New Wearable Shunt Monitor Offers New Hope to Hydrocephalus Patients

A majority of people reach for ibuprofen only when they get a headache, but for someone with hydrocephalus, that is not the case.

Hydrocephalus is known as a potentially life-threatening condition, wherein excess amounts of fluid accumulate in the brain region—a headache can suggest a serious issue that can lead to a hospital visit and cost thousands of dollars in radiation, scans, and at times, even surgery.

Northwestern University has now developed a novel wireless, band-aid-like sensor that could transform the way patients manage hydrocephalus and possibly save millions of dollars for the U.S. health care system.

The device, called a wearable shunt monitor, was successfully tested on five adult patients suffering from hydrocephalus by a Northwestern Medicine clinical study. The results of the study will be reported in Science Translational Medicine.

Hydrocephalus can impact both children and adults. The child is usually born with this condition, while in adults, it can be manifested by specific trauma-related injury, for example, a brain tumor or bleeding inside the brain.

In the present standard of care, a straw-like catheter called a “shunt” is surgically implanted that drains the excess amounts of fluid from the brain and directs it to another part of the body.

Since shunts have an almost 100% failure rate for more than 10 years, it is very difficult to diagnose their failure. In fact, over a million Americans are living with shunts along with the constant risk of failure.

The next-generation sensor, devised by the Rogers Research Group at Northwestern, can potentially create significant savings and enhance the quality of life for almost one million people in the United States alone.

Impact

Failure of the shunt will cause the patient to experience nausea, headaches, and low energy. If any of these symptoms are experienced by patients, they should visit a hospital immediately because if these symptoms are induced by a malfunctioning shunt, then this could endanger their life. Once the patients are at the hospital, they must get either an MRI or a CT scan and sometimes have to undergo surgery to see if the shunt is functioning properly or not.

During the clinical study, when the innovative sensor was placed on the patients’ skin, it enabled them to establish within five minutes whether the fluid was flowing through their shunt. Using measurements of temperature and heat transfer, the soft, flexible sensor non-invasively informs if and how much fluid is flowing through the shunt.

“We envision you could do this while you’re sitting in the waiting room waiting to see the doctor,” stated Siddharth Krishnan, co-lead author and a fifth-year PhD student in the Rogers Research Group. “A nurse could come and place it on you and five minutes later, you have a measurement.”

A device such as this would change the life of Willie Meyer, 26, who has spent almost all holidays in the emergency room, undergone 190 surgeries, and nearly missed his high-school graduation due to emergency brain surgeries.

I’m trying to live a normal life, and I really can’t because of the headaches.

Willie Meyer, Hydrocephalus Patient

Beth, Meyer’s mother, stated that she came to know about Willie’s condition when he was just two years old and complained that “his hair hurt.”

Fatigue and headaches are symptoms of a malfunctioning shunt that are analogous to symptoms of other illnesses, which lead to stress and confusion for caregivers.

“Every time your kid says they have a headache or feels a little sleepy, you automatically think, ‘Is this the shunt?’” stated Dr. Matthew Potts, co-senior author and assistant professor of neurological surgery at Northwestern University Feinberg School of Medicine and a Northwestern Medicine physician. “We believe that this device can spare patients a lot of the danger and costs of this process.”

According to co-lead author Dr Amit Ayer, who was responsible for treating Willie’s hydrocephalus over the last four years, his patients are the reason behind his motivation to get the novel device to market.

“Our patients want to know when they can actually use the device and be part of the trial,” stated Ayer, who is a neurosurgery resident at Northwestern Medicine and a student at Kellogg School of Management at Northwestern. “I want to get it out there, so we can help make their lives better.”

How it works

“It looks like a Band-Aid that’s talking to a cellphone. There’s nothing like this out there today.”

John A. Rogers, Louis Simpson and Kimberly Querrey Professor of Materials Science and Engineering, Biomedical Engineering and Neurological Surgery

The sensor is integrated with a tiny rechargeable battery. This Bluetooth-enabled device can talk to a smartphone and send the readings through an Android app. The new sensor improves concepts in skin-like “epidermal electronics,” which the Rogers Research Group has been studying for almost 10 years

It utilizes a thermal transport measurement, meaning that the sensor actually employs very small amounts of thermal power to slightly increase the skin’s temperature.

The sensor will be able to measure a characteristic heat signature if the shunt is functioning and the surplus cerebral spinal fluid is draining correctly. In a similar way, if the fluid does not flow because of the malfunctioning of the shunt, the sensor will rapidly indicate that via heat flow measurements.

After testing the device in the laboratory, the researchers eventually headed to the clinic to carry out a pilot study on five hydrocephalus patients at Northwestern Memorial Hospital. They were able to identify distinct variations in cases between measurements over operating shunts and on adjoining confusing control locations without flow.

“This means if someone wants to check if their shunt is working, say, when they have a headache, they can quickly do what we call a ‘spot measurement,’” stated Dr Tyler Ray, co-lead author and a postdoctoral research fellow in the Rogers Research Group. “This device can also measure flow throughout the day enabling, for the first time, the possibility of continuously monitoring shunt performance. This can lead to important insights into the dynamics of cerebral spinal fluid flow previously inaccessible with current diagnostic tools and flow measurement techniques.”

In this context, a larger pediatric clinical trial will be shortly started at Ann & Robert H. Lurie Children’s Hospital of Chicago with an aim to target this extremely vulnerable group. To support this study and further improve the technology, the study authors are also examining outsourced production on the scale of several hundred sensors.

The research was supported by the Center for Bio-Integrated Electronics, with small additional funding via the Dixon Translational Grant at Feinberg.