RF Ablation Probes with Power Multiplexor for Uniform Lesions
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Solution Overview
Problem
Current radiofrequency electrosurgical systems face challenges in creating large, uniform tissue ablation lesions, particularly when treating tumors, due to limitations in heat dispersion and non-uniform heating patterns caused by varying tissue perfusion and electrode arrangements, leading to inefficient and unpredictable ablation processes.
Innovation Solution
A tissue ablation system that uses a power multiplexor to split and attenuate RF power signals, allowing continuous delivery of power to multiple probes while alternating between nominal and attenuated energy levels to prevent tissue charring and ensure efficient heating across all probes, with feedback control for adjusting power based on tissue impedance or temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If generator output is increased to create larger lesions with a single probe insertion, then lesion diameter is improved, but tissue vaporization and charring occur due to local temperature exceeding 100°C
Solution Approach 1:
The patent divides the single high-power ablation source into multiple lower-power probes, each delivering a fraction of the total power. This segmentation allows the system to achieve large lesion volumes through multiple probe insertions rather than one high-power probe, preventing tissue vaporization and charring that occur when local temperature exceeds 100°C
Solution Approach 2:
The patent employs nested cannulas with multiple probes that can be inserted through a single access point. The probes are nested within expandable baskets or cannulas, allowing sequential or simultaneous deployment of multiple probes to create large ablation zones without requiring multiple separate skin punctures
2Volume of moving object
If multiple electrode placements are performed to ablate larger lesions, then ablation coverage is improved, but treatment duration and patient discomfort increase
Solution Approach 1:
The patent combines multiple probes into a single integrated assembly that can be inserted through one cannula. This merging of multiple probe functions into one deployable unit allows simultaneous ablation of multiple tissue sites, achieving comprehensive coverage without the sequential time required for separate probe insertions
Solution Approach 2:
The patent transitions from linear sequential ablation to three-dimensional simultaneous ablation by deploying probes in radial patterns around the tumor. The expandable baskets and multi-directional probe arrangements enable volumetric ablation coverage in a single procedural step rather than sequential planar ablations
3Volume of moving object
If multiple probes are used to create large lesions, then ablation volume is improved, but power distribution and heating uniformity become difficult to control
Solution Approach 1:
The patent incorporates temperature sensors and impedance monitoring at each probe tip to provide real-time feedback on tissue heating conditions. This feedback enables the control system to dynamically adjust power delivery to individual probes, ensuring uniform heating across the entire ablation zone and preventing hot spots or under-treated regions
Solution Approach 2:
The patent allows independent power control and parameter adjustment for each probe based on local tissue characteristics. Different probes can deliver different power levels, frequencies, or pulse durations tailored to the specific tissue density, vascularity, and thermal conductivity at each location, achieving uniform overall heating despite local variations
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 enables more efficient and predictable tissue ablation, reducing treatment duration and improving lesion uniformity by maintaining continuous energy delivery to all probes, thereby enhancing the effectiveness of tumor treatment without causing tissue charring.
Implementation Method 1
RF energy may be delivered to diseased regions (e.g., tumors) for the purpose of ablating predictable volumes of tissue... RF energy translates into ion agitation, which is converted into heat and induces cellular death via coagulation necrosis
Data Source
AI summary
A tissue ablation system comprises an ablation source, such as an RF ablation source, configured for generating a common power signal, and a power multiplexor configured for splitting the power signal into first and second power signals, substantially attenuating the second power signal relative to the first power signal to create nominal and attenuated power signals, and sequentially delivering the nominal power signal to each tissue ablation probe, while delivering the attenuated power signal to the remaining ablation probes to which the nominal power signal is currently not delivered.