Medical device, apparatus and instruments for use in the field of medical imaging, namely, acoustic sensors, modules for determining the position of acoustic sensor on a medical device in relation to the whole anatomy of a patient and visualizing thereof; ultrasound imaging system; acoustic sensor tracking and imaging system of an ultrasound system; acoustic sensors for medical devices including catheters, needles, surgical tools and diagnostic tools; modules for visualizing the acoustic sensor position; modules for visualizing the patient anatomy; modules for determining the position of acoustic sensors in relation to the patient anatomy; Medical ultrasound device and apparatus to assist in therapeutic, surgical and/or diagnostic procedures, namely, ultrasound imaging apparatus, non-therapeutic acoustic sensors to assist in guidance, placement or securing of medical devices in vivo