Ariane Garrett Paves the Way for More Accurate Blood Pressure Monitoring
By Gwyn Moe
Ariane Garrett is no stranger to innovation. As a Biomedical Engineering PhD student in Professor Darren Robyler’s lab, she’s changing the game for medical professionals with her work on a new device that measures blood pressure with more frequency and precision than currently available technology.
Garrett has always had a love for science. Her mother is a professor of biochemistry at Vassar College, so you could say it runs in the family. After graduating high school, she studied biomedical engineering (BME) at the University of Connecticut. She chose BME because the field combined her love of math and science with her desire to do something good for the world. It turns out she chose correctly, coming to love the field more than she could have ever imagined, and went on to pursue her doctorate in the same subject at Boston University.
“I started my PhD in 2020. So, I moved here very much in the thick of Covid, and a lot of things were remote. Moving to a new city and then also having Covid happening at the same time was definitely a difficult transition,” says Garrett. But, after the rocky start, everything clicked into place once she began her research. “It’s been a great experience,” says Garrett. “I sometimes talk to people considering PhDs and they’re like, ‘oh my God, I hear it’s terrible,’ And I’m like, ‘no, it can be a really good and satisfying.’”
During her first year at BU, Garrett circled through three lab rotations before ultimately deciding to join Darren Roblyer’s lab, which works to develop a suite of optical technologies to study tissue structure and function. They specialize in the development of optical technologies to study cancer and cardiovascular disease.
“I was pretty conflicted about which lab to choose,” Garrett explains. “I also rotated in Xin Zhang’s and Michelle Sander’s labs. But they did more microscopy work, microscopy and spectroscopy. While Darren’s lab is more diffuse optics, a little bit more translational. I just really liked the vibe of his lab, and so I ended up choosing that program in [the] spring of 2021.”
Soon after joining Robyler’s lab, Garrett became one of the first PhD students to work with Roblyer’s blood pressure monitoring project.
Check out this BU Short on the Roblyer Lab’s related research efforts!
“The project came about from a collaboration with Darren [Roblyer] and David Boas,” explains Garrett. “David had been working with Meta and they had a sponsored research agreement where they wanted to look into using speckle imaging for blood pressure.”
When thinking of blood pressure monitoring, a doctor’s cuff kit probably comes to mind, wrapping around your arm and inflating to stop the flow of blood in your artery. However, despite this being the most common and widely used way to measure someone’s blood pressure, research has revealed that these single-time measurements are not representative of a patient’s blood pressure in their daily life. To acquire more accurate readings, it is required to take measurements more frequently.
“There’s a few issues [with current blood pressure technology], one is that they’re kind of bulky, so it’s hard to wear that entire cuff around all day. And, when it goes off, it’s disruptive to your daily life. That makes it difficult to acquire blood pressure measurements outside of the clinical setting,” Garrett explains.
To tackle this problem, Garrett is working on a way to measure blood pressure without the cuff. Her work focuses on the development of a new measurement technique, known as Speckle Contrast Optical Spectroscopy––or SCOS. This new technique uses long-coherence laser illumination, at wavelengths sensitive to both red blood cell scattering and hemoglobin absorption, to measure changes in blood flow and volume from speckle images.
The speckle images are collected at high framerates (390 Hz), which Garrett describes “enabl[es] the measurement of relative changes in blood flow and volume within each cardiac pulse.” Because changes in blood flow and volume are directly related to changes in blood pressure, features of the waveforms from those measurements can be input into a machine learning model that can estimate blood pressure.
This process enables Garrett and her team to measure blood pressure without the need for a pressurized arm cuff. Instead, Garret explains, “the measurements are taken on the wrist and the finger using optical fibers. In addition, we can obtain a blood pressure measurement much more frequently than a cuff-based device.”
But her work won’t stop after graduation. As she finishes her PHD program this spring, Garrett is starting a company with professor David Boas and her advisor Darren Robyler, called Rivus Optics.
“For the first phases of working at Rivus Optics, we’ll start developing the wearable version of SCOS here at Boston University.” Which, Garrett explains, is part of what’s so great about receiving funding from the National Institutes of Health’s (NIH) Small Business Technology Transfer (STTR). “It encourages collaboration between the academic institution and the company. So we will continue to use BU’s resources to work on the device.”
While working at BU they will also continue to seek future funding opportunities from grants or private capital, but that process has recently become daunting.
With the current political climate in the United States, researchers like Garrett have concerns about the future of funding. Over both terms, the Trump administration has repeatedly expressed its intention to cut NIH funding, and on February 7 of this year, the NIH announced a new policy that will limit indirect funding for laboratories receiving federal research grants to 15%. If the policy is allowed to continue grantee institutions would stand to lose billions of dollars each year. These cuts would force universities and research institutes to fund the remainder of costs, and many simply can’t. The policy has been blocked so far, but the future remains uncertain.
Many new companies, including Rivus Optics, rely on grants from NIH to get them started. These grants give researchers non-dilutive funding, which helps companies spin out from the academic setting. With this uncertainty, many labs are having to pose some difficult questions: how do we tighten our budgets? Can we still hire new students? What will the next couple of years look like?
“There is a general sentiment of fear right now about grants not getting funded and funding being cut for grants that already exist,” said Garrett. Despite these concerns, Garrett is excited about the future and the impact her SCOS technology will have. “More than 100 million adults in the US alone have hypertension, and the current methods for diagnosing and managing hypertension are not sufficient,” says Garrett. “An accurate, wearable BP monitor has the potential to greatly improve cardiovascular disease management and prevent suffering for millions of people.”