A new technique enables the conversion of an ordinary camera into a light-field camera capable of recording high-resolution, multiperspective images.
The biomedical application of lasers and laser spectroscopy, which promises to change significantly the way medicine is currently practiced, has won a 52 percent increase in federal funding for its national center, the Laser Biomedical Research Center (LBRC) of the George R. Harrison Spectroscopy Laboratory at MIT.
The Laboratory operates two laser instrumentation resources, the LBRC and the MIT Laser Research Facility, a physical science resource supported by the National Science Foundation. Together, these two centers house the largest collection of lasers in the US devoted to fundamental and applied research.
The National Institutes of Health, which established the LBRC at MIT in 1984, has awarded the Center a $4.1 million renewal grant for the next five years. The LBRC is NIH's resource center for research in the field of applications of lasers and spectroscopy to biology and medicine.
The LBRC has made significant advances in the early detection of cancer in different organs of the body including the mouth, esophagus, colon and bladder, as well as diagnosis of atherosclerosis in coronary arteries using laser-induced fluorescence. Portable clinical laser-based systems have been developed, and data are taken in several hospitals in the Boston area and outside.
Another technique successfully employed is the use of Raman spectroscopy, which the MIT researchers have shown can provide quantitative biochemical analysis of a small sample of tissue in a fraction of a second without the need for tissue removal. In the case of atherosclerosis, disease progression can be measured in terms of the buildup of cholesterol lipids and mineral deposits. The same technique is also being employed for breast cancer diagnosis, to develop new and more accurate methods to differentiate between benign and malignant tumors.
One important current and future thrust of the research at the LBRC is to develop laser-based endospectroscopic techniques and spectral imaging methods for improved guidance of biopsies and real-time diagnosis of disease without biopsy. In some cases, standard endoscopic visualization is unreliable; in others, biopsy is difficult if not impossible. Spectroscopic techniques can provide quantitative biochemical information about the state of the tissue which is not obtainable using standard pathology.
Optical tomography, another area of LBRC investigation, explores the use of ultrashort pulses to image disease within the body. This project has developed methods based on the use of time-resolved fluorescence, and a novel theoretical description of the migration of photons in biological tissue (which diffuses light very strongly) based on Feynman path integrals. The initial experiments using phantoms to simulate breast tissue demonstrate that an embedded object such as a small breast tumor several millimeters in size can be located to within about one millimeter. Future clinical experiments using photodynamic therapy drugs, in collaboration with Roswell Park Cancer Institute in Buffalo, NY, are being considered.
The Center's facilities are provided free of charge to researchers in universities, industry and hospitals to pursue independent research projects. The LBRC also sponsors workshops in biomedicine and provides training in the use of lasers and laser spectroscopy.
Collaborative research involves clinical investigations with a number of medical centers: colon cancer investigations at Brigham and Women's Hospital in Boston; esophageal cancer studies at the Brockton/West Roxbury VA Medical Center; early detection of bladder cancer, breast cancer and coronary artery disease at the Cleveland Clinic Foundation; studies of peripheral artery disease at MetroWest Medical Center in Natick; studies of oral cancer at the New England Medical Center, and non-invasive measurement of blood chemicals at Beth Israel Hospital in Boston.
The Spectroscopy Laboratory is directed by Professor Michael Feld of the Department of Physics. Professor Jeffrey Steinfeld of the Department of Chemistry and Dr. Ramachandra Dasari, principal research scientist in the Laboratory, are associate directors. Professors Moungi Bawendi, Robert Field, Stephen Lippard and Keith Nelson of chemistry, Professors Daniel Kleppner and Toyoichi Tanaka of physics, and Professor Steven Tannenbaum of the chemistry department and the Division of Toxicology are core investigators of the Laboratory.
A version of this article appeared in MIT Tech Talk on October 2, 1996.