TABLE OF CONTENTS

• Structure of the Skull
• Standard Headform Models
• Baseplate
• Skullcap
• Kirigami Design
• Future Design Considerations
  • Clayco Whitepapers Analysis
  • STUDSON Helmet
  • Koroyd Material
  • DYNEEMA Composite Fabric

STRUCTURE OF THE SKULL

The image provided above is an anatomical diagram of the human skull, highlighting the various bones and structures that make up the cranium.

The skull is composed of several bones that fuse together over time to form a protective casing for the brain. The key bones labeled in the image are:

1. Frontal bone: The bone that forms the forehead.
2. Parietal bone: The bones that form the upper, side portions of the skull.
3. Temporal bone: The bones that form the temples.
4. Sphenoid bone: A centrally located bone that connects to several other skull bones.
5. Ethmoid bone: A bone that forms part of the nasal cavity and connects to the frontal bone.
6. Lacrimal bone: Small bones located near the eyes.
7. Nasal bone: The bones that form the bridge of the nose.
8. Zygomatic bone: Also known as the cheekbone.
9. Maxilla: The upper jawbone.
10. Mandible: The lower jawbone.

What about the Occipital bone?

You’re right, the occipital bone is another important component of the skull structure that is labeled in the diagram. The occipital bone forms the back and lower portions of the skull.

Specifically, the occipital bone:

• Forms the back and lower portions of the cranium.
• Contains the foramen magnum, the large opening at the base of the skull through which the spinal cord passes.
• Articulates with the first cervical vertebra (atlas) to allow for nodding and rotation of the head.
• Provides attachment points for several muscles of the neck and back of the head.

The occipital bone is a critical part of the skull as it protects the brainstem and spinal cord, while also facilitating important head and neck movements. Its position at the base of the skull makes it vulnerable to injury in trauma cases, so understanding its anatomy is important for medical professionals dealing with head and neck injuries.

The occipital bone is a crucial part of the skull when considering helmet design, as it helps support and protect the neck region. Let me take another close look at the diagram and see if there are any other important skull structures that I may have missed.

Looking more closely, the one other notable structure I see that wasn’t explicitly mentioned is the Lambdoid suture. The Lambdoid suture is the junction between the occipital bone and the parietal bones at the back of the skull. This is another important anatomical landmark for medical professionals, as it can be a site of injury or fusion issues.

Beyond that, the diagram appears to cover the major bones that make up the human skull – the frontal, parietal, temporal, sphenoid, ethmoid, lacrimal, nasal, zygomatic, maxilla, mandible, and occipital bones. It also highlights key structures like the Pterion region and the Alveolar processes.

Please let me know if there are any other specific skull structures or regions you feel are important to consider for your helmet design project. I’m happy to provide any additional details or clarification on the cranial anatomy shown in this diagram.

The Pterion is a specific region of the skull where four bones come together – the frontal bone, parietal bone, temporal bone, and sphenoid bone. This area is considered a weak point in the skull structure, as it is the thinnest part of the cranium. The Pterion is an important landmark for neurosurgeons, as it is a common point of access for certain surgical procedures.

Understanding the anatomy of the skull and the significance of the Pterion region is crucial for medical professionals, particularly in the fields of neurosurgery, trauma care, and craniofacial surgery. This knowledge helps them navigate the complex structure of the skull and plan effective treatments for various conditions or injuries affecting the head and brain.

What are sutures and how do they help connect the different skull bones?

Great question! The sutures are the thin, fibrous joints that connect the various bones of the skull together. They play an important role in the structure and function of the human skull.

The main sutures labeled in the diagram are:

1. Coronal suture – This runs between the frontal bone and the parietal bones.
2. Lambdoid suture – This connects the occipital bone to the parietal bones at the back of the skull.
3. Sagittal suture – This runs between the two parietal bones at the top of the skull.
4. Squamous suture – This connects the temporal bone to the parietal bone.

These sutures allow the skull bones to shift and move during childbirth, enabling the skull to pass through the birth canal. They also permit continued growth of the skull as the brain expands during childhood development.

The sutures are made of fibrous connective tissue that hardens and ossifies over time, eventually fusing the bones together. This gives the adult skull its characteristic rigid structure while still maintaining some flexibility.

The presence and configuration of the sutures is important for medical professionals, as they can be used to assess developmental abnormalities or identify fracture patterns in cases of skull trauma. Understanding the sutures is a key part of comprehensive cranial anatomy knowledge.

STANDARD HEADFORM MODELS

References:

• https://www.cdc.gov/niosh/npptl/topics/respirators/headforms/default.html
• https://www.cdc.gov/niosh/data/datasets/rd-10130-2020-0/default.html

We will use anthropometric data gathered during the 2003 NIOSH survey, parameters for new head-forms in five size categories were developed by the National Personal Protective Technology Laboratory (NPPTL) of NIOSH.

Shown below are three-dimensional (3D) scans of five individuals, who most closely represented a given size category were averaged together.

The resulting models include facial features not found on current standard head-forms. Five distinct sizes (small, medium, large, long/narrow, and short/wide) of digital 3D head-forms have been created to account for the overall size and shape of the face. The NIOSH head-forms are symmetric and represent the facial size and shape distribution of current U.S. respirator users.

The five NIOSH headforms commonly used for respiratory testing are Small, Medium, Large, Short Wide, and Long Narrow. These categories were developed based on extensive anthropometric studies to represent a broad range of human facial dimensions and shapes. Let’s clarify them in detail:

1. Small Headform

• Purpose: Represents individuals in the lower percentile for head size.
• Key Characteristics: Smaller cranial and facial dimensions, including reduced width and shorter facial length.
• Applications: Testing the performance of respirators for individuals with small head and facial features.

2. Medium Headform

• Purpose: Represents the median (50th percentile) head size and is the most common standard for testing.
• Key Characteristics: Balanced dimensions, providing a typical or average facial structure.
• Applications: Used as a baseline for performance testing of respiratory protective devices.

3. Large Headform

• Purpose: Represents individuals with larger cranial and facial dimensions.
• Key Characteristics: Broader and longer facial structure compared to the medium headform.
• Applications: Ensures that respirators effectively fit users with above-average head sizes.

4. Short Wide Headform

• Purpose: Accounts for individuals with shorter faces but wider head dimensions.
• Key Characteristics: Reduced facial length combined with increased width, reflecting a broad but compact structure.
• Applications: Critical for ensuring fit and seal in populations with this unique morphology, such as certain ethnic groups.

5. Long Narrow Headform

• Purpose: Represents individuals with elongated faces and narrower head dimensions.
• Key Characteristics: Increased facial length and reduced width, reflecting a slimmer cranial and facial structure.
• Applications: Addresses the needs of individuals with this facial shape to ensure the efficacy of respiratory devices.

Importance of These Headforms

NIOSH uses these headforms to:

1. Test Fit and Seal: Ensuring that respirators and other protective devices fit securely across a wide range of facial shapes.
2. Promote Inclusivity: Represent diverse populations, including variations due to ethnicity, gender, and other factors.
3. Standardize Testing: Provide a consistent framework for evaluating the safety and functionality of respiratory protective equipment.

Applications Beyond Respirators

For smart PPE, like our additively manufactured helmets, integrating these headform types can help:

• Refine Design: Account for varying head and face shapes in product development.
• Optimize Fit: Ensure that sensors or smart components are positioned correctly for all users.
• Enhance Comfort: Improve wearability across diverse user groups.

BASEPLATE

Shown above is the baseplate that can morph into any head form procured by scanning. The 42 control points indicated by the black dots define the extents of the shape of the head and its articulation for the folding movement:

• transverse – top-down along the z-axis,
• saggitarial – left-right along the y-axis,
• coronal – rotation along the y-axis about an offset pivot point,
• rotational – rotation along the vertical z-axis.

These will be the four variants of the design of the folding pattern for the helmet.

SKULLCAP

Represented below is how the control points project to the extremities of the headform (head/skull cap) and morphs to fit the different standardized shapes:

PARAMETERIC FIT TEST TO THE DIFFERENT HEADFORMS

1. Armadillo: Front baseplate curve used for sliver->slat->slice. Pivot point will not be the origin of the baseplate. p (distance from Pivot to front end) will be less than q (distance from Pivot to rear end). q-p will be the total thickness of all the slats.
2. Athena: Both front and rear curves of the baseplate will be used. In this case to Pivot will not be the origin of the baseplate and it will be more towards the front. If q-p can be the total thickness of the slats, Pivot point can be decided by this.
3. Hercules: Since it is symmetrical, either the left or right side can be used to design the sliver.

NITIN UCHIL Founder, CEO & Technical Evangelist
nitin.uchil@numorpho.com