Bench evaluation of 7 home-care ventilators

Portable ventilators continue to decrease in size while increasing in performance. We bench-tested the triggering, battery duration, and tidal volume (V(T)) of 7 portable ventilators: LTV 1000, LTV 1200, Puritan Bennett 540, Trilogy, Vela, iVent 101, and HT50.

We tested triggering with a modified dual-chamber test lung to simulate spontaneous breathing with weak, normal, and strong inspiratory effort. We measured battery duration by fully charging the battery and operating the ventilator with a V(T) of 500 mL, a respiratory rate of 20 breaths/min, and PEEP of 5 cm H(2)O until breath-delivery ceased. We tested V(T) accuracy with pediatric ventilation scenarios (V(T) 50 mL or 100 mL, respiratory rate 50 breaths/min, inspiratory time 0.3 s, and PEEP 5 cm H(2)O) and an adult ventilation scenario (V(T) 400 mL, respiratory rate 30 breaths/min, inspiratory time 0.5 s, and PEEP 5 cm H(2)O). We measured and analyzed airway pressure, volume, and flow signals.

At the adult settings the measured V(T) range was 362-426 mL. On the pediatric settings the measured V(T) range was 51-182 mL at the set V(T) of 50 mL, and 90-141 mL at the set V(T) of 100 mL. The V(T) delivered by the Vela at both the 50 mL and 100 mL, and by the HT50 at 100 mL, did not meet the American Society for Testing and Materials standard for V(T) accuracy. Triggering response and battery duration ranged widely among the tested ventilators.

There was wide variability in battery duration and triggering sensitivity. Five of the ventilators performed adequately in V(T) delivery across several settings. The combination of high respiratory rate and low V(T) presented problems for 2 of the ventilators.