(Đồ án hcmute) design of a gel card reader for blood grouping tests

MINISTRY OF EDUCATION AND TRAINING
HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION
FACULTY OF ELECTRICAL AND ELECTRONICS ENGINEERING

GRADUATION THESIS
MAJOR: BIOMEDICAL ENGINEERING

DESIGN OF A GEL CARD READER FOR
BLOOD GROUPING TESTS

ADVISOR: Assoc. Prof. Dr. NGUYEN THANH HAI
STUDENT’S NAME: TRUONG HOANG GIA BAO
STUDENT ID: 16129007
STUDENT’S NAME: NGUYEN MINH DUC
STUDENT ID: 16129017

SKL 0 0 7 8 2 7

HO CHI MINH CITY, JANUARY 2021

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HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION
FACULTY OF ELECTRICAL AND ELECTRONICS ENGINEERING
DEPARTMENT OF ELECTRONICS - BIOMEDICAL ENGINEERING
---------------------------------

GRADUATION THESIS
MAJOR: BIOMEDICAL ENGINEERING

PROJECT NAME:

DESIGN OF A GEL CARD READER FOR
BLOOD GROUPING TESTS

Advisor: Assoc. Prof. Dr. NGUYEN THANH HAI
Truong Hoang Gia Bao
Student ID: 16129007
Nguyen Minh Duc
Student ID: 16129017

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HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION
FACULTY OF ELECTRICAL AND ELECTRONICS ENGINEERING
DEPARTMENT OF ELECTRONICS - BIOMEDICAL ENGINEERING
---------------------------------

GRADUATION THESIS
MAJOR: BIOMEDICAL ENGINEERING
PROJECT NAME:

DESIGN OF A GEL CARD READER
FOR BLOOD GROUPING TESTS
Advisor: Assoc. Prof. Dr. NGUYEN THANH HAI
Truong Hoang Gia Bao
Student ID: 16129007
Nguyen Minh Duc
Student ID: 16129017

Ho Chi Minh City, January 2021

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HCMC UNIVERSITY OF TECHNOLOGY AND EDUCATION
Faculty of Electrical & Electronics Engineering
Department of Electronics Industrial-Biomedical Engineering

THE SOCIALIST REPUBLIC OF VIETNAM
Independence – Freedom– Happiness

Ho Chi Minh City, January 20, 2021

MISSION
Student name:
Major:
Type of training:
Year:

Trương Hoàng Gia Bảo
Nguyễn Minh Đức
Biomedical Engineering
Regular full time
2016

Student ID: 16129007
Student ID: 16129017
Major ID:

D520212
Code:
1
Class:
161290

I. GRADUATION PROJECT:
II. MISSION
1. Initial resources:
● Raspberry Pi 4B.
● Webcam Hoco D101.
● Gel Card.
2. Implementation:
● Use a Python programming language.
● Design PCB and make a power supply board.
● Design and make a 3D model.
● Design the entire model of the project.
● Self-evaluate the entire project.
III. DATE OF DELIVERY:
IV. DATE OF COMPLETION:
V. ADVISOR NAME:

ADVISOR

07/10/2020
20/01/2021
Assoc. Prof. Dr. NGUYEN THANH HAI

DEPARTMENT OF ELECTRONICS INDUSTRIALBIOMEDICAL ENGINEERING

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HCMC UNIVERSITY OF TECHNOLOGY AND EDUCATION THE SOCIALIST REPUBLIC OF VIETNAM
Faculty of Electrical & Electronics Engineering
Independence – Freedom– Happiness
Department of Electronics Industrial-Biomedical Engineering
----o0o----

Ho Chi Minh City, October 28, 2020

SCHEDULE
Student name: Trương Hoàng Gia Bảo
Student ID: 16129007
Student name: Nguyễn Minh Đức
Student ID: 16129017
Class: 161290
Graduation project: Design of a Gel Card reader for blood grouping test.
Week
Week 1st
(October 12 October 18)

Task description

Lecturer
confirm

- Meet the advisor to listen to the request for doing

a project, choose a project topic.

Week 2nd
(October 19 October 25)
Week 3rd
(October 26 –
November 1 )
Week 4th & week
5th
(November 2 November 15)
Week 6th & week
7th
(November 16 –
November 29)
Week 8th & week
9th
(November 30 December 13)
Week 10th & week
11th
(December 14 December 27)

- Advisor reviews topic.

- Write an abstract of the selected topic: what the
topic purpose is, the design request, the limits of the
topic.

- Research into a theoretical basis of the project on
many resources.

- Buy components, make the power supply board.
- Design the prototype and conduct experiments.

- Design software, hardware for the product and
conducting experiments.

- Check the product's accuracy with actual samples
and recalibrate.
- Write the thesis report.

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Week 12th & week
13th
(December 28 –
January 10)
Week 14th & week
15th
(January 11 January 24)

- Continue conducting experiments.
- Complete the model and the thesis report.

- Submit the final version of the thesis report and
report the thesis.
- Submit to the advisor for the last inspection.

Week 16th
(January 25 –
January 31)

- Make a presentation.

ADVISOR
(Sign and write your full name)

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GUARANTEE
We guarantee that this project is our research, under Assoc. Prof. Dr. NGUYEN
THANH HAI 's guidance. The results published in this project are honest and are not
replicated from any other work.
Students:
Nguyễn Minh Đức
Trương Hoàng Gia Bảo

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ACKNOWLEDGMENTS
In order to complete this graduation project, the first words of our group would
like to say sincere thanks to Assoc. Prof. Dr. NGUYEN THANH HAI for his

dedication that helps us a lot in order to accomplish our project. In the process of
doing this thesis, Dr. Hai not only provides us useful knowledge but also trains us to
have a serious attitude in scientific research, which is very necessary for the career
path later.
The group would like to thank the teachers in the Department of Industrial
Electronics - Biomedical Engineering for providing the best conditions for us to
complete the topic. Besides, we would like to thank all the lecturers who taught us
foundation knowledge in the previous semesters for the group was able to complete
the project. Thank you to Ms. Huong, Head of Laboratory Department - Thu Duc
General Hospital, to provide Gel Card samples for us to complete this project. Thank
you to Nghia Tin Medical Equipment Co., Ltd, to support the group with the
equipment and ideas to implement the topic. Thank Mr. Ngo Thien Ha - Deputy
Director of Duong Phu Technology Co., Ltd has provided the group facilities and
equipment to implement the project. Thank parents, for your hard-working in raising
us to school. The more extended the period spending on working, the more we
understand the suffering of our parents.
Finally, we would like to express our sincere thanks to the people who have
contributed and helped the group to implement this project successfully.

Sincerely thanks!

Ho Chi Minh City, January 20, 2021
Students
Nguyễn Minh Đức
Trương Hoàng Gia Bảo
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TABLE OF CONTENTS
Cover ........................................................................................................................... i
Mission ....................................................................................................................... ii
Schedule .................................................................................................................... iii
Guarante ............................................................................................................ ix
Acknowledgments ............................................................................................. ixi
Table of contents .............................................................................................. ixii
List of figures ...................................................................................................... x
List of tables ..................................................................................................... xii
Abstract .......................................................................................................... xiiii

Chapter 1. INTRODUCTION ....................................................................... 1
1.1. PROBLEM STATEMENT ...............................................................................1
1.2. OBJECTIVE .....................................................................................................2
1.3. THESIS CONTENTS .......................................................................................2
1.4. LIMITATIONS .................................................................................................2
1.5. BRIEF SUMMARY OF THESIS .....................................................................2

Chapter 2. LITERATURE REVIEW ........................................................... 4
2.1. TYPES OF HUMAN BLOOD .........................................................................4
2.2. GEL CARD METHOD AND TYPE OF GEL CARDS ..................................5
2.2.1 Gel Card method .............................................................................................5
2.2.2 Type of Gel Cards ...........................................................................................6
2.3. IMAGE PROCESSING ALGORITHM. ..........................................................8
2.3.1 Dilation method ..............................................................................................8
2.3.2 Edge detection method ...................................................................................8
2.4. IMAGE CAPTURING DEVICES ...................................................................9
2.4.1 Microprocessor introduction ...........................................................................9
2.4.2 Description of power supply .........................................................................12

Chapter 3. DESIGN AND CALCULATION ............................................. 13
3.1. INTRODUCTION ..........................................................................................13
3.2. CALCULATION AND DESIGN...................................................................13
3.2.1 Block Diagram Of An Capturing Device .....................................................13
3.2.2 Image Capturing Device ...............................................................................14
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3.2.3 Central Processing Unit ................................................................................14
3.2.4 Image Display and Peripherals .....................................................................15
3.2.5 Calculation of Power Supply ........................................................................15
3.2.6 Case designs for the Gel Card Reader ..........................................................25
3.3. DEVICE CONNECTION ...............................................................................27
3.4. FLOWCHART AND PROGRAM ALGORITHM ........................................28
3.4.1 Functional summary of Gel Card Reader .....................................................28
3.4.2 Flowchart ......................................................................................................28
3.4.3 A flowchart of agglutination level and blood type .......................................29
3.5. PRINCIPLE OF OPERATION ......................................................................36

Chapter 4. CONNECTION OF SYSYTEM PARTS ................................. 37
4.1. INTRODUCTION ..........................................................................................37
4.2. POWER SUPPLY ..........................................................................................37
4.2.1 Assembly of the Power Supply.....................................................................37
4.2.2 Execution of The Power Supply ...................................................................37
4.2.3 Inspection of The Power Supply...................................................................40
4.3. EXECUTION THE CASE OF GEL CARD READER .................................41
4.4. SYSTEM CONSTRUCTION .........................................................................41
4.4.1 User Interfere Design ....................................................................................41

4.4.2 Model Construction ......................................................................................42
4.5. PROGRAMMING SOFTWARE ...................................................................42
4.5.1 Python Programming Software.....................................................................42
4.5.2 Image processing program ............................................................................43
4.5.3 QT Designer ..................................................................................................44

Chapter 5. RESULTS AND DISCUSSION ................................................ 46
5.1. GENERAL RESULTS ...................................................................................46
5.2. ACHIEVEMENT RESULTS .........................................................................46
5.2.1 Power Supply ................................................................................................46
5.2.2 GUI ...............................................................................................................49
5.2.3 System modelling result ...............................................................................50
5.2.4 Test results ....................................................................................................50
5.2.5 Result of Gel Card Reader ............................................................................51
5.2.6 Actual Results ...............................................................................................54
5.3. INSTRUCTION ..............................................................................................55
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5.4. DISCUSSIONS ...............................................................................................56
5.4.1 Advantages....................................................................................................56
5.4.2 Disadvantages ...............................................................................................56

Chapter 6. FUTURE WORKS AND CONCLUSION ............................... 57
6.1. CONCLUSION ...............................................................................................57
6.2. FUTURE WORKS .........................................................................................57

REFERENCES

APPENDIX

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LIST OF FIGURES
Figure

Page

Figure 2. 1. The ABO blood grouping system (Source: Wikipedia) ..........................4
Figure 2. 2. Gel Card and parts inside the Gel Card tube ...........................................5
Figure 2. 3. Interpretation of results ............................................................................6
Figure 2. 4. Sample of Forward grouping Gel Card ...................................................7
Figure 2. 5. Dilation in image processing (Source: www.cs.auckland.nz) .................8
Figure 2. 6. Raspberry Pi 4B (Source: www.deskmodder.de) ..................................11
Figure 3. 1. Block diagram of the system .................................................................13
Figure 3. 2. Webcam Hoco D101..............................................................................14
Figure 3. 3. Block diagram of the switching power supply ......................................16
Figure 3. 4. Schematic of noise filter and primary voltage rectifier circuit ..............20
Figure 3. 5. Schematic of pulse generator circuit .....................................................22
Figure 3. 6. Schematic of secondary voltage rectifier circuit ...................................23
Figure 3. 7. Schematic of secondary voltage feedback circuit .................................24
Figure 3. 8. Schematic of switching power supply circuit ........................................25
Figure 3. 9. Frontside (a) and backside (b) of the base holder ..................................26
Figure 3. 10. The frontside (a) and backside (b) of the Gel Card Reader case .........27
Figure 3. 11. The connection of the entire project Interpret connection diagrams ...27
Figure 3. 12. Flowchart of Gel Card Reader system ................................................29

Figure 3. 13. A flowchart of agglutination level and blood type ..............................30
Figure 3. 14. Image area is cropped in Gel Card (red border) ..................................31
Figure 3. 15. The result after image cutting in Gel Card Reader ..............................31
Figure 3. 16. RGB to HSV diagram ..........................................................................32
Figure 3. 17. Results after converted image from RGB to HSV ..............................32
Figure 3. 18. The selectable color threshold for filtering..........................................32
Figure 3. 19. Image after processed with threshold ..................................................33
Figure 3. 20. Determine binary image area and draw contour. .................................34
Figure 3. 21. The value belong x and y axis of center point in binary image ...........34
Figure 3. 22. Flowchart of blood type determination in Gel Card Reader ...............35
Figure 4. 1. The top side (a) and bottom side (b) of PCB .........................................39
Figure 4. 2. The 5 Volt switching power supply .......................................................39
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Figure 4. 3. The inspection output voltage of power supply board ..........................40
Figure 4. 4. Base holder (a) and case (b) of Gel Card Reader ..................................41
Figure 4. 5. Graphic User Interface of Gel Card Reader ..........................................42
Figure 4. 6. PyCharm IDE for python programming ................................................43
Figure 4. 7. Gel Card GUI is built on QT Designer ..................................................45
Figure 5. 1. Input, output jacks of the switching power supply. ...............................47
Figure 5. 2. Measure output voltage when the load is connected. ............................48
Figure 5. 3. GUI of a Gel Card Reader .....................................................................49
Figure 5. 4. Gel Card Reader system ........................................................................50
Figure 5. 5. Sample is put into Gel Card Reader ......................................................51
Figure 5. 6. The Result interpretation .......................................................................52
Figure 5. 7. Wrong Gel Card recognition .................................................................52
Figure 5. 8. The result interpretation (Sample 1: O- ; Sample 2: B+) ......................53

Figure 5. 9. The result interpretation (Sample 1: A+ ; Sample 2: B-) ......................53
Figure 5. 10. DG Reader of GRIFOLS .....................................................................54
Figure 5. 11. Gel Card Reader and GRIFOLS’s DG Reader Comparison ...............55

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LIST OF TABLES
Table

Page

Table 2. 1. Raspberry Pi all generations comparison. ...............................................11
Table 3. 1. The consumption power of the circuit ....................................................15
Table 3. 2. Electronic component of the input filter and rectifier circuit .................20
Table 3. 3. Electronic component of pulse generating circuit ..................................21
Table 3. 4. Electronic component of secondary voltage rectifier circuit ..................23
Table 3. 5. Electronic component of secondary voltage feedback circuits ...............24
Table 4. 1. Electronic component of the switching power supply board ..................37
Table 5. 1. Outputs/Inputs voltage of power supply testing .....................................48
Table 5. 2. The Accuracy and Efficiency of Gel Card Reader ………………….…54

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ABSTRACT

Subject "Design of a Gel Card Reader for blood grouping tests." will have the
function of reading Gel Card in the blood group test, identifying faulty Card and
managing patient information. Here use a unique feature, agglutination of the gel
columns, to calculate the results. Results of the project have identified Gel Card in
different blood types and have high accuracy. First, the Gel Card image will be
captured by the camera after manipulating the user interface. The data is then
transferred to the Raspberry Pi 4B for image processing for input processing and
result computation. The results will be displayed on the user interface. Also, the
system has the function of saving results to manage patient information.

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CHAPTER 1. INTRODUCTION

Chapter 1. INTRODUCTION
1.1. PROBLEM STATEMENT
Health plays a vital role in our lives. Now blood testing has become an important
area, including biochemical testing, hematology, blood clotting, and blood grouping.
It detects early signs of abnormalities in the blood and tends to treat promptly. From
centuries ago, the discovery of inadequacies in blood transfusion prompted scientists
to find the reason for not transfusing blood from person to person. In 1901, Karl
Landsteiner, who is an Austrian doctor, an essential individual in blood transfusion,
for the first time discovered three human blood types A, B and O. One year later, the
4th blood type (AB) recorded by A. Decastrello and A. Sturli. More than 40 years
later, a factor considered to be the leading cause of blood transfusion reactions (Rh
factor) was discovered by Karl Landsteiner, Alex Wiener, Philip Levine and RE
Stetson. Along with the ABO blood type system, the Rh factor is seen as a

breakthrough in blood banking [1].
In the last century, the blood grouping test consisted of two main methods:
testing on enamel slabs and in vitro. These methods have the advantage of being
simple, easy to manipulate, cheap in price but have the disadvantage of easy technical
errors and confusion in administrative procedures, depending on the user's skills and
qualifications. In 1988, Dr. Yves Lapierre developed Gel technology in blood
grouping to minimize the problems occurring compared with the old method. The
Gel Card is considered the most popular form to be the most effective in blood
grouping in hospitals, clinics and laboratories [2].
A Gel Card Reader was invented and used to determine the blood grouping.
Currently, hospitals in Vietnam and around the world are using this device. However,
A Gel Card Reader presently is distributed in Vietnam is not less than 5000 USD.
Therefore, the idea of researching and manufacturing a Gel Card Reader with a
similar blood group determination function but with a much lower price will
significantly contribute to the field of medical tests. For the above reasons, the group
decided to implement the graduation thesis “Design of a Gel Card Reader for blood
grouping tests.” The Gel Card Reader uses a camera to take pictures of the Gel Card
containing the treated blood. The camera will send a Gel Card image to a central
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CHAPTER 1. INTRODUCTION
processing unit. The central processor will use an image processing algorithm
programmed to process the Gel Card image and produce the defined blood group
results.

1.2. OBJECTIVE
This project aims to create a system that can read the Gel Card for classifying
blood group. In particular, this system consists of a Raspberry Pi 4B, a camera, a
screen and algorithms of image processing.

1.3. THESIS CONTENTS
●

CONTENT 1: Research on blood group system, Gel Card method.

●

CONTENT 2: Research the functions of Gel Card Reader.

●

CONTENT 3: Design flowchart, write the code for image processing.

●

CONTENT 4: Designing a power supply for Gel Card Reader.

●

CONTENT 5: Designing a case for Gel Card Reader.

●

CONTENT 6: Design a graphical user interface (GUI) for the system.

●

CONTENT 7: Execute the system, evaluate the results, compare with similar
equipment, re-evaluate the advantages and disadvantages.

●

CONTENT 8: Write a thesis report.

1.4. LIMITATIONS
●

No results will be saved in the event of a power failure.

●

Card Reader only reads with popular Cel Cards as Forward, Forward and
Reverse, CrossMatch, Coombs.

●

The instrument does not recognize the type of Gel Cards through the barc1.5.

BRIEF SUMMARY OF THESIS
 Chapter 1: Introduction
This chapter shows the Gel Card method's importance, point out the topic's
limitations, goals, and make lists.
 Chapter 2: Materials and methods
This chapter describes the theoretical basis of “Design of a Gel Card Reader for
blood grouping tests” and the model's working principle.

 Chapter 3: Design and Calculation

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CHAPTER 1. INTRODUCTION
This chapter presents to choose the components and learn how to connect them,
and suggest the system's design method.
 Chapter 4: Connection of system parts
This chapter shows how the system is executed and applied to the image
processing method.
 Chapter 5: Result and discussion
This chapter discusses the results achieved after completing the system,
commenting on the results achieved.
 Chapter 6: Conclusion and future works
This chapter shows the conclusion about the things that we complete, not
complete and some drawbacks. Present the plan of the topic in the future.

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CHAPTER 2. LITERATURE REVIEW

Chapter 2. LITERATURE REVIEW
In this chapter, an overview of theories related to the Gel Card Reader
implementation is presented.
2.1. TYPES OF HUMAN BLOOD
Blood in humans is divided into 4 main parts: Red blood cells, white blood cells,
plasma and platelets. Red blood cells are the main basis in blood type determination.
ABO blood type system is the main blood type system that helps people identify
blood types such as A, B, AB, O.
Blood types are classified based on the presence or absence of a particular
antigen. An antigen is a foreign substance that induces an immune response in the
body alone or after complex formation with larger molecules. When A antigens are
present on red blood cells, a person is said to have blood type A. A person with B
antigens on red blood cells is considered blood type B. When both A and B antigens
are all present on red blood cells, the person's blood type is classified as AB. In the
absence of antigens, A and B, the person is said to have Blood Type O.

Figure 2. 1. The ABO blood grouping system (Source: Wikipedia)
This is called a basic grouping system and can be classified into eight groups
when considering the Rhesus factor or the ‘Rh 'factor. The name Rhesus is derived
from the Rhesus monkey, where the antigen was first found. If Rhesus D factor is
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CHAPTER 2. LITERATURE REVIEW
found in the blood, then the person is considered Rhesus positive, and for people

without Rhesus D factor, they are said to be Rhesus negative. So when people are
classified under both systems, they are said to have either AB blood type or negative
O blood type.
The Rhesus factor plays an important role during pregnancy because the infant's
life can be in danger if the baby inherits Rhesus positive from the father, while the
mother's blood is Rhesus negative. This will cause the mother's body to form
antibodies against the child's blood.

2.2. GEL CARD METHOD AND TYPE OF GEL CARDS
2.2.1 Gel Card method
In Gel Technology, the reaction is performed in a specially designed plastic card
called the Gel Card. This plastic card consists of six or eight micro tubes. These
microtubules are pre-filled with the corresponding gel and reagent (Anti A, Anti B,
Anti D, AHG) depending on the card parameter. Gel plates are used for different sizes
and act together as a sieve that only a single normal red blood cell can pass through
and show negative. The agglomerated erythrocytes are trapped in the gel column. The
gel and gel particle size will determine the sensitivity of the system.

Figure 2. 2. Gel Card and parts inside the Gel Card tube
A red blood cell suspension was prepared using LISS (Low Ion Strength
Solution), red blood cell suspension, and serum / plasma added to the reaction
chamber of the microtubules. Then the gel tag is incubated and the antigen antigen
reaction takes place in the reaction chamber. After incubation, the Gel Card was
centrifuged for 10 minutes (Force 85g). Under these controlled conditions when the
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CHAPTER 2. LITERATURE REVIEW
card is centrifuged, only a single normal RBC can pass through the gel and settle to
the bottom of the microtubule to form a knot. The reacted or agglomerated cells are
retained either on the gel column or in the gel column, their position in the gel will
depend on the size of the agglutination and thus facilitate the classification of the
reaction.

Figure 2. 3. Interpretation of results
4 + RBCs are agglutinated at the top of the gel column.
3 + Most of the agglutination erythrocytes remain in the upper half of the gel
column.
2 + Red cell agglutination is observed throughout the length of the column. A few
groups of red blood cells may also be displayed at the bottom of the gel column.
1 + Most RBCs are in the lower half of the column. Some can also be shown at the
bottom of the gel column.
All red blood cells pass through and form a compact knot at the bottom of the gel.
All 4+ 3+ 2+ 1+ case are positive, 0 or - considered negative.

2.2.2 Type of Gel Cards
a) Forward grouping Gel Card
Forward grouping Gel Card has 8 micro tubes, each test uses 4 tubes A, B, D
and Ctrl. Tube A contains antibodies A, tube B contains antibodies B, tube D contains
antibodies D, tube Ctrl is a neutral environment. Figure 2.4 has shown below is an
example of the Forward card.
Suppose a patient has blood type A, that is, their blood has A antigens and B
antibodies, after diluting the patient's erythrocyte solution and LISS solution, inject

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CHAPTER 2. LITERATURE REVIEW
the upper suspension into 3 tubes of ABD. Then into a centrifuge at 880 rpm for 10
minutes, the results will be displayed on the Gel Card as follows:
 Column A contains antibodies A, so the patient's A antigen will be retained by
antibody A and not pulled down by centrifugal force. The result will be positive.
 Column B contains antibody B, so the patient's A antigen will not be retained
by antibody A. The results will be negative.
 Column D is used to determine the blood group system of patients with Rh + or
Rh- systems, if there is a positive agglutination present, Rh + patients, if
negative, Rh- patients
 Ctrl column to check the quality of Gel Card, if the value shown in that column
is a negative value, it shows that Gel Card is still available, otherwise, Gel Card
is no longer valid.

Figure 2. 4. Sample of Forward grouping Gel Card
b) Card Reader
Gel Card after adding all the ingredients will be rotated in a centrifugal camera
with 85g force (if the card has AHG tube to incubate at 37 degrees C for 15 minutes).
Then the agglutination result will be displayed on the card, in order to read the card
quickly and effectively, a Gel Card Reader is based on image processing method to
determine the degree of condensation. in the gel column.
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CHAPTER 2. LITERATURE REVIEW

2.3. IMAGE PROCESSING ALGORITHM.
2.3.1 Dilation method
The expansion operation is defined as A⊕B = ⋃Bx where x⊂A where A is an
object in the image, B is an image element structure. This calculation works to make
the original thing in the image increase in size (expand). The image structure element
(image structuring element) is a predefined cube that interacts with the image to see
if it is available. Some common element structures are squares and cross-shaped
facilities.

Figure 2. 5. Dilation in image processing (Source: www.cs.auckland.nz)
In some practical applications, the image expansion algorithm is used in product
classification, detecting license plates, in the graduation project of Phan Thanh
Phong, Nguyen Hien Minh with the topic "ỨNG DỤNG XỬ LÝ ẢNH TRONG HỆ
THỐNG PHÂN LOẠI SẢN PHẨM " [3]. using image expansion to clarify objects to
increase accuracy in classifying or in the graduation project of Vo Danh Quan,
Nguyen Minh Hao with the topic "ĐẾM SỐ LƯỢNG VIÊN THUỐC CÓ TRONG
VỈ THUỐC"

[4]

also use expansion math to clarify the image of the pill so that the

microcontroller can handle it.
2.3.2 Edge detection method
Canny Edge Detection is an algorithm used to extract edges from images.

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CHAPTER 2. LITERATURE REVIEW
The algorithm has four stages:
 First - Performs noise reduction with a Gaussian Blur.
 Second - Gets the gradient direction and magnitude with a Sobel kernel.
 Third - Applies non-maximum suppression, which removes unwanted pixels
that are not part of a contour.
 Fourth — Applies the Hysteresis Thresholding that uses min and max values to
filter the contours by the intensity gradient [5].
In practical applications, edge detection is used in object detection and
recognition. In Nguyen Thanh Huy's master's thesis, University of Da Nang, the topic
“ỨNG DỤNG PHƯƠNG PHÁP PHÁT HIỆN BIÊN TRONG NHẬN DẠNG CÁC
ĐỐI TƯỢNG HÌNH HỌC [6].” Uses an edge detection method to detect objects.

2.4. IMAGE CAPTURING DEVICES
One of the most important parts of the subject is the image capturing device, as
they take primary responsibility for capturing images, the use of a large-resolution
camera (1920x1080) along with having to capture close-up is not a small problem.
We decided to use the HOCO DI01 webcam as an image recognition camera because
of its good price, high resolution, ease of use. The webcam is connected to the microcontrol via a USB port. The use of cameras in image processing has become prevalent
from product counting and classification systems, face recognition, and license plate
detection.
2.4.1 Microprocessor introduction
The use of microcontrollers in embedded programming is not too unfamiliar,

from lines like microcontrollers PIC16F887, STM32, Arduino, Intel Galileo,
Raspberry Pi. Each type will have its own characteristics suitable for the purpose of
use. In image processing, Raspberry Pi is popularly used because its configuration
far exceeds other types of microcontrollers, from simple applications like product
color checking, license plate detection to complex applications like facial recognition,
machine learning.
The Raspberry Pi is a microcontroller that is widely used in real-world
applications. Specifically, the graduation project of Nguyen Phuc Bao, Nguyen Le
DEPARTMENT OF ELECTRONIC – BIOMEDICAL ENGINEERING

do an

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CHAPTER 2. LITERATURE REVIEW
Gia Bach, HCMUTE with the topic "DESIGN OF AN IMAGE ACQUISITION
SYSTEM FOR THE DETECTION OF OCCLUSAL DENTAL PROBLEMS

[7]

."

Also using a Raspberry Pi 3B as a microcontroller or in the graduation project of Le
Hoang Thanh, Ho Dinh Vuong, HCMUTE, with the topic "THIẾT KẾ VÀ THI
CÔNG HỆ THỐNG BẢO MẬT ỨNG DỤNG XỬ LÝ ẢNH

[8]

. " There is also use

of the Raspberry Pi 3B as a microcontroller.
Launched in 2019, Raspberry Pi 4B is one of the most powerful embedded
computers with 3 times more power than the Pi 3B, in addition, the Pi 4B also offers
RAM options like 2Gb, 4Gb, 8Gb. The use of raspberry Pi 4B in image processing is
no longer something too strange. Compared to other embedded kits such as Arduino,
Intel Galileo, NVidia Jetson Nano ... the Raspberry is considered the most efficient
embedded Kit, in the Pi 4B version there has been a significant upgrade of RAM, as
the team's image processing algorithm uses a python programming language, so it
requires a micro-control that can run the language as well as have sufficient power to
perform the necessary image processing operations , with the goal of this topic to
create a compact Gel Card Reader, the Raspberry is considered the most suitable
micro-control.

DEPARTMENT OF ELECTRONIC – BIOMEDICAL ENGINEERING

do an

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