Worldwide every year over 4 million infants dice within a calendar month of birth. Of this number, 3.ix million belong to the developing globe. Some (25%) of this deaths are caused due to complications of prematurity, nearly often due to improper heat regulation, water loss and neonatal jaundice. An infant incubator provides stable levels of temperature, relative humidity and oxygen concentration. Temperature control system is the about important part of a babe incubator which has to be maintained effectually 37 o C. In the nowadays piece of work we accept designed and developed an enhanced temperature command organization incorporating a combination of Pulse Width Modulation (PWM) and simple ON-OFF command system, where thermistors accept been used as temperature sensors. The range of variation of temperature against the ready temperature (37 o C) has been found to be 1 o C which is satisfactory. A temperature monitor has been designed through a circuit network incorporating a thermistor so that the voltage output is linearly related to the temperature. This immune the employ of a simple millivoltmeter to display the temperature direct through appropriate scaling. To ensure the condom of the infant an warning excursion was designed which provides audio alarms for personnel attending if the temperature goes beyond a specified safe range, chosen hither as 26 o C – 38 o C. In developing countries, like Bangladesh frequent power cuts need an uninterrupted operation of incubator and a battery back up system, which could too be powered past a solar panel, has been suggested for this purpose.

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DESIGN OF AN ENHANCED TEMPERATURE Command

Arrangement FOR NEONATAL INCUBATOR

Tamanna Afrin Tisa, Zinat Ara Nisha and Md. Adnan Kiber

Department of Applied Physics, Electronics & Communication Applied science

University of Dhaka, Dhaka, Bangladesh

email: tisa.afrin@yahoo.com, xinat.elahi.nisha@gmail.com, ma_kiber@yahoo.com

ABSTRACT: Worldwide every twelvemonth over four one thousand thousand infants dice within a month of nativity. Of this number, iii.9 million

vest to the developing world. Some (25%) of this deaths areastward acquired due to complications of prematurity, nearly

ofttimes due to improper heat regulation, water loss and neonatal jaundice. An babe incubator provides stable levels of

temperature, relative humidity and oxygenorthward concentration. Temperature control organisation is the most important function of a

infant incubator which has to be maintained effectually 37o C . In the present work we have designed and developed an

enhanced temperature control system incorporating a combination of Pulse Width Modulation (PWM) and simple

ON-OFF control system, where thermistors take been used every bit temperature sensors. The range of variation of

temperature against the set temperature (37oC) has existen found to be oneoC which is satisfactory. A temperature

monitor has been designed through a circuit network incorporating a thermistor so that the voltage output idue south linearly

related to the temperature. This allowednesday the use of a unproblematic millivoltmeter to display the temperature straight

through advisable scaling. To ensure the condom of the baby an alarm circuit wa south designed which provides audio

alarms for personnel attention if the temperature goes beyond a specified rubber range, chosen hither as 26o C – 38oC. In

developing countries, similar People's republic of bangladesh frequent power cuts demand an uninterrupted performance of incubator and a

battery back up system, which could also be powered by a solar console, has been suggested for this purpose.

Keywords: Premature infants, Incubator, Temperature control, Pulse Width Modulation (PWM), Temperature

indicator, Emergency alarm command.

i. INTRODUCTION

Every twelvemonth, about 1 meg infants in the developing world die due to prematurity complications [ane].

Premature infants are born before the organs are mature enough to allow normal postnatal survival. As the

premature infants are at risk to develop hypoxia, hypothermia and many other associated adverse

weather, they need special care and attending. One of the major troubles that newborns confront is

improper thermoregulation. The temperature inside the female parent's womb is 38 ⁰ C (100.4⁰F). Leaving thursdaye

warmth of the womb at birth, the wet new born finds itself in a much colder environment and

immediately starts losing heat. In the first x-xx minutes, the new built-in who is not thermally protected

may lose plenty heat for the body temperature to fall by two-4⁰C (3.vi-7.ii⁰F), with even greater falls in the

post-obit hours if proper intendance is not given [2,iii]. If heat loss is not prevented and is allowed to go on,

the baby will develop hypothermia and is at increased risk of developing wellness problems and of death.

Therefore an babe incubator is necessary which attempts to create the necessary environment for the

babe's survival [4 ]. This device may include an ac-powered heater, a fan to circulate the warmed air, a

container for water to add together humidity, a command valve for oxygen supply and admission ports for nursing care.

The first incubator was adult in 1857 named warmwännaen. In 1833, Pierre-Victor-Adolph

published an account of another incubator, developed by Etienne Stephane Tarnier for use of enormous

Paris Maternite named couveuse. In 1891 reports came of a new incubator design in France, designed by

Alexander Lion of Nice. Today developments are still constantly underway to try and create an ever more

womb like environment; controlling oxygen levels and other vital southystems, with an array of sensors,

monitors and alarms [v]. There are unlike types of incubator such adue south Open up box blazon incubator, Close

type incubator, Manually controlled incubator, Servo controlled incubator and Ship incubator [6].

Temperature regulation is of chief importance in an incubator. The present work therefore focuses on

the temperature control and simultaneous monitoring of an incubator. This also should have an alarm

system to indicate accidental situations of failure. For uninterrupted operations, a ability system based on

bombardment back up may beast used. For remote areas where mains electricity is not bachelor, a solar panel may

be used to provide necessary ability. This is an of import criterion that needs to be considecerise for

incubators in developing countriedue south like ours where frequent failure of mains supply is a regular feature.

ii. Blueprint and Development

The temperature of the infant incubator needs to be maintained at a constant level of 37oC. A temperature

indicator together with an alarm for accidental failures is too needed. This was the principal challenge of the

nowadays work. We commencement designed a simple ON-OFF temperature control system which did not announced to exist

satisfactory. Thereafter we designed and developed an enhanced temperature command organisation which had a

combination of a Pulse Width Modulation control and an ON-OFF temperature control system. The

functioning of this combined system was satisfactory. We have also designed a temperature indicator

using a elementary milli-voltmeter by linearizing the performance of thermistor in the range of temperature

30-twoscoreo C. This organisation also incorporates loftier temperature (38oC) and low temperature (25oC) alarm for

medical attention in the case of accidental failure of the temperature regulation organization.

two.one Design of Temperature Control Arrangement

If the temperature falls below the set value appropriate amount of rut free energy needs to be supplied in the

incubator to maintain the temperature at that level.

This can be done by a simple turn ON and OFF control system which volition turn ON the heater when the

temperature is below the set level and turn OFF otherwise.

Temperature command system is an of import integral part of a baby incubator. Southwardelection of an advisable

temperature sensor is important for effective control of temperature in the incubator. Comparison the

sensitivity and response time of available temperature sensors like thermistor, thermocouple, RTD in the

range of temperature 25-40oC along with accuracy, repeatability, term stability, linearity, self heating;

thermistor is the best choicdue east in this instance [7,viii].

2.ane.1 Blueprint of Uncomplicated ON-OFF Control System

Block diagram of a simple ON-OFF command excursion is given below in Fig. i.

Fig. 1: Block diagram of simple ON-OFF control circuit

To improve the temperature sensitivity of the system, the thermistor was placed in 1 arone thousand (R 4 ) of a

Wheatstone span, as shown in Fig.2, rather than in a voltage divider circuit. Firstly a balance is obtained

through adjustments of the resistors in the other arms (R i /R 3 = R2 /R 4 ) . The unbalanced output voltage of

the bridge as shown was used to give a measure of the temperature modify. It is well known that this

sensitivity is the greatest when Rfour is almost equal to Rii [9].

Fig. 2: Wheatstone bridge circuit.

Fig. 3 shows a graph of the resistance of a 4.7kΩ thermistor with temperature. It can be seen that the

resistance of the thermistor changes between 4.4KΩ-3.2KΩ in the range of temperature betwixt 31-twoscoreoC.

The average resistance in that range is 3.85KΩ. A resistor of this value is not practically bachelor so we

have used 4KΩ in the bridge excursion for R2 .

Fig. three: Resistance-Temperature

Feature of 4.7KΩ NTC

Thermistor.

The circuit and a graphical response for the Uncomplicated

ON-OFF control

organisation are given below in Fig. iv.

Fig. 4: (a) A Simple ON-OFF control circuit

(b) Temperature response graph

From Fig. iv(b) it isouth seen that during the heating bike (blue line), the heater was fully ON until the

temperature reached 38.5oC and during the cooling cycle (red line) the heater was not turned ON until the

temperature was 35.5oC. Ideally, it is expected that the heater should turn ON and OFF at the specified

temperature which is 37oC. The graph southhows that the range of temperature swing was iiioC which is not

satisfactory for an incubator. Therefore, we designed a modified temperature control organisation using a Pulse

Width Modulation (PWM) control system where we tin can command the duty cycle of the heater.

2.1.ii Design of a Temperature Control Arrangement using Pulse Width Modulation (PWM)

To construct a simple PWM command system nosotros accept used two integrated 555 timers as shown in Fig.5.

The correct hand part of the circuit in Fig.v is a monostable circuit whose timing is controlled by a

Thermistor and so that the pulse width decreases with temperature. The left manus part of the circuit in Fig.5 is

an astable circuit running at a frequency of 100Hz which triggers the monostable circuit to produce a train

of pulses whose width is modulated by temperature.

Fig. 5: Circuit diagram of avant-garde PWM control unit

Hither, the frequency of oscillation is =1

= 1.44

+2 … (3 )

To get a frequency of 100Hz the values of the resistances and capacitor were chosen as:

RA =10KΩ , RB =two.2KΩ and C= 1µF

The pulse width of the monostable circuit is given by,

= 1.1 where RT is the resistance of the

thermistor and CT is the timing capacitor of this circuit.

Therefore, the duty wheel of the PWM betoken is given by, TH / T … (4)

Fig. half-dozen: Duty cycle variation as a function of

temperature for PWM Control Unit

The duty cycle variation as a function of temperature for PWM Command Unit is shown in Fig.six. It tin be

seen that the duty cycle is about 37% at the set temperature of 37 . There will always be a finite non-

zero resistance of the thermistor. Therefore, the duty wheel cannot be made nada. This means that the

incubator will still continue to be heated further.

So, nosotros need another control system in addition to this PWM control to completely switch OFF the heater

at the ready temperature. The new advanced control arrangement which is a combination of PWM and simple

ON-OFF command system is described now.

ii.one.iii Blueprint of Combined Enhanced Temperature Control Organization

The block diagram of the combined enhanced temperature control system is shown in Fig.vii.

Fig.seven: Block diagram of the combined enhanced temperature control organisation

As long as the output of the Simple ON-OFF circuit is loftier the output of the AND gate follows the PWM.

And then, the duty bike of the heater or the amount of heat energy delivered is controlled by the output of the

PWM, tapering off to a low value near 37 . Westwardhen the temperature reaches the set up temperature the output

of the elementary ON-OFF command circuit becomes zero which forces the output of the AND gate to zero and

overrides the PWM. So, it finally shuts down the heater at the set temperature (37 ). However, the

temperature overshoots a little due to thermal inertia, but considering of the reduced heating earlier switching

off the overshoot is 1000uch less than that encountered in a simple ON-OFF system described before.

The complete circuit diagram of this combined avant-garde temperature control system is shown below in

Fi1000.8.

Fig. 8: Circuit diagram of a combined advance temperature control system.

Fig. 9: Temperature variation as a office of time for the combined control unit.

The performance of the combined ON-OFF & PWM temperature control system (enhanced system) is

shown in Fig.nine. Once the temperature reaches the set value information technology remains almost constant, varying within a

maximum and minimum of 37.5o C and 36.50C, giving a maximum range of variation of temperature of

1o C. This is a reasonable range from a practical signal of view.

2.2 Design of a Temperature Indicator

To monitor the temperature at the bed level of the incubator a temperature indicator wa southward designed using a

thermistor and the output displayed using a simple milli-voltmeter. This demands the resistance-

temperature characteristics to be linear only unfortunately the response of a thermistor is nonlinear. 1

arroyo to brand the response of a thermistor linear is simply shunting it with a stock-still resistor [8, 9]. The

principal disadvantage to this technique is that linearization can only be achieved inside a narrow range. A

uncomplicated analysis based on parallel combination of resistors led to value of nearly 840 Ω for the fixed

resistance. The practical response is shown in Fig. 10.

Fig. ten: Linearization of NTC Thermistor using 840Ω as a Shunt Resistor.

The circuit developed and the response for the temperature indication are shown in Fig.11.

Fig. eleven: (a) Circuit diagram for the temperature indicator. (b) Response graph

From the graph of the temperature indicator shown in Fig. 11(b) it tin beastward seen that an actual temperature

of 37oC is indicated as 37.2oC which is adequate for this awarding.

2.3 Pattern of an Alarm Control System

An alert excursion is safety measure to ensure the safety of the baby, by calling the attention of medical

personnel, whenever the system fails, or crossed the set limits.

Here, we have designed an alarm control excursion which will provide loftier temperature indication when the

temperature of the incubator exceeds 38⁰C, and likewise provides low temperature indication when

temperature of incubator is below 25⁰C and in both case it will produce loud sound from the speaker for

medical attending.

The complete circuit diagram of

designed alarm control system is

shown in Fig.12.

Fig. 12: Circuit diagram of

designed alarm command system

To sense the high temperature we

have used a iii.6V zener diode for

reference while for the low

temperature we have used a v.5V

zener diode. This alarm command

unit practically gave indication

when the temperature increased

beyond 38.5⁰C or vicious beneath

26⁰ C, producing a loud sound

from the speaker for medical

attention.

For uninterrupted supply a bombardment

based power system tin can be used.

A solar panel may be used to accuse the bombardment.

3. Discussion

An incubator plays a vital role in saving premature babies. One of the main functions of infant incubator

is temperature control which is required to achieve thermo-neutrality in infant's body. To serve this

purpose nosotros have designed a simple ON-OFF control circuit which will maintain the temperature of the

incubator at a desired level (370C). But at that place is a iii 0C swing in temperature range against the set value.

This could be due to the fact that, information technology takes time for the distribution of heat free energy from the heater to the

environment and thither is a lag of response time for the temperature sensor to respond to the change in

temperature. To overcome this problem an enhanced regulation system was developed based on a

combination of a PWM circuit and an ON-OFF circuitry. The PWM circuit tapers off the energy supplied

to heat the incubator as the temperature rises to 37oC. This reduces the thermal inertia when the heating

circuit is then switched off. The temperature increased by only 0.fiveoC, i.e., to 37.5 oC which is an

acceptable value. While the incubator cooled off, the heater switched on again at 36.fiveoC. Thus using the

enhanced control system, the temperature swing was only one0C, which is satisfactory and acceptable for a

neonatal incubator.

The linearization excursion fabricated for the thermistor gave a satisfactory performance as can be seen through

the measured values in the graphs. The linearity was skillful for the temperature range of xxx 0 C-400 C which

is acceptable for this awarding too. This allowed monitoring of the temperature directly using a simple

millivoltmeter through appropriate voltage adjustment. The alert circuit designed worked satisfactorily

too. This produced a loud sound alarm to depict the attending of medical attendants if the temperature went

above 380C or went below 260 C.

Audio

generator

and

speaker

In developing countries like ours frequent power cutting occurs, it needs to be add togetherressed for continuous

operation of the incubator. A bombardment dorsum up has been suggested to operate the incubator under such

situations. A solar console may also exist used to provide the necessary power. Thus the present work paves

the way to design and develop a complete incubator that could salve lives in rural areas of developing

countries like Bangladesh.

REFERENCES

1. World Wellness Report 1998; Life in the 21st century: A vision for all

2. " Thermoregulation", Thermolugation_final_5.4.98.pdf

3. World Wellness Organization, Maternal or newborn health/ Safe motherhood unit, Segmentation of

reproductive health (Technical Back up) "Thermal Protection of newborn: a applied guide",

Geneva, (Twelvemonth??)

4. Guler* and M. Burunkaya, "Humidity control of an incubator using the microcontroller-based

active humidifier system employing an ultrasonic nebulizer" , J of Medical Engineering &

Technology, Vol. 26, No.ii, 2002, p.82– 88.

5. Katie Proctor, "Transferring the incubator: Fairs and freaks shows as agents of alter", 2004.

www.people.cornell.edu/pages/ked42/Infant_Sideshow_Paper.pdf. (WHO/RHT/MSM/1997, 2nd

Ed).

6. Emergency Care Research Institute (ECRI), "Healthcare Product Comparing System – Infant

Incubators", February 2003, www.ecri.org.

7. Albert D. Helfrick & William D. Cooper, Modern Electronics Instrumentation and Measurement

Techniques. P.337-370.

8. B.L.Theraja, Basic Electronics Solid Land. P. 564-575.

nine. <r esearch.cs.tamu.edu/prism/lectures/iss/iss-l4.pdf>

... To overcome this problem, a medical equipment is required that can supersede the function of womb which has like condition with mother's womb. he temperature, humidity, oxygen, and the light level for developing the baby's low body weight is crucial. It is not only the infant's temperature, humidity, and dissonance factors that must be considered, only also other issues that can interfere the baby health such as; factor of peel contact among the family members directly too contribute to crusade a affliction for the infant, because baby pare is still more sensitive, and it potentially volition be infected [5]. ...

... About of the previous research [5][6][7][8][nine][10][xi] just controls and monitors temperature and monitors humidity. This study will develop previous research by including monitoring the level of racket in the bedchamber incubator. ...

... More often than not, optimal thermal conditions are achieved when infant's temperature remains in the range between 36.8°C -37.2 °C (Miller and T.Thou.O, 1966;Phillippe Chessex and Jean, 1988) and both oxygen consumption (heat product) and insensible water losses (estrus loss) are at minimum levels (Tisa, Nisha and Kiber, 2012;Hey and Katz, 1970). The radiant warmers and incubators are used to maintain optimal temperature of preterm babies. ...

... Mathew et al. [half dozen] described the design and implementation of a fully digital and programmable temperature system for the Babe Incubator. The transmitter circuits were also designed and implemented for all the variables of the incubator that are used every bit command signals like the air temperature sensor (thermistor), baby pare temperature sensor (probe) [7]- [8]. ...

This system used to monitor and control the sudden alter in temperature in neonatal incubator depending on two parts: commencement is the microcontroller which is a compact integrated circuit designed to run a specific functioning in an embedded organisation, and LabVIEW which is engineering software used for applications that crave examination, measurement, and control with rapid access to hardware and data insights. those 2 of import parts along with other components (heaters, fans, information acquisition cards) will be used to design the desired system. This system has the backdrop of being cheap, easy to use, able to deal with many units as possible at the same time and finally can be operated automatically or by one person. this organization will give a temporary solution for a flow of time till the responsible person would fix the primary problem.

... Information technology is well know [5], [6], [7] that newborn temperature levels have to be kept within the range of 36.5 and 37.5 • C. Thus, the algorithm developed has to consider this upper and lower temperature limits. Every bit shown in the Algorithm 1, the Arduino uno will turn on the heating resistor and likewise the fan of the heating in order to elevate the temperature of the incubator's baby expanse if this falls below 36.five • C (which is detected by the DHT11 sensor). ...

  • Abd Kholiq
  • Lamidi Lamidi

Premature babies who are born alive before 37th calendar week of gestation or babies built-in with weight criteria of less than 2500 grams demand to exist treated in an infant incubator because they are very susceptible to viruses in open spaces and will provide protection to newborns by providing premature babies stable temperature and humidity. Stable temperature regulation is needed to preclude hypothermia or hyperthermia that will occur in premature babies. Care of the baby in an infant incubator causes the separation of mother and baby. Mothers who have premature babies are found to lack trust in caring for their babies compared to mothers who have term babies. The purpose of this study was to analysis of temperature on baby incubator command system. In club to get a stable and precise temperature, the temperature sensor is positioned according to the standard of the baby incubator at the hospital. This inquiry uses LM35 and DS18B20 temperature sensors which will be processed using Atmega 328 Microcontroller and volition be displayed on a PC (personal calculator). Based on the measurement results obtained an average value of min difference for sensor readings on the LM35 has the largest value of 0.22°C and the boilerplate max value difference has the largest value of 0.38°C and the average value of the min difference for the sensor readings on the LM35 has a value the largest is 0.39°C and the average departure in the value of max has the largest value that is 0.55°C. Information technology can be concluded that the LM35 sensor is meliorate than the DS18B20 sensor because it has smaller oscillations and also good accuracy. The results of this report can exist implemented in baby incubators in accordance with established standards and tin can exist produced at affordable prices in the domestic market.

The Earth health Organization estimates that most 8 one thousand thousand babies die prematurely worldwide. Almost of these cases are found in low-income countries (LICs). The use of neonatal incubators has proven to be very useful in the reduction of baby mortality. All the same, access to this important medical device is not always easy in LICs. This article presents the implementation of a multi-function neonatal incubator with remote monitoring, fingerprint scanner, phototherapy, and heart charge per unit monitoring. In this view, proportional integral (PI) control algorithm and an Android application were developed. Furthermore, an initial social affect of the implemented neonatal incubator usage was performed in some hospitals in Republic of cameroon.

This paper aims to develop an automatic neonatal incubator equipped with phototherapy, biometric fingerprint reader, remote monitoring and heart rate control modules for developing countries due to the lack of neonatal incubators. The proposed device consists of an conquering module that senses temperatures (of the enclosure and the baby) and humidity, a biometric fingerprint reader to identify the user, a remote monitoring module in charge of supervising the temperature and the center charge per unit of the baby, a video surveillance module which allows filming and transmitting the images to the web server in order to give parents and nurses the possibility of being able to visualize whatsoever their location the newborn infant, a phototherapy module used to treat newborn jaundice by lowering the bilirubin levels in the babe's blood, a digital control module from a pulse width modulation (PWM) bespeak generated past a microcontroller of Arduino Nano blazon for system operation monitoring, and a human machine interface module for setting parameters. The equations describing the energy balance and estrus transfer for newborn baby (Ostrowski and Rojczyk, 2018) are taken into account for the implementation of power supply and the choice of the heating resistor. The desired temperature of 37 °C was obtained after but a few minutes within the incubator.

Relative humidity levels of an incubator were measured and controlled. An ultrasonic nebulizer organisation equally an active humidifier was used to humidify the incubator environment. An integrated circuit-type humidity sensor was used to measure the humidity level of the incubator environment. Measurement and command processes were achieved past a PIC microcontroller. The high-performance and high-speed PIC provided the flexibility of the system. The developed arrangement tin be used effectively for the intensive care of newborns and/or premature babies. Since the humidifier generates an droplets in ambience conditions, it is possible to provide the high relative humidity level for therapeutic and diagnostic purposes in medicine.

  • Robert G. Breckenridge

The detailed study of thing in the solid state has become i of the most active fields of modernistic physics. Solid state electronics, including the study of semiconductors, was greatly stimulated by the wartime development of crystal diodes, which were extensively used in radar and are at present finding numerous applications in electronic components. The recent discovery of the transistor, a crystal triode which may exist used equally a replacement for vacuum tubes in amplifiers, has intensified interest in the subject. Although the semiconductor has been used in several practical applications, physical interpretation of the semiconducting phenomena is far from complete. For this reason, the major current objective of the solid state physics program at the National Bureau of Standards concerns the fundamental study of semiconducting systems. Some closely related bug of crystal properties are likewise beingness investigated in society to obtain the knowledge necessary for the maximum utilization of these and other new materials in electronic components. Recent developments in semiconductor physics, especially the discovery of the transistor (See William Shockley&apos;s article, Holes and Electrons, in the October, 1950, issue of Physics Today), have greatly stimulated the entire field of solid country electronics. The present article reviews recent piece of work in this subject area at the National Agency of Standards.

Life in the 21st century: A vision for all two

World Health Written report 1998; Life in the 21st century: A vision for all 2. " Thermoregulation", Thermolugation_final_5.four.98.pdf

Healthcare Product Comparison Organization – Baby Incubators

Emergency Care Research Constitute (ECRI), " Healthcare Production Comparison System – Infant Incubators ", February 2003, www.ecri.org.