Design of a Steerable Laparoscopic Aspirator-Irrigator

Design of a Steerable Laparoscopic Aspirator-Irrigator: FlowFlex

Groen, Gijs-Bart (TU Delft Mechanical, Maritime and Materials Engineering)

Breedveld, P. (mentor)
Scheltes, J.S. (mentor)

Delft University of Technology

Mechanical Engineering

2021-07-09

Laparoscopy is a type of minimally invasive surgery in which instruments with long, slender shafts between handle and end effector are inserted through small incisions in the abdominal wall. A laparoscopic aspirator-irrigator (LAI) has a hollow shaft used to evacuate undesirable substances using a vacuum pressure, rinse tissue using a stream of pressurized saline, and manipulate adherent tissue.
Although laparoscopic instruments typically have a steerable tip to compensate for the loss of maneuverability due to the small incision, all currently available laparoscopic aspirator-irrigators lack a steerable tip. This lack is associated with sub-optimal aspiration and irrigation efficacy, mechanical trauma resulting from interference with obstructive tissue, interference with other instruments, and a lack of fine motor control of the tip. Although LAI’s with a steerable tip are known from patent literature [1]–[6], they all seem to have been abandoned, which suggests that the implementation of a steerable tip on an LAI tends to compromise performance relative to cost. Therefore, the objective of the current study is to design a new laparoscopic aspirator-irrigator (FlowFlex) with a steerable tip that mitigates the limitations of a conventionally rigid, straight tip to the extent of warranting its additional cost.
To meet the objective, design requirements have been generated, tentative prototypes have been designed and evaluated, and a Final Prototype has been designed based on the superior tentative prototypes. Its steerable tip consists of an inner tube that is rigid and straight and an outer tube with an elastic, pre-curved silicone tip. Whereas the inner tube is stationary, the user can rotate, retract, or protract the outer tube by moving the tip control wheel on its proximal end using the index or middle finger, causing the tip to rotate, straighten, or deflect.
The Final Prototype meets all important design requirements; it is cost-effective, due to the particularly simple and cheap steerable tip, it has ample flow rate capacity, it is unsusceptible to clogging, and it is sufficiently maneuverable. Although its main limitation is the low stiffness of its pre-curved tip, the ability of the tip to be rigidized by straightening makes it at least as capable of manipulating tissue as a conventional laparoscopic aspirator-irrigator.

Laparoscopy
Aspiration
Suction
Irrigation
Steerable
Surgery
Medical
Instrument
Design
Vacuum
Flushing
Steerable tip
Handheld
Handpiece
Aspirator
Irrigator

http://resolver.tudelft.nl/uuid:4495256c-4324-4db5-b411-5cbbd578f411

Student theses

master thesis

© 2021 Gijs-Bart Groen