Testing and Fixture Design

Customers frequently come to Omnica with a new technology or intellectual property they want to develop into a manufacturable medical device. They may not have begun the project, or are perhaps unsure of the next step in the process. Our Advanced Technical Services Team are experts in designing fixtures and test equipment for exploring feasibility and proof of concept.

Production fixtures are those specifically used for manufacturing and assembly, and the mechanical engineering group is usually the primary team for developing them. Testing equipment is more often used in feasibility, R&D, component verification, or cause-of-failure studies. The accompanying images and descriptions are examples of test equipment, and a functional testing fixture – a device we designed to test pre-production parts.

Implantable lens testing device

R & D Fixture
Our customer needed a lab fixture that would imitate the lens flexing movements of the tiny muscles in a human eye. We designed and built a device that featured a flexible plastic holder with eight legs, where each leg is attached to a spring and a computer-driven stepper motor. An artificial ocular lens was then suspended in the center of the holder. When the motor pulled on its attached leg the lens would flex. Activating two or more motors distorted the polymer lens through a range of motion similar in action to a lens in vivo. Two cameras mounted to the outer case were used to monitor and record all movements. The fixture was used as a lab device to test different implantable lens materials.

Proof of Concept Fixture
A client came to us with a proprietary catheter terminated with eight temperature-sensitive sensors (thermistors). They wanted to prove that during a cardiovascular insertion procedure their catheter was accurate enough to register minute temperature changes in the walls of cardiac arteries.

We developed a testing model that mimicked an artery with multiple hotspots and other conditions the catheter would encounter in the human body. Testing proved the concept. We successfully developed a cart-sized diagnostic intravascular thermography system based on their catheter.

Functional Testing Fixture      

For a clients’ new oxygen delivery system, we had developed an innovative air manifold that  supplanted a veritable plumber’s nightmare of air hoses and connections. The molded parts were complex, with tight tolerances. After assembly it was mandatory that the manifold would perform as expected and remain air tight.

Finalizing the right materials and bonding methods required extensive testing. This fixture detected leaks by subjecting the three-component assembly to operational air pressures. After validating hundreds of assemblies we deemed the final design ready for manufacturing.