Colloquia

Summary

Coronary artery disease is a common cardiovascular disease that blocks heart arteries from providing oxygen-rich blood to the heart. One procedure to remove the blockade is the off-pump coronary artery bypass procedure (OPCAB), which is a type of bypass that lets the heart beat during surgery. It has a steep learning curve where deployment of a simulator would greatly benefit the training of cardio thoracic surgeons.

The Thorax Centrum Twente at the Medisch Spectrum Twente hospital is developing a training model for the OPCAB procedure to train future surgeons to re-establish itself as one of the leading centres in this procedure. The previous training model underwent a redesign of the movement mechanism, as analysis had shown it to be the bottleneck in the design process. The previous model had a production process of eighteen steps for one movement mechanism.

A contemporary design methodology of design sprints combined with rapid prototyping had been adapted better to suit the qualities of the simplified production techniques. 3D printing is used to print the movement mechanism directly using thermoplastic polyurethane, a soft and flexible material. The 3D-printed parts have been designed to be a structural part which creates the movement, a rubber balloon has been inserted to make the movement airtight. 

The final design has been assessed quantitatively through measuring percentile expansion and degrees of twist. A qualitative test of the new movement mechanism has been assessed by surgeons of the Medisch Spectrum Twente. The new movement mechanism has proven to function like the previous version. The result is a newly designed movement mechanism that works with the existing simulator while halving the number of production steps from eighteen to nine. The print is easier and cheaper to produce and is well suited to adapt for further design versions of the simulator.

The next steps of the simulator have been identified to include a redesign of the driving system, an improvement to the scale and the restoration of the simulated blood system.