Analysis of a composition

A method for analyzing a composition of an object to be examined, comprising the steps of:

• emitting a monitoring beam to image a target region in or on the object during a monitoring period;
• emitting an excitation beam to excite at least a portion of the target region during an excitation period overlapping with the monitoring period, the excited portion of the target region constituting an excitation area which is thus imaged by the monitoring beam;
• and
• simultaneously displaying the imaged target region and the imaged excitation area.

A method for spectral non-invasive analysis of a composition of blood comprising the steps of:

• imaging a target region by emitting a monitoring beam substantially coinciding with a blood vessel during a monitoring period;
• exciting at least a portion of the target region with an excitation beam during an excitation period substantially overlapping with the monitoring period, the excited portion of the target region constituting an excitation area which is thus imaged by the monitoring beam;
• simultaneously displaying the imaged target region and the imaged excitation area;
• and
• detecting scattered radiation from the target region generated by the excitation beam with imaging the target region using the monitoring beam.