Mechanical Behaviors of Flutter VRP1. Shaker. and Acapella Devices
BACKGROUND: Flutter VRP1. Shaker. and Acapella are devices that combine positive expiratory
pressure (PEP) and oscillations. OBJECTIVES: To compare the mechanical performance of the
Flutter VRP1. Shaker. and Acapella devices. METHODS: An experimental platform and a ventilator.
used a flow generator at 5. 10. 15. 20. 26. and 32 L/min. were employed at angles of ?30¡Æ. 0¡Æ.
and 30¡Æ to evaluate Flutter VRP1 and Shaker. whereas Acapella was adjusted at intermediate.
higher. and lower levels of resistance. including positive expiratory pressures (PEP) along with air
outflow rates and oscillation frequencies. RESULTS: When the relationships between pressure
amplitudes of all air flows were analyzed for the 3 devices at low and intermediate pressures levels.
no statistically significant differences were observed in mean pressure amplitudes between Flutter
VRP1 and Shaker devices. However. both devices had different values from Acapella. with their
pressure amplitude values being higher than that of Acapella (P .04). There were no statistically
significant differences in PEP for the 3 angles or marks regarding all air flows. The expected
relationships between variables were observed. with increases in PEP. compared to those of air
flows and resistance. Nevertheless. there was a statistically significant difference in frequency of
oscillation between these devices and Acapella. whose value was higher than those of Flutter VRP1
and Shaker devices (P .002). At intermediate pressure levels. the patterns were the same. in
comparison to low pressures. although the Acapella device showed frequencies of oscillation values
lower than those of Flutter VRP1 and Shaker (P < .001). At high pressures. there were no statistically
significant differences among the 3 devices for frequency of oscillations. CONCLUSIONS:
The Flutter VRP1 and Shaker devices had a similar performance to that of Acapella in many
aspects. except for PEP. Key words: Flutter VRP1; Shaker; Acapella; positive expiratory pressure; PEP;