公开(公告)号：US20190170841A1

公开(公告)日：2019-06-06

申请号：US16207372

申请日：2018-12-03

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Sho KAWAJIRI ,  Norio Togawa ,  Kazuhiro Hamaya

IPC: G01R33/385 ,  G01R15/20 ,  G01R19/00

Abstract: 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.

公开(公告)号：US20180372820A1

公开(公告)日：2018-12-27

申请号：US16010640

申请日：2018-06-18

Applicant: Canon Medical Systems Corporation

Inventor： Sho KAWAJIRI ,  Motohiro MIURA ,  Masahi HORI ,  Takahiro KOBAYASHI

IPC: G01R33/385

Abstract: 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.