In this paper, we present a machine learning model to estimate the blood pressure (BP) of a person using only his photoplethysmogram (PPG) signal. We propose algorithms to better detect some critical points of the PPG signal, such as systolic and diastolic peaks, dicrotic notch and inflection point. These algorithms are applicable to different PPG signal morphologies and improve the precision of feature extraction. We show that the logarithm of dicrotic notch reflection index, the ratio of low- to high-frequency components of heart rate (HR) variability signal, and the product of HR multiplied by the modified Normalized Pulse Volume (mNPV) are the key features in accurately estimating the BP using PPG signal. Our proposed method has achieved higher accuracies in estimating BP compared to the previously reported methods that only use PPG signal. For the systolic BP, the achieved correlation coefficient between the estimated values and the real values is 0.78, the mean absolute error of the estimated values is 8.22 mmHg, and their standard deviation is 10.38 mmHg. For the diastolic BP, the achieved correlation coefficient between the estimated and the real values is 0.72, the mean absolute error of the estimated values is 4.17 mmHg, and their standard deviation is 4.22 mmHg. The achieved results fall within Grade A for diastolic, Grade C for systolic and Grade B for mean BP based on BHS standard.

中文翻译：

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使用光体积描记信号及其形态特征的血压估计

在本文中，我们提出了一个机器学习模型，仅使用一个人的光电容积图 (PPG) 信号来估计他的血压 (BP)。我们提出算法以更好地检测 PPG 信号的一些关键点，例如收缩压和舒张压峰值、重搏切迹和拐点。这些算法适用于不同的PPG信号形态，提高了特征提取的精度。我们表明，重波切迹反射指数的对数、心率 (HR) 变异信号的低频与高频分量之比以及 HR 乘以修正的归一化脉搏量 (mNPV) 的乘积是使用 PPG 信号准确估计 BP。与之前报道的仅使用 PPG 信号的方法相比，我们提出的方法在估计 BP 方面取得了更高的准确度。对于收缩压，估计值与实际值的相关系数为 0.78，估计值的平均绝对误差为 8.22 mmHg，标准差为 10.38 mmHg。对于舒张压，估计值与实际值的相关系数为 0.72，估计值的平均绝对误差为 4.17 mmHg，标准差为 4.22 mmHg。根据 BHS 标准，所取得的结果属于舒张压 A 级、收缩压 C 级和平均血压 B 级。估计值与实际值的相关系数为0.72，估计值的平均绝对误差为4.17 mmHg，标准差为4.22 mmHg。根据 BHS 标准，所取得的结果属于舒张压 A 级、收缩压 C 级和平均血压 B 级。估计值与实际值的相关系数为0.72，估计值的平均绝对误差为4.17 mmHg，标准差为4.22 mmHg。根据 BHS 标准，所取得的结果属于舒张压 A 级、收缩压 C 级和平均血压 B 级。