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:
Sep. 03, 1996
Filed:
Nov. 30, 1994
Cornelis L Ham, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
Magnetic resonance imaging includes a system of gradient coils (3) for generating gradient fields in a measuring space (35), a power supply source (7) for the gradient coils, and a communication system for transferring acoustic information from at least a first region (39) in which the level of gradient noise generated by the gradient coils (3) is comparatively high to at least a second region (41). The communication system includes a reference signal generating device for generating a reference signal which is dependent on the gradient noise, a microphone (43) which is arranged in the first region (39) so as to pick up a mixture of sound information and gradient noise, and a sound reproduction device (65, 67), at least a part of which is situated in the second region (41). The communication system also includes a noise suppression device, formed by a filter device (61) for converting the reference signal into a signal which corresponds substantially to the gradient noise at the area of the microphone (43), and a summing device (63) for adding the output signal of the filter device to the output signal of the microphone in phase opposition, the output of the summing device being connected to the sound reproduction device. Between the microphone (43) and the summing device (63) a signal delay device (53) is inserted which delays the microphone signal for a predetermined period of time. The sound reproduction device (65, 67) is provided with a device (69) for attenuating sound which does not originate from the sound reproduction device.