Reducing electrosensation while treating a subject using alternating electric fields by controlling ramp-up characteristics
AssigneeNovocure GmbH
InventorsYoram Wasserman, Michael Shtotland
Life of this patent
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Abstract
When transducer arrays (i.e., arrays of electrode elements) are used to apply alternating electric fields to a subject's body, the subject may experience electrosensation. This electrosensation can be ameliorated by changing the way the voltage ramps up from zero to its peak when the AC voltage is first applied to any given transducer array, and also when the alternating electric field switches direction.
Claims14
A method of imposing alternating electric fields in a target region of a subject's body, the method comprising:
- (a) imposing a first alternating electric field with a first orientation in the target region during a first interval of time, the first alternating electric field having an amplitude that increases during a plurality of first subsections of the first interval of time and either remains constant or decreases during a plurality of second subsections of the first interval of time, wherein each of the plurality of second subsections of the first interval of time is at least 10 ms long and comes immediately after a respective one of the first subsections of the first interval of time, wherein the first alternating electric field has an amplitude that remains constant during a third subsection of the first interval of time, and wherein the third subsection of the first interval of time comes after a final one of the first subsections of the first interval of time.
An apparatus for applying electrical signals to first, second, third, and fourth sets of at least one electrode element, the apparatus comprising:
- an AC signal generator having a first output, a second output, and at least one control input;
- and
- a controller configured to apply a sequence of control signals to the at least one control input of the AC signal generator,
- wherein the sequence of control signals commands the AC signal generator to
- (a) apply a first AC output signal to the first output during a first interval of time, wherein the first AC output signal has an amplitude that increases during a plurality of first subsections of the first interval of time and either remains constant or decreases during a plurality of second subsections of the first interval of time, wherein each of the plurality of second subsections of the first interval of time is at least 10 ms long and comes immediately after a respective one of the first subsections of the first interval of time, wherein the first AC output signal has an amplitude that remains constant during a third subsection of the first interval of time, and wherein the third subsection of the first interval of time comes after a final one of the first subsections of the first interval of time.
Dependencies are inferred from the claim text.