Method and apparatus for monitoring blood chemistry

摘要

An improved system is disclosed for monitoring a patient's blood chemistry, wherein the system intermittently draws blood samples from the patient into a special sensor assembly having a plurality of analytical sensors, each sensitive to a particular parameter of the blood. After signals produced by these various sensors have been read, the system reinfuses the blood samples back into the patient. Withdrawal of the successive samples to a desired, optimal position within the sensor assembly is achieved by monitoring signals produced by one or more of the analytical sensors, themselves. This allows a catheter that connects the sensor assembly to the patient to have a variable length and internal volume and obviates the need for a separate, dedicated sensor for detecting the arrival of the blood sample at the desired position.