Interferometric probe stabilization relative to subject movement

A system for active probe stabilization, the probe stabilization relative to movement of a subject, the system comprising:

• a manipulator, the manipulator couplable to a probe, the probe being insertable into the subject, the manipulator operable to move the probe within the subject in response to a control voltage;
• an interferometer, the interferometer operable to transmit a first light beam to the subject and to receive a reflected light beam;
• the interferometer further operative to modulate a second light beam with a modulating signal to form a reference light beam and to combine the reflected light beam and the reference beam to form an interference pattern;
• a demodulator coupled to the manipulator and to the interferometer, the demodulator operable to detect the interference pattern to determine a displacement signal, the displacement signal proportional to an amount and direction of subject movement, and to convert the displacement signal to the control voltage.

A system for active probe stabilization, the probe stabilization relative to movement of a subject, the system comprising:

• a manipulator, the manipulator couplable to a probe, the probe being insertable into the subject, the manipulator operable to move the probe within the subject, in response to a control voltage, in a direction of the probe axis;
• an interferometer, the interferometer operable to split a laser light beam to form a first light beam and a second light beam, to transmit the first light beam to the subject and to receive a reflected light beam;
• the interferometer further operative to modulate the second light beam with a radio frequency signal to form a reference light beam and to combine the reflected light beam and the reference beam to form an interference pattern;
• a processor coupled to the manipulator and to the interferometer, wherein the processor includes instructions to quadrature demodulate a phase shift of a radio frequency component of the interference pattern to determine a displacement signal, the displacement signal proportional to an amount and direction of subject movement, and to convert the displacement signal to the control voltage.