I am a Professor of Medical Physics and lead the Near Infrared Spectroscopy Group in the Department of Medical Physics and Bioengineering at UCL. My interest is in the development and application of techniques which use light to monitor and image the brain. Optical techniques provide us with an opportunity to study the brains of subjects in whom the use of other, more invasive, neuroimaging technologies are limited. For this reason much of my work has focused on studying acute brain injury in critically ill neonatal and adult patients, as well typical and atypical neurodevelopment in young infants.

In 2011, my work using the optical technique near infrared spectroscopy (NIRS) to investigate cerebral oxygenation, haemodynamics and metabolism in acute brain injury in adults attracted the attention of researchers interested in cerebral malaria. As a result, an NIRS system was transported from our lab in the UK to a general hospital in India where data were acquired to reveal a previously unreported relationship between oscillations in cerebral oxygenation and the severity of cerebral malaria.  This study demonstrated that the portability, low cost and ease of use of NIRS technology made it well suited to applications in global health applications.

Functional near infrared spectroscopy (fNIRS) describes the measurement of functional brain activation using NIRS. This technique has found widespread application particularly in the investigation of the developing brain, and has been the focus of my longstanding collaboration with Professor Mark Johnson and Dr. Sarah Lloyd-Fox at the Centre for Brain and Cognitive Development at Birkbeck, University of London. 

Our publications using fNIRS to study brain development in infants, combined with the successful use of NIRS in the earlier cerebral malaria study, led to the collaboration with Professor Andrew Prentice at the International Nutrition Group, London School of Hygiene and Tropical Medicine London. With funding from a Phase One Grand Challenge Exploration grant from the Bill and Melinda Gates Foundation, we are using fNIRS to investigate the effects of malnutrition on cognitive function in infants in rural Gambia. Our aim is to provide a viable tool for assessing brain development in resource poor settings and to deliver markers to inform and evaluate targeted interventions.

As a physicist, I am interested in how further innovations in engineering can better address the needs of those investigating the brain, especially in global health studies.