Honorary degree for pioneering biomedical engineer
- By Deborah Minors
Emeritus Professor of Physiological Mechanics, Imperial College, London and Wits benefactor, Colin Gerald Caro returned to South Africa in May 2010 for the first time in 25 years to receive an honorary degree in engineering from his alma mater in recognition of his scholarship and research in the field of biomedical engineering.
A recognised world authority in the field of fluid flow and vascular disease, Caro was the first to link the physics of blood flow with the occurrence of atherosclerosis – the arterial disease that causes major conditions including heart attack and stroke.
Born in Durban, South Africa on 3 October 1925, Colin Gerald Caro matriculated from Parktown Boys’ High and began studying medicine at Wits, but interrupted his studies to volunteer for the South African Navy during World War II. He resumed his studies after the war but pursued a BSc (Physiology) instead.
Caro (BSc Hons (Physiology), MBBCh 1950) obtained his medical degree simultaneously with a postgraduate degree in physiology, and completed internships at what is now the Chris Hani Baragwanath Hospital in Joburg, and at Durban’s Addington Hospital.
During the 1950s, Caro held physician posts at the Canadian Red Cross Hospital Special Unit for Juvenile Rheumatism, and at Hammersmith Hospital, UK. He later held research posts at the State University of New York and the University of Pennsylvania.
In 1961, Caro received a PhD (Medicine) from Wits for his thesis entitled, ‘Pulmonary Function in Patients with Kyphoscoliosis’ [curving of the spine], in which he demonstrated that lung elastic recoil strongly determines airway resistance.
Later that decade, Caro’s ‘low wall shear’ finding would revolutionise thinking on vascular biology and atherosclerosis. He demonstrated that arterial geometry causes blood flow to swirl and suppress stagnant regions, which are preferred sites for the development of vascular disease. Caro showed that arteries which experienced ‘lower wall shear stress’ (a strain produced in the structure of a substance) are more likely to develop atherosclerosis than regions experiencing ‘higher wall shear stress’. This finding was counter to the prevailing view that lesions/plaques caused by damage to the arterial wall, inflicted by the flowing blood, caused atherosclerosis.
Caro’s finding was integral to shaping the course of research into vascular biology and atherosclerosis and the initial publication of his finding in Nature (1969) and Proc. Roy. Soc. Lond. B. (1971) have together been cited over a thousand times.
In 1966, Caro co-founded and directed the Imperial College Department of Bioengineering where he remains senior research investigator today. The unit established the Caro Research Studentship in 2007, the same year that Wits University created the Colin G. Caro Award for the Most Distinguished Student in Biomedical Engineering.
Caro later advanced understanding of vascular fluid mechanics and mass transport in biology and disease, by highlighting the three-dimensionality of arterial geometry and flow. This work led Caro to establish Veryan Medical Ltd in 2003, a company that uses “its advanced understanding of the physics of blood flow” to develop a range of surgical implantable vascular devices to address vascular disease.
In order to apply his work in vascular biology and disease to fluid handling industries, Caro founded spin-off company, HeliSwirl Technologies Ltd in 2005, an engineering design company that makes products with the ‘Small Amplitude Helical Technology’ (SMAHT) that Caro invented, based on the geometry and flow patterns observed in natural blood vessels. HeliSwirl products thus increase the transport efficiency of single and mixed phase fluids inside pipe-work systems.
HeliSwirl received the 2006 Amec Award for Innovation and Excellence in SMEs (small and medium enterprises) from the Institute of Chemical Engineers.
Caro, 86, remains active in both Veryan Medical Ltd and HeliSwirl Technology Ltd as research director.