Nudelman S, Manson A L, Hall A F, Kovács S J
Cardiovascular Biophysics Laboratory, Jewish Hospital at Washington University Medical Center, St. Louis, MO 63110, USA.
Ultrasound Med Biol. 1995;21(8):989-99. doi: 10.1016/0301-5629(95)00040-x.
Anatomic/physiologic and kinematic mathematical models of diastolic filling which employ (lumped) parameters of diastolic function have been used to predict or characterize transmitral flow. The ability to determine model parameters from clinical transmitral flow, the Doppler velocity profile (DVP), is equivalent to solving the "inverse problem" of diastole. Systematic model-to-model and model-to-data comparison has never been carried out, in part due to the requirement that DVPs be digitized by hand. We developed, tested and verified a computerized method of DVP acquisition and reproduction, and carried out numerical determination of model-to-model and model-to-data goodness-of-fit. The transmitral flow velocity of two anatomic/physiologic models and one kinematic model were compared. Each model's ability to fit computer-acquired and reproduced transmitral DVPs was assessed. Results indicate that transmitral flow velocities generated by the three models are 'graphically indistinguishable and are able to fit the E-wave of clinical DVPs with comparable mean-square errors. Nonunique invertibility of the anatomic/physiologic models was verified, i.e., multiple sets of model parameters could be found that fit a single DVP with comparable mean-square error. The kinematic formulation permitted automated, unique, model-parameter determination, solving the "inverse problem" for the Doppler E-wave. We conclude that automated, quantitative characterization of clinical Doppler E-wave contours using this method is feasible. The relation of kinematic parameters to physiologic variables is a subject of current investigation.
采用舒张功能（集总）参数的舒张期充盈的解剖学/生理学和运动学数学模型已被用于预测或描述二尖瓣血流。从临床二尖瓣血流、多普勒速度剖面（DVP）确定模型参数的能力等同于解决舒张期的“反问题”。系统的模型间和模型与数据间的比较从未进行过，部分原因是需要手动将DVP数字化。我们开发、测试并验证了一种DVP采集和再现的计算机化方法，并对模型间和模型与数据间的拟合优度进行了数值测定。比较了两种解剖学/生理学模型和一种运动学模型的二尖瓣血流速度。评估了每个模型拟合计算机采集和再现的二尖瓣DVP的能力。结果表明，三种模型产生的二尖瓣血流速度在图形上无法区分，并且能够以可比的均方误差拟合临床DVP的E波。验证了解剖学/生理学模型不可唯一求逆，即可以找到多组模型参数，以可比的均方误差拟合单个DVP。运动学公式允许自动、唯一地确定模型参数，解决了多普勒E波的“反问题”。我们得出结论，使用这种方法对临床多普勒E波轮廓进行自动、定量表征是可行的。运动学参数与生理变量之间的关系是当前研究的一个课题。
