Page 409 - Flexible Robotics in Medicine

EndoGoose: a flexible and steerable endoscopic forceps 403

biopsy is conducted [14,15]. This is because the passively bending forceps would conform to
the surrounding structures, eliminating the operator’s ability to angle the forceps in a precise
manner to operator needs. As such, the endoscope should be moved closer to the region of
interest for biopsy. However, as shown in Fig. 18.1, this limits the field of view, reducing
operability to conduct the biopsy effectively and efficiently, and leaving with a smaller room
for the operation. Hence, in order to obtain a larger field of view, operators require a flexible
biopsy forceps that is actively bendable so that the operator can place the endoscope further
away and manually control the forceps to achieve the desired angle and position [16,17].

Precise bending motions could be achieved by trajectory projection [18], multichannel
concentric tube [19], magnetic endoscopes [20], or flexible robots [21,22]. Disposable
endoscopic robotic systems [23,24] could also be used for precise biopsy procedures.
Automation of the biopsy procedure could be done using multisensor data fusion [25],
visual SLAM [26], wireless power transfer [27], and other novel methods [28,29]. Soft
robotics [30], using sensors [31,32] and flexible manipulators [33 35], could be actuated
by different mechanisms such as motors, pneumatic, magnetic, and shape memory actuation
[36,37]. The endoscope should be fabricated using biocompatible materials [38] and should
reduce fractures [39] and other uncertainties [40,41]. The robotic systems [42 44] could be
incorporated with sensing capabilities [45 48] and artificial intelligence [49] to automate
the entire procedure.

This intended prototype of flexible endoscopic end-effectors is to maneuver corners that are
otherwise difficult to reach. The primary objective of the new prototype is to enable a
biopsy in the lumenal region, which can only be reached if there was controllable bending.
The primary considerations of the design are to ensure sufficient steerable section with an
appropriate bending moment to do a biopsy and to control the degree of bending.

EndoGoose consists of flexible forceps intended to be used for collecting biopsy. It is first
inserted through the endoscope, pushed out of the distal end, and steered toward the growth
needed to be analyzed. Forceps is then be employed to snap on a morsel of the tissue to be
withdrawn. Forceps have to be rigid enough when it is not being steered to allow the
grasping of the sample instead of being limp once it is out of the distal end of the
endoscope. An active steering forceps is able to bend after it is extruded from the distal end
of the flexible endoscope; hence, the diameter of the forceps has to be less than that of
most endoscopic working channels, and the steering of the bending section has to be from
the proximal end of the endoscope. As an example here, forceps should not have an
external diameter of more than 3 mm to be inserted into the lumen of an endoscope. The
flexible, yet actively steerable, forceps shall meet the following design acceptance criteria:
• Forceps should be able to bend with at least one degree of freedom after being extruded
out of the endoscope.
• Forceps can be actively steered by the operator from the proximal end.