1.0 Introduction
A temperature controlled incubator is a device in which the user can maintain a specific temperature over a duration of time. These incubators include those for hatching eggs, conducting scientific experiments and caring for infants born prematurely.
In their elaborate forms these incubators usually possess the ability to regulate temperature and also control the humidity or carbon (IV) oxide level of their internal environment. This is important in the cultivation of mammalian cells, where the relatively humid environment is typically greater than 95% and a slightly acidic pH is achieved by maintaining a CO2 level of 5%.
Most temperature controlled incubator includes a timer; some can also be programmed to cycle through different temperatures, humidity levels, etc. These incubators can vary in sizes from tabletop units to sizes of small rooms.
Types of Temperature Controlled Incubators
- Incubators for Scientific Experiment: This type of incubator is a device used to grow and maintain microbiological cultures or cell cultures. This incubator maintains optimal temperature, humidity and other conditions such as carbon (IV) oxide (CO2) and oxygen content of the atmosphere inside it. Scientific incubators are essentially for a lot of experimental work in cell biology, microbiology and molecular biology, and are used to culture both bacterial as well as eukaryotic cells. The simplest incubator of this type are insulated boxes with an adjustable heater typically going from 60 to 65oC (140 to 150oF) though some can go slightly higher (generally to not more than 100oC).
- Infant incubator: This is often referred to as Isolette and it is an enclosed clear plastic housing that provides a heated and sheltered environment for the care of infants that are too small or sick to maintain their own body temperature. The heat adjusts automatically to keep an infant's body temperature constant. It is also programmed to create optimal condition through precise control of its hood temperature and humidity.
- Hatcher or Egg Incubator: An egg incubator is used to hatch bird or reptile eggs. The incubator keeps the egg warm, allowing the fetuses inside of them to grow and hatch without the mother present. The incubator is set at 98oF (37oC) and the eggs are placed inside. Chicken eggs usually hatch after 21 days, while other birds may take more or less than this.
There are several reasons why an egg incubator may be used. One of such reasons is that a farmer may want to hatch some chicks, but none of his or her hens are broody, hence the only alternative is to use the incubator. These incubators are used in large chicken raising facilities. Another common use of this incubator is in classroom, where students learn about eggs and chicken through watching the eggs hatch after incubating for a few weeks.
Factors Affecting Design and Construction of An Incubator
- Thermo-neutrality: Thermo-neutrality is one of the major environmental factors affecting the performance of an incubator. Severe temperature differences inside an incubator lead to heat loss which is related to air flow and air velocity. In order to prevent this, it is usually necessary to insulate the incubator to prevent any form of heat loss by conduction, convection, radiation or even evaporation.
- Biocompatibility of material: Biocompatibility testing is required for all parts of the device that have direct or indirect contact with the egg or fetus to be incubated. It is usually performed to determine the potential toxicity that can result from contact of the component materials of the device with the egg of fetus. The materials used in the construction of the device should not, either directly or indirectly through the release of their material constitute, produce unreasonable risk of adverse local or systemic affects; be carcinogenic; or cause adverse reproductive and developmental effects.
- Labeling: It is important to the user that the labeling for the incubator bear clear, accurate, and complete information for use concerning any relevant indication for use, conditions and limitations of use, hazards, contradictions and precautions in their use.
- Temperature: Proper incubation temperature is critical to ensuring maximum hatchability of the eggs as well as the best physical condition of embryonic mort. To ensure a proper incubation temperature provision must be made to avoid any increase in temperature above 37oC.
- Humidity: Proper control of the incubator's humidity is also critical for successful hatching of eggs to reach the correct weight loss.
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