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首页> 外文学位 >THE EFFECT OF PULSE MODULATION OF VISIBLE LIGHT ON THE TIME UNTIL THRESHOLD PAIN SENSATION IN IRRADIATED SKIN.
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THE EFFECT OF PULSE MODULATION OF VISIBLE LIGHT ON THE TIME UNTIL THRESHOLD PAIN SENSATION IN IRRADIATED SKIN.

机译：可见光的脉冲调制对经过辐照的皮肤中直至阈值时间痛感的影响。

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摘要

The comparative toxicities of continuous and modulated non-ionizing electromagnetic radiations (300 kHz - 300 GHz) are poorly understood. Since present exposure standards are based largely on CW experiments, it is not known whether they are adequate to prevent harm from exposure to modulated fields.; A simple experimental model of a harmful/thermal bioelectromagnetic effect was used to investigate the relationship between modulation and toxicity. The inner forearms of eleven human subjects were exposed to intense continuous and pulse-modulated thermal radiation from a projector bulb. The time of irradiation required to produce threshold pain sensation was measured as a function of the average power density ((LESSTHEQ) 2500 mW/cm('2)), the pusle repitition frequency (CW, 0.4 Hz, 8 Hz), and the duty cycle (CW, 0.33, 0.50). Data for a total of 32 time-intensity curves were collected.; In every case, the relationship between the irradiation time, (DELTA)t,(, )and the average power density, W, was a power function:; (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI); The value of m varied from 1.20 to 6.72 and was found to depend only on the modulation of the radiation. A decrease in the duty cycle caused the value of m to increase dramatically. There was also a slight positive relationship between the pulse repitition frequency and m. Minimum average power densities which could elicit pain were found to be independent of the modulation of the radiation. However, these threshold intensities decreased as the age of the subject increased or as the environmental heat load decreased.; Published time-intensity data for lethality, cataractogenesis, and threshold pain sensation were compared to the results of this experiment. Intensities were first converted from incident power densities to SAR's in the appropriate critical organ. All the data could be described by a single power function equation. The value of m was found to depend on the effect as well as modulation of the radiation.; A radiation protection guide was developed to prevent injuryfrom the known harmful effects of electromagnetic irradiation.Limits were derived in light of the experimental and published time-intensity relationships. The most significant result is the necessityof a critical organ ceiling value of 60 W/kg due to the uncertaintyin the value of m.
机译：对连续和调制非电离电磁辐射（300 kHz-300 GHz）的比较毒性了解得很少。由于目前的暴露标准主要基于连续波实验，因此尚不清楚它们是否足以防止暴露于调制场的伤害。使用有害/热生物电磁效应的简单实验模型来研究调制与毒性之间的关系。十一名人类受试者的前臂内侧受到来自投影机灯泡的强烈连续和脉冲调制热辐射的照射。测量产生阈值疼痛感所需的辐照时间与平均功率密度（（LESSTHEQ）2500 mW / cm（'2）），脓液重度频率（CW，0.4 Hz，8 Hz）和占空比（CW，0.33，0.50）。总共收集了32条时间强度曲线的数据。在每种情况下，照射时间Δt，（，）与平均功率密度W之间的关系是幂函数： （省略了图表，表格或图形...请参见DAI）; m的值在1.20至6.72之间变化，并且被发现仅取决于辐射的调制。占空比的减小导致m的值急剧增加。脉冲再分配频率与m之间也存在轻微的正相关关系。发现可能引起疼痛的最小平均功率密度与辐射的调制无关。然而，这些阈值强度随着受试者年龄的增加或环境热负荷的降低而降低。将已发布的杀伤力，白内障发生和阈值疼痛感的时间强度数据与本实验的结果进行了比较。首先将强度从入射功率密度转换为适当关键器官中的SAR。所有数据都可以用一个幂函数方程式描述。已发现m的值取决于辐射的效应和调制。制定了辐射防护指南以防止受到电磁辐射的已知有害影响而造成伤害。根据实验和公开的时间-强度关系推导了限值。最重要的结果是，由于m值的不确定性，必须达到60 W / kg的临界器官上限值。

著录项

  • 作者

    MILLER, TIMOTHY MARK.;

  • 作者单位

    Northwestern University.;

  • 授予单位 Northwestern University.;
  • 学科 Biophysics General.
  • 学位 Ph.D.
  • 年度 1981
  • 页码 403 p.
  • 总页数 403
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 生物物理学;
  • 关键词

  • 入库时间 2022-08-17 11:51:32

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