Ultrasound provides many advantages as a promising tool for medical diagnostic: it is comfortable for the final-end user, non-invasive, and safe, as it does not involve ionizing radiation. Ultrasonic sensors present applications in many fields such as for continuous vital parameter monitoring, to detect tumors and even to prevent hydrocephalus. However, the hardware development of an ultrasound device still presents many challenges. The pulser that drives the excitation signal into the ultrasound sensors is the most complex part, as it requires high DC voltages (±100 V) and current (approximately 1-2 A). The need of a large battery to provide this power supply make state-of-the-art implementations of the pulser very bulky and heavy, and therefore, inappropriate for a compact and/or wearable ultrasound system. In this work, two compact and low-power pulser approaches will be presented and compared. Both ultrasound pulsers are driven by digital signals supplied by an FPGA. The pulsers serve as the input signals of piezoelectric transducers that are used to detect arterial hemodynamic changes. These pulser designs enable accurate detection of variations of the arterial diameter with a reduction of the applied voltage by 40 % (±60 V).