A STUDY OF ULTRASOUND MEASUREMENT UTILIZED FOR THE LIVER TESTING

Transcription

1 INTERNATIONNAL JOURNAL OF APPLIED BIOMEDICAL ENGINEERING VOL.4, NO A STUDY OF ULTRASOUND MEASUREMENT UTILIZED FOR THE LIVER TESTING Adisorn Leelasantitham and Supaporn Kiattisin, ABSTRACT Presently, there are many elders obtained from liver diseases in the case of an unknown before by themselves. If they do not diagnose such liver diseases before, they may die. There are many methods for diagnosing the liver e.g. a puncture of blood, ultrasound, computed tomography (CT) scan, X-ray and magnetic resonance imaging (MRI). These methods can be selected to verify the liver diseases depending on situations, chances and environments for human living. Therefore, we need to know these methods before, and how to choose suitable methods for diagnosis of our liver. This paper presents a study of ultrasound measurement utilized for the liver testing. In this study, we use ultrasonic to produce ultrasound waves at frequency 3.5 MHz for testing the liver which we use a pig liver instead of human liver. The pig liver is put in a small acyclic box with the soaked water. There are three conditions for testing ultrasound waves i.e. water, normal liver and abnormal liver (burn or disease). The ultrasound waves are sent to the small acyclic box containing the pig liver and dispatched to a probe of oscilloscope for measurement. These waves are shown by the oscilloscope and they are differently between the normal and abnormal livers. In this experiment, we test 10 times for both the normal and the abnormal livers. The results show that the average velocities of the ultrasound waves in water, normal liver and abnormal liver are at approximately 1,500 m/s, 1,590 m/s and 2,000 m/s, respectively. 1. INTRODUCTION Nowadays, many elders have been liver diseases (LDs) but they do not know such LDs before. Generally, the LDs are obtained from many reasons such as inflamed from Virus B, Virus C, alcohols or others etc. Such reasons can be the cause of cancers. If we diagnose it before, we will cure it earlier through the use of a new liver substituted for the old liver for stopping the distribution of cancers to inner and outer arteries of the liver. Therefore, it is necessary Manuscript received on April 5, 2011., The authors are with the Technology of Information System Management Program, Faculty of Engineering, Mahidol University, Thailand, egadisorn@mahidol.ac.th and tom kiattisin@hotmail.com to know the diagnosis methods for checking the liver firstly. Finally, there are normally five methods of diagnosis for the LDs [1] such as 1) a puncture of blood, 2) ultrasound, 3) computed tomography (CT) scan, 4) X-ray and 5) magnetic resonance imaging (MRI). From the summary of five methods [1] (i.e. puncture of blood, ultrasound, CT scan, X-ray and MRI), we can conclude that the ultrasound is suitable method to use for diagnosis of our liver because it is easy and not harmful to test the liver. Another reason of advantage for the ultrasound may be a low cost compared to those methods. Recently, there have been research papers reporting the use of the ultrasound utilized for the change of tissue caused by diseases (e.g. cancer). For example, the paper [2] has proposed a measured 3D distribution of parameters on tissue elasticity and viscosity using the ultrasound. The paper [3] has presented the use of ultrasound transducers for a measurement of directivity pattern. It means that the beam pattern of ultrasound waves is emitted from the transducers of varying resonance frequencies depending on the frequency of the transducers. In this paper, the study of ultrasound measurement is presented through the liver testing to find the velocities of the ultrasound waves in water and liver. We use ultrasonic to produce ultrasound waves at frequency 3.5 MHz for testing the liver which we use a pig liver instead of human liver. The pig liver is put in a small acyclic box with the soaked water. There are three conditions for testing ultrasound waves i.e. water, normal liver and abnormal liver (burn or disease). 2. METHODOLOGY Figure 1 shows methodology for the ultrasound measurement of the liver testing. It can be seen from Fig. 1 that the ultrasound generator will produce ultrasound waves of the frequency at 3.5 MHz. This frequency is sent to the liver and then it is dispatched to such the liver. Finally, this dispatched frequency is measured by the oscilloscope to show the output 2. 1 EQUIPMENTS AND TESTING CON- DITIONS Speed calculation of ultrasound in the water This section will describe an example of speed cal-

2 20 A. Leelasantitham and S. Kiattisin: A Study of Ultrasound Measurement Utilized For The Liver Testing(19-23) (a) Fig.1: Methodology for the ultrasound measurement of the liver testing. culation of ultrasound in the water. A basic concept of speed calculation is that we need to know distance and time usage time before. The speed equation can be defined as V = S/T (1) where V is the wave speed, S is the distance obtained by moving wave from the start point to the end point. T is the usage time derived by spending the time of distance of wave traveling. For example of speed calculation, Figure 2 shows distances and time divisions of measuring the ultrasound wave in the water. It can be seen from Figs. 2 (a) and (b) that the distances of traveling ultrasound in the water (between the shooting head and edge of box) are 4.5 cm, and the time divisions are 6 blocks. The times of one division are 10 s; therefore, the total times of traveling ultrasound in the water are 60 s i.e = 60 µs. The speed of ultrasound in the water (go and back) using equation (1) is 1,500 m/s i.e. (4.5cm/60 µs)x2 = 1,500 m/s Equipments Figure 3 shows equipments prepared for the ultrasound measurement of the liver testing. It can be seen from Fig. 3 that the main equipments consist of 5 parts as follows. The 1 st part is ultrasound generator, as shown in Fig. 3(a). The 2 nd part is a shooting head of the ultrasound generator, as shown in Fig. 3(b) and the 3 rd part is a big acyclic box covered black color of four sides, as shown in Fig. 3(c). The 2 nd part is taken into the 3 rd part as shown in Fig. 3(d). The 4 th part is oscilloscope to measure the output signal, as shown in Fig. 3(e). Finally, the 5 th part is a computer including program of collecting the signal into digital data, as shown in Fig. 3(f). Figure 4 (b) Fig.2: (a) Distances and (b) time divisions of measuring the ultrasound waves in the water. shows all of connected equipments for preparing the liver testing Testing conditions For the testing conditions, we use a pig liver instead of human liver for testing output results in different between normal and abnormal liver (burn or disease). Figure 5 shows a big acyclic box covered black colors (or the 2 nd part) and a small acrylic box of transparence. These two boxes will contain the water together. It can be seen from Fig. 5 that the small acrylic box is contained into the big acyclic box whilst the pig liver also is contained into the small box. The 1 st range is distance between the shooting head and the edge of small box, as well as the 2 nd range is distance of the gap in the small box. There are three conditions of the liver testing as follows. The 1 st, 2 nd and 3 rd conditions are small acrylic box of transparence with the water, the pig liver and the burned pig liver. 3. EXPERIMENTAL RESULTS AND FUTHER STUDY In this study, the ultrasound is selected at frequency 3.5 MHz. This study is to test 10 times for the

3 INTERNATIONNAL JOURNAL OF APPLIED BIOMEDICAL ENGINEERING VOL.4, NO Fig.5: A big acyclic box covered black colors (or the 2 nd part) and a small acrylic box of transparence. Fig.3: Equipments prepared for the ultrasound measurement of the liver testing, (a) ultrasound generator, (b) a shooting head of the ultrasound generator, (c) a big acyclic box covered black color of four sides, (d) the 2 nd part taken into the 3 rd part, (e) oscilloscope and (f) a computer. Fig.4: All of connected equipments for preparing the liver testing. three conditions i.e. water, normal pig liver and abnormal pig liver (burn or disease), as shown in Table 1. Table 1 shows three conditions of the liver testing corresponding to Fig. 5. Table (a) shows the 1 st, 2 nd and 3 rd conditions are small acrylic box of transparence with the water, the pig liver and the burned pig liver. It can be seen from Table 1 (b) that the distances corresponding to the three conditions are summarized in terms of the 1 st and 2 nd ranges of 4.5 and 1 cm, respectively. Table 1 (c) shows numbers of time divisions (oscilloscope) which are measured from the experiments in the three conditions. The results of output waveform show that the numbers of the 1 st range are 6 divisions of all three conditions, whilst the numbers of the 2 nd range are 1.333, 1.258, and 1 divisions of the 1 st, 2 nd and 3 rd conditions, respectively. Table 1 (d) shows the calculated results of time delay using the speed calculation based on Tables 1 (b) and (c) for the 1 st, 2 nd and 3 rd conditions. Figures 6, 7 and 8 show examples of practical testing for the 1 st, 2 nd and 3 rd conditions, respectively. Tables 2, 3 and 4 show summaries of the liver testing in terms of the frequency, voltage and velocity, for the 1 st, 2 nd and 3 rd conditions, respectively. The overall results can be summarized as follows. The results show that the average velocities of the 2nd range in the water, normal liver and abnormal liver (burn or disease) are at approximately 1,500 m/s, 1,590 m/s and 2,000 m/s, respectively. These experimental results are closely to the results from theory [4] revealed by the approximate velocities of ultrasound waves in water and in liver are 1,480 m/s and 1,570 m/s, respectively. For the further study of these results, we can extend and apply this work for practical measurements of the human liver based on, for example, microcontroller, embedded systems or FPGA etc.

4 22 A. Leelasantitham and S. Kiattisin: A Study of Ultrasound Measurement Utilized For The Liver Testing(19-23) Table 1: Three conditions of the liver testing corresponding to Fig. 7. Fig.7: Examples of practical testing for the 2 nd Fig.6: Examples of practical testing for the 1 st Table 3: Summaries of the liver testing in terms of the frequency and velocities for the 2 nd condition ,500 1, ,500 1, ,500 1, ,500 1, ,500 1, ,500 1, ,500 1, ,500 1, ,500 1, ,500 1,590 Table 2: Summaries of the liver testing in terms of the frequency and velocities for the 1 st condition ,500 1, ,500 1, ,500 1, ,500 1, ,500 1, ,500 1, ,500 1, ,500 1, ,500 1, ,500 1,500 Table 4: Summaries of the liver testing in terms of the frequency and velocities for the 3 rd condition ,500 2, ,500 2, ,500 2, ,500 2, ,500 2, ,500 2, ,500 2, ,500 2, ,500 2, ,500 2,000

5 INTERNATIONNAL JOURNAL OF APPLIED BIOMEDICAL ENGINEERING VOL.4, NO Fig.8: Examples of practical testing for the 3 rd 4. CONCLUSION This paper has presented the study of ultrasound measurement utilized for the liver testing. In this study, we use ultrasonic to produce ultrasound waves at frequency 3.5 MHz for testing the liver which we use the pig liver instead of human liver. The pig liver is put in a small acyclic box with the soaked water. There are three conditions for testing ultrasound waves i.e. the water, normal liver and abnormal liver (burn or disease). The ultrasound waves are sent to the small acyclic box containing the pig liver and dispatched to the probe of oscilloscope for measurement. Shapes of these waves are shown by the oscilloscope and they are differently between the normal and abnormal livers. In this experiment, we test 10 times for both the normal and the abnormal livers. The results show that the average velocities of the ultrasound waves in the water, normal liver and abnormal liver are at approximately 1,500 m/s, 1,590 m/s and 2,000 m/s, respectively. These experimental results are closely to the results from theory [4]. References [1] Adisorn Leelasantitham, A Study of various methods for Diagnosis Human Liver, The 3 rd Biomedical Engineering International Conference (BMEiCON2010), Kyoto, Japan, 26-August 26-27, [2] Tsuyoshi Shiina, In Vitro 3-D Measurement of Tissue Viscoelasticity by Ultrasound, International Journal of Applied Biomedical Engineering (IJABME), Vol. 1, No. 1, July-December 2008, pp [3] Sumet Umchid, Directivity Pattern Measurement of Ultrasound Transducers, International Journal of Applied Biomedical Engineering (IJABME), Vol. 2, No. 1, January-June 2009, pp [4] William R. Hendee, E. Russell Ritenour, Medical Imaging Physics, 4 th Edition, Wiley Publisher, May Adisorn Leelasantitham received the B.Eng. degree in Electronics and Telecommunications and the M.Eng. degree in Electrical Engineering from King Mongkut s University of Technology Thonburi (KMUTT), Thailand, in 1997 and 1999, respectively. He received his Ph.D. degree in Electrical Engineering from Sirindhorn International Institute of Technology (SIIT), Thammasat University, Thailand, in He is currently the Assistant Professor in Technology of Information System Management Program, Faculty of Engineering, Mahidol University, Thailand. His research interests include analog circuits, image processing, medical images, computer graphics, AI, neural networks, microcontrollers, embedded systems, robotics and applications of chaos systems. Supaporn Kiattisin received B.Eng. in Computer Engineering from Chiangmai University in 1995, M.Eng. in Electrical Engineering and Ph.D. in Electrical and Computer Engineering from King Mongkuts University of Technology Thonburi (KMUTT), Bangkok, Thailand. She currently works at Technology of Information System Management Program, Faculty of Engineering, Mahidol University, Thailand. Her research interests include medical imaging, computer vision and modeling. She is member of TESA, ThaiBME, IEICE and IEEE. 5. ACKNOWLEDGEMENT The authors are grateful to Mr. Apirat Tachompoo, Mr. Tinankorn Chamnansutha, Mr. Kampanart Chomchuy for their useful help in this work and to thank Mr. Arthorn Sanpanich for his support of facilities in Research Laboratory, Department of Electronic Engineering, KMITL.