Magnetic stimulator power and control circuit
AssigneeR. B. Carr Engineering, Onc.
InventorsDavid J. Perreault, Scott Mogren
Life of this patent
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Abstract
An electromagnetic stimulator circuit has a precharge power supply, a capacitor, a set of switches, and a stimulator coil. The switches, which can be implemented using a variety of devices, enable flexible control over the coil current waveform without requiring the physical reconfiguration of circuit elements. The shape of the output current pulse is controlled by the modulation of the switches, and much of the energy applied to the coil is returned from the coil to the capacitor for reuse on the succeeding pulse. Less power is required and less heat energy is generated.
Claims18
A magnetic stimulator system, comprising:
- a capacitor;
- a capacitor pre-charge circuit, in electrical communication with said capacitor, for selectively establishing an electric potential across said capacitor;
- and
- a coil switching circuit, in communication with said capacitor, comprising an inductive stimulator coil for generating a magnetic field in response to a current flow therethrough, said current resulting from dissipation of said electric potential across said capacitor, and a bridge circuit comprised of first and second half-bridge circuits, each of said half-bridge circuits having two respective switching elements in a serial arrangement and providing an output terminal in communication a respective end of said inductive stimulator coil.
A method of providing a desired current profile through a stimulus coil, comprising:
- providing a bridge circuit comprised of two half-bridge circuits, wherein a first of said half-bridge circuits is comprised of two serially arranged switching elements each having a forward direction towards a respective common node therebetween and wherein a second of said half-bridge circuits is comprised of two serially arranged switching elements each having a forward direction away from a respective common node therebetween;
- disposing said stimulus coil intermediate said common nodes of said first and second half-bridge circuits;
- providing a capacitor having a positive terminal in electrical communication with a first end of said first and second half-bridge circuits and a negative terminal in electrical communication with a second end of said first and second half-bridge circuits;
- providing a capacitor pre-charge sub-circuit in electrical communication with said capacitor;
- opening said switching elements of said bridge circuit;
- operating said pre-charge sub-circuit to pre-charge said capacitor to a first voltage level;
- selectively closing at least two of said switching elements to at least partially discharge said capacitor voltage across said stimulus coil;
- selectively closing and opening said switching elements to re-establish at least a portion of said first voltage level from said stimulus coil to said capacitor.
Dependencies are inferred from the claim text.