What is claimed is:
1. 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 cylinder having a first diameter to a cylinder having a second diameter, the plurality of elongated beams each having a beam width in a circumferential direction; and
a plurality of ductile hinges connecting the plurality of beams together in the substantially cylindrical device, the ductile hinges having a substantially constant width in a circumferential dimension along a portion of a hinge length which is at least a total hinge length, 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.
2. The expandable medical device according to claim 1, further comprising an abrupt transition between each of the elongated beams and each of the ductile hinges.
3. The expandable medical device according to claim 1, further comprising a plurality of axial slots between adjacent elongated beams and a plurality of circumferential slots, wherein the plurality of ductile hinges are each formed between an axial slot and a circumferential slot.
4. The expandable medical device according to claim 3, wherein the ductile hinges are formed at opposite ends of the circumferential slots.
5. The expandable medical device according to claim 1, wherein the ductile hinges are each in the shape of a curved prismatic beam.
6. The expandable medical device according to claim 5, wherein the curved prismatic beams are positioned such that during stent expansion, tensile strain is distributed along a convex surface of the curved prismatic beam.
7. The expandable medical device according to claim 1, wherein the plurality of elongated beams are formed of wire and the plurality of ductile hinges are reduced diameter portions of the wire.
8. The expandable medical device according to claim 1, wherein expansion of the substantially cylindrical device from the first diameter to the second diameter which is at least two times the first diameter results in substantially no axial contraction.
9. The expandable medical device according the claim 1, further comprising a geometric deflection limiting feature for limiting an amount of bending of the ductile hinges.
10. The expandable medical device according to claim 9, wherein the geometric deflection limiting feature is a V-shaped notch having side surfaces which contact each other when a maximum amount of bending is reached.
11. The expandable medical device according to claim 1, wherein the plurality of elongated beams extend substantially axially and a plurality of circumferential beams are each connected at first and second ends to one of the axial beams by a ductile hinge.
12. An expandable medical device comprising:
a cylindrical tube;
a plurality of axial slots formed in the cylindrical tube in a staggered arrangement to define a network of elongated struts, wherein each of the elongated struts are axially displaced from adjacent struts; and
a plurality of ductile hinges formed between the elongated struts, the ductile hinges allowing the cylindrical tube to be expanded or compressed from. a first diameter to a second diameter by deformation of the ductile hinges, the ductile hinges being 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.
13. The expandable medical device according to claim 12, wherein the elongated struts have a substantially constant width in a circumferential direction, and the ductile hinges have a width in the circumferential direction which is less than the width of the struts.
14. The expandable medical device according to claim 13, 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.
15. The expandable medical device according to claim 12, wherein the plurality of ductile hinges are curved prismatic beams having a convex side surface and a concave side surface.
16. The expandable medical device according to claim 12, wherein a ratio of a length of the ductile hinges to a length of the axial struts is 1:6 or less.
17. The expandable medical device according to claim 12, further comprising a geometric deflection limiting feature for limiting an amount of bending of the ductile hinges.
18. The expandable medical device according to claim 12, wherein the ductile hinges are designed to deform plastically upon radial expansion or compression of the expandable medical device while the elongated struts experience no plastic deformation upon radial expansion or compression.
19. The expandable medical device according to claim 12, wherein the expandable medical device is formed of Nitinol, and the ductile hinges are designed to deform upon radial expansion or compression of the expandable medical device and can be returned to an original configuration by heating.
20. The expandable medical device according to claim 12, wherein the elongated struts include a beneficial agent for delivery to a patient.
21. An expandable medical device comprising:
a plurality of elongated beams having a substantially constant beam cross sectional area along a beam length;
a plurality of ductile hinges connecting the plurality of beams together in a substantially cylindrical device which is expandable or compressible from a first diameter to a second diameter by plastic deformation of the ductile hinges; and
a plurality of deflection limiting members positioned at a plurality of the ductile hinges to limit the deflection at the ductile hinges.
22. The expandable medical device according to claim 21, wherein the deflection limiting members include angled side walls on opposite sides of a ductile hinge which engage one another to limit deflection at ductile hinge.
23. The expandable medical device according to claim 22, wherein the deflection limiting members are V-shaped notches.
24. An expandable medical device which is visible in x-ray and fluoroscope images, the device comprising:
a plurality of struts arranged to form an expandable cylindrical tube; and
a plurality of ductile hinges connecting the plurality of struts, wherein the struts and ductile hinges have a thickness in a radial direction of the cylindrical tube of at least 0.003 inches (0.0762 mm).
25. The expandable medical device according to claim 24, wherein the device is formed of stainless steel.
26. The expandable medical device according to claim 24, wherein the thickness of the struts and ductile hinges is at least 0.005 inches (0.127 mm).
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A speed bump system for a roadway that encourages a driver of a passenger vehicle to slow down and that does not substantially impede an emergency vehicle, the system comprising a structure for disposing on the roadway to encourage the driver of a passenger vehicle to slow down before driving over the structure, the structure including
a raised middle portion,
a first raised outer portion proximal to one end of the raised middle portion,
a second raised outer portion proximal to the other end of the raised middle portion, which three raised portions are traversable by the passenger vehicle,
a first gap between the first raised outer portion and the raised middle portion, the first gap having a first width, and
a second gap between the second raised outer portion and the raised middle portion, the second gap having a second width, wherein the first width, the second width and the distance between the first and second gaps allow the emergency vehicle to pass through the first and second gaps.
2. The speed bump system of claim 1, wherein the distance between the first gap and the second gap is substantially equal to the distance between two front tires of the emergency vehicle and wherein the first width and the second width are each wider than the widest tread width of the emergency vehicle.
3. The speed bump system of claim 1, wherein the first raised outer portion, the raised middle portion and the second raised outer portion are substantially collinear.
4. The speed bump system of claim 1, wherein the first raised outer portion, the raised middle portion and the second raised outer portion are not collinear.
5. The speed bump system of claim 1, wherein the elongate structure comprises a plurality of segments adjoined together.
6. The speed bump system of claim 1, wherein the elongate structure comprises a plurality of segments abutted together.
7. The speed bump system of claim 1, further comprising a first reflector in or proximal to the first gap and a second reflector in or proximal to the second gap for increasing visibility thereof.
8. The speed bump system of claim 1, wherein the first width, the second width and the distance between the first and second gaps are such as to not allow the passenger vehicle to pass the speed bump system without going over at least one of the raised middle portion, the first raised outer portion and the second raised outer portion.
9. The speed bump system of claim 8, further comprising affixing means for affixing the first raised outer portion, the second raised outer portion and the raised middle portion to the roadway.
10. The speed bump system of claim 8, further comprising reflectors disposed in or proximal to the first and second gaps for easier visibility.
11. The speed bump system of claim 8, in which not all of the middle raised portion, the first raised outer portion and the second raised outer portion are collinear.
12. A method for encouraging a driver of a passenger vehicle traveling on a roadway to slow down while not substantially impeding an emergency vehicle, the method comprising:
disposing on the roadway a raised middle portion;
disposing on the roadway a first raised outer portion proximal to one end of the raised middle portion;
disposing on the roadway a second raised outer portion proximal to the other end of the raised middle portion, which three raised portions are traversable by the passenger vehicle;
leaving a first gap, having a first width, between the first raised outer portion and the raised middle portion; and
leaving a second gap, having a second width, between the second raised outer portion and the raised middle portion, wherein the first width, the second width and the distance between the first and second gaps are such as to allow the emergency vehicle to pass through the first and second gaps.
13. The method of claim 12, wherein the distance between the first gap and the second gap is substantially equal to the distance between two front tires of the emergency vehicle and wherein the first width and the second width are each wider than the widest tread width of the emergency vehicle.
14. The method of claim 12, wherein the first raised outer portion, the raised middle portion and the second raised outer portion are substantially collinear.
15. The method of claim 12, wherein the first raised outer portion, the raised middle portion and the second raised outer portion are not collinear.
16. The method of claim 12, further comprising
providing a first reflector in or proximal to the first gap; and
providing a second reflector in or proximal to the second gap for increasing visibility thereof.
17. The method of claim 12, wherein the first width, the second width and the distance between the first and second gaps are such as to not allow the passenger vehicle to pass the speed bump system without going over at least one of the raised middle portion, the first raised outer portion and the second raised outer portion.
18. The method of claim 17, further comprising
providing a first reflector in or proximal to the first gap; and
providing a second reflector in or proximal to the second gap for increasing visibility thereof.
19. The method of claim 17, wherein the first raised outer portion, the raised middle portion and the second raised outer portion are substantially collinear.
20. The method of claim 17, wherein the first raised outer portion, the raised middle portion and the second raised outer portion are not collinear.
21. A speed bump system for a roadway that encourages a driver of a passenger vehicle to slow down and that does not substantially impede an emergency vehicle, the system comprising a structure for disposing on the roadway to encourage the driver of a passenger vehicle to slow down before driving over the structure, the structure including
a first raised portion,
a second raised portion proximal to the first raised portion, which two raised portions are traversable by the passenger vehicle, and
a gap between the first raised portion and the second raised portion, the gap having a particular width that allows the emergency vehicle to pass therethrough.
22. A method for encouraging a driver of a passenger vehicle traveling on a roadway to slow down while not substantially impeding an emergency vehicle, the method comprising:
disposing on the roadway a first raised portion;
disposing on the roadway a second raised portion proximal to the first raised portion, which two raised portions are traversable by the passenger vehicle; and
leaving a gap, having a particular width, between the first raised portion and the second raised portion, wherein the particular width of the gap allows the emergency vehicle to pass therethrough.