Abstract: A method for obtaining information about a brain comprises the steps of providing a recording system of the electromagnetic activity produced by the brain, selecting a target pattern of the electromagnetic activity produced by the brain, recording a sample of the electromagnetic activity of the brain using the recording system, and analyzing the sample of the electromagnetic activity of the brain to identify a portion which contains the target pattern. The method further includes identifying a portion which contains the target pattern and which has a focal source at a location in the cortex of the brain, and determining the location in the thalamus which corresponds to the location of this focal source in the cortex of the brain. This determination may be followed by selecting a course of treatment which is directed to the location in the thalamus identified in the step of determining the location in the thalamus, such as a surgical, stimulative, or pharmaceutical treatment.

Abstract: A superconductor device has a substrate with an inclined surface that divides the substrate surface into a lower planar substrate surface and an upper planar substrate surface. A lower layer of an anisotropic superconductor material is epitaxially deposited on the lower planar substrate surface so that an a-axis of the anisotropic superconductor material of the lower layer is exposed at a top edge of the lower layer. An upper layer of an anisotropic superconductor material is epitaxially deposited on the upper planar substrate surface so that an a-axis of the anisotropic superconductor material of the upper layer is exposed at a top edge of the upper layer. A layer of a non-superconductor material overlies the inclined surface and the layers of anisotropic superconductor material.

Abstract: A cooling apparatus includes a dewar and a quantity of liquid nitrogen within the container. Gaseous helium is contacted to the liquid nitrogen, either by contacting its top surface or by being bubbled through the liquid nitrogen. The temperature of the cryogenic liquid is lowered by the contact of the gas.

Abstract: A method of measuring liquid flows in a living organism comprises the steps of applying an applied magnetic field to a living organism, introducing a time-varying quantity of a magnetizable fluid into a flow of liquid in the living organism, and measuring the variation in an induced magnetic field emanating from the living organism as a measure of the flow of the magnetizable fluid and the liquid within the living organism. The measurement of the induced magnetic field is preferably accomplished with at least two magnetic field sensors positioned at different locations relative to the living organism, whose outputs are detected with SQUID detectors. A cross correlation of the outputs of the magnetic field sensors permits the flow of liquid to be deduced as a function of time and location.

Abstract: A biomagnetometer includes a dewar vessel having a helmet-shaped recess at the lower end of its body. The recess is angled at about 45 degrees to the dewar body axis of the dewar vessel. Biomagnetic sensors are positioned within the interior of the dewar vessel body around the periphery of the recess. The angled recess permits the biomagnetometer to be used with subjects whose heads are inclined from 0 to 90 degrees to the horizontal by pivoting the dewar vessel over an angle of from -45 degrees to +45 degrees to the vertical, without spilling the cryogenic fluid within the dewar or causing excessive evaporation of the cryogenic fluid.

Abstract: A measured magnetocardiography signal has a relatively small heart signal mixed with a large noise signal. To produce a heart signal having a reduced noise content, the times of occurrence of a time-series of isoelectric intervals of the measured signal is first determined and a time-series isoelectric artifact curve is formed from the measurements made at those times of occurrence. A time-series non-isoelectric artifact curve for other times is determined from this information. The time-series isoelectric and nonisoelectric artifact curve is subtracted from the measured magnetocardiography time-series signal to yield a time-series heart amplitude signal having reduced noise and undistorted form.

Abstract: A method of forming a high-Tc microbridge superconductor device is disclosed, which comprises the steps of forming an inclined step on the surface of a substrate, the inclined step having an angle of inclination of from about 20 to about 80 degrees; depositing a layer of c-axis oriented superconductor material overlying the substrate such that there is a break in the layer of superconductor material at the inclined step; and depositing a layer of normal material overlying the layer of c-axis oriented superconductor material.

Abstract: An apparatus and process for making biomagnetic measurements of a biological organism permits the internal sources of the activity to be identified. An array of dipole sources is identified by providing a plurality of biomagnetic sensors disposed at locations external to the biological organism, measuring a measured biomagnetic response at each of the sensors, and amplifying and filtering the measured biomagnetic response. A solution of dipole sources within the biological organism is determined by forward calculating a computed biomagnetic response at each of the sensors resulting from the biomagnetic activity of a plurality of dipole sources, each of which dipole sources contributes a normalized total signal strength at the sensors, and solving for the strengths of each of the dipole sources by a minimum norm estimation procedure.

Abstract: A magnetometer comprises a magnetic field pickup coil and a magnetic field detector that receives electrical signals from the pickup coil and produces an electrical detector output responsive thereto. The pickup coil and detector, which are preferably made of high temperature superconductors, are enclosed in an insulated enclosure having no vacuum insulation structure. Preferably, the enclosure is made of a foamed polymer material such as styrofoam. A coolant is provided to the interior of the enclosure, to cool the pickup coil and detector to a temperature below their superconducting transition temperature. A number of such modular magnetometers may be connected together to form an array.

Abstract: A thermally conductive feedthrough has a conductive member extending through a fiber-reinforced plastic plate. The feedthrough is sealed against leakage from one side of the plate to the other by placing the plate in local compression to seal it against the plate and/or by using small individual conductive members that minimize the effects of thermal expansion differences. The feedthrough can be used between vacuum and cryogenic liquids.

Abstract: A thermally conductive feedthrough has a conductive member extending through a fiber-reinforced plastic plate. The feedthrough is sealed against leakage from one side of the plate to the other by placing the plate in local compression to seal it against the plate and/or by using small individual conductive members that minimize the effects of thermal expansion differences. The feedthrough can be used between vacuum and cryogenic liquids.

Abstract: A biomagnetometer includes a magnetic field sensor including a magnetic field pickup coil and a detector of small electrical currents flowing within the pickup coil. A vacuum-tight enclosure surrounds the sensor. The enclosure has a concavely upwardly curved first wall, with the magnetic field pickup coil located adjacent to the first wall. A vented reservoir of liquefied gas is located within the enclosure, and a solid thermal conductor extends from the sensor. There is a vacuum-tight thermal feedthrough by which the solid thermal conductor passes between the interior and the exterior of the enclosure. Electronic circuitry for filtering and amplifying the signals of the detector is also provided. Such a biomagnetometer is placed below the body of a reclining subject, and a second portion of the biomagnetometer can be placed above the body.

Abstract: A biomagnetometer includes a dewar vessel having a helmet-shaped recess at the lower end of its body. The recess is angled at about 45 degrees to the dewar body axis of the dewar vessel. Biomagnetic sensors are positioned within the interior of the dewar vessel body around the periphery of the recess. The angled recess permits the biomagnetometer to be used with subjects whose heads are inclined from 0 to 90 degrees to the horizontal by pivoting the dewar vessel over an angle of from -45 degrees to +45 degrees to the vertical, without spilling the cryogenic fluid within the dewar or causing excessive evaporation of the cryogenic fluid.

Abstract: A magnetically shielded room has four walls, a floor, and a ceiling. One of the walls has a doorway therethrough, and a sliding door 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 to exclude radio frequency energy from the interior of the room, and at least one layer of high magnetic permeability material 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 and a layer of high magnetic permeability material 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.

Abstract: A biomagnetometer comprises an array of biomagnetic sensors, the array comprising a first plurality of magnetic field pickup coils, and a second plurality of detectors, each of which receives a pickup coil output from a pickup coil. There is a third plurality of signal processors, each of which receives an output from a detector, the third plurality of signal processors being fewer in number than the first plurality of pickup coils. The biomagnetometer further includes a selector that selects a subset of pickup coils, equal in number to the third plurality of signal processors, from the first plurality of pickup coils for signal processing by the signal processors. This biomagnetometer permits the placement of a very large array of relatively inexpensive pickup coils adjacent to a subject, and then processing information from subsets of that large array selected to optimize the gathering of data, while maintaining the cost of the signal processing electronics at a more economical level.

Abstract: A magnetometer includes a support. The support has two support surfaces that intersect each other along an intersection line. The intersection line is perpendicular to a reference axis of the support. The support surfaces are preferably perpendicular to each other and are each inclined at an angle of 45 degrees to the reference axis. A planar sensor/detector array is mounted on each support surface. Each array includes at least two pairs of magnetic field sensors and associated SQUID detectors arranged such that the magnetic field sensors lie on a line that is parallel to the intersection line of the two support surfaces. The magnetometer can be used adjacent to a surface to measure components and spatial variation of the magnetic field near the surface, with the measured components resolved into the magnetic field vectors parallel to and perpendicular to the surface.

Abstract: A biomagnetometer includes a magnetic field sensor unit having a magnetic field pickup coil. A vessel contains the sensor unit. The vessel includes a flexible contact face with the magnetic field sensor unit mounted in the interior of the vessel adjacent to the flexible contact face. Insulation at the flexible contact face of the vessel prevents excessive heat flow through the flexible contact face. Pickup units using this structure can be connected together into flexible or rigid arrays. In operation, the pickup coil is cooled to a temperature of less than its superconducting transition temperature. A detector measures the magnitude of magnetic fields sensed by the sensor unit.

Abstract: A thermally conductive feedthrough has a conductive member extending through a fiber-reinforced plastic plate. The feedthrough is sealed against leakage from one side of the plate to the other by placing the plate in local compression to seal it against the plate and/or by using small individual conductive members that minimize the effects of thermal expansion differences. The feedthrough can be used between vacuum and cryogenic liquids.

Abstract: A sensor positioning aid includes a concavely curved transparent dish having a shape congruent with a lower surface of a sensor, and locating means on the dish for establishing external reference positions in relation to the dish. The locating means preferably includes a rim around the dish and markings on the dish. The positioning aid is placed at a selected location on the head, and the sensor is aligned to the head by aligning it to the rim of the positioning aid. The positioning aid is removed, and the head translated in relation to the sensor to place it closely adjacent to the sensor, without reorienting the sensor. The placement aid is removed and measurements are taken using the sensor. If necessary, the sensor is thereafter reoriented by reference to the markings.

Abstract: A microbridge superconductor device includes a substrate, made of a material such as LaAlO.sub.3, having a lower planar substrate surface, an inclined surface having an overall upward inclination of from about 20 to about 80 degrees from the plane of the lower planar substrate surface, and an upper planar substrate surface parallel to the lower planar substrate surface and separated from the lower planar substrate surface by the inclined surface. A layer of a c-axis oriented superconductor material, made of a material such as YBa.sub.2 Cu.sub.3 O.sub.7-x, is epitaxially deposited on the lower planar substrate surface, and has an exposed a-axis edge adjacent the intersection of the lower planar substrate surface with the inclined surface. The a-axis exposed edge is beveled away from the intersection. A layer of a c-axis oriented superconductor material is epitaxially deposited on the upper planar substrate surface, and has an exposed a-axis edge adjacent the inclined surface.