Medical Device Link.

SHOWSTOPPERS

A selection of innovative new products exhibited in Germany at Medica (Düsseldorf), Productronica (München), and Euromold (Frankfurt)

Materials

HF-weldable polyolefin film introduced as alternative to polyurethane

A new family of polyolefin films features a variety of desirable properties and characteristics for medical device manufacturers and can be welded by means of high-frequency (HF) sealing technology. Until now, polyvinyl chloride, thermoplastic polyurethane, and EVA were among the few types of film that could be HF welded. Introduced by the Dow Chemical Company, Fabricated Products (Midland, MI, USA) at Medica, Covelle films reportedly allow manufacturers to process polyolefin films without investing in new capital equipment. In addition, they may be able to downgauge their material without compromising performance.

"Covelle films are a drop-in product for HF welding," European market development manager for specialty films Valerie Beaumon told EMDM at the company's stand. "No equipment modification is necessary. Converters can process this material on the welding equipment they are currently using in their plant," says Beaumon. And because it is a polyolefin-based product, Covelle is a competitively priced film that can offer users substantial savings over a wide range of materials they may be currently using, she adds. "Polyolefins have a lower density, which enables an increase in yield of up to 30% compared with PVC," Beaumon says.

A stable film that will not turn brittle, the material can be sealed either by high-frequency or heat methods. Properties of the Dow film include flexibility and tear and puncture resistance. The weldable strength of Covelle HF film gives it a distinct advantage over EVA in certain applications, notes Beaumon. "Manufacturers who make pouches that come into contact with lipids, for example, may be able to reduce the thickness of the material yet achieve the same mechanical characteristics by using polyolefin," she explains. In addition to bags and pouches, the material is suited for use with inflatable devices and it can be heat-seal laminated with nonwovens for the fabrication of surgical gowns.

Polyolefin generally withstands gamma and EtO sterilization, and resists a wide range of chemicals. Covelle is currently available for evaluation and can be clear or white, smooth or embossed.

Rapid prototyping equipment

Laser sintering system creates large parts in less time

Plastic laser sintering systems allow manufacturers to build complex functional prototypes, design models, and casting patterns directly in one piece. The EOSINT P 360, displayed at Euromold by EOS GmbH (Planegg/München, Germany) boasts a building height of 620 mm, increased from 600 mm. "Our [previous] EOSINT P 350 already had the largest build size of any system worldwide," says company spokesperson Elke Fritz. "The P 360 is even larger, and [this capacity is] combined with reduced build times," she says.

In addition to increased building height, the P 360 system is supplied with process software that implements a new exposure-temperature control strategy to improve part quality while reducing build time. Sintering time is further reduced by the presence of an exchangeable frame. "In previous models, the system would build both the part and the surrounding frame through laser sintering," explains Fritz. "In the P 360, the exchangeable frame allows the system to build only the part." Fritz notes that the new hardware and software features allow manufacturers to increase productivity by up to 30%, depending on part geometry and material. As in previous EOSINT models, parts are cooled outside of the machine, making it possible to start new jobs without delay.

Founded as a supplier of stereolithography systems, EOS now specializes in the development and worldwide marketing of laser sintering products. The company also produces sintering machines that build metal parts and tools.

Electronic components

Simplified teach-in function optimizes compact sensor

Measuring only 32 * 10 * 17 mm, a sensor features a push-button teach-in function. The F 20 was exhibited along with numerous related components by SensoPart Industriesensorik GmbH (Wieden, Germany) at the recent Productronica exhibition.

"Teach-in couldn't be simpler," says Martin Stengel, a sales executive from the company's Nürnberg office. "You place the object within the sensing zone and press the button on top of the housing. Then you remove the object and press the button again. That's all there is to it," says Stengel. An integrated microprocessor evaluates the difference in energy between the two events and defines the optimum switching point. Dynamic adjustments up to 1000 Hz can be performed without interrupting the production process. To prevent unintentional adjustments, the button is slightly recessed.

All functions, including reversal of the output function, can be adjusted by means of the push button or the control line. Depending on mounting requirements, either M8 or four-conductor cables can be used as connectors, and the IP 67—compliant ABS housing is fitted with elongated holes and a smart mounting bracket.

The company supplies an array of light barriers, proximity light switches, glass-fibre optical components, and laser, optical, inductive, capacitive, and ultrasonic sensors. Custom sensor solutions are also available.

Manufacturing equipment

Versatile welder suited for cleanroom production of IV bags

Originally shown as a prototype at the 1998 K show in Düsseldorf, Germany, a shuttle-table welding machine, now in series production, returned to Düsseldorf for Medica. Designed and manufactured by Paul Kiefel GmbH (Freilassing, Germany), the KST 70/40 HF is particularly well suited for IV bag sealing.

"Because it uses servomotors for the welding press and shuttle-table trays, the machine doesn't stir up dust or dirt," says Johann Haas, a company engineer specializing in medical industry applications. "In addition, the welding unit itself is enclosed, making the machine ideal for use in cleanroom environments."

The KST 70/40 HF can be operated manually or semiautomatically, and it offers both high-frequency and thermocontact welding methods. "The thermocontact welding technology that was developed by Kiefel allows the processing of polyolefins," notes Haas. An HF changeover switch and air-exhaust evacuation pipes are available on machines supplied to the medical device manufacturing industry.

All of the company's KST machines, which are available with working-surface areas of 500 x 350, 700 x 400, and 700 x 800 mm, share many features such as programmable logic controllers with the company's larger series, according to Haas. "The KST series is designed for startup companies and smaller manufacturers who can't make a big capital investment but require a degree of quality that is usually found only on the bigger machines," says Haas.

Manufacturing services

Moulds supplied to medical industry

Precision injection moulds are produced for such medical applications as syringes, infusion components, and inhalers, as well as petri dishes, test tubes, and other laboratory supplies. Kebo Formenbau AG (Neuhausen, Switzerland) displayed a range of applications for the device sector at its stand at the Euromold show in Frankfurt. The company specializes in the production of high-quality, long-life tools with a maximum number of cavities.

Acknowledging the stringent requirements of the medical industry, managing director Charles Bodenmann notes that Kebo's moulds offer high efficiency, short cycle times, and a maximum number of injection operations. He adds that moulds are put through a series of tests in the company's test room until they meet customer requirements.

Bodenmann points out that the company, which has produced over 1500 moulds, performs all of its machining in-house and also produces many hot-runner systems. "We offer our customers in-house production, with only one company contact who is 100% responsible for the entire mould production process," he says.

In addition to mould-making services, the firm also offers a team of in-house engineers for project development and analysis. "Our customers don't just get a mould," says Bodenmann. "They also get advice on successful engineering of plastic parts."

IV components

OEM catheter features enhanced trackability in tortuous paths

A semicompliant rapid-exchange catheter for OEM use incorporates technology that reportedly provides improved pushability and trackability compared to conventional models. The HSC135 PTCA/Stent Delivery System was exhibited at Medica by AngioDynamics Ltd. (Enniscorthy, County Wexford, Ireland).

The most innovative feature of the device, according to managing director Andrew Jones, is the "smooth transition, via a power transition piece, from the stiff proximal shaft to the distal HDPE assembly. That tends to be a weak point in the design of other PTCA catheters," says Jones.

The high-pressure balloon has a compliance of approximately 10% and achieves nominal pressure at 6 atm, rated pressure at 16 atm, and average burst pressure at 22 atm. Balloon diameters range from 2.5 to 4.0 mm, and they can be supplied in custom lengths. Radiopaque gold image marker bands enable reliable positioning of stents.

Acknowledging the stringent requirements of the medical industry, managing director Charles Bodenmann notes that Kebo's moulds offer high efficiency, short cycle times, and a maximum number of injection operations. He adds that moulds are put through a series of tests in the company's test room until they meet customer requirements.

Design services

Engineering firm offers production facilities

By coupling its engineering services with small-series manufacturing capabilities, the Development Center Schuss (DCS; München, Germany) is able to offer device manufacturers a one-stop solution for product development. The firm, which exhibited at Euromold, also has operations in Nürnberg, Speyer, and Buchloe. DCS employs 25 engineers.

Working from initial concepts, the company creates innovative industrial designs for the medical sector. Through its subsidiary DCS Modellbau Buchloe GmbH, the firm also provides its clients with small-series production runs of functional prototypes. In-house CNC services are offered, including milling, stamping, turning, grinding, and eroding. The company can process steel, aluminium, and a range of alloys. In-house plastic moulding is also available, and rapid prototyping services are offered through a business partner. Manufacturing processes are certified to ISO 9002/EN 46002, and quality certification for the engineering services is expected this year.

"We can offer our customers a whole range of industrial design services," says Werner Schuss, the company's president and founder. Schuss adds that the firm's extensive experience in a variety of industries gives it an advantage in the medical sector: "We benefit from a certain synergy that arises between different applications," he says, pointing out that the company's work on consumer products often yields expertise that proves useful in medical designs.

Recent medical applications undertaken by DCS have included a brain surgery navigation system, a dental syringe, a Class II massage therapy device, and a salt-blasting dental handpiece (pictured). The company is currently working on the design of a multiple-parameter blood monitoring device for one of its clients in München.

Electric components

Reliability is key feature of vacuum pumps

Recognizing a growing demand for pumps and compressors suited for such uses as portable medical equipment, Charles Austen Pumps Ltd. (W Byfleet, Surrey, UK) has extended its Capex V2 range of vacuum pumps. The primary advantage of these pumps, according to export manager Jim Bass, is their reliability.

"These pumps will run and run even under the most extreme conditions. They were even used in the Amazon to monitor the air...that's how durable they are," says Bass. The pumps are available with either a 12- or a 24-V motor. A single-ended unit attains pressure of 2.2 bar with a flow rate of 16 L/min; when the pumps are run in series, the flow rate remains the same but a pressure of 3.0 bar and vacuum of 280 mbar are attained. "If you put the pumps in parallel," adds Bass, "you can increase your flow to 32 L/min with 2.2-bar pressure and 280-mbar vacuum."

Manufacturing equipment

Laser welder enhances process control via power feedback

A laser welder that combines pulse shaping and feedback control of peak power and energy reportedly achieves enhanced process control in precision joining operations. The LW 400E was shown by Weld-Equip Europe (Helmond, Netherlands) at the recent Productronica exhibition.

According to the company, the device is the first 400-W Nd:YAG laser of its type to include a power feedback mechanism as standard equipment. Unlike other feedback systems that measure the total pulse energy and correct it after one pulse, the LW 400E checks and controls peak power in every pulse, thereby delivering real-time pulse-shape and amplitude control. Every 0.1 millisecond, a microprocessor compares the peak power with the pulse shape programmed by the user. Any deviations that occur are immediately corrected.

Because of these features, the laser is suited for the series production of spot and seam welds on difficult materials. Easy to integrate into production lines, the LW 400E can be configured to share energy with up to six fibres. The company has extensive experience providing turnkey solutions for customer-specific precision joining systems.

Electric components

Robust diaphragm pump introduced

A proprietary linear electromagnetic drive confers an exceptionally long working life to a diaphragm pump that was introduced at Medica by Schwarzer Präzision (Essen, Germany). "This pump will run for more than 10,000 hours at peak efficiency," says managing director Marcus Schwarzer. The company holds several patents on the diaphragm, piston, and valve designs, he adds. "Our valve technology along with the pump's aluminium housing have also enabled us to achieve a reduction in noise, making the pump very interesting for medical applications," says Schwarzer.

Medical uses for the pump cited by Schwarzer include suction devices, respiratory equipment, and anaesthetic equipment. "It has even been used in electrotherapy procedures to create a vacuum so that the electrodes stick to the skin," he notes.

The linear diaphragm pump attains 1.6-bar pressure and 0.75-bar vacuum. Flow rates of 70 L/min are routinely achieved. "The pump can be tailored to customer requirements," adds Schwarzer. "Some products are sold off the shelf," he says, "but we truly specialize in adapting our pumps to OEM requirements."

Testing equipment

Leak tester frees users from calculating complex conversions

Many leak testers used in industrial applications operate according to the pressure-decay principle, which results in a pressure-drop-over-time formula. Users that need to determine the leakage volume over time are then required to perform a complicated conversion equation. An automatic leak tester exhibited at Productronica by SI-Special Instruments GmbH (Nördlingen, Germany) eliminates this step.

"We have resolved this issue by using what we call the slipstream method," says general manager Peter Binder, who described the process. The object being tested is filled with air to the predetermined test pressure, which is then maintained at a stable level. If a leak is present, the pressure regulator lets in sufficient air to compensate for the drop in pressure. The volume of leakage is then displayed on a mass flowmeter in standard millilitres per minute. The measured value is a function of the test pressure and the size of the leak. The remainder of the testing procedure follows the steps typically used by pressure-decay instruments.

The leak tester can be operated manually or automatically by means of a control system.

Printing equipment

Flexographic printer designed to integrate with packaging machines

Developed specifically to print on materials that are being run through externally powered conveyors, a flexographic printer is suited for use with stop-and-start sealing systems and other packaging equipment. Bein Pack & Print (Kennelbach, Austria) presented the unit at Medica.

The Rotating Flexo-Printer FDE-260-450 is driven by a servomotor with a flanged planetary gear train. During stop and start operations, notes company director Helmut Bein, the conveyor system's speed is monitored by an encoder, which transmits the data to the printer's computerized control system. "Shortly before the transport system stops and after the printing operations have been completed, the printer motor switches to standby," says Bein. This ensures that the cylinder remains evenly inked, he adds. The rotational speed in standby mode can be adjusted to run slightly slower or faster than the conveyor speed.

After each 320° rotation, the computer verifies that the system is ready for the next operation. "If the system is ready, the printer initiates a synchronization process to ensure that printing commences at 0°," says Bein.

The unit, which can accommodate material lengths up to 450 mm and widths of 150, 220, 400, and 600 mm, attains 40 cycles per minute.

Manufacturing equipment

EDM machine drills microholes while minimizing material degradation

A microdriller uses electrical discharge machining (EDM) to create high-precision cylindrical holes down to 0.020 mm diam with minimal material alteration. "This is the only machine I know of that can make EDM holes that small without material alteration," says Franck Leleu, sales manager at Sarix S.A. (Losone, Switzerland).

The SR-VHPM features a special electrode-wear compensation unit and collets designed to accommodate a range of complex-shape electrodes. The unit's ability to create perfectly round holes without causing material alteration makes it suitable for use in the fabrication of surgical needles, implants, pacemaker components, and intraocular lenses.

The machine, displayed at Euromold, can drill stainless steel, ceramic, titanium, and nitinol without causing cracking or material porosity. A high-precision rotation axis is complemented by a high-pressure flushing system and an automatic refeeding electrode system for continuous production. A new programmable micropulse generator optimizes erosion performance to suit different materials. DNC software is included, offering full program control.

"There is an inherent cost reduction that comes from the process itself," says Leleu, pointing out that manufacturers normally need to perform pretreatment, centering, drilling, reaming, and deburring in order to create such holes. "We incorporate all of this into one step with great accuracy and short cycle time," he says.

Electric components

Diaphragm pumps boost performance of sterilization instruments

Diaphragm vacuum pumps presented at Medica are designed to help meet heightened technical standards for autoclaves. The N836-series pumps have been specially developed by KNF Neuberger GmbH (Freiburg, Germany) to comply with vapour sterilization and vacuum drying requirements that will be addressed by a planned European norm, according to public relations manager Nancy López. "These processes can be carried out faster and more reliably by using these pumps," says López.

The components are equipped with coated, anodized pump heads that have primed aerodynamic channels to help evacuate condensation. Models with an integrated magnetic valve are available for applications in which large amounts of condensation are present. To accelerate drying processes, the pumps can be supplied with an integrated cooler. "In fact, the pumps are available in several basic designs that can then be modified to suit customer requirements," says López. "KNF is very much a custom-oriented company," she adds, noting that water-cooled pumps are also available for specific projects.