Abstract: A system (method and apparatus) for hemodynamic measurements of the cardiac activity, including the stroke volume and cardiac output on the basis of a blood pressure pulse wave of a patient. Using a function that relates cardiac activity to an anthropometric parameter of the patient (height or arm span), ordinates of the pulse wave, and time intervals of certain characteristic points of the pulse wave, the stroke volume and/or cardiac output are obtained. The pulse wave can be determined by means of an optical sensor clipped to an ear lobe of the patient. The characteristic points and time intervals from the initial point of the pulse wave to the characteristic points are obtained under computer control. The measured values of the time intervals and ordinates are inputted to the computer which computes cardiac output, stroke volume and other cardiac information related thereto.