Going Separate Ways

Originally Published MPMN July 2006

PRODUCT UPDATE

Going Separate Ways

Precision filtration and venting products offer a range of benefits

Selecting a filter depends on the application, the fluid or gas to be filtered, and the filter material. Most medical devices require a membrane filter that is less than 0.1 mm thick, with a precise pore diameter. Modern membranes are produced under rigid parameters to deliver high porosity and support high flow rates.

Filtration products, as well as components for use in IV equipment, are featured below. A buyers guide with a complete listing of companies that offer filters and IV components follows on page 42.

New Product Line Offers 50-mm Filters

A maker of filters has launched a line of 50-mm filtration products. Filtertek (Hebron, IL) offers the filters for venting or liquid filtration applications. Available in either overmolded or welded versions, the filters come with a range of standard inlet-outlet connection options. The company also offers custom connections.

"We initially conceived the 50-mm filter line as overmolded products," said Bruce Daniels, vice president of medical marketing and business development. "However, opportunities exist where the lower- profile design and lower cost of a welded version will be important to our customers."

Filters can be used for sterilizing gases or filtering protein solutions. Performance can be enhanced through media selection. The firm provides other membrane options for the customer to qualify and validate.

Venting Media Grow to 5 µm

A supplier of specialized venting and filtration media offers a 5-µm venting product. Gore (Elkton, MD) has designed its 5-µm medical membrane for use in devices that require extremely high airflow as well as liquid resistance.

To contain bulk liquids while allowing for the free exchange of airflow, the membrane uses a two-layer laminate. The laminate combines hydrophobic expanded PTFE with a nonwoven membrane support. "Airflow and water breakthrough pressure need to be considered when venting medical devices," says Carrie Ortiz, product manager. "The combination of properties in the 5-µm medical membrane provides more than twice the airflow, as compared with our 3-µm membranes."

The company's medical membranes are available in a variety of forms and are easily processed in automated manufacturing environments. The robust construction of the membranes provides a high level of protection for healthcare workers, patients, and equipment.

Medical applications include intravenous air elimination, ostomy pouch venting, and urine collection.

Needleless Injection Sites Are Pressure Activated

Injection sites designed to access IV lines without the use of a needle are pressure activated. The needleless sites offered by DirectMed Inc. (Glen Cove, NY) make any line or device available via a standard male luer. A seal between the injection site and the syringe is secured by the four-part site. Fittings used in the sites meet ANSI and ISO 594 standards, and all materials used in their construction are USP Class VI compliant and free of latex and DEHP. Housings are made of polycarbonate and valves of silicone. The four standard design options available for these injection sites are a male luer injection cap, y site, tubing access port, and burette cap.

Metal Filters Have Many Medical Applications

All-metal filters and porous metal products from Mott Corp. (Farmington, CT) are suitable for use in medical devices that require efficiency, exact flow specifications, and biocompatibility. Metal filters also offer resistance to high temperatures and harsh chemicals. Examples of these products include biocompatible porous titanium filters, implantable devices, and test stand filters. Metal filters can also be used to prevent clogging in catheters.

Four-Port Stopcock Replaces Three-Port Models

A stopcock allows for one-handed IV injections. The Twist-N-Ject stopcock from G L Medical (Beverly Hills, CA) is a four-way, four-port unit that can replace three-port models. It offers two needleless IV injection sites. To use the stopcock, a fluid-filled syringe is attached to the axial port located on top of the lever. The syringe barrel is then twisted to point the lever toward the desired port, and the fluid is injected.

Drip-Chamber Level Sensors Use Ultrasonic Technology

Level sensors are custom designed for use with soft-bodied drip chambers and tubing in a range of sizes. The sensors from Introtek International (Edgewood, NY) help to overcome drip-chamber conditions, such as relaxation, slippage, or vibration, that could normally cause false air alarms. The sensors have a simple, unibody construction with no moving parts.

The sensors use the company's patented pulse-type ultrasonic technology. The technology provides reliable, noninvasive, liquid-level or air-detection capabilities. The sensors provide constant visual confirmation of liquid levels. The units are not affected by fluid color or tubing material. Field calibration is not required.

Medical applications include dialysis machines, infusion pumps, liquid and chemical dispensing, and blood- processing equipment.

Filter Components Offer Design Flexibility

A variety of filter components provide engineers with design flexibility. Silver Cloud Manufacturing Co. (Millville, NJ) offers conductive and nonconductive gaskets and adhesives for its Duralan II filters. The components are available in most sizes, thicknesses, and materials. Conductive adhesives and gaskets are suitable for filters being used in EMI/RFI-shielded applications. Filters can include printing and can be configured in most shapes and layouts. The Duralan II display enhancement filters are constructed of high-performance plastics and can meet various compliance regulation requirements. They are available in a variety of surface finishes designed for antiglare, maximum light transmission properties, and optimum durability. Standard filters from the smallest to the largest commercial displays are available in thicknesses from 0.007 to 0.400 in. and sizes up to 44 × 60 in.

Y-connectors Have Flow Adjustment Capability

Precision y-connectors are equipped with a Tuohy-Borst adapter. The large-bore, high-pressure, precision y-connectors from Excel Medical Products LLC (Fenton, MI) are commonly used in PTCA and stent procedures. The Excel-6 hemostasis valve and y-connector measures 0.083 in.; the Excel-9 is 0.120 in. Both units incorporate a flow adjustment feature to enhance control, as well as an angle designed for ease of use. Each includes a rotating male luer that meets ANSI standards. An adjustable cap provides more surface area. The connectors come packaged in individual or bulk units and can be gamma or EtO sterilized. Custom sizes are available.

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