Development of a head-phantom and measurement setup for lightning effects.

Area of Science:

• Biophysics
• Electrical Engineering
• Medical Physics

Background:

• Direct lightning strikes pose severe risks to the human head, including Lichtenberg figures, unconsciousness, and death.
• Understanding current distribution within the head is crucial for elucidating lightning strike injury mechanisms.

Purpose of the Study:

• To develop and validate a simplified head-phantom model for investigating the effects of direct lightning strikes.
• To analyze current distribution and flow dynamics within different head layers during simulated lightning impulses.

Main Methods:

• A multi-layered head-phantom (brain, skull, scalp) was constructed using conductive agarose hydrogels.
• The phantom was subjected to simulated lightning impulses using two different impulse generators.
• Current distribution and effective current were measured across the phantom's layers.

Main Results:

• Without external flashover, approximately 70% of the current flowed through the brain layer, 23% through the skull, and 6% through the scalp.
• A complete flashover on the phantom drastically reduced the current within the head to near zero.
• Higher impulse current levels accelerated flashover formation and decreased current exposure time.

Conclusions:

• The head-phantom model effectively simulates current distribution during lightning strikes.
• Flashover mechanisms play a critical role in mitigating current flow through the head, offering a potential explanation for lightning strike survivability.
• These findings contribute to a better understanding of the biophysical effects of lightning on the human head.