Treating a tumor or the like with electric fields at different orientations

An apparatus for selectively destroying or inhibiting the growth of rapidly dividing cells located within a target region of a patient, the apparatus comprising:

• at least three insulated electrodes, wherein each of the electrodes has a surface configured for placing against the patient's body;
• and
• an AC voltage source having at least three outputs, each output being electrically connected to a respective one of the electrodes,
• wherein the AC voltage source and the electrodes are configured so that when the electrodes are placed against the patient's body, an AC electric field is imposed in the target region of the patient with an orientation that rotates with respect to the target region, the imposed electric field having frequency characteristics that correspond to a vulnerability of the rapidly dividing cells, wherein the electric field is strong enough to damage, during the late anaphase or telophase stages of cell division, a significant portion of the rapidly dividing cells whose long axis is generally aligned with the lines of force of the electric field, and wherein the electric field leaves non-dividing cells located within the target region substantially unchanged.

An apparatus for selectively destroying or inhibiting the growth of rapidly dividing cells located within a target region of a patient, the apparatus comprising:

• at least three insulated electrodes, wherein each of the electrodes has a surface configured for placing against the patient's body;
• and
• an AC voltage source having at least three outputs, each output being electrically connected to a respective one of the electrodes,
• wherein the AC voltage source and the electrodes are configured so that, when the electrodes are placed against the patient's body, an AC electric field is imposed in the target region of the patient with an orientation that rotates with respect to the target region, the imposed electric field having frequency and field strength characteristics that cause the electric field to (a) selectively damage cells that are undergoing cell division and (b) leave cells that are not undergoing cell division substantially unharmed.