Patent ID: 7367942

Claim:
An apparatus for automatically and periodically measuring a patient's blood glucose level comprising: a testing unit, infusion lines to connect said testing unit to a source of infusion fluid and to a catheter placed in a patient's blood vessel, reversible peristaltic pump means to move infusion fluid or blood either forwardly through said testing unit into said blood vessel catheter or backwardly into said testing unit and said infusion line, a main channel for blood or infusion fluid within said testing unit, a side channel in the testing unit connected to said main channel, a test chamber within said side channel for glucose testing, and valve means for controlling fluid flow through said main channel and isolating said test chamber in said side channel, wherein said valve means includes first and second valves in said side channel for isolating a blood sample in said test chamber, said first and second valves being adjacent to and on opposite sides of said test chamber, further comprising third valve means in said main channel for diverting fluid flow into said side channel, further comprising a calibration fluid channel in fluid communication with said side channel and fourth valve means in said calibration fluid channel to allow calibration fluid to flow through said side channel and said test chamber, wherein each of said valve means is a balloon valve.