Biosafety implications in sample introduction: module design characteristics for discrete-sample systems used in...

Systems designed for the measurement of pH/blood gases and expanded versions of these systems that include the ability to measure electrolytes or other related quantities, all incorporate one or more sampling modules that are limited in their ability to allow for the safe handling of potentially biohazardous blood samples. Systems that provide for injection of sample from a syringe use more than the required volume for sample testing and have the potential for causing splash-back of the sample if the introduction port is blocked. The probes of aspiration-based systems require manual dexterity by the operator and present the possibility of operator injury with a contaminated probe tip or the possibility of system damage as the probe extends and the operator moves the collection device into place. Some systems have the potential for both types of biohazards. This report describes the implications for system design of the sample collection devices commonly in use, and it offers a design solution that combines the ergonomics of an injection system and the operational advantages of an aspiration system, in combination, addressing the biosafety aspects in a unique fashion.