Using Diagnostic Innovation to Measure What Matters 

Creative Ventures invested in Rhaeos’ Series Seed round in July 2021. Rhaeos is a clinical-stage medical device company developing wearable, wireless diagnostic solutions to monitor fluid flow peripherally throughout the body. Its first device, FlowSense*, is designed to assess cerebrospinal fluid in shunts of hydrocephalus patients in the hospital and home.

Fearing the unknown

Imagine living alongside the constant fear that mild and non-specific symptoms like a headache are warning signs of a life-threatening event. In the midst of an ongoing global pandemic, it’s easier than ever to step into these shoes with COVID-19 symptoms being easily mistaken for those of the flu, common cold, or allergies.

Ambiguity often begets vivid anxieties of the worst-case scenario. After all, we’re only human. 

But unlike those with COVID-19, we’re asking you to imagine feeling this way with a life-long disease—one that has no cure, only a mitigation procedure that is bound to fail.

This is the reality of people living with hydrocephalus. 

What is hydrocephalus?

Hydrocephalus is a condition where excess fluid is accumulated in the brain, giving it the nickname “water on the brain.” If left untreated, hydrocephalus is a life-threatening disease, and while can be acquired in patients’ adult years, it’s mostly seen in children who are born with the condition.

Currently, the only treatment for hydrocephalus is to place a shunt in order to drain the excess fluid. Patients rely on these shunts for the rest of their lives but shunts are bound to fail. The failure rate is as high as 50% just 18 months after the placement.

And as mentioned earlier, the symptoms of shunt failure are non-specific; headaches, dizziness, and nausea. So even though shunt malfunction is only responsible for a single-digit percentage of hydrocephalus mortality, it’s substantial enough to require ongoing management and visits to the emergency room when symptoms arise. 

Measuring what matters

Similar to how the importance of units is drilled in for those in science and engineering, it’s intuitive to measure parameters relevant to the function in question as feasible.

Current standard hydrocephalus diagnostic tools for the shunts’ functions are imaging (ultrasound, CT, MRI, X-ray), along with physical exams. However, they do not translate to a direct quantitative read of the most relevant function: the flow rate. For example, from the image, things like swollen tissues may be detected as a result of shunt failure. The combination of a qualitative read and an implied correlation may, in part, explain the rather large range of sensitivity, meaning that on the lower end (~50% sensitivity), there’s a ~1:1 chance of a false negative readout; that patients with non-functional shunts may be discharged without appropriate intervention.

So, if achievable, a quantitative read of the actual flow rate should increase the accuracy of the shunt failure diagnosis. If what needs to be known is whether the shunt is still sufficiently draining the brain excess fluid, why go the roundabout way?

Chronic disease and emergency: an opportunity for a novel diagnostic method

The National Institution of Health (NIH) estimated that about half of shunt surgeries are considered “life-and-death” emergencies. The estimation coincides with a historical breakdown of the hydrocephalus admissions published by Patwardhan and Nanda: 22% urgent, 33% emergent, and 43% elective.

The procedure’s time-sensitive nature, coupled with non-specific symptoms and life-threatening worst-case scenarios, calls for an accurate, rapid, simple, cost-effective, and determinative test. 

Despite exhibiting a large range of sensitivity, imaging is a standard diagnostic approach today. Even then, it is not always available, especially in hospitals or healthcare facilities located in sparsely populated areas. Globally, the situation is even direr; up to two-thirds of the world population lacks adequate access to imaging diagnosis.

With pressure on all sides—timing, accessibility, sensitivity, and a potentially severe outcome—there’s a clear market-pull opportunity for a point-of-care diagnosis for hydrocephalus patients. There’s a gap in hydrocephalus diagnosis that remains to be filled, whether in clinics, in-patient settings, or emergency departments. 

Beyond the in-hospital setting

Intuitively, it would be a relief to get a determinative readout without having to rush into a hospital every time a hydrocephalus patient has a headache and feels nauseous. 

As Anna Lisa Somera, CEO of Rhaeos, stated in her interview with Medgadget in 2020, this is all part of the company’s plan:

“In our next-generation device, which we’ve recently begun to develop with a strategic partner, patients will be able to use the device at home – much like many of us use wearable fitness trackers – to not only assess flow at a given time but also to predict a shunt failure before it sends them to the emergency room.”

There are certainly a few overlapping elements between hydrocephalus at-home use vision and our view on remote patient monitoring investments. The urgency to adopt is prominent, as echoed by many hydrocephalus patients and their caretakers.

From in-hospital to at-home uses, we’re excited to back Rhaeos’ amazing team. Not only did they win the world’s biggest medical device competition last year, MedTech Innovator, ranking #1 out of >1000 companies, but they hit numerous value inflection milestones with approved reimbursement codes, published clinical data in Science and Nature family journals, and more. With their unique noninvasive thermal flow sensor technology that has been designated as a breakthrough device by the FDA, Rhaeos has great potential to transform subdermal flow diagnosis, starting with hydrocephalus patients. Most recently, Rhaeos was awarded a $4 million, multi-year grant from the NIH SBIR program. If any of our readers would like to learn more, feel free to reach out.

* Investigational use only. Products have not been approved by the FDA.

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