Method for generating position data of an instrument

摘要

A method for generating position data of an instrument (1), in particular a medical instrument, wherein the method includes the following steps: capturing position measurement data by way of at least one position sensor (7, 9) arranged on the instrument, determining a movement state of the instrument on the basis of the captured position measurement data, filtering the captured position measurement data on the basis of the determined movement state. A system for presenting an instrument, a computer program product including a program code, a computer program and a data storage medium including a program code.

主权项

1. A method for generating position data of a medical instrument, the method comprising the following steps:
capturing position measurement data of at least two electromagnetic position sensors which are arranged on the medical instrument, the position measurement data indicating a measured position of the medical instrument; implementing by a data processor:
determining a movement state of the medical instrument on the basis of the captured position measurement data, the movement state being defined by how the medical instrument is being moved and a speed the medical instrument is being moved, the movement state being one of a positioning state in which the medical instrument is kept still in a position or moved or rotated with a speed lower than a predetermined value, a rotation state in which the medical instrument is swung around its own axis, a moving state in which the medical instrument is moved with a speed higher than a predetermined value, and an interference state in which the measured position of the medical instrument is influenced by another object, the determination comprising:calculating variables describing a correlation between the position signals of the position sensors on the basis of the captured position measurement data, the calculated variables describing a correlation between the position signals of the position sensors are correlation coefficients for each degree of freedom of the medical instrument,calculating variables describing a dimension of the divergence of captured and previously measured position measurement data, the calculated variables describing a dimension of the divergence of captured and previously measured position measurement data are variances for each degrees of freedom of the medical instrument,determining the respective movement state of the medical instrument by means of an algorithm for classification comprising comparisons of the calculated variables with predetermined values where the algorithm for classification based on a decision tree comprising decision criteria to be checked, each decision criterium comparing the calculated variables to predefined values, depending on the result of a first decision criterium, at least one further decision criterium is checked and at the end of the decision tree a different threshold value is allocated to each of the determined movement states, andfiltering the captured position measurement data on the basis of at least one comparison of the allocated threshold value with a predefined plausibility value to determine if the predefined plausibility value exceeds the allocated threshold value; and displaying an image data set based on the filtered captured position measurement data on a display, the image data set including a graphical depiction of the medical instrument, the graphical depiction being displayed on the display only when the predefined plausibility value does not exceed the allocated threshold value.