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CHAPTER 5

Time-Managed Use: You Choose When to Take It Off

If people are required to wear a device all the time, they will not keep it up. So each person is given an allowance of mask-off time and chooses when and where to use it.

Time-managed PAPR use enables a balanced approach to infection control and personal freedom
Y. Fujii — Scientific Reports, Vol.16, 2878, 2026.
https://doi.org/10.1038/s41598-025-32625-3

Role: Time-managed use (operational design)

Designs, builds and validates PWS-NET (PAPR Wearing-Status Networked Management System), which manages the wearing status of public-use PAPRs in conjunction with a smartphone.

  • SAT (Saved Allowance Time): a daily allowance of mask-off time; within it, people choose when and where not to wear the PAPR.
  • Components: a differential-pressure sensor that detects wear (worn above 10 Pa, not worn below; data sent every 2 s), a smartphone app for declaring location, and a web server that updates SAT daily.
  • Weighting by location: for example, an outdoor walk might be weighted 0.5, so one hour without the PAPR uses 30 minutes of SAT.
  • Validation: in four scripted scenarios with a mannequin, SAT updates and violation judgments worked correctly. Built from off-the-shelf parts; 631 g; about 5.5 h of continuous operation.

The design lets governments optimise infection control without excessive regulation, while citizens keep their freedom in daily life. Detection accuracy (false positive and false negative rates) has not yet been quantified.

Research plan (JSPS KAKENHI, Scientific Research (B))

The research plan towards practical use is published in the following paper (in Japanese). Its three pillars are (1) development of the public-use PAPR and a set of evaluation devices, (2) design of a networked wearing-rate management system, and (3) small community field trials to assess effectiveness and acceptability.

Y. Fujii, "Research project: a socio-technical system using powered air-purifying respirators as an alternative to lockdown (first report)", Japanese Journal of Social Safety and Privacy, Vol.9, No.1, pp.1–17, 2025 (Japanese).
https://jjssp.e-jikei.org/ARCHIVES/vol09no01/JpnJSSP_vol09_no01_p01.pdf

Wearing data and privacy

Wearing status and location declarations are information about personal behaviour. Networked wear management needs its own evaluation of privacy impact; the infrastructure for that is the subject of Chapter 7.

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Contents

Measures for the Next Pandemic: engineering and social infrastructure for controlling infection without stopping society | Yusaku Fujii (Gunma University)
This site presents research-stage work; figures are model calculations or prototype measurements.