Disposable intra-luminal ultrasonic instrument

A disposable intra-luminal catheter probe type ultrasonic instrument for the examination and/or treatment of blood vessels having a small transverse cross-section, said instrument including a flexible, guidewire receiving, catheter comprising a body and a tip having a distal end and a distal end portion adapted to be introduced into a lumen of a blood vessel and a proximal portion, said catheter having a diameter no greater than 3 millimeters, and a small motor in said tip having a length no greater than approximately 6 millimeters, a diameter no greater than approximately 2.4 millimeters and drive shaft extending from one end of said motor, a rotatable member having an acoustical mirror face mounted in said tip and one said drive shaft for being rotated by said motor at a selected rpm synchronized with a raster across a visual display to which echoes of sound waves received by said mirror face are supplied, the angular position of the acoustic mirror face being oriented to correspond to the angle of an echo display line on the visual display, and means including a transducer facing said mirror face for generating and supplying sound waves along an axis of propagation to said rotatable acoustical mirror face at a frequency no greater than 60 megahertz for reflection therefrom to obtain a sufficient depth of field with sufficient resolution to determine the makeup or constitution of the matter, such as tissue or plaque, in the space being investigated around said catheter tip, said rotatable acoustic mirror face being located in said distal end portion, and said mirror face lying in a plane that intersects, at an angle, the axis of the drive shaft and the axis of the propagation of sound waves from said means for generating sound waves.