Diaper with Wet Diaper Monitoring Device

Abstract

A diaper includes a diaper body and a wet diaper monitoring device, which includes a disposable pouch and a monitoring device. The monitoring device includes a monitoring casing, a first sensor electrode, a second sensor electrode, a sensing circuitry and an indicator. The first sensor electrode and the second sensor electrode are provided on an inner surface of and received in the monitoring casing, and form a single planar capacitor when the diaper body is dry. When the diaper body becomes wet, a capacitance between the first sensor electrode and the second sensor electrode increases substantially so as to transform the single planar capacitor of the first sensor electrode and the second sensor electrode into two much larger series connected capacitors.

What is claimed is: 
     
         1 . A wet diaper monitoring arrangement for a diaper comprising a diaper body having an inner layer, an outer layer, and an absorbent layer sandwiched between said inner layer and said outer layer, said wet diaper monitoring arrangement comprising:
 a disposable pouch affixed on a front portion of said diaper body, said disposable pouch having a receiving cavity; and   a monitoring device, which comprises:   a monitoring casing provided in said receiving cavity at a position adjacent to an inner surface of said disposable pouch;   a first sensor electrode and a second sensor electrode spacedly provided on an inner surface of and received in said monitoring casing, said first sensor electrode and said second sensor electrode forming a single planar capacitor when said diaper body is dry;   a sensing circuitry received in said monitoring casing and electrically connected to said first sensor electrode and said second sensor electrode, said sensing circuitry comprising:   a touch sensor IC electrically connected to said first sensor electrode and said second sensor electrode, said touch sensor IC being configured as an electronic detector to determine if the capacitance between said first sensor electrode and said sensor electrode is greater than a predetermined threshold value, said touch sensor IC comprising:   an analog input terminal for connection to said first sensor electrode;   a reference terminal for connection to said second sensor electrode;   a capacitor connected between said analog input terminal and said reference terminal to reduce an input sensitivity so that said sensor IC is insensitive to insignificant capacitance change, but responsive to substantial capacitance change caused by a wet diaper situation;   a plurality of digital input terminals for accepting digital commands from an external controller, said digital commands altering said digital sensitivity, digital threshold, and response time so as to cause said sensor IC to become insensitive to insignificant capacitance change but responsive to substantially capacitance change caused by said wet diaper situation;   at least one digital output terminal to indicate whether or not if a capacitance between said first sensor electrode and said second sensor electrode exceeds said predetermined capacitance level, wherein when said capacitance exceeds said predetermined capacitance level, said digital output terminal is arranged to change logic state to alert said wet situation of said diaper.   
     
     
         2 . The wet diaper monitoring arrangement, as recited in  claim 1 , wherein said disposable pouch has an inner surface, an outer surface and a flap, said inner surface being coated with an adhesive layer, while said outer surface being linked to said flap in such a manner that when said monitoring device is inserted into said pouch, said flap is folded to cover and seal said receiving cavity of said disposable pouch. 
     
     
         3 . The wet diaper monitoring arrangement, as recited in  claim 2 , wherein said disposable pouch is configured to be flexible and stretchable so as to normally exert a constant compression force against said monitoring device for preventing formation of air pocket between said disposable pouch and said monitoring casing. 
     
     
         4 . The wet diaper monitoring arrangement, as recited in  claim 3 , wherein said monitoring device further comprises a pushbutton provided on said monitoring casing and electrically connected to said sensing circuitry, said pushbutton being configured as a momentary switch for initializing a new monitoring process after completing a diaper change. 
     
     
         5 . The wet diaper monitoring arrangement, as recited in  claim 4 , wherein said monitoring casing has a first casing surface and a second casing surface, said first casing surface being defined as a surface that is formed closest to said diaper body, said second casing surface being defined as a surface which is opposite to said first casing surface, said first sensor electrode and said second sensor electrode being electrically connected to said sensing circuitry and positioned to be in direct contact with said first casing surface of said monitoring casing. 
     
     
         6 . The wet diaper monitoring arrangement, as recited in  claim 5 , wherein said monitoring device further comprises a wireless Radio Frequency transmitter electrically connected to said sensing circuitry for wirelessly transmitting radio frequency signal when said sensing circuitry detects that said diaper body is wet. 
     
     
         7 . The wet diaper monitoring arrangement, as recited in  claim 6 , wherein said disposable pouch is fabricated using by the same material as said outer layer of said diaper body. 
     
     
         8 . The wet diaper monitoring arrangement, as recited in  claim 7 , wherein said disposable pouch is pre-fabricated on said outer layer of said diaper body.