Events in Physics
David Delpy, EPSRC
Non-invasive monitoring and imaging of the brain and breast with near infrared light:
The use of optical techniques for the diagnosis of disease and the monitoring of patients is as old as medicine, although before the mid 1800s, the data was of a qualitative and observational nature, doctors (whether knowingly or not!) using their eyes as the optical detector and spectral analyser. Optical methods were put on a more scientific and objective basis following the development in the first half of the 20th century of instrumentation enabling quantitative measurement of spectral content and light intensity. However, the most dramatic changes have taken place over the last thirty years, driven by the parallel technical developments in lasers, optical fibres and semiconductors. The specific transparency of tissue to light in the near infrared (NIR) means that it is now possible to use optical techniques (often in a non-invasive manner) to provide accurate and localised measurements of parameters such as blood oxygenation, volume and flow, tissue metabolism, biochemical makeup and structure. This talk will illustrate the advances in NIR instrumentation and the parallel developments in image reconstruction techniques that together enable us to now use "mere light" to do everything from monitoring individual cell function to imaging whole organs, all in a safe, non invasive manner and often at the bedside.