Patient-specific Epidural Simulator for Training and Assessment
This source preferred by Venky Dubey
Authors: Vaughan, N.
Editors: Dubey, V.N. and Wee, M.Y.K.
Epidurals are used in many areas of medicine including pain relief for chronic or labour pain and anaesthesia for surgery. The epidural procedure itself is recognised as one of the most difficult technical skills to teach. The reduction in training time due to European legislation, the challenges presented by the obesity epidemic and increasing litigation burden adds urgency to improving training in the epidural procedure. The research involves development of a patient-specific virtual reality based epidural simulator which can provide a realistic, accurate and immersive experience for training and assessment. Epidural simulators are used to train epiduralists to perform needle insertions for the epidural procedure. The developed patient-specific simulator allows practice on virtual patients of any shape, size or BMI applying a data-driven approach measured from actual patients, adjusting the simulated patient model forces to match. This research is aimed at developing a novel simulator to be used for training from novice to experienced epiduralists with varying degrees of difficulty. There are several novel aspects that have been included in this research which help to improve the realism and accuracy of the procedure. Initial in-vivo data was collected from a porcine trial which measured needle insertion force and tested out the components in preparation for the clinical trial. A clinical trial was conducted with our developed device on obstetric patients at Poole Hospital NHS Foundation Trust. The trial identified the relationship between body mass index (BMI) and needle insertion force, which contributed to the creation of an epidural simulator able to model patients with various weight, height and BMI. The force data has been used to configure a haptic device connected to the epidural simulator. A computer based synthetic ultrasound simulation was developed for ultrasound guided epidural needle insertion and catheterisation and Magnetic Resonance Images (MRI) images were analysed from patients and incorporated into simulation to create in-vivo characteristics in the simulator. This is the first epidural simulator using virtual reality interface and able to simulate multiple patient positions increasing the degrees of freedom in the simulation possibilities and realism. Stereoscopic 3D glasses are incorporated allowing the 3D graphical models and ligaments to be viewed with depth perception which is an important aspect of epidural needle placement. Models of human tissues including organs, ligament, fat, bone and skin were developed as soft and hard materials using real-time deformation based on spring-mass-damper model. The resultant virtual reality model can simulate any size or body shape each with unique BMI and body measurements, matching closely patient characteristics. A set of epidural assessment criteria was developed and incorporated into our simulation to assess trainees and provide feedback on performance. This thesis gives details of how each of the novel features was incorporated into the simulator with the potential to improve training and assessment thereby improving success and safety in the epidural procedure.