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公开(公告)号：US10884083B2
公开(公告)日：2021-01-05
申请号：US16207372
申请日：2018-12-03
发明人： Sho Kawajiri , Norio Togawa , Kazuhiro Hamaya
IPC分类号： G01R31/00 , G01R33/385 , G01R19/00 , G01R15/20
摘要： A gradient magnetic field power supply, connected to a first coil and a second coil for each applying a gradient magnetic field to an object, the power supply, according to an embodiment includes a first current sensor and a second current sensor. The second current sensor is provided such that a direction of a current detectable by the second current sensor crosses a direction of a current detectable by the first current sensor.
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公开(公告)号：US10371772B2
公开(公告)日：2019-08-06
申请号：US15377249
申请日：2016-12-13
发明人： Sho Kawajiri , Motohiro Miura , Naoyuki Furudate , Yutaka Machii
IPC分类号： G01V3/00 , G01R33/385 , G01R33/3875
摘要： According to one embodiment, a magnetic resonance imaging apparatus includes a gradient magnetic field power supply, a voltmeter, and processing circuitry. The gradient magnetic field power supply includes an amplifier amplifying an input signal based on information of a gradient magnetic field waveform and outputting the amplified input signal to a gradient coil, a power supply device supplying power to the amplifier, and a capacitor bank supplying power, together with the power supply device, to the amplifier. The voltmeter measures a voltage of the capacitor bank. The processing circuitry calculates frequency characteristics of an impedance of the gradient coil, based on a voltage variation of the capacitor bank which was measured by the voltmeter, and controls imaging in accordance with the calculated frequency characteristics.
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公开(公告)号：US11372062B2
公开(公告)日：2022-06-28
申请号：US17070078
申请日：2020-10-14
发明人： Sadanori Tomiha , Takafumi Ohishi , Sho Kawajiri , Satoshi Imai
IPC分类号： G01R33/34
摘要： According to one embodiment, a coil element includes an extendable and contractible coil and a capacitor. The capacitor is connected to the coil and has an electrostatic capacity which changes due to a physical change in response to extension or contraction of the coil.
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公开(公告)号：US11105872B2
公开(公告)日：2021-08-31
申请号：US16010640
申请日：2018-06-18
发明人： Sho Kawajiri , Motohiro Miura , Masashi Hori , Takahiro Kobayashi
IPC分类号： G01R33/385
摘要： According to one embodiment, a magnetic resonance imaging apparatus includes an amplifier, a gradient coil, and adjusting circuitry. The amplifier includes pulse width modulation circuitry modulating a pulse width of a driving signal, which is input to switching elements, in accordance with an input of a control signal corresponding to a waveform of a gradient magnetic field. The gradient coil generates the gradient magnetic field by an electric current supplied in accordance with an output voltage which is output from the amplifier. The adjusting circuitry executes adjustment of a gain of the amplifier, which is included in the control signal, or adjustment of the pulse width of the driving signal, in accordance with a dead time included in a switching cycle of the switching elements.
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公开(公告)号：US10989775B2
公开(公告)日：2021-04-27
申请号：US16183055
申请日：2018-11-07
发明人： Sho Kawajiri , Motohiro Miura , Masashi Hori
IPC分类号： G01R33/385 , G01R33/36 , G01R33/48 , G01R33/54
摘要： According to one embodiment, a magnetic resonance imaging apparatus includes amplifiers, processing circuitry, and a power supplier. The amplifiers supplies power for each of a plurality of channels of gradient coils. The processing circuitry obtains, for each of the channels, a voltage gradient that represents a temporal change of a power supply voltage for supplying a current to the amplifiers. The power supplier supplies the power to an amplifier corresponding to a specific one of the channels on a priority basis in accordance with the voltage gradient.
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