A method for treating upper respiratory obstructions in a patient by electrical stimulation of muscles of the upper airway including surgically implanting a impedance sensing circuit into the patient such that the impedance sensor is capable of providing a signal characteristic of transthoracic impedance...http://www.google.es/patents/US5540732?utm_source=gb-gplus-sharePatente US5540732 - Method and apparatus for impedance detecting and treating obstructive airway disorders
Method and apparatus for impedance detecting and treating obstructive airway ...
