Iryou kikigaku (The Japanese journal of medical instrumentation)
Online ISSN : 1884-054X
Print ISSN : 1882-4978
ISSN-L : 1882-4978
Current issue
Displaying 1-10 of 10 articles from this issue
Original Contribution
  • Kai Ishida
    2022 Volume 92 Issue 1 Pages 2-13
    Published: 2022
    Released on J-STAGE: April 05, 2022
    JOURNAL RESTRICTED ACCESS

    Passive intermodulation may generate when two signals are input in the receiver and is an issue that threatens wireless communications. It has been recommended that medical facilities operating wireless medical telemetry services should be conduct zone management for avoiding the effect of passive intermodulation. In this study, the occurrence frequency of passive intermodulation in a wireless medical telemetry service was investigated using simulated environment. Passive intermodulation occurred when two input signal levels were high and frequency deviation of two signals were narrow. The amplitude of passive intermodulation depends on the input signal level in which near its frequency. Passive intermodulation effected the reception of wireless medical telemetry services and degraded carrier to noise ratio as 2 to 4 dB worse rather than Gaussian noise. The signal level of wireless medical telemetry service coming from another floor has no potential to cause passive intermodulation by conducting zone management as properly. However, the output power of wireless communication devices that using same frequency of wireless medical telemetry services such as telecontrol devices is generally greater (10 mW). When the introduction of these devices, it would be desirable for clinical settings to conduct prepare zone management to avoiding passive intermodulation.

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  • Shigeharu Oie, Shinya Kawai
    2022 Volume 92 Issue 1 Pages 14-18
    Published: 2022
    Released on J-STAGE: April 05, 2022
    JOURNAL RESTRICTED ACCESS

    The fabric structures of re-usable (cotton, polyurethane, polyester 95% with polyurethane 5%, polyester 95% with spandex 5%) face masks compared to disposable non-woven masks were observed under scanning electron microscopy. We found re-usable face masks in general have homogeneous pore sizes of approximately 0.1 - 0.5 mm. In comparison, non-woven masks have two fiber layers separated by one densely non-woven labyrinthine layer with disordered three dimensional microfibers. We found most (7 out of 8) non-woven masks shared this similar dense second layer composition. Our observation for masks under the electron microscopy provides structural evidence underlying infection-preventing superiority of non-woven over re-usable (cotton, polyurethane, polyester 95% with polyurethane 5%, polyester 95% with spandex 5%) face masks. Furthermore, we found that non-woven masks do not always have the disordered dense middle layer, which suggests that some products of non-woven masks may not provide equal protection for infection.

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  • Shota Sogabe, Chihiro Nishimoto, Jun Yoshioka, Takashi Shibamoto, Take ...
    2022 Volume 92 Issue 1 Pages 19-27
    Published: 2022
    Released on J-STAGE: April 05, 2022
    JOURNAL RESTRICTED ACCESS

    The 2019 version of the dialysate drainage standard states that it will comply with the sewerage law exclusion standard. Hydrogen ion concentration (pH) and temperature are particularly important items. In the hemodialysis room, cleaning and disinfection are performed for the purpose of maintaining cleanliness. Therefore, we investigated the collection of wastewater from the terminal hemodialysis monitoring device. Furthermore, the neutralization method was experimentally examined. In the neutralization experiment, the cases where distilled water and dialysate stock solution were used were compared. In the effluent survey, each effluent tended to be acidic or alkaline, COD was high at the time of acidic irrigation effluent, and DO did not affect environmental pollution. The maximum drainage temperature was observed to be 60 °C. In the neutralization experiment, the dialysate could be neutralized with a smaller dilution rate than distilled water. In order to avoid the impact on public sewerage facilities and environmental pollution, it is essential to neutralize and drain the water. It was also considered possible to develop a wastewater treatment system that reuses dialysate.

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Short Report
Outline
Review / Guideline for Disinfection and Sterilization in Central Sterile Supply Department
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