Hazard [Health Devices Apr 1990;19(4):142-5]
This article was initially issued as a hazard bulletin on February 7,
Essential Safety Features
The first four features listed below, which are lacking on many older
monitors (and some newer ones), are necessary for effective monitoring. Parents can
continue to use existing monitors, but should arrange to replace or modify them as soon as
possible. The fifth feature is also important for safe monitoring, but replacing or
modifying a unit without it is not as crucial if parents take the precautions discussed
1. Heartbeat Detector
Apnea monitors must include a built-in heartbeat detector. No apnea monitor is capable of detecting every apnea.
Because apneas of 20 seconds or longer are often accompanied by decreases in
heart rate, most apnea monitors have a built-in heartbeat detector as a backup.
Therefore, if an apnea monitor equipped with this feature fails to detect and
alarm for the baby's apnea, it can still alarm if a decrease in heart rate also
2. Remote Alarm
Apnea monitors must have a remote alarm feature to alert parents in other
rooms. An apnea monitor alarm can go
undetected by a parent working or sleeping in a separate room from the baby. At
present, most apnea monitors have remote alarm capability, but few monitors are
used with a remote alarm.
3. Power-Loss Alarm (Nonbattery-Operated Units)
Apnea monitors that operate on line power only must have an audible
power-loss alarm. If a power failure occurs, the
parents will then be alerted and can watch the baby until power is restored.
These alarms are usually powered by a small replaceable battery. Until a
replacement is available, parents should use a separate power-loss alarm
(available from most hardware stores).
4. Safe Electrodes
Apnea monitors must not have lead wires that can be plugged into an
extension cord while connected to a baby. Providers
must replace older-style lead wires that have this capability. Electrode lead
plugs have been accidentally plugged into 120-volt extension cords or electrical
outlets, causing electrocution and severe burns. Most lead wires now in use have
protected plugs to prevent such accidents.
5. Battery-Charge or AC-Power Indicator
Apnea monitors should have an indicator that shows the user whether the
unit is operating on battery power or is being powered (and charged) from line (AC) power. If a monitor does not have a
battery-charge or AC-power indicator, parents should obtain a remote alarm to
help alert them to a low-battery condition and should also thoroughly check the
monitor before each use.
Battery-operated monitors that do not have a battery-charge or AC-power
indicator present a safety risk. For example, a user may incorrectly connect the power
cable plug such that the unit is not charging. In this case, the monitor will continue to
work until the battery voltage is too low and a low-battery alarm sounds. However, with a
poorly charged or older battery, the voltage may drop quickly to a point where the alarm
stops sounding—perhaps so quickly that a parent will not be alerted. Using a remote
alarm and performing a daily check as described below reduce the need to immediately
obtain a unit with such an indicator.
Essential Safety Practices
The following guidelines will help ensure that apnea monitors will perform
effectively. Remember: Monitors cannot detect all types of apnea and may miss some apneas.
On the other hand, some monitors may seem to frequently sound false alarms. Parents should
not ignore alarms or stop using a monitor just because it alarms when the baby seems to be
1. Daily Check Before Use
- At least once a day, parents should verify that the
monitor and remote alarms sound by disconnecting the leads from the baby.
Because of the loudness of the alarm, parents may wish to do the daily check
at a time when it will not disturb the baby.
- If the monitor has a self-test feature, parents
should follow the manufacturer's instructions for using it.
- Parents should carefully inspect electrodes, lead
wires, and power cords and plugs.
- Parents should immediately notify the home care service of any signs of
electrode or cable damage or of any signs of unusual monitor
2. Monitoring Check During Use
- Any time the apnea monitor sounds an alarm, parents
should immediately check the baby, even if the unit alarms momentarily.
- Whenever possible, parents should operate the
monitor on line power. They should be sure that the battery is charging by
checking the battery-charge or AC-power indicator or by checking that the
power cord or charger cable is plugged in. They should also keep unused
extension cord and wall outlets capped.
- Each time parents check the baby, they should check
the monitor. The respiration light, if present, should blink only once with
each breath, and the heartbeat light should blink in a consistent pattern.
Parents should look for any unusual performance of the monitor, such as an
unusually high number of breath or heartbeat detections.
- Parents should keep a logbook to record the time and date of
any event, including unusual observations about monitor operation. If the monitor is not
operating as expected, they should immediately call the home care service and keep
using the monitor.
3. Monitor Placement
Parents should place the monitor on a table, dresser, or shelf, not on the
floor. They should be sure that toys or other items are not nearby because they may block
displays or muffle audible alarms.
4. Electrical Interference
Parents should place the apnea monitor and the baby several feet away from
electrical devices such as televisions, nursery monitor intercoms, oscillating fans, and
humidifiers. Although uncommon, interference from such devices may affect apnea monitor
performance. In rare cases, severe interference from local television and radio stations
or from "ham" or CB radio transmitters may affect the monitor.
Apnea monitors, like other electronic devices, contain complex circuitry
that, at this time, is not immune to all forms of electrical interference. Frequent false
alarms or an unusually high number of heartbeat or breath detections may indicate an
interference problem. (Reminder: The respiration light should blink only once with each
breath, and the heartbeat light should blink in a consistent pattern.)
If parents suspect an interference problem, they should immediately call
the home care service and keep using the monitor.
5. Remote Alarm
Parents should place a remote alarm in their bedroom if they sleep in a
separate room from the baby. They should also use the remote alarm in other areas where
they may spend time and the monitor alarm may not be heard (e.g., basement, laundry room,
6. Baby's Bed
Parents, children, and pets should not sleep with a baby that is being
monitored. Their movement can interfere with the apnea monitor and prevent it from working
7. Monitor Settings
Babies are typically monitored for eight months or more and grow fast
during that time. Therefore, the settings may have to be changed periodically to match the
infant's growth. Only a doctor or home care professional should change monitor settings.
Parents should be trained to use the monitor correctly, to perform
cardiopulmonary resuscitation (CPR), and to recognize the signs of apnea. They should
review and understand educational material provided on infant apnea and on operation of
Home care service professionals should provide regular follow-up visits to
reinforce training and verify proper operation of the monitor. They should inspect the
monitor at least every three months to verify proper performance, preferably using a
patient simulator, and document their findings.
- Providers should ensure that apnea monitors have
the critical safety features described above, including:
- Built-in heartbeat detector
- Remote alarm
- Power-loss alarm (line-power-only units)
- Safe electrode leads
- If a monitor does not meet these criteria, parents
should obtain a new or modified unit as soon as possible. While waiting for
a new or modified monitor, they should continue to use the existing unit
following the safe practices outlined in this article.
- Parents and caregivers should always follow the
safe practices for use of apnea monitors listed above, regardless of which
brand or model monitor is used.
- Providers should make this information available to parents and address
these issues in apnea monitor training programs.
Connection of electrode lead wires to line power [hazard report]. Health
Devices 16(2):44-6 (Feb 1987).
Infant home apnea monitors [evaluation]. Health Devices
16(3-4):79-109. (Mar-Apr 1987).
Infantile apnea and home monitoring. U.S. Department of Health and Human
Services. NIH Publication No. 87-2905.
Apnea Monitors [12-575]
Cause of Device-Related
Device factor: Design/labeling error
User errors: Accidental misconnection; Failure
to read label; Inappropriate reliance on an automated feature
External factors: Power supply; Electromagnetic
or radio-frequency interference (EMI and RFI)
Support system failure: Failure to train and/or credential
Mechanism of Injury or
Monitoring failure; Suffocation