Electrosurgical Generator Power Determination Residual Oscillation
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Solution Overview
Problem
Existing electrosurgical generators often provide incorrect effective power values due to residual oscillations and pulsing of high-frequency alternating current, which affect the accuracy of power determination units.
Innovation Solution
Incorporating a switch unit, such as an AND gate, to decouple residual oscillations and a correction mechanism based on the duty cycle to ensure accurate power determination by only processing signals when the high-voltage generator is active, and adjusting the low-pass filter output accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the effective power determination unit continuously processes detector output signals, then the power measurement is continuously available, but incorrect readings occur due to residual oscillations after the high-voltage generator is switched off
Solution Approach 1:
The patent extracts and isolates the problematic residual oscillation signals from the main power determination process by using a switch unit that separates active generator operation signals from residual oscillation signals. This allows the system to process only valid signals during active operation while ignoring residual oscillations that occur after shutdown, thereby maintaining measurement accuracy without requiring complex filtering algorithms.
Solution Approach 2:
The switch unit is configured to preemptively block residual oscillation signals before they can contaminate the power determination process. By using the generator's operational state signal to control the switch in advance, the system prevents incorrect readings from occurring in the first place, rather than attempting to correct them after detection.
2Measurement precision
If the low-pass filter processes all incoming detector output signals, then the phase shift determination is continuous, but residual oscillations cause incorrect power values to be calculated
Solution Approach 1:
The switch unit acts as an intermediary component positioned between the phase shift determination unit and the low-pass filter. It selectively passes or blocks detector output signals based on the generator's operational state, ensuring that only valid signals during active operation reach the low-pass filter for processing, while residual oscillation signals are blocked before contamination can occur.
3Productivity
If the system processes signals during both active operation and residual oscillation phases, then complete signal coverage is achieved, but power determination accuracy deteriorates due to contaminated measurements
Solution Approach 1:
The patent segments the signal processing into two distinct phases: active operation phase and residual oscillation phase. The switch unit uses the generator's operational state signal to divide the continuous signal stream into these segments, processing only the valid active operation phase signals while excluding the contaminated residual oscillation phase signals from power determination calculations.
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 solution significantly improves the reliability of effective power determination by eliminating incorrect readings from residual oscillations and pulsing, providing accurate power output measurements.
Implementation Method 1
The low-pass filter converts this detector output signal into a DC voltage, the magnitude of which represents the phase shift
Implementation Method 2
a high-voltage generator, which is electrically connected to the connectors for the electrosurgical instrument and which is designed to produce a high-frequency alternating current in its activated state
Data Source
AI summary
An electrosurgical generator having connectors for an electrosurgical instrument including a high-voltage generator electrically connected to the connectors and produces a high-frequency alternating current in its activated state and output said high-frequency alternating current via the connectors. The electrosurgical generator has an effective power determination unit including a phase shift determination unit that supplies an output signal representing a phase shift between the current and the voltage of an alternating current output during operation. The phase shift determination unit produces a pulsed DC voltage signal, in which the pulse width reflects a time difference between the zero crossings of the current and the voltage—and consequently the phase shift—and to process the pulsed DC voltage signal by way of a low-pass filter to form a low-pass filter output signal, the magnitude of which depends on the pulse width of the pulses of the pulsed DC voltage signal.