EP0100506A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A method of forming a cannula, and a dielectric heating device for forming a cannula
Assignee: Shiley Inc
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Filing: 1981-05-13
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Granted: —
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Expires: 2001-05-13
Abstract
Abstract A method and apparatus for forming a cannula 10 is described. The cannula, for insertion into a body cavity, duct, or vessel of a patient, includes a parent cannula member 12 and an integral radiopaque tip 14. The tip 14 is configured so as to be distinguishable from internal body parts in an X-ray or fluoroscopic image, thus serving to precisely locate the position of the cannula within the patient without substantially obstructing the physician's view of such body parts. The cannula tip 14 and parent member 12 are separately pre-formed from a non-toxic polymeric material and can be constructed so as to have different hardnesses. The pre-formed tip and parent member are dielectrically heated and welded securely together to form a unitary, integral cannula using a dielectric heating apparatus 50. The electrodes 58, 60 of the dielectric heating apparatus 50 are connected to dies 54, 56 whose diametrical dimensions conform closely to those of the tip 14 and parent member 12 to provide the cannula with completely smooth interior and exterior surfaces. In order to prevent burning of the cannula during this heating process, air is vented from the junction area by providing the outer die 54 with a convex interior surface 62 and by forming longitudinal grooves 82 in the external surface of the inner die or mandrel 56. The inner mandrel is formed by encapsulating the inner electrode with a highly insulative material to further inhibit burning of the cannula.
Inventors
- 👤 Perry A. Nebergall
- 👤 Robert C. French
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 00:18
CPC Classifications
A; A61; A61M; A61M25/00; A61M25/10; A61M25/1027; A61M25/1036; A61M25/01; A61M25/0105; A61M25/0108; B; B29; B29C; B29C65/00; B29C65/02; B29C65/04; B29C66/00; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/114; B29C66/1142; B29C66/116; B29C66/1162; B29C66/12; B29C66/122; B29C66/1222; B29C66/1224; B29C66/342; B29C66/50; B29C66/51; B29C66/53; B29C66/534; B29C66/5344; B29C66/61; B29C66/612; B29C66/70; B29C66/73; B29C66/731; B29C66/7315; B29C66/73151; B29C66/73152; A61B; A61B90/00; A61B90/39; B29C65/08; B29C65/38; B29C66/71; B29L; B29L2031/00; B29L2031/753; B29L2031/7542
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
323 words
A dielectric heating device for generating a high frequency electrical current to heat the mated ends of a cannula member and a radiopaque tip, thereby joining said mated ends at a joint to form a unitary, integral cannula for insertion into the body of a patient, said dielectric heating device comprising: an annular outer electrode positioned over said cannula proximate said joint so that the interior surface of said outer electrode closely surrounds said cannula, said interior surface comprising: a mid-section positioned generally adjacent said joint, the inner diameter of said mid-section closely approximating the outer diameter of said cannula providing means for concentrating said heat at said joint and forming a substantially smooth exterior surface on said cannula; and tapered end sections having gradually increasing inner diameters just slightly larger than said inner diameter of said mid-section for providing air vent means for permitting the escape of air from the vicinity of said joint and for preventing the burning of said cannula; an elongate inner electrode inserted within said cannula so as to be generally opposite said outer electrode, said inner electrode having an enlarged section located generally at said joint for concentrating said heat at said joint; insulation means encapsulating said inner electrode for (i) preventing said cannula from burning and (ii) forming an inner mandrel, the outer diameter of said inner mandrel closely approximating the inner diameter of said cannula for forming a substantially smooth interior surface on said cannula, said mandrel including groove means for venting air from the vicinity of said joint and preventing the burning of said cannula; means for conducting high frequency electrical current through said electrodes and said mated ends of said cannula to heat said mated ends; and means for exerting an axial force on said tip for eliminating irregularities in the mating surfaces of said cannula member and said tip and for fusing said mating surfaces together to form said unitary, integral, cannula.
Claim 2
Dependent Claim
323 words
A dielectric heating device for generating a high frequency electrical current to heat the mated ends of a cannula member and a radiopaque tip, thereby joining said mated ends at a joint to form a unitary, integral cannula for insertion into the body of a patient, said dielectric heating device comprising: an annular outer electrode positioned over said cannula proximate said joint so that the interior surface of said outer electrode closely surrounds said cannula, said interior surface comprising: a mid-section positioned generally adjacent said joint, the inner diameter of said mid-section closely approximating the outer diameter of said cannula providing means for concentrating said heat at said joint and forming a substantially smooth exterior surface on said cannula; and tapered end sections having gradually increasing inner diameters just slightly larger than said inner diameter of said mid-section for providing air vent means for permitting the escape of air from the vicinity of said joint and for preventing the burning of said cannula; an elongate inner electrode inserted within said cannula so as to be generally opposite said outer electrode, said inner electrode having an enlarged section located generally at said joint for concentrating said heat at said joint; insulation means encapsulating said inner electrode for (i) preventing said cannula from burning and (ii) forming an inner mandrel, the outer diameter of said inner mandrel closely approximating the inner diameter of said cannula for forming a substantially smooth interior surface on said cannula, said mandrel including groove means for venting air from the vicinity of said joint and preventing the burning of said cannula; means for conducting high frequency electrical current through said electrodes and said mated ends of said cannula to heat said mated ends; and means for exerting an axial force on said tip for eliminating irregularities in the mating surfaces of said cannula member and said tip and for fusing said mating surfaces together to form said unitary, integral, cannula.
Claim 3
Dependent Claim
155 words
A dielectric heating device for integrally joining mated ends of a pair of tubular members to form a cannula for insertion into the body of the patient, said dielectric device capable of generating a high frequency electrical current, comprising: an outer electrode adapted to surround said mated ends of said tubular members; an inner electrode positioned within said tubular members and generally opposite said outer electrode; means for conducting said high frequency electric current between said electrodes and through said mated ends of said tubular members to heat and securely join said mated ends together to form said cannula; and die means on said electrodes for (i) forming substantially smooth surfaces on said cannula to prevent the accumulation of mucus and other bodily secretions within said cannula and to prevent injury to said patient, and (ii) preventing the burning or scorching of said cannula during said heating of said mated ends of said tubular members.
Claim 4
Dependent Claim
155 words
A dielectric heating device for integrally joining mated ends of a pair of tubular members to form a cannula for insertion into the body of the patient, said dielectric device capable of generating a high frequency electrical current, comprising: an outer electrode adapted to surround said mated ends of said tubular members; an inner electrode positioned within said tubular members and generally opposite said outer electrode; means for conducting said high frequency electric current between said electrodes and through said mated ends of said tubular members to heat and securely join said mated ends together to form said cannula; and die means on said electrodes for (i) forming substantially smooth surfaces on said cannula to prevent the accumulation of mucus and other bodily secretions within said cannula and to prevent injury to said patient, and (ii) preventing the burning or scorching of said cannula during said heating of said mated ends of said tubular members.
Claim 5
Independent Claim
178 words
A method for integrally joining mated ends of a pair of tubular members together to form a cannula for insertion into a patient's body, said method utilising a dielectric heating device having a pair of electrodes positioned adjacent said mated ends of said tubular members, comprising: joining said mated ends of said tubular members to form a common joint; venting air from the interstices between said electrodes and said mated ends of said tubular members to prevent the burning or scorching of said cannula; covering one of said electrodes with a highly insulative material to further prevent burning or scorching of said cannula; passing a high frequency electrical current between said electrodes and through said mated ends of said tubular members to heat said members and fuse them together at said joint to form said integral cannula; and forming said mated ends of said tubular members while in a heated condition to provide smooth surfaces on said cannula to inhibit the accumulation of mucus and other bodily secretions within said cannula and to prevent injury to said patient.
Claim 6
Independent Claim
178 words
A method for integrally joining mated ends of a pair of tubular members together to form a cannula for insertion into a patient's body, said method utilising a dielectric heating device having a pair of electrodes positioned adjacent said mated ends of said tubular members, comprising: joining said mated ends of said tubular members to form a common joint; venting air from the interstices between said electrodes and said mated ends of said tubular members to prevent the burning or scorching of said cannula; covering one of said electrodes with a highly insulative material to further prevent burning or scorching of said cannula; passing a high frequency electrical current between said electrodes and through said mated ends of said tubular members to heat said members and fuse them together at said joint to form said integral cannula; and forming said mated ends of said tubular members while in a heated condition to provide smooth surfaces on said cannula to inhibit the accumulation of mucus and other bodily secretions within said cannula and to prevent injury to said patient.
References Cited (Backward Citations)
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