Electrosurgical Generator RF Waveform Segmentation
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Solution Overview
Problem
Conventional electrosurgical generators fully coagulate tissue before cutting, leading to desiccation and reduced effectiveness of the electrosurgical cut due to the lack of moisture, requiring longer application times or ineffective cuts.
Innovation Solution
An electrosurgical generator that supplies a coagulating RF waveform for an initial period, followed by a cutting RF waveform for a predetermined time, and then re-applies the coagulating waveform, allowing for effective cutting without prior complete coagulation, and automating the process through a single activation of the footswitch or handswitch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the generator supplies coagulating RF waveform for a long period before cutting, then tissue coagulation is complete and bleeding is prevented, but tissue becomes desiccated and cutting effectiveness is reduced
Solution Approach 1:
The patent divides the RF waveform supply into distinct segments: an initial coagulation phase followed by a cutting phase. The controller supplies coagulating RF waveform for a first predetermined period, then switches to cutting RF waveform for a second predetermined period. This segmentation allows each phase to be optimized independently, preventing tissue desiccation during cutting while ensuring adequate coagulation during the initial phase.
Solution Approach 2:
The patent implements periodic action by alternating between coagulating and cutting RF waveforms in predetermined time intervals. The controller automatically switches between waveform types based on elapsed time, creating a periodic pattern that maintains tissue moisture during cutting while achieving coagulation objectives. This periodic alternation resolves the contradiction by preventing continuous exposure to coagulating energy that would cause desiccation.
2Manufacturing precision
If the generator supplies cutting RF waveform immediately without prior coagulation, then tissue moisture is preserved and cutting is effective, but bleeding occurs during surgery
Solution Approach 1:
The patent applies preliminary action by supplying coagulating RF waveform for a first predetermined period before switching to cutting RF waveform. This preliminary coagulation phase seals blood vessels and prevents bleeding during the subsequent cutting phase, while the limited duration of coagulation prevents excessive tissue desiccation. The controller automatically manages this preliminary coagulation step based on time control.
3Ease of operation
If the generator requires separate activation for coagulation and cutting, then precise control is achieved, but surgical efficiency is reduced due to multiple activations
Solution Approach 1:
The patent merges the coagulation and cutting operations into a single automated sequence controlled by one activation of the footswitch or handswitch. The controller automatically supplies coagulating RF waveform for a first predetermined period, then switches to cutting RF waveform for a second predetermined period without requiring additional user input. This combining of operations maintains control precision through automated timing while significantly improving surgical efficiency by eliminating the need for multiple separate activations.
Solution Approach 2:
The controller performs self-service by automatically managing the transition between coagulation and cutting phases based on predetermined time intervals. Once activated, the system autonomously controls the RF waveform supply sequence, switching between modes and managing timing without continuous user intervention. This self-service capability maintains precise control while freeing the surgeon to focus on the surgical procedure, thereby improving efficiency.
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 approach ensures effective tissue cutting with sufficient moisture preservation, reducing the risk of over-coagulation and automating the coagulation and cutting process, thereby improving surgical efficiency and tissue handling.
Implementation Method 1
an electrosurgical generator for generating radio frequency power... a controller operable to cause the system to supply a first coagulating RF waveform to the output connections or a second cutting RF waveform to the output connections
Data Source
AI summary
An electrosurgical generator for generating radio frequency power, includes a radio frequency output stage having three or more output connections, and one or more sources of radio frequency output power coupled to the output stage. A controller causes the system to supply a first coagulating RF waveform to the output connections or a second cutting RF waveform to the output connections. The first RF waveform is delivered between a first pair of the output connections, and the second RF waveform is delivered between a second pair of the output connections. In a first mode of operation the controller supplies the first coagulating RF waveform, and in a second subsequent mode of operation the controller supplies the second cutting RF waveform for a first predetermined period of time followed by the first coagulating RF waveform for a second predetermined period of time, both periods being in excess of 1 second.