CARDIAC OUTPUT DETERMINATION METHOD FOR USE WITH DYE DILUTION PROCEDURES

• US 3,618,591 A
• Filed: 04/09/1969
• Issued: 11/09/1971
• Est. Priority Date: 04/09/1969
• Status: Expired due to Term

• Current Assignee: Edward C. Bradley, John W. Barr
• Original Assignee: Edward C. Bradley, John W. Barr
• Inventors: Bradley, Edward C., Barr, John W.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US04/814,551
• Time in Patent Office: 944 Days
• Field of Search: 128/2.5F,2.5R,2.5V 235/78,83,84,116
• US Class Current: 600/526
• CPC Class Codes: A61B 5/0275 using tracers, e.g. dye dilution
• CPC Class Codes: G06G 1/12 logarithmic graduations, e.g. for multiplication

Abstract

The disclosure concerns a method and apparatus for quickly determining the area under a dye dilution curve, based upon triangle congruency, for use in rapid determination of cardiac output.

Claims

1. In the method of estimating cardiac output by determining blood flow rate from the heart, the steps that include a. suddenly injecting a quantity I of dye into a body blood flow channel, b. determining the peak concentration PC of the dye flowing in the blood in a body vessel, c. determining the time interval T50 that elapses between the occurrences of approximately 50 percent peak concentrations of the dye during increase and decrease of said dye concentrations in that vessel, and d. obtaining a value for said blood flow as a function of I/PC X T50.

2. The method of claim 1, wherein said step (d) comprises determining a value for flow in ml./min. by evaluation of the expression 51.4 X I/PC X T50 X CF where I is measured in milligrams PC is measured in millimeters T50 is measured in seconds and CF is a calibration factor correlating recorder output with dye concentration in the blood, and said steps (b) and (c) include detecting and recording the concentration of dye in the blood as a function of time.