[Scheduled urine collection using disposable diapers with an acoustic signal emitter].

Usually, urine is collected from infants by means of a urine bag. This procedure has some disadvantages, as it can cause discomfort and may even be painful for the child if repeated application of the bags is necessary. Correct placement is difficult for parents or other untrained people and bag displacement is common especially in older mobile children. Urine collection with disposable diapers followed by urine extraction for analysis might be a simple alternative procedure especially for field studies. Urine output is measured by weighing the diapers. A moisture sensor with a sound signal indicates the moment of urination. Stool contaminated diapers must not be excluded from urine collection, if the stool is quickly removed after defecation using diaper liners. Wet diapers are sealed in plastic bags and may be stored at -20 degrees C until extraction. With a hydraulic press urine is extracted from the diapers for measuring concentrations of urinary constituents. After extracting urine after 1 hour and 10 hours contact time only the pH falls significantly. Concentrations of the other constituents tested (creatinine, urea, phosphorus, calcium, sodium, potassium, magnesium, chloride) and total osmolality are not effected. After freezing the wet diapers for storage osmolality and the concentration of creatinine tend to be slightly lower. For clinical practice these effects can be neglected. However, they must be considered using this urine collection method in research.(ABSTRACT TRUNCATED AT 250 WORDS)