Originally Published MPMN January 2006

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Assembly System Offers New Method of Catheter Crimping

Shana Leonard

When approached to fix crimp failure in catheters, a maker of integrated assembly and test systems saw its chance to shine. Promess Inc. (Brighton, MI), which boasts the nickname the “Problem Solver,” proposed a new method of crimping catheters. The result was a robust product that would not fail at a medically critical time.

Because they aid in vital bodily functions, catheters with faulty crimps could have dire consequences. “If the crimp isn’t perfect, it will either come apart when it’s pulled on, or it will close off the tube completely, rendering the catheter useless,” says Larry Stockline, president of Promess.

The crimping process is typically performed by a hydraulic press. However, manufacturers were unable to accurately measure and control the force generated by the hydraulics. After several attempts at modifying the crimping process, a manufacturer approached Promess about applying its Electro Mechanical Assembly Press (EMAP) technology to catheter crimping. The servo-controlled press is suited for assembly operations requiring precise control. In this case, the precision control over force and position proved to be the key in producing effective crimps.

“The key to maintaining consistent quality in the catheter-crimping operation is monitoring both the amount of force being applied and the exact position of the crimping tool simultaneously,” says Stockline. “Once we were able to quantify both parameters of a known good operation, we use that force and position signature as the benchmark to measure subsequent operations.”

Crimp quality is closely monitored by the system. Capable of integration with software and sensors, the crimping station is equipped with a differential monitoring capability. This process enables the machine to detect parts that do not meet user-supplied criteria for production.

In order to ensure that crimps are the correct depth, the EMAP-based system includes transducers for tool monitoring. In addition, the system features crimping force repeatable to 0.5%.

Configured with these monitoring functions and precision control, the EMAP-based crimping station so far has achieved the initial goal of producing strong crimps. And in the process, the company was able live up to its nickname.

Copyright ©2006 Medical Product Manufacturing News