Battery life of the "four-hour" lithium ion battery of the LTV-1000 under varying workloads.
OBJECTIVE
The objective of this study was to determine the effects of inspired oxygen concentration (FIO2), positive end-expiratory pressure (PEEP), and breath type on the battery life of the LTV-1000 external lithium ion battery (LiB).


METHODS
An LTV-1000 ventilator and external LiB were tested in the laboratory. The ventilator was operated using pressure and volume breaths set to deliver a tidal volume of 750 mL. FIO2 was varied from room air (0.21) to 1.0. PEEP was set a 0, 10, and 20 cm of H2O. Duration of operation was determined from measurements of delivered tidal volume.


RESULTS
At a baseline of volume control at an FIO2 of 0.21 and a PEEP of 0 cm of H2O, the ventilator operated for 300 +/- 11.6 minutes. Increasing FIO2 to 1.0 reduced battery life to 247 +/- 2.1 minute (p < 0.001). The addition of PEEP to 20 cm of H2O reduced battery life to 211 +/- 3.5 minutes (p < 0.001). The combination of FIO2 of 1.0 and PEEP of 20 cm of H2O further reduced battery life to 188 +/- 6.3 minutes (p < 0.001). At the baseline FIO2 and PEEP (0.21 and 0 cm of H2O), the use of pressure control reduced battery life to 142 +/- 3.5 minutes.


CONCLUSIONS
Battery life of the external LiB is significantly reduced by the use of pressure control, increasing PEEP, and increasing FIO2. This information is critical to resource planning for medical missions.
Rodriquez
Dario
D
Center for Sustainment of Trauma and Readiness Skills, USAF CSTARS, Cincinnati, OH 45219, USA.
Branson
Richard
R
Barnes
Stephen A
SA
Johannigman
Jay A
JA