Head exposure system for a human provocation study to assess the possible influence of UMTS-like electromagnetic fields on cerebral blood circulation using near-infrared imaging.

Bioelectromagnetics · 2012 · Unclear · Insufficient evidence

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UnclearInsufficient evidencePaper 4446

Study snapshot

PublicationBioelectromagnetics · 2012

Study typeengineering

Reported directionUnclear

Evidence ratingInsufficient

Abstract

A head exposure setup for efficient and precisely defined exposure of human subjects equipped with a near-infrared imaging (NIRI) sensor is presented. In a partially shielded anechoic chamber the subjects were exposed to Universal Mobile Telecommunications System (UMTS)-like electromagnetic fields (EMF) by using a patch antenna at a distance of 4 cm from the head. The non-contact design of the exposure setup enabled NIRI sensors to easily attach to the head. Moreover, different regions of the head were chosen for localised exposure and simultaneous NIRI investigation. The control software enabled the simple adaptation of the test parameters during exploratory testing as well as the performance of controlled, randomised, crossover and double-blind provocation studies. Four different signals with a carrier frequency of 1900 MHz were chosen for the exposure: a simple continuous wave signal and three different UMTS signals. Furthermore, three exposure doses were available: sham, low (spatial peak specific absorption rate (SAR) = 0.18 W/kg averaged over 10 g) and high (spatial peak SAR = 1.8 W/kg averaged over 10 g). The SAR assessment was performed by measurement and simulation. Direct comparison of measurement and numerical results showed good agreement in terms of spatial peak SAR and SAR distribution. The variability analysis of the spatial peak SAR over 10 g was assessed by numerical simulations. Maximal deviations of -22% and +32% from the nominal situation were observed. Compared to other exposure setups, the present setup allows for low exposure uncertainty, combined with high SAR efficiency, easy access for the NIRI sensor and minimal impairment of test subjects.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeengineering

Effect directionunclear

Populationhuman subjects

Sample sizeNot supplied

ExposureRF · 1900 MHz · 1.8 W/kg

Evidence strengthInsufficientConfidence: 74% · Peer reviewed: yes

Main findings

A non-contact head exposure setup using a patch antenna (4 cm from the head) was presented for UMTS-like RF-EMF exposure during NIRI measurements. Four signals at 1900 MHz and three exposure doses (sham, 0.18 W/kg, 1.8 W/kg spatial peak SAR over 10 g) were implemented; SAR assessment by measurement and simulation showed good agreement, with simulated spatial peak SAR deviations of -22% to +32% from nominal.

Outcomes measured

Development/description of a head exposure setup for human provocation studies with near-infrared imaging (NIRI)
Exposure characterization and SAR assessment (measurement and simulation agreement; SAR distribution)
Variability/uncertainty analysis of spatial peak SAR over 10 g

View raw extracted JSON

{
  "study_type": "engineering",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 1900,
    "sar_wkg": 1.8,
    "duration": null
  },
  "population": "human subjects",
  "sample_size": null,
  "outcomes": [
    "Development/description of a head exposure setup for human provocation studies with near-infrared imaging (NIRI)",
    "Exposure characterization and SAR assessment (measurement and simulation agreement; SAR distribution)",
    "Variability/uncertainty analysis of spatial peak SAR over 10 g"
  ],
  "main_findings": "A non-contact head exposure setup using a patch antenna (4 cm from the head) was presented for UMTS-like RF-EMF exposure during NIRI measurements. Four signals at 1900 MHz and three exposure doses (sham, 0.18 W/kg, 1.8 W/kg spatial peak SAR over 10 g) were implemented; SAR assessment by measurement and simulation showed good agreement, with simulated spatial peak SAR deviations of -22% to +32% from nominal.",
  "effect_direction": "unclear",
  "limitations": [],
  "evidence_strength": "insufficient",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "UMTS-like",
    "RF-EMF",
    "1900 MHz",
    "patch antenna",
    "head exposure system",
    "provocation study",
    "double-blind",
    "randomised crossover",
    "near-infrared imaging",
    "NIRI",
    "specific absorption rate",
    "SAR assessment",
    "anechoic chamber",
    "sham exposure"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1002/bem.20688
PubMed: 21842517

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