Advanced biomedical imaging tools
Gated image acquisition for microscope imaging and intervention in the beating heart
Three-dimensional fluorescence microscopy is an increasingly indispensable tool for biological research, offering the ability to study natural processes over time in a living organism. One example of this is in studying the development of the zebrafish heart, a popular animal model for cardiac development. However a 3D image cannot generally be obtained instantaneously, and must instead be reconstructed from a series of individual snapshots at different depths or angles in the sample. We have developed non-contact optical imaging techniques that allow us to synchronize that acquisition to the periodic motion of the heart without having to obtain an ECG signal.
This enables us to eliminate motion artifacts that would normally prevent 3D imaging in such moving structures. By integrating novel real-time image processing capabilities into a combined brightfield and fluorescence imaging system, we are able to obtain high resolution images like the one shown here of the living, beating zebrafish heart, and continuously image growth and immune response continuously over a period of 24 hours or more . The same techniques are allowing us to build up a detailed time-resolved picture of the 3D blood flow in the heart and circulatory system, information that is crucial for understanding the interplay between flow and structural development in the heart.
Our in vivo imaging work, in collaboration with biomedical researchers at Edinburgh University, is opening up new possibilities for high resolution imaging and interaction with biological processes within the heart itself. In addition academic dissemination routes, our work has been featured by the British Heart Foundation in their monthly supporters magazine.
New optical techniques for imaging and microscopy
We are also researching other methods for improving the capabilities of microscope imaging systems. Our research includes: extending the depth of field of an imaging system, including tracking in 3 dimensions; minimally-invasive optical biopsy; improved tolerance of light scattering in biological tissue; sparse and compressive imaging to take the camera out of the loop and directly measure the characteristics of interest without the need to form an image as an intermediary. We have recently benefitted from significant investment from EPSRC to equip a new advanced interdisciplinary microscopy lab, which has significantly enhanced our in-house capabilities for collaborative research at the life sciences interface.
Above image: Cutaway 3D reconstructed image (false colour) showing the complex internal structure of the ventricle of a zebrafish embryo. The data for this 3D image of the 100µm wide structure was obtained while the heart was beating normally, thanks to our synchronized imaging techniques.