Optical fiber pressure transducer

• US 4,611,600 A
• Filed: 11/21/1983
• Issued: 09/16/1986
• Est. Priority Date: 11/21/1983
• Status: Expired due to Term

• Current Assignee: Cordis Corporation Miami FA A Corporation of FA
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: Cohen, Donald M.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Hanley, John C.
• Application Number:
  US06/553,581
• Time in Patent Office: 1,030 Days
• Field of Search: 73/705, 128/748, 128/667, 128/673, 128/675, 128/634, 250/231 P
• US Class Current: 600/480
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/02154 by optical transmission
• CPC Class Codes: G01L 9/0076 using photoelectric means

Abstract

The optical blood pressure catheter includes an elongated flexible light conductor for transmitting light received at its proximal end to its distal end and for transmitting light received at the distal end back to the proximal end. A pressure transducer is located adjacent the distal end and includes a light reflector which is spaced along a light path from the distal end and is fixed in position relative thereto so as to receive and reflect light emitted from the distal end back into the distal end. A pressure responsive membrane is located intermediate the distal end and the reflector and is movable transversely of the light path in dependence upon the pressure exerted on the exterior surface of the membrane. A shutter carried by the membrane moves therewith transversely of the light path for blocking light along the light path so that the light received by the distal end is attenuated in dependence upon the pressure exerted on the membrane.

Claims

1. Apparatus for measuring blood pressure at a remote location, comprising:

an elongated flexible tubular member;

a blood pressure transducer assembly including a transducer housing secured to the distal end of said member and being adapted to be positioned at a said remote location;

light conducting means carried within said tubular member for transmitting light to and receiving light from said transducer assembly;

said transducer housing having a cavity in light communication with said light conducting means, light reflecting means mounted in said cavity and fixed in position relative to said light conducting means for receiving light therefrom and reflecting light back thereto, shutter means located in said cavity intermediate said light conducting means and said light reflecting means and movable transversely thereof for varying the amount of light reflected back into said light conducting means, said cavity having a side opening, a pressure sensitive membrane covering said opening and being responsive to exterior pressure applied thereto to move inwardly or outwardly of said cavity, said shutter means being carried by said membrane for blocking light in dependence upon said pressure, said light conducting means is a single optical fiber of circular cross section, and said shutter means is rectangular and aligned with the distal end of said optical fiber and is of a uniform width transversely of the distal end less than the diameter of the optical fiber by an amount sufficient to linearly attenuate light as a function of pressure.

2. Apparatus for measuring blood pressure at a remote location, comprising:

an elongated flexible tubular member;

a blood pressure transducer assembly including a transducer housing secured to the distal end of said member and being adapted to be positioned at a said remote location;

light conducting means carried within said tubular member for transmitting light to and receiving light from said transducer assembly;

said transducer housing having a cavity in light communication with said light conducting means, light reflecting means mounted in said cavity and fixed in position relative to said light conducting means for receiving light therefrom and reflecting light back thereto, shutter means located in said cavity intermediate said light conducting means and said light reflecting means and movable transversely thereof for varying the amount of light reflected back into said light conducting means, said cavity having a side opening, a pressure sensitive membrane covering said opening and being responsive to exterior pressure applied thereto to move inwardly or outwardly of said cavity, said shutter means being carried by said membrane for blocking light in dependence upon said pressure, said light conducting means is a single optical fiber of circular cross section, and the distal end of said optical fiber is masked so as to provide a rectangular-shaped light emitting-receiving aperture of a width uniformly less than that of said shutter means by an amount sufficient to obtain linear attenuation of light with membrane movement as a function of pressure.