IE84154B1 - A catheter - Google Patents

Abstract

ABSTRACT A catheter (1) has an elongate tube (2) having an open proximal end for connection to a medication fluid supply and a closed distal end (3) for deployment in an anatomical region of a patient for controlled dispensing of the medication in the anatomical region. A plurality of spaced—apart fluid discharge openings (4) extends through the side wall (5) of the tube (2) at the distal end (3). A flexible support spiral coil spring (6) is mounted within the distal end (3) of the tube (2) to support the distal end of the tube (2) whilst allowing flexing of the distal end (3) of the tube (2).

Description

"A catheter" This invention relates to medical catheters, and in particular to a catheter for delivery of a fluid medication to an anatomical region.

Various types of infusion catheter for delivering liquid medication to anatomical regions of the human body are known. Basically, these comprise a catheter having a proximal end which is adapted for connection to a fluid medicine supply source or reservoir. Said fluid medicine is delivered through the bore of the catheter to a distal end of the catheter. A number of spaced-apart discharge holes are provided in the side wall of the catheter at the distal end of the catheter for dispensing the fluid medicine. A problem can arise with kinking of the distal end of the catheter during insertion of the catheter into the body of the patient and also when deployed at a desired anatomical region within the patients body which can adversely effect the delivery of the liquid medicine to said anatomical region.

The present invention is directed towards overcoming this problem.

According to the invention there is provided a drug delivery catheter for controlled dispensing of a medication fluid in an anatomical region, including: a tube, said tube having an open proximal end and a closed distal end, said proximal end for connection to a medication fluid supply, and said distal end for deployment in the anatomical region, a plurality of spaced—apart fluid discharge openings extending through a side wall of the tube at the distal end of the tube, and a flexible support means mounted within the tube at said distal end of the tube to support the distal end of the tube whilst allowing flexing of said distal end of the tube with a view to resisting kinking of the distal end of the tube in use, the flexible support means being a coil spring having an open construction to allow through passage of the fluid medication between coils of the spring, the coil spring being retained at the distal end of the tube by having an outermost end of the coil spring embedded in or fused with a closed end portion or tip of the tube. Thus the coil spring provides support for the distal end of the catheter whilst at the same time not interfering with the flow of the medication.

Various other methods may be employed for retaining the coil spring at the distal end of the tube to prevent movement or displacement of the coil from the distal portion of the catheter. in another embodiment the spring is housed solely in the distal end of the tube. The spring extends throughout the outermost end of the tube and may conveniently be of length in the order 100-300mm. Typically for example the spring might have a length in the order of 200mm. That is, the spring purely extends through the outermost 200mm or so of the catheter. in another embodiment adjacent discharge openings in the distal end of the tube are both axially and circumferentially displaced from each other. That is, they are spacedgapart around the circumference of the tube. in a further embodiment the discharge openings have a diameter not greater than 0.001 inches (0.0254mm) or an equivalent cross sectional area if not round.

Preferably the diameter of the discharge openings is in the range 0.0005 inches (0.0t27mm) to 0.0008 (0.02032mm) and most preferably the diameter is about .0006 inches (0.01524mm) or have a corresponding cross-sectional area. in another embodiment the discharge openings are of uniform size.

Alternatively, if desired the discharge openings may be of variable size with the discharge openings located towards the proximal end being of smaller size than the discharge openings adjacent the tip of the distal end of the catheter.

Ld C .) In another embodiment the coils of the spring are of rectangular section in the order of 0.003 inches (0.0762mm) by 0.0015 inches (0.0381mm).

The invention will be more clearly understood by the following description of some with reference to the accompanying drawing which is an enlarged sectional elevational view of a distal end of a drug delivery catheter of the invention. embodiments thereof, given by way of example only, Referring to the drawing, there is illustrated a drug delivery catheter according to the invention indicated generally by the reference numeral 1. The catheter 1 has an elongate tube 2 having an open proximal end (not shown) and a closed distal end indicated generally by the reference numeral 3. The proximal end of the tube 2 is for connection to a medication fluid supply and the distal end 3 is for deployment in an anatomical region of a patient for controlled dispensing of the medication in the anatomical region. A plurality of spaced-apart fluid discharge openings 4 extend through a side wall 5 of the tube 2 at the distal end 3 of the tube 2 for discharge of liquid medication delivered through the tube 2 into the anatomical region of a patient in which the distal end 3 of the tube 2 is deployed. A flexible support spiral coil spring 6 is mounted within the distal end 3 of the tube 2 to support the distal end of the tube 2 whilst allowing flexing of the distal end 3 of the tube 2. This support spring 6 advantageously provides additional support in the distal end 3 of the tube 2 to resist kinking of the distal end 3 of the tube 2 during use either when inserting the catheter 1 into a patient or while it is in situ in the patient.

The tube 2 may typically be formed of a plastics material such as polyethylene or polypropylene. The tube 2 has a bore 7 extending through the tube 2 for delivery of a liquid medication from a medication supply source or resen/oir to the distal end 3 of the tube 3. The distal end 3 of the tube 2 has a closed outer end 8 which is rounded on the exterior which aids delivery to the anatomical region.

The discharge openings 4 are both axially and circumferentially displaced from each other. These openings 4 are preferably laser drilled holes sized in the range 0.0005 inches (0.0127mm) to 0.0008 inches (0.02032mm) diameter and most preferably have a diameter of about 0.0006 inches (0.0152mm). The holes 4 are located at a dispensing portion at an outermost end of the distal end 3 which may for example be of length in the order of 200mm.

The spiral coil support spring 6 is of stainless steel material and preferably the coils of the spring are of rectangular section in the order of 0.003 inches (0.0762mm) by 0.0015 inches (0.0381mm). An outer end 10 of the spring 6 is fused with or embedded in the outer end 8 of the distal end 3 of the catheter 1. It will be noted that the spring 6 is of an open configuration which allows a free flow of medication fluid between the coils for discharge through the openings 4.

In use, the distal end 3 of the catheter 1 is inserted into the anatomical region of a patient in the usual fashion. Fluid medication is delivered through the bore 7 of the tube 2 and is discharged through the openings 4 in a controlled manner for delivery of the medication to the anatomical region of the patient. it will be noted that during insertion of the catheter 1 and during use the spring 6 provides support for the tube 2 preventing kinking or collapse of the tube 2 to ensure a free flow of medication liquid through the bore 7 for discharge through the openings 4. it will be appreciated that the coil spring maintains the shape of the distal end of the tube and prevents kinking. This is advantageous both during deployment of the catheter and during use so that the flow of medication to the distal end of the catheter and outwardly through the discharge holes is not adversely effected and proceeds in a controlled manner for an even distribution of the medication at the anatomical region.

While the spring in the preferred embodiment described above is of stainless steel, it may be possible to use other materials such as plastics providing they provide the desirable support and flexibility. Any suitable material may be used for the tube.

Typically the tube will be of plastics material such as are suitable for medical use, many of which are readily known and available to those skilled in the art.

The invention is not limited to the embodiment hereinbefore described which may be varied in both construction and detail within the scope of the appended claims.

Claims (4)

1. A drug delivery catheter for controlled dispensing of a medication fluid in an anatomical region, including: a tube, said tube having an open proximal end and a closed distal end, said proximal end for connection to a medication fluid supply, and said distal end for deployment in the anatomical region, a plurality of spaced-apart fluid discharge openings extending through a side wall of the tube at the distal end of the tube, and a flexible support means mounted within the tube at said distal end of the tube to support the distal end of the tube whilst allowing flexing of said distal end of the tube with a view to resisting kinking of the distal end of the tube in use, the flexible support means being a coil spring having an open construction to allow through passage of the fluid medication between coils of the spring, the coil spring being retained at the distal end of the tube by having an outermost end of the coil spring embedded in or fused with a closed end portion or tip of the tube.

2. A catheter as claimed in claim 1 wherein the spring has a length in the range 100—300mm.

3. A catheter as claimed in claim 2 wherein the spring is 200mm long.

4. A catheter as claimed in any preceding claim wherein the discharge openings have a diameter not greater than 0.001 inches (0.0254mm) or have an equivalent cross-sectional area, A catheter as claimed in claim 4 when the discharge openings have a diameter in the range 0.0005 inches (0.0127mm) to 0.0008 inches (0.02032mm). A catheter as claimed in any preceding claim wherein the discharge openings have a diameter of about 0.0006 inches (0.01524mm). A catheter as claimed in any preceding claim wherein the discharge openings are of uniform size. A catheter as claimed in any of claims 1 to 6 wherein the discharge openings are of variable size. A catheter as claimed in claim 8 wherein the discharge openings located towards the proximal end of the tube are of smaller size than the discharge openings adjacent to the tip of the distal end of the catheter. A catheter as claimed in any preceding claim wherein the coils of the spring are of rectangular section in the order of 0.003 inches (0.0762mm) by 0.0015 inches (0.0381 mm). A catheter substantially as hereinbefore described with reference to the accompanying drawings.