Temperature-controlled exposure systems for investigating possible changes of retinal ganglion cell activity in response to high-frequency electromagnetic fields.

Two exposure systems were developed for the measurement of retinal ganglion cell responses to light under the influence of pulsed high-frequency electromagnetic fields. Exposure characteristics were determined numerically for the GSM standards (900/1,800 MHz) and the UMTS standard (1,966 MHz) with specific absorption rates, averaged over the region of interest, of 0.02, 0.2, 2 und 20 W kg(-1). Extracellular multi- and single unit recordings of light responses from several retinal ganglion cells per retina could be obtained in these exposure systems on a regular basis, using two recording electrodes simultaneously. With appropriate temperature control adjustment, maximal temperature deviations at exposure onset and offset were well below the range of +/-0.1 degrees C for all SAR values.