A novel, intuitive instrument positioner for endoscopy, involving surgeons in design and feasibility.

BACKGROUND: Existing laparoscopic instrument holders do not seem to sufficiently fulfil the needs of surgeons performing minimally invasive surgery (MIS) in several respects. Therefore, we developed and tested a novel laparoscopic instrument positioner in close cooperation between surgeons and engineers. MATERIAL AND METHODS: Design requirements were established by attending laparoscopic interventions, interviews and involving surgeons during the design cycle by evaluation of early mock-ups and prototypes. RESULTS: Two concepts, based on a scissor- and a deflectable ball principle, were elaborated and evaluated yielding a simple, affordable system, fixating all degrees of freedom in the centre of motion. A sterile functional prototype was fabricated and successfully tested during three clinical interventions. Users reported a stable image, easy and intuitive handling and no interference with other surgical instrumentation. The posture was conceived to be more ergonomic and surgeons liked the ability to control the positioning of the endoscope directly themselves. CONCLUSIONS: Three successful interventions show that involving surgeons in the design and testing phase of product development leads to a novel instrument positioner that can be used safely in a clinical setting. It can be concluded that the system is simple and intuitive to use, as there was no learning curve.

The Minimally Invasive Manipulator: an ergonomic and economic non-robotic alternative for endoscopy?

INTRODUCTION: Since the da Vinci robotic system was introduced, it has been reported to have ergonomic advantages over conventional laparoscopy (COV). High investments associated with this system challenged us to design a more economical, mechanical alternative for improvement of laparoscopic ergonomics: the Minimally Invasive Manipulator (MIM). MATERIAL AND METHODS: An earlier reported MIM prototype was investigated. Its shortcomings were input for the establishment of design criteria for a new prototype. RESULTS: A new prototype was developed, aiming at improved intuitiveness and ergonomics. The handle and instrument tip were redesigned and the parallelogram mechanism was converted from linear moving parts to mainly rotating parts. DISCUSSION: The new prototype was tested by a panel of experts and novices during an indicative ergonomic experiment. A major advantage of the MIM seems to be the possibility to perform laparoscopic surgery in a sitting position, in line with the working axis, instead of standing at the side of the patient. At an estimated cost level of 10% of the da Vinci system, the MIM can be an economical alternative for the enhancement of laparoscopy ergonomics. However, further development for clinical feasibility is necessary.