Abstract: A method and apparatus is described comprising: receiving or generating a signal for transmission, wherein the signal for transmission is based on an input signal; and converting the signal for transmission into a variable magnetic field directed towards a human or animal body, wherein the variable magnetic field induces eddy currents in order to generate an electrical current signal in the human or animal body.

Abstract: A method and an arrangement to monitor localization, movement, and properties of an object, such as human body. An excitation signal is connected to a first division of selected conductors of a transducer which includes a distribution of conductors such as a matrix. A first signal including information about coupling impedance between a first and a second selected division of conductors is derived from a coupling of the excitation signal between the first and the second selected divisions of conductors of said transducer. The object is monitored by studying changes of the coupling impedance caused by the object to be monitored during subsequent repeated cycles of the above mentioned steps.

Abstract: The invention relates to a method and an arrangement to monitor localisation, movement and properties of an object (O), such as human body according to the invention an excitation signal (HS) is connected to first division of conductor of a transducer (TRANSDUCER MATRIX) which includes a distribution of conductor such as a matrix, a signal (AS) is derived from second division of conductor of said transducer (TRANSDUCER MATRIX) and said operations are to be repeated with other divisions of the transducer (TRANSDUCER MATRIX) and based on information related to coupling between divisions said monitoring will be performed.

Abstract: The invention relates an arrangement including a method and means, which may be used for registration of signals, such as EEG, ECG and EMG, from one or several objects, such as human body, animal, apparatus or equipment, or from apparatus or equipment especially in environment, such as e.g. in MRI environment, where registration is not allowed to disturb operation and correspondingly some other operation is not allowed to disturb registration or cause damages to object from which registration takes place and it is characteristic to the invention that that transducers (T1, T2) and to them attached signal means (SC, RT1, RT2) are supplied with driving energy via transmission line (TLS, TL1, TL2) and via at least one isolation means (ISOLATION) and said transfer of driving energy takes place at radio frequency essentially higher than that of said disturbing electromagnetic energy.

Abstract: A vacuum cleaner has a nozzle (N) connected to suction tubing (T) which passes air flow produced by suction from a central unit with a motor pump (M) that sucks air through the nozzle (N) and tubing (T). A portion of the air flow comes from ambient atmosphere (A) through a separate aperature (W) and passes by an ionization electrode (IP) and is directed onto the surface to be cleaned (SC) where dust particles have their electrical charge neutralized by the ionized air flow.

Abstract: The invention relates to a novel magnetic resonance imaging apparatus. The nuclei, protons or the paramagnetic electrons of an imaged object are cyclically polarized during a period of about one second with a permanent magnet which is then quickly shifted away from the imaged object in a permanent magnet carrier tube, so that the field of the permanent magnet would not have an interfering effect on the immediately following signal-collection for MRI-imaging. The permanent magnet can be manipulated or shifted back and forth in the tube either magnetically, pneumatically, hydraulically or mechanically. The apparatus also includes another permanent magnet or a resistive magnet coil couple, which is located in the tube near the opposite end of the tube, and which generates a homogeneous magnetic field within the imaged area.

Abstract: The invention relates to a method based on the NMR phenomenon and magnetic resonance imaging techniques for the examination of an object, such as a human body, an animal or a tree trunk, wherein the image-related information is collected by effecting several times the operations required by a so-called imaging sequence, wherein the excitation procedure is followed by coupling across the object a magnetic field gradient, a so-called phase-encoding gradient, produced as a resultant of one or more divergent gradient fields, and thereafter a so-called read-out gradient during which a nuclear magnetic resonance signal is collected. One or more component gradient fields of said phase-encoding gradient produce a read-out gradient in some of the sequence repetition times.

Abstract: A method for providing reference markers in magnetic resonance (MR) images which are highly discernible and accurately defined in the MR image. The method may be carried out with short imaging times. The reference markers have a volume containing NMR active nuclei and an electron spin resonance relaxant During the MRI examination procedure of an object, electron spin resonance energy is supplied to the reference markers to amplify the NMR signal from the markers by dynamic nuclear polarization. The amplification improves the visibility of the reference marker in the MR image of the object while permitting the size of the marker to be reduced to improve the accuracy by which other features appearing in the image may be located by reference to the markers. The reference markers may be used to locate anatomical features in a portion of a human body undergoing MRI examination.

Abstract: An operative instrument for the examination of an object, for example a biopsy tube or a capsule of a radioactive substance intended for radiation therapy. A part of the operative instrument, the active part, is adapted to be detected by NMR methods, such as magnetic resonance imaging, either in a manner that the active part contains a substance having NMR active nuclei or in a manner that the NMR active nuclei in proximity of the active part of the object can emit NMR signals in connection with an NMR or magnetic resonance imaging examination arrangement. A substance, a relaxant, is arranged in interaction with said NMR active nuclei, said relaxant causing activation of the NMR signal by means of dynamic nuclear polarization (DNP) when the electron spin system of said substances is saturated with external energy, i.e. saturation energy.

Abstract: The invention relates to a coil and coupling arrangement for use in equipment based on magnetic resonance, which arrangement can be applied e.g. to magnetic resonance imaging (MRI). The apparatus is adapted to operate on more than one polarizing magnetic field strength and the apparatus includes a coil arrangement for producing and detecting a resonance signal as well as for changing the energy states of spin systems. The operating states and physical properties, such as e.g. the resonance frequency, of the coil arrangement are changed by using switches or couplings whose state is controlled by the polarizing magnetic field.

Abstract: The invention relates to an imaging method for the examination of an object such as a human body, an animal or a tree trunk, based on the NMR phenomenon and magnetic resonance imaging techniques. The amplitude of excitation pulses used for producing an NMR signal is selected in a manner that a so-called excitation angle is smaller than 90.degree. and the object of these excitation pulses is subjected to electromagnetic irradiation at a frequency which is different from the resonance frequency of an NMR signal recording on the magnetic image of said object.

Abstract: The invention relates to a method and apparatus for the examination of a moving component by the application of NMR methods and dynamic nuclear polarization (DNP). The saturation of electron spins required by DNP is adapted to occur within such area of an object in which the polarizing magnetic field has a different strength from the area of object which is subjected to NMR operations.

Abstract: The invention relates to an apparatus for the examination of an object by the application of methods, such as magnetic imaging, based on nuclear magnetic resonance. The apparatus includes means for creating a first magnetic field over an object to be examined as well as means for creating and registering a nuclear magnetic resonance signal. The apparatus further includes means for creating a second magnetic field in a manner that the formation of nuclear magnetization occurring between successive excitation and signal pick-up events is at least partially effected while the second magnetic field is switched on.

Abstract: The invention relates to a method of mapping the local distribution of B.sub.1 -dispersion of relaxation tim T.sub.1.rho. of the nucleus of a certain element, such as hydrogen or phosphorus of an object, such as e.g. a human body or a part of it, or the trunk of a tree. In the method of this invention, an object area is first subjected to a first excitation pulse, which tilts the magnetization of the nuclei of said object area preferably 90.degree. and thereafter to a locking pulse, whose phase and frequency are selected in a manner that relaxation with respect to the magnetic vector of this locking pulse takes place, followed by performing the required procedures by applying per se known nuclear spin imaging methods, and the above sequence of operations is repeated as many times as desired by changing the amplitude of said locking pulse.

Abstract: A method of mapping the local distribution of the coupling constant J and for the application of this method, as for example, for examining the dynamic properties of an object. The object is excited with a first (90.degree.) excitation pulse. A magnetic field gradient is applied to the object and after a first time delay, the object is subjected to a second (180.degree.) excitation pulse. A magnetic field gradient is reapplied and after a second time delay, the spin echo signal is obtained. The sequence is repeated by changing the first and second delay times and changing the time integrals of the magnetic field gradients in accordance with the selected NMR imaging method. The second excitation pulse is preferably maintained at the midway point of the time between the first excitation pulse and the spin echo. The method may be used to analyze metabolic or physiological properties by using tracers with nuclei having coupling constants differing from the nuclei normally present in the object.

Abstract: A method for determining the spatial distribution of an NMR responsive element in a selected volume of an object to be examined and the relaxation time in the rotating frame (Tl .rho.) of nuclei of the element. An external magnetic field is applied to the selected volume of the object. The nuclei in the selected volume are excited by a first electromagnetic pulse for generating a nuclear magnetization transverse to the direction of the main magnetic field. A second electromagnetic pulse is applied to the selected volume. The second pulse is oscillatory and has a phase selected such that the magnetic component of the pulse is directed parallel to the direction of the processing transverse nuclear magnetization. The relaxation obtained during this second pulse occurs in a rotating reference frame and is characterized by the relaxation time Tl .rho..

Abstract: The invention relates to a method of recovering nuclear spin or NMR information about a target, such as a human body placed in at least substantially homogenous magnetic field, a desired part of the target being excited by means of a radiofrequency magnetic field which preferably deviates nuclear magnetization through 90.degree., a so-called spin echo is generated by utilizing a second excitation of the target volume which preferably deviates nuclear magnetization through 180.degree., said spin echo is recorded and said excitation sequence is repeated. At least one magnetic field is applied to the target in a manner that the duration and/or amplitude of said magnetic field gradient are varied between various repetitions, so that the difference between the absolute values of time integral of a value following said 180.degree. pulse and a value preceding said 180.degree. pulse of said magnetic field gradient obtains a different value. This way, the use of bipolar current sources is avoided.

Abstract: A nuclear magnetic resonance signal is collected from a target by using a special pulse sequence which is repeated and, between various repetitions, the relative temporal ratio of signal collection and excitation events is changed. The pulse sequence consists e.g. of the following actions: a target zone is first excited with a so-called 90.degree. pulse followed by coupling of magnetic field gradients in a manner that re-excitation of the target with a 180.degree. pulse serves to generate a so-called spin echo, which is stored and during which at least one magnetic field gradient is turned on. If the purpose is to image a three-dimensional target, e.g. the first excitation event can be effected by using so-called selective excitation and by using a gradient pulse orthogonal to the direction of a read gradient for phase encoding a nuclear system.

Abstract: The invention relates to a nuclear spin or NMR imaging assembly, comprising apparatus (1) for generating a homogeneous magnetic field in a region to be imaged of a target examined, sets of gradient coils (3) for producing one or more magnetic field gradients perpendicular to each other in said homogeneous magnetic field, a signal coil (2) surrounding at least substantially a region to be imaged for exciting said region with radio-frequency pulses and for receiving the generated NMR signals from the region to be imaged, amplifiers (5, 7) and filters (9, 10) for detected NMR signals, as well as a data processor and display equipment for imaging the collected information.

Abstract: An adjustable signal coil, for example a solenoid, saddle or Helmholz type of signal coil which is used in a nuclear spin or NMR examination assembly, includes a pair of adjustable conductor guide and profile supports which hold one or more turns of a conductor forming the signal coil. The coil volume is changed by adjusting the supports to correspond to different sizes of targets to be positioned and examined inside the coil. In a disclosed embodiment, the coil volume is cylindrical and has its diameter changed by adjusting the spacing between the pair of supports, and the coil turn length and size, are adjusted by sliding guides within guideways of the supports.