Development a 'dry alarm' that can help children and adolescents become dry at night.

Enuresis / Bedwetting is a common problem causing much emotional distress. Most children are dry by the age of 5 years, but a significant number of older children still wet their bed. This can be very distressing for child and family. There is also an associated cost due to extra laundry and impact of lost sleep.

Programmes to help children become dry at night often include the use of a moisture alarm. The alarms sound when the child begins to wet the bed, waking them up to go to the toilet instead. Most alarms work by detecting wetness, sounding the alarm when the child starts to pass urine. As such, they still need to change pyjamas and bed sheets.

The investigators aim to develop a 'dry alarm' that can help children and adolescents become dry at night. The alarm will sound when the bladder is full, before the child passes urine. This would avoid wet beds. The investigators have engineered parts for this alarm, but need to work on making it ready for use. This device will enable children to have dry nights whilst learning bladder control.

This study has several phases. The alarm will consist of a small box worn over the abdomen. The aim is to test this overnight, and adjust it for comfort and ease. The device uses a mini ultrasound machine, which measures how much urine is in the bladder. There will be a series of tests to calibrate the device compared to a clinical ultrasound device. Then children with enuresis/ bed wetting will wear it overnight. It will be linked to an alarm which will sound once the bladder is full.

This particular study will determine the feasibility of the product, to confirm the design and specifications, including a comfort trial, calibration and comparison with clinical scans, and operating process prior to a future clinical trial.

The total number of participants is 25 - however this will be split over the different phases of the trial.

Comfort Trial - 5 Calibration trial 3 month testing phase - 10

Inclusion Criteria:

• Age 7 years to 12 years
• Bedwetting twice a week or more
• Good understanding of English language
• For the initial comfort trials and the calibration trial healthy volunteers may be invited to take part.

Exclusion Criteria:

• there is a medical cause for bedwetting
• they have significant learning difficulties
• they are obese (above 98th centile for Body Mass Index)
• they have severe hearing impairment