Offset Conductive Member for Uniform RF Energy Dissipation
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Solution Overview
Problem
Existing RF treatment devices for bodily tissue often experience uneven energy dissipation due to poor electrical contact between the probe and cannula, leading to hot spots and inadequate energy transmission, particularly when the probe is thinner than the cannula.
Innovation Solution
A device featuring a hub with a mounting structure and a shaft with electrically conductive materials on both inner and outer surfaces, along with a conductive member that extends through the shaft's lumen, creating an offset between the conductive member's and shaft's axes to enhance electrical contact and ensure more uniform energy distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the probe is made thinner to minimize tissue damage, then the tissue damage is reduced, but the electrical contact with the cannula becomes poorer leading to uneven energy dissipation
Solution Approach 1:
The probe is nested within the cannula, with the conductive member positioned inside the shaft. The offset configuration allows the conductive member to contact the inner surface of the shaft at multiple points along its length, ensuring reliable electrical contact while maintaining a thin probe design that minimizes tissue damage.
Solution Approach 2:
The conductive member is positioned offset from the central longitudinal axis of the shaft, creating an asymmetric configuration. This offset positioning ensures that the outer surface of the conductive member makes contact with the inner surface of the shaft, providing reliable electrical contact throughout the length of the probe while allowing the probe to remain thin.
2Ease of operation
If the probe is made thinner than the cannula, then the device flexibility and insertion ease are improved, but the electrical contact between probe and cannula becomes insufficient causing hot spots
Solution Approach 1:
The conductive member is nested within the shaft, allowing the thin probe to be inserted through the cannula with ease. The offset configuration ensures that despite the thin profile, the conductive member maintains continuous contact with the inner surface of the shaft, preventing hot spots and ensuring uniform energy dissipation.
Solution Approach 2:
The inner surface of the shaft acts as an intermediary between the conductive member and the external environment. The offset configuration ensures that the conductive member contacts this intermediary surface, which then distributes the electrical energy uniformly along the length of the probe, preventing hot spots while maintaining ease of insertion.
3Device complexity
If conventional aligned configuration is used, then the device structure is simple, but the electrical contact is poor leading to uneven energy transmission
Solution Approach 1:
The conductive member is positioned asymmetrically with respect to the shaft's central axis, creating an offset configuration. This asymmetric positioning ensures that the outer surface of the conductive member makes contact with the inner surface of the shaft along its length, providing uniform electrical contact and energy transmission without significantly increasing device complexity.
Solution Approach 2:
Instead of relying solely on radial alignment, the invention introduces an offset in the radial dimension. This dimensional change allows the conductive member to contact the shaft's inner surface at multiple points along its length, ensuring uniform electrical contact and energy transmission while maintaining relatively simple device structure.
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 configuration improves electrical contact and energy dissipation, reducing hot spots and ensuring more consistent energy delivery to the treatment site, thereby enhancing the effectiveness of RF lesion creation.
Implementation Method 1
The shaft includes an electrically conductive material on at least a portion of an inner surface and an electrically conductive material on at least a portion on an outer surface. A conductive member... assists in creating electrical contact between the conductive member outer surface and the shaft inner surface.
Implementation Method 2
Resistance to the high frequency electrical current at the tip of the electrode causes heating of adjacent tissue and when the temperature increases sufficiently, the tissue coagulates.
Data Source
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AI summary
A device for forming a lesion includes a hub defining a passageway therethrough and having a mounting structure at one end of the passageway and a shaft attached to the hub and defining lumen therethrough having a longitudinal axis. The shaft has a proximal end attached to the hub in communication with the passageway and a distal end extending away from the hub. The shaft includes an electrically conductive material on at least a portion of an inner surface and an electrically conductive material on at least a portion on an outer surface. A conductive member has a longitudinal axis and is attached to a mounting structure mateable with the mounting structure of the hub so that the conductive member extends through the passageway into the lumen so that at least near the hub the conductive member longitudinal axis is spaced from the lumen longitudinal axis, thereby assisting in creating electrical contact between the conductive member outer surface and the shaft inner surface.