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PSZ 19:16 (Pind. 1/07)

DECLARATION OF THESIS / UNDERGRADUATE PROJECT PAPER AND

COPYRIGHT

Authors full name : NURUL ATIKAH BINTI ABD GHANI

Date of birth : 16TH DECEMBER 1988

Title : BILIRUBIN LEVEL DETECTOR USING LABVIEW FOR JAUNDICE

TREATMENT

Academic Session : 2012/2013

I declare that this thesis is classified as :

I acknowledged that Universiti Teknologi Malaysia reserves the right as follows:

1. The thesis is the property of Universiti Teknologi Malaysia.

2. The Library of Universiti Teknologi Malaysia has the right to make copies

for the purpose of research only.

3. The Library has the right to make copies of the thesis for academic

exchange.

Certified by

SIGNATURE SIGNATURE OF SUPERVISOR

881216-05-5020 PUAN MITRA BINTI MOHD ADDI

(NEW IC NO. /PASSPORT NO.) NAME OF SUPERVISOR

Date : 25th JUNE 2013 Date : 25th JUNE 2012

CONFIDENTIAL (Contains confidential information under the

Official Secret Act 1972)*

RESTRICTED (Contains restricted information as specified by the organization where research was done)*

OPEN ACCESS I agree that my thesis to be published as online

open access (full text)

I hereby declare that I have read this thesis and in my

opinion this thesis is sufficient in terms of scope and quality for the

award of the degree of Bachelor of Engineering

(Electrical-Medical Electronic Engineering)

Signature :

Name of Supervisor : PUAN MITRA BINTI MOHD ADDI

Date : 25th

JUNE 2013

BILIRUBIN LEVEL DETECTOR USING LABVIEW FOR JAUNDICE

TREATMENT

NURUL ATIKAH BINTI ABD GHANI

A report submitted in partial fulfillment of the

requirements for the award of the degree of

Bachelor of Engineering

(Electrical-Medical Electronic Engineering)

Faculty of Electrical Engineering

Universiti Teknologi Malaysia

JUNE 2013

ii

I declare that this report entitled Bilirubin Level Detector Using Labview For

Jaundice Treatment is the results of my own research except as cited in the

references. The report has not been accepted for any degree and is not currently

submitted in candidature of any other degree.

Signature : .

Name : NURUL ATIKAH BINTI ABD GHANI

Date : 25th

JUNE 2013

iii

Blessing and peace be upon Prophet Muhammad S.A.W

This thesis is special dedicated to my beloved ibu and ayah

iv

ACKNOWLEDGMENT

Alhamdulillah. Thanks to Allah S.W.T for His blessing that has given me a

good health and strength and the opportunity to complete my final year project along

with the thesis. Throughout the journey from the beginning until my final war, I have

been through sweet and bitter memories to be remembered. But of course I am not

facing this war alone by myself because I have people who have always supported

me from behind.

First of all I would like to express my special thanks to my supervisor, Puan

Mitra Mohd Addi. Thank you for the supervision, support, guidance and

encouragement that really helped me a lot in my journey to complete my final year

project.

My great appreciation is dedicated to all my friends especially to all SEPs,

thanks for the support and friendship. My deepest gratitude to my ibu and ayah and

also my kakaks and abang for their endless love, advice, and encouragement

throughout my final year project.

Not to forget to my rowing team, thank you for being my second family in

UTM, whoever supported me directly or indirectly, may ALLAH bless all of you.

Thank you.

v

ABSTRACT

Phototherapy is a form of treatment for skin conditions using light and

commonly used to treat jaundice. Common light source used in phototherapy

devices include fluorescent lamp, halogen lamp, fiberoptic system and also LEDs.

Blue LEDs have been used as one of the light sources in phototherapy devices for

jaundice treatment. This is due to its unique characteristics which includes emission

of high intensity narrow band of blue light, power efficient, light in weight, less

heat production, low in cost and a longer lifetime. Previously, the Automated

Phototherapy Vest (APV) for infants was designed as an alternative device to

reduce bilirubin level jaundice babies. A bilirubin level detector is designed to

measure bilirubin level and several experiment were conducted to compare the

efficiency of blue LEDs in reducing bilirubin level in infants compared to

fluorescent light.

vi

ABSTRAK

Fototerapi adalah merupakan perubatan untuk keadaan kulit

menggunakan cahaya dan kebiasaannya digunakan untuk mengubati jaundis. Cahaya

yang biasa digunakan pada mesin fototerapi termasuk lampu kalimantang, lampu

halogen, system fiberoptik dan juga LED. LED biru telah digunakan sebagai salah

satu daripada punca cahaya dalam mesin fototerapi untuk mengubati jaundis. Ini

berikutan cirri-cirinya yang unik yang mana termasuklah pancaran intensiti yang

tinggi pada cahaya biru, kuasa yang efisien, ringan, penghasilan haba yang kurang,

murah dan mempunyai jangka hayat yang panjang. Sebelum ini, Automated

Phototherapy Vest (APV) untuk bayi telah direka sebagai satu langkah alternative

untuk mengurangkan paras bilirubin pada bayi jaundis,Pengesan paras bilirubin

direka untuk mengukur paras bilirubin dan beberapa eksperimen dijalankan untuk

membandingkan kecekapan LED biru dalam mengurangkan paras bilirubin pada bayi

berbanding dengan lampu kalimantang.

vii

TABLE OF CONTENTS

CHAPTER TITLE PAGE

DECLARATION

ii

DEDICATION

iii

ACKNOWLEDGEMENT

iv

ABSTRACT

v

ABSTRAK

vi

TABLE OF CONTENT

vii

LIST OF TABLES

x

LIST OF FIGURES

xi

LIST OF ABBREVIATION

xiii

LIST OF APPENDICES

xiv

1 INTRODUCTION

1.1 Background of study

1.2 Problem statement

1.3 Objectives

1.4 Scope

1.5 Thesis overview

1

1

3

3

4

4

viii

2 LITERATURE REVIEW

2.1 Hyperbilirubinemia (Jaundice)

2.2 Bilirubin

2.2.1 Metabolism

2.2.2 Measuring tools & devices

2.3 Phototherapy

2.3.1 Light sources of phototherapy devices

2.3.2 Efficacy of phototherapy lights

2.4 Phototherapy treatment in vitro and in vivo

research studies

2.5 Automated Phototherapy Vest (APV)

6

6

7

8

11

12

16

19

24

3

METHODOLOGY

3.1 Project Overview

3.2 Experimental Preparation

3.2.1 Bilirubin Solution Preparation and Detection

using Spectrophotometer

3.2.1.1 Spectrophotometer Wavelength

Determination

3.3.1.2 Bilirubin Calibration Curve

3.2.2 Light Exposure

3.2.2.1 Blue LEDs

3.2.2.2 LEDs Arrangement and Design

Considerations

3.2.2.3 Fluorescent Light

3.3 Software Development

3.3.1 Importing Data into LabView from

Spectrophotometer

3.3.2 Bilirubin Reading using LabView

3.4 Flow Chart

26

27

28

30

31

32

32

33

35

36

36

39

40

4 RESULT AND DISCUSSION

4.1 Determination of Optimum Wavelength

4.2 Relationship between Absorbance and Bilirubin

Concentration

42

43

ix

4.3 Bilirubin Degradation Experiment A

Comparison between Different Light Sources

4.3.1 LEDs Circuit Design

4.3.2 Bilirubin Degradation Experiments

4.4 Bilirubin Level Detector using LabView

4.5 Discussion

4.5.1 Interference during Experiments

45

45

46

48

50

51

5 CONCLUSION AND RECOMMENDATIONS

5.1 Conclusions

5.2 Recommendation for future work

52

53

REFERENCES 54

APPENDICES 56

x

LIST OF TABLES

TABLE NO. TITLE PAGE

2.1 Comparison of phototherapy devices 15

2.2 Practice consideration for optimal administrative of

phototherapy

18

3.1 Different bilirubin concentration 29

4.1 Wavelength determination 43

4.2 Relationship between absorbance and bilirubin

concentration 44

4.3 Results for the light exposure experiment 47

4.4 Comparison of both light sources 47

xi

LIST OF FIGURES

FIGURE

NO.

TITLE PAGE

2.1 Bilirubin metabolism 7

2.2 Babys blood sample taken from the heel 9

2.3 Urine strip reagent 9

2.4 Bilirubin level measurement using bilirubinometer 10

2.5 Visible range of lights 11

2.6 Fluorescent tube in Olympib BiliLite 12

2.7 Halogen spotlight 13

2.8 BiliSoft LED 14

2.9 Natus neoBLUE LED 14

2.10 Important factors in the efficacy of phototherapy 17

2.11 Comparison of both in vitro and in vivo efficacy of

bilirubin degradation between the blue LED and

conventional phototherapy unit

19

2.12 Efficacy comparison between LEDs 20

2.13 Comparison of efficacy between different light sources 21

2.14 Comparison of in vitro efficacy of existing

phototherapy device 22

2.15 Absorbance spectrum of light exposure 23

2.16 Bilirubin degradation percentage using sunlight and

conventional phototherapy 23

2.17 APV Full set-up 24

3.1 Block diagram of the project 26

3.2 Absorbance determination 29

3.3 Absorbance color chart 30

3.4 Example of calibration curve 31

3.5 Blue LED 33

3.6 AAP guidelines for all gestational ages 34

xii

3.7 Fluorescent tube 35

3.8 Block diagram 36

3.9 (a) Input port detection

(b) Read input data 37

3.10 Output data from spectrophotometer 37

3.11 Elimination process 38

3.12 Result after elimination process 38

3.13 Bilirubin level detection 39

3.14 Spectrophotometer sample racks 40

3.15 Flowchart of the experiment 41

4.1 Preparation of different bilirubin concentrations 43

4.2 Calibration curve of absorbance vs concentration for

bilirubin solution 44

4.3 LEDs circuit 45

4.4 Bilirubin degradation experiments 46

4.5 Comparison of bilirubin degradation in blue LED and

fluorescent light (in percentage difference) 48

4.6 User interface of bilirubin level detector 49

4.7 Exporting data into Excel 50

xiii

LIST OF SYMBOLS & ABBREVIATION

LabVIEW Laboratory Virtual Instrumentation Engineering Workbench

AAP American Academy of Pediatric

APV Automated Phototherapy Vest

LED Light-emitting diode

BSA Body Surface Area

nm nanometer

W/cm2/nm microwatt per centimeter square per nanometer

cm2

Centimeter square

mg/dL Milligram per deciliter

mol/L Micromol per liter

DC Direct Current

xiv

LIST OF APPENDICES

APPENDIX

NO.

TITLE PAGE

A UV-Visible Spectrophotometer 56

B RS 232 Port Line 59

C Completed Block Diagram 61

D LabView User Interface for Blirubin Level

Detection Using LabView for Jaundice Treatment 62

CHAPTER 1

INTRODUCTION

1.1 Background of Study

Jaundice or hyperbilirubinemia is the yellow discoloration of the skin, sclera

(white of the eyes) and other tissues due to excessive bilirubin in the blood. It is

common disease in newborn infants, where 60% of term and 80% of preterm

neonates develop jaundice in the first week of life. It was also found that at one

month of age, these newborns are still jaundiced for 10% of breastfeed babies [1].

Most of the infant happened to have some mild jaundice and the condition.

Normally, most infants happened to have a mild jaundice which is temporary and

not too dangerous. However, these infants must be monitored closely as it can

cause the development of a more serious condition for the baby such as kernicterus.

Kernicterus happens due to excessive jaundice which can cause damage to the

infantss brain [2]. The condition can also cause loss of hearing, late development

in growth and yellow staining of the basal ganglio which can lead a baby to death

[1].

Bilirubin is actually a normal part of the red blood cells. When the body

breaks down the red blood cells, the old red blood cells will be removed by the liver

from the system. Extra bilirubin will then be stored in the skin and when this

2

happens, it causes the babys skin to become yellow. A normal infant should have a

bilirubin level of less than 35mol/L or 2mg/dL [2]. When the bilirubin reading is

more than the normal reading, treatment is required to reduce the bilirubin level.

In the early 1950s, sunlight was recognized as a treatment to reduce

jaundice in infants. The treatment was found by a nurse in England who observed

that jaundiced infants became less yellow after a certain period of exposure under

the sun [3]. The observation has led the future researchers to conduct an experiment

using blue fluorescent tubes as light sources to treat jaundice. The result showed

that bilirubin level in infants declined when they were exposed to the blue

fluorescent tubes, which led to the introduction of phototherapy.

Until now, phototherapy has been widely used as a jaundice treatment for

more than four decades [4]. Design of devices had been developing throughout the

years, with the aim of reducing bilirubin level efficiently at shorter exposure

duration. The available light sources used in phototherapy devices include

fluorescent tubes, halogen spotlights, fiberoptic systems and LEDs. There are

advantages and disadvantages of using these light sources depending on their own

specifications and requirement. There are several factors that determine the

efficiency of these phototherapy lights; spectral qualities, irradiance (light

intensity), exposed body surface area, duration of exposure, skin thickness and

pigmentation, and the amount of bilirubin degradation [5]. Suitable wavelength

used is 400nm to 520nm 2ith a peak of 460 10nm, which is in the range of blue

spectrum [5]. Bilirubin is found to be more sensitive to blue and blue-green regions

of the visible spectrum as it is closer to the bilirubin absorbance spectrum [6].

3

1.2 Problem Statement

Phototherapy treatments are commonly conducted in hospitals which may

taje several days. Most hospitals have sufficient numbers of phototherapy devices

to treat jaundice patients. However, in some developing countries and third-world

countries, there are limited numbers of these devices which may cause a longer

waiting period between patients. Due to this condition, a portable phototherapy

device was introduced to make phototherapy treatment available everywhere.

A design of an Automated Phototherapy Vest (APV) was proposed as an

alternative device to help reduce bilirubin level in infants. The APV which used UV

LEDs as the light source was found to be low in cost. This is a positive indicator

that it may be affordable to be used by patients in rural areas, especially those in the

third-world countries. However, there were several limitations of the current APV

which includes uneven LED brightness.

Thus, the type of LED was changed to blue LED as previous researches has

found that it is he most efficient in reducing bilirubin level of infants with jaundice.

However, the efficiency of the blue LEDs to be used on the APV are yet to be

proved.

1.3 Objectives

The main objective of this project is to verify that blue LEDs that are to be

used on the Automated Phototherapy Vest is able to reduce bilirubin level

effectively compared to other conventional phototherapy light sources. in vitro

experiments using bilirubin solution will be conducted to verify this. A bilirubin

4

level detector will also be designed using LabView as a measuring instrument for

the in vitro experiments.

1.4 Scope

The scope of this project includes:

Preparing bilirubin solution in accurate measurement

Developing a calibration curve which explains the relationship between

absorbance and concentration of bilirubin level in bilirubin solution.

Conducting in vitro experiments using bilirubin solution which are exposed

to blue LED and fluorescent lights.

Designing a user interface to analyze bilirubin degradation of bilirubin

samples and displaying the result in LabView

1.5 Thesis Overview

The thesis is organized into five main chapters.

Chapter 1 briefly explains the overview of the project, problem statements,

objectives and also scopes of the project.

5

Chapter 2 discusses about the basic concept of jaundice, bilirubin

mechanism, jaundice treatment and bilirubin measuring tools. The literauter review

discuss on this chapter are based on previous studies conducted by researchers that

covers the comparison between the efficiency of LED with other light sources used

in jaundice treatment.

Chapter 3 focuses on the methodology used in the project which explains on

the sequence of the experiment conducted and also description of the software and

hardware used in the project.

Results and analysis of the experiments are discussed in Chapter 4. The

overall functions of the bilirubin level detector are also explained in this chapter.

The last chapter provides a conclusion from the in vitro experiments

including future work and recommendations of the project.

CHAPTER 2

LITERATURE REVIEW

2.1 Hyperbilirubinemia (Jaundice)

Hyperbilirubinemia or jaundice is a common disease encountered by

infants. Over 60% of newborn develop jaundice by 48 to 72 hours of age in the

early weeks of birth [7]. Jaundice happens when the amount of bilirubin in blood is

higher than the normal rate which is less than 2mg/dL. Hight bilirubin level in

blood causes a yellowing discoloration effect which is mostly noticeable on the skin

and whites of the eyes. Early stage of jaundice, termed as physiological jaundice is

generally harmless [1]. However, the condition may get serious and worsen infants

health. Prolong jaundice develop kercniterus which is a disease that cause brain

damage when bilirubin is spread to the brain. infants may also loss their hearing,

delay in growth development, suffer sequalae like athetoid cerebral palsy, paralysis

of ipward gaze and dental dysplasia [8]. Traditionally, sunlight used as a jaundice

treatment to cure jaundice infants. Infants will be exposed to sunlight everyday for

about 20 to 30 minutes and bilirubin were monitored once is complete. Since

sunlight can be hazardous to infants, phototherapy technology has been improved to

make the treatment easier and faster.

7

2.2 Bilirubin

2.2.1 Metabolism

Figure 2.1: Bilirubin metabolism

Bilirubin is a part of the red blood cells. For an adult, the life span of the red

blood cells is 120 days and will be excreted through urine or stool after that period.

As the red blood cells breakdown, the hemoglobin will degrade into globin and

heme. The heme molecule will break apart and convert into bilirubin, an orange-

yellow pigment. The process occurs in the reticuloendothelial cells which include the

liver, spleen and bone marrow. Bilirubin starts out as unconjugated bilirubin which is

not water soluble. The unconjugated bilirubin reacts with glucoric acid once it is

transported to the liver. After biochemical alteration in the liver, the unconjugated

bilirubin becomes conjugated bilirubin which is more soluble. It is then excreted into

the bile and goes through the gall bladder into the gut. At this stage, there is a variety

of pigments created when the bilirubin changes. 80% of the pigments which are

called stercobilin will be excreted in the feces and the other 20% called uribilinogen

8

will be reabsorbed to the liver and back into the blood. About 90% of uribilinogen in

the liver will be re-excreted into the bile and the other 10% goes into the blood to be

transported to the kidneys.

Compared to an adult, the liver of a newborn baby is immature and is not able

to remove extra bilirubin efficiently. Besides that, their red blood cells have a shorter

life span compared to an adult [1]. This is because the quantity of unconjugated

bilirubin to be converted into conjugated bilirubin has exceeds the capacity of the

liver [9]. When this happens, the bilirubin is stored in the skin giving it a yellow

discoloration which is known as jaundice. Besides that, incompatibility between

motjers and infants blood group may also lead to the development of jaundice.

Furthermore, infants of diabetic mothers, premature infants and also infants who a

born with a lot of bruising to their scalp or face may also have a high risk of getting

jaundice [10, 11].

2.2.2 Measurement Tools & Devices

Bilirubin measurement tools and devices are used to measure the level of

bilirubin in infants blood to evaluate the liver function. These tools and devices

utilized to diagnose the circulation level of bilirubin of the infants liver whether it is

normal or abnormal and to determine if jaundice is still present [12]. It helps doctor

to diagnose jaundiced infants whether on-going phototherapy treatment is needed.

Bilirubin measurements can be conducted in two ways, invasive or non-invasive. It

includes blood test, urine test and also bilirubinometer.

9

a) Blood Test

Figure 2.2: Blood sample taken from an infant's heel

Blood test is the most common method used in hospitals to measure bilirubin

level. Blood sample is taken from the infant by puncturing the heels with a small

needle rather than from their veins. This is because an infants vein is very small and

it can be easily damaged. The blood sample is taken to the laboratory for diagnoses.

However, this method is invasive, painful, costly and may be risk the infants to

infection. Moreover, it can cause significant blood loss which is a concern in preterm

infants when repeated blood sampling is conducted [13].

b) Urine Test

Figure 2.3: Urine strip reagent

10

The procedure is done by dipping the reagent strip into the urine sample and

removing it immediately to avoid dissolving of the reagent pads. The color change

on the reagent strip is compared to the corresponding color chart on the bottle label.

How ever, the result from this measurement method is unreliable due to color

interference and interpretation. Sample of urine should not be exposed to light since

bilirubin is very sensitive to light and will lead to inaccurate test results.

c) Transcutaneous Bilirubinometry

Figure 2.4: Bilirubin level measurement using bilirubinometer [14]

The latest technology in bilirubin measurement is transcutaneous

bilirubinometry. It is preferable as it is a non-invasive method and is able to provide

accurate measurements instantaneously. It works by directing the light into the skin

and measureing the intensity of specific wavelength that is reflected from the

newborns tissues. These optical signals are converted into electrical signal by a

photocell. The signal are analyzed by a microprocessor to generate a serum bilirubin

value in mol/L or mg/dL [14]. The commonly used site to measure bilirubin level is

on the forehead and upper end of sternum.

11

2.3 Phototherapy

In the early 1950s, a nurse, Jean Ward from Rochford General Hospital in

Essex, England had recognized that when jaundiced infants were exposed to the sun

they become less yellow. The observation has led a pediatric resident, R.J. Cremer to

conduct an experiment. The first experiment was to expose the naked infants to

direct sunlight alternating with shades for 15 to 20 minutes. The experiment resulted

in the decreasing of bilirubin level. This further led Cremer and his team to design a

phototherapy apparatus using blue fluorescent tubes. The lamps emitted light in a

spectral range of 420nm 480nm and the treatment was given interrupted

intermittently [15]. Bilirubin level was found to drop using these blue fluorescent

tubes and this is how phototherapy was first introduced. The findings had led many

more researchers to conduct research on different phototherapy treatment [3].

Figure 2.5: Visible range of lights

12

2.3.1 Light Sources for Phototherapy Devices

Phototherapy is a form of treatment for jaundice. There are several

phototherapy devices that are available to be used for jaundice treatment includes

Olympic BiliLIte, BiliSoft LED and etc. Each of these light sources has their own

specifications, advantages, disadvantages and usage requirement [11].

a) Fluorescent Tubes

Figure 2.6: Fluorescent tubes in Olympic BiliLite [16]

Fluorescent tube is the commonly used light source in phototherapy as it is

available in most hospitals. Figure 6 displays a phototherapy unit by Olympic

BiliLite that uses special blue fluorescent tubes as the light source. The standard

distance for light exposure is 40cm which is able to deliver an irradiance of

11W/cm2/nm while for special blue tubes it can deliver the irradiance up to

24W/cm2/nm but at the distance of 14cm [5]. Even though fluorescent tubes are

inexpensive and can be easily get, its light intensity reduces with time and need to be

replaced after every 1,000 to 2,000 hours of usage [6].

13

a) Halogen spotlights

Figure 2.7: Halogen Spotlight

The examples of phototherapy unit that used halogen spotlight is Ohmeda

BiliBlanket Plus, Datex-Ohmeda Spot Phototherapy Lamp and Hill-Rom Microlight

Phototherapy. Ohmeda BiliBlanket Plus can be applied directly to neonates because

there is no heat produced whereas the other two phototherapy units must be placed

about 50cm from neonates. Halogen spotlight is able to provide fairly high irradiance

exceeding 20W/cm2/nm [5]. This light source should not be applied too closely and

borne in mind when used for treatment because it tend to generate considerable heat

that will cause thermal injury to infant [5, 6]. It is also must be properly shielded

because it can emit ultraviolet radiation and some other clinical responses.

b) Fiberoptic System

Fiberoptic system has been intoduced for jaundiced treatment since late

1980s that consist of a light that delivered to halogen bulb from a tungsten through a

fiberoptic cable and emitted from the sides and end of the fibers inside a plastic pad

[3]. It can be used directly to the infants and can deliver the irradiance up to

35W/cm2/nm and able to determines the uniformity of light emission. Fiberoptic

14

system has an advantages over conventional phototherapy since it does not need an

eye patches for covering infants eyes and infant can be held during the phototherapy

treatment [5]. However, this phototherapy can only cover small body surface area

and it led to decreasing the spectral power of fiberoptic systems. Figure 2.8 shows

the example of fiberoptic system.

Figure 2.8: BiliSoft LED

c) LEDs

Figure 2.9: Natus neoBLUE LED, courtesy of Natus Medical Incorporated

The latest technology phototherapy devices using high intensity blue LEDs

that has many advantages over the other conventional light sources. It has been used

15

as the prototype of phototherapy devices since 1990s [6]. Blue LED has been widely

used nowadays in medical devices because of its unique characteristics. LED

produce less heat so it can be use directly to infants without cause any injury and it

can deliver output energy up to 100W/cm2/nm [11]. LED have longer lifetime

which it can be used for more than 20,000 hours, emit high intensity (250mW/cm2)

with narrow-band light in the spectrum (470 60nm or 470 15nm FWHM)[5] and

it resulting in shorter treatment times [4]. Besides that, it is also power efficient, low

in cost, light in weight, low energy requirement and emit little infrared with no

ultraviolet radiation [4, 5, 17]. A research has found that LED can be effective as

conventinal phototherapy when it is used at a low irradiance of 5 to 8W/cm2/nm

[3].The examples of phototherapy devices that using blue LEDs technology is Natus

neoBlue as in Figure 2.9.

Table 2.1: Comparison of phototherapy devices[11]

Device

Lamp source

Minimum

recommended

treatment distance

(mW.cm-2)

Is the

effective

light field

>700cm2

Draeger Photo-

Therapy 4000 Unit

Folded fluorescent 3.39 (4 blue tubes and

2 white tubes) 4.07 (6

blue tubes)

Yes

Draeger Heraeus

Phototherapy Lamp

Gas discharge bulb 5.03 Yes

Ohmeda BiliBlanket

Plus

Halogen bulb 4.83 No

Natus neoBLUE LED

Phototherapy

System

LEDs 852 Blue

320 Yellow

13 Red

2.29 Yes

16

2.3.2 Efficacy of Phototherapy Lights

Since phototherapy was first evaluated in 1990s, during this period of time,

methods for reporting and measuring phototherapy doses are not standardized [18].

Phototherapy generally used according to the guidelines published by the Americans

Academy Pediatrics in 2004 [19]. Phototherapy is well known as the standard

treatment for jaundiced infants. Many researchers had conducted a research to

determine the efficacy of phototherapy for jaundice treatment. Since it first invented

in 1950s, there is a lot of research has been done in order to improve the applications

of phototherapy units with higher efficacy and safe to be used

The efficacy of phototherapy is depends on the following factors:

i. Wavelength range and peak

ii. Light intensity (irradiance)

iii. Body surface area (BSA) exposure

iv. Skin thickness and pigmentation

v. Duration of exposure

vi. Decreasing of total bilirubin concentration

Bilirubin is a yellow coloring pigment that very sensitive to light. Bilirubin

absorption spectrum is used as the basic to design a phototherapy light sources [5].

Blue light is most effective for phototherapy because increasing of wavelength cause

transmittance of skin increased. The best wavelength to be use is 400nm to 520nm

with the peak centered around 460nm 10nm because at this range it is most closely

to the bilirubin absorption spectrum [5, 19]. This result has been proven in both in

vitro and in vivo experiments in order to determine the degradation of bilirubin. To

maximize the area exposed to light, change the infants posture for every 2 to 3 hours

so that when the area of exposure is greater, the greater the decreasing of bilirubin

total rate [18].

17

Skin thickness and pigmentation has been reported to obstruct the

phototherapy efficacy. Besides that, the longer time taken for phototherapy exposure

to infants resulting in increasing rate of decline in total bilirubin levels [5]. For an

effective treatment, within 4 to 6 hours initiation treatment it should be able to

decrease more than 2mg/dL (34mol/L) in serum bilirubin concentration. Figure

2.10 shows important factors in the efficacy of phototherapy that should be taken

into account. The important factors that need to be considers as shown in Table 2.2.

Figure 2.10: Important Factors in the Efficacy of Phototherapy[19]

18

Table 1.2: Practice Considerations for Optimal Administration of Phototherapy[18]

Checklist Recommendation Implementation

Light source (nm) Wavelength spectrum in

460- 490nm blue-green light

region

Know the spectral

output of the light

source

Light irradiance

(W/cm2/nm)

Use optimal irradiance:

30W/cm2/nm within the

460 to 490nm waveband

Ensure uniformity

over the light

footprint area

Body surface area (cm2) Expose maximal skin area Reduce blocking of

light

Timeliness of

Implementation

Urgent or crash-cart

intervention for excessive

hyperbilirubinemia

May conduct

procedures while

infant is on

phototherapy

Continuity of therapy Briefly interrupt for feeding,

parental

bonding, nursing care

After confirmation

of adequate

bilirubin

concentration

decrease

Efficacy of intervention Periodically measure rate of

response in bilirubin load

reduction

Degree of total

serum/ plasma

bilirubin

concentration

decrease

Duration of therapy Discontinue at desired

bilirubin threshold; be aware

of possible

rebound increase

Serial bilirubin

measurements

based on rate of

decrease

19

2.4 Comparison of Phototherapy Research Studies

Several researches were conducted to identify the best and effective light

source for jaundice treatment. Many researchers have found that the use of blue LED

for phototherapy treatment is more efficient compared to the other light source.

These researches were carried out by comparing the percentage of bilirubin

degradation when the solution exposed to the LEDs and other phototherapy light

source. They were also conducted an experiment by comparing the effectiveness of

existing phototherapy available in market. Below are the results from the study

conducted:-

a) LEDs vs Halogen Bulb [4]

In vitro and in vivo Efficacy of New Blue Light Emitting Diode Phototherapy

Compared to Conventional Halogen Quartz Phototherapy for Neonatal

Jaundice

Figure 2.11: Comparison of both in vitro and in vivo efficacy of bilirubin

degradation between the blue LED and conventional phototherapy unit [4]

A research conducted by Korean Team entitled as stated above compared the

percentage of bilirubin degradation for in vitro and in vivo experiment using LED

20

and Halogen Bulb as the photoherapy light source. For in vitro experiment, bilirubin

solution was exposed to this light source for 5 hours at room temperature at 45 cm

distance. While for in vivo experiment, twenty of 8-day old jaundiced Gunn rats

were used and exposed to each light source for 5 hours at room temperature at 45 cm

distance. Based on the result in Figure 2.11, the researcher has found that the

percentage of bilirubin degradation is higher when using blue LED compared to the

conventional phototherapy. It is proven in both in vitro and in vivo experiment. After

the exposure time, the percentage of bilirubin degradation when using blue LED

increased to 44% for in vitro and 30% for in vivo meanwhile when using

conventional light source the percentage of bilirubin is 35% and 16% for both in

vitro and in vivo respectively. It can be concluded that the study conducted shows

that LED light source is more efficient than conventional light source for degradation

of bilirubin. The efficacy is determining by two major factors which is the

wavelength and the intensity of the light emitted during phototherapy.

b) Blue LED vs different color of LED and other light sources [17].

Light-Emitting Diodes: A Novel Light Source for Phototherapy

Figure 2.12: Efficacy comparison between LEDs [17]

21

Another research is by Vreman and his team. They has conducted an

experiment by comparing the efficiency between different colors of the LEDs and

also compared the efficiency of phototherapy light sources (Mini Bili Lite,

BiliBlanket, Photo-Spot, and Bili Lite). Based on the result in Figure 2.12, blue LED

has proven to be able reduced the bilirubin level by 28% followed by blue-green

LED, white light and green LED with the percentage of bilirubin degradation is 18%,

14% and 11% respectively. The in vitro efficacy of bilirubin degradation was then

compared blue LEDs with several conventional phototherapy devices and the result

as in Figure 2.13.

Figure 2.13: Comparison of efficacy between different light sources

Based on the result, the greatest irradiance and the most effective light source

for bilirubin degradation are when using blue LED. The other light source has

significantly different in their ability for bilirubin degradation except for Mini Bili-

Lite and BiliBlanket where both of them had almost the same result [17].

22

c) LED vs Existing Phototherapy Devices [20].

In Vitro Efficacy Measurements Of Led-Based Phototherapy Devices

Compared To Traditional Light Sources In A Model System

Figure 2.14: Comparison of in vitro efficacy of existing phototherapy devices [20]

This research was conducted by Vreman and his team during EASL

International Bilirubin Workshop in 2004. This experiment is comparing the existing

phototherapy product in market. They use the same bilirubin solution but different

type of phototherapy. Based on the time taken to reduce bilirubin level, PortaBed and

neoBlue which using blue LEDs is shorter than the other phototherapy devices. The

most efficient phototherapy devices is PortaBed which is it has higher irradiance and

can reduced bilirubin level in shorter time. Irradiance is not the primary factor to

determine the efficacy for both preterm and term neonates eventhough the maximum

irradiance levels between phototherapy devices vary widely [20]. The important

factors to determine the potential efficacy of a device such as the quality of the light,

size of the subject, mean irradiance of the treatable BSA, and percentage treatable

BSA [20].

23

d) Sunlight vs Conventional Phototherapy [9].

Can sunlight replace phototherapy units in the treatment of neonatal jaundice?

An in vitro study

Figure 2.15: Absorbance spectrum of light exposure [9]

Figure 2.16: Bilirubin degradation percentage using sunlight and conventional

phototherapy [9]

24

Some researcher found that sunlight can be an alternative to replaced

phototherapy in jaundice treatment. In his research, Fadhil M. Salih reported that the

absorbance of bilirubin is higher when sunlight is used compared to phototherapy

unit for the same time interval. The percentage of bilirubin degradation is close when

using sunlight and phototherapy unit. Sunlight can well be suggested as an

alternative source of light in the treatment of neonatal jaundice in circumstances

where phototherapy units are not available such as at third world countries or at

developing countries [9]

However, the time of sunlight exposure must be monitored very carefully and

should be in short time. This is because sunlight could impose biological hazard as it

contains a considerable amount of ultraviolet radiation [9].

2.5 Automated Phototherapy Vest (APV)

Figure 7: APV Full Set-up [11]

25

The Automated Phototherapy Vest (APV) was designed as an alternative

phototherapy device to help in reducing bilirubin level, by exposing infants under

UV LED lights [11]. The device is able to monitor an infants body temperature. It

will automatically turn OFF once the infants body temperature exceeds the set

temperature. Addition to that, the APV requires a low power which is 7.5V, it easy to

use and can be comfortably operated either in hospitals or at home. With the

Breastfeeding mothers can feed their babies easily while treatment is still in progress.

The APV also has some safety features as one of its advantages. It will send an

alarm to indicate that the treatment time is over and will also turn off automatically

once the treatment session ended. This is a precautious action to prevent babies from

being exposed to excessive UV light.

However, there are several limitations on this first APV prototype. One of the

limitation is the brightness of the UV lights are uneven. When this happens, the

lights that are exposed to the baby will have produce different irradiance. This may

due to the type of LEDs that are not able to provide a uniform light ignition. The use

of Blue LED is proposed to overcome this limitation. The UV-LED has a wavelength

of 385nm 395nm while blue LED has a wavelength in the range of 460nm

480nm. UV-LED may be able to reduce bilirubin level in infants body but not as

efficient as blue LED. This is because bilirubin has a peak absorption in the range of

450nm 470nm and it matches better with the wavelength of blue LED. Besides

that, UV-LED has a low power emission which is 80mW. The power emission for

the blue LED is much higher, which is 180mW. In addition to that, the difference in

sizes between blue LED (10mm in diameter) and UV-LED (5mm in diameter) may

cause the blue LED to be able provide higher luminous intensity compared to UV-

LED.

CHAPTER 3

METHODOLOGY

3.1 Project Overview

Figure 3.1: Block diagram of the project

Figure 3.1 illustrates the block diagram of the project. First of all, bilirubin

solution will be prepared before conducting the experiment. Solution of bilirubin will

be prepared by dissolving it in a buffer solution which contain Sodium Hydroxide

27

(NaOH) and saline for further dilution and filled into clear cuvette. The clear cuvette

containing bilirubin concentration will be exposed to different light sources which

are the blue LEDs and fluorescent light at certain distance for a certain period of

time.

The absorbance value for the bilirubin concentration will be recorded before

and after the light exposure using a UV-Spectrophotometer. The spectrophotometer

measures the light absorbed by the solution and the output produced was in term of

absorbance and transmittance. Sample solutions placed into the spectrophotometer

represent the bilirubin concentration before the light exposure, and sample after the

light exposure for blue LED and fluorescent light. Spectrophotometer will measure

the absorbance of the bilirubin concentration one sample at each time. Then, the

absorbance value will convert the data into concentration. This output will be linked

into the LabView programming by using RS232 to calculate the bilirubin

concentration. The value of concentration will be displayed in Graphical User

Interface (GUI) for comparison purpose.

3.2 Experimental Preparation

The experimental part for this project can be divided into two parts which is

bilirubin detection using UV-Spectrophotometer and light exposure for bilirubin

level degradation. We need to do the preparation for both experiment and the

specification will be explained below.

28

3.2.1 Bilirubin Solution Preparation and Detection using Spectrophotometer

For the first part of the experiment, we need to prepare 17 samples of

bilirubin concentration. There is a specification needed for the preparation to be

followed. First, 5 mg of bilirubin was dissolved in 10 ml of 0.05 M Sodium

Hydroxide (NaOH). This mixture will be used as the stock solution for the next

dilution preparation. This stock solution stored in a brown glass container and we

need to prepare the fresh solution for every experiment. Then, make several dilution

of bilirubin standard solution from 50 mg/dl to 500 mg/dl by dilute the stock solution

with saline. Table 3.1 shows the different bilirubin concentration and the amount

needed for the mixture.

After each of the different concentration are prepared, bilirubin solution filled

into the clean clear cuvette. The cuvette must be clean and not scratched to ensure

that the reading obtain is accurate. Then, the cuvette will be placed inside the sample

rack of the spectrophotometer. The absorbance value for each concentration was

measured and recorded. Before that, we need to pre-heating the spectrophotometer

for about 30 minutes so that the spectrophotometer reading is in stable condition and

will give the accurate value.

Figure 3.2 shows the basic routine operations of the spectrophotometer. Pre-

heating is required for the lamp and the electronic parts to reach heat balance. The

wavelength is set to the desired value. 100%T adjustment and zero adjustment are

done in order to get the accurate measuring status. The scale is then set to

Absorbance and the sample is put into the light path. . The data will be displayed at

the LED display window.

29

Figure 3.2: Absorbance determination

Table 3.2: Different bilirubin concentration

Bilirubin concentration

(mg/dL)

Stock solution (mL) Saline (mL)

50

100

150

200

250

300

350

400

450

500

0.30

0.60

0.90

1.20

1.50

1.80

2.10

2.40

2.70

3.00

5.70

5.40

5.10

4.80

4.50

4.20

3.90

3.60

3.30

3.00

30

3.2.1.1 Spectrophotometer Wavelength Determination

A spectrophotometer was used to measure the amount of light that passes

through the solution and measure the light absorbed by the solution to determine the

concentration of solutes at certain wavelength. The working principle follows the

Beer Lamberts Law which relates the absorption of light travelling through the

properties of the material. Beer and Lambert also found out that the relationship of

the absorbance of the solution is linear to the concentration of an absorbing solute.

Before the analysis or conducting the experiment, we need to identify the wavelength

at which will give the maximum absorbance value. This is because the wavelength

determined will be used for the next analysis or experiment. The unit of the

wavelength is in nm.

Determination of the wavelength was done by choosing one of the solution

prepared; in this experiment 500 mg/dl concentration was used. Note that bilirubin is

in yellow color which will absorb blue-violet light which at the wavelength from

560nm to 600nm. As stated in Figure 2.10 in Chapter 2, blue light was found to be

the most effective light absorbed to reduce bilirubin level. Thus, the maximum

absorbance value can be determined and will be used for the whole experiment.

Figure 3.3 can be a reference for the color absorbed and its observed color.

Figure 3.3: Absorbance color chart

31

3.2.1.2 Bilirubin Calibration Curve

The purpose of measuring the absorbance value for each of the different

concentration is to obtain the calibration curve of the bilirubin. We can determine the

concentration of the bilirubin by using a calibration curve where it will translate the

absorbance values into concentration values.

The calibration curve, Figure 3.4 was constructed by plotting a graph of

absorbance versus bilirubin concentration. Then, a straight line curve is created.

From the calibration curve, we can determine the linear equation for the solution.

Equation 3.1 is a linear equation, y = mx + c, where m is the slope and c is the y-

intercept. We can also calculate the concentration value manually by draw a

horizontal line to the calibration curve line once we identify the absorbance value at

y-axis. Then, draw a vertical line from the intersection to the x-axis to determine the

concentration value.

Figure 8: Example of calibration curve

-0.05

0

0.05

0.1

0.15

0.2

0.25

-100 100 300 500 700 900

Ab

sorb

ance

Concentration (mg/dl)

Ralationship between Absorbance and Concentration

32

y = mx + c

y: Absorbance value

m: Slope

x: Bilirubin concentration

3.2.2 Light Exposure

The second part of the experiment is the light exposure to the bilirubin

concentration. There are two types of light used in this experiment which is blue

LEDs and fluorescent light. This experiment was conducted to determine the

efficiency of blue LEDs compared to fluorescent light by comparing the level of

bilirubin degradation after the exposure. Besides, this experiment is also to determine

the relationship between absorbance values and the bilirubin level degradation with

the exposure time.

3.2.2.1 Blue LEDs

The 10mm blue LED as shown in Figure 3.5 is one of the light sources used in

the experiment. Blue LEDs was chosen because researches has found that it is able

reduce bilirubin effectively compared to other LEDs and also other phototherapy

light source [17]. This is also because of it unique characteristics which is it emit a

higher intensity, light in weight, less heat produced, and have a longer lifetime [4].

(Eq. 3.1)

33

The most important thing is its wavelength is 465nm to 470nm which it suitable in

reducing the bilirubin.

Figure 3.5: Blue LED

3.2.2.2 LEDs Arrangement and Design Considerations

In order to design the LEDs arrangement, there are some factors that need to

be considered. The calculation for the irradiance was made to identify the optimum

light exposure. The factors need to be considered is the effective light field,

maximum power dissipation and also the light wavelength. The calculations to

determine the positions and the distance of the LEDs are as follows:

From the datasheet, we can obtain the LED Peak Wavelength and the Maximum

Power Dissipation

LED Peak Wavelength = 465nm 470nm

Maximum Power Dissipation = 180mW

34

Effective light field = (Length x Width) of LED exposure area

= 3cm x 3cm

= 9cm2

By using these data, we can calculate the irradiance of the LEDs.

Irradiance = (Max Power Dissipation / Effective light field) / Peak Wavelength

= (180mW /9cm)/(467.5nm)

= 42.78 W/cm/nm

The calculated irradiance obtained is higher than the required irradiance

determined by the American Academy of Pediatric (AAP) guideline as in Figure 3.6.

The AAP guideline requires that the blue light should be used if the intensive

phototherapy is required. The irradiance deliver to the infants should be at least

30W/cm2/nm to the greatest surface area available.

Figure 3.6: AAP guidelines for all gestational ages [21]

35

3.2.2.3 Fluorescent Light

Figure 3.7: Fluorescent tube

Fluorescent light is the commonly used light source in phototherapy device as

we can see in most of hospital. Olympic Bililite is one of the phototherapy device

that using fluorescent tube as the light source. The fluorescent tube used in this

project is Philips TL/52 20W where TL represents the type of the lamp and 52 is its

color which is blue lamp. The wavelength for this light source is 400nm to 500nm

but the maximum wavelength is at 450nm. However care must be taken to ensure the

effective light irradiance delivery is maximize to the body surface area (BSA) and

provide eye protection during the exposure [22].

The distance from the light source should be closer to the infant as possible to

get the maximum spectral irradiance on the body surface. Usually the distance from

light source to the infant is 45cm to 50 cm[9, 20] and this will give the irradiance for

the light to be 10 15W/cm2/nm [23]. However, researches found that these light

sources are less effective and has a number of disadvantages including heat

production and the exposure to the surface area is limited.

In this project, one tube of fluorescent light will used for the experiment and

it using electronic ballast to turn it on. The distance between the light source to the

cuvette contains bilirubin concentration is adjusted to 45cm.

36

3.3 Software Development

LabView software is for visual programming language developed by National

Instruments. It is commonly used for industrial automation, instrument control and

for data acquisition. Basically, LabView program or subroutine is called virtual

instruments (VIs) consist of block diagram, a front panel and a connector panel.

Controls and indicators built in the front panel. Control is the inputs that allow the

information to the VI from the user while indicator is the output which indicate or

display the result given from the input. The block diagram contains the source code

for the graphical programming. It contains the structures and functions to perform the

operation on controls and send the data to indicators.

3.3.1 Importing data into LabView from Spectrophotometer

Figure 3.8: Block diagram

37

LabView programming can read the data from the spectrophotometer by

using RS 232. Before that we must installed DAQ-mx software into the computer

used and set the port to COM1. The block diagram for the LabView system shows as

in Figure 3.8. The system operates in stacked sequence where it consist one or more

sub-diagrams that execute sequentially. It works by allows the process proceed to the

next executions when the first sub-diagram finish its process.

Figure 3.9: (a) Input port detection (b) Read input data

VISA Resource Name used to specify the resource to which a VISA session

will be opened while VISA serial is to determine the instance to use by manually

select the instance. As in Figure 3.9 (a), this part will detect the input port from

spectrophotometer by using RS 232. Then, VISA Read Figure 3.9 (b) will read the

input data from the spectrophotometer which specify by VISA Resource Name and

return the data in Read Buffer. The output from spectrophotometer contains in Read

Buffer will be displayed at front panel as shown in Figure 3.10.

Figure 3.10: Output data from spectrophotometer

38

However, for the mathematical operation, symbol A= must be eliminate for the

calculation purpose. This system will be connected to the equation to determine the

relationship between absorbance and bilirubin concentration. Figure 3.11 shows how

the elimination process was done.

Figure 3.11: Elimination process

Figure 3.12: Result after elimination process

39

3.3.2 Bilirubin reading using LabView

Linear equation obtained for relationship between absorbance and bilirubin

concentration from the first experiment was inserted into the mathematical operation

in LabView system. This equation will be used to convert the absorbance value to

concentration. The While Loop function will repeat the process until the STOP

button pressed.

Figure 3.13: Bilirubin level detection

However, the system design is not suitable for the project because it cannot

display all the data simultaneously. This is because spectrophotometer has four

sample racks but it cannot measure the absorbance for all samples simultaneously.

The experiment requires the system to read all the data and display it in one graph for

comparison purpose. To fix this problem, stacked sequence was used as explained

earlier and the system is also use Wait (ms) function and Shift Register. Wait (ms)

function will not complete the execution until the specified time has elapsed. Since

40

the systems need to display the data simultaneously, Shift Register was used to pass

the value to the next iteration. So, the previous measured value will remain in the

graph.

Figure 3.9: Spectrophotometer sample racks

3.4 Flow Chart

The flowchart in Figure 3.15 presents the flow of the data measurement from

spectrophotometer into LabView.

The operation of the system starts by place the bilirubin concentration into the

spectrophotometer sample rack. Sample A represent the bilirubin concentration

before the light exposure while sample B and sample C represent the bilirubin

concentration after the light exposure for both blue LEDs and fluorescent light. Next,

41

the absorbance value was measured and then the value is converted to concentration

value. After one measurement, the process will stop until we push the Next button it

will continue the process until 4 reading has been measured. After the 4th

measurement or we discontinue the measurement, the system will stop and all the

data will be displayed.

Figure 3.15: Flowchart of the experiment

CHAPTER 4

RESULTS AND DISCUSSIONS

This section will discuss on the results and data analysis obtained throughout

the project.

4.1 Determination of Optimum Wavelength

Bilirubin solutions with different concentration (as shown in Figure 4.1) were

prepared and the absorbance for each different concentration was measured using a

spectrophotometer. Prior to this, the optimum absorbance wavelength for bilirubin

need to be determined as there is only one optimal wavelength for each chemical

element or chemical compound.

Table 4.1 displays the results of absorbance reading when 500mg/dL of

bilirubin solution was tested using different wavelength settings (560nm 600nm).

The results show that the highest absorbance value is 0.150, which occured at

560nm. Thus, 560nm was fixed as the optimum absorbance wavelength to be used

throughout the experiment.

43

Figure 4.1: Preparation of different bilirubin concentrations

Table 4.3: Determination of optimum absorbance wavelength

Wavelength (nm) Absorbance

0 0

560 0.150

570 0.116

580 0.095

590 0.079

600 0.067

4.2 Relationship between Absorbance and Bilirubin Concentration

The relationship between bilirubin absorbance and concentration was

determined by measuring the absorbance for different bilirubin concentration at a

fixed wavelength using a spectrophotometer. The results are illustrated in Table 4.2.

Generally, bilirubin absorbance is directly proportional to bilirubin concentration.

From the results, a calibration curve (as shown in Figure 4.2) was plotted to

determine the mathematical equation that relates bilirubin absorbance and

concentration.

44

Table 4.4: Measurement of absorbance for different bilirubin concentrations

Concentration (mg/dL) Absorbance

50 -0.011

100 0.065

150 0.094

200 0.153

250 0.206

300 0.304

350 0.420

400 0.432

450 0.532

500 0.599

Figure 4.2: Calibration curve of absorbance vs concentration for bilirubin solution

From the calibration curve, a linear equation (Equation 4.1) is obtained.

y = 1.151x 0.075

R2 = 0.996

y = 1.1512x - 0.0751

R = 0.9962

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0 0.1 0.2 0.3 0.4 0.5 0.6

Ab

sorb

ance

Concentration (mg/dl)

Relationship between Absorbance and Concentration

(Eq. 4.1)

45

The value of the correlation is closely approaching 1, which indicates that

there is a strong positive linear relationship between X (concentration) and Y

(absorbance). It also means that bilirubin absorbance and bilirubin concentration

tends to increase and decrease proportionally. The linear equation obtained was used

in the concentration calculation in LabView.

4.3 Bilirubin Degradation Experiment A Comparison between Different

Light Sources

4.3.1 LEDs Circuit Design

The calculation for irradiance and optimum light exposure which was

conducted in Chapter 3 resulted in the design of the LEDs circuit. 18 super bright

blue LEDs were arranged as in Figure 4.3. The supplied direct current (DC) voltage

was 9.5V and resistors with resistance values of 39 were arranged in series with

each LED.

Figure 4.3: LEDs circuit

46

4.3.2 Bilirubin Degradation Experiments

Two sets of five samples of 100mg/dL bilirubin solution were prepared. Both

sets of bilirubin solutions were exposed to blue LEDs and fluorescent light at five

time intervals; 10 minutes, 30 minutes, 60 minutes, 120 minutes and 180 minutes.

The absorbance value for each sample was measured before and after the light

exposure.

(a)

(b)

Figure 4.4: Bilirubin degradation experiments (a) Blue LEDs exposure (b)

Fluorescent light exposure

Table 4.3 exhibits the absorbance measurements, before and after light

exposure at each time intervals while Table 4.4 displays the degradation of bilirubin

47

concentrations in mg/dl and in percentage difference. Based on the results in Figure

4.5, the percentage difference of bilirubin degradation for blue LEDs is higher than

the fluorescent light. the experimental findings proved that blue LEDs more efficient

in redusing bilirubin level compared to fluorescent light.

Table 4.5: Results (in absorbance) of bilirubin degradation experiment

Time

(minutes)

Absorbance

Blue LEDs Fluorescent Light

Before After Before After

10 0.059 0.058 0.062 0.062

30 0.057 0.043 0.060 0.059

60 0.055 0.038 0.056 0.054

120 0.055 0.034 0.053 0.047

180 0.048 0.024 0.041 0.031

Table 6.4: Results (in concentration & percentage difference) of bilirubin

degradation experiment

Time

(minutes)

Concentration (mg/dl)

Blue LEDs Fluorescent light

Before After Difference

(%) Before After

Difference

(%)

10 0.117 0.116 0.85 0.119 0.119 0

30 0.115 0.103 10.43 0.117 0.116 0.87

60 0.113 0.098 13.27 0.114 0.112 1.75

120 0.113 0.095 15.92 0.111 0.106 4.39

180 0.107 0.086 19.63 0.101 0.092 8.91

48

Figure 4.5: Comparison of bilirubin degradation in blue LED and fluorescent light

(in percentage difference)

The percentage difference of bilirubin degradation was calculated using

equation 4.2:

100

4.4 Bilirubin Level Detector using LabView

LabView was used as the platform to measure bilirubin level in samples of

bilirubin solutions. Figure 4.6 displays the user interface of the bilirubin level

detector. Initially, user will need to select the input port from the instrument that

interfaces with the computer. The port detection for this project is at COM1, as had

been set before the experiment. As mentioned earlier, the spectrophotometer has four

slots on the sample rack. The first slot was used for the blank/empty cuvette for

0

5

10

15

20

25

10 30 60 120 180

% b

iliru

bin

de

grad

atio

n

Time (minutes)

Percentage Difference of Bilirubin Degradation

Blue LEDs

Fluorescent light

(Eq. 4.2)

49

instrument calibration purpose, while the other three slots were used for bilirubin

solution samples.

Figure 4.6: User interface of bilirubin level detector

Once the absorbance reading is obtained from the spectrophotometer,

the ABSORBANCE VALUE tab will display the value of absorbance for a

specific sample. The system runs the calculation automatically and converts the

absorbance data into concentration. The converted bilirubin concentration value is

displayed graphically and in the numeric form.. Once the measurement is completed,

the system will wait until the user pushes the NEXT MEASUREMENT button to

analyze the next measurement. Before that, the user will need to push the push-pull

rod to the next position.

50

The measurement process will start again for the next sample while the data

from the first measurement remains in the waveform graph for comparison purpose.

The system will stop once it reach l the fourth measurement or at anytime when the

user pushes the STOP button. The final results will display all four measurements

simultaneously on the waveform graph, making it easier for the user to make any

comparison between several data. The data from the waveform graph can be saved in

Excel by right-clicking at the waveform graph and exporting the data into Excel, as

shown in Figure 4.7. User can either print or save the data for future reference.

Figure4.7: Exporting data into Excel

4.5 Discussion

In the earlier experiment to determine the optimum absorbance

wavelength, the spectrophotometer was used to measure the bilirubin solution

concentration based on the principle of color absorbance. Different bilirubin

51

solutions were used to determine the absorbance- concentration relationship and also

to test the reliability of the bilirubin detector system in displaying measured data. In

relation with real applications, blood or urine samples can be used to test the

bilirubin level in an infants body.

In the bilirubin degradation experiment, several samples of similar bilirubin

concentration were used to identify the efficacy of blue LEDs and fluorescent light.

It is proven that blue LEDs is more efficient in reducing bilirubin level compared to

fluorescent light. Results from the bilirubin samples that were exposed to blue LEDs

gave a higher concentration difference, before and after light exposure. These

samples also showed a higher percentage difference in bilirubin degradation

compared to the sample which was exposed to the fluorescent light.

4.5.1 Interference during Experiments

It is suspected that, there might be some interference that occurred during the

experiments. This might be the cause that resulted in negative absorbance values for

a few samples of bilirubin concentration. All measurement values should be positive.

Another possible reason might be due to the inaccuracy of measurement during the

bilirubin solution preparation. During the bilirubin degradation experiment, light

interference may also occur, which will affect the bilirubins absorbance, as the

substance is very sensitive to light.

Besides that, another factor which may lead to inaccuracy of data is the

condition of the spectrophotometer. It should be fully warmed up before use and

should not be ON for a long period of time.

CHAPTER 5

CONCLUSIONS AND RECOMMENDATIONS

5.1 Conclusions

Bilirubin level detector using LabView for jaundice treatment is continuity

from the Automated Phototherapy Vest (APV) project. A simple spectrophotometric

method using spectrophotometer has been found to be the cheapest way to measure

the degradation of bilirubin level. This is because the spectrophotometric method is

simple, easy to operate, highly sensitive and is widely used for data analyzing in

industrial applications.

The main objective of the project is to verify that blue LEDs which are

proposed to be used as the light source in the APV is able to reduce bilirubin level in

infants efficiently and effectively compared to conventional phototherapy device,

such as fluorescent light. An experiment was conducted to determine the efficacy of

blue LEDs compared to fluorescent light. Samples of bilirubin solution were

prepared and exposed to each light source. Based on the experimental results, it is

proven that blue LEDs were more efficient in reducing bilirubin concentration

compared to fluorescent light.

53

The bilirubin level detector system was developed to measure bilirubin

concentration using LabView by translating absorbance value into bilirubin

concentration before displaying the data. The graphical user interface enables user to

compare bilirubin measurements of several samples which can be saved into Excel

for future reference.

5.2 Recommendation for future work

There are several recommendations that can be used to improve the current

limitations of the project. The recommendations include:

Implementing a suitable LEDs arrangement for the APV and verifying that

the blue LED on the APV is able to reduce bilirubin efficiently.

Comparing the efficiency of blue LEDs on the APV with other portable

phototherapy device such as the BiliBlanket and neoBLUE blanket LED.

Designing a system which is able to automatically identify the required time

exposure depending on the bilirubin concentration level.

54

REFERENCES

1. Health, N.C.C.f.W.s.a.C.s., Neonatal Jaundice2010: Royal College of

Obstetricians and Gynaecologists.

2. Jaundice in newborn babies. BMJ Publishing Group Limited 2012.

3. M. Jeffrey Maisels, M., BCh, Phototherapy - Traditional and Nontraditional.

J. Perinatol 2001; 21:S93-S97.

4. YS Chang, J.H., et al. , In vitro and in vivo Efficacy of New Blue Light

Emitting Diode Phototherapy Compared to Conventional Halogen Quartz

Phototherapy for Neonatal Jaundice. J Korean Med Sci 2005; 20:61-4.

5. HJ Vreman, R.W., DK Stevenson, Phototherapy: Current Methods and

Future Directions. Semin Perinatol 2004; 28:326-333.

6. Wentworth, S.D.P., Neonatal phototherapy - today's lights, lamps and

devices 2005. 6:14-19.

7. Ramesh Agarwal, R.A., Ashok Deorari, Vinod K Paul, Jaundice in the

newborn. All India Institute of Medical Sciences.

8. Malaysia, M.o.H., Management Of Jaundice In Healthy Term Newborn.

Academy of Medicine, February 2003.

9. Salih, F.M., Can sunlight replace phototherapy unit in the treatment of

neonatal jaundice?An in vitro study. Photomed 2001; 17:272-277.

10. Newborn jaundice (Hyperbilirubinemia), N.C.W.s. Hospital, Editor 2002.

11. Daud, S.A., Automatic Phototherapy Vast (APV), in Faculty of Electrical

Engineering2012, University Teknologi Malaysia.

12. Bilirubin Test. 2012.

13. Tanja Karen, H.U.B.a.J.-C.F., Comparison of a new transcutaneous

bilirubinometer (Bilimed) with serum bilirubin measurements in preterm

and full-term infants. BMC Pediatr., 2009.

14. Krishnasamy, M., Non-Invasive, Hand Held Transcutaneous Bilirubinometer,

H.T.A.S.M.D. Division, Editor 2009, Ministry of Health Malaysia.

55

15. Bruzell, E.M., Phototherapy of newborns suffering from hyperbilirubinaemia.

An experimental study. Doctor Scientarium Thesis 2003.

16. Phototherapy in Clinical Applications. Available from:

http://www.sytledepartment.com/phototherapy-in-clinical-applications-2/.

17. Hendrik J. Vreman, R.J.W., David K. Stevenson, et al., Light-Emitting

Diodes: A Novel Light Source for Phototherapy. Pediatr. Res; 44: 804-9,

1998.

18. Bhutani, V.K., Phototherapy to Prevent Severe Neonatal Hyperbilirubinemia

in the Newborn Infant 35 or More Weeks of Gestation. American Academy of

Pediatrics, 2011.

19. M. Jeffrey Maisels, A.F.M., Phototherapy for Neonatal Jaundice. N Engl J

Med; 358:920-8, 2008.

20. Hendrik J. Vreman, R.J.W., David K. Stevenson, et al., In vitro Efficacy

Measurement of LED-Based Phototherapy Devices Compared to Traditional

Light Sources In a Model System. EASL International Bilirubin Workshop,

2004: p. 51-56.

21. Management of Hyperbilirubinemia in the Newborn Infant 35 or more weeks

of gestation. Pediatr 2004; 114 (1),297-316.

22. Light sources for phototherapy, 2009, Koninklijke Philips Electronics N V.

23. Belma Saygili Karagol, O.E., Begum Atasay, Saadet Arsan, Efficacy of Light

Emitting Diode Phototherapy In Comparison To Conventional Phototherapy

In Neonatal Jaundice. Med sci 2007;31-34.

56

APPENDIX A

UV-VISIBLE SPECTROPHOTOMETER

Figure 1

Figure 2

13 12 11

14

17 16 5 15

Spectrumlab 752s

UV VIS Spectrophotometer

MODE FUNC. 0%ADJ. 100%ADJ.

TRANS.

ABS.

FACT.

CONC.

4

3

2

1

10 9 6 7 8

57

Instrument Appearance and Operation Keys

1. /100% button: It is used to automatically adjust 100%T when the

transmittance indicating lamp is lit. It can be pushed

once more as the end position is not reached yet.

Display- - - - is appeared to indicate the adjustment is

undergoing. This button is used to automatically adjust

0 absorbance when the absorbance indicating lamp is

lit. It can be pushed once more as the end position is

not reached yet. Display- - - - is appeared to indicate

the adjustment is undergoing. It is used to increase

concentration factor setting when conc. factor

indicating lamp is lit. One action for one push. The

concentration factor increases rapidly when the button

is kept pressing for more than 1 second. Setting value is

automatically confirmed after entered into rapid

increasing by pressing Mode button.

2. /0% button: It is used for automatically adjusting 0%T (adjusting

range

58

5. Sample rack push-pull rod: For changing sample trough positionfour

positions

6. Four digit LED display window: For display readings and error message.

7. Transmittanceindicating lamp: Indicating that the window is displaying

transmittance data.

8. Absorbanceindicating lamp: Indicating that the window is displaying

absorbance data.

9. Concentration factorindicating lamp: Indicating that the window is

displaying concentration factor data.

10. Conc. direct read-outindicating lamp: Indicating that the window is

displaying concentration direct read-out data.

11. Power source socket: For connecting power cord.

12. Fuse socket: For setting fuses.

13. Main switch: ONOFF power source

14. RS232C serial port: For connecting RS232C serial cord

15. Sample compartment: For sample testing

16. Wavelength display window: For wavelength display

17. Wavelength adjusting knob: For wavelength adjustment

59

APPENDIX B

(A) RS 232 PORT LINES

60

(B) RS 232 IMAGE

61

APPENDIX C

COMPLETED BLOCK DIAGRAM

First page

Second page

62

APPENDIX D

LABVIEW USER INTERFACE FOR BILIRUBIN LEVEL DETECTION

USING LABVIEW FOR JAUNDICE TREATMENT

OLE_LINK5OLE_LINK6