Abstract:
A magnetically shielded room has four walls (22), a floor (24), and a ceiling (20). One of the walls has a doorway (26) therethrough, and a sliding door (32) is provided to close the doorway. Each of the four walls, the floor, the ceiling, and the door is formed of at least one layer of electrically conductive material (40) to exclude radio frequency energy from the interior of the room, and at least one layer of high magnetic permeability material (42) to exclude magnetic fields from the interior of the room. Preferably, at least the wall with the doorway therethrough and the door are formed of two electrically conductive plates (54) and a layer of high magnetic permeability material (58) on each of the plates, the electrically conductive plates of the wall being spaced sufficiently far apart that the sliding door slides into the space between the plates when the doorway is opened. In this preferred approach, the door is mechanically, electrically, and magnetically sealed to the doorway in the wall by inflating bladders (56) in the door that force the electrically conductive plates (54) of the door against the respective plates of the wall (70), and the high magnetic permeability layers (58) of the door against the respective layers of the wall.
Abstract:
An apparatus for making bioelectromagnetic measurements of the human body includes an apparatus for measuring the bioelectromagnetic reaction (18) of a living body to a tactile stimulation and a tactile stimulator (40) that controllably applies a tactile stimulation to the body without creating a magnetic or electrical field that is detected directly by the apparatus for measuring the bioelectromagnetic reaction. The tactile stimulator includes a pressure chamber (52) closed on one side by a movable body such as a piston (76) or flexible membrane (56), a conduit (60) that transmits pneumatic pressure to the pressure chamber, and apparatus for applying pneumatic pressure (62) to the conduit. The measuring apparatus, such as a biomagnetometer (18), may be located within a shielded room (28), and in this case the pressure chamber (52) and movable body (76,56) are preferably located within the shielded room (28), the apparatus for applying pneumatic pressure (62) is located outside the room, and the conduit (60) passes from the exterior to the interior of the room.
Abstract:
A shielded room is constructed with walls having one shell made of electrically conductive facing sheets that prevent penetration of electromagnetic energy into the room, and two shells made of high magnetic permeability facing sheets that prevent penetration of magnetic fields into the room, one within the electrically conductive sheet and one outside the electrically conductive sheet. The edges of the conductive facing sheets are sealed to each other against leakage of electromagnetic energy with a joint compound made of a mixture of electrically conductive metallic particles in a flowable viscous base that enhances the electrical conductivity across the joint and excludes air from the sealed region. To prevent deterioration, the edges of the high magnetic permeability facing sheets are sealed to each other against leakage of magnetic fields with a joint compound made of a mixture of a high magnetic permeability material in a flowable viscous base that enhances the "magnetic conductivity" of the joint and excludes air from the sealed region.
Abstract:
A shielded room is constructed with walls having one shell made of electrically conductive facing sheets that prevent penetration of electromagnetic energy into the room, and two shells made of high magnetic permeability facing sheets that prevent penetration of magnetic fields into the room, one within the electrically conductive sheet and one outside the electrically conductive sheet. The edges of the conductive facing sheets are sealed to each other against leakage of electromagnetic energy with a joint compound made of a mixture of electrically conductive metallic particles in a flowable viscous base that enhances the electrical conductivity across the joint and excludes air from the sealed region. To prevent deterioration, the edges of the high magnetic permeability facing sheets are sealed to each other against leakage of magnetic fields with a joint compound made of a mixture of a high magnetic permeability material in a flowable viscous base that enhances the "magnetic conductivity" of the joint and excludes air from the sealed region.