any detials when training my own pretrain model

[Beenking]

thanks for your excellent work! there are some question

1. we all know that voxel "Spacing" is important when sampling Medical Image Data, which spacing in your training dataset, and test dataset?
2. the scale (32, 64) per patient, such as "32 means I extracted 32 sub-volumes per patient, 64 means 64 sub-volumes per patient", why donnt you sampling data on-demand when pick one patient for much more sub-volumes.
3. what is means HU_thred and len_depth in function infinite_generator_from_one_volume.