The challenge
Fixtures are used in product development and manufacturing for a variety of purposes. Most commonly they are used as a holding or support device, ensuring that all components are assembled accurately and repeatably. This will guarantee that the products produced are uniform and conform to desired specifications. When working with abnormally long or unwieldy parts, fixtures are commonly designed and built to hold parts together while building the assembly so that a second set of hands (adding cost) is not needed. Synectic was approached by a startup company to design for manufacture and build two different catheters each having handles with a complex mechanism inside.
Synectic's solution
Due to the excessive length of the catheter tubes, the devices are unwieldy causing the handles to shift around during assembly. The constant shifting made uniform assembly of the device difficult. To address this issue, a fixture was designed and built completely in-house to hold the components.
Since both catheters required a similar build process, the fixture was designed to accommodate both devices. First, the fixture base and catheter supports were comprised of five different pieces of acrylic, cut with our in-house laser cutter. Acrylic was chosen because it is inexpensive, readily available, and can easily be cut using the laser cutter. The laser cutter provided an added benefit of creating clean cuts. Since the cuts were clean, no secondary cleaning process was needed before use, cutting down building and production time significantly.
Next, three nests were designed and built from fused deposition modeling (FDM) using our in-house 3D printer. Since the assembly process requires the device to be moved several times during assembly, three nests were designed to hold the handle mechanism steady. Once built, the nests were attached in a line on the fixture using off-the-shelf hardware. Since the nests were designed and built in-house any changes to the design could be adjusted and rebuilt in hours instead of days. Outsourcing this task would have added considerable time and cost to the fixture.
To hold the catheters steady two pieces of tubing, specific to the different catheter diameters were cut to size in our machine shop. The tubing was attached to the catheter supports using some off-the-shelf ring clamps. Finally, rubber feet were added to the bottom to prevent the entire fixture from moving when in use.
What would normally take around a week to design and outsource, took less than an hour using our in-house laser cutter, 3D printer, and machine shop. The cost was also significantly less both due to the reduction in labor time as well as the type of material used.
The result
An inexpensive and quick custom medical device fixture, that aided assembly time, cutting overall build time by reducing the amount of handling significantly of two separate catheter devices.
