Intravascular oximetry catheter
First Claim
1. Apparatus for monitoring a percentage of oxygen saturation in blood flowing through a blood vessel, comprising:
- (a) a flexible catheter having an elongated cylindrical shape and a diameter sufficiently small to enable the catheter to be advanced into the blood vessel as the blood is flowing through the blood vessel;
(b) a pair of optical fibers disposed within the catheter and extending generally along the length of the catheter, from a point adjacent to a distal end of the catheter, one of said optical fibers being adapted for coupling to a transmitter and being used for conveying light from the transmitter, another of said optical fibers being adapted for coupling to a receiver and conveying reflected light to the receiver; and
(c) an oxygen sensor for indicating the percentage of oxygen saturation in the blood flowing through the blood vessel, the oxygen sensor including the transmitter and the receiver and being coupled to the proximal end of the catheter, the optical fibers being generally centered about a central longitudinal axis of the catheter, to maximize a distance between each distal end of each optical fiber and a periphery of the catheter, so that reflection of light emitted from a distal end of said one optical fiber from a wall of the blood vessel, which would cause an error in the percentage of oxygen saturation determined by the oxygen sensor, is substantially reduced.
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Accused Products
Abstract
Apparatus and a method for monitoring a percentage of the oxygen saturation in the hemoglobin of blood flowing through a blood vessel. An optical sensor that detects the percentage oxygen saturation in blood is disposed proximate a proximal end of the catheter. A thermistor is disposed adjacent to the distal end of the catheter and it is employed to detect changes in blood temperature that indicate the position of the catheter'"'"'s distal end in the blood vessel. Indicia or marks visible at intervals on the outer surface of the catheter enable a medical practitioner to determine the length of the catheter that has been introduced into the blood vessel. A strain relief that is flexible and resists stretching extends along the length of the catheter. For flushing the distal end of the catheter, a fluid supply may be connected to a lumen running through the catheter to provide the flushing fluid. A removable guide wire is inserted in the lumen when positioning the distal end of the catheter at a location in the blood vessel and provides enhanced rigidity for this purpose. The catheter may be coated with an anticoagulant such as heparin, to prevent blood from coagulating on the exterior surface of the catheter.
122 Citations
31 Claims
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1. Apparatus for monitoring a percentage of oxygen saturation in blood flowing through a blood vessel, comprising:
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(a) a flexible catheter having an elongated cylindrical shape and a diameter sufficiently small to enable the catheter to be advanced into the blood vessel as the blood is flowing through the blood vessel; (b) a pair of optical fibers disposed within the catheter and extending generally along the length of the catheter, from a point adjacent to a distal end of the catheter, one of said optical fibers being adapted for coupling to a transmitter and being used for conveying light from the transmitter, another of said optical fibers being adapted for coupling to a receiver and conveying reflected light to the receiver; and (c) an oxygen sensor for indicating the percentage of oxygen saturation in the blood flowing through the blood vessel, the oxygen sensor including the transmitter and the receiver and being coupled to the proximal end of the catheter, the optical fibers being generally centered about a central longitudinal axis of the catheter, to maximize a distance between each distal end of each optical fiber and a periphery of the catheter, so that reflection of light emitted from a distal end of said one optical fiber from a wall of the blood vessel, which would cause an error in the percentage of oxygen saturation determined by the oxygen sensor, is substantially reduced. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A catheter for monitoring a percentage of oxygen saturation in blood flowing through a blood vessel, comprising:
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(a) a lumen disposed within the catheter and extending along a length of the catheter; (b) a pair of optical fibers extending through the lumen to a distal end of the catheter; (c) a proximal end of one of the pair of optical fibers being adapted to couple to an optical transmitter disposed at a proximal end of the catheter to convey light emitted by the optical transmitter to a distal end of said one of the pair of optical fibers, for emission therefrom into the blood; and (d) a proximal end of the other of the pair of optical fibers being adapted to couple to an optical receiver disposed at a proximal end of the catheter to convey light reflected from hemoglobin in red blood cells in the blood, distal ends of the pair of optical fibers being disposed substantially at a center of the distal end of the catheter to maximize a distance between a periphery of the catheter and the distal ends of the pair of optical fibers, and thereby to reduce the light emitted from the distal end of said one of the pair of optical fibers that is reflected from a wall of the blood vessel so that the light reflection does not cause a substantial error in an accuracy with which the percentage of oxygen saturation in the blood flowing through the blood vessel is monitored.
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22. A method for monitoring the percentage of oxygen saturation in blood flowing through a blood vessel, comprising the steps of:
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(a) opening an incision in a body of a patient, the incision providing an access into the blood vessel; (b) providing a catheter that includes an optical fiber sensing system, said optical fiber sensing system including a transmitting optical fiber and a receiving optical fiber, a distal end of the transmitting optical fiber and a distal end of the receiving optical fiber being disposed substantially at a center of a distal end of the catheter, to maximize a distance between each distal end of each optical fiber and a periphery of the catheter, so that reflection of light emitted from a distal end of said one optical fiber from a wall of the blood vessel, which would cause an error in the percentage of oxygen saturation determined by the oxygen sensor, is substantially reduced; (c) inserting the catheter into the blood vessel through the incision; (d) positioning the distal end of the catheter at a position in the blood vessel, away from a wall of the blood vessel; and (e) monitoring a percentage of the oxygen saturation in the blood flowing through the blood vessel with the optical fiber oxygen sensing system. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31)
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Specification