Electrosurgical Generator Impedance Feedback Control
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Solution Overview
Problem
Current electrosurgical systems lack precise control over energy output based on sensed tissue feedback, leading to potential tissue damage and inefficiencies in procedures like ablation and coagulation.
Innovation Solution
A system and method that continuously monitor tissue impedance, generate a variance impedance curve, calculate a slope and bubble factor, and adjust power output to maintain minimum impedance and maximum conductance, ensuring efficient energy transfer and preventing tissue damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high radio frequency electrical current is applied to tissue for ablation, then tissue heating and destruction is achieved, but current density becomes very high near the needle electrode tip causing excessive tissue damage
Solution Approach 1:
The system continuously monitors tissue impedance during electrosurgical energy delivery and uses this feedback to dynamically adjust the power output. The microprocessor calculates impedance changes and adjusts generator output to maintain optimal energy delivery while preventing excessive tissue damage from high current density at the electrode tip.
Solution Approach 2:
The system dynamically changes the electrical parameters (power output, current delivery) based on real-time impedance measurements. By adjusting the generator output in response to impedance variations, the system maintains effective tissue heating while preventing harmful effects of excessive current concentration.
2Productivity
If electrosurgical energy is delivered to tissue, then surgical procedures (cutting, coagulation, ablation) are performed, but precise control over energy output based on tissue feedback is lacking
Solution Approach 1:
The system continuously monitors tissue impedance during electrosurgical energy delivery and uses this feedback to dynamically adjust the power output. The microprocessor calculates impedance changes and adjusts generator output to maintain optimal energy delivery while preventing excessive tissue damage from high current density at the electrode tip.
Solution Approach 2:
The system replaces manual control of electrosurgical energy with automated electronic control based on real-time impedance measurements. The microprocessor-based system substitutes for manual adjustment mechanisms, providing precise, dynamic control of power output based on actual tissue conditions.
3Productivity
If power output is increased to improve surgical effectiveness, then tissue treatment efficiency increases, but tissue impedance increases and conductance decreases
Solution Approach 1:
The system continuously monitors tissue impedance during electrosurgical energy delivery and uses this feedback to dynamically adjust the power output. The microprocessor calculates impedance changes and adjusts generator output to maintain optimal energy delivery while preventing excessive tissue damage from high current density at the electrode tip.
Solution Approach 2:
The system dynamically adjusts power output in real-time based on changing tissue impedance conditions. Rather than using fixed power levels, the generator output is continuously modified to adapt to tissue changes during the procedure, maintaining optimal energy delivery and conductance throughout the treatment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for precise control of electrosurgical energy delivery, maximizing tissue conductance and minimizing tissue damage by maintaining optimal bubble formation and absorption rates, thereby enhancing the accuracy and repeatability of procedures like ablation and coagulation.
Implementation Method 1
application of high radio frequency electrical current to a surgical site to cut, ablate, coagulate or seal tissue
Implementation Method 2
the current density is very high near the tip of the needle electrode, which tends to heat and destroy surrounding tissue
Implementation Method 3
sensor circuitry adapted to continuously monitor tissue impedance to generate a variance impedance curve
Implementation Method 4
The generator includes a microprocessor adapted to calculate a slope of a segment of the variance impedance curve and adjust an output of the generator in response to the calculated slope
Data Source
AI summary
An electrosurgical system and method are disclosed. The system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue. The generator includes sensor circuitry adapted to continuously monitor tissue impedance to generate a variance impedance curve and a microprocessor adapted to calculate a slope of a segment of the variance impedance curve. The microprocessor also calculates a bubble factor that represents the rate of formation and absorption of bubbles within tissue to determine minimum tissue impedance and maximum tissue conductance. The system further includes an electrosurgical instrument which includes one or more active electrodes adapted to apply electrosurgical energy to tissue.