The system utilizes a triple CCD colour camera coupled through a PCI bus frame grabber to a Pentium PC which handles the acquisition and image processing functions. The PC is interfaced to a hardware unit which handles various control functions. Principle of blood-flow correlation and imaging apparatus. Two adjacent, closely-coupled optical fibres are placed in the image plane of an inverted microscope and positioned to sample light transmitted through a flowing vessel. Optical density changes from the flowing rbc's are auto-correlated using dsp software.
Algorithms are under development to find and characterize objects of interest.
Our approach is based on object edge finding by using a 'difference of boxes' smoothing filter to produce closed outlines of zero-crossings at optical density changes. This system will find wide applications in common microscopy tasks and will at least partially eliminate errors caused by repetitive human observations. Fluorescence imaging of cell nuclei is used to 'find' cells and to position them automatically above micro-irradiation beams. In connection with the Laboratory's particle microbeam facility, we have upgraded the imaging system by installing an image intensifier coupled with a fast lens to the existing high-resolution CCD camera. Some 10-20 photons are collected by the microscope for each particle traversal so a high sensitivity is essential.