PRODUCT UPDATE
Lee Products Ltd.
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A two-way microminiature inert liquid-handling valve is offered for portable instrument applications in which a smaller claim on space and lower power consumption are desirable. The normally closed Series 300 LFN microvalve from Lee Products Ltd. (Gerrards Cross, Bucks, UK; www.leeproducts.co.uk) supports higher packing density; that is, more valves can be positioned within a given area, resulting in smaller manifolds and a smaller design footprint. Its centre-to-centre spacing is 0.30 in., by contrast with 0.50 in. for a predecessor valve series.
In addition, close spacing enables the reduction of transport volumes. Less reagent is needed, and sample transport time is minimized. The valve has an internal volume of just 13 µl, which may increase the rate of throughput as well as cut down on the amount of fluid needed. Its fast response of 20 microseconds also accelerates throughput and allows for handling smaller volumes in dispensing applications.
The valve’s relatively low power draw minimizes the generation of heat. This has the additional benefit of making possible passive, fan-free cooling. The low power requirement translates into long battery life or the accommodation of a space-saving smaller battery.
Plastomer Technologies
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A specialist company machines medical-grade engineered plastics into custom pump and valve components for flow control in medical devices. Among the materials Plastomer Technologies (Houston, TX, USA; www.plastomertech.com) processes is a high-purity PTFE it produces in-house. In addition, the company manufactures PTFE stent and suture fibres. PTFE provides purity, wear resistance, chemical resistance, and a low coefficient of friction, properties useful in medical applications.
The tight-tolerance custom components the company machines to specific requirements include connectors, couplings, seals, check valves, diaphragms, plugs, and more. These are used in imaging, laboratory, surgical, and other critical equipment. Machining and fabricating only plastics in its ISO 9001:2000–certified facility in order to avoid material cross-contamination, the firm processes PEEK, ultra-high-molecular-weight polyethylene, Ultem, acrylic, and polypropylene, in addition to PTFE. Its array of capabilities includes custom CNC machining, turning, routing, fabrication, and assembly.
Beswick Engineering Company, Inc.
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A series of lightweight miniature ball valves provide nonrestricted flow in medical and laboratory equipment and instrumentation applications up to 250 psig. Available from Beswick Engineering Company, Inc. (Greenland, NH, USA; www.beswick.com), the series includes the 9-g stainless-steel MBV-1010 standard shutoff valve and the 12-g MBVT-1010 three-way diverting and MBVMD-1010 three-way mixing-diverting valves, these latter configurations also in stainless steel. The mixing-diverting valve allows either port to be individually selected or both ports to be selected simultaneously with no shutoff.
All of the compact valves have bodies made from Type 303 or 316 stainless steel, Type 316 stainless-steel ball elements, and seals constructed from Buna-N rubber, EPDM, or Viton. The standard size of the inlet and outlet ports is 10-32 UNF, but other sizes may be requested. The manufacturer specializes in high-performance miniature fluid power components that feature leaktight captured O-ring face seals, corrosion-resistant materials of construction, and space-saving designs.
Fluid Metering Inc.
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Designed to provide precision fluid control in analytical and process instrumentation, a metering and dispensing pump from Fluid Metering Inc. (Syosset, NY, USA; www.fmipump.com) features precision stepper motor control. The Model STRH pump integrates patented CeramPump valveless piston pumping with the stepper control. The piston stroke displacement is adjusted by means of an easy-grip flow-control ring graduated in 450 divisions, which results in an accuracy of at least 1%. This design is suited for applications that require both frequent and highly accurate changes in dispense volume or flow rate.
The pump is capable of dispensing 0 to 100 µl per stroke at rates up to 50 ml/min, and it provides continuous metering at pressures to 100 psig. Its low-dead-volume pump head design ensures maximum bubble clearing. Typical stroke-to-stroke precision is 0.5% or better.
The manufacturer offers a range of stepper motor controllers extending from those that offer simple quick-start control through more-sophisticated models that have intelligent programmable control capabilities.
B. Braun Medical Inc.
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Two needle-free valve options are available from an ISO 13485–certified, US FDA–registered provider of contract manufacturing services and medical device components. The safety devices developed by B. Braun Medical Inc. (Bethlehem, PA, USA; www.bbraunusa.com) are the Ultrasite needle-free IV system and the Safsite valve.
The Ultrasite positive-displacement IV system features a needleless design suited for the intermittent injection, aspiration, or infusion of fluids. This device is a normally closed valve with female and male luer-lock connections. When accessed with any male luer-lock fitting, such as a syringe or IV adapter, the valve opens to allow bidirectional flow at rates to 250 ml/min. The latex-free, lipid-resistant valve automatically closes when the male luer is removed, thus preventing backflow. It is designed to provide more than 600 cycles of injection and aspiration without performance degradation.
The Safsite needle-free valve offers a simple means of safe IV-line access via any standard male luer connection. The male adapter opens the valve to allow bidirectional flow, and then the valve closes automatically when the male luer is removed, preventing backflow.
Bartels Mikrotechnik GmbH
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A pair of customizable micropumps provide a flexible platform for fulfilling requirements in a range of applications. Besides being versatile, the mp5 and mp6 pumps, which are produced by Bartels Mikrotechnik GmbH (Dortmund, Germany; www.bartels-mikrotechnik.de), are small and portable systems suited for use in medical technology. Adaptation of the pumps to wide-ranging requirements is facilitated by the simplicity of the pumps’ piezomembrane design principle. The pumps can be customized to provide a larger flow range or greater flow accuracy, and they can be built from materials having specific properties to achieve particular application demands. Possibilities include high-pressure, high-flow-volume versions and controlled-loop micropumps.
Parker Fluid Control Div.
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Solenoid valves designed for incorporation into medical equipment and instrumentation, among other applications, are available with an integrated coil for easy installation. The Parker Fluid Control Div. (New Britain, CT, USA; www.parker.com/fcd) introduced the integrated coil to extend its portfolio of options for the small yet powerful Series 204 and Series 304 solenoid valves. The integrated NEMA 4X coil with rotating conduit hub facilitates installation. These valve series also can be supplied with interchangeable ac and dc coils and with the high-temperature, watertight tab coil originally designed for them, providing flexible production alternatives.
The two-way Series 204 and three-way Series 304 are available as normally closed and normally open valves. They deliver high flow rates through orifices ranging in size from 1⁄32 through 5⁄32 in. The line is also manufactured with 1⁄8-in. NPT port connections.
This family of direct-acting solenoid valves for air and liquid applications includes high-performance models for long operating life and maximum pressure ratings, and economy models that serve for less- demanding applications. Both the integrated coil and high-temperature tab coil have been evaluated by Underwriters Laboratories, and the entire series complies with the European RoHS standard.
