Live Tissue Classification Using RF Impedance for Energy Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ultrasonic and electrosurgical devices require separate generators and user interfaces due to their unique drive signals, feedback needs, and capacitive coupling issues, limiting their ability to recognize interchangeable instruments and optimize control processes, especially in noisy environments.
Innovation Solution
A control circuit and generator system that integrates ultrasonic and electrosurgical devices, employing adaptive algorithms to identify tissue type and adjust device parameters, and a modular communication hub for data processing, enabling simultaneous energy delivery and unified user interfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If distinct generators are used for ultrasonic and electrosurgical devices, then each device can have optimized control and sensing, but device complexity increases and adaptability decreases
Solution Approach 1:
The patent combines ultrasonic and electrosurgical generation capabilities into a single integrated generator. The system uses a single RF amplifier that can operate in both ultrasonic and electrosurgical modes, eliminating the need for separate generators. The switch matrix dynamically routes the RF signal to either the ultrasonic transducer or electrosurgical electrodes based on the selected mode, achieving functional integration while maintaining optimized control for each modality.
Solution Approach 2:
The integrated generator is designed to perform multiple functions through a single device. The RF amplifier and control system can seamlessly switch between ultrasonic and electrosurgical operations, providing universal functionality. The system adapts its parameters and control algorithms based on the selected modality, enabling one generator to replace what would traditionally require two separate devices.
2Ease of operation
If instruments are made disposable or interchangeable, then ease of operation and sterility improve, but the ability to recognize instrument configuration and optimize control decreases
Solution Approach 1:
The system performs preliminary detection and identification of the connected instrument type before initiating the surgical procedure. The control system queries the instrument's characteristics (such as impedance, capacitance, or identification circuits) during the setup phase, stores this information, and uses it to pre-configure the optimal control parameters. This preliminary action ensures that when a disposable or interchangeable instrument is connected, the generator automatically adapts its control algorithm and parameters to match the specific instrument configuration.
Solution Approach 2:
The system continuously monitors electrical parameters (impedance, current, voltage) during operation to detect changes in instrument configuration or tissue interaction. This feedback mechanism allows the control system to dynamically adjust control parameters and identify the specific instrument type connected, ensuring optimized performance regardless of whether the instrument is disposable or reusable. The real-time feedback enables automatic adaptation to interchangeable instruments.
3Reliability
If RF amplitude is increased to improve tissue sealing, then sealing effectiveness improves but capacitive coupling increases causing patient exposure to leakage currents
Solution Approach 1:
The system dynamically adjusts the RF amplitude and pulse duration based on real-time tissue feedback and the specific surgical task being performed. Rather than using fixed high amplitudes, the control system modulates the RF parameters adaptively, increasing power only when and where needed for effective sealing. This dynamic control achieves adequate tissue sealing while minimizing overall capacitive coupling and patient exposure to leakage currents.
Solution Approach 2:
The system employs periodic or pulsed RF delivery rather than continuous high-amplitude RF. By delivering RF energy in controlled pulses with appropriate duty cycles, the system achieves effective tissue sealing during the active phases while allowing capacitive coupling to dissipate during off phases. This periodic action reduces the cumulative exposure to leakage currents while maintaining sealing effectiveness.
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
Enables precise tissue transection and coagulation with improved control and reduced patient exposure to leakage current, while facilitating seamless operation of combined ultrasonic and electrosurgical instruments in noisy environments.
Implementation Method 1
Heat generated by the current flowing through the tissue may form hemostatic seals within the tissue
Implementation Method 2
Vibrating at high frequencies (e.g., 55,500 cycles per second), the ultrasonic blade denatures protein in the tissue
Implementation Method 3
the ultrasonic blade denatures protein in the tissue to form a sticky coagulum
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A radio frequency (RF) instrument may include a method of classifying a tissue in live time. The method may include activating the instrument for a first period of time T1 when the RF instrument contacts the tissue, plotting at least three electrical parameters associated with the tissue to classify the tissue into distinct groups, and applying a classification algorithm to classify the tissue into a distinct group in live time. The parameters may include an initial impedance of the tissue, a minimum impedance of the tissue, and an amount of time that the impedance slope is ∼0. The instrument may collect the parameters during a predetermined amount of time, such as within the first 0.75 seconds of the activation of the device. The classification algorithm may include a support vector machine algorithm that may use a linear, polynomial, or radial basis set.