MXPA99006703A - Double lumen tubing design for catheter - Google Patents

Abstract

A double lumen tubing which is adapted for use as a catheter. The tubing accommodate multiple sized guidewires and has increased resistance to kinking. A lumen wall divides the outer tubular wall into the two lumens and has a central arcuate portion shaped to allow insertion of relatively large guidewires through one of the lumens, while still leaving space for smaller guidewires through the other lumen. Resistance to kinking is increased by varying internal diameters or axes of the interior lumen walls to increase the wall thickness of the tubing in selected areas, and by varying the thickness of the wall that divides both lumens in the middle or where the dividing wall meets the outer tubular wall.

Description

DOUBLE LOMEN PIPE DESIGNED FOR CATHETER BACKGROUND OF THE INVENTION Field of the Invention The present invention relates generally to medical devices which are used to provide access in the human body. More particularly, the present invention is directed to double lumen catheters which are used to provide infusion and / or removal of fluids from the body.

Description of the Related Technique Central venous catheters are relatively broad tubular devices which have narrow distal tips which were designed to enter the central veins to provide a dedicated route of infusion of fluid into the body. The original venous catheters were only lumen devices which provided the ability to infuse a single fluid into the vein at the same time. The multiple lumen catheters have since been developed which allow the introduction Ref .: 30833 simultaneous of two or more fluids in the vein. The dual lumen catheter is a common design which has been widely used for a number of years. Dual lumen catheters include a tubular wall which forms a fluid conduit which normally has a circular cross section. A single wall of lumen or divider is formed within the tubular wall to divide the circular fluid conduit into two lumens. In several examples, it is desirable that the two lumens have cross sectional areas which are substantially the same. For example, equal lumen size is desirable in situations where the ability to provide two ducts with maximized fluid released velocities on both lines is important. Guidewires are usually used to insert and locate catheters within the vascular system. The distal end of the guide wire is normally inserted into the vascular system and moved to the desired location for the catheter. The distal end of the catheter then slides over the guidewire and the catheter inserted in the position as it was oriented by the wire. Once the catheter is in position, the guidewire will be removed. It is important that the dual lumen catheter be designed to accommodate the use of the guide wires. Some dual lumen catheters include separate lumens which are specifically designed to receive the guidewire while others have used one or both of the two lumens of fluid as a lumen of temporary guidewire. One advantage of designing and using a specific fluid lumen to receive the guide wire is that of the total size of the dual lumen catheter that is minimized. This reduces the size of the wound made during the insertion of the catheter into the body and reduces the healing time of the wound. An important consideration in the design of dual lumen catheters is to make the catheter as resistant to bends as possible. In the past, doubling the catheter during insertion into the body has been a major problem. Accordingly, it is desirable that the cross sectional configuration and other design features be chosen for maximum resistance to bending of the catheter. The dual lumen catheters currently available are suitable for their intended purpose. However, there is a continuing need to develop better dual lumen designs. For example, this is a continuing need to provide lumen catheters dual where the cross sectional areas, ie the size, of the lumens are kept considerably similar while at the same time improving the bending strength and compatibility of the guidewire of the dual lumen catheter.

SUMMARY OF THE INVENTION In accordance with one embodiment of the present invention, a dual lumen tubing is provided which is specifically designed to be used as a catheter where the cross sectional areas of the two lumens are substantially equal. The cross sectional design of the dual lumen catheter is such that the size of the lumens is stored therein while increasing the capacity of the catheter to receive guide wires of multiple sizes, In addition, the cross sectional design of the catheter provided to increase the bending resistance. In an alternative embodiment, the increased ability of the catheter to receive multiple size guidewires and increase bending strength is provided in a dual lumen tubing with two lumens having cross sections which are unequal in size even though both are appropriate to receive guide wires or to pass fluid or other instruments. The present invention provides a double lumen tubing adapted for use as a catheter, comprising a tubular wall having an outer surface located on a longitudinal central axis and an inner surface. The inner surface of the cross section is defined by a first circular lumen portion located along a first lumen radius on a first longitudinal axis and a second circular lumen portion located along a second lumen radius on a second longitudinal axis. The pipe further includes a lumen wall extending longitudinally parallel to the central axis and extending transversely through the tubular conduit between the spaced locations on the inner surface. The lumen wall comprises an arcuate central portion and has a first surface which, with the first lumen portion of the inner surface, borders a first lumen, the first lumen has a sectional cross-sectional area. The lumen wall additionally comprises a second opposite surface of the first surface which, with the second lumen portion of the inner surface, borders a second lumen, the second lumen has a cross sectional area. The first surface of the lumen wall has a central convex arcuate portion and the adjacent wing portions extending in opposite directions to the tubular wall, while the second surface of the lumen wall has a central concave arcuate portion and portions of the lumen wall. adjacent wings extending in opposite directions to the tubular wall. The concave arcuate portion is in the form of a circular arc which has a radius that is 50 to 90 percent of the radius of the second lumen portion of the inner surface, and a region of circular primary guiding wire the region is formed in the second lumen bordered on one side by the concave arcuate portion and on the other side by the second lumen portion, the first guidewire region has a radius of 50 to 70 percent of the radius of the second lumen portion. In a specific embodiment, the lumens are substantially equal in cross section and the concave central arcuate portion is in the form of a circular arc having a radius that is 50 to 60 percent of the radius of the second lumen portion of the inner surface. The concave central arcuate portion, when combined with the second portion of lumen form a circular guide wire region in the second lumen which has a radius that is 50 to 60 percent of the radius of the second lumen portion. This particular shape of the lumen wall allows the use of guide wires which are relatively broad with respect to the total cross sectional cross-sectional area of the tubular conduit defined by the tubular wall, while at the same time the cross-sectional areas of the first and second lumens can be considerably the same As an aspect of the present invention, the outer surface of the tubular wall may have a circular cross section which is located concentrically on the inner surface of the tubular wall. In these situations, the bending strength of the pipe is increased by making the radius of the first lumen portion of the inner wall smaller than the radius of the second lumen portion whereby a tubular wall having varying thicknesses is provided. where the thickness of the tubular wall adjacent to the first lumen is greater than the thickness of the tubular wall adjacent to the second lumen. The design of the arched lumen wall results in a larger circumferential section of the tubular wall being unsupported in the first lumen portion unlike of the second lumen portion. Therefore, the increase in thickness in the lumen wall along the first lumen portion provides the increase in bending resistance which is specifically applicable to the feature of the arched lumen wall of Applicants' invention. The particular position and shape of the lumen wall which according to the present invention provides a dual lumen tubing which is particularly a cavity suitable for use as a dual lumen catheter having a relatively broad guidewire compatible and resistant to fold The above discussed and other features and concurrent advantages of the present invention will be better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a cross sectional view of a preferred double lumen pipe according to the present invention.

FIGURE 2 is a cross sectional view of a second preferred dual lumen tubing according to the present invention.

FIGURE 3 is a cross sectional view of a third preferred double lumen tubing according to the present invention.

FIGURE 4 is a cross sectional view of a fourth preferred double lumen pipe according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The double lumen tubing according to the present invention is designed to be used as a catheter. The tubing can be used in any catheter application and as part of any catheter device where a dual lumen tubing required has two lumens with substantially the same cross sectional area. Cross sectional areas are considered to be substantially the same according to the present invention if the larger of the two areas is not more than about 15% wider than the smaller. A preferred exemplified double lumen pipe according to the present invention is generally shown as 10 in FIG. 1. Double lumen tubing 10 includes a tubular wall 12 and a lumen wall 14. The tubular wall 12 has an outer surface 16 and an inner surface 18. The inner surface 18 has a circular cross-section located on a longitudinal central axis 20. The inner surface 18 defines a conduit tubular through which lumen wall 14 extends transversely. The lumen wall 14 also extends parallel to the longitudinal central axis 20. In this preferred embodiment, the outer surface 16 has a circular cross section which is located concentrically on the inner surface 18.

The lumen wall 14 is connected to the tubular wall 12 and formed to divide the total tubular conduit into first and second lumens 30 and 32 which have substantially the same cross-sectional cross-sectional areas. In addition, the lumen wall 14 is formed to provide a pri- mary region of guidewire which allows a relatively broad guidewire to pass through in at least one of the lumens. In the preferred embodiment, the lumen wall 14 is formed to allow a relatively broad guidewire to pass through the second lumen 32. The inner surface 18 is divided into a first portion of lumen 22 and a second lumen portion 24. first lumen portion 22 is located along a first radius of lumen measured from the axis longitudinal central 20 as represented by arrow 26. The second lumen portion is located along a second lumen radius measured from the longitudinal central axis as represented by arrow 28. As an aspect of the present invention, the The first lumen portion radius 26 is smaller than the second lumen radius 28 to provide a tubular wall 12 which has various thicknesses. Specifically, the thickness of the tubular wall 12 adjacent the first lumen 30 is slightly greater than the thickness of the tubular wall 12 adjacent to the second lumen 32. This variation in thickness is due to the differences in radii 26 and 28. According to to the present invention, the strength of the tubular wall 12 increases due to this variation in the thicknesses. As can be seen from FIGURE 1, the thickness of the first lumen portion 22 is greater than the thickness of the second lumen portion 2. The slight increase in thickness of the tubular wall 12 adjacent to the first lumen portion 22 provides a slight increase in the strength of this section of the tubular wall 12, which is not supported when the second lumen 32 is used as a step of guide wire. The increase in the thickness of the tubular wall 12 to the first lumen portion should be relatively less when stored so that they can be maintained considerably equal preferably lumen cross sections. Increasing the thickness of the wall (variations between radii 26 and 28.) are preferably in the range of 0.0254 to 0.0762 mm (0.001 to 0.003 inch) for example, for 7 French type catheters.A proportional increase in the thickness of the wall within this range should provide a discernible increase in bending strength.In order to achieve the above preferences of the cross-sectional area of equal lumen and broad guidewire capabilities, the lumen wall 14 is formed in the arcuate configuration as shows in FIGURE 1. More particularly, the lumen wall 14 has a first surface 34 and a second surface 36. The first surface 34 includes a first central arcuate portion of lumen 38 and two first lumen wing portions 40 and 42 located on opposite sides of the first central arcuate portion of lumen 38. The second surface 36 of the lumen wall 14 also includes a second arc portion. central lumen port 44 and two second lumen wing portions 46 and 48 which are located on opposite sides of the second lumen portion 44. The first and second central arched portions of lumen 38 and 44 are in the form of circular arcs which are concentrically located on an axis 50. According to the present invention, the second central arcuate portion of lumen 44 has a radius 59 measured from the axis 50 which is equal to 50 to 60 percent of the radius 28 of the second lumen portion interior surface 24. The second central arcuate portion of lumen 44, in combination with the second lumen portion 24, defines a region of circular primary guidewire 52 which is shown by the imaginary circular line 54 in the FIGURE. 1. The radius of the guidewire region 52 on the axis 51 is shown by the arrow 56. It should be noted that the central axis 51 of the circular guidewire region 52 does not fall exactly to the central axis 50 by the concentric arcuate portions. from the lumen wall 38 and 44. The preferred radius 56 for the guidewire region 52 is about 52 percent of the radius 28 for the second lumen portion 24 of the inner surface 18. In addition to accepting the guidewires through the guidewire primary region 52, the Double lumen tubing 10 according to the present invention can also receive guide wires through the first lumen 30. For the guide wires to pass through the lumen 30 there must necessarily be a smaller radius for that the guide wires pass through the guide wire region 52. The location through which the guide wires can be passed in the lumen 30 is shown as a secondary region of guide wire 57. The circular edge of the wire region guide 57 is shown by the imaginary circular line 58 which has a radius 60 on the axis 62. Desirably, in the lumen double pipe has considerably equal lumens, the radius of the secondary region of guidewire 57 in the first lumen 30 is between about 60 and 70 percent of the radius of the primary guide wire region 52 to the second lumen 32. The double lumen piping 10 is suitable for use in a wide variety of situations where a dual lumen catheter having two lumens is required with considerably equal cross sectional areas. The unique shape of the mutually arcuate lumen wall 14 provides two lumens with substantially equal cross sectional areas which at the same time also allow the use of relatively large guide wires in the primary guidewire region 52 and / or relatively smaller guidewires in a secondary region of guide wire 57. In addition, the use of a relatively smaller radius for the first portion of lumen 22 of the inner surface 18 increases the thickness of the pipe wall 12 as discussed above to increase the dooiez resistance of the pipe 10. Preferred double lumen pipes are those where the cross sectional area of the first and second lumens is between 0.645 and 3.871 mm2 (0.0010 and 0.0060 in2). Seven double-lumen French type pipes having 16/16 individual lumens coupled are preferred. For one of seven French double lumen pipes, the transversal sectional areas of the first and second lumens are approximately 1,032 mm2 (0.0016 in2). Cross sectional areas of 1.1226 mm2 (0.00174 in2) are also preferred, because this size allows a guide wire of at least 0.889 mm (0.035 inch) in diameter to pass through the lumens. Preferably, the radius 28 of the second lumen portion 24 of inner surface 18 is between about 0.889 and 1.016 mm (0.035 and 0.040 inch). It is preferred that the radius 26 of the first lumen portion 22 of the inner surface 18 is about 0.0254 to 0.0762 mm (0.001 to 0.003 inch) shorter than the radius 28 of the second lumen portion 24. The cross sectional area of the second lumen 32 is desirable between 98% and 115% of the area of first lumen 30, and more preferably the area of the second is within 98% and 100% of the first. The approximate dimensions for a preferred double-lumen and prestressed pipe 10 as shown in FIGURE 1 are as follows. The outer surface radius of the tubular wall 16, as measured from the longitudinal center axis 20 is 1181 mm (0.0465 inch). The radius 26 for the first lumen portion 22 of inner surface 18 is 0.927 mm (0.0365 inch). The radius 28 of the second lumen portion 24 of the inner surface 18 is 0.953 mm (0.0375 inch). The radius 59 of the second central arcuate portion of lumen 44, as measured from the axis 51, is 0.521 mm (0.0205 inch). The radius 56 of the primary guide wire region 52, as measured from the axis 50, is 0.495 mm (0.0195 inch). The radius of the first central arcuate portion of lumen 38 (as measured from axis 50) is 0.749 mm (0.0295 inch). The lumen walls can be made from any of the conventional materials used in making double lumen catheters. Exemplary materials include polyvinyl chloride (PVC), polyurethane, silicone, polyamides, fluoropolymers (for example TEFLON), polyolefins (polyethylene, polypropylene), metallocenes, and elastomers thermoplastics. Polyurethane is the preferred material for use in the manufacture of double lumen pipes according to the present invention. A second preferred embodiment of the present invention is shown generally with numeral 110 in FIGURE 2. The dual lumen tubing 110 is similar to the first tubing embodiment 10 in which both lumens have substantially equal cross sectional areas and both lumens are able to receive a relatively broad guidewire through one of the lumens. The main difference between the two embodiments is that the wing portions of the lumen wall in the pipe 110 are formed differently to provide the supports which are thicker at their point of attachment to the tubular wall. Referring to FIGURE 2, the double lumen tubing 110 includes a tubular wall 112 and a lumen wall 114. The tubular wall 112 has an exterior surface 116 and an interior surface 118. The interior surface 118 has a cross-section located on a longitudinal central axis 120. The inner surface 118 defines a tubular conduit through which the lumen wall 114 extends transversely. The lumen wall 114 also extends parallel to the longitudinal central axis 120.

In this preferred embodiment, the outer surface 116 has a circular cross-section which is located concentrically on the inner surface 118. The lumen wall 114 is connected to the tubular wall 112 and is formed to divide the total tubular conduit into the first and second lumens 130 and 132 which have substantially the same cross sectional areas. In addition, the lumen wall 114 is formed to provide a first region of guidewire which allows a relatively large guidewire to pass through at least one of the lumens. In the preferred embodiment, the lumen wall 114 is formed to allow a relatively wide guidewire to pass through the second lumen 132. The inner surface 118 is divided into a first lumen portion 122 and a second lumen portion 124. The first lumen portion 122 is located along a first lumen radius measured from the longitudinal central axis 120 as represented by the arrow 126. The second lumen portion is located along a second lumen radius measured from the longitudinal central axis as represented by the arrow 128. As was the case with the first embodiment, the first lumen portion radius 126 is smaller than the second radius of lumen 128 to provide a tubular wall 112 which has various thicknesses. Specifically, the thickness of the tubular wall 112 adjacent the first lumen 130 is slightly greater than the thickness of the tubular wall 112 adjacent the second lumen 132. This variation in thickness is due to differences in radii 126 and 128. According to with the present invention, the strength of the tubular wall 112 increases due to this variation in thicknesses. As can be seen from FIGURE 2, the thickness of the first lumen portion 122 is greater than the thickness of the second lumen portion 124. The slight increase of the tubular wall 112 adjacent the second lumen portion 122 provides a slight increase in the strength of this section of the tubular wall, which is not supported if the second lumen 132 is used exclusively as a guidewire passage. In order to achieve the above objectives of substantially equalizing the lumen cross-sectional area and broad guidewire capabilities, the lumen wall 114 is formed in the arcuate configuration as shown in FIGURE 2. More particularly, the lumen wall 114 has a first surface 134 and a second surface 136. The first surface 134 includes a first portion lumen central arcuate 138 and two first lumen wing portions 140 and 142 located on opposite sides of the first central arcuate portion of lumen 138. The second surface 136 of the lumen wall 114 also includes a second lumen central arcuate portion 144. and two second lumen wing portions 146 and 148 which are located on opposite sides of the second arched portion of lumen 144. The first and second central arched portions of lumen 138 and 144 are in the form of circular arcs which are located concentrically on a central axis 150. In accordance with the present invention, the second central arcuate portion of lumen 144 has a radius 159 measured from the axis 150 which is equal to 50 to 60 percent of the radius 128 of the second interior surface of portion of lumen 124. The second central arcuate portion of lumen 144, in combination with the second portion of lumen 124, defines a region of primary guidewire c ircular 152 which is shown by the imaginary circular line 154 in FIGURE 2. The radius 156 of the guide wire region 152, as measured from the central axis 151, and by the second lumen portion 124, is shown by the arrow 156. The preferred radius 156 for the primary guide wire region 152 is approximately 52 percent of the radius 128 for the second portion of lumen 124 of the inner surface 118. In addition to accepting the guide wires through the primary guide wire region 152, the double lumen pipe 110 according to the present invention can also receive the guide wires through the first lumen 130. The guide wires passed through the lumen 130 must necessarily have a smaller radius than the guide wires passed through the guide wire region 152. The location by which the guide wires can be passed into the lumen 130 is shown as in the secondary guide wire region 157. The circular edge of the guide wire region 157 is shown by the imaginary line 158 which has a radius 160 about axis 162. The double lumen pipe 110 is suitable for use in a wide variety of situations where a dual lumen catheter has two lumens with required substantially equal cross-sectional cross-sectional areas. The unique shape of the multi-curved arch lumen wall 114 provides two lumens with substantially equal cross sectional areas which also allow the use of relatively large guidewires in the primary region of guide wire 152 and / or smaller guidewires in the region. secondary 157. In addition, the use of a relatively smaller radius for the first lumen portion of the inner surface 118 increases the thickness of the pipe wall 112 as discussed above to increase the bending strength of the pipe 110. In addition, the lumen wall 114 is formed to provide transition supports 164 and 166 between lumen wall 114 and tubular wall 112 which are thicker than lumen wall 114. These transition supports 164 and 166 provide additional reinforcement for the pipe 110 which increases the strength and resistance for the bending of the pipe. The approximate dimensions for this second mode are the same to that set later for the first mode (FIGURE 1). A third preferred embodiment of the present invention is generally shown at number 210 in FIGURE 3. The dual lumen tubing 210 is similar to the first and second embodiments in that both lumens are capable of receiving a relatively broad guidewire through one of the lumens, and the pipe has increased the strength for bending. The main difference in the third mode is that the interior surfaces of the two lumens, formed in such a way that they have different centers, and the opposing arched surfaces of a wall that separates the lumen are also non-concentric. further, the lumen wall is located next to or slightly offset from a transverse centerline away from the lumen defining a primary region of guidewire so that the lumens are unequal in size even though both are suitable for receiving guidewires or for passing fluid or other instruments. With refce to FIGURE 3, the double lumen pipe 210 includes an outer tubular wall 212 and an inner lumen wall 214. The tubular wall 212 has an outer surface 216 having a circular cross section located along a central axis. longitudinal 220, and an inner surface 218. The inner surface 218 defines a tubular conduit through which the lumen wall 214 extends transversely. The lumen wall 214 also extends longitudinally parallel to the longitudinal central axis 220, and generally transverse along the transverse central line 221. In this embodiment, the outer surface 216 is concentric over only a portion of the inner surface 218 , as explained later. The inner surface 218 is divided into a first lumen portion 222 and a second portion of lumen 222. lumen 224. The first lumen portion 222 is located along a first lumen radius measured from the longitudinal central axis 220 as represented by a radius arrow 226. The second lumen portion 224 is located along a lumen 224. second lumen radius measured from a longitudinal axis 227, as represented by a radius arrow 228. In contrast to the first and second embodiments, the first radius of the lumen portion 226 is equal to the second radius of the lumen portion 228 The longitudinal axis 227 is parallel but offset from the central axis 220 towards the second lumen portion 224, and along the transverse central line 229 perpendicular to the transverse central line 221. Due to this configuration, the tubular wall 212 adjacent to the the first lumen portion 222 is slightly larger than the thickness of the tubular wall 212 adjacent the second lumen portion 224. This variation in thickness is due to the compensation axis 227 of the second a portion of lumen 224, but the thickness variation can alternatively be created by compensating the axis of the first lumen portion 222. Accordingly, the force of the tubular wall 212 in the adjacent region of the first lumen portion 222 is greater than the strength of the tubular wall adjacent to the second portion of lumen 224. This provides the increase of bending strength to tubular wall 212 adjacent to first lumen portion 222, which is not supported if second lumen 232 is used exclusively as a guidewire passage. The lumen wall 214 is connected to the tubular wall 212 and is formed to completely divide the tubular conductor in the first and second lumens 230 and 232. In addition, the lumen wall 214 is formed to provide a primary region of guidewire which it allows the passage of a relatively broad guide wire through at least one of the lumens. In the preferred embodiment, the lumen wall 214 is formed to allow the passage of a relatively large guide wire through the second lumen 232. In order to adapt the capacity of the broad guide wire in one of the lumens, the lumen wall 214 is formed with an arched section; as shown in FIGURE 3. More particularly, the lumen wall 214 has a first surface 234 and a second surface 236, opposite the first surface. The first surface 234 includes a convex arcuate central portion 238 and two adjacent wing portions 240 and 242. The second surface 236 of the lumen wall 214 includes a concave central arcuate portion 244 and two adjacent wing portions 246 and 248.

The concave and convex central arcuate portions 238 and 244 are in the form of circular arcs non-concentrically located on longitudinal axes 250 and 252, respectively, which are offset along the transverse central line 229. More specifically, the arched convex portion 238 it is located on a radius 254 centered on the longitudinal axis 250, and the concave arcuate portion 244 is located on the radius 256 centered on the longitudinal axis 252. The axis 250 is offset toward the second portion of lumen 224 by a predetermined distance as along the center line 229 from the axis 252. The length of the radius 254 is greater than the length of the radius 256 by the distance between the axes 250, 252 plus the thickness of the lumen wall 214 along the centerline 229 The offset between the shafts 250, 252 means that the convex arcuate portion 238 has a wider radius of curvature than the concave arcuate portion 244. Thus, the wall of Lumen 214, in the arched central region, narrows in the center and gradually thickens towards the adjacent wings. Furthermore, as seen in FIGURE 3, the wings are considerably thicker than any section of the central arched portion, which increases the bending strength of the pipe 210 while maximizing the cross sectional area of 230 lumens, 232 along the transverse center line 229. This provides a maximum space to pass the wide guide wires through the lumens 230, 232. The concave central arcuate portion 244, in combination with the second lumen portion 224, defines a region of circular primary guidewire 258 which is shown by the imaginary circle in the second lumen 232. The guidewire region 258 is centered on or near the axis 250 of the concave arcuate portion 244. Preferably the radius of the region of guidewire 258 is slightly smaller than the radius of the concave arcuate portion 244. To ensure a large area for the primary guidewire region 258, the lumen wall 214 is located adjacent to the transverse centerline 229 and the concave arcuate central portion. 244 having a radius which is desirable between about 50% and 70% of the radius of the second lumen portion 224. Accordingly, the guide wire region 258 it has a radius which is also desirable between about 50% and 70% of the radius of the second portion of lumen 224, although slightly less than the radius of the concave central arcuate portion 244.

This preferred radius is only one example, and moderate divergences of the preferred range may still be useful, and serve the purposes of providing a two lumen pipe with a broad guide wire space formed in one, an improved bending strength, and preferably a relatively large space in the other lumen to pass fluids or devices. For example, the fourth embodiment shown in FIGURE 4 has a second larger lumen than any of the first three embodiments, and the concave central arcuate portion is compensated from the primary guide wire region centered with a radius of 70% greater than the radius of the second, lumen portion. In addition the guide wires are accepted through the primary wire region 258, the double lumen pipe 210 according to the present invention can also receive the guide wires through the first lumen 230. The guide wires passed through the lumen 230 must necessarily have a smaller radius than the guide wires passed through the minor guide wire region 258. The location by which the guide wires can be passed in the lumen 230 is shown with a secondary region of guide wire 260, the which is shown by the imaginary circle in the first lumen 230. In a preferred embodiment, the secondary guidewire region 258 has a radius which is approximately 40% to 60% of the radius of the primary guide wire region 258. In an exemplary embodiment of the double lumen tubing 210 of FIGURE 3, the tubular wall 212 has an OD of 2.54 mm (0.100 inch), the first lumen portion 222 has a radius of 1.016 mm (0.040 inch), the second lumen portion 224 also has a radius of 1.016 mm (0.040 inch), the convex central arched portion 238 has a radius of 0.914 mm (0.036 inch), the concave central arcuate portion 244 has a radius of 0.868 mm (0.027 inch), and shafts 250 and 252 are spaced apart by 0.102 mm (0.004 inch). The primary region of guide wire 258 has a radius of 0.635 mm (0.025 inch), and the secondary region of guide wire 260 has a radius of 0.336 mm (0.014 inch), or approximately 53% of the radius of the primary wire region guide. The cross sectional area of the first lumen 230 is of 1. 232 mm2 (.00194 in2), while the cross sectional area of the second lumen 232 is 1,796 mm2 (.00278 in2), or approximately 1.4 times the area of the first lumen.

A fourth preferred embodiment of the present invention is generally shown in No. 310 of FIGURE 4. The dual lumen tubing 310 is similar to the first, second and third embodiments in that both lumens are capable of receiving a relatively large guide wire. through one of the lumens, and the pipe has increased the resistance to bending. The main difference in the fourth embodiment is that the opposite arched surfaces of a wall separating the lumen are not concentric, and the lumens defined therein have considerably different cross sections. Additionally, the lumen wall is compensated from a transverse centerline away from the lumen defining a primary region of guidewire so that the lumens are unequal in size even though both are suitable for receiving guidewires or for passing fluid or other instruments. With reference to FIGURE 4, the double lumen tubing 310 includes an outer tubular wall 312 and an inner lumen wall 314. The tubular wall 312 has an outer surface 316 having a transverse circular section located along a central axis. longitudinal 320, and an inner surface 318. The inner surface 318 defines a tubular conductor a through which the lumen wall 314 extends transversely. The lumen wall 314 also extends longitudinally parallel to the longitudinal central axis 320, and transversely generally parallel to the central line 321. In this mode, the outer surface 316 is concentric on the inner surface 318. The inner surface 318 is divided into a first lumen portion 322 and a second lumen portion 324. The first lumen portion 322 is located along a first radius of lumen (not shown) measured from the longitudinal central axis 320. The second lumen portion 324 is located along the second lumen radius measured from the measurement of the longitudinal central axis 320, as represented by an arrow of radius 328. In In contrast to the first and second embodiments, the first radius of the lumen portion is equal to the second radius of the lumen portion 328. The lumen wall 314 is connected to the tubular wall 312 and formed to divide the tubular conduit completely into the first and second lumens 330 and 332. In addition, the lumen wall 314 is formed to provide a primary region of guidewire that allows the passage of a relatively broad guide wire through at least one or of the lumens. In the preferred mode, the lumen wall 314 is formed to allow a relatively broad guidewire to pass through the second lumen 332. In order to adapt the guide wire capacity in one of the lumens, the lumen wall 314 is formed with a section arched as shown in Figure 4. More particularly, the lumen wall 314 has a first surface 334 and a second surface 336, opposite the first surface. The first surface 334 includes a convex central arcuate portion 338 and two adjacent wing portions 340 and 342. The second surface 336 of the lumen wall 314 includes a concave central arcuate portion 344 and two adjacent wing portions 346 and 348. concave and convex central arches 344 and 338 are in the form of non-concentric circular arcs located on the longitudinal axes 350 and 352, respectively, which are offset along the transverse central line 329 perpendicular to the transverse central line 321. More specifically , the convex arcuate portion 338 is located on a radius 354 centered on the longitudinal axis 350, and the concave arcuate portion 344 is located on the radius 356 centered on the longitudinal axis 352. The axis 350 is offset to the wall of lumen 314 at a predetermined distance along the centerline 329 of the axis 352. The length of the radius 354 is approximately equal to the length of the radius 356. The offset between the axes 350, 352 means that the lumen wall 314 has a thickness in the central arched region which is slightly larger in the center than in the adjacent wings. In addition, as seen in FIGURE 4, the wings are slightly thinner than any section of the central arched portion. The thickness of the wings can be manipulated in conjunction with the thickness of the central arched region to ensure a good bending strength of the pipe. Thus, if the central portion is built relatively thin, the wings can be increased in size to compensate, and vice versa. Alternatively, the thickness through the entire lumen wall can be relatively constant. The concave central arcuate portion 344, in combination with the second lumen portion 324, defines a circular primary region of guide wire 358 which is shown by the imaginary circle in the second lumen 332. The guidewire region 358 is centered between the axes 350 and 352. Preferably the radius of the guide wire region 358 is slightly smaller than the radius of the concave arcuate portion 344. To secure a long area for the primary guidewire region 358, the lumen wall 314 is compensated from the transverse centerline 329 toward the first lumen portion 322 and the concave central arcuate portion 344 having a radius 356 which adapts a radius of the guide wire region 358 desirably between about 50% and 70% of the radius of the second lumen portion 324. In the embodiment shown, the axis 352 of the concave arcuate portion 344 it is compensated away from the lumen wall 314, and the radius 356 is necessarily wider than the radius of the guide wire region 358, and conceivably wider than 70% of the radius of the second lumen portion 324. In addition to accepting The guide wires through the primary guide wire region 358, the double lumen pipe 310 according to the present invention can also receive the guide wires through the first lumen 330. Guide wires that pass through lumen 330 must necessarily have a smaller radius than the guide wires that pass through the minor guide wire region 358. The location by which the guide wires can be passed in lumen 330 is shown in FIG. the secondary region of guidewire 360, which is shown by an imaginary circle in the first lumen 330. In a preferred embodiment, the secondary guide wire region 358 has a radius which is approximately 40% to 60% of the radius of the first guidewire region 358. In an exemplary embodiment of the lumen tubing double 310 of FIGURE 4, the tubular wall 312 has an OD of 2.54 mm (0.100 inch), the first and second lumen portions 322, 324 each have a radius of 1.016 mm (0.040 inch), the convex central arched portion 338 has a radius of 0.813 mm (0.032 inch), the concave central arcuate portion 344 has a radius of 0.838 mm (0.033 inch), and axes 350 and 352 are spaced apart by 0.178 mm (0.007 inch). The primary guide wire region 353 has a radius of 0.686 mm (0.027 inch), and the secondary guide wire region 360 has a radius of 0.279 mm (0.011 inch), or approximately 40% of the radius of the primary wire region guide. The cross sectional area of the first lumen 330 is 0.843 mm2 (.00131 in), while the cross sectional area of the second lumen 332 is 2.141 mm2 (.00332 in2), or approximately 2.5 times (254%) the area of the first lumen. . The double lumens according to the present invention use in an improved manner the area available from the tubular cross-section of the total lumen to provide maximum lumen areas for flow, and the walls required to provide a structure that is sufficiently resistant to bending, without wearing away any additional area. This double lumen configuration provides the maximum possible flow rates for the two lumens with minimal risk of the tube bending and restricting fluid flow. Having thus described the exemplified embodiments of the present invention, it should be noted that by that skill in the technique of the descriptions are even only examples and that other alternatives, adaptations and modifications can be made within the scope of the present invention. Accordingly, the present invention is not limited to the specific embodiments as illustrated herein. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers. Having described the invention as above, property is claimed as contained in the following:

Claims (21)

1. A double lumen tubing adapted to be used as a catheter, the double lumen tubing characterized in that it comprises: a tubular wall having an outer surface located on a longitudinal central axis and an inner surface, the cross section of the inner surface is defined by a first portion of a circular lumen located along a first lumen radius on a first longitudinal axis and a second portion of a circular lumen located along a second lumen radius on a second longitudinal axis; and a lumen wall extending longitudinally parallel to the central axis and extending transversely through the tubular conduit between the spaced locations on the inner surface, the lumen wall comprises a central arched portion and has a first surface which, with the first lumen portion of the inner surface borders a first lumen, the first lumen has a sectional cross-sectional area, the lumen wall additionally comprises a second opposing surface of the first surface which, with the second portion of lumen of the inner surface, borders a second lumen, the second lumen has a sectional cross-sectional area, the first surface of the lumen wall has a central convex arcuate portion and the adjacent wing portions extending in opposite directions to the tubular wall , the second surface of the lumen wall has a central concave arcuate portion and the adjacent wing portions extending in opposite directions to the tubular wall, wherein the concave arcuate portion is in the form of a circular arc which has a radius which is from 50 to 90 percent of the radius of the second lumen portion of the inner surface, and wherein a region of circular primary guide wire is formed in the second lumen bordered on one side by the concave arcuate portion and on the other side by the second lumen portion, the first guide wire region has a radius from 50 to 70 percent of the radius of the second lumen portion.

2. A double lumen pipe according to claim 1, characterized in that the outer surface has a circular cross-section concentrically located on the inner surface and wherein the radius of the first portion of lumen is smaller than the radius of the second portion of lumen for which a tubular wall having several thicknesses is provided wherein the thickness of the tubular wall adjacent to the first lumen is greater than the thickness of the tubular wall adjacent to the second lumen ,

3. A double lumen pipe according to claim 1, characterized in that the outer surface has a circular cross-section non-concentrically located on a portion of the inner surface for thereby providing a tubular wall having various thicknesses where the thickness of The tubular wall adjacent to the first lumen is greater than the thickness of the tubular wall adjacent to the second lumen.

4. A double lumen pipe according to claim 3, characterized in that the central axis is coincident with the first longitudinal axis and the second longitudinal axis is compensated for and towards the second lumen portion.

5. A double lumen pipe according to claim 1, characterized in that the concave arched portion is located with respect to the second lumen portion of the inner surface so that the primary guidewire region has a radius of between about 50 and 60 percent of the radius of the second lumen portion.

6. A double lumen pipe according to claim 5, characterized in that the concave arcuate portion is in the form of a circular arc having a radius between about 50 and 60 percent of the radius of the second lumen portion.

7. A double lumen pipe according to claim 1, characterized in that the concave arcuate portion is not concentric over the first region of guide wire.

8. A double lumen tubing according to claim 1, characterized in that the concave arcuate portion and the convex arcuate portion of the lumen wall is formed so that the central arcuate portion of the lumen wall has a variable thickness.

9. A double lumen pipe according to claim 8, characterized in that the portion Concave arcuate is not concentric with respect to the convex arcuate portion.

10. A double lumen pipe according to claim 8, characterized in that the central arched portion is thicker in the middle part.

11. A double lumen pipe according to claim 8, characterized in that the central arched portion is ter in the middle part.

12. A double lumen pipe according to claim 1, characterized in that the wing portions of the first and second opposing surfaces of the divergence of the lumen wall while they approach the inner surface of the tubular wall to provide a resistance of additional fold to the double lumen tubing.

13. A double lumen pipe according to claim 1, characterized in that the wing portions of the first and second opposite surfaces of the lumen wall are greater in thickness than the thickness of the central arched portion for provide an additional bending resistance to the lumen piping.

14. A double lumen pipe according to claim 1, characterized in that the concave arcuate portion has a wider radius than the primary region of guide wire.

15. A double lumen tubing according to claim 1, characterized in that the cross sectional area of the second lumen is between about 98% to about 254% of the cross sectional area of the first lumen.

16. A double lumen tubing according to claim 15, characterized in that a circular secondary guide wire region is formed in the first lumen bordered by the convex arcuate portion and the first lumen portion which has a radius of 40 to 60 percent of the radius of the primary region of guide wire.

17. A double lumen tubing according to claim 15, characterized in that the cross sectional area of the second lumen is considerably equal to the cross sectional area of the first lumen.

18. A double lumen tubing according to claim 17, characterized in that the cross sectional area of the second lumen is between about 98% to about 115% of the cross sectional area of the first lumen.

19. A double lumen tubing according to claim 17, characterized in that the circular secondary guide wire region is formed in the first lumen bordered by the convex arcuate portion and the first lumen portion which has a radius of 60 to 70 percent of the radius of the primary region of guide wire.

20. A guide wire introduction system characterized in that it comprises a double lumen pipe according to claim 19, and a guide wire located witthe secondary guidewire region.

21. A guide wire introduction system characterized in that it comprises a double lumen pipe according to claim 1, and a guide wire located witthe primary region of guide wire. SUMMARY OF THE INVENTION A double lumen tube which is adapted to be used as a catheter. The pipe adapts guide wires of multiple sizes and has an increased resistance to bending. A lumen wall divides the outer tubular wall into the two lumens and has a central arcuate portion formed to allow the insertion of relatively large guide wires through one of the lumens, while still leaving room for smaller guide wires through the another lumen. The resistance to bending is increased by internal variable diameters or axes of the inner lumen walls for the wall thickness of the pipe in selected areas, and by varying thicknesses of the wall that divides both lumens in the middle part or where the dividing wall meets the external tubular wall. 2/4