Probe for optical imaging
A 3D-scanning optical imaging probe which inhibits rotation unevenness of rotational sections, shaft run-out, friction, and rotation transmission delay by reducing the occurrence of torque loss and rotation transmission delay, and which is capable of obtaining 3D scans and observation images within a fixed frontal range. A substantially tubular catheter has, provided along substantially the same line therein: a fixed-side optical fiber; a first optical path conversion means which is rotationally driven by a first motor, and which rotates and emits a beam of light forwards and tilted at an angle with respect to a rotational axis; and a second optical path conversion means which, at a tip side of a rotation-side optical fiber rotationally driven by a second motor, tilts an optical path by a micro-angle with respect to the rotational axis, and rotates and emits the beam of light to irradiate the first optical path conversion means therewith.
1. A probe for optical imaging which guides light entering a tip side to a rear side, the probe comprising:
a fixed side optical fiber non-rotatably disposed and incorporated in a substantially tube-shaped catheter;
a first optical path conversion means disposed on a tip side of the fixed side optical fiber and driven and rotated by a first motor to rotate and emit a light ray forward at an angle inclined with respect to a rotation center;
a rotation side optical fiber disposed between the fixed side optical fiber and the first optical path conversion means, optically connected by an optical rotary connector, and driven and rotated by a second motor; and
a second optical path conversion means for rotating and emitting light to a tip side of the rotation side optical fiber by tilting an optical path by a minute angle with respect to a rotation center, and emitting a light ray toward the first optical path means,
wherein the fixed side optical fiber, the first optical path conversion means, the rotation side optical fiber, and the second optical path conversion means are substantially collinearly disposed,
wherein the light ray is emitted forward by penetrating the optical rotary connector, the second optical path conversion means, and the first optical path conversion means in order from the fixed side optical fiber.
2. The probe for optical imaging according to claim 1 ,
wherein a rotating shaft of the first motor has a hollow shape, the first optical path conversion means is fixed thereto, and the rotation side optical fiber rotatably penetrates into a hollow hole, and
a rotating shaft of the second motor has a hollow shape, and the rotation side optical fiber is fixed to a hole corresponding to the hollow shape and rotated.
3. The probe for optical imaging according to claim 1 , wherein the first optical path conversion means is a rotatable prism.
4. The probe for optical imaging according to claim 1 , wherein the second optical path conversion means is a prism having a substantially inclined flat surface at a tip.
5. The probe for optical imaging according to claim 1 , further comprising:
a first pulse generating means for generating at least one or more pulses per rotation according to a rotation angle of the first motor;
a second pulse generating means for generating at least one or more pulses per rotation according to a rotation angle of the second motor; and
a control means for adjusting rotation speeds of the first and the second motors by pulses from the first and second pulse generating means,
wherein the light ray is emitted forward from the first optical path conversion means at a rotation speed of N 1 [rotations/second] by setting a relation between a rotation speed N 1 of the first motor and a rotation speed N 2 of the second motor to N 2 =N 1 −X [rotations/second], and an emission angle of the light ray with respect to the rotation center is changed at a speed of X [reciprocations/second].
6. The probe for optical imaging according to claim 1 , wherein a condensing lens, a first prism, and a second prism are substantially collinearly disposed in the second optical path conversion means.
7. The probe for optical imaging according to claim 1 , wherein the rotatable prism and the substantially inclined flat surface at the tip of the prism of the second optical path conversion means are nonparallel to each other in the first optical path conversion means.
8. The probe for optical imaging according to claim 1 , wherein the second optical path conversion means is a prism having a substantially spherical surface inclined to the tip or a ball lens having a reflecting surface corresponding to a substantially flat surface in a portion of a substantially hemispheric shape.