Patent EP0391586A2 successfully refreshed from Google Patents.
EP0391586A2
Expired / Lapsed
EP
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Method of producing a tapered vascular graft prothesis
Assignee: Livanova Holding USA Inc
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Filing: 1990-03-26
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Granted: —
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Expires: 2010-03-26
Abstract
Abstract PTFE vascular tubing (12) is guided on to a tapered ultrasonic horn (8) as the horn (8) is oscillating at a high frequency. This action causes the end of the tubing (12) moved onto the horn (8) to expand. The expanded tubing (12) is then positioned on a mandrel (14) having a desired shape, such as tapered, and resintered. The finished tubing (12) with an expanded diameter on one end and a non-expanded diameter on the other end is then removed from the mandrel (14), and is ready for use. Untapered tubing (12) can also be radially expanded by this method to provide a thinner wall.
Inventors
- 👤 Alfred E. Primm
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 16:45
CPC Classifications
B; B29; B29C; B29C67/00; B29C67/0014; A; A61; A61F; A61F2/00; A61F2/02; A61F2/04; A61F2/06; A61L; A61L27/00; A61L27/14; A61L27/16; A61L27/50; A61L27/507; B29C55/00; B29C55/22; B29C55/24; B29C43/00; B29C43/32; B29C43/36; B29C43/361; B29C2043/3636; B29C2791/00; B29C2791/004; B29C2791/008; B29K; B29K2027/00; B29K2027/12; B29K2027/18; B29L; B29L2031/00; B29L2031/753; B29L2031/7532; Y; Y10; Y10S; Y10S623/00; Y10S623/901
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
196 words
A method for expanding flexible tubing (12) useful for making a vascular prosthesis tubing characterized by the steps of: energizing an elongated ultrasound horn (8) having a free end which increases from a cross-section smaller than an internal cross-section of said tubing to a cross-section larger than the internal cross-section of the tubing; placing an end of said tubing on the free end of said horn and guiding said tubing further onto said horn as the horn is vibrating, whereby a portion of said tubing moved onto the larger cross-section of the horn is expanded in cross-section; de-energizing said horn after said tubing has been expanded; and maintaining said tubing on said horn for a predetermined time period to allow the expanded tubing portion to cool in its expanded state; removing said tubing from the horn and placing it on a mandrel (14); restraining the ends of said tubing in a manner (16) to prevent the tubing from shrinking axially; and sintering said tubing for a predetermined time at a temperature sufficient to cause the expanded tubing to shrink radially to the shape of the mandrel and to maintain such shape when removed from said mandrel.
Claim 2
Independent Claim
196 words
A method for expanding flexible tubing (12) useful for making a vascular prosthesis tubing characterized by the steps of: energizing an elongated ultrasound horn (8) having a free end which increases from a cross-section smaller than an internal cross-section of said tubing to a cross-section larger than the internal cross-section of the tubing; placing an end of said tubing on the free end of said horn and guiding said tubing further onto said horn as the horn is vibrating, whereby a portion of said tubing moved onto the larger cross-section of the horn is expanded in cross-section; de-energizing said horn after said tubing has been expanded; and maintaining said tubing on said horn for a predetermined time period to allow the expanded tubing portion to cool in its expanded state; removing said tubing from the horn and placing it on a mandrel (14); restraining the ends of said tubing in a manner (16) to prevent the tubing from shrinking axially; and sintering said tubing for a predetermined time at a temperature sufficient to cause the expanded tubing to shrink radially to the shape of the mandrel and to maintain such shape when removed from said mandrel.
Claim 3
Dependent Claim
23 words
The method of Claim 1 further characterized by applying a liquid to said tubing (12) before placing the tubing on the horn (8).
Claim 4
Dependent Claim
26 words
The method of Claim 1, wherein said energizing step is performed in a manner to cause said horn (8) to oscillate axially at a high frequency.
Claim 5
Dependent Claim
30 words
The method of Claim 1, wherein said energizing step is performed with a horn (8) having a length greater than two times a wavelength ultrasound energy applied to the horn.
Claim 6
Dependent Claim
32 words
The method of Claim 8, wherein said energizing step is performed with a horn (8) having a length of from about 2 to 8 wavelengths, in half wavelength increments, of said energy.
Claim 7
Dependent Claim
11 words
The method of Claim 1, wherein said mandrel (14) is tapered.
Claim 8
Dependent Claim
28 words
The method of Claim 1, wherein said sintering is performed by heading said tubing to approximately 325° to 450°C for a period of from three to ten minutes.
Claim 9
Dependent Claim
20 words
The method of Claim 2, including dipping said tubing in a liquid for facilitating feeding the tubing on said horn.
Claim 10
Dependent Claim
18 words
The method of Claim 1, wherein said energizing step is performed with a 40kHz 700 watt power supply.
Claim 11
Dependent Claim
19 words
The method of Claim 1, wherein said energizing step is performed with a 20 kHz 3200 watt power supply.
Claim 12
Dependent Claim
13 words
The method of Claim 1, wherein said tubing (12) is made of PTFE.
Claim 13
Dependent Claim
12 words
Tubing (12) made by the method of Claim 1 through Claim 11.
References Cited (Backward Citations)
No citation records indexed.
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