Introduction - Microsurgery: Advances, Simulations, and Applications - page 20

the applied torsion. The interaction between the catheter tip and
the vascular wall should be sensed, too, for minimizing the risk of
puncturing the vascular wall.
If gum rollers as used as grasping mechanism, they may
accumulate blood residues making them unsuitable for sterilization.
A linear stepping mechanism (LSM) using a mechanical pencil-like
mechanism to grasp the catheter was proposed by Arai et al . [53].
During the irst half of the cycle, the mechanism closes the chalk to
grasp the catheter, and then it pulls the catheter. Then during the rest
of the cycle, the chalk is open to release the catheter, and then it is
restored to the initial position to start the cycle, and it is compatible
with sterilization process. A similar traction system was designed
by Ikeda et al . [54]. This device uses encoders as unique feedback
source. This LSM is able to insert and extract the catheter with a
controlled motion from 0.1 mm to 6 mm per stroke and to twist
the catheter at different speeds. This slave device gave us the basis
for in vitro catheter insertion paths reconstruction; this is achieved
by placing a microcoil on the catheter tip for motion capture and
LSM feedback control. This system is used in Chapter 7 for catheter
insertion path reconstruction.

1.2.6 Modular Robots for Endoluminal Surgery

The increment in the space restriction of SPS and natural oriice
transluminal surgeries has motivated the application of modular
robots to these interventions. In this case the modules are delivered
through the surgical port and they integrate inside the patient's body
into a complex robotic for providing the treatment. The projects
Assembling Reconigurable Endoluminal Surgical system (ARES)
and Array of Robots for Augmenting the Kinematics of Endoluminal
Surgery (ARKANES) are being developed by Dario et al . [57]. These
projects aim to develop a modular robot deployable through the
esophagus of the patient into the stomach. Once deployed into the
stomach, using specialized modules the robot would provide new
diagnosis and treatment options to the stomach and surrounding
organs (Fig. 1.20). Magnetic manipulation, levitation, and propulsion
[58-59] are also being investigated for modular robots for the
digestive tract and may play a key role in the development of concepts
as the one proposed in [57] (Fig. 1.21).