Concentration analyzer

• US 5,477,468 A
• Filed: 01/14/1994
• Issued: 12/19/1995
• Est. Priority Date: 01/14/1994
• Status: Expired due to Term

• Current Assignee: Project Cd
• Original Assignee: Project Cd
• Inventors: Shapiro, Philip, Warhurst, Julian D.
• Primary Examiner(s): Voeltz, Emanuel T.
• Assistant Examiner(s): CHOI, KYLE JAEHUN
• Application Number:
  US08/181,060
• Time in Patent Office: 704 Days
• Field of Search: 364/496, 364/497, 364/499, 128/632, 128/635, 128/692, 436/52, 436/53, 73/61.61
• US Class Current: 702/25
• CPC Class Codes: G01N 27/06 of a liquid involving electrolysis G01N27/26
• CPC Class Codes: Y10T 436/118339 with formation of a segmented stream

Abstract

The concentration analyzer of the present invention is used to determine the cross-sectional concentration at multiple locations within a fluid line, such as an artery or vein, of dissolved substances within a moving fluid flowing through the vein which fluid consists of a first solution of unknown concentration.

Claims

1. A concentration analyzer for determining the cross-sectional concentration at multiple locations within the cross section of a moving fluid stream of dissolved substances within said moving fluid flow stream consisting of a first solution of unknown concentration, comprising:

injection means, for introducing a second solution of known concentration of dissolved substances into the fluid flow;

sensor means, for measuring the conductivity of the first solution and second solution mixture wherein the sensor means comprises

a plurality of electrodes configured with a center probe electrode and two outer hexagonal rings of electrodes for transmitting signals relating to sensed conductivity;

a constant current source, connected to a pair of said electrodes at any one time interval, for applying current to said pair of said electrodes;

a conductance meter which receives the transmitted signals from said electrodes and converts the signals to conductivity measurements; and

an interface connector, comprising a plurality of pins connected to said plurality of electrodes and to said conductance meter;

storage means, for storing the measured conductivity at a plurality of time intervals as the moving fluid stream continues moving; and

computing means, for converting the measured conductivity into a concentration value and for computing the concentration of the first solution based upon the known concentration of the second solution.

2. A concentration analyzer for determining the cross-sectional concentration at multiple locations within the cross section of a moving fluid stream of dissolved substances within said moving fluid flow stream consisting of a first solution of unknown concentration, comprising:

injection means, for introducing a second solution of known concentration of dissolved substances into the fluid flow;

sensor means, for measuring the conductivity of the first solution and second solution mixture wherein the sensor means comprises

a plurality of electrodes configured with a center probe electrode and two outer hexagonal rings of electrodes for transmitting signals relating to sensed conductivity;

a constant current source, connected to a pair of said electrodes at any one time interval, for applying current to said pair of said electrodes;

a conductance meter which receives the transmitted signals from said electrodes and converts the signals to conductivity measurements, wherein said conductance meter comprises

an input multiplexer comprising a plurality of channels, the number of said plurality of channels being equal to the number of said plurality of electrodes;

an instrumentation amplifier;

wherein any two of said plurality of channels can be activated at a predetermined time by connecting one of said channels at one end to said constant current source and by connecting another of said channels at one end to ground, thereby activating two of said channels, and by connecting the other end of each of said two activated channels to said instrumentation amplifier, said instrumentation amplifier amplifying the differential potential between said two activated channels;

an interface connector, comprising a plurality of pins connected to said plurality of electrodes and to said conductance meter;

storage means, for storing the measured conductivity at a plurality of time intervals as the moving fluid stream continues moving; and

computing means, for converting the measured conductivity into a concentration value and for computing the concentration of the first solution based upon the known concentration of the second solution.

3. A concentration analyzer for determining the cross-sectional concentration at multiple locations within the cross section of a moving fluid stream of dissolved substances within said moving fluid flow stream consisting of a first solution of unknown concentration, comprising:

injection means, for introducing a second solution of known concentration of dissolved substances into the fluid flow;

sensor means, for measuring the conductivity of the first solution and second solution mixture wherein the sensor means comprises

a plurality of electrodes configured with a center probe electrode and two outer hexagonal rings of electrodes for transmitting signals relating to sensed conductivity;

a constant current source, connected to a pair of said electrodes at any one time interval, for applying current to said pair of said electrodes, wherein said constant current source comprises a constant mirror comparator for generating said constant current;

a conductance meter which receives the transmitted signals from said electrodes and converts the signals to conductivity measurements; and

an interface connector, comprising a plurality of pins connected to said plurality of electrodes and to said conductance meter;

storage means, for storing the measured conductivity at a plurality of time intervals as the moving fluid stream continues moving; and

computing means, for converting the measured conductivity into a concentration value and for computing the concentration of the first solution based upon the known concentration of the second solution.