Surgical Generator Control Circuit for Ultrasonic and Electrosurgical Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ultrasonic and electrosurgical devices require separate generators due to their unique drive signal, sensing, and feedback needs, leading to limitations in recognizing instrument configurations and optimizing control and diagnostic processes, as well as patient safety concerns from capacitive coupling and leakage current.
Innovation Solution
A surgical generator system that includes a power amplifier for generating drive signals for both ultrasonic and electrosurgical devices, with a control circuit and method for synchronizing sampling of current and voltage samples, determining motional branch current, and modifying drive signal waveforms to reduce amplitude errors, and incorporating a transformer and capacitor configuration for patient-side isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate generators are used for ultrasonic and electrosurgical devices, then each device can have optimized control and sensing, but the system complexity increases and patient safety is compromised due to capacitive coupling and leakage current
Solution Approach 1:
The patent combines ultrasonic and electrosurgical generator functions into a single integrated system. The control circuit receives inputs from both device types and processes them through unified signal conditioning and filtering pathways, eliminating the need for separate isolated generators while maintaining optimized control for each device type through software-based signal processing
Solution Approach 2:
The patent introduces an isolation transformer as an intermediary component between the ultrasonic and electrosurgical circuit portions. This transformer provides galvanic isolation that eliminates harmful capacitive coupling and leakage current while allowing controlled signal and power transfer, thereby resolving the safety issue without requiring completely separate generator systems
2Measurement precision
If a tuning inductor is used to match ultrasonic transducer capacitance, then frequency lock capability is improved, but the device requires different tuning inductors for different transducers and cannot adapt to electrosurgical devices
Solution Approach 1:
The patent replaces fixed tuning inductors with dynamic, software-controlled impedance matching. The control circuit continuously measures transducer impedance characteristics and adjusts circuit parameters in real-time to maintain optimal frequency lock, allowing the same hardware to adapt to different ultrasonic transducers and electrosurgical devices without requiring physical component changes
Solution Approach 2:
The patent changes the operating parameters of the control circuit based on detected device type and characteristics. By measuring impedance, resonant frequency, and other electrical parameters, the system dynamically adjusts filtering, amplification, and frequency control parameters to optimize performance for each specific device configuration
3Reliability
If separate control circuits are used for ultrasonic and electrosurgical devices, then each circuit can be optimized for its specific device, but the overall system complexity and difficulty of detecting and measuring device states increases
Solution Approach 1:
The patent implements a universal control circuit that can detect and control both ultrasonic and electrosurgical devices through a single interface. The circuit uses unified sensing pathways that measure electrical parameters (voltage, current, impedance, phase) common to both device types, enabling the system to automatically identify device type and apply appropriate control algorithms without requiring separate detection circuits
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A control circuit of a surgical device is disclosed. The control circuit includes a first circuit portion coupled to at least one switch operable between an open state and a closed state. The first circuit portion communicates with a surgical generator over a conductor pair to receive a control signal to determine a state of the at least one switch.