text:
A process for producing a carbon foam heat sink is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications. The foam is encased and filled with a phase change material to provide a very efficient heat sink device.
1. A temperature control apparatus for aiding in maintaining the temperature of an object in contact therewith below 1800� C. comprising an encased carbon foam containing in at least some of its pores a phase change material that melts at an elevated temperature above about 800� C. but does not vaporize below 1800� C.
2. An apparatus as defined in
3. An apparatus as defined in
4. An apparatus as defined in
5. A temperature control apparatus for aiding in maintaining the temperature of an object in contact therewith below 1200� C. comprising an encased carbon foam containing in at least some of its pores a phase change material that melts at an elevated temperature above about 800� C. but does not vaporize below 1200� C.
6. An apparatus as defined in
7. An apparatus as defined in
8. An apparatus as defined in
This application is a (1) divisional of U.S. patent application Ser. No. 09/489,640 filed on Jan. 24, 2000 now U.S. Pat. No. 6,780,505, which itself is a (2) continuation of U.S. patent application Ser. No. 09/093,406, filed on Jun. 8, 1998 now U.S. Pat. No. 6,037,032, which is itself a continuation-in-part of U.S. patent application Ser. No. 08/921,875 filed Sep. 2, 1997 now U.S. Pat. No. 6,033,506 and U.S. patent application Ser. No. 08/923,877 filed on Sep. 2, 1997 now abandoned, and (3) a continuation-in-part of U.S. patent application Ser. No. 09/337,027 filed Jun. 25, 1999 now U.S. Pat. No. 6,261,485, which itself is a continuation of U.S. patent application Ser. No. 08/921,875 filed Sep. 2, 1997, and (4) a continuation-in-part of U.S. patent application Ser. No. 09/136,596 filed Aug. 19, 1998 now U.S. Pat. No. 6,398,343, which itself is a divisional of U.S. patent application Ser. No. 08/92 1,875 filed Sep. 2, 1997.
This application is a continuation-in-part of an earlier filed U.S. patent application-Ser. No. 08/921,875, filed on Sep. 2, 1997, and U.S. patent application Ser. No. 08/923,877, filed Sep. 2, 1997, both of which are herein incorporated in their entirety by reference.
The United States Government has rights in this invention pursuant to contract No. DE-AC05-960R22464 between the United States Department of Energy and Lockheed Martin Energy Research Corporation.
The present invention relates to porous carbon foam filled with phase change materials and encased to form a heat sink product, and more particularly to a process for producing them.
There are currently many applications that require the storage of large quantities of heat for either cooling or heating an object. Typically these applications produce heat so rapidly that normal dissipation through cooling fins, natural convection, or radiation cannot dissipate the heat quickly enough and, thus, the object over heats. To alleviate this problem, a material with a large specific heat capacity, such as a heat sink, is placed in contact with the object as it heats. During the heating process, heat is transferred to the heat sink from the hot object, and as the heat sink's temperature rises, it "stores" the beat more rapidly than can be dissipated to the environment through convection. Unfortunately, as the temperature of the heat sink rises the heat flux from the hot object decreases, due to a smaller temperature difference between the two objects. Therefore, although this method of energy storage can absorb large quantities of heat in some applications, it is not sufficient for all applications
Another method of absorbing heat is through a change of phase of the material, rather than a change in temperature. Typically, the phase transformation of a material absorbs two orders of magnitude greater thermal energy than the heat capacity of the material. For example, the vaporization of 1 gram of water at 100� C. absorbs 2,439 joules of energy, whereas changing the temperature of water from 99� C. to 100� C. only absorbs 4.21 Joules of energy. In other words, raising the temperature of 579 grams of water from 99� C. to 100� C. absorbs the same amount of heat as evaporating 1 gram of water at 100� C. The same trend is found at the melting point of the material. This phenomenon has been utilized in some applications to either absorb or evolve tremendous amounts of energy in situations where heat sinks will not work.
Although a solid block of phase change material has a very large theoretical capacity to absorb heat, the process is not a rapid one because of the difficulties of heat transfer and thus it cannot be utilized in certain applications. However, the utilization of the high thermal conductivity foam will overcome the shortcomings described above. If the high conductivity to foam is filled with the phase change material, the process can become very rapid. Because of the extremely high conductivity in the struts of the foam, as heat contacts the surface of the foam, it is rapidly transmitted throughout the foam to a very large surface area of the phase change material. Thus, heat is very quickly distributed throughout the phase change material, allowing it to absorb or emit thermal energy extremely quickly without changing temperature, thus keeping the driving force for heat transfer at its maximum.
Heat sinks have been utilized in the aerospace community to absorb energy in applications such as missiles and aircraft where rapid heat generation is found. A material that has a high heat of melting is encased in a graphite or metallic case, typically aluminum, and placed in contact with the object creating the heat. Since most phase change materials have a low thermal conductivity, the rate of heat transfer through the material is limited, but this is offset by the high energy absorbing capability of the phase change. As heat is transmitted through the metallic or graphite case to the phase change material, the phase change material closest to the heat source begins to melt. Since the temperature of the phase change material does not change until all the material melts, the flux from the heat source to the phase change material remains relatively constant. However, as the heat continues to melt more phase change material, more liquid is formed. Unfortunately, the liquid has a much lower thermal conductivity, thus hampering heat flow further. In fact, the overall low thermal conductivity of the solid and liquid phase change materials limits the rate of heat absorption and, thus, reduces the efficiency of the system.
Recent developments of fiber-reinforced composites, including carbon foams, have been driven by requirements for improved strength, stiffness, creep resistance, and toughness in structural engineering materials. Carbon fibers have led to significant advancements in these properties in composites of various polymeric, metal, and ceramic matrices.
However, current applications of carbon fibers have evolved from structural reinforcement to thermal management in application ranging from high-density electronic modules to communication satellites. This has stimulated research into novel reinforcements and composite processing methods. High thermal conductivity, low weight, and low coefficient of thermal expansion are the primary concerns in thermal management applications. See Shih, Wei, "Development of Carbon-Carbon Composites for Electronic Thermal Management Applications," IDA Workshop, May 3–5, 1994, supported by AF Wright Laboratory under Contract Number F33615-93-C-2363 and AR Phillips Laboratory Contract Number F29601-93C-0165 and Engle, G. B., "High Thermal Conductivity C/C Composites for Thermal Management," IDA Workshop, May 3–5, 1994, supported by AF Wright Laboratory under Contract F33615-93-C-2363 and AR Phillips Laboratory Contract Number F29601-93-C-0165. Such applications are striving towards a sandwich type approach in which a low-density structural core material (i.e. honeycomb or foam) is sandwiched between a high thermal conductivity facesheet. Structural cores are limited to low density materials to ensure that the weight limits are not exceeded. Unfortunately, carbon foams and carbon honeycomb materials are the only available materials for use in high temperature applications (>1600� C.). High thermal conductivity carbon honeycomb materials are extremely expensive to manufacture compared to low conductivity honeycombs, therefore, a performance penalty is paid for low cost materials. High conductivity carbon foams are also more expensive to manufacture than low conductivity carbon foams, in part, due to the starting materials.
In order to produce high stiffness and high conductivity carbon foams, invariably, a pitch must be used as the precursor. This is because pitch is the only precursor which forms a highly aligned graphitic structure which is a requirement for high conductivity. Typical processes utilize a blowing technique to produce a foam of the pitch precursor in which the pitch is melted and passed from a high pressure region to a low pressure region. Thermodynamically, this produces a "Flash," thereby causing the low molecular weight compounds in the pitch to vaporize (the pitch boils), resulting in a pitch foam. See Hagar, Joseph W. and Max L. Lake, "Novel Hybrid Composites Based on Carbon Foams," Mat. Res. Soc. Symp ., Materials Research Society, 270:29–34 (1992); Hagar, Joseph W. and Max L. Lake, "Formulation of a Mathematical Process Model Process Model for the Foaming of a Mesophase Carbon Precursor," Mat. Res. Soc. Symp., Materials Research Society, 270:35–40 (1992); Gibson, L. J. and M. F. Ashby, Cellular Solids: Structures & Properties, Pergamon Press, New York (1988); Gibson, L. J., Mat. Sci. and Eng A110, 1 (1989); Knippenberg and B. Lersmacher, Phillips Tech. Rev., 36(4), (1976); and Bonzom, A., P. Crepaux and E. J. Moutard, U.S. Pat. No. 4,276,246, (1981). Then, the pitch-foam must be oxidatively stabilized by heating in air (or oxygen) for many hours, thereby, crosslinking the structure and "stabilizing" the pitch so it does not melt during carbonization. See Hagar, Joseph W. and Max L. Lake, "Formulation of a Mathematical Process Model Process Model for the Foaming of a Mesophase Carbon Precursor, Mat. Res. Soc. Symp., Materials Research to Society, 270:35–40 (1992); and White, J. L., and P.M. Shaeffer. Carbon, 27:697 (1989). This is a time consuming step and can be an expensive step depending on the part size and equipment required. The "stabilized" or oxidized pitch is then carbonized in an inert atmosphere to temperatures as high as 1100� C. Then, graphitization is performed at temperatures as high as 3000� C. to produce a high thermal conductivity graphitic structure, resulting in a stiff and very thermally conductive foam.
Other techniques utilize a polymeric precursor, such as phenolic, urethane, or blends of these with pitch. See Hagar, Joseph W. and Max L. Lake, "Idealized Strut Geometries for Open-Celled Foams," Mat. Res. Soc. Symp., Materials Research Society, 270:41–46 (1992); Aubert, J. W., MRS Symposium Proceedings, 207:117–127 (1990); Cowlard, F. C. and J. C. Lewis, J. of Mat. Sci., 2:507–512 (1967); and Noda, T., Inagaki and S. Yamada, J. of Non-Crystalline Solids, 1:285–302, (1969). High pressure is applied and the sample is heated. At a specified temperature, the pressure is released, thus causing the liquid to foam as volatile compounds are released. The polymeric precursors are cured and then carbonized without a stabilization step. However, these precursors produce a "glassy" or vitreous carbon which does not exhibit graphitic structure and, thus, has low thermal conductivity and Low stiffness. See Hagar, Joseph W. and Max L. Lake, "Idealized Strut Geometries for Open-Celled Foams," Mat. Res. Soc. Symp., Materials Research Society, 270:41–46 (1992).
In either case, once the foam is formed, it is then bonded in a separate step to the facesheet used in the composite. This can be an expensive step in the utilization of the foam.
The extraordinary mechanical properties of commercial carbon fibers are due to the unique graphitic morphology of the extruded filaments. See Edie, D. D., "Pitch and Mesophase Fibers," in Carbon Fibers, Filaments and Composites, Figueiredo (editor), Kluwer Academic Publishers, Boston, pp. 43–72 (1990). Contemporary advanced structural composites exploit these properties by creating a disconnected network of graphitic filaments held together by an appropriate matrix. Carbon foam derived from a pitch precursor can be considered to be an interconnected network of graphitic ligaments, or struts, as shown in
The process of this invention overcomes current manufacturing limitations by avoiding a "blowing" or "pressure release" technique to produce the foam. Furthermore, an oxidation stabilization step is not required, as in other methods used to produce pitch based carbon foams with a highly aligned graphitic structure. This process is less time consuming, and therefore, will be lower in cost and easier to fabricate. The foam can be produced with an integrated sheet of high thermal conductivity carbon on the surface of the foam, thereby producing a carbon foam with a smooth sheet on the surface to improve heat transfer.
An object of the present invention is production of encased high thermal conductivity porous carbon foam filled with a phase change material wherein tremendous amounts of thermal energy are stored and emitted very rapidly. The porous foam is filled with a phase change material (PCM) at a temperature close to the operating temperature of the device. As heat is added to the surface, from a heat source such as a computer chip, friction due to re-entry through the atmosphere, or radiation such as sunlight, it is transmitted rapidly and uniformly throughout the foam and then to the phase change material. As the material changes phase, it absorbs orders of magnitude more energy than non-PCM material due to transfer of the latent heat of fusion or vaporization. Conversely, the filled foam can be utilized to emit energy rapidly when placed in contact with a cold object.
Non-limiting embodiments disclosed herein are a device to rapidly thaw frozen foods or freeze thawed foods, a design to prevent overheating of satellites or store thermal energy as they experience cyclic heating during orbit, and a design to cool leading edges during hypersonic flight or re-entry from space.
Another object of the present invention is to provide carbon foam and a composite from a mesophase or isotropic pitch such as synthetic, petroleum or coal-tar based pitch. Another object is to provide a carbon foam and a composite from pitch which does not require an oxidative stabilization step.
These and other objectives are accomplished by a method of producing carbon foam heat sink wherein an appropriate mold shape is selected and preferably an appropriate mold release agent is applied to walls of the mold. Pitch is introduced to an appropriate level in the mold, and the mold is purged of air by applying a vacuum, for example. Alternatively, an inert fluid could be employed. The pitch is heated to a temperature sufficient to coalesce the pitch into a liquid which preferably is of about 50� C. to about 100� C. above the softening point of the pitch. The vacuum is released and an inert fluid applied at a static pressure up to about 1000 psi. The pitch is heated to a temperature sufficient to cause gases to evolve and foam the pitch. The pitch is further heated to a temperature sufficient to coke the pitch and the pitch is cooled to room temperature with a simultaneous and gradual release of pressure. The foam is then filled with a phase change material and encased to produce an efficient heat storage product.
In another aspect, the previously described steps are employed in a mold composed of a material such that the molten pitch does not adhere to the surface of the mold.
In yet another aspect, the objectives are accomplished by the carbon foam product produced by the methods disclosed herein including a foam product with a smooth integral facesheet.
In still another aspect a carbon foam composite product is produced by adhering facesheets to the carbon foam produced by the process of this invention.
In order to illustrate the carbon foam heat sink product of this invention, the following examples are set forth. They are not intended to limit the invention in any way.
Acetic acid has a heat of melting of 45 J/g at a melting point of 11� C. The heat of melting of food, primarily ice, is roughly 79 J/g at 0� C. Therefore, take a block of foam and fill it with liquid acetic acid at room temp. The foam will be encased in a box made from an insulating polymer such as polyethylene on all sides except the top. The top of the foam/acetic acid block will be capped with a high thermal conductivity aluminum plate that snaps into place thus sealing the foam/acetic acid inside the polymer case (illustrated in
Produce a carbon-carbon composite with the foam in which the foam is a core material with carbon-carbon face sheets (
Currently, the shuttle orbiter experiences extreme heats during reentry. Specifically, the leading edges of the craft can reach 1800� C. and the belly of the craft can reach temperatures as high as 1200� C. If a foam core composite panel is placed at the surface of the leading edges and at the surface of the belly (
For example, Germanium has a heat of formation (heat of melting) of 488 J/g. This would require 1.0 Kg of Germanium to reduce the temperature of 1 Kg of existing carbon/carbon heat-shield by 668� C. In other words, if the existing carbon-carbon were replaced pound-for-pound with germanium filled foam, the maximum temperature of the heat shield would only be about 1131� C. instead of about 1800� C. during re-entry, depending on the duration of thermal loading.
Pitch powder, granules, or pellets are placed in a mold with the desired final shape of the foam. These pitch materials can be solvated if desired. In this example, Mitsubishi ARA-24 mesophase pitch was utilized. A proper mold release agent or film is applied to the sides of the mold to allow removal of the part. In this case, Boron Nitride spray and Dry Graphite Lubricant were separately used as a mold release agent. If the mold is made from pure aluminum, no mold release agent IS necessary since the molten pitch does not adhere to the aluminum and, thus, will not stick to the mold. Similar mold materials may be found that the pitch does not adhere and, thus, they will not need mold release. The sample is evacuated to less than 1 torr and then heated to a temperature approximately 50 to 100� C. above the softening point. In this case where Mitsubishi ARA24 mesophase pitch was used, 300� C. was sufficient. At this point, the vacuum is released to a nitrogen blanket and then a pressure of up to 1000 psi is applied. The temperature of the system is then raised to 800� C., or a temperature sufficient to coke the pitch which is 500� C. to 1000� C. This is performed at a rate of no greater than 5� C./min. and preferably at about 2� C./min. The temperature is held for at least 15 minutes to achieve an assured soak and then the furnace power is turned off and cooled to room temperature. Preferably the foam was cooled at a rate of approximately 1.5� C./min. with release of pressure at a rate of approximately 2 psi/min. Final foam temperatures for three product runs were 500� C., 630� C. and 800� C. During the cooling cycle, pressure is released gradually to atmospheric conditions. The foam was then heat treated to 1050� C. (carbonized) under a nitrogen blanket and then heat treated in separate runs to 2500� C. and 2800� C. (graphitized) in Argon.
Carbon foam produced with this technique was examined with photomicrography, scanning electron microscopy (SEM), X-ray analysis, and mercury porisimetry. As can be seen in the
A thermogravimetric study of the raw pitch was performed to determine the temperature at which the volatiles are evolved. As can be seen in
Samples from the foam were machined into specimens for measuring the thermal conductivity. The bulk thermal conductivity ranged from 58 W/m�K to 106 W/m�K. The average density of the samples was 0.53 g/cm3. When weight is taken into account, the specific thermal conductivity of the pitch derived from foam is over 4 times greater than that of copper. Further derivations can be utilized to estimate the thermal conductivity of the struts themselves to be nearly 700 W/m�K. This is comparable to high thermal conductivity carbon fibers produced from this same ARA24 mesophase pitch.
X-ray analysis of the foam was performed to determine the crystalline structure of the material. The x-ray results are shown in
The compression strength of the samples were measured to be 3.4 MPa and the compression modulus was measured to be 73.4 MPa. The foam sample was easily machined and could be handled readily without fear of damage, indicating good strength.
It is important to note that when this pitch is heated in a similar manner, but only under atmospheric pressure, the pitch foams dramatically more than when under pressure. In fact, the resulting foam is so fragile that it could not even be handled to perform tests. Molding, under pressure serves to limit the growth of the cells and produces a usable material.
An alternative to the method of Example 4 is to utilize a mold made from aluminum. In this case two molds were used, an aluminum weighing dish and a sectioned soda can. The same process as set forth in Example 4 is employed except that the final coking temperature was only 630� C., so as to prevent the aluminum from melting.
In the second case, as shown in
The following examples illustrate the production of a composite material employing the foam of this invention.
Pitch derived carbon foam was produced with the method described in Example 4. Referring to
Pitch derived carbon foam was produced with the method described in Example 4. It was then machined into a block 2″�2″� 1/2″. Two pieces of carbon-carbon material, 2″�2″� 1/2″, were coated lightly with a mixture of 50% ethanol, 50% phenolic Durez� Resin available from Occidental Chemical Co. The foam block and carbon-carbon material were positioned together and placed in a mold as indicated in Example 6. The sample was heated to a temperature of 150� C. at a rate of 5� C./min and soaked at temperature for 14 hours. The sample was then carbonized under nitrogen to 1050� C. and then graphitized to 2800� C., resulting in a foam with carbon-carbon facesheets bonded to the surface. This is also shown generally at 30 in
Pitch derived carbon foam was produced with the method described in Example 4. The foam sample was then densified with carbon by the method of chemical vapor infiltration for 100 hours. The density increased to 1.4 g/cm3, the flexural strength was 19.5 MPa and the flexural modulus was 2300 MPa. The thermal conductivity of the raw foam was 58 W/m�K and the thermal conductivity of the densified foam was 94 W/m�K.
Pitch derived carbon foam was produced with the method described in Example 4. The foam sample was then densified with epoxy by the method of vacuum impregnation. The epoxy was cured at 150� C. for 5 hours. The density increased to 1.37 g/cm3 and the flexural strength was measured to be 19.3 MPa.
Other possible embodiments may include materials, such as metals, ceramics, plastics, or fiber-reinforced plastics bonded to the surface of the foam of this invention to produce a foam core composite material with acceptable properties. Additional possible embodiments include ceramics, glass, or other materials impregnated into the foam for densification.
Based on the data taken to date from the carbon foam material, several observations can be made outlining important features of the invention that include:
1. Pitch-based carbon foam can be produced without an oxidative stabilization step, thus saving time and costs.
2. High graphitic alignment in the struts of the foam is achieved upon graphitization to 2500� C., and thus high thermal conductivity and stiffness will be exhibited by the foam, making them suitable as a core material for thermal-applications.
3. High compressive strengths should be achieved with mesophase pitch-based carbon foams, making them suitable as a core material for structural applications.
4. Foam core composites can be fabricated at the same time as the foam is generated, thus saving time and costs.
5. Rigid monolithic preforms can be made with significant open porosity suitable for densification by the Chemical Vapor Infiltration method of ceramic and carbon infiltrants.
6. Rigid monolithic preforms can be made with significant open porosity suitable for activation, producing a monolithic activated carbon.
7. It is obvious that by varying the pressure applied, the size of the bubbles formed during the foaming will change and, thus, the density, strength, and other properties can be affected.
The following alternative procedures and products can also be effected by the process of this invention:
1. Fabrication of preforms with complex shapes for densification by CVI or Melt Impregnation.
2. Activated carbon monoliths with high thermal conductivity.
3. Optical absorbent.
4. Low density heating elements.
5. Firewall Material
6. Low secondary electron emission targets for high-energy physics applications.
The present invention provides for the manufacture of pitch-based carbon foam heat sink for structural and thermal composites. The process involves the fabrication of a graphitic foam from a mesophase or isotropic pitch which can be synthetic, petroleum, or coal-tar based. A blend of these pitches can also be employed. The simplified process utilizes a high pressure high temperature furnace and thereby, does not require and oxidative stabilization step. The foam has a relatively uniform distribution of pore sizes (−100 microns), very little closed porosity, and density of approximately 0.53 g/cm3. The mesophase pitch is stretched along the struts of the foam structure and thereby produces a highly aligned graphitic structure in the struts. These struts will exhibit thermal conductivities and stiffness similar to the very expensive high performance carbon fibers (such as P-120 and K1100). Thus, the foam will exhibit high stiffness and thermal conductivity at a very low density (−0.5 g/cc). This foam can be formed in place as a core material for high temperature sandwich panels for both thermal a,id structural applications, thus reducing fabrication time. By utilizing an isotropic pitch, the resulting foam can be easily activated to produce a high surface area activated carbon. The activated carbon foam will not experience the problems associated with granules such as attrition, channeling, and large pressure drops.
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Expert Available on Wildfire Policy and Southern California
As wildfires continue to rage across Southern California, burning more than 400,000 acres and destroying more than 1300 homes, people are beginning to ask, "Does this have to happen?" "What can we do to stop this from happening again?"
Char Miller, an expert in U. S. environmental politics and policy, and federal public-lands management, is available to answer these questions as well as:
- If we have to evacuate 500,000 people in San Diego in the face of raging flames, what are we doing wrong?
- Why are the politics of fire as supercharged as conflagrations themselves?
- What makes Southern California so prone to wildfires, and do other places burn like Southern California?
- What changes are necessary in urban development to decrease fire danger to Southern California residents?
- What is the role of urban planning in mitigating fire danger, and why are more rigorous regulations essential?
Miller, a visiting professor of environmental analysis at Pomona College, notes that:
"We have a couple of options. We either accept that we will burn out every few years but don't expect massive amounts of money being spent on rescue. Or, we pay the taxes that are required to underwrite a full-fledged, fire-fighting operation on an annual basis, which neither Californians nor anyone else seem quite willing to do."
"L.A. burns as does Australia, British Columbia, Indonesia, and the Mediterranean basin --anywhere in fact where there are fire-adapted tree species. Putting Los Angeles in its proper context is the only way to understand why Malibu, Lake Arrowhead, and San Diego regularly burn. It is also the only way to develop rigorous restrictions on urban development that will bring it into line with the realities of fire in the Southland."
"One thing flood-prone areas know post-Katrina is that you don't allow people to live in landscapes that you know will kill them. Fire is much more predictable and recurring than floods. The question is why do national, state and local regulations prohibit or discourage people from living in low-lying areas or make it impossible to get flood insurance when there are no such regulations to prohibit people from living in wildfire ecosystems.
"Yes, this would pose a problem for California. Yet we're spending billions fighting this fire and spent hundreds of millions in 2003. You'd think we'd get the hint.
"What's interesting is that Australia, India, British Columbia and elsewhere are wrestling with same problems. They're living in ecosystems that burn up all the time, because that's what they do. At an international conference last week about climate change and forest fires, every single country in the world is wrestling with these same issues: population growth and the sprawling presence of human beings."
Miller is the author of Ground Work: Conservation in American Environmental Culture (2007); Gifford Pinchot and the Making of Modern Environmentalism (2001), winner of the 2002 Independent Publishers Association Biography Prize; and co-author of The Greatest Good: 100 Years of Forestry in America (1999; 2nd ed., 2004). He is also the editor of the forthcoming Cities in Nature: Urban Environments in the American West(University of Nevada Press) and Fluid Arguments: Five Centuries of Western Water Conflict (2001), among other volumes and scores of articles in professional journals.
A visiting professor at Pomona College for the 2007-08 academic year, Miller is teaching Crisis Management: The National Forests and American Culture, Water in the West, Environmental History, and Cities by Nature: Time, Space, Place.
He is based at Trinity University in San Antonio, Texas, where he has been a member of the history faculty since 1981 and director of Urban Studies since 2001. In 2007, he was named a Distinguished Lecturer for the Organization of American Historians and in 2002 was recognized as a Piper Professor, a state-wide honor awarded by the Minnie Stevens Piper Foundation for excellence in teaching and service to higher education in Texas. He earned his Ph.D. from The Johns Hopkins University.
Char Miller can be reached at his office (909) 607-8343 or at email@example.com

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Welcome to Australian Mantlepiece Company . . .
Australian Mantlepiece Company Firegrates combine the expertise and experience of Australia's oldest creative fireplace specialists for over 25 years. Our design and manufacture work includes unique hand crafted Mantlepieces and Fireside accessories for both traditional and contemporary fireplace concepts.
"The Creative Fireplace Specialists!"
We offer you the widest possible range of quality products and services, from original Victorian, Edwardian and Georgian timber and marble Mantelpieces & Firegrates. We can meet your needs to Art Deco and ultra modern styles with our custom made creations.
We also provide a chimney design and construction service, consultants for chimney problems, repairs, renovations and spare parts. Whilst our speciality is custom made items, our showroom also features an exclusive range of firegrates, screens, firetools, Gasfires and other accessories. Specialists in the repair and replacement of parts for Victorian and Edwardian cast iron grates and provide complete replacement & inserts if required.
Australian Mantlepiece and Antique Firegrates prides itself on a solid reputation, offering a complete service from start to finish. All our works are managed by our small, long serving team of trades people and artisans with our clients benefiting from our continuity and attention to detail throughout every project.


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ConnectLine and your TV 10/05/2010 01:07 PM 10/13/2010 03:11 PM
ConnectLine TV Adaptor -

Finally there's a BluetoothTM TV solution that solves the latency problem.

Attractive and unobtrusive, this small adaptor connects to the output of any TV and runs on its own power supply. Your patients can then enjoy high quality audio - streaming binaurally through their hearing instruments. They can listen at their own preferred volume level and without the latency delay problem of off-the-shelf Buuetooth transmitters. There is no need for recharging and no additional gadgets or loop installation. The ConnectLine adapter pairs to Streamer with a punch of the button and then connects automatically whenever the streamer is activated.

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The Jericho is a "Baby Desert Eagle", made in Israel.
Pretty decent gun.
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Rippling Waters
Rippling Waters
Next Steps:
Features of this Property
- Jacuzzi/Whirlpool
- Woodburning Fireplace
- High Speed Internet Access
- Elderly Friendly
- Charcoal Grill
- Lush Wooded View
Property Description
Regular rate for 2 adults $89 per night
Peak rate for 2 adults $109
Service Fee $25.00
One Level - Queen bedroom suite with two-person whirlpool, Living Room/ Dining area/ Kitchen - One Big room
Area beside house offers a picnic area with park grill
25" color television
DVD Player
High Speed Internet Access
FREE Unlimited Long Distance
It's great to know before you go! We have vacation rentals you can believe in. All the reviews displayed here are 100% verified to come from past guests.
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Address: 112 Cook Drive/Ski Mtn Rd., Gatlinburg, TN 37738
Need Reservation Help? Contact us at firstname.lastname@example.com for assistance.


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Licensed Roofing Contractors In Gilbert, Mesa, AZ
Welcome to Payne & Sons Construction, a family owned and operated Phoenix, Mesa, Gilbert roofing contractor. Our company has helped many homeowners with their roofing needs in the Phoenix, Mesa, Gilbert and Chandler areas for more than 25 years. We strive to achieve excellence with every Mesa roofing job we earn. Our team of professionally licensed Phoenix roofers are here to fix or install your new roof with the highest quality of both service and integrity. There are many options when it comes to roofing from Phoenix tile roofing, foam roofing, shingle roofs and more.
Your roof is a very important part of your home and any damage to your Arizona roof must be handled immediately by professionals. We are fully licensed, bonded and insured to handle any type of home improvement work needed in your home as an Arizona General Contractor. We execute Mesa roofing on the highest level of quality with rates that are affordable to all. It's time to find out why choosing Payne & Sons Construction is the right decision for all of your Phoenix roofing needs. We are available for all of your roofing damage repairs, or new installations day or night. Just call us or email us now for immediate assistance.
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We provide roofing and roof installation services in the following Arizona cities:
Phoenix, Tempe, Scottsdale, Mesa, Gilbert, Chandler, Queen Creek, Maricopa, Apache Junction


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Hundreds of people protested in front of the Japanese embassy in Beijing on Saturday amid rising tensions over disputed East China Sea islands as police struggled to quell the angry demonstration.
The protests were held after the Japanese government earlier this week announced the completion of its purchase of the islands, which it administers and calls Senkaku, but which China claims and calls Diaoyu.
Six Chinese ships sailed into waters around the archipelago Friday, with Beijing saying they were there for "law enforcement", leading Tokyo to summon the Chinese ambassador to protest what it insisted was an incursion into its territory.
An AFP photographer saw objects being thrown outside the embassy as police attempted to hold back angry crowds. Roads were cordoned off and a helicopter hovered overhead monitoring the protest.
Demonstrators have staged protests in front of the embassy for most of the week. On Thursday, hundreds sang the Chinese national anthem and waved flags to condemn Tokyo's purchase of the disputed island chain.
China and Japan are Asia's two biggest economies with close trade and business ties. The political relationship, however, is often tense due to the territorial dispute and Chinese resentment over historical issues.
A Japanese diplomat told AFP on Friday that Tokyo had issued a safety warning to its citizens in China after six "serious" cases of assault and harassment.
Agence France-Presse


text: Smaller schools? More charters? Those are yesterday's headlines in the world of school reform. The hot-button topic now is the inclusion of student test scores in teacher evaluations. Yet as school administrators and the teachers union battle it out in current contract negotiations in Los Angeles, who would have guessed that state law addressed this issue long ago?


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Try With These Products:
- $46.99
- Beauty Club Card $44.99
- $59.99
- Beauty Club Card $57.99
- From $2.99 - $7.99
- Beauty Club Card $2.79
- $4.49
- Beauty Club Card $3.99
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Hot Shot Tools Nano Ceramic Taper Iron 1 Inch
By Hot Shot Tools
Sally Item # SBS-510323
In Stock Online, Available In Sally Stores
Quantity: One
Diameter: 1''
- $45.99
- Beauty Club Card $42.99
We're sorry, this product cannot ship to the following locations: Canada
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Additional Information
- Forms diverse natural-looking curls
- Tapered nano ceramic 1" barrel
- Includes heat resistant glove
- Pulse-auto heat control
Hot Shot Tools Nano Ceramic Taper Iron has a tapered barrel that allows you to make either tight or looser curls, depending on where you wrap your hair.
Designed with Pulse Auto-Heat Control which maintains precise temperatures for uniterupted, consisten heat. Heats up quickly and heat recovery is instant.
Nano Ceramic emits far-infrared heat that is kinder to hair, seals the cuticle and eliminates frizz, leaving hair soft and shiny. When used on curly hair it tames frizz and controls curls.
Professional salon quality features include a rheostat control with variable heat settings up to 450°F. A non-slip padded grip allows for comfort and precision control.
Safety features include a an extra-long cool tip and build in foldaway safety stand. Separate On/Off switch and 8-ft. professional swivel cord.
Bonus! Includes a Heat-resistant Glove.
Share your look or technique and get featured
Share your look or technique and get featured
Hot Shot Tools Nano Ceramic Taper Iron 4 4
Worst curling iron ever This curling iron burnt my hair. I tried it at different settings but this iron just kept burning my hair. July 12, 2014
Love it I got this for my 8 year old girl, it does a really great job, the curls last all day.Heats up fast,I love it I would buy again. February 8, 2013
Love them! This was the first time I used a taper curling iron. It took some getting used to but i totally love it. Makes beautiful, smooth curls that most of the time last through our Louisiana heat. I've used these irons to do a couple of wedding parties and it cut my time down almost in half! LOVE THEM! August 26, 2012
Best Purchase EVER! I have never had good luck with curling irons, EVER. I have gone through about 5 or 6 with no luck ever. This curler is heaven in a box! It is the best curler I have ever put on my hair, salon and home appliances! The heat up time is less than 5 minutes, gives you the perfect curl for a 10-15 second hold around the barrel, with medium-long hair that is thick i can do my hair from root to tip in 20 minutes, can make the perfect tight or loose curls, curls hold ALL night, with or without hair spray! FOR EXAMPLE: I curled my hair in loose curls at about 8:30AM for a birthday party that evening. I went to work all day until 9:30PM (I work in a toy store & it was just before Christmas so it was VERY busy), went to the birthday party afterwards & my hair was still done as though it was 9:00AM! Recommend this to anyone and everyone, best product EVER! I WILL NEVER GO BACK! February 3, 2012
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RICHMOND, Va (WTVR) – The foreclosure notices were mounting on the kitchen table and so were the packed boxes in the living room.
"I'm embarrassed of my situation," said Rain Burroughs.
It was a nerve-wracking situation for Burroughs and her daughter, who were just hours away from being put out of their home if they couldn't come up with $13,000 by Thursday.
"I'm a doer. I wasn't doing for myself," said Burroughs.
Instead, she'd been doing for others. During the last few years, Burroughs led many demonstrations, including an Occupy Richmond protest next to the home of Richmond Mayor Dwight Jones. However this time, she had to make sure her home stayed occupied.
"I'm getting goose bumps thinking about it. People should have hope and ask for help," said Burroughs.
That's exactly what she did, putting together a web video that went viral. People responded, not just with web clicks, but checks that added up to more than $15,000 in just two days. "I was like, it just can't be done, but, it's done," said Burroughs.
"This cause is bigger than she is," said marketing expert Dave Saunders. Saunders told CBS 6, the family was able to raise the money so quickly, not just because of the power of Twitter and Facebook, but because people understand what Burroughs is going through.
"She hit a cord. With so many Americans right now fighting foreclosure and so many people having a hard time trying to pay their bills," said Saunders.


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Both Elementary and Intermediate Chinese courses are offered. Please consult MTSU's online class schedule for class hours and other course information.
Study abroad program
Interested students can participate in KIIS's China program.
For further information
If you have any questions concerning Chinese study at MTSU, please feel free to contact us using the contact form at this website .


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Australia's largest manufacturer of equine flyveils that guarantee quality, exceptional design and pricing. Proudly made in country Victoria, Australia.
Exciting new product this season!
100% Blockout Shaped Noses
We have taken our most popular nose cover design and added white ripstop canvas to the mesh creating the ultimate UV protection while still allowing room around the nostrils.


text:
Posted 3 years ago
By Post Staff
NORTH PLATTE, Neb. (AP) – A North Platte man who spent more than a decade in prison for killing an 18-year-old girl is now facing several drug charges.
North Platte Police arrested 29-year-old Tyler Keup (KEP) on Sunday on suspicion of helping distribute methamphetamine. Keup faces additional charges because he was carrying a knife, marijuana and some of the drug Adderall.
Keup was released from prison in 2011 after an appeal because he was 16 when he shot Maricella Martinez and the judge ruled he couldn't form the intent to kill. He was originally sentenced to 30-60 years.
Keup's attorney didn't immediately respond to a message.
Keup remained jailed Tuesday on $250,000 bond.
A 30-year-old woman who was riding in Keup's car is also facing charges because she had drug paraphernalia and a knife.


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Surry Village Charter School is a tuition-free public school alternative. We teach the Common Core with a project-based approach that instills a true passion for learning in students. If you're looking for a different learning environment for your child, then the small, multi-grade classrooms at Surry Village Charter School could be the right choice for you.
|Matora Fiorey - Director
|Office Support
|Nicole Conroy - Office Manager
|Classroom Teachers
|Jennifer Wichland - Kindergarten
|Fawn Woudenberg - 1st/2nd
|Sarah Gray - 3rd/4th
|Deb McGahie - 5th/6th
|Anne Guerriero - 7th/8th
|Classroom Assistants
|Georgia Tasoulas - 1st/2nd
|Jan Walters - Kindergarten
Sheila Vara- 3rd/4th
|Karen Newell - 5th/6th
Angela Winchester- 5th/6th
Amy Dearth - 7th/8th
|Enrichment Teachers
|Judy Dubriske - PE
|Greenough Nowakoski - Spanish
Anna Johnson - Music/Band
|Special Education
|Barbara Bryce - SPED liaison
Kirsten Smith - Special Educator
Joanne Dexter
Title I
|Gretchen Tillson
Kerri Harrington
Before Care
|Jan Walters
After Care
|Amy Dearth
|Erin Bowen
|Catherine Seltzer
|Jon Scott - Custodian
|Keith Fiorey - Facility Manager


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|The most helpful favorable review
|The most helpful critical review
3 of 3 people found the following review helpful:
By Andrew from Canada on 2010-12-25 10:29:03Things I liked:Well, It look's like Daisy went and changed their pellet design again, but this time for the better. The pellet's lead composition has changed, as well as the pellet's design, Gone is the overly graphiteized , and soft lead composition. It seems that a little more antimony is being used, and the skirt is sloped much like a Crosman Premeir to the head of the round. The skirts are a tad thicker, and very uniform now. On the range, these pellet's are surprisingly accurate now,much more so than the old design, and like before one of the most inexpensive pellets you can purchase, Plink all day with out spending alot of money.
Things I would have changed:In all honesty, Not a thing,,Thank's Daisy, for listening to your customer's. Two thumbs up!
What others should know:Guy's, These are definately not your Dad's "Daisy's. If you haven't tried these out for a while, I urge you to give them another try, You'll be pleasantly surprised. At 14gr,. they're the right weight for most sub-FAC a/g's. I'm getting excellent groupings on the range, and they don't turn your fingers black after 10 minutes of shooting. I will put these round's to the test in the new year on my next JackRabbit hunt, and will follow up with another review. Cheer's, and Happy Huntin', Andy.
0 of 0 people found the following review helpful:
By KEVIN from USA on 2013-04-23 16:48:36Things I liked:Cheapest 22 pellet avalable makes them a perfect choice for braking in a new barrel. Just dont expect them to have any real accuracy beyond 30 yards.
Things I would have changed:These are the dirtyest, most deformed pellets I have ever seen. I have a can in .177 that were horrible. For some reason, I thought I'd give them another try, this time in .22 cal. NOPE. They were WORSE than the .177's! Deformed skirts are the NORM. It took me 120 pellets sorted through and hand picked to find 10 good ones for accuracy potential. (Still not that great, even when hand picked) I done this in both the .177 pile I had for the Crosman 760, and the .22's I just got in for my new Crosman Nitro Venom rifle I just got from Pyramid. The BEST hand picked, washed pick of the litter with a clean barrel 5 shot group I got with these at 30 yards was 2.75". I then shot a UNSORTED group, just picking pellets randomly out of the tin, and got a 4.9" shot group. :-/ I then switched to the Eun Jin .22 Cal. 32.4 Grain pointed pellet without cleaning the barrel and fired a 5 shot 1.25" group!
|By nikolaos from USA on 2014-07-16
|By randall from USA on 2015-05-19
|By RonaldDale from USA on 2014-03-15
|By William Davis from USA on 2011-12-14
|By Nicholas from USA on 2011-04-17
|By Paul from USA on 2011-05-15
CheckoutSubtotal (USD):
does not include shipping and tax


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1966 Mercedes Benz 230SL '66 Mercedes Benz 230SL in red with black interior and comes with a soft top only. Equipped with a manual transmission.... More
1962 Mercedes Benz 220SE Cabriolet '62 Mercedes Benz 220SE Cabriolet in black with beautiful red interior and a black canvas soft top. A very... More
This beautiful 1969 high grill mercedes 280se cabroliet has been restore 4 years ago with new paint,top,,leather and chrome.It drives as nice as it... More
1961 MERCEDES BENZ 190SL DB 334 Light Blue This very nice driver would be an excellent candidate for a partial restoration or to enjoy for the weekend. Overall... More
Chequered Flag International is pleased to offer this 1966 Mercedes 230 SL in its original colors of Black (code 040) with Black (040)... More
1967 Mercedes-Benz 250SL '67 Mercedes-Benz 250SL with 2 tops in red with white interior. Comes equipped with an automatic transmission and euro lamps. Originally... More
1965 Mercedes-Benz 230SL '65 Mercedes-Benz 230SL with 2 tops in white with red interior. Comes equipped with a manual transmission and air conditioning and spot... More
PRICE IN EUROS : 69950,- Beautiful Mercedes 280 SL Pagode in a very good and healthy condition. Delicious drivers car with perfect fits for all... More
*1967 250SE Coupe *Blue Paint *Parchment Vinyl Interior *Very Good Condition *Air Conditioning *Recent upgrades done by Bud's -Fuel Injection and Tuning -Shifter Bushings -Clutch assembly and mounts -Full brake job (calipers, rotors,... More
PRICE IN EUROS 114950,- Very nice European delivered Mercedes Benz 190 SL Roadster. Restored and engine overhauled some years ago. Equipped with its original... More
Mercedes Benz 300 SE Coupe W112 1964 in good condition 1964 Mercedes Benz 300SE Coupe. It is an old restoration and the car is in... More
Mercedes Benz 280 SL Pagode 1968 projectcar 1968 Mercedes Benz 280 SL. A very good and solid base for complete restoration. This car has the... More
Park Place Ltd is pleased to present this gorgeous 1961 Mercedes 190SL Roadster in Red over Black leather interior featuring a black hardtop with... More
1963 Mercedes-Benz 190SL '63 Mercedes-Benz 190SL in primer but originally came from the factory 40G black with white interior. Same owner since 1979. Solid body.... More
1967 Mercedes-Benz 250SL '67 Mercedes-Benz 250SL with 2 tops in burgundy with cognac interior. Comes equipped with an automatic transmission. Very presentable car as is.... More


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Transform static artwork into interactive Flash-based content without writing code.
Shows how to use Illustrator CS5 to create graphics for use in web sites, video compositions, and mobile apps.
Demonstrates how to create and publish interactive Flash (SWF) content without writing code.
Every aspect of integrating Illustrator and Flash, such as using mobile applications and working with colors, symbols, and text.
Mordy Golding explains how to create Illustrator files that will work efficiently in Flash using Live Paint, Live Trace, and Live Effects.
"Your service has educated me so much that I've taken my web design business to a level I never thought I would get to. I learned Photoshop, Flash, InDesign, and Illustrator. With your help I can provide a service in my area that no one else can match." —Ernesto O.
more from our members »


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Colbert Moran Funeral Home
Melba Fitzgerald Barbour
(May 2, 1945 - May 19, 2010)
Gretna......Melba Fitzgerald Barbour, age 65 of 4389 Blue Ridge Drive, Gretna went home to be reunited with her ancestors and maker Wednesday, May 19, 2010 at her home surrounded by her family. Melba was born May 2, 1945 in Pittsylvania County and was the daughter of the late George Thomas Fitzgerald and Nannie Ella Rowland Fitzgerald. She was predeceased by her husband, Larry "Pete" Barbour, and a daughter, Penny Barbour Wright. She was a member of The Church of Jesus Christ of Latter-day Saints, Gretna Branch. She was formerly employed by Sarah Lee Knitting of Gretna, and was a retired health care provider. Melba was the kind of person who never met a stranger and no matter where she was could always find someone to talk to. She had a twinkle in her eye, rosy cheeks, and a subtle wit just like her father. She had a passion for reading and dancing, and was a regular attendee of the New London Ruritan Club. She is survived by a daughter, Patty Dix and her husband, Jimmy of the residence, a son Michael Barbour and partner David Clay of Roanoke, a granddaughter, Brittany Dix of the residence; two grandsons, Zachary Wright of Amherst, and Aaron Dix of Lynchburg; two sisters, Patsy Queen and husband Clyde of Hurt, and Frances Shelhorse and husband, Barney of Gretna. Melba is also survived by many dear friends, including Josephine Keen, Bonnie Hart, Lois Wheeler, Candy Payne, Dustin Wood, and her beloved dog Frisky. Also a special thank you to Dr. Van Dyke and everyone at Centra Hospice. Funeral services will be conducted 1:00 p.m. Saturday, May 22, 2010 at the Colbert-Moran Chapel by President J. William Fowler . Burial will follow in Gretna Burial Park. The family will receive friends from 7 to 8:30 p.m. Friday at Colbert-Moran Funeral Home and other times will be at the residence. Colbert-Moran Funeral Home, Gretna is in charge of arrangements.


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Finally! A PROVEN Step-by-Step System for Starting And Building Your Own In Home Care Business!
HOME CARE HOW TO – The Guide To Starting Your Senior In Home Care Business
Take Your Passion and Start a Home Care Business!
|Home Care How To – The Guide to Starting Your Senior In Home Care Business is a step-by-step "How-To" manual for anyone thinking of or wanting to start a home care business and grow an existing home care agency. Packed with all the training, home care industry information, home care forms and tools you'll need to start your private duty home care agency using an easy to follow, step-by-step action format.
Author Brendan John states:
In addition to the full recipe for your home care business success, rest comfortably knowing you also have an experienced, seasoned, professional business support team to help you succeed whenever you need!
Starting a Home Care Business Isn't Rocket Science, People From all Career Backgrounds Are Successful!
Are you in the health care field? A Nurse, CNA, LVN/LPN? Maybe you've worked in a service industry already? Perhaps you've had a loved one that needed care already and through that experience, a door opened to considering this field? People from all career backgrounds are succeeding in this industry and business. You'll quickly discover that a home care agency is not a difficult business to learn.
Having a background in the care or hospitality industry, providing a service or a love of helping others certainly helps, though not a prerequisite. Individuals like attorneys, insurance brokers, stay at home moms, auto industry executives, engineers, accountants, computer industry and many others are successfully running their agencies today. Will you join the group?
Learn the secrets, Systems and Action Steps Home Care Franchisees are Paying $20,000 to $100,000 to obtain!!
If you're considering the purchase of a home care franchise, you already understand how intimidating it can be and how important it is to do your homework in advance. Perhaps you've looked at franchises like Home Instead, Comfort Keepers, Right at Home or Living Assistance? Or maybe a membership group with companies like Companion Connection or The Seniors Choice? HOME CARE HOW TO – The Guide to Starting Your Senior Home Care Business provides a section that details what you should know and questions to ask. Before you sign contract and pay the upfront cash investment of $20k to $100+k (plus 4-7% in monthly royalties or $500+ per month in ongoing membership fees), learn what questions to ask and gain upfront insight to the home care industry.
As a non-medical home care provider, your company and staff will be providing one-on-one services in client's homes like:
For the very affordable investment of a book, you'll discover what the home care industry is about, good and bad, how a franchise or membership investment can help or hurt you, and what to consider in the process. Learn what franchises and membership reps won't tell you! Be certain you're making the right decision and know confidently it's the right decision when you do.
Once you've made your decision, the step-by-step plan to help walk you through setting up and launching your agency is at your fingertips!
Future Outlook for Home Care Agencies
According to the US Census Report from 2000, the current year value of companion services is estimated at just over $6 billion. As the Baby Boom population ages,estimates indicate the companion industry to grow past $8 billion. Here are some attractive statistics:
The Home Care Industry, medical and non-medical inclusive, cater to these boomers and their elderly parents. The time to start your home care agency is TODAY! HOME CARE HOW TO will help you do it!
Seniors Prefer To Age In Place by Staying in Their Own Home!
Would YOU Want to Live In a Nursing Home or Care Facility?
It's more comfortable at home, studies indicate increased life span and it often costs less than a care facility! In order to stay out of assisted living communities and nursing homes, seniors and their families are actively looking for quality private duty agencies that provide both medical and non medical in home care services.
Here's What Readers Are Saying About the Book . . .
Will Your Success Story Be Next?
Picture yourself firing your boss and working for yourself!
Imagine for a moment: One year from today, you're working for yourself and the owner of a business that helps seniors and disabled improve their quality of daily life with the use of your services! How would your life be different a year from now? As a respected community business owner helping seniors, their families AND the economy by offering jobs to caregivers and office staff. Would that change your life?
YES! I'm Ready To Purchase


text:
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Select an edition for more focused local news coverage when you visit NOLA.com.
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Nolascience check your facts again....
NolaScience isn't very smart. Don't spout off incorrect facts if you are trying to prove a point. The #1 killer of adults in the US is heart disease. Just Google it, the CDC will tell you..... Nor is second hand smoke the major cause of respiratory problems in children. Google it too. I have lost all confidence in anything you post from here on out.
The title of this article is saying "George LaFargue Jr. is DIFFERENT than everyone else because he is black and is going to be king of a prestigious parade that has predominately white members" isn't that what we are trying to avoid? Everyone equal with the same rights? Aren't we as a society trying to say black is no different than white? WELL as long as news is reported this way we are saying that black is different than white. The title of the article should read: "The 2012 King of Endymion is George LaFargue Jr."
Is this a lame attempt to copy the 6-10 Stompers?
Good deal. Spring will come early.... He is right only 39% of the time.
Alabama will get 2 field goals only if they are kicking from inside the 20.... The have a 5% chance of making it from 37+ yards according to their kicking stats this season.
Gotcha.... I think LSU will win as you stated but if Alabama would win how dumb does that make the BCS look when they didn't when their conference championship and didn't even play in it.
Curious if a loss by LSU would the BCS still have LSU #1? They do have a decent margin as of now.
You just wrote an article on November 19th titled "It's hard to argue LSU Coach Les Miles knows best with his quarterbacks" Now you are doing a complete 360? Are you schizo?
Who gives a flying "duck"....
Dumb Alabama fans....it's whats on our message boards!
Narrow minded comment? I just chuckled at your lack of intelligence.
Soon you will disappear from these boards with your tail between your legs never to be seen for the rest of this year. I'm going to predict that if LSU wins you will make up some excuses of why they won (Cheating, poor officiating etc. etc.). I live in Alabama now and know your type. Auburn fans have a lot more class than UA fans period. Which brings me to a joke that rings true.... Q : Why don't Bama fans fart?
A : Their mouths are never closed long enough to build up any pressure!
madskillsno - I made the same bet and ended up with a Fleur De Lis tat on my ankle. (Never was a fan of tats but love this one!) Same bet this year and I do feel another one coming on....
Not Guilty.....
1nocynic ----- What is wrong with a "Whites Only" heritage? There are many places, celebrations and events that are "Black Only". So is it so wrong for white folk to want to preserve their heritage?
Why is it that low income "whites" aren't fighting to get low income housing in "black" neighborhoods? (Yes, it is a rhetorical question)
This isn't a racists question and comment so all you people who cry racism for ever little thing don't get your panties in a wad. I'm just trying to understand.
If this goes up I want a 300 foot statue of the almighty FSM (Flying Spaghetti Monster) erected. It is only fair that my god is included.
All of you are wrong, regardless if you want to blame George Bush or Barrack Obama. It is government as a whole that is not working (President, Congress and the rest of them on Capitol Hill). The only time this country is going to start heading in the right direction is when the common person stops being influenced by the media, churches and other authority figures and start thinking for themselves. Cast your next vote not on who they tell you to vote for but do a little research and pick your candidate with reason. You better start thinking now while it is still legal.
Back to the Saints... I just hope we have a football season. I'm going to be really bored on Sundays if not.
We need them to protect us from our government.... Duh!
**** "The popular child tax credit and mortgage interest deduction also would be eliminated." *****


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Getting your money back when something doesn't work isn't an unfamiliar concept. But what if the money you paid was for a charity? Many viewers who shelled out $4.95 to watch Bill O'Reilly vs. Jon Stewart live online during their Saturday night debate were frustrated when there were streaming problems that didn't allow them to actually watch the event. Half of the proceeds from said event were meant to go to charity, so is asking for a refund the thing to do? [More]
Should You Demand A Refund If A Charity Event Goes Awry?
The Daily Show: Couple "Forecloses" On Bank Of America
The couple who "foreclosed" on Bank of America got The Daily Show treatment last night. John Oliver caught up with the homeowners to find out how they showed up with repo men and sheriff's deputies at a Bank of America branch office and got the bank to pay them money they were owed. It all began when the bank tried to foreclose on them, even though they had no mortgage at all, and owned their home free and clear. [More]
Daily Show VS CNBC: "They Burned The F-ing House Down With Our Money And Walked Away Rich As Hell"
It's the final countdown… Oh, sorry. Jim Cramer appeared on The Daily Show last night to settle the war of words between The Daily Show and CNBC that had been going on since Rick "You Are All Losers" Santelli canceled. Did it get nasty? You bet your ass it did, though we were looking forward to a bout of Jello wrestling that never quite materialized.
Daily Show Explains Net Neutrality
"The point is that with net neutrality all internet packets – whether they come from a big company or a single citizen – are treated in the exact same way."
Jon Stewart on Trucker Bombs
We're sure you're as fascinated by the trucker bomb phenomenon as we are. Honestly, we are seriously considering making our next Consumerist photo contest dedicated to them, or perhaps merely a contest to see who can send the most trucker bombs to Poppy Z. Brite's house in payback for the many literary trucker bombs she's forced us all to endure over the years. Note to Poppy's attorneys over at CyberTrialLawyer.com: just kidding!


text:
A deformable intracapsular implant device for shaping an enucleated lens capsule sac for use in cataract procedures and refractive lensectomy procedures. In one embodiment, the intraocular implant devices rely on thin film shape memory alloys and combine with the post-phaco capsular sac to provide a biomimetic complex that can mimic the energy-absorbing and energy-releasing characteristics of a young accommodative lens capsule. In another embodiment, the capsular shaping body is combined with an adaptive optic. The peripheral capsular shaping body carries at least one fluid-filled interior chamber that communicates with a space in a adaptive optic portion that has a deformable lens surface. The flexing of the peripheral shaping body in response to zonular tensioning and de-tensioning provides an inventive adaptive optics mechanism wherein fluid media flows between the respective chambers "adapts" the optic to increase and decrease the power thereof. In one embodiment, the capsular shaping body carries a posterior negative power adaptive optic that can be altered in power during accommodation to cooperate with an independent drop-in exchangeable intraocular lens.
1. An accommodating intraocular lens, comprising:
a central optic portion, the central optic portion comprising a lens having an optical axis, the lens comprising anterior and posterior optic surfaces through which the optical axis passes wherein at least one optic surface is deformable for altering optic power;
a peripheral non-optic portion, the non-optic portion comprising an anterior-most portion; and
a flowable media,
wherein the non-optic portion is configured for engagement of the interior of a lens capsule, and is adapted to deform in response to a lens capsule shape change due to ciliary muscle movement to move the flowable media from the non-optic portion to the optic portion, and wherein an anterior-most portion of the anterior optic surface is disposed along the optical axis posterior to the anterior-most portion of the non-optic portion.
2. An accommodating intraocular lens as in
3. An accommodating intraocular lens as in
4. An accommodating intraocular lens as in
5. An accommodating intraocular lens, comprising:
a central optic portion having an optical axis, wherein the optic portion comprises anterior and posterior optic surfaces through which the optical axis passes, and wherein at least a portion of the optic portion is adapted to be deformed to change the power of the intraocular lens; and
a peripheral non-optic portion, the peripheral portion comprising an anterior-most portion, wherein the peripheral portion is configured for engagement of the interior of a lens capsule, and wherein the peripheral portion is adapted to deform in response to a lens capsule shape change due to ciliary muscle movement, and
wherein an anterior-most portion of the anterior optic surface is disposed along the optical axis and is disposed posterior to the anterior-most portion of the non-optic portion, and
wherein the peripheral portion is not disposed along the optical axis.
6. The accommodating intraocular lens as in
7. The intraocular lens of
8. The intraocular lens of
9. The intraocular lens of
10. The intraocular lens of
11. The intraocular lens of
12. The intraocular lens of
13. The intraocular lens of
14. The intraocular lens of
15. The intraocular lens of
16. The intraocular lens of
wherein an anterior-most portion of the optic chamber is disposed posterior to an anterior-most portion of the non-optic portion chamber.
17. The intraocular lens of
18. The intraocular lens of
wherein an anterior-most portion of the optic chamber is disposed posterior to an anterior-most portion of the non-optic portion chamber.
19. The intraocular lens of
This application claims benefit under 35 U.S.C. �119(e) of Provisional U.S. Patent Application Ser. No. 60/353,847 filed Feb. 2, 2002 titled Intraocular Lens and Method of Making. This application also claims benefit of the following other Provisional U.S. Patent Applications: Ser. No. 60/362,303 filed Mar. 6, 2002 titled Intraocular Lens and Method of Making; Ser. No. 60/378,600 filed May 7, 2002 titled Intraocular Devices and Methods of Making; Ser. No. 60/405,471 filed Aug. 23, 2002 titled Intraocular Implant Devices and Methods of Making, Ser. No. 60/408,019 filed Sep. 3, 2002 titled Intraocular Lens and Ser No. 60/431,110 filed Dec. 4, 2002 titled Intraocular Implant Devices and Methods of Making. All of the above applications are incorporated herein in their entirety by this reference.
1. Field of the Invention
The present invention is directed to intraocular implant devices and more specifically to shape memory capsular shaping devices for combining with a post-phacoemulsification capsular sac to provide a biomimetic complex that can mimic the energy-absorbing and energy-releasing characteristics of a natural young accommodative lens capsule. The shape memory capsular shaping devices can further be combined with an independent or integrated optics to provide an accommodating intraocular lens.
2. Description of the Related Art
The human lens capsule can be afflicted with several disorders that degrade its functioning in the vision system. The most common lens disorder is a cataract which consists of the opacification of the normally clear, natural crystalline lens matrix in a human eye. The opacification usually results from the aging process but can also be caused by heredity or diabetes.
Mechanisms of Accommodation. Referring to
Accommodation occurs when the ciliary muscle CM contracts to thereby release the resting zonular tension on the equatorial region of the lens capsule 102. The release of zonular tension allows the inherent elasticity of the lens capsule to alter it to a more globular or spherical shape, with increased surface curvatures of both the anterior and posterior lenticular surfaces. The lens capsule together with the crystalline lens matrix and its internal pressure provides the lens with a resilient shape that is more spherical in an untensioned state. Ultrasound biomicroscopic (UBM) images also show that the apex of the ciliary muscle moves anteriorly and inward—at the same time that the equatorial edge the lens capsule moves inwardly from the sclera during accommodation.
When the ciliary muscle is relaxed, the muscle in combination with the elasticity of the choroid and posterior zonular fibers moves the ciliary muscle into the unaccommodated configuration, which is posterior and radially outward from the accommodated configuration. The radial outward movement of the ciliary muscles creates zonular tension on the lens capsule to stretch the equatorial region of lens toward the sclera. The disaccommodation mechanism flattens the lens and reduces the lens curvature (both anterior and posterior). Such natural accommodative capability thus involves contraction and relaxation of the ciliary muscles by the brain to alter the shape of the lens to the appropriate refractive parameters for focusing the light rays entering the eye on the retina—to provide both near vision and distant vision.
In conventional cataract surgery as depicted in
Prior Art Pseudo-Accommodative Lens Devices. At least one commercially available IOL, and others in clinical trials, are claimed to "accommodate" even though the capsular sac shrink-wraps around the IOL as shown in
Since surgeons began using IOLs widely in the 1970's, IOL design and surgical techniques for IOL implantation have undergone a continuous evolution. While less invasive techniques for IOL implantation and new IOL materials technologies have evolved rapidly in the several years, there has been no real development of technologies for combining the capsular sac with biocompatible materials to provide a biomimetic capsular complex. What has stalled all innovations in designing a truly resilient (variable-focus) post-phaco lens capsule has been is the lack of sophisticated materials.
What has been needed are materials and intraocular devices that be introduced into an enucleated lens capsule with a 1 mm. to 2.5 mm. injector, wherein the deployed device and material provide the exact strain-absorbing properties and strain-releasing properties needed to cooperate with natural zonular tensioning forces. Such an intraocular device will allow for the design of dynamic IOLs that can replicate natural accommodation. Microdevices of intelligent elastic composite materials can provide the enabling technology to develop new classes of accommodating IOL systems.
This invention relates to novel shape memory devices, materials and capsular shaping elements (CSEs) that can be implanted using conventional techniques to create a biomimetic lens capsule complex. The capsular shaping element, or more specifically an intracapsular implant, is designed to provide the implant/lens capsule complex with a shape and resiliency that mimics the elasticity of a young, still-accommodative lens capsule. In one embodiment, the capsular shaping element incorporates at least one thin-film expanse of a shape memory alloy (SMA) material in a three dimensional shape to impart the required elasticity to the CSE. The capsular shaping element will enable, and can be integrated with, several classes of optic elements to provide an accommodative IOL system that cooperates with ciliary muscle tensioning and de-tensioning to provide variable focusing power. The accommodating IOL corresponding to the invention can be used following typical cataract surgeries, or can be used in refractive lensectomy procedures to treat presbyopia.
In a preferred embodiment, the capsular shaping element incorporates a least one formed expanse of thin-film nickel titanium alloy (NiTi or Nitinol). Nitinol materials have the unique capability to absorb energy by a reversible crystalline transformation (superelasticity) which is orders of magnitude higher than can be absorbed in plastic deformations of conventional resilient materials, such as a polymers used in other so-called accommodating IOL designs. In addition, such NiTi materials have the ability to avoid localization of plastic deformations—and thus can spread the absorbed energy over a much larger region of the material. Further, a capsular shaping element that relies on NiTi for its shape memory characteristics need only be microns in thickness for compacted introduction into the lens capsule. The implant, in fact, may be little thicker than the lens capsule itself. Nickel titanium alloys are also known to be biocompatible. In preferred variants of biomimetic CSEs described herein, the implant carries at least one seamless expanse of thin-film NiTi material that three dimensionally formed to engage the anterior and posterior capsules—while leaving an open central optic zone. Various types of optic elements can be coupled to the capsular shaping element of the invention.
In such preferred embodiments, the capsular shaping body also comprises in part a shape memory polymer (SMP) component that encases the shape memory alloy form, whether of a thin film SMA or another formed structure of a nickel titanium alloy. The shape memory polymer is capable of a memory shape as well as a compacted temporary shape. In its temporary compacted shape, the polymer together with the embedded superelastic nickel titanium can be ultrathin and three dimensionally stable to be rollable for use in standard diameter injector or even a sub-1 mm. injector.
In another preferred embodiment, the non-optic or peripheral body portion of the implant is again of a shape memory polymer, and optional SMA form, that engages the enucleated lens capsule to provide a post-phaco biomimetic complex that mimics the energy-absorbing and energy-releasing characteristics of an accommodative lens capsule. An adaptive lens element is coupled to the annular peripheral body portion. In this embodiment, the peripheral capsular shaping portion of the implant body carries at least one fluid-filled interior chamber that communicates with a central chamber in the adaptive lens element that actuates a deformable surface thereof. The flexing of the peripheral body portion in response to zonular tensioning and de-tensioning provides an adaptive optic mechanism wherein fluid media flows between the respective chambers to deform the lens surface to increase or decrease lens power. For example, in one embodiment, the peripheral body portion carries a posterior negative power lens that can be altered in power during accommodation to cooperate with a second lens element to provide variable focus.
Accordingly, a principal advantage of the present invention is the provision of deformable, rollable intraocular devices such as capsular shaping devices that utilize shape memory alloy forms, such shaping devices enabling an artificial lens system to provide accommodative amplitude (diopters of power modification).
The invention advantageously provides a capsular shaping element with integrated optics that require only a very small entry incision for implantation—for example a sub-1 mm. minimal incision through the cornea.
The invention advantageously provides an independent module comprising a capsular shaping structure of a thin film material that conforms to and maintains an intracapsular volume for receiving an IOL.
The invention provides a capsular shaping structure of a superelastic shape memory alloy form within a a shape memory polymer envelope that conforms to and maintains an intracapsular volume.
The invention advantageously provides an independent module comprising a capsular shaping structure that can cooperate with drop-in fixed focus IOL or a drop-in accommodating IOL.
The invention advantageously provides an independent module comprising a capsular shaping element that allows for simplified lens exchange.
The invention provides an independent module comprising a capsular shaping structure that is adapted to cooperate with, and amplify, zonular tensioning and de-tensioning caused by ciliary muscle relaxation and contraction to enable various types of an accommodating lens systems.
The invention advantageously provides a modular capsular shaping element that is adapted to cooperate with both (i) vitreous displacement caused by ciliary muscle contraction; and (ii) zonular tensioning and de-tensioning caused by ciliary muscle relaxation and contraction, to amplify lens translation in a novel types of accommodating lens systems.
The invention provides an IOL with optic or non-optic body portions that carry a photomodifiable SMP that can be irradiated to adjust an operational parameter of an adaptive optic or accommodating lens system.
The invention provides an IOL with a polymer non-optic body portion that carries an anti-fibrotic pharmacological agent for release about the capsular sac for preventing or limiting fibrosis and shrinkage of the capsular sac.
These and other objects of the present invention will become readily apparent upon further review of the following drawings and specification.
In order to better understand the invention and to see how it may be carried out in practice, some preferred embodiments are next described, by way of non-limiting examples only, with reference to the accompanying drawings, in which like reference characters denote corresponding features consistently throughout similar embodiments in the attached drawings.
I. Principles of Superelasticity and Shape Memory in Classes of Ophthalmic Implant Materials
The capsular shaping element (CSE) of the invention is adapted for providing a biomimetic lens capsule complex that will enable an accommodative lens system, which can have several variants. The term biomimetic lens capsule is derived from the word biomimesis, which defines the development of structures that mimic life, or that imitate biological systems. In this case, the objective is to develop an implant that mimics the inherent elasticity of a young lens capsule for cooperating with the ciliary muscle to alter the shape or translation of an implanted optic element.
The biomimetic lens capsules corresponding to the invention are enabled by the phenomena of shape memory and superelasticity that are unique to certain newly developed so-called intelligent materials. In particular, one embodiment of CSE comprises a thin-film expanse of a nickel titanium alloy that is fabricated in a vacuum chamber deposition process. The nickel titanium form is embedded within a thin biocompatible polymer envelope. In the prior art, the principal uses of nickel titanium alloys have been developed from uniaxial models of superelasticity, such as in wires and other bulk materials. The invention extends the use of nickel titanium fabricated in thin film expanses. Additional embodiments comprise, at least in part, an expanse of a shape memory polymer (SMP), a shape memory polymer foam, or a bioerodible shape memory polymer.
In order to understand the invention, it is useful to describe the phenomena of shape memory and superelasticity that are unique to nickel titanium alloys, which are utilized in preferred embodiments of the capsular shaping structures of the invention. In an unstressed state, the nickel titanium alloy component will present itself in an austhenite phase—in which phase it exhibits linear elasticity. When stress is applied to the material, the austhenite phase transforms into a martensite phase that also exhibits linear elasticity, however, each phase has a different constant as can be seen in
The superelastic properties of NiTi, and its strain-induced martensite transformation, can be understood by schematic illustrations of its crystalline lattice structure. The austhentite and martensite phases each define a very distinct crystalline structure or phases, as depicted in
The thin-film NiTi expanse of the invention can be fabricated as described in U.S. Pat. No. 5,061,914 to D. Busch and A. D. Johnson and the following published U.S. patent applications to A. D. Johnson et al.: No. 20020046783 A1 published Apr. 25, 2002; and No. 20010039449 A1 published Nov. 8, 2001. All of the patents and applications referred to in this paragraph are incorporated herein in their entirely by this reference.
The capsular shaping portion of the intracapsular implant corresponding to the invention also can be made in part, or in its entirety, from a class of shape memory polymer (SMP). The term "shape memory" is used in a different context when referring to SMPs. A shape memory polymer is said to demonstrate shape memory phenomena when it has a fixed temporary shape that can revert to a memory shape upon a selected stimulus, such as temperature. A shape memory polymer generally is characterized as defining phases that result from glass transition temperatures in segregated linear block co-polymers: a hard segment and a soft segment. The hard segment of SMP typically is crystalline with a defined melting point, and the soft segment is typically amorphous, with another defined transition temperature. In some embodiments, these characteristics may be reversed together with glass transition temperatures and melting points.
In one embodiment, when the SMP material is elevated in temperature above the melting point or glass transition temperature of the hard segment, the material then can be formed into a memory shape. The selected shape is memorized by cooling the SMP below the melting point or glass transition temperature of the hard segment. When the shaped SMP is cooled below the melting point or glass transition temperature of the soft segment while the shape is deformed, that (temporary) shape is fixed. The original shape is recovered by heating the material above the melting point or glass transition temperature of the soft segment but below the melting point or glass transition temperature of the hard segment. (Other methods for setting temporary and memory shapes are known which are described in the literature below). The recovery of the memory original shape is thus induced by an increase in temperature, and is termed the thermal shape memory effect of the polymer. The temperature can be at or below body temperature (37� C.) or a selected higher temperature.
Besides utilizing the thermal shape memory effect of the polymer, the memorized physical properties of the SMP can be controlled by its change in temperature or stress, particularly in ranges of the melting point or glass transition temperature of the soft segment of the polymer, e.g., the elastic modulus, hardness, flexibility, permeability and index of refraction. The scope of the invention of using SMPs in capsular shaping elements extends to the control of such physical properties, particularly in elastic composite structure described further below.
Examples of polymers that have been utilized in hard and soft segments of SMPs include polyurethanes, polynorborenes, styrene-butadiene co-polymers, cross-linked polyethylenes, cross-linked polycyclooctenes, polyethers, polyacrylates, polyamides, polysiloxanes, polyether amides, polyether esters, and urethane-butadiene co-polymers and others identified in the following patents and publications: U.S. Pat. No. 5,145,935 to Hayashi; U.S. Pat. No. 5,506,300 to Ward et al.; U.S. Pat. No. 5,665,822 to Bitler et al.; and U.S. Pat. No. 6,388,043 to Langer et al. (all of which are incorporated herein by reference); Mather, Strain Recovery in POSS Hybrid Thermoplastics, Polymer 2000, 41(1), 528; Mather et al., Shape Memory and Nanostructure in Poly(Norbonyl-POSS) Copolymers, Polym. Int. 49, 453-57 (2000); Lui et al., Thermomechanical Characterization of a Tailored Series of Shape Memory Polymers, J. App. Med. Plastics, Fall 2002; Gorden, Applications of Shape Memory Polyurethanes, Proceedings of the First International Conference on Shape Memory and Superelastic Technologies, SMST International Committee, pp. 115-19 (1994); Kim, et al., Polyurethanes having shape memory effect, Polymer 37(26):5781-93 (1996); Li et al., Crystallinity and morphology of segmented polyurethanes with different soft-segment length, J. Applied Polymer 62:631-38 (1996); Takahashi et al., Structure and properties of shape-memory polyurethane block copolymers, J. Applied Polymer Science 60:1061-69 (1996); Tobushi H., et al., Thermomechanical properties of shape memory polymers of polyurethane series and their applications, J. Physique IV (Colloque C1) 6:377-84 (1996)) (all of the cited literature incorporated herein by this reference).
The scope of the invention extends to the use of SMP foams for use in elastic composite structures, wherein the capsular shaping element utilizes the polymer foam together with an expanse of nickel titanium alloy. See Watt A. M., et al., Thermomechanical Properties of a Shape Memory Polymer Foam, available from Jet Propulsion Laboratories, 4800 Oak Grove Drive, Pasadena Calif. 91109 (incorporated herein by reference). SMP foams function in a similar manner as the shape memory polymers described above. The scope of the invention also extends to the use of shape memory polymers that are sometimes called two-way shape memory polymers that can moved between two predetermined memory shapes in response to varied stimuli, as described in U.S. Pat. No. 6,388,043 to Langer et al. (incorporated herein by reference).
Other derivatives of SMPs within the scope of the invention fall into the class of bioerodible shape memory polymers that again may be used in certain elastic composite capsular shaping structures. As will be described below, one embodiment of capsular shaping element may be designed with composite portions that define a first modulus of elasticity for a period of time after implantation to resist force that may be applied by fibrosis during wound healing, followed by a second modulus of elasticity following biodegradation of a surface portion of the elastic composite structure.
In all variants of capsular shaping element that make use of expanses of thin films or composites of shape memory materials, the principal objectives relate to the design of an implant that will impart to the implant/lens capsule complex an unstressed more spherical shape with a lesser equatorial diameter when zonular tension is relaxed, and a stressed flatter shape with a greater equatorial diameter in response to zonular tensioning forces. The superelastic component will provide the ability to absorb known amounts of stress—and release the energy in a predetermined manner in millions of cycles over the lifetime of the implant in cooperation with an optic that will provide variable focus.
II. Exemplary Biomimetic Intracapsular Devices with Superelastic or Elastic Composite Components
A. Type "A" Implantable Intraocular Devices.
The IOD 100 of
Of particular interest, the capsular shaping element 100 of
The capsular shaping element 100 of
The capsular shaping element 100 (
The ciliary muscles CM, choroid and zonular fibers each have a modulus of elasticity, and the capsular shaping element 100 in combination with the capsular sac (i.e., implant/capsule complex) defines a lower modulus of elasticity than any of these tissues to insure they do not unnaturally deform during accommodation. A capsular shaping element 100 that carries a nickel titanium alloy form, in its superelastic state when at body temperature, is the optimal material for deforming in response to zonular tension by absorbing stress and thereafter releasing the absorbed energy to return the complex of the shaping element and lens capsule to its memory shape. In one embodiment corresponding to the invention, the intraocular device carries a seamless thin-film shape memory form that demonstrates a stress/strain recovery greater than 3% at 37� C. More preferably, the thin-film shape memory form demonstrates a stress/strain recovery greater than 5% at 37� C.
The second advantage offered by the device 140 of
This aspect of the invention is shown in
In all of the above described embodiments, the capsular shaping element and the remaining capsule sac is adapted to mimic a natural lens capsule in balancing its energy-absorbing and energy-releasing characteristics with the forces applied by the ciliary muscle. The capsular shaping element will thus prevent atrophy of the ciliary muscle and allow it to cooperate with, and adjust, the next optional component of the invention which is a cooperating independent IOL or an integrated optic element.
Still, it should be appreciated that the capsular shaping devices of
B. Type "B" Implantable Intraocular Devices. The Type "B" intraocular devices generally combine any of the Type "A" capsular shaping structures of the invention with an integrated optic portion to thereby provide an integrated accommodating IOL system.
In the implant 500C of
In one embodiment as depicted in
Now turning to
In a disaccommodative state, referring to
In any design of capsular shaping body or for an accommodating lens system, it may be necessary to provide post-fabrication adjustment means for (i) adjusting the flexibility and response to the peripheral body's deformation after implantation, (ii) the exact shape of a dimension of the implant to engage the lens capsule, (iii) the amplitude of accommodation, as well as (iv) providing for adjustment of lens optic parameters. To provide for such adjustments,
The previous embodiments have illustrated peripheral body portions that are substantially thin and provided with an elastic response due to the superelastic SMA form 120 insert-molded therein. Embodiments of adaptive optic lens systems as described above are possible without, or with less reliance on, a superelastic shape memory alloy form in the implant. In order to provide a polymer peripheral body portion with suitable resilient characteristics for shaping the capsular sac and responding to zonular tensioning forces, a resilient gel-like shape memory polymer 745 can be used to define a memory shape that occupies a substantial peripheral portion of the capsular sac as in implant 700A of
Those skilled in the art will appreciate that the exemplary systems, combinations and descriptions are merely illustrative of the invention as a whole, and that variations in the dimensions and compositions of invention fall within the spirit and scope of the invention. Specific characteristics and features of the invention and its method are described in relation to some figures and not in others, and this is for convenience only. While the principles of the invention have been made clear in the exemplary descriptions and combinations, it will be obvious to those skilled in the art that modifications may be utilized in the practice of the invention, and otherwise, which are particularly adapted to specific environments and operative requirements without departing from the principles of the invention. The appended claims are intended to cover and embrace any and all such modifications, with the limits only of the true purview, spirit and scope of the invention.
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