Extract info and analyses of PDF graphs

I need someone that knows how to use WebPlotDigitizer or some other similar program to extract information out of approximately 250 graphs recorded in images, and to pass that data into an excel file. The graphs (uploaded image) refer to blood pressure values and I need all the top ends, bottom ends and intersections to be recorded (Systolic, Diastolic blood pressures from blue lines, and mean arterial pressure from intersection, respectively) together with the time intervals and periods of hypotensive and hypertensive frames (for how long and when did they start exactly). Image and excel linked to a better understanding. The word file contains already dozens of graphs to be analyzed , most go together with a table that was created automatically by the program I use when working with the patients - the table is just so you can have an idea about the numbers, but you can simply ignore it. What I need are the values hidden on the graph, hence this project.