Engineering problems [electrical and/or mechanical occur is automated systems and they can also occur in physiology. In this blog we have been concerned with our discovery of broken feedback systems involving the regulation of breathing, stressing all other systems of the body and in particular, visibly affecting the functions of mood, locomotor activity and speed and the mind. What happens when the neural or motor components of the respiratory system break down? Without observations and measurement, scientist are not even aware of if or when the system breaks down. We found out that Paula’s ventilatory system is broken and Dr Emile Kraepelin found the same in thousands of patients with manic depressive insanity. Engineering, electrical and mechanical problems can be fixed one way or another. This is true for cars and planes and computers and is certainly true in human beings. Understanding this takes an engineering approach to physiology. Once the problem is identified, it is easier to discover how to fix it.
We are trying to tell you what the technical problem is so you can help fix it! read past blogs on minute ventilation and hypercapnia and abnormal breathing rates in order to review the findings we discuss. This is a multidisciplinary issue, it requires a passing knowledge of motor aspects of respiratory failure [with normal lungs] respiratory physiology, mechanical engineering [control theory, feedback systems, auto regulatory processes] and the autonomic nervous system. it requires thinking about system failure affecting regulation of PCO2 in the blood and hormonal and physical responses to failure of this system. It is a fascinating subject, especially when you identify the problem, which Kraepelin did and now we measure the same defect/injury in Paula. In health and in illness!
In a 1954 paper on a closed-loop control model of the respiratory chemostat, Grodins and colleagues put it thus: “The essence of physiology is regulation. It is this concern with purposeful system responses which distinguishes physiology from biophysics and biochemistry. Thus, physiologists study the regulation of breathing, of cardiac output, of blood pressure, of water balance, of body temperature and of a host of other biological phenomena. Grodins FS, Gray JS, Schroeder KR, Norins AL, Jones RW (1954) Respiratory responses to CO22 inhalation. A theoretical study of a nonlinear biological regulator. J Appl Physiol 7(3):283–308 quoted in Control theory in biology and medicine Introduction to the special issue Peter J. Thomas, Mette Olufsen, , Rodolphe Sepulchre, Pablo A. Iglesias, Auke Ijspeert & Manoj Srinivasan Biological Cybernetics volume 113, pages1–6(2019).
Biological Cybernetics is pleased to present this special issue as a collection of papers by several of the participants in the MBI workshops.
The papers cover a broad range of topics within control theory. Optimization problems arising in the design of efficient controllers for neuronal, cardiac, and motor systems are discussed in [2, 7, 28, 29]. Optimal feedback controlsFootnote 2 intrinsic to the organism are analyzed for homeostasis of blood pressure  and neuronal firing rates . One paper  discusses optimizing a new approach to regulation of blood sugar in a diabetes model. Another broad theme concerns parameter identifiability and parameter estimation: both estimating physiological parameters from experimental data [8, 32] and exploring how an organism might estimate parameters related to the stability of its own movements . Controllability of systems with nonlinear dynamics is discussed in the context of ultrasensitivity and robust rhythm generation , and robust generation of waves in excitable media . The role of the nervous system itself as a controller is emphasized in [15, 19]. Control theory in biology and medicine Introduction to the special issue Peter J. Thomas, Mette Olufsen, , Rodolphe Sepulchre, Pablo A. Iglesias, Auke Ijspeert & Manoj Srinivasan Biological Cybernetics volume 113, pages 1–6(2019).
To be continued.