IN THE diagnosis and therapy of the patient in shock, as in no other clinical area, it has become apparent that satisfactory care demands that the physician be able to obtain physiologic data and to derive the significant physiologic correlations on an online basis. To do this at a cost and degree of complexity which is compatible with good patient care requires the development of new techniques by which quantification of circulatory parameters can be carried out, the utilization of relatively inexpensive computer hardware, and the creation of "software" or assessment-oriented programs for the computer evaluations of the critically ill patient. In an attempt to apply these criteria for physiologic assessment to the patient, a physiologic system which can be brought to the bedside has been developed enabling detailed physiologic measurements to be made and the data obtained therefrom to be quantitatively evaluated. Materials and Methods Techniques for bedside cardiac