• 한국전자파학회논문지
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• 제28권10호
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• pp.802-809
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• 2017

본 논문에서는 IR-UWB 레이다 신호를 이용하여 무호흡 검출과 호흡수를 측정할 수 있는 방법을 제안한다. 제안한 방법에서는 무호흡 검출과 호흡수 측정을 동시에 지원하기 위해서 레이다 신호의 크기, 도래시간 및 선택된 주파수 대역에서의 전력 정보를 이용한다. 하드웨어 실험을 통해서 제안한 방법을 사용하여 정확한 호흡수 측정이 가능함을 보인다. 또한, 제안한 방법을 사용하여 무호흡과 호흡의 선택비가 최소 50 dB 이상이 됨을 보인다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.514-517
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• 2003

산소공급은 신체 요구 중 가장 기본적인 것이다. 호흡은 뇌의 연수(medulla oblongata)에 있는 호흡중추와 폐의 정상적 기능에 의해 조절된다. 즉 폐와 환경 사이의 공기 이동인 외 호흡과 헤모글로빈과 단세포 사이의 세포수준에서의 산소 이동인 내 호흡을 말한다. 성인의 호흡수는 보통 1분에 15-20회이나 연령, 운동, 기온, 심리적 변호, 질병상태, 대기의 산소 함량, 약물 투여 등에 따라 차이가 난다. 호흡측정은 대상자가 쉬고 있을 때 하는 것이 중요하다. 호흡 측정은 측정하고 있다는 사실을 대상자가 모르도록 기술적으로 해야한다. 현재 사용하는 방법은 주의를 끌지 않도록 대상자의 팔목에 손을 댄 채로 맥박을 측정한 바로 직후 계속해서 대상자의 가슴의 움직임을 관찰하면서 호흡을 측정하는 것이다. 본 논문에서 구현하고자 하는 것은 관성의 오차 및 압력의 오차에 영향을 거의 받지 않는, 그리고 반영구적으로 사용이 가능한 초음파 센서를 이용한 임베디드 환경의 호흡 량 측정기이다.

• 한국ITS학회 논문지
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• 제12권2호
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• pp.45-51
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• 2013

본 논문에서 호흡 기반의 운전자 졸음 감지 센서 시스템에 대해 언급하였다. 센서 시스템은 운전자의 복부 부분 안전벨트에 장착된 PZT 압력센서와 개인용 컴퓨터로 구성됐다. PZT 압력센서는 호흡 시 운전자 복부의 움직임에 의해 압력센서에 가해지는 압력의 변화를 측정하기 위해 사용되었고 운전자의 졸음을 감지하기 위한 신호처리는 Labview를 사용하여 개발됐다. 30세 남자 운전자를 상대로 운전자 졸음 감지 관련 실험들이 수행되어 졌다. 운전자가 각성상태일때 호흡의 크기는 졸음상태일 때보다 컸으며 반대로 호흡 주파수는 낮았다. 이런 실험을 바탕으로 제작된 졸음 감지 센서 시스템은 운전자의 졸음을 성공적으로 실시간 감지할 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권12호
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• pp.4891-4894
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• 2015

Background: To evaluate the value of combined detection of serum carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA21-1), and carbohydrateantigen 125 (CA125) for the clinical diagnosis of nonsmall cell lung cancer (NSCLC). Materials and Methods: Serum CEA, CYFRA21-1 and CA125 were assessed in 140 patients with NSCLC, 90 patients with benign lung disease and 90 normal control subjects, and differences of expression were compared in each group, and joint effects of these tumor markers in the diagnosis of NSCLC were analyzed. Results: Serum CEA, CYFRA21-1 and CA125 in patients with NSCLC were significantly higher than those with benign lung disease and normal controls (P<0.05). The sensitivity of CEA, CYFRA21-1 and CA125 were 49.45%, 59.67%, and 44.87% respectively. As expected, combinations of these tumor markers improved their sensitivity for NSCLC. The combined detection of CEA + CYFRA21-1 was the most cost-effective combination which had higher sensitivity and specificity in NSCLC. Elevation of serum CEA and CYFRA21-1 was significantly associated with pathological types (P<0.05) and elevation of serum CEA, CYFRA21-1 and CA125 was significantly associated with TNM staging (P<0.05). Conclusions: Single measurement of CEA, CYFRA21-1 and CA125 is of diagnostic value in the diagnosis of lung cancer, and a joint detection of these three tumor markers, could greatly improve the sensitivity of diagnosis on NSCLC. Combined detection of CEA + CYFRA21-1 proved to be the most economic and practical strategy in diagnosis of NSCLC, which can be used to screen the high-risk group.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.183-184
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• 1998

Respiration monitoring is important in many clinical situations due to its relationship to vitality. But present commercial monitoring systems are bulky and expensive, so they are inadequate to be used for long term recording or out-patients application. We have developed a low cost, low power, handhold respiration monitoring system based on airflow measurement. Respiration flow is indirectly detected using a thermister or a themocouple sensor. Real time recording of respiration rate, abnormality detection and apnea alarming are available.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.334-343
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• 2014

In this paper, we suggest a method to improve the fusion of an accelerometer and gyro sensor by using a Kalman filter to produce a more high-quality respiration signal to supplement the weakness of using a single accelerometer. To evaluate our proposed algorithm's performance, we developed a chest belt-type module. We performed experiments consisting of aerobic exercise and muscular exercises with 10 subjects. We compared the derived respiration signal from the accelerometer with that from our algorithm using the standard respiration signal from the piezoelectric sensor in the time and frequency domains during the aerobic and muscular exercises. We also analyzed the time delay to verify the synchronization between the output and standard signals. We confirmed that our algorithm improved the respiratory rate's detection accuracy by 4.6% and 9.54% for the treadmill and leg press, respectively, which are dynamic. We also confirmed a small time delay of about 0.638 s on average. We determined that real-time monitoring of the respiration signal is possible. In conclusion, our suggested algorithm can acquire a more high-quality respiration signal in a dynamic exercise environment away from a limited static environment to provide safer and more effective exercises and improve exercise sustainability.

• 전기학회논문지P
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• 제59권1호
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• pp.58-63
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• 2010

In this paper, we proposed a wearable respiration measurement system with textile capacitive pressure sensor. Belt typed textile capacitive pressure sensor approach of respiration measurement, from which respiration signatures and rates can be derived in real-time for long-term monitoring, are presented. Belt typed textile capacitive pressure sensor has been developed for this measurement system. the distance change of two plates by the pressure of motion has been used for the respiration measurement in chest area. Respiration rates measured with the textile capacitive pressure sensor was compared with standard techniques on 8 human subjects. Accurate measurement of respiration rate with developed sensor system is shown. The data from the method comparison study is used to confirm theoretical estimates of change in capacitance by the distance change. The current version of respiratory rate detection system using textile capacitive pressure sensor can successfully measure respiration rate. It showed upper limit agreement of $3.7997{\times}10^{-7}$ RPM, and lower limit of agreement of $-3.8428{\times}10^{-7}$ RPM in Bland-Altman plot. From all subject, high correlation were shown(p<0.0001). The proposed measurement method could be used to monitor unconscious persons, avoiding the need to apply electrodes to the directly skin or other sensors in the correct position and to wire the subject to the monitor. Monitoring respiration using textile capacitive pressure sensor offers a promising possibility of convenient measurement of respiration rates. Especially, this technology offers a potentially inexpensive implementation that could extend applications to consumer home-healthcare and mobile-healthcare products. Further advances in the sensor design, system design and signal processing can increase the range and quality of the rate-finding, broadening the potential application areas of this technology.

• 전기학회논문지
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• 제58권10호
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• pp.2071-2078
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• 2009

In this paper, we proposed a non-contact respiration measurement system with ultrasonic proximity sensor. Ultrasonic proximity sensor approach of respiration measurement which respiration signatures and rates can be derived in real-time for long-term monitoring is presented. 240 kHz ultrasonic sensor has been applied for the proposed measurement system. The time of flight of sound wave between the transmitted signal and received signal have been used for a respiration measurement from abdominal area. Respiration rates measured with the ultrasonic proximity sensor were compared with those measured with standard techniques on 5 human subjects. Accurate measurement of respiration rate is shown from the 50 cm measurement distance. The data from the method comparison study is used to confirm the performance of the proposed measurement system. The current version of respiratory rate detection system using ultrasonic can successfully measure respiration rate. The proposed measurement method could be used for monitoring unconscious persons from a relatively close range, avoiding the need to apply electrodes or other sensors in the correct position and to wire the subject to the monitor. Monitoring respiration using ultrasonic sensor offers a promising possibility of non-contact measurement of respiration rates. Especially, this technology offers a potentially inexpensive implementation that could extend applications to consumer home-healthcare and mobile-healthcare products. Further advances in the sensor design, system design and signal processing can increase the range of the measurement and quality of the rate-finding for broadening the potential application areas of this technology.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권10호
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• pp.733-740
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• 2004

In this paper, an improved algorithm for the extraction of respiration signal from the electrocardiogram (ECG) is proposed. The whole system consists of two-lead electrocardiogram acquisition (lead Ⅰ and Ⅱ), baseline fluctuation elimination, R-wave detection, adjustment of sudden change in R-wave area using moving average, and optimal lead selection. In order to solve the problem of previous algorithms for the ECG-derived respiration (EDR) signal acquisition, we proposed a method for the optimal lead selection. An optimal EDR signal among the three EDR signals derived from each lead (and arctangent of their ratio) is selected by estimating the instantaneous frequency using the Hilbert transform, and then choosing the signal with minimum variation of the instantaneous frequency. The proposed algorithm was tested on 15 subjects, and we could obtain satisfactory respiration signals that shows high correlation (r>0.9) with the signal acquired from the chest-belt respiration sensor.

• 한국정보통신학회논문지
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• 제23권1호
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• pp.70-76
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• 2019

UWB(Ultra-wideband)는 송신 안테나에서 UWB 대역을 송신한 신호를 수신 안테나를 통해 받은 신호를 가지고 목표물을 판단하는 고해상도 근거리 초광대역 레이더로 비접촉으로 사람의 호흡 및 심박을 감지할 수 있고, 환경에 영향을 받지 않아 최근 활용도가 높아지고 있다. 본 논문에서는 UWB 레이더 신호를 이용하여 사람의 호흡과 심박수를 감지하는 알고리즘을 구현한다. 인체에서부터 반사되어 들어온 레이더 신호를 메디안 필터, 칼만 필터, 밴드 패스필터 등을 이용하여 처리한다. 또한 호흡수와 심박수를 추출하기 위하여 CZT를 이용한다. 비교하는 심박 데이터로는 ECG(Electrocardiogram)를 사용하였으며, 약 98% 이상 일치함을 확인하였다.