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Bioelectromagnetism

 

3–50 μm, and far-infrared with 50–1,000 μm. Johann Wilhelm Ritter (1776–1810), a German physicist,

found in 1801 that invisible ultraviolet (UV) radiation from sunlight through their action in darken­

ing silver chloride. Te frst industrial application of near-infrared radiation began in the 1950s. In the

frst applications, near-infrared spectroscopy (NIRS) was used only as an add-on unit to other optical

devices that used other wavelengths such as UV, visible, or mid-infrared spectrometers.

Several other medical applications of optical radiations will be introduced. Next, as historically well-

known medical applications, the UV light of the electromagnetic spectrum was used. In Greek and

Roman times, the exposure to the sun had been practically used for health and therapeutic reasons.

In the eighteenth and early nineteenth century, sun therapy was recommended afer the fact that UV

light could kill various bacteria had been frmly established. In 1899, Erik Johan Widmark (1850–1909),

professor in Ophtalmiatrics at the Karolinska Institute, had shown that UV light is responsible for ery­

thema and pigmentation of the skin (Rowbottom and Susskind, 1984).

Niels Ryberg Finsen (1860–1904) developed the Finsen lamp based on electric carbon arcs. First,

he designed and used a source of artifcial light in therapy. Ten he modifed it. For a lens, common

glass was initially used and later he replaced it with fused quartz to allow the separation of light and

the formation of UV light (Grzybowsli and Pietrzak, 2012). Light treatment had two uses: natural sun

therapy and artifcial light therapy. In 1893, he observed that light had a benefcial efect on smallpox

scars. Niels Ryberg Finsen, professor at the University of Copenhagen, Denmark, was the founder of light

therapy (Figure 2.16) (Finsen, 1899, p. 67). He was born in the Faroe Islands and educated in Iceland and

Copenhagen. Te Nobel Prize in Physiology or Medicine in 1903 was awarded to Finsen in recognition

of his work on the treatment of diseases, and in particular the treatment of lupus vulgaris by means of

concentrated light, by which he has opened a new avenue of light therapy for medicine. Unfortunately, he

died the following year. His Nobel Prize entered into some controversy. His supporters argued that Finsen

had a great mind, and his research was innovative and benefcial all humanity. However, his opponents

claimed that Finsen’s contribution to medicine had too little theoretic foundation and was not academic

enough. During the Nobel Prize decision process, the members of the Nobel Prize Committee paid a few

FIGURE 2.16 Treatment in the Finsen lamp (From Finsen, 1899.)