Medical Device Link.

A recent development in printing technology is the introduction of radio-frequency identification (RFID) labels, or so-called smart labels. Manufacturers can encode data in the labels, which appear and function like standard labels, explains Matt Ream, senior product manager for RFID systems at Zebra Technologies Europe Ltd. (High Wycombe, Bucks, UK). The encoded data can be read with a handheld or fixed-position RFID reader/writer.

"One of the advantages of the smart label is that it uses radio frequency to read the data on the label," says Ream. "This means it does not require direct contact or line-of-sight. Unlike a bar code, you don't have to see it to read it, which makes it very suitable for harsh environments. If you scratch up the label or get dirt on it, you can still read the tag. One of the other advantages is that it's a read-and-write technology. After you print and program the label, you can actually update the information as needed." For example, label data can be changed when it is necessary to reship an item to a different location, or quantity numbers can be modified to maintain up-to-the-minute inventory tracking.

Zebra has just released the R-140 transfer printer for the production of smart labels. The R-140 has been designed to work like Zebra's direct-thermal and thermal-transfer printers: "Operators can print and encode in one step without having to learn anything new," Ream says.

Ream contends that RFID represents a major innovation in medical labelling, not only for its usefulness in tracking and traceability, but also because it has the potential to introduce substantial clinical improvements. For example, Zebra has been working with a company called En-Vision America (Normal, IL), which has developed a product called ScriptTalk that reads RFID drug labels aloud to patients who are unable to read the labels themselves. Ream also notes that critical applications such as blood storage can benefit from this technology. In France, for example, a major effort is under way to standardize the labelling of blood bags using RFID labels to ensure traceability.

Leslie Laine

SURFACE TREATMENT

Laser Deposition Technique Creates Thin Coatings on Implants

Hip and knee implants are expected to benefit from a company's coating of hydroxylapatite applied via pulsed laser deposition.

Introduced in February at the Micro and Nano Technologies in the Life Sciences conference in Zürich, Switzerland, a company's technique for the laser deposition of hydroxylapatite (HA) holds promise for coating technology in implants and other medical applications.

Erothitan Titanimplantate AG (Schmalkalden, Germany) has developed a technique that allows very thin coatings of HA to adhere tightly to the surfaces of implants. Laserapatite coatings—which require no implant surface preparation—can be applied in layers as thin as 1–3 µm to titanium, as well as to a variety of other metals, ceramics, and polished surfaces, including glass and optical devices.

Erothitan has developed a special grade of HA powder that offers superior adhesion to substrates used in orthopaedic and dental implants. The firm then applies this powder to implants via pulsed laser deposition. Laserapatite is formed when an excimer laser strikes the powder in a vacuum chamber filled with argon gas.

"The advantage for manufacturers of medical products is that they can coat delicate components, such as spinal implants, without the burning associated with plasma spray coating," says Wolfgang Roth, president of Erothitan. Furthermore, notes Roth, Laserapatite has been shown to display better adhesion to implants and less brittleness than HA coatings applied through plasma spray. "With plasma spray coating, you get about 30 MPa of adhesion," says Roth, adding that many companies abandoned their use of HA for this reason, opting instead for metal coatings. "But we get almost twice this adhesion with Laserapatite, and we achieve a smooth, homogeneous coating," he says.

Applications expected to benefit from the use of Laserapatite include hip implants and knee implants. Stent coating and drug-delivery are other possible application areas, notes Roth.

Both in vitro and in vivo tests have been performed on Laserapatite, and the coating is currently undergoing clinical trials in Europe and the United States.

Erothitan envisions supplying medical OEMs with contract coating services, or licensing the technology to interested parties. The company also plans to apply Laserapatite to its own line of implants, says Roth. He adds that the firm is also developing a nickel-free shape-memory titanium alloy that will be easier to machine than nitinol and will alleviate concerns about allergic reactions in patients.

Benjamin Lichtman

CURING TECHNOLOGY

UV Curing System Uses Fibre Optics

The FiberFire curing system uses fibre-optic light guides to minimize energy loss and degradation problems.

Offering an alternative to conventional liquid-transmission machines, a curing system uses fibre optics to precisely deliver UV light in an array of medical manufacturing applications.

The FiberFire system from Lightwave Energy Systems Co. (Torrance, CA, USA) works in combination with the company's line of lamps to direct 30 W/cm² of A-range UV light to adhesives, coatings, and inks. With a total optical power of 50 W/cm², the machine can also produce UVB, UVC, and visible light. Special fibre construction minimizes energy loss, delivering 25% of the source light to the end of each strand. The use of fibres also eliminates some of the degradation problems associated with fluid-based systems.

The system "still degrades slowly," says sales manager Phil Smith, "but only through the bulb, not the fibre-optic light guide." Custom configurations allow multiple points to be cured simultaneously or in rapid succession. Heat controls enable the system to be used with thermally sensitive materials. Optical-feedback intensity control ensures consistent output and a guaranteed lamp life of 1000 hours. Real-time data acquisition and user-programmable NIST calibration are among other features of the system.

Zachary Turke

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