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:
Jul. 14, 1987
Filed:
Jan. 04, 1985
Floyd L Gray, Hales Corners, WI (US);
Thomas F Schubert, Pewaukee, WI (US);
Kenneth M Bradshaw, Waukesha, WI (US);
Joshua O Kolawole, Wauwatosa, WI (US);
General Electric Company, Milwaukee, WI (US);
Abstract
A method is provided for reducing acoustical noise generated when gradient coils which are part of a nuclear magnetic resonance (MR) scanner are energized by current pulses in the course of an MR study. The acoustical noise is due to vibrations of a fiber-glass coil form on which the coils are wound. The vibrations are excited by high frequency components in the squared-edged conventional current pulses. Significant noise reduction is achieved by shaping the leading and trailing current pulse edges to eliminate the objectionable high frequency components. Advantageously, the pulse edges can be shaped using sinusoidal and Bessel function waveforms. Another useful waveform for pulse shaping is a ramp function with rounded transition points.