Abstract: The sleep-apnea syndrome is classified into a so-called central type caused by an abnormality in the respiratory center, an obstructive type by an upper airway obstruction, and a mixed type by a combination thereof. Among the rest, the obstructive type is often observed clinically and is considered to be caused by a morphological abnormality in the upper airway tract, such as tonsillar hypertrophy or micrognathia, or by a tonus of the upper airway muscle for broadening the airway. The inventors of this application have clarified by experiments that the upper airway can be recovered from obstruction which causes apnea stimulating the genioglossus, which is one of the dilator muscles of the upper airway, with pulses of a frequency of 40 to 150 Hz, a peak value of 1 to 50 volts and a rise-up time constant of 0.

Abstract: The sleep-apnea syndrome is classified into a so-called central type caused by an abnormality in the respiratory center, an obstructive type by an upper airway obstruction, and a mixed type by a combination thereof. Among the rest, the obstructive type is often observed clinically and is considered to be caused by a morphological abnormality in the upper airway tract, such as tonsillar hypertrophy or micrognathia, or by a tonus of the upper airway muscle for broadening the airway. The inventors of this application have clarified by experiments that the upper airway can be recovered from obstruction which causes apnea stimulating the genioglossus, which is one of the dilator muscles of the upper airway, with pulses of a frequency of 40 to 150 Hz, a peak value of 1 to 50 volts and a rise-up time constant of 0.