• 제목/요약/키워드: Bio-sensors

검색결과 328건 처리시간 0.019초

A Low-noise Multichannel Magnetocardiogram System for the Diagnosis of Heart Electric Activity

  • Lee, Yong-Ho;Kim, Ki-Woong;Kim, Jin-Mok;Kwon, Hyuk-Chan;Yu, Kwon-Kyu;Kim, In-Seon;Park, Yong-Ki
    • 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.

노지 과수원에서 토양수분센서 설치 위치에 따른 토양수분 변화 비교 (Comparison of Soil Moisture Changes Based on the Installation Position of Soil Moisture Sensors in the Korean Orchard Field Soils)

  • 김종균;김현석;강경진;김종윤
    • 생물환경조절학회지
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    • 제33권2호
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    • pp.107-113
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    • 2024
  • 노지 토양의 효율적인 수분관리를 위해서는 토양수분센서를 알맞게 사용하여야 하며, 특히 노지 과수와 같이 넓은 뿌리환경을 가지는 토양 환경에서는 적합한 센서 설치 위치가 매우 중요하다. 이에 본 실험에서는 노지 과수원에서 다양한 거리와 깊이에 토양수분장력 센서를 설치하여 각 위치의 토양수분장력 값을 측정하고, 센서 설치 위치에 따른 토양수분 변화 정도를 비교하여, 이에 따른 최적 토양수분센서 설치 위치를 알아보기 위해 수행하였다. 국내 두 지역에 위치한 사과 및 배 과수원에서 각 과수의 수간으로부터 거리 20, 40, 60cm, 토양표면으로부터 깊이 10, 20, 30cm로 각각 9개의 토양수분장력센서(TEROS 21, METER Group)를 설치하여 2년간의 토양수분장력 변화 정도를 비교 분석하였다. 두 과수원 모두 센서가 과수의 수간으로부터 가까울수록, 토양의 표면으로부터 얕게 설치되어 있을수록 토양수분장력 값의 변화 정도가 크게 나타났으며, 20cm × 10cm(과수의 수간으로부터 거리 × 토양표면으로부터 깊이) 지점에서의 토양수분장력 값의 변화 정도가 가장 큰 것으로 나타나 토양수분센서 설치에 가장 적합한 지점으로 판단되었다. 그러나 연도가 달라짐에 따라 과수의 뿌리가 생장하며 센서 설치 위치에 따른 토양수분장력의 변화 정도 양상이 조금씩 변하는 것을 확인할 수 있었다. 노지과수와 같이 장기간 재배하는 작물의 토양수분 환경을 알맞게 측정하기 위해서는 현장에서의 주기적인 토양수분 변화 관찰 및 보완을 통해 센서 설치 위치를 변경하는 노력도 필요할 것으로 나타났다.

생체정보를 이용한 유비쿼터스 심리상태 인식 모델 연구 (A Study on Ubiquitous Psychological State Recognition Model Using Bio-Signals)

  • 전기환;최형진
    • 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.

Bio-Composite Materials Precursor to Chitosan in the Development of Electrochemical Sensors: A Critical Overview of Its use with Micro-Pollutants and Heavy Metals Detection

  • Sarikokba, Sarikokba;Tiwari, Diwakar;Prasad, Shailesh Kumar;Kim, Dong Jin;Choi, Suk Soon;Lee, Seung-Mok
    • 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.

진동감지를 이용한 사용자 걸음걸이 인식 (Estimating Human Walking Pace and Direction Using Vibration Signals)

  • 정은석;김대은
    • 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.

친환경 종이 혈당 비이오센서 개발 (Development of Eco-Friendly Paper Glucose Bio-Sensor)

  • 김아영;이영태
    • 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.

Synthetic bio-actuators and their applications in biomedicine

  • Neiman, Veronica J.;Varghese, Shyni
    • 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.

Alizarin Red S modified electrochemical sensors for the detection of aluminum ion

  • Chang, Seung-Cheol
    • 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 $25\;{\mu}M$.

수면 단계에 따른 심전도 신호의 상관관계 분석 (Correlation Analysis of Electrocardiogram Signal according to Sleep Stage)

  • 이지은;유선국
    • 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.

단위 픽셀 회로의 간소화를 통해서 해상도를 향상시킨 이차원 윤곽 검출용 시각칩 (Vision chip for edge detection with resolution improvement through simplification of unit-pixel circuit)

  • 성동규;공재성;현효영;신장규
    • 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.