Complex new medical instruments often get stuck at the prototype stage. That is expensive and time-consuming. Ewout Arkenbout therefore developed a new, virtual design method with which instruments can be evaluated and adjusted at an earlier stage. Arkenbout obtained his PhD on this subject at TU Delft last month.
Safety
'Minimally Invasive Surgery (keyhole surgery) seeks to reduce the burden on patients during operations. Specially designed instruments should help the surgeon to do this,' says Ewout Arkenbout. 'But in practice, we often find that poor design choices in such instruments can complicate procedures and compromise patient safety.'
Multi-branched
Arkenbout's doctoral research has included a closer look at multi-branched instruments for endoscopic surgery through natural body openings. An example of a procedure where a multi-branched instrument can be very useful is the removal of a tumour near the pituitary gland, where one enters through the nose. Multi-branched instruments have a shaft from which two or more steerable instrument branches emerge. Such an instrument should allow the surgeon to perform two-handed surgical tasks (such as suturing and tying knots) in operations.
Prototypes
'Over the last decade, dozens of prototypes of such multi-branched instruments have been developed,' says Arkenbout. 'However, the designers focus on incorporating too many degrees of freedom and thus introduce too much control complexity in the new instruments. As a result, in most cases, the potential advantages do not outweigh the disadvantages. Consequently, the designed instruments rarely make it out of the prototype stage.'
Gesture
Developing a prototype is a time-consuming and expensive process. 'So you actually want to be able to evaluate instruments already in the design phase, and gain new insights without having to build an expensive prototype. One solution I suggest for this is gesture-based design. Here, hand and finger movements in a test setup are measured live with sensors and then linked to virtually simulated instrument movements. By trying out playful pairings, and evaluating them, a steerable instrument can then be evaluated without needing a full operational prototype. We have tested this successfully, including in collaboration with surgeons at LUMC and AMC.'
Freedom
Gesture-based instrument design potentially gives great freedom in instrument design. For example, Arkenbout, in collaboration with Floris van den Berg, developed and evaluated a way to control four surgical instruments with two hands. 'Gesture-based instrument design is a relatively inexpensive and promising method that, especially with current technological advances in measurement systems for hand and finger movements, can develop into an easy-to-apply design method.
The video below explains the method:
Source: TU Delft
