Vivo 50 Manual says:
Ventilator tester (Fluke VT Plus or IMT PF-300)
Or:
– Flow meter (TSI 4040, Breas part no 004839)
– Pressure manometer (Thommen HM 28, Breas part no 001937)
– Measuring instrument for tidal volume and minute volume/rate.
Of course you can use any other vent tester.