The best time to record fetal heart rate
30 minutes after waking up.
30-60 minutes after lunch.
30 minutes before going to bed at night.
During the above period, due to changes in the physical state of pregnant women, food digestion activities and other needs to provide oxygen, the relative oxygen supply to the fetus. becomes less, which is likely to cause fetal hypoxia symptoms. At this time, the detection of fetal heart rate can reflect the health of the fetus (Normal range of fetal heart rate: 110-160 bpm).
The method of finding fetal heart sound
Early pregnancy(12-24 weeks), the position of the fetal heart is usually lower, just below the navel or slightly near the pubic hair, evenly spread the couplant on the surface of the probe, turn on the machine, lie down and hold the probe move slowly at the position where the fetal heart is located to find the fetal heart sound.
Pregnant metaphase( 24-32 weeks), the position of the fetal heart rate is usually below or on both sides of the navel, moving slowly around the navel to find the fetal heart rate.
Later stages of pregnancy(32-40 weeks), late pregnancy when the baby's body is relatively large, so the fetal heart position is generally above of the navel, if can not find, you can try around the navel.
 |  |  |
| Early pregnancy (12-24 weeks) | Pregnant metaphase ( 24-32 weeks) | Later stages of pregnancy (32-40 weeks) |
INTENDED USE
The intended use of this device is detection of the fetal heart rate and fetal heart beat sound listening as an aid for determining fetal viability.
CONTRAINDICATIONS
The device is not for invasive use, not for no-intact skin and not for use near the eyes.
This device is not intended for use with HF surgical equipment.
LIMITATIONS
The theory of device is beyond the scope of this manual, but is covered in many recent publications. The device is designed to be reliable, but as with all medical instruments, should be treated with care. While the device augments the user’s skills, it is not a substitute for medical training and knowledge.
Note: The device provides the listener with information about the fetal condition. Under poor signal conditions, the fetal heart sounds and readings may not be accurate. If there is any doubt the fetal condition after using the device, further investigation should be initiated immediately.
SAFETY
Read this manual fully before use.
In order to preserve, pregnant woman and improve the quality of the environment, protect human health and utilize natural resources prudently and rationally - do not dispose of waste electrical or electronic equipment (WEEE) as unsorted municipal waste. Contact local WEEE disposal sites or manufacturer to dispose or equipment.
Warning: This device is not explosion proof. Do not use it in the presence of flammable or explosive gases. Do not immerse the device in fluids and do not autoclave .
MARK AND SAFETY SUMMARY
DEVICE STRUCTURE VIEW
PRODUCT DESCRIPTION
Display ：The TFT display interface is as follows
TURNING DEVICE ON/OFF
Turn the device on by pressing the On/Off button for 1 second. TFT backlight will be switched on to indicate
the power status .
The device automatically shuts itself off after 1 minute if it is not being used. This complete power shutdown preserves the life of the batteries and ensures the device will be ready for operation in case it was accidentally left on.
OBTAINING FETAL SIGNALS
For any examination, it is essential that an adequate supply of coupling gel is used to transmit the ultrasound energy from the probe to the surface of the skin. Re-apply more gel if it
starts to dry out or spread so thinly that an air gap occurs
between the probe and the skin. It is not necessary to cover the entire surface of the probe, only the probe face. Applying too much gel makes the device difficult to clean and does not aid in the performance of the probe.
In some person the fetal heart can be heard as early as 9 to 12 weeks. It should be audible 95% of the time in 12-week pregnancies and nearly 100% after 14 weeks.
The exam is most easily done with the mother supine, although it may also be accomplished in a sitting or standing position. Expose the abdomen and apply a generous amount of coupling gel to the face of the probe. It is important to maintain good coupling at all times with no air bubbles between the probe and the abdomen.
The key to the examination is to intercept the fetal heart with the beam from the probe. The beam travels in a relatively straight direction much like a flashlight beam.
In the first trimester, the best technique is to start with the probe on the midline of the abdomen and aimed downward behind the pubic bone. The probe should be moved very slowly to search the most likely area. Because the fetal heart sounds are faint at this time, be careful not to scan too quickly or the sounds may be missed.
It is often difficult to find the fetal heartbeat during the first trimester and this by itself is not a cause for alarm. A full bladder may make finding the heartbeat a little easier.
The fetal heartbeat sounds like a galloping horse and is about twice the speed of the mother’s heart rate. The heart rate will be displayed in the TFT display. The placental blood flow sounds more like a whirlwind.
Note: The device provides the listener with information about the fetus, however if there is any doubt about fetal condition after using the device, further investigation must be initiated immediately.
Warning: Use only the probe which supplied by the original manufacturer.
VOLUME CONTROLLER
The audio level can be adjusted using next buttons: 
Push button "UP" to increase the volume and "DOWN" to decrease it.
DISPLAY MODE
For the TFT model, there are two display modes which can
be changed if short press the On/Off button for (less than 1 second). 
ALARM FUNCTION
When the fetal heart rate is lower than 110 bpm or higher than 160 bpm for 10 consecutive seconds, the machine will beep.
BATTERY MONITORING
The device performs continuous battery monitoring and give a visual indication of battery level. TFT display units use a multiple level battery shaped icon that indicates the
voltage level of the battery.
AFTER USE
Press and release the On/Off button to switch off the product.
Excess gel should be wiped off prior to docking the probe to the probe holder. Refer to the CLEANING AND DISINFECTION section before storing or using the device on another pregnant woman.
The control unit and the body of the probes are robust and require no special handling. However, the probe tip is delicate and must be handled with care.
Warning: If the device is to be stored for longer than 30 days without use, take out the AA battery.
CLEANING AND DISINFECTION
Remove excess gel after using the device. Clean with a mild soap and detergent.Do not allow fluid to seep into the product.
Warning: This device is not intended to be used on open
skin. If there is evidence of open wound contamination, disinfect the probe before using again as described below.
Warning: The device is not designed for liquid immersion. Do not soak or drop the main unit or probes in liquids. Use only spray or wipe cleaners and disinfectants.
Warning: The device is not designed for sterilization processes such as autoclaving or gamma radiation.
MAINTENANCE
This device requires very little maintenance. However, it is important to continuing function of the unit and the health of the patients that the unit is cleaned and examined regularly per the following guideline:
Annually inspect the main unit and probes for signs of cracks or breaks in the mechanical housing. Inspect cables and connectors for signs of wear or failure. The user should discontinue use of the unit with any sign of loss of housing integrity. Contact Manufacturer Technical Services Department or your local representative for instructions.
TROUBLE CLEARING
Poor sound quality
- Inadequate gel use
- Try and relocate the probe for a better signal
- Interference from other equipment Heart Rate inaccurate
- Try and relocate the probe for a better signal
- Ensure maternal sounds are not mixing with fetal sounds Battery indicator flashing
- Replace the battery
ELECTROMAGNETIC INTERFERENCE
This equipment may generate, use and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to other devices in the vicinity. However, there is no guarantee that interference will not occur in a particular installation.
If this equipment does cause harmful interference to other devices, which can be determined by turning the equipment off and on, the user in e
by one or more of the following measures:
- Reorient or relocate the receiving device.
- Increase the separation between the equipment.
- Consult the manufacturer or field service technician for help.
WARRANTY
All the products have a one year limited warranty .
If any technical problem or question faced, please contact Manufacturer Technical Services Department or your local representative for instructions.
SPECIFICATIONS
Product size: 132× 104× 34mm Display: 1.77 inch TFT
Probe frequency: 2.5MHz ± 10%
Fetal heart rate range: 50bpm～240bpm Resolution: 1bpm
Accuracy：士2bpm
Power consumption: <0.8W Battery type: 2* 1.5V AA batteries
Normal working conditions:
Ambient temperature: 5℃～40℃
Relative humidity: 30%～80%
Atmospheric pressure: 70.0kPa～106.0kPa
Transport storage conditions:
Transport/Storage temperature: -20℃～55℃
Transport/Storage humidity: 10%～90%
Atmospheric pressure: 50.0kPa～106.0kPa