When Yock started getting involved in training, he worked with John Simpson and the mentoring changed his life. One thing that was starting to become clear in mid 80's was that there was a problem with angioplasty – arteries were narrowing at an alarming rate. Hence surgical procedure had a 40% recurrence rate. Yock started to focus on the need to visualize during a surgery and hence the need to get inside the blood vessel. With Simpson, Williams and Fogarty, Paul started a company with technology that went inside the artery and saw in high resolution. He talks further about this technology.