Ultrasonic Surgical Switch Assembly With Cut-Completion Feedback
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Solution Overview
Problem
Current ultrasonic surgical instruments face challenges in effectively sealing blood vessels and providing visual feedback to users during tissue cutting, which can lead to incomplete cuts and potential damage to the instrument and surrounding tissue.
Innovation Solution
The development of a surgical system that includes an ultrasonic surgical instrument with a tissue impedance module, which monitors tissue impedance to determine the completion of a cut and provides feedback to the user, and a drive system that applies a frequency step function to mechanically displace the blade in multiple modes for effective tissue separation and sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If clamp force is increased to separate tissue layers for vessel sealing, then sealing effectiveness is improved, but device complexity and potential tissue damage increase
Solution Approach 1:
The patent applies ultrasonic vibration to the blade to mechanically separate tissue layers (adventitia from muscle layer) without requiring excessive clamp force. The ultrasonic vibrations at high frequency create friction and heat that facilitates layer separation, thereby achieving effective vessel sealing while avoiding the need to increase mechanical clamp force to problematic levels.
Solution Approach 2:
The patent changes the operational parameters by introducing ultrasonic frequency vibration as a new parameter to assist tissue separation. This parameter change allows the system to achieve layer separation through vibrational energy rather than purely mechanical force, resolving the contradiction between sealing effectiveness and device complexity/clamp force requirements.
2Productivity
If ultrasonic energy is applied without visual feedback of cut completion, then cutting speed is maintained, but incomplete cuts and instrument damage occur
Solution Approach 1:
The patent implements a feedback mechanism that monitors tissue impedance changes during the cutting process. When the cut is complete, the impedance changes characteristically, providing feedback to the user (through display, haptic, or audible signals) that the cut is complete. This allows the surgeon to maintain cutting speed while ensuring complete cuts and preventing instrument damage from continued activation.
Solution Approach 2:
The patent replaces visual feedback (which may not be available in all surgical contexts) with electrical impedance-based detection. The system uses electrical properties of the tissue to detect cut completion, substituting a mechanical/optical sensing approach with an electrical sensing approach that provides reliable real-time feedback.
3Ease of operation
If continuous ultrasonic activation is used without cut completion detection, then operational simplicity is maintained, but heat damage to tissue and instrument occurs
Solution Approach 1:
The patent uses tissue impedance monitoring to automatically detect when a cut is complete and provides feedback to stop or reduce ultrasonic activation. This feedback mechanism allows the system to operate simply for the surgeon while automatically preventing overheating and heat damage by deactivating the ultrasonic energy when the cut is complete, thus resolving the contradiction between operational simplicity and heat damage prevention.
Solution Approach 2:
The system performs self-monitoring through impedance detection and self-regulation by providing feedback that indicates cut completion. This allows the ultrasonic instrument to essentially 'know' when to stop, reducing heat damage without requiring complex manual control from the surgeon, thereby maintaining ease of operation while preventing harmful effects.
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 enhances the ability to seal blood vessels efficiently by mechanically separating tissue layers and provides visual, audible, and tactile feedback to users, ensuring complete cuts without damaging the instrument or surrounding tissue.
Implementation Method 1
Vibrating at high frequencies (e.g., 55,500 times per second), the ultrasonic blade denatures protein in the tissue to form a sticky coagulum
Implementation Method 2
A generator may include a tissue impedance module configured for detecting a change in tissue impedance
Implementation Method 3
the generator applies a frequency step function to mechanically displace the blade in multiple modes for effective tissue separation and sealing
Data Source
AI summary
Ultrasonic surgical instruments including a handle housing, a switch frame, and a switch assembly are disclosed. The switch assembly may include a first switch arrangement movably supported on a distal portion of the handle housing and selectively movable relative to a first switch contact supported by the switch frame. The switch assembly may further include a second switch arrangement including a right switch button movably supported on a right side of the handle housing and selectively movable relative to a right switch contact supported by the switch frame, and a left switch button movably supported on a left side of the handle housing and selectively movable relative to a left switch contact supported by the switch frame. The first and second switch arrangements may be configured to be selectively actuatable by a single hand supporting the handle housing.