Technology news
Digital Machine Vision System Increases Inspection Speed
A fully digital machine vision system was recently introduced that attains unprecedented levels of inspection speed and accuracy, according to Joe Christenson, president of PPT Vision Inc. (Eden Prairie, MN, USA). "Digital serial communications plus new accelerated image-capture and data-processing hardware combine to provide a system that offers higher performance and more flexibility than any existing technology," says Christenson. It is also less expensive to implement, maintain, and expand, he adds.
Passport DSL achieves these performance gains partly because it does not suffer from the inherent limitations of analogue systems. Whereas analogue machine vision installations require bulky cables with multiple conductors to control camera and I/O operations, Passport DSL enables high-speed bidirectional transmission of control information and acquisition data through simple twisted-pair wiring. In addition, the repeatability of digital serial communications allows users a great deal of latitude in establishing the transmission distance between cameras and the processor without incurring signal distortion and degradation, as may be the case with analogue systems, notes Christenson.
The system's remote processor is linked to a network of digital serial hubs to facilitate wiring, modification, and expansion. According to Christenson, Passport DSL can simultaneously operate more cameras and remote I/O devices than any other vision system currently available. A variety of camera types, including analogue, with different operating characteristics and varying resolutions can be accommodated.
The high-speed image acquisition and data-transfer capabilities of the system, which attains communication speeds of 330 MByte/ sec, are reinforced by proprietary hardware components configured to provide matching processing power. Setup is facilitated by company software that replaces lines of code with a set of flexible graphic programming tools that users can drag and drop into a flowchart. The Passport DSL system operates in a Windows environment and communicates directly with other Windows-based applications.
Hydrocolloid Formulations Eliminate Animal-Derived Materials
New hydrocolloids developed by Avery Specialty Tape Division N.V. (Turnhout, Belgium) are formulated without animal-derived materials to meet the requirements of demanding wound- and ostomy-care applications. "Avery has been able to use its expertise in hot-melt adhesives to develop novel hydrocolloids that have lower irritation potential than many of the competing products," says Colleen Ward, director of the division's medical business unit. "We believe that our new products offer unique opportunities to device developers in terms of the range of properties available for custom-engineered adhesives."
The thin and comfortable fully integrated constructions will maintain a high absorption level without leaving residue in the wound base. The adhesives can be supplied in roll form, and can be prelaminated or combined with any of the company's standard films, foams, or nonwovens. Produced in a Class 10,000 cleanroom at the firm's ISO 9001registered European headquarters in Turnhout, the adhesive materials are sterilizable via gamma and E-beam radiation. The products offer low cold flow and good shear strength, and are available in standard, white, and translucent versions.
Nylon Developed for Rapid Prototyping Applications Is Approved for Medical Use
DTM GmbH (Hilden, Germany), a manufacturer of selective laser sintering (SLS) stations and developer of the SLS process, has introduced a USP Class VI material designed for use in rapid prototyping. Medical device prototypes created in Fine Nylon MG (medical grade) can be introduced into the operating theatre and may be used in vivo for 24 hours or less. The material was tested by NAMSA (Münster, Germany) according to ISO 10993 parameters.
"To the best of my knowledge," says DTM's UK sales and applications representative Simon van de Crommert, "Fine Nylon MG is the only rapid prototyping material that, after sterilization in a common autoclave, can be directly used in medical applications. You can take it directly to the patient after sterilization. Other rapid prototyping systems require the user to take additional steps."
DTM's material can withstand repeated sterilization by autoclave. Some technologies, such as fused deposition modelling, use materials that require gamma sterilization, while the liquid resin derived products that are fabricated by other rapid prototyping equipment are toxic and cannot come into direct contact with the patient, says van de Crommert. "Because we are using powders rather than resins, we are also able to process 11 different materials on the same platform," he adds.
The availability of Fine Nylon MG enables manufacturers to use the DTM Sinterstation in most phases of product development. One example cited by van de Crommert involves orthopaedic applications. A supplier of prosthetic devices, he notes, can use Fine Nylon MG to make a prototype joint that can be tested for form and fit while the patient is in the operating room. The same platform can be loaded with a material to produce precise patterns for investment casting of the medical device, and metal moulds can be fabricated by means of the company's RapidTool LR process.
Fine Nylon MG can also be used as a preoperative planning aid--to model a bone structure, for example--or to produce prototypes of plastic parts used in such medical instruments as endoscopes and pacemakers.
Current users of DTM's Sinterstation systems will not need to upgrade their equipment to begin processing the new material, adds van de Crommert.
