A method and apparatus for optical detection and imaging of regional circulatory flow in biological tissues for research purposes. An animal or plant organ is perfused with a saline suspension of colored and/or fluorescent microspheres. The organ is excised and fixed in the form of a specimen...http://www.google.com.au/patents/US5682244?utm_source=gb-gplus-sharePatent US5682244 - Automated optical detection of tissue perfusion by microspheres
