Originally Published MPMN June 2002

HOTLINE

Paper or Plastic? Medical Nonwoven Combines Best Properties of Both Tapes

Benefits include easy tearing in any direction and conformability

An embossed medical nonwoven tape offers the bidirectional tearability generally associated with perforated plastic tapes and the comfort and extended-wear capabilities of microporous tapes. 3M Medical Specialties (St. Paul, MN) introduced the product at the Index '02 nonwovens exposition in Geneva, Switzerland, in April.

The 9914 tape has a "unique pattern that is achieved by combining rayon, polyester, and thermoplastic fibers with an embossing process," according to David Cromie, business development manager, East Europe and Middle East. "This imparts bidirectional tearing properties and increases the tape's conformability," he says. "The new tape takes the desirable features of our Micropore and Transpore brands, which are often referred to respectively as paper and perforated plastic tapes, and combines them into one product," adds Cromie.

Designed to present a clean, professional appearance during wear, the surface of the nonwoven material is engineered not to fluff up. This is especially beneficial in wound dressing applications, notes Cromie. "The absence of pilling and fluffing will actively help to reduce contamination, scuffing, and other undesirable features."

The tape also benefits from 3M's ongoing R&D activities related to medical-grade adhesives. "The adhesive used on the 9914 tape fits well with our coating processes, which, in turn, helps us to supply a consistently coated product," says Cromie. He adds that the adhesive is formulated to be hypoallergenic while providing enhanced skin adhesion compared with traditional microporous tapes.

Available with or without a protective paper release liner, the EtO- and gamma-sterilizable tape has broad "stick-to-skin" applications, according to Cromie. Sports medicine tapes, island dressings, and electrode backing applications are among the product's primary uses, according to the firm.

Norbert Sparrow

3M Medical Specialties, Bldg. 275-4E-01, St. Paul, MN 55144-1000; phone: 800/228-3957; fax: 480/473-2051; www.3m.com

Thin-Film Coater Improves Process Control

Precision equipment is suitable for stent coating

A precision machine lays down precise submicron- to micron-thin coatings of often-costly liquids onto any 3-D solid or mesh surface. The MediSonic coater from Sono-Tek Corp. (Milton, NY) exerts extreme control over coating thickness and area—coatings are continuous, uniform, conformal, and, in the case of meshes or micromeshes such as stents, web free.

Unlike pressure coating equipment, the MediSonic device uses a proprietary process that does not rely on air pressure to break up the liquid stream into droplets. In an evacuated reaction chamber, small pulses dispense the material of interest in liquid form. An inert gas then propels the liquid through an ultrasonic nozzle that atomizes it. The process closely controls coating thickness and coverage area, and reduces the risk of contamination. The droplets are small and uniform to enable fast curing and good coverage in even the smallest opening in the target substrate.

The standard MediSonic coater accommodates any workpiece that fits in a 3-in.-diam x 14-in.-long tube. Coating thicknesses can be set anywhere within the submicron to several-microns range and maintained within 5% of the set point. Coating viscosities can be anywhere from 1 to 50 cP. Maximum throughput is 0.4 gal/hr. The unit operates on 120-V, 60-cycle power and uses an argon supply for vacuum chamber purging.

Susan Wallace

Sono-Tek Inc., 2012 Route 9W, Milton, NY 12547; phone: 845/795-2020; fax: 845/795-2720; www.sono-tek.com

Chips Propel Advances in Medical Imaging Equipment

An open platform with enhanced imaging functions targets a variety of medical applications

A family of chips can perform up to 40 billion video-processing operations per second. Using the chips from Equator Technologies Inc. (Campbell, CA), the University of Washington's image computing systems laboratory developed functions that enable the software-programmable chips to support the specific requirements of various medical imaging equipment. The chip's platform is well suited for the imaging devices, which require high accuracy, a high level of overall image quality, and real-time processing of substantial amounts of data.

Equator's system has 129 highly optimized functions including arithmetic, morphology, spatial and frequency-domain filtering, segmentation, contrast enhancement, 3-D volume manipulation, and rendering, as well as geometric manipulations and transformation.

"When we decided to explore medical imaging, it quickly became clear that we would need a powerful programmable processor that would be capable of handling the many complex algorithms and data flows needed in each medical imaging modality," says Yongmin Kim, professor and chair of bioengineering at the University of Washington. "Equator's BSP processor was the only engine fast enough to support our high-level image computing requirements, and its software programmability ensured that new codes and algorithms could be quickly and easily developed."

Susan Wallace

Equator Technologies Inc., 1300 White Oaks Rd., Campbell, CA 95008; phone: 408/369-5200; www.equator.com

Medical Product Manufacturing News is always on the lookout for innovative products and services. If you are aware of any that have recently been or are about to be introduced, please call the Hotline editor, at 310/445-4265.

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