Chapter 2 - Control in Physiology and Medicine

Abstract

This chapter examines ways, in which concepts of control relate to the study of physiological and medical systems, both in the insight that can be gained and in therapy planning as a part of the patient management processes. The chapter introduces the conceptually simple, but powerful, framework of the four-element cybernetic model that provides a basis for examining the dynamics that occur in physiology and medicine. This basic model can be further developed at various levels of resolution. This is followed by an exploration of the basic control concepts, demonstrating, through examples, their relevance in describing and interpreting the processes and regulation of physiological dynamics. The chapter focuses on the basic feedback model, developing this framework, so as to encompass both the diagnostic and the therapeutic processes. It is then shown how this framework can be employed to specify the requirements for health care delivery systems, with an example from chronic disease management. Finally, the planning of drug therapy is viewed as a control problem, demonstrating the relevance of a feedback modelling framework, illustrating this view of drug administration with diabetes.