The present invention relates to a device for recognising, measuring and quantitatively determining at least one exogenous substance in an endogenous liquid. According to the invention, the device comprises: —；a means for suctioning (1) an endogenous liquid containing at least one exogenous substance； —；a means for collecting (2) the endogenous liquid containing at least one exogenous substance； —；a spectrometer (3), preferably a Raman or infrared spectrometer, capable of acquiring and analysing said collected liquid； —；a database-type data storage means comprising spectra relating to at least one exogenous substance； —；a means for comparison between the spectrum or spectra acquired and the spectrum or spectra of the database； —；a means (4) for controlled introduction of at least one exogenous substance into the endogenous liquid, as a function of the result of said comparison. The invention also relates to the method implemented by such a device.
