Biopsy Device Selective Coupling Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing biopsy devices face challenges such as increased risk of needle-stick injuries due to inadvertent activation, difficulty in aspirated tissue collection, and complications when used with endoscopes, including potential damage to the working channel during insertion.
Innovation Solution
A biopsy device with a selective coupling mechanism that allows the cannula and stylet to be decoupled from the actuator assembly, enabling free movement and independent repositioning, facilitating aspiration and reducing the risk of needle-stick injuries by allowing the stylet to be moved without activating the actuator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the stylet and cannula are permanently coupled to the actuator assembly, then the device structure is simpler, but the risk of needle-stick injury increases due to inadvertent activation and the ability to perform aspiration is lost
Solution Approach 1:
The coupling mechanism transitions from a static permanent connection to a dynamic selective connection. The stylet and cannula can be coupled to the actuator assembly during biopsy operations for controlled advancement, and decoupled during aspiration or repositioning maneuvers, allowing the system to adapt its degree of coupling based on operational requirements
Solution Approach 2:
The coupling mechanism is divided into separate coupling elements for the stylet and cannula, each with independent coupling and decoupling capabilities. This segmentation allows selective separation of components from the actuator assembly, enabling aspiration through the cannula lumen when the stylet is removed and the cannula is decoupled
2Ease of operation
If the stylet is advanced to expose the tissue collection tray for sample recovery, then the tissue sample can be recovered, but the actuator remains in a primed state creating safety risks
Solution Approach 1:
The stylet is extracted from the actuator assembly coupling during the sample recovery phase. By decoupling the stylet from the actuator, the system allows the stylet to be advanced independently to expose the tissue collection tray while eliminating the risk of inadvertent actuator activation that would occur if the stylet remained coupled
3Adaptability or versatility
If the stylet fills the cannula lumen to enable core tissue collection, then core biopsy is effective, but aspiration through the cannula lumen becomes impossible
Solution Approach 1:
The system dynamically reconfigures its component arrangement based on the desired collection mode. For core biopsy, the stylet is inserted into the cannula lumen to enable tissue core collection. For aspiration, the stylet is removed and the cannula is decoupled from the actuator, opening the lumen for suction. This dynamic reconfiguration allows a single device to perform multiple collection functions
Solution Approach 2:
The biopsy device is designed to perform multiple functions through selective configuration. The same cannula and stylet components can be arranged to enable either core tissue collection via the stylet tray or aspirated collection via the cannula lumen, making the device universal for different tissue sampling needs without requiring separate dedicated devices
4Object-affected harmful factors
If the stylet and cannula are retracted into the protective sheath during insertion, then damage to the endoscope working channel is prevented, but the risk of stylet piercing the sheath increases during maneuvering
Solution Approach 1:
The decoupling mechanism acts as an intermediary control system that allows independent manipulation of the stylet and cannula relative to the protective sheath. By decoupling the components from the actuator assembly, operators can carefully maneuver and reposition the stylet and cannula during insertion and withdrawal, reducing the risk of accidental piercing while maintaining protection of the working channel
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 enhances user safety and operational ease by allowing controlled movement of the stylet and cannula independently, enabling effective tissue sampling and reducing the risk of damage to endoscope working channels during insertion.
Implementation Method 1
The actuator assembly comprises a biasing member arranged to move the cannula relative to the stylet between a retracted position and an extended position
Data Source
Figure 1a~1d
Figure 2a~3b
Figure 4a~5b
AI summary
A biopsy device (100, 200) comprising: a cannula (102; 202) comprising an elongate cannula body (106) extending between a cannula distal end (108) and a cannula proximal end (110) to define a lumen, wherein the cannula (102; 202) comprises a cutting portion (112) at the cannula distal end (108); a stylet (104) comprising an elongate body (114) having a stylet distal end (116) and a stylet proximal end (118), the stylet (104) being slidably disposed within the lumen, wherein the stylet (104) comprises a tissue sampling portion (120). The tissue sampling portion (120) is formed by a notch in the body of the stylet (104) at or near the stylet distal end. The biopsy device (100; 200) further comprises an actuator assembly (126; 226), the actuator assembly arranged to move the cannula (102; 202) relative to the stylet (104; 204) between a retracted position in which at least part of the tissue sampling portion (120) is exposed and an extended position in which the cannula (102; 202) at least partly surrounds the tissue sampling portion (120). The actuator assembly (126; 226) comprises a cannula actuator (128; 228) moveable between a primed configuration and an actuated configuration to move the cannula (102; 202) between the retracted position and the extended position. The biopsy device (100; 200) further comprises a selective coupling mechanism (130; 230) arranged to provide a selective coupling between the actuator assembly and one or both of the stylet and the cannula.