Engineering a Device to Fight Child Abuse

April 17, 2019

UA Emergency Medicine physician Dale Woolridge teams up with senior engineering students to create a bruise age measurement device for use in child abuse and domestic violence cases.

A 2-year-old child shows up to daycare with a bruise on her arm. Her dad dropped her off today, she was at her mom's house the day before, and she was staying with her grandparents the day before that. All the guardians are pointing fingers at one another. Who is to blame?

"The forensic ability to accurately determine the age of a bruise has long evaded the medical community, which hasn't been able to answer questions about how old bruises are with any degree of accuracy," said Dale Woolridge, MD, professor of emergency medicine and pediatrics and director of the Southern Arizona Children's Advocacy Center at the University of Arizona.

In 2017, 72 percent of all child fatalities in the U.S. caused by physical abuse occurred in children younger than 3 years old, according to the U.S. Department of Health & Human Services. Dr. Woolridge, who is also director of the Banner Suspected Child Abuse and Neglect program for the Western region, works with these cases regularly, and the idea for a device to age bruises stemmed from his desire to help children. However, such a device could also be used in worker's compensation cases, domestic violence situations or other circumstances where a person can't answer questions about who or what caused their bruises.

In 2018, Woolridge approached Urs Utzinger, associate professor and associate department head for undergraduate affairs in the Department of Biomedical Engineering, about creating a device that could determine the age of a bruise by measuring the way it reflects light.

Woolridge and Utzinger decided to sponsor a project in the Engineering Design Program and ask a team of seniors to take the first step toward creating it. In the Engineering Design Program, teams of four to six seniors spend a year creating industry- and university-sponsored technologies with real-world applications. This team of five biomedical engineers and one mechanical engineer is this year's only all-woman engineering design team.

Blue, Purple, Green and Yellow

Anyone who has ever had a bruise knows its color changes over time, moving through blue, purple, green and yellow tones before fading away.

As Utzinger said, "Most people know that when they have a bruise, they think it's ugly. Then, it gets uglier," said Utzinger, who is also an associate professor of obstetrics and gynecology, electrical and computer engineering and optical sciences, and a member of the UA BIO5 Institute. "We're using a specialized camera and, through our software, enhancing the image information in order to better evaluate the color of the bruise," team member Ghazal Moghaddami said.

The final version of the device will measure just a few inches across and hold a spectrometer, two microprocessors, a display screen and a memory card to hold the data of multiple patients. Social workers and physicians can take measurements by gently applying the portable device to affected skin. 

"They'll take one base measurement to compare the bruise to the person's regular skin," team lead Samantha Davidson said. "Then they're going to take measurements on the bruise itself. The idea is that we'll be able to remove the memory card and put it in a computer to analyze the data."

Everyone Needs an Engineer

The team members have a broad range of interests: Davidson is going on to pursue a master’s in epidemiology at the UA. Alexandra Janowski is also pursuing a UA master’s, in biomedical engineering. Others have plans to become physicians’ assistants, enter medical school or work in the biotech industry. But they all were drawn to the opportunity to create this device.

“This project could potentially help people,” Davidson said. “I felt like this was going to have an impact.”