1
|
Marcôndes DWC, Paterno AS, Bertemes-Filho P. Parasitic Effects on Electrical Bioimpedance Systems: Critical Review. SENSORS (BASEL, SWITZERLAND) 2022; 22:8705. [PMID: 36433301 PMCID: PMC9693567 DOI: 10.3390/s22228705] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Parasitic capacitance represents the main error source in measurement systems based on electrical impedance spectroscopy. The capacitive nature of electrodes' impedance in tetrapolar configuration can give origin to phase errors when electrodes are coupled to parasitic capacitances. Nevertheless, reactive charges in tissue excitation systems are susceptible to instability. Based on such a scenario, mitigating capacitive effects associated with the electrode is a requirement in order to reduce errors in the measurement system. A literature review about the main compensation techniques for parasitic capacitance was carried out. The selected studies were categorized into three groups: (i) compensation in electronic instrumentation; (ii) compensation in measurement processing, and (iii) compensation by negative impedance converters. The three analyzed methods emerged as effective against fixed capacitance. No method seemed capable of mitigating the effects of electrodes' capacitance, that changes in the frequency spectrum. The analysis has revealed the need for a method to compensate varying capacitances, since electrodes' impedance is unknown.
Collapse
|
2
|
Morcelles KF, Bertemes-Filho P. Hardware for cell culture electrical impedance tomography: A critical review. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:104704. [PMID: 34717415 DOI: 10.1063/5.0053707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
Human cell cultures are powerful laboratory tools for biological models of diseases, drug development, and tissue engineering. However, the success of biological experiments often depends on real-time monitoring of the culture state. Conventional culture evaluation methods consist of end-point laborious techniques, not capable of real-time operation and not suitable for three-dimensional cultures. Electrical Impedance Tomography (EIT) is a non-invasive imaging technique with high potential to be used in cell culture monitoring due to its biocompatibility, non-invasiveness, high temporal resolution, compact hardware, automatic operation, and high throughput. This review approaches the different hardware strategies for cell culture EIT that are presented in the literature, discussing the main components of the measurement system: excitation circuit, voltage/current sensing, switching stage, signal specifications, electrode configurations, measurement protocols, and calibration strategies. The different approaches are qualitatively discussed and compared, and design guidelines are proposed.
Collapse
Affiliation(s)
- K F Morcelles
- Department of Electrical Engineering, Santa Catarina State University, Joinville 89219-710, Brazil
| | - P Bertemes-Filho
- Department of Electrical Engineering, Santa Catarina State University, Joinville 89219-710, Brazil
| |
Collapse
|
3
|
Hanitra MIN, Criscuolo F, Carrara S, De Micheli G. Real-Time Multi-Ion-Monitoring Front-End With Interference Compensation by Multi-Output Support Vector Regressor. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2021; 15:1093-1106. [PMID: 34623275 DOI: 10.1109/tbcas.2021.3118945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Ion-sensors play a major role in physiology and healthcare monitoring since they are capable of continuously collecting biological data from body fluids. Nevertheless, ion interference from background electrolytes present in the sample is a paramount challenge for a precise multi-ion-monitoring. In this work, we propose the first system combining a battery-powered portable multi-channel electronic front-end, and an embedded Multi-output Support Vector Regressor (M-SVR), that supplies an accurate, continuous, and real-time monitoring of sodium, potassium, ammonium, and calcium ions. These are typical analytes tracked during physical exercise. The front-end interface was characterized through a sensor array built with screen-printed electrodes. Nernstian sensitivity and limit of detection comparable to a bulky laboratory potentiometer were achieved in both water and artificial sweat. The multivariate calibration model was deployed on a Raspberry Pi where the activity of the target ions were locally computed. The M-SVR model was trained, optimized, and tested on an experimental dataset acquired following a design of experiments. We demonstrate that the proposed multivariate regressor is a compact, low-complexity, accurate, and unbiased estimator of sodium and potassium ions activity. A global normalized root mean-squared error improvement of 6.97%, and global mean relative error improvement of 10.26%, were achieved with respect to a standard Multiple Linear Regressor (MLR). Within a real-time multi-ion-monitoring task, the overall system enabled the continuous monitoring and accurate determination of the four target ions activity, with an average accuracy improvement of 27.73% compared to a simple MLR, and a prediction latency of [Formula: see text].
Collapse
|
4
|
Analysis, Simulation, and Development of a Low-Cost Fully Active-Electrode Bioimpedance Measurement Module. TECHNOLOGIES 2021. [DOI: 10.3390/technologies9030059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A low-cost 1 kHz–400 kHz operating frequency fully-active electrode bioimpedance measurement module, based on Howland current source, is presented in this paper. It includes a buffered positive feedback Howland current source, implemented with operational amplifiers, as well as an AD8421 instrumentation amplifier, for the differential voltage measurements. Each active electrode module can be connected to others, assembling a wearable active electrode module array. From this array, 2 electrodes can be selected to be driven from a THS413 fully differential amplifier, activating a mirrored Howland current source. This work performs a complete circuit analysis, verified with MATLAB and SPICE simulations of the current source’s transconductance and output impedance over the frequency range between 1 kHz and 1 MHz. Resistors’ tolerances, possible mismatches, and the operational amplifiers’ non-idealities are considered in both the analysis and simulations. A comparison study between four selected operational amplifiers (ADA4622, OPA2210, AD8034, and AD8672) is additionally performed. The module is also hardware-implemented and tested in the lab for all four operational amplifiers and the transconductance is measured for load resistors of 150 Ω, 660 Ω, and 1200 Ω. Measurements showed that, using the AD8034 operational amplifier, the current source’s transconductance remains constant for frequencies up to 400 KHz for a 150 Ω load and 250 kHz for a 1200 Ω load, while lower performance is achieved with the other 3 operational amplifiers. Finally, transient simulations and measurements are performed at the AD8421 output for bipolar measurements on the 3 aforementioned load resistor values.
Collapse
|
5
|
Morcelles KF, Negri LH, Bertemes-Filho P. Design of Howland Current Sources Using Differential Evolution Optimization. JOURNAL OF ELECTRICAL BIOIMPEDANCE 2020; 11:96-100. [PMID: 33584909 PMCID: PMC7851979 DOI: 10.2478/joeb-2020-0014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Indexed: 06/12/2023]
Abstract
Howland circuits have been widely used in Electrical Bioimpedance Spectroscopy applications as reliable current sources. This paper presents an algorithm based on Differential Evolution for the automated design of Enhanced Howland Sources according to arbitrary design constraints while respecting the Howland ratio condition. Results showed that the algorithm can obtain solutions to commonly sought objectives, such as maximizing the output impedance at a given frequency, making it a versatile method to be employed in the design of sources with specific requirements. The mathematical modeling of the source output impedance and transconductance, considering a non-ideal operational amplifier, was validated against SPICE simulations, with results matching up to 10 MHz.
Collapse
Affiliation(s)
| | - Lucas Hermann Negri
- Federal Institute of Education, Science and Technology of Mato Grosso do Sul. Nova Andradina, Brazil
| | | |
Collapse
|
6
|
Zhang Q, Jiang X, Brunello D, Fu T, Zhu C, Ma Y, Li HZ. Initial coalescence of a drop at a planar liquid surface. Phys Rev E 2019; 100:033112. [PMID: 31639928 DOI: 10.1103/physreve.100.033112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Indexed: 06/10/2023]
Abstract
The initial coalescence of a pendant drop at bulk liquid was jointly investigated by an ultrahigh-speed DC electrical device, a high-speed camera, and a fast micro-Particle Image Velocimetry (micro-PIV). Extended to highly viscous non-Newtonian liquids, the variation of the coalescing width vs time confirms the distinct regimes reported for drop-drop configuration: linear in the inertially limited viscous regime; square root in the inertial regime; possibly a transient viscous regime in between with a logarithmic correction. The measured flow fields during coalescence reveal the transformation of surface energy to kinetic energy, so that the highly located inertia could play a dominant role in relation to the viscous force.
Collapse
Affiliation(s)
- Qindan Zhang
- Laboratory of Reactions and Process Engineering, CNRS, University of Lorraine, 1, rue Grandville, BP 20451, 54001 Nancy Cedex, France
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
| | - Xiaofeng Jiang
- Laboratory of Reactions and Process Engineering, CNRS, University of Lorraine, 1, rue Grandville, BP 20451, 54001 Nancy Cedex, France
| | - David Brunello
- Laboratory of Reactions and Process Engineering, CNRS, University of Lorraine, 1, rue Grandville, BP 20451, 54001 Nancy Cedex, France
| | - Taotao Fu
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
| | - Chunying Zhu
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
| | - Youguang Ma
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China
| | - Huai Z Li
- Laboratory of Reactions and Process Engineering, CNRS, University of Lorraine, 1, rue Grandville, BP 20451, 54001 Nancy Cedex, France
| |
Collapse
|
7
|
Grando Sirtoli V, Coelho Vincence V, Bertemes-Filho P. Mirrored enhanced Howland current source with feedback control. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:024702. [PMID: 30831761 DOI: 10.1063/1.5079872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 01/12/2019] [Indexed: 06/09/2023]
Abstract
An impedance spectrum is calculated by the ratio between an injecting current and a resulting measured voltage, which allows the extraction of electrical properties from the material under study. The current source is considered an essential block to deliver a controlled current to a wide range of working loads and large bandwidth. To comply with such requirements, the current source output impedance must be much higher than the load impedance at each discrete frequency within the range. However, stray capacitance from cables and circuitry reduce the output impedance, especially at higher frequencies. We proposed a modified mirrored enhanced Howland current source (MEHCS) by using the feedback technique for a wide frequency range applications on electrical bioimpedance. We implemented four MEHCS circuits [with/without multiplexer (MUX) and with/without feedback], and then the output current and impedance were measured up to 20 MHz. The proposed current source showed an improvement in the frequency response at lower and higher frequencies when compared to the standard circuit. The measured output impedance was 10 times higher in the proposed circuit than in the standard MEHCS. The use of a feedback also increased the bandwidth in almost one decade in low and high frequencies when loaded with a resistor of about 1 kΩ.
Collapse
Affiliation(s)
- Vinicius Grando Sirtoli
- Univeridade do Estado de Santa Catarina (UDESC), Rua Paulo Malschitzki, 200, Campus Universitario Prof. Avelino Marcante, Bairro Zona Industrial Norte, Joinville, SC, Brazil
| | - Volney Coelho Vincence
- Univeridade do Estado de Santa Catarina (UDESC), Rua Paulo Malschitzki, 200, Campus Universitario Prof. Avelino Marcante, Bairro Zona Industrial Norte, Joinville, SC, Brazil
| | - Pedro Bertemes-Filho
- Univeridade do Estado de Santa Catarina (UDESC), Rua Paulo Malschitzki, 200, Campus Universitario Prof. Avelino Marcante, Bairro Zona Industrial Norte, Joinville, SC, Brazil
| |
Collapse
|
8
|
Design and Evaluation of an Electrical Bioimpedance Device Based on DIBS for Myography during Isotonic Exercises. JOURNAL OF LOW POWER ELECTRONICS AND APPLICATIONS 2018. [DOI: 10.3390/jlpea8040050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Electrical Bioimpedance Spectroscopy (EIS) is a technique used to assess passive electrical properties of biological materials. EIS detects physiological and pathological conditions in animal tissues. Recently, the introduction of broadband excitation signals has reduced the measuring time for application techniques such as Electrical Bioimpedance Myography. Therefore, this work is aimed at proposing a prototype by using discrete interval binary sequences (DIBS), which is based on a system that holds a current source, impedance acquisition system, microcontroller and graphical user interface. Measurements between 5 Ω to 5 kΩ had impedance acquisition and phase angle errors of aproximately 2% and were lower than 3 degrees, respectively. Based on a proposed circuit, bioimpedance of the chest muscle (Pectoralis Major) was measured during isotonic exercise (push-up). As a result, our analyses have detected tiredness and fatigue. We have explored and proposed new parameters which assess such conditions, as both the maximum magnitude and tiredness coefficient. These parameters decrease exponentially with consecutive push-ups and were convergent in the majority of the sixteen days of measurement.
Collapse
|
9
|
Sirtoli VG, Morcelles KF, Vincence VC. Design of Current Sources for Load Common Mode Optimization. JOURNAL OF ELECTRICAL BIOIMPEDANCE 2018; 9:59-71. [PMID: 33584922 PMCID: PMC7852011 DOI: 10.2478/joeb-2018-0011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Indexed: 05/27/2023]
Abstract
Bioimpedance measurement systems often use the Howland current sources to excite the biological material under study. Usually, difference or instrumentation amplifiers are used to measure the resulting voltage drop on this material. In these circuits, common mode voltage appears as artifacts in the measurement. Most researches on current sources are focused on improving the output impedance, letting other characteristics aside. In this paper, it is made a brief review on the load common mode voltage and output swing of various topologies of Howland current sources. Three circuits are proposed to reduce load common mode voltage and enhance load capability by using a fully differential amplifier as active component. These circuits are equated, simulated and implemented. The three proposed circuits were able to deliver an output current with cut-off frequency (-3dB) higher than 1 MHz for loads as big as 4.7 kΩ. The worst measured load common mode voltage was smaller than 24 mV for one of the circuits and smaller than 8 mV for the other two. Consequently, it could be obtained increases in the Common Mode Rejection Ratio (CMRR) up to 60 dB when compared to the Enhanced Howland Current Source (EHCS).
Collapse
Affiliation(s)
- Vinicius G Sirtoli
- Department of Electrical Engineering, Santa Catarina State University (UDESC), Joinville, Brazil
| | - Kaue F Morcelles
- Department of Electrical Engineering, Santa Catarina State University (UDESC), Joinville, Brazil
| | - Volney C Vincence
- Department of Electrical Engineering, Santa Catarina State University (UDESC), Joinville, Brazil
| |
Collapse
|
10
|
Morcelles KF, Sirtoli VG, Bertemes-Filho P, Vincence VC. Erratum: "Howland current source for high impedance load applications" [Rev. Sci. Instrum. 88, 114705 (2017)]. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:129901. [PMID: 29289226 DOI: 10.1063/1.5016966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- K F Morcelles
- Department of Electrical Engineering, Santa Catarina State University, Joinville 89.219-710, Brazil
| | - V G Sirtoli
- Department of Electrical Engineering, Santa Catarina State University, Joinville 89.219-710, Brazil
| | - P Bertemes-Filho
- Department of Electrical Engineering, Santa Catarina State University, Joinville 89.219-710, Brazil
| | - V C Vincence
- Department of Electrical Engineering, Santa Catarina State University, Joinville 89.219-710, Brazil
| |
Collapse
|