Originally Published MPMN September 2002

HOTLINE

Device Tests Curved and Straight Needles

Both penetration and bend testing can be accomplished

A needle tester can measure the performance of both curved and straight needles. Traditionally, the test of needle sharpness is the measurement of the force required for it to penetrate a consistent membrane. Curved needles have been difficult to analyze because side loading is eliminated, which can skew the measurement of force.

The Model AE-3 needle tester from Acculine Engineering (Waterbury, CT) solves this problem with precision alignment features that minimize off-loading during the penetration process. The instrument performs both penetration and bend testing for both straight and curved medical and surgical needles.

A real-time graph of the test results enables immediate analysis of test validity as well as of the test results. The penetration test calculates the maximum force during a test and writes that value to a spreadsheet.

The bending strength test calculates several values. The first is the moment at a two-degree offset of the initial slope. The slope is calculated between two constraints based on the maximum force found in the test. Once the slope is determined, the software moves over two degrees of rotation and constructs a line parallel to the slope. The intersection of this line and the original curve is the two-degree-offset yield moment calculation.

The instrument features precise motor control for synchronization of needle movement and data collection, a Sony 14-in. fine-pitch monitor for needle alignment, optional software for statistical analysis, and optional computer controls for completely automated needle alignment and testing. The components are mounted in a workstation that meets cleanroom requirements.

Susan Wallace

Acculine Engineering, 5 Mattoon Rd., Waterbury, CT 06708; phone: 203/753-1122; fax: 203/753-0721; www.acculineengineering.com

Copyright ©2002 Medical Product Manufacturing News