• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.89-95
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• 2015

Compresses sensing (CS) technique is beneficial for reducing power consumption of biopotential acquisition circuits in wireless healthcare system. This paper investigates the maximum possible compress ratio for various biopotential signal when the CS technique is applied. By using the CS technique, we perform the compression and reconstruction of typical electrocardiogram(ECG), electromyogram(EMG), electroencephalogram(EEG) signals. By comparing the original signal and reconstructed signal, we determines the validity of the CS-based signal compression. Raw-biopotential signal is compressed by using a psuedo-random matrix, and the compressed signal is reconstructed by using the Block Sparse Bayesian Learning(BSBL) algorithm. EMG signal, which is the most sparse biopotential signal, the maximum compress ratio is found to be 10, and the ECG'sl maximum compress ratio is found to be 5. EEG signal, which is the least sparse bioptential signal, the maximum compress ratio is found to be 4. The results of this work is useful and instrumental for the design of wireless biopotential signal monitoring circuits.

• ETRI Journal
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• v.42 no.4
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• pp.534-548
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• 2020

This study presents a new architecture for a field programmable analog array (FPAA) for use in low-frequency applications, and a generalized circuit realization method for the implementation of nth-order elliptic filters. The proposed designs of both the FPAA and elliptic filters are based on the operational transconductance amplifier (OTA) used in implementing OTA-C filters for biopotential signal processing. The proposed FPAA architecture has a flexible, expandable structure with direct connections between configurable analog blocks (CABs) that eliminates the use of switches. The generalized elliptic filter circuit realization provides a simplified, direct synthetic method for an OTA-C symmetric balanced structure for even/odd-nth-order low-pass filters (LPFs) and notch filters with minimum number of components, using grounded capacitors. The filters are mapped on the FPAA, and both architectures are validated with simulations in LTspice using 90-nm complementary metal-oxide semiconductor (CMOS) technology. Both proposed FPAA and filters generalized synthetic method achieve simple, flexible, low-power designs for implementation of biopotential signal processing systems.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.12-18
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• 2004

본 글에서는 인체로부터 생체전기신호를 측정하고 처리 및 해석하는 기술을 소개한다. 일반적인 계측 시스템을 구성하는 필수적인 네 가지 요소는 측정대상, 센서부, 신호처리부, 그리고 출력부이다. 생체전기신호의 측정에서 측정대상은 인체를 포함하는 생명체이다. 경우에 따라서는 생명체로부터 떼어 낸 특정 부위가 측정대상이 될 수도 있으나 본 글에서는 살아 있는 인체를 측정대상으로 설정하기로 한다. 또한 인체로부터 방사되는 에너지를 측정하는 비접촉 방식은 다루지 않고, 측정 부위를 인체의 내부 또는 표면으로 제한한다. 즉, 센서를 측정 부위에 직접 부착하는 접촉형 인체-센서 인터페이스 방법을 사용하는 경우만을 다루기로 한다.(중략)

• Journal of Sensor Science and Technology
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• v.25 no.4
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• pp.235-242
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• 2016

A system for measuring the electrodermal activity (EDA) signal occurring at the sweat glands in the left palm and left finger of the human body was implemented in this study. The EDA measurement system (EDAMS) consisted of an algometer, a biopotential measurement system (BPMS), and a PC. Two experiments were performed to evaluate the function and clinical applicability of EDAMS. First, an experiment was carried out on the linearity of the voltage and the pressure that comprised the output signals of the algometer used for applying a pressure stimulus. Second, the amplitude of the EDA signal acquired from the electrode attached to the left palm or finger was measured while increasing the pressure stimulus of the algometer. When the pressure stimulus of the algometer applied to the left scapula was increased, the amplitude of the EDA signal increased. The amplitude of the EDA signal at the left palm was observed to be greater than that at the left finger. The amplitude of the EDA signal was observed to increase in a relatively linear relation with the intensity of the pressure stimuli. In addition, the latency of the EDA signal acquired from the electrode attached to the left palm or finger was measured while increasing the pressure stimulus of the algometer. When the pressure stimulus of the algometer applied to the left scapula was increased, the latency of the EDA signal decreased. The latency of the EDA signal at the palm was observed to be less than that at the finger. The latency of the EDA signal was observed to decrease nonlinearly with the pressure stimuli.

• International Journal of Control, Automation, and Systems
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• v.5 no.5
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• pp.601-605
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• 2007

In this paper, we propose a simple and relative electrode contact monitoring method. By exploiting the power line interference, which is regarded as one of the worst noise sources for bio-potential measurement, the relative difference in electrode impedance can be measured without a current or voltage source. Substantial benefits, including no extra circuit components, no degradation of the body potential driving circuit, and no electrical safety problem, can be achieved using this method. Furthermore, this method can be applied to multi-channel isolated bio-potential measurement systems and home health care devices under a steady measuring environment.

• Transactions on Electrical and Electronic Materials
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• v.17 no.3
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• pp.150-154
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• 2016

Contact electrodes pose threats like inflammation, metal poisoning, and allergic reaction to the user during long term ECG procedure. Therefore, we present a novel noncontact electrocardiographic electrode designed through microelectromechanical systems (MEMS) process. The proposed ECG electrode consists of small inner and large outer circular copper plates separated by thin insulator. The inner plate enables capacitive transduction of bio-potential variations on a subject’s chest into a voltage that can be processed by a signal processing board, whereas the outer plate shields the inner plate from environmental electromagnetic noise. The electrode lead wires are also coaxially designed to prevent cables from coupling to ground or electronic devices. A prototype ECG electrode has an area of about 2.324 cm², is very flexible and does not require power to operate. The prototype ECG electrode could measure ECG at about 500 um distance from the subject’s chest.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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• pp.181-187
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• 2005

In this study, a microchip system fabricated with MEMS technology was developed to detect bioelectrical signals. The developed microchip using the conductivity of gold nanoparticles could detect the biopotential with a high sensitivity. For designing the microchip, simulations were performed to understand the effects of the size and number of nanoparticles, and the sensing width between electrodes on the detection of biosignals. Then, a series of experiment was performed to validate the simulation results and understand the feasibility of the proposed microchip design. Both simulation and experimental results showed that as the sensing width between electrodes increased the conductivity decreased. Also, the conductivity increased as the density of gold nanoparticles increased. In addition, it was found that the conductivity that changes with the nanoparticles density could be approximated by a cumulative normal distribution function. The developed microchip system could effectively apply when a biosignals should be measured with a high sensitivity.

• Korean Journal of Acupuncture
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• v.28 no.4
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• pp.41-48
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• 2011

Objectives : This study aimed to explore the passive multi-channel time series analysis method by measuring bio-potentials of acupuncture point and the peripheral region Methods : Bio-potential was measured at ST36 and the peripherical region of ST36 of 5 healthy volunteers at three times. The diagram of the potential changes over time were smoothed by moving average method and similarities of ST36 and the other points were calculated. Results : In the normal weight group, bio-potential similarity tended to decrease in proportion to the distance from the acupuncture point. In the obesity group, bio-potential similarity appeared in a very wide area. Bio-potential similarity had positive correlation with BMI value. Conclusions : The passive multi-channel time series analysis method showed the possibility be appropriate for the electrical characteristics study of meridians.

• The Journal of Korea Robotics Society
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• v.13 no.4
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• pp.265-271
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• 2018

The recent prosthetic technologies pursue to control multi-DOFs (degrees-of-freedom) hand and wrist. However, challenges such as high cost, wear-ability, and motion intent recognition for feedback control still remain for the use in daily living activities. The paper proposes a multi-channel knit band sensor to worn easily for surface EMG-based prosthetic control. The knitted electrodes were fabricated with conductive yarn, and the band except the electrodes are knitted using non-conductive yarn which has moisture wicking property. Two types of the knit bands are fabricated such as sixteen-electrodes for eight-channels and thirty-two electrodes for sixteen-channels. In order to substantiate the performance of the biopotential signal acquisition, several experiments are conducted. Signal to noise ratio (SNR) value of the knit band sensor was 18.48 dB. According to various forearm motions including hand and wrist, sixteen-channels EMG signals could be clearly distinguishable. In addition, the pattern recognition performance to control myoelectric prosthesis was verified in that overall classification accuracy of the RMS (root mean squares) filtered EMG signals (97.84%) was higher than that of the raw EMG signals (87.06%).

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.371-372
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• 2008

Many kinds of electrodes have been developed in various forms and shapes for measurement of bio potential signal. Textile electrode has benefit of collect long tenn data monitoring because of it is non-consciousness, convenient and do not occur skin irritation. However, It is very difficult to acquire available data due to high impedance of electrode and unstable skin-electrode contact which generate motion artifact. Also snap button which usually used as mediator between textile and measurement device cause change of electrical characteristics. In this paper, we inflated textile electrode to stabilize contact and add conductive silver paste between textile and snap button to improve conductance. To compare the performance of two methods, flat or inflated and add conductive paste or not, four types of electrodes are tested on each impedance and SNR by ECG measurement. In result, the first type electrode which flat and non-conductive paste showed the worst performance and the last type electrode which is inflated shape and contain conductive paste show the best performance.