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Title: Ergonomics of the operative field in paediatric minimal access surgery
Author: Lee, Alex Chi Hang
ISNI:       0000 0004 2676 9950
Awarding Body: Imperial College London (University of London)
Current Institution: Imperial College London
Date of Award: 2009
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This thesis studies the physical and sensorial aspects of surgical ergonomics in relation to paediatric MAS. The aims of the project are to optimise the choice of instrument size, to evaluate alternative illumination sources in paediatric MAS, and to investigate the role of shadows in potentially assisting visual perception in MAS. The ergonomic limitation of the small size of the endoscopic operative field is evaluated and a paediatric simulator is developed using anthropometric data from healthy infants to provide the experimental workspace for ergonomic studies. A study on the effect of the size of instruments on paediatric endoscopic intra-corporeal knot tying shows that using smaller instruments results in faster performance and less discomfort for the surgeon without compromising knot quality, suggesting that smaller instruments should therefore be used when operating on infants. The development of solid-state semiconductor lighting technology as an alternative to the conventional arc-lamp light source is discussed. A light-emitting diode (LED) based endoscopic illumination system, the LED endo-illuminator, is developed with favourable characteristics and fine details recognition is shown to be better compared to the conventional illumination methods. A study on distance estimation in static images does not show that the presence of endoscopic shadows improves depth perception. A further experiment shows that when the light source moves, the resultant shadow movements can give conflicting information to the viewer in the interpretation of the endoscopic scene. Therefore the light source should be stationary if endoscopic shadow is produced in the MAS illumination system. A laser-based illumination system is also developed and proof-of-concept tests show promising characteristics. Its low intensity precludes its use in large cavities but would suit the small endoscopic field in paediatric MAS.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available