Fig. 4
From: Experimental validation of a portable tidal volume indicator for bag valve mask ventilation
a Visual cues produced by the LED ring at varying levels of target VT achieved (shown as % VT). As an inspiration is delivered, the LEDs light up consecutively around the ring, changing from green (between 0 to 50% target VT), to yellow (50% to 100%), and finally to red (> 100%) signaling that the full target tidal volume has been delivered. VT = tidal volume. b LED display during status mode. The top half of the LED ring displays the current tidal volume setting via purple lights aligned with volumes (in mL) printed into the casing of the BENGI. The bottom half of the LED ring displays battery life, with green, yellow, and red together representing full battery, yellow and red together representing medium battery life, and red alone representing low battery