Revisiting 35 and 94 GHZ Millimeter Wave Exposure to the Non-Human Primate Eye

Area of Science:

• Biophysics
• Ophthalmology
• Electromagnetic field effects

Background:

• Previous studies on millimeter wave (MMW) corneal effects in non-human primates showed significant temperature variations and dosimetry uncertainties.
• Accurate thermal dosimetry is crucial for establishing safety guidelines for MMW exposure.

Purpose of the Study:

• To re-evaluate the thermal effects of MMW exposure on primate corneas using improved models and dosimetry.
• To determine revised safety margins and minimal visible lesion thresholds for MMW eye exposures.

Main Methods:

• Conducted non-human primate corneal exposures at 35 and 94 GHz.
• Employed an improved three-layer, one-dimensional thermodynamic model for predicting surface temperature rise.
• Validated model predictions against experimental data.

Main Results:

• Experimental data showed good agreement with the thermodynamic model.
• Original safety margins for eye exposures were underestimated by 41 ± 20%.
• Revised minimal visible lesion thresholds are 10.6 ± 1.5 J/cm² at 35 GHz and 7.1 ± 1.0 J/cm² at 94 GHz for non-blinking subjects.

Conclusions:

• Improved MMW dosimetry and thermodynamic modeling provide more accurate predictions of corneal temperature rise.
• Revised safety thresholds are necessary for MMW exposures to prevent ocular damage.
• The blink reflex significantly influences safe power density limits for MMW exposure.