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:
Jan. 02, 1996
Filed:
May. 13, 1994
Richard Rzedzian, Lexington, MA (US);
Advanced NMR Systems, Inc., Wilmington, MA (US);
Abstract
A unitary, generally cylindrical member supports both the primary and shielding coils. By supporting both coils on a unitary member it is possible to take advantage of the antiphase relationship between the primary and shielding coils and thereby reduce the acoustic noise generated by the gradient coil assembly. The unitary member can be formed by starting with a mandrel to which the primary coil is applied, and then successively adding layers each having a cylindrical outer surface aligned with the same longitudinal axis. Each new cylindrical surface is formed by adding material and then removing some of the material while rotating the member about the longitudinal axis (e.g., turning on a lathe, or passing a blade past a still liquid skim coat). Additional primary and shielding coils are applied after each new aligned, cylindrical surface is formed. One or more correction coils are located outside of the shielding coils to cancel any gradient field present there as the result of misalignment between the primary and shielding coils. Litz wire is used in the primary and shielding coils to reduce coil resistance.