System and method for characterizing circulatory blood flow

A method for characterizing a circulating blood volume in an animal body in a response to at least one stress, the method comprising:

• characterizing a first circulating blood volume by:
• receiving, by a computing device, a first biological signal emulating an arterial pulse wave from a sensor associated with the animal body,
• calculating, by the computing device, a first plurality of integer harmonics of a heart rate from the first biological signal wherein each of the first plurality of integer harmonics is characterized by a first integer harmonic amplitude,
• calculating from the plurality of first integer harmonic amplitudes of the heart rate, by the computing device, at least one first derived parameter in a frequency domain comprising a first measure of total harmonic distortion, and
• characterizing the first circulating blood volume by comparing, by the computing device, the at least one first derived parameter to a first baseline value;
• applying at least one stress to the animal body;
• determining a measure of a second circulating blood volume by:
• receiving, by the computing device, a second biological signal emulating an arterial pulse wave from a sensor associated with the animal body,
• calculating, by the computing device, a second plurality of integer harmonics of a heart rate from the second biological signal, wherein each of the second plurality of integer harmonics is characterized by a second integer harmonic amplitude,
• calculating from the plurality of second integer harmonic amplitudes of the heart rate, by the computing device, at least one second derived parameter in a frequency domain comprising a second measure of total harmonic distortion, and
• characterizing the second circulating blood volume by comparing, by the computing device, the at least one second derived parameter to a second baseline value;
• and
• comparing, by the computing device, the characterization of the first circulating blood volume to the characterization of the second circulating blood volume to characterize the circulating blood volume as a response to the at least one stress.