A 16-mm microextrusion system designed to process fluoropolymers for miniature medical device applications such as fine-wire jacketing for neuromodulation, microdialysis tubing, and neonatal intravenous (IV) catheter tubing is available from American Kuhne Inc. For producing such devices as microtubes with x-ray striping, the extruder is capable of processing high-performance ETFE, PFA, and FEP at such low volumes as 3.4 g/min. A chief benefit offered by an extruder of this size for microminiature component applications, besides the minimal output rate, is the short residence time in the barrel, which helps to minimize thermal degradation of the extrusion material. The machine manufacturer supplies a range of integrated precision microextrusion equipment, including modular microextruders, touch screen control systems, spiral-flow crossheads, automatic concentricity adjustment technology, heated cooling tanks, and servo-driven puller-cutter systems.
American Kuhne Inc.
The Model 620B multiwelder from Beahm Designs Inc. is used to perform catheter shaft or balloon bonding. Providing an alternative to laser welding technology, the system combines multiple process steps and stabilizes the process of bonding thermoplastic components, essentially eliminating the risk of operator error. To create smooth, seamless transitions along a shaft, traditional catheter tube-bonding methods require the use of a hot-air station for preshrinking and a radial compression bonder to create the tube joint. In contrast, this tube-bonding system has the ability to preshrink the sleeve and then bond or fuse two components via an automated single-cycle sequence. Its split-die technology allows the generation of high-precision bonds in a range of widths and diameters, including narrow weld profiles of the sort typically produced with lasers. As a result, the system fulfills the requirements of demanding applications such as short balloon bonds and ultrasmooth lap joints.
Beahm Designs Inc.
Los Gatos, CA
Custom pad printing systems
Engineers at Pad Print Machinery of Vermont can work closely with medical device manufacturers to create fully automated in-line pad printing systems. They accomplished this task when the company integrated its KE13 printer into an established production line to off-load multiple catheters directly from the line onto its own conveyor, print all six parts of the catheter simultaneously, and then unload them onto the client's existing off-load conveyor. To minimize total system footprint, the designers of the custom application added a 90° rotational device to the pad bar to allow the tubular parts to be printed perpendicularly to the machine. The servo controls and Windows-based operating system on the printers belonging to the series involved in this application make it possible for job parameters to be stored and instantly recalled. These parameters include all print phases plus print and cliché pauses. The stored values enable the operator to quickly change from tubing of one diameter to that of another.
Pad Print Machinery of Vermont
East Dorset, VT
Automated inspection systems
NSX-series macrodefect inspection systems from Rudolph Technologies Inc., a provider of process characterization equipment and software, are designed for critical device manufacturing applications in which 100% quality assurance inspection is normally required. When performing fast, repeatable inspections of the pressure sensors used in catheter-balloon inflation devices, the automated systems are engineered to detect potentially yield-inhibiting defects 0.5 µm and larger in size. They are suited for quickly and accurately checking components for defects at any stage of the production process.
Rudolph Technologies Inc.
Leak and flow tester
The customizable, pneumatically controlled Optima vT multisensor leak and flow tester can be used to perform vacuum-decay tests, pressure-decay leak tests, differential-pressure-decay leak tests, and back-pressure and differential-pressure mass-flow leak detection. In addition, the system performs tests of upstream and downstream cracking pressure, pressure-rise tests, burst tests, laminar-flow tests, force-decay tests, and occlusion tests. It enables users to tackle such difficult applications as multilumen catheter testing. At the heart of the system from Uson L.P. is the manufacturer's second-generation test control unit, which offers flexibility through a choice of one or two test channels with as many as four high-resolution sensors per channel. Thus, either four or eight independent cavities can be tested simultaneously. The tester can be configured for high-throughput simultaneous testing using all sensor inputs or for sequential testing in a variety of modalities. It features a full-color touch screen display with intuitive user interface, built-in automated calculators, and data-handling, storage, and enclosure options.
Linear assembly system
The LS 280 linear palletized assembly system available from Weiss North America Inc. can be the versatile foundation of plant assembly systems customized for the manufacture of a variety of medical devices, such as catheters, hypodermic needles, inhalers, diagnostic pens, and blood-sugar test kits. The system features a robust design, with workpiece carriers being transported and interlocked on a cylindrical cam that combines positioning precision of ±0.03 mm in the x- and y-axes and ±0.06 mm in the z-axis with stable interlocks. Pallet indexing times of half a second are typical. One of the company's straight-line assembly systems based on this modular transfer concept is 12 m in length and incorporates 15 processing stations and 42 circulating pallets. System modules are delivered to assembly line creators complete with a solid-steel machine base so that customers do not have to build a frame. In addition, the footprint is designed to accommodate assembly cell control cabinets and a master programmable logic controller.
Weiss North America Inc.
Modeling software for microcatheter development
Roth Technologies LLC produces radiopacity-modeling software for the development and optimization of catheter marker bands and radiopaque polymer formulations. The software predicts marker band visibility (RP Index) under fluoroscopy. Its algorithms take into account part material, geometry, and tolerances to compute the RP index mean, minimum, and maximum values for a design based on expected statistical variations and process capability. Compatible with Windows XP and Windows 7 operating systems, the software can also be integrated with Microsoft Excel. It includes an extensive library of marker band materials commonly used in the medical device industry. Stored in a MySQL server that is accessed via an Internet connection, the managed database can be configured and customized at the customer level to meet specific design requirements.
Roth Technologies LLC
San Antonio, TX