Reducing incremental measurement sensor error

Abstract

For position sensors, e.g., a fiber-based system, that build a shape of an elongated member, such as a catheter, using a sequence of small orientation measurements, a small error in orientation at the proximal end of the sensor will cause large error in position at distal points on the fiber. Exemplary methods and systems are disclosed, which may provide full or partial registration along the length of the sensor to reduce the influence of the measurement error. Additional examples are directed to applying selective filtering at a proximal end of the elongated member to provide a more stable base for distal measurements and thereby reducing the influence of measurement errors.

1 . (canceled) 
     
     
         2 . A method for registering a tool to a pre-operative three-dimensional model with the use of an imaging sensor and a localization sensor, the method comprising:
 obtaining imaging data from an imaging sensor coupled to a tool moving within a blood vessel;   obtaining localization data from the localization sensor;   generating an image of the blood vessel from the imaging data and localization data;   correlating the generated image to a pre-operative three-dimensional model of the blood vessel to register the tool to the pre-operative three-dimensional model.   
     
     
         3 . The method of  claim 2 , wherein the generated image comprises a sequence of images or a three-dimensional reconstruction. 
     
     
         4 . The method of  claim 2 , wherein the localization data comprises position or shape data. 
     
     
         5 . The method of  claim 2 , wherein the imaging sensor is an intravascular ultrasound probe. 
     
     
         6 . The method of  claim 5 , wherein the image generated by the intravascular ultrasound probe is a two-dimensional cross-sectional view of the blood vessel. 
     
     
         7 . The method of  claim 2 , wherein the imaging sensor is an optical coherence tomography sensor. 
     
     
         8 . The method of  claim 7 , wherein the image generated by the optical coherence tomography sensor is a local three-dimensional view of the blood vessel. 
     
     
         9 . The method of  claim 2 , wherein generating the image of the blood vessel from the imaging data and localization data and correlating the generated image to a pre-operative three-dimensional model are performed by implementing a single recursive filtering algorithm. 
     
     
         10 . The method of  claim 9 , wherein the single recursive filtering algorithm utilizes a Bayesian filter to estimate a position of the tool relative to the pre-operative three-dimensional model. 
     
     
         11 . The method of  claim 10 , wherein the Bayesian filter comprises an Extended Kalman Filter, an Unscented Kalman Filter, or a particle filter. 
     
     
         12 . The method of  claim 9 , wherein implementing the single recursive filtering algorithm comprises predicting a motion of the tool in the pre-operative three-dimensional model, and performing an update of the prediction at each time step based on new sensor measurements. 
     
     
         13 . The method of  claim 12 , wherein performing the update of the prediction at each time step is performed using a kinematic model. 
     
     
         14 . The method of  claim 13 , wherein performing the update of the prediction at each time step comprises applying a correction to a Bayesian filter state by comparing a predicted vessel wall position to a sensed position of the blood vessel. 
     
     
         15 . The method of  claim 2 , further comprising displaying the position and shape of the tool within the pre-operative three-dimensional model without using intra-operative fluoroscopy. 
     
     
         16 . The method of  claim 2 , further comprising sensing an environment around the tool using the imaging sensor, and positioning and displaying sensed environmental features relative to the pre-operative three-dimensional model. 
     
     
         17 . The method of  claim 16 , wherein displaying the sensed environmental features relative to the pre-operative three-dimensional model comprises providing a real-time view of an output of the imaging sensor alongside a view of the tool positioned in the pre-operative three-dimensional model. 
     
     
         18 . The method of  claim 17 , wherein displaying the sensed environmental features relative to the pre-operative three-dimensional model comprises superimposing the sensed environmental features on the pre-operative three-dimensional model. 
     
     
         19 . The method of  claim 2 , further comprising processing the image to obtain an estimate of a curve or surface representing a wall of the blood vessel.