Patent ID: 11944389
Assignee: ST. JUDE MEDICAL, CARDIOLOGY DIVISION, INC.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 2:
3. A method for detection and correction of an impedance shift in an impedance based coordinate system, comprising:
receiving an impedance location of an electrode in an impedance based coordinate system and a magnetic location of a magnetic position sensor in a magnetic based coordinate system;
computing a transformed impedance location of the magnetic position sensor using a first electromagnetic registration between the impedance based coordinate system and the magnetic based coordinate system;
determining a difference between the transformed impedance location of the magnetic position sensor and the magnetic location of the magnetic position sensor;
determining that an impedance shift exists based on the difference between the transformed impedance location of the magnetic position sensor and the magnetic location of the magnetic position sensor; and
applying a second electromagnetic registration, in response to the determination that the impedance shift exists, to transform the impedance location of the electrode from a shifted impedance based coordinate system into a shift corrected location of the electrode in the magnetic based coordinate system, using the second electromagnetic registration,
wherein determining the difference between the transformed impedance location of the magnetic position sensor and the magnetic location of the magnetic position sensor includes determining a mean of the difference over a first time scale and determining a covariance of the difference over a second time scale.