Brackenridge Intro – Emma Ahlgren

My name is Emma and I am a rising senior majoring in Mechanical Engineering with a minor in Bioengineering. I’m grateful and excited for the opportunities provided by the Brackenridge Fellowship as this is my first experience with academic research. My previous professional experiences have been in industry; over the past few years I completed Pitt’s co-op program and worked for three different companies during alternating semesters. My final rotation was with a medical device company, where I worked on the Research & Development team for a heart implant. I loved getting to apply foundational concepts from mechanical engineering to the human body and the cardiovascular system specifically. My research this summer continues that theme, and I will be working in Dr. David Vorp’s Vascular Bioengineering Lab to improve the diagnosis and treatment of patients with Abdominal Aortic Aneurysms.

An Abdominal Aortic Aneurysm (AAA) is a swelling of the aorta, the body’s largest blood vessel. It occurs when the walls of the aorta weaken and lose elasticity, due to factors such as aging, smoking, or high cholesterol. Once formed, AAA’s grow in size and become at risk of bursting, which can cause severe internal bleeding and potentially death – in fact, AAA rupture is the 13th leading cause of death in the US [1]. Currently, physicians determine the severity of an AAA and decide that surgical intervention is necessary if its diameter exceeds 5-5.5 cm. However, this diagnostic metric is only a rough estimate, and studies have shown that many AAA’s ruptured before reaching the 5cm benchmark, while others larger than the benchmark never ruptured at all.

In order to more accurately predict when the aortic wall will break, current biomechanics research attempts to quantify the internal forces in the aorta, as opposed to just its external shape. Unfortunately, it is not possible to directly measure the forces in a patient’s aortic wall without removing tissue during invasive surgery. However, recent experiments on concrete and polymers have shown that material failure can also be predicted using its density – specifically, materials with a lower density will fail more easily when subjected to an applied force. The goal of my research is to show that this behavior can be extended to aortic tissue. To do so, I am going to treat sections of porcine aortic tissue with a chemical solution that will break down certain proteins and reduce the tissue’s overall density. I will then use a tensile testing machine to measure the strength of both treated and untreated samples, to determine if the sample of lower density fails more easily than that of higher density. My project offers exciting possibilities for improving predictions of AAA rupture. Because density can potentially be measured using an MRI scanner, physicians could therefore assess the biomechanical forces in an AAA in a clinical setting and make more informed decisions for their patients.

Looking to the future, I feel that the fields of biomechanics, bioengineering and cardiovascular health are a perfect mix of my academic interests and I am still exploring which specific path I’d like to take within that area. I enjoyed designing medical devices in industry and am interested to experience the greater flexibility and exploratory projects offered in an academic research setting. I also really enjoy my part-time job as an Artificial Heart Technician at UPMC, where I care for patients who are on mechanical circulatory support devices in the hospital. I would love to continue to work in a clinical setting as a liaison between medical device engineers and the patients that they treat. The Brackenridge Fellowship is a great way to strengthen those communication skills, dive more deeply into cardiovascular health, and meet and learn from my fellow students. I am really looking forward to this summer and thank you to the University Honors College for this opportunity!

A picture of me at UPMC during one of my artificial heart shifts. There was a display about the product I worked on during my medical device internship and I was very excited

[1] Abdominal aortic aneurysm. Abdominal Aortic Aneurysm | Society for Vascular Surgery. (n.d.). Retrieved December 24, 2021, from

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