How do I operate and troubleshoot Sonotrax fetal Doppler?

Step 1: Opening package and checking

Check components according to the packing list.

Step 2: Installing battery

(1) Open the battery compartment.
(2) Place a new battery to the battery connector in the compartment. Slide the compartment cover back to close the compartment.

Step 3: Probe operation

First, hold the main unit with one hand, then take out the top of the probe with another hand, finally take out the whole probe from the probe frame.

Step 4: Switch on the Doppler

Press the POWER button on the front panel to switch on the Doppler.

Step 5: Modes setting

Sonotrax basic fetal doppler monitor has 5 mode options; press the mode button to switch to the next mode.

If Sonotrax basic worked on mode 1/ mode 2/ mode 3 last time before shutdown, the Doppler will enter the same mode after self-testing automatically. If its last mode is Mode 4/ Mode 5, it will enter mode 1 after self-testing.


(1) Real time FHR Display Mode ( Mode 1)
When the Doppler works on Mode 1, the working mode on LCD displays 1.
As soon as the fetal heart signal is detected, the heart shape on LCD flashes. The real time fetal heart rate displays in the FHR display area.
(2) Averaged FHR Display Mode ( Mode 2)
When the Doppler works on Mode 2, the working mode on LCD displays 2.
The heart shape on LCD flashed when the fetal heart signal is detected. The FHR value indicates the average value of 8 beats, which changes slowly.
(3) Manual Mode (Mode 3)
When the Doppler works on Mode 3, the working mode on LCD displays 3.
Press “START/STOP” button and start counting immediately, count 1 on the moment when the button is pressed. The heart shape flashes and signal “---” displays on LCD screen. Press the button again on the 10th count (after 9 intervals).
The Doppler automatically calculates the FHR averaged over the 10 beat counts and displays the result. This rate will remain until another measurement starts or the mode is changed.
(4) Back Light Brightness Setting Mode (Mode 4)
When the Doppler works on Mode 4, the working mode on LCD displays 4.
Press START/STOP button to set the brightness of white back light. “OFF” means the white back light is active and “ON” means the white back light is inactive.

Step 6: Fetal Heart (FH) Monitoring

Fetal Heart Monitoring with 3.0 MHz waterproof probe.
(1) Feel the correct position of the fetus by hand.
(2) Apply some gel to the faceplate of the probe.
(3) Place the faceplate of the probe at the correct position for detecting fetal heart.
(4) Adjust the probe to obtain an optimum audio signal by angling the probe around.
(5) Adjust the volume.

The fetal heart rate is sent out via built-in speaker or attached earphone; the fetal heart rate is displayed on LCD.

Step 7: Switch off the Doppler

(1) When the monitoring is finished, wipe off the remaining gel off the probe with a clean soft cloth, then put probe back into the probe frame.
(2) If there is no signal input or no operation done for 60 seconds, it will automatically shut down. Or you can press and hold the “POWER” button for 3 seconds to switch it down manually.

Troubleshooting for Sonotrax Baby Doppler Basic with 3MHz Probe

1. What should I do when Doppler gives out an alarm indicating the battery is low?
You should replace the battery.
(1) Shut down the Doppler.
(2) Open the battery compartment.
(3) Take out the battery connector from the compartment and change the old battery.
(4) Put in a new battery into the connector and place the connector back to the battery compartment.
(5) Slide the compartment cover back to close the compartment.

2. How do I clean my fetal Doppler after using?
Before cleaning, you should make sure to switch off the power and take out the batteries.Clean the exterior surface (display screen included) of the unit with a dry, soft cloth. You also can clean it with a soft cloth soaked with water or solution of soap and dry it with a clean cloth immediately.
Clean the probe with a piece of wet soft cloth (soaked with water and soap only) to remove any remaining gel.

3. How do I disinfect my 3.0 MHz waterproof probe?
Immerse the probe into solutions of Benzalkonium Bromide, 0.5% chlorhexidine, 2% Glutaraldehyde or 75% ethanol to make it disinfected. After that, wipe the probe with a dry clean cloth to remove any remaining moisture.
NOTE: Please pay attention to the depth into which the probe is immersed. Be careful to prevent sterilant from inpour of probe socket.


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