Continuous cardiac output measurements with a newly developed pulmonary artery Doppler catheter.

连续心输出量测量方法的开发已经进行了十多年。尽管血管内超声技术已经用于连续测量心输出量，但是问题在于超声波束和血流之间的入射角，这将构成速度测量和心输出量测量中的误差。我们研制了一种新的肺动脉多普勒导管，它能提供真实的血流速度，而不受超声束和血流形成的入射角的影响，一对超声换能器以固定的角度安装在肺动脉导管的远端，定位在主肺动脉内。多普勒频移（DELTAF 1，DELTAF 2）由两个换能器在主肺动脉中的紧密间隔的两个点处采样来检测。用DELTAF 1和DELTAF 2值计算两个流速测量值，并计算肺动脉的真实流速。 ...更多信息 使用以下公式计算：V=（（V1）^2+（V2）^2）^<1/2>，其中V=真实速度，V1和V2=由换能器1和2检测到的速度。使用新开发的相位微分技术的速度计算。用热稀释法测定心输出量和肺动脉真实流速。根据肺动脉真实血流速度连续计算心输出量。IRB批准后，在动物实验中评价肺动脉多普勒导管（Aloka，Tokyo，Japan）。将多普勒导管推进到麻醉犬（19- 30 kg）的肺动脉。开胸后，将电磁流量探头放置在肺动脉周围。同时用肺动脉多普勒导管（CO-Doppler）、热稀释法（CO-Thermo）和电磁流量计（CO-EMF）测定心输出量，并比较CO-Doppler、CO-Thermo和CO-EMF的差异，CO-Doppler与CO-EMF高度相关（Y=1.16x-0.27，r^2=0.99，n=71，p<0.001）。CO-Doppler与CO-Thermo也有相关性（r^2=0.72）。我们提出的技术将是上级在测量心输出量在真实的时间的基础上比其他改进的热稀释技术连续心输出量监测。少

Development of a method for continuous cardiac output measurements has been under way over a decade. Although intravascular ultrasound techniques have been used for measuring cardiac output continuously, a problem would be the angle of incidence between the ultrasound beam and the blood flow, which would constitute the errors in velocity measurements and in cardiac output measurements. We newly developed pulmonary artery Doppler catheter which could provide true flow velocity independent of the angle of incidence formed by the ultrasound beam and the flow.A pair of ultrasonic transducers positioned at a fixed angle was mounted on the distal section of pulmonary artery catheter to be positioned in the main pulmonary artery. The Doppler shifts (DELTAf1, DELTAF2) were detected by two transducers sampling at closely spaced two points in the main pulmonary artery. The values of DELTAF1 and DELTAf2 were used to compute two velocity measurements, and true flow velocity of pulmonary artery was … More calculated using following equation : V= ((V1)^2+(V2)^2)^<1/2>, where V=true velocity, V1 and V2=velocity detected by the transducer 1 and 2. The velocities were calculated using newly developed phase differential techniques. Cardiac output by thermodilution technique and true flow velocity of pulmonary artery were measured simultaniously. Then, cardiac output was calculated from true flow velocity of pulmonary artery continuously. After IRB approval, the pulmonary artery Doppler catheter (Aloka, Tokyo, Japan) was evaluated in animal experiments. The Doppler catheter was advanced to the pulmonary artery of anesthetized dogs (19-30kg). After thoracotomy, an electromagnetic flow probe was placed around the pulmonary artery. Cardiac output was measured by the pulmonary artery Doppler catheter (CO-Doppler), by thermodilution method (CO-Thermo) and by electromagnetic flowmeter (CO-EMF) simultaneously, and CO-Doppler, Co-Thermo and CO-EMF were compared.Co-Doppler was highly correlated with CO-EMF (Y=1.16x-0.27, r^2=0.99, n=71, p<0.001). CO-Doppler was also correlated with CO-Thermo (r^2=0.72).Using a newly developed pulmonary artery Doppler catheter, we are able to estimates cardiac output continuously. Our technique presented would be superior in measuring cardiac output at real time basis than other modified thermodilution techniques for continuous cardiac output monitoring. Less