The Numerical Assessment of RF Human Exposure to Microwave Ovens with Contact-Type Doors

Abstract

Overview

This study evaluates the potential electromagnetic exposure risks to pacemaker wearers from microwave ovens with contact-type doors, using advanced simulation through COMSOL Multiphysics.

Methodology

Researchers used a detailed thoracic cavity model including a heart and unipolar pacemaker, and a model of a microwave oven to simulate exposure scenarios. Various factors like distance from the oven and oven door gap were adjusted to understand their effect on exposure.

Findings

• Thoracic and Heart Tissue: Both the specific absorption rate (SAR10g) and temperature increase showed an inverse relationship with the distance from the microwave source and a direct relationship with the oven door gap size.
• Pacemaker Exposure: Indicators like electric field intensity, temperature increase, and induced voltage at the pacemaker electrode were analyzed, showing that although most parameters were within safe limits, the induced voltage exceeded certain pacemaker sensitivity settings, thereby highlighting a potential interference risk.

Conclusion

The exposure due to microwave ovens generally remains within safe limits under typical conditions. However, specific conditions where induced voltage exceeds safety thresholds merit attention, especially concerning pacemaker functionality. Recommendations include maintaining a safe distance from operating microwave ovens and considering the adoption of bipolar pacemakers to mitigate risks.