Multifiber gradient-index lens laser angioplasty probe

A novel laser angioplasty probe fabricated with a gradient-index (GRIN) lens positioned at the tip of a seven-fiber bundle is presented. The combination of the GRIN lens and the fiberoptic bundle provides selectable optical directionality in either the axial direction or one of six off-axis directions for illumination of the arterial wall. The probe diameter (1 mm) is small enough for use in coronary laser angioplasty, and the probe is shown to transmit laser light and receive fluorescent signals simultaneously. In a 2 mm diameter lumen, the spot width in a plane normal to the axis of the lens is about 2 mm and the lateral spot size is approximately 10 mm long. The ability to direct the probe's beam pattern angularly should provide flexibility in both diagnosis and treatment.