43 results about "Electric field NMR" patented technology

A magnetic field measuring device useful for measuring a magnetic field associated with an electric current, including a bus section connectable into the path of the electric current, a first magnetoresistive (MR) bridge oriented to be sensitive to the magnetic field of a current in the bus section, a second MR bridge oriented to be substantially insensitive to the magnetic field of a current in the bus section, a biasing coil configured and positioned to apply a magnetic field to the first and second MR bridges, whereby the sensitivity of the first MR bridge can be controlled; and a signal processing device responsive to a voltage output of the second MR bridge to control the current through the biasing coil. The device exhibits good rejection of stray magnetic and electric fields, is convenient to use, and can be fabricated in a single chip, with or without associated signal processing and conditioning circuitry, using conventional IC processing techniques.

A magnetic field measuring device useful for measuring a magnetic field associated with an electric current, including a bus section connectable into the path of the electric current, a first magnetoresistive (MR) bridge oriented to be sensitive to the magnetic field of a current in the bus section, a second MR bridge oriented to be substantially insensitive to the magnetic field of a current in the bus section, a biasing coil configured and positioned to apply a magnetic field to the first and second MR bridges, whereby the sensitivity of the first MR bridge can be controlled; and a signal processing device responsive to a voltage output of the second MR bridge to control the current through the biasing coil. The device exhibits good rejection of stray magnetic and electric fields, is convenient to use, and can be fabricated in a single chip, with or without associated signal processing and conditioning circuitry, using conventional IC processing techniques.

Nanosecond pulsed electric field (nsPEF) treatments of a tumor are used to cause the tumor to express calreticulin and stimulate an immune response against the tumor and other tumors in a subject. An immune response biomarker can be measured, and further nsPEF treatments can be performed if needed to stimulate or further stimulate the immune response. Cancers that have metastasized may be treated. The treatment can be combined with CD47-blocking antibodies, doxorubicin, CTLA-4-blocking antibodies, and / or PD-1-blocking antibodies. Electrical characteristics of nsPEF treatments can be based on the size, type, and / or strength of tumors and / or a quantity of tumors in the subject.

A method and apparatus for exciting gas that involves generating an alternating magnetic field unidirectionally through a magnetic core defining a gap, across the gap and through a plasma vessel that includes dielectric material. The magnetic field induces an electric field in the plasma vessel that generates the plasma.

A RF field sensor in which a magnetostrictive film is deposited on one or more electrodes of one or more quartz resonator(s) in which an electric field of the RF field is detected along one axis of the RF field sensor and a magnetic field of the RF field is detected along an orthogonal axis of the RF field sensor simultaneously.

NMR probe coils designed to operate at two different frequencies, producing a strong and homogenous magnetic field at both the frequencies. This single coil, placed close to the sample, provides a method to optimize the NMR detection sensitivity of two different channels. In addition, the present invention describes a coil that generates a magnetic field that is parallel to the substrate of the coil as opposed to perpendicular as seen in the prior art. The present invention isolates coils from each other even when placed in close proximity to each other. A method to reduce the presence of electric field within the sample region is also considered. Further, the invention describes a method to adjust the radio-frequency tuning and coupling of the MAR probe coils.

NMR probe coils designed to operate at two different frequencies, producing a strong and homogenous magnetic field at both the frequencies. This single coil, placed close to the sample, provides a method to optimize the NMR detection sensitivity of two different channels. In addition, the present invention describes a coil that generates a magnetic field that is parallel to the substrate of the coil as opposed to perpendicular as seen in the prior art. The present invention isolates coils from each other even when placed in close proximity to each other. A method to reduce the presence of electric field within the sample region is also considered. Further, the invention describes a method to adjust the radio-frequency tuning and coupling of the MAR probe coils.

A coil apparatus for use in a transcranial magnetic stimulation apparatus is provided in which the coil apparatus includes a coil arranged to oppose a surface of a head of a human to generate a current by an induced electric field in a magnetic stimulation-target region in a brain by electromagnetic induction, and to stimulate neurons. The coil apparatus includes the coil configured by winding a conductive wire along a predetermined reference surface; and a magnetic body arranged between the head and the coil to oppose the coil, and arranged at a position at an opposite side of the head. The magnetic body is provided for flowing a current therein by an induced electric field when the coil is driven, and for increasing the current flowing by the induced electric field in a magnetic stimulation-target region of the brain as compared with that with no magnetic body.

RF electric fields produced by electric potential differences in the NMR probe coil windings may penetrate the NMR sample and sample tube causing sensitivity loss and increased noise in NMR spectroscopy. Electrically conducting strips in close proximity to the windings of the NMR probe coil and oriented at right angles to direction of the coil winding they cross provide an alternative path for these electric fields while causing negligible effect upon the RF magnetic field, thereby increasing the sensitivity of the NMR probe.

RF electric fields produced by electric potential differences in NMR probe coil windings may penetrate the NMR sample and sample tube causing sensitivity loss and noise in NMR spectroscopy. Counter-wound spiral coils placed on the opposite surfaces of a planar substrate or on two adjacent planar substrates produce electric potentials that minimize the electric field over the sample region, thereby increasing the sensitivity of the NMR probe. Alternatively counter-wound spiral coils placed adjacent to each other on the outer surface of two concentric cylindrical surfaces that surround the NMR sample minimize the electric field over the sample region. The electric potential of the spiral coils is reduced by adjusting a length of at least one coil.

With a view to attaining a high quality of a diagnostic image there is provided a magnetic resonance imaging apparatus wherein an image is formed on the basis of magnetic resonance signals received from a subject with an electromagnetic wave transmitted thereto in a static magnetic field. The magnetic resonance imaging apparatus is provided with plural receiving coil units for receiving the magnetic resonance signals, the receiving coil units each comprising a coil body configured to receive a corresponding one of the magnetic resonance signals and output an electrical signal and an optical modulator configured to use an electric field of the electric signal outputted from the coil body directly as a modulation signal.

The invention relates to a microwave and plasma interacting device in magnetic plasma, in particular to a microwave and plasma interacting device in magnetic plasma under the condition that a magnetic field and an electric field are perpendicular. The microwave and plasma interacting device aims to solve the problem that no microwave and plasma interacting device under the characteristic situation of the different magnetic plasma exists in the prior art. The microwave and plasma interacting device comprises a microwave generator, a ferrite isolator, an attenuator, a directional coupler, a waveguide tube, an insulation microwave window, a vacuum cavity, a plurality of solenoids, a diaphragm, a plasma source, two Langmuir probes, a cut-off tube, a matching microwave load, a loop antenna, a magnetic probe, an electrostatic probe, a multiple-grid probe and a plasma visualizer, wherein the plasma source is a sparking plasma source, generated sparking voltage is used for controlling the density of the plasma, and the attenuator is used for adjusting microwave power. The microwave and plasma interacting device is used for researching the interaction between the microwave and the plasma under the characteristic condition of the different magnetic plasma.

A magnetic coil system featuring a multi-layer structure (312a, 312b), a spherical shape, or both allows for efficient generation of a gradient magnetic field that induces an electric field in air in a region proximate to the coil. By subjecting at least a portion of a person's brain to the induced electric field various psychiatric disorders can be treated.

The invention discloses a passive optical electric field sensor for measuring electric fields or high voltages, belonging to the technical field of electric measurement. The passive optical electric field sensor comprises two optical crystals, wherein one of the optical crystals is positioned in the environments of a tested electric field as well as interference fields such as temperature, vibration and the like, and the other optical crystal is only positioned in the environments of interference fields such as the same temperature, vibration and the like; and after polarized light is emittedby the two crystals, modulation of interference fields such as temperature, vibration and the like is eliminated. A signal which is proportional to the tested electric field or a high voltage is output though a signal processing circuit, and is not influenced by interference factors such as temperature, vibration and the like. The optical electric field sensor disclosed by the invention can be used for measuring electric fields or high voltages, is particularly used for detecting electric fields in the power industry, monitoring electric fields or high voltages of buses, has high stability, and is not influenced by temperature or stress easily.

A microwave generator comprises a magnetron having an anode and a cathode, oscillating by the current supplied to the anode, and generating a microwave, electric-field controlling means for controlling one of the frequency / phase and the amplitude of the microwave by varying the electric field, and magnetic-field varying means for stabilizing the other by varying the magnetic field.

The present invention provides a system for detecting and analyzing at least one of an electric field and an electromagnetic field. The system includes a micro / nanomechanical oscillator which oscillates in the presence of at least one of the electric field and the electromagnetic field. The micro / nanomechanical oscillator includes a dense array of cantilevers mounted to a substrate. A charge localized on a tip of each cantilever interacts with and oscillates in the presence of the electric and / or electromagnetic field. The system further includes a subsystem for recording the movement of the cantilever to extract information from the electric and / or electromagnetic field. The system further includes a means of adjusting a stiffness of the cantilever to heterodyne tune an operating frequency of the system over a frequency range.

A pulsed electrostatic / electric field generator apparatus providing a source of large quantity, free slow-speed high energy free electrons, or high energy positive ions, contained in an electrostatic / electric field capacity exceeding 1 Joule. The pulsed electrostatic / electric field generator apparatus encapsulates an enclosed non-equilibrium, non-thermal pulsed power plasma. A key subcomponent of this apparatus incorporates an innovative unipolar piezoelectric capacitor creating high voltage nanosecond rise time pulses in a multistage high energy step-up pulsed plasma generation sequence of steps. The resulting multi-Joule electrostatic / electric field is then tapped to provide a source of current and / or potential for use by external loads.

The present invention describes NMR probe coils that are designed to operate at two different frequencies, producing a strong and homogenous magnetic field at both the frequencies. This single coil, placed close to the sample, provides a method to optimize the NMR detection sensitivity of two different channels. In addition, the present invention describes a coil that generates a magnetic field that is parallel to the substrate of the coil as opposed to perpendicular as seen in the prior art. The present invention isolates coils from each other even when placed in close proximity to each other. A method to reduce the presence of electric field within the sample region is also considered. Further, the invention describes a method to adjust the radio-frequency tuning and coupling of the NMR probe coils.

The Centroidal Cyclotron reveals an apparatus and method for accelerating and trapping charged particles in a solenoid magnetic field. An oscillating electric field is applied generally transverse to the magnetic field axis accelerating and trapping charged particles by their inherent cyclotron frequency at a given magnetic field of the solenoid magnetic field producing charged particle orbits with minimum canonical angular momentum orbits and gyro-phase synchrony.

The invention discloses a magnetic deflection mass spectrometer based on a cylindrical electric field analyzer, and belongs to the technical field of instruments. The magnetic deflection mass spectrometer mainly comprises an ion source, a first slit, a cylindrical electric field analyzer, a second slit, a magnetic field analyzer and an ion flow detector; wherein, the cylindrical electric field analyzer and the magnetic field analyzer are connected in a reversed series connection; the magnetic deflection mass spectrometer ensures mutual offset of energy dispersion generated by magnetic fields and electric fields, so that the magnetic deflection mass spectrometer has dual focusing capability of energy and direction, and distinguishing ability is substantially improved.

The invention relates to the field of medical diagnostics and can be used in magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) for increasing the quality of diagnostics of the internal organs of humans and animals. By virtue of a metamaterial, which is used as an electromagnetic field amplifier, being made from a set of advantageously oriented conductors, it becomes possible to spatially rearrange magnetic and electric fields operated at radio frequencies. In particular, in the examined object area, the radio frequency magnetic field is resonantly amplified, which makes it possible to increase the signal / noise ratio in MRI and to obtain better quality images and / or to perform the MRI examinations more quickly as there is no need to accumulate the signal. The proposed design of the metamaterial makes it possible to distance the radio frequency electric field from the area where the examined object is located, therefore enhancing safety of MRI scanning.

The invention discloses a comprehensive electric / magnetic field generation system. The system comprises an upper computer, a gradient magnetic field generation device and an electromagnetic field device, wherein the upper computer is connected with the gradient magnetic field generation device through a data line; the gradient magnetic field generation device is connected with the electromagneticfield device through a power cable; the electromagnetic field device comprises a first plate gradient coil, a second plate gradient coil which is parallel to the first plate gradient coil, and a plurality of plane excitation electric field coils which are alternately arranged between the first plate gradient coil and the second plate gradient coil; and during the work, magnetic fields in graded distribution are formed on the surfaces of the plane excitation electric field coils between the first plate gradient coil and the second plate gradient coil, and the plane excitation electric field coils at different positions generate different electric fields, so that two physical field environments such as electric field and magnetic field are realized. The system can be used for researching biological effects and biological response mechanisms under multi-physical field environment.

The present invention provides a method and apparatus for delivering an electric field to a body by delivering a first magnetic field from a first coil in a first orientation to a body and directed at a desired target within the body, and delivering a second magnetic field from a second coil in a second orientation directed at the desired target within the body to induce an electric field across the desired target, wherein only one magnetic field is delivered to the body at any one time.

The invention belongs to the technical field of electric field measurement, and particularly relates to a method for jointly analyzing an air gap discharge process by means of optical and electric field signals. The method comprises the steps of applying voltages of different amplitudes multiple times, and measuring ultraviolet transient optical power emitted by halos and amplitude at an electricfield jumping position, and determining an initial moment of the halo and severity of corona ionization by utilizing spatial electric field changes. The voltages of different amplitudes are applied repeatedly at each interval of certain time, thereby ensuring that spatial charges generated in the discharging process are sufficiently dissipated. Through comparing the electric field changes obtainedthrough measurement by means of an electric field sensor with the corona luminous intensity measured by means of a photomultiplier tube, the effectiveness of the severity of the corona measured by means of an electric field sensor is illustrated.

An electric stimulator for heart (as in heart pacemakers), brain (as in DBS), organs and general cells, with a supporting structure where there exists a first plurality of electrically isolated electrodes called field-shaping electrodes that are located under the surface of the supporting structure, and a second plurality of ordinary electrically stimulating electrodes called active electrodes, that are located at the surface of the supporting structure, capable of injecting electric charges in the space surrounding the supporting structure. Both types of electrodes are controlled by an appropriate electronics control unit and powered by some electric energy storage, as a battery. Field-shaping electrodes are electrically insulated, being unable to inject current in the surrounding medium, but they are capable of shaping the electric field, which has consequence on the path of the stimulating currents injected by active electrodes. The invention also discloses positioning the field-shaping electrodes underneath the active electrodes.

A magnetic coil system featuring a multi-layer structure (312a, 312b), a spherical shape, or both allows for efficient generation of a gradient magnetic field that induces an electric field in air in a region proximate to the coil. By subjecting at least a portion of a person's brain to the induced electric field various psychiatric disorders can be treated.

A microwave generator comprises a magnetron having an anode and a cathode, oscillating by the current supplied to the anode, and generating a microwave, electric-field controlling means for controlling one of the frequency / phase and the amplitude of the microwave by varying the electric field, and magnetic-field varying means for stabilizing the other by varying the magnetic field.

The invention discloses an electron shift type electric field intensity sensor based on the principle that electron beam shifts in electric field under vacuum environment, and belongs to the technicalfield of electric field measurement. The sensor mainly comprises an electron gun assembly, an accelerating electric field, a speed screening magnetic field generation device, screening holes, a decelerating electric field assembly, a charge coupling device, an electric field shielding cover, and a magnetic field shielding cover. According to the electron shift type electric field intensity sensor, the electric field sensor is less affected by body potential, and is suitable for measuring electrostatic field, DC electric field, and low frequency AC electric field; the miniaturization of the sensor product can be realized; the measurement resolution and the result accuracy is high; one set of the device can realize two-dimensional measurement of the electric field; two sets of the same devices placed vertically can realize three-dimensional measurement of the electric field, wherein the second set of the device can share parts of components of the first set of the device; and the electric field sensor can be used to measure two-dimensional or three-dimensional electric field intensity, and can also be used to measure two-dimensional or three-dimensional magnetic field intensity.