Continuous wave (CW) bidirectional doppler equipped with electronic probes for high sensitivity and low background noise. - Bidirectional graphic separation of flow (forward and reverse) - LCD graphic display for real time display of forward and reverse flow in bidirectional or separate mode - Selectable amplitude scale: 1, 2, 4, 8 kHz. during the test and before printing. Preset zero line. - 5 minutes (300 sec.) continuous and reviewable memorized test. Operator can select the most meaningful exam and print it. - Calculation of: heart rate, peak flow and mean flow. - Simultaneous connection of high sensitivity probes - Internal rechargeable large capacity battery (Ni-Cd 1.8 Ah); the system can be operated during charging. Autonomy 8 hours use or 1 hour print. - Footswitch for freezing or memorizing the graphs - Hardcopy may or may not include the parameter calculation - Printing time scale: 25 mm/s. - Hi-fi audio output for correct acoustic diagnosis