BioWatch: A Noninvasive Wrist-Based Blood Pressure Monitor That Incorporates Training Techniques for Posture and Subject Variability
Open Access
- 20 July 2015
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Journal of Biomedical and Health Informatics
- Vol. 20 (5), 1291-1300
- https://doi.org/10.1109/jbhi.2015.2458779
Abstract
Noninvasive continuous blood pressure (BP) monitoring is not yet practically available for daily use. Challenges include making the system easily wearable, reducing noise level and improving accuracy. Variations in each person's physical characteristics, as well as the possibility of different postures, increase the complexity of continuous BP monitoring, especially outside the hospital. This study attempts to provide an easily wearable solution and proposes training to specific posture and individual for further improving accuracy. The wrist watch-based system we developed can measure electrocardiogram and photoplethysmogram. From these two signals, we measure pulse transit time through which we can obtain systolic and diastolic blood pressure through regression techniques. In this study, we investigate various functions to perform the training to obtain blood pressure. We validate measurements on different postures and subjects, and show the value of training the device to each posture and each subject. We observed that the average RMSE between the measured actual systolic BP and calculated systolic BP is between 7.83 to 9.37 mmHg across 11 subjects. The corresponding range of error for diastolic BP is 5.77 to 6.90 mmHg. The system can also automatically detect the arm position of the user using an accelerometer with an average accuracy of 98%, to make sure that the sensor is kept at the proper height. This system, called BioWatch, can potentially be a unified solution for heart rate, SPO2 and continuous BP monitoring.Funding Information
- National Science Foundation (CNS-1150079)
- Semiconductor Research Corporation
- Texas Analog Center of Excellence
This publication has 27 references indexed in Scilit:
- Characters available in photoplethysmogram for blood pressure estimation: beyond the pulse transit timeAustralasian Physics & Engineering Sciences in Medicine, 2014
- Cuffless and Non-Invasive Estimation of a Continuous Blood Pressure Based on PTTPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2010
- A protocol design for evaluation of wearable cuff-less blood pressure measuring devices2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2009
- Continuous blood pressure monitoring during exercise using pulse wave transit time measurement2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2007
- A Correlation Study on the Variabilities in Pulse Transit Time, Blood Pressure, and Heart Rate Recorded Simultaneously from Healthy Subjects2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2005
- Descriptive Epidemiology of Blood Pressure Response to Change in Body PositionHypertension, 1999
- Effects of psychological and physiological challenges on heart rate, T-wave amplitude, and pulse-transit timeInternational Journal of Psychophysiology, 1996
- Posture, Place, and Mood Effects on Ambulatory Blood PressurePsychophysiology, 1990
- Effect of posture on blood pressure in the elderly.Heart, 1973
- The valsalva maneuver as a test of cardiac function: Pathologic physiology and clinical significanceThe American Journal of Medicine, 1957