The invention relates to a method for monitoring glycemia and maintaining it at a preset level and to an apparatus for injecting insulin to a patient suffering from diabetes mellitus. According to the invention, the method consists in monitoring the glycemia level at certain time intervals using a micro spectrometer mounted on a blood vessel, i.e. a vein, and continuously introducing an amount of insulin, by means of an osmotic diffuser which provides an adequate level of basal insulinemia as well as the discontinuous injection of a number of insulin units, depending on the glycemia level and the patients weight, in accordance with the command that a coordinating chip gives to a micro pump and by means of an injecting unit which performs the injection directly into the blood flow of a blood vessel, i.e. an arteriole. The apparatus, as claimed by the invention, comprises an internal unit implanted into the abdominal wall of a patient affected by insulin-requiring diabetes mellitus, which consists of a cylinder-shaped body (1) made of mechanically-resistant plastics, connected by some flexible tubes to three external units (2, 3 and 4), namely: an insulin injecting unit (2) for injecting it directly into the blood flow of an arteriole, a unit (3) having an osmotic diffuser which provides an adequate basal insulinemia level and a unit (4) for monitoring the glycemia level at certain time intervals, such as an electronic micro spectrometer mounted on a vein, a tight flexible sheath (5) made of a biocompatible material which also covers, almost completely, the external units (2, 3 and 4) while leaving uncovered only some titanium surfaces thereof which come into direct contact with the patients tissues, a titanium nozzle (6) for releasing the glucagon into the patients blood circuit, in case of hypoglycemia, as well as a watch-like external unit to be placed on the patients wrist.Invenţia se referă la o metodă de monitorizare şi menţinere a unui nivel prescris al glicemi
