71

The History of Bioelectromagnetism

visits to the institute before the fnal decision was made (Grzybowsli and Pietrzak, 2012). Special attention

is paid to that Finsen donated much of his Nobel Prize award to both his institute and the sanatorium for

heart patients. Currently, it should be mentioned that light therapy is treated with much greater caution

because over exposure to UV light can lead to melanoma and other skin cancer.

Next, we introduce another topic. Te infrared region lies between the visible and microwave por­

tions of the electromagnetic spectrum. Infrared radiation is invisible to the human eye but it can be

focused, refected, and polarized just like visible light. Te NIR band has a wavelength range from 0.78

to 3 μm. NIRS uses near-infrared radiation. In the 1980s, a single-unit, stand-alone NIRS system was

made available, but the application of NIRS was focused more on chemical analysis. With the introduc­

tion of optical-fber in the mid-1980s and with the monochromator-detector developments in the early

1990s, NIRS became a more powerful tool for other than chemical analysis. Te use of NIR for bio­

medical measurements dates back to 1977, when Frans Jöbsis (1929–2006), professor at Duke University,

published the non-invasively measurement of the changes of oxygenation of the brain in an intact cat

head (Jöbsis, 1977). In the 1990s, it became clear that NIRS could capture changes in hemoglobin con­

centration that were linked to changes in the blood fow in the brain, which was linked to neural activity.

Tis attracted great attention as a new functional imaging method, fNIRS. Te fNIRS is the term used

in contrast to fMRI, which detects changes in the magnetic susceptibility of hemoglobin and images

it to obtain BOLD information. On the other hand, fNIRS captures changes in the absorption of light

as changes in the concentration of hemoglobin. Te diference is that fNIRS can measure the cerebral

cortex with surface optical sensors and fMRI is used to visualize deeper brain activity.

Under the suggestion of Jöbsis, Mamoru Tamura (1943–2009), professor at the Research Institute

for Electronic Science, Hokkaido University, and David Tomas Delpy, professor at University College

London, produced great advances in fNIRS (Delpy et al., 1987; Cope and Delpy, 1988). Tamura published

with instrumental support from Hamamatsu Photonics, K.K., and Shimazu Corporation the frst fNIRS

human studies (Hoshi and Tamura, 1993a, b). Tey observed bilateral prefrontal cortex oxygenation

changes in 14 volunteers during a mental task using CW instruments, each equipped with a single chan­

nel. Jöbsis is the founder of NIRS. Tamura was known as one of the great pioneers in biomedical optics

and fNIRS. Japanese organizations such as Hamamatsu Photonics, K.K, and Shimazu Corporation sup­

port greatly to the development and the use of optical radiation in biology, chemistry, and medicine.

In 2008, Delpy received the Rosalind Franklin Medal and Prize for his pioneering development of a

range of novel techniques and instruments to monitor the health of patients in intensive care units

and to image tissue physiology and metabolism. Te Rosalind Franklin Medal and Prize is given for

distinguished contributions to physics applied to life science including biological physics. Tis Medal

and Prize was named afer Rosalind Elsie Franklin (1920–1958), a British chemist and X-ray crystal­

lographer. She performed X-ray analysis of DNA and helped the creation of the Watson-Crick Model.

In 1935, Karl Matthes (1905–1962), a German physician, made a device which measured continuously

the oxyhemoglobin saturation of human blood, the in vivo transillumination of the ear (Severinghaus,

1986). In 1939, using two diferent wave lengths of light (red and infrared) he developed the frst red and

infrared ear oxygen saturation meter. Infrared wavelength is absorbed more by oxygenated hemoglobin

and red wavelength is absorbed more by deoxygenated hemoglobin. Glenn Allan Millikan (1906–1947),

an American physiologist, inventor, University of Pennsylvania, Philadelphia, was the son of Robert

Andrews Millikan (1868–1953), an American experimental physicist. Father Millikan won the Nobel

Prize in Physics in 1923 for the measurement of the elementary electric charge and for his work on the

photoelectric efect. Glenn Millikan made an ear oximeter (Millikan and Taylor, 1942). Although the

ear oximeter performed very poorly due to the fact that light absorption of ear is afected very little by

arterial blood, he coined term oximeter. Te pulse-oximeter would consist of a probe attached to the

patient’s ear lobe or fnger and a display unit. Using NIR in the range of 0.6–1 μm, the pulse-oximeter

was used as a non-invasive method for monitoring a person’s oxygenation of the blood. Te oxygenation

of the blood was measured as a function of time by determining the absorption at two diferent wave­

lengths. In 1947, Glenn Millikan was killed by a falling rock during mountain climbing.