Barry Teshima

Surface finish is one of those specifications that tends to receive less attention than it deserves until something goes wrong. The print calls for a finish value, the supplier delivers parts within that value, and the program moves on. At macro scale, this is usually fine. The finish is a quality attribute, the process produces it within tolerance, the conversation ends there. At micro scale, surface finish stops behaving like a quality attribute and starts behaving like a functional one....

When a device development organization hears that an engineer wants to attend a catheter manufacturing workshop, the request usually gets processed through the same mental category as a conference, a certificate program, or a continuing education credit. It is filed as professional development — a nice-to-have for the engineer, a line item on the L&D budget, and a low priority against the pressing demands of the current program. This categorization is wrong, and it has a real cost. A serious...

A catheter design team is in late-stage prototype on a steerable electrophysiology platform. The mechanics are right. The shaft construction is right. The pull wire actuation feels clean at the handle. But the deflection is inconsistent across units. Some tips curl smoothly to the target angle. Others whip past it. Some return to neutral cleanly. Others hold a residual bias. The team checks the wire tension, the braid layup, the handle linkage. Everything passes inspection. The problem is in...