Roots of the Mac Series?

One of John Dickinson's colleagues and closest friends was Arthur C. Guyton (1919 - 2003) the renowned U.S. physiologist, educator, and author.

His Textbook of Medical Physiology, appeared in 14 editions, and 15 languages. It provided thousands of physicians worldwide with a deeper understanding of human physiology. His major research interest was devoted to biological cybernetics.

In the 1972 Annual Reviews of Physiology he presented his monumental model of cardio-vascular control. It seems quite plausible that this model not only became a frequent topic between the two friends, but that it might well have triggered John Dickinson's idea for the series of physiological computer models.

(Guyton, A C, T G Coleman, and H J Granger. 1972. “Circulation: Overall Regulation.” Annual Review of Physiology 34 (1): 13–44.