Light and not bulky, the device guarantees accurate parameter setting by microprocessor control. In case of long-lasting use of the pacer, battery replacement can be carried out without interrupting the pacing activity thanks to the availability of stand-by batteries which ensure power supply for the time required. The connectors on the top of the pacer accept every lead commonly marketed. They enclose a locking system to prevent accidental slipping out of lead pins. Safety functions include power-on self-test, on line test of battery charge level, power-on inhibition in case of low charge level, an independent anti-runaway circuit and an alarm in case of disconnection of the lead. A “beep” and a notice in the display will alert the operator in conditions of danger.
           The keyboard provides a self-explanatory user interface and allows for quick program selection.

The available pacing models are: VVI and VVO (asynchronous). In the VVO mode tachyarrhythmia’s can be handled by means of either a burst at a rate quadruple than the set value, or a decreasing ramp. A quick pacing start under safety parameters can be obtained by using the EMERGENCY key (asynchronous pacing at 72 ppm). The AUTO key permits to start a demand pacing with automatic adjustment of rate, threshold and sensing amplitude values.
Both in EMERGENCY and in AUTO the values can subsequently be further adjusted manually.

The unit’s main characteristics are :

· Synchronous and asynchronous modes of operation.
· Fully microprocessor operated control allowing a high precision setting of stimulation parameters and a complete and continuous check for correct operation of the unit.
· Back-lighted LCD display
· AUTO and EMERGENCY keys for a quick start-up of both synchronous and asynchronous stimulation with safety parameters.
· Stimulation capability with quadruple rate and decreasing ramp to reduce tachycardia events.
· Stand-by batteries for replacement of main batteries without interrupting the stimulation.
· A large number of safety functions: self-test at power on; on-line control of the batteries level; turn-on inhibition with low battery charge; check for run-away and lead connection; protection against defibrillation discharges and electromagnetic interference. Dangerous situations are signalled to the operator by an acoustic alarm and a suitable display message.
· Easy and safety connection of patient cable or lead to SENSE and PACE socket.
· Sockets are black for – and red for +. Diameter is 2 mm and accept only connection with 2 mm plugs. Sockets have a screw knob to fix the plugs inserted into 4427.