1. Department of Neurosurgery, Medical University of Lodz, Łódź, Poland.
2. Independent engineering consultant, Lodz, Poland.
3. Department of Neurosurgery, Public Hospital Medicam, Gryfice, Poland.
4. Faculty of Medicine, Department of Neurosurgery, Jagiellonian University Medical College, Kraków, Poland.
5. Center of Research and Development, Provincial Specialist Hospital in Wroclaw, Wroclaw, Poland.