Patents by Inventor David L. Purdy
David L. Purdy has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5562729Abstract: A multi-leaflet (usually trileaflet) heart valve composed of biocompatible polymer which, in all of its embodiments, simultaneously imitates the structure and dynamics of biological heart valves and avoids promotion of calcification. The valve includes a plurality of flexible leaflets dip cast on a mandrel, which leaflets are then bonded with a bonding agent to the interior surfaces of a plurality of struts on a metal-reinforced prosthetic stent. The leaflets open and close in response to the pumping action of the heart and, due to the design of the leaflets, fatigue resistance of the heart valve is high. The leaflets and the polymer components of the prosthetic stent are manufactured of biocompatible polymers exhibiting intrinsic calcification-resistant properties.Type: GrantFiled: November 1, 1994Date of Patent: October 8, 1996Assignee: Biocontrol Technology, Inc.Inventors: David L. Purdy, James R. Cupp, Frederick J. Shipko, Robert D. Norman
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Patent number: 5460177Abstract: Method for non-invasive detection of the concentration of a constituent in blood of a living animal includes the steps of irradiating a body part of the animal with intensity-modulated radiation over a continuous spectrum; determining the intensity of radiation emitted from the body part at wavelength ranges within the continuous spectrum; and using the determined intensity to calculate the concentration of the constituent. A radiation source including a radiating bulb and a chopper for periodically interrupting radiation emitted from the bulb may be provided.Type: GrantFiled: May 7, 1993Date of Patent: October 24, 1995Assignee: Diasense, Inc.Inventors: David L. Purdy, Perry Palumbo, Mark DiFrancesco
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Patent number: 5379764Abstract: A method of non-invasive determination of the concentration of at least one analyte in the blood of a mammal, includes the steps of projecting near-infrared radiation on a portion of the body of the mammal, the radiation including a plurality of wavelengths; sensing the resulting radiation emitted from the portion of the body; deriving from the sensed resulting radiation emitted from the portion of the body a first expression for the magnitude of the sensed radiation as a function of wavelength of the sensed radiation; pretreating the first expression to minimize the influence of offset and drift to obtain a second expression for the magnitude of the sensed radiation as a function of wavelength; and performing multivariate analysis of the second expression to obtain a value for the concentration of the analyte.Type: GrantFiled: December 9, 1992Date of Patent: January 10, 1995Assignee: Diasense, Inc.Inventors: Russell H. Barnes, Jimmie W. Brasch, Sr., David L. Purdy, William D. Lougheed
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Patent number: 5360004Abstract: A method and apparatus for non-invasive determination of the concentration of at least one analyte in a mammal. A portion of the body of the mammal is irradiated with incident radiation, where the incident radiation includes two or more distinct bands of continuous-wavelength incident radiation. The resulting radiation emitted from the portion of the body is sensed and a value for the concentration of the analyte is derived therefrom.Type: GrantFiled: May 7, 1993Date of Patent: November 1, 1994Assignee: Diasense, Inc.Inventors: David L. Purdy, Richard L. Wiggins, Paul Castro
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Patent number: 5070874Abstract: Radiation in the near infrared over a limited range of wavelengths about 1660 nanometers is projected on a portion of the body, for example, the ear, of the patient. The resulting radiation emitted by the portion, either scattered from the portion or transmitted after absorption and scattered by the portion, is processed to derive an expression of the resulting radiation as a function of the wavelength. The second derivative of this function over a very narrow range of this function between 1640 and 1670 nanometers is expanded and the glucose concentration is determined from the magnitude, or intensity, of the scattered or transmitted radiation at the maximum or minimum point of this derivative apparatus for non-invasive determination of glucose concentration in the patient. Radiation in the near infrared is transmitted through a first fiber-optic radiation conductor to the outer surface of a portion of the patient's body, penetrating into the portion.Type: GrantFiled: January 30, 1990Date of Patent: December 10, 1991Assignee: Biocontrol Technology, Inc.Inventors: Russell H. Barnes, Jimmie W. Brasch, Sr., David L. Purdy
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Patent number: 4907593Abstract: A rate-changing implantable heart-stimulating device is disclosed, one that avoids use of moving parts and making unwanted rate changes. The device senses and responds to skeletal myopotential signals derived from the body of the wearer, preferably considering both amplitude and frequency of myopotential voltage signals which exceed a predetermined threshold value. The device preferably has two-way radio communication with an external programmer means.Type: GrantFiled: May 21, 1987Date of Patent: March 13, 1990Assignee: Biocontrol Technology, Inc.Inventors: Charles M. Rapach, David L. Purdy, Orlando Maytin
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Patent number: 4892518Abstract: Hemodialysis port assembly including a port and a catheter assembly. The port includes an inlet septum subtended by an inlet plenum and an outlet septum subtended by an outlet plenum. The catheter assembly includes an inlet channel connected to the inlet plenum and an outlet channel connected to the outlet plenum. The port and catheter assembly are completely implanted in the chest of a patient with the port subcutaneous and the end of the catheter assembly remote from the port injected into the subclavian vein. The blood flow in this vein is in the direction away from the end of the catheter assembly. Near this remote end the catheter assembly or the inlet channel terminates in an inlet valve and the outlet channel terminates in an outlet valve. Each of these valves is essentially a flapper on which the blood is incident in a generally perpendicular direction so that its flow is substantially unimpeded.Type: GrantFiled: December 4, 1987Date of Patent: January 9, 1990Assignee: Biocontrol Technology, Inc.Inventors: James R. Cupp, Robert D. Norman, David L. Purdy, Orlando Maytin
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Patent number: 4041956Abstract: A method of making a pacemaker which includes, in a container a subassembly of, a battery nested in an electrical converter serving to produce heart-pacing pulses. This subassembly is encapsulated in a mold in rigid, polyurethane foam of low weight and capable of protecting the encapsulated components from shock. The body formed by prepotting is generally ellipsoidal and is nested snugly in one of the sections of an ellipsoidal container. Another section of the container is welded to the one section along the congruent rims. Additional potting material is injected through the boards between the sides of the encapsulated body and the adjacent walls of the container. The encapsulated body is held firmly in the container without potting material between the top and bottom and ends of the body and the container. The potting material is injected through the hole in which the electrical feedthrough is subsequently welded.Type: GrantFiled: February 17, 1976Date of Patent: August 16, 1977Assignee: Coratomic, Inc.Inventors: David L. Purdy, Vernon L. Speicher, Frederick J. Shipko, William L. Johnson
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Patent number: 4006039Abstract: In a thermoelectric generator, a component comprises a ceramic insulator, having over limited areas thereof, each area corresponding to a terminal end of thermoelectric wires, a coating of a first metal which adheres to the insulator, and an electrical thermoelectric junction including a second metal which wets said first metal and adheres to said terminal ends but does not wet said insulator, and a cloth composed of electrically insulating threads interlaced with thermoelectric wires.Type: GrantFiled: November 13, 1975Date of Patent: February 1, 1977Assignee: ARCO Medical Products CompanyInventor: David L. Purdy
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Patent number: 4006038Abstract: Threads are interlaced with thermoelectric wires to provide a woven cloth in tape form, there being an intermediate layer of heat radiation reflecting material (e.g., aluminum foil) insulated electrically from said wires, which are of opposite thermoelectric polarity and connected as a plurality of thermocouples.Type: GrantFiled: November 13, 1975Date of Patent: February 1, 1977Assignee: ARCO Medical Products CompanyInventor: David L. Purdy
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Patent number: 3989546Abstract: A cylindrical casing has a central shielded capsule of radioisotope fuel. A plurality of thermonuclear modules are axially arranged with their hot junctions resiliently pressed toward the shield and with their cold junctions adjacent a transition member having fins radiating heat to the environment. For each module, the assembly of transition member and fins is hinged to the casing for swinging to permit access to and removal of such module. A ceramic plate having gold layers on opposite faces prevents diffusion bonding of the hot junction to the shield.Type: GrantFiled: March 11, 1974Date of Patent: November 2, 1976Assignee: ARCO Medical Products CompanyInventors: David L. Purdy, Zalman M. Shapiro, Thomas F. Hursen, Gerould W. Maurer
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Patent number: 3989547Abstract: An electrical generator having an Isotopic Heat Capsule including radioactive fuel rod 21 as a primary heat source and Thermoelectric Modules 41 and 43 as converters. The Biological Shield for the Capsule is suspended from Spiders at each end each consisting of pretensioned rods 237 and 239 defining planes at right angles to each other. The Modules are mounted in cups 171 of transition members 173 of a heat rejection Fin Assembly whose fins 195 and 197 extend from both sides of the transition member 173 for effective cooling.Type: GrantFiled: March 11, 1974Date of Patent: November 2, 1976Assignee: ARCO Medical Products CompanyInventors: David L. Purdy, Zalman M. Shapiro, Thomas F. Hursen, Gerould W. Maurer
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Patent number: 3987799Abstract: A heart pacer to be implanted between the pectoralis major muscle and the skin a short distance below the clavicle having an outer container in the shape of an ovaloid. Such a heart pacer adapts itself positionally, cosmetically and with a minimum of discomfort to implantation.Type: GrantFiled: February 14, 1975Date of Patent: October 26, 1976Assignee: Coratomic Inc.Inventors: David L. Purdy, George J. Magovern, Nicholas P. D. Smyth
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Patent number: 3981750Abstract: A nuclear heart pacer having a heat-to-electricity converter including a solid-state thermoelectric unit embedded in rubber which is compressed to impress hydrostatic precompression on the unit. The converter and the radioactive heat source are enclosed in a container which includes the electrical circuit components for producing and controlling the pulses; the converter and components being embedded in rubber. The portions of the rubber in the converter and in the container through which heat flows between the radioactive primary source and the hot junction and between the cold junction and the wall of the container are of thermally conducting silicone rubber.The primary radioactive source material Pu.sub.238 is encapsuled in a refractory casing of WC-222 (T-222) which in turn is encapsuled in a corrosion-resistant casing of platinum rhodium, a diffusion barrier separating the WC-222 and the Pt-Rh casings. The Pt-Rh casing is in a closed basket of tantalum.Type: GrantFiled: July 12, 1973Date of Patent: September 21, 1976Assignee: Coratomic Inc.Inventor: David L. Purdy
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Patent number: 3944438Abstract: A heat-to-electricity converter is disclosed which includes a radioactive heat source and a thermoelectric element of relatively short overall length capable of delivering a low voltage of the order of a few tenths of a volt. Such a thermoelectric element operates at a higher efficiency than longer higher-voltage elements; for example, elements producing 6 volts. In the generation of required power, thermoelectric element drives a solid-state converter which is controlled by input current rather than input voltage and operates efficiently for a high signal-plus-noise to signal ratio of current. The solid-state converter has the voltage gain necessary to deliver the required voltage at the low input of the thermoelectric element.Type: GrantFiled: March 11, 1974Date of Patent: March 16, 1976Assignee: Arco Medical Products CompanyInventors: Thomas F. Hursen, Steven A. Kolenik, David L. Purdy
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Patent number: RE30028Abstract: A heart pacer to be implanted between the pectoralis major muscle and the skin a short distance below the clavicle having an outer container in the shape of an ovaloid.[...]. .Iadd.being, except where the heart lead is connected, curved in all dimensions and free of corners and shape ends. .Iaddend.Such a heart pacer adapts itself positionally, cosmetically and with a minimum of discomfort to implantation.Type: GrantFiled: January 13, 1977Date of Patent: June 12, 1979Assignee: Coratomic, Inc.Inventors: David L. Purdy, George J. Magovern, Nicholas P. D. Smyth