Stress test devices and methods

摘要

One method for diagnosing a cardiovascular-related condition in a breathing person comprises interfacing a valve system to the person's airway. The valve system is configured to decrease or prevent respiratory gas flow to the person's lungs during at least a portion of an inhalation event. The person is permitted to inhale and exhale through the valve system. During inhalation, the valve system functions to produce a vacuum within the thorax to increase blood flow back to the right heart of the person, thereby increasing blood circulation and blood pressure. Further, at least one physiological parameter is measured while the person inhales and exhales through the valve system. The measured parameter is evaluated to diagnose a cardiovascular condition.