Hypertension is a major cardiovascular risk factor that is treatable, but undetected or uncontrolled, in many people in the US and India. Unobtrusive and affordable blood pressure (BP) monitoring technology could improve hypertension detection and control, especially in low resource settings. A potential approach for realizing such technology is pulse transit time (PTT). Indeed, PTT correlates with diastolic BP, as evidenced by many studies, and can be estimated simply from the relative timing between proximal and distal arterial waveforms. But, challenges remain in conveniently measuring the two waveforms, accurately estimating PTT, calibrating PTT to BP, and determining systolic BP from PTT. The overall objective is to overcome these challenges and thereby establish technologies for unobtrusive, affordable, and high throughput or individualized BP monitoring via PTT.
The specific aims are: (1) to develop inexpensive systems for convenient and accurate contact measurement of proximal and distal arterial waveforms;(2) to develop low cost systems for noncontact measurement of proximal and distal arterial waveforms;(3) to develop methods for estimation of PTT with high accuracy and at both systole and diastole;(4) to develop systems for accurate and convenient calibration of PTT to BP;and (5) to validate the systems and methods against reference BP measurements from humans. Ballistocardiograph (BCG)-based systems in the form of a weighing scale, chair, and shoe will be built and interfaced with photoplethysmograph (PPG) sensors for seamless measurement of the proximal (BCG) and distal (PPG) waveforms. Video processing systems in the form of a webcam and surveillance camera will be created to obtain non-contact PPG waveforms from the face (proximal) and hand (distal) of still and less cooperative people. Arterial modeling methods will be devised to estimate PTT accurately from the entire waveforms, rather than via the conventional foot-to-foot time delay, and at both systole and diastole. Physical oscillometric modeling methods will be designed and combined with arterial modeling methods to construct an accurate, subject-specific calibration curve using a cuff but without involving an operator, and regression methods will be created to form the calibration curve without using a cuff from only basic subject information (e.g., age). Data will be collected from healthy volunteers and hypertensive outpatients with auscultation used for reference BP values and some hypertensive patients in the ICU with unstable BP and catheters in place for gold standard reference BP values. The systems and methods will be tested in various ways including BP error and high BP detection. Finally, the technology will be optimized for cost and integrated to smartphones for ease of operation. Successful completion of this project could ultimately help reduce mortality and morbidity in the US and India.

Public Health Relevance

Hypertension is a major cardiovascular risk factor that is treatable, but often undetected or uncontrolled, especially in low resource settings. Ultra-convenient and cheap blood pressure monitoring technologies will be established to markedly improve hypertension detection and control.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project--Cooperative Agreements (U01)
Project #
1U01EB018818-01
Application #
8745161
Study Section
Special Emphasis Panel (ZEB1-OSR-F (M1))
Program Officer
Pai, Vinay Manjunath
Project Start
2014-08-01
Project End
2019-07-31
Budget Start
2014-08-01
Budget End
2015-07-31
Support Year
1
Fiscal Year
2014
Total Cost
$676,397
Indirect Cost
$99,124
Name
Michigan State University
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
193247145
City
East Lansing
State
MI
Country
United States
Zip Code
48824
Moslehpour, Mohsen; Kawada, Toru; Sunagawa, Kenji et al. (2016) Nonlinear identification of the total baroreflex arc: chronic hypertension model. Am J Physiol Regul Integr Comp Physiol 310:R819-27
Martin, Stephanie L-O; Carek, Andrew M; Kim, Chang-Sei et al. (2016) Weighing Scale-Based Pulse Transit Time is a Superior Marker of Blood Pressure than Conventional Pulse Arrival Time. Sci Rep 6:39273
Gao, Mingwu; Olivier, N Bari; Mukkamala, Ramakrishna (2016) Comparison of noninvasive pulse transit time estimates as markers of blood pressure using invasive pulse transit time measurements as a reference. Physiol Rep 4:
Kim, Chang-Sei; Ober, Stephanie L; McMurtry, M Sean et al. (2016) Ballistocardiogram: Mechanism and Potential for Unobtrusive Cardiovascular Health Monitoring. Sci Rep 6:31297
Wiens, Andrew D; Inan, Omer T (2015) Accelerometer body sensor network improves systolic time interval assessment with wearable ballistocardiography. Conf Proc IEEE Eng Med Biol Soc 2015:1833-6
Moslehpour, Mohsen; Kawada, Toru; Sunagawa, Kenji et al. (2015) Nonlinear identification of the total baroreflex arc. Am J Physiol Regul Integr Comp Physiol 309:R1479-89
Javaid, Abdul Qadir; Wiens, Andrew D; Fesmire, Nathaniel Forrest et al. (2015) Quantifying and Reducing Posture-Dependent Distortion in Ballistocardiogram Measurements. IEEE J Biomed Health Inform 19:1549-56
Wiens, Andrew D; Inan, Omer T (2015) A novel system identification technique for improved wearable hemodynamics assessment. IEEE Trans Biomed Eng 62:1345-54
Kim, Chang-Sei; Carek, Andrew M; Mukkamala, Ramakrishna et al. (2015) Ballistocardiogram as Proximal Timing Reference for Pulse Transit Time Measurement: Potential for Cuffless Blood Pressure Monitoring. IEEE Trans Biomed Eng 62:2657-64
Mukkamala, Ramakrishna; Hahn, Jin-Oh; Inan, Omer T et al. (2015) Toward Ubiquitous Blood Pressure Monitoring via Pulse Transit Time: Theory and Practice. IEEE Trans Biomed Eng 62:1879-901

Showing the most recent 10 out of 11 publications