PROF. SREEJOY PATNAIKSHANTI OMNI SUPER SPECIALITY

HOSPITAL , CUTTACK ,ODISHA

ENDO-VISION SYSTEM IT’S MAINTANENCE AND

TROUBLE SHOOTING

EVERY SURGEON SHOULD KNOW THESE BASICS PRIOR TO STARTING A LAP. UNIT

ENDOVISION SYSTEM-‘EYE OF THE SURGEON’

• Revolution in optics & imaging technology helps to produce real ‘life like’ images in a magnified way, thereby helping accurate dissection.

• ELECTRONIC EYE INSIDE THE ABDOMEN

• The imaging system includes-– Laparoscope / Telescopes– Light source– Light cable– Cameras– Monitors

• For a ‘perfect image’ all of them should be of good quality.• A GOOD ENDOVISION IMPROVES THE QUALITY

& PRECISION OF SURGERY & ITS OUTCOMES.

THE ENDOVISION EQUIPMENTSTHE ARMAMENTERIUM

1.LAPAROSCOPE OR TELESCOPE

• Invented by Hopkins in 1953 Rod Lens system.• Present day laparoscopes - series of rod lenses in

centre with a rim of optical fibers on the outer aspect.• Optical fibers carry light into the abdominal cavity &

rod lens system transmits the image from abdomen to the camera.

• From the camera (attached to the proximal end or eye piece of the scope) the images are displayed on to a monitor.

CONVENTIONAL VS OPTICAL LENSES

A TYPICAL ROD LENS SYSTEM

LAPAROSCOPES( TELESCOPES)

Laparoscope may vary in size ( dia.)

Size 0.8mm - (Needlescope) to 15 mm in dia.

Angle of vision - 0° /30°/ 45°, 70. 0 & 120

Rigid, flexible or semi flexible

Brightness of the image reduces with the size of the scope

The angled scopes 30° / 45° provide

Flexible field of vision.

Unobstructed view from distance

More space for maneuverability of instruments

Ability to look around the corners

Normal Hopkins Forward Oblique Scope -300

Diameter – 10 mmLength - 33 cmExtra Long – 43 cmAutoclavable

SEMI FLEXIBLE – TIP OF THE SCOPE [ SILS ]

2. CAMERA SYSTEM

• It is the most important and vital part of the imaging system and should be of good quality.

• It consists of 2 parts-• Camera head connects to the prox. End or eye

piece of the laparoscope.• Camera Microprocessor unit which receives,

processes and transmits the pictures to monitor.

Requirement of Cameras

Camera Specifications

Three important Features 1.Horizontal Resolution2.Minimum Luminance 3.Signal to Noise Ratio

Horizontal Resolution (lines)

It is a measure that shows to what extent details can be distinguished on the monitor.

It can be evaluated by establishing the limits to which lines can be distinguished on a test pattern.

A larger resolution value means a broader frequency band of the video signal.

Minimum Luminance (lux)

It is a measure that shows to how sensitive the camera can produce a good picture.

It is measured in lux or footcandle unit.

1 Footcandle = 10 lux

Signal to Noise Ratio (dB)

An S/N ratio is noise to actual total video signal

It shows how much higher the signal level is to the level of noise

It is expressed in decibels (dB)

Bigger the value - better the picture

Features of Cameras

Horizontal resolution (lines)Higher ---------> Better

Minimum luminance (lux)Higher ---------> Worse

Signal to noise ratio (dB)Higher ---------> Better

CAMERA SYSTEM

• Resolution of the camera directly proportionate to the no. of pixels.

• Presently CCD cameras used – consists of tiny bits of silicon (divided into multiple tiny sensors) called ‘pixels.’These are arranged in rows & columns and are sensitive to light.

• When light strikes a pixel, the silicon emits electricity, that is transmitted to the monitor.

• Electronic signals are sensed to provide the recording image.

The resolution from the CCD is dependent upon the quantity of the pixels on the sensor.

The resolution is defined as the amount of vertical lines that may be discriminated separately in 3 quarters from the width of the monitor screen.

The lap. Camera requires at a min. 300 lines of resolution to supply a sufficient image.

CAMERA SYSTEM - RESOLUTION

TODAY’S LAPAROSCOPIC CAMERAS

Available in Single or 3 Chip

We all know the 3 Primary colours– R / G / B

All the colours are a mixture of these 3 Primary Colours in different proportion.

Single Chip- All 3 primary colours are sensed by a single or 1 chip.

Three Chip- CCD- chips separately sense, capture and as well as process the Primary colours.

TYPES OF CAMERA SYSTEMS

1. SINGLE CHIP

2. THREE CHIP OR CCD

3. HIGH DEFINITION

4. 3D

5. ROBOTIC PLATFORM

SINGLE CHIP CAMERA– Multiple color sensors provided

in a single chip providing a single image

– Monitor resolution needed is usually 400 – 600 lines.

– Adequate for routine basic surgeries.

Single Chip Camera

3- CHIP CAMERA– In 1989 , the field of surgery experienced a revolution in

the form of ‘Laparoscopic surgery ’ with the introduction of CCD cameras (charged couple devices) and better light sources.

– Captures light in its 3 components– Unified light slit into its components ‘ red, green, &

blue’(RGB) by prism located in head of the camera– Signals are then captured by separate CCD’s containing

multiple sensors & are processed and sent to monitor.– Currently available cameras have ability of producing

videos of resolution of 950 lines i.e. ‘high quality images’.

– Great help in advanced lap surgeries.

HD CAMERA

• The latest generation of cameras are high definition cameras• They produce the resolution of 1080 horizontal lines per inch.• Require HD monitors to reproduce the same quality of picture• Offers a superior image with a wide, more natural 16:9 format

and 1080p resolution for FULL HD with 2 million pixels.• That is the highest resolution in the medical industry.

• At present it is very costly.

HD CAMERA & IMAGING

4 Types of Video Camera Outputs

1.RGBComponent signal

2.S-VHS or Y/CComponent signalChrominance & Luminance (color & light)

3.Composite video signal or BNC -- All components of the picture combined into one video signal

4.Digital Signals

3 - D CAMERAS

POLARISATION GOGGLES

3 D MONITORCAMERA HEAD WITH PROCESSOR

DUAL CHANNELTELESCOPES

The human brain combines two images to one 3D impression

BINOCULAR EFFECT-WORKING PRINCIPLE

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5-8 % of humans don‘t have the binocular effect

STANDARD 2D- EFFECT

CCU

Camera Head Object2D Endoscope

(one channel)

Sensor

2D HD Monitor (1080 lines x 1920 pixels)

one image (all lines/pixels can be seen with both eyes)

left Eye

right Eye

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THE 3D- EFFECT

CCU

Camera Head Object

Dual Channel Endoscope

Sensor 1

Sensor 2

Sterile Adapter

3D Full HD 32“ Monitor Odd lines (line 1,3,5,7…)

even lines (line 2,4,6,8…)Polarisation Glasses

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Polarisation filter

Dual channel endoscope creates two live-images

Camera head has two sensors

Flat screen has a polaristion filter and shows two images simultaneously

Even-numbered-lines on screen (2,4,6….) show image 1

Odd-numbered-lines on screen (1,3,5 ….) show image 2

Polarisation glasses select from image 1to (right eye) from image 2 to (left eye)

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THE POLARISATION EFFECT

Circular polarising glasses separate the two images in front of the eye:

- the even lines can be seen only with the right eye

- the odd lines can be seen only with the left eye

The human brain receives a true 3D impression from flat display

The displayed object seems to grow out of the flat screen

The surgeon gets a true depth percecption

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Stereoscopic visual effect

Restores the surgeon’s natural 3D vision and depth perception.

Provides depth cues and precise spatial orientation

Shown to enhance dissection, grasping skills, suturing, stapling and overall surgical efficiency.( Correct picking up of delicate tissues & exact positioning of needles.)

Requires no additional certification or training for those surgeons certified to perform laparoscopic procedures.

Reduced learning curve for young surgeons.

Enhances task performance leading to lower procedure times and costs.

*data on file

Benefits of

Cameras -Advantages & Disadvantages• All cameras need

– White balancing

– Focus – manual / auto• Some cameras have options of

– Zooming – useful for finer dissection

– Digital enhancement – provides sharper images .

– Disadvantages – development of grains which may distort

– image quality• HD cameras

– Provide stereoscopic vision

– Costly & no clear cut advantage over existing cameras

3D Cameras ( Disadvantages )

– No optical zoom

– Scope not rotatable

– Presently scope available only as 10 mm & 00

- Wearing of Polarisation glasses

- Costly

FLUORESCENCE IMAGING SYSTEM STORZ

NIR/ ICG – FLUORESCENCE IMAGING

Near Infra Red & Indo Cyanine Green enables non-radioactive visualization of the entire lymphatic system surrounding a tumor in real time.Advtg:1. Non- radio active LN detection2. Multi disciplinary use – Gyaenecology, Surgery ,

Urology3. Easy switch over from standard to fluorescence

mode by a foot switch.4. Accuracy in en-bloc dissection during radical

lymphadenectomy

3.LIGHT SOURCES

• Thanks to Edison for inventing the Electric Bulb.

• MAS depends on artificial light to inspect the closed body cavity.

• Quality of Image obtained depends on the quantity of light at each step of Opto-Electronic system.

• Essential vital equipment for producing images.

1.Halogen ( Quartz) Highly efficient, Halogen Gas is used, excellent colour

rendering.Gives yellow coloured light.Economical. .Sufficient for Basic Lap. Surgeries.Available in 150 watts.Colour temp.- 5000-6000KAv. Life- 2000 hrs.

2.Metal Halide-Mix of a compound ( Rare salts of the earth +

Halides)Ex; Iron & Gallium Iodide Lamp .Provides high intensity heat alongwith brighter light.

250 W. Av. Life- 250 hrs.

TYPES OF LIGHT SOURCES

3.Xenon-Consists of quartz glass ( high grade fused silica)But cold white light, its tip generate considerable heat, so direct contact with the internal organs to be avoided. Better visual clarity175/300 watts, approx. life of bulb 500 hrsColour temp: 6000-6400 kSlightly Costly Av. Life – 500 hrsNatural white light

4.LED-

TYPES OF LIGHT SOURCES

PARTS OF THE LIGHT SOURCE

1. Lamp / Bulb

2. 2.Heat Filter

3. 3.Condensing Lens

4. Manual/ Auto Intensity Control Unit

1. LAMP:

Most important part .Quality depends on the type of lamp used.

2. HEAT FILTEREnergy consumption of a Normal light source98% heat / 2% light.Filter reduces the heat & provides a cool light as heat gets dissipated during transportation along the cable and the telescope.

3. CONDENSING LENS:Converges light emitted by the lamp to the area of the light cable input to the scope.It increases the light intensity per sq m area

4.MANUAL/ AUTO INTENSITY CONTROL CIRCUIT

All light sources – in built circuit to adjust light intensity either manually by the surgeon or automatically ( newer L S)

This AGC ( Auto Gain Control) of light source works synchronously with the advanced camera systems.

4.LIGHT CABLES• Working Principle- light conducted through a curved

glass rod by total multiple internal reflections, from one end to other end of the cable .

1. Fiber optic cables – more user friendly consists of bundles of glass fibers, thread swaged at both ends.

Size of fibres- 10- 25 mm dia. High quality transm. Disdv—fragile, breaks at bends ( dark spots ) 2 Fluid filled cables

– Made of liq. Crystal gel, swaged at both ends.– Transmits more light – 30% more.– Disadvantages – stiff , fragile, cannot be autoclaved Conducts more heat - Use – Movies / TV as LCD /Photography

Light Cable

4. MONITORS

• Final limb of imaging chain• Quality of monitor essential for adequate quality of

image• If monitor does not support resolution of camera, then

all the advantages of using high end camera is lost.• Principle-Horizontal linear scanning on the face of the

picture tube.Each picture frame consists of several lines depending on the type of system used.

Final image on the Monitor depends on:

1. No. of lines of Resolution – denotes No.of B&W lines both vertical & horizontal.

2. Pixels – denotes picture elements & details3. Dot Pitch – denotes a restricting factor & represents the

phosphor element size.

INPUT CABLES INTO THE MONITOR4. Composite- Video- via a BNC connector5. Y/C or S- Video- via a 4-pin DIN connector.6. RGB Video – via a multi head BNC cable connector.7. DVI input- compatible to HD monitor / flat panel.8. HDMI Input Lap. Cameras supports 1 & 2 above.

New flat panel TV support – RGB input No.3

Monitor - Compatibility with Cameras

• Monitors with resolution of 600 lines for single chip , > 900 lines for three chip & 1080 and above for HD for optimal resolution are required

• High end analog digital and HD flat panel monitors are now available, – they can be placed at more ergonomically viable

positions, – avoid various head, neck, shoulder ailments in Lap

surgeons

Monitors

HD MONITORS

Maintenance

• Light Cable – Handle with care. Do not twist.• Outer surface should be cleaned with mild detergent. • Periodical cleaning with moist alcohol swabs. • Avoid pt. burns under drapes.• Light Source-• Xenon bulb has life of 500 hrs.- Change bulb if intensity of light decreases.- Don’t cover light source while working- excess heating can cause

damage to it- Periodical check of Light source exhaust fan.

*****DO NOT SEARCH FOR THE BIOMEDICAL STAFF, TRY TO LEARN AND SOLVE IT YOURSELF.

MaintainenceTelescopes-

-Avoid any thermal or mechanical injury to tip of telescope.

- Clean the eye piece, light cable slot and tip with warm water. - Chemical sterilization with Glutaldehyde or Cidex solution is

done. Few scopes are autoclavable

Camera head- -Avoid any injury to camera head and its cable. - Camera cover should be used to avoid contamination of

operating field.

Trouble shooting

• Poor picture quality may be due to- Fogging of scopes

– It is a big problem– Gives a dull & hazy image– Warm water/ betadine soaked gauze / anti fog soln. are

used to clean the telescope lens*[Connecting the insufflations tube to the optical trocar

and passage of cold CO2 causes more fogging]

Trouble shooting• Poor picture quality – needs cleaning of scope tips and

camera head.Flickering electrical interface -caused by loose connection.

- Moisture in camera cable connecting plug - dry it with the help of drier

- Poor cable shielding - replace cables- Insecure connections - reattach cables• Blurring or Distortion of picture is due to incorrect focus

- adjust camera focus- Cracked lens internal moisture - replace scope

Trouble shooting

-Inadequate Lighting may be - caused by loose connection of light cable at source or with scope - Adjust connector light on- man. to auto. - Bulb is burnt out- replace the bulb.- Fiber optic cable are damaged - replace light

cable.- Monitor brightness turned down- adjust settings.

Trouble shooting

-Light is too bright -Light is on manual max- turn on to auto mode. -Light boost activated- deactivate boost -Monitor brightness up- readjust -White balancing is mandatory for obtaining

natural colour – target against a white object.

Troubleshooting-

• No Picture on Monitor-- Camera control unit or other components are

not on - check power supply to all the units and turn on power.

- Cable connection between camera head to camera control unit and/or monitor is not attached properly - check all connections.

White Balancing

Warm up the light source

Gain in STANDARD position

Fill monitor with white surface

Focus so threads are visible (no glare)

Depress WHITE BALANCE for 3 sec.

Hold image steady on white surface until the tint on the monitor stabilizes for 2 sec.

OR DEPRESS THE REMOTE ON THE CAMERA HEAD

BEST BUY FOR A LAP SET1.Reputation of the Company2.After sales and service ( Locality/ state )3. List of installations ( Add / Contact No. )4.Check in the Internet.5.Ask for Demo for 2 weeks.6.Ask for Invoice/ Quotation of supplied or cheques received7.Bargain for the best price..8.Ask for a Package.( Hand instrument set)9. Ask for an extended warranty.10. Lastly, ask for supply on a rental basis/ Payments in Installments.