Abstract: A magnetic nerve stimulator comprises a capacitor which is charged to a high voltage, then discharged through a coil placed near the head. The magnetic field produced induces eddy currents in the brain that stimulate neurons. When the capacitor is fully discharged, the discharge path is broken by opening a switch. The inductive action of the coil forces a diode to turn on and the energy from the collapsing magnetic field around the coil charges a second capacitor. The charge on the second capacitor is augmented by a power source to make up for any losses, and the process is repeated. The stimulator of the invention can pulse rapidly, does not cause excessive heating of the coil, and uses comparatively little energy. As a result, high level cognitive functions in the brain can be disrupted for diagnostic purposes.

Abstract: The present invention relates to humidifiers as used in research and in the calibration of humidity measuring instruments for producing a saturated gas stream. Specifically the invention relates to humidifiers comprising a bubble type and an extended surface type humidifier in gas flow communication one to the other and including temperature control means.