Final Project - Designing Mechatronic Systems for Rehabilitation. Laparoscopy surgery is a minimally invasive surgery (MIS) performed in the pelvis or abdominal cavity. This technique is part of a broader field known as endoscopy. Which applies the same principles to different body parts. Sorbonne Université - 5th Year - 1st Semester - Mechatronic Systems for Rehabilitation.

1. DESIGNING MECHATRONIC SYSTEMS FOR REHABILITATION
REPORT
PARIS, FRANCE, JANUARY 28TH, 2017
Skill Learning in Surgical Application
Laparoscopy Training
LUÍS RITA
3702256, luis.domingues_rita@etu.upmc.fr
Laparoscopy Open Surgery

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Introduction
A. Laparoscopy
Laparoscopy surgery is a minimally invasive surgery (MIS) performed in the pelvis or abdominal
cavity. [1] This technique is part of a broader field known as endoscopy. Which applies the same
principles to different body parts (Figure 1). One example is the thoracoscopic surgery focused
on the thoracic area. [2]
Generally, the main procedure is the following: abdomen starts for being insufflated
(pneumoperitoneum) with carbon dioxide gas (common to the human body and it can be
absorbed by the tissue or removed by the respiratory system). Usually, this is done using a Veress
needle responsible for the puncture, generally, in the navel or in the upper left part of the
abdomen. Afterwards, a trocar is used to open as manyportals as necessary to allow the entrance
and exit of devices such as endoscope, graspers or staplers. Although, the surgery is not over until
the cavity is unfilled of CO2, all the external devices removed, and the portals sutured. [3]
Figure 1 – Laparoscopy.

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Advantages [1]
® Reduced hemorrhagic events, consequently reducing the need of blood transfusion in
unexpected situations;
® Due to a smaller incision, the recovery time and pain are reduced (and, consequently, the
medication needed to handle it).This happens due to a decreased size of a post-operative
scar tissue and a reduced exposure of internal organs to possible external contaminants.
Thus, decreasing the probability of infections;
® Although the surgery itself may take slightly longer, the patient is discharged significantly
sooner, sometimes in the same day.
® The number of surgeries of this kind, mainly in gastrointestinal system, keeps increasing
due to the release of new and more sophisticated technologies, and because it
significantly decreases post-operative issues.
Disadvantages [1]
® 2D image which leads to the loss of depth perception;
® Loss of dexterity caused by the limited range of movements the surgeon is able to
perform with the available laparoscopic tools;
® The lack of tactile sensation that may be useful in open-surgery is lost in laparoscopy. In
the case of tumor removal, it can be useful to decide the area to exclude. The probability
of harming the patient may also increase, once the doctor may not be completely aware
of the force he/she is applying;
® Fulcrum effect - due to the presence of a pivot point, when the surgeon’s hands move in
a direction, the tool endpoint moves in the opposite one (leading to a non-intuitive motor
skill).
Risks [1]
® Right at the beginning of surgery, trocar insertion may cause abdominal wall hematoma,
umbilical hernias, umbilical wound infections or the unintentional perforation of blood
vessels or bowel;
® Some patients may also suffer from electrical burning caused by the leakage of current
from hypothetical electrodes being used;
® Increased risk of hypothermia or peritoneal trauma caused by the exposition to cold and
dry gases during insufflation;

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® Some patients may not tolerate gas in the abdominal cavity (pneumoperitoneum).
Leading to an open surgery after a first try of laparoscopy;
® Coagulation disorders may also constitute a risk.
Considering all these risks, it is understandable the need for practicing before actually performing
laparoscopic surgeries in patients, in a real environment. Then, beginners’ readiness depends
upon the number of hours spent in a simulator and on how realistic the simulation was. To sum
up, it is desirable to carefully go through the next steps: [4]
1.Observation phase – when the student study the processes in a global manner and the
teachers give general explanations on how to do the task or overcome adversities;
2.Integrative phase – taking place in the simulator room, the students train and repeat simple
gestures, so that they are able to perform them in a smooth and accurate way;
3.Automatic phase – students perform more complex tasks and in the operating room. This
is the stage just before they become experts.
Although not used in the present study, augmented reality may allow users to train in even
more realistic environments. Some projects were already developed in the area (suture a knot,
where the tip of the instruments had to remain inside a dome, drawn in the endoscopic image),
but there is still a big potential to explore. Taking into consideration the promising results in terms
of improved precision demonstrated by the learning curves of the respective students. [4]

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Simulator
The number of disadvantages when training in the operating room are endless. The fact of being
in a highly stressful environment and the exposure of the patient to unexperienced students may
lead to a decline in the learning process, as well as compromise the effectiveness of surgery.
Furthermore, teachers are only able to provide verbal advices to students which can be, in some
situations, very subjective. Plus, the high cognitive exigency of the practice, they may be impaired
of learning and memorizing several of the taught concepts. Finally, it is also proved that a good
way to keep the student motivated is by showing him his progress. The most effective solution
the go around these issues is the development of a simulated environment as close as possible
to reality (Figure 2).
Figure 2 – Szabo-Berci-Sackier Laparoscopic trainer by Karl Storz.

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Objective
To assess whether a tactile feedback is helpful in facilitating learning of laparoscopic technique,
when compared to a control and visual feedback groups. Consequently, amplitude of deviation,
cumulative deviation and the total time necessary to finish each task, was obtained and used to
evaluate the effectiveness of different methods.
Subjects & Materials
Subjects
Three different groups of 8 people undertook the experiment as part of control,
visual and tactile feedback group. Thus, the total number of recruited subjects
was 24 healthy users without any previous laparoscopic experience.
Before initiating the experience, a consent was signed by each subject.
Materials
1. Pelvi-trainer (Szabo-Berci-Sackier Laparoscopic trainer by Karl Storz);
2. Robotic arm;
3. Endoscopic camera;
4. Laparoscopic instrument (Figure 4);
5. Optical camera (NDI PolarisTM
– Figure 3);
6. Optical sensors;
7. Displaying device (computer);
8. 2D workspace (white sheet with orientating drawings).
Method & Discussion
The training was divided in 4 different sessions of 20 minutes. Each
session containing 10 trials. Among these, there were some that were
performed using a tactile, visual or without feedback at all. Every user
experienced at least a non-feedback situation (in the case of control
group, they never performed with feedback). The proportion was 1:5,
in which the 1st
and last trials were without feedback and the remaining
with.
At the beginning, it was explained to the user that the goal was
to draw an 8-shape trajectory (2 circles of 3 cm radius) in a 2D workspace
Figure 3 – Optical camera
(NDI PolarisTM)
Figure 4 – Different laparoscopic instruments.

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sheet under the laparoscopic operating device. The location of the center of each circle was
already drawn, as well as the intersection of both circles and a fourth point, defining the plane of
intersection of those. Each time before going forward, the virtually drawn figure is shown to the
user, in order to allow him to improve his drawing next time.
In Figure 2, it is represented the setup used along the experiment. An optical camera and
the displacement of a set of optical sensors in the handle of laparoscopic tool allowed the
experimenter to record the complete movement. Thus,once it was not the tip of the laparoscopic
device being recorded, but the handle, a matrix transformation was performed such that the
coordinates in the interface of contact were represented instead.
The tool being used by the user is a real one and commonly used in common surgical
environment. Allowing operations like grasping, cutting or clipping.
A robotic arm is connected to the laparoscopic tool. This was the responsible for
providing the tactile feedback when necessary. It was coded using C++ language environment.
The plot of the traveled path, along with the expected one and the correspondent error margins
(+- 2 mm dashed line) were shown in Matlab (Figure 5). On the other hand, in the case of visual
feedback, no force was applied by the robot, but a drawing of the target path was displayed in a
screen in front of the user. The source of the image from this device is an endoscopic camera
present under the table where the surgery tool was being manipulated.
Figure 5 – Ideal and traveled path by the tip of the laparoscopic tool after one of the trials.

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Conclusions
In spite of not being able to conclude what were the results, once the experience was not finished
by the time of writing this report, some predictable conclusions were postulated based in the
article [4]. The expectable scenario would be to see that the users who had a tactile training
performed better, after the 4 sessions, when comparing with the group without feedback or with
visual feedback.
Indeed, the tactile group not only was able to perform much precise movements (not
degrading with time), but also seemed more confident after the training sessions.
On the other hand, although visual group performed better than control during training,
the effects of these did not remain after removing the visual aid. They showed a high dependency
on visual feedback and did not show any improvements when relating with the control group.

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References
[1] “Laparoscopy,” Wikipedia. 23-Jan-2018.
[2] “Endoscopy,” Wikipedia. 10-Jan-2018.
[3] “Laparoscopia,” Wikipédia, a enciclopédia livre. 22-Nov-2015.
[4] N. Candalh-Touta, D. Reversat, P. Poignet, and J. Szewczyk, “Can In-Line Multi-Sensory
Feedbacks Improve the Learning of Laparoscopic Surgery?”