The following aspects you may consider when you choose a pocket.

1)      Integrated probe or exchangeable probe.

Integrated probe is built into body of the Doppler. Doppler with integrated probe usually costs less. However it can’t change the probe . If the Doppler has a display, patient self is hard to read the display. Separate probe is usually exchangeable among same brand Doppler

2)      Water proof probe or water resistant probe.

Water proof probe is total sealed from water penetration. It can be immersed in water without problem. Underwater deliver requires water proof probe. If the probe is not water proof , it must be water resistant.

Water resistant probe is sealed from water in front end. It can be used with water based gel without problem.

3)      Frequency of probe.

For different application, different frequency of probe should be chosen.

1mhz : for continuous monitoring in later term pregnancy

2mhz : for later term pregnancy ,or for large fat built on belly

3mhz : most common use , for early detect fetal heart beat .

4mhz: for detecting deep blood flow

5mhz : for detecting deep blood flow

8mhz : for detecting superficial blood flow

The availability of probe for each brand varies. Please check the comparison chart.

4)      Display

Some low cost Dopplers are not equipped with display.

Backlighted Display can be viewable in dark area. Non-backlighted display can’t be viewable in dark area.

Generally the display will display the fetal heart rate , battery level and frequency of probe.

5)      Built-in Speaker

The model without built-speaker must listen the heart beat from the earphone or headphone.

Almost all the dopplers have a earphone socket. Earphone can be used even Doppler equipped with built-in speaker

6)      Noise level

Usually low cost model has higher noise level. We rate the noise level based on customer feedback . 1 star is the lowest . 5 star is the best.

7)      Audio recorder

With this feature, Doppler can record the fetal heart beat of last few minutes.

8)      Durability.

Professional models are made from better material. The cord , connector and probe usually last longer. We rate the durability based on customer feedback . 1 star is the lowest . 5 star is the best.

9)      Carrying case.

Some model comes with carrying case.