June 29, 2025

องค์ความรู้

Microwave Imaging for Breast Cancer Detection- A Comprehensive Review

Bhargava D. Jiamjiroch K. and Rattanadecho P. “Microwave Imaging for Breast Cancer Detection- A Comprehensive review“ Engineered Science,vol 30, pp.1116 2024,DOI:10.30919/es1116 Scopus, Q1 : Impact Factor 16.6 Abstract The paper presents an extensive discussion on Microwave Imaging (MI) for breast cancer detection. Breast cancer has become a major cause of death among women worldwide, this makes the early detection of the cancerous tumor very essential in providing a rapid and effective treatment. Microwave Breast Imaging (MBI) is an emerging technique that is non-ionizing, non-invasive, safer and cheaper in comparison to the conventional techniques. It uses microwave radiation to generate an internal image of the breast, showing the tumor embedded in the breast layers. The paper begins by introducing the basic working principles of MBI and its types, anatomy of the breast, and the differences in the dielectric properties between normal and malignant tissues. Active type of MBI – tomography and radar-based imaging are mainly covered in this paper. The most important part of active microwave imaging, i.e. antennas used for scanning the breast are also discussed. Moreover, numerical, experimental as well as clinical studies performed over the years are highlighted. In the end, challenges in the current techniques and future prospective of MBI are presented. Overall, this review paper provides a comprehensive insight into the techniques used in MBI, and the state-of-the-art research in this field.

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Tissue poromechanical deformation effects on steam pop likelihood in 3‑D radiofrequency cardiac ablation

Preechaphonkul W. and Rattanadecho P. , “The effects of dielectric & thermal property functions on the thermal response during the focused microwave ablation treatment in the liver cancer model: numerical investigation“, Engineered Science, 2022, Scopus, Q1 : Impact Factor 2.436 Abstract Radiofrequency Cardiac Ablation (RFCA) is a common procedure that heats cardiac tissue to destroy abnormal signal pathways to eliminate arrhythmias. The complex multiphysics phenomena during this procedure need to be better understood to improve both procedure and device design. A deformable poromechanical model of cardiac tissue was developed that coupled joule heating from the electrode, heat transfer, and blood flow from normal perfusion and thermally driven natural convection, which mimics the real tissue structure more closely and provides more realistic results compared to previous models. The expansion of tissue from temperature rise reduces blood velocity, leading to increased tissue temperature, thus affecting steam pop occurrence. Detailed temperature velocity, and thermal expansion of the tissue provided a comprehensive picture of the process. Poromechanical expansion of the tissue from temperature rise reduces blood velocity, increasing tissue temperature. Tissue properties influence temperatures, with lower porosity increasing the temperatures slightly, due to lower velocities. Deeper electrode insertion raises temperature due to increased current flow. The results demonstrate that a 5% increase in porosity leads to a considerable 10% increase in maximum tissue temperature. These insights should greatly help in avoiding undesirable heating effects that can lead to steam pop and in designing improved electrodes.

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Specific absorption rate and temperature elevation in the human head due to overexposure to mobile phone radiation with different usage patterns

Bhargava D. , Leeprechanon N. Rattanadecho P. and Wessapan T., “Specific Absorption Rate and Temperature Elevation in the Human Head Due to Overexposure to Mobile Phone Radiation with Different Usage Patterns”, International Journal of Heat and Mass Transfer, Vol 130, pp. 1178-1188, 2019: Impact Factor 4.94 (Q1) Abstract Accidental overexposure to non-standard mobile phone radiation can occur in many situations. The overpower limit of mobile phone radiation interacts with the human body which could result in an adverse effect on human health. It is envisaged that the severity of the physiological effect can take place with small temperature increase in the delicate organs or tissues such as eyes, brain, skin, etc. However, the resulting thermo-physiological response of the body tissues to overpower limit of mobile phone radiation is still not well implemented. The aim of this study is to analyze the effect of overexposure of mobile phone radiation on the specific absorption rate (SAR) and temperature increase in three-dimensional heterogeneous human head models. The study focuses attention on the differences in the electromagnetic (EM) absorption characteristics with higher power level among different usage pattern. The effect of three different usage patterns – voice calling, video calling, and texting- on SAR and temperature distributions in different types of head tissues is systematically investigated. This paper also investigates the effects of different user ages, radiated powers, and gap distances between mobile phone and human heads, on SAR and temperature distributions. Results obtained from this analysis considering the safety guidelines show a high impact of mobile phone radiation in the voice calling position. Hence, comparisons of the absorption of mobile phone radiation are calculated between an adult and a 7-year-old child head model, for the voice calling position at different gap distances. In addition, the results indicate that child head always has a higher absorption rate of mobile phone radiation than the adult head. The rate of absorption in tissue increases as the distance between mobile phone and head decreases and the radiated power increases, depending on their dielectric and thermal properties. The obtained results can be helpful in determining exposure limits for the power output of the mobile phone, and the distance a user should maintain from the mobile phone in thermo-physiological aspects.  

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Temperature induced in human organs due to near-field and far-field electromagnetic exposure effects

Wessapan, T. and Rattanadecho, P. “Temperature Induced in Human Organs due to Near-Field and Far-Field Electromagnetic Exposure Effects“. International Journal of Heat and Mass Transfer, Vol 119, pp. 65-76, 2018: Impact Factor 4.94 (Q1) Abstract The main biological effect from exposure to electromagnetic (EM) radiation is a temperature rise in the human body and its sensitive organs, which results from absorbing electromagnetic field (EMF) power. EM near-field and far-field sources, which have different operating frequencies and exposure distances, result in different EMF distribution patterns and EMF power absorptions by the human body. Actually, the severity of the physiological effect can occur with small temperature increases in the sensitive organs. However, the EM absorption characteristics and the temperature increase distribution resulting from different field radiation patterns from EM sources are not well established. To adequately explain the biological effects that are associated with the EMF energy absorption, a systematic study of different EMF distribution patterns and how they interact with body tissue is needed. This study considers the computationally determined specific absorption rate (SAR) and the heat transfer in a heterogeneous human torso model with internal organs exposed to near-field and far-field EM radiations at different frequencies. The electric field, SAR, and the temperature distributions in various organs during exposure to EMFs are obtained through the numerical simulation of EM wave propagation and an unsteady bioheat transfer model. The findings indicate that the field radiation pattern and the operating frequency of an EM source significantly influence the electric field, the SAR, and the temperature distribution in each organ. Moreover, the tissue’s dielectric properties also affect the temperature distribution patterns within the body tissue. These findings enable researchers to more accurately determine the exposure limits for the power output of wireless transmitters, and the distance that they should remain from the humans.  

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Temperature induced in the testicular and related tissues due to electromagnetic fields exposure at 900 MHz and 1800 MHz

Wessapan, T. and Rattanadecho, P. “Temperature induced in the testicular and related tissues due to electromagnetic fields exposure at 900 MHz and 1800 MHz“. International Journal of Heat and Mass Transfer, Vol102, pp. 1130-1140, 2016: Impact Factor 4.94 (Q1) Abstract Increased testicular temperature adversely affects the reproductive system in the male. Environmental conditions, namely high ambient temperature and electromagnetic fields (EMFs), influence the temperature increase in the human body. This study considers the computationally determined specific absorption rate (SAR) and the heat transfer in a piecewise-homogeneous human model of the male reproductive organs and upper thigh exposed to an electric dipole antenna. The study focuses on increases in testicular temperature due to EMF absorption. Much attention is paid to the effects of the operating frequency and exposure time on the SAR and temperature increases induced by exposure to a near-field EMF. The electric field, SAR and temperature distributions in various tissues during exposure to EMFs are obtained by numerical simulation of EM wave propagation and an unsteady bioheat transfer model. This study indicated that when the model is exposed to EMFs at the frequencies of 900 and 1800 MHz, the highest SAR values are obtained in the scrotum. In the testis, which is the most sensitive part of the male reproductive system, the SAR value of the 900 MHz frequency is significantly higher than that of 1800 MHz, while there are no significant differences in the temperature increases between the two operating frequencies. The obtained results may be of assistance in determining exposure limits for the power output of wireless transmitters, and their operating frequency for use with humans. Significant of this work: The study focuses on increases in testicular temperature due to EMF absorption. Much attention is paid to the effects of the operating frequency and exposure time on the SAR and temperature increases induced by exposure to a near-field EMF. The electric field, SAR and temperature distributions in various tissues during exposure to EMFs are obtained by numerical simulation of EM wave propagation and an unsteady bioheat transfer model. The obtained results may be of assistance in determining exposure limits for the power output of wireless transmitters, and their operating frequency for use with humans.