aUniversity of Montpellier, IES UMR 5214, 860 Rue Saint Priest, CC 05 003, F-34000 Montpellier, FrancebCNRS, IES UMR 5214, 860 Rue Saint Priest, CC 05 003, F-34000 Montpellier, FrancecUniversity of Montpellier, Department of Thoracic and Cardiovascular Surgery, A de Villeneuve hospital 371 Av Giraud, F-34295 Montpellier, France
Checking for direct PDF access through Ovid
Tissue temperature control during cardiac surgery is crucial for myocardial protection. To preserve the tissue, a hypothermic cardioplegia is applied in order to decrease the heart temperature down to around Symbol. The monitoring of the thermal evolution of the myocardium is then of importance to minimize deleterious effects on the heart. The present work aims at evaluating the potential of an ultrasonic velocimetric thermometry on the monitoring of in vitro tissues heating. An indentation process is first proposed to identify the experimental linear relationship linking, in myocardia, the speed of the ultrasonic longitudinal wave to the tissue temperature. An extension of this method based on the echo-tracking principle is then proposed to approach surgical conditions. Temperature changes are measured by monitoring the induced time delays of backscattered ultrasonic echoes. These results are compared to T-type thermocouple reference measurements. They are then discussed in terms of measurement precision and in situ applications.HighlightsEvaluation of ultrasound thermometry potential on the myocardium warming monitoring.Identification of a linear relation linking the speed of sound to the temperature.Presentation of an echo tracking principle to approach surgery conditions.Discussion in terms of measurement precision and in situ applications.