Fig. 9.

Verification of tissue-catheter contact in the presence of blood. An exemplary example of spectra acquired in contact and 2mm above the tissue surface. Measurements were made on excised swine heart tissue submerge in whole blood to assess changes in reflectance seen with catheter contact. The grey line shows a measurement taken with the catheter 2 mm above the tissue, not in contact. A large signal increase is seen when the catheter is in contact with the tissue (black line). Mean +/− standard deviation.