Mary I Frecker | PubMed Health

PubMed2005

Design of a multifunctional compliant instrument for minimally invasive surgery.

A new multifunctional compliant instrument has been designed for use in minimally invasive surgery. The instrument combines scissors and forceps into a single multifunctional device. The main advantage of using multifunctional instruments for minimally invasive surgery is that instrument exchanges can be reduced, thus reducing procedure time and risk of inadvertent tissue injury during instrument exchanges. In this paper, the length, width, and thickness of the multifunctional compliant mechanism tool tip is optimized to maximize the jaw opening and the grasping force. The optimized design is then modeled to simulate the stresses encountered in the scissors mode. A 5.0 mm diameter stainless steel prototype is fabricated using electro-discharge machining and is shown to grasp and cut successfully.

Computer Simulation↗

PubMedDate not supplied

Laparoscopic multifunctional instruments: design and testing of initial prototypes.

BACKGROUND: Advances in minimally invasive surgical techniques will require new types of instrument end-effectors for smaller, longer, and flexible instruments. These include a new class of multifunctional instruments capable of performing more than 1 task with a single set of working jaws. Furthermore, it is desired that multifunctional instruments be designed to provide improved dexterity compared with that in currently commercially available instruments. METHODS: Three prototypes of multifunctional laparoscopic surgical instruments are described: (1) a mechanical scissors-grasper, (2) a mechanical scissors-grasperarticulator, and (3) a compliant mechanism scissors-grasper. Methods of baseline analysis, design methods and considerations, and subjective evaluations of interim prototypes are presented. RESULTS: The 3 prototypes demonstrate promising early results. However, based on subjective evaluation, these prototypes do not perform individual functions as well as basic disposable single-function laparoscopic instruments do. CONCLUSIONS: The concept of multifunctionality and increased end-effector dexterity is achievable as demonstrated by the prototypes presented. Further work is required to refine, simplify, and improve the multifunctional instruments to a point where they may be useful as surgical tools.

Equipment Design↗