Instrument and Equipment Maintenance

Electrical connections

Socket outlets should be mounted on the walls or ceiling, or if possible, sunk into floor. These need to be carefully planned because of the safety hazard with water.

  All in socket should be double and the fuse box kept in the theatre, with the potential to increase electrical capacity if needed. The position of the operating tables needs to be decided before placing the electrical sockets. Wires lying around the floors are hazardous. Sockets should be close to the pieces of equipment they serve. All sockets must be properly earthed. Ophthalmic surgery is very delicate and can be dangerous if the operating room conditions are not favorable. The theatre must have a back up electrical supply (generator) in case the main electricity fails. If the electrical system is not reliable it is worthwhile putting all machinery onto voltage regulators. These stabilise the electrical input and protect the equipment from blowing fuses and bulbs.

• - Always check that the primary voltage of the instrument matches that of the power source.
• - Always switch off the main switch on the control panel before connecting or disconnecting electrical cords and /or cables
• - Always ground the power cable, as specified by local electrical regulations.
• - Frequent switching on and off of bulbs will shorten the life span.
• - Always hold the plug or connection firmly when disconnecting cords and / cables and never pull directly on the cords or cables
• - When storing equipment, take the following into consideration. The instrument should never be stored in a location where water will drip or splash on it.
• - The instruments should be carefully covered with its vinyl dust cover
• - Do not store where it the instrument can be exposed air pressure, temperature, humidity, strong ventilation or wind, direct sunshine, dust and salty or sulphuric air. In other words, it should be stored in an air conditioned room when available.
• - If the instrument does not work please check the following points before calling for help:
  • - Check whether all connector cords and cables are correctly and securely connected
  • - Check fuse holders and replace blown fuses
  • - Check both illuminator lamps and replace if necessary

Microscopes

Microscopes are essential instruments in the micro-surgery of the eye.

They require constant attention. Microscope bulbs have a finite life. They are replaced when they are fused out. Usually microscopes have one or more extra bulbs that can be pushed in as replacement bulb for the fused bulb so that the surgery may proceed without interruption. To achieve this, extra bulbs should be checked before the commencement of the first surgery case using that microscope. The fused out bulb should be replaced immediately after the last surgery is over

Caution

The bulb will remain hot for some time after it is fused out. Wait for sufficient time for the bulb to cool off before replacing it. Turn off the power while the bulb is being replaced.

Care of microscope includes

1. Cleaning the optics using distilled water or lens cleansing solution. Optics includes eye pieces,magnifier and objective lens.
2. The power cord, bulb, foot switch, illumination and the optics are to be checked.
3. Check the mechanical parts, and lubrication must be done after cleaning to keep the wheel movement smooth.

Trouble shooting

Problem	Solution
Microscope is not working	Check the power cord and plug
bulb is not glowing	Check the fuse and switch Check the bulb. If there is any problem with the bulb,change the bulb.
Fan is not working	Check the fan and voltage, check the wires leading tothe fan and replace them if necessary
Up/down is not working	Same as above
Illumination is not good	Clean the optics. Check the fibre Optic cable fitting and position of the bulb.

  Whenever a new machine is installed, the specifications are to be read and followed.

Phacomachine

This equipment is used in the phacoemul sification technique of cataract extraction. In this method ultrasound energy is used to break the nucleus of the lens into smaller pieces within the capsular bag and then remove them, The machine has 3 parts:

• - Console
• - Hand piece
• - Foot pedal

The hand piece has a main body to which 3 lines are attached:

1. The ultrasonic power line which conducts the ultrasonic power to the tip
2. Irrigation tube through which the irrigating fluid is carried to the eye
3. Aspiration tube through which lens matter and fluid is removed.

  There is a tip at the end of the hand piece. The tip is made of a hollow titanium needle, which moves backward and forward. The opening of the tip acts as the aspiration port. There is a silicon sleeve which fits around the tip. There are 2 ports in this sleeve through which irrigating fluid enters the eye.

  The console of the phacomachine displays the following parameters

1. Ultrasonic power
2. Vacuum
3. Bottle height
4. Flow rate
5. Irrigation
6. Aspiration

  The foot pedal is used to control the different functions of the hand piece.

Trouble shooting

Problem	Possible cause	Correction
Low vacuum, insufficient aspiration.	Hand piece tubing improperly installed through peristaltic pump Irrigation pinchvalve,aspiration porttubing is damaged, kinked or worn out Hand piece tip is clogged	Remove tubing and reinstall. Check tubing and/or replace Flush hand piece with sterile water, replace tip
Hand piece error	Hand piece tip is looseor power to the hand piece is disabled.	Tighten hand piece tip and retry. If the same problem recurs ,change the hand piece
Ground fault error	Ground fault. Power to hand piece is disabled.	Replace the hand piece.

Phaco machine maintenance

• - Remove drip chamber from irrigation bottle.Disconnect irrigation tubing from drip chamber.
• - Disconnect irrigation and aspiration tubing from the hand piece. Do not connect irrigation and aspiration tubing together
• - Remove all accessory pack components and tips from hand pieces.
• - Unplug hand pieces from the console
• - In irrigation free-flow mode, remove tubing from irrigation pinch valve.
• - Turn system power off
• - Clamp a hemostat immediately below the blue aspiration T fitting

Surgical instruments

Handling of ophthalmic instruments

• - All ophthalmic instruments need exceptionally careful handling.
• - The tips of the scissors are extremely delicate and should not be touched.
• - All scissors, needle holders and fine forceps need their tips protected. The protectors must cover the whole blade or jaws of the instruments.
• - Scalpel blades and knives must be passed to the surgeon by the handle with the cutting edge pointing downwards. Artery forceps must be used to remove the blade
• - Never re-sterilise disposable needles.

Cleaning

Distilled water is preferred for cleaning purposes. If distilled water is not available, freshly boiled tap water may be used.

  The following method should be used after each operation. Three containers are required.

Container-1 Hot soapy water

• - The instruments must be supported carefully while cleaning
• - A soft tooth brush can be used to clean each instrument individually.
• - Needle holders, scissors and artery forceps must be fully opened and cleaned inside the jaws.
• - Cannulae must be flushed thoroughly.
• - Cotton wool should not be used to clean the instruments as it damages the tips.

Container - 2 Lubricant

• - A lubricant prevents the development of stiff joints and inhibits the development of corrosion.
• - Lubricant is needed only for hinged instruments like scissors, needle holders and artery forceps.
• - If a lubricant is not available, the instruments should be rinsed in clean water.

Container - 3 Clean hot water

• - Excess lubricant or soap is rinsed off and the instruments left in the open dismantled position on a clean absorbent cloth.
• - Cannulae must be flushed thoroughly again to remove any soap debris.

Drying

• - Instruments must be dried thoroughly before being stored. If the instruments are put away in a wet or damp state they start rusting.
• - A hair dryer is very effective for drying the joints and crevices of instruments. If a hair dryer is not available, dry gauze may be used cautiously.

Corrosion and rust

• - Most instruments are made from stainless steel. Stainless steel usually does not rust, however it can corrode if washed in saline or left to soak for a long period of time in any liquid.
• - Once the instrument has started to rust, it will become weak, and the rust will eventually destroy and break the instrument

Oiling

With repeated sterilisation instruments will become stiff and difficult to open. A good quality sewing machine oil or silicon oil should be used each week on such instruments. This is especially relevant when working in a very hot, dry climate.

Repair

If forceps, lens-holding forceps, needle holders or scissors get bent they can be straightened with stainless steel nose pliers and gently sharpened with a silicon carbide stone.

  Retina surgery instruments are very costly, so special care must be taken in handling them.

Cleaning procedure for such instruments

Disconnect the handle from the forceps or scissors. Connect the small adapter to the forceps or scissors for cleaning. Three 20 cc syringes and two bowls are required.One bowl should contain distilled water and another contains spirit.

Step by step procedure

• - Take 20ml distilled water in one syringe and flush the instrument twice
• - Take another syringe with 10 ml spirit and flush it once
• - Take third syringe with air and flush it three times
• - Handle is to be cleaned by ultrasound cleaner
• - Handles of forceps or scissors are dried with a hair dryer

Summary

Surgery instruments are very precious and costly. So they must be handled carefully. If there is any repair required the staff should know how to rectify and maintain the instrument. This helps to reduce costly maintenance. If maintained properly, the equipment should last for a long time.

Key points to remember

• - Clean the optics using distilled water or lens cleansing solution
• - Whenever a new machine is installed , the instructions are to be read and followed
• - The tips of all sharp instruments are to be covered appropriately
• - When there is a break down the ‘down time’ should be at a minimum.
• - Never re sterilise disposable needles

Student exercise

Answer the following

1. 1. Write short notes on
   • Microscope and its care
   • Phacho machine and its parts
   • Handling of ophthalmic instruments.
2. Write in detail the cleaning procedure of surgical instruments.
3. Mention any three problems that occur in a microscope and how they could be rectified.
4. Give possible cause and corrections for the following troubles
   • Low vacuum, insufficient aspiration
   • Hand piece error
   • Ground fault error
5. Describe how to maintain the phacho machine.