Brian Andrew Hills

Brian Andrew Hills, born 19 March 1934 in Cardiff, Wales,^[1] died 13 January 2006 in Brisbane, Queensland,^[1] was a physiologist who worked on decompression theory.

Early decompression work was done with Hugh LeMessurier's aeromedicine group at the department of Physiology, University of Adelaide.^[2] His "thermodynamic decompression model" was one of the first models in which decompression is controlled by the volume of gas bubbles coming out of solution. In this model, pain only DCS is modelled by a single tissue which is diffusion-limited for gas uptake, and bubble-formation during decompression causes "phase equilibration" of partial pressures between dissolved and free gases. The driving mechanism for gas elimination in this tissue is inherent unsaturation, also called partial pressure vacancy or the oxygen window, where oxygen metabolised is replaced by more soluble carbon dioxide. This model was used to explain the effectiveness of the Torres Strait Islands pearl divers' empirically developed decompression schedules, which used deeper decompression stops and less overall decompression time than the current naval decompression schedules. This trend to deeper decompression stops has become a feature of more recent decompression models.^[2]

Hills made a significant contribution to the mainstream scientific literature of some 186 articles between 1967 and 2006. The first 15 years of this contribution are mostly related to decompression theory.^[2] Other contributions to decompression science include the development of two early decompression computers, a method to detect tissue bubbles using electrical impedance, the use of kangaroo rats as animal models for decompression sickness, theoretical and experimental work on bubble nucleation, inert gas uptake and washout, acclimatisation to decompression sickness, and isobaric counterdiffusion.^[2]