OPTICAL MEASURING CATHETER

• US 3,814,081 A
• Filed: 03/30/1972
• Issued: 06/04/1974
• Est. Priority Date: 04/02/1971
• Status: Expired due to Term

• Current Assignee: Toshiyuki Mori
• Original Assignee: Toshiyuki Mori
• Inventors: Mori, Toshiyuki
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US05/239,693
• Time in Patent Office: 796 Days
• Field of Search: 128/2R,2L,2M,2.5R,2.5D,2.5F,4-8,348,349B 350/96B 356/41
• US Class Current: 600/337
• CPC Class Codes: A61B 5/02154 by optical transmission
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: G01N 21/8507 Probe photometers, i.e. with optical measuring part dipped into fluid sample

Abstract

Optical measuring catheter for measuring the degree of oxygen saturation in the blood of a living body utilizing an illuminating fiber optical system and a light receiving fiber optical system arranged closely along each other the forward ends of which are adapted to be inserted together into an organ of the living body in which the blood is flowing. By supplying light having a wave length of about 600 - 750 m Mu or light having a wave length of about 800 m Mu to the illuminating fiber optical system, the degree of oxygen saturation in the blood is determined by the light incident to the blood and reflected thereby so as to be received by the light receiving fiber optical system due to the fact that the absorption spectrum of Hb is different from that of HbO2. The optical measuring catheter comprises an optical member attached to the forward ends of the fiber optical systems for preventing the forward ends from directly contacting the inner wall of the organ into which the forward ends are inserted while insuring the optical communication of the forward ends with the exterior of the optical member.

Claims

1. In an optical measuring catheter inclUding an illuminating fiber optical system, a light receiving fiber optical system closely juxtaposed to said illuminating fiber optical system, said systems having respective forward ends juxtaposed in flush relationship and adapted to be inserted into an organ of a living body containing flowing blood and respective rear ends, light supplying means for supplying to the rear end of said illuminating fiber optical system light having wavelengths of about 600 to 750 m Mu and of about 800 m Mu , whereby the supplied light is emitted from the forward end of said illuminating fiber optical system and partly transmitted from the forward end of said light receiving fiber optical system to the rear end of the latter system, a photoelectric element positioned to receive said transmitted light and generating an output signal in response to the received light, detecting means connected to said element for indicating said output signal, and a transparent abutment secured to said forward ends for preventing said forward ends from contacting directly an inner wall of said organ while permitting passage of said light, the improvement which comprises:

said abutment means including a transparent, elastic diaphragm, securing means spacedly securing said diaphragm in front of said forward ends, said securing means, said diaphragm, and said forward ends bounding a sealed space, a coating on the surface of said diaphragm in said space, said coating reflecting light of a wave length of less than about 650 m Mu while transmitting light of greater wave length, said light supplying means including means for supplying light having a wave length of less than about 650 m Mu , whereby the amount of light of said last-mentioned wave length received by said forward end of said light receiving fiber optical system varies in response to ambient pressure and the resulting curvature of said diaphragm.

2. In an optical measuring catheter including an illuminating fiber optical systems, a light receiving fiber optical system closely juxtaposed to said illuminating fiber optical system, said systems having respective forward ends juxtaposed in flush relationship and adapted to be inserted into an organ of a living body containing flowing blood and respective rear ends, light supplying means for supplying to the rear end of said illuminating fiber optical system light having wavelengths of about 600 to 750 m Mu and of about 800 m Mu , whereby the supplied light is emitted from the forward end of said illuminating fiber optical system and partly transmitted from the forward end of said light receiving fiber optical system to the rear end of the latter system, a photoelectric element positioned to receive said transmitted light and generating an output signal in response to the received light, detecting means connected to said element for indicating said output signal, and a transparent abutment secured to said forward ends for preventing said forward ends from contacting directly an inner wall of said organ while permitting passage of said light, the improvement which comprises:

said abutment including an elastic diaphragm having a reflecting surface directed toward said forward ends and bounding a sealed space, and a semi-transparent mirror located between said space and said forward ends, said mirror transmitting light having a wave length of less than about 650 m Mu but reflecting light of greater wave length outward of said catheter and angularly away from said diaphragm, said light supplying means including means for supplying light of said wave length of less than about 650 m Mu , whereby the amount of light of said last-mentioned wave length received by said forward end of said light receiving fiber optical system varies in response to ambient pressure and the resulting curvature of said diaphragm.