研究のタイプ: 医学/生物学の研究 (experimental study)

[2つの異なるパルス磁界シーケンスへのばく露の後に生じるヒトEEGのアルファ波活動の変化] med./bio.

Changes in human EEG alpha activity following exposure to two different pulsed magnetic field sequences.

掲載誌: Bioelectromagnetics 2009; 30 (1): 9-20

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研究目的(著者による)

To examine the effects of pulsed extremely low frequency magnetic field sequences upon alpha wave activity (8-13 Hz) of the human EEG over the occipital-parietal regions.

詳細情報

Two previous studies (see publication 11906 and publication 10628) determined that exposure to pulsed extremely low frequency electromagnetic fields can affect the EEG, notably the alpha wave frequency (8-13 Hz). In the present study 22 participants from two previous studies (see publication 11906 [sequence 2 with a refractory period of 5000 ms] and publication 10628 [sequence 1 with a refractory period of 1200 ms]) and 10 additional subjects were randomly assigned to two different pulsed magnetic field sequences, used in the previous studies. Participation consisted of two sessions (exposure and sham exposure), separated by approximately 1 week (7+/-2 days).

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 0–500 Hz
Modulation type: pulsed
ばく露時間: continuous for 15 min

General information

two different pulse forms were used a) pulses with a refractory period of 1200 ms b) pulses with a refractory period of 5000 ms

ばく露1

主たる特性
周波数 0–500 Hz
タイプ
  • magnetic field
ばく露時間 continuous for 15 min
Modulation
Modulation type pulsed
Pulse width 853 ms
Rise time 1 ms
ばく露装置
ばく露の発生源/構造
ばく露装置の詳細 three orthogonal square Helmholtz coils with 2.0 m, 1.75 m, 1.5 m sides and 10 turns of 8-gauge stranded conductor each
Sham exposure A sham exposure was conducted.
パラメータ
測定量 種別 Method Mass 備考
磁束密度 200 µT peak 測定値 - -

Reference articles

  • Cook CM et al. (2005): [パルス低周波磁界ばく露による安静時EEG効果]
  • Cook CM et al. (2004): [安静時EEGはELFパルス磁界ばく露に影響される]
  • Thomas AW et al. (2001): [磁界ばく露と行動モニタリング装置]
  • Thomas AW et al. (2001): [パルス(200マイクロT)磁界にばく露された関節リウマチおよび線維筋痛患者および健常対照群の比較:健全な立位平衡に与える影響]
  • Thomas AW et al. (2001): [パルス磁界(200μT) へばく露されたヒト:正常な直立バランスへの影響]
  • Thomas AW et al. (1998): [カタツムリにおける特定のパルス磁界の鎮痛効果:繰り返しばく露の結果、耐性およびDPDPEとのクロス耐性の関係]
  • Thomas AW et al. (1997): [カタツムリでのパルス磁界による”無痛覚”誘発とμ、δ、κオピオイド受容器アゴニスト・拮抗薬の効果]
  • Thomas AW et al. (1997): [陸生巻貝「セパエラ・ネモラリス」に対するパルス磁界の抗侵害受容作用]

ばく露を受けた生物:

方法 影響評価項目/測定パラメータ/方法

研究対象とした生物試料:
研究対象とした臓器系:
調査の時期:
  • ばく露前
  • ばく露中
  • ばく露後

研究の主なアウトカム(著者による)

Compared to sham exposure, alpha wave activity was lowered over the occipital-parietal regions of the brain during exposure to sequence 1, while alpha wave activity over the same regions was higher after sequence 2 exposure. The effects occured after 5 min of exposure and were dependent on the order of exposure (magnetic field followed by sham exposure).
This study supports previous observations of EEG changes after 5 min pulsed extremely low frequency magnetic field exposure. The results also suggest that a previous exposure to the pulsed magnetic field sequence determined subjects´ responses in the present experiment, i.e. subjects previously exposed to sequence 1(and now to sequence 2) displayed higher occipital alpha wave activity after magnetic field exposure. Subjects previously exposed to sequence 2 (and now sequence 1) displayed lower alpha wave activity over posterior scalp regions in the present study.

研究の種別:

研究助成

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