Medical photoacoustic imaging using optical ultrasound detection: from light to sound…and back
February 2, 2023, 4:00–5:00 PM
Location: 105 Annenberg
Speaker: Professor Paul Beard, Department of Medical Physics and Biomedical Engineering, University College London
Photoacoustic imaging provides new opportunities to visualise the structure and function of soft tissues by exploiting the use of laser generated ultrasound waves. Achieving high quality 3D images places significant demands on the photoacoustic detection system however. It requires the use of ultrasound detectors with high sensitivity for deep imaging, a wideband frequency response to accurately record the broadband photoacoustic wavefield and small element size to minimise spatial averaging. Meeting these requirements is challenging using conventional piezoelectric and CMUT based detection schemes. Ultrasound sensors based on Fabry Perot polymer etalons and other optically resonant structures offer the prospect of addressing the limitations of current technology by providing wide-bandwidths in the tens of MHz range, micron-scale element sizes and high detection sensitivity. Over the last two decades we have taken this technology from first principles at component level to engineering practical imaging instruments that can provide highly detailed 3D vascular images at real-time image frame rates. These systems include small-animal scanners for characterising mouse models of cancer and other diseases. Non-invasive clinical imaging scanners have also been developed. They are currently being evaluated via first-in-human clinical studies for the assessment of inflammatory conditions, cardiovascular disease, diabetes and guiding reconstructive surgery. Additionally, for minimally invasive use, a range of rigid and flexible endoscopic probes have been developed for guiding laparoscopic cancer surgery in abdominal organs such as the liver or informing GI tract resections. The operating principles and engineering challenges of this novel technology as well as its application in medicine and biology will be discussed.
Department of Medical Physics and Biomedical Engineering, University College London
Paul Beard is Professor of Biomedical Photoacoustics at UCL. He founded and currently leads the Photoacoustic Imaging Group within UCL Department of Medical Physics and Biomedical Engineering and the Wellcome/EPSRC Centre for Interventional and Surgical Sciences at UCL. His research is directed towards the development of novel photoacoustic instrumentation based on interferometric acoustic sensing methods, modelling photoacoustic signals, image reconstruction algorithms, spectroscopic methods and the application of the technology in medicine and biology. He is the author or co-author of over 200 publications in these areas.
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