Rotatable Stylet Hub for Flexible Biopsy Sampling Modes
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Solution Overview
Problem
Existing biopsy devices are limited to either single insertion single sample (SISS) or single insertion multiple sample (SIMS) modes, lacking flexibility and efficiency in sample collection.
Innovation Solution
A biopsy apparatus with a releasable stylet assembly that allows independent movement from the operator mechanism, enabling both SISS and SIMS modes by disconnecting the stylet assembly for proximal movement, facilitating multiple sample extraction without removing the cutting cannula.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the stylet assembly is fixed to the operator mechanism, then the device structure is simpler, but the adaptability between SISS and SIMS modes is reduced
Solution Approach 1:
The stylet hub is designed with rotational capability to transition between engaged and disengaged positions, transforming a static connection into a dynamic one. This allows the same structural component to serve dual purposes: providing stable connection during SISS mode and enabling independent stylet movement during SIMS mode, thereby resolving the contradiction between adaptability and structural simplicity
Solution Approach 2:
The operator mechanism is designed to perform multiple functions through the rotatable stylet hub configuration. The same operator mechanism can both control the cutting cannula and, when the stylet hub is rotated to disengaged position, allow independent stylet manipulation for multiple samples. This multi-functionality eliminates the need for separate mechanisms for different biopsy modes
2Productivity
If the stylet assembly moves independently in proximal direction, then multiple samples can be collected, but the operator mechanism complexity increases
Solution Approach 1:
The operator mechanism is segmented into two independent control paths: one through the arm member for cannula control, and another through the rotatable stylet hub for stylet control. This segmentation allows each component to be optimized for its specific function while maintaining overall system simplicity, enabling multiple sample collection without requiring a completely complex new mechanism
Solution Approach 2:
The rotatable stylet hub provides a dynamic control interface that simplifies the operator mechanism. By rotating the hub to disengaged position, the operator enables independent stylet movement for multiple sample retrieval without requiring additional actuators or complex control systems, thus improving productivity while maintaining mechanism simplicity
3Measurement precision
If the cutting cannula is repositioned for each sample, then sample accuracy is improved, but the procedure time increases
Solution Approach 1:
The stylet hub's rotational capability creates a dynamic system where the cutting cannula remains stationary while the stylet can be independently repositioned by rotating the hub to disengaged position and moving the stylet proximally. This allows rapid sample retrieval from different positions without time-consuming cannula repositioning, reducing procedure time while maintaining sampling accuracy
Solution Approach 2:
The stylet function is extracted from the cannula system, allowing independent stylet manipulation. The stylet can be pulled back independently through the rotatable hub mechanism to retrieve samples from different locations along the cannula length, eliminating the need to reposition the entire cannula assembly and thus reducing procedure time while preserving sampling precision
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
Enables flexible operation between SISS and SIMS modes, allowing for efficient and versatile biopsy sampling with the ability to collect multiple samples without repositioning the cannula, enhancing procedural efficiency and sample retrieval.
Implementation Method 1
a cannula firing spring configured to propel the cutting cannula in a distal direction to move over the sample notch of the inner stylet
Data Source
AI summary
A biopsy apparatus includes a cannula assembly having a cannula hub and a cutting cannula. A stylet assembly has a stylet hub and a stylet. The stylet is coaxial with the cutting cannula. An operator mechanism is configured to effect axial movement of the stylet hub and the cannula hub. The operator mechanism has a head portion configured to releasably engage the stylet hub and an arm member configured to releasably engage the cannula hub. The stylet hub is configured to be rotationally movable between an engaged position and a disengaged position, wherein in the engaged position the stylet hub is releasably connected to the head portion of the operator mechanism, and in the disengaged position, the stylet hub is disconnected from the head portion of the operator mechanism to facilitate axial movement of the stylet assembly in a proximal direction independent of the operator mechanism.