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This study was made in order to prove the feasibility of two of the most promising thermal therapies to treat bone tumors. Microwave (MW) and ultrasound (US) ablation were analyzed. For MW ablation, a single slot antenna was designed. The best characteristics of the antenna, to generate an electromagnetic field and its absorption by the bone, were obtained by a parametric modeling. Length and location of the slot and work frequency were analysed. On the other hand, for US ablation, the acoustic propagation of a 4 MHz spherical transducer was done. Then, two models were proposed: in water and in a 2 layer media (water and bone). Four antennas with the best characteristics to heat up bone were chosen (best cases scenarios). The optimal length position was 6.9 mm (slot length 1 mm & 2 mm) and 4.9 (slot length: 3 mm & 4 mm). These antennas work properly from 2.45 GHz– 2.60 GHz. The SWR was around 1.22±0.07 (m±sd). Finally, these antennas show a covered area of 10.23±0.05 cm2 (m±sd) of bone tissue. Acoustic and thermal distributions depict that US can enter 5 mm in the bone. This results show that both techniques are suitable to treat bone tumors.

The first results in the design of a pulsed Doppler ultrasound system are presented, which aims to detect alterations of diabetic foot cataloged as “high risk”, associated with the processes that lead to occlusion of blood vessels. Therefore, measurement of blood flow gives the level of damage in the affected area and the state of the blood vessels, constituting a noninvasive diagnostic test. The system was designed from the classical conceptions of Pulsed Doppler systems and it incorporates advanced digital design techniques, based on hybrid hardware-software implementations (FPGA) on reconfigurable platforms. Analog system architecture is shown and finally, its most outstanding features and the expected results of the design are exposed.

Welcome to the Global Medical Engineering Physics Exchanges (GMEPE) and Pan American Health Care Exchanges (PAHCE) Conference 2017. This event reinforces the tradition of the PAHCE in our continent. The purpose of this event is to create cooperation, collaboration and knowledge sharing opportunities between professionals and researchers in the areas of health care, biomedical engineering and medical technology industries. The conference will cover various subjects ranging from engineering and medical research to industrial practices. It will examine the latest progress and developments in biomedicine, bioengineering, clinical engineering and the health industry.

The drugs delivered in the central nervous system can be used for the treatment of Parkinson or Alzheimer by acting directly in the affected zones. The problem is that the Blood Brain Barrier (BBB), only allows the passage of certain substances to protect the brain. The focused ultrasound (FUS) with ultrasonic contrast agents (UCA), have demonstrated the reversible opening of the BBB. This paper presents the modeling of the acoustic field for a Focused Ultrasound transducer by finite element method (FEM), that allows evaluating a craniotomy with the less dimension to improve the propagation of ultrasonic waves without deforming the transducer's focus and cause minimal damage to the rat. For this work the head of a rat of 300 gr, following the dimensions and actual geometry of the murine models and a concave monoelemental transducer with a frequency of 2 MHz a focal length of 20 mm and a radius of 10 mm were taken as reference.

A multifunctional magneto-plasmonic CoFe2O4@Au core-shell nanoparticle was developed by iterative-seeding based method. This nanocargo consists of a cobalt ferrite kernel as a core (Nk) and multiple layers of gold as a functionalizable active stratum, (named as Nk@A after fifth iteration). Nk@A helps in augmenting the physiological stability and enhancing surface plasmon resonance (SPR) property. The targeted delivery of Doxorubicin using Nk@A as a nanopayload is demonstrated in this report. The drug release profile followed first order rate kinetics optimally at pH 5.4, which is considered as an endosomal pH of cells. The cellular MR imaging showed that Nk@A is an efficient T2 contrast agent for both L6 (r2-118.08 mM−1s−1) and Hep2 (r2-217.24 mM−1s−1) cells. Microwave based magnetic hyperthermia studies exhibited an augmentation in the temperature due to the transformation of radiation energy into heat at 2.45 GHz. There was an enhancement in cancer cell cytotoxicity when hyperthermia combined with chemotherapy. Hence, this single nanoplatform can deliver 3-pronged theranostic applications viz., targeted drug-delivery, T2 MR imaging and hyperthermia.

Myocardial infarct cause myocardial tissue disease increasing the probability to have arrhythmias such as ventricular fibrillation, these cardiac problems are cause of death. This paper implement a support vector machine classifier trained with the JTp/JT, Tpe/JTp and Tpe/JT intervals ratios extracted from ECG signals of healthy patients and patients with post myocardial infarct diagnosis. The accuracy for the system trained with the time ratios above mentioned is around 90% to 100% for both classes, others classifiers implemented 2 to 5 times the amount of input data with other methods and obtaining 80% of accuracy.

To determine the evolution of diabetic foot, instruments that measure the changes in different physical properties of foot tissues were proposed. These properties are affected by the diabetes disease. The information provided by each instrument will be concentrated and will be presented on a single screen. The proposed instruments measure the temperature at the plant of the foot, present the thermography image of the foot, scan the electrical impedance at the plant and measure the blood flow. It is proposed a single electronic instrument that will contain independent modules of each measurement system. There will be a data bus used to transmit the information for recording and retrieving the measurements as well as the clinical history of each patient. This article shows the first results of the electronic proposal and the results of the first tests in patients.

In this paper the results of pathology detection in the diabetic foot using an ultrasonic elastography technique and thermography technique using an infrared camera are compared. Detection infrared camera is based on the temperature difference of the soles of the feet, especially in areas that are more prone to ulcerations, which are the big toe and heel. For ultrasonic elastography speckle interferometry system ultrasonic signals obtained at passage one low frequency wave is used. To determine the temperature of the soles of the feet a thermal camera “Fluke Ti32” is used; a system for activation and capture of thermal imaging was performed. Comparative study of the results of both techniques and their possible applications in early detection of diabetic foot pathology is performed.

Currently the controlled release of drugs in specific areas is of great importance for the treatment of diseases such as cancer, Parkinson, Alzheimer and others. This project works with focused ultrasound (HIFU) in rats, more specifically in the application of HIFU in a specific area of the brain called the substantia nigra, in order to generate opening in the membrane of this area called blood-brain barrier (BBB) with the purpose of introducing vectors containing the drug used to treat Parkinson, proposed by the Department of Physiology, Biophysics and Neuroscience Research Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional. This work is the beginning of the investigation based on the modeling of a HIFU transducer in bone tissue of rats weighing approximately 400 gr. In order to obtain the sound field pattern, focus size, pressure and ultrasound path in a time dependent study. All of the above in order to get a clear idea of what you will get when it comes to experimentation.

In this paper a series of designs of micro coaxial antennas for MWA therapy to be used for the treatment of breast cancer tumors coupled to both breast and tumoral tissue is presented. The designs were modeled and optimized using Finite Element Method (FEM) simulation to ensure the minimal SWR possible value and obtain several parameters of interest such as the antenna's radiation patterns, temperature distributions and estimated lesion sizes.

Elastography allows an elastic map from a soft biological tissue using shear waves. The technique consists of exciting the tissue or organ to be analyzed with an external mechanical low frequency pulse and detecting the displacements of each small region of tissue when receiving the shear wave. This is done by obtaining the records of the echographic signals of the region analyzed with a transducer ultrasound. The speckle interferometry of the Ascan signals is then performed. Thus the displacement produce by the shear wave of the each small region of tissue is determined. In this way a map of the shear wave velocity is obtained across the scanned area. The Young's modulus of the analyzed region is computed from this velocity value. In this work, this new technique is applied to study the diabetic foot, making an elastic map of the sole, allowing detect diseased areas.

The strongest therapeutic effects in ultrasonic physiotherapy are mainly produced at the first centimeters, i.e. close to the applicator surface and, in general, only in the near-field zone. The acoustic field produced in practice by this type of transducers differs from the classical models because the vibration distribution on the real transducer surfaces is non-uniform. However, neither models using uniform distribution, nor those using typical non-uniform distribution patterns for the source accurately represent the radiation of this kind of transducers. Although this therapy is widely used and many efforts have been made in experimentally studying the patterns of ultrasound radiation produced during physiotherapy applications (IEC-61689, 1998), additional modeling researches still would be needed in order to achieve improved models giving field patterns closer to the measured ultrasonic results. In this paper, acoustic patterns produced from two source radiation functions are proposed and evaluated for field modeling of physiotherapy applicators. Both the functions are approximations to the pressure distribution measured close to the emitting surface and they are based on the modulation of the classical simply-supported function using either sinusoidal or Bessel-type distributions. The simply-supported function is accounted for the radiator-fixing condition and the modulation function simulates the complex vibration distribution of this kind of transducer. The modulator Bessel function is based on reports about Bessel-type vibration distributions found in piezoelectric disk resonators. The use of a selected sinusoidal segment represents another analytical option for obtaining an approximated behavior of the measured data in a real applicator. Both the field models are implemented using the finite element method (FEM) to obtain the numerical solution of wave equation at each point in the radiated space. The solution is reached by considering axisymmetric radiation in attenuation-free media. The results indicate the viability of applying an adequate model for acoustic field calculation by simulating the radiating distribution on the emitting surface as either sinusoidal or Bessel-modulated functions. Models using both the functions describe reasonably real behaviors, but those based on Bessel functions are better correlated with the measurements. The results for three commercial applicators indicate the possibility of representing, with adequate verisimilitude, the acoustic field radiated by physiotherapy ultrasound transducers using linear combinations of Bessel profiles describing the radiation source.

Magnetic heating used for inducing hyperthermia and thermal ablation is particularly promising in the treatment of cancer provided that the therapeutic temperature is kept constant during the treatment time throughout the targeted tissue and the healthy surrounding tissues are maintained at a safe temperature. The present study shows the temperature increment produced by different concentrations of magnetic nanoparticles (ferrofluid and magnetoliposomes) inside a phantom, after irradiating tissuemimicking materials (phantoms)with a minimally invasive coaxial antenna working at a frequency of 2.45GHz. This frequency was chosen because maximum dielectric loss of water molecules begins at 2.4GHz and because this is an ISM (industrial, scientific and medical) frequency. Temperature sensors were placed inside and outside the tumor phantom to assess the focusing effect of heat produced by nanoparticles. Results have shown that the temperature increments depend on the nanoparticles concentration. In this way, a temperature increment of more than 56◦C was obtained with a ferrofluid concentration of 13.2 mg/mL, whereas the increment in the reference phantom was only of ≈ 21◦C. Concerning the magnetoliposomes, the temperature achieved was similar to that obtained with the ferrofluid but at a lesser concentration of nanoparticles. These results Received 1 February 2012, Accepted 27 March 2012, Scheduled 30 May 2012 * Corresponding author: Joan Estelrich (joanestelrich@ub.edu). 230 Garcia-Jimeno et al. demonstrate that it is possible to achieve higher temperatures and to focus energy where the nanoparticles are located.

Hyperthermia also called thermal therapy or thermotherapy is a type of cancer treatment in which body tissue is exposed to high temperatures. Research has shown that high temperatures can damage and kill cancer cells, usually with minimal injury to normal tissues. Otherwise, ablation or high temperature hyperthermia, including lasers and the use of radiofrequency, microwaves, and high-intensity focused ultrasound, are gaining attention as an alternative to standard sur- gical therapies. The electromagnetic microwave irradiation applied to the tumor tissue causes water molecules to vibrate and rotate, resulting in tissue heating and subsequently cell death via thermal-induced protein denaturation. The effective- ness of this technique is related to the temperature achieved during the therapy, as well as the length time of treatment and cell and tissue characteristics. Numerical electromagnetic and thermal simulations are used to optimize the antenna design and predict heating patterns. A computer modeling of a double slot antenna for interstitial hyperthermia was designed us- ing two different numerical methods, the Finite Element Method and a Finite-Difference Time-Domain. The aim of this work is to analyze both numerical methods and finally experiments results are compared to the simulated results generated by a thermal model. Our results show that normalized SAR patterns using FEM and FDTD look broadly similar. Further- more, the computed 60 °C isotherm using FEM and the measured lesion diameter in ex vivo tissue results agree very well.

A technical challenge in hyperthermia therapy is to locally heat the tumor region up to an appropriate temperature to destroy cancerous cells, without damaging the surrounding healthy tissue. Magnetic fluid hyperthermia (MFH) is a novel, minimally invasive therapy aiming at concentrating heat inside cancerous tissues. This therapy is based on the injection of different superparamagnetic nanoparticles inside the tumor. In our study, superparamagnetic nanoparticles, which we developed and characterized, consisted of iron oxide nanoparticles stabilized with polyethylene glycol. Moreover, a new technique for MFH using a specially designed external electromagnetic waveguide as applicator is presented. Three magnetite concentrations were used for making the tumor phantoms, which were embedded in muscle phantoms. The phantoms were radiated and located at three different distances from the applicator. Furthermore, two volumes of tumor (2.5mL and 5.0mL) were assayed. Heating curves, as a function of time, allowed the establishment of a more appropriate nanoparticle concentration for obtaining the temperature increase suitable for hyperthermia therapy. The results shown in this Received 29 September 2011, Accepted 19 October 2011, Scheduled 1 November 2011 * Corresponding author: Citlalli Jessica Trujillo-Romero (ctrujillo@cinvestav.mx). The technical contribution of the second author to this work was as significant as the first

The motion of the current prostheses is sequential and does not allow natural movements. In this work, complex natural motion patterns from a healthy upper limb were characterized in order to be emulated for a trans-humeral prosthesis with three degrees of freedom at the elbow. Firstly, it was necessary to define the prosthesis workspace, which means to establish a relationship using an artificial neural network (ANN), between the arm-forearm (3-D) angles allowed by the prosthesis, and its actuators length. The 3-D angles were measured between the forearm and each axis of the reference system attached at the elbow. Secondly, five activities of daily living (ADLs) were analyzed by means of the elbow flexion (EF), the forearm prono-supination (FPS) and the 3-D angles, from healthy subjects, by using a video-based motion analysis system. The 3-D angles were fed to the prosthesis model (ANN) in order to analyze which ADLs could be emulated by the prosthesis. As a result, a prosthesis kinematics approximation was obtained. In conclusion, in spite of the innovative mechanical configuration of the actuators, it was possible to carry out only three of the five ADLs considered. Future work will include improvement of the mechanical configuration of the prosthesis to have greater range of motion.

During hyperthermia treatments, for determining internal temperature by using non-invasive ultrasound estimation, it is necessary to know some tissue ultrasonic characteristics around the hyperthermia range. The aim of this work was to determine in detail the changes of some ultrasonic properties (velocity and attenuation) of muscle, fat and liver tissues in the specific range of 26 °C to 50 °C. We proposed an experimental setup which allows minimizing the expansion effects in the biological samples. The ultrasonic signal passes through tissue and it is reflected by a 1-mm needle arrangement, inserted in the tissue sample. The results in the propagation speed behaviour, for the three studied tissues, appear to be quasi-linear with temperature changes. The attenuation coefficients are also presented for different temperatures.

Purpose: This paper presents a computerized segmentation method for breast lesions on ultrasound(US)images. Methods: It consists of first applying a contrast-enhanced approach, i.e., a contrast-limited adaptive histogram equalization. Then, aiming at removing speckle and enhancing the lesion boundary, an anisotropic diffusion filter, guided by texture descriptors derived from a set of Gabor filters, is applied. To eliminate the distant pixels that do not belong to the tumor, the resulting filtered image is multiplied by a constraint Gaussian function. By doing so, both the segmentation and the marker functions are generated and could be used in the marker-controlled watershed transformation algorithm to create potential lesion boundaries. Finally, to determine the lesion contour, the average radial derivative function is evaluated. The proposed method was tested with 50 breast USimages and 60 simulated “ultrasound-like” images. Accuracy and precision of the segmentation method were then assessed. For the accuracy, three parameters were used: Overlap ratio (OR), normalized residual value (nrv), and proportional distance (PD) between contours. Results: The average results for USimages were OR = 0.86 ± 0.05 , nrv = 0.16 ± 0.06 , and PD = 6.58 ± 2.52 % . For simulated ultrasound-like images, a better performance ( OR = 0.92 ± 0.01 , nrv = 0.08 ± 0.01 , and PD = 3.20 ± 0.53 % ) was achieved. Conclusions: The segmentation method proposed was capable of delineating the lesion contours with high accuracy in comparison to both the radiologists’ delineations and the true delineations of simulated images. Moreover, this method was also found to be robust to human-dependent parameters variations.

Optimization of efficiency in hyperthermia requires a precise and non-invasive estimation of internal distribution of temperature. Although there are several research trends for ultrasonic temperature estimation, efficient equipments for its use in the clinical practice are not still available. The main objective of this work was to research about the limitations and potential improvements of previously reported signal processing options in order to identify research efforts to facilitate their future clinical use as a thermal estimator. In this document, we have a critical analysis of potential performance of previous ultrasonic research trends for temperature estimation inside materials, using different processing techniques proposed in frequency, time and phase domains. It was carried out in phantom with scatterers, assessing at their specific applicability, linearity and limitations in hyperthermia range. Three complementary evaluation indexes: technique robustness, Mat-lab processing time and temperature resolution, with specific application protocols, were defined and employed for a comparative quantification of the behavior of the techniques. The average increment per degrees C and mm was identified for each technique (3 KHz/ degrees C in the frequency analysis, 0.02 rad/ degrees C in the phase domain, while increments in the time domain of only 1.6 ns/ degrees C were found). Their linearity with temperature rising was measured using linear and quadratic regressions and they were correlated with the obtained data. New improvements in time and frequency signal processing in order to reveal the potential thermal and spatial resolutions of these techniques are proposed and their subsequent improved estimation results are shown for simulated and measured A-scans registers. As an example of these processing novelties, an excellent potential resolution of 0.12 degrees C into hyperthermia range, with near-to-linear frequency dependence, could be achieved. Specifically defined "numerical" and physical multi-scatter phantoms are described, which mimic ultrasound velocity in tissues of about 1560 m/s @ 35 degrees C and have a quasi-uniform internal scattering structure designed to assure standard signal patterns adequate for processing comparisons in the same time and sound velocity conditions for all the techniques analyzed, and to obtain easily repeatable multi-pulse echo-patterns. A perfect lineal dependence (100% of correlation coefficient) between the unitary average increment measured by each technique and temperature rising was observed while working with simulated A-scan registers, where all the parameters are under an accurate control. Nevertheless a very small quadratic tendency appeared in the results obtained from experimental echo registers, which are more similar to a real tissues case. It would be an interesting future work to analyze the behavior of these techniques in real tissues in order to confirm or reject this light quadratic tendency. Finally, new methods were detailed and applied in order to precisely quantify the advantages of each estimation technique; their respective intrinsic limitations were also underlined.

Piezoelectric arrays with different connectivities are widely used in actuators, transformers, and special ultrasonic transducers. In this study, the global matrix method is presented to describe the resonance radial modes in thin piezoelectric annular arrays with an arbitrary number of elements. Each annular element of the arrays is modeled as a three-port system with one electrical and two mechanical ports. The cored matrix model for radial modes, in a singular ring, is presented in the form of a translation matrix. The dynamic behavior of two annular arrays, a transformer and a Bessel transducer, is simulated assuming that the major surfaces of each element are stress-free, while the laterals are matched with neighbor elements. Thus, the inner and outer lateral surfaces of the system are loaded with an external medium. The simulated and experimental results are in good agreement when the thickness effects are neglected.

This work investigates the use of electronic tongues for environmental monitoring. Electronic tongues were based on arrays of potentiometric sensors plus a complex data processing by artificial neural networks and data transmission by radiofrequency. A first application, intended for a system simulating real conditions in surface water, performed a simultaneous monitoring of ammonium, potassium, sodium, chloride, and nitrate ions. The proposed system allowed us to assess the effect of natural biodegradation stages for these species. A second application was used to monitor concentrations of ammonium, potassium, and sodium in the ‘Ignacio Ramirez’ dam (Mexico). The electronic tongue used here allowed us to determine the content of the three cations in real water samples, although a high matrix effect was encountered for sodium determination. The implemented radio transmission worked robustly during all the experiments, thus demonstrating the viability of the proposed systems for automated remote applications.

A disposable all-solid-state planar-type potentiometric electronic tongue has been developed with a five-sensor array screen-printed on a polymeric substrate. The fabrication method enables simple and reproducible mass-production of low-cost electronic tongue systems, since the sensors showed good reproducibility (0.96% RSD), repeatability (0.58% RSD) and lifetime (8% decrease of sensitivity after 37 days in solution). The system was used for the simultaneous determination of NH4 +, K+ and Na+ ions in synthetic and natural surface water samples. The signals were processed by using a multilayer artificial neural network which was optimized for that purpose. Correct results were obtained for the three ions in synthetic samples. In natural surface waters, ammonium and potassium ions could be determined, while sodium ions showed biased results due to the effect of the complex matrix.

Pb(Mg1/3Nb2/3)O3-PbTiO3 based ceramics were produced by conventional sintering method and their electric-field induced electromechanical properties were determined. Large fieldinduced electromechanical coupling factors, with high piezoelectric anisotropy, were obtained in this relaxor material at relatively low DC electric bias field. A circular ultrasonic transducer with non uniform radial induced polarization was constructed using this material for field diffraction control.

The aim of this article is to design a miniaturized sEMG signal acquisition system with integrated dry electrodes in order to reduce the induce noise due to the cables. The miniaturization of the system allows to reduce the electronic noise produce by the components and to reduce the acquisition area in a more punctually way. The use of dry electrodes allows us to make long term acquisition so that we can use te system in myoelectric prosthesis control. In order for the system to be stablished as a functional sEMG acquisition sytem we measured the standards propoused by the AAMI for the electrodes and the standards for sEMG acquisition systems propoused by the ISEK.

The study of modal sensors and actuators is motivated by their ability to control the resonance frequency and the vibration modes of mechanical structures. In this work, a non-homogeneous poling method to obtain a radial modal sensor from a piezoelectric disc is presented. The construction method for three modal elements is described and their electrical behavior is presented and analyzed in comparison to a uniform poled disc.

This work describes a voltammetric electronic tongue, in which the quantitative information contained in voltammograms obtained from amperometric sensors is firstly extracted employing the discrete wavelet transform (DWT) and then processed employing artificial neural networks (ANNs). The analytical case studied is the direct determination of the oxidizable aminoacids tryptophan, cysteine and tyrosine, and its application in the direct measurement of these amino acids in animal feed samples. A conventional voltammetry cell with a Pt working electrode is the experimental set-up and differential pulse voltammetry the selected technique. Due to the complexity of the obtained signals, the DWT pre-treatment was needed in order to eliminate noise components and compress voltammograms by selecting and extracting significant information. The ANN was subsequently used to model the system departing from the reduced information, and obtaining the concentrations of the considered species. Best results were obtained when using two hidden layers in a backpropagation neural network trained with the Bayesian regularization algorithm.

In the study of voltammetric electronic tongues, a key point is the preprocessing of the departure information, the voltammograms which form the response of the sensor array, prior to classification or modeling with advanced chemometric tools. This work demonstrates the use of the discrete wavelet transform (DWT) for compacting these voltammograms prior to modeling. After compression, a system based on artificial neural networks (ANNs) was used for the quantification of the electroactive substances present, using the obtained wavelet decomposition coefficients as their inputs. The Daubechies wavelet of fourth order permitted an effective compression up to 16 coefficients, reducing the original dimension by ca. 10 times. The case studied is a mixture of three oxidizable amino acids:tryptophan, cysteine, and tyrosine. With the reduced information, one ANN per specie was trained using the Bayesian regularization algorithm. The proposed procedure was compared with the more conventional treatments of ...

An array of eight nonspecific potentiometric sensors was used in combination with multivariate calibration for the simultaneous determination of NH, K+ and Na+ ions. The sensors were of the all-solid-state type and employed a PVC polymer membrane. Signals were processed by using a multilayer artificial neural network (ANN). The ANN configuration used was optimized by using 8 neurons in the input layer, 5 in the hidden layer and 3 in the output layer. Use of the Bayesian Regularization algorithm allowed a quick building of an accurate model, as confirmed by random multi-starting of network weights. The system was used to analyze synthetic and river water, waste water and fertilizer samples. Correct results were obtained for the three ions in synthetic and real water samples; in fertilizers, ammonium ion can be determined, while sodium and potassium show biased results.

A method for determining ammonium ion concentration from complex aqueous samples is presented in this work. It does not need to eliminate chemical interferences, mainly sodium and potassium, because an array of potentiometric sensors with intrinsic responses is used. The measurements taken from the array are processed with a multicomponent data treatment. This approach is already known as electronic tongue. Multivariable calibration was implemented with an artificial neural network, trained under the rules of the Bayesian regularization. The developed system has been applied to water samples from rivers and wastewaters with ammonium content in the range 1 × 10−4–5 × 10−2 mol L−1. Results are similar to those obtained with other reference methods.

Breast cancer represents a rising problem concerning public health worldwide. Current efforts are aimed to the development of new minimally invasive and conservative treatment procedures for this disease. A treatment approach for invasive breast ductal carcinoma could be based on electroporation. Hence, in order to determine the effectiveness of electrochemotherapy in the treatment of this disease, 12 electrode models were investigated on realistic patient-specific computational breast models of 3 patients diagnosed by Digital Breast Tomosynthesis imaging. The electrode models exhibit 4, 5, and 6 needles arranged in 4 geometric configurations (delta, diamond, and star) and 3 different needle spacing resulting in a total of 12 needle-electrode arrays. Electric field distribution in the tumors and a surrounding safety margin of 1 cm around the tumor edge is computed using the finite element method. Efficiency of the electrode arrays was determined hierarchically based on (1) percentage of tumor volume reversibly electroporated, (2) percentage of tumor volume irreversibly electroporated, (3) percentage of treated safety margin volume, (4) minimal invasiveness, that is, minimal number of electrodes used, (5) minimal activated electrode pairs, and (6) minimal electric current. Results show that 3 electrode arrays (4 needle-delta, 5 needle-diamond, and 6 needle-star) with fixed-geometry configuration could be used in the treatment with electrochemotherapy of invasive breast ductal carcinomas ranging from 1 to 5 cm3 along with a surrounding safety margin of 1 cm.

High Intensity Focused Ultrasound (HIFU) is a non-invasive technique used for oncology treatment through tumor ablation. When an impedance mismatch is present between the ultrasound transducer and the excitation device, a reflected wave is produced which can damage the excitation device. To avoid this possible damage is important to know the forward and reflected power of ultrasound transducers. The purpose of this work is to develop a power meter which can measure the forward and reflected power of ultrasound transducers and calculate the Standing Wave Ratio with the finality to avoid damage at the excitation device.

This paper shows an instrument that uses electronic technology to characterize the effects of the diabetes in tissues, by measuring changes in the skin impedance on the sole. The bioimpedance system generates a signal at different frequencies and supplies it to the tissue via electrodes. This system uses the 3 electrodes technique: the first electrode where the generator signal wave at different frequencies is supplied, the second electrode receives the supplied signal with the modulation of the skin and the third electrode is the reference. Bioimpedance system 149 generates sinusoidal signals at different frequencies ranging from 10 Hz to 22 kHz and a amplitude current below the of perception of the human body. This signal is placed on the first electrode on the sole. With the meter bioimpedance can be characterized tissue impedance of the sole of healthy people with diabetes problems, Directory to locate differences that help to monitor the status of the foot in people with diabetes and prevent some complications of this disease.

Breast cancer is one of the most common diseases and has high mortality among Mexican women. Thermic therapies are one of the most promising techniques these days. Microwave ablation transmits electromagnetic energy inducing a focalized temperature increment to achieve tumor necrosis in a minimally invasive way. One of the main limitations in the development of thermotherapy percutaneous applicators is the measurement of certain parameters in biological tissue. The proposed solution is the fabrication of a phantom that emulates the dielectric properties (permittivity and conductivity) of breast tumor tissue in order to make coupling measurements of the applicator in an experimental setting. A methodology for the fabrication and measurement of a breast tumor phantom was developed, achieving, with low error, the imitation of dielectric properties of the breast tumor tissue reported in the literature. The use of low-cost materials and the simplicity of the methodology allow reproducibility of the phantom for experimentation in the fields of diagnostic and treatment of breast cancer through RF in the microwave range.

Recently, attempts have been made to construct actuators with similar behaviour to natural muscles. However the results have been inadequate for application to practical prostheses. For example, muscle wire, which has too low an efficiency to be powered by batteries and McKibben muscles which require two power supplies, one electric and one pneumatic. Electrochemical muscles are still in the development stage and cannot yet be used for prostheses. In this paper, a new electromechanical actuator is presented, which provides rectilinear movement and linear characteristics. This electromechanical actuator is based on a ball screw and rare earth magnet coreless motors. The system has been characterised and some of the most important results are that it produces a force of 167N while developing a velocity of 7x10(-3)m/s. The force developed is proportional to the current drained. Its efficiency is about 32%, its total mass 0.19kg and it is light and compact enough to be used in practical clinical prosthesis.

Because stable chronic recordings of electromyographic (EMG) signals are being required in the clinical practice, electrical impedance in the electrode–skin interface and the electrode–muscle location, must be maintained unmodified. However, because of some factors, these requirements have not been completely fulfilled. Implantable electrodes represent an alternative solution to inherent problems associated with conventional surface electrodes. In this work, an in vivo evaluation of the impedance of implanted electrodes developed for chronic recordings in rabbit is presented. The fibrous tissue formed around the implanted electrodes and affixation maintain the electrode in location. Two types of electrode configuration were evaluated: bipolar and multipolar. Seven months after implantation of the bipolar electrode, values of impedance were stable. In contrast, impedance at low frequency (0.5 and 1.0 Hz) of the multipolar configuration did not achieve stability.

The present article is a summary of noninvasive imaging techniques, which aim is to assess feet and legs' ulcer formation and development. The objective is to early detect if an ulcer is about to develop to apply prompt treatment and reverse the process or at least lessen it. Hyperspectral imaging, plantar pressure imaging, photographic imaging and thermic imaging techniques are presented as a recapitulation of the state of the art of imaging techniques and their results.

In this article, we present a feasibility study using transducer edge waves to center a hydrophone during field characterization. A mathematical analysis is presented to study amplitude changes in edge waves; this analysis is based on the impulse response method and considers the transducer as a piston embedded in a rigid planar baffle. The experimental setup used to measure the edge waves is also presented. It has been observed, mathematically and experimentally, that edge wave amplitude reaches its maximum when the hydrophone is centered and that these amplitude changes are very sensitive to position, approximately 70% of its maximal amplitude; however, amplitude changes in front planar waves are less evident (10%). Agreement between experimental and calculated results demonstrates that changes in edge wave amplitude can be used to center the hydrophone in an objective way.

Histological studies were carried out to evaluate long-term tissue biocompatibility of implanted materials which are commonly used to fabricate ISFET-devices sensitive to pH. Silicon nitride was the ion-sensitive material. Three experimental series were performed. The first consisting of three rabbits and the second of eight, both during 7 days of implantation, and the third consisting of four animals for 8 weeks of implantation. Teflon containers were used to limit movements of the samples. Glass was used as a control material and a P -type semiconductor with a deposited 900 Angstroms layer of silicon nitride was used as the experimental sample. Biocompatibility was assessed through the study of the local inflammatory response and by performing a differential count of the cells accumulated in the implanted chambers that contained the glass or the silicon nitride deposit. There were no significant differences between the local tissue reaction, either acute or chronic one, to the control or the experimental materials. These results suggest that silicon nitride has an adequate biocompatibility for a period of time that makes these sensors suitable for long-term and continuous in vivo measurements.

A new fabrication method for ion-sensitive field-effect transistors (ISFETs) with back contacts has been developed. The connections between the drain and the source diffusions and the back contacts are achieved by diffusing impurities from both sides of the wafer, until a conductive path has been formed through the thickness of the wafer. After these conductive paths are built, an FET structure is constructed on the front face of the chip. The back access allows for a clean face where the chemically active gate is placed. This contrasts with more traditional devices where the gate and the contacts are placed on the same face of the transistor. It is also set apart from devices featuring back contacts with anisotropically etched pits that require a different processing laboratory separated from the main clean-room facilities. The aim of the present work is to produce ISFET-based chemical sensors with back contacts featuring a clean technology using standard silicon foundry facilities. These sensors are more compact, easier to encapsulate and with a longer lifetime when compared to devices produced with more traditional structures.

Globally, breast cancer is the most common type of cancer among women, which comprises 23% of all female cancers that are newly diagnosed in more than 1.1 million women each year. Over 411 000 deaths result from breast cancer annually; this accounts for over 1.6% of female deaths from all causes. Hyperthermia also called thermal therapy or thermotherapy is a type of cancer treatment in which body tissue is exposed to high temperatures. Research has shown that high temperatures can damage and kill cancer cells, usually with minimal injury to normal tissues. Otherwise, ablation or high temperature hyperthermia is defined as the direct application of chemical or thermal therapies to a tumor to achieve eradication or substantial tumor destruction. Many ablation modalities have been used, including cryoablation, ethanol ablation, laser ablation, and radiofrequency ablation. The most recent development has been the use of microwave ablation in tumors. Furthermore, The use of breast cancer mammography screening has allowed detecting a greater number of small carcinomas and this has facilitated treatment by minimally invasive techniques. Currently, physicians test minimally invasive ablation techniques to determine if they will be acceptable substitutes for surgical removal of primary breast tumors. Therefore, numerical electromagnetic and thermal simulations are used to optimize the antenna design and predict heating patterns. A review of different hyperthermia ablative therapies, for breast cancer treatment is summarized in this work. Otherwise, advanced computer modeling in high hyperthermia treatment and experimental model validation will be referred to in this chapter.

High Intensity Focused Ultrasound (HIFU) has emerged as an interesting technology for different medical treatments such as thermal ablation, hyperthermia, and bleeding control (hemostasis). Bleeding control requires a coupling material to deliver the ultrasonic energy provided by the focalized transducer to the tissue to be treated; therefore, improvement in application methods and coupling materials of HIFU are necessary in hemostasis treatment. This paper describes a finite element simulation model of polyacrylamide (PAA) and low density polyethylene (LDP) as coupling materials between the transducer/tissue interface. Both materials were selected due to their acoustic properties, biocompatibility, hardness and durability. The modeled geometry represents a PAA-filled cone made of LDP which works as a coupling material between HIFU transducer and treatment zone. The simulated model comprises a 1.965 MHz concave transducer which was previously characterized within water. Results of time dependent simulations considering PAA and LDP as coupling materials showed an intensity of 3000 W/cm2 at the focal zone of treated tissue which achieved a temperature increase above 62°C on treatment tissue after 1 s. Ultrasound hemostasis could be obtained due to the thermal and mechanical effects. Finite element modeling is a helpful method to simulate HIFU propagation waves and heating on homogenous medium.

Microwave energy is a promising alternative in breast cancer treatment because it can preferentially heat and damage highwater-content breast carcinomas. In order to evaluate the feasibility of using this technique to treat breast cancer, a coaxial slot antenna computer simulation based on an axisymmetric finite element method model was used to compare heating differences between cancer and normal breast tissue. According to the results, the computer modeling demonstrated that the difference in dielectric properties and thermal parameters between malignant and normal adipose-dominated tissue was able to cause preferential heating of tumor during microwave ablation using a coaxial slot antenna.

This paper presents the finite element modeling of the acoustic pressure spatial distribution of a spherically-curved transducer with operation frequency of 1.965 MHz and its comparison with the transducer characterization using a PZTZ44-0400 hydrophone. Concave transducers are only one of the different techniques used to deliver high-intensity focused ultrasound (HIFU) into a target during oncologic treatments in order to provoke tumor ablation. However, the acoustic field characterization for HIFU transducers is made at low power level in order to avoid hydrophone damage, while in therapy high acoustic power is applied. HIFU focus size is usually in the order of mm, making difficult its location during experimentation. Finite element modeling is helpful method to simulate focused ultrasound propagation and interaction in a simulated medium with ultrasonic properties similar to soft tissues. In this work, comparison is made in water as propagation wave medium.

Microwave ablation computational model, on COMSOL Multiphysics 4.0a, was presented in this paper using two types of coaxial antenna, one-slot and two-slot antenna. Computational model was done using electric and thermal properties of healthy breast tissue and tumoral breast tissue. Maximum temperature reached with two-slot coaxial antenna on healthy breast tissue was 110 °C, and on tumoral breast tissue was 141 °C. One-slot coaxial antenna model got maximum temperature of 120 °C on healthy tissue and 137 °C on tumoral tissue. Better results were achieved for two-slot coaxial antenna.

This summary describes the design and construction of a modular hip prostheses, it has polycentric mechanism with three links that mimic the trajectory of the human hip's geometric center. In presence of one of the lower limbs, the system provides an additional running at all stages at speeds of 6 km/h in an instrument with a weight of 560 gr. The prosthetic system is uniaxial, presenting a two-dimensional displacement in one plane that is, doesn't have patellar movement on orthogonal planes to the motion axis, being unnecessary for this.

This work, explains the process carried out to make a design of mechanism of knee of polycentric type of 4 bars with mechanical actuator for modular prosthesis. The goal, emulate behavior and functioning of the knee for flexion and extension covering the basic needs of people with trans-femoral amputation of external prostheses modular with a low cost of production.