Methods and systems for measuring and using the oxidation-reduction potential of a biological sample
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.
1. A method for evaluating or monitoring the ability of a banked blood product to transfer oxygen to tissues, comprising:
a. measuring a capacity oxidation-reduction potential (cORP) of the banked blood product, wherein measuring the cORP of the banked blood product comprises:
passing a current through a sample of the banked blood product; and
monitoring a voltage across the sample while passing the current through the sample over at least a first period of time;
determining a quantity of charge passed to the sample during the first period of time to obtain the cORP of the banked blood product;
b. comparing the measured cORP to a normal cORP reference value from a banked blood product from a relevant healthy population to determine the status of the ability of the banked blood product to transfer oxygen to tissues, wherein:
1) a measured cORP value that is less than the normal cORP reference value indicates banked blood having a reduced ability to transfer oxygen to tissues; and
2) a measured cORP value that is the same as the normal cORP reference value indicates banked blood having a normal ability to transfer oxygen to tissues; and
c. treating the banked blood product based on the ability of the banked blood product to transfer oxygen to tissues;
wherein if the ability of the banked blood product is reduced the step of treating is selected from the group consisting of discarding the banked blood product, admixing the banked blood product with a reducing agent, and administering the banked blood product to a recipient in conjunction with the administration of a reducing agent to the recipient; or
wherein if the ability of the banked blood product is normal the step of treating is selected from the group consisting of not discarding the banked blood product, administering the banked blood product to a recipient, and continuing to store the banked blood product.
2. The method of claim 1 , wherein measuring the cORP of the banked blood product further includes identifying an inflection point in the monitored voltage across the sample.
3. The method of claim 2 , wherein the first period of time extends from a start time to the identified inflection point.
4. The method of claim 3 , wherein the quantity of charge passed to the sample is determined by integrating the current over the first period of time.
5. The method of claim 4 , wherein the start time is a time at which the monitored voltage has stabilized.