Patents by Inventor Kohjiro IWASAWA
Kohjiro IWASAWA has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11885856Abstract: Provided is a coil device capable of improving operability or durability thereof, being attached to a subject in a close contact state regardless of the size of a head of the subject, and obtaining a high-quality MRI image. The coil device includes at least one coil unit which has a coil element and a coil support portion which has a mechanism for attaching the coil unit to a head of a subject. The coil support portion includes a base portion, a support body which is connected to the base portion and has an elastic member, and a holder which connects the support body to the at least one coil unit and the holder has at least three contact points which are formed directly or indirectly with respect to the base portion.Type: GrantFiled: October 23, 2020Date of Patent: January 30, 2024Assignee: FUJIFILM HEALTHCARE CORPORATIONInventors: Kohjiro Iwasawa, Takanori Nishiyama, Kazuyuki Kato, Hideta Habara, Yosuke Otake, Satoshi Yamashita, Toru Shirai
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Patent number: 11774527Abstract: The receiving coil device includes one or a plurality of receiving coils configured to cover a head of a subject, a base portion on which the head of the subject is to be placed, a holder portion supported by the base portion, one of the receiving coils being fixed to the holder portion, a mechanism portion configured to bring the receiving coil fixed to the holder portion into close contact with a part of the head, and further, a detection unit configured to detect a physical quantity related to a displacement of the holder portion on the holder portion or the base portion. The physical quantity detected by the detection unit is sent to an MRI apparatus including the receiving coil device.Type: GrantFiled: January 26, 2022Date of Patent: October 3, 2023Assignee: FUJIFILM Healthcare CorporationInventors: Kohjiro Iwasawa, Yosuke Otake, Hideta Habara, Kazuyuki Kato, Toru Shirai, Yukio Kaneko, Hikaru Hanada
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Publication number: 20220268864Abstract: The receiving coil device includes one or a plurality of receiving coils configured to cover a head of a subject, a base portion on which the head of the subject is to be placed, a holder portion supported by the base portion, one of the receiving coils being fixed to the holder portion, a mechanism portion configured to bring the receiving coil fixed to the holder portion into close contact with a part of the head, and further, a detection unit configured to detect a physical quantity related to a displacement of the holder portion on the holder portion or the base portion. The physical quantity detected by the detection unit is sent to an MRI apparatus including the receiving coil device.Type: ApplicationFiled: January 26, 2022Publication date: August 25, 2022Inventors: Kohjiro IWASAWA, Yosuke OTAKE, Hideta HABARA, Kazuyuki KATO, Toru SHIRAI, Yukio KANEKO, Hikaru HANADA
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Patent number: 11199596Abstract: A high-frequency array coil for an MRI apparatus includes: a plurality of coil units each of which includes a plurality of RF reception coils including a conductor loop and adjusted to receive a magnetic resonance signal; an extension conductor which includes a part of each conductor loop of each RF reception coil of the plurality of coil units and a conductor connecting the parts; and an extension conductor control circuit which adjusts a reception frequency of the extension conductor. The extension conductor is disposed so as to be wound in a spiral shape when the extension conductor is disposed on a subject and a direction of a magnetic field to be detected intersects a direction of a magnetic field detected by the RF reception coil constituting the coil unit. Accordingly, the detection efficiency of an RF coil can be increased and an image with a high SNR can be obtained.Type: GrantFiled: August 23, 2018Date of Patent: December 14, 2021Assignee: HITACHI, LTD.Inventors: Yosuke Otake, Kohjiro Iwasawa, Masayoshi Dohata, Hisaaki Ochi, Takahide Shimoda
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Patent number: 11193993Abstract: A flexible RF coil with excellent portability is provided. The RF coil includes a first coil, a first skeleton, and a second skeleton, the first skeleton and the second skeleton being rod shaped. The first coil includes a first loop made from a conductor that receives radio frequency signals, and a first signal detector that is inserted in series into the first loop and that detects the signals received by the first loop. The first skeleton and the second skeleton are arranged with a spacing in the short axis direction, the first signal detector is mounted on the first skeleton, and a portion of the first loop that faces the first signal detector is mounted on the second skeleton. The first loop is deformable, and the spacing between the first skeleton and the second skeleton is changeable in accordance with the deformation of the first loop.Type: GrantFiled: January 31, 2020Date of Patent: December 7, 2021Assignee: HITACHI, LTD.Inventors: Yosuke Otake, Kohjiro Iwasawa, Toru Shirai
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Publication number: 20210278489Abstract: Provided is a coil device capable of improving operability or durability thereof, being attached to a subject in a close contact state regardless of the size of a head of the subject, and obtaining a high-quality MRI image. The coil device includes at least one coil unit which has a coil element and a coil support portion which has a mechanism for attaching the coil unit to a head of a subject. The coil support portion includes a base portion, a support body which is connected to the base portion and has an elastic member, and a holder which connects the support body to the at least one coil unit and the holder has at least three contact points which are formed directly or indirectly with respect to the base portion.Type: ApplicationFiled: October 23, 2020Publication date: September 9, 2021Inventors: Kohjiro IWASAWA, Takanori NISHIYAMA, Kazuyuki KATO, Hideta HABARA, Yosuke OTAKE, Satoshi YAMASHITA, Toru SHIRAI
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Publication number: 20210072331Abstract: A high-frequency array coil for an MRI apparatus includes: a plurality of coil units each of which includes a plurality of RF reception coils including a conductor loop and adjusted to receive a magnetic resonance signal; an extension conductor which includes a part of each conductor loop of each RF reception coil of the plurality of coil units and a conductor connecting the parts; and an extension conductor control circuit which adjusts a reception frequency of the extension conductor. The extension conductor is disposed so as to be wound in a spiral shape when the extension conductor is disposed on a subject and a direction of a magnetic field to be detected intersects a direction of a magnetic field detected by the RF reception coil constituting the coil unit. Accordingly, the detection efficiency of an RF coil can be increased and an image with a high SNR can be obtained.Type: ApplicationFiled: August 23, 2018Publication date: March 11, 2021Inventors: Yosuke OTAKE, Kohjiro IWASAWA, Masayoshi DOHATA, Hisaaki OCHI, Takahide SHIMODA
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Patent number: 10852372Abstract: An MRI image with high image quality can be acquired regardless of a size of an examinee. An array coil includes: a coil unit in which a plurality of sub-coils which includes a loop coil portion in which a conductor having flexibility with a predetermined length is curved and which is adjusted to receive a magnetic resonance signal from an examinee are arranged at predetermined intervals; and a coil casing that is formed of a sheet-shaped material which expands and contracts in at least one direction and accommodates the coil unit therein. At least one position of each of the plurality of sub-coils is fixed to the coil casing and an inter-center distance between the sub-coils varies with expansion and contraction of the coil casing.Type: GrantFiled: April 15, 2019Date of Patent: December 1, 2020Assignee: HITACHI, LTD.Inventors: Kohjiro Iwasawa, Yosuke Otake, Kazuyuki Kato, Hisaaki Ochi
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Patent number: 10761158Abstract: A multichannel array coil of an MRI apparatus achieves both a wide sensitivity and low noise. An RF coil (array coil) is provided with a plurality of subcoils. Each of those subcoils is adjusted to be receivable of nuclear magnetic resonance signals, and also adjusted so that a part of current (first current) passing through one subcoil upon receipt of the signals flows into the other subcoil in the form of sub-current. A flowing direction of the first current is opposite to the flowing direction of the sub-current, and an electric field generated by the first current within a subject and an electric field generated by the first sub-current within the subject intensify each other in the space between a first loop coil unit and a second loop coil unit. Accordingly, noise correlation that is determined by an inner product of the electric fields is reduced, thereby achieving low noise.Type: GrantFiled: February 17, 2017Date of Patent: September 1, 2020Assignee: HITACHI, LTD.Inventors: Yosuke Otake, Hisaaki Ochi, Kohjiro Iwasawa
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Publication number: 20200256937Abstract: An object of the present invention is to provide a radio-frequency coil device that can be brought into close contact with a subject regardless of a size of the subject and can obtain a high-quality MRI image. The radio-frequency coil device includes at least one flexible coil unit, and a fixture is disposed to surround an outer periphery of the coil unit. The fixture includes, for example, a pair of panels disposed on both sides of the coil unit, and a fixing belt that is provided between the panels and fastens and fixes the panels. The coil unit is deformed by fastening the fixture, to be disposed in close contact with various head shapes.Type: ApplicationFiled: January 31, 2020Publication date: August 13, 2020Inventors: Kohjiro IWASAWA, Kazuyuki KATO, Hideta HABARA, Yosuke OTAKE, Satoshi YAMASHITA
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Publication number: 20200249291Abstract: A flexible RF coil with excellent portability is provided. The RF coil includes a first coil, a first skeleton, and a second skeleton, the first skeleton and the second skeleton being rod shaped. The first coil includes a first loop made from a conductor that receives radio frequency signals, and a first signal detector that is inserted in series into the first loop and that detects the signals received by the first loop. The first skeleton and the second skeleton are arranged with a spacing in the short axis direction, the first signal detector is mounted on the first skeleton, and a portion of the first loop that faces the first signal detector is mounted on the second skeleton. The first loop is deformable, and the spacing between the first skeleton and the second skeleton is changeable in accordance with the deformation of the first loop.Type: ApplicationFiled: January 31, 2020Publication date: August 6, 2020Applicant: HITACHI, LTD.Inventors: Yosuke OTAKE, Kohjiro IWASAWA, Toru SHIRAI
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Patent number: 10641845Abstract: A technique for reconciling large sensitivity area and high sensitivity for deep part in a multi-channel array coil of an MRI apparatus without complicating the configuration, and realizing both higher speed imaging and high image quality is provided. An RF coil (array coil) of a magnetic resonance imaging apparatus comprising a plurality of subcoils is provided. At least one of the subcoils is a first subcoil of which resonance frequency as that of the subcoil alone differs from magnetic resonance frequency. The first subcoil is adjusted so that it magnetically couples with a second subcoil, which is at least one other subcoil, and thus resonates at the same frequency as the magnetic resonance frequency. Input and output terminals of the first subcoil and the second subcoil are connected to different low input and output impedance signal processing circuits, respectively.Type: GrantFiled: August 7, 2015Date of Patent: May 5, 2020Assignee: Hitachi, Ltd.Inventors: Yosuke Otake, Hisaaki Ochi, Kohjiro Iwasawa
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Patent number: 10520564Abstract: In a multi-channel array coil used as an RF coil of an MRI apparatus, even when magnetic coupling occurs between the respective sub-coils, it is possible to suppress the influence of a current flowing through the sub-coil of a coupling counterpart to maintain the desired sensitivity and suppress deterioration of image quality. Therefor, even when magnetic coupling occurs between sub-coils constituting the multi-channel array coil used as the RF coil of the MRI apparatus, the sub-coils are connected to a signal processing circuit so that a phase difference between a rotating magnetic field generated by the influence of a current flowing through the sub-coil of the coupling counterpart and a rotating magnetic field generated by the sub-coil is less than 90 degrees.Type: GrantFiled: August 22, 2016Date of Patent: December 31, 2019Assignee: Hitachi, Ltd.Inventors: Yosuke Otake, Hisaaki Ochi, Kohjiro Iwasawa
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Publication number: 20190383891Abstract: An MRI image with high image quality can be acquired regardless of a size of an examinee. An array coil includes: a coil unit in which a plurality of sub-coils which includes a loop coil portion in which a conductor having flexibility with a predetermined length is curved and which is adjusted to receive a magnetic resonance signal from an examinee are arranged at predetermined intervals; and a coil casing that is formed of a sheet-shaped material which expands and contracts in at least one direction and accommodates the coil unit therein. At least one position of each of the plurality of sub-coils is fixed to the coil casing and an inter-center distance between the sub-coils varies with expansion and contraction of the coil casing.Type: ApplicationFiled: April 15, 2019Publication date: December 19, 2019Applicant: Hitachi, Ltd.Inventors: Kohjiro IWASAWA, Yosuke OTAKE, Kazuyuki KATO, Hisaaki OCHI
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Publication number: 20190041476Abstract: A multichannel array coil of an MRI apparatus acheives both a wide sensitivity and low noise. An RF coil (array coil) is provided with a plurality of subcoils. Each of those subcoils is adjusted to be receivable of nuclear magnetic resonance signals, and also adjusted so that a part of current (first current) passing through one subcoil upon receipt of the signals flows into the other subcoil in the form of sub-current. A flowing direction of the first current is opposite to the flowing direction of the sub-current, and an electric field generated by the first current within a subject and an electric field generated by the first sub-current within the subject intensify each other in the space between a first loop coil unit and a second loop coil unit. Accordingly, noise correlation that is determined by an inner product of the electric fields is reduced, thereby achieving low noise.Type: ApplicationFiled: February 17, 2017Publication date: February 7, 2019Inventors: Yosuke OTAKE, Hisaaki OCHI, Kohjiro IWASAWA
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Publication number: 20180180690Abstract: In a multi-channel array coil used as an RF coil of an MRI apparatus, even when magnetic coupling occurs between the respective sub-coils, it is possible to suppress the influence of a current flowing through the sub-coil of a coupling counterpart to maintain the desired sensitivity and suppress deterioration of image quality. Therefor, even when magnetic coupling occurs between sub-coils constituting the multi-channel array coil used as the RF coil of the MRI apparatus, the sub-coils are connected to a signal processing circuit so that a phase difference between a rotating magnetic field generated by the influence of a current flowing through the sub-coil of the coupling counterpart and a rotating magnetic field generated by the sub-coil is less than 90 degrees.Type: ApplicationFiled: August 22, 2016Publication date: June 28, 2018Inventors: Yosuke OTAKE, Hisaaki OCHI, Kohjiro IWASAWA
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Publication number: 20170254864Abstract: A technique for reconciling large sensitivity area and high sensitivity for deep part in a multi-channel array coil of an MRI apparatus without complicating the configuration, and realizing both higher speed imaging and high image quality is provided. An RF coil (array coil) of a magnetic resonance imaging apparatus comprising a plurality of subcoils is provided. At least one of the subcoils is a first subcoil of which resonance frequency as that of the subcoil alone differs from magnetic resonance frequency. The first subcoil is adjusted so that it magnetically couples with a second subcoil, which is at least one other subcoil, and thus resonates at the same frequency as the magnetic resonance frequency. Input and output terminals of the first subcoil and the second subcoil are connected to different low input and output impedance signal processing circuits, respectively.Type: ApplicationFiled: August 7, 2015Publication date: September 7, 2017Inventors: Yosuke OTAKE, Hisaaki OCHI, Kohjiro IWASAWA