One of the objective of the four year European project CLINICIP - Closed Loop Insulin Infusion in Critically Ill Patients - is the study of the metabolism of the adipose tissue in intensive care patients, by means of continuous monitoring of pH, pO2, pCO2. Microdialysis is the approach followed for the extraction of the sample from the subcutancous adipose tissue; the drawn interstitial fluids flows through a microfluidic circuit formed by the CMA60 microdialysis catheter in series with a glass capillary on the internal wall of which the appropriate chemistry is immobilised. The modulation of the fluorescence lifetime is the optical working principle used for the detection of oxygen and carbon dioxide, whereas absorption modulation is the one utilised for the pH detection. On this basis, two different optoelectronic units were developed for the interrogation of the glass capillary, one for life-time measurements and the other for absorption measurements. Preliminary tests demonstrated a resolution of 0.03 pH units for pH; <= 0.55 mmHg for oxygen and <= 0.6 mmHg for carbon dioxide; and an accuracy of 0.07 pH units for pH; <= 1 mmHg for oxygen and <= 1.5 mmHg for carbon dioxide. In vitro tests with the catheter CMA60 were performed for the metabolities O2 and pH and a recovery of about 100% and 70% respectively was measured.
Optical sensor for the control of the metabolism of adipose tissue
F Baldini;A Giannetti;AA Mencaglia;
2008
Abstract
One of the objective of the four year European project CLINICIP - Closed Loop Insulin Infusion in Critically Ill Patients - is the study of the metabolism of the adipose tissue in intensive care patients, by means of continuous monitoring of pH, pO2, pCO2. Microdialysis is the approach followed for the extraction of the sample from the subcutancous adipose tissue; the drawn interstitial fluids flows through a microfluidic circuit formed by the CMA60 microdialysis catheter in series with a glass capillary on the internal wall of which the appropriate chemistry is immobilised. The modulation of the fluorescence lifetime is the optical working principle used for the detection of oxygen and carbon dioxide, whereas absorption modulation is the one utilised for the pH detection. On this basis, two different optoelectronic units were developed for the interrogation of the glass capillary, one for life-time measurements and the other for absorption measurements. Preliminary tests demonstrated a resolution of 0.03 pH units for pH; <= 0.55 mmHg for oxygen and <= 0.6 mmHg for carbon dioxide; and an accuracy of 0.07 pH units for pH; <= 1 mmHg for oxygen and <= 1.5 mmHg for carbon dioxide. In vitro tests with the catheter CMA60 were performed for the metabolities O2 and pH and a recovery of about 100% and 70% respectively was measured.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
