摘要 |
A method and apparatus for evaluating the viability of a tissue of interest, particularly that presents as dead but may be merely stunned or hibernating with reduced or no obvious activity, such as contractility. Dynamic measurement of oxidative metabolism or other metaboic function permits distinguishing between different stages of compromised tissue such as myocardium. Measurements can be made using near-infrared illumination and detection coupled with infusion of one or more metabolic substrates to the region of interest to evaluate whether a metabolic pathway cascade or a trans-membrane ionic potential are intact and thereby provide an indication of the viability of the cell. One preferred instrument includes a catheter having a tip configured to be positioned adjacent to the tissue to be monitored. Optical fibers extend through the catheter to transmit a monitoring light beam from the tip into the tissue, and to receive a cytochrome-redox-response-dependent light beam from the tissue. Needles in the tip releasably anchor the catheter to the tissue and deliver metabolism-stimulating substances. Redox signals representative of cytochrome aa3 redox responses in the tissue are generated by a spectrometer coupled to the optical fibers. A computer coupled to the spectrometer generates metabolism readings as a function of the redox signals. |