Conceptual Design for VolumeControlled External Ventricular Drainage

Sammanfattning

This project investigates how volume-controlled external ventricular drainage (EVD) of cerebrospinal fluid (CSF) drainage could be implemented in a closed and motorized drainage system. Traditional pressure-based drainage methods are often imprecise and sensitive to the movements of the patient. To improve safety and accuracy, non-invasive to the closed drainage loop, two measurement concepts were evaluated: ultrasonic flow sensing based on transit-time principles, and gravimetric based volume estimation using external sensors. Both methods were analyzed with respect to clinical relevance, technical feasibility, and integration into the existing drainage platform. Theoretical calculations and risk assessments were used to model system behaviour under realistic conditions, including pressure fluctuations caused by the activity of the patient. The results show that both approaches can regulate drainage volume dynamically and compensate for unintended overdrainage. The proposed solutions are well suited for spinal CSF drainage and lay a foundation for future clinical testing and system development.