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US 8,265,745 B2Granted
Contact sensor and sheath exit sensor
AssigneeSt. Jude Medical, Atrial Fibillation Division, Inc.
InventorsJohn A. Hauck, Jeffrey A. Schweitzer, Kenneth H. Drew
Life of this patent
Estimating the term…
Abstract
A system and method is provided that allows for determining the local impedance of one or more electrodes of an electrode catheter. Such local impedance may be utilized to identify the relative position of an electrode catheter to a sheath of a guiding introducer. In another arrangement, local impedance of a catheter electrode can be utilized to calibrate a catheter electrode to provide improved contact sensing.
Claims20
A method for performing a medical procedure, comprising the steps of:
- guiding a catheter to an internal patient location, wherein the catheter includes at least first and second electrodes;
- providing first and second separate electrical signals having equal frequency and phase to the first and second electrodes, respectively, wherein an amplitude of one of the first and second electrical signals is adjustable relative to an amplitude of the other of the first and second electrical signals;
- monitoring the first and second electrical signals as applied to the first and second electrodes, respectively, to identify first and second input responses;
- adjusting the amplitude of at least one of the first and second electrical signals as applied to a corresponding one of the electrodes to generate an initial relative response of the first and second electrodes;
- identifying a level of the initial relative response;
- identifying a change in the initial relative response;
- scaling the change based on the level of the initial relative response to generate a scaled change of response;
- and
- generating an output based on the scaled change of response.
6 more elements
A method for performing a medical procedure, comprising the steps of:
- positioning a catheter within an internal patient location, wherein the catheter includes a plurality of electrodes;
- providing a plurality of separate electrical signals to the plurality of electrodes disposed at the internal patient location, respectively;
- monitoring the plurality of electrical signals as applied to the plurality of electrodes, respectively, to identify a plurality of impedances;
- adjusting an amplitude of at least one of the electrical signals as applied to at least one of the electrodes relative to at least one of the other electrical signals to match impedances of at least two of the plurality of electrodes while the electrodes are free of contact with a wall of the internal patient location;
- identifying a level of an initial response of the electrodes having matching impedances;
- identifying a change in the impedance of one of the electrodes;
- scaling the change based on the level of the initial response to generate a scaled change of impedance;
- and
- assessing contact between the catheter and the wall based on the scaled change of impedance.
6 more elements
An apparatus for performing a medical procedure, comprising:
- means for providing a plurality of separate electrical signals to a plurality of electrodes of a catheter disposed at an internal patient location, respectively;
- means for monitoring the plurality of electrical signals as applied to the plurality of electrodes, respectively, to identify a plurality of impedances;
- means for adjusting an amplitude of at least one of the electrical signals as applied to at least one of the electrodes relative to at least one of the other electrical signals to match impedances of at least two of the plurality of electrodes while the electrodes are free of contact with a wall of the internal patient location;
- means for identifying a level of an initial response of the electrodes having matching impedances;
- means for identifying a change in the impedance of one of the electrodes;
- means for scaling the change based on the level of the initial response to generate a scaled change of impedance;
- and
- means for assessing contact between the catheter and the wall based on the scaled change of impedance.
5 more elements
Dependencies are inferred from the claim text.