Germany. Fax: 149-7071-295-569.

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Robotics and systems technology for advanced endoscopic procedures:
experiences in general surgery
q
Marc O.Schurr
*
,Alberto Arezzo,Gerhard F.Buess
Section for Minimally Invasive Surgery,Eberhard-Karls University,Tuebingen,Germany
Abstract
The advent of endoscopic techniques changed surgery in many regards.This paper intends to describe an overview about technologies to
facilitate endoscopic surgery.The systems described have been developed for the use in general surgery,but an easy application also in the
®eld of cardiac surgery seems realistic.The introduction of system technology and robotic technology enables today to design a highly
ergonomic solo-surgery platform.To relief the surgeon from fatigue we developed a new chair dedicated to the functional needs of
endoscopic surgery.The foot pedals for high frequency,suction and irrigation are integrated into the basis of the chair.The chair is driven
by electric motors controlled with an additional foot pedal joystick to achieve the desired position in the OR.A major enhancement for
endoscopic technology is the introduction of robotic technology to design assisting devices for solo-surgery and manipulators for micro-
surgical instrumentation.A further step in the employment of robotic technology is the design of`master-slave manipulators'to provide the
surgeon with additional degrees of freedom of instrumentation.In 1996 a ®rst prototype of an endoscopic manipulator system,named
ARTEMIS,could be used in experimental applications.The systemconsists of a user station (master) and an instrument station (slave).The
surgeon sits at a console which integrates endoscopic monitors,communication facilities and two master devices to control the two slave
arms which are mounted to the operating table.Clinical use of the system,however,will require further development in the area of slave
mechanics and the control system.Finally the implementation of telecommunication technology in combination with robotic instruments
will open new frontiers,such as teleconsulting,teleassistance and telemanipulation.q1999 Elsevier Science B.V.All rights reserved.
Keywords:Endoscopic surgery;Robotics;Solo-surgery;Systems;Telemedicine
1.Introduction
1.1.The role of technology in minimally invasive surgery
The advent of endoscopic techniques changed surgery in
many regards.Besides the adaptation to newkinds of instru-
mentation and operative maneuvers,the surgeon had to cope
with a full range of new devices resulting in a signi®cant
change of his work-place environment.Starting out fromthe
early 1990s,the design of dedicated surgical work-place
systems for minimally invasive surgery still is a major
topic for research and industry.
With the increasing complexity of endoscopic surgery in
the various clinical specialties,such as general,cardiac or
gynaecologic surgery,came the demand for improved
instrumentation.This paper intends to describe an overview
about technologies to facilitate endoscopic surgery.The
systems described have been developed for the use in
general surgery.However,due to the technical similarities
in all surgical disciplines using minimally invasive techni-
ques,devices and experiences collected with themshould be
transferable to cardiac surgery as well.
Besides improvements in the ®eld of endoscopic vision
systems [1±3] leading research groups world wide focus
their scienti®c interest especially on the increase of instru-
ment functionality.Robotics was soon recognized as a major
pacemaker in the drive towards the technological future of
endoscopic surgery.The initial steps in the use of robotics for
increasing instrument functions were in the ®eld of endo-
scope guidance,where robotic instrument holders were
employed to direct the endoscope during surgery [3±5].
Robotic endoscope manipulators proved to be safe and ef®-
cient invarious ®elds of use andare nowacceptedas assisting
devices among endoscopic surgeons [6].
The ®eld of robotics for enhancing surgical instrumenta-
tion did not emerge as quickly as the former due to its higher
technical complexity and safety questions linked to the use
of robotic devices for surgical tissue manipulation.It is,
European Journal of Cardio-thoracic Surgery 16 (Suppl.2) (1999) S97±S105
1010-7940/99/$ - see front matter q 1999 Elsevier Science B.V.All rights reserved.
PII:S1010-7940(99)00281-X
www.elsevier.com/locate/ejcts
q
Presented at the International Symposium`Present State of Minimally
Invasive Cardiac Surgery ± Meet the Experts',Dresden,Germany,Decem-
ber 3±5,1998.
* Corresponding author.Section for Minimally Invasive Surgery,Eber-
hard-Karls University,Waldhoernlestrasse 22,D-72072 Tuebingen,
Germany.Fax:149-7071-295-569.
however,of key scienti®c and clinical interest for endo-
scopic suturing.
Besides robotics,systems technology will have signi®-
cant impact on work processes in the OR.The integration
of the different devices used for endoscopic operations into
systems structures,which are easy to control and to main-
tain,is an important prerequisite for optimizing processes
and resource allocation in surgery.
Finally,telecommunication technologies applied to
surgery will help to leverage surgical expertise among
centers,facilitate information transfer and accelerate the
diffusion of surgical techniques among leading centers.
2.Enabling technologies in the endoscopic OR
Newtechnologies are of great help in the design of instru-
ments for endoscopic OR.The introduction of system tech-
nology and robotic technology enables today to design a
highly ergonomic solo-surgery platform.With the addition
of telecommunication technology assistance,consulting and
manipulation from a remote distance become possible.
3.Systems technology to create an ergonomic work place
in the OR
Minimally invasive interventions require a multitude of
technical devices,such as cameras,light-sources,high-
frequency and isuf¯ation.The devices used today often
represent stand-alone units.They need to be put into the
OR and set-up right before each speci®c surgery.From
each of the single devices,cables,hoses and other supplies
lead into the operative ®eld.They have to be connected on
both sides.This does not only cause long set-up times in the
OR but is also a source for infringement of the sterility of
the operating ®eld.The major drawback of the standard
solution lies in the lack of direct control of the devices
and the confusing display of parameters and technical status
of the single devices.
The ®rst approach to solve these problems has been made
with the Dornier OREST system in the early 1990s [7].
OREST (Fig.1) integrates all devices into a mobile cabinet.
The single devices are connected to a central computer and
can be controlled remotely by the surgeon via a multifunc-
tional monitor and input panel.This panel also informs
about all function parameters on a graphical display.All
supplies are guided into the sterile ®eld through an articu-
lated arm.Up to four multi-plugs are used to connect all
lines at a central terminal within the sterile area.
Based on the same principle,other system solutions are
nowavailable on the market fromdifferent companies,such
as the ENDOSURG system (Olympus,Tokyo) and the
HERMES system (Computer Motion,Goleta).
The posture of the surgeon during endoscopic interven-
tions differs signi®cantly fromregular open procedures.The
long shafts of the instruments and the ®xation of the line of
sight to the video monitor decrease the freedomof motion of
the surgeon.Compared to open surgery the endoscopic
surgeon remains ®xed to his position during the operation
with little opportunity to move his body and change his
posture.This ®xation in a relatively unergonomic position
can cause fatigue especially during longer interventions.We
developed a newsurgeon's chair dedicated to the functional
needs of endoscopic surgery (Fig.2).The foot pedals for
high frequency,suction and irrigation are integrated into the
basis of the chair.This provides for an intuitive alignment of
the foot pedals to the feet of the surgeon.The chair is driven
by electric motors controlled with an additional foot pedal
joystick.The seat offers a special ergonomic shape,which
allows both comfortable sitting in a semi-standing position
and inclination towards the OR table without slipping off.
The chair is applicable for various kinds of endoscopic
surgery.The device can be used in conventional team
surgery with one surgeon and one or two assistants.
However the combination with endoscopic solo-surgery
techniques seems particularly attractive.
4.Robotics and solo-surgery
Currently robotics technology has two main applications
in minimally invasive surgery:assisting devices for solo-
M.O.Schurr et al./European Journal of Cardio-thoracic Surgery 16 (Suppl.2) (1999) S97±S105S98
Fig.1.OREST II system (Dornier,Germany).
surgery and robotic manipulators for enhanced microsurgi-
cal instrumentation.
4.1.Solo-surgery
Since minimally invasive surgery appeared,the vision of
the operating surgeon has depended by an assistant surgeon
responsible for positioning the endoscope.This task
requires to keep the surgical point of interest in the center
of the video frame,providing an appropriate magni®cation
and maintaining a horizontal image.
The use of positioning devices returns direct control of
the whole procedure to the operating surgeon.This
increases precision of action and reduces costs.In the
past,mechanical arms and pneumatically assisted devices
derived fromopen surgery were used.The lack in ergonomy
resulted in a scarce diffusion of use of these systems.The
introduction of manipulator technology,has opened new
frontiers in the development of MIS systems.
The ®rst endoscopic positioning system appeared on the
market was the AESOP arm (Computer Motion,Goleta) in
1995 [5].It moves the endoscope around a pivoting point.
Up to now more than 50 000 procedures have been
performed in the United States.The experience in clinical
settings was used to upgrade the systemsubstantially,®rst in
the version named 2000,with the implementation of a voice
control system,then,in the least version,named 3000,with
a second joint that allows to reduce space requirements.
Another system also available on the market is the
ENDOASSIST (Armstrong Helthcare,UK).The system
moves the endoscope around an invariant point of constraint
motion,that has to be pre-adjusted.Apointer is placed in the
front of a helmet held by the surgeon and a visual detector
over the monitor.This way each movement of the head is
detected and the information transferred to the computer
that moves the optic in a correspondent way.The system
is ®xed on a trolley and its architecture design has minimum
space requirements.
In cooperation with the Research Center,Karlsruhe we
designed a passive positioning arm,named TISKA
Endoarm[8] (Fig.3) and a remote controlled optic position-
ing arm,named FIPS Endoarm,for endoscopic surgery.
Both prototypes are based on an architecture that ®xes an
invariant point of constraint motion.TISKAEndoarmmain-
tains a stable position by means of an electromagnetic fric-
tion that is released by footpedal.The operation of the
system is possible by using only one hand.The system is
highly appreciated when used as instrument retractor.FIPS
Endoarm (Fig.4) is an optic positioning system driven by
voice control or by a ®nger ring joystick which is clipped on
the handle of the operating instrument.As the tip of the
second ®nger is introduced in the controller,its movements
correspond to the movement of the optic.
In different trials conducted on phantoms at our institu-
tion more than 300 procedures were performed.Endoscopic
solo-surgery proved feasibility and safety.A number of
surgeons involved in the study declared positive judgment
in terms of comfort for each of the different interfaces
tested.All endoscope positioning systems combined with
an instrument retractor allowed a precise and comfortable
control of the optic.With all combination of systems opera-
tive time requirement was shorter than human assistance.
Nevertheless,the shorter operative time was registered
when the endoscope was driven by a passive system
TISKA Endoarm.This demonstrates the important role of
the man-machine interface,that in none of the solutions
tested showed an intuitiveness and reliability competitive
with hand positioning.
The trials conducted allowed us also to focus on the
crucial aspect concerning the position of the devices around
the operating table.We were able to de®ne criteria,how to
performendoscopic solo-surgery ergonomically (Fig.5).To
limit possible interferences between surgeon and the assist
devices,these have to be placed all opposite to the surgeon.
The surgeon works in a comfortable position having access
to the surgical ®eld by means of a conventional straight
instrument and a curved instrument as designed by
Cuschieri.
4.2.Robotic microsurgical manipulators
In endoscopic operations the mobility of the instrument is
signi®cantly decreased due to the invariant point of insertion
through the patient's abdominal or thoracic wall [9±11].
Only four of the seven`natural'degrees of freedom
(DOF) of the human arm remain [11].This reduction of
instrument mobility is not an issue in simple manipulations
dominating laparoscopic cholecystectomy or hernia
surgery,but it can lead to signi®cant handling restrictions
M.O.Schurr et al./European Journal of Cardio-thoracic Surgery 16 (Suppl.2) (1999) S97±S105 S99
Fig.2.Ergonomic chair for endoscopic surgery.
for the surgeon in interventions where complex dissection or
tissue connection techniques are required.
Complex,user driven robotic systems,called`master-
slave manipulators'have been developed to provide the
surgeon with additional DOF of instrumentation.The
master-slave mode of operation is a control principle in
which all movements done with a master input device are
transformed in real-time to the slave output device [12,13].
The entire manipulator systemcan be guided by the user,no
pre-programmed`robotic'motion is happening.
Our own development in the area of surgical robotics
started in 1991,together with the Karlsruhe Research
Center,Karlsruhe,Germany.In 1996 a ®rst prototype of
an endoscopic manipulator system could be used in experi-
mental applications.
The ARTEMIS (Advanced Robotic TElemanipulator for
Minimally Invasive Surgery) manipulator system has two
basic components,the user station (master) and the instru-
ment station (slave).The surgeon sits at a console which
integrates endoscopic monitors,communication facilities
and two master devices to control the two slave arms
which are mounted to the operating table.
The slave arm is an external kinematic unit to guide a
steerable instrument around the invariant point of insertion
into the body of the patient.The arm has two segments and
four joints,which are driven by integrated electromotors.
The steerable instruments have a bending section,which
allows to incline the tip around 908.
The functional unit of both,steerable instrument and
guiding arm,restores full spatial mobility of the instrument
tip with 6 DOF of motion.Two slave units (Fig.6) can be
attached to the operating table.
The surgeon's work place comprises an endoscopic 3D
monitor for visualization of the operative ®eld,as well as
two additional monitors for display of a graphical model of
the slave arms and various system data.
After appropriate system function and safety could be
proven in phantom models,animal experiments were
performed in domestic pigs (female,weight approx.50
kg) under general anesthesia.
ARTEMIS arm was employed for mobilization of the
sigmoid colon and ligation of sigmoid vessels for laparo-
scopic sigmoidectomy.The master arm was positioned
aside the operating table,the surgeon was in a sitting posi-
tion (Fig.7).After dissection of the sigmoid colon and
fenestration of the mesentery the blood vessels were
encircled and ligated with the ¯exible section of the steer-
able instrument.Several ligatures were placed at different
heights of the colon.The maneuver was easy to perform.It
was found,however,that geometric changes in the ¯exible
tip section are required to improve practicality of the device.
Further steps of surgical evaluation are planned after modi-
®cation of the prototype.
5.Telecommunication technology
Telematics applications are of interest in various ®elds of
M.O.Schurr et al./European Journal of Cardio-thoracic Surgery 16 (Suppl.2) (1999) S97±S105S100
Fig.3.TISKA endoarm.
medicine.In therapeutic areas,such as all surgical disci-
plines,telemedicine has future relevance,but is not as wide-
spread as on the diagnostic side.
Three levels of telematics applications in surgery can be
distinguished:teleconsulting,teleassistance and telemani-
pulation.Whereas the ®rst is based on intraoperative video-
conferencing and bilateral audio-visual communications,
the two other levels include remote guidance of an endo-
scope or even surgical instruments by a remote expert.
We estimate,that teleconsulting techniques will enter the
clinical routine of centers relatively soon,whereas teleas-
sistance and telemanipualtion technologies will not result in
clinical breakthroughs within the next few years.
Clinical and ambulatory patient care are processes with a
great deal of information to be handled.Therefore advanced
information management and telecommunications services
are of particular interest for the various medical disciplines
[13,14].
The technological basis of teleconsulting applications
usually is ISDN teleconferencing using two ISDN B-chan-
nels totaling to a transmission rate of 128 kbit/s (Europe) or
112 kbit/s (USA).These transmission rates are not suitable
for real-time applications.Image resolution and image rates
per second are visibly reduced compared to PAL or NTSC
TV standards.
5.1.Surgical teleconsulting
In the clinical ®eld we were able to study teleconsulting
applications with several external partners in a six B-chan-
nel setting providing a bandwidth of 384 kbit/s.
A four site teleconsulting trial was performed including
Tuebingen University Hospital,the Karlsruhe Research
Center and the Institute of Research on Digestive Tract
Cancers (IRCAD),Strasbourg,and a moderator located at
Kiel.The clinical case was an endoscopic removal of a
rectal tumour through the transanal TEM approach.
The scienti®c question to answer through the experiments
was whether the given bandwidth is suf®cient for appropri-
ate image quality.In different phases of the intervention
(tumour dissection,closure of the rectal wall defect) exter-
nal`teleconsultants'from both the technical side (Karls-
ruhe) and the clinical side (Strasbourg) were confronted
with questions on the case by the operating surgeon.
The image resolution was judged by all teleconsultants to
be suf®cient but at the lower end of acceptability for on-line
investigations.Usually video transmission is perceived real-
time with a bandwidth not less than 2 mbit/s.This requires
ATMconnections which are costly and hardly available for
most hospitals.
The overall judgment of the participants in the experi-
ments was that six B-channel teleconferencing techniques
are feasible for intraoperative surgical consulting,provided
that the operative ®eld,the instruments or the endoscope
itself are not moving signi®cantly.
Considering the simple and standardized technological
basis of ISDN telephone systems surgical intraoperative
M.O.Schurr et al./European Journal of Cardio-thoracic Surgery 16 (Suppl.2) (1999) S97±S105 S101
Fig.4.FIPS endoscope guiding system.
Fig.5.Placement of positioning systems for endoscopic solo-surgery.
teleconsulting could soon become clinically feasible for
surgical centers.
5.2.Surgical teleassistance
During intraoperative teleassistance the remote consul-
tant has access to move the endoscope to adjust the endo-
scopic image according to his own preferences.This
requires the combination of telecommunications with
robotics technology.Several trials have been made by our
group as well as by several other researchers worldwide.In
all applications a robotic endoscope guidance system is
connected to any kinds of communication lines or networks.
Control data are transmitted along appropriate lines (ISDN
or B-ISDN) together with video and voice data.Usually
robotic control data require a lower bandwidth compared
to mass data such as video or audio so that their transmission
does not add too much complexity to the set-up in terms of
telecom capacities.
Our current research is focused on using bundled ISDN
lines for remote guidance of the FIPS endoscope guiding
system.
5.3.Surgical tele-manipulation
The ®eld of surgical tele-manipulation is subject to inten-
sive research worldwide.
Surgical tele-manipulation is characterized by perform-
ing an operation or phases of an operation without being
physically present at the operating table.The ®eld of surgi-
cal tele-manipulation is always linked to both advanced
communication technologies and robotics.
A number of research groups worldwide have assessed
the potential of tele-manipulation systems in experimental
settings for several years.Especially the medical engineer-
ing group at SRI,Menlo Park,put particular emphasis on
this topic [15].
Our own involvement in this ®eld started in 1994 with our
initial evaluations of the DISTEL manipulator system [16].
The Karlsruhe DISTEL manipulator system was modi®ed
for this purpose.The original system is a one arm master
slave manipulator with six motion axes.Its purpose of use is
remote handling of dangerous substances in the technical
®eld.For surgical application a conventional rigid instru-
ment was attached to the manipulator arm.The distance
between both sides of the system was 1.3 km.Communica-
tion and data transfer between both sites are possible along a
bundle of 12 ®beroptic cables.With the appropriate trans-
mission bandwidth the distance between the two sites is not
relevant.Through broad band ATM connections there
would be no major functional difference between the present
1.3 kmor several thousands of kilometers.With this system
several tests were carried out for the assessment of telesur-
gical working conditions for the user.
A standardized series of repetitive task-board experi-
ments was carried out by two groups,surgeons and engi-
neers [16].It was found that persons with experience in
endoscopy adapted much faster to the remote handling
situation than those without appropriate experience.
M.O.Schurr et al./European Journal of Cardio-thoracic Surgery 16 (Suppl.2) (1999) S97±S105S102
Fig.6.The ARTEMIS manipulator system.The steerable instrument is introduced into a phantom.
Telecommunications technology will have great impact
on future scienti®c and clinical work in most medical areas
[13,14,17].Surgery,being a therapeutic specialty,has not
been very receptive for telematics applications so far.
M.O.Schurr et al./European Journal of Cardio-thoracic Surgery 16 (Suppl.2) (1999) S97±S105 S103
Fig.8.Newendoscope (MGB,Berlin) with additional illumination source for enriching image contrast.In addition,the scope has nozzles for rinsing the front
lens.
Fig.7.The manipulator applied in an animal experiment (one arm version).
Teleconsulting techniques based on intraoperative tele-
conferencing are becoming clinically feasible and are
already used in specialized centers.Teleassistance techni-
ques with remote control of the endoscope is getting tech-
nically feasible for routine use,too,after it has been widely
demonstrated by different research groups.From our point
of view these applications will ®nd entrance into clinical
surgery within the next few years.However,If the complex
technologies merging robotics and telematics for telemani-
pulation will be of practical clinical value in the near and
mid-term future,is still doubtful.
6.Discussion
The restoration of functional qualities,which are avail-
able in open surgery,is an important demand for furthering
endoscopic surgery.This is of particular interest for the
restoration of basic functions of man-environment interac-
tions,such as spatial vision [1,2],tactile sense and instru-
ment mobility in the operative ®eld [18].Developments of
the last few years in the ®eld of endoscopic vision systems
[3] have led to more natural endoscopic visualization in
terms of improved image resolution,illumination,and
clear vision maintenance techniques (Fig.8).The advan-
tages of these new vision systems are improved handling
accuracy and time savings in endoscopic manipulations
[19±21].
In recent years endoscopic surgery has become increas-
ingly widespread,supported by new developments in the
instrumentation available.Less attention has been paid to
the comfort of the ®rst surgeon and his assistant,who were
often forced into tiring standing positions and monotonous
tasks.Moreover,high costs of the operating theater,even for
standard laparoscopic procedures,require the involvement
of less experienced fellows,such as residents,which leads to
a further increase in the operation time.Especially in
community hospitals and private institutions,where the
role of the surgical assistant is assumed either by assistant
physicians or trained nurses,the introduction of positioning
systems for laparoscopic procedures may alleviate some of
the pressure due to limited resources.Improved architecture
design and interface of systems will lead to improved ergon-
omy and intuitive mode of operation of systems,in order to
offer the surgeons better control.
Restoration of full instrument mobility is a further tech-
nological challenge in endoscopic surgery.First prototypes
of steerable endoscopic instruments with two additional
DOF were introduced by our group in 1992 [22].A ®rst
functional master slave manipulator for surgery was intro-
duced by Hill et al.,fromSRI International,Menlo Park,CA
[15].The SRI telemanipulator was not designed for endo-
scopic use and had only four DOF in its ®rst alignment of
the grasper according to the operative situation.
The restoration of full spatial mobility of the instrument
in laparoscopic or thoracoscopic surgery is a complex
research task.The ARTEMIS system was the ®rst 6 DOF
master-slave manipulator for endoscopic surgery found in
the literature [23].Clinical use of the system,however,will
require further development in the area of slave mechanics
and the control system.Intensive research and development
efforts are currently put on manipulators for endoscopic
microsurgery by various work groups at scienti®c institu-
tions and industry.Several devices have already entered
preclinical testing,and it appears to be highly probable
that master slave manipulators will be in practical surgical
use before the next millennium.
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