Patent ID: 6128174
Filing Date: 2000-10-03
Classification: A61B,A61F,A61N,H01F,H02N

Abstract:
A method of rapidly changing a magnetic field having a controlled magnitude and produced by a coil, the method comprising the steps of:(a) applying a first current of I.sub.1 Amperes to the coil;(b) transitioning to a second current of I.sub.2 Amperes applied to the coil by continuously varying the current, where I.sub.1 .noteq.I.sub.2 ; and(c) during at least a portion of a transition period between the application of I.sub.1 and the application of I.sub.2, applying a time-varying current I(t) to the coil, where dI(t)/dt varies as a function of time t, the magnitude of dI(t)/dt varying in a direction opposite to that in which the magnitude of I(t) varies.