System and Method for Reducing Angular Geometric Distortion in an Imaging Device

Abstract

A system and method are provided for significantly reducing or substantially eliminating angular geometric distortions in devices designed for imaging and/or inspection of an interior portion or surface of a cavity. A series of processing steps or methods may be employed to eliminate Non-Uniform Rotational Distortion (NURD) in such devices, for example, unidirectional and bi-directional intravascular ultrasonic (IVUS) imaging systems. The system may include a processor and an electronic module which control operation of a transducer assembly provided at a distal end of a catheter assembly. The system invokes a first processing step or method to collect and store raw angle and line data, as well as one or more of second and third processing steps or methods which adjust for NURD experienced during backlash of a bi-directional imaging system and a fourth processing step or method which performs a line-to-line correlation function.

1 - 65 . (canceled) 
     
     
         66 . A system for imaging a vessel, comprising:
 a processing system configured to be in communication with a flexible elongate member having an ultrasound imaging device attached thereto, the ultrasound imaging device configured to rotate in a first direction and a second direction opposite the first direction, the processing system configured to:
 receive imaging data from the ultrasound imaging device while the ultrasound imaging device is rotated in the first and second directions; and 
 reduce non-uniform rotational distortion (NURD) generated in the received imaging data by performing at least one of:
 removing backlash NURD that is generated when the rotational direction of the ultrasound imaging device is changed between the first and second directions based on backlash NURD data associated with the ultrasound imaging device; and 
 performing angular correlation to remove backlash NURD that is generated when the rotational direction of the ultrasound imaging device is changed between the first and second directions. 
 
   
     
     
         67 . The system of  claim 66 , wherein the imaging data received by the processor from the ultrasound imaging device includes line data corresponding to each angle of rotation of the ultrasound imaging device. 
     
     
         68 . The system of  claim 67 , wherein the processing system is configured to store the angle and corresponding line data in a data table. 
     
     
         69 . The system of  claim 68 , wherein the processing system is configured to detect changes in the rotational direction of the ultrasound imaging device between the first and second directions based on changes in the angle data contained in the data table. 
     
     
         70 . The system of  claim 66 , wherein the flexible elongate member is a catheter. 
     
     
         71 . The system of  claim 66 , further comprising a display in communication with the processing system. 
     
     
         72 . The system of  claim 66 , further comprising an electronics module configured to be in communication with the ultrasound imaging device, the electronics module configured to transmit an ultrasonic pulse to a transducer assembly of the ultrasound imaging device. 
     
     
         73 . The system of  claim 72 , further comprising an angle encoder in communication with the electronics module. 
     
     
         74 . The system of  claim 72 , wherein the processing system is included in the electronics module. 
     
     
         75 . The system of  claim 72 , wherein the processing system is a separate unit from the electronics module. 
     
     
         76 . A system for imaging a vessel, comprising:
 a processing system configured to be in communication with a flexible elongate member having an optical coherence tomography (OCT) imaging device attached thereto, the OCT imaging device configured to rotate in a first direction and a second direction opposite the first direction, the processing system configured to:
 receive imaging data from the OCT imaging device while the OCT imaging device is rotated in the first and second directions; and 
 reduce non-uniform rotational distortion (NURD) generated in the received imaging data by performing at least one of:
 removing backlash NURD that is generated when the rotational direction of the OCT imaging device is changed between the first and second directions based on backlash NURD data associated with the OCT imaging device; and 
 performing angular correlation to remove backlash NURD that is generated when the rotational direction of the OCT imaging device is changed between the first and second directions. 
 
   
     
     
         77 . The system of  claim 76 , wherein the imaging data received by the processor from the OCT imaging device includes line data corresponding to each angle of rotation of the OCT imaging device. 
     
     
         78 . The system of  claim 77 , wherein the processing system is configured to store the angle and corresponding line data in a data table. 
     
     
         79 . The system of  claim 78 , wherein the processing system is configured to detect changes in the rotational direction of the OCT imaging device between the first and second directions based on changes in the angle data contained in the data table. 
     
     
         80 . The system of  claim 76 , wherein the flexible elongate member is a catheter. 
     
     
         81 . The system of  claim 76 , further comprising a display in communication with the processing system. 
     
     
         82 . The system of  claim 76 , further comprising an electronics module configured to be in communication with the OCT imaging device. 
     
     
         83 . The system of  claim 82 , further comprising an angle encoder in communication with the electronics module. 
     
     
         84 . The system of  claim 82 , wherein the processing system is included in the electronics module. 
     
     
         85 . The system of  claim 82 , wherein the processing system is a separate unit from the electronics module.