EXPANDABLE MEDICAL DEVICE WITH DUCTILE HINGES

• US 20080249609A1
• Filed: 06/16/2008
• Published: 10/09/2008
• Est. Priority Date: 03/30/1998
• Status: Active Grant

• Current Assignee: John F. Shanley
• Original Assignee: John F. Shanley
• Inventors: Shanley, John F.
• Granted Patent: US 8,052,735 B2
• Time in Patent Office: Days
• US Class Current: 623/1.16
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0029 differing in bending or flexure capacity
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir

Abstract

An expandable tissue supporting device of the present invention employs ductile hinges at selected points in the expandable device. When expansion forces are applied to the device as a whole, the ductile hinges concentrate expansion stresses and strains in small well defined areas. The expandable medical device including ductile hinges provides the advantages of low expansion force requirements, relatively thick walls which are radio-opaque, improved crimping properties, high crush strength, reduced elastic recoil after implantation, and control of strain to a desired level. The expandable tissue supporting device includes a plurality of elongated beams arranged in a cylindrical device and connected together by a plurality of ductile hinges. Although many ductile hinge configurations are possible, the ductile hinges preferably have a substantially constant hinge cross sectional area which is smaller than a beam cross sectional area such that as the device is expanded from a first diameter to a second diameter, the ductile hinges experience plastic deformation while the beams are not plastically deformed.

Claims

1-26. -26. (canceled)

27. An expandable medical device comprising:

a plurality of elongated beams, the plurality of elongated beams joined together to form a substantially cylindrical device which is expandable from a first diameter to a second diameter and;

a plurality of ductile hinges connecting the plurality of beams together in the substantially cylindrical device, wherein the hinge width is smaller than the beam width such that as the device is expanded from the first diameter to the second diameter the ductile hinges experience plastic deformation while the beams are not plastically deformed, each of the ductile hinges being in the shape of a curved beam having first and second arcuate surfaces facing the same direction with the second arcuate surface being larger than the first arcuate surface, the curved beams being positioned such that during expansion tensile strain is distributed along the second arcuate surface of the curved prismatic beam.

28. The expandable medical device according to claim 27, wherein the hinge width is smaller than the hinge thickness.

29. The expandable medical device according to claim 27, wherein the hinge width is no greater than 60% of the hinge thickness.

30. The expandable medical device according to claim 27, wherein the hinge width is at least 50% smaller than the beam width.

31. The expandable medical device according to claim 27, wherein the device is expandable by a balloon catheter pressurized by an inflation pressure of 1 to 5 atmospheres.

32. The expandable medical device according to claim 27, wherein the hinge width is less than ⅔

the beam width.

33. The expandable medical device according to claim 27, wherein a transition between the cross sectional area of the struts and the cross sectional area of the ductile hinges is an abrupt transition which extends less than 10 percent of a length of a strut.

34. The expandable medical device according to claim 27, wherein a ratio of a length of the ductile hinges to a length of the axial struts is 1:

6 or less.

35. The expandable medical device according to claim 27, wherein the elongated struts include a beneficial agent for delivery to a patient.

36. The expandable medical device according to claim 27, wherein the ductile hinges are asymmetrically configured to reach a predetermined strain level upon a first percentage expansion and to reach the predetermined strain level upon a second percentage of compression, wherein the first percentage is larger than the second percentage.

37. The expandable medical device according to claim 27, wherein ductile hinges are configured such that during crimping of the device onto a balloon, tensile strain is distributed along the first arcuate surface of the curved prismatic beam.

38. The expandable medical device according to claim 27, wherein the second side surface is an arcuate surface.

39. An expandable medical device comprising:

a plurality of elongated beams each defining a beam width in the circumferential direction of the cylindrical device, the plurality of elongated beams joined together to form a substantially cylindrical device which is expandable from a first diameter to a second diameter; and

a plurality of ductile hinges connecting the plurality of beams together in the substantially cylindrical device, each hinge defining a hinge width in the circumferential direction of the cylindrical device and having first and second side surfaces, wherein the hinge width is smaller than the beam width such that as the device is expanded from the first diameter to the second diameter the ductile hinges experience plastic deformation while the beams are not plastically deformed, the ductile hinges being asymmetrically configured with a first side surface placed in compression during expansion of the device and a second side surface placed intension during expansion of the device, wherein the first side surface has a length smaller than a length of the second side surface;

wherein the second side surface is a convex arcuate surface.

40. The expandable medical device according to claim 39, wherein the hinge width is at least 50% smaller than the beam width.

41. The expandable medical device according to claim 39, wherein the hinge width is less than ⅔

the beam width.

42. The expandable medical device according to claim 39, wherein a transition between the cross sectional area of the struts and the cross sectional area of the ductile hinges is an abrupt transition which extends less than 10 percent of a length of a strut.

43. The expandable medical device according to claim 39, wherein the elongated struts include a beneficial agent for delivery to a patient.