System and method for determining state of rf devices using impedance measurements
AssigneeBoston Scientific Scimed, Inc.
InventorsSteven Kinio, Christian Balkovec, Laurentiu Murtescu, Deep Patel
Life of this patent
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Abstract
A radiofrequency (RF) generator for use in a tissue puncture system for puncturing a tissue in a body is disclosed. The RF generator includes an RF energy source to couple to an active electrode of an RF puncture device and to couple to a return electrode and a controller coupled to the RF energy source. The controller causes the RF energy source to generate each of a puncture signal and a test signal, the test signal having a lower power than the puncture signal, measures an impedance of the test signal, determine a state of the active electrode based on the impedance measurement, and displays the state on a display device.
Claims27
A tissue puncture system for accessing a left atrium of the heart through a transseptal puncture, comprising:
- a radiofrequency generator configured to generate radiofrequency energy;
- a transseptal guidewire configured to deliver radiofrequency energy from the radiofrequency generator to tissue via an active electrode;
- a controller configured to:
- measure impedance during energy delivery using the active electrode, wherein the measured impedance includes complex impedance having magnitude and phase angle information;
- determine the state of the active electrode from a plurality of states based on the measured impedance, wherein the state of the active electrode is based on the position of the active electrode with respect to the tissue;
- and
- control an output of the radiofrequency generator based on the determined state of the active electrode.
A tissue puncture system for accessing a left atrium through a transseptal puncture, comprising:
- a radiofrequency generator configured to generate radiofrequency energy;
- a transseptal guidewire configured to deliver radiofrequency energy from the radiofrequency generator to tissue via an active electrode;
- a measurement circuit configured to monitor complex impedance including magnitude and phase angle information of the radiofrequency energy during energy delivery;
- a controller configured to:
- determine a state of the active electrode from a plurality of states based on the monitored phase angle during energy delivery, wherein the plurality of states includes a delivery assembly state where the active electrode is positioned in a delivery assembly, a tissue contact state where the active electrode is in tissue contact, and a blood contact state where the active electrode is in blood contact;
- determine a change in the state of the active electrode from the tissue contact state to the blood contact state;
- and
- in response to determining the transition from the tissue contact state to the blood contact state, control an output of the tissue puncture system.
A method of controlling a tissue puncture system for accessing a left atrium of the heart through a transseptal puncture, comprising:
- delivering radiofrequency energy to tissue via an active electrode of a transseptal guidewire during a transseptal puncture procedure;
- measuring, using a measurement circuit, complex impedance including phase angle of electrical impedance using the active electrode during energy delivery;
- determining, using a controller, a state of the active electrode from a plurality of states based on the measured phase angle, wherein the plurality of states includes a tissue contact state and a blood contact state;
- and
- controlling, using the controller, an output of the tissue puncture system based on a determined transition from the tissue contact state to the blood contact state.
A tissue puncture system for accessing a left atrium of the heart through a transseptal puncture, comprising:
- a radiofrequency generator configured to generate radiofrequency energy;
- a transseptal guidewire configured to deliver radiofrequency energy from the radiofrequency generator to tissue via an active electrode;
- a measurement circuit configured to measure complex impedance including a phase angle using the active electrode during energy delivery;
- and
- a controller configured to:
- determine a state of the active electrode from a plurality of states based on the measured phase angle, wherein the plurality of states includes a tissue contact state and a blood contact state;
- and
- generate an output corresponding to the determined state.
Dependencies are inferred from the claim text.