The abnormal function of cells can be detected by anatomic or physiological registrations. Most of modern approaches, as ultrasound, RMN or CT, show anatomic parametric modifications of tissues or organs. They highlight areas with a larger diameter 1 cm. In the case of skin or superficial cancers, local temperature is different, and it can be put out by thermal imager. Medical imaging is a leading role in modern diagnosis for abnormal or normal tissues or organs. Some information has to be improved for a better diagnosis by reducing or removing some unwanted information like noise affecting image texture. The traditional technologies for medical image enhancement use spatial or frequency domain methods, but whole image processing will hide both partial and specific information for human signals. A particular kind of medical images is represented by thermal imaging. Recently, these images were used for skin or superficial cancers diagnosis, but very clear outlines of certain alleged affected areas need to be shown. Histogram equalization cannot highlights the edges and control the effects of enhancement. A new filtering method was introduced by Huang by using the empirical mode decomposition, EMD. An improved filtering method for thermal images, based on EMD, is presented in this paper, and permits to analyze nonlinear and non-stationary data by the adaptive decomposition into intrinsic mode surfaces. The results, evaluated by SNR ratios, are compared with other filtering methods.
Amorphous materials are metastable, more reactive than the crystalline ones, and have to be evaluated before
pharmaceutical compound formulation. Amorphicity is interpreted as a spatial chaos, and patterns of molecular
aggregates of dexamethasone, D, were investigated in this paper by using fractal dimension, FD. Images having three
magnifications of D were taken from an optical microscope, OM, and with eight magnifications, from a scanning
electron microscope, SEM, were analyzed. The average FD for pattern irregularities of OM images was 1.538, and about
1.692 for SEM images. The FDs of the two kinds of images are less sensitive of threshold level. 3D images were shown
to illustrate dependence of FD of threshold and magnification level. As a result, optical image of single scale is enough
to characterize the drug amorphicity. As a result, the OM image at a single scale is enough to characterize the
amorphicity of D.
The purpose of this paper is to present a new method for evaluation of 3D object shapes which are inside of different
environments, and a direct visual contact is not possible. High resolution sensors could solve this kind of problem,
mainly by inverse electromagnetic scattering using antenna arrays or synthetic apertures. A cheaper solution is to radiate acoustic field inside of the searched environment. The object detection is realized when the level of received signal exceeds a certain value. The object shape could be appreciated by analyze of 10 consecutive resonant frequencies. Spectral distribution of the resonant frequencies represents the object "signature", and it is related to spatial object dimensions. For a given object, this spectral distribution could show how large the object is, in what way the outer surface is smooth or rough or how large the roughness is. The simulation results for three types of objects: pyramid, sphere, and ellipsoid cavities, smooth and rough are presented. Two roughnesses were selected for each object. The resonant frequencies of different objects could be stored and used for medical application (for instance, diagnosis of a tissue whether it is benign or malignant), mine detection buried in ground or evaluation of the different substances filling up the buried objects.
Signals with linear frequency modulation are used in synthetic aperture radar to improve spatial resolution and signal/noise ratio. Acoustic field is proposed in this paper to investigate objects, because it could penetrate them, and propagate inside. When input signal frequency is about resonance frequency, the attenuation is increased, and as a result, the scattered acoustic field is decreased as well. So, a linear frequency modulation signal with constant amplitude is sent to the investigated object, and variable amplitude is reflected, corresponding to the object resonance frequencies. A new method for detection the amplitude modulation of these signals in presence of noise is presented. The method uses the fractional Fourier transform in two steps. In the first step a rotation of signal by the angle=45<sup>0</sup> is done. The all spectral components outside central band are canceled. After that a new rotation of new function with the same angle is done. The simulated results are presented. The method gives good results of amplitude modulation detection for signals with complex modulation signals having signal - noise ratio in power up to - 5 dB. By knowing the resonance frequencies it is possible to specify the largest 3D object dimension, appreciate the relative values of the other dimensions, and do a rough classification of that object. The presented method could be used for rough classification of buried objects in earth or to early diagnose whether a tumor tissue is or not malignant.
One of the most widely used denoising techniques with well preserving edge features in medical imaging is
anisotropic diffusion filtering. It is based on the iterative solving of the diffusion equation that takes into account only the
heat propagation by conduction<sup>1</sup>. At living beings, blood perfusion represents another important way to transfer the heat.
In this case, we used a new equation modeling the heat propagation, mainly Pennes equation<sup>2</sup>, processing both
conductive and convective heat components. Unlike heat, white noise, which accompanies the signal detected by a
thermal sensor, is not a solution to this equation. The new filtering method consists in an iterative solving of bio-heat
equation by using Crank-Nicolson convergent algorithm. Bazan’s criterion for stopping iterations agrees well with the
behavior of this filter. The filter was tested on some theoretical models of images simulating different signals and noises,
and on many thermal images of healthy people or patients suffering from different types of thyroid disorders. One image
processing of a patient suffering from papillary carcinoma is shown at different time moments. The noise is rapid
attenuated, and it is possible to assess the contour shape or to locate more outbreaks in a certain area, if any.
The skin is the largest organ of the body and it protects against heat, light, injury and infection. Skin temperature is an
important parameter for diagnosing diseases. Thermal analysis is non-invasive, painless, and relatively inexpensive,
showing a great potential research. Since the thyroid regulates metabolic rate it is intimately connected to body
temperature, more than, any modification of its function generates a specific thermal image on the neck skin. The shapes
of thermal signatures are often irregular in size and shape. Euclidean geometry is not able to evaluate their shape for
different thyroid diseases, and fractal geometry is used in this paper. Different thyroid diseases generate different shapes,
and their complexity are evaluated by specific mathematical approaches, fractal analysis, in order to the evaluate selfsimilarity
and lacunarity. Two kinds of thyroid diseases, hyperthyroidism and papillary cancer are analyzed in this paper.
The results are encouraging and show the ability to continue research for thermal signature to be used in early diagnosis
of thyroid diseases.
The rapid diffusion of wireless communication systems has caused an increased concern for the potential detrimental
effects on human health deriving from exposure to electromagnetic field. It penetrates the body and acts on all the
organs, altering the cell membrane potential and the distribution of ions and dipoles. The thyroid gland is one of the most
exposed vital organs and may be a target for electromagnetic radiation. This paper presents the computed temperature
and specific absorption rate inside to a generic model of a human thyroid using signals radiated by an antenna operating
in the 2450 MHz band and the power density levels up to 100 W/cm<sup>2</sup>. Calculations were carried out using the Finite
Difference Time Domain method for the solving of two coupled differential equations, Maxwell and Pennes. The results
show that the temperature can rise up to very dangerous levels, i.e., 46 °C, in a very short time. The estimated
temperature distribution in the human thyroid due to exposure from microwave signals can be used to design the
dangerous aria for personal working around high power emitted antenna and for medical applications.
Cancer is a leading cause of death worldwide, and about 30% of cancer deaths can be prevented. In the
next future, the number of global cancer deaths is projected to increase 45% in the future. A general
treatment has not yet been found. The best defense against cancer is early detection, when tumor
dimensions are very small. The methods as mammography, ultrasounds, MRI, CT, etc., can detect
anatomic or structural changes like tumors and cysts. They are anatomical imaging procedures,
consequently, they have the ability to locate the area of the tumor, but they cannot detect a fast-growing
cancer in the pre-invasive stage. Thermograms are looking for the physiologic changes in tissue; which
may indicate a risk of developing cancer in the future. The results using a new device, operating in
infrared band, are described. The paper focuses on thyroid cancer because it allows investigations on
larger areas before surgery and on residual, smaller areas following surgery. The experiment results for 24
patients with thyroid nodules are described. Malign tumors have a distinct infrared signature. Only the
area affected is thermal registered and that has an irregular shape and a strong nonuniform structure with
rapid variations on skin temperature.
Heat is one of the most important parameters of living beings. Skin temperature is not the same on the entire body and
so, a thermal signature can be got. Infrared map on serial imaging can constitute an early sign of an abnormality.
Thermography detects changes in tissue that appear before and accompany many diseases including cancer. As this map
has a better resolution an early cancer diagnosis can be done. The temperature of neoplasic tissue is different up to 1.5 °C
than that of the healthy tissue as a result of the specific metabolic rate. The infrared camera images show very quickly
the heat transferred by radiation. A lot of factors disturb the temperature conversion to pixel intensity. A sensitive
temperature sensor with a 10 Mpixels video camera, showing its spatial position, and a computer fusion program were
used for the map with high spatial-temperature resolution. A couple of minutes are necessary to get a high resolution
map. The asymmetry and borders were the main parameters analyzed. The right cancer diagnosis was for about 78.4% of
patients with thyroid cancer, and more than 89.6% from patients with breast cancer. In the near future, the medical
prognosis will be improved by fractal analysis.
The growing of RF/Microwave industry for satellite, mobile and terrestrial communications relies on new devices and design technologies. Metamaterials may offer a these capabilities, even so they were investigated in the research laboratory only. A power divider is an indispensable component commonly used to split an input signal into two output signals in RF, microwave or millimeter communication systems. A new power divider, composed of metamaterials is theoretically investigated. By adjusting the parameters, the power divider shows perfectly symmetric power division. The results are compared to Wilkinson splitter. The new power divider may be o good choice for aria where weight, size, low insertion loss, simplicity, and symmetric power division are critical design factors.
Humans and animals in general, are usually in a thermal steady state with respect to their surroundings. The tissues heat, generated at normal or diseases states, is lost to environment though several mechanisms: radiation, conduction, convection, evaporation, etc. Skin temperature is not the same on the entire body and a thermal body signature can be got. The temperature at skin level was measured by a thermistor, conduction component and by an IR camera, radiation component. A theoretical analysis using Weinhaum and JIJI model was done. The three images are investigated in order to get a cheap method for the early cancer diagnosis.
Metamaterials have negative refractive index and EM waves bend negatively. This negative bending allows a variety of applications from microwaves to optical frequencies. Negative refraction can be exploited to make novel lenses having flat surfaces and focus electromagnetic waves as well as produce a real 3-D image. These flat lenses do not have unique optical axes and the aperture sizes are smaller than a square wavelength. The electromagnetic field propagation on a multilayer structure: normal-metamaterial-normal is investigated and compared with homogenous media. The numerical method, FDTD, was used for a Gaussian source and for more sinusoidal sources. The point focusing analysis of a flat lens is presented.