Flexible Biopsy Needle Assembly with Bending Section
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Solution Overview
Problem
Existing biopsy needles are limited in flexibility and orientation, leading to increased force requirements and potential binding issues during prostate biopsy procedures, which can result in tissue damage and reduced needle longevity.
Innovation Solution
A flexible biopsy needle assembly with a bending section and cannula designed to bend through an angle of at least 40 degrees, featuring a smaller cross-sectional area and longer length than the sampling section, reducing friction and allowing for controlled directional placement within a guide assembly, facilitating easier tissue sampling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If standard straight biopsy needles are used, then the needle structure is simple and manufacturing is easy, but the needle cannot adapt to limited rectal entry angles and requires excessive force for advancement
Solution Approach 1:
The needle is divided into distinct functional sections: a body portion with larger cross-section for structural support, a sampling section with reduced cross-section for tissue engagement, and a bending section with minimal cross-section for flexibility. This segmentation allows each portion to perform its specific function optimally while reducing overall complexity.
Solution Approach 2:
Different portions of the needle have different cross-sectional areas optimized for their specific functions. The body portion has a larger cross-section (0.032-0.040 inches) for strength, the sampling section has a reduced cross-section (0.024-0.032 inches) for tissue interaction, and the bending section has the smallest cross-section (0.016-0.024 inches) for flexibility. This local variation in quality resolves the contradiction between adaptability and complexity.
2Force
If flexible biopsy needles with reduced cross-section are used, then the force required for needle advancement is reduced, but the needle requires precise alignment within the guide assembly
Solution Approach 1:
The needle and cannula are pre-aligned within the guide assembly before the biopsy procedure. The guide assembly's channel is configured to receive the needle-cannula assembly in a predetermined orientation, ensuring proper alignment is established before the flexible needle is advanced into the prostate. This preliminary alignment action compensates for the reduced alignment tolerance inherent in flexible needle design.
3Loss of energy
If the bending section has a smaller cross-sectional area, then friction during needle advancement is reduced, but the needle becomes more susceptible to binding in the guide assembly
Solution Approach 1:
The needle is designed with dynamic flexibility rather than static rigidity. The bending section can dynamically adjust its shape and orientation as it passes through the guide assembly channel, allowing it to navigate the channel's geometry without binding. This dynamic adaptation reduces friction while maintaining reliability by preventing the needle from becoming stuck.
4Productivity
If standard straight needles are used, then the guide assembly design is simple, but multiple firings require repositioning and increase procedure time
Solution Approach 1:
The flexible needle assembly with its bending section and reduced cross-section sampling portion can perform multiple tissue sampling functions from a single insertion position. The needle can be fired multiple times to collect samples from different tissue locations without requiring removal and repositioning, as the flexible design allows the sampling section to engage tissue at various angles and depths. This multi-functionality increases productivity while the guide assembly complexity remains manageable.
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 flexible design reduces the force needed for needle advancement, enhances tissue sampling precision, and increases the reliability and longevity of the needle assembly, while also decreasing manufacturing costs and potential failure modes.
Implementation Method 1
a bending section proximal of the sampling section. The bending section and body portion of the needle are both preferably formed with circular cross-sections. The bending section has a substantially smaller cross-section than that of the body portion, and a substantially longer length than that of the sampling section.
Data Source
AI summary
A needle assembly and delivery system for biopsying tissue of a patient includes a flexible biopsy needle, a cannula for receiving and supporting the biopsy needle, and a guide assembly which defines at least one guide assembly for receiving, guiding, and orienting the flexible biopsy needle and cannula through an angle of at least forty degrees through the needle guide assembly to a fixed orientation and position for biopsying tissue of the patient. The biopsy needle includes a sampling section which has smooth or rounded edges, a bending section which has a first circular cross-section, and a body portion proximal of the bending section which has a second circular cross-section larger than the first circular cross-section. The flexible biopsy needle, cannula, and guide assembly may be used with a biopsy ultrasound delivery system which includes an ultrasonic probe and a biopsy gun.