Catheter apparatus

Claim 2

Catheter apparatus as in claim 1 characterized in that the distal aperture of each light guide is substantially cylindrical in cross section. 3. Catheter apparatus according to any of the preceding claims characterized in that the light guides are in parallel relationship to each other in the region of the distal aperture. 4. Catheter apparatus according to any of the preceding claims characterized in that the light guides are contiguous in the region of the distal aperture. Catheter apparatus as defined in claim 1 wherein each of said optical fibers has a diameter in the range from about 3 to 15 mils, each fiber terminating at a substantially planar surface oriented substantially normal to the long- itudinal axis of the fiber near one end thereof, said planar surfaces of the fibers being disposed in substantially coplanar and contiguous relationship at corresponding ends thereof which are disposed to contact a fluid sample. 6. Apparatus as in claim 1 comprising at least one con- tinuous filament disposed in one of the first or second conduits along the length of the tube and having a higher modulus of elasticity than the modulii of elasticity of the combined pair of light guides and tube. 7. Apparatus as in claim 1, wherein the total combined areas of the light guide outlet port and inlet port are not greater than 360 square mils. 8. Apparatus as in claim 1 wherein the first one of said 4804. 6 6 78,9 29 n conduits contains liquid. 9. Apparatus as in claim 5 wherein said light guides are clad throughout their length with an optically opaque material. Apparatus as in claim 9 wherein said clad material is impervious to fluid. 11. Apparatus as in claim 10 wherein said clad material is a metal. 12. Apparatus as in claim 11 wherein said clad material is selected from the group consisting of titanium and thodium. 13. Apparatus as in claim an inflatable member surrounding the wall of the tube at its distal tip; a fluid aperture through the wall of said tube near the distal end thereof communicating with the conduit con- taining the light guides and with the interior of the in- flatable member; and connection means to the conduit containing the light guides near the proximal end thereof for introducing fluid under pressure to inflate the inflatable member. 14. Catheter apparatus as in claim 13 wherein said first one of the conduits contains the flexible light-guides, a stress-resistant filament, and conduit fluid under pressure to inflate the distal inflatable member. DATED this 26th day of May, 1977. OXIMETRIX, INC. Aarr-_ G. W. HALFORD Fellow institue of PatennAttorneys of Australia of SHELSTON W 7ERS( 48 4,3 6 6 78,9 29 175 48 4.3 66 9I,9 29 nr. 48 4.3 6 6 78,9 2 9 n 54 58 53 i06. PERCENT OXYGEN SATURATION CATHETER OXIMETER COMPUTED MEASUREMENT40 NCT33% NCT44/ 20 CM/SEC C/SEC 40 CM/SEC '40CI/SEC 60CM/SEC '6OCM/SEC 0 0 20 40 CO 80 l00 PERCENT OXYGEN SATURATION STANDARD CFREFERENCE BLOODSAMPLE MEASUREMENT 8 484,3 66 78,929 SATURATION ACCURACY CPHIIDIl tIV 11 p I- C 0 I o~ I 7.0 75 PH (PRIOR ART) 100%LINE VARIATION IN OXYGENSATURATION ACCURACY, ASA FUNCTION OF pH o0% LINE 7.0 7.5 39 484,366