摘要:
Systems and methods for estimating tissue parameters, including mass of tissue to be treated and a thermal resistance scale factor between the tissue and an electrode of an energy delivery device, are disclosed. The method includes sensing tissue temperatures, estimating a mass of the tissue and a thermal resistance scale factor between the tissue and an electrode, and controlling an electrosurgical generator based on the estimated mass and the estimated thermal resistance scale factor. The method may be performed iteratively and noniteratively. The iterative method may employ a gradient descent algorithm that iteratively adds a derivative step to the estimates of the mass and thermal resistance scale factor until a condition is met. The non-iterative method includes selecting maximum and minimum temperature differences and estimating the mass and the thermal resistance scale factor based on a predetermined reduction point from the maximum temperature difference to the minimum temperature difference.
摘要:
A system and method for determining completion of an ablation procedure is provided. An electrosurgical generator provides an electrosurgical energy source to an electrode probe assembly. The generator is connected to a thermal feedback assembly that includes at least one temperature sensor assembly. The generator includes a computer configured to (1) measure a time of energy delivered to the target tissue, (2) receive a temperature reading from the thermal feedback assembly, (3) estimate a size of an ablation volume based on the temperature reading, a distance between the electrode probe assembly and each temperature sensor assembly, and the measured time, (4) calculate a growth rate of the ablation volume based on the estimated size. The computer may also determine the ablation procedure is complete when the growth rate is less than or equal to a threshold.
摘要:
The invention relates to a temperature distribution determining apparatus for determining a temperature distribution within an object caused by applying energy to the object. A temperature distribution measuring unit (6, 7) measures a spatially and temporally dependent first temperature distribution in the object (3), while the energy is applied to the object (3) such that the object (3) is heated to a temperature within a first temperature range, and a temperature distribution estimating unit (5) estimates a spatially and temporally dependent second temperature distribution in the object (3) within a second temperature range, which is different to the first temperature range, based on the spatial and temporal dependence of the measured first temperature distribution. Since temperature distributions can be obtained not only in the first temperature range, but also in the second temperature range, the overall temperature range, in which the temperature distribution can be determined, can be increased.
摘要:
The present invention includes a system for delivering energy to an airway wall of a lung comprising an energy delivering apparatus and a PID controller having one or more variable gain factors which are rest after energy deliver has begun. The energy delivering apparatus may include a flexible elongated member and a distal expandable basket having at least one electrode for transferring energy to the airway wall and at least one temperature sensor for measuring temperature. The PID controller determines a new power set point base on an error between a preset temperature and the measured temperature. The algorithm can be Pi+1 = Pi + G(αe i + βe i-1 + γ e i-2 ) where α, β and γ are preset values and α is from 1 to 2; β is from -1 to -2; and γ is from -0.5 to 0-5. In another variation, the controller is configured to shut down if various measured parameters are exceeded such as, for example, energy, impedance, temperature, temperature differences, activation time and combinations thereof. Methods for treating a target medium using a PID algorithm are also provided.
摘要:
This relates to treating an asthmatic lung and more particularly, relates to advancing a treatment device into the lung and treating the lung with the device. This also includes additional steps of treating the airway wall, applying energy or heat to the airway wall in an asthmatic lung.
摘要:
An ablation electrode (16) carries a temperature sensing element (94) for measuring the temperature of the tissue being ablated. A thermal insulating element (88) associated with the sensing element blocks the transfer of heat energy from between the temperature sensing element (94) and the electrode (16). The temperature sensing element therefore measures temperature without being affected by the surrounding thermal mass of the electrode (16).
摘要:
Systems and methods well suited for use in catheter based tissue ablation systems employ thermocouples (80) for temperature sensing at an energy emitter site (30). The sensed temperature is used to control the energy output from the energy source to maintain tissue temperature within desired parameters. The systems combine accuracy with compact, low profile construction.
摘要:
This invention is a system and associated method to ablate body tissue using multiple emitters (30) of ablating energy. The system and method convey ablating energy individually to each emitter (30) in a sequence of power pulses. The system and method periodically sense the temperature of each emitter (30) and compare the sensed temperatures to a desired temperature established for all emitters (30) to generate a signal individually for each emitter (30) based upon the comparison. The system and method individually vary the power pulse to each emitter (30) based upon the signal for that emitter to maintain the temperatures of all emitters essentially at the desired temperature during tissue ablation.
摘要:
Systems and methods employ an energy emitting electrode (16) to heat tissue. The systems and methods control the application of energy to the electrode (16) using adjustments that take into account, in a non-linear fashion, changes in monitored operating conditions.
摘要:
A minimally-invasive surgery apparatus (10) for causing the lumen of a vein to collapse to prevent blood flow through the vein, e.g., a varicose vein or a side branch of the saphenous vein, includes an electrode (20) which is electrically connected to a power source (14), and the electrode (20) is percutaneously advanced into the vein. Then, the power source (14) is activated to energize the electrode (20) and thus the blood vein until the blood vein sufficiently collapses to block the lumen of the vein. A feedback loop including a microprocessor (44) is also provided for sensing electrical impedance of the tissue within the vein being energized and for deenergizing the electrode (20) when the impedance reaches a predetermined value. The apparatus (10) can also be used to block a fallopian tube.