# A Smartphone-Based Device for Cuff-Less and Calibration-Free Blood Pressure Monitoring

> **NIH NIH R01** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2022 · $338,832

## Abstract

PROJECT SUMMARY/ABSTRACT
High blood pressure (BP) is a major cardiovascular risk factor that is treatable, yet hypertension
awareness and control rates are low. Ubiquitous BP monitoring technology could improve
hypertension management, but existing devices require an inflatable cuff and thus do not afford
anytime, anywhere measurement of BP. The broad goal of this project is to extend the oscillometric
principle, which is applied by most automatic cuff devices, for cuff-less and calibration-free monitoring
of BP via only a smartphone. The idea is for the user to serve as the actuator (instead of the cuff) by
pressing her fingertip against the phone to steadily increase the external pressure of the underlying
artery, while the phone serves as the sensor (rather than the cuff) by measuring the applied pressure
and resulting variable-amplitude blood volume oscillations. The phone also provides visual feedback
to guide the finger actuation and applies an algorithm to compute BP from the measurements just like
a cuff. A smartphone-based device for BP monitoring via this oscillometric finger pressing method
will be established. The specific aims are: (1) to develop an advanced sensor-unit to robustly
measure the finger blood volume and applied finger pressure; (2) to develop an advanced algorithm
to accurately compute BP from the measurements in a diverse user population; and (3) to validate the
integrated device according to a widely accepted protocol. An initial device will be developed to
acquire a comprehensive set of potentially useful measurements including the pulsatile component of
the finger pressure arising from the tonometric principle. This device will consist of a multi-
photoplethysmography sensor array to identify the location of the finger artery and measure the blood
volume oscillations from therein and a multi-force sensor array to measure the area of force
application. The advanced sensor-unit will mitigate the impact of imprecise finger positioning. A
training dataset will be collected with this device and cuff-based devices in a diverse user population.
This dataset will be analyzed to develop an algorithm to accurately compute BP. The algorithm will
include leveraging the smartphone camera and image processing to obtain the BP measurement at
heart level and computing finger and brachial systolic, diastolic, and mean BP based on various
physiologic models of the measurements. A final smartphone-based device will be built that
incorporates the requisite sensing and algorithm. The device will be prospectively tested according to
the standard Association for the Advancement of Medical Instrumentation protocol for automatic cuff
devices. This protocol includes 85 subjects encompassing a wide BP range with auscultation cuff BP
as the reference. Successful completion of this project could ultimately translate to widespread BP
monitoring and thereby help reduce the incidence of cardiovascular mortality.

## Key facts

- **NIH application ID:** 10145065
- **Project number:** 5R01HL146470-04
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** RAMAKRISHNA MUKKAMALA
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $338,832
- **Award type:** 5
- **Project period:** 2019-05-15 → 2025-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10145065

## Citation

> US National Institutes of Health, RePORTER application 10145065, A Smartphone-Based Device for Cuff-Less and Calibration-Free Blood Pressure Monitoring (5R01HL146470-04). Retrieved via AI Analytics 2026-06-11 from https://api.ai-analytics.org/grant/nih/10145065. Licensed CC0.

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