Fully automated tester for electric safety compliance testing

for medical devices

Overview
Automated testing system for surgical instruments designed to perform reproducible electrical continuity and high‑voltage (hipot) integrity tests after production. The system handles multi‑pole instruments and verifies electrode insulation without damaging delicate DUTs.

Industry
Medical technology / surgical instrument manufacturing

Task
Replace manual test stations with an automated solution to shorten cycle times and support a high number of product variants. Contacting must be automatic, gentle and provide low transition resistance for fragile parts.

Solution
Test programs are selected by barcode so semi‑skilled staff can run tests. Electrical continuity is checked with up to two continuity tests per instrument. Insulation between electrodes and plastic wrap integrity are verified by applying high voltage; the DUT is inserted into a narrow metal tube that serves as the hipot potential. Various length‑adjustable test adapters allow coverage of many versions. Contacting uses spring contact pins and pneumatic pins for hypersensitive DUTs; pneumatic pins can also fix the DUT. PC software stores an arbitrary number of test programs and assigns test scopes and data per DUT. Results are automatically saved in XML or Access format to a network location. Up to ten DUTs can be inserted into a test adapter and tested in parallel for the hipot test; failed DUTs are retested individually to identify the defective unit. A light curtain protects the operator and enables shorter cycle times. A separate test dummy performs an automatic daily system verification; the system requires a passed dummy test before allowing further testing.

Benefits

• Turnkey solution including DUT handling, adaptation and workplace design
• Simple, intuitive operation for semi‑skilled personnel
• Single connection per DUT; the test sequence then runs automatically
• Network operation: automatic saving of all test data to the specified location/database
• Long service life and service‑friendly design
• Short cycle times due to efficient workplace design with light curtain
• All values and settings configurable via software
• Automatic dummy test for daily system verification
• Workplace safety compliant with EN 50191
• Automatic test program selection by barcode
• Easy and quick retooling for different versions
• Short test duration by parallel testing of up to ten DUTs
• 100% process safety by 4‑wire technology in the hipot test

Technical characteristics / specifications

• Hipot test: 5,500 V AC / 6,000 V DC / 100 mA (not safety‑current‑limited) in 4‑wire technology
• Continuity test: 5 V; up to two continuity tests per instrument
• 4‑wire measurement used to monitor correct contacting in the hipot test
• Parallel testing of up to ten DUTs in the hipot test with individual retest of failed DUTs
• Automatic test program selection via barcode
• Storage of arbitrary number of test programs in PC software
• Test result export: XML or Access format to network location
• Test adapters adjustable in length to cover many product versions
• Contacting via spring contact pins and pneumatic pins for hypersensitive DUTs
• Integrity of plastic wrap checked by inserting DUT into a metal pipe serving as the hipot potential
• Light curtain for operator protection to reduce cycle time
• Separate automatic test dummy required for system start‑up verification