Surgical Co2 Laser

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Surgical co2 laser

The CO2 laser is used in a broad range of clinical applications. The surgical

laser can augment and, in many instances, even replace traditional

instruments and methods. The Aesculight and Luxar CO2 surgical lasers are

useful in procedures where

!urface penetration is desired"

!oft tissue is the target.

Laser # Tissue $nteraction

Lasers differ from each other by the wavelength of light they produce. The

CO2 laser wavelength of %&,'&& nanometers is highly absorbed by soft

tissues with high water content # see the water absorption spectrum below.

(any tens thousands of CO2 surgical lasers are being used today in surgical

suites around the world.

The Luxar laser is operated in a non#contact fashion. The tip is held close to,

but does not touch, the target tissue. The tissue effects are different from


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contact lasers, where the primary effect is a result of heat conducted from

the tip to the tissue. The primary determinants of laser effect on tissue are

)avelength"

Tissue type"

*ower density"

+xposure time.

+xact guidelines on various surgical laser techniues are presented in the

Aesculight Laser Operator-s (anual as well as Luxar Laser Operator-s

(anual.

Laser *hysiology

The CO2 laser is cleared by the /A for soft tissue procedures only. The

laser is an effective hemostatic tool for vascular tissue. )hen the CO2 laser

is used for muscle dissection there is minimal heating or contraction of the

muscle. This helps facilitate certain procedures and reduce post#surgical pain

and edema. *roper use of Luxar CO2 surgical lasers within the /A#cleared

indications for use may offer some of the following advantages over

conventional treatment

$mproved access to some areas, compared to the scalpel"

0educed operative time in some procedures"

Tissue sculpting ability" +asier removal of lesions without distortion of surrounding tissue"

Less bleeding, often with less trauma"

Less need for suturing"

0educed postoperative pain and discomfort"

(inimi1ed ecchymosis and edema.


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*atients often report less postoperative pain with laser wounds. The laser is

more versatile than conventional surgical instruments because it can

$ncise or excise"

apori1e or ablate"

*rovide hemostasis.

As is the case with any other surgical instrument, no one should use the

Luxar surgical laser, or any other medical laser, without specific training in

both medical laser use and laser safety.

The CO2 laser is not cleared by the /A for use on bone or in hard tissueprocedures in the 3nited !tates.

Laser surgery benefits for the clinician

Improved visibility of the surgical field

The laser beam seals capillaries and small blood vessels as it 4cuts4 the

tissue. This dramatically reduces bleeding, resulting in a much drier and

clearer surgical site. $n addition, the Luxar surgical laser does not use the

very distracting aiming beam usually associated with outdated articulatedarm CO2 laser systems.

Reduction of procedure time


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The hemostatic effect of the CO2 laser beam and the improved visibility of

the surgical field reduce the time needed to perform the surgery, and may

also reduce the need for sutures, bandaging, and other after#care measures.

Pinpoint accuracy and control

The diameter of the beam may be ad5usted down to a small fraction of a

millimeter or expanded to address a much wider swath. The power of the

beam may be set for rapid removal of relatively large tissue amounts, or

ad5usted to remove only one or two cell layers at a time.

Increased surgical capabilities

Laser surgery changes the character of many procedures by ma6ing them

simpler or by reducing ris6. This opens up the possibility of expanding the

clinician-s surgical repertoire to include procedures that are not practical

with conventional scalpel#based techniues.

Laser surgery benefits for the patient

Less Pain

The laser seals lymphatics and nerve endings as it cuts, resulting in less

edema and pain that leads to a more comfortable post#operative recovery.

Reduced risk of infection

CO2 laser surgery is a 4no touch4 technology. The laser beam 6ills bacteria

in its path, producing a saniti1ing effect.

Quicker recovery time

0educed ris6 of infection, less bleeding, less swelling, and less pain often

allow the patient a more rapid return to normal activities.


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Lasers in Cancer Treatment

The word LA!+0 actually stands for Light mplification by Stimulated

!mission of Radiation.

Laser light is different from regular light. The light from the sun or from alight bulb has many wavelengths and spreads out in all directions. Laser

light, on the other hand, has a single wavelength and can be focused in a

very narrow beam. This ma6es it both powerful and precise. Lasers can be

used instead of blades 7scalpels8 for very careful surgical wor6, such as

repairing a damaged retina in the eye or cutting through body tissue.

Types of lasers

Lasers are named for the liuid, gas, solid, or electronic substance that is

used to create the light. (any types of lasers are used to treat medical

problems, and new ones are being tested all the time. Today, 9 6inds of

lasers are commonly used in cancer treatment. carbon dioxide 7CO28, argon,

and the neodymium yttrium aluminum garnet 7:d;A


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through thin flexible tubes called endoscopes to get to hard#to#reach parts

inside the body, such as the swallowing tube 7esophagus8 or large intestine

7colon8. This light can also travel through optical fibers, which can be bent

and placed into a tumor to heat it up and destroy it.

$ther lasers used in medicine

!ome newer types of lasers B the erbium yttrium aluminum garnet

7+r;A


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!trict safety precautions must be followed in the operating room when

lasers are used. or example, the entire surgical team and the patient

must wear eye protection.

The effects of some laser treatments may not last long, so they may

need to be repeated. And sometimes the laser cannot remove all of the

tumor in one treatment, so more treatments may be needed.

Treating cancer +ith lasers

Lasers were first used on s6in tumors in %E'%. Today one of the most

common medical uses of lasers is in cancer treatment. They can be used in 2

ways to treat cancer

To shrin6 or destroy a tumor with heat

To activate a chemical B 6nown as aphotosensitizing agentB that6ills only the cancer cells. 7This is calledphotodynamic therapyor

PDT.8

Though lasers can be used alone, they are most often used along with other

cancer treatments, such as chemotherapy or radiation.

Lasers are also being studied for treating or preventing side effects of

common cancer treatments. or instance, some studies are loo6ing at how

lasers might be used to prevent or treat severe mouth sores caused by

chemotherapy, and how they may be used to treat the swelling7lymphedema8 that can result after breast surgery. (ore research is needed to

learn about these possible uses for lasers.

Shrinking or destroying tumors directly

The CO2and :d;A< lasers are used to shrin6 or destroy tumors. They can

be used with thin, flexible tubes called endoscopesthat let doctors see inside

certain parts of the body, such as the bladder or stomach. The light from

some lasers can be sent through an endoscope fitted with fiber optics. This

lets doctors see and wor6 in parts of the body that could not otherwise bereached except by ma5or surgery. $t also allows very precise aim of the laser

beam.

Lasers can be used with low#power microscopes, too. This gives the doctor a

larger view of the area being treated. )hen used with a an instrument that

allows very fine movement 7called a micromanipulator8, laser systems can


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produce a cutting area as small as 2&& microns in diameter B less than the

width of a very fine thread.

Lasers are used to treat many 6inds of cancer. $n the intestines or large

bowel, lasers are used to remove polyps, small growths that may become

cancer. The CO2laser can be used to treat pre#cancerous tissue and very

early cancers of the cervix, vagina, and vulva.

Lasers are also used to remove tumors bloc6ing the swallowing tube

7esophagus8 and large intestine 7colon8. This does not cure the cancer, but it

relieves some symptoms, such as trouble swallowing.

The :d;A< laser has also been used to remove cancer that has spread to

the lungs from other areas. This helps patients avoid surgery that would

reuire removing large sections of lung. This type of laser cannot curecancer, but it can improve breathing and other symptoms in many patients.

Cancers of the head, nec6, airways, and lungs can be treated 7but usually not

cured8 with lasers. !mall tumors on the vocal cords may be treated with

lasers instead of radiation in some patients. As with tumors bloc6ing the

esophagus, tumors bloc6ing the upper airway can be partly removed to ma6e

breathing easier. Dloc6ages deeper in the airway, such as in the branches of

the breathing tubes 7bronchi8, can be treated with a flexible, lighted tube

called a bronchoscope and an :d;A< laser.

Laser-induced interstitial thermotherapy7L$TT8 is based on the same idea

as a cancer treatment called hyperthermia. Doth methods use heat to help

shrin6 tumors by damaging cells or depriving them of the things they need

to live 7li6e oxygen and food8. $n L$TT, the laser light is passed through a

fiber optic wire and right into a tumor, where it heats up, damaging or 6illing

cancer cells. L$TT is sometimes used to treat tumors in the liver.

Photodynamic therapy

$n photodynamic therapy 7*/T8, a special drug called a photosensiti1ingagent is put into the bloodstream. Over time it is absorbed by body tissues.

The drug stays in or around cancer cells for a longer time than it does in

normal tissue. !hining a certain 6ind of light on the drug that is in the cancer

cells causes a chemical reaction that then 6ills the cancer cells.


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*hotosensiti1ing agents are Fturned onG or activated by a certain wavelength

of light. or example, an argon laser can be used in */T. )hen cancer cells

that contain the photosensiti1ing agent are exposed to red light from this

laser, it causes the chemical reaction that 6ills the cancer cells. Light

exposure must be carefully timed so that it is used when most of the agent

has left healthy cells, but is still in the cancer cells.

*/T can have some advantages over other treatments. Cancer cells can be

singled out and destroyed but most normal cells are spared. The damaging

effect of the photosensiti1ing agent happens only when the drug is exposed

to light, and the side effects are fairly mild.

!till, */T as it is currently used is not without its problems. Argon laser

light cannot pass through more than about % centimeter of tissue 7a little

more than one#third of an inch8, which means it=s not as useful againstdeeper tumors. And the photosensiti1ing agents used today can leave people

very sensitive to light, causing sunburn#li6e reactions after only very brief

sun exposure. This can greatly limit the patient=s activities until the body

gets rid of the drug, which often ta6es wee6s.

*/T is sometimes used to treat cancers and pre#cancers of the swallowing

tube 7esophagus8, and certain 6inds of lung cancer that can be reached with

thin, flexible tubes calledendoscopes. */T is being studied for use in other

cancers, such as those of the brain and prostate. 0esearchers also are loo6ing

at different 6inds of lasers and new photosensiti1er drugs that might wor6even better.

.

The outlook for lasers in cancer treatment

Decause of their power and precision, lasers are well#suited for certain

cancer surgeries, and doctors are trying to find new and better ways to use

them. As more cancer surgeons learn to use lasers, as the lasers themselves

become smaller and cheaper, and as technology improves to allow tumorsdeep within the body to be treated, lasers will probably be used more often

as part of cancer treatment.

Lasers in Cancer Treatment


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Key Points

Laser light can be used to remove cancer or precancerous growths or to relieve

symptoms of cancer. $t is used most often to treat cancers on the surface of the

body or the lining of internal organs.

Laser therapy is often given through a thin tube called an endoscope, which can

be inserted in openings in the body to treat cancer or precancerous growths insidethe trachea 7windpipe8, esophagus, stomach, or colon.

Laser therapy causes less bleeding and damage to normal tissue than standard

surgical tools do, and there is a lower ris6 of infection.

owever, the effects of laser surgery may not be permanent, so the surgery may

have to be repeated.


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Laser instruments for gynaecology

The CO2laser wavelength is carried via hollow tubes, waveguides, and mirrors.

Conventional fiberoptics are not currently available for clinical use. The

laparoscopic use of this wavelength is possible with the use of a focusing cube

and an operative laparoscope or with a variety of waveguides designed for

multi-puncture laparoscopic applications. The focusing cube permits the use of

the CO2laser in a free beam mode for cutting, vaporization, and coagulation of

tissue. The focusing cube also is capable of transmitting an aiming beam. This

feature makes it easier for the surgeon to direct the laser energy to the desiredtarget. variety of procedures, such as myomectomy, partial oophorectomy,

resection and ablation of endometriomas, adhesiolysis, and even

cholecystectomy have been accomplished successfully with this delivery

system. Cholecystectomy re!uires a "c#ernan-type approach. The successful

use of this approach re!uires knowledge and facility with the operative

laparoscope and the surgeon$s ability to visualize the desired target and

maneuver a micromanipulator or %oystick. The surgeon can alter the tissue

effect by focusing or defocusing the laser beam as well as varying the laser

wattage selected. &aser waveguides are hollow tubes with mirror-like surfaces

that reflect the CO2wavelength. 'aveguides are available in both rigid and

fle(ible versions and can be used to achieve a spot size )ie, burn or incision*

that is in the range of +.mm to 2.2mm. s a general principle, the waveguide

is used in a noncontact fashion, particularly because tissue contact can

obstruct the waveguide and li!uid can be drawn into the hollow waveguide by


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capillary action. The result of these events is the irreversible destruction of the

waveguide. ecent developments include the Omniguide, which is a small-

diameter solid chalcogenide glass waveguide and which is currently being used

in otolaryngology and neurosurgical applications.

The successful use of this laser for dissection and hemostasis re!uires that the

surgeon be adept and e(pert with the laser, as this will affect the ability to

dissect tissues and achieve an ade!uate degree of hemostasis. oth the

focusing cube and waveguide systems re!uire a direct line of sight or the use of

angled mirrors. This further complicates the maneuverability of these devices

more so than fiber capable lasers and conventional instruments. oth

configurations re!uire flowing gas to cool the system and to prevent vaporized

tissue plume from being thrown into the device. The most fre!uently used

purge gases are argon and carbon dio(ide. /igh CO2gas flow rates can actuallyabsorb the laser energy and reduce its efficiency )ie, the transmission of

energy from the laser to the tissue*. Therefore, lower flow rates )ie, 0&1min*

are suggested. ome laser systems are e!uipped with a nitrogen purge gas

system. The surgeon should 3OT use nitrogen during laparoscopy, because its

absorption from the peritoneum can cause 4the bends.5

The optimal use of the CO2laser for laparoscopic or open use is achieved when

the beam is oriented perpendicular to the desired target. /emostasis is

enhanced by tissue compression, the use of epinephrine-containing local

anesthetic solutions and the ability of the operator to recognize the presence

of a vessel prior to its division. 6nder these conditions, the surgeon defocuses

the laser )ie, moves the handpiece, waveguide, or operating laparoscope

farther away from the target* and then applies short bursts of energy to the

vessel in the area to be divided. This maneuver heats and coagulates the

vessel, thereby enabling its division by the focused beam. The surgeon should

use the highest power setting with which he or she is comfortable, because this

will enable more efficient cutting, better hemostasis, and less thermal in%ury

to the wound edges by minimizing conductive and radiative heat loss into thewound. 7ntermittent evacuation of the vaporized tissue plume or the use of a

recirculating filtration system assure a clear field of view and prevent

absorption of to(ic products of combustion by the patient. This problem is

identical in magnitude and to(icity to the vaporized tissue plume created

byany electrosurgical, thermal, or laser source. imilarly the 4smoke5 should


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not be vented into the operating room, because it is considered hazardous for

O personnel. O/137O/ has written regulations that re!uire that O staff

be protected from vaporized tissue plume regardless of its source.

ARGON LASER

The argon laser has been used e(tensively for gynecologic laparoscopic

procedures in the past.0+,887t has largely been replaced by other technologies

today. This laser produces light in the visible portion of the spectrum. This

laser actually produces 9 lines )wavelengths*. /owever, the ma%ority of the

laser output is in the blue-green spectrum )wavelength : ;


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the more selective absorption of the wavelength in hemoglobin enables the

surgeon to photocoagulate vessels before their division by bringing the fiber

away from the tissue surface. This maneuver is similar to defocusing the free

beam. The defocused mode is used to vaporize endometriomas. ome

manufacturers produce a variety of sculpted fibers and metal-%acketed fiberdelivery systems. These fibers are constructed to be more durable and work

4more like a scalpel5 due to absorption of some of the laser energy in the fiber

resulting in heating of the fiber. This produces an optically driven cautery

effect. o-called bare or urologic fibers are easily used and are cleaved and

stripped as the fiber end degrades with use. Optimal cutting occurs by using

the tip of the fiber either end-on or obli!ue to the plane of the dissection.

ecause these wavelengths are color dependent, the surgeon should note that

white or lightly colored tissue, such as meniscus and tumor implants, will notcut efficiently and will not be vaporized )ablated* unless they are first painted

with 7ndia ink, indigo carmine dye, or another e(ogenous chromophore.

droplet of blood placed on the surface is sometimes effective for this purpose.

lackened or ebonized instruments and the use of optical backstops are

re!uired to prevent beam reflection and iatrogenic in%ury.

One of the main drawbacks of the laparoscopic use of the argon laser is the

camera1eye safety filter. The eye and camera filters must block the 9 lines )ie,

wavelengths* produced by the laser. These filters are usually a deep orange

color and absorb 8+A to 9+A of the visible spectrum. s a result, the color

balance of the image is distorted, and the need for a high-powered light source

is critical to the surgeons$ ability to visualize the operative field. "any laser

systems have intermittent shutter mechanisms that place the filter in the

visual field only while the laser is actually being fired. The surgeon must be an

e(pert at the local anatomy and the details of the procedure prior to

attempting to work with this laser. This laser system is rarely used today due to

the availability of #TB and #B laser systems, which are much less cumbersome

to use.

Nd: YAG LASER

The neodymium ?@ laser produces near infrared light at a wavelength of

0+9+nm. This wavelength is carried via conventional fiberoptics, and, like

visible light lasers, the energy will be transmitted through water. The energy

can be applied to tissues with a wide array of delivery systems including


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cleaved bare fibers )ie, urologic fibers*, polished @7 fibers, sapphire tips )ie,

the delivery device that is marketed as the Contact &aser*, sculpted fiber )eg,

"icrocontact tip and various other proprietary versions of this technology*, as

well as free beam via a micromanipulator or "icroslad unit.0,8, ?@ laser is intensely absorbed by tissue protein andchromophores and is highly scattered in tissue. These properties result in deep

penetration of the energy and much greater damage below the tissue than can

be appreciated at the surface. This makes noncontact )ie, @7 fiber, free beam*

and bare-fiber applications of the 3d> ?@ laser e(tremely dangerous unless

the surgeon has a thorough understanding of the laser-tissue interaction and

orients the beam in a direction that would reduce the likelihood of damaging

nearby structures. pecialized angled delivery or fibers have been

developed for use in photocoagulation of the prostate. These devices pro%ect

the beam at right angles to the long a(is of the probe, thereby allowing the

prostatic tissue to be photocoagulated or vaporized. These applications re!uire

knowledge of the anatomy and tissue effects. The surgeon orients the laser

output toward the 0+>++ and 02>++ positions and will fire the laser at a preset

energy for a specified length of time based on the volume of tissue to be

photocoagulated.

The 3d> ?@ laser is a poor cutting instrument when it is used in a noncontact

mode. The development of sapphire tips and sculpted fiber technologies

facilitate use of this laser in contact with tissue. Dree-beam type applications

can result in damage to 0cm to 2cm of liver tissue and the photocoagulation of

vessels up to ;mm in diameter. /owever, the sapphire tip technology is a

combination of a combined thermal and optical interaction with tissue. "uch of

the 3d> ?@ energy is absorbed by the sapphire or fiber tip and converted to

heat. The result is to produce optically driven cautery. The temperature of the

tip can be tightly regulated for some applications. These instruments improve

the cutting ability of the laser, but the tissue damage and the e(tent of

coagulation are reduced dramatically. The histology of these devices is !uite

similar to the results produced by electrosurgical devices. ince their main

tissue interaction is thermal cautery, the rate of incision and the degree of

hemostasis can be reduced when these devices are used in the presence of

irrigating fluids or in the a!ueous environment of the bladder or %oint space.


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olography for nondestructive testing

Optical olographic techniues can be used for nondestructive testing of materials

7:/T8. :onoptical olography techniues include Acoustical, (icrowave, H#0ay and

+lectron beam olography.:/T essentially measures deformations on the surface of the ob5ect. owever, there is

sufficient sensitivity to detect sub# surface and internal defects in metallic and composite

specimens.$n :/T techniues, the test sample is interferometrically compared with the sample

after it has been stressed 7loaded8. A flaw can be detected if by stressing the ob5ect it

creates an anomalous

deformation of the surface around the flaw.Optical holography is an imaging method, which records the amplitude and phase of light

reflected from an ob5ect as an interferometric pattern on film. $t thus allows

reconstruction of the full 9#/ image of the ob5ect. $n :/T, the test sample isinterferometrically compared in two different stressed states.

!tressing can be mechanical, thermal, vibration etc. The resulting interference pattern

contours the deformation undergone by the specimen in between the two recordings.

!urface as well as subsurface defects show distortions in the otherwise uniform pattern.$n addition, the characteristics of the component, such as vibration modes, mechanical

properties, residual stress etc. can be identified through holographic inspection.

Applications in fluid mechanics and gas dynamics also abound.The light used to illuminate the surface of the specimen must be coherent, which means

that it must also be monochromatic, and the only practical source is a laser. +ach type of

laser emits a


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characteristic wavelength, e.g. a helium#neon laser emits '92.>nm" a ruby laser emits

'[email protected]. Laser diodes are nowadays an exciting and compact alternative. $ndeed,

holography using laser pointers have also been demonstrated.igh#resolution films are another necessity for holography. )ith the advent of CC/ and

digital image processing, digital holographic interferometry offers tremendous flexibility

and real#time visuali1ation.urthermore, image#processing schemes can provide computerised analysis of patterns

for automated defect detection and analysis.

inally since intricate interferometric patterns have to be recorded, vibration isolation isalso reuired.

:ovel schemes have been proposed, including use of pulsed lasers to record holograms in

factory environments.

Advances and developments in lasers, computers, and recording materials introduce newtechniues such as electronic 7or T8 holography, multi#wavelength recording,

thermoplastic medium, timeaveraged holography, dynamic holographic interferometry,

cineholography, and digital holography with each new development. (ethods that once

held only academic interest often become practically viable with these developments inhardware and software.

:/T is widely applied in aerospace to find impact damage, corrosion, delamination,debonds, and crac6s in high performance composite aircraft parts as well as turbine

blades, solid propellant roc6et motor casings, tyres and air foils. Dut olography is also

finding new applications in commercial and defense related industries to investigate andtest ob5ect ranging from microscopic computer chips and circuits to cultural articles,

paintings and restoration.

olographic nondestructive testing techniues 7:/T8 are used to locate and evaluatecrac6s, disbonds, voids, delaminations, inhomogeneity and residual stresses in a test

sample without destruction of the sample. The holographic interferometry techniues are

applied for nondestructive testing of materials.

The :/T techniues can be used for the testing of laminated structures, turbine blades,

solid propellant roc6et motor casings, tyres and air foils. These techniues are also usefulin medical and dental research. $n :/T techniues, the test sample is

interferometrically compared with the sample after it has been stressed 7loaded8. A flaw

can be detected if by stressing the ob5ect it creates an anomalous deformation of the

surface around the flaw. The holographic interferogram will show up the anomalousdeformation by an abrupt change in the shape of the interference pattern.

The ob5ect can be stressed by mechanical stressing, pressure or vacuum stressing, thermal

stressing, vibrational stressing and magnetic stressing. The stressing of the ob5ect can

create gross deformation and rigid body motion of the ob5ect. This will produce fineinterference fringes in the interferogram if the test area is large. $n such a situation, the

interference fringes around the flaw will be very fine and it would not be detected by

unaided eye. Dy using fringe control methods, the effects of gross deformation and rigid

body motion can be compensated.


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Applications of holographic interferometry

ield Applications

Aerospace /efects in honeycomb plates

Testing of construction materials,Testing of welding methods

$nspection of roc6et bodies

low visuali1ation in wind tunnelsibration modes of turbine blades

Automobiles Testing of oil pressure sections

Testing of welding methods0esearch in construction of

automobile bodies

Construction of engines

(achine tools and precision

instruments

(easurement of deformations of machine parts,

5igs and tools(easurement inside cylinders

(easurements of stiffness 7heat, static ordynamic8

Analysis of construction of instruments and tools

+lectrical and electronic

industries

ibration modes of turbine blades, motors,

transformers, loudspea6ersTesting of welding and adhesion

Testing of circuit parts

Analysis of audio euipmentsLea6 test of batteries

Civil +ngineering Analysis of constructions

/esign of pipes0esearch in concrete.


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Chemical industry (easurement of mixed fluids. Tyre, rubber and

:/T of tyres, plastics

Testing of molded products

(easurement of adhesion defects

(edicine (easurement on living bodies

Chest deformation due to inhalation(easurement on teeth and bones

Testing materials for dental surgery

Testing of urinary trac6 (easurement on eyes, ears, etc.

(usical instruments (easurement of vibration modes

Cultural articles and paintings :/T and restoration.

Surgical Co2 Laser

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