Shao Jiang, Shi Ping, Hu Sijung, Yu Hongliu
Institute of Rehabilitation Engineering and Technology, University of Shanghai for Science and Technology, Shanghai 200093, China.
Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK.
Sensors (Basel). 2020 Apr 13;20(8):2205. doi: 10.3390/s20082205.
Initial calibration is a great challenge for cuff-less blood pressure (BP) measurement. The traditional one point-to-point (oPTP) calibration procedure only uses one sample/point to obtain unknown parameters of a specific model in a calm state. In fact, parameters such as pulse transit time (PTT) and BP still have slight fluctuations at rest for each subject. The conventional oPTP method had a strong sensitivity in the selection of initial value. Yet, the initial sensitivity of calibration has not been reported and investigated in cuff-less BP motoring. In this study, a mean point-to-point (mPTP) paring calibration method through averaging and balancing calm or peaceful states was proposed for the first time. Thus, based on mPTP, a factor point-to-point (fPTP) paring calibration method through introducing the penalty factor was further proposed to improve and optimize the performance of BP estimation. Using the oPTP, mPTP, and fPTP methods, a total of more than 100,000 heartbeat samples from 21 healthy subjects were tested and validated in the PTT-based BP monitoring technologies. The results showed that the mPTP and fPTP methods significantly improved the performance of estimating BP compared to the conventional oPTP method. Moreover, the mPTP and fPTP methods could be widely popularized and applied, especially the fPTP method, on estimating cuff-less diastolic blood pressure (DBP). To this extent, the fPTP method weakens the initial calibration sensitivity of cuff-less BP estimation and fills in the ambiguity for individualized calibration procedure.
对于无袖带血压测量而言，初始校准是一项巨大挑战。传统的单点到点（oPTP）校准程序仅使用一个样本/点来获取特定模型在平静状态下的未知参数。事实上，对于每个受试者，诸如脉搏传输时间（PTT）和血压等参数在静息状态下仍会有轻微波动。传统的oPTP方法在初始值选择上具有很强的敏感性。然而，无袖带血压监测中校准的初始敏感性尚未见报道和研究。在本研究中，首次提出了一种通过平均和平静或安宁状态平衡的平均点到点（mPTP）配对校准方法。因此，基于mPTP，进一步提出了一种通过引入惩罚因子的因子点到点（fPTP）配对校准方法，以改进和优化血压估计性能。使用oPTP、mPTP和fPTP方法，在基于PTT的血压监测技术中对来自21名健康受试者的总共超过100,000个心跳样本进行了测试和验证。结果表明，与传统的oPTP方法相比，mPTP和fPTP方法显著提高了血压估计性能。此外，mPTP和fPTP方法，尤其是fPTP方法，在估计无袖带舒张压（DBP）方面可广泛推广和应用。在此程度上，fPTP方法削弱了无袖带血压估计的初始校准敏感性，并填补了个体化校准程序的空白。
