Noisy switching - Flicker effect

input - -Continuous signal: binary - 0/1

Signal Details: Fault in system - 0 ; System is normal - 1

this input has to be processed for noise...

Lets say... For some reasons, noise in other systems, tend to switch the input from 1 to 0 but this wont stay long (Flicker effect) let say under 1 sec

What is the best way to create a MBD model, where the o/p will not switch state unless the signal stays in the same state for a pre-defined confirmation time (delta_t).

The easy way I thought of, was to add a integ. matlab func. block and have a wait timer inside.

How to model the same using simulink blocks?

Thanks in advance.