Understanding of the heat transport within living biological tissues is crucial to effective heat treatments. The heat transport properties of living biological tissues with temperature-dependent properties are explor...Understanding of the heat transport within living biological tissues is crucial to effective heat treatments. The heat transport properties of living biological tissues with temperature-dependent properties are explored in this paper. Taking into account of variable physical properties, the governing equation of temperature is first derived in the context of the dualphase-lags model(DPL). An effective method, according to the Laplace transform and a linearization technique, is then employed to solve this nonlinear governing equation. The temperature distribution of a biological tissue exposed to a pulsed heat flux on its exterior boundary, which frequently happens in various heat treatments, is predicted and analyzed. The results state that a lower temperature can be predicted when temperature dependence is considered in the heating process.The contributions of key thermal parameters are different and dependent on the ratio of phase lag and the amplitude of the exterior pulsed heat flux.展开更多
Based on the diffusion approximate theory （DA）, a theoretical model about the distribution of the intensity of a narrow collimation beam illuminating on a semi-lnfinite biological tissue is developed. In order to ve...Based on the diffusion approximate theory （DA）, a theoretical model about the distribution of the intensity of a narrow collimation beam illuminating on a semi-lnfinite biological tissue is developed. In order to verify the correctness of the model, a novel method of measuring the distributions of the intensity of light in Intralipid-10% suspension at 650 nm is presented and ts of the distributions of the distance-dependent intensity of scattering light in different directions are made. The investigations show that the results from our diffusion model are in good agreement with the experimental results beyond and in the areas around the light source, and the distance-dependent intensity in the incident direction attenuates approximately in the exponential form. Furthermore, our theoretic results indicate the anisotropic characteristics of the intensity in different directions of scattering light inside the biological tissue.展开更多
Biological soft tissues manipulation,including conventional(mechanical)and nonconventional(laser,waterjet and ultrasonic)processes,is critically required in most surgical innervations.However,the soft tissues,with the...Biological soft tissues manipulation,including conventional(mechanical)and nonconventional(laser,waterjet and ultrasonic)processes,is critically required in most surgical innervations.However,the soft tissues,with their nature of anisotropic and viscoelastic mechanical properties,and high biological and heat sensitivities,are difficult to manipulated.Moreover,the mechanical and thermal induced damage on the surface and surrounding tissue during the surgery can impair the proliferative phase of healing.Thus,understanding the manipulation mechanism and the resulted surface damage is of importance to the community.In recent years,more and more scholars carried out researches on soft biological tissue cutting in order to improve the cutting performance of surgical instruments and reduce the surgery induced tissue damage.However,there is a lack of compressive review that focused on the recent advances in soft biological tissue manipulating technologies.Hence,this review paper attempts to provide an informative literature survey of the state-of-the-art of soft tissue manipulation processes in surgery.This is achieved by exploring and recollecting the different soft tissue manipulation techniques currently used,including mechanical,laser,waterjet and ultrasonic cutting and advanced anastomosis and reconstruction processes,with highlighting their governing removal mechanisms as well as the surface and subsurface damages.展开更多
The main objective of this proposed article is to provide explanations to justify the validity of the results of the studies of the interaction between the electromagnetic fields and the human body. It can also find d...The main objective of this proposed article is to provide explanations to justify the validity of the results of the studies of the interaction between the electromagnetic fields and the human body. It can also find direct applications in the characterization and modeling of the macroscopic electrical properties of the biological media for assessing the effects of fields induced by electromagnetic radiation sources in the human body to set up new standards <span>on the Human exposure to electromagnetic fields. To do this, we have taken into account the different physical phenomena of propagation of a hyper-frequency electromagnetic plane wave and on the other hand, the expe</span>rimental values <span></span><span><span><span style="font-family:;" "="">in order to model the electrical behavior of human biological tissues based on an equivalent electronic circuit model composed of capacities, resistance and reel, which assimilates the biological tissues of the skin, grease, blood. This model using the characteristic impedance of the dielectric support makes it possible to evaluate the voltage induced by the electromagnetic waves of the hyper-frequencies in the studied biological system. The results of the simulations obtained from computer tools demonstrate that the hyper-frequency electromagnetic waves can result in an elevation of the electrical potential of the biological tissues. Despite this potential is a decreasing function of the penetration depth.</span></span></span>展开更多
The anisotropic continuum stored energy density (ACSED) functional is applied for accurate constitutive modeling of biological tissues and finite element implementation without the isochoric—volumetric split, the ani...The anisotropic continuum stored energy density (ACSED) functional is applied for accurate constitutive modeling of biological tissues and finite element implementation without the isochoric—volumetric split, the anisotropic—isotropic split, or the anisotropic invariant split. Related stress and elasticity tensors in the reference and current configurations are worked out. A new kinematic model is derived based on the tangent Poisson’s ratio as a cubic polynomial function of stretch. The ACSED model, along with the kinematic model, accurately fits uniaxial extension test data for compressible human skin, bovine articular cartilage, and human aorta samples.展开更多
The resting potential is the potential difference that exists between the inner and outer sides of the cell membrane when the cell is not stimulated.The resting membrane potential is a key regulator of phenomena such ...The resting potential is the potential difference that exists between the inner and outer sides of the cell membrane when the cell is not stimulated.The resting membrane potential is a key regulator of phenomena such as cell proliferation,morphogenesis,migration and differentiation.In this paper,we proposed a model of electrified cell clusters that considers the resting potential of cell clusters in the resting state.By measuring the potential difference between the inner and outer sides of biological tissues,it is verified that the cell cluster has a negative potential difference when taking the outer potential as the reference.In the absence of external conductors,the tissue is electrically neutral;while in the presence of external conductors,the positive net charges escape freely under repulsive forces and the biological tissues form a negative electrical equilibrium system.The model proposed in this study explored the potential situation above the cellular level in the resting state,providing a new perspective for the research on resting potential.展开更多
Application of matrix-assisted laser desorption/ionization mass spectrometry imaging(MALDI-MSI) to investigate the spatiotemporal alterations of lipids in biological tissues has brought many significant results.Howeve...Application of matrix-assisted laser desorption/ionization mass spectrometry imaging(MALDI-MSI) to investigate the spatiotemporal alterations of lipids in biological tissues has brought many significant results.However, the presence of structural isomers varying in C=C double bond(DB) locations makes isomerresolved MSI an urgent need. Herein, we introduce a new type of light-driven on-tissue [2 + 2] cycloaddition reaction coupled with MALDI-MS/MS imaging to identify lipid DB position isomers and their spatial signatures in biological tissues. 3-Benzoylpyridine was introduced as a novel derivatization reagent, and it exhibited great reactivity toward lipid C=C bond to form oxetanes under both ultraviolet light and visible light irradiation. With this approach, DB position isomers of lipids were imaged with highly differential levels in distinct regions of rat brain, providing an accurate and spatially resolved approach to study tissue lipidomics.展开更多
The thermal effects induced by a moderate intensity focused ultrasound and enhanced by combined laser pulses for bio-tissues and tissue-phantom are studied experimentally and theoretically. At first, the heating effec...The thermal effects induced by a moderate intensity focused ultrasound and enhanced by combined laser pulses for bio-tissues and tissue-phantom are studied experimentally and theoretically. At first, the heating effects of bio-tissues and tissue-phantom induced by ultrasound and enhanced by laser are measured experimentally. The heating processes induced by attenuations of focused ultrasonic waves and cavitation effects of the focused ultrasound and combined laser are analyzed theoretically. By analyzing the mechanisms of these effects, it is found that the laser nucleation makes the cavitation bubble generation more easily, which can effectively enhance the ultrasonic cavitation effects, and then enhance the thermal effects of the samples. On the other hand, to evaluate quantitatively the heating processes induced by the focused ultrasound and enhanced by the pulsed laser, by fitting the theoretical calculations to the experimental results, the corresponding cavitation bubbles and rising temperatures induced by the focused ultrasound with and without laser can be estimated approximately.展开更多
Elasticity is of profound significance to evaluating the function of a biological soft tissue. When the elasticity of a tissue is macroscopically changed, it means that the biological function of the tissue is abnorma...Elasticity is of profound significance to evaluating the function of a biological soft tissue. When the elasticity of a tissue is macroscopically changed, it means that the biological function of the tissue is abnormal and some disease or injury may occur. In the present work, an elastometer is developed to measure the elasticity of biological soft tissues. The measurement is based on the indentation method and the force is measured by the bending of the cantilever. The force-indentation data of the soft tissue is experimentally measured by this elastometer and Young＇s modulus of the tissue is calculated using the Hertz-Sneddon model. For comparison, a numerical model for the indentation method is established using the finite element method. The difference between the actual modulus and the measured modulus is discussed. The effect of the thickness of the specimen on the measurement is investigated. Young＇s moduli of beef, porcine liver and porcine kidney are experimentally measured. The results indicate that our elastometer is effective in measuring Young＇s modulus of a soft tissue quantitatively.展开更多
The study of Electromagnetic Compatibility is essential to ensure the harmonious operation of electronic equipment in a shared environment. The basic principles of Electromagnetic Compatibility focus on the ability of...The study of Electromagnetic Compatibility is essential to ensure the harmonious operation of electronic equipment in a shared environment. The basic principles of Electromagnetic Compatibility focus on the ability of devices to withstand electromagnetic disturbances and not produce disturbances that could affect other systems. Imperceptible in most work situations, electromagnetic fields can, beyond certain thresholds, have effects on human health. The objective of the present article is focused on the modeling analysis of the influence of geometric parameters of industrial static converters radiated electromagnetic fields using Maxwell’s equations. To do this we used the analytical formalism for calculating the electromagnetic field emitted by a filiform conductor, to model the electromagnetic radiation of this device in the spatio-temporal domain. The interactions of electromagnetic waves with human bodies are complex and depend on several factors linked to the characteristics of the incident wave. To model these interactions, we implemented the physical laws of electromagnetic wave propagation based on Maxwell’s and bio-heat equations to obtain consistent results. These obtained models allowed us to evaluate the spatial profile of induced current and temperature of biological tissue during exposure to electromagnetic waves generated by this system. The simulation 2D results obtained from computer tools show that the temperature variation and current induced by the electromagnetic field can have a very significant influence on the life of biological tissue. The paper provides a comprehensive analysis using advanced mathematical models to evaluate the influence of electromagnetic fields. The findings have direct implications for workplace safety, potentially influencing standards and regulations concerning electromagnetic exposure in industrial settings.展开更多
The actions and health effects of electromagnetic fields in the radio frequency (RF) domains, referred to as radio frequencies and HV transmission networks have been studied for several decades. Following the appearan...The actions and health effects of electromagnetic fields in the radio frequency (RF) domains, referred to as radio frequencies and HV transmission networks have been studied for several decades. Following the appearance of questions and debates within the population, the actions and potential effects of radiofrequency and HV transport networks on health, in connection with the development of new wireless technologies, are generating a certain revival of interest. Thus, the increasing exposure to electromagnetic fields and the concerns of the public have led health organizations to undertake large-scale research programs to respond to the concerns expressed. These research programs have contributed to significantly increasing the number of studies on the actions and effects of electromagnetic pollution as well as their consequences on living beings. The objective of our research is focused on the analysis, sources, and study of the biological consequences of electromagnetic pollution. To do this, we have used physical laws and theorems, in particular Maxwell-Ampère, Maxwell-Gauss, Maxwell-Faraday, and Ohm’s law, to model the interactions between electromagnetic fields and living matter. In this article we have chosen the approach based on the electrical model of human biological tissue, taking into account on the one hand the physical phenomena of the propagation of an electromagnetic microwave plane wave in the range from 0 to 300GHz and on the other hand, the experimental values to simulate the relaxations α, β and γ and the impedance of the biological tissue faced with the variation of the frequency of propagation of the electromagnetic waves to identify the biological consequences relating thereto. The results obtained in the literature show the linear dependence of bio-impedance on frequency, these observations suggest that the tissue can be physiologically stressed at high frequencies. This can cause biological consequences for humans. The 2D simulation based on the proposed model has been developed as well as the verification of the consistency of the different mathematical models, by comparing the fractal dimensions of the results of the program with those of the figures obtained experimentally.展开更多
An acoustic dipole radiation model for magnetoacoustic tomography with magnetic induction （MAT-MI） is pro- posed, based on the analyses of one-dimensional tissue vibration, three-dimensional acoustic dipole radiatio...An acoustic dipole radiation model for magnetoacoustic tomography with magnetic induction （MAT-MI） is pro- posed, based on the analyses of one-dimensional tissue vibration, three-dimensional acoustic dipole radiation and acoustic waveform detection with a planar piston transducer. The collected waveforms provide information about the conductiv- ity boundaries in various vibration intensities and phases due to the acoustic dipole radiation pattern. Combined with the simplified back projection algorithm, the conductivity configuration of the measured layer in terms of shape and size can be reconstructed with obvious border stripes. The numerical simulation is performed for a two-layer cylindrical phantom model and it is also verified by the experimental results of MAT-MI for a tissue-like sample phantom. The proposed model suggests a potential application of conductivity differentiation and provides a universal basis for the further study of conductivity reconstruction for MAT-MI.展开更多
We develop a fast microwave-induced thermoacoustic tomography system based on a 320-element phase-controlled focus linear transducer array. A 1.2-GHz microwave generator transmits microwave with a pulse width of 0.5 ...We develop a fast microwave-induced thermoacoustic tomography system based on a 320-element phase-controlled focus linear transducer array. A 1.2-GHz microwave generator transmits microwave with a pulse width of 0.5 μs and an incident energy density of 0. 45 mJ/cm^2, and the microwave energy is delivered by a rectangular waveguide with a cross section of （80.01 ± 0.02） × 10^-4 m^2. Compared to single transducer collection, the system with the multi-element linear transducer array can eliminate the mechanical rotation of the transducer, hence can effectively reduce the image blurring and improve the image resolution. Using a phase-controlled focus technique to collect thermoacoustic signals, the data need not be averaged because of a high signal-to-noise ratio, resulting in a total data acquisition time of less than 5 s. The system thus provides a rapid and reliable approach to thermoacoustic imaging, which can potentially be developed as a powerful diagnostic tool for early-stage breast caners.展开更多
Optical coherence tomography(OCT)and Raman spectroscopy(RS)can be complementary biological tissue optical analysis methods.To study the internal structure and tissue compositions of biological samples,an OCT-RS system...Optical coherence tomography(OCT)and Raman spectroscopy(RS)can be complementary biological tissue optical analysis methods.To study the internal structure and tissue compositions of biological samples,an OCT-RS system was built to carry out OCT section imaging and RS analysis in common.Neocaridina denticulate sinensis were collected regularly for morphological observation by OCT imaging and biochemical investigation based on the Raman spectra.The internal structure of the N.denticulate sinensis was imaged by OCT,and the morphology of the tissues and the position in the body were distinguished according to the gray scale changes.The imaging depth along the vertical direction of Z-axis in N.denticulate sinensis is about 1.60 mm.RS detection was selectively performed based on the OCT images.The main Raman peaks of the rostrum,the cephalothorax,the abdominal segment,and the telson section are at 1006,1156,1447,1491 and 1515 cm-1,which are identified as proteins and amino acids.The presence of 1497 cm-1 at the cephalothorax is different from other parts,probably due to the presence of organs such as ovary,whose compositions are different from those of other tissues.The combination of optical coherence tomography and Raman spectroscopy can provide information about morphological and biochemical features of tissues,and has potential applications in biomedical detection and imaging.展开更多
This mini-review gives a brief account of the emergence of the electron paramagnetic resonance(EPR)spectroscopy in the second half of the 20th century and reports the continuous wave EPR spectroscopy studies on human ...This mini-review gives a brief account of the emergence of the electron paramagnetic resonance(EPR)spectroscopy in the second half of the 20th century and reports the continuous wave EPR spectroscopy studies on human and animal blood.The question posed by this review is whether the EPR spectroscopy in the form it appeared 70 years ago is still able to provide useful information about different pathological conditions in humans,particularly in the area of diagnosis.展开更多
基金Project supported by the National Science Foundation of China (Grant Nos.51676086 and 51575247)。
文摘Understanding of the heat transport within living biological tissues is crucial to effective heat treatments. The heat transport properties of living biological tissues with temperature-dependent properties are explored in this paper. Taking into account of variable physical properties, the governing equation of temperature is first derived in the context of the dualphase-lags model(DPL). An effective method, according to the Laplace transform and a linearization technique, is then employed to solve this nonlinear governing equation. The temperature distribution of a biological tissue exposed to a pulsed heat flux on its exterior boundary, which frequently happens in various heat treatments, is predicted and analyzed. The results state that a lower temperature can be predicted when temperature dependence is considered in the heating process.The contributions of key thermal parameters are different and dependent on the ratio of phase lag and the amplitude of the exterior pulsed heat flux.
基金Project supported by the National Natural Science Foundation of China （Grant No 60278007）, the Natural Science Foundation of Tianjin （Grant No 033601311） and the Natural Science Foundation of Guangdong Province （Grant No 04011427）.
文摘Based on the diffusion approximate theory （DA）, a theoretical model about the distribution of the intensity of a narrow collimation beam illuminating on a semi-lnfinite biological tissue is developed. In order to verify the correctness of the model, a novel method of measuring the distributions of the intensity of light in Intralipid-10% suspension at 650 nm is presented and ts of the distributions of the distance-dependent intensity of scattering light in different directions are made. The investigations show that the results from our diffusion model are in good agreement with the experimental results beyond and in the areas around the light source, and the distance-dependent intensity in the incident direction attenuates approximately in the exponential form. Furthermore, our theoretic results indicate the anisotropic characteristics of the intensity in different directions of scattering light inside the biological tissue.
基金National Natural Science Foundation of China(Grant Nos.51735003,51805091)Guangdong Provincial Natural Science Foundation of China(Grant No.2018A030313713).
文摘Biological soft tissues manipulation,including conventional(mechanical)and nonconventional(laser,waterjet and ultrasonic)processes,is critically required in most surgical innervations.However,the soft tissues,with their nature of anisotropic and viscoelastic mechanical properties,and high biological and heat sensitivities,are difficult to manipulated.Moreover,the mechanical and thermal induced damage on the surface and surrounding tissue during the surgery can impair the proliferative phase of healing.Thus,understanding the manipulation mechanism and the resulted surface damage is of importance to the community.In recent years,more and more scholars carried out researches on soft biological tissue cutting in order to improve the cutting performance of surgical instruments and reduce the surgery induced tissue damage.However,there is a lack of compressive review that focused on the recent advances in soft biological tissue manipulating technologies.Hence,this review paper attempts to provide an informative literature survey of the state-of-the-art of soft tissue manipulation processes in surgery.This is achieved by exploring and recollecting the different soft tissue manipulation techniques currently used,including mechanical,laser,waterjet and ultrasonic cutting and advanced anastomosis and reconstruction processes,with highlighting their governing removal mechanisms as well as the surface and subsurface damages.
文摘The main objective of this proposed article is to provide explanations to justify the validity of the results of the studies of the interaction between the electromagnetic fields and the human body. It can also find direct applications in the characterization and modeling of the macroscopic electrical properties of the biological media for assessing the effects of fields induced by electromagnetic radiation sources in the human body to set up new standards <span>on the Human exposure to electromagnetic fields. To do this, we have taken into account the different physical phenomena of propagation of a hyper-frequency electromagnetic plane wave and on the other hand, the expe</span>rimental values <span></span><span><span><span style="font-family:;" "="">in order to model the electrical behavior of human biological tissues based on an equivalent electronic circuit model composed of capacities, resistance and reel, which assimilates the biological tissues of the skin, grease, blood. This model using the characteristic impedance of the dielectric support makes it possible to evaluate the voltage induced by the electromagnetic waves of the hyper-frequencies in the studied biological system. The results of the simulations obtained from computer tools demonstrate that the hyper-frequency electromagnetic waves can result in an elevation of the electrical potential of the biological tissues. Despite this potential is a decreasing function of the penetration depth.</span></span></span>
文摘The anisotropic continuum stored energy density (ACSED) functional is applied for accurate constitutive modeling of biological tissues and finite element implementation without the isochoric—volumetric split, the anisotropic—isotropic split, or the anisotropic invariant split. Related stress and elasticity tensors in the reference and current configurations are worked out. A new kinematic model is derived based on the tangent Poisson’s ratio as a cubic polynomial function of stretch. The ACSED model, along with the kinematic model, accurately fits uniaxial extension test data for compressible human skin, bovine articular cartilage, and human aorta samples.
基金This work was partially supported by the National Natural Science Foundation of China(No.62271023)the Beijing Natural Science Foundation(No.7202102)the Fundamental Research Funds for Central Universities.
文摘The resting potential is the potential difference that exists between the inner and outer sides of the cell membrane when the cell is not stimulated.The resting membrane potential is a key regulator of phenomena such as cell proliferation,morphogenesis,migration and differentiation.In this paper,we proposed a model of electrified cell clusters that considers the resting potential of cell clusters in the resting state.By measuring the potential difference between the inner and outer sides of biological tissues,it is verified that the cell cluster has a negative potential difference when taking the outer potential as the reference.In the absence of external conductors,the tissue is electrically neutral;while in the presence of external conductors,the positive net charges escape freely under repulsive forces and the biological tissues form a negative electrical equilibrium system.The model proposed in this study explored the potential situation above the cellular level in the resting state,providing a new perspective for the research on resting potential.
基金supported by the National Natural Science Foundation of China (Nos. 81903571, 21904080)the Taishan Scholars the Taishan Scholars Program (C. Sun, No. tsqn202103096)the Shandong Province “Double-Hundred Talent Plan” Program。
文摘Application of matrix-assisted laser desorption/ionization mass spectrometry imaging(MALDI-MSI) to investigate the spatiotemporal alterations of lipids in biological tissues has brought many significant results.However, the presence of structural isomers varying in C=C double bond(DB) locations makes isomerresolved MSI an urgent need. Herein, we introduce a new type of light-driven on-tissue [2 + 2] cycloaddition reaction coupled with MALDI-MS/MS imaging to identify lipid DB position isomers and their spatial signatures in biological tissues. 3-Benzoylpyridine was introduced as a novel derivatization reagent, and it exhibited great reactivity toward lipid C=C bond to form oxetanes under both ultraviolet light and visible light irradiation. With this approach, DB position isomers of lipids were imaged with highly differential levels in distinct regions of rat brain, providing an accurate and spatially resolved approach to study tissue lipidomics.
基金supported by the National Natural Science Foundation of China(11304160)Special Funds for Quality Supervision,Inspection and Quarantine Research in Public Interest of China(201510068)
文摘The thermal effects induced by a moderate intensity focused ultrasound and enhanced by combined laser pulses for bio-tissues and tissue-phantom are studied experimentally and theoretically. At first, the heating effects of bio-tissues and tissue-phantom induced by ultrasound and enhanced by laser are measured experimentally. The heating processes induced by attenuations of focused ultrasonic waves and cavitation effects of the focused ultrasound and combined laser are analyzed theoretically. By analyzing the mechanisms of these effects, it is found that the laser nucleation makes the cavitation bubble generation more easily, which can effectively enhance the ultrasonic cavitation effects, and then enhance the thermal effects of the samples. On the other hand, to evaluate quantitatively the heating processes induced by the focused ultrasound and enhanced by the pulsed laser, by fitting the theoretical calculations to the experimental results, the corresponding cavitation bubbles and rising temperatures induced by the focused ultrasound with and without laser can be estimated approximately.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11274342,11304353,11404245 and 11474042
文摘Elasticity is of profound significance to evaluating the function of a biological soft tissue. When the elasticity of a tissue is macroscopically changed, it means that the biological function of the tissue is abnormal and some disease or injury may occur. In the present work, an elastometer is developed to measure the elasticity of biological soft tissues. The measurement is based on the indentation method and the force is measured by the bending of the cantilever. The force-indentation data of the soft tissue is experimentally measured by this elastometer and Young＇s modulus of the tissue is calculated using the Hertz-Sneddon model. For comparison, a numerical model for the indentation method is established using the finite element method. The difference between the actual modulus and the measured modulus is discussed. The effect of the thickness of the specimen on the measurement is investigated. Young＇s moduli of beef, porcine liver and porcine kidney are experimentally measured. The results indicate that our elastometer is effective in measuring Young＇s modulus of a soft tissue quantitatively.
文摘The study of Electromagnetic Compatibility is essential to ensure the harmonious operation of electronic equipment in a shared environment. The basic principles of Electromagnetic Compatibility focus on the ability of devices to withstand electromagnetic disturbances and not produce disturbances that could affect other systems. Imperceptible in most work situations, electromagnetic fields can, beyond certain thresholds, have effects on human health. The objective of the present article is focused on the modeling analysis of the influence of geometric parameters of industrial static converters radiated electromagnetic fields using Maxwell’s equations. To do this we used the analytical formalism for calculating the electromagnetic field emitted by a filiform conductor, to model the electromagnetic radiation of this device in the spatio-temporal domain. The interactions of electromagnetic waves with human bodies are complex and depend on several factors linked to the characteristics of the incident wave. To model these interactions, we implemented the physical laws of electromagnetic wave propagation based on Maxwell’s and bio-heat equations to obtain consistent results. These obtained models allowed us to evaluate the spatial profile of induced current and temperature of biological tissue during exposure to electromagnetic waves generated by this system. The simulation 2D results obtained from computer tools show that the temperature variation and current induced by the electromagnetic field can have a very significant influence on the life of biological tissue. The paper provides a comprehensive analysis using advanced mathematical models to evaluate the influence of electromagnetic fields. The findings have direct implications for workplace safety, potentially influencing standards and regulations concerning electromagnetic exposure in industrial settings.
文摘The actions and health effects of electromagnetic fields in the radio frequency (RF) domains, referred to as radio frequencies and HV transmission networks have been studied for several decades. Following the appearance of questions and debates within the population, the actions and potential effects of radiofrequency and HV transport networks on health, in connection with the development of new wireless technologies, are generating a certain revival of interest. Thus, the increasing exposure to electromagnetic fields and the concerns of the public have led health organizations to undertake large-scale research programs to respond to the concerns expressed. These research programs have contributed to significantly increasing the number of studies on the actions and effects of electromagnetic pollution as well as their consequences on living beings. The objective of our research is focused on the analysis, sources, and study of the biological consequences of electromagnetic pollution. To do this, we have used physical laws and theorems, in particular Maxwell-Ampère, Maxwell-Gauss, Maxwell-Faraday, and Ohm’s law, to model the interactions between electromagnetic fields and living matter. In this article we have chosen the approach based on the electrical model of human biological tissue, taking into account on the one hand the physical phenomena of the propagation of an electromagnetic microwave plane wave in the range from 0 to 300GHz and on the other hand, the experimental values to simulate the relaxations α, β and γ and the impedance of the biological tissue faced with the variation of the frequency of propagation of the electromagnetic waves to identify the biological consequences relating thereto. The results obtained in the literature show the linear dependence of bio-impedance on frequency, these observations suggest that the tissue can be physiologically stressed at high frequencies. This can cause biological consequences for humans. The 2D simulation based on the proposed model has been developed as well as the verification of the consistency of the different mathematical models, by comparing the fractal dimensions of the results of the program with those of the figures obtained experimentally.
基金Project supported by the National Basic Research Program of China （Grant No. 2011CB707900）, the National Natural Science Foundation of China （Grant No. 10974098）, the Natural Science Foundation of Jiangsu Province, China （Grant No. BK2009407）, and the Specialized Research Fund for Doctoral Program of High Education of China （Grant No. 20093207120003）.
文摘An acoustic dipole radiation model for magnetoacoustic tomography with magnetic induction （MAT-MI） is pro- posed, based on the analyses of one-dimensional tissue vibration, three-dimensional acoustic dipole radiation and acoustic waveform detection with a planar piston transducer. The collected waveforms provide information about the conductiv- ity boundaries in various vibration intensities and phases due to the acoustic dipole radiation pattern. Combined with the simplified back projection algorithm, the conductivity configuration of the measured layer in terms of shape and size can be reconstructed with obvious border stripes. The numerical simulation is performed for a two-layer cylindrical phantom model and it is also verified by the experimental results of MAT-MI for a tissue-like sample phantom. The proposed model suggests a potential application of conductivity differentiation and provides a universal basis for the further study of conductivity reconstruction for MAT-MI.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60378043 and 30470494, and the Natural Science Foundation of Guangdong Province （015012 04010394 2004B10401011）.
文摘We develop a fast microwave-induced thermoacoustic tomography system based on a 320-element phase-controlled focus linear transducer array. A 1.2-GHz microwave generator transmits microwave with a pulse width of 0.5 μs and an incident energy density of 0. 45 mJ/cm^2, and the microwave energy is delivered by a rectangular waveguide with a cross section of （80.01 ± 0.02） × 10^-4 m^2. Compared to single transducer collection, the system with the multi-element linear transducer array can eliminate the mechanical rotation of the transducer, hence can effectively reduce the image blurring and improve the image resolution. Using a phase-controlled focus technique to collect thermoacoustic signals, the data need not be averaged because of a high signal-to-noise ratio, resulting in a total data acquisition time of less than 5 s. The system thus provides a rapid and reliable approach to thermoacoustic imaging, which can potentially be developed as a powerful diagnostic tool for early-stage breast caners.
基金supported by National Natural Science Foundation of China(No.41476081)the Major Research and Development Project in Shandong Province(No.2019GHY112027)。
文摘Optical coherence tomography(OCT)and Raman spectroscopy(RS)can be complementary biological tissue optical analysis methods.To study the internal structure and tissue compositions of biological samples,an OCT-RS system was built to carry out OCT section imaging and RS analysis in common.Neocaridina denticulate sinensis were collected regularly for morphological observation by OCT imaging and biochemical investigation based on the Raman spectra.The internal structure of the N.denticulate sinensis was imaged by OCT,and the morphology of the tissues and the position in the body were distinguished according to the gray scale changes.The imaging depth along the vertical direction of Z-axis in N.denticulate sinensis is about 1.60 mm.RS detection was selectively performed based on the OCT images.The main Raman peaks of the rostrum,the cephalothorax,the abdominal segment,and the telson section are at 1006,1156,1447,1491 and 1515 cm-1,which are identified as proteins and amino acids.The presence of 1497 cm-1 at the cephalothorax is different from other parts,probably due to the presence of organs such as ovary,whose compositions are different from those of other tissues.The combination of optical coherence tomography and Raman spectroscopy can provide information about morphological and biochemical features of tissues,and has potential applications in biomedical detection and imaging.
文摘This mini-review gives a brief account of the emergence of the electron paramagnetic resonance(EPR)spectroscopy in the second half of the 20th century and reports the continuous wave EPR spectroscopy studies on human and animal blood.The question posed by this review is whether the EPR spectroscopy in the form it appeared 70 years ago is still able to provide useful information about different pathological conditions in humans,particularly in the area of diagnosis.
