West Coast First Aid Training

How do Little Anne and Little Junior QCPR Work?

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Little Anne and Little Junior QCPR include a hardware module with a QCPR Sensor to measure compressions and ventilations.

The QCPR Sensor is an integrated electronic device that registers compressions and ventilations, mounted under the Rib plate. It communicates QCPR feedback wirelessly to external devices via Bluetooth or wired via the SkillGuide (I2C).

The manikin connects to the QCPR Apps via Bluetooth and to SkillGuide via a 2,5mm audio jack connector.

Illustrations for Little Anne and Little Junior QCPR


Measurement system


Compressions are measured by an infrared proximity sensor which measures the distance from the chest plate to the back section. The sensor sends infrared light to the reflector and analyzes the distance based on the intensity of the light returning from the reflector. Ventilations are measured by an inductive sensor which measures how much the chest is rising when the manikin is ventilated. The manikin’s lungs expand and press the chest plate downwards and the chest upwards. The sensor measures the change in induction and translates that into feedback on chest rise.
 

Inductive sensor (ventilations)

An inductive coil PCB is mounted close to the inside of the Rib plate. A sheet metal disc is glued to the inside of the Chest skin.
When the lung is expanded the Chest skin and the sheet metal will be lifted from the Rib plate causing a change in the electromagnetic field that is picked up by an inductive sensor through the coil PCB.

IR sensor (compressions)

A sensor on the back of the Rib plate emits Infrared light to a reflective surface in the Back section. The intensity of the reflected light is used to determine the distance from the sensor to the reflective surface.

Ventilation measurement

Ventilating the manikin will give a rise of the chest skin relative to the Rib plate and also a compression of the rib plate towards the Back section. Due to this, the ventilations are measured using both sensors. The lung expansion in combination with the compression of the chest is used to calculate an approximate value in ml for inflated lung volume.

Compression measurement

Compressing the chest will give a decrease in distance between the Rib plate and the Back section that is measured by the IR distance sensor and used to calculate the value for the compression in mm


ON/OFF

The QCPR Sensor does not have an ON/OFF button. It is either in “standby” mode or “ON”.

ON Condition QCPR Sensor automatically wakes up from standby mode when the user compresses the chest (deeper than 20 mm for a duration of > 250 millisecond)
OFF Condition Connected to an external device via BLE
QCPR Sensor automatically goes into standby mode after being inactive for 30 minutes Not connected to an external device via BLE
1) If no compressions are performed, QCPR Sensor automatically goes into standby after 5 minutes.2) If more than 30 compressions are performed, QCPR Sensor enters summative feedback mode after 30 seconds of compression inactivity. After 45 seconds in summative feedback mode, the QCPR sensor goes into standby mode.
Standby Mode

Power status

STANDBY All systems are shut down except for the IR sensor that will check for movement of the chest every 125 ms.
    ON The system is on and connectable. System operations will be as described in section “CPR Session” below.


Selftest

When entering the ON state, QCPR sensor shall perform a selftest to verify that the compression and ventilation sensors are functional. Passing the selftest will be notified by an audible beep. If selftest is not passed the sensor will shut down.


Indicators

Sound – One beep Unit is ON Unit has woken up from standby mode
Blue LED – Blinking Ready to connect Unit is available and ready to establish a bluetooth (BLE) connection
Blue LED – Steady on Connected Unit has established a BLE connection with a mobile Device
LED Status