Surgical Science, 2012, 3, 499-502 Published Online October 2012 (
Lapar oscopic Trainer with Pneumoperitoneum
José L. Ortiz Simón1, Arturo Minor Martínez2, Neftalí Prado Coronado2, Ricardo Ordorica Flores3
1Department of Electrical and Electronics Engineering, Technological Institute of Nuevo Laredo, Nuevo Laredo, México
2Bioelectronics Section, Center for Research and Advanced Studies of the IPN, México DF, México
3Pediatrics Section, Federico Gómez Children’s Hospital, México DF, México
Received May 12, 2012; revised June 15, 2012; accepted July 3, 2012
The development of skills and abilities in laparo scopy is directly related to the use of trainers. The trainer should model
the patient with all its natural complexities as closely as possible. In this article we propose a system for training the
establishment of pneumoperitoneum executing the basic tasks to create the workspace in the trainer, the insertion of
primary umbilical trocar and simulate some of the ev eryday proble ms in surger y. Materials and Methods: A group of
electrical with biomedical engineers and laparoscopic surgeons developed a physical trainer that allows implementing
the pneumoperitoneum. The system uses pneumatic electro valves that are controlled with a dedicated microprocessor.
The user can program the system to set the parameters of the pneumoperitoneum. Results: This new trainer facilitated
the programming of right values of parameters to distend the abdominal cavity according a specific clinical case. The
model developed enab les the trainee to consolidate his knowledge on establishing the parameters re quired within clini-
cal practice, as well as the entry techniques. Conclusions: A new physical model for laparoscopic training was designed.
The system enables the laparoscopic surgeon to set the parameters for establishing the workspace according to the
clinical case. The trainer allows the surgeon to train in the Hasson technique for the introduction of the first trocar, as
well as the placement of the rest of surgical instruments with video assistance. We think this new trainer system will
help minimize entry-related injuries.
Keywords: Laparoscopy; Trainer; Pneumoperitoneum
1. Introduction
Laparoscopic trainers enable surgeons to develop their
skills and consolidate new methodologies in solving
surgical problems [1]. From the appearance of the first
physical trainers, until the latest generation of trainers
both hybrid and virtual [2], the surgeon has been reinfor-
cing his entire knowledge and developing the abilities
necessary for carrying out routine procedures with tools
which are explicitly developed to simulate problems that
occur in the operating room [3]. Add itionally, througho ut
the whole process of finding the best training methodo-
logy, it has been demonstrated that integrating virtual and
real training is the best method for achieving training
objectives [4]. The establishment of the pneumoperiton-
eum has been neglected in the majority of trainers con-
ceived solely as a workspace. The reality is that this
requires a variety of important criteria, in accordance
with the clinical symptoms of the patient [5]. We consi-
der the surgeon should consolidate his technical knowle-
dge as part of his surgical practice, since more than 50%
of greater complications in laparoscopy take place in this
stage of the procedure [6]. It is common to find errors
resulting from lack of skills in surgical practice during
initial entry to establish the pneumoperitoneum [7], such
as the exaggerated perforation of the entrances with the
oft-repeated correction on carrying out knots around the
trocar. It is also common to find a lack of adequate
knowledge for the establishing of pneumoperitoneum in
a newborn infant. Surgeons may confuse the exact entry
point of the trocars between a baby patient and an adult,
besides the risks of abdominal pressurization [8]. For this
reason, we propose a new trainer for laparoscopy with
the capacity to generate the pneumoperitoneum with the
different clinical variables that may arise in the operating
2. Materials and Methods
The pneumoperitoneum is the workspace of a laparos-
copic surgeon. It is b ased on the introduction of CO2 gas
at a certain pressure and flow, through the main entry
port through which enters the laparoscope [9].
The pressure and flow required to generate the pneu-
moperitoneum depend on variables such as the type of
operation, the position, the age and weight of the patient
[10,11]. Due to this, it is important that the laparoscopic
surgeon knows the clinical case perfectly. This new tra ine r
opyright © 2012 SciRes. SS
uses pressured air to eliminate the unnecessary cons-
umption of CO2. The basic parameters used to establish
the pneumoperitoneum are listed on Table 1, according
to the clinic case of the patient [12].
The system is build with a microcontroller that uses
the data of a pressure sensor to control the inlet valve of
air pumped into the cavity. Figure 1 shows the block
diagram of the electronic system implemented. The correct
pressure and flow parameters for the pneumoperitoneum
the required values are programmed through a control
panel. The outlet valve allows fine control of air. It
allows complete venting of gases produced by electro-
cauterization minimizing the lack of visibility. The values
programmed into the system are calibrated in millimeters
of mercury.
A soccer ball inner bladder, made of low density neoprene
and 3 mm thickness, was placed in a child mannequin. It
allows the skin of the trainer to be flexible and can be
lifted up as with human skin. It adjusts to the trocar size
and can be sutured. An air compressor was used as a
source of gas. A zero degree optic laparoscope was used as
a source of video and a commercial television set as a
monitor. The new trainer was tested with a specialized
Table 1. Parameters for establishment of the pneumoperi-
Age Pressure Flow
New born 5 mmHg 0.5 lt
Infant < 5 - 7 mmHg 1.0 lt
Infant > 7 - 10 mmHg 2.0 lt
Pre-school aged
children 10 - 12 mmHg 3.0 lt
School aged
children 10 - 12 mmHg 4.0 lt
Adolescents 10 - 13 mmHg 5.0 lt
Adults <15 mmHg
Inlet valve
Ou tlet va l v e
Pressure sensor
Gas supply
Control panel
an d data
Figure 1. Block diagram of the electronic pressure control
surgeon, carrying out puncture with the Hasson technique.
The pressure control system was programmed cons id eri ng
a normal clinical case of a 3-year-old child for laparo-
scopic cholecystectomy procedure. The suggested values
were 6mmHg and 1.0 L [12]. The first trocar was intro-
duced under direct vision. The trainer was insufflated and
a surrounding ex ploration was carried out. After that, two
trocars were inserted with the assistance of the endocam-
era. The system was tested simulating a different clinical
case: a 15 years old adolescent with diagnosed Appendi-
citis. The suggested parameters to establish the pneu-
moperitoneum were set at 11mmHg gas pressure and 4 L
as a maximum flow. A Veress needle insertio n following
the “safe insertion technique” allowed access to the peri-
toneal cavity (Figure 2(a )) [13].
After inserted the Veress needle, air was pumped up to
7 mmHg to create the workspace and verify there were
no air leaks. After that, the pressure was increased to
11mmHg and a brief surrounding exploration was made.
Two more 5 mm trocars were placed in the usual position
to get the configuration of three entrances for appendi-
cectomy [14] with the assistance of the laparoscope
(Figure 2(b)). Finally, a cutting task was performed in-
side the pressurized chamber. The task consisted of cut-
ting a circle of the chamber wall without perforating the
exterior layer simulating a dissection (Figure 3(a)). The
trainer allows adding material or tasks to work with. The
intraperitoneal air pressure was maintained to 11 mmHg
throughout the task ex ecution. An expert surgeon carried
out the task with no time restriction. Securing of the tro-
car and knot techniques were also practiced in order to
keep the trocar fixed during the introduction and extrac-
tion of the instrument (Figure 3(b)).
Different training exercises were carried out such
transfer, cutting and suturing tasks inside the pressurized
work space. An animal model dissection was performed
as well (Figure 4).
3. Discussion
Trainers for laparoscopic surgery do not facilitate training
of all of the necessary maneuvers of a real surgery [15].
The abilities of the laparoscopic surgeon should be com-
plemented by small tricks, which enable them to resolve
real problems in the operating room. The creation of the
pneumoperitoneum is a critical stage; it requires a priori
knowledge of the technology and methods implied to
achieve it. The pneumoperitoneum is one of the first ob-
stacles the new surgeon is going to be confronted with.
Current trainers do not contemplate the establishment of
the work space parameters with the functional conditions
of the patient. The introduction of the first trocar and
maintaining the variabl es of the pneumoperitoneum within
Copyright © 2012 SciRes. SS
J. L. O. SIMÓN ET AL. 501
Figure 2. (a) Puncture with a Veress needle; (b) Insertion of
trocars with video assistance.
Figure 3. (a) Cutting task inside the pressurized chamber;
(b) Suture to fix the trocar to the proper height.
Figure 4. Tasks inside the pressurized chamber: a) Trans-
ferring rubber rings; b) MISTELS cutting task modality; c)
Animal model dissecting.
safe ranges are not considered because this possibility
does not exist in current trainers.
Th e present design of trainer teaches to program the nec-
essary parameters for establishing the pneumoperitoneum
according to the particular clinical case. It allows the novice
surgeon to perform the maneuver of inserting the first trocar
under direct vision with the Hasson technique. This trainer
system accustoms the surgeon carry out the initial sur-
rounding exploration. Besides, the trainer allows him to
introduce the rest of the trocars with video-assistance and
with the implicit knowledge of the surgical technique to
apply. Additionally, this trainer allow s s urg eon s put tricks
Copyright © 2012 SciRes. SS
Copyright © 2012 SciRes. SS
into practice for avoiding gas leaks caused by the widen-
ing out of entry ports. We have used the same bladder up
to 10 times successfully. This novel trainer will allow
including critical variables of intra-abdominal pressure
during practice sessions in a dynamic and realistic way.
This trainer will certainly allow establish a one more step
to the training tasks collection th at contributes to enh an ce
the quality of newly graduated lapa roscopic surgeons.
4. Conclusion
We developed the first physical trainer with pneumo-
peritoneum. This novel trainer facilitates the integration
of the knowledge of the surgeon, based on the clinical
conditions of the patient. It allows the surgeon to practice
the Hasson technique, the safe insertion of the Veress
needle through an incision beneath the umbilical scar
while the abdominal wall is lifted with Alice forcep s. W e
tried basic laparoscopy MISTEL’s tasks that we do not
see any problem to simulate perivisceral laparoscopy
tasks. Entry related injuries such perforation of subsur-
face blood vessels will be reduced in the operating room
with the use of this system to train new laparoscopic
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