An implanted system includes at least two optical sensors implanted proximate to an artery of a patient such that one optical sensor is upstream of another optical sensor. Arterial pulses of the patient may be detected based on electrical signals from at least one of the optical sensors. In addition, electrical signals from the optical sensors may be used to minimize the effects of motion artifacts on the detection of arterial pulses. For example, a detected pulse may be determined to be a spurious pulse if the optical sensors indicate the occurrence of the pulse within a predetermined range of time. As another example, a first optical sensor signal may be shifted in time relative to a second optical sensor signal, and the signals may be correlated. An arterial pulse may be detected at a time at which a peak or trough amplitude value of the correlated signal is observed.
