Development and testing of a grasper for NOTES powered by variable stiffness pneumatic actuation

Two-Dof Upper Limb Rehabilitation Robot Driven by Straight Fibers Pneumatic Muscles

In this paper, the design of a 2-dof (degrees of freedom) rehabilitation robot for upper limbs driven by pneumatic muscle actuators is presented. This paper includes the different aspects of the mechanical design and the control system and the results of the first experimental tests. The robot prototype is constructed and at this preliminary step a position and trajectory control by fuzzy logic is implemented. The pneumatic muscle actuators used in this arm are designed and constructed by the authors' research group.

Additive Manufacturing Applications on Flexible Actuators for Active Orthoses and Medical Devices

This paper describes the results of research projects developed at the University of L'Aquila by the research group of the authors in the field of biomedical engineering, which have seen an important use of additive manufacturing technologies in the prototyping step and, in some cases, also for the realization of preindustrialization prototypes. For these projects, commercial 3D printers and technologies such as fused deposition modelling (FDM) were used; the most commonly used polymers in these technologies are acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). The research projects concern the development of innovative actuators, such as pneumatic muscles and soft pneumatic actuators (SPAs), the development of active orthoses, such as a lower limb orthosis and, finally, the development of a variable-stiffness grasper to be used in natural orifice transluminal endoscopic surgery (NOTES). The main aspects of these research projects are described in the paper, highlighting the technologies used such as the finite element analysis and additive manufacturing.

Snake-like surgical forceps for robot-assisted minimally invasive surgery

BACKGROUND

Surgical instruments greatly impact the performance of robot-assisted minimally invasive surgery (RMIS) because they operate on tissues.

METHODS

A snake-like surgical instrument, designed with 4 degrees of freedom (DOFs), is proposed for RMIS. The DOFs are as follows: opening and closing motions of the forceps, rotation of the forceps and bi-directional bending of the instrument. The performance of the instrument was evaluated using a prototype in vitro.

RESULTS

All DOFs of the instrument were experimentally evaluated and proven sufficient for RMIS. In vitro testing showed that the operations of the proposed model were powerful and steady.

CONCLUSIONS

The position and posture of the surgical instrument could be adjusted in the body of the patient by its bending and rotational movements. The proposed model could therefore work as a competent assistant in multi-port RMIS and allow surgeons to perform better.

Natural orifice transluminal endoscopic surgery with a snake-mechanism using a movable pulley

BACKGROUND

Natural orifice transluminal endoscopic surgery is an emerging technique. We aimed to develop an advanced surgical robot mechanism for natural orifice surgery.

METHODS

We propose the active-controlled overtube-type platform with multiple channels for an endoscopic camera and surgical tools. To make such a platform, we suggest an advanced snake mechanism comprising movable pulleys to make a snake mechanism with multiple degrees of freedom and high operating force.

RESULTS

The stiffness and maneuverability of the active-controlled platform appeared satisfactory. Using prototypes and ex vivo experiments, we confirmed that the mechanism was suitable for a snake-like robotic platform for natural orifice surgery.

CONCLUSIONS

The suggested snake mechanism using movable pulleys has the advantages of stiffness and maneuverability. This new mechanism can be an alternative platform for natural orifice surgery.