ABSTRACT
Objective:To investigate the effect of conventional coronary CT angiography (CCTA) bolus injection of contrast agent on the diameter and angle of the left main coronary artery (LMA) bifurcation area, and to provide a basis for the application of CCTA to accurately measure the coronary artery.Methods:In Cangzhou Central Hospital of Hebei Province from January to December 2020, the clinical data of 54 patients with suspected coronary heart disease who underwent coronary artery calcification score (CACS) and CCTA with conventional bolus injection of contrast agent were retrospectively analyzed. Two physicians measured middle lumen diameter of LMA (d1), proximal lumen diameter of left anterior descending (LAD) (d2), proximal lumen diameter of left circumflex (LCX) (d3) and bifurcation angle between LAD and LCX (∠1). The consistency of 2 physicians was compared, and the results of CACS and CCTA were compared.Results:The consistency analysis result showed that only d3 measured by CCTA had a moderate consistency (intra-group correlation coefficient = 0.717), and the remaining indexes were in good agreement (intra-group correlation coefficient >0.75). There were no statistical differences in indexes measured results between CACS and CCTA ( P>0.05). According to the degree of left coronary artery stenosis, 54 patients were divided into 2 groups: LMA and branches normal or stenosis degree < 50% group (25 cases) and LMA and branches 1 or more branches stenosis degree≥50% group (29 cases). There were no statistical differences in indexes measured results between CACS and CCTA in patients with different disease severity ( P>0.05). Conclusions:In the CCTA examination, the conventional bolus injection of contrast agent does not affect the diameter and angle of the lumen of the LMA bifurcation area of the coronary artery.
ABSTRACT
The paper describes how to develop a digital heart sound signal detection device based on high gain MEMS MIC that can accurately collect and store human heart sounds. According to the method of collecting heart sound signal by traditional stethoscope, the system improves the traditional stethoscope, and a composite probe equipped with a MEMS microphone sensor is designed. The MEMS microphone sensor converts the sound pressure signal into a voltage signal, and then amplifies, converts with Sigma Delta, extracts and filters the collected signal. After the heart sound signal is uploaded to the PC, the Empirical Mode Decomposition (EMD) is carried out to reconstruct the signal, and then the Independent Component Analysis (ICA) method is used for blind source separation and finally the heart rate is calculated by autocorrelation analysis. At the end of the paper, a preliminary comparative analysis of the performance of the system was carried out, and the accuracy of the heart sound signal was verified.