Balloon-anchored biopsy device stabilizes flexible needle alignment
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Solution Overview
Problem
Existing flexible Tru-cut biopsy needles face issues with insufficient force transfer, loss of alignment, and instability during navigation, making it difficult to obtain viable tissue samples safely, particularly for liver biopsies via peripheral access routes.
Innovation Solution
A balloon-anchored biopsy device with a dual catheter system and an inflatable balloon anchor stabilizes the biopsy needle within the hepatic vein, maintaining alignment and enabling effective tissue penetration at a predefined angle, using a flexible Tru-cut needle with a self-alignment mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a flexible Tru-cut biopsy needle is used for peripheral access, then patient safety is improved by avoiding major vessel punctures, but force transfer capability deteriorates making tissue penetration difficult
Solution Approach 1:
The device is divided into multiple functional segments: a flexible catheter for navigation, a separate cutting cannula for tissue penetration, and a stylet for support. This segmentation allows each component to be optimized independently - the catheter remains flexible for safe navigation while the cutting cannula provides sufficient structural integrity for force transfer during tissue penetration.
Solution Approach 2:
The cutting cannula acts as an intermediary between the flexible catheter and the tissue target. It receives the flexible catheter's navigational capability while providing the rigid structure needed for effective cutting, thereby mediating between the conflicting requirements of flexibility and force transfer.
2Adaptability or versatility
If a long flexible biopsy needle is used for peripheral access, then adaptability is improved by reaching distant targets, but alignment stability deteriorates causing loss of directional control
Solution Approach 1:
The catheter is first advanced to the target location and positioned/stabilized before the cutting cannula is deployed. This preliminary positioning ensures that the flexible navigation path is established and secured, providing a stable base for subsequent cutting operations and preventing alignment loss during tissue penetration.
Solution Approach 2:
By separating the navigation function (catheter) from the cutting function (cannula), the device allows the catheter to achieve adaptability through flexibility while the cannula maintains alignment stability during the cutting action, as each segment performs its specialized function independently.
3Strength
If a stiff Tru-cut needle is used for biopsy, then cutting effectiveness is improved, but navigation capability deteriorates preventing peripheral access
Solution Approach 1:
The device separates navigation and cutting functions into distinct components: the catheter provides flexibility for easy navigation through peripheral vessels, while the cutting cannula provides stiffness and structural integrity for effective tissue penetration. This segmentation resolves the contradiction by allowing each component to be optimized for its specific function.
Solution Approach 2:
The system transitions from a static stiff needle to a dynamic multi-component system where the catheter remains flexible during navigation, then the cutting cannula is advanced to provide stiffness during cutting. This dynamic reconfiguration allows the system to adapt its mechanical properties to the requirements of each operational phase.
4Manufacturing precision
If percutaneous liver biopsy is performed, then biopsy sample quality is improved, but complication risk deteriorates due to capsule puncture
Solution Approach 1:
The flexible catheter acts as an intermediary that routes the biopsy device through the venous system rather than directly puncturing the liver capsule. This intermediary pathway avoids the harmful effect of capsule puncture and associated bleeding risks while still enabling high-quality tissue sampling through the cutting cannula.
Solution Approach 2:
The device replaces the direct mechanical puncture through the liver capsule with a vascular access route. Instead of forcing the needle through the capsule and parenchyma in one motion, the system uses vascular navigation to reach the liver and then performs cutting from within the vascular space, substituting a safer mechanical pathway.
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 device ensures stable and efficient acquisition of biopsy samples by maintaining alignment and force transfer, reducing the risk of complications associated with traditional methods.
Implementation Method 1
a balloon that when inserted into a blood vessel of a target organ of a subject and expanded, anchors the section in the blood vessel
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
A balloon-anchored, biopsy device includes a first elongated tube, a second elongated tube, and a flexible biopsy needle. A section of the first elongated tube near the distal tip may include a balloon for insertion into a blood vessel that when inflated, anchors the section in the blood vessel near a biopsy site. The second elongated tube includes a beveled distal exit of a second lumen, which may be positioned at the biopsy site when the first elongated tube is anchored in the blood vessel by the inflated balloon. The flexible biopsy needle is configured to exit the beveled distal exit for penetration into tissue at the biopsy site at a predefined angle between a longitudinal axis of the section of the first elongated tube and a longitudinal axis of the flexible biopsy needle, and to acquire a biopsy sample of the target organ at the biopsy site.