Page 459 - Flexible Robotics in Medicine

Flexible drill manipulator utilizing different rolling sliding joints for transoral drilling 453

1 3to1 7 to bend opposite the drilling direction. Hence, this “step” cut helps create an
equal force to push the bent segments back into place, reducing the bending moment.

Fig. 19.S5 shows the connecting segment, 1 4, which composes of holes 5 3, for the
cable wires and 5 4 for the drilling wire. 5 1 and 5 2 are areas for the previous and the
following segments to latch onto when the cable wires are tensioned.

Fig. 19.S6 shows the connecting segment, 1 5, which composes of holes 6 4 for the cable
wires and 6 3 for the drilling wire. 6 1 is the space used to allow the modular segment to
latch onto the previous connector segment. On the other end, 6 2, a different “J” cut is
used to allow the pieces to at the end to collect easily once the ratchet mechanism starts to
tighten the segments together.

Fig. 19.S7 shows the second distal-most segment, 1 6, which composes of holes 7 3 for
the cable wire and 7 4 for the drilling wire. 7 1 is used to fit with the “J” cut in segment
6 2, and 7 2 is a similar cut to allow for easy collection when the wires are tensioned.

Fig. 19.S8 shows the distal-most segment, 1 7, which is also where the drill tip surfaces to
conduct the tracheostomy process. 8 1 fits with 7 2 of segment 1 6, and the drill tip will
surface from 8 3 after entering from 8 2. Primarily, we will only be using a pair of cable
wires, and two loops will be formed at the drill tip surface.

Fig. 19.S9 shows our entire device, including the gears for the ratchet mechanism. By
adjusting 9 1, we can coil the wires and tighten the shaft. 9 2 latches onto 9 1 to prevent
it from rotating in the opposite direction, which results in the loosening of wires. Gear 9.4
helps to decrease the circle diameter of 9.1 to fit in 9 3, which acts as a knob. When
released, we can uncoil and loosen the wires.
The advantage of the ratchet mechanism is that we can generate enough force when the
gears are made with sturdy material such as steel or other metals which are able to
withstand high shear stresses or forces. Furthermore, the gears make a compact system, not
taking up too much space, which allows us to make our device small, portable, lightweight,
and thus, reducing the bulkiness and complexity of our design.

Acknowledgment

This work was in part supported by the National Key Research and Development Program, The Ministry of
Science and Technology (MOST) of China (No. 2018YFB1307703).

References

[1] J.P. Reed, J.P. Kemph, W. Hamelberg, F.A. Hitchcock, J. Jacoby, Studies with transtracheal artificial
respiration, Anesthesiology 15 (1) (1954) 28 41. ,http://reference.medscape.com/medline/abstract/
13124793..