Small-Diameter Electrosurgical Radiating Tip for Vascularized Tissue
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrosurgical instruments with larger radiating tip portions often cause excessive bleeding and scarring when used in highly vascularized regions like the liver, and they can lead to burns due to excessive heating during microwave energy delivery.
Innovation Solution
The electrosurgical system employs a small-diameter (1.0 mm or less) radiating tip portion and delivers pulsed microwave energy to minimize bleeding, reduce heating, and prevent damage to healthy tissue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a small-diameter radiating tip portion (1.0 mm or less) is used, then bleeding is minimized and insertion hole size is reduced, but excessive heating of the radiating tip portion occurs during microwave energy delivery
Solution Approach 1:
The electrosurgical system delivers microwave energy in pulsed intervals rather than continuously. The generator supplies microwave energy in a series of pulses with specific duty cycles (e.g., 10%, 20%, 30%), allowing periodic heating and cooling cycles that prevent excessive temperature buildup in the small-diameter radiating tip while maintaining effective tissue ablation capability
Solution Approach 2:
The system changes the operational parameters of microwave delivery by controlling pulse duration, pulse repetition frequency, and duty cycle. These parameter adjustments allow optimization of energy delivery to achieve effective tissue heating while preventing overheating of the radiating tip itself, resolving the contradiction between small diameter and thermal management
2Length of moving object
If a small-diameter radiating tip portion is used, then insertion hole size is minimized facilitating healing, but transmission of microwave energy causes excessive heating
Solution Approach 1:
Pulsed microwave delivery creates intermittent heating cycles that allow thermal diffusion and cooling during pulse intervals, enabling the small radiating tip to deliver sufficient energy for effective ablation without accumulating excessive heat that would damage surrounding healthy tissue or cause burns
3Use of energy by moving object
If conventional larger radiating tip portions are used, then microwave energy transmission is effective, but excessive bleeding and scarring occur in highly vascularized regions
Solution Approach 1:
The system changes the physical parameter of radiating tip diameter from conventional sizes (2-3 mm) to a smaller size (1.0 mm or less), fundamentally altering the interaction with vascularized tissue. This parameter change reduces mechanical trauma and bleeding while pulsed energy delivery parameters compensate for the reduced cross-sectional area to maintain effective energy transmission for ablation
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
The system effectively treats target biological tissue while minimizing bleeding and damage to surrounding healthy tissue, making it particularly suited for use in highly vascularized regions like the liver.
Implementation Method 1
Water molecules have a permanent electric dipole moment, meaning that a charge imbalance exists across the molecule. This charge imbalance causes the molecules to move in response to the forces generated by application of a time varying electric field as the molecules rotate to align their electric dipole moment with the polarity of the applied field. At microwave frequencies, rapid molecular oscillations result in frictional heating and consequential dissipation of the field energy in the form of heat. This is known as dielectric heating.
Implementation Method 2
By delivering the microwave energy in a pulsed manner, it is possible to avoid excessive heating of the radiating tip portion. Such excessive heating may cause burns and thus damage healthy tissue.
Data Source
AI summary
Various embodiments provide an electrosurgical system for treating biological tissue. The system comprises: an electrosurgical generator configured to supply pulsed microwave energy; and an electrosurgical instrument. The electrosurgical instrument comprises a flexible coaxial cable arranged to convey the pulsed microwave energy; and a radiating tip portion connected at a distal end of the coaxial cable and configured to receive the pulsed microwave energy. The radiating tip portion has a maximum outer diameter that is 1.0 mm or less, and wherein the maximum outer diameter of the radiating tip portion is smaller than an outer diameter of the coaxial cable. Also, the radiating tip portion comprises: a proximal coaxial transmission line for conveying the pulsed microwave energy; and a distal needle tip mounted at a distal end of the proximal coaxial transmission line, the distal needle tip being arranged to deliver the pulsed microwave energy into biological tissue.