Photometry system for analyzing fluids

• US 6,063,051 A
• Filed: 06/22/1998
• Issued: 05/16/2000
• Est. Priority Date: 11/06/1997
• Status: Expired due to Fees

• Current Assignee: Aquintel, Inc.
• Original Assignee: Aquintel, Inc.
• Inventors: Stern, Roger A.
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US09/102,926
• Time in Patent Office: 694 Days
• Field of Search: 600/309, 600/310, 600/322, 600/573, 600/578, 600/579, 600/584, 604/27-30, 604/65-67, 604/317, 604/318, 604/322
• US Class Current: 604/27
• CPC Class Codes: A61B 10/0045 Devices for taking samples of body liquids devices for taking blood samples A61B5/15
• CPC Class Codes: A61B 5/20 for measuring urological functions restricted to the evaluation of the urinary system A61B5/4375 takes precedence
• CPC Class Codes: A61B 5/4283 gastrointestinal secretions, e.g. bile production
• CPC Class Codes: A61B 5/4881 Determining interstitial fluid distribution or content within body tissue measuring analytes in interstitial fluid in-vivo A61B5/1451
• CPC Class Codes: A61M 1/777 Determination of loss or gain of body fluids due to suction-irrigation, e.g. during surgery
• CPC Class Codes: A61M 2205/3375 Acoustical, e.g. ultrasonic, measuring means
• CPC Class Codes: A61M 2205/3393 by weighing the reservoir
• CPC Class Codes: A61M 2230/005 Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/65 Impedance, e.g. conductivity, capacity
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters
• CPC Class Codes: A61M 5/16895 by monitoring weight change, e.g. of infusion container
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: G01N 21/62 Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
• CPC Class Codes: G01N 21/69 specially adapted for fluids , e.g. molten metal

Abstract

A computer based system for tracking a patient'"'"'s fluid volume and electrolyte (cation or anion concentration) balances, during the period extending from before surgical procedures through the recovery process, which will assist the attending physician in maintaining proper balances in the patient. The system contains automatic sensors for measuring the volumes of fluids administered to and recovered from the patient. The system also preferably contains sensors for measuring electrolyte concentrations in these fluids, and, when sensors are not available, assists the attending physician in estimating. The system assists the attending physician in creating baseline values for a patient'"'"'s fluid and electrolyte values, and then accounts for the fluids going into and out of the patient to continuously track current values. Out of bounds conditions for these balances, when detected, will cause the system to issue alarms and make suggestions to the attending physician for remedial action.

Claims

1. A fluid and electrolyte balance monitoring system, comprising:

input fluid measuring means for measuring a volume of input fluid that will enter a patient;

input fluid analyzing means for determining electrolyte parameters of said input fluid;

output fluid measuring means for measuring a volume of output fluid that has exited the patient;

flame photometry means for determining electrolyte parameters of said output fluid; and

fluid volume and electrolyte tracking means for calculating and monitoring a fluid volume status and an electrolyte status of the patient based on information obtained from said input fluid measuring means, said input fluid analyzing means, said output fluid measuring means, and said flame photometry means.

2. A method for monitoring fluid and electrolyte balances, comprising the steps of:

measuring a volume of input fluid that will enter a patient;

determining electrolyte parameters of the input fluid;

measuring a volume of output fluid that has exited the patient;

determining electrolyte parameters of the output fluid using flame photometry; and

calculating and monitoring a fluid volume status and an electrolyte status of the patient based on the measured volume of the input fluid, the determined electrolyte parameters of the input fluid, the measured volume of the output fluid, and the determined electrolyte parameters of the output fluid.

3. The method of claim 2, wherein determining output fluid electrolyte parameters comprises the steps of:

positioning a first electrode in the output fluid;

positioning a second electrode in close proximity to the output fluid;

causing an electrical current to flow between the second electrode and the output fluid so as to create a spark or arc between the second electrode and the output fluid;

collecting the light emitted by the spark or arc;

determining the amount of light emitted at wavelengths of interest;

analyzing the amount of light emitted at wavelengths of interest to determine concentrations of substances of interest; and

using the output fluid volume to convert the concentrations to total amounts of the substances of interest present in the fluid.

4. The method of claim 3, wherein a reference fluid containing known concentrations of certain substances is first analyzed to establish a reference for the amount of light emitted at wavelengths of interest.

5. The method of claim 4, wherein the reference fluid contains known concentrations of one or more substances expected to be found in the output fluid.

6. The method of claim 4, wherein the reference fluid contains known concentrations of one or more substances not expected to be found in the output fluid.

7. The method of claim 2, wherein determining output fluid electrolyte parameters comprises the steps of:

positioning a first electrode in the output fluid;

positioning a second electrode in close proximity to the output fluid;

causing an electrical current to flow between the second electrode and the output fluid so as to create a spark or arc between the second electrode and the output fluid;

collecting the light emitted by the spark or arc;

determining the amount of light emitted at wavelengths of interest;

analyzing the amount of light emitted at wavelengths of interest to determine a relative concentration of a substance of interest;

using one or more reference measurements that represent the total concentrations of substances present to convert the relative concentration of the substance of interest to an absolute concentration; and

using the output fluid volume to convert the absolute concentration to a total amount of the substance of interest present in the fluid.

8. The method of claim 7 wherein the electrical conductivity of the output fluid is measured at one or more alternating current frequencies and the electrical conductivity measurements are used as the reference measurements to convert a relative substance concentration to an absolute substance concentration.