Biopsy Device Outer Needle Countersink Tissue Retention
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Solution Overview
Problem
Current full core biopsy devices face challenges in obtaining intact, large tissue samples from soft tissues due to issues with cutting, separating, retaining, and delivering the specimen, particularly in small gauge needles, which often result in crushed or lost samples.
Innovation Solution
A biopsy device with coaxially disposed inner and outer needles, featuring a Franseen tip on the outer needle and a countersink or forcing cone on the inner surface to enhance tissue retention, along with a mechanism for precise positioning of the inner needle to prevent tissue compression and facilitate clean cutting and sample retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a standard core biopsy needle is used to obtain soft tissue samples, then the procedure is simple and quick, but the tissue sample is crushed and distorted during extraction
Solution Approach 1:
The needle is divided into functionally distinct segments: a cutting edge portion for clean tissue sectioning and a retention portion with internal features for sample holding. This segmentation allows each portion to perform its specific function optimally without interfering with the other, resolving the contradiction between sample integrity and extraction ease.
Solution Approach 2:
The retention features act as an intermediary mechanism between the cutting action and sample extraction. These internal features (such as ridges or chambers) temporarily hold the tissue sample during extraction, mediating the transition from cutting to retrieval without requiring complex manual manipulation.
2Quantity of substance
If FNA device is used to obtain soft tissue core samples, then full core samples can be obtained, but the procedure is time-consuming and technique-dependent
Solution Approach 1:
The cutting edge is designed to perform the tissue separation action preliminarily and efficiently during the initial advancement phase. By optimizing the cutting geometry and positioning, the tissue is cleanly sectioned before extraction begins, eliminating the need for time-consuming manual teasing or rotation operations.
Solution Approach 2:
The retention features within the needle lumen automatically capture and hold the tissue sample as it is cut and advanced into the needle. This self-retaining mechanism eliminates the need for operator dexterity to manually secure the sample, making the procedure less technique-dependent and faster.
3Productivity
If automated biopsy device is used, then the procedure is fast and simplified, but the tissue sample is pushed aside rather than drawn into the needle
Solution Approach 1:
Different regions of the needle have specialized qualities: the cutting edge has sharp, clean-cutting geometry for precise tissue sectioning, while the retention portion has internal features optimized for sample capture and holding. This local differentiation allows automated advancement to work effectively while maintaining sample capture accuracy.
Solution Approach 2:
The retention features are positioned and designed to counteract the pushing effect of automated advancement before it can cause sample loss. As the tissue is being cut and advanced, the retention features immediately engage to prevent the sample from being pushed aside, providing preliminary anti-action against the harmful effect.
4Volume of moving object
If small gauge needle is used for biopsy, then the access size is minimized, but the tissue sample retention is compromised
Solution Approach 1:
The retention features are nested within the limited space of the small gauge needle lumen. Internal ridges, chambers, or other retention structures are positioned concentrically within the needle bore, maximizing sample retention capability without increasing the external needle diameter, thus maintaining minimal access size.
Solution Approach 2:
Instead of relying on needle diameter for sample retention, the invention utilizes the internal dimensional space of the needle lumen creatively. Retention features extend radially and axially within the available space, using three-dimensional positioning to achieve effective sample holding in a small gauge format.
Data Source
AI summary
A biopsy device includes coaxially disposed inner and outer needles in which the outer needle tip is configured for obtaining a tissue sample. The inner surface of the outer needle includes a tissue retention feature which includes a countersink having a predetermined length from the distal cutting edge of the outer needle.