Myocardial spectrometer probe and a method of monitoring the heart muscle

A method of monitoring molecular concentrations in a tissue of interest by spectroscopy, comprising:

• providing at least two separate light guides, insertable into the tissue, wherein a first light guide is arranged to deliver light and a second light guide is arranged to collect light,
• inserting the light guides into the tissue of interest such that the first light guide and the second light guide are arranged distinct to each other by mounting the first and second light guides in a jig so that at least a portion of intact tissue separates the first light guide from the second light guide, so that light delivered by the first light guide will travel through said intact tissue to reach the second light guide,
• repeatedly delivering light from the first light guide and collecting light delivered from the first light guide by the second light guide, to form a plurality of signals corresponding to the light collected;
• and
• monitoring the plurality of signals thus obtained
• wherein a tip of the first and second light guide are angled in 70-90 degrees with respect to a respective longitudinal axis of the first and second light guide, and
• wherein the light guides are coated so as to make the light guides stiff to support penetration of a surface, and other layers, of the tissue in question.