Johns Hopkins University

An Alternative Infant Incubator

Incubators for Third World Countries

Qingwen Kawaji

An infant incubator designed for third world countries in Eco Health Engineering led by Dr. Thakor.

Medical Need and Background Information:

Incubator is the most common device that can provide an environment where newborn

babies can healthily grow in. Although incubators are used for all infants, they are especially

important in the case of preterm babies. There are a few reasons that contribute this need.

Firstly, infants’ large surface area, poor thermal insulation and a small mass (especially for those

with a low birth weight) all contribute to infants’ bodies behaving as a heat sink, which is why

infants have poor temperature regulation.i Secondly, infants aren’t like adults; when they are

cold, they cannot help themselves with a blanket. Babies exchange heat with their environment

by conduction, radiation, convection, and evaporation. Preterm babies are at especially high risk

of heat loss due to “a high surface area to volume ratio and increased transepidermal water

loss.”iiFurthermore, the normal surge in metabolic rate that occurs after birth is much reduced,

which results in limited heat production. Finally, “development in the control of skin blood flow

is also delayed in the immature baby, reducing the ability to maintain heat by peripheral

vasoconstriction.”iii With heat loss through four different methods and an inability to produce and

maintain heat, preterm infants are at high risk for medical complications and death.

To make matters worse, preterm infant birth rates are especially high in developing

countries, where the facilities and the after-birth care are the worst. The combination of poor

facilities, poor after-birth care, and a lack of knowledge propelled preterm birth to be one of the

leading causes of infant mortality in developing countries. According to World Health

Organization, it is estimated that in 2005, “12.9 million births, or 9.6% of all births worldwide,

were preterm.”iv About 85%, or 11 million of all preterm births took place in Africa and Asia,

deeming preterm birth is a leading cause for neonatal mortality and morbidity.v

Several studies have shown that infant survival rates significantly increase when their

surrounding environment is ideal. vi Infants thrive at a specific temperature range, the

temperature that’s very similar to body temperature. Preterm infants lose heat quickly and

cannot regulate their own body temperature. Being able to provide such warmth is a great value

to a baby’s health, this is especially true for preterm infants. Hospitals all over the United States

use incubators to provide a steady and ideal environment for preterm babies. However, this

luxury does not exist in developing countries.

Two major obstacles that are keeping the developing countries from having these

helpful devices are accessibility and price. An example of the state of the art incubator, used

often in high ranking hospitals in the US, is the Giraffe Incubator produced by GE health care.

These incubators not only have extremely precise

and accurate temperature control, they also have

countless other functions such as controlled

humidifier, built in scale, oxygen intake measure,

and etc. These incubators are also “smart,” in a

way that they can record data and be connected to

the main computers at the hospital to be controlled

virtually. Incubators with such complicated process programs cannot be used anyone.

One must receive proper training provided by GE Health Care in order to be qualified to

operate. These trainings alone cost up to $4000 dollars. One can only imagine the actual

cost of the machine. Of course, this is an incubator that’s on the top of the shelf.

However, the average cost of incubators in most hospitals is still more than just a few

thousands. This price, may be reasonable to hospitals in the developed countries, is

impossible for third world countries. Before price, there is also the question of

accessibility. Even if developing countries were to obtain incubators as a donation from

developed countries, it would be hard for them to learn an entire system of operations of

these new machines. Also, because these machines are built elsewhere, it is virtually

impossible to find the same parts for replacement or fix-ups in these developing countries

if anything were to go wrong with these incubators.

The purpose of this project is to strike a balance between price and functionality,

to invent an incubator that’s good at what it must do -- to keep baby warm and healthy,

but does not cost a whole village’s fortune. Also, the incubator must be built with

materials that are readily accessible in the home country so that trained staff can easily

replace and rebuild.

Analysis of Current Devices:

The problem of incubators has been tackled by a variety of organizations. Currently,

there are a few incubators available to third world countries. Although each one has its

merits in one way or another, they all have areas that need improvements. Before diving

Figure 1 Giraffe Incubator From GE

into our design, we must assess each of the already existed projects to gain insights as to

how ours can be more useful.

The Embrace is one of the current devices in providing infant care. The

design costs $25. However, although the device is very cheap, it has many

downfalls. The mechanics of this device involves heating the phase-

change material in the device using hot water or an electric heating pad.

The pouch will heat up to 37 degrees (the ideal incubator temperature)

and placed into the sleeping bag.vii The sleeping bag then wraps the baby

inside to keep them warm. The phase change material will stay around the

same temperature for about four hours. Then it would need to be heated up again.

Although innovative, this incubator does not have any temperature control within, which

is crucial to any device. Without an temperature control, no one would notice if anything

were wrong with the device, if it would to be defective. Furthermore, wrapping the baby

in a sleeping bag forbids caregiver to observe the baby openly, which is important in

many cases to determine a baby’s reaction to the environment or whether or not they are

sick.

The Car Part Incubator is another interesting innovation. The idea of

this incubator is to provide an device that can reuse old car parts. This

solution, while mildly low cost ($1000), need vehicle parts, which can

be expensive and unattainable.viii In third world countries, working car

parts cannot be cheap. Most of these parts are used to build “new” cars

or to fix cars rather than to be sold for incubators. Another problem

with this design is that there is no access to the infant through “sleeves.” It has not been

tested for its ability to prevent infections and bacteria growth. It is also fairly complicated

to build.

The HEBI (Hemel Baby Incubator) is an incubator project

launched by Dr. Hemel and first used in Uganda in 1968.ix

This incubator cost about $500, not including the light

Figure 2 The Embrance

Figure 3 Car Part Incubator

Figure 4 HEBI Incubator

bulbs. It also has to be shipped from Amsterdam airport to any developing countries in

need. This incubator uses incandescent light bulbs are a source of heat. It has been tested

to prevent infection and bacteria growth. However, it does not have temperature control

unit as it is heated solely by turning on and off the lightbulbs. Another problem with this

incubator is that it uses the fact that incandescent light bulbs are inefficient and therefore

emit heat. However, because of this inefficiency, incandescent light bulbs have also been

replaced by fluorescent light bulbs and to make the world a “greener” place, most

companies have stopped producing them.

Solution and Design

Through studies and analysis of the current designs, we have gathered their pros and cons

and created our very own incubator.

Incubator Material Wood

Incubator heat source Car Heater

Incubator ventilation Used PC Fans

Incubator Humidifier Aluminum foil cooking pan

Incubator window Polyethylene sheets and Window film

Incubator Temperature Control Digital Temperature Control with Sensor LM

335

The incubator will be built from wood due to its accessibility and price. Also, we have

contacted the HEBI organization and through them we learned several reasons why they

used wood as the construction material for incubators: 1) wood gives a strong

construction; 2) wood has good insulation; 3) it’s easy to regulate relative humidity; 4)

it’s easy to obtain especially in third world countries. The material of the observation

window in most incubators is acrylic glass. This material is expensive and hard to get in

third world countries. In order to replace acrylic glass with another material that’s safe to

use and also provide insulation and clear observation, we contacted 3m company and

decided to use polyethylene sheets. Firstly, when polyethylene sheets breaks, it will not

harm the baby in anyway. Secondly, polyethylene sheets are cheap and easily available.

In order to improve the UV reflection ability of these polyethylene sheets, window films

are used to adhere to the

polyethylene sheets.

As for heat source, car heaters

are used due to their availability,

price, and efficiency. This heater

is also part of the humidifier

system embedded under the main

incubator. The humidifier system

involves a cooking pan filled

with water, heater, and PC fans.

Used PC fans are used for

ventilation of the incubator to allow exchange of air. Finally, the thermo-regulator unit is

used to adjust and relay the system. When the temperature rises above 38 degrees, the

regulator turns off the heater until the temperature inside the incubator has fallen down to

a specified 36 degrees. The fans will be turned on when the unit is above 38 degrees and

off when it’s below 36 degrees. This relay system is important in the regulation of the

temperature inside the incubator. Below is a diagram of the thermo-regulation unit and of

its inside circuitry.

Furthermore, in order to protect the

circuitry of the thermo-regulator unit,

a special case was specifically

designed using pro-engineering and

U-print 3D prototype printer. This

case perfectly encloses the thermo-

regulator unit while offering an LCD

screen view and exposing the

switches for temperature displays.

Cost analysis

Overall Design Analysis

i Lyon, Andrew. (2006) "Applied physiology: Temperature control in the newborn infant." Current Pediatrics 16, 386-392ii Lyon, Andrew. (2006) "Applied physiology: Temperature control in the newborn infant." Current Pediatrics 16, 386-392iii Lyon, Andrew. (2006) "Applied physiology: Temperature control in the newborn infant." Current Pediatrics 16, 386-392iv Beck, Stacy, et al. “The Worldwide Incidence of Preterm Birth: A WHO Systematic Review of Maternal Mortality and Morbidity.” Bulletin of the World Health Organization (2009): 10.2471.v Beck, Stacy, et al. “The Worldwide Incidence of Preterm Birth: A WHO Systematic Review of Maternal Mortality and Morbidity.” Bulletin of the World Health Organization (2009): 10.2471.vi Day, Richard L., et al. "BODY TEMPERATURE AND SURVIVAL OF PREMATURE INFANTS." Pediatrics 34.2 (1964): 171-81.vii The Embrance. Web. <http://embraceglobal.org/>viii Design That Matters. Web. <http://www.designthatmatters.org/news/dtm-blog/project/incubator/>ix HEBI Hemel Baby Incubator. Web. <http://www.hebiincubator.org/templates/heb/global/index.php?lngid=2&sqlmode=1&fid=144>