Patent ID: 7715911

Claim:
An apparatus for delivering electrical stimulation to body tissue, the apparatus comprising: first and second terminals configured to be electrically coupled to the body tissue; a first capacitor having a first electrode coupled to the first terminal and having a second electrode, wherein the first capacitor is sized to store a tissue stimulation voltage for discharge through the body tissue; a voltage source having an output; a first switch for coupling the second electrode to the output of the voltage source; a second switch configured for coupling the second electrode to a reference potential; a third switch configured for coupling the second terminal to the reference potential; and a current smoothing circuit coupled between the output of the voltage source and the first switch, a microprocessor configured to provide a first control signal to control at least an amplitude of the a tissue stimulation voltage to be stored in the first capacitor when the apparatus is operational, wherein the microprocessor is configured to control operation of the first, second, and third switches when the apparatus is operational, wherein the apparatus is configured such that when the first and third switches are closed and the second switch is open a charging circuit is provided to charge the first capacitor to the tissue stimulation voltage when the apparatus is operational, and wherein the apparatus is configured such that when the first switch is open and the second and third switches are closed a discharge circuit is provided to discharge the first capacitor through the body tissue when the apparatus is operational, and further wherein the first capacitor is the sole capacitor in the discharge circuit used to provide the tissue stimulation.