Systems and methods for alignment of a laser beam

• US 10,470,843 B2
• Filed: 04/27/2018
• Issued: 11/12/2019
• Est. Priority Date: 12/05/2014
• Status: Active Grant

• Current Assignee: Convergent Dental, Inc.
• Original Assignee: Convergent Dental, Inc.
• Inventors: Courtin, Christopher B., Groves, Jr., William Harris
• Primary Examiner(s): Smith, Maurice C
• Application Number:
  US15/964,952
• Publication Number:
  US 20180243049A1
• Time in Patent Office: 564 Days
• CPC Class Codes: A61B 18/201 with beam delivery through a hollow tube, e.g. forming an articulated arm through a flexible conduit A61B18/22; Hand-pieces therefor
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/2025 with a pilot laser
• CPC Class Codes: A61C 1/0015 Electrical systems
• CPC Class Codes: A61C 1/0046 Dental lasers surgical lasers A61B18/20; working by laser beam in general B23K26/00; lasers per se H01S3/00
• CPC Class Codes: A61C 1/085 for multiple drills, for simultaneous drilling
• CPC Class Codes: A61C 3/02 Tooth drilling or cutting instruments; Instruments acting like a sandblast machine
• CPC Class Codes: G02B 26/0816 by means of one or more reflecting elements
• CPC Class Codes: G02B 7/005 Motorised alignment
• CPC Class Codes: H01S 3/0014 Monitoring arrangements not otherwise provided for photometry G01J1/00, e.g. G01J1/4257; radiation pyrometry G01J5/00; measuring coherence of light G01J9/00; measuring wavelength of light G01J9/00, e.g. G01J9/0246; measuring optical pulses G01J11/00; calorimetrically measuring power of laser beams G01K17/003
• CPC Class Codes: H01S 3/0071 Beam steering, e.g. whereby a mirror outside the cavity is present to change the beam direction

Abstract

A dental laser treatment system includes a treatment laser beam and a pilot (e.g., aiming/marking) laser beam sharing a collinear beam path, where the beam path is guided by a guidance system through a handpiece/main chamber assembly having a beam exit. A laser beam presence detector is removably affixed to or within the handpiece/main chamber assembly. The laser beam presence detector provides feedback to a computer which can control actuation of the treatment laser beam and the pilot laser beam, and the beam guidance system. The computer performs a search for determining the center location of the beam exit based on the feedback and controls the beam guidance system to guide the beam path approximately to the center of the beam exit, thereby providing automatic alignment of the laser beam with the beam exit or an optional hollow waveguide.

Claims

1. A laser-based treatment system, comprising:

a beam guidance system for directing a laser beam along a beam path;

a handpiece having one of a beam exit for directing the laser beam toward a treatment area and a hollow waveguide;

a sensor assembly; and

a processor programmed to receive a plurality of signals from the sensor assembly and, in response, control an initial position of the beam guidance system to adjust the beam path through a center of one of the beam exit and an inlet of the hollow waveguide.

2. The laser-based treatment system of claim 1, wherein the beam guidance system comprises a pair of galvanometer controlled mirrors.

3. The laser-based treatment system of claim 1, wherein at least a portion of the sensor assembly is housed within the handpiece.

4. The laser-based treatment system of claim 1, wherein the sensor assembly is located in a detachable housing.

5. The laser-based treatment system of claim 1, wherein at least one of an electrical communication link between the sensor assembly and the processor and an electrical communication link between the processor and the beam guidance system comprises a wireless communication link.

6. A method of aligning a laser beam, the method comprising the steps of:

(a) controlling by a processor a beam guidance system to direct a laser beam along a first beam path so that the laser beam is detected by a sensor;

(b) controlling by the processor the beam guidance system to adjust a path of the laser beam up to a second beam path so that the sensor detects an absence of the laser beam;

(c) recording by the processor a first set of co-ordinates associated with the beam guidance system and corresponding to the second beam path;

(d) controlling by the processor the beam guidance system to direct the laser beam along one of the first beam path and a third beam path, so that the laser beam is detected by the sensor;

(e) controlling by the processor the beam guidance system to adjust a path of the laser beam up to a fourth beam path so that the sensor detects an absence of the laser beam;

(f) recording by the processor a second set of co-ordinates associated with the beam guidance system and corresponding to the fourth beam path; and

(g) computing by the processor a set of co-ordinates associated with a beam exit.

7. The method of claim 6, further comprising adjusting by the processor an initial position of the beam guidance system using the set of co-ordinates associated with the beam exit.

8. The method of claim 7, wherein the laser beam comprises at least one of a treatment laser beam and a marking laser beam.

9. The method of claim 7 further comprising directing by the beam guidance system the laser beam according to a specified pattern, shape, and size.

10. The method of claim 7, wherein the step of adjusting the initial position of the beam guidance system is performed at least one of prior to the directing step and during two iterations of the directing step.

11. A laser-based treatment system facilitating automatic alignment of a laser beam, the system comprising:

a beam guidance system adapted to direct a laser beam through an aperture;

a sensor adapted to provide a feedback signal in response to the laser beam passing through the aperture; and

a processor adapted to determine a center of the aperture based on the feedback signal and adjust the beam guidance system for directing the laser beam through the aperture center.

12. The laser-based treatment system of claim 11, wherein the beam guidance system comprises a pair of galvanometer-controlled mirrors controlled by the processor.

13. The laser-based treatment system of claim 11 further comprising a handpiece, the aperture formed by a beam exit of the handpiece.

14. The laser-based treatment system of claim 11 further comprising a handpiece having a hollow waveguide, the aperture formed by an inlet of the hollow waveguide.

15. The laser-based treatment system of claim 11 further comprising a handpiece, the sensor comprising an annular sensor disposed within the handpiece, the aperture formed by an opening formed in the annular sensor.

16. The laser-based treatment system of claim 11, further comprising:

a handpiece; and

an annular reflector disposed within the handpiece, the aperture comprising an opening formed in the annular reflector with the sensor being oriented to face the annular reflector.

17. The laser-based treatment system of claim 16 further comprising a diffusor comprising a translucent material disposed over the annular reflector.

18. The laser-based treatment system of claim 16, wherein the aperture is located upstream along a beam path from a beam exit of the handpiece.

19. The laser-based treatment system of claim 11, wherein the sensor is adapted to provide:

a first feedback signal indicating detection of laser energy by the sensor above a specified threshold level; and

a second feedback signal indicating absence of laser energy above the threshold level.

20. The laser-based treatment system of claim 11, wherein the sensor is adapted to provide the second feedback signal indicating absence of laser energy.

21. The laser-based treatment system of claim 11, wherein the sensor comprises at least one sensor element selected from the group consisting of a photoresistor, a photodiode, a phototransistor, a thermoelectric device, and a far-IR optical sensor.

22. The laser-based treatment system of claim 11 further comprising a diffusor comprising a translucent material disposed over the sensor.

23. The laser-based treatment system of claim 11 further comprising an amplifier for amplifying an output signal of the sensor.

24. The laser-based treatment system of claim 11 further comprising circuitry:

comparing a sensor signal obtained from the sensor with a reference signal;

producing a first feedback signal if the sensor signal is greater than the reference signal; and

otherwise producing a second feedback signal.