Fluid dispensers and pumps
Suitable for use in medical diagnostic and analytical instrumentation, an OEM line of fluid dispensers and metering pumps from Fluid Metering Inc. is designed to offer precision, accuracy, and chemical resistance. Available in either fixed- or variable-displacement configurations, all of the low-flow dispensers and pumps have a patented valveless, one-moving-part design. The line comprises standard models with dispense capabilities ranging from a low of 500 nl per dispense to a high of 1.28 ml. Custom dispensers and pumps designed to meet specific application requirements are also available. The components feature coefficients of viscosity of 0.5% or better and exhibit accuracy of ±1%. In addition, stepper control kits available from the manufacturer range from basic levels of control to advanced programmable stepper development kits for achieving precision fluid control.
Fluid Metering Inc.
Micro diaphragm pump
Capable of handling liquids in a range of medical device and analyzer applications, the customizable Type NF1.25 high-pressure micro diaphragm pump from KNF Neuberger Inc. can be used to dose or transfer liquids or liquid-gas mixtures at flow rates up to 300 ml/min. The small, powerful unit has been engineered to operate either intermittently or continuously against pressures as high as 87 psig over its lifetime. Versions that handle pressures up to 145 psig can also be specially developed. Mountable in any position, the self-priming pump features a patented valve system and sophisticated diaphragm technology. It can also run dry and requires virtually no maintenance. Motor options include iron-core dc, ironless-core dc, and brushless dc units. The brushless version can be supplied either with simple two-wire operation or with four wires to allow advanced tachometer output, speed control input, and a highly linear control curve. The use of polypropylene, PTFE, EPDM, and FFMP materials for components that come into contact with pumped media enables good chemical resistance.
KNF Neuberger Inc.
In-line check valve
The A220-ADM16 in-line check valve developed by NP Medical is suited for such medical device applications as infusion therapy and enteral feeding. The acrylic valve features a preloaded, normally closed latex-free silicone diaphragm that allows flow in one direction while preventing flow in the opposite direction. Composed of a sonically bonded, DEHP-free thermoplastic body and an elastomeric diaphragm, the valve provides an opening pressure of 0.05 bar with consistent flow characteristics. Fully tested for back pressure and cracking pressure, it withstands a minimum internal air pressure of 3.1 bar with no visible signs of leakage. Manufactured in a Class 100,000 cleanroom in ISO 13485–certified facilities under CGMP guidelines, the valve is made from USP Class VI–approved materials and fits 3.4-mm-OD tubing.
A pair of single-handed hemostasis valves from Qosina Corp. are available in two models: part number 80328, which features an internal diameter that accepts tubing up to 7 Fr, and part number 80329, which accepts tubing up to 9 Fr. Both valves include an easy push-pull mechanism that allows the operator to open and close the valve with one hand. In addition, the valves can be closed traditionally by turning the cap three times to create a seal. Once sealed in this fashion, the valve locks and cannot be reopened via the push-pull method. Made of polycarbonate and silicone, these valves have a rotating male luer lock and a female-luer-lock side port for flushing out the line or checking pressure.
Custom check valves and pumps
A family of check valves and pumps for precise flow control of liquids and gases in advanced low-pressure, low-flow applications is available from Smart Products. The manufacturer offers all of its valves with customized plastic body materials, O-rings, and the desired opening spring pressures, which can range from 0.07 to 20 psi. Designed for easy insertion into any medical device requiring precise flow control, the pumps are configured as single-diaphragm, positive-displacement, or rotary-diaphragm units and offer a range of output pressures and flow rates. The company’s ISO 9001:2008–certified manufacturing facility is equipped to meet both medical device industry requirements and specific customer design criteria. It also provides cleanroom molding and assembly, gamma or EtO sterilization, autoclaving, and other capabilities. Custom assembly, special testing, and other value-added services are offered as well.
MORGAN HILL, CA
High-resolution syringe pump
A high-resolution syringe pump for use in automated medical instrumentation is suitable for a variety of applications, including sheath flow and cell counting. Offering up to 192,000 microsteps per full stroke, the C24000 from TriContinent Scientific Inc. addresses the need for low-flow, minimal-pulsation fluid handling. Capable of dispensing microliter to 12.5-ml quantities of fluid per stroke, the company’s C-series syringe pumps utilize a proprietary direct-drive design that eliminates the use of belts, which often stretch and wear out, according to the company. The pumps’ self-lubricating drive mechanism has been life-tested to several million cycles without the need for maintenance. In addition, the pumps use standard communication protocols and mounting configurations, eliminating the need for redevelopment.
TriContinent Scientific Inc.
GRASS VALLEY, CA
At 4.5 mm wide, a flipper-type isolation valve supports miniaturization while matching or surpassing 10-mm valves in terms of fluid-handling performance, according to its manufacturer. The Type 6650 valve from Bürkert Fluid Control Systems enables manufacturers of medical equipment and instruments to pack more valves and functionality into a given space. Its optimized internal design facilitates flushing of materials through the device in the manner of rocker valves, helping to eliminate reagent waste and cross-contamination while enhancing process safety. Patented flipper technology incorporates an elastomeric element that moves between two opposed valve seats under the force of permanent magnets fixed to the flipper element, opening one seat as it closes the other. Because this operation requires only a temporary pulse, it exhibits a short response time. The low-wear valve ensures reproducible fluid-handling performance.
Bürkert Fluid Control Systems
Published in MPMN, March 2012, Volume 28, No. 2
- Previous story: Software: The Brains Behind the Medical Device
- Next story: Manufacturing Systems Today: Test, Measurement, and Inspection