Projector (Light Therapy)

PROJECTOR, an apparatus in which a carbon arc is used for local light treatment. The scientific substantiation of this method belongs to Finsen and his school. The projector consists of an arc lantern with a strength of 15–30 amperes, of at least 30 volts of direct or alternating current. Alternating current devices are less powerful. The voltaic arc is obtained by passing an electric current through carbons impregnated with salts of various metals. Above the carbons, an automatic device is placed to bring the carbons closer together as they burn down, which makes it possible to maintain a steady arc for a long time. Behind the carbons is a nickel-plated reflector that is easily moved so that the arc can always be placed in its focus. The arc lantern is mounted in a metal cylinder in such a way that it can easily rotate in any plane. The arc light, when reflected from the reflector, takes a parallel direction and can be directed

at any part of the body. The luminous and

pure energy of the projector according to its physical and chemical properties is very close to the solar spectrum. The thermal energy of the projector penetrates deep into the tissues. A 15-ampere projector at a distance of 2 meters gives 66°, and at 25 amperes—93°. In intensity, the chemical energy of the projector even surpasses solar energy. According to Vermel, projector light, after passing through a significant thickness of tissues, retains the ability to cause photochemical and bactericidal effects. Before administering the procedure, by moving the reflector forward or backward, it should be positioned so that the voltaic arc falls at its focus, i.e., so that a bright, uniform circle is obtained on the screen. The latter is then directed to the area subjected to irradiation. The procedure is administered with the patient in a sitting or lying position at a distance of 2–3 meters from the projector, depending on heat tolerance. The number of sessions is usually 3–12. In Germany, a combined method of light treatment is used, in which the projector is directed to different areas of the skin of a patient sitting in a light bath. Sometimes projector treatment is used with monochromatic light, for which red and blue light filters are placed in front of the voltaic arc (see figure). The projector acts as a pain reliever, bactericide, and resolvent, causing a light skin tan after several sessions.--Indications for the use of the projector: neuralgia and myositis of various origins, dry pleurisy, exudates in the small pelvis. Symptomatically as a pain reliever, the projector is prescribed for gastrointestinal neuroses, hepatic and renal colics, bronchitis, and bronchial asthma. Disadvantages of the apparatus include pollution of room air by carbon combustion products. Therefore, recently the projector has been gradually displaced by more convenient and simple devices that provide radiation rich in both the right and left parts of the spectrum (Jupiter, Ultrazon, Ult-Balyuks lamps, and others).

E. Pasynkov,