A multi-chanel electrical impedance meter based on digital lock-in technology

Vizvári, Zoltán; Kiss, Tibor; Vér, Csaba; Máthé, Kálmán; Kuljic, Bojan; Henezi, Ferenc; Ódry, Péter

doi:10.1556/606.2019.14.2.19

Cited by 10 publications

(17 citation statements)

References 15 publications

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“…The above-detailed changes comprise a significant improvement, compared to the instruments published by Vizvari et al [ 34 ]. Of course, the further development of the measuring system has been carried out in other ways.…”

Section: Methodsmentioning

confidence: 89%

“…In the case of the implementation of four-electrode techniques, the realization of differential measurements results in significant errors in the data, while the above techniques can only be used by application of a current generator [ 12 ]. Therefore, we performed BIS measurements using a method based on the four-electrode technique published by Vizvari et al [ 33 , 34 ], which is a voltage comparison technique that can be applied to both current or voltage with generator excitation. The authors have shown that the application of this self-developed data acquisition and evaluation process, compared with other techniques, increases the effectiveness and the accuracy of BIS measurements over a wide frequency range [ 34 ].…”

Section: Methodsmentioning

confidence: 99%

“…Therefore, we performed BIS measurements using a method based on the four-electrode technique published by Vizvari et al [ 33 , 34 ], which is a voltage comparison technique that can be applied to both current or voltage with generator excitation. The authors have shown that the application of this self-developed data acquisition and evaluation process, compared with other techniques, increases the effectiveness and the accuracy of BIS measurements over a wide frequency range [ 34 ]. The effectiveness of this method relies on the fact that we implement a common-mode rejection of errors in data collection and data processing specially developed for this purpose [ 34 ].…”

Section: Methodsmentioning

confidence: 99%

“…The authors have shown that the application of this self-developed data acquisition and evaluation process, compared with other techniques, increases the effectiveness and the accuracy of BIS measurements over a wide frequency range [ 34 ]. The effectiveness of this method relies on the fact that we implement a common-mode rejection of errors in data collection and data processing specially developed for this purpose [ 34 ]. In this case, we wanted to model a life-like measurement scenario (i.e., to maximise the error effects that occur during the measurement).…”

Section: Methodsmentioning

confidence: 99%

“…Our research group developed the digital lock-in algorithms [ 36 ], following the improvement of the previous software published by Vizvari et al [ 34 ], and their optimisations for this four-channel instrument (in particular, with respect to the measurement noise). The lock-in measurement procedure around the reference frequency selects signals in a specific frequency range, effectively discarding all other frequency components from the signal, thus having a selective filter character.…”

Section: Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Physical Validation of a Residual Impedance Rejection Method during Ultra-Low Frequency Bio-Impedance Spectral Measurements

Vizvári

Gyorfi

Odry

et al. 2020

Sensors

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Accurate and reliable measurement of the electrical impedance spectrum is an essential requirement in order to draw relevant conclusions in many fields and a variety of applications; in particular, for biological processes. Even in the state-of-the-art methods developed for this purpose, the accuracy and efficacy of impedance measurements are reduced in biological systems, due to the regular occurrence of parameters causing measurement errors such as residual impedance, parasitic capacitance, generator anomalies, and so on. Recent observations have reported the necessity of decreasing such inaccuracies whenever measurements are performed in the ultra-low frequency range, as the above-mentioned errors are almost entirely absent in such cases. The current research work proposes a method which can reject the anomalies listed above when measuring in the ultra-low frequency range, facilitating data collection at the same time. To demonstrate our hypothesis, originating from the consideration of the determinant role of the measuring frequency, a physical model is proposed to examine the effectiveness of our method by measuring across the commonly used vs. ultra-low frequency ranges. Validation measurements reflect that the range of frequencies and the accuracy is much greater than in state-of-the-art methods. Using the proposed new impedance examination technique, biological system characterization can be carried out more accurately.

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Section: Methodsmentioning

confidence: 89%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Physical Validation of a Residual Impedance Rejection Method during Ultra-Low Frequency Bio-Impedance Spectral Measurements

Vizvári

Gyorfi

Odry

et al. 2020

Sensors

Self Cite

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Reproducibility analysis of bioimpedance-based self-developed live cell assays

Vizvari,

Gyorfi,

Maczko

et al. 2024

Sci Rep

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Bioimpedance spectrum (BIS) measurements have a great future in in vitro experiments, meeting all the requirements for non-destructive and label-free methods. Nevertheless, a real basic research can provide the necessary milestones to achieve the success of the method. In this paper a self-developed technology-based approach for in vitro assays is proposed. Authors invented a special graphene-based measuring plate in order to assess the high sensitivity and reproducibility of introduced technique. The design of the self-produced BIS plates maximizes the detection capacity of qualitative changes in cell culture and it is robust against physical effects and artifacts. The plates do not influence the viability and proliferation, however the results are robust, stable and reproducible regardless of when and where the experiments are carried out. In this study, physiological saline concentrations, two cancer and stem cell lines were utilized. All the results were statistically tested and confirmed. The findings of the assays show, that the introduced BIS technology is appropriate to be used in vitro experiments with high efficacy. The experimental results demonstrate high correlation values across the replicates, and the model parameters suggested that the characteristic differences among the various cell lines can be detected using appropriate hypothesis tests.

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