Biopsy Needle Sheath Sequencing to Limit Contamination and Tip Damage
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Solution Overview
Problem
Existing biopsy needles face issues with tissue collection and risk of infection due to bacterial transfer during insertion, exacerbated by antibiotic resistance.
Innovation Solution
A biopsy needle arrangement with a three-step pushing sequence, utilizing actuators to precisely control the movement of the needle and sheath, minimizing collisions and bacterial transfer, and incorporating dynamic force mechanisms to maintain safety and precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a needle arrangement is used to take biopsy samples, then tissue sampling capability is improved, but the risk of bacterial contamination and infection increases
Solution Approach 1:
The needle arrangement is divided into separate functional components: a needle for tissue penetration, a sheath for containing the needle and controlling the sampling process, and a cutting mechanism. This segmentation allows each component to perform its specific function while minimizing bacterial exposure - the sheath acts as a barrier that prevents bacteria from contaminating the needle during insertion, and the cutting mechanism isolates the sampling action from the insertion path.
Solution Approach 2:
The harmful function of bacterial contamination is extracted and isolated from the main biopsy sampling function. The sheath is designed to contain any bacteria encountered during needle insertion, separating the contamination risk from the tissue sampling process. The cutting mechanism further extracts the sampling action from the insertion path, ensuring that bacteria collected during insertion do not contaminate the sampled tissue.
2Productivity
If the needle is pushed forward into tissue, then biopsy sampling efficiency is improved, but the risk of needle tip damage increases
Solution Approach 1:
The sheath is pre-loaded and positioned around the needle before the biopsy procedure begins. This preliminary arrangement ensures that when the needle is pushed forward into tissue, the sheath is already in place to support and protect the needle tip. The pre-positioned sheath prevents accidental needle tip damage during the high-speed insertion phase, maintaining both efficiency and reliability.
Solution Approach 2:
The sheath acts as a cushioning element that is already in place before needle insertion. During the pushing forward action, the sheath provides mechanical support and protection to the needle tip, absorbing potential impacts or resistances that could damage the needle. This beforehand cushioning allows for efficient needle advancement while preserving needle tip integrity.
3Speed
If the sheath is pushed forward to cut tissue, then biopsy sampling speed is improved, but the risk of collision with needle tip increases
Solution Approach 1:
A controlled interaction mechanism serves as an intermediary between the sheath and needle tip during the tissue cutting phase. This mechanism ensures that when the sheath is pushed forward to cut tissue, it does so in a controlled manner that prevents accidental collision with the needle tip. The intermediary control allows for high-speed tissue cutting while maintaining safety through precise coordination of the sheath's movement relative to the needle.
Solution Approach 2:
The collision risk is reduced by replacing purely mechanical pushing with a more controlled actuation system. The actuator device provides precise control over the sheath's forward movement, substituting uncontrolled mechanical force with regulated actuation. This allows the sheath to cut tissue at high speed while the control system prevents excessive force that could cause collision with the needle tip.
4Device complexity
If a two-step pushing sequence is used, then device complexity is reduced, but the precision of needle-sheath coordination deteriorates
Solution Approach 1:
The actuator device employs dynamic control where the pushing speed and force are adjusted in real-time during the three-step sequence. Rather than using fixed mechanical stops or pre-set positions, the system dynamically modulates the actuation parameters to achieve precise needle-sheath coordination. This dynamic approach maintains relatively simple device architecture while achieving high coordination precision through active control during operation.
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 solution effectively minimizes the risk of needle damage and bacterial collection, ensuring safe and precise biopsy procedures while reducing the risk of infection.
Implementation Method 1
The actuator device comprises a spring element configured to push the needle arrangement distally
Implementation Method 2
wherein the actuator device comprises a biasing element configured to apply a closing force
Data Source
AI summary
An actuator device comprises first, second and third actuators operatively connected to a biopsy needle arrangement comprising a needle inside a sheath. The needle arrangement has a closed state and an open state, a tip portion abutting a needle sheath in the closed state, and the tip portion extending from the distal end of the needle sheath in the open state. The first actuator pushes the needle distally in a sliding direction x relative to the needle sheath a first distance, d1, at which the needle arrangement is in its open state. The second actuator pushes the needle sheath distally in the sliding direction x relative to the needle a second distance, d2. The third actuator pushes the needle sheath distally in the sliding direction x relative to the needle a third distance, d3, where d3 is smaller than d2, at which the needle arrangement is in its closed state.