John H Broadhurst

US Patent:

48795186, Nov 7, 1989

Filed:

Oct 13, 1987

Appl. No.:

7/107093

Inventors:

John H. Broadhurst - Golden Valley MN

Assignee:

Sysmed, Inc. - Eden Prairie MN

International Classification:

H05H 900
H05H 502

US Classification:

328233

Abstract:

An electrostatic linear accelerator includes an electrode stack comprised of primary electrodes formed or Kovar and supported by annular glass insulators having the same thermal expansion rate as the electrodes. Each glass insulator is provided with a pair of fused-in Kovar ring inserts which are bonded to the electrodes. Each electrode is designed to define a concavo-convex particle trap so that secondary charged particles generated within the accelerated beam area cannot reach the inner surface of an insulator. Each insulator has a generated inner surface profile which is so configured that the electrical field at this surface contains no significant tangential component. A spark gap trigger assembly is provided, which energizes spark gaps protecting the electrodes affected by over voltage to prevent excessive energy dissipation in the electrode stack.

US Patent:

52784185, Jan 11, 1994

Filed:

Apr 6, 1992

Appl. No.:

7/864319

Inventors:

John H. Broadhurst - Golden Valley MN

International Classification:

G01N 2320

US Classification:

25039004

Abstract:

A method for detecting the presence of a predetermined amount of oxygen and nitrogen in a luggage type container as a screening technique for determining the presence of an explosive in the container. Generating and accelerating a beam of monoenergetic protons at a neutron generating target formed of boron. Rapidly and periodically subjecting the proton beam to an energy degrading medium upstream of the neutron generating target to thereby selectively degrade the energy of the protons of the proton beam during the time the median is in place while allowing the energy of the proton beam to remain at the original energy when the degrading median is removed. Directing the energy variant proton beam at the boron target to generate an energy variant neutron beam, the neutron beam containing on resonant neutrons at a resonant energy of nitrogen or oxygen nuclei and containing off resonant neutrons outside the resonant energy of the nuclei of nitrogen and oxygen. First detecting, measuring and comparing on resonant neutrons removed by interactions with nuclei of oxygen, and off resonant neutron passing through the luggage container, and, in response to a determination of the presence of predetermined amount of oxygen in the container, then detecting, measuring and comparing on resonant neutrons removed by interactions with nuclei of nitrogen, and off resonant neutrons passing through the luggage container for determining the presence of a predetermined level of nitrogen.

US Patent:

51374293, Aug 11, 1992

Filed:

Apr 15, 1991

Appl. No.:

7/685428

Inventors:

John H. Broadhurst - Golden Valley MN

Assignee:

Spectrameasure Inc. - Golden Valley MN

International Classification:

F04F 900

US Classification:

417152

Abstract:

A high vacua diffusion pump for use in a vacuum system including a chamber to be evacuated and a positive displacement pump. The diffusion pump includes a pump body structure having an open upper end and a closed lower end. A boiler and jet assembly is yieldably supported within the pump body and produces jet streams that impel the residual air molecules through the exit port. A ceramic heat break having a labyrinth passage therethrough positively separates the temperature of the condensing wall surface from the boiler temperature. A cooling system permits selective rapid cooling of the boiler and is openable to permit rapid re-heating of the boiler. In one embodiment, the pump includes a room temperature condensing surface, and in another embodiment a non-room temperature condensing surface is provided.

US Patent:

48503711, Jul 25, 1989

Filed:

Jun 13, 1988

Appl. No.:

7/205668

Inventors:

John H. Broadhurst - Golden Valley MN
Marvin B. Bacaner - Minneapolis MN

International Classification:

A61B 508

US Classification:

128719

Abstract:

A non-invasive apparatus for continuously measuring the cardiac output and cardio-respiratory function includes a gas sampling device which is inserted into the mouth of a human subject. The gas sampling device may be a disposable endotracheal tube or a smaller disposable mouthpiece. Each of these gas sampling devices is provided with a plurality of passages for sampling the lung gases and for continuously sampling the gas pressure on opposite sides of a capillary restriction member. A miniature motor pump mass spectrometer module is mounted on the upper end of the endotracheal tube or mouthpiece. Electronic circuitry connected to the mass spectrometer permits constant visual monitoring of the cardiac output and cardio-respiratory function.

US Patent:

49661418, Oct 30, 1990

Filed:

Jun 12, 1989

Appl. No.:

7/364109

Inventors:

Marvin B. Bacaner - Minneapolis MN
John H. Broadhurst - Golden Valley MN

International Classification:

A61M 1600

US Classification:

12820714

Abstract:

A non-invasive apparatus for continuously measuring the cardiac output and cardio-respiratory function includes a gas sampling device which is inserted into the mouth of a human subject. The gas sampling device may be a disposable endotracheal tube or a smaller disposable mouthpiece or facial mask. Each of these gas sampling devices is provided with a plurality of passages for sampling the lung gases and for continuously sampling the gas pressure on opposite sides of a capillary restriction member. A miniature motor pump mass spectrometer module is mounted on the upper end of the endotracheal tube or mouthpiece. Electronic circuitry connected to the mass spectrometer permits constant visual monitoring of the cardiac output and cardio-respiratory function.

US Patent:

48621358, Aug 29, 1989

Filed:

Sep 29, 1988

Appl. No.:

7/250609

Inventors:

John H. Broadhurst - Golden Valley MN

Assignee:

Sysmed, Inc. - Golden Valley MN

International Classification:

H01C 106

US Classification:

338 64

Abstract:

A resistor device for use with electrostatic particle accelerators includes a resistor element positioned within a tubular housing having a fixed end cap at one end thereof and a movable end cap at the other end thereof. The tubular housing, fixed end cap, and movable end cap serve as an electromagnetic field for the resistor element. Conductive disks engage opposite ends of the resistor element and concentrically position the resistor element within the tubular housing. Helical springs engage the conductive disks and the end caps to yieldably support the movable end caps and resistor element for yieldable axial movement relative to the tubular housing. An annular conducting ring is secured to the tubular housing and is spaced radially from the movable end cap and cooperates with the latter to define an annular spark gap.

US Patent:

45582238, Dec 10, 1985

Filed:

Feb 5, 1982

Appl. No.:

6/345940

Inventors:

John H. Broadhurst - Golden Valley MN
Marvin B. Bacaner - Minneapolis MN

Assignee:

Sysmed, Inc. - Eden Prairie MN

International Classification:

G01T 118

US Classification:

250374

Abstract:

A method for increasing the efficiency of gas ionization detectors for diagnostic x-rays by matching a detector gas absorption edge with the energy level of an x-ray source to produce photons of only slightly higher energy. Sequential x-ray images using different matched gas absorption edges and x-ray source energies allows contrast information to be obtained to distinguish calcium deposits or dye from bone, for example. Specific ionization detectors useful for practicing the inventive methods are also described. One such detector uses ultrafast electronics associated with individual wires of a multiwire two dimensional proportional counter. Another detector employs a conductor backed sheet of insulating material to immobilize positive gas ions in a density distribution conforming to the x-ray image. The density distribution may subsequently be read out by electromechanical means for sensing the potential differences on the sheet. The potential sensing means may be located within or outside the detector chamber.

US Patent:

50435760, Aug 27, 1991

Filed:

Apr 7, 1989

Appl. No.:

7/334932

Inventors:

John H. Broadhurst - Golden Valley MN
Marvin B. Bacaner - Minneapolis MN

International Classification:

B01D 5944
H01J 4900

US Classification:

250293

Abstract:

A non-invasive apparatus for continuously measuring the cardiac output and cardio-respiratory function includes a gas sampling device which is inserted into the mouth of a human subject. The gas sampling device may be a disposable endotracheal tube or a smaller disposable mouthpiece. Each of these gas sampling devices is provided with a plurality of passages for sampling the lung gases and for continuously sampling the gas pressure on opposite sides of a capillary restriction member. A miniature motor pump mass spectrometer module is mounted on the upper end of the endotracheal tube or mouthpiece. Electronic circuitry connected to the mass spectrometer permits constant visual monitoring of the cardiac output and cardio-respiratory function.