Virtual reality simulation allows surgeons to practice surgical procedures on 3D virtual patient models before performing actual surgery. This improves surgical planning and provides opportunities for error correction. Key applications of virtual reality in surgery include training and education, surgical planning, image guidance during procedures, and telesurgery. However, fully realistic simulation of tissue deformation and haptic feedback remains challenging due to the complex biomechanics involved.

1. Virtual reality simulation in SURGERYVirtual reality simulation in SURGERY
Dr sumer yadavDr sumer yadav

2. What isWhat is virtual realityvirtual reality ??
 Virtual realityVirtual reality ((VRVR))
is a technology whichis a technology which
allows a user toallows a user to
interact with ainteract with a
computer-simulatedcomputer-simulated
environment, whetherenvironment, whether
that environment is athat environment is a
simulation of the realsimulation of the real
world or an imaginaryworld or an imaginary
world.world.

3. simulation
network communication
full-body immersion telepresence
immersion
artificiality
interaction
Components of virtual reality

4. What isWhat is simulationsimulation ??
 SimulationSimulation is theis the imitationimitation of some real thing.of some real thing.
 UsesUses
 1. natural systems or human systems in order to1. natural systems or human systems in order to
gain insight into their functioning.gain insight into their functioning.
 2. Testing2. Testing
 3.Training3.Training
 4. Education4. Education
 5.Simulation of technology for performance5.Simulation of technology for performance
optimizationoptimization
 6. Video games6. Video games

6. What isWhat is Virtual surgeryVirtual surgery ??
virtual reality simulation of surgicalvirtual reality simulation of surgical
procedures.procedures.
analog for the actual surgery whereanalog for the actual surgery where
doctors can practice on a virtual patientdoctors can practice on a virtual patient
before performing the surgery.before performing the surgery.

7. Advantage to the surgeonsAdvantage to the surgeons
1.Improved surgical planning1.Improved surgical planning
2. practice surgery process on 3D2. practice surgery process on 3D
modelsmodels

8. VIRTUAL SURGERY SIMULATIONVIRTUAL SURGERY SIMULATION
2 STEPS
3D IMAGE SIMULATION TOUCH SIMULATION

9. 3D IMAGE SIMULATION3D IMAGE SIMULATION
 generate a 3D modelgenerate a 3D model
of the part of the bodyof the part of the body
that undergoesthat undergoes
surgery.surgery.
 first construct afirst construct a
reference model of areference model of a
normal person.normal person.

10.  anatomical images cananatomical images can
be derived from a seriesbe derived from a series
of patient’s Magneticof patient’s Magnetic
Resonance ImagesResonance Images
(MRI), Computed(MRI), Computed
Tomography (CT) orTomography (CT) or
video recording, whichvideo recording, which
are 2D images. Theseare 2D images. These
images are segmentedimages are segmented
using varioususing various
segmentation methodssegmentation methods

11.  final model is obtained byfinal model is obtained by
deforming the reference modeldeforming the reference model
according to the condition ofaccording to the condition of
organ that is operated upon.organ that is operated upon.
 The image is digitally mappedThe image is digitally mapped
on to theon to the polygonal meshpolygonal mesh
representing whatever part ofrepresenting whatever part of
the body on organ is beingthe body on organ is being
examined. Each vortex of theexamined. Each vortex of the
polygon is assigned attributespolygon is assigned attributes
like colour and reflectivity fromlike colour and reflectivity from
the reference model.the reference model.

12.  software algorithmssoftware algorithms that canthat can
calculate the whereabouts ofcalculate the whereabouts of
the virtual instrument andthe virtual instrument and
determines whether it hasdetermines whether it has
collide with a body part orcollide with a body part or
anything else.anything else.
 algorithms to solvealgorithms to solve how ithow it
looks or behave when thelooks or behave when the
body part is cutbody part is cut. We need. We need
models of how various tissuesmodels of how various tissues
behave when cut, prodded,behave when cut, prodded,
punctured and so on.punctured and so on.

13. The parameters of this model can then beThe parameters of this model can then be
tweakedtweaked to match what a surgeonto match what a surgeon
experiences during an actual procedure.experiences during an actual procedure.
To create graphic that move withoutTo create graphic that move without
flickering collision detection and tissueflickering collision detection and tissue
deformation must be calculated at least 30deformation must be calculated at least 30
times/sec.times/sec.

14. whole-body voxel humanwhole-body voxel human
modelsmodels
 Whole-bodyWhole-body voxelvoxel humanhuman
models depict the shapemodels depict the shape
of the human bodyof the human body
(tissues and organs) as(tissues and organs) as
an aggregate of minutean aggregate of minute
elements. Each minuteelements. Each minute
block, or voxel, is labeledblock, or voxel, is labeled
with a tag representingwith a tag representing
the name of a tissue orthe name of a tissue or
an organ such as musclean organ such as muscle
or fat, and assigned withor fat, and assigned with
the electrical, physicalthe electrical, physical
properties and color ofproperties and color of
the respectivethe respective
tissue/organ.tissue/organ.

15. TOUCH SIMULATIONTOUCH SIMULATION
hapticshaptics = the ability to simulate touch= the ability to simulate touch
Physicians rely a great deal on their sensePhysicians rely a great deal on their sense
of touch for everything from routineof touch for everything from routine
diagnosis to complex, life saving surgicaldiagnosis to complex, life saving surgical
procedure. So haptics, or the ability toprocedure. So haptics, or the ability to
simulate touch, goes a long way to makesimulate touch, goes a long way to make
virtual reality simulators more life like.virtual reality simulators more life like.

16.  While the brain can be tricked into seeingWhile the brain can be tricked into seeing
seamless motion by flipping through 30 orseamless motion by flipping through 30 or
so images per second, touch signals needso images per second, touch signals need
to be refreshed up to once a millisecondto be refreshed up to once a millisecond
 The precise rate at which a computerThe precise rate at which a computer
must update a haptic interface variesmust update a haptic interface varies
depending on what type of virtual surfacedepending on what type of virtual surface
is encounteredis encountered

17. soft object require lower update rates thansoft object require lower update rates than
harder objectsharder objects
Why??Why??
A low update rate may not prevent a usersA low update rate may not prevent a users
surgical instrument fromsurgical instrument from sinking into thesinking into the
virtual fleshvirtual flesh, but in soft tissues that sinking, but in soft tissues that sinking
is what is expected.is what is expected.

18. Most difficult to simulate is two floppyMost difficult to simulate is two floppy
objects interacting with each other-suchobjects interacting with each other-such
as colon and sigmoidocope, the longas colon and sigmoidocope, the long
bendable probe used to view the colon-bendable probe used to view the colon-
because of multiple collision point. Inbecause of multiple collision point. In
addition, the mechanics of such interactionaddition, the mechanics of such interaction
are complicated, because each objectare complicated, because each object
may deform the other.may deform the other.

19. simulating touch sensationsimulating touch sensation
 calculate the forces applied to cut, probed,calculate the forces applied to cut, probed,
puncture the various tissues.puncture the various tissues.
 Also how they react or behave when cut,Also how they react or behave when cut,
probed, punctured using surgical instruments.probed, punctured using surgical instruments.
 First we have to make physical models ofFirst we have to make physical models of
various tissues. The major difficulty in modelingvarious tissues. The major difficulty in modeling
organs is the physical behavior as they have allorgans is the physical behavior as they have all
kinds of complexities-they are anisotropic, nonkinds of complexities-they are anisotropic, non
homogeneous and nonlinear.homogeneous and nonlinear.

20.  If the haptic device is to give a realistic impression of sayIf the haptic device is to give a realistic impression of say
pressing the skin on a patient’s arm, the mechanicalpressing the skin on a patient’s arm, the mechanical
contributions of the skin, the fatty tissue benefit, musclecontributions of the skin, the fatty tissue benefit, muscle
and even bone must be summed up.and even bone must be summed up.
 The equations to solve such a complex problem areThe equations to solve such a complex problem are
known, but so far the calculations cannot be made fastknown, but so far the calculations cannot be made fast
enough to update a display at 30Hz, let alone update aenough to update a display at 30Hz, let alone update a
haptic interface at 500-1000Hz.haptic interface at 500-1000Hz.

21. VIRTUAL SURGERY SIMULATOR
POWERFUL PC HAPTIC INTERFACER

23. Working principleWorking principle
 force feedback loop.force feedback loop.

24. Advantage to the surgeonAdvantage to the surgeon
 Surgeons improve surgery plans and practice surgery process on 3DSurgeons improve surgery plans and practice surgery process on 3D
models.models.
 Pre operative evaluation of results.Pre operative evaluation of results.
 Error correction - repeat the surgical procedure as many number of timesError correction - repeat the surgical procedure as many number of times
 Better anatomical picture of procedure – wide angles availableBetter anatomical picture of procedure – wide angles available
 Familiarity with actual procedureFamiliarity with actual procedure

25. VIRTUAL REALITY APPLICATIONS IN SURGERY
TRAINING AND EDUCATION
SURGICAL PLANNING
IMAGE GUIDANCE
TELESURGERY

26. TRAINING AND EDUCATIONTRAINING AND EDUCATION
 Surgeon must be ready to manage potentially life-Surgeon must be ready to manage potentially life-
threatening situations in dynamic, unpredictablethreatening situations in dynamic, unpredictable
environments.environments.
Traditional teaching
textbook images cadavers

27. DisadvantageDisadvantage
 textbook images, limit one’stextbook images, limit one’s
perspective of anatomicalperspective of anatomical
structures to 2D planestructures to 2D plane
 cadavers; limited in supply andcadavers; limited in supply and
generally allowing one-timegenerally allowing one-time
use only.use only.

28. Advantage of VR simulatorAdvantage of VR simulator
 view the anatomy from a wide range of anglesview the anatomy from a wide range of angles
and “fly through” organs to examine bodies fromand “fly through” organs to examine bodies from
inside. The experience can be highly interactiveinside. The experience can be highly interactive
allowing students to strip away the variousallowing students to strip away the various
layers of tissues and muscles to examine eachlayers of tissues and muscles to examine each
organ separately.organ separately.
 Unlike cadavers, VR models enable the user toUnlike cadavers, VR models enable the user to
perform a procedure countless times.perform a procedure countless times.

29. It is interactive.It is interactive.
An instructor presence is not necessaryAn instructor presence is not necessary
Changes can be made that demonstrateChanges can be made that demonstrate
variation in anatomy or disease statevariation in anatomy or disease state
Students could also try different techniqueStudents could also try different technique
and loot at tissues from perspective thatand loot at tissues from perspective that
would be impossible during realwould be impossible during real
operations.operations.

30. SURGICAL PLANNINGSURGICAL PLANNING
 In traditional surgery planning, the surgeon calculatesIn traditional surgery planning, the surgeon calculates
various parameters and procedure for surgery from hisvarious parameters and procedure for surgery from his
earlier experience and imaginationearlier experience and imagination
 The surgeon does not have an exact idea about theThe surgeon does not have an exact idea about the
result of the surgery after it has been performed.result of the surgery after it has been performed. So theSo the
result of the surgery depends mainly on human factorsresult of the surgery depends mainly on human factors
 This leads to lots of errors and even to the riskThis leads to lots of errors and even to the risk
of losing the life of the patientsof losing the life of the patients

31. examplesexamples
minimally invasive neurosurgicalminimally invasive neurosurgical
procedures.procedures.
craniofacial surgery.craniofacial surgery.
Liver resection on a 3D deformable liverLiver resection on a 3D deformable liver
model with aid of a virtual laparoscopicmodel with aid of a virtual laparoscopic
tooltool

32.  If we want something to come to an abrupt stopIf we want something to come to an abrupt stop
that is in the case of bone , etc it requires athat is in the case of bone , etc it requires a
higher update rates than bumping intohigher update rates than bumping into
something a little squishy like skin, liver etc.something a little squishy like skin, liver etc.
 But still, simulating squish is no easy task either.But still, simulating squish is no easy task either.
The number of collision point between a virtualThe number of collision point between a virtual
squishy object and a virtual instrument is largersquishy object and a virtual instrument is larger
and more variable than between a virtual rigidand more variable than between a virtual rigid
object and an instrument.object and an instrument.

33. ‘‘The virtual reality technology can serve asThe virtual reality technology can serve as
useful adjunctuseful adjunct to traditional surgicalto traditional surgical
planning techniques.planning techniques.
3D reconstruction of important anatomical3D reconstruction of important anatomical
structuresstructures
complex anatomical relationships incomplex anatomical relationships in
specific patientspecific patient prior to surgery and also toprior to surgery and also to
examine and display the microsurgicalexamine and display the microsurgical
anatomy of various internal operations.anatomy of various internal operations.

34. IMAGE GUIDANCEIMAGE GUIDANCE
computer-aided surgery.computer-aided surgery.
integration ofintegration of
Advanced imaging
3D graphicsimage processing

35. application of computationalapplication of computational
algorithm and VR visualizationalgorithm and VR visualization
Diagnostic imaging
intraoperative surgical navigation
preoperative surgical planning

36. Navigation in surgeryNavigation in surgery
stereotactic principlesstereotactic principles
ability to locate a given point usingability to locate a given point using
geometric referencegeometric reference
Used till now in neurosurgery and RoboticUsed till now in neurosurgery and Robotic
SurgerySurgery

37. ‘‘X-ray vision’ of surgeonX-ray vision’ of surgeon
intra operative mapping of 3D imageintra operative mapping of 3D image
overlays on live videooverlays on live video
used in conjunction with an open MRIused in conjunction with an open MRI
scanscan
updates of patient’s position and intraupdates of patient’s position and intra
operative shape changes in soft tissuesoperative shape changes in soft tissues
with in reasonable time frame.with in reasonable time frame.

38. TELESURGERYTELESURGERY
 allows surgeons to operate on people who areallows surgeons to operate on people who are
physically separated from themselves.physically separated from themselves.
 master-slave robotmaster-slave robot
 video cameras configured to provide avideo cameras configured to provide a
stereoscopic viewstereoscopic view
 surgeon relies on a 3D virtual representation ofsurgeon relies on a 3D virtual representation of
the patientthe patient
 successful in humans undergoing endoscopicsuccessful in humans undergoing endoscopic
Coronary Artery Bypass graftingCoronary Artery Bypass grafting
 basic vascular and urologic procedures inbasic vascular and urologic procedures in
swinesswines

39. VIRTUAL REALITY APPLICATIONS IN SURGERY
TRAINING AND EDUCATION
SURGICAL PLANNING
IMAGE GUIDANCE
TELESURGERY

40. IMPORTANCE OF VIRTUALIMPORTANCE OF VIRTUAL
REALITY IN SURGICAL FIELDREALITY IN SURGICAL FIELD
Intelligent computer backup minimizes theIntelligent computer backup minimizes the
number of medical ‘mistakes’number of medical ‘mistakes’
More effective use of minimal-accessMore effective use of minimal-access
surgical techniquesurgical technique
Better training in anatomy and surgicalBetter training in anatomy and surgical
skill, with reduced need for cadavers.skill, with reduced need for cadavers.

41. current limitations of VRcurrent limitations of VR
implementationimplementation
 shortcomings in the realism ofshortcomings in the realism of
the simulations.the simulations.
 cost and processing power ofcost and processing power of
available hardware.available hardware.
 Need to improve human-Need to improve human-
computer interfacescomputer interfaces
 problem of time delays in theproblem of time delays in the
simulator’s response to thesimulator’s response to the
users movementsusers movements
 Simulator sicknessSimulator sickness eyestrain,eyestrain,
nausea, loss of balance andnausea, loss of balance and
disorientationdisorientation

42. CONCLUSIONCONCLUSION
 A recent report released by Institute of Medicine inA recent report released by Institute of Medicine in
Washington DC, estimates thatWashington DC, estimates that medical errors maymedical errors may
cause 1,00,000 patient deaths each year in US alonecause 1,00,000 patient deaths each year in US alone
 Proponent of virtual reality believes that incorporation ofProponent of virtual reality believes that incorporation of
this technology into medical training will bring this grimthis technology into medical training will bring this grim
statistic downstatistic down..
 the benefits of VR systems in medicines have clearlythe benefits of VR systems in medicines have clearly
been established in several areas, including improvedbeen established in several areas, including improved
training, better access to services, and increase costtraining, better access to services, and increase cost
effectiveness and accuracy in performing certaineffectiveness and accuracy in performing certain
conventional surgical procedures.conventional surgical procedures.

43. Thank youThank you