What is fatigue?

Fatigue is the body’s response to continued physical or mental activity or sleep loss, characterized by:

• diminished ability to do work, loss of attention, slower reactions, poor response, deterioration of vigilance and alertness, impaired judgment, and other problems;

• subjective feelings of tiredness, loss of motivation, desire for rest

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Causes of fatigue

Inadequate rest

Sleep loss and/or disrupted sleep

Displaced biological rhythms

Excessive mental or cognitive work

Excessive physical activity

1)general body fatigue (cardiovascular system) (Physiological).

2) muscular fatigue (muscles) (physiological),

3) Mental fatigue (brain) (psychological).

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•Fatigue can occur in different parts of the body:

Mental fatigue

Feeling of tiredness after extended or repeated performance, particularly of tasks that are not predominantly physical

Feeling of monotony or boredom created by lack of novel stimulation

Mental fatigue is more pronounced and our alertness level decreases if we are tired and drowsy due to loss of anticipated sleep.

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Factors affecting fatigue

Quality and quantity of prior rest

Individual physical fitness

Endurance, exposure to level of task demand

Number of sustained work episodes

Time of day

Type of task

Workload (mental or physical)

Motivation and other individual differences

Environmental conditions

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The purpose of rest is to minimize the health The purpose of rest is to minimize the health effects of fatigue including musculoskeletal effects of fatigue including musculoskeletal discomfort and mood disturbances associated discomfort and mood disturbances associated with continuous work at computer workstation.with continuous work at computer workstation.

Rest can restore energy, but it cannot substitute for sleep, nor can lack of sleep be corrected simply by resting.

Rest is a break or even a simple change of activity from a fatiguing task; we remain awake.

Effect of rest breaks:

1)Spontaneous pauses: are the obvious pauses for the rest that the workers take on their own initiative. These are usually not very long. Nevertheless, may be frequent if the job is strenuous.

2)Disguised pauses: are times when worker

occupies himself or herself with some easier, routine task in order to relax from concentrating on the main job. Example: cleaning some part of the machine.

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Types of rest pauses:

3)Work-conditioned pauses, i.e. pauses arising from the nature of work are all those interruptions that arise either from the operation of the machine, or organization of the work; for example, waiting for the machine to complete a phase of its operation, for a tool to cool down.

4) Prescribed pause: are breaks in the work that are laid down by the management, for example, the

midday break, and other pauses for snacks, e.g. coffee break.

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METHODOLOGY

• Apparatus: The instruments that will be used to perform this project are:

electromyography (EMG), skin resistance device, electrocardiography (EKG), micro-computer, CRT display monitor, keyboard as response station and four software programs written in Microsoft Visual Basic language.

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Twenty students will be served as subjects in the four experiments ‘tasks’. All subjects will be normal or fully corrected vision. In addition, all will be right-handed.

Subjects:

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Experimental design and procedures:

The four different groups of subjects will perform four visual tasks. Each assigned of subjects (e.g., at least five subjects) will perform one task.

The first task is the data entry; the others two are belong to cognitive tasks.

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the subject will be asked to enter the alphabetic or numeral set that is showed up in the middle of the monitor as soon as he recognize the stimulus while keeping accuracy of entering data as high as possible. Subjects will be told to enter all digits in the set, digit followed by digit, by pushing the appropriate marked keys on the key board .

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1)The first task is the data entry :

2)Locate:

• view and memorize all reference. View an initial matrix cell and test symbol correspondence to the reference. If a test succeeds, visually find the row and column identifiers and respond with those identifiers; otherwise, visually move to the next cell.

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Example:

Which cell contains LKJ:

1 2 3 4 5 6 1 BNL SNV FJS GJE KGW MGD 2 IDK HDL HJG YWI GHD LHD 3 SJH RYE JHK LKJ SMO QAJ 4 YUJ UYU SFD JHK HHF SJH

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3)Compare:

view the first reference symbol, then the field symbol in the adjacent position for a correspondence test. If the test fails, response no; otherwise, moves the sequential position and continues to the last symbol test succeeds. Hence, response yes.

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Example:

Are the strings identical?

Q R B N K J S D I P X Z M A

Q R B N K I S D I P X Z M A

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4)Concentration grid:

• concentration grid exercise was used as a training tool and as a measure of Concentration.The concentration grid used in this study consisted of a grid of 100 squares (dimensions) arranged in a 10x10 square. Two digit numbers (from 00 to 99) were placed randomly in the centre of each of the squares. The task of the participant was to mark off as many consecutive numbers (always starting from00) as possible within a 1-min period.

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FUTURE WORK PLAN

• In this semester, the problem description, literature review, and solution methodology are defined in details and presented in this report. Next semester, completing the software, collecting data for the four experiments, and analyzing the collected data using SPSS software will be considered. Finally, reporting the results and conclusions will be written.

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