A bio-impedance readout IC with frequency sweeping from 1k-to-1MHz for electrical impedance tomography

Ha, Hyunsoo; Konijnenburg, Mario; Lukita, Budi; Wegberg, Roland van; Xu, Jiawei; Hoven, R. van den; Lemmens, Marijn; Thoelen, Ronald; Hoof, Chris Van; Helleputte, Nick Van

doi:10.23919/vlsic.2017.8008471

Cited by 28 publications

(8 citation statements)

References 4 publications

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“…The above measurement methodology is realized using a MUSEIC V2.0, a low power sensor with multiplexing capabilities developed by IMEC, Belgium [43]. The EIT image reconstruction made with the framework of EIDORS which is used in MATLAB 2018b, a compilation of algorithms that falls under the GNU Public License [44].…”

Section: Measurement Patternmentioning

confidence: 99%

Fully printed, stretchable and wearable bioimpedance sensor on textiles for tomography

Jose

Lemmens

Bormans

et al. 2021

Flex. Print. Electron.

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Electrical impedance tomography (EIT) is a non-invasive, real-time, continuous imaging technique that has multiple applications in health care. EIT is a realizable technique for radiation-free medical imaging ranging from real-time monitoring of bone fracture repair to lung functioning. This work explores the prospect of printing a wearable bioimpedance sensor on textiles for EIT imaging. Screen printing and stencil printing were applied to fabricate the sensor on the textile substrate and the imaging was carried out with the worn sensor on the human body. The first part of this work focuses on developing a flexible textile sensor in the form of a bracelet to obtain cross-sectional images of the forearm that unravel bone features like shape, size and position. However, body parts such as the thorax have added complexities due to their constantly varying perimeter and uneven shape. It is a significant prerequisite for the wearable sensors to apply to dynamic body parts where irregular shape and continuous volume variations occur. The second part of the paper therefore addresses the fabrication and testing of a stretchable textile-based sensor to address such instances of body dynamicity. The proposed stretchable sensor, worn on the thorax, demonstrates the feasibility of imaging such an uneven and dynamic body part. Although the EIT images are inherently attributed to low resolution, this work shows the prospect of wearable imaging applications in health monitoring. Apart from demonstrating the printed sensor for EIT imaging, this paper shows the image rendering quality dependency over the frequency of the signal and the number of electrodes. This work could initiate further research on wearable EIT based health monitoring devices for real-life scenarios.

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Section: Measurement Patternmentioning

confidence: 99%

Fully printed, stretchable and wearable bioimpedance sensor on textiles for tomography

Jose

Lemmens

Bormans

et al. 2021

Flex. Print. Electron.

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“…As a key design parameter, the sensitivity of BioZ is derived as follows: (Fig. 12) [17], thus the 1/f noise of each current mirror is upmodulated to fDEM/(N+1), where N is the current gain. Fig.…”

Section: B Bio-impedance (Bioz) Modementioning

confidence: 99%

A 36 μW 1.1 mm² Reconfigurable Analog Front-End for Cardiovascular and Respiratory Signals Recording

Konijnenburg

et al. 2018

IEEE Trans. Biomed. Circuits Syst.

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This paper presents a 1.2 V 36 μW reconfigurable analog front-end (R-AFE) as a general-purpose low-cost IC for multiple-mode biomedical signals acquisition. The R-AFE efficiently reuses a reconfigurable preamplifier, a current generator (CG), and a mixed signal processing unit, having an area of 1.1 mm2 per R-AFE while supporting five acquisition modes to record different forms of cardiovascular and respiratory signals. The R-AFE can interface with voltage-, current-, impedance-, and light-sensors and hence can measure electrocardiography (ECG), bio-impedance (BioZ), photoplethysmogram (PPG), galvanic skin response (GSR), and general-purpose analog signals. Thanks to the chopper preamplifier and the low-noise CG utilizing dynamic element matching, the R-AFE mitigates ${\text{1}}\text{/}f$ noise from both the preamplifier and the CG for improved measurement sensitivity. The IC achieves competitive performance compared to the state-of-the-art dedicated readout ICs of ECG, BioZ, GSR, and PPG, but with approximately 1.4×-5.3× smaller chip area per channel.

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“…By reducing the demodulator operation frequency, e.g., from 10 MHz (= f in ) to 10 kHz (= f IF ), the overall IC power consumption is drastically decreased. This technique performing the frequency shift in front of the IA was proposed before, but only for the quadrature demodulation architecture [15], [16]. The proposed impedance-measurement IC is the first one that applies the frequency-shift technique to the polar demodulation architecture.…”

Section: Introductionmentioning

confidence: 99%

A Power-Efficient, Wide-Frequency-Range Impedance Measurement IC Using Frequency-Shift Technique

Cheon

Kweon

Kim

et al. 2021

2021 IEEE International Symposium on Circuits and Systems (ISCAS)

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This paper presents an impedance-measurement integrated circuit (IC) that extends the input frequency range to 10 MHz at low power consumption. The proposed IC directly measures the magnitude and phase of the target impedance while adopting a reference resistor, which is connected in series with the target impedance, to obviate the nonideal delays that may be introduced by the voltage-controlled current source and the receiver's signal processing paths. On the receiver side of the IC, a frequency shift is performed by a chopper in front of the first-stage instrumentation amplifier (IA). The chopper downconverts the frequency of the incoming signal, which ranges to 10 MHz, to a common intermediate frequency of 10 kHz. As a result, the requirements on the IA bandwidth and the comparator delay are greatly relaxed, leading to a significant power saving. Furthermore, this technique improves the phase accuracy because the time interval corresponding to the phase at a high frequency increases at the down-converted frequency. Finally, the auto-zeroing technique is used to cancel out the comparator offset, thus reducing the magnitude and phase errors. The proposed IC designed in a 180-nm CMOS process consumes only 544 µW for a frequency range from 100 Hz to 10 MHz with the maximum magnitude and phase errors of 1.0% and 1.8 • , respectively.

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A bio-impedance readout IC with frequency sweeping from 1k-to-1MHz for electrical impedance tomography

Cited by 28 publications

References 4 publications

Fully printed, stretchable and wearable bioimpedance sensor on textiles for tomography

Fully printed, stretchable and wearable bioimpedance sensor on textiles for tomography

A 36 μW 1.1 mm² Reconfigurable Analog Front-End for Cardiovascular and Respiratory Signals Recording

A Power-Efficient, Wide-Frequency-Range Impedance Measurement IC Using Frequency-Shift Technique

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A bio-impedance readout IC with frequency sweeping from 1k-to-1MHz for electrical impedance tomography

Cited by 28 publications

References 4 publications

Fully printed, stretchable and wearable bioimpedance sensor on textiles for tomography

Fully printed, stretchable and wearable bioimpedance sensor on textiles for tomography

A 36 μW 1.1 mm2 Reconfigurable Analog Front-End for Cardiovascular and Respiratory Signals Recording

A Power-Efficient, Wide-Frequency-Range Impedance Measurement IC Using Frequency-Shift Technique

Contact Info

Product

Resources

About

A 36 μW 1.1 mm² Reconfigurable Analog Front-End for Cardiovascular and Respiratory Signals Recording