WS/T 655-2019 in English

The WS/T 655-2019 standard has established a ventilator safety management framework that includes 4 major management systems, 5 types of technical tests and 3 levels of status identification, which is applicable to the full process supervision of the clinical use of invasive ventilators and non-invasive ventilators in various medical institutions.

Performance test standards

• Tidal volume deviation: ≤10% (test before use)/≤15% (periodic test)
• Oxygen concentration error: ≤5% absolute value (21%-100% range verification)
• Alarm response: power failure alarm delay <10 seconds, gas source interruption alarm <15 seconds

Maintenance specifications

1. Air compressor filter replacement cycle: ≤3 months
2. Oxygen sensor calibration: every 6 months or 5000 hours
3. Machine performance test: mandatory annual inspection + mandatory inspection after maintenance

Solutions to Typical Problems

Case 1: Tidal Volume Drift
After three years of continuous use, a PB840 ventilator in an ICU experienced a phenomenon where the setting was 600ml → the actual measured volume was 550ml. According to Article 5.2.4 of the standard, the following should be done:
1) Check the calibration of the flow sensor
2) Test the tightness of the pipeline
3) Replace the pressure regulating valve when necessary

Information management path

• Establish an electronic archive system to automatically remind the inspection cycle
• Use QR code labels instead of traditional labels, and scan the code to view the complete inspection record
• Develop a ventilator sharing platform to achieve emergency deployment

Compared with previous specifications, WS/T 655-2019 has the following major breakthroughs:
1) For the first time the three-level management organizational structure
2) Added a mandatory safety confirmation process before use (Chapter 6)
3) Refine the quantitative indicators of performance testing (Article 5.2.3)