Research DRIVEs Toward New Vital Signs in Patient Monitoring

Many acute and chronic medical and surgical conditions require health care providers to make accurate assessments of a patient's circulating blood volume. However, the current standards of care for determining volume status are not always accurate and can put the patient at risk.

In their search to define the “new normal” of critical care patient monitoring, MCIRCC Members Hakam Tiba, MDKevin Ward, MDAlbert Shih, PhD, and Barry Belmont, MS have developed a new vital sign measurement that accurately assesses a patient’s circulating blood volume using non-invasive technology.

They call this innovation Dynamic Respiratory Impedance Volume Evaluation, a.k.a. DRIVE, which is based on the dynamic relationship between venous return, the function of the right ventricle, and its interaction with lung mechanics as key determinants of estimating intravascular volume status. “Essentially, we have found a correlation between a patient’s ultrasound measures of the inferior vena cava diameter and our DRIVE bioimpedance measurements taken from the surface of a patient’s arm,” stated Dr. Tiba.

The DRIVE technology, research initiated by MCIRCC, was tested in emergency department patients and control patients using off-the-shelf commercially available components, thanks to support from the MTRAC program. With promising test results, the team was able to garner additional funding from a global healthcare company. As a result, the device is currently being tested in critically ill and injured patients undergoing volume resuscitation or volume removal in the intensive care unit.

U-M and this industry sponsor are now in the process of exploring technology licensing following a recent on-site DRIVE demonstration. During the visit, a test patient being monitored with the DRIVE technology began to experience a drop in blood pressure, triggering clinicians to respond by administering fluids. Afterwards, the team analyzed the data and found a strong correlation between the DRIVE data and the ultrasound data indicating that the patient would benefit from additional fluids.

“This patient event, although unanticipated, demonstrated DRIVE’s impact value,” stated Dr. Tiba, “that the science behind the technology works in the real world, on real patients.”

The team is also developing a small wearable prototype with wireless capabilities dedicated to the DRIVE vital sign. This device will provide continuous, easily interpreted information useful for many levels of intravascular volume management care, from the hospital to the home.  The technology also allows for precise respiratory rate monitoring including the ability to detect apnea.

This new vital sign technology could transform critical care for trauma, heart failure, sepsis, burns and resuscitation by personalizing the diagnosis and treatment plan for volume and fluid management of the individual patient—in other words, allowing us to treat the person versus the disease.