# Non-invasive measurements of central blood pressures by RF sensors

> **NIH NIH R21** · CORNELL UNIVERSITY · 2024 · $118,371

## Abstract

Project Summary/Abstract
Arterial blood pressure (BP) and pulmonary arterial pressure (PAP) are fundamental for diagnosis and
management of both systemic and pulmonary hypertension and for monitoring of surgical and critically ill
patients. Systemic hypertension is the most common modifiable risk factor for cardiovascular disease and the
leading contributor to mortality and disability in the world. Pulmonary hypertension is a group of pulmonary
vascular disorders leading to increased PAP, right ventricular failure, and death. It is also common in the
intensive care unit. Diagnosis of pulmonary hypertension remains challenging.
Arterial BP is most commonly monitored with the non-invasive cuff-based sphygmomanometer, which only
outputs brachial systolic and diastolic BP, differs from the critical central BP, and is prone to errors in the
presence of arrhythmias. Instead of providing a continuous measurement, its BP values are averaged over many
pulses. Invasive catheterization allows for direct arterial BP monitoring, but the technique is not risk-free.
Noninvasive estimates of PAP from echocardiography, computed tomography (CT) scan and magnetic
resonance imaging (MRI), although useful, remain variable and operator-dependent. Therefore, right heart
catheterization is still the gold-standard diagnosis for PAP and pulmonary hypertension, despite being highly
invasive. Monitoring of PAP at home or primary care is currently unfeasible.
The overarching aim of this proposal is to evaluate whether a non-invasive radio-frequency (RF) sensor can
retrieve central BP and PAP transients accurately and non-invasively. We hypothesize that the near-field
coherent sensing (NCS) by RF carriers, which has been benchmarked on heartbeat and respiration
waveforms with the gold-standard devices, can also be applied to derive central BP from the vibration
characteristics of the aorta and pulmonary arteries in the entire cardiac cycle. The principle of operation
is similar to that of the ground penetrating radar and air-puff tonometry, where Hilbert-Huang Transforms and
machine learning can be adapted for BP signal processing.
Our effort will start from building a phantom heart model, which will allow direct pumping control and host the
NCS and catheter-based pressure sensors. We will also explore the multiple-input-multiple-output (MIMO) NCS
to improve the local mapping of vibration characteristics. We will use anesthetized pigs as animal models for
aortic BP and PAP studies, where similar sensors from the phantom will be deployed. The accuracy of the
sensors and their ability to track changes in relation to the gold-standard pressure catheters will be benchmarked.
Aortic BP studies will be modified by infusion of inotropes and vasopressors, while PAP by acutely changing the
fraction of inspired oxygen (FiO2) and by inducing surfactant depletion followed by lung recruitment. Additionally,
electrocardiogram (ECG) and photo-plethysmography (PPG) will be synchronized on th...

## Key facts

- **NIH application ID:** 10896368
- **Project number:** 5R21EB034562-02
- **Recipient organization:** CORNELL UNIVERSITY
- **Principal Investigator:** Joaquin Araos
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $118,371
- **Award type:** 5
- **Project period:** 2023-08-01 → 2025-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10896368

## Citation

> US National Institutes of Health, RePORTER application 10896368, Non-invasive measurements of central blood pressures by RF sensors (5R21EB034562-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10896368. Licensed CC0.

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