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EP0435518A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

A flexible, kink-resistant catheter

Assignee: Cook Research Inc
•
Filing: 1990-12-13
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Granted: —
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Expires: 2010-12-13
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Abstract

Abstract An extremely small diameter epidural catheter (101) is disclosed which is both flexible and kink-resistant when flexed. The catheter (101) includes a tubular sheath or tube (104) having a passageway therein for the delivery of fluids to biological tissue. Positioned in the passageway is a coil (105) which is expansion-fitted therein to form a composite wall structure which is extremely flexible and kink-resistant. This composite wall structure is utilized to form a catheter having an extremely small outside diameter (106) in a range of 0.010" to 0.032" for delivering acceptable levels of fluid volume. The coil (105) comprises a plurality of closely spaced turns (110) extending from the proximal to almost the distal end thereof. About the distal end of the coil (105) is a number of loosely coupled or relaxed turns (111) which adds further flexibility to the distal end of the catheter (101). The tubular sheath (104) of the catheter (101) comprises a high tensile or flexural strength material which does not rupture or tear when the catheter (101) is bent or flexed. Maintaining the ratio of the outside diameter (107) of the wire coil (105) to the cross-sectional diameter (113) of the individual turns within a range of 4 to 10 prevents the tubular sheath (104) from either rupturing or kinking when the catheter (101) is flexed or bent.

Inventors

  • 👤 Neal Edward Fearnot
  • 👤 Richard Brian Sisken

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-23 11:24
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/82; A61F2/94; A61M; A61M25/00; A61M25/0043; A61F2230/00; A61F2230/0063; A61F2230/0091; A61M2025/0007; A61M2025/0059; A61M25/005; A61M25/0053

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 80 words
A catheter for insertion into biological tissue, said catheter comprising a tubular sheath (104) having a longitudinal passageway therein capable of transporting a fluid to the tissue, and being able to maintain fluid flow when said sheath is flexed; and an elongated coil (105) within and contacting said longitudinal passageway of said tubular sheath, characterised in that the outer surface of the coil and the inner surface of the sheath are friction fitted in order to permit frictional movement therebetween.
Claim 2
Dependent Claim 38 words
The catheter of claim 1, characterised in that the sheath has a nominal tensile strength greater the 2,109,300Kg. per square metre (3,000 pounds per square inch), or at least 14,062,000Kg. per square metre (20,000 pounds per square inch).
Claim 3
Dependent Claim 34 words
The catheter of claim 1, characterised in that said tubular sheath has an outside diameter less than 0.084cms (0.033"), and/or an inside dfiameter in a range of 0.02 cms to 0.066cms (0.008" to 0.026").
Claim 4
Dependent Claim 17 words
The catheter of claim 1, characterised in that said tubular sheath comprises a plastic material, or polyimide.
Claim 5
Dependent Claim 66 words
The catheter of claim 4, characterised in that the tubular sheath and the coil have a combined thickness in a range of 0.005cms to 0.015cms (0.002" to 0.006"), and/or the catheter has an outside diameter in a range of 0.0254cms to 0.08cms (0.010" to 0.032"), and/or said coil includes a spiral member having a cross-sectional dimension in a range of 0.00254cms to 0.00762cms (0.001" to 0.003").
Claim 6
Dependent Claim 18 words
The catheter of any one preceding claim, characterised in that said spiral member comprises a stainless steel wire.
Claim 7
Dependent Claim 31 words
The catheter of claim 1, characterised in that said coil has a passageway therein, and in that said catheter further comprises a second tube positioned within the passageway of said coil.
Claim 8
Dependent Claim 44 words
The catheter of any one preceding claim, further characterised by a strand either spirally positioned around a length of said elongated coil and attached about the opposite ends thereof, or positioned through a passageway of said coil and attached about the opposite ends thereof.
Claim 9
Dependent Claim 18 words
The catheter of any one preceding claim, characterised in that the turns of said coil are variably spaced.
Claim 10
Dependent Claim 41 words
The catheter of claim 9, characterised in that the coil includes a first plurality of turns and a second plurality of turns positioned about a distal end thereof, the second plurality being more loosely coupled than said first plurality of turns.
Claim 11
Dependent Claim 41 words
The catheter of claim 3, characterised in that the sheath has a wall thickness in a range of 0.00254 to 0.00762cms (0.001" to 0.003"), and/or the coil has an outside diameter in a range of 0.02 to 0.066cms (0.008" to 0.026").
Claim 12
Dependent Claim 27 words
The catheter of claim 11, characterised in that the ratio of the outside coil diameter to said member diameter is in a range of 4 to 10.
Claim 13
Dependent Claim 25 words
The catheter of claim 7, characterised in that the second tube has a wall thickness in a range of 0.00254 to 0.00762cms (0.001" to 0.003").

References Cited (Backward Citations)

US3757768A Cited
FR2204430A1 Cited
US3841308A Cited
FR2505191A1 Cited
US4425919A Cited

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