Low-Intensity Electromagnetic Millimeter Waves for Pain Therapy
Taras I. Usichenko, Hardy Edinger, Vasyl V. Gizhko, Christian Lehmann, Michael Wendt and Frank Feyerherd
Department of Anesthesiology and Intensive Care Medicine, Ernst Moritz Arndt University, Greifswald, Germany
Millimeter wave therapy (MWT), a non-invasive complementary therapeutic technique is claimed to possess analgesic properties. We reviewed the clinical studies describing the pain-relief effect of MWT. Medline-based search according to review criteria and evaluation of methodological quality of the retrieved studies was performed. Of 13 studies, 9 of them were randomized controlled trials (RCTs), only three studies yielded more than 3 points on the Oxford scale of methodological quality of RCTs. MWT was reported to be effective in the treatment of headache, arthritic, neuropathic and acute postoperative pain. The rapid onset of pain relief during MWT lasting hours to days after, remote to the site of exposure (acupuncture points), was the most characteristic feature in MWT application for pain relief. The most commonly used parameters of MWT were the MW frequencies between 30 and 70 GHz and power density up to 10 mW cm2. The promising results from pilot case series studies and small-size RCTs for analgesic/hypoalgesic effects of MWT should be verified in large-scale RCTs on the effectiveness of this treatment method.
Keywords: analgesia, millimeter waves, pain therapy, review
Introduction
Inadequate pain therapy increases both morbidity and health care costs (1,2). The dominant method of pain control in modern medicine, pharmacotherapy, can cause numerous side effects (3–5). In order to increase the quality of pain man- agement, various complementary non-pharmacological anal- gesic techniques, including millimeter wave therapy (MWT), have been tested (6). MWT is a non-invasive technique, con- sisting of the exposure of parts of the human body to electro- magnetic radiation with frequencies 30–300 GHz (extremely high frequency electromagnetic field) and corresponding wavelengths from 10 to 1 mm (7). The discovery of resonance- like frequency dependence of biological effects of millimeter waves (MW) provided the theoretical background for their clinical application (8,9). Industrial continuous-wave genera- tors (e.g. G4-142) using the backward-wave oscillator or Gunn diode-based generators are used for MWT (Fig. 1).
2006-Usichenko