Helmet Subliner Segmentation for Angular Acceleration
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Solution Overview
Problem
Current helmets inadequately address the reduction of head angular acceleration during impacts, which is linked to the development of chronic traumatic encephalopathy (CTE) in athletes, particularly due to repetitive concussive and sub-concussive head impacts.
Innovation Solution
A helmet subliner system comprising three types of subliner elements made of energy-absorbing viscoelastic foam materials, strategically positioned around the head to distribute impact forces and reduce angular acceleration, including a first type aligned with the headband area, a second type in the middle area, and a third type with a flat surface tangent to the head, all attached to the inner shell using a hook and loop fastener mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional single-type subliner is used, then manufacturing simplicity is maintained, but head angular acceleration reduction effectiveness is insufficient
Solution Approach 1:
The subliner is divided into three distinct types of elements (first, second, and third types) with different material properties and compression characteristics, strategically positioned in different head regions to address varying impact forces and reduce angular acceleration effectively
Solution Approach 2:
Each subliner element type is assigned specific material properties and compression stress characteristics appropriate for its designated head region, with the first type having higher compression resistance for lateral impacts, the second type for moderate regions, and the third type with flat surface for crown protection
2Reliability
If uniform foam material is used throughout the subliner, then manufacturing simplicity is maintained, but impact force distribution across different head regions is inadequate
Solution Approach 1:
The subliner is segmented into three element types with distinct material properties, allowing each segment to be optimized for the specific impact forces and anatomical features of its designated head region
Solution Approach 2:
Different foam materials with specific compression stress characteristics are assigned to different head regions: first type elements (≥50 psi) for high-impact lateral regions, second type elements (<10 psi) for moderate regions, and third type elements (≥50 psi) for crown protection, matching material properties to local impact requirements
3Reliability
If subliner elements are positioned without strategic alignment, then installation simplicity is maintained, but angular acceleration reduction during lateral impacts is insufficient
Solution Approach 1:
Subliner elements are strategically positioned and oriented according to the specific anatomical features and impact vulnerability of each head region, with first type elements aligned with headband area for lateral impact protection, second type elements in middle areas, and third type elements with flat surfaces tangent to the crown
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 subliner system effectively reduces head angular acceleration during impacts, thereby mitigating the risk of CTE by distributing and absorbing forces more efficiently across the head, enhancing protection and comfort.
Implementation Method 1
The first type of subliner elements are constructed of an energy absorbing viscoelastic foam material capable of exhibiting a compressive stress of at least 50 psi for a dynamic compression of 50%
Implementation Method 2
The subliner system effectively reduces head angular acceleration during impacts, thereby mitigating the risk of CTE by distributing and absorbing forces more efficiently across the head
Implementation Method 3
capable of exhibiting a compressive stress of at least 50 psi for a dynamic compression of 50%
Data Source
AI summary
A helmet to be worn on a head having an annular headband shaped area. The headband shaped area positioned near an upper junction of the ears and the wearer's head. A top area is centered about a top of the wearer's head. A middle area defined between the headband area and the top area. The helmet includes a shell having an inner surface. A first type of subliner elements extend from the inner surface at a location such that the first type of subliner elements are aligned with the headband area. A second type of subliner elements extend from the inner surface at a location such that the second type of subliner elements are aligned with the middle area. A third type of subliner element extends from the inner surface at a location such that the third type of subliner element is aligned with the top area.