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US 8,998,826 B2Granted
Contact sensor and sheath exit sensor
AssigneeSt. Jude Medical, Atrial Fibrillation 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 monitoring the position of an electrode relative to an introducer, comprising:
- providing an electrical signal to an electrode attached to a body of a catheter at least partially disposed within an interior of an introducer;
- measuring an initial impedance response of the electrode to the electrical signal when the electrode is disposed within the interior of the introducer and a subsequent impedance response of the electrode to the electrical signal upon displacement of the catheter relative to the introducer, wherein said measuring is performed using an impedance measurement module;
- and
- processing the said initial impedance response and said subsequent impedance response to:
- identify an impedance change between said initial impedance response and said subsequent impedance response;
- access predetermined threshold information stored in memory, said predetermined threshold information corresponding to a physical configuration of at least one of the catheter and the introducer;
- compare said impedance change to said predetermined impedance threshold information;
- and
- upon said change exceeding at least one predetermined impedance threshold level, generating an output indicative of a displacement of said electrode relative to an end of said introducer.
6 more elements
A medical system comprising:
- an electrical power system configured to provide a first electrical signal to a first electrode of a catheter at least partially disposed within an interior of an introducer;
- an impedance measurement module configured to measure a first impedance of the first electrode in response to the first electrical signal while the first electrode is located at a first position within the introducer and measure a second, impedance of the first electrode upon displacement of the catheter relative to the introducer;
- a data structure configured to store predetermined impedance threshold information corresponding to a physical configuration of at least one of the catheter and the introducer;
- and
- a processor configured to:
- identify an impedance change between said first impedance and said second impedance;
- access predetermined impedance threshold information stored in said data structure;
- compare said impedance change to said predetermined threshold impedance information;
- and
- upon said change exceeding at least one predetermined threshold level, generate an output indicative of a relative displacement of said electrode to an end of said introducer, wherein the electrode is located at a second position relative to the introducer.
7 more elements
A method for monitoring the position of an electrode relative to an introducer, comprising:
- providing first and second electrical signals to first and second electrodes, respectively, attached to the body of the catheter, wherein the catheter is at least partially disposed within an interior of an introducer;
- measuring first and second impedance responses of the first and second electrodes to the first and second electrical signals, respectively, to generate an initial relative response while the catheter is located at a first position within the catheter;
- identifying a change in the initial relative response, upon displacement of the catheter from said first position to a second position;
- scaling said change based on a level of the initial response to generate a scaled change of impedance;
- and
- generating an output indicative of a displacement of at least one of said electrodes relative to an end of said introducer based on said scaled change of impedance.
3 more elements
Dependencies are inferred from the claim text.