Abstract: Method and apparatus are disclosed for determination and display of hemodynamic characteristic values of a patient in a variety of statistical forms and in relative or absolute terms, the measurement determination being made by non-invasive impedance plethysmography under control of a central processor. A characteristic value representative of variation of blood vessel cross-sectional area is measured across a patient's body section, blood pressure is measured in the body in simultaneity with the characteristic value, and signals representative of the characteristic value and blood pressure are then processed to obtain the hemodynamic characteristic values.

Abstract: A method and apparatus for determining and displaying hemodynamic characteristics of a living body instantaneously and over a time period, i.e., rate of blood flow, stroke volume, cardiac output, cardiac index, systemic vascular resistance, useful power of the heart and elastic properties of the walls of blood vessels. The improved method and apparatus deal with physical measurements of body electrical impedance and blood pressure in relationship with other known or derived factors to produce signals representing these characteristics and which may be displayed for the information of surgeons or others who may be interested in this information.