ARCHITECTURE
PC controller and microcontroller code were designed to be each other’s watchdogs. Each will trigger an alarm if the other stops responding.
The machine & microcontroller code have been designed to keep working when the pc crashes or stops.
ALARMS
| Blockage / no flow alarm | Flow sensor measures zero flow – PC controller sees zero flow during inspiratory phase & triggers alarm | |
| Disconnect / no pressure alarm | Pressure sensors measures zero pressure – PC controller sees zero flow during inspiratory phase & triggers alarm | |
| Power interrupt alarm | PSU output voltage is being measured on the main board. Loss of power is detected and alarm is triggered. Machine changes over to battery power without interruption. | |
| Low battery alarm | yes | |
| PEEP value incorrect or PEEP disconnected | yes | |
| PC disconnect alarm | Microcontroller does not receive acknowledgements from pc and triggers alarm. Machine keeps running with the current settings. | |
| Sensor disconnect alarm | yes, machine goes to conservative operation settings. | |
| Microcontroller failure alarm | PC acts as microcontroller watchdog and gives alarm if microcontroller stops communicating for more than 3 seconds. | |
| Configurable volume threshold | yes | |
| Configurable pressure threshold | yes | |
