Flexible Loop Biopsy Device for Cell Yield and Tissue Protection
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Solution Overview
Problem
Existing biopsy and cytology devices for pancreatic cysts, such as EUS-FNA and through-the-needle cytologic brushes, face challenges in efficiently harvesting cells while minimizing tissue damage and manufacturing costs, with risks of injury and breakage during operation.
Innovation Solution
A biopsy/cytology device with a hollow needle, an elongated member, and a flexible member at its distal end that expands to form a loop, protected by a tubular sheath, allowing for increased cell harvesting with reduced tissue damage and improved mechanical robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a through-the-needle cytologic brush is used to harvest cells from pancreatic cysts, then cell yield is improved, but risk of bleeding and tissue damage increases
Solution Approach 1:
The brush element is constructed with flexible bristles made of soft material that can conform to the cyst wall geometry without causing mechanical trauma. The flexibility allows gentle contact with the lining to dislodge cells while minimizing penetration depth and force applied to the tissue, thereby reducing bleeding risk.
Solution Approach 2:
The brush element parameters such as bristle stiffness, diameter, and length are optimized to achieve effective cell harvesting. By adjusting these parameters, the device maintains sufficient mechanical interaction to detach cells while staying below the threshold that causes significant tissue damage or bleeding.
2Quantity of substance
If a spiral shaped distal end is used to maximize contact area with cyst wall, then cell harvesting is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The distal end of the elongated member is formed with a spiral or curved geometry that naturally maximizes contact area with the cyst wall. This curved configuration is achieved through simple forming processes during manufacturing, avoiding complex assembly steps while effectively increasing the surface area for cell harvesting.
Solution Approach 2:
The spiral-shaped distal end serves multiple functions: it maximizes contact area for cell harvesting, provides structural support for the brush element, and enables rotational movement during operation. This multi-functionality reduces the need for additional components, simplifying the overall device design.
3Ease of operation
If a flexible shaft is used throughout the needle length, then ease of operation is improved, but manufacturing cost increases
Solution Approach 1:
The needle assembly has different structural characteristics at different locations: the distal end portion containing the brush element is flexible to allow rotation and conforming to cyst geometry, while the proximal portion can be more rigid for stable handling and insertion. This localized flexibility optimizes both operability and manufacturing efficiency.
Solution Approach 2:
The elongated member is divided into functional segments: a flexible distal end with the brush element for cell harvesting, and a more rigid proximal portion for structural support and operator control. This segmentation allows each part to be optimized independently for its specific function while reducing overall manufacturing complexity.
4Adaptability or versatility
If the distal end is made spiral shaped to conform to cavity shape, then adaptability is improved, but reliability during operation and retraction decreases
Solution Approach 1:
The brush element uses flexible bristles that can bend and conform to irregular cavity shapes without experiencing excessive stress. This flexibility allows the distal end to adapt to various cavity geometries while the material properties prevent fracture during insertion, rotation, and withdrawal through the needle.
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 effectively increases cell yield by conforming to cavity geometry, reducing tissue damage, and maintaining structural integrity during operation, compatible with EUS-FNA procedures.
Implementation Method 1
the flexible member is made of a superelastic material, preferably a shape memory alloy
Implementation Method 2
The device further comprises a tubular sheath arranged outside the elongated member and configured to be moved along the elongated member inside the lumen of the needle to contact the expanded loop outside the lumen
Data Source
Figure 1a~1c
Figure 2a~2c
Figure 3a~3c
AI summary
A device for detaching cells or tissue from a cavity in a subject, the device comprising: an elongated member arranged to be moved within a lumen of a needle or a catheter; and at least one flexible member arranged at a distal end of the elongated member, wherein the flexible member is configured to be brought between a first, constrained configuration within the lumen of the needle or catheter, and a second, expanded configuration outside said lumen, wherein the flexible member in the second, expanded configuration is configured to conform to an inner geometry of a cavity in which the device is inserted.