A syringe pump that includes integral valves for the aspiration and dispensation of antibodies and wash fluid complete the process in this step. Time-metered dispense is simple and inexpensive but has some accuracy limitations, so the system designer must pay attention to regulation of the reagent reservoir pressure and fluidic restriction of the components located hydraulically in series. Time-metered dispense is an ideal means of providing a simple wash system when aspiration is not required. Usually, the individual cuvettes are disposed of after elimination of the liquid assays. In some systems, the cuvettes are incinerated along with the liquid waste.
Air is readily available and there often is no other engineering consideration than filtration.
Anesthetic agents, however, may promote swelling of elastomers used as internal valve seals. Materials such as Viton, EPDM, Kalrez, or Chemraz may be required. Noninvasive blood pressure monitors and anesthetic monitors are two of the most common automated instruments that use pneumatic fluid control systems. A noninvasive system automates blood pressure monitoring. The cuff is inflated via a miniature air compressor and deflated in small discrete steps through a normally closed two-way valve as systolic and diastolic blood pressure measurements are recorded.