Here's how it works: In the initial setup, you program a time limit—say, 20 minutes—for your future bathroom. From that point on, whenever you close the door and activate the alarm, the Help Lock will sound a preliminary alarm after the allotted time, giving the bathroom inhabitant 30 seconds to deactivate it. After that, the doorknob will initiate an alert call to whatever number you've chosen to enter, whether it be a neighbour or emergency services.
The concept seems like a pragmatic approach to a real problem for senior citizens, but begs for one minor modification. Does forcing an old person to scramble from a bathtub to deactivate an alarm that your forgot about sound like a good idea? Throw another minute on there and we've probably got a winner. Check out a more in-depth description of the Help Lock's functionality at [Yanko]