Methods of determining catheter orientation
Inventors
Panescu, Dorin • Koblish, Josef Vincent • CHUN, Donghoon • Johnson, Jessi E. • Schultheis, Eric Andrew
Assignees
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Publication Number
US-11179197-B2
Publication Date
2021-11-23
Expiration Date
Abstract
Systems, devices and methods of determining orientation of a distal end of a medical instrument (e.g., electrode-tissue orientation of an RF ablation catheter) are described herein. One or more processors may be configured to receive temperature measurements from each of a plurality of temperature-measurement devices distributed along a length of the distal end of the medical instrument and determine the orientation from a group of two or more possible orientation options based on whether temperature measurement values or characteristics of temperature response determined from the temperature measurement values satisfy one or more orientation criteria.
Core Innovation
The invention relates to determining an orientation of a distal end of an ablation catheter with respect to a target region using signals indicative of temperature from a plurality of temperature sensors distributed along the distal end. Temperature measurement values are determined at time points over a first period of time and a second period of time after the first period of time, and an initial temperature value or starting temperature value is calculated for each temperature sensor based on the determined temperature measurement values.
A rate of change of temperature is calculated for each temperature sensor by subtracting the initial temperature value or starting temperature value from a moving average value and dividing by a time elapsed from the first period to the second period or during the period of time. At each time point, the orientation of the distal end relative to the target region is determined based on a comparison of the calculated rate of change of at least two temperature sensors.
The orientation is determined whether the calculated rates of change satisfy one or more orientation criteria, where the orientation criteria are different for each of three orientation options including parallel, perpendicular, and oblique options. The invention further provides catheter hardware and signal-conditioning for heat management and high-resolution mapping in RF ablation catheter systems, including composite or split electrodes with insulating gaps and band-pass filtering implemented with filtering elements such as capacitors configured to manage RF impedance behavior.
Heat shunting elements can be thermally coupled to a fluid conduit or irrigation conduit to reduce localized hot spots, and radiometry or temperature estimation can be used with integrated mapping, contact sensing, and tissue-type feedback.
Claims Coverage
The patent includes two independent claims. The claims focus on distributed distal temperature sensing across time periods, computing an initial or starting temperature and a moving-average-based rate of change, and classifying distal-end orientation into parallel, perpendicular, and oblique options using orientation criteria that differ for each orientation option.
Moving-average-based temperature rate-of-change orientation classification
Receiving signals indicative of temperature from a plurality of temperature sensors distributed along the distal end at time points in a first period of time and a second period of time, calculating an initial temperature value at each sensor, calculating a rate of change by subtracting the initial temperature value from a moving average value and dividing by time elapsed, and determining orientation by comparing calculated rate of change of at least two sensors against orientation criteria for one of three orientation options including parallel, perpendicular, and oblique options, with different orientation criteria for each orientation option.
Starting-temperature-based moving-average temperature rate-of-change orientation classification
Receiving signals indicative of temperature from a plurality of temperature sensors distributed along a distal end at time points over a period of time, determining temperature measurement values at each time point for each sensor, calculating a rate of change between determined temperature values and a starting temperature value by subtracting the starting temperature value from a moving average value and dividing by time elapsed during the period of time, and determining orientation at each time point based on comparison of calculated rate of change of at least two sensors, including determining whether calculated rates of change satisfy orientation criteria for one of three orientation options including parallel, perpendicular, and oblique options, with orientation criteria different for each orientation option.
Across the independent claims, orientation of the distal end is determined by computing a moving-average-based temperature rate of change relative to an initial or starting temperature from distributed distal temperature sensors, then comparing at least two sensors against orientation criteria mapped to parallel, perpendicular, and oblique orientation options.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
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