Bedwetting alarm

A bedwetting alarm or enuresis alarm is an electronic device used as a treatment option for nocturnal enuresis. Nocturnal enuresis can be divided into two types: primary and secondary. Secondary enuresis is when the child has had at least one six month period during which no wetting occurred—in primary enuresis there is no history of a sustained dry period. The alarm activates when the wearer urinates.^[1]

Alarms come in several different styles: wearable alarms, wireless alarms, and pad-type alarms. While there is some variation in the styles of the alarms, they all function similarly; each alarm has a moisture sensor component and an alarm component. When the child or patient first begins to urinate the sensor will detect the moisture and trigger the alarm.

Bedwetting alarms are a treatment tool designed to teach people to respond to a full bladder by waking and using the toilet. Upon alarm activation, the child should get awaken and finish off in the toilet. In time, this is intended to result in classical conditioning between a full bladder and waking up to go to the toilet.^[2] Although insufficient evidence exists to recommend additional behavioral interventions such as journal keeping, fluid restrictions, and night awakenings, these supportive approaches are acceptable, benign starting points. Conditioning with an enuresis alarm and overlearning, which involves giving extra fluids at bedtime after successfully becoming dry, and intermittent reinforcement before ending treatment, is a highly effective first-line management approach.^[3]

Success rates and the time to achieve success using bedwetting alarms can vary substantially between individuals. For children, a parent or caregiver often has to supervise a child when a bedwetting incident occurs. Commitment on the part of the patient and caregiver is essential to improving the success rate of alarm therapy. The conveniences provided by the bedwetting alarm being used can substantially contribute to positive attitudes and willingness to participate. The success of alarms requires a motivated time and effort commitment of 3 to 6 months. Typical success with bedwetting alarms (behavioral therapy) is 25% to stop nighttime wetting in 30 days, 50% in 60 days, and 90% in 90 days.^[4]

The bedwetting alarm, also referred to in the medical community as an enuresis alarm, is categorized as D.M.E. (Durable Medical Equipment). As such, the cost may be a reimbursable covered expense by healthcare insurance carriers when it is prescribed by a pediatric physician, urologist, or other accepted medical authority.

Types of alarms

Wearable alarms

Wireless Bedwetting Alarm

A wearable alarm is a design in which the child or patient wears the moisture sensor in or on their underwear or pajamas. This type of sensor will detect moisture almost immediately. The sensor is attached to the alarm unit with an electricity conducting wire or cable that can be worn under the shirt. Many wearable alarms vibrate as well as sound to wake deep sleepers.

Wireless alarms

A wireless bedwetting alarm is one in which the sensor and the alarm unit communicate by a means other than a wire. The transmitter, which senses the moisture, is directly attached to the child's underwear. The signal is transmitted wirelessly to a unit that is across the room from the child or an alarm unit in the child's room. Once the alarm unit is activated, it is necessary to get out of bed to turn it off. New wireless alarms add the convenience of also sounding an alarm in the caregiver's room, allowing both patient and caregiver to sleep in the comfort and privacy of their own beds and rooms. Multiple alarms in the house can further increase convenience. Remote controls can facilitate using the wireless bedwetting alarm system, and be especially convenient for the parent or caregiver.

Pad-type alarms

Bell-and pad alarms do not attach to the child in any way. The moisture sensor is in the form of a pad or mat that the child sleeps on top of. The pad detects moisture after urine has leaked onto it. The alarm unit is connected with a cord and usually sits on the bedside stand. This alarm requires a larger amount of urine before the sensor can detect moisture. The person must be on the pad for it to sense moisture.

Sensors

A urine sensor is a necessary part of any bedwetting alarm. A basic urine sensor consists of two electricity conductors separated by moisture absorbing insulating material. A low DC electric voltage, provided by batteries, is applied across these conductors. This low voltage is usually about 3 volts, so as not to be dangerous to the user. When this insulating material (frequently cotton cloth as in common briefs) absorbs urine, it allows electricity to pass through it and between the conductors, resulting in a small electric current in the conductors. The conductors are attached to an alarm device, which triggers an alarm when it senses this current. Most sensors and alarms are engineered based on this concept. Note that unless the urine reaches the sensor mechanism and adequately wets the briefs (or insulator between the conductors), the urine may not be sensed and the alarm will not activate.

Sensors are usually classified in terms of their attachment mechanisms to the briefs or other urine absorbing medium. The major sensor attachment categories are mechanical clips, sticky tape or pads for flat surface sensors, magnetic attachment, and wiring sewed into special briefs.

Stainless steel clips are most often used and are easily attached and detached to the briefs at the point of urination. Flat surface sensors require sticky tape or pads to be attached to the briefs. The magnetic sensors are magnetically attached to the briefs. Magnetic sensors and wired briefs are typically used for wireless alarms.

Another consideration is how the sensor (through its cable, if applicable) is attached to its alarm or transmitter in the case of wired alarms or wireless alarms. Some wireless alarms are truly wireless, with the transmitter being part of the sensor and completely self-contained. For wired alarms, the sensor's wire (or cable) runs from the sensor (located at the point of urination) underneath the user's pajama shirt to wherever the alarm is located on the body (frequently on the collar of the pajama shirt, so that it is close to the ear). The attachment mechanism to the alarm, through which the electric current flows to the alarm, is important. If it is easily detached (unintentionally comes out from the alarm during use) the alarm may not be triggered. Most connectors are plastic telephone jacks which are very unlikely to be detached unintentionally (RJ-11, RJ-12, 616E, etc.).

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