Cuffless blood pressure estimation using only a smartphone

Area of Science:

• Biomedical Engineering
• Cardiovascular Technology
• Mobile Health

Background:

• Cuffless blood pressure (BP) measurement aims to monitor BP without traditional cuffs.
• Existing cuffless methods often require ECG, photoplethysmogram, and frequent calibration.
• There is a need for simpler, more accessible BP monitoring solutions.

Purpose of the Study:

• To develop a simplified cuffless BP measurement method using only smartphone-based data.
• To validate the accuracy of the proposed method for estimating mean arterial pressure (MAP), systolic BP (SBP), and diastolic BP (DBP).

Main Methods:

• Developed a novel cuffless BP estimation technique utilizing heart rate (HR) and modified normalized pulse volume (mNPV).
• Leveraged the relationship between BP, cardiac output (CO), and total peripheral resistance (TPR): ln BP = ln CO + ln TPR.
• Employed an exponential transformation of a linear polynomial equation: (a × ln HR) + (b × ln mNPV) + constant.

Main Results:

• Achieved estimation accuracy of R > 0.70 for MAP, SBP, and DBP using only smartphone measurements.
• Demonstrated that HR correlates with CO and mNPV correlates with TPR.
• Validated the feasibility of the simplified cuffless BP monitoring approach.

Conclusions:

• A simple, cuffless BP measurement method using smartphone-derived HR and mNPV has been developed.
• This technology has the potential to transform smartphones and smartwatches into simplified sphygmomanometers.
• The findings suggest a future of more accessible and widespread BP monitoring.