The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 27, 1995
Filed:
Oct. 28, 1994
Shin'ichi Shimode, Ibaraki, JP;
Hiroshi Inouye, Ibaraki, JP;
Norihide Saho, Tsuchiura, JP;
Shinya Okabe, Shimizu, JP;
Masayuki Otsuka, Katsuta, JP;
Yukiji Iwase, Ushiku, JP;
Etsuji Yamamoto, Akishima, JP;
Hidemi Shiono, Akigawa, JP;
Kenji Takiguchi, Kodaira, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An active noise cancellation apparatus of an MRI apparatus, including a detector for detecting vibration of a bobbin or a driving signal of a magnetism generator as a noise source signal, error signal detectors for detecting actual noise near the ears of a patient, a circuit for generating a noise cancellation signal having an opposite phase to a phase of a noise signal generated by an MRI apparatus and having an amplitude proportional to the output of the error signal detectors, from the detected noise source signal and the output of the error signal detectors, and a sound generator for generating a sound wave by the noise cancellation signal.