ItemMEDICAL GASES OXYGEN CONCENTRATORS SUCTION PUMPS VENTILATORS(UHANDISI WA BIOMEDICAL, 2020) ItemX-Ray Automatic FIlm Processor(WHO, 2004) McClelland, Ian RThe aim is to provide routine maintenance procedures for the automatic film processor.This module presents a series of regular maintenance schedules. When used with sensitometry techniques, this module can be used to implement a quality control programme. Repair procedures for the processor are provided in module 11.1 page 199. A processor maintenance schedule should be followed regularly. Performing this maintenance will ensure optimum quality of processed films, and allow detection of problems before they become serious. On completion of this module, the student will be familiar with maintenance procedures for the automatic film processor. These procedures should be used together with the maintenance instructions in the operators’ manual. A routine maintenance check-sheet is provided in appendix ‘D’ page 186. ItemFault diagnosis and repair modules(WHO, 2006) McClelland, Ian R.The aim is to provide information for common proce-dures involved in diagnosing or repairing a problem. Most of these procedures are applicable to all of the fault diagnosis and repair modules. With any trouble-shooting technique, it is not necessary to approach a problem from any specific direction or set of rules. Rather, you should first observe, consider a possibility and then devise a test to check that assumption. Consider which items are quick or easy to check. This can save time if first carried out.When a problem occurs, record how the equipment was used just before the problem occurred. This allows a similar procedure to be used as a test, in case the symptoms of the recorded problem are not easily reproduced. During the process of locating the cause of a problem, record the tests or checks made, and the results.This will provide a valuable record if it becomes necessary to ask advice from the service department. ItemX-Ray Routine maintenance modules(WHO, 2004) McClelland, IanRoutine maintenance is a procedure to ensure equip- ment is kept in good condition, and provide a long operating life. Routine maintenance may also discover potential problems, which could cause equipment failure. Potential problems can then be corrected, with a minimum of down time. ‘Quality control’ procedures, to ensure correct operation and calibration, are also a part of routine maintenance. Carrying out routine maintenance produces good knowledge of the equipment, and in case of a problem, this knowledge will help to locate the cause. Where there is a more serious problem, accurate reporting for assistance will allow faster and more economic response. For example, the service engineer can then arrive with suitable parts and test equipment. A major part of routine maintenance is just inspec- tion of equipment.This should be done as if seeing the equipment for the first time. At the same time, make note of less understood operation areas, and refer to the operation manual for explanation. ItemSurgical diathermy machine(WHO, 1996)In surgical diathermy, a high-frequency electric current (0.5—2 MHz) is used to produce heat to seal (by coagulation) blood vessels, or to cut and seal at the same time. The heating can be regulated by a variable resistance. There are two types of diathermy machine: monopolar and bipolar. ItemStethoscopes(WHO, 1996)Stethoscopes require little maintenance apart from replacement of lost, cracked, or broken parts, such as ear-pieces and diaphragms (Fig. 3.3). On the older types, the tubing may perish and need replacing. While it is possible to buy proper, but expensive, stethoscope tubing, ordinary tubing of a suitable size may be fitted. Most newer stethoscopes have tubing that does not perish, though it can become sticky if certain chemicals come into contact with it. ItemPipettes(WHO, 2008)Pipettes are devices used for measuring or transferring small volumes of liquid from one container to another with great precision. There are many pipette models. Initially, they were made of glass; at present, there is a wide range of options. Fixed volume and variable volume pipettes with mechanical controls are highlighted herein. Recently, pipettes with electronic controls have been introduced into the market. This chapter deals with aspects referring to the maintenance and calibration1 of mechanical pipettes. ItemMicroplate Washer(WHO, 2008)The microplate washer has been designed to supply cleaning buffers required for the ELISA technique in a controlled manner. In the same fashion, the equipment removes from each well, substances in excess from the reaction. Depending on the test performed, the washer can intervene from one to four times, supplying the washing buffer, agitating and removing the unbound reagents1 until the programmed times and cycles are completed. The washer has of two reservoirs; one for the washing buffer, the other for the waste generated during the washing process. ItemMicroplate Reader(WHO, 2008)The microplate reader also known as “Photometric micro-plate reader or ELISA reader” is a specialized spectrophotometer designed to read results of the ELISA test, a technique used to determine the presence of antibodies or specific antigens in samples. The technique is based on the detection of an antigen or antibodies captured on a solid surface using direct or secondary, labelled antibodies, producing a reaction whose product can be read by the spectrophotometer. The word ELISA is the acronym for “Enzyme-Linked Immunosorbent Assay”. This chapter covers the use of microplate readers for ELISA testing. For additional information on the instrument principles of operation and maintenance, consult Chapter 11 discussing the spectrophotometer. ItemDispenser(WHO, 2006)The dispenser is a piece of equipment in the pipette and dilutor family. The word dispenser comes from the prefix dis which implies privation, and from the Latin word pensum which means task. There are different types of dispensers such as, models meeting chemical work requirements and others used in microbiology, bacteriology, immunology and pharmacology. There are automated dispensing units controlled by computer programs, which are used in institutions where there is a high testing demand and thus a need for automated procedures. This chapter features manual dispensers, also called repeater pipettes, as these are the most commonly used. ItemColorimeters(2008)A colorimeter is an electrically powered instrument which measures the concentration of analytes in coloured solutions. It is a simple version of a photometer. The difference in the quality of its filters makes it less sensitive. The colorimeter is used for clinical chemistry, namely for determining haemoglobin concentrations. Colorimeters are made by several manufacturers and include types with inbuilt individual removable filters or filter wheels for up to ten wavelengths. Some models are adapted for hot and humid climates with gelatine filters encased in glass to prevent fungal growth and coated individual components to prevent corrosion. ItemCell counters(WHO, 1996)Cell counters are used for haematological measurement. Semi-automated and automated cell counting has proved to be much more reliable than microscopic cell counting, because a far greater number of cells can be counted rapidly in a specimen by an analyser system, resulting in greater precision. However, the improvement in precision does not necessarily imply a simultaneous improvement in accuracy. For the study of pathological cell types, microscopic examination of a blood smear by an experienced investigator is still most valuable, and in many instances the method of choice. ItemX-ray diagnostic equipment(????, 1990)X-rays are invisible. Because of their high energy and short wavelength they can penetrate almost all materials, but are absorbed to a different extent by different tissues. In the human body, absorption is high for bones, and low for muscles and other soft tissues. These differences in absorption can be shown on a photographic film as differences in density: the result is a radiograph. Thus, radiographic examination consists of irradiating a part of the patient with a uniform beam of X—rays and recording the emerging rays on a double emulsion film sandwiched between a pair of fluorescent screens. The screens convert the X-rays into light, which in turn exposes the X-ray film. The screens and the film are enclosed in a cassette for protection from daylight. After the exposure, the film must be processed, manually or automatically, in a darkroom by means of developer and fixer solutions.