• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.5
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• pp.21-27
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• 2008

Despite recent studies on development of pulse diagnosis systems and needs for commercializing them, the reproducibility is one of the most controversial issues as ever. Because the pulse pressure value, which is one of the important parameters to evaluate reproducibility, is very vulnerable to moving artifacts, the reproducibility can not be obtained easily. In this paper, we suggested a moving artefacts detection system for a pulse diagnosis system so that a pulse diagnosis system can be robust to theses kinds of artefacts by excluding the contaminated parts from the pulse wave signal to be analyzed. This moving artifacts detection system was designed to consist of a three-axis accelerometer, an electromyography amplifier and a two-axis tilt sensor. To assess the suitability of the system, we examined the characteristics of each sensor's output signals with regard to the three specific motions such as extension, flexion and rotation. And, we also examined the each sensor's response to the high-frequency and low-frequency moving artifacts while the pulse wave signal was acquired from a pressure sensor for the pulse diagnosis. From these results, we could find that the response to subject's motions would be reflected in electromyography signal first, in accelerometer signals and in tilt sensor sequently. And, the facts that a stable pulse wave can be acquired in two seconds after high frequency or low frequency motions ended, were also found. Consequently, based on these findings, we set up some rules on the moving artifacts detection and designed an algorithm which is fit for our moving artifacts detection system.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.207-212
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• 2015

We propose a noise estimation method using edge detection in moving pictures. Edge detection is to exclude structures and details which have an effect on the noise estimation. To detect edge, we use Sobel and morphological closing operators which are robust to details of images. The proposed noise estimation method is more efficiently applied to noise estimation in various types of moving images and has better results than those of existing noise estimation methods. Also, proposed algorithm can be efficiently applied to image and video applications.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.246-248
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• 2012

심전도는 측정 기기에서 발생하는 전기적 잡음이나 근육에서 발생하는 근전도에 의한 잡음, 전극을 부착한 사람의 움직임에 의한 동잡음 등에 민감한 특성을 보인다. 또한 심장의 이상으로 인하여 왜곡이 심하게 발생하므로 심전도에서 의미 있는 구간을 검출하기 위해서는 이들을 보완하는 알고리즘이 필수적이라 할 수 있다. 논문에서는 심전도 분석의 보조를 위하여 입력된 심전도가 가지는 잡음과 왜곡을 제거하고 구간의 위치를 출력하는 시스템을 제안한다. 이를 위해 관련 알고리즘 중, 가장 널리 알려진 'Pan & tompkins algorithm'을 시스템에 이식하였고 알고리즘의 각 단계를 알아보기 쉽게 출력하는 인터페이스를 구성하였다. 시스템의 기능을 확인하기 위해 MIT/BIH 데이터베이스를 이용하였으며, 잡음과 왜곡이 심하여 육안으로 구간을 확인하기 힘든 심전도에서도 높은 구간검출 정확도를 확인할 수 있었다.

• Journal of Biomedical Engineering Research
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• v.20 no.3
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• pp.323-329
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• 1999

This paper proposed a method for the cancellation of the moving artifact which was produced during the detection of drowsiness usmg electrodermal activity signal. Two types of wrist electrode were developed to overcome the defect of the steering wheel type electrode which couldn't eliminate the moving artifacts due to driver's movements. Wrist type electrode II which has been modified from electrode type I was most effective for eliminating movmg artifacts compared to wheel type electrode and wrisL type electrode 1. The decIsion criteria(if IRI$\leq$10 and 1.1$\leq$dNz) for detecting moving artifact was determined from the virtual driving experiments. An algorithm which substituted past value of Nz for the current value of Nz whenever an EDA signal satisfied the criteria was developed. The experimental resulls of virtual driving and road test showed that the proposed algorithm had been successfully removed the most of the error due to the moving artifact Therefore, the developed system which use electrode type II and the algorithm might be less influenced by moving artifacts and could measure an accurate arousal state.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.839-842
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• 2009

It is used to differential image for moving object detection in general. But it is difficult to detect the accurate detection which uses differential image between frames. In this paper, the proposed method overcome the noise that is generated by camera, grabber card, or weather condition. It extract to moving big object such as human or vehicle. The proposed method process morphological filtering and binary for the image with noise, reduce error. We are expect to apply to a real-time moving object detection system at fog condition, pass the limit of the object detection method using the differential image.

• The Korean Journal of Applied Statistics
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• v.33 no.6
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• pp.813-821
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• 2020

Recently, research using unstructured data such as images and videos has been actively conducted in various fields. Edge detection is one of the most useful image enhancement techniques to improve the quality of the image process. However, it is very difficult to perform edge detection in noise images because the edges and noise having high frequency components. This paper uses a linear model and standard deviation as an effective edge detection method for noise images. The edge is detected by the difference between the standard deviation of the pixels included in the pixel block and the standard deviation of the residual obtained by fitting the linear model. The results of edge detection are compared with the results of the Sobel edge detector. In the original image, the Sobel edge detection result and the proposed edge detection result are similar. Proposed method was confirmed that the edge with reduced noise was detected in the various levels of noise images.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1411-1412
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• 2015

본 연구에서는 맥박 측정에서 생기는 잡음들 중 많은 오류를 생기게 하는 동잡음 개선을 위하여 회로를 제안하고 설계하였다. 기존의 맥박추정 장비에서 가변저항, 광원 스위칭, 디지털 필터를 사용함으로써 정확도 향상을 위한 연구를 하였다. 손가락에서 광전용적맥파를 측정시 측정부의 광원을 2개를 사용하고, 이를 스위칭을 통해 파형을 측정을 하였다. 실험에서 PPG의 측정은 반사형 방식을 사용하고 이를 광원스위칭을 통해 신호를 받아들였다. 이를 저주파통과필터와 고주파통과필터를 사용하여 0.5~5Hz대역을 필터링 함으로써 PPG이외의 잡음을 제거하고 신호를 검출하였다. 검출된 파형을 지수가중이중필터로 필터링을 함으로써 정확성을 높였다. 이를 통하여 광원스위칭을 통한 PPG의 출력과 발광다이오드 한 개를 사용한 출력을 비교 분석을 보여줄 것이다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.3
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• pp.14-21
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• 2010

For the ubiquitous healthcare environment, real-time measurement of biomedical signals and accuracy of the measured biomedical information are very important. In addition, it is important to develop a healthcare device with low power In this paper, the synchronized pulse in a heartbeat was detected from the radial artery using the piezo film sensor, in order to eliminate inconvenience to wear a pulse detection finger probe. We can get a best output after applying the adaptive noise canceller using two piezo film sensor signals, pulse signal having motion artifacts and motion artifacts reference signal. To detect heartbeat, we use maximum point detection method from pulse removed motion artifacts.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.40-47
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• 2009

A motion adaptive video noise reduction scheme is proposed by cascading a temporal filter and a spatial filter. After a noise-robust motion detection is performed with a pre-spatial filter, the strength of the motion adaptive temporal filter is controlled by the amount of temporal movement. In order to fully utilize the temporal correlation of video signal, noisy input image is processed first by the temporal filter, therefore, image details of temporally stationary region are quite well preserved while undesired noises are suppressed. In contrast to the pre-spatial filter used for the robust motion detection, the cascaded post-spatial filter removes the remained noises by considering the strength of the temporal filter and the spatial self-similarity search results obtained from the pre-spatial filter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.365-367
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• 2006

광용적맥파를 이용하여 일상생활에서 심장 박동을 관찰하고 심장 박동의 이상을 경고할 수 있는 저렴하면서도 간단한 심박 측정 장치를 구성하고 심장박동을 검출하였다. 심장박동의 검출을 위해 Ring형 광용적맥파 센서를 635nm의 적색 LD와 Si Photodiode로 제작하였다. 제작된 Ring형 광용적맥파 센서는 잡음 및 오차로 작용하는 외부 광원을 차단하였으며, 동(動)잡음의 영향을 최소화하기 위해 측정부위에 밀착하도록 하였다, 측정결과 제작된 센서는 심장박동 신호를 외부 영향 없이 안정적인 검출이 가능함을 알 수 있었다.