• 융합정보논문지
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• 제8권5호
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• pp.131-135
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• 2018

현대인의 사망원인 2위를 차지하고 있는 심장병은 자각 증세 없이 갑자기 돌연사를 당할 수 있는 무서운 질병으로 예방이 중요하다. 심장병 중 대동맥판막 협착증을 판단하기 위해서 physioNet에서 제공하는 심음 데이터 중 S1과 S2 사이의 수축 심음 데이터를 이용하여 병명을 진단하였다. 대동맥 판막은 좌심실에서 대동맥으로 피가 유출되는 부위의 판막이다. 심장병 중 대동맥판막 협착증은 대동맥판막이 좁아져 좌심실의 수축 시 판막이 열리지 않는 질환이다. 위 논문에서는 정상인과 대동맥판막 협착증 환자를 합쳐 특징이 180개로 이루어진 3126개의 샘플 심음 데이터를 실험데이터로 사용하였다. 정상과 대동맥판막 협착증 환자를 구분하기 위해 가중퍼지신경망(NEWFM, Neural Network with Weighted Fuzzy Membership Function)이용하였다. 가중퍼지신경망의 특징선택 방법으로 가중치의 평균 방법을 이용하였으며, 분류 결과는 91.0871%의 정확도를 나타내었다.

• 대한의용생체공학회:의공학회지
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• 제45권3호
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• pp.109-117
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• 2024

We developed a device that integrates digital otoscope and stethoscope for telemedicine. The integrated device was utilized for the collection of tympanic membrane images and cardiac auscultation data. Data accumulated on the platform server can support real-time diagnosis of heart and eardrum diseases using artificial intelligence. Public data from Kaggle were used for deep learning. After comparing with various deep learning models, the MobileNetV2 model showed superior performance in analyzing tympanic membrane data, and the VGG16 model excelled in analyzing cardiac data. The classification algorithm achieved an accuracy of 89.9% for eardrums data and 100% for heart sound data. These results demonstrate the possibility of diagnosing diseases without the limitations of time and space by using this platform.

• 대한의용생체공학회:의공학회지
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• 제22권5호
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• pp.439-448
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• 2001

이식형 양심실 보조 장치 (Biventricular Assist Device, BVAD)에서 판막이 닫힐 때 나는 소리의 특성과 판막의 물리적인 상태의 상관성을 고찰하였다. 본 연구에서 Bj rk Shiley Convexo Concave tilting disk 판막을 사용했으며, 모의 순환계와 양의 체내에서 동작하는 BVAD 에서 판막음을 측정하였다. 모의 순환계에서는 정상 판막. 기계적으로 손상된 판막. 모의 혈전이 형성된 판막의 3가지를 고려하였다. 양에 이식된 BVAD의 경우, 이식 후 1일부터 5일 동안 규칙적인 간격으로 판막음을 측정하였다. 측정된 신호의 스펙트럼 특성은 Multiple Signal Classification (MUSIC)을 이용하여 추정하였다. MUSIC의 최적 차수는 Bayesian Information Criterion (BIC)을 이용하여 계산하였다. 실험 결과, 판막의 기계적인 손상은 판막 폐쇄음의 주파수 스펙트럼 구조를 변화시키고 있으며, 혈전의 형성은 판막음 스펙트럼의 기본 구조는 유지하지만 피크 주파수와 에너지의 크기를 변화시키는 것으로 관찰되었다. 최대 에너지를 가지는 MSP (maximum spectral peak)는 정상 판막에서는 2 kHz에 위치하고 있으나 모의 혈전을 부탁한 판막에서는 3 kHz로 이동하였다. 손상된 판막은 7 kHz 부근에서 강한 피크 보이고 있다 실험 동물 내에서 판막에 혈전이 형성되어감에 따라 판막음은 저주파 성분 (〈 2kHz)이 상대적으로 크게 감소하였고, Ist 2nd. 3rd MSP 주파수는 약간씩 상승하였다. 또한 혈전이 형성되어 감에 따라 반복해서 측정된 판막음의 1st, 2nd. 3rd MSP 주파수의 변화 정도 및 BIC 차수는 감소하는 것으로 나타났다

• Journal of Chest Surgery
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• 제12권3호
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• pp.281-288
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• 1979

For years, physicians and anatomists have been interested in the heart that has one functioning ventricle. Various terms have been suggested for this entity including single ventricle, common ventricle, double-inlet left ventricle, cor biatriatum triloculare, and primitive ventricle. In this report, the term "single ventricle" is utilized as suggested by Van Praagh, and is defined as that congenital cardiac anomaly in which a common or separate atrioventricular valves open into a ventricular chamber from which both great arterial trunks emerge. An outlet chamber, or infundibulum, may or may not be present and give rise to the origin of either of the great arteries. This definition excludes the entity of mitral and tricuspid atresia. An 11 year old cyanotic boy was admitted chief complaints of exertional dyspnea and frequent upper respiratory infection since 2 weeks after birth. He was diagnosed as inoperable cyanotic congenital heart disease, and remained without any corrective treatment up to his age of 11 year when he suffered from aggravation of symptoms and signs of congestive heart failure for 2 months before this admission. On 22nd of May 1979, he was admitted for total corrective operation under the impression of tricuspid atresia suggested by a pediatrician. Physical check revealed deep cyanosis with finger and toe clubbing, and grade V systolic ejection murmur with single second heart sound was audible at the left 3rd intercostal space. Development was moderate in height [135 cm] and weight[28Kg]. Routine lab findings were normal except increased hemoglobin [21.1gm%], hematocrit [64 %], and left axis deviation with left ventricular hypertrophy on EKG. Cardiac catheterization and angiography revealed 1-transposition of aorta, pulmonic valvular stenosis, double inlet of a single ventricle with d-loop, and normal atriovisceral relationship [Type III C solitus according to the classification of Van Praagh]. At operation, longitudinal incision at the outflow tract of right ventricle in between the right coronary artery and its branch [LAD from RCA] revealed high far anterior aortic valve which had fibrous continuity with mitral annulus, and pulmonic valve was stenotic up to 4 mm in diameter positioned posterolaterally to the aorta. Ventricular septum was totally defective, and one markedly hypertrophied moderator band originated from crista supraventricularis was connected down to the imaginary septum of the ventricular cavity as a pseudoseptum of the ventricle. Size of the defect was 3X3 cm2 in total. Patch closure of the defect with a Teflon felt of 3.5 x 4 cm2 was done with interrupted multiple sutures after cut off of the moderator band, which was resutured to the artificial septum after reconstruction of the ventricular septum. Pulmonic valvotomy was done from 4 mm to 11 mm in diameter thru another pulmonary arteriotomy incision, and right ventriculotomy wound was closed reconstructing the right ventricular outflow tract with pericardial autograft of 3 x 4 cm2. Atrial septal defect of 2 cm in diameter was closed with 3-0 Erdeck suture, and atrial wall was sutured also when rectal temperature reached from 24`C to 35.5`C. Complete A-V block was managed with temporary external pacemaker with a pacing rate of 110/min. thru myocardial wire, and arterial blood pressure of 80/50 mmHg was maintained with Isuprel or Dopamine dripping under the CVP of 25-cm saline. Consciousness was recovered one hour after the operation when his blood pressure reached 100 /70 mmHg, but vital signs were not stable, and bleeding from the pericardial drainage and complete anuria were persisted until his heart could not capture the pacemaker impulse, and patient died of low output syndrome 320 min after the operation.

• Journal of Chest Surgery
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• 제12권3호
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• pp.289-296
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• 1979

For years, physicians and anatomists have been interested in the heart that has one functioning ventricle. Various terms have been suggested for this entity including single ventricle, common ventricle, double-inlet left ventricle, cor biatriatum triloculare, and primitive ventricle. In this report, the term "single ventricle" is utilized as suggested by Van Praagh, and is defined as that congenital cardiac anomaly in which a common or separate atrioventricular valves open into a ventricular chamber from which both great arterial trunks emerge. An outlet chamber, or infundibulum, may or may not be present and give rise to the origin of either of the great arteries. This definition excludes the entity of mitral and tricuspid atresia. An 11 year old cyanotic boy was admitted chief complaints of exertional dyspnea and frequent upper respiratory infection since 2 weeks after birth. He was diagnosed as inoperable cyanotic congenital heart disease, and remained without any corrective treatment up to his age of 11 year when he suffered from aggravation of symptoms and signs of congestive heart failure for 2 months before this admission. On 22nd of May 1979, he was admitted for total corrective operation under the impression of tricuspid atresia suggested by a pediatrician. Physical check revealed deep cyanosis with finger and toe clubbing, and grade V systolic ejection murmur with single second heart sound was audible at the left 3rd intercostal space. Development was moderate in height [135 cm] and weight[28Kg]. Routine lab findings were normal except increased hemoglobin [21.1gm%], hematocrit [64 %], and left axis deviation with left ventricular hypertrophy on EKG. Cardiac catheterization and angiography revealed 1-transposition of aorta, pulmonic valvular stenosis, double inlet of a single ventricle with d-loop, and normal atriovisceral relationship [Type III C solitus according to the classification of Van Praagh]. At operation, longitudinal incision at the outflow tract of right ventricle in between the right coronary artery and its branch [LAD from RCA] revealed high far anterior aortic valve which had fibrous continuity with mitral annulus, and pulmonic valve was stenotic up to 4 mm in diameter positioned posterolaterally to the aorta. Ventricular septum was totally defective, and one markedly hypertrophied moderator band originated from crista supraventricularis was connected down to the imaginary septum of the ventricular cavity as a pseudoseptum of the ventricle. Size of the defect was 3X3 cm2 in total. Patch closure of the defect with a Teflon felt of 3.5 x 4 cm2 was done with interrupted multiple sutures after cut off of the moderator band, which was resutured to the artificial septum after reconstruction of the ventricular septum. Pulmonic valvotomy was done from 4 mm to 11 mm in diameter thru another pulmonary arteriotomy incision, and right ventriculotomy wound was closed reconstructing the right ventricular outflow tract with pericardial autograft of 3 x 4 cm2. Atrial septal defect of 2 cm in diameter was closed with 3-0 Erdeck suture, and atrial wall was sutured also when rectal temperature reached from 24`C to 35.5`C. Complete A-V block was managed with temporary external pacemaker with a pacing rate of 110/min. thru myocardial wire, and arterial blood pressure of 80/50 mmHg was maintained with Isuprel or Dopamine dripping under the CVP of 25-cm saline. Consciousness was recovered one hour after the operation when his blood pressure reached 100 /70 mmHg, but vital signs were not stable, and bleeding from the pericardial drainage and complete anuria were persisted until his heart could not capture the pacemaker impulse, and patient died of low output syndrome 320 min after the operation.