• Title, Summary, Keyword: PPG

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Tracking Heart Rate Algorithm Based on PPG (PPG 기반 심박동수 추정 알고리즘)

  • Baek, Yong Hyun;Lee, Keun Sang;Park, Young Chul
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.3
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    • pp.71-78
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    • 2009
  • In this study, estimation of heart rate from measured PPG signal is proposed. PPG signal is to be measured blood flow in a blood vessel effected by systole and diastole. PPG sianl has single frequency so that PPG frequency can be tracked by 2nd IIR adaptive notch filter. PPG frequency is obtained continually from updating filter coefficient throughout adaptive algorithm and then the heart rate of human is approximately estimated.

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Isothermal Crystallization Behavior of PCL-PPG-PCL Triblock Copolymers (PCL-PPG-PCL 3블록 공중합체의 등온결정화 거동)

  • 김영호;장진성
    • Textile Science and Engineering
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    • v.34 no.11
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    • pp.784-792
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    • 1997
  • A new method for the estimation of the initial portion of the crystallization exotherm, normally obscured due to the response time of the DSC in the case of fast crystallization, was developed. This method allowed a more accurate analysis of the DSC isothermal crystallization data. Poly(propylene glycol)(PPG)-poly($\varepsilon$-caprolactam) (PCL)-PPG triblock copolymers with various PPG contents were synthesized via anionic copolymerization of $\varepsilon$-cairo-lactam and the macroactivators which contain PPG units. Isothermal crystallization behaviors of the synthesized block copolymers were allalyzed with Avrami equation by using above-mentinned non-linear curve fitting program and conventional Avraml plot. At PPG contents greater than 10%, the overall crystallization rate decreased because of the uncrystallizable PPG unit. The induction time for crystallization increased, and the ratio of primary crystallization to overall crystallization increased at the same degree of undercooling. On the other hand, crystal growth rate increased with PPG content. The presence of PPG unit in the block copolymer has two opposing effects on crystallization. First, as the amount of PPG unit increases it interferes with nucleation. As a result the induction time for crystallization increases and the crystallization rate decreases. Secondly, it increases the mobility of the block copolymers because of the ether linkage and allows faster diffion of the copolymer chain to the crystal surface. Consequently the crystal growth rate after nucleation increases. Between the two effects the first one seems to be dominating and the overall crystallization rate decreases with increasing PPG content in block copolymers. Furthermore there are some different crystallization behaviors between the block copolymers and PCL homo polymer. Nucleation of block copolymers of PPG content up to 10% occurs faster than in the case of homo PCL because small amounts of PPG unit may act as heterogeneous nuclei. Also the chain mobility increased with the introduction of PPG unit, therefore the overall crystallization rate was faster than homo PCL. But if the PPG content exceeds 10% the overall crystallization rate of the block copolymers becomes slower than homo PCL.

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Analysis for the Fluctuation of the Photoplethysmographic Waveform derived by Temperature Stress of Measuring Position (측정부 온도 부하에 따른 광용적맥파 파형 요동 특성 분석)

  • Lee, Chungkeun;Shin, Hangsik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.2
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    • pp.304-309
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    • 2015
  • Applicable range of Photoplethysmography (PPG) becomes wider as a non-invasive physiological measurement technique. However, PPG waveform is easy to be distorted by ambient light or vascular variation from temperature changes. Especially, irregular variation of PPG waveform caused by ambient temperature not only severely distorts the PPG, but also leads miss interpretation in clinical applications. Therefore, the investigation of between temperature and PPG waveform is quite important in using PPG. The purpose of this research is to quantify the PPG waveform characteristic and to investigate the waveform variation following the temperature change on measuring site. To quantify the fluctuation of PPG waveform, we use two techniques; detrended fluctuation analysis (DFA) and AC/DC analysis of PPG. We record PPG under temperature stress, which applied by medical use heat pack ($40^{\circ}C$) and ice pack ($0^{\circ}C$). Ten participants were applied to the experiment, and the result was evaluated to approve the temperature effect with statistical method, Wilcoxon signed rank test. The result shows that the AC component (p<0.05) and perfusion index DFS scale exponent (p<0.01) of PPG have the significance to temperature stress except for a DC component of PPG.

Noise-Robust Algorithm for PPG Signal Measurement (동잡음에 강건한 PPG 신호 측정 방안)

  • Kim, Minho;Kim, Taewook;Jang, Sunghwan;Ban, Dahee;Min, Byungseok;Kwon, Sungoh
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.12
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    • pp.1085-1094
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    • 2013
  • In this paper, we propose a methods to eliminate PPG sensor noise resulted from user motion during measurement. Measured PPG signals require approperiate signal processing methods since various types of noises such as a motion noise by user movement and signal noises occurred from the change of measuring environments. This paper suggests a signal processing method that eliminates motion noises by measuring several PPG channels that are based on the stable patterns of the practical users. The PPG signals are measured by the two channels in this experiment. When the individual error rates are 20%, the proposed algorithm reduces the errors to 9.56%.

Motion Artifacts reduction from the PPG based on the Improved PMAF for the U-Healthcare System (U-헬스케어 시스템을 위한 개선된 PMAF 기반의 PPG 신호의 동잡음 제거)

  • Lee, Han-Wook;Lee, Ju-Won;Jeong, Won-Geun;Jun, Jae-Chul;Lee, Gun-Ki
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.5
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    • pp.28-34
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    • 2008
  • The real-time biomedical signal monitoring is a very important factor to realize the ubiquitous healthcare environment. Most of these devices for monitoring the biomedical information get the PPG signal from the user, and these signals are utilized for monitoring their health. It is inconvenient to get the PPG because the user should wear the finger probe with his finger for measuring the PPG signal. Also it is difficult to get the PPG correctly, because of the motion artifacts from the movement of the user. In this paper, we develop the watch type biomedical signal monitoring system without the finger probe, and propose the new algorithm for reducing the motion artifacts from the PPG signal. We designed the system which gets the PPG from the sensor on the wrist band strip. As compared with the finger probe type, this system we proposed is more affected by the motion artifacts. So to filter this motion artifacts, we propose the new method; the improved PMAF(Periodic Moving Average Filter) method.

Accuracy improvement of respiration rate based on photo-plethysmography by enhancing motion artifact (광용적맥파(PPG)를 이용한 호흡수 측정에 있어서 동잡음을 이용한 정확도 향상)

  • Huh, Young-Jung;Yoon, Gil-Won
    • Journal of Sensor Science and Technology
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    • v.17 no.6
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    • pp.447-453
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    • 2008
  • Respiration rate is one of the important vital signs. Photo-plethysmography (PPG) measurement especially on a finger has been widely used in pulse oximetry and also used in estimating respiration rate. It is well known that PPG contains respiration-induced intensity variation (RIIV) signal. However, the accuracy of finger PPG method has been controversial. We introduced a new technique of enhancing motion artifact by respiration. This was achieved simply by measuring PPG on the thorax. We examined the accuracy of these two PPG methods by comparing with two existing methods based on thoracic volume and nostril temperature changes. PPG sensing on finger tip, which is the most common site of measurement, produced 6.1 % error. On the other hand, our method of PPG sensing on the thorax achieved 0.4 % error which was a significant improvement. Finger PPG is sensitive to motion artifact and it is difficult to recover fully small respiratory signal buried in waveform dominated by absorption due to blood volume changes. Thorax PPG is poor to represent blood volumes changes since it contains substantial motion artifact due to respiration. Ironically, this inferior quality ensures higher accuracy in terms of respiration measurement. Extreme low-cost and small-sized LED/silicon detector and non-constrained reflection measurement provide a great candidate for respiration estimation in ubiquitous or personal health monitoring.

Implementation of Heart Rate Monitoring System using PPG Sensor (PPG 센서를 이용한 심박 모니터링 시스템 구현)

  • Lee, Won-Seok;Jung, Kyung Kwon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.5
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    • pp.138-142
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    • 2017
  • Photoplethysmography (PPG) is a simple and low-cost optical technique that can be used to detect blood volume changes in the microvascular bed of tissue. It is often used non-invasively to make measurements at the skin surface. In this paper, we described the implementation heart rate monitoring system using PPG sensor. Proposed system is collected data using PPG sensor and heart rate was detected using second derivative method. In order to verify the effectiveness of the proposed method, we performed the measurements of RR-intervals with a commercial medical device.

Development of portable PPG sensor based on smart phone (스마트폰 기반의 휴대용 PPG센서 개발)

  • Kim, Jung-han;Cho, Kyoung-lae;Kim, Sang-yoon;Kang, Sung-in;Bae, Sung-ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.1009-1011
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    • 2013
  • 최근 U-헬스케어 서비스가 증가함에 따라 예방과 건강증진 등에 관심과 연구가 활발히 이루어지고 있다. 이러한 U-헬스케어에 사용되는 ECG, EMG, PPG EEG등이 스마트폰 기반의 휴대용 장비와 연동된 센서들의 연구 역시 활발히 진행 중이다. 일반적으로 PPG신호는 적외선센서를 이용하여 모세혈관의 혈중 헤모글로빈 농도 변화에 의한 맥파를 측정한다. PPG신호의 잡음을 제거하기 위해 필터를 사용하였다. 필터된 정보를 ADC하여 스마트폰으로 BlueTooth통신을 이용하여 전송한다. 최종적으로 스마트 디바이스에 PPG신호를 그린다. 제작결과 PPG아날로그 신호를 보는 것과 동일하게 스마트 디바이스에 그릴 수 있음을 보였다. 이후 PPG신호를 이용하여 혈관건강도 및 건강예방의 측정의 연구를 계속해서 한다.

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Development of Blood Pressure Estimation Methods Using The PPG and ECG Sensors (PPG 및 ECG 센서를 이용한 혈압추정 기법 개발)

  • Park, Hyun-Moon;Lee, Jung-Chul;Hwang, Tae-Ho
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.6
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    • pp.1257-1264
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    • 2019
  • The traditional cuff-based method for BP(Blood Pressure) measurement is not suitable for continuous real-time BP measurement techniques. For this reason, the previous studies estimated various blood pressures by fusion with the electrocardiography (ECG) and photoplethysmogram (PPG) sensor signals. However, conventional techniques based on PPG bio-sensing measurement face many challenging issues such as noisy supply fluctuation, small pulsation, and drifting non-pulsatile. This paper proposed a novel BP estimation methods using PPG and ECG sensors, which can be derived from the relationship between PPG and ECG using PTT(Pulse Transit Time) and PWV(Pulse Wave Velocity). Unlike conventional height ratio features, which are extracted on the basis of the peaks in the PPG and ECG waveform. The proposed method can be reliably obtained even if there are missing peaks among the sensed PPG signal. The increased reliability comes from periodical estimation of the peak-to-peak interval time using ECG and PPG. After 250,000 times trials of the blood pressure measurement, the proposed estimation technique was verified with the accuracy of ±28.5% error, compared to a commercialized BP device.

A Study on the Properties and Preparation of Silicon-based Defoamer Used in the Purification of Wasted-Water Extruded in the Paper-Fabrication (제지공장의 폐수처리에 사용되는 실리콘계 소포제의 제조 및 물성에 관한 연구)

  • Choi, Sang-goo;Lee, Nae-Taek
    • Applied Chemistry for Engineering
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    • v.16 no.5
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    • pp.614-619
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    • 2005
  • The water-soluble defoamers were fabricated by the mixing polyol, modified silicon resin, silicon resin and surfactant. For the defoamers, the various properties such as phase-separation time, viscosity and defoamerability were examined. The phase-saparation time of PPG mixtures was found to be PPG 400>PPG 3,000>PPG 1000. When PPG 1000 was mixed, mixtures represented the excellent defoamerability. The phase-saparation time of silicon resin mixtures was TSF-451-350>TSF-451-200>TSF-451-50. As more of high molecular silicon resin was mixed, the resulting mixtues showed reduced defoamerability. When the TSF-451-50 was mixed, the mixture's volume was increased because of the reduction of solubility. The modified silicon resin was smoothly dispersed in water, but the compatibility with PPG was not good. The defoamerability of surfactant was SPAN 20>SPAN 60>SPAN 80. SPAN 80 showed good miscibility for the silicon resin, but not good for YAS 6406 or PPG 1000.