Yes, PULSES is a Scrabble word!

Letter values in Scrabble US: P 3, U 1, L 1, S 1, E 1, S 1.

Is it a valid word?

PULSES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

(electronics) a sharp transient wave in the normal electrical state (or a series of such transients)
the rhythmic contraction and expansion of the arteries with each beat of the heart
the rate at which the heart beats; usually measured to obtain a quick evaluation of a person's health
edible seeds of various pod-bearing plants (peas or beans or lentils etc.)

expand and contract rhythmically; beat rhythmically
produce or modulate (as electromagnetic waves) in the form of short bursts or pulses or cause an apparatus to produce pulses
drive by or as if by pulsation

Also: pulse rate, heart rate.