Ultra-short Waves

Ultra-short waves were first applied in therapy by Schliephake. The alternating currents used in diatherapy are characterized by a frequency of 800,000 to 1 million oscillations per second with a wavelength of 300-400 m. At present, currents with a frequency of 10-100 million oscillations per second have been introduced into therapy. Waves from 30 to 10 m in length (short waves) and waves shorter than 10 m (ultra-short waves) should be distinguished. To obtain short waves, either electron tubes or spark dischargers can be used. In the first case, undamped oscillations are obtained, in the second, damped ones. When applying this therapy, it is necessary to take into account the wavelength, the determination of which is carried out by a special device - a wavemeter. Unlike tissue heating in diatherapy, the latter with short waves can be better localized. While in diatherapy the skin is particularly heated and burns are often obtained, with short waves this does not occur, and at the same time it becomes possible to heat such poorly heat-conducting tissues as, for example, bones and fat. This can be particularly noted on the skull, where the effect of short waves on the brain is fully manifested, whereas in diatherapy the currents are mostly deflected by poorly heat-conducting bones. Thus, it becomes possible to directly affect the most vital centers of the brain. A further feature of short-wave therapy lies in the possibility, by using waves of different lengths, to selectively act on certain cells or tissues. The basis of the action apparently lies in the thermal effect, along with which one cannot reject the existence of a certain specific action. The reasons for the increase in temperature are not yet sufficiently clear. According to some authors, the heat generated is induced under the influence of high-frequency currents. Others believe that heat is partially released by the body itself due to increased metabolism. Already in the first works with short waves, their relationship to microorganisms was noted. Experiments, however, gave contradictory results. More precise experiments were conducted by Haase and Schliephake, who, comparing the death of a suspension of microbes when heated to 50-80° in a capacitor field and on a water bath, established that in the capacitor field the microbes die faster. This is particularly noticeable at lower temperatures, which also indicates a specific effect of short waves. According to Liebesny, Wertheim, and Scholz, when experiments are conducted with the complete exclusion of the thermal factor, different microbes show different reactions to short waves. According to the experiments of Lippelt and Heller (the effect of short waves from 4 to 8 m in length on cultures of pneumococci, Staphylococcus albus haemolyticus and Bact. coli commune was studied), a bionegative and biopositive effect of short waves should be distinguished. Three factors are important: wavelength, field intensity, and duration of exposure. There are a number of works on elucidating the biological effect of short waves. Schereschewsky studied the effect of a field with a wavelength from 2.2 to 36.1 m on mice. He notes the following phenomena: after several minutes of quiet state, signs of excitement appear. The limbs and ears become inflamed, turn blue, salivation and nasal discharge appear, the body is covered with sweat. Then convulsive seizures begin, ending in respiratory arrest. The heart continues to beat for some time. The body temperature of the mouse after death was usually slightly elevated, and sometimes reached 44° in the rectum. Experiments by Plotnikov from Brushtein's laboratory revealed the effect of a field with waves from 20 to 50 m on flax seeds, with prolonged exposure sharply reducing seed germination. However, if the current is turned on at the moment when steam appears on the walls of the test tube, then with waves 20 and 26 m long, the percentage of germination sharply increases. The same applies to soy and oat seeds. Insects (bugs, weevils) with waves from 14.5 to 30 m died within a period of several seconds to a little over one minute. A white mouse dies with wavelengths from 12.5 to 50 m within a period of 3 sec. to 39 min., depending on the wavelength. Pflomm studied the effect on blood. The concentration of hydrogen ions in the irradiated part of the body as a rule increases. In addition, due to the increased permeability of capillaries, there is apparently an improvement in tissue lymphatic circulation, which in turn leads to an increased exchange of substances between blood and tissue. Diphtheria antitoxin after irradiation with a 2 m wave, with a sufficiently long experiment, can be completely destroyed (Szymanowski). According to Jorns, who studied the effect of short waves on phagocytosis of leukocytes, the latter is weakened with a large dose and strengthened with a medium dose. On blood vessels, the phenomenon of reverse flow from dilated veins into capillaries, also maximally dilated, is observed. The same phenomenon as a result of a hot water bath disappears, and the capillaries quickly return to normal if the heated part is moistened with adrenaline. The situation is different with capillaries dilated by the action of a short-wave field: they do not return to their normal width. Their dilation persists for 4 hours after irradiation. Apparently here there is a decrease in the tone of the sympathetic nerve and an increase in the tone of the vagus nerve.-From various sides, the selective effect of short waves has been claimed, i.e., the dependence of heating on the wavelength. However, to this day this question has not yet received a final resolution. According to Raab, there is no need to distinguish wavelengths of 5, 6 and 15 m for therapy. The results are equally good. As for the so-called biological selectivity, which means the specific effect of individual wavelengths, for example on bacteria, there are observations of different effects of different waves on the same strain (Schliephake and Haase, Liebesny). However, this question also requires further study. The therapeutic use of short electric waves first took place in 1929 in the case of a furuncle on the nose. Subsequently, along with furuncles, which are indicated for this therapy, good results were obtained with carbuncles, hidroadenitis, panaricia and paronychia, diseases of the teeth, varicose ulcers of the leg, empyema of the nasal cavities, catarrhs of the upper respiratory tract (runny nose, laryngitis, angina), paraurethral abscess, joint diseases, osteomyelitis, etc. Attempts to affect cancerous tumors have not yet given any noticeable results (Schliephake, Raab). Experiments were conducted with sarcoma in mice (Schereschewsky, Pflomm, Reiter). In a certain percentage, it was possible to destroy the tumor with wavelengths from 2.7 to 4.5 m. Regarding lung diseases, in Schliephake's opinion, this method can a priori count on a successful result, since in localized foci there are favorable dielectric conditions. Lung tissue contains a lot of air, and therefore dielectric losses here should be less. At the same time, good blood supply prevents tissue overheating and thus makes it possible to use large energies without harm to healthy lung tissue. In such a relatively favorable dielectric, foci of disease are located in the form of special masses representing completely different dielectric relations. In them, there is stronger heating than in healthy tissue. Technique: on the sick side from the front and back, a plate 20 cm in diameter is applied, the strength of the capacitor field varies (the patient should feel pleasant warmth in the depth), the duration of the session on average is 10 min. Often when treating organs of the chest cavity, an increase in temperature of 0.5-1° is observed, disappearing within 1-2 hours and being a residual phenomenon of the heat caused by the capacitor field. Temperature reactions, as is the case with non-specific therapy, are very rarely observed. The experience relates to chronic pneumonias. Good results were also obtained with bronchiectases in not too advanced cases. The first attempts to use short waves in tuberculosis of the lungs do not yet allow one to speak definitely about the importance of this therapy here (general condition improves, weight increases, temperature drops). The results obtained in pleural empyema are very effective. After only 4 sessions (session 20 min., wavelength 4 m), the temperature dropped to normal, general condition quickly improved, weight began to increase, and after 14 days the patient came to treatment on foot. The bactericidal effect of different waves varies. In this respect, as well as in terms of tissue heating, waves in the range from 3 to 20 m are most effective. However, one cannot think that the basis of this therapy lies in the direct destruction of bacteria. Rather, one should think that it is about strengthening the body's defense forces. Short-wave therapy is mainly used in locally limited diseases. It weakens the vital activity of pathogenic microbes by increasing tissue temperature.

According to Pfloom's data, in the area of the short-wave field, dilation of capillaries and arterioles occurs almost instantaneously, resulting in the development of strong active hyperemia under conditions of good blood flow. This hyperemia arises not only due to heating but also due to an increase in parasympathetic and a weakening of sympathetic tone of the vascular walls. It persists for several days. The short-wave field also affects the permeability of capillaries, which leads to an increased exchange between blood and tissues, and consequently to increased absorption of fluid. Furthermore, since acidic metabolic products predominate in the inflammatory focus, more intense heating occurs there, as apparently it is precisely on acidic substances that short waves exert a particularly strong effect. Short-wave therapy at present cannot yet be subjected to any precise accounting, as it operates with 3 variable factors that influence its effect. These factors are time, field strength, and wavelength. Finally, individual differences also have significance. The methodology of short-wave therapy cannot yet be considered established. Kowarschik devoted a special study to this question. There are 3 basic methods of transferring the energy of short-wave current to the human organism: 1) directly with the help of metal electrodes applied to the body (the oldest method and most frequently used in electrotherapy, such as in diathermy, galvanization, and faradization, but relatively rarely in short-wave therapy); 2) by the intermediate inclusion of a dielectric (a certain amount of air between the electrode and the body)—the most common method, introduced by Schlippecke as treatment with a capacitor field or treatment in an electric field, and finally 3) by placing the body in an electromagnetic field of short-wave current, where radiation already takes place. From this it naturally follows the proposal—to place the body inside a solenoid, through the spiral of which a short-wave current passes. This method makes it possible to concentrate electromagnetic energy within certain limits, irradiating not only the entire body but also its individual parts.