Effects of Three Kinds of Artificial Respirators on the Pulmonary Ventilation and Arterial Blood of Patients with Chronic Respiratory Insufficiency* *From the Texas Institute for Rehabilitation and Research, Research Project A-24. This investigation was supported in part by the General Clinical Research Center for Chronic Illness under Public Health Service Research Grant FR-129, from the National Institutes of Health; and by Project RT-4 from the Vocational Rehabilitation Administration, Department of Health, Education, and Welfare, Washington, D.C.