• Journal of Biomedical Engineering Research
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• v.43 no.6
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• pp.424-433
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• 2022

As the proportion of non-contact telemedicine increases and the number of electrocardiogram (ECG) data measured using portable ECG monitors increases, the demand for automatic algorithms that can precisely analyze vast amounts of ECG is increasing. Since the P, QRS, and T waves of the ECG have different shapes depending on the location of electrodes or individual characteristics and often have similar frequency components or amplitudes, it is difficult to distinguish P, QRS and T waves and measure each parameter. In order to measure the widths, intervals and areas of P, QRS, and T waves, a new algorithm that recognizes the start and end points of each wave and automatically measures the time differences and amplitudes between each point is required. In this study, the start and end points of the P, QRS, and T waves were measured using six Deep Neural Networks (DNN) that recognize the start and end points of each wave. Then, by synthesizing the results of all DNNs, 12 parameters for ECG characteristics for each heartbeat were obtained. In the ECG waveform of 10 subjects provided by Physionet, 12 parameters were measured for each of 660 heartbeats, and the 12 parameters measured for each heartbeat well represented the characteristics of the ECG, so it was possible to distinguish them from other subjects' parameters. When the ECG data of 10 subjects were combined into one file and analyzed with the suggested algorithm, 10 types of ECG waveform were observed, and two types of ECG waveform were simultaneously observed in 5 subjects, however, it was not observed that one person had more than two types.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.2
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• pp.258-264
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• 2022

The smart farm for livestock, in which information and communication technology (ICT) is combined with livestock farm, is mostly based on the cloud computing paradigm. A cloud-based smart livestock farm has disadvantages such as increased response time, burden on cloud resource caused by the increased number of IoT sensors, traffic burden on the network, and lack of failure resilience mechanisms through collaboration with adjacent IoT devices. In this paper, with these problems in mind, we propose an IoT collaboration system based on edge computing. By using the relatively limited computing resources of the edge device to share the cloud's web server function, we aim to reduce the cloud's resources needed and improve response time to user requests. In addition, through the heartbeat-based failure recovery mechanism, IoT device failures were detected and appropriate measures were taken.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.4
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• pp.53-60
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• 2010

Biometrics are methods of recognizing a person based on the physiological or behavioral characteristics of his of her body. They are highly secure with little risk of loss or falsification by others. This paper has designed and implemented a security system of biometrics by precisely measuring heartbeat signals at two fingertips and using a photoplethysmogram, which is applicable to biometrics. A performance evaluation has led to the following result. The security system of biometrics for personal authentication which has been designed and implemented by this study has achieved a recognition rate of 90.5%. The security system of biometrics suggested here has merits of time saving and easy accessibility. The system is touch-based and collects the necessary biometrics information by simply touching the machine with fingers, so anyone can utilize the system without any difficulty.

• The Journal of Korean Medicine
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• v.43 no.3
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• pp.164-180
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• 2022

Objectives: The purpose of this study was to evaluate the effects of shenfu injection on myocardial protective effects after mitral valve replacement surgery. Methods: We searched four international databases (PUBMED, Embase, Web of Science and CNKI) and three domestic electronic databases (OASIS, RISS and NDSL) for relevant studies. We used following keywords 'shenfu', 'valve replacement', 'mitral valve' at PUBMED, Embase and Web of Science; '二尖瓣', '参附注射液', '瓣膜' at CNKI and '이첨판', '판막', '삼부' at domestic databases. The search range included randomized controlled trials. When appropriate, meta-analyses were performed. Results: Seven randomized controlled trials were selected. All studies used Shenfu injection after mitral valve replacement surgery. We analyzed myocardial damage, cardiac function, patients' recovery rate, with various evaluation indicators. We also used meta-analysis for CK-MB, cTnI, MDA and voluntary recovery of heartbeat. CK-MB was analyzed in two subgroups: 8 hours and 24 hours after surgery. Std was -2.34(95% CI -4.10, -0.58) for 8 hours and -1.95(95% CI -4.79 to 0.88) for 24 hours. 8 hours showed statistically significant difference. cTnI appeared significant decrease with Std of -2.13(95% CI -2.60, -1.66). MDA showed significant decrease with Std of -0.95(95% CI -1.43 to -0.47). Voluntary recovery of heartbeat significantly increased with the odd ratio of 4.34(95% CI 1.76, 10.70). Conclusions: We suggest that Shenfu injection after Mitral valve replacement surgery may have significant myocardial protective effects in terms of reducing myocardial damages, reactive oxygen species, increasing cardiac function and patients' recovery after surgery. However, the evidence is limited, further research is required.

• Journal of electromagnetic engineering and science
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• v.12 no.1
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• pp.37-44
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• 2012

This paper describes a compact and novel wireless vital sign sensor at 2.4 GHz that can detect heartbeat and respiration signals. The oscillator circuit incorporates a planar resonator, which functions as a series feedback element as well as a near-field radiator. The periodic movement of a human body during aerobic exercise could cause an input impedance variation of the radiator within near-field range. This variation results in a corresponding change in the oscillation frequency and this change has been utilized for the sensing of human vital signs. In addition, a surface acoustic wave (SAW) filter and power detector have been used to increase the system sensitivity and to transform the frequency variation into a voltage waveform. The experimental results show that the proposed sensor placed 20 mm away from a human body can detect the vital signs very accurately.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.583-585
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• 2011

이 논문에서는 비접촉 방식의 심박 및 호흡 검출이 가능한 FFT를 이용하는 새로운 검출 방식의 알고리즘을 제안한다. 기존 FFT 방식은 주파수 도메인에서 필터링을 수행한 후 IFFT 후 특징점 추출 알고리즘을 수행하여 심박 및 호흡을 추출한다. 이 논문에서는 제안된 FFT 방식을 사용하여 기존의 FFT 방식과 달리 FFT를 한 후 주파수 영역에서 바로 심박수 및 호흡수를 추출할 수 있음을 제안한다.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.305-308
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• 2009

This paper presents the design and analysis of RF Front End for Wireless Heartbeat measurement System. In this work LNA, an inductor connected at the gate of the cascode transistor and capacitive cross-coupling are strategically combined to reduce the noise and the nonlinearity influences of the cascode transistors in a differential LNA. The Mixer is implemented by using the Gilbert-type configuration, cross pmos injection technique and the resonating technique for the tail capacitance. The resulting LNA achieves 1.26 dB NF, better than 1.88dB NF Typical Also Mixer resulting achieves 9.8dB at 100KHz.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.231-234
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• 2003

This paper designs and implements fault-tolerant server of meta server for shared filesystem (SANfs) in SAN environment. SANfs is the filesystem that many clients can share data in Network-attached storage in SAN environment and meta server is the server that processes file operation in SANfs. The focus of this paper is the implementation of fault-tolerant server of meta server in SANfs. In the event of a meta server, meta server failovers to a fault-tolerant server where its processing continues seamlessly. If meta server doesn't restore, fault-tolerant server searches reliable client and makes another fault-tolerant server and work as meta server. Heartbeat monitors meta server and shadow server and controls them.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.88-88
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• 2000

As more and more critical commercial applications move on the Internet, providing highly available servers becomes increasingly important. One of the advantages of a clustered system is that it has hardware and software redundancy. High availability can be provided by detecting node or daemon failure and reconfiguring the system appropriately so that the workload can be taken over bi the remaining nodes in the cluster. This paper presents how to provide the guaranteeing high availability of clustering web server. The load balancer becomes a single failure point of the whole system. In order to prevent the failure of the load balancer, we setup a backup server using heartbeat, fake, mon, and checkpointing fault-tolerance method. For high availability of file servers in the cluster, we setup coda file system. Coda is a advanced network fault-tolerance distributed file system.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.250-255
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• 2010

This paper presents a non-contact measurement method of vital signal by the use of multiple-input multiple-output (MIMO) bio-radar system, configured with two antennas that are separated by a certain distance. The direction of arrival (DOA) estimation algorithm for coherent sources was applied to detect vital signals coming from different spatial angles. The proposed MIMO bio-radar system was composed of two identical transceivers sharing single VCO with a PLL. In order to verify the performance of the system, the DOA estimation experiment was completed with respect to the human target at angles varying between $-50^{\circ}$ and $50^{\circ}$ where the bio-radar system was placed at distances (corresponding to 50 cm and 95 cm) in front of a human target. The proposed MIMO bio-radar system can successfully find the direction of a human target.