CA2015287A1 - Contamination-free method and apparatus for measuring body fluid chemical parameters - Google Patents

Abstract

A sample of a body fluid, such as blood, is collected in a cartridge having a sample chamber for storing the sample and one or more calibration chambers, each for storing a respective calibration fluid. The fluid sample is drawn into the sample chamber by placing the sample chamber in fluid communication with a needle inserted into the fluid sample and applying a vacuum to the chamber using either a syringe or internal vacuum. A body fluid sample may also be drawn into the sample chamber from a syringe or capillary tube containing the fluid sample. The cartridge may be either planar or cylinrical. The chambers of a cylindrical cartridge may be either elongated voids symmetrically positioned about the longitudinal axis of the cartridge or axially spaced annular voids. One or more sensors, such as ion-sensitive electrodes, are placed in contact with the fluid sample and calibrating fluid(s) by either placing the sensor(s) in contact with externally accessible chambers or by allowing the fluid sample calibrating fluid(s) to flow from the chambers past the sensor(s). In the event that the sensor(s) are placed in direct contact withexternally accessible chambers, the sensor(s) may be scanned from one chamber to the next by an automatic drive mechanism.