Blood flow indicator and process

• US 3,349,762 A
• Filed: 10/21/1964
• Issued: 10/31/1967
• Est. Priority Date: 10/21/1964
• Status: Expired due to Term

• Current Assignee: Narinder S. Kapany
• Original Assignee: Narinder S. Kapany
• Inventors: Kapany, Narinder S.
• Application Number:
  US04/405,409
• Time in Patent Office: 1,105 Days
• US Class Current: 600/479
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: G01F 1/661 using light

Claims

1. A METHOD FOR OBTAINING THE VELOCITY OF BLOOD FLOWING WITHIN A BLOOD VESSEL COMPRISING THE STEPS OF:

DETERMINING THE WAVE LENGTH OF LIGHT THAT EXHIBITS MINIMUM VARIATION IN TRANSMISSION OR REFLECTION FROM CHANGES IN OXYGEN CONTENT OF THE FLOWING BLOOD;

INSERTING FIRST AND SECOND FIBER OPTICAL PATHS INTO SAID BLOOD VESSEL, SAID PATH TERMINATING IN OPTICAL COMMUNICATION WITH SAID FLOWING BLOOD;

DIRECTING LIGHT OF A WAVE LENGTH IN SUBSTANTIAL CONFORMANCE WITH SAID DETERMINED WAVE LENGTH ALONG SAID FIRST OPTICAL PATH INTO OPTICAL COMMUNICATION WITH SAID FLOWING BLOOD;

MEASURING THE INTENSITY OF SAID LIGHT THAT PASSES FROM SAID FLOWING BLOOD INTO OPTICAL COMMUNICATION WITH SAID SECOND OPTICAL PATH;

CONVERTING THE MEASURED INTENSITY OF SAID COMMUNICATED LIGHT TO AN ELECTRICAL SIGNAL;

AND DETERMINING THE VELOCITY OF THE FLOWING BLOOD FROM THE AMPLITUDE OF THE ELECTRICAL SIGNAL.