The Relationship between Pulse Transit Time and Systolic Blood Pressure on Individual Subjects after Exercises

Continuous monitoring of blood pressure (BP) is always important to critically ill patients and to the patients who undergo major vascular and intracavitary surgeries. Pulse transit time (PTT) is one of the potential parameters which can be utilized for non-invasive and continuous monitoring of BP. PTTp and PTTf are the time intervals measured from the R-wave of electrocardiographic signal to the peak and the foot of photoplethysmographic signal respectively. In this study, the relationship between systolic blood pressure (SBP) and PTTs on 12 healthy subjects, aged 25plusmn2 years, was investigated after exercises. Results showed that SBP was correlated with PTTp and PTTf wherein the means of individual correlation were r=-0.77 and r=-0.92 respectively. The means of the standard deviation of the difference between the measured SBP and the SBP predicted from regression lines in scatter plots of SBP~PTTp and SBP~PTTf were 6.6 mmHg and 4.3 mmHg respectively. In summary, the results supported that PTTf was a potential parameter which could be implemented in a personalized wearable device for continuous SBP monitoring at home