Ferromagnetic foreign body detection with background canceling

(54) FERROMAGNETIC FOREIGN BODY DETECTION WITH BACKGROUND CANCELING

(75) Inventors: William F. Avrin, San Diego, CA (US);

Peter V. Czipott, San Diego, CA (US);
R. Kemp Massengill, Leucadia, CA
(US)

(73) Assignees: MedNovus, Inc., Escondido, CA (US);

Quantum Magnetics, Inc., San Diego,
CA (US)

( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.

(21) Appl. No.: 09/960,878

(22) Filed: Sep. 21, 2001

(65) Prior Publication Data

US 2002/0077537 Al Jun. 20, 2002

Related U.S. Application Data

(63) Continuation-in-part of application No. 09/818,700, filed on Mar. 27,2001, which is a continuation-in-part of application No. 09/741,774, filed on Dec. 15, 2000, which is a continuation of application No. 09/135,890, filed on Aug. 18,1998, now Pat. No. 6,208,884, which is a continuation-in-part of application No. 08/670,393, filed on Jun. 25,1996, now Pat. No. 5,842,986.

(51) Int. CI. A61B 5/05

(52) U.S. CI 600/409; 324/207.21; 324/260

(58) Field of Search 600/407, 409,

600/410; 324/260, 261, 207.11-207.19,

67

OTHER PUBLICATIONS

Avrin, W.; Improved Nondestructive Evaluation of Deep, Inaccessible Flaws in Metal Structures; National Science Foundation Phase I final Report; pp. 1-29; Dec, 1995.

(List continued on next page.)

Primary Examiner—Marvin M. Lateel
Assistant Examiner—Eleni Mantis Mercader
(74) Attorney, Agent, or Firm—Gerald W. Spinks

(57) ABSTRACT

Methods are disclosed for non-invasive screening ol the human body by rejecting the magnetic response from biological tissues in the region ol interest and outputting data corresponding to the magnetic response ol a lerromagnetic foreign body within the region ol interest.

34 Claims, 7 Drawing Sheets

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* cited by examiner