Effects of a brain tumor in a human head on SAR and temperature rise due to RF sources at 4G and 5G frequencies

Abstract

Effects of a brain tumor in a human head on SAR and temperature rise due to RF sources at 4G and 5G frequencies Kaburcuk F. Effects of a brain tumor in a dispersive human head on SAR and temperature rise distributions due to RF sources at 4G and 5G frequencies. Electromagn Biol Med. 2019 Mar 20:1-9. doi: 10.1080/15368378.2019.1591441. Abstract In this paper, effects of a brain tumor located in a dispersive human head model on specific absorption rate (SAR) and temperature rise distributions due to different types of RF sources at 4G and 5G cellular frequencies are investigated with the use of a multiphysics model. This multiphysics model analyzes the dispersive human head with the brain tumor and provides the SAR and temperature rise distributions in the head due to the RF source operated at 4G and 5G cellular frequencies in a single finite-difference time-domain simulation. An adjacent antenna operated at 4G and 5G cellular frequencies to the human head is considered as the RF source for near-field exposure, while a plane wave field radiated by base stations operated at 4G and 5G cellular frequencies is considered as the RF source for far-field exposure. Numerical results show that the brain tumor in the head slightly affects the SAR and temperature rise distributions due to different RF sources at 4G and 5G cellular frequencies. ncbi.nlm.nih.gov Conclusion The effects of the brain tumor in the dispersive human head on the SAR1g and temperature rise distributions due to the near-field and far-field exposures are investigated at 4G and 5G cellular frequencies with the aid of multiphysics model. In the multiphysics model, these distributions in the head are calculated at 2.1 and 3.6 GHz in a single simulation. Numerical results show that the SAR1g and temperature rise distributions are slightly affected by the presence of the brain tumor in the head. The calculated SAR1g values and temperature rise in the area of the brain tumor are higher than those calculated in the same area of the healthy head because the EM and thermal parameters of the brain tumor are different from those of the healthy tissues in the same area of the head. Moreover, it has been realized that the distributions are affected by the frequencies and type of the RF sources.

AI evidence extraction

Main findings

Using a multiphysics finite-difference time-domain simulation of a dispersive human head model with a brain tumor, numerical results indicated the tumor slightly affects SAR1g and temperature rise distributions for both near-field (adjacent antenna) and far-field (base-station plane wave) RF exposures at 4G/5G cellular frequencies. SAR1g and temperature rise in the tumor region were higher than in the corresponding region of a healthy head model, attributed to different electromagnetic and thermal parameters of tumor tissue.

Outcomes measured

• SAR (SAR1g) distribution
• Temperature rise distribution

Limitations

• Numerical/simulation study using a human head model (not measurements in people)
• Specific model assumptions for tissue electromagnetic and thermal parameters are not detailed in the abstract
• Results limited to the modeled frequencies (2.1 and 3.6 GHz) and the specific near-field/far-field source configurations

Suggested hubs

• 5g-policy (0.55)
  Models RF exposure at 5G-relevant frequency (3.6 GHz) and compares with 4G (2.1 GHz).

{
    "study_type": "engineering",
    "exposure": {
        "band": "RF",
        "source": "adjacent antenna (near-field) and base-station plane wave (far-field)",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": null,
    "sample_size": null,
    "outcomes": [
        "SAR (SAR1g) distribution",
        "Temperature rise distribution"
    ],
    "main_findings": "Using a multiphysics finite-difference time-domain simulation of a dispersive human head model with a brain tumor, numerical results indicated the tumor slightly affects SAR1g and temperature rise distributions for both near-field (adjacent antenna) and far-field (base-station plane wave) RF exposures at 4G/5G cellular frequencies. SAR1g and temperature rise in the tumor region were higher than in the corresponding region of a healthy head model, attributed to different electromagnetic and thermal parameters of tumor tissue.",
    "effect_direction": "mixed",
    "limitations": [
        "Numerical/simulation study using a human head model (not measurements in people)",
        "Specific model assumptions for tissue electromagnetic and thermal parameters are not detailed in the abstract",
        "Results limited to the modeled frequencies (2.1 and 3.6 GHz) and the specific near-field/far-field source configurations"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "brain tumor",
        "dispersive human head model",
        "multiphysics model",
        "finite-difference time-domain",
        "FDTD",
        "SAR1g",
        "temperature rise",
        "near-field exposure",
        "far-field exposure",
        "base station",
        "4G",
        "5G",
        "2.1 GHz",
        "3.6 GHz"
    ],
    "suggested_hubs": [
        {
            "slug": "5g-policy",
            "weight": 0.5500000000000000444089209850062616169452667236328125,
            "reason": "Models RF exposure at 5G-relevant frequency (3.6 GHz) and compares with 4G (2.1 GHz)."
        }
    ]
}

Comments

Log in to comment.

No comments yet.