More than 150 years have passed since the birth of the idea of intermittent mechanical ventilation. Many types of ventilatory disorders can result in excessive loading of the respiratory muscles, thus causing them to fail. We now have several types of ventilatory assist devices to choose from so that we can select a system that fulfills the physical, physiologic, and psychological needs of patients and return them to a more satisfactory level of living in the home. This is successful when the care team and the patient and family set realistic goals and maintain close clinical supervision. Much more study is needed to determine the optimal times for respiratory muscle rest. Future technologic designs for ventilatory systems should aim to decrease cost and increase efficiency, ease of use, and durability.