Restrict keyboard simulator input using javascript

Question

How to detect keypress event triggered by a keyboard simulator software in a web application. The input needs to be restricted if it is not manually entered using a physical keyboard. The option to verify using captcha and floating image is not considerable keeping in mind the design constraint and user ease. The keyboard simulation restriction is specific to the application requirement. An alternative for keyboard simulation has already been provided in the application in order to bypass the manual entry but the user is still using keyboard simulation which needs to be restricted.