‘Daring’ to Succeed in Automotive Safety: Q&A with Valentina Graci, PhD

By Kate Knab

Editor’s Note: In this Q&A, meet Valentina Graci, PhD, a researcher in the Center for Injury Research and Prevention and leader of the Sled Laboratory for Automotive Safety and Rehabilitation Biomechanics at Children’s Hospital of Philadelphia Research Institute. She explains how she found her passion for automotive safety research, how her unique background led her to CHOP, and how she hopes to inspire future generations of engineers.

What is your professional background, and how did that path lead you to CHOP?

I’m a biomechanist, so I study human motion in different scientific arenas. In automotive safety, I explore how vehicle occupants move in different types of vehicle maneuvers and crashes. I also study how humans move after a stroke or an event that disrupts their motor behavior.

I’ve studied human movement across my entire career, but the path that led me to CHOP is a little eclectic. I did my undergrad and masters in psychology. During that time, I had the chance to strengthen my technical skills, and I learned how to code. I learned how to use a 3D-motion capture system to acquire the coordinates of several parts of the body when someone moves.

This led me to my PhD program that focused on gait and upper limb movement analysis. My PhD program home was in an optometry and vision science department at the University of Bradford in the United Kingdom, but my primary advisor was a mechanical engineer. This experience solidified for me the benefit of a multidisciplinary approach to biomechanics.

Automotive safety biomechanics is, by nature, multidisciplinary because the human brain relies on the neuromotor system to control movements. Expectations, experiences, and anticipation of events also shape the way we plan and execute movement. Therefore, you need to analyze situations in traffic safety research through more than just a mechanical engineering lens.

I found my passion in automotive research because it is a multidisciplinary field, and CHOP encourages this approach in many of their labs. I knew CHOP would value my eclectic background and allow me to do the research I was most excited about without pushing me into a specific discipline.

You received the Foerderer Award, an internal CHOP research grant, to study return-to-driving among teenagers post anterior cruciate ligament (ACL) reconstruction surgery. Are you working with anyone else at CHOP? What do you hope to accomplish by combining your expertise?

Receiving this grant would not have happened without my existing collaboration with Elliot Greenberg, PT, DPT, PhD, OCS, and Ted Ganley, MD. Dr. Greenberg is a sports medicine physical therapist at CHOP and an assistant professor at the University of Pennsylvania in the Department of Orthopedics. He works with Dr. Ganley, who is the Director of CHOP’s Sports Medicine and Performance Center and the Bisignano Family Distinguished Endowed Chair in Sports Medicine. Dr. Ganley is an expert on pediatric ACL reconstruction surgery and pioneered an innovative surgical technique to help improve rehabilitation.

I took a step into their world of orthopedic medicine and sports medicine when they needed a programmer and someone who was skilled in 3D-motion capture system technique. I provided technical skills and support with my expertise in biomechanics.

Our collaboration began when we realized that there are no guidelines for when adolescents can safely return to driving after ACL reconstruction surgery. Dr. Greenberg and Dr. Ganley see these kinds of patients all the time in the clinic, so having their hands-on expertise was instrumental in filling clinical gaps in my knowledge. What we are trying to accomplish with this grant is to reduce the rate of crashes and the risk of injury for adolescents by providing evidence-based guidelines that could serve as a gold standard for return-to-driving times for pediatric practitioners to utilize.

Another exciting aspect of this grant is that we’re also collaborating with one of my colleagues from Drexel University, Hasan Ayaz, PhD, who created a mobile neuroimaging tool that helps us understand the neurological factors that affect adolescents after they have the reconstruction surgery and during rehabilitation. We’re trying to determine how the cognitive load for these patients may impact the way they move their knee after ACL reconstruction, which can then influence the way they drive and the injury rates.

Why is it important to study return-to-driving times after major surgeries, especially for adolescents?

Motor vehicle crashes are the leading cause of the death in adolescents, so we need to look at the whole body for a more holistic view of teen medicine and injury prevention. ACL injuries are not just mechanical injuries. Adolescent brains and bodies are still developing when the injury occurs, and the brain rewires very quickly to adapt to the new movement patterns both before and after ACL surgery. This is the reason why it’s important to get these patients into rehabilitation programs early and to understand when they can handle the vehicles pedals safely once they return to driving.

Your Sled Lab, which works with human volunteer sleds that can mimic on road vehicle impact-avoidance maneuvers, is featured in a Lab Life video. Can you tell us how the work you do with Sled lends itself to your partnership with the Neuromotor Performance Lab?

In the Sled Lab, we do a variety of biomechanics studies spanning from automotive safety to medical device testing. We collaborate across disciplines because CHOP’s expertise is so broad that it’s easy to connect with physical therapists, for example, who are looking for biomechanists and engineers. Through a colleague, I learned that Laura Prosser, PhD, the Director of the Neuromotor Performance Lab (NMPL), needed a biomechanist for programming, building, and coding custom devices that her research program was developing.

There’s a direct link between the NMPL and my lab because neuromotor control is another area where we can conduct interdisciplinary research that is biomechanics-oriented. We’re looking at how certain factors can impact the motor development and rehabilitation of movement in children.

With NMPL, we exchange some of the same tools and knowledge, and as a testimony of that partnership, we have a shared PhD student right now. We brainstorm ideas and advise each other on projects because we’re all working in the field of biomechanics. We just come at it from different walks of life.

Is there a particular aspect of your current work or an ongoing research project that you are most proud of?

One of the research projects I’m most proud of looks at Automatic Emergency Braking (AEB). The idea came to me when I first joined CHOP to lead a study aimed at tracking the motion of occupants in a moving car using a 3D motion-capture system.

We examined occupant kinematics during emergency braking, evasive swerving, and other vehicle maneuvers to determine how the vehicle dynamics impact passengers’ motion. One of the maneuvers we examined in that study was emergency braking performed by the vehicle and not manually by the driver. I noticed the acceleration during AEB differed from manual emergency braking.

I found the AEB technology interesting because I realized that each car performs that automatic stop differently. I examined the AEB of different vehicles, and I was one of the first researchers to publish a peer-reviewed study that AEB braking acceleration changes between vehicle makes and models from more abrupt to less abrupt.

Understanding how occupants move during this variety of braking pulses is important because if the braking is not successful and the occupants end up in a crash, this emergency maneuver changes the posture the occupants assumed before that crash, influencing their injury risk.

This topic is of particular interest for me because beginning in 2029, all new cars will be equipped with the AEB technology. However, most of attention and investigation of AEB has focused on pedestrian and rear-end crash avoidance. We are one of the few laboratories that instead focuses on the effect of AEB on the vehicle occupants.

My current research project on AEB aims to reproduce a variety of AEB acceleration in the laboratory to provide a repetitive and controlled environment to better understand the effect of AEB on occupants’ motion. Due to limited space and funds, we had to determine a way to perform different AEBs in the Sled Lab without a linear sled device, which would require an enormous space. We’ve created a rotational sled model that we’ve been developing over the last few years. This innovative sled device will allow us to test a range of AEB pulses on a human passenger in a reasonable lab space.

I want to understand what the most advantageous braking acceleration would be for occupants to decrease their potential injury risk. The results of this investigation could inform new regulations and policies that would make this technology even safer not only for pedestrians but also for all occupants.

What drives your passion for investigating road traffic safety through the lens of biomechanical engineering? Do you have any advice for young women who may be interested in pursuing a similar path?

Automotive and traffic safety is one of the few fields I can think of where being a psychologist with PhD experience in vision science and engineering can be used to answer broader research questions. Automotive safety biomechanics is my passion because I’ve found a home where I can utilize all my unique interests in a meaningful way.

Usually, in science, we always tell young women they have to persevere. They can’t let failure stop them; they have to keep going. These are all true things, absolutely, but they also have to be daring. I encourage young women to speak up and say the things that may sound implausible and pursue creative ideas. We always need more creative solutions for safety in the ever-changing technological world, and there are always opportunities to apply your creative thinking, if you are daring enough to propose new ideas.

Any additional thoughts you’d like to share?

I am the inaugural faculty in the pediatric engineering initiative between CHOP and Drexel University. This role has helped me to find an engineering home in the School of Biomedical Engineering at Drexel, which has a focus on medical devices and engineering as whole, so it was a perfect fit for my lab. My lab was already on Drexel’s campus, and we were using their machine shop and collaborating with their faculty, so it felt like a natural progression to be considered for this CHOP-Drexel partnership.

This initiative is going to fuel research in Pediatric Engineering, particularly in injury prevention and injury rehabilitation. Pediatric Engineering is a highly needed discipline, as children are not small adults; they have unique needs and physiology, and engineering solutions need to take that into account. It’s been a great experience to train the next generation of engineers in thinking of safety solutions specifically for children. I look forward to continuing doing so under the CHOP-Drexel umbrella.