Phase Match Detector for Electrosurgical Insulation Breach
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Solution Overview
Problem
Existing electrosurgical systems fail to effectively detect aberrant current flow due to breaches in the insulation sheath surrounding the protective shield conductor, which can lead to thermal injuries to patients.
Innovation Solution
A transformer with a primary and secondary winding, an AC reference frequency signal generator, and a phase match detector circuit are used to inject a reference frequency signal and detect phase shifts indicative of impedance changes between the shield conductor and the return conductor, allowing for the detection of aberrant current flow and automatic deactivation of the electrosurgical signal generator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If monitoring circuitry compares shield current values to threshold values, then shield faults can be detected, but aberrant current flow due to insulation sheath breach cannot be detected
Solution Approach 1:
The system performs preliminary detection by injecting a reference frequency signal through the shield conductor before actual electrosurgical operation. This allows the monitoring circuitry to establish a baseline impedance measurement and detect insulation breaches proactively, rather than waiting for aberrant current flow during operation to trigger detection
Solution Approach 2:
The system changes the detection parameter from monitoring only shield current magnitude to measuring impedance at a reference frequency. By using impedance measurement at a specific frequency different from the electrosurgical frequency, the system can detect insulation breaches through changes in electrical properties without being overwhelmed by the high-power electrosurgical signal
2Productivity
If the electrosurgical signal generator continues operating, then surgical procedure productivity is maintained, but thermal injury risk increases due to undetected insulation breaches
Solution Approach 1:
The system performs preliminary detection of insulation breaches before electrosurgical operation begins. By checking the impedance of the shield conductor at reference frequency in advance, the system can identify insulation failures and prevent generator activation, thereby eliminating thermal injury risk while maintaining productivity by allowing safe procedures to proceed without interruption
Solution Approach 2:
The system takes preliminary anti-action by detecting insulation breaches and preventing generator operation before aberrant current flow can occur. The monitoring circuitry actively seeks out potential hazards through impedance measurement and blocks the electrosurgical signal generator from operating when insulation integrity is compromised, counteracting the thermal injury mechanism before it can manifest
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 effectively prevents thermal injuries by accurately detecting aberrant current flow and ensuring the electrosurgical signal generator is deactivated in case of insulation breaches, providing enhanced patient safety during surgical procedures.
Implementation Method 1
The first and second windings are magnetically coupled such that the injected reference frequency signal in the first winding induces an AC reference frequency signal in the second winding
Implementation Method 2
a dielectric insulator located between the protective shield conductor and the active conductor
Data Source
Figure 1~2
Figure 3A~3B
Figure 4A~4B
AI summary
An apparatus is provided to detect electrical contact between anatomical tissue and a shield conductor: a transformer; an alternating current (AC) reference frequency signal generator to inject a reference frequency signal to a primary winding of the transformer; a reactive impedance coupled in parallel with a secondary winding of the transformer between a first node and a second node; and a phase match detector circuit to detect a phase match between the reference frequency signal and a reflected reference frequency signal that is reflected from the secondary winding to the primary winding.