Method and apparatus for synchronized treatment of obstructive sleep apnea

A method and apparatus for synchronized treatment of obstructive sleep apnea. In one embodiment such stimulation is provided by an implantable pulse generator, the implantable pulse generator having a stimulation stage to output stimulation pulses to a body structure, a sensing stage to sense the respiratory effort of a patient, and a controller, to coordinate, and preferably to synchronize, the output stimulation pulses with the sensed respiratory effort. The respiratory effort of a patient is sensed through the use of two electrodes disposed such that the diaphragm is positioned between, and the high frequency current is injected from one electrode to the other and the corresponding impedance is measured, the corresponding impedance thus being a function of the diaphragm position, itself indicating the respiratory effort of the patient. In such a manner the present invention permits the delivery of stimulation to be precisely controlled by the actual respiratory effort of the patient.