Effects of pulse parameters on the temperature distribution of a human head exposed to the electromagnetic pulse

Shan Wang,Guozhen Guo,Yanning Yuan,Jianjun Kang,Zhongguo Song

doi:10.1038/s41598-021-02396-8

Abstract

The presence of blood–brain barrier (BBB) is a major obstacle to effectively deliver therapeutics to the central nervous system (CNS); hence, the outcomes following treatment of CNS diseases remain unsatisfactory. Fortunately, electromagnetic pulses (EMPs) provide a non-invasive method to locally open the BBB. To obtain the optimal pulse parameters of EMP-induced BBB opening to ensure the effective delivery of CNS drugs, it is particularly important to measure and assess the effects of pulse parameters on the temperature distribution in the human head exposed to EMPs. In this paper, the specific anthropomorphic mannequin phantom was adopted and the temperature increase in the human head induced by EMPs of different parameters was estimated in the software “COMSOL Multiphysics”. The results show that the temperature distribution profiles with different EMP parameters have almost similar characteristics, the highest temperature increase values in the human head are positively correlated with variations of EMP parameters, and potential hazards to the human head may occur when EMP parameters exceed the safety threshold, which will provide theoretical basis for seeking the optimal EMP parameters to open the BBB to the greatest extent within a safe range.

Highlights

The presence of blood–brain barrier (BBB) is a major obstacle to effectively deliver therapeutics to the central nervous system (CNS); the outcomes following treatment of CNS diseases remain unsatisfactory
This article breaks through the limitations of existing experimental research, investigates the temperature increase in the human head exposed to electromagnetic pulses (EMPs) of different parameters due to the probable negative effects of electromagnetic radiation (EMR) on the human health, and obtains the safety threshold of EMPs on the human head, which would provide theoretical basis for seeking the optimal EMP parameters to make the BBB disruption to the greatest extent within a safe range
The temperature distribution and the specific absorption rate (SAR) distribution of the head exposed to an EMP of 250 MHz are shown in Fig. 3 according to the parameters used by other sub-group experiments (E = 720 kV/m, n = 800, τ = 40 ns, f = 10 Hz), which are used as the benchmark parameters in this study

Summary

Introduction

The presence of blood–brain barrier (BBB) is a major obstacle to effectively deliver therapeutics to the central nervous system (CNS); the outcomes following treatment of CNS diseases remain unsatisfactory. The results show that the temperature distribution profiles with different EMP parameters have almost similar characteristics, the highest temperature increase values in the human head are positively correlated with variations of EMP parameters, and potential hazards to the human head may occur when EMP parameters exceed the safety threshold, which will provide theoretical basis for seeking the optimal EMP parameters to open the BBB to the greatest extent within a safe range. This article breaks through the limitations of existing experimental research (animals only), investigates the temperature increase in the human head exposed to EMPs of different parameters due to the probable negative effects of EMR on the human health, and obtains the safety threshold of EMPs on the human head, which would provide theoretical basis for seeking the optimal EMP parameters to make the BBB disruption to the greatest extent within a safe range

Methods

Results

Conclusion