Brachytherapy Applicator Orientation Device
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Brachytherapy catheter orientation is challenging due to the flexible shaft's inability to transmit torque reliably, leading to unpredictable twisting and untwisting, making precise orientation difficult during radiation therapy.
Innovation Solution
A device with a manually engageable gripping element and engaging elements that securely hold and orient the brachytherapy applicator, preventing rotational movement and allowing controlled axial and rotational positioning without relying on internal structures, thus reducing shaft twist and stick-slip issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a flexible catheter shaft is used for brachytherapy applicator insertion, then ease of insertion and adaptability to treatment cavity is improved, but torque transmission capability deteriorates, causing unpredictable twisting and untwisting
Solution Approach 1:
The catheter shaft is divided into multiple rigid or semi-rigid segments connected by joints, allowing the shaft to bend and adapt to the treatment cavity while maintaining torque transmission capability through the segmented structure. Each segment can rotate relative to adjacent segments, enabling flexible positioning without losing rotational control.
Solution Approach 2:
The catheter shaft is constructed using composite materials that combine flexibility with torsional rigidity. The composite structure allows the shaft to bend smoothly for insertion and positioning while resisting unwanted twisting, providing both adaptability to the treatment cavity and reliable torque transmission for precise orientation.
2Ease of operation
If direct rotational force is applied to the shaft by hand, then orientation adjustment is attempted, but precision deteriorates due to shaft twisting and friction between applicator and tissue
Solution Approach 1:
An intermediary orientation mechanism is introduced between the operator's hand and the catheter shaft. This mechanism, such as a rotational control device or steering mechanism, provides mechanical advantage and direct rotational control, eliminating the twisting and friction problems associated with direct hand manipulation while maintaining ease of operation.
Solution Approach 2:
The orientation control system applies rotational force through a mechanism that provides mechanical advantage, allowing the operator to apply smaller forces that are amplified into precise rotational movements. This partial action approach enables fine-tuned orientation adjustments without overcoming tissue friction directly.
3Reliability
If engaging elements are added to prevent rotational movement, then orientation control is improved, but device complexity increases
Solution Approach 1:
The engaging elements are designed to automatically engage and disengage based on the operational state of the catheter. For example, the engaging elements may automatically lock into position during insertion and orientation, then automatically disengage when the catheter is properly positioned, eliminating the need for manual operation and reducing overall system complexity while maintaining reliable rotational control.
Data Source
AI summary
A device for orienting a brachytherapy applicator implanted in a treatment cavity may include an elongated body defining an open channel adapted for slidably receiving at least a portion of a shaft or catheter body of a brachytherapy applicator. A manually engageable gripping element at an end of the elongated body is actuated to constrict at least a portion of the channel around a portion of the shaft to help prevent shaft twist and rotational movement between the elongated body and brachytherapy applicator. At least one engaging element on the elongated body is actuated to releasably engage at least one corresponding engaging element on a brachytherapy applicator. Shaft twist and rotational discontinuity between the elongated body and brachytherapy applicator are further prevented when the at least one engaging element of the elongated body engages the at least one corresponding element of the brachytherapy applicator. The device can advantageously be mounted and removed while the applicator is inside the treatment cavity. Furthermore, the device is an “external tool” that engages the brachytherapy applicator externally about its outer surface.