Abstract: In accordance with the present invention, a breathing exercise training apparatus is provided for increasing the endurance of inspiratory muscles. This is accomplished by setting a target breathing frequency, target inhalation time and target inhalation pressure on a target generator, and then having the trainee breathe into a resistive breathing device that imposes a predetermined resistance to inhalation and communicates actual inhalation pressure to the target generator. The target generator includes structure for comparing the actual inhalation time and pressure with the target values and provides a feedback signal in response thereto. A preset time interval is provided within which the trainee must attain the target inhalation pressure after an inhalation cycle begins, or a "fault" signal is given to the trainee. Thus, the apparatus of the invention forces the trainee to exercise his inspiratory muscles in order to achieve the target inhalation pressure within the target time.

Abstract: A ventilatory muscle training apparatus is disclosed which utilizes a gas rebreathing system having a reservoir and a mouthpiece for use in conveying gas into and out of the reservoir during inhalation and exhalation. An adjustable valve-like aperture is located in the system in a position to vent some expired gas to the ambient atmosphere during exhalation and in a position such that some ambient air is drawn into the system from the ambient during inhalation. This aperture structure is capable of being adjusted so as to normalize the carbon dioxide content of the gas breathed in during inhalation to a patient's normal respiratory level. The reservoir used is preferably an enclosed chamber which is open to the ambient air remote from the mouthpiece. The apparatus also includes a means for use in monitoring the air flow through the mouthpiece so that the patient can determine that his or her breathing is in accordance with the intended manner of use of the apparatus.