Triaxial exposure system providing static and low-frequency magnetic fields for in vivo and in vitro biological studies

Studies on the biological effects of magnetic fields, particularly the effects produced by the combined contribution of static and dynamic magnetic fields, have shown the need for exposure systems able to control of all the components with high precision. In order to yield exposure conditions independent of the local geomagnetic field, an exposure system was realized that allows the real time control of static magnetic field components, in addition to the production of ELF magnetic fields. This paper describes the design, construction and results of the evaluation of the system. The exposure apparatus consisted of three independent nested systems, each realized by a four square coil set. ELF dynamic field generation and static field control was realized by a software routine. A numerical method was used to determine the isofield regions, to characterize the system and to set the coil dimensions in the final design. Experimental measurements showed good agreement with theoretical calculation.