A combination of a portable monitoring device and a medical device, wherein medical device comprises a portable drip infusion set with a liquid supply, a drip chamber, a flexible tube connecting said drip chamber with an injection needle, a housing, a signal emitter, a timing device for measuring a time interval, a circuit interconnecting the timing device and the emitter and causing the emitter to emit a signal at the end of said time interval, a power supply, a circuitry for monitoring functional parameters such as voltage of said power supply or other output of medical device such as deviations in functional parameters of the infusion set, causing emitter to emit a second signal if any of said deviations are registered, and two sets of electrical contacts the monitoring device comprises a housing, a receiver, a timing device for measuring a time interval, an alarm device producing an alarm if said receiver has not received a signal at the end of said time interval or if said second signal is received, a power supply, and two sets of electrical contacts. Two sets of electrical contacts are used for interconnecting said medical and monitoring devices for transmitting electronic data and/or electrical power between these devices. The medical device further comprises programming means, which comprises blocking means for preventing the programming function if said monitoring and medical devices are not interconnected through said two sets of electrical contacts.
