• 대한의용생체공학회:의공학회지
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• 제27권4호
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• pp.154-163
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• 2006

A 64-channel magnetocardiogram (MCG) system using low-noise superconducting quantum interference device (SQUID) planar gradiometers was developed for the measurements of cardiac magnetic fields generated by the heart electric activity. Owing to high flux-to-voltage transfers of double relaxation oscillation SQUID (DROS) sensors, the flux-locked loop electronics for SQUID operation could be made simpler than that of conventional DC SQUIDs, and the SQUID control was done automatically through a fiber-optic cable. The pickup coils are first-order planar gradiometers with a baseline of 4 em. The insert has 64 planar gradiometers as the sensing channels and were arranged to measure MCG field components tangential to the chest surface. When the 64-channel insert was in operation everyday, the average boil-off rate of the dewar was 3.6 Lid. The noise spectrum of the SQUID planar gradiometer system was about 5 fT$_{rms}$/$\checkmark$Hz at 100 Hz, operated inside a moderately shielded room. The MCG measurements were done at a sampling rate of 500 Hz or 1 kHz, and realtime display of MCG traces and heart rate were displayed. After the acquisition, magnetic field mapping and current mapping could be done. From the magnetic and current information, parameters for the diagnosis of myocardial ischemia were evaluated to be compared with other diagnostic methods.

• 한국통신학회논문지
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• 제35권2B호
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• pp.232-243
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• 2010

본 논문에서는 다양한 생체신호들을 이용하여 심리상태와 생체정보를 판별하고, 외부환경 정보와 함께 이용자의 현재 상황을 인식하여 그에 맞는 적절한 서비스를 제공하는 생체정보기반 상황인식시스템(Bio-Signal Context aware system :BSC)을 설계하고 구현한다. 본 논문에서 구현한 생체정보기반 상황인식시스템은 센서를 통하여 측정된 뇌파(EEG), 심전도(ECG), 피부전도도(GSR) 등의 생체신호들로부터 특징들을 추출하고 분석하였으며, 분석된 결과를 입력받아 평온, 집중, 긴장, 우울의 네 가지 심리상태를 판별하였다. 판별된 심리상태의 결과와 함께 심박변이도(HRV), 피부전도도, 체온 등의 생체신호로부터 분석된 생체 상황정보, 그리고 외부 환경의 상황정보로부터 이용자의 현재 상황을 추론하고 인식하여 현재 생체 상황에 맞는 적절한 서비스를 제공하였다.

• 공업화학
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• 제31권3호
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• pp.237-257
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• 2020

The role of nano bio-composites precursor to chitosan are innumerable and are known for having different applications in various branches of physical sciences. The application to the sensor development is relatively new, where only few literature works are available to address the specific and critical analysis of nanocomposites in the subject area. The bio-composites are potential and having greater affinity towards the heavy metals and several micro-pollutants hence, perhaps are having wider implications in the low or even trace level detection of the pollutants. The nano-composites could show good selectivity and suitability for the detection of the pollutants as they are found in the complex matrix. However, the greater challenges are associated using the bio-composites, since the biomaterials are prone to be oxidized or reduced at an applied potential and found to be a hinderance for the detection of target pollutants. In addition, the materials could proceed with a series of electrochemical reactions, which could produce different by-products in analytical applications, resulting in several complex phenomena in electrochemical processes. Therefore, this review addresses critically various aspects of an evaluation of nano bio-composite materials in the electrochemical detection of heavy metals and micro-pollutants from aqueous solutions.

• 제어로봇시스템학회논문지
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• 제20권5호
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• pp.481-485
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• 2014

In service robots, a number of human movements are analyzed using a variety of sensors. Vibration signals from walking movements of a human provide useful information about the distance and the movement direction of the human. In this paper, we measure the intensity of vibrations and detect both human walking pace and direction. In our experiments, vibration signals detected by microphone sensors provide good estimation of the distance and direction of a human movement. This can be applied to HRI (Human-Robot Interaction) technology.

• 센서학회지
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• 제22권3호
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• pp.202-206
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• 2013

In this paper, a disposable glucose sensor was made of paper. Glucose sensor strip using carbon electrode is appropriate for the low price ones because it requires cheap materials and low cost production. Most of blood glucose sensors were developed with plastics, but it causes pollution problems. Therefore we developed disposable carbon electrode glucose sensor using paper. This sensor consists of upper and bottom plate. On the upper plate, three-dimensional channel are formed through pressing process. The fabricated paper glucose sensor shows relatively short sensing time of about 5seconds, excellent reproducibility ($R^2$=0.9558), and fabrication yield as well.

• Smart Structures and Systems
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• 제7권3호
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• pp.185-198
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• 2011

The promise of biomimetic smart structures that can function as sensors and actuators in biomedicine is enormous. Technological development in the field of stimuli-responsive shape memory polymers have opened up a new avenue of applications for polymer-based synthetic actuators. Such synthetic actuators mimic various attributes of living organisms including responsiveness to stimuli, shape memory, selectivity, motility, and organization. This article briefly reviews various stimuli-responsive shape memory polymers and their application as bioactuators. Although the technological advancements have prototyped the potential applications of these smart materials, their widespread commercialization depends on many factors such as sensitivity, versatility, moldability, robustness, and cost.

• 센서학회지
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• 제19권6호
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• pp.421-427
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• 2010

Alizarin Red S modified screen printed carbon electrodes were developed for the electrochemical detection of aluminum ion. The electrodes developed use screen-printed carbon electrodes(SPCEs) coupled with chemical modification with an organic chelator, Alizarin Red S(ARS), for aluminum ion detection in aqueous solution. For sensor fabrication ARS was directly immobilized on the surface of SPCEs using PVA-SbQ(The poly(vinyl alcohol) bearing stryrylpyridinium groups). Aluminum concentrations were indirectly estimated by amperometric determination of the non-complexed ARS immobilized on the electrodes, after its complexation with aluminum. The sensitivity of the sensor developed was $3.8\;nA{\mu}M^{-1}cm^{-2}$ and the detection limit for aluminum was $25\;{\mu}M$.

• 한국멀티미디어학회논문지
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• 제21권12호
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• pp.1370-1378
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• 2018

There is a problem to measure neutral bio-signals during sleep because of inconvenience of attaching lots of sensors. In this study, we measured single electrocardiogram(ECG) signal and analyzed the correlation with sleep. After R-peak detection from ECG signal, we extracted 9 features from time and frequency domain of heart rate variability(HRV). Mean of HRV, RR intervals differing more than 50ms(NN50), and divided by the total number of all RR intervals(pNN50) have significant differences in each sleep stage. Specially, the mean HRV has an average of 87.8% accuracy in classifying sleep and awake status. In the future, the measurement ECG signal minimizes inconvenience of attaching sensors during sleep. Also, it can be substituted for the standard sleep measurement method.

• 센서학회지
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• 제17권1호
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• pp.15-22
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• 2008

When designing image sensors including a CMOS vision chip for edge detection, resolution is a significant factor to evaluate the performance. It is hard to improve the resolution of a bio-inspired CMOS vision using a resistive network because the vision chip contains many circuits such as a resistive network and several signal processing circuits as well as photocircuits of general image sensors such as CMOS image sensor (CIS). Low resolution restricts the use of the application systems. In this paper, we improve the resolution through layout and circuit optimization. Furthermore, we have designed a printed circuit board using FPGA which controls the vision chip. The vision chip for edge detection has been designed and fabricated by using $0.35{\mu}m$ double-poly four-metal CMOS technology, and its output characteristics have been investigated.

• 대한조선학회논문집
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• 제45권2호
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• pp.144-150
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• 2008

Ships and offshore structures are exposed to wave and engine excitation loadings during navigation and cargo/ballasting operations. These excessive loads may cause damages to hull and may result loss of life the ship. Therefore, it is important to develop a system that allow accurate measurements of global hull loads. The objective of the study is developing a fiber optic monitoring system that is capable of monitoring, recording and warning of the vessel performance. A method for measurement of global loads on a vessel, using strain measurements from a network of fiber optic strain sensors and extensive finite-element analyses(FEA) with idealistic load cases, is presented. The method has been successfully validated on the idealized ship structure model with strain sensors.