Keeping an Ear on Animals’ Vital Signs
For their senior design project, Stevens seniors team up with an alumna to save dogs’ lives during surgery
A single veterinarian surgeon in a high-quality high-volume spay-neuter clinic can perform as many as 50 procedures a day, clearing those dogs and cats to potentially find their forever homes through adoption. However, within this fast-paced, lower-budget environment, it’s nearly impossible to constantly monitor each animal’s vital signs. Of the roughly 21 million dogs and cats spayed or neutered every year in the U.S., about 84,000 animals are lost from complications due to anesthesia.
Stevens alumna Lindsay Daly, DVM '12, treats animals in high-volume shelters. The observations she shared with one biomedical engineering senior design team inspired the development of the simple, affordable “Animal Sign of Life” monitor to help these clinics save lives.
“When we first heard about this project, our plan was to create a better pulse oximeter, or a better placement of the pulse oximeter, for measuring blood oxygen levels,” said Henry Johnson '22, who is pursuing a master’s in engineering management after graduation. “Spay-neuter centers already use pulse oximeters, but the devices aren’t very reliable, especially through fur or dark skin tones, and it’s hard to keep them on the animal anyway. We also considered things like light and electrical activity. But our idea finally morphed into leveraging a stethoscope to use sound to monitor the heart and lungs. It was great to experience that adaptability as we kept working through and changing ideas to be able to end up with our product.”
That decision presented the team’s major technical challenge. The easiest path would have been to use two stethoscopes: one to measure heart sounds, and a second for respiratory sounds. Instead, the team devised a single device that could accurately capture and filter both sounds, which significantly reduces the cost as well.
Integrated into a secure, adjustable harness, the Animal Sign of Life Monitor incorporates a commercially available digital electronic stethoscope snugly attached with an elastic bandage to the left side of the animal’s chest. The stethoscope picks up any sounds, which are imported into MATLAB, converted into a digital signal and filtered to separate the heart and lung sounds while ignoring other noises. If the vital signs fall out of a safe range, the computer dashboard emits an alarm in both sound and color.
“The clinic staff would put the harness on as soon as the animal came in to be prepped for surgery, before being injected with the anesthetic,” said Sadie Clark '22, who will be returning to Stevens this fall for her master’s degree in bioengineering, with the goal of working in biopharmaceutical research. “Once injected, it takes up to 10 minutes to fully put the animal under, so the harness would stay on to be sure the animal is safe. And then, because it's out of the way, the harness would remain on to keep recording vitals during and after surgery. It’s accurate, consistent, efficient, easy-to-use and affordable for the clinic, and comfortable and safe for the animal.”
The team particularly appreciated Daly’s ongoing support throughout the process.
“Dr. Daly provided invaluable insights into the issues she encounters,” noted Aleese Mukhamedjanova '22, who will earn her master’s degree in biomedical engineering from Stevens in the fall, with plans to continue to obtain her Ph.D. “She helped us comprehend the project scope, requirements and limitations, and she led us to relevant data and literature. She had also gone through the senior design project process, and it was great to learn from her experiences and to help her now with her career.”
The project also helped the students focus on their own career plans and interests.
“I found it amusing to pick a project related to animals, because I’m also working on bird wing prosthesis research with Sally Shady, the teaching associate professor and associate chair of undergraduate studies in the Department of Biomedical Engineering,” Mukhamedjanova added. “Going through this whole process of a full project has been a valuable experience. It’s helped me realize that I like the vibe and work of academic research, and I’m interested in continuing on this path.”