Laser treatment using acoustic feedback

A method for controlling a laser system to deliver laser energy to a target in a body of a subject, the method comprising:

• directing laser energy produced by the laser system to the target via an optical pathway;
• receiving, via an acoustic sensor, an acoustic signal resulting from pressure waves in liquid media produced by the laser energy incident on the target;
• measuring, via an acoustic feedback controller circuit, one or more acoustic properties from the received acoustic signal, the one or more acoustic properties including temporal information about a peak of the acoustic signal, wherein the temporal information represents time elapsed for the laser energy to travel from the laser system to target through the liquid media and time elapsed for the acoustic signal to travel to the acoustic sensor;
• estimating a distance between a distal end of the optical pathway and the target based at least in part on the temporal information about the peak of the acoustic signal;
• and
• generating, via the acoustic feedback controller circuit, a first control signal for controlling the laser system to produce laser energy for delivery to the target based on the estimated distance between the distal end of the optical pathway and the target.