Last year, a group of biomedical engineering students at Colorado State University shadowed health care workers at UCHealth’s Medical Center of the Rockies (MCR) and Poudre Valley Hospital. The experience was part of CSU’s Clinical Immersion Program, a partnership with MCR and the University of Colorado Health Clinical Education and Innovation Center that aims to give young bioengineers a closeup look at the medical world that might one day use devices they design.

That environment is often portrayed as a hotbed of innovation and cutting-edge technology. But during a ride-along on a UCHealth ambulance, a student in the Clinical Immersion Program noticed something odd and distinctly old school: a roll of tape that revealed brightly colored sections when it was unfurled.

The student, Sam Schroeder, was surprised to learn that paramedics used the unassuming object – called a Broselow Pediatric Emergency Tape – to measure the height of a young patient and use that number to estimate their weight and calculate the proper medication dose to administer.

The tape seemed more likely to provide a guesstimate of weight rather than a reliable measurement, particularly during high-stress medical emergencies. From that insight, an idea was born, said Tanara Morrell, a fellow biomechanical engineering student.

“[Sam Schroeder] noticed the need for a scale to more accurately weigh pediatric patients,” Morrell said.

After completing the Clinical Immersion Program, Schroeder successfully pitched that engineering challenge as a senior design project, said Morrell, who was part of a five-member group that applied to work on it. Morrell and her teammates succeeded and set to work on developing an emergency pediatric scale that could decrease the risk of harmful medication dosing errors.

After months of work, the five — all of them now graduates — completed the work and earned a third-place award in Biomedical Engineering at CSU’s Engineering Days (E Days), held April 19.

A practical way to improve pediatric patient safety

It was a project with an important purpose, said team member Maddie Shafer.

“It’s 2024, we are in the age of technology, and pediatric patients are one of our most vulnerable populations,” she said. “They are one of the most protected in the scope of Food and Drug Administration guidelines and yet there is no metric or guideline on how accurate these [weighing] methods need to be.”

The students’ research showed that the lack of precision had harmful results, Shafer added. For example, a 2022 study showed that the Broselow method of estimating weight was accurate to within 10% of only 51.3% of pediatric patients.

“We’ve tolerated the old method of calculating weight because it is better than guessing,” said Nick Nudell, who advised the students as manager of the Trauma Research Department for UCHealth. “Improving the accuracy of drug dosing was a noble cause and could lead to improving patient outcomes.”

The need for a solution was clear, but the students had the challenge of designing the path to it. The most straightforward idea was to use good old-fashioned scales – think the one in your bathroom – to weigh patients, so they set to the task of learning how they actually work. That challenge was part of an “intense planning phase,” Morrell said, accomplished with the help of a second adviser, Jared Struck, a CSU biomedical engineering graduate and senior mechanical engineer at medical device manufacturer Stryker.

Time for testing

The group produced a pair prototypes – a series of scales inside a length of high-strength plastic material that could be folded and unfolded to fit the patient. But to lay the groundwork for that work, Nudell helped them get the clinical perspective of paramedics who would ultimately use the new device.

Working with UCHealth Senior Director of 911 Services for Northern Colorado Kevin Waters and Thompson Valley EMS Chief James Robinson, Nudell arranged a trip for the students to UCHealth Emergency Medical Services headquarters in Windsor. There they climbed into an ambulance to get an idea of the paramedics’ work environment and the equipment they used.

“That trip produced some of the biggest learning moments,” Nudell said. The students came away understanding the obstacles facing a first responder caring for patients who quickly need a potentially lifesaving medication like epinephrine for cardiac arrest.

For starters, a scale would have to accommodate ill and injured patients who come in all shapes and sizes. A paramedic’s workspace is also unpredictable – a far cry from a clean, well-lighted emergency room, Nudell said. A call could summon them to the side of a road, a shadowy living room, a grassy park, or the floor of a school room.

“We take care of people in the dark, in rain and snow and 100-degree heat,” Nudell said. “The students needed a purpose-built design to address these challenges.”

A need for feedback

Morrell said the visit to EMS headquarters was crucial for the students. “Going there pretty much determined all of our goals,” she said. “I think we had a rough idea of what we wanted to do from an engineering standpoint, but going to UCHealth helped us determine what kind of product it needed to be and how it was actually going to be something that people might use to satisfy the need.”

After developing the first prototype of the new scale, the students returned to the headquarters, this time at shift change, where paramedics learned how it worked, tested it on a simulation mannequin, and offered feedback for improvements, which the team implemented with Struck’s help.

After completing a second prototype of the scale, the students met with paramedics for another round of feedback. That led to more suggestions for improvements and the decision to create a third prototype, Shafer said.

A promising new feature

The key change, made shortly before E Days, was a mobile app loaded with common pediatric medications and dosages. The app receives the weight from the digital scale via Bluetooth, the paramedic chooses the medication, and the app automatically calculates the dosage.

Shafer, who stressed the app needs further development, said she used information from the Centers for Disease Control and Prevention website to build the medication and dosage database.

An app that frees paramedics from scanning and reading a card covered in fine print to find the correct medication dosage could be a “huge cognitive offload” for paramedics juggling multiple responsibilities in difficult environments, Nudell said.

It’s one feature that could improve the marketability of the device for a company that invests additional resources to produce it on a large scale, Morrell added.

“We thought the second prototype was fantastic and that it met all our goals,” Shafer said. The experience was a reminder that “the best engineering design isn’t always the best user design. So the feedback was invaluable,” she added.

A product with plenty of promise

The project may be a work in progress, but Shafer noted that the industry advisers who judged the E Day designs were impressed by the team’s success in moving from a concept to “an almost marketable product” with a business model in one year.

“A lot of products don’t get to where we did until maybe their second year,” Shafer said.

Nudell said he was grateful for the chance to help the team get and use crucial clinical insights from paramedics in designing the new device.

“Getting opinions and experiences from a variety of paramedics was a unique opportunity for [the students] to make an end product that is much closer to being commercialized,” he said. “They did a lot to get to the point that a company could take it over. That shows its value, and I am impressed by the quality of work that they performed.”