Safety Cannula Assembly With Film-Hinged Body and Auto Retraction
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Solution Overview
Problem
Existing safety cannula arrangements face issues with contamination risk due to open base bodies and lack of automatic actuating elements, complicating assembly and increasing manufacturing effort.
Innovation Solution
A safety cannula design with a base body composed of three parts connected via film hinges, featuring a supported actuating element and a secure locking mechanism, simplifying assembly and ensuring automatic retraction of the cannula upon use completion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the base body is composed of multiple parts connected via film hinges, then assembly is simplified and manufacturing complexity is reduced, but the structural stability and precision of the base body may be compromised
Solution Approach 1:
The base body is divided into multiple parts (first base body part, second base body part, third base body part) that can be assembled separately and connected via film hinges. This segmentation allows for simplified manufacturing and assembly processes, as each part can be produced independently and then joined together to form the complete base body structure.
Solution Approach 2:
Film hinges are used to connect the base body parts, providing a flexible yet stable connection mechanism. The thin film material allows for easy assembly and disassembly while maintaining sufficient structural integrity during use, resolving the contradiction between assembly simplicity and structural stability.
2Reliability
If an actuating element is added to enable automatic retraction, then safety is improved by preventing needlestick injuries, but the device complexity increases
Solution Approach 1:
The actuating element is designed to automatically retract the cannula into the base body after use without requiring manual intervention. This self-service mechanism improves safety by ensuring the cannula is always retracted when not in use, preventing needlestick injuries while minimizing the need for additional complex control systems.
Solution Approach 2:
The actuating element serves as an intermediary mechanism between the user's action (pressing the release mechanism) and the cannula retraction. It translates the user's simple input into the automatic retraction motion, improving safety while keeping the interface simple and intuitive.
3Ease of operation
If the cannula is kept accessible for easy operation, then ease of use is improved, but contamination risk increases
Solution Approach 1:
The cannula is designed to be dynamically positioned - extended and accessible during use for easy operation, and automatically retracted into the base body when not in use to prevent contamination. This dynamic positioning resolves the contradiction between accessibility and contamination risk by adapting the cannula's position to the operational state.
Solution Approach 2:
The automatic retraction mechanism performs preliminary anti-action by retracting the cannula into the base body immediately after use, preventing contamination before it can occur. This proactive measure ensures the cannula is protected from contamination while maintaining ease of operation during the actual use period.
Data Source
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AI summary
The invention relates to a safety cannula assembly (1) comprising: a) a cannula (17) for puncturing human or animal tissue, a distal end portion of said cannula having a tip (18); b) a sliding body (15), the distal end portion (49) of which is provided with the cannula (17) and the proximal end portion (46) of which is provided with a flexible tube (5), wherein there is a fluidic connection extending through the sliding body (15) between the tip (18) of the cannula (17) and a proximal end of the tube (5); c) a main body (2) in which the sliding body (15) can be displaced from a use position, in which the tip (18) of the cannula (17) is located outside the main body (2), to a safety position, in which the tip (18) of the cannula (17) is located inside the main body (2), wherein the main body (2) is composed of at least three main body parts (10, 11, 12), of which - a first main body part (10) is in the form of a sleeve and encloses a distal end portion (49) of the sliding body (15) when said sliding body is in its use position, - a second main body part (11) adjoins the first main body part (10) in the proximal direction and is connected [note: may be in an articulated or rigid manner] thereto, the second main body part (11) being U-shaped, L-shaped, C-shaped or lid-shaped in a cross-section, and - a third main body part (12) and the second main body part (11) can be joined together to form a hollow body that is open at both opposite end faces, the third main body part (12) being lid-shaped, C-shaped, L-shaped or U-shaped and being connected to the second main body part (11) or the first main body part (10) via a film hinge (13, 14); d) an adjusting element (21) which is located between the main body (2) and the sliding body (15) and by means of which the sliding body (15) can be displaced from the use position to the safety position; and e) a trigger mechanism (37) which is located on the main body (2) and by means of which it is possible to trigger the displacement of the sliding body (15) from the use position to the safety position, wherein the trigger mechanism (37) has at least one trigger member (67a, 67b) to which a radially directed compressive force or a torque can be applied by a person using the safety cannula assembly (1) and which is provided with a locking element (61a, 61b) which, as a result of being subjected to the compressive force or the torque, can be displaced from a locking position, in which said locking element engages with the sliding body (15) and locks said sliding body in the use position, to a trigger position, in which said locking element is disengaged from the sliding body (15) so that said sliding body moves into the safety position. In order to create a main body (2) that is easy to manufacture and a safety cannula assembly (1) that is easy to assemble, according to the invention the distal end of the adjusting element (21) is supported on a support surface (21s) of the first main body part (10).