title: Continuous haematic pH monitoring in extracorporeal circulation using a disposable florescence sensing element.
abstract: During extracorporeal circulation (ECC), blood is periodically sampled and analyzed to maintain the blood-gas status of the patient within acceptable limits. This protocol has well-known drawbacks that may be overcome by continuous monitoring. We present the characterization of a new pH sensor for continuous monitoring in ECC. This monitoring device includes a disposable fluorescence-sensing element directly in contact with the blood, whose fluorescence intensity is strictly related to the pH of the blood. In vitro experiments show no significant difference between the blood gas analyzer values and the sensor readings; after proper calibration, it gives a correlation of R>0.9887, and measuring errors were lower than the 3% of the pH range of interest (RoI) with respect to a commercial blood gas analyzer. This performance has been confirmed also by simulating a moderate ipothermia condition, i.e., blood temperature 32°C, frequently used in cardiac surgery. In ex vivo experiments, performed with animal models, the sensor is continuously operated in an extracorporeal undiluted blood stream for a maximum of 11 h. It gives a correlation of R>0.9431, and a measuring error lower than the 3% of the pH RoI with respect to laboratory techniques.
authors: University of Modena and Reggio Emilia, Department of Engineering Enzo Ferrari, Strada Vignolese 905, I-41125, Modena, Italy. luca.ferrari@unimore.it
authors: Luca
authors: L
authors: Ferrari
authors: Luigi
authors: L
authors: Rovati
authors: Paola
authors: P
authors: Fabbri
authors: Francesco
authors: F
authors: Pilati
mesh_terms: D000818:Animals; D001769:Blood / Q000378:metabolism*; D001784:Blood Gas Analysis / Q000295:instrumentation / Q000706:statistics & numerical data; D005112:Extracorporeal Circulation; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000706:statistics & numerical data; D055096:Optical Devices; D055100:Optical Fibers; D055620:Optical Phenomena; D034561:Sheep, Domestic; D013050:Spectrometry, Fluorescence / Q000295:instrumentation* / Q000706:statistics & numerical data; D034421:Sus scrofa; D014159:Transducers