Page 131 - Flexible Robotics in Medicine

Modular origami joint operator to create bendable motions with multiple radii 117

navigate these obstacles, compensating for lack of user expertise with its intuitive
operation. By the same principle, the MOJO can provide tunable deflection and stability
to its distal tip.

Third, the MOJO’s simplistic design allows it to be fabricated at a low cost using 3D
printing, and its modular property allows for parts to be rearranged and assembled to adapt
to the anatomical variations of different subjects. The MOJO’s minimal number of parts
and lack of moving parts further allows it to incur less of an assembly cost and makes it
easier to sterilize. The MOJO has a much lesser risk of experiencing problems associated
with friction and intricate mechanisms and thus has a much lower risk of failure.
The MOJO has a modular snake-like structure with two mirrored halves connected by
origami universal joints made from acetate. MOJO is driven by a motor, and its actuation is
transmitted through two cables that weave across the structure to control the bending. When
the cables are taut, the modules bend toward each other, and the halves compress to stabilize
the structure. Stabilizing wires made from hard but elastic materials such as Nitinol can be
inserted into perforations shown in the cross-section of each module. In this application, two
discrete tubes are inserted into the lumen created in the gap between the two halves of
MOJO. One can accommodate a drilling wire while the other can contain an optical fiber for
endoscopic surveillance. Both the rigid backbone and hinges can be replaced and rearranged
to achieve different degrees of bending.
The MOJO’s novel design enables a low cost, disposable design, and operational
advantages, making it a suitable candidate to perform the novel procedure of TT as well as
offer a practical and accessible alternative.

5.2.4.3 Modifications of the preferred embodiments

The current system conferring advantages in design could be useful for other endoscopic
surgeries with modifications to the number of modules, geometry (Fig. 5.11 or Fig. 5.13
presents an example), or tendon actuation through a routing channel for more
comfortable control (Fig. 5.13).

5.3 Design rationale and specifications

MOJO is a bending mechanism that uses an origami universal joint as a hinge between
modules of similar shapes and different lengths. It can achieve bending angles at specific
locations through mechanical forces such that it can go through the oral cavity and into the
trachea without the need to extend the neck. Moreover, modules of different lengths allow
for customization so that more subjects are able to receive tracheostomy procedures.

While endotracheal tubes require the need for an endotracheal introducer or guide due to
the lack of control, the proposed device does not need an introducer as it can be controlled
mechanically, such that we are able to bend the device accordingly when going into the oral