Problem about receiving input signal from parallel port

In my experiment, the presentation of the visual stimuli is linked to participants’ real-time heartbeats. Therefore, the experiment PC need to receive signals about the heartbeat from a parallel port during the task. However, there is no this kind of ‘Parallel Input’ function even in the newest version of psychopy. Just a ‘Parallel Out’ function which could be used to send EEG triggers out.

Do you have any idea about how to recive signal from an parallel port in Psychopy?

Thanks a lot.