EP0341049A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Multi-layer cannula structure
Assignee: Ethicon Inc
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Filing: 1989-05-04
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Granted: —
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Expires: 2009-05-04
Abstract
Abstract A swellable cannula is formed of concentric inner and outer hydrophilic and substantially non-hydrophilic layer structures (12, 14, 40, 42, 44). The hydrophilic layer structure (12, 14, 40) comprises at least 2/3rds of the cross-sectional area of the wall of the cannula. The substantially non-hydrophilic layer structure (14, 12, 42, 44) is either substantially water impermeable or allows water to pass through at a controlled rate. The substantially non-hydrophilic layer structure may also control the diffusion of medicaments. The cannula has control softenability and swellability characteristics.
Inventors
- 👤 Jack M. Walker
- 👤 Joseph R. Thomas
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 19:50
CPC Classifications
A; A61; A61M; A61M25/00; A61M25/0043; A61M25/0045; A61L; A61L29/00; A61L29/04; A61L29/06; A61M2025/0057; A61M2025/0063; A61M2025/0064; A61M25/0054
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
213 words
A cannula having a multi-layer wall structure with proximal and distal end portions (22,26,20,32) and an inner lumen (36), and comprising: a) a hydrophilic layer structure having one or more hydrophilic layers (12,14,40) having respective outer and inner surfaces and being formulated of a hydrophilic material which increases in volume more than 1.3:1 upon contact with an aqueous medium at 37 o C, said hydrophilic layer structure comprising at least 2/3rds of the cross-sectional area of said wall structure, said inner lumen swelling such that its cross-sectional area increases more than 20% upon contact of said hydrophilic layer structure with said aqueous medium at 37 o C; and b) a substantially non-hydrophilic layer structure having one or more substantially non-hydrophilic layers (14,12,42) having respective outer and inner surfaces and being formulated of a substantially non-hydrophilic material; an outer or inner surface of each of said hydrophilic layers being bonded to a corresponding inner or outer surface of at least one of said substantially non-hydrophilic layers, said bonded hydrophilic and substantially non-hydrophilic layers being of a construction such that they remain bonded to one another following swelling of said lumen such that its cross-sectional area increases more than 20% upon contact of said hydrophilic layer structure with said aqueous medium at 37 o C.
Claim 2
Dependent Claim
213 words
A cannula having a multi-layer wall structure with proximal and distal end portions (22,26,20,32) and an inner lumen (36), and comprising: a) a hydrophilic layer structure having one or more hydrophilic layers (12,14,40) having respective outer and inner surfaces and being formulated of a hydrophilic material which increases in volume more than 1.3:1 upon contact with an aqueous medium at 37 o C, said hydrophilic layer structure comprising at least 2/3rds of the cross-sectional area of said wall structure, said inner lumen swelling such that its cross-sectional area increases more than 20% upon contact of said hydrophilic layer structure with said aqueous medium at 37 o C; and b) a substantially non-hydrophilic layer structure having one or more substantially non-hydrophilic layers (14,12,42) having respective outer and inner surfaces and being formulated of a substantially non-hydrophilic material; an outer or inner surface of each of said hydrophilic layers being bonded to a corresponding inner or outer surface of at least one of said substantially non-hydrophilic layers, said bonded hydrophilic and substantially non-hydrophilic layers being of a construction such that they remain bonded to one another following swelling of said lumen such that its cross-sectional area increases more than 20% upon contact of said hydrophilic layer structure with said aqueous medium at 37 o C.
Claim 3
Dependent Claim
53 words
A cannula according to claim 1, wherein an innermost of said hydrophilic and substantially non-hydrophilic layers is a first of said substantially non-hydrophilic layers (14) and defines said lumen and wherein a first of said hydrophilic layers (12) has its inner surface bonded to the outer surface of said first substantially non-hydrophilic layer.
Claim 4
Dependent Claim
34 words
A cannula according to claim 2, wherein said substantially non-hydrophilic layer structure includes a second substantially non-hydrophilic layer (42) having its inner surface bonded to the outer surface of said first hydrophilic layer (12).
Claim 5
Dependent Claim
32 words
A cannula according to claim 2 or 3, wherein a second of said hydrophilic layers (40) has its outer surface bonded to the inner surface of said first substantially non-hydrophilic layer (14).
Claim 6
Dependent Claim
34 words
A cannula according to claim 4, wherein said substantially non-hydrophilic layer structure includes a third substantially non-hydophilic layer (44) having its outer surface bonded to the inner surface of said second hydrophilic layer (40).
Claim 7
Dependent Claim
85 words
A cannula according to claim 5, wherein said first substantially non-hydrophilic layer (14) controls the diffusion rate of water or medicaments between said first hydrophilic layer (12) and said lumen, said third substantially non-hydrophilic layer (44) controls the diffusion rate of water or medicaments between said second hydrophilic layer (40) and the outer surface of said third substantially non-hydrophilic layer (44), and said second substantially non-hydrophilic layer (42) substantially prevents the diffusion of water or medicaments between said first and second hydrophilic layers (12, 40).
Claim 8
Dependent Claim
60 words
A cannula according to claim 3, wherein said first substantially non-hydrophilic layer (14) controls the diffusion rate of water or medicaments between said first hydrophilic layer and said lumen and wherein said second substantially non-hydrophilic layer (42) controls the diffusion rate of water or medicaments between said first hydrophilic layer and the outer surface of said second substantially non-hydrophilic layer.
Claim 9
Dependent Claim
51 words
A cannula according to claim 1, wherein an innermost of said hydrophilic and substantially non-hydrophilic layer is a first of said hydrophilic layers (14) and defines said lumen and wherein a first of said non-hydrophilic layers (12) has its inner surface bonded to the outer surface of said first hydrophilic layer.
Claim 10
Dependent Claim
37 words
A cannula according to claim 8, wherein said first substantially non-hydrophilic layer (12) controls the diffusion rate of water or medicaments from said first hydrophilic layer (14) to said outer surface of said first substantially non-hydrophilic layer.
Claim 11
Dependent Claim
33 words
A cannula according to any one of claims 1 to 9 and further including, in said lumen: at least one partition (45) separating said lumen into at least two generally coextensive channels (46).
Claim 12
Dependent Claim
46 words
A cannula according to any one of claims 1 to 10, wherein said first substantially non-hydrophilic layer (12, 14) extends from a proximal end portion of said cannula and into the tissue of a patient but stops short of said distal end portion of said cannula.
Claim 13
Dependent Claim
41 words
A cannula according to any one of claims 1 to 11, wherein at least a first substantially non-hydrophilic layer (12, 14) of said substantially non-hydrophilic layer structure includes controlling means for controlling the lengthwise expansion of said cannula as it swells.
Claim 14
Dependent Claim
27 words
A cannula according to claim 12, wherein said controlling means comprises a plurality of fibers oriented lengthwise and located in said first substantially non-hydrophilic layer (12, 14).
Claim 15
Dependent Claim
22 words
A cannula according to claim 12, wherein said controlling means comprises residual axial stress in said first substantially non-hydrophilic layer (12, 14).
Claim 16
Dependent Claim
32 words
A cannula according to claim 12,13 or 14 wherein said controlling means controls said lengthwise expansion to be no more than 5% when an outer diameter of said wall increases to 15%.
Claim 17
Dependent Claim
25 words
A cannula according to any one of claims 1 to 15, wherein said one substantially non-hydrophilic layer (12, 14) is formulated of a thermoplastic material.
Claim 18
Dependent Claim
25 words
A cannula according to any one of claims 1 to 15, wherein said one substantially non-hydrophilic layer (12, 14) ia formulated of a polyurethane material.
Claim 19
Dependent Claim
25 words
A cannula according to any one of claims 1 to 15, wherein said one substantially non-hydrophilic layer (12, 14) is formulated of an elastomeric material.
Claim 20
Dependent Claim
27 words
A cannula according to any one of claims 1 to 18, wherein said one substantially non-hydrophilic layer (12, 14) has a softening ratio of more than 5:1.
Claim 21
Dependent Claim
39 words
A cannula according to any one of claims 1 to 19, wherein said one hydrophilic layer (12, 14) is formulated of a material having a 2.5% Secant modulus of less than 20,000 psi when hydrated at 37 o C.
Claim 22
Dependent Claim
32 words
A cannula according to any one of claims 1 to 20, wherein said cannula decreases in 2.5% Secant modulus more than 10:1 upon exposure to an aqueous medium at 37 o C.
Claim 23
Dependent Claim
107 words
A cannula according to any one of claims 1 to 21, wherein said hydrophilic layer material of said cannula comprises: a) a first phase which comprises a substantially non-hydrophilic polymeric component; and b) a second phase which comprises a hydrophilic polymeric component; said material (i) being capable of absorbing water to an extent that it softens with a softening ratio of at least about 2:1 and/or swells with a swelling ratio of at least 1.3:1; and (iii when substantially completely hydrated at 37 o C, having an energy to break of at least 700 N-cm/cm³ and a 2 5% Secant modulus of less than about 7,000 N/cm².
References Cited (Backward Citations)
No citation records indexed.
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