PhysioNet 2018 external validation result

[dosaming]

Thank you for your excellent work.
We are trying to reproduce your external validation on PhysioNet dataset and we would be grateful if you could clarify a few points.

1. How was the test set of 100 subjects selected from the PhysioNet dataset? Was it selected through random sampling?
2. If possible, could you share the coefficients used in the logistic regression classifier for the PhysioNet evaluation?
3. Was there any form of fine-tuning performed on the PhysioNet data before running the external validation?

It would really help us reproduce your results more accurately!