Method and system for characterizing and visualizing electromagnetic tracking errors

摘要

A calibration/surgical tool includes an electromagnetic sensor array of two or more electromagnetic sensors in a known geometrical configuration. Electromagnetic tracking errors are characterized by a mapping of pre-operative absolute and relative errors based on a movement of a calibrated calibration/surgical tool through a pre-operative electromagnetic field. Using statistical mapping, a desired absolute error field is measured either in the clinic as the part of daily quality control checks, or before the patient comes in or in vivo. A resulting error field may be displayed to the physician to provide clear visual feedback about measurement confidence or reliability of localization estimates of the absolute errors in electromagnetic tracking.

主权项

1. An electromagnetic tracking system, comprising:
an electromagnetic sensor array including at least two electromagnetic sensors arranged in a known geometrical configuration; and a data processor in electrical communication with the electromagnetic sensor array to receive signals indicative of a sensing of an electromagnetic field by the electromagnetic sensors, the data processor including
a relative error measurer module operable to compute intra-operative relative errors responsive to a movement of the electromagnetic sensor array to numerous estimation positions within an intra-operative electromagnetic field,
wherein each intra-operative relative error is an absolute differential between a calibrated distance between an electromagnetic sensor pair and a sensed distance between the electromagnetic sensor pair within the intra-operative electromagnetic field, andan absolute error estimator module operable to estimate intra-operative absolute errors responsive to a plotting of the intra-operative relative errors within a pre-operative error map representative of a statistical relationship between pre-operative absolute errors and pre-operative relative errors derived from a movement of the electromagnetic sensor array to numerous measurement positions within a pre-operative electromagnetic field,
wherein each pre-operative absolute error is an absolute differential between a measurement position of an electromagnetic sensor within the pre-operative electromagnetic field and a sensed position of an electromagnetic sensor within the pre-operative electromagnetic field, andwherein each pre-operative relative error is an absolute differential between a calibrated distance and a sensed distance between an electromagnetic sensor pair within the pre-operative electromagnetic field.