Optimized catheter sheath for Rx catheter

A catheter, comprising:

• a sheath having a first lumen, wherein a stiffness of the sheath tapers from a higher stiffness at a proximal end to a lower stiffness at a distal end;
• and
• a rapid exchange segment having a second lumen which extends from a distal entry port to a proximal exit port of the rapid exchange segment,
• wherein the sheath and the rapid exchange segment are attached to each other in a lengthwise direction such that the second lumen is offset and angled with respect to the first lumen,
• wherein the rapid exchange segment has an angled joint or a proximal stub, a tubular shaft, and a soft and atraumatic distal tip, and the proximal stub is slightly angled with respect to the tubular shaft, and the distal tip is smooth without sharp edges or flash,
• wherein the sheath comprises a proximal portion, a mid-shaft portion, and a window portion, wherein the first lumen extends from the proximal portion through the mid-shaft portion and at least partially through the window portion,
• wherein the rapid exchange segment is a monolithic structure comprised of the stub portion (A), a tubular body (B), and a distal tip (C) arranged in this order distally to the sheath,
• wherein the second lumen connects the distal entry port located at the distal tip with the proximal exit port located on a side of the stub portion at a proximal end of the tubular body,
• wherein the rapid exchange segment has an outer diameter tapered in the lengthwise direction of the tubular body such that a first outer diameter OD1 at the proximal end of the tubular body is larger than a second outer diameter OD2 at a distal end of the tubular body,
• wherein the second lumen is tapered from the distal entry port to the proximal exit port by having an inner diameter tapered from the exit port to the entry port such that a first inner diameter ID1 at the exit port is smaller than a second inner diameter ID2 at the entry port of the rapid exchange segment,
• wherein the outer diameter of the rapid exchange segment and the inner diameter of the second lumen are inversely tapered from the distal tip such that OD2<OD1 and ID1<ID2, ID2 is concentric with OD2, and ID1 is not concentric with OD1,
• wherein the second lumen is offset with respect to the outer diameter of the rapid exchange segment on at least at one of the entry port and the exit port, and
• wherein the proximal stub of the rapid exchange segment is mated with the sheath at the distal end of the first lumen by inserting the proximal stub into an opening in the window portion of the sheath.

A catheter, comprising:

• a tubular sheath having an outer surface and an inner surface arranged coaxially to each other and defining a wall that encloses a tool lumen that extends from a proximal end to a distal end of the tubular sheath, wherein a stiffness of the tubular sheath tapers from a higher stiffness at the proximal end to a lower stiffness at the distal end;
• and
• an exchange segment having an outer surface and an inner surface arranged at least partially coaxially to each other and defining a wall that encloses a guidewire lumen,
• wherein the tubular sheath includes, in order from the proximal end to the distal end, a proximal section, a mid-shaft section, and a distal section,
• wherein the distal section of the tubular sheath includes a transparent window for side-view imaging,
• wherein the tool lumen extends from the proximal portion through the mid-shaft section and partially through the distal section,
• wherein the exchange segment has a soft and atraumatic distal tip and has an angled joint or a proximal stub, and the angled joint or the proximal stub is mated with the tubular sheath at the distal end thereof in such a manner that the angled joint or the proximal stub is inserted into an opening in the distal end of the tubular sheath and the exchange segment and the tubular sheath partially overlap each other at an angle and the guidewire lumen is offset with respect to the tool lumen by a predetermined distance to form a monolithic catheter structure comprised of the tubular sheath and the rapid exchange segment,
• wherein the monolithic structure comprises the proximal stub (A), a tubular body (B), and a distal tip (C) arranged in this order distally to the tubular sheath,
• wherein the guidewire lumen connects a distal entry port located at the distal tip with a proximal exit port located on a side of the stub portion at a proximal end of the tubular body,
• wherein the exchange segment has an outer diameter tapered in the lengthwise direction of the tubular body such that a first outer diameter OD1 at the proximal end of the tubular body is larger than a second outer diameter OD2 at a distal end of the tubular body,
• wherein the guidewire lumen is tapered from the distal entry port to the proximal exit port by having an inner diameter tapered from the exit port to the entry port such that a first inner diameter ID1 at the exit port is smaller than a second inner diameter ID2 at the entry port of the exchange segment,
• wherein the outer diameter of the exchange segment and the inner diameter of the guidewire lumen is inversely tapered from the distal tip to the proximal end of the tubular body such that OD2<OD1 and ID1<ID2, ID2 is concentric with OD2, and ID1 is not concentric with OD1, and
• wherein the guidewire lumen is offset with respect to the outer diameter of the exchange segment on at least at one of the entry port and the exit port.