In vitro exposure apparatus for ELF magnetic fields

• Published in: Bioelectromagnetics Vol. 25; no. 8; pp. 582 - 591
• Main Authors: Schuderer, Jürgen, Oesch, Walter, Felber, Norbert, Spät, Denis, Kuster, Niels
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.12.2004
• Subjects: Cell Culture Techniques - instrumentation; Cell Culture Techniques - methods; dosimetry; Electromagnetic Fields; Electromagnetic Phenomena - instrumentation; Electromagnetic Phenomena - methods; Environment, Controlled; Equipment Design; Equipment Failure Analysis; extremely low frequency; Radiation Dosage; Radiometry - instrumentation; Transducers; uniform magnetic fields
• ISSN: 0197-8462; 1521-186X
• DOI: 10.1002/bem.20037

For in vitro studies on the effect of extremely low frequency (ELF) magnetic field exposures in different laboratories, a programmable, high precision exposure system enabling blinded exposures has been developed and fully characterized. It is based on two shielded 4 coil systems that fit inside a commercial incubator. The volume of uniform B field exposure with 1% field tolerance is 50% larger compared to a Merrit 4 coil system with the same coil volume. The uncertainties for the applied magnetic fields have been specified to be less than 4%. The computer controlled apparatus allows signal waveforms that are composed of several harmonics, blind protocols, monitoring of exposure and environmental conditions and the application of B fields up to 3.6 mT root‐mean‐square amplitude. Sources of artifacts have been characterized: sham isolation >43 dB, parasitic incident E fields <1 V/m, no recognizable temperature differences in the media for exposure or sham state, and vibrations of the mechanically decoupled dish holder <0.1 m/s2 (= 0.01 g), which is only twice the sham acceleration background level produced by the incubator and fan vibrations. Bioelectromagnetics 25:582–591, 2004. © 2004 Wiley‐Liss, Inc.