Patents Assigned to Ecole Polytechnique
  • Patent number: 5311873
    Abstract: Body surface potential map (BSPM) pace-mapping is a system and method that can be used in medicine to localize with precision the site of origin of abnormal cardiac electrical activity and to guide the positioning of a catheter over this site of origin, such as the site of ventricular preexcitation in patients with the Wolff-Parkinson-White syndrome or the focus of ectopic activity in patients with tachycardia. Body surface potential distributions are measured with a large number of electrodes, e.g. 24 to 128, distributed over the entire torso surface. The electrical signals are first amplified, converted into digital data and treated to remove electrical or muscle artifacts. Data recorded during abnormal activation (reference beat) are aligned with data recorded during cardiac pacing (paced beat) so as to maximize the average value of the correlation coefficient between the reference and the paced potential distributions during a preset time interval following the beginning of the QRS complex.
    Type: Grant
    Filed: August 28, 1992
    Date of Patent: May 17, 1994
    Assignee: Ecole Polytechnique
    Inventors: Pierre Savard, Reginald Nadeau, Marc Dubuc
  • Patent number: 5298343
    Abstract: The invention relates to polycomponent electrocatalysts suitable for use at the cathode of electrochemical and fuel cells. More particularly, the invention relates to a polycomponent electrode comprising a catalytic electrode including a mixture of a metallic component including at least one metal selected from palladium, platinum, ruthenium, rhodium, iridium or osmium and a chemical component including at least one compound selected from the group consisting of suitable oxometallates and metallic acids. Preferably, the metallic component comprises at least one metal selected from the group consisting of platinum and palladium and the chemical component comprises at least one compound selected from the group consisting of tungstic acid, molybdic acid, ammonium tungstate, ammonium molybdate, sodium tungstate and sodium molybdate. The electrode is operable in fuel cells which employ readily available oxygen or air.
    Type: Grant
    Filed: June 19, 1992
    Date of Patent: March 29, 1994
    Assignee: Ecole Polytechnique de Montreal
    Inventors: Oumarou Savadogo, Abdeltif Essalik
  • Patent number: 5255678
    Abstract: An electrode balloon for use in anatomical cavities, such as cardiac chambers, to pick up bioelectrical signals from the walls thereof simultaneously in a multitude of sites for the mapping of the activation potentials thereof comprises an inflated tight rubber balloon having an opening at a proximal end thereof communicating with a filling tube which defines apertures for dispensing fluid in the rubber balloon. An extensible knitting which covers the rubber balloon is provided with a plurality of electrode heads distributed thereon to contact the walls of the cavity when the rubber balloon is inflated by a fluid conveyed therein through the tube. Insulated electrical conductors connect the electrodes to a signal recording and processing device.
    Type: Grant
    Filed: June 21, 1991
    Date of Patent: October 26, 1993
    Assignee: Ecole Polytechnique
    Inventors: Antoine Deslauriers, Pierre Savard, Pierre Page, Rene Cardinal, Josee Rousseau
  • Patent number: 5119453
    Abstract: The optical waveguide coupler device is formed on two laterally adjacent optical fibers for splitting with wavelength-flattened ratios an incident light intensity into the two fibers. Adjacent sections of the two fibers are fused together and first and second concatenated tapered portions are formed. These two tapered portions are separated by a central optical waveguide portion including two parallel branches of slightly different lengths, each capable of propagating a light signal from either tapered portion to the other. The first and second tapered portions define optical waveguide couplers presenting coupling ratios varying with optical wavelength in accordance with different curves. The different lengths of the two parallel branches of the central portion cause a shift .phi. between the phases of the optical signals propagating through these two branches. The coupling ratios of the tapered portions and the phase shift .phi. are selected to wavelength-flatten the coupling ratios of the coupler device.
    Type: Grant
    Filed: April 5, 1991
    Date of Patent: June 2, 1992
    Assignee: Ecole Polytechnique
    Inventors: Francois Gonthier, Denis Ricard, Suzanne Lacroix, Jacques Bures
  • Patent number: 5110980
    Abstract: Hypochlorite digestion of bacterial biomass to recover intracellular poly-.beta.-hydroxylalkanoic acid (PHA) has not been used on a large scale since it has been widely reported to severely degrade the polymer. The process of the invention proposes to optimize the initial biomass concentration, the digestion time and pH of the hypochlorite solution to minimize degradation. Consequently, PHA of up to 95% purity with an average molecular weight of 600,000 can be recovered from biomass initially containing PHA having a molecular weight of 1,200,000. By incorporating a pretreatment step with an anionic surfactant solution, PHA of 99% purity with a molecular weight of 1.20.times.10.sup.6 was obtained from biomass containing 57% PHA by weight with an initial molecular weight of 1.25.times.10.sup.6.
    Type: Grant
    Filed: September 20, 1989
    Date of Patent: May 5, 1992
    Assignee: Ecole Polytechnique
    Inventors: Bruce A. Ramsay, Juliana Ramsay, Eric Berger, Claude Chavarie, Gerhart Braunegg
  • Patent number: 5101437
    Abstract: Apparatus and method for comparing a test handwriting signature with a reference signature where each of the test and reference signatures have been acquired by generating three electrical digital position signals characterizing a trajectory of a handwriting signature. The apparatus comprises a device for calculating variations of simple dynamic parameters of the test signature with respect to the simple dynamic parameters of the reference signature, by calculating a first evaluating function C1; a device for comparing C1 with a first threshold value, and rejecting said test signature if C1 passes the first threshold value; a device for calculating local intrinsic correlations of V.sub..sigma. and V.sub..theta.
    Type: Grant
    Filed: February 11, 1991
    Date of Patent: March 31, 1992
    Assignee: Ecole Polytechnique
    Inventor: Rejean Plamondon
  • Patent number: 5080503
    Abstract: The present disclosure describes an optical waveguide device and a method for making such device. The device comprises a substrate; a waveguide embedded in the substrate, the waveguide having a refractive index higher than the refractive index of the substrate; and first and second optical mirrors placed respectively in two different positions along the waveguide. The method comprises steps of (a) cleaning a substrate by means of a cleaning agent; (b) embedding a waveguide in the substrate; and (c) placing first and second optical mirrors respectively at two different positions in the substrate, the steps (b) and (c) being performed in such a manner that the mirrors being positioned along the waveguide.
    Type: Grant
    Filed: October 1, 1990
    Date of Patent: January 14, 1992
    Assignee: Ecole Polytechnique
    Inventors: Seyed-Iraj Najafi, Kenneth O. Hill, John F. Currie
  • Patent number: 5077802
    Abstract: The apparatus and method for digitizing and segmenting a handwriting movement comprises an electrical transducer for generating three electrical digital position signals characterizing a trajectory of the handwriting movement. The apparatus comprises a device for low-pass filtering the electrical signals; a device for deriving the electrical signals by predetermined time and transfer functions for generating V.sub.x and V.sub.y electrical components which represent respectively speeds of the point according to X and Y axes of a cartesian reference; and a device for calculating V.sub..sigma. and V.sub.74 values from the V.sub.x and V.sub.y values. The apparatus also comprises a device for calculating handwritten components and handwritten strings, where each of the handwritten components is delimited by two successive liftings of the point along the trajectory, and each of the handwritten strings is delimited by two successive portions of the trajectory where the V.sub..theta.
    Type: Grant
    Filed: February 11, 1991
    Date of Patent: December 31, 1991
    Assignee: Ecole Polytechnique
    Inventor: Rejean Plamondon
  • Patent number: 4988543
    Abstract: A method and an apparatus for impregnating one side of a porous board, such as gypsum boards, with a precise amount of compatible phase change material. A predetermined amount of the phase change material is applied at a predetermined uniform rate to the one surface of the board so that a predetermined amount of the phase change is impregnated. The rate of application is lower than the absorption rate of phase change material. Also, the temperature of the board must be above the melting point of the phase change material during the impregnation. The process and apparatus may be either a continuous, a semi-continuous or a batch operation, and the resulting product is intended as a building construction material.
    Type: Grant
    Filed: September 25, 1989
    Date of Patent: January 29, 1991
    Assignee: Ecole Polytechnique
    Inventors: Jean-Francois Houle, Jean Paris
  • Patent number: 4946250
    Abstract: A wavelength filter is integrated to a single-mode optical fiber capable of propagating a light signal and comprising a longitudinal and opaque outer jacket enveloping the fiber. This fiber is stripped of its jacket on a given length thereof to obtain a non-jacketed length of optical fiber. The so produced non-jacketed fiber length is formed with first and second concatenated biconical tapers separated from each other by a given distance and each having a given profile. By appropriately selecting the distance separating the two tapers and the given profile thereof, the filter will enable transmission of a first, predetermined wavelength of the propagated light signal while it will stop a second, predetermined wavelength of the signal. A method of integrating such a filter to a single-mode optical fiber is also proposed.
    Type: Grant
    Filed: September 7, 1989
    Date of Patent: August 7, 1990
    Assignee: Ecole Polytechnique
    Inventors: Francois Gonthier, Xavier Daxhelet, Suzanne LaCroix, Richard J. Black, Jacques Bures
  • Patent number: 4695792
    Abstract: A method and system for simultaneously detecting the amplitude and phase angle of harmonics in a periodic signal. A tunable tracking filter is connected to an input of the system to receive a periodic signal having a frequency within a predictable range. A conditioning circuit is connected to the input to tune the tracking filter to a selected harmonic in the periodic signal. A programmable frequency multiplier forms part of the conditioning circuit and is connected for locking the clock frequency of the filter to tune it to the selected harmonic of the periodic signal to provide at its output an output signal having the amplitude and corresponding phase of the selected harmonic.
    Type: Grant
    Filed: December 16, 1985
    Date of Patent: September 22, 1987
    Assignee: Ecole Polytechnique
    Inventor: Gilles Roy
  • Patent number: 4294015
    Abstract: An extensometer for detecting traumatized ligaments where the elongation of the ligament is either abnormally large or abnormally small compared to the elongation measured on a healthy ligament for an angle of flexion of the knee. The extensometer includes at least one flexible member having a strain gauge secured thereto to measure deflexion of the flexible member from its normal configuration. The flexible member has a free end and is secured at its opposed end to a support base. A clamping member is provided to retain the free end of the flexible member on a ligament while maintaining the support base substantially stationary with respect to the ligament whereby elongation of the ligament is detected by the deformation of the flexible member from its initial configuration.
    Type: Grant
    Filed: December 27, 1979
    Date of Patent: October 13, 1981
    Assignee: Ecole Polytechnique
    Inventors: Gilbert Drouin, Jacques Sibille