DUANE BOYD CRUM
Pilots at Kingsgate Sq, San Diego, CA

4793355, Dec 27, 1988

Apr 17, 1987

7/039515

Duane B. Crum - San Diego CA
Ronald C. Wesley - Cardiff CA
Richard E. Greenblatt - San Diego CA
Roberta M. Toussaint - Olivenhain CA
Eugene C. Hirschkoff - Leucadia CA

Biomagnetic Technologies, Inc. - San Diego CA

A61B 505

128653

Apparatus for making biomagnetic measurements includes a biomagnetometer for measuring magnetic fields produced by the body and an electromagnetic location measurement and recording system for automatically determining the location of the portion of the body from which the magnetic signals are being gathered. The electromagnetic location recording system permits establishing a real time body frame of reference with respect to the biomagnetometer, so that biomagnetic signals can be correlated directly with body location and structure. The electromagnetic location recording system may be operated continuously at radiation wavelengths which do not interfere with the taking of data, or intermittently with the taking of biomagnetic data, to avoid interference with the measured values of the biomagnetic data. The elements of the electromagnetic location recording system have substantially no residual magnetism when the location recording system is not operating, as the biomagnetic signals are typically so small that even normal residual magnetism might be erroneously recorded as a biomagnetic signal.

5109196, Apr 28, 1992

Mar 5, 1991

7/664640

John P. Wikswo - Brentwood TN
Nestor G. Sepulveda - Nashville TN
W. Patrick Henry - Nashville TN
Duane Crum - San Diego CA

Vanderbilt University - Nashville TN

G01R 3302

324263

Flaws in an electrically conductive sample object are detected by cancelling the magnetic field generated by a detection current passed through the sample object by passing the current back through an unflawed field cancelling object placed next to the sample object, and measuring the uncancelled field produced by any flaw, preferably with a superconducting quantum interference device (SQUID) magnetometer. Elongated objects such as tubes and rods are fed through a sleeve which forms the field cancelling object, with the current applied to the elongated member and passed to the field cancelling sleeve through sliding contacts.

5016128, May 14, 1991

Apr 27, 1988

7/187017

Mark S. DiIorio - San Diego CA
Stephen E. Robinson - San Diego CA
Duane B. Crum - San Diego CA
Douglas N. Paulson - Del Mar CA
D. Scott Buchanan - San Diego CA
James R. Marsden - San Diego CA

Biomagnetic Technologies, Inc. - San Diego CA

G11B 5012

360 9701

An information storage device includes a magnetic recording medium, preferably supported upon a rotating disk, an electromagnetic writing device that writes magnetic patterns into the recording medium, and a superconducting quantum interference device (SQUID) that reads the magnetic patterns in the recording medium, the writing device and the SQUID preferably being mounted upon a read/write head. The SQUID as operated in its superconducting state is a highly sensitive and directional detector of the magnetic state of the recording medium, permitting it to be spaced relatively distantly from the recording medium yet read the state of small areas of the medium. Use of high temperature superconductors in the SQUID permits practical construction of the information storage device. The read/write head may support a plurality of write devices, and an array of SQUIDs can be utilized so that little or no relative movement of the read/write head is required to read and write from all tracks of the disk.

5932810, Aug 3, 1999

Feb 25, 1998

9/030315

Bruce Westermo - San Diego CA
Duane Crum - San Diego CA
William Law - San Diego CA
Larry D. Thompson - Descanso CA
Robert Trombi - San Diego CA
Raemon M. Polk - Atlanta GA

Strain Monitor Systems, Inc. - Norcross GA

G01G 1912

73768

A passive deflection gauge to detect peak deflection in a structural material or system since a given time is disclosed. The gauge includes any type of mechanical deflection sensor using a moveable or extensible core for measuring deflection. A stop moves the core only if a strain greater than the previously occurring maximum strain is present in the structural material or system. Any other movement of the stop will not move the core. Furthermore, a friction member may be incorporated to prevent spurious movement of the core.

5027819, Jul 2, 1991

Jul 12, 1990

7/551882

Duane B. Crum - San Diego CA

Biomagnetic Technologies, Inc. - San Diego CA

A61B 505

128653R

A biomagnetometer measures the magnetic field produced by the brain as a result of a visual stimulus delivered by a display device such as a cathode ray tube (CRT). The output signal of the biomagnetometer is filtered to remove noise introduced by the operation of the display device itself, such as the repetitive scan signal of the CRT, and the CRT monitor is otherwise operated from DC power to minimize periodic variations that can interfere with the detection of brain signals. The filtering is preferably accomplished using a comb-notch filter. Cancellation coils and shielding are also preferably used to remove a portion of the noise introduced by the display device.