The
system and method of the present invention relates to using
spectroscopy, for example, Raman spectroscopic methods for diagnosis of tissue conditions such as
vascular disease or
cancer. In accordance with a preferred embodiment of the present invention, a
system for measuring tissue includes a
fiber optic probe having a proximal end, a distal end, and a
diameter of 2 mm or less. This small
diameter allows the
system to be used for the diagnosis of
coronary artery disease or other small lumens or
soft tissue with minimal trauma. A delivery
optical fiber is included in the probe coupled at the proximal end to a
light source. A filter for the delivery fibers is included at the distal end. The system includes a collection
optical fiber (or fibers) in the probe that collects Raman scattered
radiation from tissue, the collection
optical fiber is coupled at the proximal end to a
detector. A second filter is disposed at the distal end of the collection fibers. An optical lens system is disposed at the distal end of the probe including a delivery
waveguide coupled to the delivery
fiber, a collection
waveguide coupled to the collection
fiber and a lens.