Dual lumen catheter

Claim 2

A dual lumen catheter for use in a vein to remove blood and to return treated blood to the vein comprising: a flexible elongate body having first and second portions; the first portion having a first cross-sectional area, a distal end, a proximal end, an outer wall and a continuous septum extending internally between spaced points on the outer wall to define D-shaped first and second passageways; the second portion being tubular and having a second cross-sectional area smaller than said first cross-sectional area, a distal end with a cross-sectional area that reduces gradually to form a tip having an end opening, a proximal end, and an outer wall; the distal end of the first portion being merged smoothly with the proximal end of the second portion at a transition portion which converges in cross-section from the first portion to the second portion; the first passageway being closed at the transition portion to form a first lumen having a distal end at the transition portion; at least one aperture at the distal end of the first lumen in the outer wall of the first portion providing access for blood into the first lumen; the second passageway meeting the tubular second portion at the transition portion to form a second lumen which terminates at said end opening to permit treated blood to be returned to the vein; and means coupled to the proximal end of the first portion to receive blood from the first lumen and to return treated blood to the second lumen.

Claim 3

A catheter as claimed in claim 1, in which apertures are provided in the outer wall of the second portion for enhanced blood flow between the second lumen and the vein.

Claim 4

A catheter as claimed in claim 1, in which apertures are provided in the outer wall of the second portion at the tip for enhanced blood flow between the second lumen and the vein and to impart greater flexibility to the tip.

Claim 5

A catheter as claimed in claim 1, in which a plurality of apertures are provided in the outer wall of the first lumen for enhanced blood flow between the first lumen and the vein.

Claim 6

A dual lumen catheter as claimed in claim 1, in which the second portion is more flexible than the first portion.

Claim 7

A dual lumen catheter as claimed in claim 1, in which the first and second portions are of different Durometer.

Claim 8

A catheter as claimed in claim 1, in which the first and second portions are formed of polyurethane having different physical properties, the material of the second portion having greater flexibility than the material of the first portion.

Claim 9

A catheter as claimed in claim 7, in which the first and second portions are of materials of different colours, each colour indicating the properties of the material.

Claim 10

A dual lumen catheter for use in a vein to remove blood and to return treated blood to the vein comprising: a flexible elongate body having first and second portions; the first portion having a first cross-sectional area, a distal end, a proximal end, an outer wall and a continuous septum extending internally between spaced points on the outer wall to define D-shaped first and second passageways; the second portion being tubular and having a second cross-sectional area smaller than said first cross-sectional area, a distal end with a cross-sectional area that reduces gradually to form a tip having an end opening, a proximal end, and an outer wall; the distal end of the first portion being merged smoothly with the proximal end of the second portion at a transition portion which converges in cross-sectional from the first portion to the second portion; a thickening of material of the outer walls of the first and second portions at the transition portion; the first passageway gradually converging towards the transition portion and terminating at the transition portion to form a first lumen having a distal end at the transition portion; at least one aperture at the distal end of the first lumen in the outer wall of the first portion providing access for blood into the first lumen so that the blood may flow without stagnation; the second passageway meeting the tubular second portion at the transition portion to form a second lumen which terminates at said end opening to permit treated blood to be returned to the vein; and means coupled to the proximal end of the first portion to receive blood from the first lumen and to return treated blood to the second lumen.

Claim 11

A dual lumen catheter for use in a vein to remove blood and to return treated blood to the vein comprising: a flexible elongate body having first and second portions; the first portion having a first cross-sectional area, a distal end, a proximal end, an outer wall and a continuous septum extending internally between spaced points on the outer wall to define D-shaped first and second passageways; the second portion being tubular and having a second cross-sectional area smaller than said first cross-sectional area, a distal end with a cross-sectional area that reduces gradually to form a tip having an end opening, a proximal end, and an outer wall; the distal end of the first portion being merged smoothly with the proximal end of the second portion at a transition portion which converges in cross-sectional from the first portion to the second portion; a thickening of material of the outer walls of the first and second portions at the transition portion; the first passageway gradually converging towards the transition portion and terminating at the transition portion to form a first lumen having a distal end at the transition portion; at least one aperture at the distal end of the first lumen in the outer wall of the first portion providing access for blood into the first lumen so that the blood may flow without stagnation; the second passageway meeting the tubular second portion at the transition portion to form a second lumen which terminates at said end opening to permit treated blood to be returned to the vein; and means coupled to the proximal end of the first portion to receive blood from the first lumen and to return treated blood to the second lumen.

Claim 12

A catheter as claimed in claim 9, in which apertures are provided in the outer wall of the second portion for enhanced blood flow between the second lumen and the vein.

Claim 13

A catheter as claimed in claim 9, in which apertures are provided in the outer wall of the second portion at the tip for enhanced blood flow between the second lumen and the vein and to impart greater flexibility to the tip.

Claim 14

A catheter as claimed in claim 9, in which a plurality of apertures are provided in the outer wall of the first lumen for enhanced blood flow between the first lumen and the vein.

Claim 15

A dual lumen catheter as claimed in claim 9, in which the second portion is more flexible than the first portion.

Claim 16

A dual lumen catheter as claimed in claim 9, in which the first and second portions are of different Durometer.

Claim 17

A catheter as claimed in claim 9, in which the first and second portions are formed of polyurethane having different physical properties, the material of the second portion having greater flexibility than the material of the first portion.

Claim 18

A catheter as claimed in claim 9, in which the first and second portions are of materials of different colours, each colour indicating the properties of the material.

Claim 19

A dual lumen catheter for use in a vein to remove blood and to return treated blood to the vein comprising: a flexible elongate body having first and second portions; a first portion having a first cross-sectional area, a distal end, a proximal end, an outer wall and a continuous septum extending internally between spaced points on the outer wall to define D-shaped first and second passageways; the second portion having first and second parts, the first part being tubular and more flexible than said first portion and having a second cross-sectional area smaller than said first cross-sectional area, a distal end with a cross-sectional area that reduces gradually to form a tip having an end opening, a proximal end, and an outer wall; the second part being tubular and having a third cross-sectional area smaller than said first cross-sectional area, a distal end, a proximal end, and an outer wall; the distal end of the first portion being merged smoothly with the proximal end of the second part at a first transition portion which converges in cross-sectional from the first portion to the second portion; the distal end of the second part being merged smoothly with the proximal end of the first part at a second portion; the first passageway being closed at the first transition portion to form a first lumen having a distal end at the first transition portion; at least one aperture at the distal end of the first lumen in the outer wall of the first portion providing access for blood into the first lumen; the second passageway meeting the tubular second part at the first transition portion and the tubular second part meeting the tubular first part at the second transition portion to form a second lumen which terminates at said end opening to permit treated blood to be returned to the vein; and means coupled to the proximal end of the first portion to receive blood from the first lumen and to return treated blood to the second lumen.

Claim 20

A dual lumen catheter for use in a vein to remove blood and to return treated blood to the vein comprising: a flexible elongate body having first and second portions; a first portion having a first cross-sectional area, a distal end, a proximal end, an outer wall and a continuous septum extending internally between spaced points on the outer wall to define D-shaped first and second passageways; the second portion having first and second parts, the first part being tubular and more flexible than said first portion and having a second cross-sectional area smaller than said first cross-sectional area, a distal end with a cross-sectional area that reduces gradually to form a tip having an end opening, a proximal end, and an outer wall; the second part being tubular and having a third cross-sectional area smaller than said first cross-sectional area, a distal end, a proximal end, and an outer wall; the distal end of the first portion being merged smoothly with the proximal end of the second part at a first transition portion which converges in cross-sectional from the first portion to the second portion; the distal end of the second part being merged smoothly with the proximal end of the first part at a second portion; the first passageway being closed at the first transition portion to form a first lumen having a distal end at the first transition portion; at least one aperture at the distal end of the first lumen in the outer wall of the first portion providing access for blood into the first lumen; the second passageway meeting the tubular second part at the first transition portion and the tubular second part meeting the tubular first part at the second transition portion to form a second lumen which terminates at said end opening to permit treated blood to be returned to the vein; and means coupled to the proximal end of the first portion to receive blood from the first lumen and to return treated blood to the second lumen.

Claim 21

A dual lumen catheter for use in a vein to remove blood and to return treated blood to the vein comprising; a flexible elongate body having first and second portions; a first portion having a first cross-sectional area, a distal end, a proximal end, an outer wall and a continuous septum extending internally between spaced points on the outer wall to define D-shaped first and second passageways; the second portion having first and second parts, the first part being tubular and more flexible than said first portion and having a second cross-sectional area smaller than said first cross-sectional area, a distal end with a cross-sectional area that reduces gradually to form a tip having an end opening, a proximal end, and an outer wall; the second part being tubular and having a third cross-sectional area smaller than said first cross-sectional area, a distal end, a proximal end, and an outer wall; the distal end of the first portion being merged smoothly with the proximal end of the first part at a first transition portion which converges in cross-section from the first portion to the second portion; the distal end of the second part being merged smoothly with the proximal end of the first part at a second transition portion; a thickening of material of the outer walls of the first and second portions at the first transition portion; the first passageway gradually converging towards the first transition portion and terminating at the first transition portion to form the first lumen having a distal end at the first transition portion; at least one aperture at the distal end of the first lumen in the outer wall of the first portion providing access for blood into the first lumen so that the blood may flow without stagnation; the second passageway meeting the tubular second part at the first transition portion and the tubular first part meeting the tubular second part at the second transition portion to form a second lumen which terminates at said end opening to permit treated blood to be returned to the vein; and means coupled to the proximal end of the first portion to receive blood from the first lumen and to return treated blood to the second lumen.

Claim 22

A dual lumen catheter for use in a vein to remove blood and to return treated blood to the vein comprising; a flexible elongate body having first and second portions; a first portion having a first cross-sectional area, a distal end, a proximal end, an outer wall and a continuous septum extending internally between spaced points on the outer wall to define D-shaped first and second passageways; the second portion having first and second parts, the first part being tubular and more flexible than said first portion and having a second cross-sectional area smaller than said first cross-sectional area, a distal end with a cross-sectional area that reduces gradually to form a tip having an end opening, a proximal end, and an outer wall; the second part being tubular and having a third cross-sectional area smaller than said first cross-sectional area, a distal end, a proximal end, and an outer wall; the distal end of the first portion being merged smoothly with the proximal end of the first part at a first transition portion which converges in cross-section from the first portion to the second portion; the distal end of the second part being merged smoothly with the proximal end of the first part at a second transition portion; a thickening of material of the outer walls of the first and second portions at the first transition portion; the first passageway gradually converging towards the first transition portion and terminating at the first transition portion to form the first lumen having a distal end at the first transition portion; at least one aperture at the distal end of the first lumen in the outer wall of the first portion providing access for blood into the first lumen so that the blood may flow without stagnation; the second passageway meeting the tubular second part at the first transition portion and the tubular first part meeting the tubular second part at the second transition portion to form a second lumen which terminates at said end opening to permit treated blood to be returned to the vein; and means coupled to the proximal end of the first portion to receive blood from the first lumen and to return treated blood to the second lumen.

Claim 23

A flexible dual lumen catheter comprising: an intake lumen having a side opening to receive fluid for extraction; and a return lumen having a portion extending longitudinally beyond the intake lumen, said portion terminating at an opening to return said fluid, and said portion having a flexibility greater than that of the remainder of the catheter.

Claim 24

A flexible dual lumen catheter comprising: an intake lumen having a side opening to receive fluid for extraction; and a return lumen having a portion extending longitudinally beyond the intake lumen, said portion terminating at an opening to return said fluid, and said portion having a flexibility greater than that of the remainder of the catheter.

Claim 25

A flexible dual lumen catheter as claimed in claim 19, in which the intake lumen terminates adjacent said portion with a cross-section reducing in the direction of said portion.

Claim 26

A flexible dual lumen catheter as claimed in claim 19, in which said portion is of a material different from the material of the remainder of the catheter.

Claim 27

A flexible dual lumen catheter having a first portion of a uniform first diameter, a second portion of a uniform second diameter, and a transition portion blending smoothly into the first and second portions, the catheter defining a first lumen having a D-shaped cross-sectional and terminating at a closed end at the transition portion, and a second lumen having a D-shaped cross-section in the first portion, a round cross-section in the second portion, and a smooth transition from D-shaped to round in the transition portion.

Claim 28

A flexible dual lumen catheter having a first portion of a uniform first diameter, a second portion of a uniform second diameter, and a transition portion blending smoothly into the first and second portions, the catheter defining a first lumen having a D-shaped cross-sectional and terminating at a closed end at the transition portion, and a second lumen having a D-shaped cross-section in the first portion, a round cross-section in the second portion, and a smooth transition from D-shaped to round in the transition portion.

Claim 29

A flexible dual lumen catheter as claimed in claim 22, in which the catheter terminates at a distal end in an opening defining the end of the second lumen and in which the first lumen includes side openings.

Claim 30

A flexible dual lumen catheter as claimed in claim 22, in which the first lumen includes a portion of diminishing cross-section adjacent the transition portion.