Digital Electrosurgical Generator Waveform Mixing for Tissue-Specific Output

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current surgical instruments lack the ability to customize power output based on the type of tissue being treated, leading to inefficiencies in surgical procedures.

Innovation Solution

A generator is configured to digitally generate and combine radio frequency (RF) and ultrasonic electrical signal waveforms, using lookup tables and digital synthesis circuits to create customizable waveforms that can be adjusted in real-time for specific tissue effects, allowing for simultaneous or sequential delivery of energies to surgical instruments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fixed waveform output is used in surgical instruments, then device simplicity is maintained, but adaptability to different tissue types is reduced

Engineering Contradiction:

Improveadaptability to different tissue typesVSAvoidwaveform generation system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic waveform generation by storing multiple predefined waveform types (sinusoidal, square, triangular, sawtooth) in lookup tables and selectively applying them based on tissue type and surgical procedure requirements. The system dynamically switches between different waveform configurations through digital control circuits, enabling adaptability without requiring complex real-time synthesis for each waveform type.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes key waveform parameters (frequency, amplitude, duty cycle, phase) based on tissue characteristics and surgical needs. Digital control circuits modify these parameters by selecting appropriate values from lookup tables and combining waveforms through digital synthesis, allowing precise parameter adjustment while maintaining relatively simple hardware architecture.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If multiple energy types are combined in surgical instruments, then surgical effectiveness is improved, but control precision becomes more difficult

Engineering Contradiction:

Improvesurgical procedure effectivenessVSAvoidenergy output control precision

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent segments the energy delivery system into distinct RF and ultrasonic channels, each with independent waveform generation and control circuits. This segmentation allows separate optimization and precise control of each energy type while maintaining the ability to deliver them simultaneously or sequentially through a unified digital control architecture.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system incorporates feedback mechanisms where tissue impedance and energy delivery parameters are monitored in real-time. Digital control circuits adjust waveform parameters based on this feedback to maintain optimal energy delivery and prevent excessive tissue heating or unintended effects, thereby improving control precision for combined energy delivery.

Inventive Principle:

Principle #23Feedback

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 enables precise control over tissue effects, enhancing the precision and efficiency of surgical procedures by adapting energy output to the specific tissue type, improving cutting, coagulation, and hemostasis processes.

Implementation Method 1

a digital-to-analog converter (DAC) circuit

Methodology Applied

Scientific EffectDigital-to-analog conversion:

Implementation Method 2

Vibrating at high frequencies (e.g., 55,500 times per second), the ultrasonic blade denatures protein in the tissue to form a sticky coagulum

Methodology Applied

Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 3

Heat generated by the current flowing through the tissue may form hemostatic seals within the tissue

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS10751108B2Protection techniques for generator for digitally generating electrosurgical and ultrasonic electrical signal waveforms

Publication Date: 2020.08.25 CILAG GMBH INTERNATIONAL

AI summary

A method of generating electrical signal waveforms. A generator includes a digital processing circuit, a memory circuit in communication with the digital processing circuit defining a lookup table, a digital synthesis circuit in communication with the digital processing circuit and the memory circuit, and a digital-to-analog converter (DAC) circuit. The method includes generating a first and second digital electrical signal waveforms, combining the first and second waveforms to form a combined waveform, modifying the combined waveform to form a modified waveform The peak amplitude of the modified waveform does not exceed a predetermined amplitude value. The method includes generating a second waveform that is a function of the first waveform. The method includes modifying a frequency of the first waveform to form a frequency modified first waveform and combining the frequency modified first and second waveforms to form a combined waveform.