Patent ID: 7778703

Claim:
Apparatus for treating a condition of a subject, comprising: an electrode device, configured to be coupled to a nerve of the subject; a sensor configured to sense at least one feature of cardiac activity of the subject; and a control unit, configured to: drive the electrode device to apply to the nerve a stimulating current, which is configured to induce action potentials in (i) a first set of nerve fibers of the nerve, and (ii) a second set of nerve fibers of the nerve having generally larger diameters than the nerve fibers in the first set, drive the electrode device to apply to the nerve an inhibiting current, which is configured to inhibit the induced action potentials in the second set of nerve fibers but not in the first set of fibers, responsively to the at least one sensed feature of cardiac activity of the subject, configure at least one current selected from the group consisting of: the stimulating current, and the inhibiting current, and regulate a heart rate of the subject by: driving the electrode device to apply the stimulating and inhibiting currents in each of a plurality of cardiac cycles of the subject in respective series of pulses, each of which pulse series is applied after a delay from a sensed point in the cardiac cycle, and varying a number of pulses applied per cardiac cycle and a length of a period of application of the respective series of pulses.