Methods and apparatus for non-uniform rotation distortion detection in an intravascular ultrasound imaging system

Apparatus for detecting non-uniform rotation distortion in an intravascular ultrasound blood vessel image, said apparatus comprising:

• a catheter for use within a blood vessel, said catheter including:
• a sheath,
• a bubbly liquid within said catheter between said transducer and said sheath, and
• a transducer mechanically rotated within said catheter, wherein said transducer emits an ultrasonic beam and receives echoes of said ultrasonic beam from micro-bubbles in said bubbly liquid and said sheath;
• and
• an image processor capable of being coupled to said transducer, said image processor including computer-readable program code fixed on tangible computer-readable medium for storing said computer-readable program, said computer-readable medium coupled to be read by said image processor, wherein said computer-readable program code performs correlation on a plurality of segments in an image vector from said echoes ultrasonic beam to detect the non-uniformity of rotation of said transducer.

A method for detecting non-uniform rotation distortion in an intravascular ultrasound blood vessel image, said method comprising the steps of:

• providing a catheter probe within a blood vessel, said catheter probe having a transducer substantially centrally located therein, wherein said transducer is mechanically controlled;
• emitting a plurality of ultrasonic beams to produce echoes reflected from a blood region within said blood vessel to obtain a plurality of successive image vectors;
• sampling said echoes at a predetermined range (r.sub.P) for each of said successive image vectors, wherein r.sub.P for each of said successive image vectors is located within said blood region;
• obtaining correlation coefficients for said sampled echoes at r.sub.P between each of said successive image vectors to determine changes in a rotational speed of said transducer.

Apparatus for detecting non-uniform rotation distortion in an intravascular ultrasound blood vessel image, said apparatus comprising:

• a catheter for use within a blood vessel, said catheter including:
• a sheath, and
• a transducer mechanically rotated within said catheter, wherein said transducer emits a plurality of ultrasonic beams to produce echoes reflected from a blood region within said blood vessel to obtain a plurality of successive image vectors;
• and
• an image processor capable of being coupled to said transducer, said image processor including computer-readable program code fixed on tangible computer-readable medium for storing said computer-readable program, said computer-readable medium coupled to be read by said image processor, wherein said computer-readable program code samples said echoes at a predetermined range (r.sub.P) for each of said successive image vectors, wherein r.sub.P for each of said successive image vectors is located within said blood region, and wherein said computer-readable program code also obtains correlation coefficients for said sampled echoes at r.sub.P between each of said successive image vectors to determine changes in a rotational speed of said transducer.