Practical Characterization of Cell-Electrode Electrical Models in Bio-Impedance Assays

This paper presents the fitting process followed to adjust the parameters of the electrical model associated to a cell-electrode system in Electrical Cell-substrate Impedance Spectroscopy (ECIS) technique, to the experimental results from cell-culture assays. A new parameter matching procedure is proposed, under the basis of both, mismatching between electrodes and time-evolution observed in the system response, as consequence of electrode fabrication processes and electrochemical performance of electrode-solution interface, respectively. The obtained results agree with experimental performance, and enable the evaluation of the cell number in a culture, by using the electrical measurements observed at the oscillation parameters in the test circuits employed.Ministerio de Economía y Competitividad TEC2013-46242-C3-1-

Sensing Cell-Culture Assays with Low-Cost Circuitry

An alternative approach for cell-culture end-point protocols is proposed herein. This new technique is suitable for real-time remote sensing. It is based on Electrical Cell-substrate Impedance Spectroscopy (ECIS) and employs the Oscillation-Based Test (OBT) method. Simple and straightforward circuit blocks form the basis of the proposed measurement system. Oscillation parameters – frequency and amplitude – constitute the outcome, directly correlated with the culture status. A user can remotely track the evolution of cell cultures in real time over the complete experiment through a web tool continuously displaying the acquired data. Experiments carried out with commercial electrodes and a well-established cell line (AA8) are described, obtaining the cell number in real time from growth assays. The electrodes have been electrically characterized along the design flow in order to predict the system performance and the sensitivity curves. Curves for 1-week cell growth are reported. The obtained experimental results validate the proposed OBT for cell-culture characterization. Furthermore, the proposed electrode model provides a good approximation for the cell number and the time evolution of the studied cultures.España, Feder TEC2013-46242-C3-1-

Monitoring Muscle Stem Cell Cultures with Impedance Spectroscopy

The aim of this work is to present a new circuit for the real-time monitoring the processes of cellular growth and differentiation of skeletal myoblast cell cultures. An impedance spectroscopy Oscillation-Based technique is proposed for the test circuit, converting the biological system into a voltage oscillator, and avoiding the use of very high performance circuitry or equipment. This technique proved to be successful in the monitoring of cell cultures growth levels and could be useful for determining the degree of differentiation achieved, of practical implications in tissue engineering.Ministerio de Economía y Competitividad TEC2013-46242-C3-1-

Remote Sensing of Cell-Culture Assays

This chapter describes a full system developed to perform the remote sensing of cell-culture experiments from any access point with internet connection. The proposed system allows the real-time monitoring of cell assays thanks to bioimpedance measurement circuits developed to count the number of cell present in a culture. Cell-culture characterization is performed through the measurement of the increasing bioimpedance parameter over time. The circuit implementation is based on the oscillation-based test (OBT) methodology. Bioimpedance of cell cultures is measured in terms of the oscillation parameters (frequency, amplitude, phase, etc.) and used as empirical markers to carry out an appropriate interpretation in terms of cell size identification, cell counting, cell growth, growth rhythm, etc. The device is capable of managing the whole sensing task and performs wireless communication through a Bluetooth module. Data are interpreted and displayed on a computer or a mobile phone through a web application. The system has its practical application in drug development processes, offering a label-free, high-throughput, and high-content screening method for cellular research, avoiding the classical end-point techniques and a significant workload and cost material reduction

A CMOS Tracking System Approach for Cell Motility Assays

This work proposes a method for studying and monitoring in real-time a single cell on a 2D electrode matrix, of great interest in cell motility assays and in the characterization of cancer cell metastasis. A CMOS system proposal for cell location based on occupation maps data generated from Electrical Cell-substrate Impedance Spectroscopy (ECIS) has been developed. From this cell model, obtained from experimental assays data, an algorithm based on analysis of the 8 nearest neighbors has been implemented, allowing the evaluation of the cell center of mass. The path followed by a cell, proposing a Brownian route, has been simulated with the proposed algorithm. The presented results show the success of the approach, with accuracy over 95% in the determination of any coordinate (x, y) from the expected center of mass.Ministerio de Economía y Competitividad TEC2013-46242-C3-1-

A Tracking Algorithm For Cell Motility Assays in CMOS Systems

This work proposes a method for the study and real-time monitoring of a single cell on a 2D electrode matrix, of great interest in cell motility assays and in the characterization of cancer cell metastasis. A CMOS system proposal for cell location based on occupation maps data generated from Electrical Cell-substrate Impedance Spectroscopy (ECIS) has been developed. From experimental assays data, an algorithm based on the analysis of the eight nearest neighbours has been implemented to find the cell center of mass. The path followed by a cell, proposing a Brownian route, has been simulated with the proposed algorithm. The presented results give an accuracy over 95% in the determination of the coordinates (x, y) from the expected cell center of mass.Ministerio de Economía y Competitividad TEC2013-46242-C3-1-

An Empirical-Mathematical Approach for Calibration and Fitting Cell-Electrode Electrical Models in Bioimpedance Tests

This paper proposes a new yet efficient method allowing a significant improvement in the on-line analysis of biological cell growing and evolution. The procedure is based on an empirical-mathematical approach for calibration and fitting of any cell-electrode electrical model. It is valid and can be extrapolated for any type of cellular line used in electrical cell-substrate impedance spectroscopy (ECIS) tests. Parameters of the bioimpedance model, acquired from ECIS experiments, vary for each cell line, which makes obtaining results difficult and—to some extent-renders them inaccurate. We propose a fitting method based on the cell line initial characterization,and carry out subsequent experiments with the same line to approach the percentage of well filling and the cell density (or cell number in the well). To perform our calibration technique, the so-called oscillation-based test (OBT) approach is employed for each cell density. Calibration results are validated by performing other experiments with different concentrations on the same cell line with the same measurement technique. Accordingly, a bioimpedance electrical model of each cell line is determined, which is valid for any further experiment and leading to a more precise electrical model of the electrode-cell system. Furthermore, the model parameters calculated can be also used by any other measurement techniques. Promising experimental outcomes for three different cell-lines have been achieved, supporting the usefulness of this technique

Remote Cell Growth Sensing Using Self-Sustained Bio-Oscillations

A smart sensor system for cell culture real-time supervision is proposed, allowing for a significant reduction in human effort applied to this type of assay. The approach converts the cell culture under test into a suitable “biological” oscillator. The system enables the remote acquisition and management of the “biological” oscillation signals through a secure web interface. The indirectly observed biological properties are cell growth and cell number, which are straightforwardly related to the measured bio-oscillation signal parameters, i.e., frequency and amplitude. The sensor extracts the information without complex circuitry for acquisition and measurement, taking advantage of the microcontroller features. A discrete prototype for sensing and remote monitoring is presented along with the experimental results obtained from the performed measurements, achieving the expected performance and outcomes

Characterization of Implanted Stents through Neointimal Tissue Bioimpedance Simulations

This work describes how is possible the definition of the light hole or lumen in implanted stents affected by restenosis processes using the BioImpedance (BI) as biomarker. The main approach is based on the fact that neointimal tissues implied in restenosis can be detected and measured thanks to their respective conductivity and dielectric properties. For this goal, it is proposed a four-electrode setup for bioimpedance measurement. The influence of the several involved tissues in restenosis: fat, muscle, fiber, endothelium and blood, have been studied at several frequencies, validating the setup and illustrating the sensitivity of each one. Finally, a real example using a standard stent, has been analyzed for stable and vulnerable plaques in restenosis test cases, demonstrating that the proposed method is useful for the stent obstruction test. Bioimpedance simulation test has been performed using the electric physics module in COMSOL Multiphysics®.Junta de Andalucía 2017/TIC-17

Efecto de un programa de ejercicio aeróbico en la composición corporal y somatotipo de un obeso mórbido infantil

La obesidad representa un problema de salud que suele iniciarse en la infancia y la adolescencia, por un desequilibrio entre la ingesta y el gasto energético, derivando en niveles altos de grasa corporal y grados peligrosos de adiposidad relativa. Por tanto, la inactividad física es un factor de riego que favorece el sobrepeso y la obesidad. El objetivo fue diseñar y aplicar un programa de ejercicio aeróbico y evaluar su efecto en la composición corporal y somatotipo en un niño con obesidad mórbida. Se abordó como un estudio de caso, con pre-test y post-test, en un niño de 10 años, con peso corporal de 88.9 kg, estatura de 158.5 cm, un IMC clasificado de obeso mórbido, no practicante de algún deporte o actividad física regular. El programa fue de 12 semanas, 5 sesiones por semana y una duración de 30-60 min por sesión y una intensidad del 55- 70% de Fcmax. La composición corporal y el somatotipo se obtuvo por mediciones de variables antropométricas. El componente graso a través de la medición de pliegues. En los resultados destacan la diferencia en el pre-test y pos-test de los pliegues: bíceps (dif. 0.0 mm), tríceps (dif. -1.2 mm), subescapular (dif. -1.0 mm.) y suprailiaco (dif. -3.2 mm). Se encontraron pequeñas diferencias en el componente graso (dif. -1.05%) y peso graso (dif. -800 grs). Con respecto a la somaocarta, la distancia de dispersión del somatotipo no mostró valores relevantes. El efecto del programa no alcanzó niveles significativos y el sujeto aún permanece en estado de alto riesgo de saludObesity represents a health problem that usually starts in childhood and adolescence, by an imbalance between the consumption and the energy use, deriving in high levels of body fat and dangerous degrees of relative adiposity. Thus, the physical inactivity is a risk factor that favours overweight and obesity. The objective was to design and apply a program of aerobic exercises and to evaluate its effect on body composition and somatotype in a child with morbid obesity. It was addressed as a case study, with pre-test and post-test, in a 10-year-old child, with a body weight of 88.9 kg, a height of 158.5 cm, a BMI classified as morbidly obese, not practicing a sport or physical activity regularly. The program was 12 weeks, 5 sessions per week and a duration of 30-60 minutes per session and an intensity of 55-70% of Fcmax. Body composition and somatotype were obtained by measuring the anthropometric variables. The fat component through the measurement of folds. The results highlight the difference in the pre-test and post-test of the folds: biceps (diff. 0.0 mm.), triceps (diff. -1.2 mm.), subscapular (diff. -1.0 mm.) and suprailiac (diff -3.2 mm.). Small differences in the fat component (diff -1.05%) and the fat weight (diff. -800 grs.) were found. Regarding the somacarta the dispersal distance of the somatotype did not show relevant values. The effect of the program did not reach significant levels and the subject remains in a state of high health risk