Contact sensing systems and methods
First Claim
1. A system for determining a contact state of a distal end portion of a medical instrument with a target region based, at least in part, on electrical measurements, the system comprising:
- at least one signal source configured to generate at least one signal to apply a first frequency and a second frequency to a pair of electrode members of a combination electrode assembly; and
a processor configured to, upon execution of specific program instructions stored on a computer-readable storage medium;
process a resulting waveform that formulates across the pair of electrode members to obtain a first electrical measurement at the first frequency;
process a resulting waveform that formulates across the pair of electrode members to obtain a second electrical measurement at the second frequency;
determine a bipolar contact impedance magnitude based on the first electrical measurement;
determine a bipolar contact impedance magnitude and a phase angle based on the second electrical measurement; and
calculate a contact indication value indicative of a state of contact between a distal end portion of a medical instrument and a target region utilizing each of;
(i) the bipolar contact impedance magnitude based on the first electrical measurement or the second electrical measurement, (ii) a determined ratio of the bipolar contact impedance magnitudes based on the first electrical measurement and the second electrical measurement, and (iii) the phase angle based on the first electrical measurement or the second electrical measurement.
4 Assignments
0 Petitions
Accused Products
Abstract
According to some embodiments, a medical instrument comprises an elongate body having a proximal end and a distal end and a pair of electrodes or electrode portions (for example, a split-tip electrode assembly). Systems and methods are described herein that perform contact sensing and/or ablation confirmation based on electrical measurements obtained while energy of different frequencies are applied to the pair of electrodes or electrode portions. The contact sensing systems and methods may calibrate network parameter measurements to compensate for a hardware unit in a network parameter measurement circuit or to account for differences in cables, instrumentation or hardware used.
953 Citations
20 Claims
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1. A system for determining a contact state of a distal end portion of a medical instrument with a target region based, at least in part, on electrical measurements, the system comprising:
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at least one signal source configured to generate at least one signal to apply a first frequency and a second frequency to a pair of electrode members of a combination electrode assembly; and a processor configured to, upon execution of specific program instructions stored on a computer-readable storage medium; process a resulting waveform that formulates across the pair of electrode members to obtain a first electrical measurement at the first frequency; process a resulting waveform that formulates across the pair of electrode members to obtain a second electrical measurement at the second frequency; determine a bipolar contact impedance magnitude based on the first electrical measurement; determine a bipolar contact impedance magnitude and a phase angle based on the second electrical measurement; and calculate a contact indication value indicative of a state of contact between a distal end portion of a medical instrument and a target region utilizing each of;
(i) the bipolar contact impedance magnitude based on the first electrical measurement or the second electrical measurement, (ii) a determined ratio of the bipolar contact impedance magnitudes based on the first electrical measurement and the second electrical measurement, and (iii) the phase angle based on the first electrical measurement or the second electrical measurement. - View Dependent Claims (2, 3, 4, 5)
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6. A system for determining a contact state of an ablation member of a medical instrument with target tissue, the system comprising:
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at least one signal source configured to deliver one or more signals to apply at least a first frequency and a second frequency to an ablation member of a medical instrument, the ablation member comprising a distal portion and a proximal portion spaced apart from the distal portion, wherein the one or more signals comprise radiofrequency signals; and a processing device configured to, upon execution of program instructions stored on a non-transitory storage medium; process a first resulting waveform across the proximal portion and the distal portion of the ablation member to obtain a first electrical measurement at the first frequency; process a second resulting waveform across the proximal portion and the distal portion of the ablation member to obtain a second electrical measurement at the second frequency; and calculate a contact indication value indicative of a level of contact between the ablation member and target tissue utilizing each of;
(i) an impedance magnitude value determined from the first electrical measurement or the second electrical measurement and (ii) a determined ratio between the impedance magnitude value determined from the first electrical measurement and an impedance magnitude value determined from the second electrical measurement. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of determining a contact state of an ablation member of a medical instrument with a target region, the method comprising:
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generating at least one signal to apply a plurality of frequencies to an ablation member positioned along a distal end portion of a medical instrument, the ablation member comprising a proximal portion and a distal portion separated by an electrically-insulating gap; processing a first resulting waveform that formulates across the proximal portion and the distal portion of the ablation member to obtain at least a first electrical measurement at a first frequency; processing a second resulting waveform that formulates across the proximal portion and the distal portion of the ablation member to obtain at least a second electrical measurement at a second frequency different from the first frequency; and calculating a contact indication value indicative of a level of contact between the ablation member and a target region utilizing a determined ratio between an impedance magnitude value determined from the first electrical measurement and an impedance magnitude value determined from the second electrical measurement and at least one of;
(i) the impedance magnitude value determined from the first electrical measurement or from the second electrical measurement and (ii) an impedance phase angle value determined from the first electrical measurement or from the second electrical measurement. - View Dependent Claims (18, 19, 20)
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Specification