chrome extension

I need a chrome extension which can monitor a tab(time interval set by me). Here are some example that I want to do: if a page doesn't contain certain word(or html) --> the extension will refresh the page or run a script (bat or powershell) if a page contains certain word(or html) --> the extension will run a script (bat or powershell) It's better if you can let me to define everything in the extension, e.g. time interval, words and action.