【摘要】 提高血压测量准确度是预防高血压的重要途径。针对示波法仅由经验确定一组比例系数使血压测量不准的问题,提出一种多方法结合的血压判定方法。将前处理后的包络特征通过分类模型匹配一组最适用的比例系数,再采用示波法估计血压。分类模型离线训练,首先利用新型k-means算法对包络唯一聚类,然后各类包络分别采用梯度下降法获取一组最优比例系数,最终由多类包络的质心向量与比例系数构成分类模型。利用33例对象做对比实验,对比水银法,测量值的相关系数可达0. 91,且准确度符合AAMI-SP10及ESH的一级标准要求;另以ESH为中间标准对比传统示波法,5 mm Hg偏差内达标量的平均增长率为10. 5%,10 mm Hg偏差内达标量的平均增长率为6. 8%。这说明,所提出的方法不仅准确性良好,而且较传统示波法具有一定优越性。更多还原

【Abstract】 The improvement of the accuracy of measuring blood pressure is an important issue to prevent hypertension. Oscillography uses statistical experience to determine a set of coefficients,which is inaccurate enough in the measurement of blood pressure. In this work,a method of measuring blood pressure by combining multiple techniques was proposed. Five characteristic parameters from the de-interference oscillometric waveform envelope were extracted to match the envelope to the best set of coefficients through the classification model and measure the blood pressure by oscillography. The classification model was trained offline. Specifically,the first thing was to uniquely cluster the envelopes using the novel k-means. Next,adaptively determined a set of optimal coefficients for each type of envelope according to the gradient descent,and there was a one-to-one correspondence between the centroid vectors and the calculated coefficients. Based on above mentioned,the classification model was finally constructed. There were 33 subjects in the experiment. Experimental results showed that the proposed blood pressure measurement was similar to that of mercury method,the correlation coefficient could reach 0. 91,and met the AAMI-SP10 standards even the first-level requirements of ESH.Furthermore,the proposed measurement was superior to oscillography,with regard to the deviations between the estimated blood pressure and the target blood pressure,the number of deviations within 5 mm Hg was increased by 10. 5% on average,and the number of deviations within 10 mm Hg was increased by 6. 8% on average.更多还原