Measurement of dye concentration in the bloodstream.

摘要

To establish indicator dilution curves a fluorescent dye is injected into the bloodstream 12 and its concentration is measured by means of a catheter 10 including an optical fibre 14. Light from source 20 is passed through filter 24 into the outer end of the fibre 14 and emerges into the bloodstream at the remote end of the catheter. Here it stimulates fluorescent emission from the dye and light at the emitted wavelength (different from the exciting wavelength) travels back along the optical fibre, through a filter 28 to a detector 30.