N33/26, G01N33/44, G01N33/46 take precedence; Haemocytometers counting blood corpuscules distributed over a surface by scanning the surface G06M11/02
• CPC Class Codes: G01N 33/48707 by electrical means G01N33/49, G01N33/493 take precedence
• CPC Class Codes: G01N 33/49 Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80

Abstract

Methods and systems for measuring and using the oxidation-reduction characteristics of a biological sample are provided. The system generally includes a test strip and a readout device. A fluid sample is placed in the test strip, and the test strip is in turn operatively connected to the readout device. The readout device provides a controlled current that is sent across the fluid in the sample chamber. In addition, the readout device identifies an inflection point or transition time at which the voltage between contacts of the test strip is changing at the highest rate. The oxidation-reduction capacity of the sample is taken as the integral of the current profile from the time at which current begins to be supplied to the sample to the identified transition time.

Claims

1. A system for identifying an oxidative capacity of a fluid, comprising:

a fluid sample;

a test strip, including;

a reference cell;

a sample chamber;

a counter electrode, wherein a first portion of the counter electrode extends into the sample chamber;

a working electrode, wherein a first portion of the working electrode extends into the sample chamber;

a reference electrode, wherein the reference electrode is in electrical contact with the reference cell;

a readout device, including;

a first contact;

a second contact;

a third contact;

a test signal power supply, wherein a first terminal of the test signal power supply is electrically connected to the first contact, and wherein a second terminal of the test signal power supply is electrically connected to the second contact;

an electrometer, wherein a first input of the electrometer is electrically connected to the second contact, and wherein a second input of the electrometer is electrically connected to the third contact;

memory;

a processor, wherein with the first contact electrically connected to the counter electrode, the second contact electrically connected to the working electrode, and the third contact electrically connected to the reference electrode, and with the fluid sample in the sample chamber, the processor is operable to execute programming code stored in the memory to;

operate the test signal power supply to supply a current across the sample chamber between the counter electrode and the working electrode for at least a first period of time;

during the first period of time, monitor and/or record the voltage sensed by the electrometer;

identify an inflection point in the voltage sensed by the electrometer;

record the time at which the inflection point is identified.

2. The system of claim 1, wherein the processor is further operable to:

integrate the current between a start time and the time at which the inflection point is reached to obtain an oxidation reduction capacity of the fluid sample.

3. The system of claim 2, wherein the processor is further operable to:

operate the test signal power supply to supply the current at a static first level for a first time segment;

after the first time segment, operate the test signal power supply to supply the current at a rising level for at least a second time segment.

4. The system of claim 1, wherein the readout device further includes:

an output device, wherein the obtained oxidation reduction capacity of the fluid sample is output to a user by the output device.

5. The system of claim 4, wherein the obtained oxidation reduction capacity is output in units of Coulombs⁻

1.

6. A readout device, comprising:

a plurality of readout contacts;

an analog front end, including;

a current supply;

an electrometer,

wherein the current supply is operable to provide a current to first and second contacts of the plurality of readout contacts, and wherein the electrometer is operable to read a voltage potential between the second contact and a third contact of the readout contacts.

7. The device of claim 6, further comprising:

a controller;

an analog to digital converter, wherein the analog to digital converter connects the electrometer to the controller;

a digital to analog converter, wherein the digital to analog converter connects the controller to the current supply.

8. The device of claim 7, wherein the controller is operable to determine an inflection point in the voltage potential, and is further operable to determine a quantity of the charge supplied between a first time and the inflection point.

9. The device of claim 8, further comprising:

a user interface, wherein the user interface includes a user output, and wherein the user output provides a cORP value derived from the determined quantity of the charge supplied between the first time and the inflection point.

10. The device of claim 9, further comprising:

a connector, wherein the connector is operative to receive a test strip containing a fluid sample, wherein the readout contacts are included in the connector, and wherein the readout contacts are placed in operative contact with leads of a test strip.

11. A method for measuring oxidation reduction potential capacity, comprising:

applying a current to a fluid sample;

measuring a voltage across the fluid sample over a first period of time, while applying the current to the fluid sample;

integrating the applied current over the first period of time to obtain a value indicative of an oxidation reduction capacity.

12. The method of claim 11, wherein the current is applied to the fluid sample between a counter electrode and a working electrode, and wherein the voltage across the fluid sample is measured between a reference electrode and the working electrode.

13. The method of claim 12, further comprising:

varying the current applied to the fluid sample.

14. The method of claim 13, further comprising:

identifying an inflection point in the measured voltage, wherein the first period of time over which the applied current is integrated ends at a time at which the inflection point is identified.

15. The method of claim 14, wherein the current is held constant during at least a first segment of the first period of time, and wherein the current is varied during at least a second segment of the first period of time.

16. The method of claim 15, wherein the first segment of the first period of time follows the second segment of the first period of time.

17. The method of claim 16, wherein the current is increased at a linear rate during the second segment of the first period of time.

18. The method of claim 16, wherein the current is increased at an exponential rate during the second segment of the first period of time.

19. The method of claim 16, wherein the current is increased according to a step function during the second segment of the first period of time.

20. The method of claim 14, wherein the inflection point is the point at which the rate of change in the measured voltage is at a maximum.