Fiberoptic Catheter

Abstract

A fiberoptic catheter for monitoring blood in vivo with avoidance of thrombus formation. A standard cardiac catheter having longitudinally extending afferent and efferent light-conducting fibers therewithin is terminated with a smoothly rounded tip. Some distance back from the tip, the fibers are directed right-angularly to one side of the catheter where ends thereof are optically finished to form an exposed light-emitting and light-receiving face at said side of the catheter. This face is spaced from walls of passages of the recipient by a fixed bend in the adjacent terminal portion of the catheter.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

Fiberoptic devices with particular reference to catheters having light-conducting fibers extending longitudinally internally through at least a substantial portion of their lengths.

2. Description of the Prior Art

A main obstacle for the use of indwelling fiberoptic catheters is thrombus formation and/or an accumulation of fibrin around or adjacent to the effective light-emitting and light-receiving distal ends of the catheters. This usually results from irregularities in the construction of the catheter ends particularly in cases where cages and the like are used to prevent these ends from coming into too close proximity with the walls of body organs or passages into which the catheters are inserted.

Heretofor, the construction of fiberoptic catheters has necessitated the use of wire cages and the like to avoid the adverse effects of the observing ends of the catheters coming into too close proximity to the walls of passages into which the catheters are inserted. The undesireable effects of this too close proximity which are referred to in the art as "wall effects," are false or unreliable readings of blood oxygen saturation, in the case in vivo oximeters, and similar unreliable indications of intravascular blood pressure and the like, in the case of fiberoptic intravascular pressure and sound determining catheter systems.

The present invention deals with the avoidance of thrombus formation, fibrin accumulation and wall effects in the use of indwelling fiberoptic catheters.

SUMMARY OF THE INVENTION

In its relationship to the aforementioned matters, the present invention accomplishes its objectives through the provision of a standard cardiac catheter having longitudinally extending afferent and efferent light-conducting fibers therewithin. The catheter is terminated with a smoothly rounded tip some distance back from which the fibers are directed right-angularly to one side of the catheter. Ends of the fibers thus form a light-emitting and light-receiving face at the side of the catheter. This face is smoothly contoured into the corresponding side of the catheter and provides a light-emitting and light-receiving pickup area on the catheter. This smoothly contoured pickup area and rounded tip of the catheter renders the catheter readily insertable into the body and capable of being held in situ for long periods of time without thrombus formation or fibrin accumulation therearound. Additionally, the present catheter is provided with a fixed bend adjacent its terminal end which is directed arcuately along the side of the catheter having the aforesaid pickup area so that the pickup area is held at all times, in spaced relationship with walls or sides of body organs or passageways under observation.

The invention will be more fully understood by reference to the following detailed description and the accompanying drawing.

DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective illustration of a preferred embodiment of the invention;

FIG. 2 is a somewhat enlarged fragmentary perspective view of the distal end of the fiberoptic catheter shown in FIG. 1;

FIG. 3 is a greatly enlarged longitudinal cross-sectional view of the portion of the catheter which is depicted in FIG. 2; and

FIG. 4 is a perspective illustration of means used in conjunction with the catheter during periods of storage thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fiberoptic catheter 10 comprises a length of standard cardiac catheter tubing 12 having a relatively short section 12a of its distal portion separated from its main section 12b by a rigid tubular internal coupling 14 which connects these sections 12a and 12b coaxially together.

A bundle 16 of afferent and efferent light-conducting fibers 18 having a relatively sharp right-angular bend 20 (FIG. 3) adjacent its terminus is extended through the major portion of the length of catheter tubing 12 with its terminus directed laterally through a slot 22 in fitting 14. This extremity of fiber bundle 16 is fixedly secured within fitting 14 with an epoxy resin or similar adhesive potting agent 24 which, at the side of face 26 of bundle 16, smoothly fills in the gap between adjacent ends of section 12a and 12b of catheter tubing 12. Also smoothly filling in the remaining spacing between sections 12a and 12b of catheter tubing 12 is a split collar 28 which extends from opposite sides of face 26 circumferentially about fitting 14.

Face 26 of fiber bundle 16 and its surrounding exposed portions of the potting agent 24, as well as collar 28, are all smoothly externally finished and tightly joined to each other and to sections 12a and 12b of catheter tubing 12 so that the joinder of such sections 12a and 12b is continuous and the tendency for thrombus formation and/or fibrin accumulation thereabout is avoided.

In further avoiding thrombus formation along catheter tubing 12, its distal end is closed with a smoothly finished semispherical tip 30. In the particular embodiment of the invention herein illustrated, tip 30 is formed of metal having an electrical lead 32 connected thereto. Lead 32 extends externally of catheter 10 to a source of electrical current (not shown) which may be used to electrically stimulate the portion of a body (e.g. the heart) into which tip 30 is placed.

According to generally standard practice in applying fiberoptic catheters to associated light-emitting and light-receiving apparatuses, catheter tubing 12 is coupled to a larger tubing 34 (FIG. 1) which, in turn, is coupled to a Y-junction block 36. Bundle 16 is continued from catheter tubing 12 through tubing 34 and then separated into two legs within block 36. Each leg is directed separately outwardly of block 36 through respective relatively short lengths of tubings 38 and 40 and into corresponding end fittings 42 and 44. The particular fibers terminating in fitting 44 may be selected for transmitting light from a source 46 afferently through catheter 10 while the fibers terminating in fitting 42 function as the efferent fibers of catheter 10 which are used to conduct light to a photodetector 48.

Those interested in actual applications of devices such as catheter 10 may refer to U.S. Pat. Nos. 3,069,739; 3,068,742 and 3,461,856, for example. In the present case, however, the light-receiving and light-emitting face 26 of catheter 10 is disposed at a side of the catheter tubing whereby light emitted from catheter 10 is directed laterally of the tubing generally as illustrated by lines 50 (FIG. 2) which represent light rays.

In order to maintain a spacing between face 26 and the walls of passageway 52 (FIG. 3) which is sufficient to permit a free flow of blood over face 26 in the passageway, the end of catheter 10 is provided with a bend as indicated by arrow 54 in FIG. 2. Having its approximate center of curvature 56 disposed forwardly of face 26, this bend acts to prevent collapse of the walls of passageway 52 against the catheter. Thus, adequate spacing between face 26 and the walls of passageway 52 is maintained at all times during insertion of the catheter into the body and while in situ.

In order to assure a permanent setting of this bend in the catheter, its distal end is preferably placed within a rigid arcuately shaped tubular keeper 58 (FIG. 4) whenever the catheter is not is use.

Modifications of the present invention may include the addition of a flexible tubule within the catheter tubing 12 for sampling or otherwise monitoring body fluids in and around the distal end of catheter 10. Such a tubule or capillary (not shown) would of course have one end extended through a side of catheter 10 for communicating with body fluids and the like externally of the catheter. A thin sleeve of translucent material (also not shown) may be placed over face 26 of the catheter should it be desired to have the light emitted from face 26 diffused into a specimen fluid, e.g. blood.

Claims

I claim:

1. In a fiber optic catheter including a catheter tubing having a bundle of light-conducting fibers extending longitudinally thereinto, the improvement comprising:

one end of said bundle of fibers being relatively sharply directed right-angularly within said catheter toward an outer side thereof and brought to a terminus disposed in exposed flush relationship with said outer side of said catheter;

means securing said one end of said fiber bundle fixedly in said catheter; and

said catheter tubing having a section being extended beyond said end of said fiber bundle arcuately about a bend having a center of curvature located approximately forwardly of said exposed terminus of said fiber bundle said section having a closed terminus and further being set to substantially permanently retain said arcuate shape of said bend.

2. In a fiberoptic catheter including a catheter tubing having a bundle of light-conducting fibers extending longitudinally thereinto, the improvement comprising:

said catheter tubing including a main section through which said bundle of light-conducting fibers extends, one end of said bundle of fibers being relatively sharply directed right-angularly within said catheter toward an outer side thereof and brought to a terminus disposed in exposed flush relationship with said other side of said catheter;

said catheter tubing further including a separate shorter section which comprises an extension beyond said one end of said fiber bundle; the terminus of said shorter section of tubing being closed;

a tubular coupling internally of said catheter tubing connecting said main and shorter sections thereof together;

means securing said one end of said fiber bundle fixedly in said catheter; and

said shorter section of catheter tubing being extended beyond said one end of said fiber bundle arcuately about a bend having a center of curvature located approximately forwardly of said exposed fiber bundle terminus.

3. A fiberoptic catheter according to claim 2 wherein the terminus of said shorter section of catheter tubing is closed by an attached smoothly rounded metallic tip and said catheter further includes an electrical lead affixed to said tip and extending efferently therefrom through said catheter.

4. A fiberoptic catheter according to claim 2 wherein said coupling has an opening in one side thereof through which said one end of said bundle of fibers is extended into said exposed flush relationship with said outer side of said catheter.

5. A fiberoptic catheter according to claim 4 wherein said securing means comprises an adhesive potting agent within said coupling, said agent extending around said terminus of said fiber bundle into smoothly finished flush relationship with adjacent outer sides of said main and shorter sections of said catheter tubing.