Design of a complex bioimpedance spectrometer using DFT and undersampling for neural networks diagnostics

Amaral, Carlos E. F. do; Lopes, Heitor Silvério; Arruda, Lúcia Valéria Ramos de; Hara, Marcos Santos; Gonçalves, Antônio José; Dias, Adilson Alves

doi:10.1016/j.medengphy.2010.11.001

Cited by 9 publications

(3 citation statements)

References 19 publications

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“…With a low-cost system there will be fundamental limitations to both these metrics because cheaper components will not be able to match the performance of expensive laboratory impedance analysers. Therefore, the majority of the cost of low-cost impedance analysers are usually focused on the components that will directly influence the accuracy and precision of the measurement [7].…”

Section: Low-cost Design Trade-offsmentioning

confidence: 99%

Undersampling and Saturation for Impedance Spectroscopy Performance

Beer

Joubert

2021

IEEE Sensors J.

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The development of low-cost impedance spectroscopy devices is limited by the capabilities of low-cost hardware. Impedance spectroscopy requires high accuracy over a large bandwidth and dynamic range for most applications. In this paper, backend signal processing solutions are examined and implemented to improve both the bandwidth and dynamic range of a typical low-cost impedance analyser without modifying the hardware. The bandwidth is improved by undersampling the input waveforms and reconstructing the signals based on the known frequency information. The bandwidth can be increased by multiple orders of magnitude and the limiting factor of the system becomes amplifier bandwidth and the Analog-to-Digital Converter (ADC) sample-andhold circuit. Despite allowing signals to become orders of magnitude larger than the ADC range, the original signal can be reconstructed based on the measured saturated signal. This saturation technique more than doubles the dynamic range for any given accuracy requirement.

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Section: Low-cost Design Trade-offsmentioning

confidence: 99%

Undersampling and Saturation for Impedance Spectroscopy Performance

Beer

Joubert

2021

IEEE Sensors J.

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“…Any changes in tissue physiology should produce changes in the tissue electrical properties [23]. Based on this phenomenon, BIA analysis has been widely used to identify or monitor the presence of various illnesses or conditions such as body fluid shift, blood flow, cardiac output, and muscular dystrophy [24][25][26][27][28][29][30][31][32][33][34][35][36][37]. Different tissues exhibit different electrical properties, in addition, tissue electrical properties change with respect to tissue status evolution.…”

Section: Tissue Identification and Monitoringmentioning

confidence: 99%

Untitled

2017

JCMAH

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This paper reviews the literature regarding the correlations between homoeostatic reserves and mortality for cancer. We will review the literature about the use of bio-impedance assessment (BIA) and heart rate variability (HRV) to assess homoeostatic reserves. We know that in the different stages of cancer the functional reserves change significantly. During the treatment and after the treatment of cancer the level of the homoeostatic reserve is a measure of morbidity and mortality. One way of measuring the functional reserves of the body is by using the bio-impedance assessment (BIA) and heart rate variability (HRV) assessment. Both the bio-impedance assessment and heart rate variability assessment are independent markers for homoeostatic reserves. For BIA the key marker appears to be the phase angle (PhA). For HRV the key marker appears to be the balance of the autonomic nervous system (ANS)

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“…Other works [28,33,34] realized BIS measurements of singlefrequency and FS undersampling in hardware systems. Do Amaral et al [35] designed a FS BIS measuring instrument based on undersampling of high-frequency signals and used it in a preliminary study of head and neck cancer. Schmitz and Green [29,36] studied multisine undersampling theory and proposed several algorithms for optimizing the frequency distribution of multisine excitation.…”

Section: Introductionmentioning

confidence: 99%

Bioimpedance spectroscopy measurement method based on multisine excitation and integer-period undersampling

Hong

Zhang

et al. 2023

Meas. Sci. Technol.

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Bioimpedance spectroscopy (BIS) is a detection technology that uses the bioimpedance characteristics and changes law of human tissue to analyze its physiological and pathological states, and is widely used in clinical and scientific research applications. Traditional BIS measurement needs to satisfy the Nyquist sampling theorem, so as to ensure that the measurement signal has no frequency aliasing, but at the same time, the sampling frequency and the number of sampling points will be increased, which will increase the computation and hardware cost. This paper proposes a novel BIS measurement method based on multisine excitation and integer-period undersampling (IPUS) technology. Firstly, the multisine-based IPUS theory was deduced, and the BIS measurement principle based on multisine excitation and IPUS technology was introduced. Secondly, a BIS measurement system based on FPGA+ADC+DAC architecture was designed, and a multisine excitation with 32 pseudo-logarithmically distributed frequency components in the range of 2-997 kHz was generated. The comparative BIS measurement experiments on three RC three-element models were carried out under the Nyquist sampling condition (fs = 2.56 MHz) and under the IPUS condition (fs = 512 kHz), respectively. Experimental results showed that the average amplitude error of BIS measurement under the Nyquist sampling condition is 0.80% (mean) ± 1.19% (std), while the average amplitude error under the IPUS condition is 1.02% (mean) ± 1.13% (std). Moreover, the signal to nosie ratio (SNRz) is calculated in 40 repeated BIS measurements, where the mean SNRz is 63.60dB under IPUS condition, similar to the value of 62.77dB under Nyquist sampling condition. The proposed multisine-based IPUS theory and its implementation method in this paper can complete a BIS measurement with only one fundamental period, and need the sampling frequency and sampling points lower than the requirements of the Nyquist theory, which lay a theoretical and technical foundation for BIS measurement system with reduced hardware requirements and computation cost.

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Design of a complex bioimpedance spectrometer using DFT and undersampling for neural networks diagnostics

Cited by 9 publications

References 19 publications

Undersampling and Saturation for Impedance Spectroscopy Performance

Undersampling and Saturation for Impedance Spectroscopy Performance

Untitled

Bioimpedance spectroscopy measurement method based on multisine excitation and integer-period undersampling

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