Cuffless and Continuous Blood Pressure Estimation from the Heart Sound Signals

Abstract

Cardiovascular disease, like hypertension, is one of the top killers of human life and early detection of cardiovascular disease is of great importance. However, traditional medical devices are often bulky and expensive, and unsuitable for home healthcare. In this paper, we proposed an easy and inexpensive technique to estimate continuous blood pressure from the heart sound signals acquired by the microphone of a smartphone. A cold-pressor experiment was performed in 32 healthy subjects, with a smartphone to acquire heart sound signals and with a commercial device to measure continuous blood pressure. The Fourier spectrum of the second heart sound and the blood pressure were regressed using a support vector machine, and the accuracy of the regression was evaluated using 10-fold cross-validation. Statistical analysis showed that the mean correlation coefficients between the predicted values from the regression model and the measured values from the commercial device were 0.707, 0.712, and 0.748 for systolic, diastolic, and mean blood pressure, respectively, and that the mean errors were less than 5 mmHg, with standard deviations less than 8 mmHg. These results suggest that this technique is of potential use for cuffless and continuous blood pressure monitoring and it has promising application in home healthcare services.

Continuous Blood Pressure Measurement From Invasive to Unobtrusive: Celebration of 200th Birth Anniversary of Carl Ludwig

“…To the best of our knowledge, the earliest platform considered for unobtrusive application was integration in a T-shirt with ECG electrodes at the wrists [22]. Other unobtrusive or mobile system can be mounted on wrists as wearable watches [20], upper arms [73], or ears [74]; attached to the chest as a patch [75] or a band [47]; and implemented through mobile phones [76,77] or weighing scales [19]. In particular, the BP watch would be one of the most popular platforms to implement the unobtrusive system.…”

Blood Pressure Estimation Using Photoplethysmography Only: Comparison between Different Machine Learning Approaches

“…The SVM algorithm has been used to estimate cuffless BP using heart sound signals, where acceptable BP measurement accuracy was achieved [ 33 ]. Similarly, in our study, the SVM algorithm was applied to PPG signal features to estimate cuffless BP.…”

Changes in Amplitude Characteristics of Heart Sound Signals during External:cuff:inflation Procedure: A Pilot Study

“…An existing study reported that amplitude of S2 from hypertensive patients was higher than that from normotensive [2]. Increased BP also led to an increase in frequency of S2 [3], [4]. The relation between S2 and the arterial BPs from both systemic and pulmonary circulations has been confirmed in [5], [6], [7].…”