Multi-Bevel Needle Tip Geometry for Lower Penetration Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hypodermic needles have tip geometries that vary in penetration force and pain perception, leading to user preferences and discomfort during injections, as different angles and configurations affect the injection experience.
Innovation Solution
A multi-beveled needle tip geometry with distinct angles of inclination and rotation, featuring a proximal bevel, intermediate bevels, and distal bevels, along with radiused transitions to smooth the edges and surfaces, reducing sharp edges and enhancing user comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional single-bevel or simple tip geometry is used, then the needle structure is simple and easy to manufacture, but the penetration force is higher and pain perception is increased
Solution Approach 1:
The needle tip is segmented into multiple bevel surfaces (first bevel, second bevel, third bevel) with different inclination angles, where each bevel performs a specific function in the penetration process. The first bevel (45-60 degrees) provides initial skin contact, the second bevel (30-45 degrees) facilitates gradual penetration, and the third bevel (15-30 degrees) enables smooth tissue passage, collectively reducing overall penetration force while maintaining structural feasibility
Solution Approach 2:
Different regions of the needle tip are given different geometric properties through multi-bevel design. The proximal region has a more aggressive angle for initial penetration, while distal regions have shallower angles for smoother passage. This local differentiation of geometric qualities allows the single needle structure to perform multiple penetration functions with reduced force requirements
2Ease of manufacture
If a conventional single-bevel or simple tip geometry is used, then the manufacturing process is simple, but the pain perception during injection is increased
Solution Approach 1:
The injection process is segmented into multiple stages corresponding to the three bevels, where each bevel handles a specific phase of skin and tissue penetration. This segmentation allows the needle to progressively engage tissues rather than forcing through all layers simultaneously, reducing pain perception while maintaining a manufacturable geometry through sequential grinding or forming operations
Solution Approach 2:
The multi-bevel design creates a more rounded, progressive tip profile compared to sharp angular single-bevel designs. The curvature distributed across multiple bevel surfaces allows smoother tissue displacement and reduced mechanical irritation, decreasing pain perception while remaining compatible with standard manufacturing processes
3Ease of operation
If different tip geometries are used to reduce penetration force and pain, then the injection experience is improved, but the device complexity increases
Solution Approach 1:
The complexity is localized to only the tip region of the needle, where the three-bevel geometry provides improved penetration characteristics. The rest of the needle maintains a simple cylindrical structure, minimizing overall device complexity while concentrating the functional improvements where they are most needed for injection performance
Data Source
AI summary
A multi-beveled needle point geometry for hypodermic needles such as pen needles. A proximal bevel is formed at a first angle of inclination, a pair of intermediate bevels at a second angle of inclination, and a pair of distal bevels at a third angle of inclination and differing angles of rotation. The second angle of inclination is substantially different than the first angle of inclination to define a marked apex at the intersections between the proximal bevel and the intermediate bevels. At least one smooth transition is typically provided between adjacent bevels, between a bevel and an outer surface of the needle, and/or between a bevel and the lumen of the needle.