Objective To study the course of a superior mesenteric artery(SMA)and the angle between SMA and abdominal aorta in early pregnancy,and to explore its significance in early diagnosis of fetal abdominal structural abnor...Objective To study the course of a superior mesenteric artery(SMA)and the angle between SMA and abdominal aorta in early pregnancy,and to explore its significance in early diagnosis of fetal abdominal structural abnormalities.Methods 50 cases of pregnant women with NT color Doppler ultrasound in our hospital and confirmed by delivery or induced labor were selected.The fetal morphology and the course of the fetal superior mesenteric artery were observed,and the angle between the superior mesenteric artery and the abdominal aorta was measured.Results 45 cases of the normal fetus and 5 cases of the abnormal abdomen were confirmed in pregnant women(1 case was missed in early pregnancy).The abnormal course of superior mesenteric artery was found in 4 cases,and the angle between the superior mesenteric artery and the abdominal aorta was abnormal in 4 cases.Conclusion The abnormal course of a superior mesenteric artery or abnormal angle between superior mesenteric artery and abdominal aorta in early pregnancy can be found by using color Doppler low-speed HD-Flow examination,which has definite significance for early diagnosis of fetal abdominal abnormalities such as abdominal fissure,omphalocele,diaphragmatic hernia,and abdominal mass.展开更多
In order to improve the accuracy and universality of the rotational speed measurement,an instantaneous rotational speed measurement method based on laser Doppler technology is proposed.The composition and working prin...In order to improve the accuracy and universality of the rotational speed measurement,an instantaneous rotational speed measurement method based on laser Doppler technology is proposed.The composition and working principle of the new system are discussed in detail.Theoretical and experimental results show that the new rotational speed measurement system belongs to the non-contact method,which eliminates the quantization error of the contact method and greatly improves the applicability and accuracy.Compared to the commonly used method,the measurement accuracy of the new rotational speed measurement system will not be affected by the system’s installation angle deviation,and it does not need to measure the radius of the rotating body,so the influence of the radius fluctuation of the rotating body on the measurement accuracy can be avoided while outputting the rotational speed in real time.The relative error of the rotational speed measurement is less than 0.06%(1σ).展开更多
文摘Objective To study the course of a superior mesenteric artery(SMA)and the angle between SMA and abdominal aorta in early pregnancy,and to explore its significance in early diagnosis of fetal abdominal structural abnormalities.Methods 50 cases of pregnant women with NT color Doppler ultrasound in our hospital and confirmed by delivery or induced labor were selected.The fetal morphology and the course of the fetal superior mesenteric artery were observed,and the angle between the superior mesenteric artery and the abdominal aorta was measured.Results 45 cases of the normal fetus and 5 cases of the abnormal abdomen were confirmed in pregnant women(1 case was missed in early pregnancy).The abnormal course of superior mesenteric artery was found in 4 cases,and the angle between the superior mesenteric artery and the abdominal aorta was abnormal in 4 cases.Conclusion The abnormal course of a superior mesenteric artery or abnormal angle between superior mesenteric artery and abdominal aorta in early pregnancy can be found by using color Doppler low-speed HD-Flow examination,which has definite significance for early diagnosis of fetal abdominal abnormalities such as abdominal fissure,omphalocele,diaphragmatic hernia,and abdominal mass.
文摘In order to improve the accuracy and universality of the rotational speed measurement,an instantaneous rotational speed measurement method based on laser Doppler technology is proposed.The composition and working principle of the new system are discussed in detail.Theoretical and experimental results show that the new rotational speed measurement system belongs to the non-contact method,which eliminates the quantization error of the contact method and greatly improves the applicability and accuracy.Compared to the commonly used method,the measurement accuracy of the new rotational speed measurement system will not be affected by the system’s installation angle deviation,and it does not need to measure the radius of the rotating body,so the influence of the radius fluctuation of the rotating body on the measurement accuracy can be avoided while outputting the rotational speed in real time.The relative error of the rotational speed measurement is less than 0.06%(1σ).
