LOW-PROFILE LOCATION PAD FOR MAGNETIC-BASED INTRA-BODY PROBE TRACKING SYSTEM

摘要

A location pad includes a housing having a flat surface and multiple field generators. The multiple field generators are fixed to the housing and are configured to generate respective magnetic fields having respective axes that are perpendicular to the flat surface. POSITION LOCATION PAD UNDER A PATIENT WITH 200 / ONE OR MORE MAGNETIC COILS ARRANGED IN AN ARRAY WITH MULTIPLE SECTIONS INSERT A CATHETER INTO THE PATIENT WITH A 210 SENSOR NEAR THE CATHETER DISTAL END GENERATE A MAGNETIC FIELD WITH A SUPERPOSITION 220-/- OF MULTIPLE FREQUENCIES FROM THE ONE OR MORE MAGNETIC COILS, EACH COIL EXCITED WITH A DIFFERENT FREQUENCY MEASURE AN ELECTRICAL VOLTAGE SIGNAL GENERATED IN THE CATHETER SENSOR WITH THE 230 / MULTIPLE FREQUENCIES IN RESPONSE TO THE MAGNETIC FIELD ESTIMATE AN INITIAL Z-DISTANCE OF THE SENSOR 240 - FROM THE LOCATION PAD BY COMPUTING AN RMS INTENSITY OF THE ELECTRICAL VOLTAGE SIGNAL WITH THE SUPERPOSITION OF THE MULTIPLE FREQUENCIES ESTIMATE THE INITIAL X-Y POSITION OF THE SENSOR 250,/ OVER A SECTION OF THE ARRAY BY ANALYZING THE RELATIVE AMPLITUDE OF THE MULTIPLE FREQUENCIES IN THE RECEIVED VOLTAGE SIGNAL USE THE INITIAL X-Y AND Z POSITION ESTIMATES 260 OF THE SENSOR IN AN ITERATION LOOP ALGORITHM SO AS TO COMPUTE THE POSITION OF THE CATHETER DISTAL END IN THE PATIENT