Contact sensor and sheath exit sensor

摘要

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.

主权项

1. A medical system for monitoring the position of a catheter relative to a sheath disposed within a patient's body, the system comprising:
one or more body surface electrodes configured for external application to the patient body; a generator configured to generate an electrical signal for receipt by a first electrode of the catheter; a measurement circuit configured to:
at a first time, measure a first response between the first electrode and said one or more body surface electrodes to said electrical signal;at a second subsequent time, measure a second response between the first electrode and said one or more body surface electrodes to said electrical signal; and a processor configured to:
demodulate a first impedance value for the first electrode based on said first response and said electrical signal;demodulate a second impedance value for the first electrode based on said second response and said electrical signal;identify an impedance change between said first impedance value and said second impedance value; andupon said impedance change exceeding at least one predetermined impedance threshold level, generate an output indicative of a relative displacement of the first electrode to an end of the sheath.