A Northwestern-trained biomedical engineer, Walker was at the University of California, San Francisco with plans to become a surgeon. While there, he spent a year working on a novel design for a urinary catheter that would reduce catheter-associated urinary tract infections. Though the IP landscape halted his work on that device, Walker–under the mentorship of his now cofounder Dr. Al Chin–developed his company, InnoVein. InnoVein is tackling venous stasis ulcers with a prosthetic valve for veins. Venous stasis ulcers impact about 4 million people in the United States, according to the company.