Hi @pmn77,
Following discussion in How to install Python packages with "pip" (Blender 2.8) I tested in Windows that you can install VTK into Blender’s python like this:
run CMD.EXE as administrator
cd C:\Program Files\Blender Foundation\Blender\2.80\python\bin
python.exe -m ensurepip
python.exe -m pip install vtk
After that you can “import vtk” in Blender’s Python Console. Edit: Currently it seems to install VTK 8.1.2 so I downgraded the add-on to use VTK 8.1.2 (was previously 8.2.0), because of the easy pip installation.
There was a bug in BVTKNodes logfile path for Windows which I fixed, so you should install the updated add-on from github. Thanks for the bug report!
PS. You can report bugs in github using the Issues tab.
BR,
Tuomo