System Identification in Physiology

Abstract

We shall now discuss some examples of system identification of sensory receptors and control systems in physiology, that is, determination of black box transfer functions. As we have noted earlier such a black box transfer function is useful in understanding the input-output relation and for studying the conditions under which instability is possible. Although such system identification is fairly indifferent to the underlying biophysical processes, an understanding of the relations between the various physiological entities is required to properly understand the feedback mechanism when present. It is also desirable to open the feedback loop if possible and obtain the open-loop transfer function so that the conditions of stability may then be analyzed. Alternatively, individual components of the physiological system in question may be isolated in experimental animals and studied. The experimental methods in these cases is as important as the analytical methods and therefore we shall examine both in some detail.