The radial artery is one of the two arteries that runs along the inside of the wrist. In recent years, due to a lower occurrence of complications, the radial artery has gained favor with cardiovascular surgeons as the access point of choice.
After working with another product designer and an industrial designer to do the early product concepting, I took over to finish the detailed design and engineering.
The first part of the project was redesigning the access tools. This included the needle (3), the sheath (1), and the dilator (7).
We did over 100 surgeon interviews and prototype sharing sessions to figure out what the surgeons needed.
Because they spend most of their time looking at the fluoroscopy screen they are largely operating by feel. Knowing this we designed a shape that was both comfortable and gave plenty of feedback about orientation of the part in the hand. As the needle pierces the artery wall it fills with blood in what’s called “flashback”. The surgeons use this as an indicator that they’ve entered the artery. To make this as obvious as possible, we created lenses on the non-grip sides to magnify the color change due to blood during “flashback”.
The second and more complicated part of the project was designing a device to apply variable pressure to the surgical access site to close the wound. The final product shown here uses a syringe (5) to inject air into a bladder (1), then uses a dial (3) to progressively dial back the pressure as the wound begins to clot. The band itself is easy to apply solo and leaves a clear view of the access site through the center (1). There is also a safety lock (4) that requires two hands to adjust pressure, which prevents tampering by disoriented semi-sedated patients.
During the concepting phase we explored tons of different closure methods that would allow for adjustable pressure. This was my favorite creation: the side access Zip-Tie.
Patient size variability was a big concern. Because the two main patient populations for these surgeries are the massively obese and the elderly, we needed to cover the full spectrum in as few SKU’s as possible. Sizing the strap and the curvature of the plastic took a lot of careful evaluation and testing.
We made dozens of prototypes. Leveraging a sample bladder from the makers of the Reebok pump shoes, I created working prototypes of the concept very early on. It was a progressive evolution of the design and I continued to refine it until I got it right and it was manufacturable.