The Dark Cool Helmet
Wearable Sensing
Background
The project sponsor, Wearable Sensing, is a company that primarily develops and produces electroencephalogram (EEG) as well as functional near-infrared spectroscopy (fNIRS) sensor headsets for commercial retailing to predominantly research entities. One of Wearable Sensing’s current products is a combined EEG and fNIRS headset marketed for its ability to be used as a mobile platform. Currently in industry this combination of sensor suites is not commonly used and is a relatively new development that provides a solution intermediate between a standard dry EEG headset and the more expensive and complex fMRI technology. As of today Wearable Sensing, has designed and marketed its hybrid EEG+fNIR headset system to several different clients worldwide.
Project Goals
Design a helmet accessory for the Wearable Sensing fNIR+EEG Hybrid Sensing Headset that:
1. Blocks light
2. Cools temperature
3. Eliminates sweat accumulation
4. Low noise
5. Lightweight
6. Aesthetically pleasing (for commercial production)
Final Design Features
Hard-shell Helmet (3D or SLS printed): Lightweight & durable
4 Fans: Quiet & Powerful
4 Specialized Vents: Block light & Speed airflow
Magnetic attachments: Secure attachment, yet quick and easy to detach
Drawstring Curtain: 360° light-blocking, suits all head sizes
Final CAD Model: Side View (top left pic), Front View (bottom left pic), Isometic View.
Keys to Success
1) Specialized Light-Blocking Vents:
Blocks 99.5% of Ambient Light (satisfactory).
Allows for great airflow.
Easy to 3D print and assemble.
Requires no print infill or support material.
Outer View of Vent
Cross-Section View showing Airflow
Exploded View
2) Powerful, yet Quiet Fans:
Low perceived sound (62dB)
High airflow (17.2 cfm)
Flyback protection against current spikes
Low Cost (~$15/unit)
Proof in the Results. . .
Humidity & Temperature sensors were implemented inside the helmets for testing the performance of the sponsor's old prototype vs. the new final prototype:
Old sponsor prototype did not affect temperature increase when the fans are turned on.
Final prototype shows major effect on temperature change as it starts dropping immediately when the fans are turned on.
Old sponsor prototype did not affect humidity inside the helmet at all.
Final prototype shows major effect on humidty. It immediately drops a lot, then as the sweat on head scalp evaporates, the humidity reading starts increasing again which is an indicator of success.
