Smart Cuff: A single device to measure multiple cardiac functions

Surgical and intensive care patients face a higher risk of death and longer hospital stays because they are susceptible to both hypotension and hemodynamic instability – or unstable blood flow.

These potential complications require round-the-clock monitoring of several cardiac functions by nurses and physicians, but there's currently no singular, convenient device on the market that can measure the most vital aspects of a patient's cardiovascular health.

Ramakrishna Mukkamala, professor of bioengineering at the University of Pittsburgh Swanson School of Engineering, and Aman Mahajan, Safar Professor and Chair of Anesthesiology and Perioperative Medicine with a secondary appointment in bioengineering at Pitt, received a $2,707,906 grant from the National Institutes of Health to develop "Smart Cuff" – a multifunction device that can reliably monitor blood pressure, cardiac output, and ventricular ejection fraction on its own.

Several hemodynamic monitoring devices are currently available, but they are invasive, manual or nonstandard. None have been widely adopted. Smart Cuff, which is worn on a patient's arm just like a typical blood pressure cuff in critical care, can eliminate all these hurdles and allow for more efficient patient care."

Ramakrishna Mukkamala, professor of bioengineering, University of Pittsburgh Swanson School of Engineering

One device smart enough for three

When blood pressure is measured, a cuff is placed around the patient's arm and then is inflated until no blood can flow through the brachial artery. Air is then slowly released from the cuff, creating a waveform – a key aspect of the Smart Cuff.

Only blood pressure is calculated from the waveform. Physiology-inspired machine learning and innovative cuff inflation-deflation patterns can enable Smart Cuff to compute cardiac output and other important variables like pulse pressure variations and left ventricular ejection fraction, or rather how well oxygen-rich blood is being pumped out of the heart throughout the body.

"Blood pressure is vital for monitoring hypotension and other potential risks to patients, but cardiac output and left ventricular ejection fraction are needed to determine treatment," Mukkamala said. "Our goal here is to improve a patient's cardiovascular outcomes and simplify evaluation tools for medical professionals."

Joining Mukkamala and Mahajan:

• Kathirvel Subramanian, professor of anesthesiology and perioperative at Pitt and director of perioperative echocardiology at UPMC
• Sanjeev Shroff, professor bioengineering and interim dean of engineering at Pitt
• Michael Pinksy, professor of critical care medicine and bioengineering at Pitt
• Jin-Oh Hahn, associate professor of mechanical engineering at the University of Maryland
• Tanya Kenkre, senior statistician at Pitt's Epidemiology Data Center

The four-year project, "Smart Cuff: Multi-Parameter Hemodynamic Monitoring via Single Convenient Device," began in March 2023. The work is being funded through the competitive funding opportunity titled NIH Research Project Grant (R01).