Patents Assigned to Massachusetts Institute Technology
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Patent number: 6404526Abstract: A method of generating a signal including: generating a first sequence of coherent optical pulses which are sufficiently close in spacing so as to overlap and interfere upon traveling a predetermined length down an optical fiber to form a first interference pattern with a first central lobe having a characteristic wavelength, wherein the energy of the pulses of the first sequence of pulses is within the non-linear regime of the optical fiber; manipulating the first sequence of optical pulses; in a similar manner generating a second sequence of coherent optical pulses; manipulating the second sequence of optical pulses; and introducing both the first and second manipulated sequences of pulses into the optical fiber, wherein the manipulating of the pulses of the first and the second sequence of pulses shifts the characteristic wavelengths of the first and second central lobes, respectively, to first and second transmission signal wavelengths.Type: GrantFiled: March 8, 2001Date of Patent: June 11, 2002Assignee: Massachusetts Institute of TechnologyInventors: Farhad Hakimi, Hosain Hakimi
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Patent number: 6402690Abstract: A monitoring system for monitoring the health status of a patient by performing measurements such as skin temperature, blood flow, blood constituent concentration, and pulse rate at the finger of the patient. The monitoring system has an inner ring proximate to the finger as well as an outer ring, mechanically decoupled from the inner ring, that shields the inner ring from external loads. Measurements are performed in accordance with a protocol that may be preprogrammed, or may be modified on the basis of real-time data or by command from a remotely located medical professional.Type: GrantFiled: April 18, 2000Date of Patent: June 11, 2002Assignee: Massachusetts Institute of TechnologyInventors: Sokwoo Rhee, Boo-ho Yang, Haruhiko H. Asada
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Patent number: 6404497Abstract: The present invention relates to the use of polarized light to measure properties of tissue. More particularly, polarized light can be used to detect dysplasia in tissue as the polarization of backscattered light from such tissues is preserved while the contribution of diffusely scattered light from underlying tissues can be removed. A fiber optic system for delivery and collection of light can be used to measure tissues within the human body.Type: GrantFiled: January 25, 1999Date of Patent: June 11, 2002Assignee: Massachusetts Institute of TechnologyInventors: Vadim Backman, Ramanchandra R. Dasari, Rajan Gurjar, Irving Itzkan, Lev Perelman, Michael S. Feld
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Patent number: 6404481Abstract: Techniques are disclosed to compensate for distortions in lithography by locally heating the membrane in a lithographic mask. The techniques may be used both to shrink and to expand areas of the mask locally, in order to adjust for varying magnitudes and signs of distortion. In one embodiment the correction method comprises two steps: (1) A send-ahead wafer is exposed and measured by conventional means to determine the overlay errors at several points throughout the field. (2) During exposure of subsequent wafers, calibrated beams of light are focused on the mask. The heating from the absorbed light produces displacements that compensate for the overlay errors measured with the send-ahead wafer. Any source of distortion may be corrected—for example, distortion appearing on the mask initially, distortion that only develops on the mask over time, or distortion on the wafer.Type: GrantFiled: May 25, 2000Date of Patent: June 11, 2002Assignees: Board of Supervisors of Louisiana State University and Agricultural and Mechanical College, Massachusetts Institute of TechnologyInventors: Martin Feldman, Henry I. Smith, Ken-Ichi Murooka, Michael H. Lim
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Patent number: 6404340Abstract: A preferred reader circuit for energizing the coils and detecting loading variations is shown in FIGS. 3A and 3B. It was designed for tabletop operation at relatively low frequencies; the amplitudes, frequencies, and time constraints listed below can be shifted as desired for other applications. The depicted schematic includes driver circuitry for three coils, it being understood that further drivers can be added as indicated in the figure. Each driver circuit includes an inductive bridge wherein a search coil 3051, 3052, 3053 is balanced against a series of reference inductors 3071, 3072, 3073; 3091, 3092, 3093; and 3311, 3112, 3113 (the latter being variable to trim residuals in the search coil's inductance). A representative pair of search coils 3051, 3052 are identically wound and driven together, and the sensing volume between them is once again indicated at 200.Type: GrantFiled: June 19, 2000Date of Patent: June 11, 2002Assignee: Massachusetts Institute of TechnologyInventors: Joseph A. Paradiso, Kai-Yuh Hsiao
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Patent number: 6397922Abstract: A new mold solves problems that arise from differential changes in geometry inherent to casting metal in a ceramic mold, by control of the internal morphology between the surfaces of the mold that face the casting, and that face the external environment. Layered fabrication techniques are used to create a ceramic mold. For example, an internal geometry composed of a cellular arrangement of voids may be created within the mold wall. Structures may be designed and fabricated so that the ceramic mold fails at an appropriate time during the solidification and/or cooling of the casting. Thus, the casting itself is not damaged. The mold fails to avoid rupture, or even distortion, of the casting. A thin shell of ceramic defines the casting cavity. This shell must be thin enough to fail due to the stresses induced (primarily compressive) by the metal next to it and partly adherent to it.Type: GrantFiled: May 24, 2000Date of Patent: June 4, 2002Assignee: Massachusetts Institute of TechnologyInventors: Emanuel M. Sachs, Won B. Bang, Michael J. Cima
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Patent number: 6400826Abstract: A system, method, and product provide distortion compensation when watermarking a host signal with a watemark signal. The watermark signal includes watermark-signal components having watermark-signal values, and the host signal includes host-signal components having host-signal values. A system includes an ensemble designator that designates a plurality of embedding generators, each corresponding to a single watermark-signal value of a co-processed group of one or more watermark-signal components. Also included is an embedding value generator that generates embedding values by each embedding generator. The system also has a point coder that sets at least one host-signal value of one or more selected host-signal components to a first embedding value to form a composite-signal value. A distortion compensator modifies at least one composite signal value.Type: GrantFiled: April 27, 1999Date of Patent: June 4, 2002Assignee: Massachusetts Institute of TechnologyInventors: Brian Chen, Gregory W. Wornell
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Patent number: 6399700Abstract: Synthetic comb copolymers which elicit controlled cellular response, methods of applying these polymers to various surfaces, and methods of using the polymers for modifying biomaterial surfaces, in tissue engineering applications and as drug delivery devices are provided. The comb copolymers are comprised of hydrophobic polymer backbones and hydrophilic, non-cell binding side chains which can be end-capped with cell-signaling ligands that guide cellular response. By mixing non-cell binding combs with ligand-bearing combs, the surface concentration and spatial distribution of one or more types of ligands, including adhesion peptides and growth factors, can be tuned on a surface to achieve desired cellular response. In one embodiment, the combs are used as stabilizing agents for dispersion polymerization of latexes. The comb-stabilized latexes can be applied to substrates by standard coating operations to create a bioregulating surface, or used as drug delivery agents.Type: GrantFiled: March 26, 2001Date of Patent: June 4, 2002Assignee: Massachusetts Institute of TechnologyInventors: Anne M. Mayes, Linda G. Griffith, Darrell J. Irvine, Pallab Banerjee, Terry D. Johnson
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Patent number: 6400495Abstract: A passively Q-switched laser is pumped by a first optical input signal to produce a train of optical pulses at a first wavelength. These pulses are then fed into a gain-switched laser. The absorption of energy at the first wavelength induces gain in the cavity of the gain-switched laser at a second wavelength, resulting in the spontaneous generation of an optical output pulse at a preferred eye-safe wavelength.Type: GrantFiled: February 15, 2000Date of Patent: June 4, 2002Assignee: Massachusetts Institute of TechnologyInventor: John J. Zayhowski
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Patent number: 6399516Abstract: Provided is a method for producing a silicon element. A substrate configuration is provided that includes a silicon layer having a first face and a thickness corresponding to a specified thickness of the silicon element to be formed. The configuration includes a layer of an electrically-insulating material located below and adjacent to the silicon layer. A substantially vertical trench is etched from the first face in the silicon layer to a depth that exposes the insulating layer. Then the trench in the silicon layer is exposed to a gaseous environment that is reactive with silicon, to substantially lateral etch the silicon layer preferentially at the depth of the insulating layer along a surface of the insulating layer. This lateral etch is continued for a duration that results in release of a silicon element over the insulating layer. Also provided is a process for etching an angled trench in a silicon layer.Type: GrantFiled: October 29, 1999Date of Patent: June 4, 2002Assignee: Massachusetts Institute of TechnologyInventor: Arturo A. Ayon
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Publication number: 20020065533Abstract: The present invention relates to methods and devices used for the formation of microconduits in a tissue. The term “microconduit” refers to a small opening, channel, or hole into, or through, a tissue, that allows transfer of materials by liquid flow, and by electrophoresis, the microconduit being formed upon impact of a plurality of accelerated microparticles with the surface of the tissue. A method is described for forming at least one microconduit in tissue including the steps of: accelerating a plurality of microparticles to a velocity that causes the microparticles to penetrate a region of tissue surface upon impingement of the microparticles on the tissue surface; and directing the microparticle towards the region of tissue surface, thereby causing the microparticles to penetrate the tissue and form a microconduit in the tissue. According to an embodiment, microparticles are accelerated by being hit with a moving, solid surface.Type: ApplicationFiled: June 7, 2001Publication date: May 30, 2002Applicant: Massachusetts Institute of TechnologyInventors: James C. Weaver, R. Rox Anderson, Terry O. Herndon, T. R. Gowrishankar, Elizabeth A. Gift, Salvador Gonzalez
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Patent number: 6395916Abstract: One aspect of the present invention relates to novel, electron-rich bidentate ligands for transition metals. A second aspect of the present invention relates to the use of catalysts comprising these ligands in transition metal-catalyzed carbon-heteroatom and carbon-carbon bond-forming reactions. The subject methods provide improvements in many features of the transition metal-catalyzed reactions, including the range of suitable substrates, reaction conditions, and efficiency.Type: GrantFiled: July 10, 1998Date of Patent: May 28, 2002Assignee: Massachusetts Institute of TechnologyInventors: Stephen L. Buchwald, John P. Wolfe, David W. Old, Ken Kamikawa, Michael Palucki
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Patent number: 6396937Abstract: A system, method, and product are provided to (1) embed a watermark signal into a host signal, thereby generating a composite signal, (2) optionally enable the composite signal to be transmitted over a communication channel, and (3) optionally extract the watermark signal from the transmitted composite signal. In one embodiment, the invention is a method for watermarking a host signal with a watermark signal. The watermark signal is made up of watermark-signal components, each having one of two or more watermark-signal values. The host signal is made up of host-signal components, each having one of two or more host-signal values.Type: GrantFiled: January 11, 2001Date of Patent: May 28, 2002Assignee: Massachusetts Institute of TechnologyInventors: Brian Chen, Gregory W. Wornell
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Patent number: 6395939Abstract: One aspect of the present invention relates to novel reaction conditions that allow the efficient synthesis of diaryl ethers from arenes bearing a leaving group and arenols under relatively mild conditions. Another aspect of the present invention relates to the dramatic effects of acidic activators on Ullmann-type couplings involving electron-poor and/or relatively insoluble substrates.Type: GrantFiled: October 5, 1998Date of Patent: May 28, 2002Assignee: Massachusetts Institute of TechnologyInventors: Jean-Francois Marcoux, Sven Doye, Stephen Buchwald
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Publication number: 20020061164Abstract: A method introduces variable time offsets into a stream of optical pulses. The method includes receiving a plurality of coherent optical pulses, receiving a plurality of control signals, and forming a coherent pulse array (CPA) from each pulse in response to one of the received control signals. Temporal spacings between pulses of each CPA are responsive to the associated one of the received control signals. For optical control signals, response times can be very short. The method further includes transmitting each pulse through a dispersive optical medium. The act of transmitting makes pulses of each CPA overlap to form an interference pattern.Type: ApplicationFiled: November 8, 2001Publication date: May 23, 2002Applicant: Massachusetts Institute of Technology, a Massachusetts corporationInventors: Katherine L. Hall, Hosain Hakimi, Farhad Hakimi, Daniel T. Moriarty, Kristin A. Rauschenbach
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Patent number: 6392313Abstract: The invention overcomes limitations of conventional power and thermodynamic sources by with micromachinery components that enable production of significant power and efficient operation of thermodynamic systems in the millimeter and micron regime to meet the efficiency, mobility, modularity, weight, and cost requirements of many modern applications. A micromachine of the invention has a rotor disk journalled for rotation in a stationary structure by a journal bearing. A plurality of radial flow rotor blades, substantially untapered in height, are disposed on a first rotor disk face, and an electrically conducting region is disposed on a rotor disk face. A plurality of stator electrodes that are electrically interconnected to define multiple electrical stator phases are disposed on a wall of the stationary structure located opposite the electrically conducting region of the rotor disk.Type: GrantFiled: July 15, 1999Date of Patent: May 21, 2002Assignee: Massachusetts Institute of TechnologyInventors: Alan H. Epstein, Stephen D. Senturia, Ian A. Waitz, Jeffrey H. Lang, Stuart A. Jacobson, Fredric F. Ehrich, Martin A. Schmidt, G. K. Ananthasuresh, Mark S. Spearing, Kenneth S. Breuer, Steven F. Nagle
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Patent number: 6389685Abstract: A current lead including a high-temperature superconductor and a normal conductive component is coupled to a superconducting device. Electric current is delivered through the current lead at a level above the critical current carrying capacity of the high-temperature superconductor, creating a current-sharing mode of conductance through at least part of both the superconducting component and the normal conductive component.Type: GrantFiled: June 9, 1999Date of Patent: May 21, 2002Assignee: Massachusetts Institute of TechnologyInventor: Yukikazu Iwasa
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Publication number: 20020058613Abstract: Agents which modulate a bcl family member to control axonal growth and regeneration are described. These bcl modulating agents promote axonal growth and regeneration in the neural cells of a subject. Compositions for promoting axonal cell growth in a subject also are described. The compositions of the present invention include an effective amount of an agent which modulates a bcl family member and in a pharmaceutically acceptable carrier. Other described aspects include packaged drugs for treating a state characterized by diminished potential for axonal growth. The packaged compounds and agents also include instructions for using the agent to promote axonal growth in a subject.Type: ApplicationFiled: November 1, 2001Publication date: May 16, 2002Applicant: Massachusetts Institute of TechnologyInventors: Gerald E. Schneider, Dong Feng Chen, Susumu Tonegowa, Sonal Jhaveri
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Patent number: 6387331Abstract: A system and method for analyzing a plurality of liquid samples. The system has a platen having two substantially parallel planar surfaces and a plurality of through-holes dimensioned so as to maintain a liquid sample in each through-hole by means of surface tension. A source of optical radiation illuminates the through-holes, and an optical arrangement analyzes the light emanating from the through-holes. The through-holes may be individually addressable, and may have volumes less than 100 nanoliters. Samples may be drawn from a planar surface by capillary action and may be accurately dispensed, diluted and mixed in accordance with embodiments of the invention.Type: GrantFiled: January 5, 1999Date of Patent: May 14, 2002Assignee: Massachusetts Institute of TechnologyInventor: Ian W. Hunter
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Patent number: 6389333Abstract: An improved navigation and display system especially suitable for small aircraft rapidly determines the attitude (roll and pitch) of an aircraft from measurements made by an inexpensive, single receiver and antenna responsive to signals obtained from a satellite positioning system, e.g., the Global Positioning System. In contrast to conventional attitude navigation systems, which determine and display conventional (body-axis referenced) pitch angle, the present system determines and displays the “pseudo-attitude” or stability axis roll and pitch (flight path) angle, so that the pilot has an instantaneous comprehension of the actual flight path angle of the aircraft without needing to correct for angle of attack as in conventional attitude information systems. A Kalman filter with a short (˜0.5 second) time constant provides data at a sufficient rate (e.g., ˜10 Hz) to enable real-time flight with the system.Type: GrantFiled: May 10, 2000Date of Patent: May 14, 2002Assignee: Massachusetts Institute of TechnologyInventors: R. John Hansman, Richard P. Kornfeld, John J. Deyst