http://www.grogans.com/research.jsp?documentid=63
and more:
http://www.peejs.com/products/bedwetting_alarms.htm
http://www.amazon.com/exec/obidos/ASIN/B000GG5ZUS/thaiherbs-20?creative=327641&camp=14573&link_code=as1
https://idiaper.3dcartstores.com/Bed-Wetting-Alarm_c_42.html