Patent ID: 8603004

Claim:
A method of filtering a respiration noise component from a localization signal of a localization system including a plurality of external localization system patch electrodes that generate a non-ionizing localization field, the method comprising: acquiring a localization signal of at least one position measurement sensor within the non-ionizing localization field; and acquiring an acceleration signal from at least one of the localization system patch electrodes, the at least one localization system patch electrode comprising an accelerometer capable of measuring acceleration in at least one direction; for a selected coordinate axis of the non-ionizing localization field: calculating a displacement signal of the at least one localization system patch electrode on the selected coordinate axis from the acceleration signal; transforming the displacement signal from the time domain into the frequency domain; calculating a fractional power of the transformed displacement signal indicative of patient respiration; comparing the calculated fractional power to a threshold value; and when the calculated fractional power exceeds the threshold value, applying a filter to the localization signal of the at least one position measurement sensor to filter out the respiration noise component on the selected coordinate axis.