Verifying Medical Assemblies by Their Resonant Fingerprint

The Challenge

In a medical device, a single escaped defect carries a cost far out of proportion to the part itself. For an assembled component, one of the hardest things to verify is whether it was built correctly, that the right internal element is present and seated, once the unit is closed up. The manufacturer needed a way to confirm correct assembly on every unit, quickly and without damaging or disassembling it.

The Approach

GrindoSonic evaluated impulse excitation as a build-verification check on supplied units, following ASTM E1876. A correctly assembled unit has a characteristic resonant peak, set by its structure and mass; a unit missing its internal component rings differently, with the energy shifting away from that peak. The resonant signature becomes a fingerprint for “built correctly,” and a simple frequency window turns it into an automatic pass or fail.

The Results

Impulse excitation reliably separated correctly assembled units from incomplete ones by their resonant signature alone, giving a fast, non-destructive build-verification with a recorded value for every unit rather than a spot check. The work was a feasibility study on supplied samples, but it validated a practical route to 100% assembly verification for a component where being sure matters more than almost anywhere else.