To circumvent the problems of repeated blood sampling for in vitro analysis, a catheter-tip L-lactate sensor has been developed. The sensor was tested in anesthetized pigs (n=6). The sensor in vivo tracked the lactate concentration non-linearly, seeming to obey Michaelis-Menten kinetics. Calibration time was short, typically 1.5 min per lactate standard. Furthermore, time drift was small, typically -1.3% to -3.3% per hour of in vivo use.
Weinzapfel, Brett T.; Ball, Mark D.; Waite, Lee R.; Abrouk, Nacer E.; and Lim, Shun P., "Tracking Plasma Lactate Concentration in Vivo with a Catheter-Tip L-Lactate Sensor" (1993). Mathematical Sciences Technical Reports (MSTR). 83.