ergonomics human performance and factors

By:- Atif JamalM-Tech (Production & Industrial Engg)

To:- Prof Mr Naveen Kumar

Information Input & Processing

Cognitive System Model

Human Factors

Energy Expenditures (Rest & Physical Activity)

Heat Stresses

Heat Disorders & Health Effects

Heat Exhaustion & Heat Stroke

Information Input and Processing

Information Theory:

Some times called cognitive psychology, cognitiveengineering, and engineering psychology.

Information is defined as the reduction of uncertainty.

The occurrence of highly certain events do not conveymuch information (such as fasten seat belt sign). But theoccurrence of highly unlikely events convey moreinformation (such as high temperature warning in a car).

The fasten seat belt sign conveys less information because it is

expected. Although it is an important message, the importance

is not directly considered in the information definition.

Because this message comes on every time the car is started, it

contains little (or no) information in the context of information

theory.

Basal Metabolic Rate

◦ BMR is rate of energy expenditure fasted, rested and supine

conditions in thermoneutral environment.

Resting Metabolic Rate (RMR) is rate of energy expenditure

when at rest but not basal (> BMR).

◦ BMR proportional to BSA, after age 20 2% & 3% per

decade in women and men, respectively

◦ BMR represents largest fraction of TEE (Total Energy

Expenditure)in Physical work.

Influence of Body Size

◦ Differences in body size usually expressed in

terms of body surface area (BSA).

◦ From 20-40, average values BMR are 38

kcal/m2 per hour for men and 36 kcal/m2 for

women.

◦ Lower BMR in women can be attributed to

woman’s larger percent body fat & smaller

muscle mass.

Energy expended during weight-bearing activities increases proportional to body mass.

There is little relationship between body mass and energy expended during non-weight-bearing activities.

Average daily Total Energy Expenditure

estimated to be 2900 – 3000 kCal for males,

and 2200 kCal for females 15-50 y.o.a.

The type of clothing worn must

be considered

Prior heat injury predisposes an

individual to additional injury.

Heat Stroke

Heat Exhaustion

Heat Cramps

Heat Collapse

Heat Rashes

Heat Fatigue

Occurs when the body's system of temperature

regulation fails and body temperature rises to critical

levels

This condition is caused by a combination of highly

variable factors, and its occurrence is difficult to

predict

Heat stroke is a medical emergency

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