Method and means for determining oxyhemoglobin association and dissociation curves of whole blood or other liquids

Claim 2

The method of claim 2 wherein the step of successively determining oxygen content is performed optically by use of an oxygen reagent and colorimetric reading means.

Claim 3

The method of claim 3 wherein the linearly increasing oxygen supply is obtained by linearly combining a volume of nitrogen gas with an equal volume of air.

Claim 5

The method of claim 5 wherein the simulated body environment is achieved by equilibrating the blood to its state in the body in appropriate foaming chambers before and after mixing with the oxygen gradient, said chambers maintained at a selected temperature and pressure.

Claim 6

The method of claim 6 wherein the step of successively determining oxygen content is performed optically by use of an oxygen reagent and colorimetric reading means.

Claim 7

The method of claim 7 wherein the linearly decreasing oxygen supply is obtained by linearly combining a volume of air with an equal volume of nitrogen gas.

Claim 8

The method of claim 8 wherein the total oxygen content of the blood is determined prior to mixing with the linearly decreasing oxygen supply.

Claim 10

Apparatus for processing, during continuous flow, samples of blood to determine the oxyhemoglobin association and dissociation curves thereof and other properties comprising: means for initiating and maintaining a confined flow of blood from a selected one of said samples through said apparatus; an albumin buffer and means for introducing said buffer first into said flow of blood; linear gradient generating means for generating a flow of gas having alternatively an increasing oxygen gradient and a decreasing oxygen gradient; a deoxygenating gas mixture and an oxygenating gas mixture and means for introducing said mixtures alternately into said flow of blood and into said linear gradient generating means; means for equilibrating said blood including a plurality of individual equilibration tubes disposed in an equilibration chamber to place the blood in the state in which it exists in the body, said deoxygenating gas mixture next introduced in and mixed with said flow of blood, said flowing blood equilibrated in a first one of said equilibration tubes, said gas having an increasing oxygen gradient next introduced in and mixed with said flow of blood, said flowing blood equilibrated in a second one of said equilibration tubes; a colorimetric means for determining instantaneous oxygen content connected to said apparatus; and means for separating the gaseous and liquid portions of said blood; said colorimetric means including means for introducing an oxygen reagent into said gaseous and liquid portions; said gaseous and liquid portions diverted individually to said colorimetric means to determine instantaneously the oxygen tension surrounding the blood and the oxygen content of the blood, said oxygenating gas mixture next introduced in and mixed with said flowing blood sample; said flowing blood equilibrated in said first of said equilibration tubes, said gas having a decreasing oxygen gradient next introduced in and mixed with said flow of blood, said flow of blood equilibrated in said second one of said equilibration tubes, the gaseous and liquid portions of said blood separated and diverted to said colorimetric means for instantaneous determination of oxygen tension and oxygen content, whereby data necessary to determine the oxygen association and dissociation curves of a sample of blood may be obtained in a single flow process in a matter of minutes.

Claim 11

The apparatus as defined in claim 11 wherein said linear gradient generator means includes a pair of syringes having respective plungers adapted for reciprocating movement therein: valve means having means for alternately connecting at least two gas inlets to respective ones of said syringes and for interconnecting said syringes; means for controlling the combined operation of said valve means and the reciprocating movement of said syringes; and means connecting one of said syringes to said means for maintaining a confined flow of blood, whereby said deoxygenating gas mixture is first admitted into one of said syringes through one of said inlets and said valve means, and said oxygenating gas mixture is thereafter admitted into the other of said syringes through said other inlet and said valve means, said plungers operating simultaneously to create a gas gradient by forcing the contents of one syringe into the other sYringe and the mixed contents of the other syringe into said flow of blood.

Claim 12

The apparatus as defined in claim 12 wherein said oxygen reagent is indigo carmine; and optical means for determining successively and instantaneously the quantity of oxygen in instantaneous portions of said flowing blood.

Claim 13

The apparatus as defined in claim 13 wherein said deoxygenating gas mixture is a mixture comprising nitrogen gas and said means for introducing into the flow of blood is a juncture of tubing disposed a selected distance from respective equilibration chambers.

Claim 14

The apparatus as defined in claim 13 wherein said oxygenating gas mixture is a mixture of air and said means for introducing into the flow of blood is a juncture of tubing disposed a selected distance from respective equilibration chambers.

Claim 15

Means for processing in stages in continuous flow samples of blood to determine the oxyhemoglobin association and dissociation curves thereof and other properties comprising: means for initiating and maintaining a confined flow of blood from said samples through a series of stages in said processing means; means for alternately deoxygenating and oxygenating said blood at selected stages in said processing means; means for generating at least two separate gas mixtures each having a linearly changing concentration with time; means for mixing said gas mixtures and said blood samples at selected stages in said processing means; means for producing optimum equilibration conditions of foaming, and regulation of temperature and pressure in said flow of blood subsequent to mixing said gas mixture therewith; and means for determining the substantially instantaneous concentration of oxygen in said flow of blood at selected stages of said processing means.

Claim 16

The processing means as defined in claim 16 wherein said stages are in order deoxygenation and linearly increasing oxygenation, and complete oxygenation and linearly decreasing oxygenation.

Claim 17

The processing means as defined in claim 17 wherein said means for simulating body conditions include equilibration chambers of selective length and diameter to promote foaming and stabilize pressure, said chambers disposed in an enclosure whose temperature is maintained at substantially 37* C.

Claim 18

The processing means as defined in claim 18 wherein said means for alternately deoxygenating and oxygenating the flow of blood include at least two gas sources and means for mixing the gas from said sources with the flow of blood at selected stages in said processing means.

Claim 19

The processing means as defined in claim 19 wherein said means for generating two gas mixtures of linearly changing concentration is connected to said two gas sources, said linearly changing concentrations being the mixture obtained by linearly combining a volume of one gas mixture with an equal volume of the other gas mixture.

Claim 20

The processing means as defined in claim 19 wherein equilibration chambers are disposed immediately succeeding the points of introduction of individual gas mixtures and linearly changing gas concentrations into said flow of blood.

Claim 21

The processing means as defined in claim 21 wherein said flow of blood is first deoxygenated by mixing therewith nitrogen gas.

Claim 22

The processing means as defined in claim 22 wherein said deoxygenated flow of blood is linearly oxygenated by mixing therewith a linearly increasing concentration of a gas mixture comprising substantially air.

Claim 23

The processing means as defined in claim 23 wherein said flow of blood is fully oxygenated by mixing therewith an air mixture comprising substantially air.

Claim 24

The processing means as defined in claim 24 wherein said fully oxygenated flow of blood is linearly deoxygenated by mixing therewith a linearly increasing concentration of a gas mixture comprising substantially nitrogen gas.

Claim 25

The processing means as defined in claim 25 wherein the oxygen content of said flOw of blood is continuously determined during the stages of linear oxygenation and linear deoxygenation and immediately subsequent to the stage of full oxygenation.

Claim 26

The processing means as defined in claim 26 wherein said means for generating two gas mixtures of linearly changing concentration includes a pair of syringes having respective plungers adapted for reciprocating movement therein; valve means having means for alternately connecting at least two gas inlets to respective ones of said syringes and for interconnecting said syringes; means for controlling the combined operation of said valve means and the reciprocating movement of said syringes; and means connecting one of said syringes to said means for maintaining a confined flow of blood, whereby said deoxygenating gas mixture is first admitted into one of said syringes through one of said inlets and said valve means, and said oxygenating gas mixture is thereafter admitted into the other of said syringes through said other inlet and said valve means, said plungers operating simultaneously to create a gas gradient by forcing the contents of one syringe into the other syringe and the mixed contents of the other syringe into said flow of blood.

Claim 27

The processing means as defined in claim 27 wherein said means for controlling the combined operation of said valve means and the reciprocating movement of said syringes includes a motor connected to said valve means; cam means connected to said motor; reciprocating means connected to said plungers; and switch means operable by said cam means and said reciprocating means so that said syringes may be connected to respective ones of said gas inlets through said valve means during travel of said plungers in one direction and to each other or to different ones of said gas inlets during travel in the reverse direction.

Claim 28

The processing means as defined in claim 28 wherein said valve means is a rotary valve having two stationary outer members and a rotatable inner member; passages in one of said outer members to which said gas inlets are connected; passages in the other of said outer members to which said syringes and a preparation line are connected, said passages in said outer members communicating with the interior surfaces thereof; said rotatable inner member positioned in sealed relationship between said outer members, said inner member having grooves on its surface adjoining said outer members of selective contour and length and passages therethrough connecting selected grooves so that said syringes may be connected to alternate ones of said gas inlets and to each other by selective rotation of said inner member.

Claim 29

The processing means as defined in claim 29 wherein the outlets of the passages in said one of said outer members are radially disposed with respect to one another, and the grooves on the adjoining surface of said inner member are circular and in register with respective outlets, the outlets of the passages in said other of said outer members symmetrically disposed with respect to the transverse axis thereof, and symmetrically disposed arcuate grooves on the adjoining surface of said inner member in register with said outlets of said outer member, an additional groove on said inner member surface adjoining said other outer member whose ends communicate with said passage outlets in said other outer member; a diagonal passage through said inner member connecting the inner of said circular grooves and the adjacent one of said arcuate grooves; and a transverse passage through said inner member connecting the outer of said circular grooves and the other of said arcuate grooves.

Claim 30

The processing means as defined in claim 30 wherein said rotatable inner member is made of teflon; a positioning and sealing ring disposed about said inner member and secured to one of said outer members; means securing both outer members and said ring together to preClude movement thereof during rotation of said inner member; and means axially connecting said inner member and said cam means to transfer rotary movement of said cam means to said inner member, said outer members and said ring made of lucite.