Inspecting Needles for Tip Sharpness

Inspecting Needles for Tip Sharpness

Customer Problem:

A manufacturer of needles used in medical and pharmaceutical applications needed to inspect the needle tips for sharpness. The tip sharpness is the single most important measure of needle quality because it determines if a needle can be used safely and the degree of discomfort it may cause the patient upon insertion. Tip integrity should be verified not only upon receipt of the needles but also after every potentially tip damaging step in the process. For example, a needle tip can become bent during a final packaging operation such as capping or labeling.  Neither pressure sensors or manual needle inspection could provide the fast, reliable quality control or the potential for real-time feedback that machine vision offers for this complex application.

Cognex Solution:

Cognex high-performance vision systems, combined with our powerful vision tools are able to handle needle inspection problems such as reflectivity, minute defects and fixture instability.  Our pattern searching and true grey-scale image analysis tools are able to overcome normal process variations such as changes in illumination, while our edge-detection tools are able to locate tip defects by accurately locating desired edges. And, Cognex systems are able to perform these complex tasks at line speeds ranging from 60 to 180 needles per minute.

Related Applications:

Cognex has systems installed for other medical needle inspection applications including:

• Verifying the absence of burrs, hooks, and other tip defects 
• Gauging needle length to achieve mandated accuracies 
• Identifying blunt or bent needles 
• Verifying printed gradations on syringes