• 한국정밀공학회지
• /
• 제21권4호
• /
• pp.19-23
• /
• 2004

생체에서 발생되는 생체신호는 신호의 발생원에 따라서, 신호의 물리적 특성에 따라서, 또는 이를 측정하는 센서의 특성에 따라서 분류할 수 있으며, 그 중에서도 임상적 진료를 위한 의료의 범위를 포함하여 다른 분야에도 광범위하게 활용될 수 있는 생체 신호는 전기적인 형태로 측정되는 생체 전기 신호라고 할 수 있다. 여기에서는 생체에서 측정되는 전기적인 신호가 어떻게 활용되고 또 활용될 수 있는지 그 응용 범위에 대하여 살펴보고자 한다.(중략)

• Journal of Chest Surgery
• /
• 제12권4호
• /
• pp.336-338
• /
• 1979

The electrocardiographic changes produced at surgery in all patients undergoing total correction of tetralogy of Fallot at the Seoul National University Hospital from 1961 through August 1979, were reviewed. Particular attention was directed to the presence of postoperative right bundle branch block combined with left anterior hemiblock and its prognosis. 14 patients [9.4%] out of 149 who were survived for 30 days postoperatively, showed right bundle branch block with left anterior hemiblock pattern in electrocardiography. But no complete heart block was occurred in these l 4 patients during the follow up periods of 2-56 months.

• 한국전자통신학회논문지
• /
• 제14권6호
• /
• pp.1257-1264
• /
• 2019

기존의 Cuff 기반의 혈압(Blood Pressure)측정 방법은 연속적인 실시간 혈압측정에는 한계를 갖는다. 이러한 이유로 ECG와 PPG 센서 신호를 상호융합한 다양한 혈압추정이 이루어졌다. 그러나 PPG 중심에 측정기법은 AC 노이즈, 작은 맥동, 비박동 등의 많은 문제를 지니고 있다. 본 논문은 ECG와 PPG 관계에 발생하는 맥파전달시간(PTT)과 맥파속도(PWV)를 이용하여 혈압을 추론기법이다. 신호 피크를 이용하는 HRF(Height Ratio Features)에 비해, 본 제안방식은 ECG, PPG의 최고점 혹은 최저점을 사용한 시차를 이용해 추정하기 때문에 PPG 센싱 시그널의 오류에도 안정적인 추출이 가능한 장점이 있다. 본 논문에서 제안 방법을 이용하여 25만 회의 혈압측정의 결과 ±28.5%의 정확도를 갖는 혈압 추정기법을 제시할 수 있었다.

• 대한약침학회지
• /
• 제13권3호
• /
• pp.15-46
• /
• 2010

Objectives: This study was performed to analyse the effects of Sweet Bee Venom(Sweet BV) on cardiovascular system in the conscious telemetered Beagle Dogs. Methods: All experiments were conducted at Biotoxtech Company, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Male Beagle dogs of 13-19 months old were chosen for the pilot study and surgical implantation was performed for conscious telemetered Beagle dogs. And after confirming condition of Beagle dogs was stable, Sweet BV was administered 4 times(first: 0.0 mg/kg, 2nd: 0.01 mg/kg, 3rd: 0.1 mg/kg, and forth: 0.5 mg/kg, one time/week) in thigh muscle of Beagle dogs. And blood pressure, heart rate, electrocardiography and clinical responses were measured. Equal amount of normal saline to the Sweet BV experiment groups was administered to the control group. Results: 1. In the analysis of body weight and taking amount, Beagle dogs did not show significant changes. 2. In the clinical observation, responses of pain and edema were showed depend on dosage of Sweet BV. 3. In the analysis of blood pressure, treatment with Sweet BV did not show significant changes in the dosage of 0.01 mg/kg, but in the dosage of 0.1 mg/kg and 0.5 mg/kg, treatment with Sweet BV increased blood pressure significantly. 4. In the analysis of heart rate, treatment of Sweet BV did not show significant changes in all dosage and period. 5. In the analysis of electrocardiography, treatment of Sweet BV was not showed significant changes in all dosage and period. Conclusion: Above findings suggest that Sweet BV is relatively safe treatment in the cardiovascular system. But in the using of over dosage, Sweet BV may the cause of increasing blood pressure. Further studies on the subject should be conducted to yield more concrete evidences.

• Clinical and Experimental Pediatrics
• /
• 제59권11호
• /
• pp.451-455
• /
• 2016

Purpose: Neurocardiogenic syncope (NCS) is the most frequent cause of fainting during adolescence. Inappropriate cardiovascular autonomic control may be responsible for this clinical event. The head-up tilt test has been considered a diagnostic standard, but it is cumbersome and has a high false-positive rate. We performed a study to evaluate whether P-wave dispersion (PWD) could be a useful electrocardiographic parameter of cardiac autonomic dysfunction in children with NCS. Methods: Fifty-four patients with NCS (28 boys and 26 girls; mean age, $12.3{\pm}1.4$ years) and 55 age- and sex-matched healthy controls were enrolled. PWD was obtained as the difference between maximum and minimum durations of the P wave on standard 12-lead electrocardiography in all patients and controls Results: The value of PWD was significantly higher in the syncope group than in the control group ($69.7{\pm}19.6$ msec vs. $45.5{\pm}17.1$ msec, respectively; P<0.001). The minimum duration of P wave was shorter in the syncope group than in the control group ($43.8{\pm}16.8$ msec vs. $53.5{\pm}10.7$ msec, respectively; P<0.001). Left atrial volume was not different between the groups on transthoracic echocardiography. Conclusion: PWD on echocardiography could be used as a clinical parameter in patients with NCS.

• 방송공학회논문지
• /
• 제18권4호
• /
• pp.543-549
• /
• 2013

자율신경계 및 중추신경계 반응 신호는 취득 시 피험자의 움직임이 있는 경우 노이즈가 첨가되어 의도한 분석이 불가능하게 될 수 있다. 본 논문에서는 생리신호 취득시 피험자의 영상을 동시에 촬영 및 분석하고 움직임을 감지하여, 생리신호의 노이즈 구간을 정의하는 방법을 제안한다. 움직임 감지를 위해 시계열에서 영상 프레임간 1차 미분하고 임계치 이상 움직임이 발생했을 때를 해당 신호의 노이즈 발생 구간으로 정의하였다. 또한, 영상을 사용하지 않는 방법으로써, 수집된 신호를 주기 단위로 분석하여 길이와 높이를 특징으로 한 정상 신호를 2차원 가우시안 확률밀도함수로 모델화하여, 신호의 훼손 구간을 정의하는 방법을 제안한다. 두 방법으로 정의된 훼손 구간은 가우시안 함수를 기반으로 보간하였다. 광혈류량 신호에 적용한 결과, 심전도 신호에서 추출된 평균 심박간격에 가까운 수치로 복원됨을 확인하였다. 또한, 영상기반 방법은 정상구간을 훼손구간으로, 신호기반 방법은 훼손구간을 정상구간으로 잘못 인식하는 경우가 나타남을 확인하였다.

• 대한의용생체공학회:의공학회지
• /
• 제17권4호
• /
• pp.449-458
• /
• 1996

Most of the conventional electrocardiowaphs foil to detect signals other than P-QRS-T due to the limited SNR and bandwidth. High-resolution electrocardiography(HRECG) provides better SNR and wider bandwidth for the detection of micro-potentials with higher frequency components such as vontricular late potentials(LP). We have developed a HRECG using uncorrected XYZ lead for the detection of LPs. The overall gain of the amplifier is 4000 and the bandwidth is 0.5-300Hz without using 60Hz notch filter. Three 16-bit A/D converters sample X, Y, and Z signals simultaneously with a sampling frequency of 2000Hz. Sampled data are transmitted to a PC via a DMA-controlled, optically-coupled serial communication channel. In order to further reduce the noise, we implemented a signal averaging algorithm that averaged many instances of aligned beats. The beat alignment was carried out through the use of a template matching technique that finds a location maximizing cross-correlation with a given beat tem- plate. Beat alignment error was reduced to $\pm$0.25ms. FIR high-pass filter with cut-off frequency of 40Hz was applied to remove the low frequency components of the averaged X, Y, and Z signals. QRS onset and end point were determined from the vector magnitude of the sigrlaIL and some parameters needed to detect the existence of LP were estimated. The entire system was designed for the easy application of the future research topics including the optimal lead system, filter design, new parameter extraction, etc. In the developed HRECG, without signal averaging, the noise level was less than 5$\mu$V$_rms RTI$. With signal averaging of at least 100 beats, the noise level was reduced to 0.5$\mu$V$_rms RTI$, which is low enough to detect LPs. The developed HRECG will provide a new advanced functionality to interpretive ECG analyzers.

• Pediatric Infection and Vaccine
• /
• 제27권3호
• /
• pp.184-189
• /
• 2020

라임병은 진드기를 매개로 하여 보렐리아속균 감염에 의해 발생하는 세균 질환이다. 가장 흔한 증상으로 초기에 유주성 홍반이 대부분의 환자에게서 관찰되며, 신경, 심혈관계 및 관절을 침범하는 증상이 발현할 수 있다. 저자들은 미국 코네티컷주로 여행력이 있는 13세 남자에게서 발현한 라임병을 진단하여 보고하는 바이다. 환자는 2016년 여름에 미국에서 숲 체험에 참여하던 중 발열, 두통, 양쪽 무릎 관절통을 호소하여 귀국하였으며, 내원 시 양 하지에 다수의 유주성 홍반이 관찰되었다. 심전도 검사에서 1도 방실 차단이 확인되었다. 간접면역형광항체법과 웨스턴블럿법 검사에서 라임병 특이 IgM 항체가 양성으로 확인되었다. 경구 doxycycline으로 4주간 치료하였으며, 유주성 홍반이 소실되고 심전도가 정상 소견으로 회복되었다. 라임병의 진단에 있어 호발 지역으로의 여행력을 확인하는 것이 중요하다. 라임병에 의한 심장염은 무증상 방실 전도차단으로 나타날 수 있고 고도 방실 차단으로 진행할 수 있어 주의를 요하며 적절한 항생제 치료를 통해 회복될 수 있다.

• Childhood Kidney Diseases
• /
• 제27권2호
• /
• pp.105-110
• /
• 2023

Purpose: To analyze electrocardiograms (ECGs) of patients with a salt-losing tubulopathy (SLT) and to determine the frequency and risk factors for long QT and arrhythmia. Methods: A total of 203 patients aged <19 years with SLT, specifically Bartter syndrome and Gitelman syndrome, who had a 12-lead ECG were included in this retrospective study. We analyzed the presence of an arrhythmia or prolonged corrected QT (QTc) on ECGs obtained for these patients. Demographic and laboratory data were compared between patients with abnormal and normal ECG findings. Results: Out of the 203 SLT patients, 38 (18.7%) underwent electrocardiography and 10 (40.0%) of 25 patients with inherited SLT had abnormal ECG findings, including prolonged QTc and arrhythmias. The abnormal ECG group had significantly lower serum potassium levels than the normal group (median [interquartile range]: 2.50 mmol/L [2.20-2.83] vs. 2.90 mmol/L [2.70-3.30], P=0.036), whereas other serum chemistry values did not show significant differences. The cutoff level for a significant difference in QTc interval was serum potassium level <2.50 mmol/L. One cardiac event occurred in a 13-year-old boy, who developed paroxysmal supraventricular tachycardia and underwent cardiac ablation. No sudden cardiac deaths occurred in this cohort. Conclusions: The incidence of ECG abnormalities in patients with inherited SLT was 40.0%, whereas the ECG screening rate was relatively low (18.7%). Therefore, we recommend ECG screening in patients with inherited SLT, especially in those with serum potassium level <2.50 mmol/L.

• Journal of Chest Surgery
• /
• 제57권2호
• /
• pp.205-212
• /
• 2024

Background: Postoperative atrial fibrillation (A-fib) is a serious complication of cardiac surgery that is associated with increased mortality and morbidity. Traditional 24-hour Holter monitors have limitations, which have prompted the development of innovative wearable electrocardiogram (ECG) monitoring devices. This study assessed a patch-type wearable ECG device (MobiCARE-MC100) for monitoring A-fib in patients undergoing cardiac surgery and compared it with 24-hour Holter ECG monitoring. Methods: This was a single-center, prospective, investigator-initiated cohort study that included 39 patients who underwent cardiac surgery between July 2021 and June 2022. Patients underwent simultaneous monitoring with both conventional Holter and patchtype ECG devices for 24 hours. The Holter device was then removed, and patch-type monitoring continued for an additional 48 hours, to determine whether extended monitoring provided benefits in the detection of A-fib. Results: This 72-hour ECG monitoring study included 39 patients, with an average age of 62.2 years, comprising 29 men (74.4%) and 10 women (25.6%). In the initial 24 hours, both monitoring techniques identified the same number of paroxysmal A-fib in 7 out of 39 patients. After 24 hours of monitoring, during the additional 48-hour assessment using the patch-type ECG device, an increase in A-fib burden (9%→38%) was observed in 1 patient. Most patients reported no significant discomfort while using the MobiCARE device. Conclusion: In patients who underwent cardiac surgery, the mobiCARE device demonstrated diagnostic accuracy comparable to that of the conventional Holter monitoring system.