Abstract: A magnetic modulator for detection of a very small magnetic field and current, comprising a rectangular or annular one-piece magnetic core divided into a plurality of core legs which are adapted to be provided with exciting inputs in opposite directions to each other and with signal inputs in parallel thereto, and detecting coils wound around each leg so as to function differentially with respect to the core noise and the exciting input and cumulatively with respect to the signal input, thereby adequately reducing the core noise and well improving the signal-noise ratio.

Abstract: This invention relates to a method of obtaining information of a specified or target area of a living body near its skin surface by the application of a nuclear magnetic resonance phenomenon (NMR). This invention comprises a static magnetic field generator for generating a static magnetic field H.sub.0, a radio-frequency magnetic field generator for generating a radio-frequency magnetic field H.sub.1 perpendicular to said static magnetic field H.sub.0 and having a nuclear magnetic resonance frequency f.sub.0, and means disposed in close proximity to said target area for focusing one or both of said magnetic fields thereon, and relates to a method of obtaining, with a high signal to noise (SN) ratio and with ease, information of a specified area of a living body from the outside or inside of the body.

Abstract: This invention relates to a method of obtaining internal information of the body to be investigated (target) by the application to the target of a nuclear magnetic resonance phenomenon, in which the measuring target is placed in a homogeneous magnetic field Ho and a static or scanning magnetic field H.sub.s is superimposed on the homogenous magnetic field Ho within a specified area of the target; from the inside or outside thereof. A high frequency field H.sub.1 of a frequency determined by the static field H.sub.o +.DELTA.H.sub.s in the measuring target area (MT) is applied uniformly to the body thereby obtaining information of a nuclear magnetic substance disposed within the specified area of the body, i.e., the measuring target in accordance with detection of a resonance frequency defined by H.sub.o +.DELTA.H.sub.s. Alternatively, the scanning field .DELTA.H.sub.s may be applied to the body only outside of the target region and a resonance frequency defined by H.sub.