Spurred by recent press reports and other concerns this thesis focuses on the quality of surgical instruments. The current situation is reviewed by considering the regulatory framework and by investigating the quality of newly purchased instruments. A range of test protocols based on British Standards and best practices from industry were developed. These were designed to be practical in the real world situation and a user-friendly database was built to collate all the relevant data and inform the Supply Chain. The conditions experienced by instruments during their lifetime in the health care environment, especially in cleaning and disinfection were studied and as many instruments implicated in Incidents as possible investigated to understand the possible root causes of failure. During this work the importance and debate over surface finish, passivation and disinfection processes became apparent and research was carried out into the effect on wettability and drying mechanism of passivation and repeated disinfection cycles on various typical surface finishes. This concentrated on the environment within the health service unlike other studies which have been concerned with more aggressive industrial situations. Standards and Procedures on the care of instruments have been established in order to improve the current management of surgical instruments and to ensure that they are and remain fit for purpose.

Robot-assisted minimally invasive surgery is used to perform intricate surgical tasks through small incisions using long, slender instruments. The miniaturization of these instruments is advantageous to both surgeon and patient because smaller instruments reduce trauma to surrounding tissue, decrease patient recovery times, and can be used in confined spaces otherwise inaccessible using larger instruments. However, miniaturization of existing designs is limited by friction between moving parts, the volume occupied by the end effector, and manufacturing and assembly constraints. The objective of this work is to develop and analyze concepts that can be used in robot-assisted needlescopic surgery. The concepts are intended for instrument shafts no larger than 3 mm in diameter. An ideal concept is one with large ranges of wrist and gripping motion. Concepts should also minimize friction and swept volume while maintaining a focus on manufacturability and ease of assembly. Multiple concepts were generated and evaluated using a tree classification scheme, proof-of-concept prototypes, and simplified mathematical models. Three unique concepts were further developed and tested—the Split CORE Grips, the Inverted Flexure Grips, and the Crossed Cylinders Wrist. The two grip concepts are instruments that incorporate one rotational degree of freedom and one gripping degree of freedom. The wrist concept incorporates two rotational degrees of freedom and could be coupled with a single DOF grip mechanism to form a functional instrument. In addition to concept development, a variety of fabrication techniques were investigated to better understand the challenges that arise when designing and fabricating devices at the 3 mm scale. To augment existing techniques, a novel fabrication technique was developed which uses layers of lithographically patterned carbon nanotube (CNT) composite material to form a 3D part. This method was used to prototype some of the designs at a 1:1 size scale.

This is an interdisciplinary research project in which the methods of Industrial and Product Design Engineering are focused upon a problem in Orthopaedics. One of the most controversial areas in Orthopaedics is the reconstruction of the anterior cruciate ligament (ACL). The current twin-instrument method for locating the ACL is difficult for surgeons with fewer than 500 surgical experiences. This was clearly demonstrated by Kohn, Busche and Cans (1995), and confirmed by Sommer, Friederich and Muller (2000), Sudhahar, Glasgow and Donell (2004), and Kuga, Yasuda, Hata et al. (2004). The above research indicates that the problem is not only one of anatomical location, but of how the operation takes place. The aim of the research was, therefore, to develop a new and improved surgical instrument and technique for locating the ACL anatomical landmarks. The research described in this thesis employs a number of design methods that can be used separately or in combination (hybrid process). They form the theory base that guides the design process. This allows the designer to engage in a flexible process that is effective in finding design solutions to the problem. Within this process, iterative case studies were employed in order to design a new surgical device for ACL reconstruction. The thesis describes a series of designed devices (case studies) that were iteratively developed and surgically tested, leading to a penultimate device. This latter device was tested via a number of surgical operations. The device provides a new method for externally locating the internal ACL attachment points. The research has resulted in a commercial association with Smith and Nephew Surgical Australia and BrainLAB AG Germany for the commercialisation of this technique. At the time of writing, the next stage of research and development is under way. This is using a frameless computer-aided image guidance system in the place of X-ray.