Exhibit 1 O 12
`
`Mako Surgical Corp. Ex. 1012
`
`

`
`u
`
`-»
`
`13‘ International Workshop on
`
`
`
`
`
`Haptie Devices
`in Medical Appfiications
`
`- R. Dillmann, T. Salb (eds.)
`
`
`
`Proceedings
`
`
`
`3”‘ of June 1999 1
`
`Paris - France
`
`,.'!¥._~‘—.m
`
`Mako Surgical Corp. Ex. 1012
`Page 1
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`Page 1
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`Mako Surgical Corp. Ex. 1012
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`

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`!
`
`© IPR
`
`Copyfight 1999
`Any kind of duplication, even in extracts, is only allowed with prior
`written agreement of the 6d1t01‘S.
`
`Institute for Process Control and Robotics. (IPR)
`Universitat Karlsruhe
`
`KajScrStr_ 12
`D_76128 Karlsmhc
`
`Pnnted 1“ Germany
`
`Summary
`
`The 1“ Internatia
`(I-IDMA) was init
`Universitat Karlsn
`views and ideas in
`this event was fou
`(CARS). This Wt
`conference office 2
`1999 in Palais des
`10 contributions w
`
`the development, u
`
`Motivation
`
`With the applicatic
`to alter intensely. P
`area intelligent intt
`offer a high deg:
`requirements in a ‘
`touch when operati
`haptic driven resea
`to offer a platform
`in this interesting ll
`
`Scope of the W4
`
`A
`
`The “1“ Intematio
`
`form
`international
`d°"°1°Pm3“‘ and
`workshop will alsc
`working in this mu
`
`0 Development of
`o Simulation of m
`° Haptics in “=16-S
`
`0 Computer based
`0 Clinical experie
`
`Further research Vt
`welcome for contri
`
`
`
`Mako Surgical Corp. Ex. 1012
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`12
`
`Robot Controlled Osteotomy in Craniofacial
`Surgery '
`
`Catherina Burghartl, Jochen Keitel‘, Stefan Hassfeldz, Ulrich Remboldl and
`Heinz Woernl
`
`1 Institute of Process Control and Robotics
`University of Karlsruhe
`D-76128 Karlsruhe, Germany
`{burghart,keitel,rembold,woern}@ira.uka..de
`2 Clinic of Maxillofacial Surgery
`University of Heidelberg
`Im Neuenheimer Feld 400, D-69120 Heidelberg, Germany
`stefan.hassfeld@med.uni-heidelberg.de
`
`Abstract. Interventions in craniofacial surgery are a great challenge to
`the operating surgeon, as high precision and long practise arerequired
`to perform optimal bone repositionings and to achieve and aesthetic and
`satisfactory result. Although methods and devices for the preoperative
`planning of bone repositionings do already exist, the accurate intraoper-
`ative transposition of a surgical plan still is a problem. For this solution a
`joint procject to develop a computer aided method using a surgical robot
`to control the surgeon's movements while cutting bone was conceived
`by the surgeons of the Clinic of Maxillofacial Surgery of the University
`of Heidelberg and the engineers at the Intitute of Process Control and
`Robotics (IPR), which we present in this paper.
`
`1
`
`Introduction
`
`Up to now the outcome of a craniofacial surgical intervention mainly depends on
`the experience of the operating surgeon. Due to the complexity of the anatomic
`structures involved bone repositionings are quite difficult to perform without
`hazards. In clinical routine the surgeon is already supported by various com-
`puter aided devices such as surgical planning systems, intraoperative navigation
`systems and stereolitographic modelling of the patient’s skull. Still, the difliculty
`is an accurate transposition of the preplanned bone osteotomies during surgery.
`In order to overcome these difficulties our surgical partners at the Clinic of Max-
`illofacial Surgery of the University of Heidelberg alnced the idea to be supported
`by a. computer aided devices restricting their hand motions while cutting bone.
`The surgeons especially favoured a surgical robot which allows them to manually
`perform the bone cuts by guiding a surgical saw attached to a robot while the
`robot constraints their cutting movements.
`_
`Several approaches for semi—active surgical devices do already exist. Davies
`uses a robot with four degrees of freedom, ‘called ACROBOT, which restricts
`the surgeon’s movements within a dissecting plane for total knee replacement
`
`by force control [1
`determine the dire
`wheel with a ham
`
`movements of a p:
`three degrees of fr
`In contrast to ‘
`
`with six degrees 0
`of a surgeon mam
`craniofacial surge:
`conception of a n
`sional cutting traj
`The surgical pl
`bone cut includin
`
`Then a security zc
`segments and arot
`of the inner cylind
`support points spl
`the surgeon is allo‘
`of the saw is restri
`
`surgeon moves th
`an increasing forc
`the boundary of 1
`movement of the 2
`
`The velocity, <
`control the surgeon
`sensor registers th
`to guide the robot
`desired aim and 0
`
`The presented
`Various bone cut:
`
`by measuring the
`ranged between 0.
`tolerance. Thus tl
`
`preoperatively de:
`trajectory of the l
`robot arm can als
`
`2 System A
`
`A first experiment
`robot assisted sav
`
`with six degrees 1
`suffices the guidli
`The position
`grated infrared n
`
`
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`
`
`raniofacial
`
`ich Remboldl and
`
`rmany
`
`t challenge to
`are required
`aesthetic and
`preoperative
`rte intraoper-
`his solution a.
`
`-urgical robot
`as conceived
`re University
`Control and
`
`nainly depends on
`by of the anatomic
`v perform without
`1 by various com-
`erative navigation
`Still, the difficulty
`.es during surgery.
`the Clinic of Max-
`
`:8. to be supported
`hile cutting bone.
`them to manually
`a robot while the
`
`:ady exist. Davies
`I‘, which restricts
`knee replacement
`
`13
`
`The Cobot by Peshkin offers the surgeon the possibility to
`by force control
`determine the direction of a device which can be best described as a spinning
`
`Troccaz controls the clutches of a joint to restrict the
`wheel with a handle
`"movements of a passive arm with two degrees of freedom [3]. A new model with
`three degrees of freedom is under construction.
`In contrast to the three devices mentioned above we use an industrial robot
`
`with six degrees of freedom and a force-torque sensor to constrain the motions
`- of a surgeon manually guiding a surgical saw attached to the robot’s flange. In
`craniofacial surgery cutting paths are not restricted to two dimensions, thusthe
`conception of a method constraining cutting movements along a threedimen—
`sional cutting trajectory was necessary .
`The surgical planning system of the IPR. sends the trajectory of the intended
`bone cut including the required orientation of the saw to the robot control.
`Then a security zone is modelled in the following manner: the path is split into
`segments and around each segment two cylinders are constructed. The diameter
`of the inner cylinder is 3mm, the diameter of the outer cylinder is 5mm. At the
`support points spheres are used instead of cylinders. Whithin the inner cylinder
`the surgeon is allowed to guide the saw without constraints. Only the orientation
`of the saw is restricted to 10° deviation of the given orientation. As soon as the
`surgeon moves the blade of the saw into the outer cylinder he has to apply
`an increasing force to continue into the desired direction. Finally, as soon as
`the boundary of the outer cylinder is reached the robot prohibits any further
`movement of the surgical saw into the forbidden zone.
`The velocity, direction and orientation which the robot applies in order to
`control the surgeon’s guiding of the saw are computed as follows: the force-torque
`sensor registers the desired orientation and position to which the surgeon wants
`to guide the robot arm within a basic cycle. An evaluation function analyzes the
`desired aim and computes the velocity and direction of the robot’s movement.
`The presented method has already been satisfactorily tested on pig cadavers.
`Various bone cuts were performed and evaluated by infrared navigation and
`by measuring the skeletized skulls. The accuracy of the performed bone cuts
`ranged between 0.5 mm and 3mm, which is just within the limits of the defined
`tolerance. Thus the developed method can support the surgeon to transpose a.
`preoperatively designed plan, while he can still take the liberty to change the
`trajectory of the bone cut, if suitable. The force controlled manual guiding of a
`robot arm can also be used for the training of future surgeons.
`
`.
`
`2. System Architecture
`
`A first experimental set up was created to develop a new method for the required
`robot assisted sawing of bones with constraints (Fig. 1). We use a RX-90 robot
`with six degrees of freedom, which can be used for surgery, as the robot itself
`suffices the guidlines for medical devices.
`_
`The position of both robot tool and patient can be detected by an inte-
`grated infrared navigation system for automatical registration (Fig. 1 and 2).
`
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`14
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`
`
`Fig. 1. Present experimental set up using an RX—90 robot and an infrared navigation
`system
`
`For this purpose titanium miniscrews are preoperatively implanted into the pa-
`tient’s skull, during the operation they are mounted with infrared diodes. In this
`manner a patient specific coordinate frame can be generated which allows the
`surgeon to chose various postions of the patient during surgery. The robot’s tool
`is detected with the help of a cylinder fitted with infrared diodes, which was
`developed for a redundant position control of the robot’s endeffector.
`In Figure 2 the present architecture for robot assisted bone cuts is depicted.
`A surgical robot based on a VME-bus is the center of focus of this set up. The
`robot’s endeffector is equipped with a force torque sensor, a cylinder fitted with
`infrared diodes and a pneumatic surgical saw, which was developed for robot
`use. The force torque sensor is connected with a PC via CAN—bus to record the
`measured forces and torques. The PC communicates with the robot control via
`serial port forwarding the force-torque data. This connection will be replaced
`in near future by a CAN—VME-card, which can be dircetly integrated into the
`robot control, thus eliminating the bottle-neck caused by the communication
`via serial port. An infrared navigation system with two CCD cameras tracks the
`positions of the patient, the robot’s endelfector and surgeon’s instrument (i.e.
`an infrared pointer). The navigation system is connected to a SGI workstation
`which serves as visualizing device. As the SGI workstation owns an ethernet
`interface the planning system sends the data of the planned bone cuts and the
`positions of the titanium mini screws to the SGI. The robot control and the
`SGI workstation exchange the data for automatic registration and the cutting
`trajectories via serial port. A
`
`Infrared cam
`
`
`
`Tool-lnterfacw
`Unit
`
`Fig
`
`3 Force Cc
`
`Controlling a rc
`torque data into
`the data are me:
`
`sensor, although
`flange. Thus the
`by using a trans
`When using :
`eliminated. Varit
`
`—- measuremen
`
`—- temperature
`— noise
`
`- weight of the
`
`In order to comp
`line is used. If n
`the moment t ar«
`
`
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`15
`
`Robot control
`
`Infrared camera array
`
` Patient with
`
`LEDs
`
`Robot
`
`Signal converter
`of fts
`
`
`
`'I‘ool—Interface
`Unit
`
`Fig. 2. System architecture of the presented robot set up
`
`3 Force Controlled Robot -Movements
`
`Controlling a robot by force implies a transformation of the measured force
`torque data into Cartesian coordinates with respect to the robot base. In addition
`the data are measured with respect to the coordinate frame of the force torque _
`sensor, although they actually effect the surgical saw attached to the robot’s
`flange. Thus they are transformed into the coordinate frame of the robot’s tool
`by using a translation.
`When using zero force control for robot movements, disturbances have to be
`eliminated. Various disturbances effect the force torque data:
`
`— measurement drift
`
`- temperature drift
`—— noise
`
`— weight of the endeffector
`
`In order to compensate temperature and measurement drift a dynamic reference
`line is used. If no further forces effect the sensor the measured data f,e¢5(t)_ at
`the moment t are stored in a variable d(t). If forces effect the sensor, the reading
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`
`
`tn infrared navigation
`
`planted into the pa-
`rared diodes. In this
`ed which allows the
`zry. The robot’s tool
`I diodes, which was
`deffector.
`
`me cuts is depicted.
`. of this set up. The
`cylinder fitted with
`ieveloped for robot
`N-bus to record the
`1e robot control via
`
`on will be replaced
`integrated into the
`the communication
`cameras tracks the
`
`n’s instrument (i.e.
`a SGI workstation
`1 owns an ethernet
`bone cuts and the
`ot control and the
`
`on and the cutting
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`16
`
`is composed of several components; the reference line cannot be determined.
`Thus the difference Af—1.n,-ts (tg) is computed by subtracting the data of two
`consecutive measurements at the moments t1 and t2 for each channel 1.
`..
`.. T
`..
`'1‘
`(1)
`Afmfts (t2)T = fmfts (t2) — fmf,_,(t;)
`The distance of the actual zeo line to the ideal zero line is depicted by value
`d,'(t2).
`
`W = {’"1;i‘tI§t*’ .’§£’;.:’ A"”"“” 5 "“ ; ie<1a2-—~-,6}
`
`<2>
`
`Thus the drift can be compensated in the following manner:
`
`(3)
`1%.... = (f7nm(t) — of)”.
`Noise is simply eliminated by a noise gate, in this case a filter which cuts off
`all measured forces smaller than 2 N and all torques smaller than 0.2 N.
`The influence of the weight of the surgical saw attached to the robot’s flange
`has to be considered as well. Its influence is eliminated by subtracting the force
`vector detected by the force torque sensor in the robot’s home position and by
`subtacting the lever action of the surgical saw.
`
`4 Definition of Safety Zones
`
`The robot is controlled by evaluating the position of the tip of the robot’s tool
`within a defined safety zone. Around each segment two cylinders are modelled 3.
`The inner cylinder defines a tolerance; the surgeon’s movements of the tool are
`not restricted. Within the second cylinder the surgeon has to apply an increasing
`force in order to steer the tip of the saw to the outer edge of the cylinder. In
`the area outside the second cylinder motions of the robot’s tool are prohibited.
`At the supporting points spheres are used instead of cylinders in order to model
`the safety zones.
`_‘
`Figure 4 depictes the method of computing the desired tool position F,,,,._,¢;,_,,,,5
`by the robot control. The vertical fof the intended position to the trajectory is
`computed and evaluated.
`If the computed distance d is smaller than the radius of the inner cylinder
`the new position intended by the surgeon's forces is allowed; the robot moves to
`the new position.
`
`53?):
`
`Innerlcylim
`zone
`
`
`
`Fig, 3_ Define.
`
`Fve;-sch
`
`Fist
`
`g
`
`‘ L6
`
`Fig. 4. Distance 01
`Pi—1Pi
`
`Zone 1
`
`-'
`
`-°
`
`*°
`
`Fneu.pos = 1Je-rach.pos; Fversch.pos E Zonal:
`
`If the computed distance of the desired position of the surgical saw F.,,,,c;,_po,
`to the trajectory is bigger than the radius of the inner cylinder but smaller than
`the radius of the outer cylinder the movements of the robot are restricted: a linear
`factor It
`is computed which decreases the distance of the robot's movements
`dependend on the distance of the intended tool position to the edge of the outer
`Cylindeh
`
`_‘
`
`(4)
`
`‘:
`
`.
`
`V
`
`3
`
`l
`
`Zone 2 Figure 5
`. I
`1
`
`Eggetso Elfglgea
`
`movements into zc
`manner:
`
`Then the new ‘
`time slot is comp:
`
`
`
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`17
`
`-
`-
`Prohibited Area:
`Zone 3
`
`Outer cylinder:
`zone 2
`
`
`
`Inner cylinder:
`zone 1
`
`Inner cylinder:
`zone 1
`
`T"3.l¢kt°l'.‘I'
`
`Outer cylinder:
`zone 2
`
`Prohibited Area:
`Zone 3
`
`Fig. 3. Defined safety zones around trajectory segments P.~_1 P; and P.-P.-+1
`
`planned
`trajektory
`
`
`
`I Fversch
`
`Flst
`
`P-1
`
`d :
`L :
`Fist :
`Fversch :
`
`distance to trajectory segment
`«Vertical
`Actual tool position
`Intended tool position
`
`Fig. 4. Distance of the desired tool position I:".,,,,-_.c;.,,,.,,
`P.'—iPi
`
`to the trajectory segment
`
`Zone 2 Figure 5 depicts the behaviour of the factor k within the three safety
`zones. In zone 1 the surgeon’s movements are not restricted. In zone 2 the surgeon
`has to apply a greate force in order to guide the surgical saw. Any intended
`movements into zone three are prohibited. Factor is is computed in the following
`
`manner:
`
`d
`Md) = l’_"_‘2_._.__
`rZonc2 ' Tzonel
`
`3 7'Zone2a7'Zone1 E R
`
`(5)
`
`Then the new postion to which the robot will move in the actual considered
`time slot is computed by multiplying the desired position F,,¢,_,c;,_,,,, with the
`
`Mako Surgical Corp. Ex. 1012
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`not be determined.
`
`mg the data of two
`'ri channel 1.
`
`(1)
`
`.s depicted by value
`
`1,2,---,6}
`
`(2)
`
`(3)
`
`filter which cuts off
`than 0.2 N.
`
`0 the robot’s flange
`ibtracting the force
`ne position and by
`
`of the robot’s too]
`lers are modelled 3.
`ents of the tool are
`
`apply an increasing
`of the cylinder. In
`2001 are prohibited.
`s in order to model
`
`:~P0Siti0n fversch.pos
`to the trajectory is
`
`"the inner cylinder
`the robot moves to
`
`(4)
`
`Iica-1 Saw -fiuerach.pa5
`er but smaller than
`2 restricted: a linear
`:obot’s movements
`
`ie edge of the outer
`
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`18
`
`Linear factor k
`
`Zone 1
`
`Zone 2
`
`Zone 3
`
`Restricted
`
`I-Yea
`movements
`
`movements
`
`"4" I
`Radius
`Zone 1
`
`F W 2
`Radius
`Zone 2
`
`d, distance to
`trajectory
`
`Fig. 5. Linear behaviour of factor k
`
`factor is.
`
`.9
`
`Fneu = ‘ Fverschpas
`
`We also tried potential finctions, but their effect on the robot’s behaviour was
`the same due .to the small distances considered.
`
`Zone 3 If an intention of the surgeon to move the tip of the saw attached to
`the robot’s flange into zone 3 is registered (by the applied forces) two cases
`have to be considered. In the first case the tip of the tool still is within the
`second safety zone; thus a movement to the outer edge of the cylinder is allowed.
`Figure 6 illustrates this case. The postion of the movement permitted has to be
`computed in the following manner: two rectangluar triangles can be constructed
`(Fig. 6. The length of the line between the actual position of the tool 13,-“ and
`the allowed position 13;.“ ca_i_1 be determined by multiplyingthe line between the
`actual position of the tool F25; and the intended position F,,.,,3ch.,,o5 by a linear
`factor .5.
`1
`P'ncu.pos = ist.pos + E ' (Fversch.pos "' Fist.pos)a 3 > 1'
`
`This factor sfiactually is the ratio of a centric extension of the smaller triangle
`with center E25,:
`
`3 =
`
`lFneu.pos “ Iristposl
`
`= __._d_:fl£_«‘-...
`Tzonez — dist
`
`(3)
`
`If the actual position of the tool I7,-s;_,,¢,5 already is on the outer edge of the
`second cylinder only movements parallel to the trajectory or back to the center
`are allowed. For this purpose a factor m is computed which influences the guiding
`behaviour of the robot:
`
`Fn¢u.pos = :2st.pos +771 ' (I-1.1’.-1 -
`
` Trajectory
`
`d :
`dist :
`Fist :
`Fneu :
`Fversch I
`
`Fig. 6.
`
`5 Control S1
`
`Arm
`
`Figure 7 depicts tl
`ered process is the
`the PC for compu
`is responsible for
`position data and
`sition of the surgi
`the allowed positie
`configuration angl
`
`6 Evaluatioi
`
`The presented me‘
`a threedirnensiona
`
`In these experimei
`a blade length of 2
`18.000 rpm and n
`
`
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`
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`19
`
`Fversch
`
`Trajectory
`
` Inner cylinder:
`
`zone 1
`
`Outer cylinder:
`zone 2
`
`d :
`dist :
`Fist:
`Fneu :
`Fversch :
`
`Intended distance to trajectorty segment
`Actual distance to trajectorty segment
`Actual tool position
`Permitted tool position
`Intended tool position
`
`Fig. 6. Intended movement of the tip of the tool into zone 3
`
`5 Control Structure for Restricted Guiding of a Robot
`Arm
`
`Figure 7 depicts the control structure implemented into our system. The consid-
`ered process is the position controler of the robot. The force torque sensor and
`the PC for computing the reading represent the measureing unit. A P controler
`is responsible for transforming the measured forces and torques into cartesian ’
`position data and orientations. Then an evaluater evaluates the intended po-
`sition of the surgical tool and computes the permitted position. The frame of
`the allowed position is sent to the robot’s motion planner, which computes the
`configuration angles of the robot.
`
`6 Evaluation
`
`The presented method of the restriced guiding of a tool attached to a robot along
`a threedimensional trajectory has already been evaluated in animal experiments.
`In these experiments we used a specially contructed oscilliating surgical saw with
`a blade length of 23 mm and a thickness of 0.1 mm. The surgical saw moves with
`18.000 rpm and needs 4 bar air pressure. Figure 8 depictes the measured force
`
`Mako Surgical Corp. Ex. 1012
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`
`
`
`
`(6)
`
`-ot ‘s behaviour was
`
`1e saw attached to
`l forces) two cases
`still is within the
`:ylinder is allowed.
`ermitted has to be
`:an be constructed
`:‘the tool Fm and
`.62 line between the
`'sch..po.s by 8. linear
`
`> 1.
`
`(7)
`
`e smaller triangle
`
`(8)
`
`outer edge of the
`ack to the center
`
`ences the guiding
`
`(9)
`
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`
`80
`
`40
`
`20
`
`o
`
`-20
`
`-40
`
`-so
`
`2WD
`
`23
`
`3
`.5
`
`E
`
`7 Conclusic
`
`In this paper a 11
`allows the surge:
`with the assistar
`
`restrict the surge
`to the robot’s fla
`surgeon can feel
`planned trajecto
`feedback in form
`respect to the t.
`information for t
`Future work
`trol the deviatio:
`a motion planne
`control the robot
`
`References
`
`1. Harris et. al.: I
`CVR.Med-MRC
`
`20
`
`Force controler
`
`
`
`
`
`Position controler Disturbances
`
`'-
`I...
`
`(f,n)Iool.neu V‘:
`
`
`6 degrees of freedom
`
`data in the x-direction. The diagram can be split into three different phases.
`At the beginnig the robot autonomously turns the surgical saw 180° degrees
`(first small regular peek) and moves to the starting point of the bone cut to be
`performed.
`Then the surgeon tries to move the saw along the planned trajectory. During
`theses experiments there was no additonal visual feedback of the actual position
`of the surgical tool with respect to the planned trajectory. Thus the surgeon
`needed some time to find the inner safety cylinder. This is indicated by the huge
`number of high peeks. The surgeon even tried to leave the trajectory by applying
`forces of up to 98 N. He also shifted the sides of the trajectory; this is shown by
`the change from positive to negative force values.
`In the third phase the surgeon finally managed to move the surgical saw
`attached to the robot along the planned trajectory. In total the bone was cut up
`to a length of 136 mm; the thickness of the bone was 3 N at the beginning up to
`5 N at the end of the cut. When guiding the robot within the inner safety zone
`forces of about 12 N were applied.
`The accuracy was measured with the help of an infrared navigation system.
`Also, at the end of each experiment, the head of the pig cadaver used was
`cut off, the soft tissue was eliminated and the head was measured. During the
`experiments the tolerance was set to 3 mm. The measurements showed that the
`surgeon always kept within the tolerance of 3 mm, which confirmed our method
`of cutting bone.
`
`
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`oler Disturbances
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`21
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`
`
`Disturbances
`
`bed to a robot with
`
`cutting
`
`forces[N]
`
`different phases,
`saw 180° degrees
`ie bone cut to be
`
`rajectory. During
`le actual position
`Thus the surgeon
`:ated by the huge
`=t0ry by applying
`this is shown by
`
`the surgical saw
`bone was cut up
`beginning up to
`nner safety zone
`
`vigation system.
`daver used was
`
`red. During the
`showed that the
`ned our method
`
`. 0
`
`5000
`
`15000
`1 0000
`Phases of sawing procedure
`
`20000
`
`25000
`
`Fig. 8. Measured x- forces when cutting bone
`
`7 Conclusion
`
`In this paper a new method for using a robot to cut bone was presented, which
`allows the surgeon to intraoperatively transpose a planned bone cut manually
`with the assistance of the robot. First results showed that by letting the robot
`restrict the surgeon’s manual movements of an oscilliating surgical saw attached
`to the robot’s flange an accuracy within the set tolerance can be achieved. The
`surgeon can feel the restriction of his movements and guide the saw back to the
`planned trajectoy. Better results were obtained when we implemented a visual
`feedback in form of dynamic bars showing the position of the surgical tool with
`respect to the trajectory on a monitor. Just a haptic feed back is too little
`information for the surgeon.
`Future work includes to implement infrared navigation to redundantly con-
`trol the deviation of the robot to the planned trajectory and of implementing
`a motion planner to check the trajectory to be performed and to addtionally
`control the robot's movements.
`
`References
`
`1. Harris et. al.: Experineces with robotic systems for knee surgery. In Proceedings:
`CVRMed—MRCAS’97,Grenoble, Rance, March 97,(1997)
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`2.
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`'Irocca.z et al.: The use of localizers, ribits and synergistic devices in CAS, In Pro-
`ceedings: CVRMed-MRCAS’97,Grenoble, France, March 97,(1997)
`3. Troccaz J. and Delmondedieu Y.: Semi—active guiding system in surgery. A two-
`dof prototype of passive arm with dynamic contraints (padyc), Mechatronics, 6,(4),
`(1996), 399-421.
`
`This article was processed using the I9’I}gX macro package with LLNCS style
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`2 Richard Wc
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`Abstract. Minimal
`by the surgeon’s lo
`minimal invasive s
`dexterous manipul:
`possibly pathogent
`terns, suitable for a
`developed. The tac
`actuators. The non
`
`RA-II receptors, re
`whereas the shear
`responsible for de;
`tric multilayer act:
`plifiers. First tests
`
`1 Introduction
`
`Reproduction of huma
`instruments for minim;
`cal technique capable C
`sis and therapy in lap
`copy and other surgic
`impeded by the surgec
`age effect and friction
`ties [01][O2][O3][04].
`tactile sense and may t
`In this context, ther
`tems capable of detect
`cal contact parameter
`several promising ap}
`have been realized du
`of tactile actuators is
`width, flexibility and
`in the gripping pads :
`vorable grip are partic
`
`
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