Folded Ultrasonic End Effector Active Length
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Solution Overview
Problem
Conventional ultrasonic surgical instruments have a limited active length, resulting in insufficient heat delivery to tissue in nodal gap regions, leading to ineffective cutting and coagulation, as the maximum amplitude occurs at the distal end and decreases to nodes where displacement is minimal.
Innovation Solution
The development of ultrasonic surgical end effectors with folded elements that extend beyond the conventional active length, allowing for increased displacement amplitude along the instrument, with folds located at or between nodes and antinodes to optimize energy delivery and tissue interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional ultrasonic end effectors are used with standard active length, then the instrument structure remains simple, but the energy delivery to tissue in nodal gap regions is insufficient
Solution Approach 1:
The end effector incorporates a folded element that extends beyond the distal end of the body, utilizing a spatial dimension change to increase the active length. The folded element projects beyond the distal end and defines a parallel acoustic path, effectively adding length in the longitudinal dimension without increasing the overall instrument footprint, thereby improving energy delivery to tissue in nodal gap regions.
2Productivity
If the active length of ultrasonic instruments is increased, then cutting and coagulation efficiency is improved, but the instrument length increases
Solution Approach 1:
The folded element is configured to extend beyond the distal end of the body and define a parallel acoustic path, effectively increasing the active length within a compact overall instrument length. This spatial arrangement allows the acoustic energy to travel a longer path through the folded element while maintaining a manageable instrument size for surgical procedures.
3Use of energy by moving object
If folded elements are added to extend active length, then energy delivery beyond quarter wavelength limit is achieved, but the device complexity increases
Solution Approach 1:
The end effector is divided into distinct segments: a body portion and a separate folded element. The folded element is coupled to the distal end of the body and can be positioned independently to define a parallel acoustic path. This segmentation allows the folded element to be optimized for extending energy delivery beyond the quarter wavelength limit while keeping the overall structure manageable and maintainable.
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 design enhances the active length of ultrasonic instruments, improving tissue cutting and coagulation efficiency by maintaining effective energy delivery beyond the traditional quarter wavelength limit, reducing tissue stickage, and enabling more effective hemostatic sealing.
Implementation Method 1
Ultrasonic vibrations, when transmitted to organic tissue at suitable energy levels using a suitable end effector
Implementation Method 2
The waveguide and end effector are most preferably designed to resonate at the same frequency as the transducer
Implementation Method 3
The extendable folded element and the outer surface of the body define a single substantially parallel acoustic path
Implementation Method 4
Vibrations generated by the transducer section are transmitted to the surgical end effector via an ultrasonic transmission component such as a waveguide extending from the transducer section to the surgical end effector. The waveguide and end effector are most preferably designed to resonate at the same frequency as the transducer
Implementation Method 5
The transducer may be constructed of one or more piezoelectric or magnetostrictive elements located in the instrument hand piece
Implementation Method 6
The transducer may be constructed of one or more piezoelectric or magnetostrictive elements located in the instrument hand piece
Data Source
AI summary
An end effector for use with an ultrasonic surgical instrument. A body extends along a longitudinal axis. The body includes a proximal end and a distal end. The body comprises an outer surface that defines an inner portion. The proximal end of the body is configured to couple to an ultrasonic transducer configured to produce vibrations at a predetermined frequency and a predetermined amplitude. An extendable folded element includes a first end coupled to the distal end of the body and extending proximally along the longitudinal axis from the distal end of the body toward the proximal end of the body. The extendable folded element comprises a second free acoustic end. The extendable folded element and the outer surface of the body define a single substantially parallel acoustic path.