Prospective, randomized, single-blind, sham treatment-controlled study of the safety and efficacy of an electromagnetic field device for the treatment of chronic low back pain: a pilot study.

OBJECTIVES: To evaluate the efficacy and safety of therapeutic electromagnetic fields (TEMF) on chronic low back pain. Secondary objectives included the investigation of the effects of TEMF on psychometric measures. SETTING: Pain Research center in an Urban Academic Rehabilitation Facility. DESIGN: Prospective, randomized, single-blind, placebo (sham) treatment-controlled design in which participants were evaluated over a 6-week period. A total of 40 subjects were randomly assigned: 20 subjects to 15 milliTESLA (mT) treatment using a prototype electromagnetic field device and 20 to sham treatment. INTERVENTIONS: After a 2-week baseline period, eligible individuals were randomized to one of the treatment groups (sham or 15 mT) for six 30-minute treatments over 2 weeks, then a 2-week follow-up period. OUTCOME MEASURES: The primary outcome measure was the self-report of pain severity using a 100 mm visual analog scale collected using a twice daily McGill Pain Questionnaire-Short Form. Several secondary measures were assessed. RESULTS: Both groups (15 mT and sham) improved over time (P < 0.05). Although groups were similar during the treatment period, treated subjects (TEMF of 15 mT) improved significantly over sham treatment during the 2-week follow-up period (20.5% reduction in pain; F(1,34) = 10.62, P = 0.003). There were no reported serious adverse events. CONCLUSIONS: This study demonstrates that TEMF may be an effective and safe modality for the treatment of chronic low back pain disorders. More studies are needed to test this hypothesis.

Therapeutic electromagnetic field effects on angiogenesis and tumor growth.

BACKGROUND: A new approach to cancer therapy based on the application of therapeutic electromagnetic fields (TEMF) has been developed by EMF Therapeutics, Inc., Chattanooga, TN, USA. This study was designed to assess the effect of TEMF on tumor vascularization and growth of murine 16/C mammary adenocarcinoma cells in C3H/HeJ mice. MATERIALS AND METHODS: Implanted tumors were allowed to grow for seven days until the tumor volume reached 100 mm3 before treatment was started. Mice (20 per control, 10 per EMF exposed group) received treatment (10 minutes per day with 0, 10 mT, 15 mT or 20 mT) with a 120 pulses per second pulsating magnetic field. Tumor growth was assessed throughout the treatment period. The extent of tumor vascularization was evaluated by immunohistochemical staining for CD31. RESULTS: Exposure to TEMF significantly reduced tumor growth, significantly reduced the percentage of area stained for CD31 indicating a reduction in the extent of vascularization and there was a concomitant increase in the extent of tumor necrosis. CONCLUSION: A novel TEMF treatment safely reduced growth and vascularization of implanted breast cancers in mice. IMPLICATION: TEMF may prove a useful adjuvant to increase the therapeutic index of conventional cancer therapy.

Magnetic and electromagnetic field therapy.

There is increasing interest in the application of magnetic/electromagnetic fields for therapeutic purposes. Magnetotherapy provides non-invasive, safe and easy to apply methods to directly treat the site of injury, the source of pain and inflammation as well as other types of dysfunction. This review summarizes several decades of experience worldwide in studying biological and clinical effects initiated by various magnetic and electromagnetic fields. The physiological basis for tissue repair as well as physical principles of dosimetry and application of magnetic fields are discussed. An analysis of magnetic/electromagnetic stimulation is followed by a discussion of the advantage of magnetic field stimulation compared with electric current stimulation. Finally, the proposed mechanisms of action are discussed.

EMF signals and ion/ligand binding kinetics: prediction of bioeffective waveform parameters.

The kinetics of an electromagnetic field (EMF) target pathway are used to estimate frequency windows for EMF bioeffects. Ion/ligand binding is characterized via first order kinetics from which a specific electrical impedance can be derived. The resistance/capacitance properties of the binding pathway impedance, determined by the kinetics of the rate-determining step, define the frequency range over which the target pathway is most sensitive to external EMF. Applied signals may thus be configured such that their spectral content closely matches that of the target, using evaluation of the signal to thermal noise ratio to optimize waveform parameters. Using the approach proposed in this study, a pulsed radio frequency (PRF) waveform, currently employed clinically for soft tissue repair, was returned by modulation of burst duration, producing significant bioeffects at substantially reduced signal amplitude. Application is made to Ca2+/Calmodulin-dependent myosin phosphorylation, for which the binding time constants may be estimated from reported kinetics, neurite outgrowth from embryonic chick dorsal root explants and bone repair in a fracture model. The results showed that the retuned signal produced increased phosphorylation rates, neurite outgrowth and biomechanical strength that were indistinguishable from those produced by the clinical signal, but with a tenfold reduction in peak signal amplitude, approximately 800-fold reduction in average amplitude and approximately 10(6)-fold reduction in average power.

Bioeffects of weak electromagnetic fields.

Time varying magnetic fields are most often employed for therapeutic purposes and are present in environmental sources. In order for an electromagnetic field bioeffect to be possible, the signal parameters should not only satisfy the dielectric properties of the target, but also induce sufficient voltage to be detectable above thermal noise. The problem of the sensitivity of living cells and tissues is discussed in relation to signal/noise ratio at the target site. Some biophysical models for interactions of weak electromagnetic fields with biological systems are summarized. Cell studies and therapeutic application of electric and magnetic fields indicate that weak electromagnetic fields can have a profound effect on a large variety of biological systems.

Use of lectins as indicators for magnetic field action on erythrocyte membranes.

The effects of magnetic fields on biological membranes in general and on the red blood cell membrane in particular have been studied intensively in the last two decades. A variety of methods for evaluation of magnetic field action on the structure and function of biological membranes has been used. It has been suggested /1/ that the cell membrane can be considered as one of the primary targets affected by magnetic field exposure.

Biophysical estimation of the environmental importance of electromagnetic fields.

The rapid development of science and technology exposes living organisms to a wide range of electromagnetic fields. Some life-style and occupational conditions are associated with a level of electromagnetic fields higher than average. A series of epidemiological studies has raised concern about possible cancer risk of electromagnetic fields generated by power lines and electrical appliances. In contrast, hundreds of thousands of patients world-wide have been cured by use of electromagnetic fields. Biological effects of low-level electromagnetic radiation have become the focus of a number of studies. However, there are not enough basic scientific data related to mechanisms of action of electromagnetic fields. This paper proposes a biophysical approach to the estimation of the environmental importance of electromagnetic fields. The methods of collecting data, dosimetry, possible mechanisms of action and open problems are discussed in this review.

Real-time algorithm for retinal tracking.

Conventional retinal laser photocoagulation is presently performed by an ophthalmologist manually aiming a low-power laser beam at a desired site and firing a high-power laser for a preselected interval of time. To automate this process a retinal tracker must acquire a target, track small saccades, and identify loss of track during a large saccade. The authors successfully implemented a real-time algorithm that used a simple computer, video digitizing card, low light video camera, and fundus camera to perform rudimentary tracking on a photograph of a retina undergoing smooth circular motion. The algorithm tracked speeds up to 5 Hz, or 27 degrees/s, which equated to the retina moving in a 525 microns diameter circle.