US6102933A
Expired / Lapsed
US
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Release mechanism utilizing shape memory polymer material
Assignee: Lawrence Livermore National Security LLC
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Filing: 1999-02-05
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Granted: 2000-08-15
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Expires: 2019-02-05
Abstract
Abstract Microfabricated therapeutic actuators are fabricated using a shape memory polymer (SMP), a polyurethane-based material that undergoes a phase transformation at a specified temperature (Tg). At a temperature above temperature Tg material is soft and can be easily reshaped into another configuration. As the temperature is lowered below temperature Tg the new shape is fixed and locked in as long as the material stays below temperature Tg. Upon reheating the material to a temperature above Tg, the material will return to its original shape. By the use of such SMP material, SMP microtubing can be used as a release actuator for the delivery of embolic coils through catheters into aneurysms, for example. The microtubing can be manufactured in various sizes and the phase change temperature Tg is determinate for an intended temperature target and intended use.
Inventors
- 👤 Abraham P. Lee
- 👤 M. Allen Northrup
- 👤 Dino R. Ciarlo
- 👤 Peter A. Krulevitch
- 👤 William J. Benett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:30
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/12; A61B17/12022; A61B17/12131; A61B17/1214; A61B2017/00831; A61B2017/00867; A61B2017/00871; A61B2017/1205; A61B2017/12054; A61B2017/12068; A61B2017/12077
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
97 words
In a release mechanism having means adapted for retaining therein and releasing therefrom an object, the improvement comprising: said means being composed of a shape memory polymer material, said shape memory material undergoes a phase transformation at a temperature Tg, whereby heating said material above the temperature Tg enables the material to soften and be reshaped to another configuration, and cooling of the material below the temperature Tg causes the material to stiffen and retain the reshaped configuration until the material is reheated to above the temperature Tg causing the material to return to its original shape.
Claim 2
Dependent Claim
97 words
In a release mechanism having means adapted for retaining therein and releasing therefrom an object, the improvement comprising: said means being composed of a shape memory polymer material, said shape memory material undergoes a phase transformation at a temperature Tg, whereby heating said material above the temperature Tg enables the material to soften and be reshaped to another configuration, and cooling of the material below the temperature Tg causes the material to stiffen and retain the reshaped configuration until the material is reheated to above the temperature Tg causing the material to return to its original shape.
Claim 3
Dependent Claim
30 words
The improvement of claim 1, additionally including means for reheating of the material from a group of heating sources consisting of thermal heating, heated fluid, resistive heating, and optical heating.
Claim 4
Dependent Claim
19 words
The improvement of claim 1, wherein said temperature Tg is in the range of -30° C. to 100° C.
Claim 5
Dependent Claim
17 words
The improvement of claim 1, wherein said shape memory polymer material is configured as a hollow member.
Claim 6
Dependent Claim
36 words
The improvement of claim 1, wherein said hollow member has an internal diameter in the range of 100 μm to 1000 μm, and an external diameter in the range of 150 μm to over 1 mm.
Claim 7
Dependent Claim
19 words
The improvement of claim 1, in combination with an object to be retained in and released from said means.
Claim 8
Dependent Claim
14 words
The combination of claim 6, wherein said object is composed of a therapeutic material.
Claim 9
Dependent Claim
17 words
The combination of claim 6, wherein said means is constructed to provide controlled deposition of said object.
Claim 10
Dependent Claim
12 words
The combination of claim 6, wherein said object includes a ball-shaped end.
Claim 11
Dependent Claim
12 words
The combination of claim 6, wherein said object includes a grooved end.
Claim 12
Dependent Claim
32 words
The actuator of claim 6, wherein said object to be retained in and released from said microtube includes a light trap, and additionally including means for providing light to said light trap.
Claim 13
Dependent Claim
82 words
A microfabricated therapeutic actuator, comprising: a microtube composed of shape memory polymer material, said shape memory material undergoes a phase transformation at a temperature Tg, whereby heating said material above the temperature Tg enables the material to soften and be reshaped to another configuration, and cooling of the material below the temperature Tg causes the material to stiffen and retain the reshaped configuration until the material is reheated to above the temperature Tg causing the material to return to its original shape.
Claim 14
Dependent Claim
82 words
A microfabricated therapeutic actuator, comprising: a microtube composed of shape memory polymer material, said shape memory material undergoes a phase transformation at a temperature Tg, whereby heating said material above the temperature Tg enables the material to soften and be reshaped to another configuration, and cooling of the material below the temperature Tg causes the material to stiffen and retain the reshaped configuration until the material is reheated to above the temperature Tg causing the material to return to its original shape.
Claim 15
Dependent Claim
26 words
The actuator of claim 12, wherein said shape memory polymer material has a phase transformation temperature Tg in the range of -30° C. to 100° C.
Claim 16
Dependent Claim
40 words
The actuator of claim 12, wherein said microtube of shape memory polymer material has an internal diameter in the range of 100 μm to 1 mm, and an external diameter in the range of 150 μm to over 1 mm.
Claim 17
Dependent Claim
19 words
The actuator of claim 12, in combination with an object to be retained in and release from said microtube.
Claim 18
Dependent Claim
21 words
The actuator of claim 15, wherein said object includes an end section selected from the group consisting of ball-shaped and grooved.
Claim 19
Dependent Claim
13 words
The combination of claim 15, wherein said object is composed of therapeutic material.
Claim 20
Dependent Claim
25 words
The combination of claim 17, wherein said therapeutic material comprises an embolic coil constructed to be delivered via a catheter to a point of use.
Claim 21
Dependent Claim
23 words
The combination of claim 15, wherein said object includes a light trap, and additionally including means for supplying light to said light trap.
Claim 22
Dependent Claim
23 words
The actuator of claim 12, wherein said microtube is constructed to operate in passageways having a diameter of about 250 microns and greater.
Claim 23
Dependent Claim
25 words
The actuator of claim 12, wherein said shape memory polymer material is a polyurethane-based material that undergoes a phase transformation at a temperature of Tg.
Claim 24
Dependent Claim
92 words
A release mechanism, comprising: means for retaining therein and releasing therefrom an object, said means being composed of a shape memory polymer material, said shape memory material undergoes a phase transformation at a temperature Tg, whereby heating said material above the temperature Tg enables the material to soften and be reshaped to another configuration, and cooling of the material below the temperature Tg causes the material to stiffen and retain the reshaped configuration until the material is reheated to above the temperature Tg causing the material to return to its original shape.
Claim 25
Dependent Claim
92 words
A release mechanism, comprising: means for retaining therein and releasing therefrom an object, said means being composed of a shape memory polymer material, said shape memory material undergoes a phase transformation at a temperature Tg, whereby heating said material above the temperature Tg enables the material to soften and be reshaped to another configuration, and cooling of the material below the temperature Tg causes the material to stiffen and retain the reshaped configuration until the material is reheated to above the temperature Tg causing the material to return to its original shape.
Claim 26
Dependent Claim
31 words
The release mechanism of claim 22, additionally including means for reheating of the material from a group of heating sources consisting of thermal heating, heated fluid, resistive heating, and optical heating.
Claim 27
Dependent Claim
20 words
The release mechanism of claim 22, wherein said temperature Tg is in the range of -30° C. to 100° C.
Claim 28
Dependent Claim
18 words
The release mechanism of claim 22, wherein said shape memory polymer material is configured as a hollow member.
Claim 29
Dependent Claim
37 words
The release mechanism of claim 25, wherein said hollow member has an internal diameter in the range of 100 μm to 1000 μm, and an external diameter in the range of 150 μm to over 1 mm.
Claim 30
Dependent Claim
20 words
The release mechanism of claim 22, in combination with an object to be retained in and released from said means.
Claim 31
Dependent Claim
12 words
The combination of claim 27, wherein said object includes a ball-shaped end.
Claim 32
Dependent Claim
12 words
The combination of claim 27, wherein said object includes a grooved end.
Claim 33
Dependent Claim
32 words
The combination of claim 27, wherein said object to be retained in and released from said microtube includes a light trap, and additionally including means for providing light to said light trap.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-08-15 | 2004-02-14 | 2004-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-08-15 | 2008-02-14 | 2008-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-08-15 | 2012-02-14 | 2012-08-15 | $7700.00 | Window Closed / Lapsed |