A method for actuating a gradient coil can include the provision of a target value for a manipulated variable, the output of the manipulated variable according to the target value to the gradient coil, the capture of an actual value of the output manipulated variable, the scaling of the captured actual value taking into consideration a scaling characteristic depending on the target value, and the transformation of the actual value captured in a scaled manner into a digital actual value.

Gradient power amplifier (GPA) systems and methods are provided. A GPA system may include a plurality of paralleled GPAs; and at least one controller operably coupled to the plurality of paralleled GPAs. The at least one controller may be configured to perform operations including: obtaining a total current parameter of the plurality of paralleled GPAs; determining, based on the total current parameter and a target current parameter, a first difference value; and determining, based on the first difference value, a first control parameter of a first GPA of the plurality of paralleled GPAs, wherein the first control parameter is configured to control an output current of the first GPA.

A method for operating an MR system with a gradient pulse amplifier unit that has an end stage connected to a gradient coil with switching elements is provided. The gradient pulse amplifier unit includes a modulator for actuating the switching elements, and lockout switches interconnected in signal paths from the modulator to the switching elements. The gradient pulse amplifier unit includes feeder circuit breakers interconnected in at least some signal paths from the modulator to the switching elements. The circuit breakers are connected in the associated signal paths downstream of the lockout switches. A gradstop unit configured to receive at least one shut-off signal and actuate the lockout switches and the feeder circuit breakers. When the gradstop unit receives a shut-off signal, the gradstop unit actuates the lockout switches to lock out and the feeder circuit breakers to output an actuation signal to the switching elements.

According to some aspects, a portable magnetic resonance imaging system is provided, comprising a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging. The magnetics system comprises a permanent B.sub.0 magnet configured to produce a B.sub.0 field for the magnetic resonance imaging system, and a plurality of gradient coils configured to, when operated, generate magnetic fields to provide spatial encoding of emitted magnetic resonance signals, a power system comprising one or more power components configured to provide power to the magnetics system to operate the magnetic resonance imaging system to perform image acquisition, and a base that supports the magnetics system and houses the power system, the base comprising at least one conveyance mechanism allowing the portable magnetic resonance imaging system to be transported to different locations. According to some aspects, the base has a maximum horizontal dimension of less than or equal to approximately 50 inches. According to some aspects, the portable magnetic resonance imaging system weighs less than 1,500 pounds. According to some aspects, the portable magnetic resonance imaging system has a 5-Gauss line that has a maximum dimension of less than or equal to five feet.

A method for operating an MR system with a gradient power amplifier having at least one output stage that is connectable to a gradient coil, and having four switching elements connected to one another as an H-bridge includes, to operate the gradient coil, in alternation: switching the switching elements attached to a common first pole of a voltage supply to conductive and switching the switching elements attached to a common second pole of a voltage supply to blocking by inverting power drivers; and switching the switching elements attached to a common first pole of a voltage supply to blocking and switching the switching elements attached to a common second pole of a voltage supply to conductive by inverting power drivers. The switching elements attached to the first pole are switched by non-inverting power drivers, and the switching elements attached to the second pole are switched by inverting power drivers.

Magnetic resonance imaging (MRI) systems and methods, involving: a main magnet configured to generate a magnet field for MRI; a transmit radio frequency (RF) coil assembly configured to transmit an RF pulse into a portion of a subject; an RF coil assembly configured to, in response to the an RF pulse, receive MR signals emitted from the portion of the subject; and a gradient coil assembly having coil windings arranged in a radial layer and a first set of electrical connectors embedded in the radial layer to reduce a radial extent occupied by the gradient coil assembly, an electrical connector in the first set of electrical connectors configured to cross over a portion of the coil windings in the radial layer, the first set of electrical connectors configured to drive the coil windings with a current sufficient to generate a perturbation in the magnet field such that the MR signals encode an MR image based on the perturbation, and the radial layer having a depressed area configured to radially constrain the electrical connector.

An asymmetric electromagnet system, method, and method of producing an asymmetric electromagnet system, wherein the asymmetric electromagnet system is for generating an imaging magnetic field in an imaging region with an imaging isocentre, the imaging region being asymmetrically positioned within a gradient coil bore inside a magnetic resonance imaging (MRI) system during imaging, the electromagnet assembly comprising: an asymmetric gradient coil configured to generate a gradient field in the asymmetrically positioned imaging region, at least one gradient axis having the gradient field with a constant offset component such that the position at which the gradient field passes through zero is offset with respect to the imaging isocentre of the asymmetrically positioned imaging region.

A magnetic resonance imaging (MRI) system with low-power miniaturization, a power supply system, and a power management system are provided. The MRI system includes: a permanent magnet using samarium-cobalt material, an MR console, a transmission RF chain, a receiving RF chain, gradient coils, gradient amplifiers, and a terminal device for user interactions. Each of above systems is a ultra-light and ultra-low-power ultra-low field brain MRI system for highly accessible healthcare applications.

A coil for receiving a magnetic resonance signal is provided. The coil may include a first conductor; and a second conductor electrically coupled to the first conductor. The second conductor may extend along the first conductor. The first conductor may have at least one first opening or the second conductor may have at least one second opening. The first conductor and the second conductor may be electrically coupled using an electronic component placed at the at least one first opening or the at least one second opening so that an electric current flows between the first conductor and the second conductor through the electronic component.

Electrical converters of the present disclosure feature a boost circuit that is fully integrated with a three phase bridge rectifier to allow for obtaining a pulsed voltage at the rectifier output. Actively switchable semiconductor switches of the boost circuit are controlled by pulse width modulation (PWM) control signals to obtain the pulsed voltage. PWM of this pulsed voltage allows control of two out of three currents at the three input terminals of the rectifier, i.e., the currents at the phase inputs having the highest and the lowest voltage levels of the three phase input voltage.