How to isolate a single heartbeat in audio using the Librosa library?

We have collected various samples of heartbeat data with different cardiovascular diseases. Some examples of our dataset are uploaded into the following folder:

We would like to use Librosa to identify the starting/ending point of each heartbeat in the file. The goal, in the end, is to create a program that will take in a heartbeat file, and and output just one beat. What would be the best way to go about it?