Electrical Properties Of Tissues Research Articles

Early-Stage Detection of Melanoma Skin Cancer Using Contactless Millimeter-Wave Sensors

Studies show that the early (stage I) diagnosis of cancer increases the survival rate of patients, and significantly reduces treatment costs. Millimeter-wave radars can detect skin tumors based on the difference between the electrical properties of melanomas and healthy skin tissues. This paper proposes a low-power multitone continuous-wave radar design at 77GHz for biomedical imaging applications, to be used for skin cancer detection. The sensor implementation is based on a low-cost Miniature Hybrid Microwave Integrated Circuit (MHMIC) design. The entire sensor was integrated on a 0.127mm thin ceramic substrate. Two 16-element patch antenna arrays are implemented in the transmitter and receiver modules. The receiver is a six-port homodyne quadrature down-converter. The integrated power detectors are fabricated using HSCH-9161 Schottky diodes. The sensor was encapsulated in a metallic fixture with dimensions 35 by 45mm. Two cascaded amplifier circuits are designed and implemented for amplifying baseband voltages at the output of each power detector. The proposed radar design has the ability to detect the dielectic properties of tissues, making it suitable for the detection of melanomas with an accuracy on the order of tens of microns.

DUAL MODALITY TRAN-ADMITTANCE MAMMOGRAPHY AND ULTRASOUND REFLECTION TO IMPROVE ACCURACY OF BREAST CANCER DETECTION

Cancer and breast tissue have a very high electrical impedance ratio, so imaging based on impedance can produce high contrast. It is very useful for the early detection of breast cancer. Trans-admittance mammography (TAM) is a modality to detect breast cancer based on impedance. The weakness of TAM is that it can only produce a projection image so that the volume and ratio of cancer to breast tissue cannot be obtained at once. The ratio of anomaly and volume is very important to be determined properly because it is related to the stage and type of cancer. TAM shortcomings can be overcome if anomalous volume information is known precisely. The ultrasound reflection modality can produce information about an anomaly depth and volume correctly. Combining TAM and ultrasound reflection data is expected to provide promising results. The study was conducted to prove the hypothesis by creating a breast phantom composed of gelatin, agar, graphite, glycerol, and distilled water to represent the electrical and acoustic physical properties of cancer and breast tissue. The results showed that the TAM data was only able to produce information about transverse position accurately, while the depth was less accurate. Acoustic devices can produce transverse position information, depth, and volume precisely. The dual-modality of TAM and ultrasound reflection can produce information about the depth position, volume, and the ratio anomaly to reference conductivity accurately.

Bayesian inversion for electrical-impedance tomography in medical imaging using the nonlinear Poisson–Boltzmann equation

We develop an electrical-impedance tomography (EIT) inverse model problem in an infinite-dimensional setting by introducing a nonlinear elliptic PDE as a new EIT forward model. The new model completes the standard linear model by taking the transport of ionic charge into account, which was ignored in the standard equation. We propose Bayesian inversion methods to extract electrical properties of inhomogeneities in the main body, which is essential in medicine to screen the interior body and detect tumors or determine body composition. We also prove well-definedness of the posterior measure and well-posedness of the Bayesian inversion for the presented nonlinear model. The new model is able to distinguish between liquid and tissues and the state-of-the-art delayed-rejection adaptive-Metropolis (DRAM) algorithm is capable of analyzing the statistical variability in the measured data in various EIT experimental designs. This leads to design a reliable device with higher resolution images which is crucial in medicine for diagnostic purposes. We first test the validation of the presented nonlinear model and the proposed inverse method using synthetic data on a simple square computational domain with an inclusion. Then we establish the new model and robustness of the proposed inversion method in solving the ill-posed and nonlinear EIT inverse problem by presenting numerical results of the corresponding forward and inverse problems on a real-world application in medicine and healthcare. The results include the extraction of electrical properties of human leg tissues using measurement data.

Anisotropic shortening in the wavelength of electrical waves promotes onset of electrical turbulence in cardiac tissue: An in silico study

Several pathological conditions introduce spatial variations in the electrical properties of cardiac tissue. These variations occur as localized or distributed gradients in ion-channel functionality over extended tissue media. Electrical waves, propagating through such affected tissue, demonstrate distortions, depending on the nature of the ionic gradient in the diseased substrate. If the degree of distortion is large, reentrant activity may develop, in the form of rotating spiral (2d) and scroll (3d) waves of electrical activity. These reentrant waves are associated with the occurrence of lethal cardiac rhythm disorders, known as arrhythmias, such as ventricular tachycardia (VT) and ventricular fibrillation (VF), which are believed to be common precursors of sudden cardiac arrest. By using state-of-the-art mathematical models for generic, and ionically-realistic (human) cardiac tissue, we study the detrimental effects of these ionic gradients on electrical wave propagation. We propose a possible mechanism for the development of instabilities in reentrant wave patterns, in the presence of ionic gradients in cardiac tissue, which may explain how one type of arrhythmia (VT) can degenerate into another (VF). Our proposed mechanism entails anisotropic reduction in the wavelength of the excitation waves because of anisotropic variation in its electrical properties, in particular the action potential duration (APD). We find that the variation in the APD, which we induce by varying ion-channel conductances, imposes a spatial variation in the spiral- or scroll-wave frequency ω. Such gradients in ω induce anisotropic shortening of wavelength of the spiral or scroll arms and eventually leads to instabilitites.

Sensibility analysis of the electrical impedance parameters by the Monte Carlo method

Electrical properties of biological tissues are used to analyze its state in different practical applications, e.g., assessing the risk of cancer. The modeling of electrical properties usually is performed by circuital models or semiempirical models as Cole-Cole. Still, another option is available, the application of the generalized effective medium theory of induced polarization. In the framework of the effective medium theory, we proposed a model for biological tissues which we called MOPET. This model links physiological parameters of tissues with their electrical properties. However, it has a higher number of parameters than the Cole-Cole and circuital models. This large number of parameters is a limitation for the use of effective medium theory to describe the electrical properties of tissue and also suggests that some of these parameters have negligible effects. We used a Monte Carlo simulation to study the effect of each MOPET parameter on the electrical impedance spectra, where uniform random variables were used to simulate the variability of the parameters of this model. We found that the heterogeneity coefficient is the most sensible parameter, i.e., a variation above 1% in this parameter alters enormously the impedance spectra.

Can Bioelectrical Impedance Analysis and BMI be a Prognostic Tool in Head and Neck Cancer Patients? A Review of the Evidence.

Background: Malnutrition can significantly affect disease progression and patient survival. The efficiency of weight loss and bioimpedance analysis (BIA)-derived measures in the evaluation of malnutrition, and disease progression and prognosis in patients with head and neck cancer (HNC) are an important area of research. Method: The PubMed database was thoroughly searched, using relative keywords in order to identify clinical trials that investigated the role of BIA-derived measures and weight loss on the disease progression and prognosis of patients with HNC. Twenty-seven studies met the criteria. More specifically, six studies examined the prognostic role of the tissue electrical properties in HNC patients; five examined the role of the tissue electrical properties on identifying malnutrition; four studies looked at the changes in the tissue electrical properties of HNC patients; and 12 examined the prognostic role of weight loss on survival and/or treatment outcomes. Results: Several studies have investigated the role of nutritional status tools on prognosis in HNC patients. Current studies investigating the potential of BIA-derived raw data have shown that phase angle (PA) and capacitance of the cell membrane may be considered prognostic factors of survival. Weight loss may be a prognostic factor for treatment toxicity and survival, despite some conflicting evidence. Conclusions: Further studies are recommended to clarify the role of BIA-derived measures on patients’ nutritional status and the impact of PA on clinical outcomes as well as the prognostic role of weight loss.

A simple and accurate FDTD based technique to determine equivalent complex permittivity of the multi-layered human tissue in MICS band

Abstract This paper proposes a methodology to determine the equivalent electrical properties of multilayered human tissue using the Finite Difference Time Domain (FDTD) method for dispersive media. In addition, the impact of fat layer thickness on the equivalent dielectric properties has also been critically analyzed. The effect of moisture content present in the skin layer has also been studied. The main advantage of the proposed method is that it can be used for any thickness and any number of layers of human tissue. The multilayer reflection and transmission coefficients of the human tissue are first calculated using the FDTD method and then the permittivity and conductivity are extracted using the Nicholson Ross Weir (NRW) Method. The results are validated analytically using the concept of transmission line analogy for plane wave propagation. The tool used is MATLAB. In this paper, a three-layered software model of the human chest for pacemaker applications has been analyzed in the Medical Implants Communication Service band (MICS). At the frequency of 403.5 MHz in the MICS band, the equivalent permittivity of 3 layered human tissue is approximately 43 and its conductivity is 0.41 s / m . Moreover, the effective permittivity, conductivity and tan delta loss decrease with the increase in fat layer thickness. These results form the basis for the development of phantom mixtures used for designing, testing and evaluation of implantable antenna and SAR measurements. The choice of using FDTD is because it is a very powerful tool for creating a numerical mixture.

Intra-arterial Injection of Lidocaine as a Cell Sensitizer during Irreversible Electroporation

PurposeTo investigate whether intra-arterial injection of lidocaine enhances irreversible electroporation (IRE) in a liver model. Materials and MethodsConventional IRE (C-IRE) and lidocaine-enhanced IRE (L-IRE) were performed in 8 pig livers. Protocol 1 (tip exposure and electrode distance of 2.0 cm each) and protocol 2 (increased tip exposure and electrode distance 2.5 cm each) were used. Animals were sacrificed 3 hours after IRE. Study goals included electrical tissue properties (eg, current, conductivity) during IRE, geometry of IRE zones analyzed using computed tomography and magnetic resonance imaging (eg, volume and sphericity index), degree of acute liver damage, and irreversible cell death analyzed using microscopy (hematoxylin and eosin staining and terminal deoxynucleotidyl transferase deoxyuridine 5-triphosphate nick end labeling). Statistical comparisons were performed using the paired t test and Wilcoxon test. ResultsAll treatments were performed without adverse events. Electrical tissue properties were not significantly different between C-IRE and L-IRE. For protocol 1, the diameter of the largest sphere within the IRE zone was significantly larger for L-IRE than for C-IRE (25.0 ± 4.7 mm vs 18.4 ± 3.1 mm [P = .013]). For protocol 2, the volume of IRE zone was significantly larger for L-IRE compared with C-IRE (46.0 ± 5.4 cm3 vs 22.6 ± 6.4 cm3 [P = .018]), as well as the diameter of the largest sphere within the IRE zone (27.1 ± 2.2 mm vs 19.8 ± 2.3 mm [P = .020]). For protocol 1, a significantly higher degree of irreversible cell death was noted for L-IRE than for C-IRE (1.8 ± 1.0 vs 0.8 ± 1.0 [P = .046]). ConclusionsIntra-arterial injection of lidocaine can enhance IRE in terms of larger IRE zones and an increase of irreversible cell death.

Low-Cost, Compact, and Rapid Bio-Impedance Spectrometer with Real-Time Bode and Nyquist Plots

Bioelectric impedance spectroscopy (BIS) has been widely used to study the electrical properties of biological tissue based on the characteristics of the complex electrical impedance dispersions. One of the problems in using the BIS method is the length of time required for the data acquisition process and possibly data analysis as well. In this research, a compact and work rapidly BIS instrumentation system has been developed at a low cost. It is designed to work in the frequency range of 100 Hz to 100 kHz, which is generally used in the fields of biophysics and medical physics. The BIS instrumentation system is built using several integrated modules. The modules are an AC current source to produce a selectable injection current; a data acquisition system to measure voltage, current, and phase difference rapidly and simultaneously; and software to calculate and display measurement results in the form of Bode and Nyquist plots in real time. The developed BIS system has been validated using a simple RC circuit as the sample being tested. The average time needed in the process of data acquisition and analysis until the formation of impedance dispersion curves in the form of Bode and Nyquist plots, for 54 sample frequencies, is less than one minute. The system is able to identify R and C values of the sample with a maximum error of 1.5%. In addition, some simple application examples are also presented in this paper.

Determination of the electrical impedance of neural tissue from its microscopic cellular constituents

The electrical properties of neural tissue are important in a range of different applications in biomedical engineering and basic science. These properties are characterized by the electrical admittivity of the tissue, which is the inverse of the specific tissue impedance. Objective. Here we derived analytical expressions for the admittivity of various models of neural tissue from the underlying electrical and morphological properties of the constituent cells. Approach. Three models are considered: parallel bundles of fibers, fibers contained in stacked laminae and fibers crossing each other randomly in all three-dimensional directions. Main results. An important and novel aspect that emerges from considering the underlying cellular composition of the tissue is that the resulting admittivity has both spatial and temporal frequency dependence, a property not shared with conventional conductivity-based descriptions. The frequency dependence of the admittivity results in non-trivial spatiotemporal filtering of electrical signals in the tissue models. These effects are illustrated by considering the example of pulsatile stimulation with a point source electrode. It is shown how changing temporal parameters of a current pulse, such as pulse duration, alters the spatial profile of the extracellular potential. In a second example, it is shown how the degree of electrical anisotropy can change as a function of the distance from the electrode, despite the underlying structurally homogeneity of the tissue. These effects are discussed in terms of different current pathways through the intra- and extra-cellular spaces, and how these relate to near- and far-field limits for the admittivity (which reduce to descriptions in terms of a simple conductivity). Significance. The results highlight the complexity of the electrical properties of neural tissue and provide mathematical methods to model this complexity.

In Silico and in Vitro Conductivity Models of the Left Heart Ventricle.

Ventricular Assist Devices (VADs) are used to treat patients with cardiogenic shock. As the heart is unable to supply the organs with sufficient oxygenated blood and nutrients, a VAD maintains the circulation to keep the patient alive. The observation of the patient's hemodynamics is crucial for an individual treatment; therefore, sensors to measure quantifiable hemodynmaic parameters are desirable.In addition to pressure measurement, the volume of the left ventricle and the progress of muscle recovery seem to be promising parameters. Ongoing research aims to estimate ventricular volume and changes in electrical properties of cardiac muscle tissue by applying bioimpedance measurement. In the case where ventricular insufficiency is treated by a catheter-based VAD, this very catheter could be used to conduct bioimpedance measurement inside the assisted heart. However, the simultaneous measurement of bioimpedance and VAD support has not yet been realized, although this would allow the determination of various loading conditions of the ventricle. For this purpose, it is necessary to develop models to validate and quantify bioimpedance measurement during VAD support.In this study, we present an in silico and an in vitro conductivity model of a left ventricle to study the application of bioimpedance measurement in the context of VAD therapy. The in vitro model is developed from casting two anatomical silicone phantoms: One phantom of pure silicone, and one phantom enriched with carbon, to obtain a conductive behavior close to the properties of heart muscle tissue. Additionally, a measurement device to record the impedance inside the ventricle is presented. Equivalent to the in vitro model, the in silico model was designed. This finite element model offers changes in material properties for myocardium and the blood cavity.The measurements in the in vitro models show a strong correlation with the results of the simulation of the in silico model. The measurements and the simulation demonstrate a decrease in impedance, when conductive muscle properties are applied and higher impedances correspond to smaller ventricle cross sections.The in silico and in vitro models are used to further investigate the application of bioimpedance measurement inside the left heart ventricle during VAD support. We are confident that the models presented will allow for future evaluation of hemodynamic monitoring during VAD therapy at an early stage of research and development.

Imaging the Electric Properties of Human Tissue with MRI

Imaging the Electric Properties of Human Tissue with MRI

Use of metallic nanoparticles for characterization of muscle tissue by electrical impedance spectroscopy (EIS)

Objectives. The electrical impedance spectroscopy (EIS) is relatively new technique used in medicine. The main problems that should be solved are its low resolution and that it fails to distinguish between tissue types, so some kind of the contrast should be applied. Magnetical nanoparticles have been used for imaging and other medical applications. For that reason, our research group decided to analyse the changes of electrical properties of chicken muscle tissue caused by three different types of metal nanoparticles at 50KHz. Methodology. Bio-Logic Science Instruments SP-150 was used as EIS device. Three different particles were analysed: two types of nanomagnetite (NM1 and NM2) and one of Gold particles (GNP). NM1 and NM2 samples were synthetized by coprecipitation and combustion method, respectively. GNP were synthetized by Turkevich method. Nanoparticles were characterized by SEM and RAMAN spectroscopy. Four needles were placed in each chicken breast to connect the EIS device. Measurements were obtained from each chicken breast at basal stage and after being injected with nanoparticles. Data was analyzed by bode graphics (module and phase). Contribution. The major changes of electrical properties of tissue were evidenced by using NM1 and GNP.

Questioning the Aloe Vera Plant and Apple Memristors.

Non-linear electrical properties of a (biological) tissue can be revealed by non-linear electrical measurements, which means that the applied stimulus itself affects the measurement. If resulting voltage–current plots exhibit pinched hysteresis loops, the underlying tissue may be classified as a memristor, a state dependent resistor. The aloe vera plant and apples have been found to be memristors. However, polarization processes on the electrodes are also non-linear and may affect the measurement. Apples and aloe vera conduct electrical current very well and it is likely that the recordings are actually dominated by the polarization impedance of the electrodes. Here, we study the non-linear properties of aloe vera and apples with two different measurement electrode types. Furthermore, we measured also on the extracted liquids from one aloe vera leaf and one apple, leading to similar results. We concluded, unlike previous studies on these subjects, that the memristive properties originate from electrochemical reactions on the electrodes rather than the apples or aloe vera themselves.

Information can be stored in the human skin memristor which has non-volatile memory

Much is already understood about the anatomical and physiological mechanisms behind the linear, electrical properties of biological tissues. Studying the non-linear electrical properties, however, opens up for the influence from other processes that are driven by the electric field or movement of charges. An electrical measurement that is affected by the applied electrical stimulus is non-linear and reveals the non-linear electrical properties of the underlying (biological) tissue; if it is done with an alternating current (AC) stimulus, the corresponding voltage current plot may exhibit a pinched hysteresis loop which is the fingerprint of a memristor. It has been shown that human skin and other biological tissues are memristors. Here we performed non-linear electrical measurements on human skin with applied direct current (DC) voltage pulses. By doing so, we found that human skin exhibits non-volatile memory and that analogue information can actually be stored inside the skin at least for three minutes. As demonstrated before, human skin actually contains two different memristor types, one that originates from the sweat ducts and one that is based on thermal changes of the surrounding tissue, the stratum corneum; and information storage is possible in both. Finally, assuming that different physiological conditions of the skin can explain the variations in current responses that we observed among the subjects, it follows that non-linear recordings with DC pulses may find use in sensor applications.

Conductivity change with needle electrode during high frequency irreversible electroporation: a finite element study

Abstract Irreversible electroporation (IRE) is a process in which the cell membrane is damaged and leads to cell death. IRE has been used as a minimally invasive ablation tool. This process is affected by some factors. The most important factor is the electric field distribution inside the tissue. The electric field distribution depends on the electric pulse parameters and tissue properties, such as the electrical conductivity of tissue. The present study focuses on evaluating the tissue conductivity change due to high-frequency and low-voltage (HFLV) as well as low-frequency and high-voltage (LFHV) pulses during irreversible electroporation. We were used finite element analysis software, COMSOL Multiphysics 5.0, to calculate the conductivity change of the liver tissue. The HFLV pulses in this study involved 4000 bipolar and monopolar pulses with a frequency of 5 kHz, pulse width of 100 µs, and electric field intensity from 100 to 300 V/cm. On the other hand, the LFHV pulses, which we were used, included 8 bipolar and monopolar pulses with a frequency of 1 Hz, the pulse width of 2 ms and electric field intensity of 2500 V/cm. The results demonstrate that the conductivity change for LFHV pulses due to the greater electric field intensity was higher than for HFLV pulses. The most significant conclusion is the HFLV pulses can change tissue conductivity only in the vicinity of the tip of electrodes. While LFHV pulses change the electrical conductivity significantly in the tissue of between electrodes.

Tissue discrimination by bioelectrical impedance during PLL resection in anterior decompression surgery for treatment of cervical spondylotic myelopathy

BackgroundThe electrical properties of biological tissues differ depending on their physical properties. This study aimed to explore if bioelectrical impedance (modulus and phase) would discriminate tissues relevant to resection of the posterior longitudinal ligament (PLL) in anterior cervical decompression surgery.MethodsPLL resection via an anterior approach was performed on the C4/5 segments in six mini-pigs. The bioelectrical impedance measurements were performed for two tissue groups (annulus fibrosus, endplate cartilage, sub-endplate cortical bone, and PLL; PLL, dura mater, spinal cord, and nerve root) using a novel probe and a precision inductance-capacitance-resistance meter. For each group, impedance was analyzed in terms of modulus and phase along a broad spectrum of frequencies (200–3000 kHz) using a nonparametric statistical analysis (Kruskal-Wallis).ResultsThe analysis showed a clear difference among the tissues. The modulus and phase show the same changing trend with frequency and present lower values at higher frequencies. Among annulus fibrosus, endplate cartilage, sub-endplate cortical bone, and PLL, it was possible to discriminate each tissue at every frequency point, considering the phase (p < 0.05), while this was not always the case (i.e., annulus fibrosus vs PLL at frequency of 200 kHz, 400 kHz, and 3000 kHz, p > 0.05) for modulus. Among PLL, dura mater, spinal cord, and nerve root, for every comparison, a statistically significant difference was reported in the modulus, phase, or both (p < 0.05).ConclusionsThe results indicated the potential of bioelectrical impedance to provide real-time tissue differentiation and enhance safe PLL resection in anterior cervical decompression surgery, particularly in robot-assisted minimally invasive surgery (RMIS).

Altered muscle electrical tissue properties in a mouse model of premature aging.

Improved methods are needed to detect and quantify age-related muscle change. In this study we assessed the electrical properties of muscle impacted by acquired mitochondrial DNA mutations via the PolG mouse, which exhibits typical age-associated features, and the impact of a potential therapy, nicotinamide mononucleotide (NMN). The gastrocnemii of 24 PolG and 30 wild-type (WT) mice (8 PolG and 17 WT treated with NMN) were studied in an electrical impedance-measuring cell. Conductivity and relative permittivity were determined from the impedance data. Myofiber cross-sectional area (CSA) was quantified histologically. Untreated PolG mice demonstrated alterations in several impedance features, including 50-kHz relative permittivity and center frequency. A potential effect of NMN was also observed in these parameters in PolG but not WT animals. Impedance values correlated with myofiber CSA. Electrical impedance is sensitive to myofiber features considered characteristic of aging and to the impact of a potential therapy.

Self-gelling electroactive hydrogels based on chitosan–aniline oligomers/agarose for neural tissue engineering with on-demand drug release

Designing biomimetic scaffolds is an intellectual challenge of the realm of regenerative medicine and tissue engineering. An electroactive substrate should meet multidisciplinary mimicking the mechanical, electrical, and electrochemical properties of neural tissues. Hydrogels have been known platforms to regulate neural interface modulus, but the lack of conductivity always hampered their applications; hence, developing conductive hydrogels with on-demand drug release has become a concern of tissue engineering. In this work, electroactive hydrogels based on chitosan–aniline oligomer and agarose with self-gelling properties were synthesized, and their electrical, thermal, and electrochemical properties were characterized by Fourier transform infrared (FTIR), cyclic voltammetry (CV), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA), and four probe method . The conductivity of the as-prepared aniline oligomer-based hydrogel was ∼10−4 S/cm; which fell within the range of conductivities appropriate for applications in tissue engineering. The aniline oligomer played a key role in controlling the hydrogel properties by regulating the glass transition temperature and thermal properties. In addition, the swelling and degradation rates were decreased because of the hydrophobic properties of the aniline oligomer. The swelling capacity of the pristine hydrogel was ∼800%, while that of the conductive hydrogel decreased to ∼300%. The conductivity of the hydrogel was regulated by modifying the macromolecular architecture through aniline oligomer incorporation thanks to its conductivity on-demand drug release was observed by electrical stimulation, in which a large amount of the drug was released by voltage application. Biocompatibility analysis of the designed hydrogel was indicative of the conductivity enhancement, as reflected in the growth and proliferation of cellular activity.

1976P - General methodology to optimize tumor treating fields delivery utilizing numerical simulations

BackgroundTumor Treating Fields (TTFields) are intermediate frequency, alternating electric fields that non-invasively treat cancer. Transducer arrays positioned on the skin in proximity to the targeted tumor transmit TTFields. A post-hoc analysis [Ballo et al. Red Jour. 2019 In Press] has shown that increased patient usage (percent of time on active treatment) and intensity of TTFields delivery direct to the tumor improved survival. Optimal array positioning may enhance TTFields intensity at the tumor site to improve patient experience and survival. Minimization of array exposure area would enhance patient comfort levels and usage to improve survival. Optimizing TTFields delivery and distribution depends on array positioning and geometry, patient anatomy, and the heterogeneous electrical properties of different tissues. We present methodology to optimize TTFields delivery using numerical simulations. MethodsTTFields delivery to the brain, lung, and abdomen utilizing representative computational models was investigated. The effects of transducer array size and position on field distribution within the phantoms was analyzed, and an approach to optimize TTFields delivery was developed. ResultsField intensity was typically the greatest in between arrays, with larger arrays transmitting higher field power. Anatomical features, such as bones (spine) or a resection cavity significantly influenced field intensity within this region. A generalized methodology to optimize TTFields delivery for improved patient care was based on: (1) Striking a balance between maximal field intensity (largest arrays feasible) and minimal skin exposure to arrays in the disease area; (2) Positioning virtual arrays on a representative, computational patient model to test tumor localization between arrays, to simulate TTFields delivery to patient, and to assess optimal delivery; and (3) Applying an iterative algorithm to shift arrays around their initial positions until field intensity is maximized directly to the tumor bed. ConclusionsA generalized treatment methodology as presented by these data will optimize TTFields delivery to the tumor site. Effective TTFields treatment planning is expected to improve patient outcomes. Legal entity responsible for the studyNovocure. FundingNovocure. DisclosureN. Urman: Full / Part-time employment: Novocure; Shareholder / Stockholder / Stock options: Novocure. Z. Bomzon: Full / Part-time employment: Novocure; Shareholder / Stockholder / Stock options: Novocure. H.S. Hershkovich: Full / Part-time employment: Novocure; Shareholder / Stockholder / Stock options: Novocure. E.D. Kirson: Full / Part-time employment: Novocure; Shareholder / Stockholder / Stock options: Novocure. A. Naveh: Full / Part-time employment: Novocure; Shareholder / Stockholder / Stock options: Novocure. R. Shamir: Full / Part-time employment: Novocure; Shareholder / Stockholder / Stock options: Novocure. E. Fedorov: Full / Part-time employment: Novocure; Shareholder / Stockholder / Stock options: Novocure. C. Wenger: Full / Part-time employment: Novocure; Shareholder / Stockholder / Stock options: Novocure. U. Weinberg: Full / Part-time employment: Novocure; Shareholder / Stockholder / Stock options: Novocure.