ENDOSCOPE

INTRODUCTIONINTRODUCTION

The name endoscope is derived from two Greek words which are endom (within) and skopein (view). The endoscope is an optical instrument used for viewing internal organs through natural openings (ear, throat, rectum, etc.) or through a small incision in the skin

HISTORY

Nitze (1879) 7 mm Cystoscope Burning platinum wire illumination. Schindler (1936) Semi-flexible gastroscope  48 lenses in spiral spring Hirchowitz (1958) – Optical fiber gastroscope Hopkins (1960) Rod lens patent filed Nippon Sheet Glass (1968) – Selfoc developed   Watanabe (1970) – 1.7 mm gradient index endoscope

The first endoscope using a miniature lens system was a cystoscope designed by Nitze with the help of an optician from Berlin and an instrument designer from Vienna. A gastroscope of similar design was built the following year. These first endoscopes incorporated a distal reflecting prism to incline the direction of view. In 1931, the first practical arthroscope was developed for knee surgery. The instrument was 3.5 mm in diameter and contained a right-angle reflecting prism at the distal tip.

Schindler introduced the first flexible endoscope with a German optical physicist named Wolf. The instrument was 77 cm long, the last 43 cm being made flexible by a steel spiral covered by rubber tubes with an outside diameter of 12 mm. Optical fiber was first used for flexible endoscope imaging in 1958 by Hirchowitz, Curtis, Peters, and Pollard. Rigid endoscope optics also improved in this time period with the introduction of the now well accepted rod lens designs of H. H. Hopkins.

External Components.

All flexible endoscopes have a light guide plug, an umbilical cable (cord), a control head and an insertion tube.

THE LIGHT GUIDE PLUG. The light guide plug fits into the light source. The air/water

and suction channels have ports in the light guide plug.

The light guide plug of a video endoscope is heavier than that of a non-video endoscope and needs to be handled with care.

The terminals in the light guide plug of the video endoscope are not waterproof and must be covered by the cap supplied with the instrument prior to cleaning

1. Proximal End. Interface point with the eye or video equipment.

2. Distal End. Furthest point from the proximal end or users eye.

3.Insertion Diameter. The diameter quoted as the actual diameter inserted into the anatomy of endoscope sheath.

4.Instrument Axis. The axis of the instrument relative to the instrument axis.

5. Optical Axis. The axis of the optical path which is displaced to the instrument axis.

Principle Terms

6. Angle of View. The agular value of displacement to the optical axis.

7. Optical Field of View. The area which the conical system covers is as a cone.

8. Fibre Illumination. The area which the fibre illumination covers as a cone and is greater than the optical field of view.

9. Working Length. The actual length embodying the insertion diameter which can be applied.

10.Light Post. Input point of the illumination when connected to a light guide and source.

11.Eyeshield. Used as a cup for the eye or a diameter for the attachment of video camera equipment

Important Points

When considering the diameters of endoscopes and sheaths and other instruments the diameters specified should be the external or outside diameter and not the bore or inside dimension.

As an example the 5.50mm of an Arthroscopic sheath (16.50Ch) should be a reference to the outside dimension of the shaft. Some confusion has occurred in the past with high flow sheaths with the inside or bore diameters specified.

The axis positions shown will vary depending on the Angle of View of the endoscope and this variance is due in part to the illumination fibre position in the main outer tube.

ANGULATION SYSTEM

The angulation system is what makes the tip articulate when the control handles on the control head are rotated and it can be broken down into three areas:

control mechanism coil pipes bending section

Control mechanism.

Either a wire pulley assembly or a chain drive can articulate endoscopes. The wire pulley is the most commonly used on flexible endoscopes. A locking mechanism allows these to be fixed in any position.

Coil pipes. These are flexible springs attached to the inner wall of the insertion tube. The coil pipes house the angulation wires, and direct them in the proper direction. They also offer protection to the internal elements from the sawing motion of the wires, which are constantly in motion while steering the distal tip.

When an insertion tube snakes into an 'S' shape the coil pipes have become crossed or detached. If the angulation system stiffens there may be a problem related to the coil pipes.

Bending section.

In the bending section several metal bands are hinged together. When the control handles are manipulated the angulation wire is pulled up through the coil pipes. The wire is threaded through a loop on each of the metal bands down to the distal tip where it is attached. As the wire is pulled it causes the distal tip to bend in that direction. A combination of up/down and left/right allows the tip to bend in any direction and be steered through most intricate lumens as far as the instrument's length will allow.

ERCP ELEVATOR CHANNEL

The Elevator Channel on the ERCP endoscope is particularly susceptible to problems. You can understand why when you see the construction of the system.

The elevator raiser is hinged at one end and attached to a wire at the other end. Pressure exerted by the motion of the wire moves the cantilevered riser up and down. Cleaning access to the cavity in which the riser moves can only occur by brushing through the instrument channel opening. You need to open or extend the riser as far as possible before brushing the cavity thoroughly. Then the riser must be elevated completely to clean behind the riser. If any debris is left behind it may solidify and impair the elevator operation as well as posing a potential infection risk. Some duodenoscopes have a removable distal cap that makes cleaning the elevator raiser shoe easier.The wire channel assembly runs the length of the insertion tube and has two components. At the distal end the wire passes through a plastic channel supported by a coil pipe that remains flexible so the tip of the endoscope can move freely. At the control body end the wire runs through the metal sus-pipe. The total length of this channel that must be flushed is approximately 125 cm long and the opening between the elevator wire and the sus-pipe is approximately 0.18 mm. This is why when the channel is flushed it results in only a slow flow of fluid.

The elevator control knob mechanism varies slightly from one model to another. The operator moves either a lever or a wheel. This movement is transferred to the elevator pivot arm that is soldered to the end of the elevator wire. If there is a delay in riser motion or if it jerks or moves erratically it needs to be sent for adjustment.

The elevator wire channel cleaning tube mount on the body allows fluids forced from a syringe to enter the tube and reach the elevator rod-sealing block. The block has two o-ring seals that allow the elevator rod to move in and out while allowing fluids to flow down the channel without entering the interior of the endoscope. A major difficulty in designing automated reprocessors is to devise a method to flush the elevator wire channel. Too little pressure doesn't produce enough flow to adequately reprocess; too much pressure allows fluid to bypass the o-rings and enter the interior of the endoscope. Some duodenoscopes (currently only the Pentax brand) have a different design where the elevator wire is sealed at the tip with an o-ring that prevents debris from refluxing up the elevator wire channel.

The elevator wire channel must be reprocessed in the same way as all other channels after each procedure.

SUCTION/BIOPSY CHANNEL.

The suction/biopsy channel is basically a length of tubing running from one end of the endoscope to the other with an on/off valve in the middle and attachments to stainless steel connectors at the ends. This tubing is required to be extremely flexible and pliable as well as stiff and strong.

The first potential problem area is the light guide plug. Cotton applicators should not be used to probe this or any channel port during cleaning. The applicator may wedge itself between opposing interior walls, catch on the milling marks and eventually break off inside as the user attempts to work it free.

Another area of concern is the bend in the channel where the umbilical cable meets the body. Aggressive cleaning with a coil spring cleaning brush or damaged brush can gradually wear through the channel.

There is a short length of tubing between the suction valve and Y pipe at the biopsy port that is often missed when brushing gross debris from the endoscope. It is only short (less than 20cm) and cleaning it requires inserting the brush at an acute angle into the valve unit. Damage will occur to the suction cylinder or the valve port if a metal coil brush is repeatedly inserted into the cylinder and passes all the way through the distal tip. Brush the short length through the suction valve and the insertion tube channel through the biopsy port.

Prompt cleaning of the endoscope after procedures and cautious insertion of anything into the suction/biopsy channels is the best way to ensure proper suction system operation. Avoid over-flexing the umbilical cable and insertion tubes to prevent kinking or collapsing of the channel.

Damage to the channel may result in the channel being unable to be properly cleaned and disinfected. It may also eventually lead to a puncture that increases the risk of fluid invading the other internal elements of the endoscope.

AIR AND WATER SYSTEM.

The air from the pump flows into the endoscope through a seal either at the air inlet pipe on the light guide plug or at the water bottle. From here it flows to the body of the endoscope and out the air/water valve. To inflate the organ being examined the air/water valve is covered, which diverts air down the insertion tube and out the distal tip.

When the air/water valve is depressed air entering the endoscope is split with some of it diverted into the water bottle which forces water into another channel in the umbilical cable. The water travels through the channel in the umbilical cable, through the air/water valve and down the insertion tube to the distal tip.

Some water bottles are pressurised directly from the air pump. Some endoscopes have an auxiliary water port that connects directly into the water channel so the water flows through the auxiliary water port prior to flowing down the insertion tube. Other endoscopes have an entirely separate auxiliary water channel.

The air/water nozzle is the point of smallest inner diameter and can become obstructed with debris or crushed from an impact. Air infused into an organ during endoscopy may produce a luminal pressure high enough to force debris to back up several centimetres into the nozzle and the air and water channels. Irrigation of the channels immediately after each procedure will prevent clogging of the nozzles or channels. Some models of endoscopes have separate air and water outlets, whilst in others the channels are joined in the distal tip and emerge through a common outlet.

Never probe the opening of the nozzle with a sharp object as it may damage or loosen the nozzle and could inadvertently scratch the image lens. A soft bristle brush should be used to clean the nozzle. Avoid using cotton tipped applicators to clean any port or component of the air/water system as fibres from the applicator may clog the channels or nozzle.

When blowing air through any of the channels, do not exceed 20 PSI of pressure. The auxiliary water port or channel should be cleaned and reprocessed in the same manner as any other channel in the endoscope

IMAGE SYSTEM.

The image system is made up of a variety of components including fibreoptics, electronics and the lens system. The internal structure of a video endoscope is virtually the same as a non-video endoscope except

for the optical system

Lighting Fiber optic bundles composed of thousands of individual fibers are used to

transmit light from the light guide plug to the distal tip of the insertion tube. An optical fiber is composed of two layers of glass of different reflective values that trap the light inside the length of the fiber. The flexibility of the fibers enables the light to be bent around corners and curves.

Non-video imaging Non-video endoscopes also use a fibre bundle to transmit the image from

the objective lens at the distal tip of the endoscope through the eyepiece to the user's eye. The image guide bundles are set up such that each fibre carries a portion of the image and is in the same place at both ends of the bundle. The final image is made up of the many small pieces of the whole image.

A broken fibre will result in a black or grey dot in the image. The fibres can be broken by trauma such as crushing of the insertion tube, severe impact or excessive bending of the insertion tube. Moisture around the fibres can cause them to become brittle which results in breakage

Video imaging In a video endoscope the image bundle is replaced with a video camera unit

consisting of a lens assembly and an electronic chip attached to about 16 small wires. Many individual sensors (pixels) make up the image by detecting light levels and colours. An external video processor then assembles the image that is transmitted along the wires to a video monitor.

Lens systems.

All endoscopes have lenses in both the lighting and image systems. A non-video endoscope has a lens system in the eyepiece that focuses on the end of the fibre bundle and magnifies the image.

All flexible endoscopes use an objective lens system at the distal tip. This reduces and focuses the image onto the surface of the image guide fibre bundle or the electronic chip.

Another lens system at the distal tip focuses light onto the area being examined to provide evenly distributed lighting.

It is important to protect these lenses from scratching or other trauma.

Grounding system.

Most endoscopes have an S-cord connector or grounding port on the light guide connector or elsewhere on the endoscope, usually the control body. All metal endoscope components are connected to this port to conduct any leakage current to ground on an electro surgical unit.

In order for manual cleaning to be effective it must: be performed by a person conversant with the structure

of the endoscope and trained in cleaning techniques be undertaken immediately after the endoscope is used

so that secretions do not dry and harden. follow a protocol which, using appropriate detergents

and cleaning equipment allows all surfaces of the endoscope, internal and external, to be cleaned

be followed by thorough rinsing to ensure that all debris and detergents are removed prior to disinfection.

Non-immersible endoscopes do not meet current reprocessing standards and thus should be removed from service.

1. Wipe the insertion tube with a disposable cloth dampened in an enzymatic detergent

solution. With the endoscope still attached to the

light source, grasp the control head and using a disposable cloth dampened in freshly prepared enzymatic detergent solution, wipe the insertion tube from the control head to the distal tip.

Discard the cloth after use.

2. Aspirate enzymatic detergent solution through the suction/biopsy channels.

Place the distal tip in the enzymatic detergent solution. Aspirate the enzymatic detergent through the entire

suction/biopsy channel system until the expelled solution is visibly clean. Immediate flushing of the biopsy/suction and air/water channels

prevents drying of organic and inorganic debris on lumen surfaces and assists in the removal of large numbers of microorganisms.

Alternate the suctioning of enzymatic detergent solution and air several times - finish by suctioning air. Alternate suctioning of fluid and air creates agitation and is more

effective than suctioning fluid alone in dislodging debris from internal lumens.

3. Purge air/water channels.

Depress and release air/water button several times to flush water channel. Occlude air button to force air through air channel. Further processing depends on the type of endoscope.

At this point either: Insert the special air/water channel feed button. Depress air/water feed button to flush with water then release for air flow to

expel water. or Disconnect the water bottle connector from the endoscope taking care not

to contaminate its end. Occlude water connector port on the light guide plug and depress water

feed button until all water expelled. or Move lever on water feed connector to close off the water supply. Depress water feed button till all water is expelled.

4. Detach removable components

Remove the endoscope from the light source. Attach protective video cap (if using video endoscope). Transport to the cleaning area in a container that does not cause

contamination of the environment. Remove all valves/buttons/caps and soak in enzymatic detergent

solution.

It is preferable to have extra supplies of valves/buttons/caps to ensure that adequate cleaning is performed prior to disinfection/sterilisation. This allows processing of valves/buttons/caps to be completed at an alternate time.

Leak testing.

It is essential to leak test the endoscope according to the manufacturers instructions.

A general outline of the procedure is provided below. All endoscopes should be leak tested prior to immersion

and between each patient use. The leak test will detect damage to the interior or exterior

of the endoscope. Perforated channels of endoscopes are an infection

control risk and damage may also occur to parts of the endoscope not designed for fluid exposure.

1. Attach the leak tester and pressurize the endoscope. Some manufacturers specify removing

detachable parts prior to leak testing - others do not.

2. Immerse the endoscope in water and observe for a continuous stream of

bubbles. If the leak tester has a pressure gauge, observe for

pressure loss prior to immersion (this indicates a significant leak).

Completely immerse the entire endoscope. Flex the distal portion of the endoscope in all directions.

Flexing may help to detect a damaged section that would otherwise go unnoticed.

Observe for a continuous stream of bubbles which indicates a leak.

Observe the head of the endoscope, the insertion tube, distal bending section and the umbilical cable for bubbles coming from the interior of the endoscope.

3. Processing endoscopes that fail the leak test. If a leak is detected, or the endoscope appears

damaged, contact the instrument manufacturer or supplier to ascertain whether reprocessing can be undertaken without additional damage to the endoscope.

If the endoscope fails the leak test, do not attempt to clear a blocked endoscope by blowing air under pressure through the lumen.

Manual Cleaning and Rinsing

CLEANING

1. Make up enzymatic solution

Make up fresh enzymatic detergent solution to the manufacturer's instructions for reprocessing each endoscope.

Fresh solution prevents cross contamination.

2. Immerse instrument.

Completely immerse the endoscope.

Whenever practical, leave the endoscope immersed in the detergent solution when performing all subsequent cleaning steps to prevent the production of aerosols of contaminated fluid

3. Disassemble removable parts and clean. Remove all buttons/valves/caps and other removable

parts (if you have not already done so). Correctly dispose of parts designated as single use. Brush and clean non-disposable parts with a small soft

brush paying particular attention to internal surfaces and lumens.

Place buttons and valves in an ultrasonic cleaner.

The endoscope must be completely disassembled so that all surfaces may be reached for thorough cleaning.

4. Brush and wipe exterior

Wash all debris from outer surfaces by brushing and wiping the instrument.

Use a soft toothbrush to gently clean the distal tip. Brush control handles and the biopsy port. Brush around valve seats and clean thoroughly. Use of non-abrasive and lint-free cleaning tools will prevent damage

to the endoscope. Soft toothbrushes are useful to clean grooved control handles and

to brush the distal tip. Valve seats and biopsy ports should be brushed using brushes

supplied by the manufacturer which are designed for this purpose. Cotton buds may be used to clean the suction valve port but should

not be used in the air/water port as threads can become caught and cause blocked channels.

Check that all visible debris has been removed. Cleaning brushes for valve ports are available from manufacturer

5. Brush all channels

Brush all accessible endoscope channels including the body, insertion tube and the umbilical cable or universal cord of the endoscope.

After each brush passage, rinse the brush tip in the detergent solution, removing any visible debris before retracting the brush and reinserting it.

Continue brushing until there is no debris visible on the brush. Clean and thermally disinfect or sterilise reusable brushes prior to reuse. Cleaning brushes for all brushable channels are supplied by the manufacturer.

Use a brush size compatible with each channel. Rinsing the brush tip maximises cleaning of the channels by ensuring that as much debris as possible is removed before retraction or reinsertion.

Cleaning and thermally disinfecting brushes reduces the risk of contamination of endoscopes by inadequately cleaned brushes.

Inspect reusable brushes between uses and replace when bristles are worn, frayed, bent, if the shaft is kinked or the brush is otherwise damaged.

Worn bristles are ineffective in cleaning and damaged brushes may damage endoscope channels

1. Water rinse

Rinse outer surfaces of the endoscope with water. Flush all channels thoroughly with water. Remove all buttons/valves from the ultrasonic cleaner. Rinse all removable parts with clean water. Clean running water should be used to remove all

traces of detergent prior to disinfection.

The use of clean water for each endoscope will limit the potential for cross infection.

The amount of water required to thoroughly rinse the endoscope after cleaning will vary according to the design and length of the instrument.

2. Dry external surfaces

Dry the outer surfaces of the endoscope with a soft, lint-free disposable cloth.

3. Purge internal channels with air. Purge water from all the channels with air to

remove rinsing water.

Removing water from all channels and the exterior of the endoscope prevents dilution of the biocide used for disinfection.

This process can be completed using a syringe or compressed air. If using compressed air see the Final drying before reuse section for information about air pressure

1. Purge all rinsing water from all

channels with air.

Follow the manufacturer's instructions for the appropriate air pressures. Follow the manufacturer's instructions for the appropriate air pressures. Avoid excessively high air pressure that can damage the internal

channels of the endoscope.

As a general rule the maximum recommended air pressure is 21 psi (lb/in2) or 145 kPa, which is equivalent to 1.45 atm.  It is important to check each instrument's manual.

Ensure that the air source has a flow regulator and use a lower air pressure on fine channels. Use bayonet (luer slip) rather than luer lock fittings to attach the air tubing to the cleaning adaptors and fit securely but not tightly - if safe pressure is exceeded the bayonet fitting will give way.

2. Dry all channels with pressurized air

3. Lubricate all 'O' rings on buttons,

valves and store separately. Lubrication is used to ensure optimal functioning of both

endoscopes and accessories. The "O" rings on suction and air/water control buttons require lubrication to prevent the buttons sticking in the depressed position.

Where silicone oil lubricants are used for suction and air/water control buttons, they should be applied immediately before the endoscope is used (after high level disinfection). It is essential to remove lubricant residue after use to allow biocide contact. Ultrasonic cleaning will remove any small remaining amounts of lubricant.

4. Reassemble the endoscope

If the instrument is to be stored see the next section on final drying before storage.

Remove the cleaning adaptors Dry the exterior surfaces with a soft, clean,

lint-free cloth. Reassemble the endoscope.

Autoscope®

Designed for high level disinfection of endoscopes

Compatible with all TGA registered high level instrument grade disinfectants

Reuses biocide Some models can process two

endoscopes independently.

Medivator®

Designed for high level disinfection of flexible endoscopes.

Uses glutaraldehyde or OPA as the biocide.

Reuses biocide Some models can process two

endoscopes independently. Heaters can be incorporated to reduce the soak

time.

Soluscope®

Leak tests the endoscope prior to and during cycle.

Uses 23% glutaraldehyde automatically diluted to ~0.25% and heated to 45°C.

Biocide discarded at end of each cycle.

Capable of processing 4 endoscopes/hr.

Problem Solving

Trouble Shooting

Symptom Possible Cause Procedure

No image, power LED not illuminated, lamp not illuminated.

Power line cord damaged or disconnected

Connect, repair, or replace as necessary

Power is not turned to "ON" Turn power on.

Interlock switch disengaged Verify that lamp replacement door is firmly and properly secured in place.

AC line fuses F1 and F2 open. Replace fuses F1 and F2 on Rear Panel Appliance Inlet (J100).

Open circuit connection Verify AC input through unit to the Power Supply (A1).

Power supply circuit defective. If Power Supply (A1) fuse F1 notblowing:Check for:110-240 VAC in at J1+15V output at J2If F1 fuse is blown:Disconnect P2 and J2 on the powersupply. Replace F1 fuse. Reapplypower. Verify output voltages at J2.If voltage is not present or if fuseblows again, replace power supply.

Other circuits loading down power Supply.

Disconnect and isolate video output board (A5) by removing connector P8.

Disconnect and isolate ballastboard (A4) by removing connector P2A.

Symptom Possible Cause Procedure

No image, Power LED isilluminated, lamp is illuminated.

Improper system setup. See Operating Manual.

Camera Head was not plugged in when box is powered on.

Connecting the Camera Head to the Power Box while the power is on may shut down the camera. This is caused by an overload protection circuit within the camera system.

Defective Camera Head Use test camera head and check for video image. Please note that, since the Camera Heads and Power Boxes are matched, the quality of the video image may be impaired. Replace Camera Head and Combined CameraModule/Front Panel Board Assembly (A7/A6).

Symptom Possible Cause ProcedureDefective Camera Model (A7)/Front Panel Board (A6) combined assembly

Check for +12V on pins 5 and 7 on J8 at Video Output Board (A5). If incorrect, troubleshoot Video Output Board.

Verify +5V at pin 13 of LEMOConnector J2, per FIGURE 9 onpage 41. Check for video signals at pins 11 and 13 of P8 on Video Output Board (A5). If video signal is present, troubleshoot output board. If not, continue this section.

Verify +12V at J3 of Front PanelBoard (A6).

Ensure that flex circuit is connected to J1.

Lightly tap the flex circuit with a hand tool while watching the video monitor. Check monitor for intermittent image.

Verify +12V, -12V and video signal input and output on Output Board (A5).

Replace Camera Head andCombined Camera Module/FrontPanel Board Assembly (A7/A6).

Advancements in the field of Endoscopy. Olympus Medical Systems Corporation has developed

key technologies, centered on "Capsule guidance system" and "Wireless power supply system", for capsule endoscopes to be used in all parts of the gastrointestinal tract, including the esophagus, the stomach and the colon. Olympus has always believed it is essential to equip capsule endoscopes with functions that enable them to be freely operated within the gastrointestinal tract without batteries, just like today's gastrointestinal endoscopes. It continues development work on the associated necessary technologies for treatment and diagnosis, as well as observation. Olympus has developed various fiberscopes and videoscopes since it unveiled the first practical gastrocamera in 1950.

One of the most recent extra-slim video endoscopes feature high-definition observation, another a distal-end outer diameter measuring only 5mm. Olympus has also prepared a range of endotherapy accessories, including devices for arresting bleeding, excising polyps and mucous membrane and recovering foreign bodies with minimum invasiveness. These promote greater efficiency in medical institutions and help improve quality of life for the patients. Gastrointestinal endoscopes are now recognized as the only medical devices that can simultaneously perform observations, diagnoses (tissue extraction), and treatment. As a result, they are now widely used in medical institutions throughout Japan.

Meanwhile, capsule endoscopes differ from conventional endoscopes in that they do not involve tube insertions. Instead, this examination method is expected to make life easier for patients because the endoscopes take the form of easy-to-swallow capsules that do not require topical anesthesia in the throat. After they have been taken orally, the capsule endoscopes generally available today are carried through the body by the peristaltic movement of the stomach and the intestines. During this process, they automatically take images of the gastrointestinal tract.

Olympus has for many years continued research into bringing the functionality of capsule endoscopes steadily closer to the functionality of conventional endoscopes. The most recently developed technologies are the key to developing the capsule endoscopes of the future. They include technology to control the capsule endoscope so that it can easily be brought closer to the part of the body that needs to be examined, and look at parts that are in shadow. Other technologies eliminate the need for batteries inside the capsule by providing electricity from outside the body, allow drugs to be delivered directly to the target affected area, and allow samples to be collected for diagnosis and analysis.

Descriptions of Individual Technologies(1) Passive capsule observation endoscopes (Technology of

capsule endoscope). These basic capsule endoscopes are equipped with the basic technologies needed for observation. The capsule is 26mm long with an external diameter of 11mm. It features compact, low power-consumption imaging technology and wireless transmission technology.

With a view to commercializing this type for use in small intestine applications, Olympus initiated clinical trials in the fall of 2004.

Compact, low power-consumption imaging technology (A supersensitive image pickup device illuminates the interior of the body and captures images through an ultra-compact lens.)

Compact, low power-consumption wireless transmission technology (The images captured by the image pickup device are transmitted outside the body by wireless through an ultra-small antenna.)

(2) Capsule guidance system This technology uses magnetism to freely control the capsule’s

movements. Olympus is working on development in a joint effort with the Arai/Ishiyama Laboratory, Research Institute of Electrical Communication, Tohoku University. The principle behind the technology calls for the creation of a uniform magnetic field in any direction (N/S Poles) by an external magnetic field generator using three pairs of opposing electromagnets arranged in three directions X, Y and Z (vertically, laterally and depths). The capsule endoscope can then be turned in any desired direction by means of its built-in magnet. The free directional magnetic field is then used to generate a rotating magnet field which rotates the capsule, generating thrust through the spiral structure on the capsule’s exterior. Since this allows free control of forward and reverse motion and motional direction, the capsule can be made to approach the part of the body to be inspected. The direction of observation can also be adjusted.

(3) Wireless power supply system This technology provides an extracorporeal supply of the

energy required for the capsule's built-in compact image pickup device and image transmission from within the capsule. Coils located outside the body use electromagnetic induction to provide electric power to the receiving coils inside the capsule. This makes it possible to secure the electric energy needed for long-term observations and the instantaneous electric power needed for high frame-rate photography.

(4) Drug delivery system

Inside the capsule there is a deflatable balloon containing drugs fitted with a small valve that can be controlled by communications from outside the body. This allows drugs to be delivered freely at any given time or place.

(5) Body fluid sampling technology There is also a negatively-pressurized

space within the capsule for storing extracted body fluids using a small valve that can be controlled by communications from outside the body. This is useful for diagnosis and analysis because it allows free collection of body fluids.

(6) Self-propelled capsule

The body of the capsule can propel itself freely within the gastrointestinal tract because it is fitted with an a mechanism that serves as a propelling mechanism and requires no external driving apparatus. Olympus is currently working on the development of several types of propelling mechanisms, including a twin-spiral type and a caterpillar-type.

(7) Ultrasound capsule

The ultrasound capsule makes it possible to conduct ultrasound scanning from inside the body because it incorporates the necessary miniaturized functions within itself. Since it radiates ultrasound from inside the body cavities, it is expected to deliver higher-resolution ultrasound images with less attenuation than those obtainable from external ultrasonography.

CDLECENTER FOR THE DEVELOPMENT OF LABORATORY EQUIPMENT KARACHI

PAKISTAN COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH