An absorbent article includes an absorbent body in contact with a moisture activatable shrinking yarn in the form of a metering string. The metering string includes a hanging portion that is at least initially visible to a user when the absorbent article is in use. By observing the change in length of...http://www.google.com.hk/patents/US20100152642?utm_source=gb-gplus-share專利 US20100152642 - Absorbent Article Saturation Indication System and Method
