phased array
Small-footprint ultrasound probe with closely-spaced elements driven with phase-controlled timing to electronically steer the beam. Cardiac imaging standard — the small footprint fits between ribs, and the wedge-shape sector image suits the cardiac window. Adult cardiac probes (~2–5 MHz) and pediatric / neonatal cardiac probes (5–8 MHz) are both phased-array; Philips S5-1, GE 5S / M5S, Siemens P4-2 / P5-1 are typical examples.
Why it matters to buyers: Cardiac application gate — you need a phased-array probe for transthoracic echo. TEE probes are also phased-array (mounted on a flexible endoscope). S5-1 and equivalents are among the higher-cost probes in the cart inventory; refurb price can be a meaningful share of total system value.
Why it matters to engineers: Worn faster than other probe types by cardiology duty cycle — high acoustic-output cases run repeatedly with the same probe. Lens delamination, crystal-stack aging, and connector wear show up first on cardiac fleets. Probe-refurbishment economics are favorable on phased-array given high replacement cost.