A system and method for monitoring a health status of a subject. The system comprises: a medical device implantable in the subject and having a passage or compartment through which blood flows through; a sensor device embedded at or near a surface of said passage within said medical device for generating signals suitable for measuring a Doppler shift effect occurring within said passage; and a control device coupled to said sensor device for measuring a liquid blood flow rate within said passage based on sensor generated signals outputs. The embedded sensor device comprises a first piezo-electric element configured to generate an acoustic excitation signal and a second piezo-electric element configured to receive said acoustic excitation signal. The second piezo-electric element emits a signal responsive to said acoustic excitation signal. Control device in real time compares a generated output signal with the input excitation signal to determine a Doppler frequency shift measurement.