28 research outputs found

    In Vivo Microwave Ablation of Normal Swine Lung at High-power, Short-duration Settings

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    To evaluate the volume and heat-sink effects of microwave ablation (MWA) in the ablation zone of the normal swine lung. MWA at 100 W was performed for 1, 2, and 3 min in 7, 5, and 5 lung zones, respectively. We assessed the histopathology in the ablation zones and other outcome measures: namely, length of the longest long and short axes, sphericity, ellipsoid area, and ellipsoid volume. The mean long- and short-axis diameters were 22.0 and 14.1 mm in the 1-min ablation zone, 27.6 and 20.2 mm in the 2-min ablation zone; and 29.2 and 21.2 mm in the 3-min ablation zone, respectively. All measures, except sphericity, were significantly less with 1-min ablation than with either 2- or 3-min ablation. There were no significant differences between the 2- and 3-min ablation zones, but all measures except sphericity were larger with 3-min ablation. Although there were no blood vessels that resulted in a heat-sink effect within the ablation zones, the presence of bronchi nearby in 5 lung ablation zones resulted in reduced ablation size. In high-power, short-duration MWA, the lung ablation volume was affected by ablation time. Some ablations showed that a heat-sink effect by a neighboring bronchus might occur

    Robotic CT-guided out-of-plane needle insertion: comparison of angle accuracy with manual insertion in phantom and measurement of distance accuracy in animals

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    Objectives To evaluate the accuracy of robotic CT-guided out-of-plane needle insertion in phantom and animal experiments. Methods A robotic system (Zerobot), developed at our institution, was used for needle insertion. In the phantom experiment, 12 robotic needle insertions into a phantom at various angles in the XY and YZ planes were performed, and the same insertions were manually performed freehand, as well as guided by a smartphone application (SmartPuncture). Angle errors were compared between the robotic and smartphone-guided manual insertions using Student’s t test. In the animal experiment, 6 robotic out-of-plane needle insertions toward targets of 1.0 mm in diameter placed in the kidneys and hip muscles of swine were performed, each with and without adjustment of needle orientation based on reconstructed CT images during insertion. Distance accuracy was calculated as the distance between the needle tip and the target center. Results In the phantom experiment, the mean angle errors of the robotic, freehand manual, and smartphone-guided manual insertions were 0.4°, 7.0°, and 3.7° in the XY plane and 0.6°, 6.3°, and 0.6° in the YZ plane, respectively. Robotic insertions in the XY plane were significantly (p Conclusion Robotic CT-guided out-of-plane needle insertions were more accurate than smartphone-guided manual insertions in the phantom and were also accurate in the in vivo procedure, particularly with adjustment during insertion

    コウダイ レンケイ ニ ヨル セツゾクキョウイク プログラム カイハツ ノ ココロミ

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    高大連携により効率的な接続教育プログラムを開発するため,高校向けアンケートを実施した。職業に就いた際に必要とされるキャリア基礎能力として本学で過去実施したアンケート結果を基にした10 要素,ならびに経済産業省の「社会人基礎力」12 要素の必要性と達成度を設問とした。その結果,社会人にもっとも必要とされるキャリア基礎能力は「コミュニケーション能力」であること,また,高校教科「情報」によりPC 基礎操作能力は十分獲得されていること,がわかった。この結果を踏まえ,高大連携プログラムの一環として高校-大学教員によるコミュニケーション教育研究会を開催し,全12 講からなる接続教育プログラム「コミュニケーションリテラシー」を開講した。Enquiries were made to upper secondary school teachers on basic vocational abilities necessary for thegraduates. Since "information literacy" was introduced recently as compulsory subject in secondary schools, itsrelation with elements necessary for an ordinary person who wishes to work in a company was investigated. Basedon the results, a project was set up with members from secondary school teachers and Shohoku College teachersand library staff. As a result, a novel coordination program, namely, "communication literacy", consisting of 12lessons, was held for secondary school third grade students

    Observation of transverse quadrupolar tune shifts in the Photon Factory storage ring

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    The frequencies (tunes) of transverse quadrupolar oscillations were measured in the 2.5-GeV Photon Factory storage ring at the High Energy Accelerator Research Organization (KEK). As a result, remarkable shifts in the quadrupolar frequencies with the bunch current were found; they were both positive and negative in the horizontal and vertical directions, respectively. This result can be explained by a focusing effect due to short-range wakefields containing a quadrupolar component

    Conceptual Design for SR Monitor in the FCC Beam Emittance (Size) Diagnostic

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    A conceptual design for emittance diagnostics through a beam size measurement using the synchrotron radiation (SR) is studied for the FCC. For the FCC-ee, a X-ray interferometer is propose to measure a nano-radian order vertical beam size. Also conceptual design of SR monitor is studied for FCC-hh. In the FCC-hh, visible SR will emitted from bending magnet in the energy range from the injection (3TeV) to top energy (50TeV). Hard X-ray SR will only available in the energy upper than 30TeV. The various instrumentations using the visible SR is usable for all energy range. Around the top energy, the X-ray pinhole camera will convenient for beam diagnostics of emittance through the beam size measurement

    First Observation of the LHC Beam Halo Using a Synchrotron Radiation Coronagraph

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    A test coronagraph for the observation of beam halo has been installed in the Synchrotron radiation monitor line LHCB2 in 2015. This coronagraph is commissioned with LHC operation at 450GeV (injection energy). After some optical testing of the coronagraph with visible Synchrotron radiation in B2, we try to observe artificially-made beam halo. The beam halo of 10⁻³ order of magnitude against the beam core is excited by the kicker of the transverse damper. We have succeeded to observe a diffraction noise free image of beam halo. The effect of beam collimator is also observed. Reduction of beam halo intensity was found nicely proportional to the simultaneously-recorded beam loss

    Improvement in the beam lifetime by means of an rf phase modulation at the KEK Photon Factory storage ring

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    In the 2.5-GeV Photon Factory storage ring at KEK, we have found that the beam lifetime can be improved by modulating the phase of an rf accelerating voltage at a frequency of 2 times the synchrotron oscillation frequency. By applying this phase modulation with a peak-to-peak amplitude of 3.2°, the beam lifetime could be improved, typically, from 22 to 36 h under a beam current of about 360 mA. At the same time, the longitudinal coupled-bunch instability could be considerably suppressed. The improvement in the beam lifetime can be explained as an improved Touschek lifetime, which was caused by a quadrupole-mode longitudinal oscillation of the stored bunches
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