Systems and methods for laser pulse monitoring and calibration

Patent metadata

Field	Value
Publication number	US-12402945-B2
Application number	US-202217664293-A
Country	US
Kind code	B2
Filing date	May 20, 2022
Priority date	May 21, 2021
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

A medical laser system for outputting laser pulses includes at least one laser cavity configured to generate at least one laser pulse, a rotating mirror configured to receive and reflect the at least one laser pulse, a beam splitter configured to receive and reflect a portion of the at least one laser pulse received from the rotating mirror, an energy-sensing device configured to detect the portion of the at least one laser pulse, an energy measurement assembly configured to generate a feedback signal based on the portion of the at least one laser pulse detected by the energy-sensing device, and a controller configured to generate an electronic control pulse based on the feedback signal received from the energy measurement assembly to generate at least one adjusted laser pulse.

First claim

What is claimed is:

1. A medical laser system for outputting laser pulses, the system comprising:
at least one laser cavity configured to generate at least one laser pulse;
a rotating mirror configured to receive and reflect the at least one laser pulse;
a beam splitter configured to receive and reflect a portion of the at least one laser pulse received from the rotating mirror;
an energy-sensing device configured to detect the portion of the at least one laser pulse;
an energy measurement assembly configured to generate a feedback signal based on the portion of the at least one laser pulse detected by the energy-sensing device;
a controller configured to generate an electronic control pulse based on the feedback signal received from the energy measurement assembly to generate at least one adjusted laser pulse; and
a memory storing at least one spectrum matrix that correlates a plurality of frequencies specified on a first axis and a plurality of pulse energies on a second axis to an average power output of the medical laser system,
wherein the medical laser system is configured to calibrate one or more laser modes based on the feedback signal and the at least one spectrum matrix.

2. The system of claim 1 , wherein the controller comprises:
a monitoring and adjustment module configured to perform a closed-loop control based on the feedback signal.

3. The system of claim 1 , wherein the controller is configured to generate the electronic control pulse based on a comparison between the feedback signal and a target laser energy level.

4. The system of claim 3 , wherein the controller is configured to generate the electronic control pulse based on a pulse width error value calculated based on the feedback signal and the target laser energy level.

5. The system of claim 1 , wherein the adjusted laser pulse is generated by adjusting a pulse width level of a laser pulse based on the feedback signal.

6. The system of claim 1 , wherein the at least one adjusted laser pulse is generated based at least on one or more correction parameters associated with the at least one laser cavity.

7. The system of claim 1 , wherein the energy-sensing device comprises laser collection optics, the laser collection optics including at least one of an attenuator, a focusing lens, or an integrating sphere.

8. The system of claim 1 , wherein the energy-sensing device comprises an optical sensor module configured to be attached to laser collection optics, the optical sensor module including a pyroelectric sensor, and a sensor circuit board.

9. The system of claim 1 , wherein the energy-sensing device is configured to generate an electrical signal based on the detected portion of at least one laser pulse.

10. The system of claim 1 , wherein the energy measurement assembly comprises a signal transformation module configured to receive an electrical signal from the energy-sensing device, the signal transformation module including an inverting operational amplifier circuit;
a signal amplification module coupled to the signal transformation module, the signal amplification module including a non-inverting amplifier circuit; and
a signal holding and sampling module coupled to the signal amplification module.

11. The system of claim 10 , wherein the signal transformation module is configured to switch a mode of the inverting operational amplifier circuit between an amplification mode and an integration mode.

12. The system of claim 10 , wherein the signal amplification module is configured to adjust a gain of the non-inverting amplifier circuit by adjusting the resistance of one or more resistors in the non-inverting amplifier circuit.

13. The system of claim 1 , wherein the at least one laser cavity comprises four laser cavities.

14. The system of claim 1 , wherein each of the at least one laser cavity comprises a glass plate arranged at a Brewster Angle.

15. The system of claim 1 , wherein the beam splitter comprises a polarization-insensitive coating.

16. A method of controlling laser pulses of a medical laser system, the method comprising:
detecting, by the medical laser system, a portion of at least one laser pulse generated by at least one laser cavity;
generating, by the medical laser system, an electrical signal based on the detected portion of the at least one laser pulse;
generating, by the medical laser system, a feedback signal based on the electrical signal;
accessing, by the medical laser system, at least one spectrum matrix that correlates a plurality of frequencies specified on a first axis and a plurality of pulse energies on a second axis to an average power output of the medical laser system;
generating, by the medical laser system, an electric control pulse based on the feedback signal and the at least one spectrum matrix; and
generating, by the medical laser system, at least one adjusted laser pulse based on the electric control pulse.

17. The method of claim 16 , further comprising:
calibrating, by the medical laser system, one or more laser modes based on the feedback signal and the at least one spectrum matrix; and
performing, by the medical laser system, a closed-loop control based on the electrical signal based on the detected portion of the at least one laser pulse and the feedback signal;
generating, by the medical laser system, the electric control pulse based on a comparison between the feedback signal and a target laser energy level; and
generating, by the medical laser system, the electric control pulse based on a pulse width error value based on the comparison between the feedback signal and the target laser energy level; and
generating, by the medical laser system, the electric control pulse by determining an adjusted electric control pulse width based on the pulse width error value.

18. The method of claim 16 , further comprising:
generating, by the medical laser system, the at least one adjusted laser pulse based at least on one or more correction parameters associated with the at least one laser cavity.

19. The method of claim 16 , further comprising:
generating, by the medical laser system, the at least one adjusted laser pulse via multiple laser cavities; and
generating, by the medical laser system, the feedback signal by:
switching, by the medical laser system, a mode of an inverting operation amplifier circuit of a signal transformation module between an amplification mode and an integration mode; and
adjusting, by the medical laser system, a gain of a non-inverting amplifier circuit of a signal amplification module by adjusting a resistance of one or more resistors in the non-inverting amplifier circuit.

20. A non-transitory computer-readable medium storing instructions for controlling laser pulses of a medical laser system, the instructions, when executed by one or more processors, causing the one or more processors to perform operations comprising:
transmitting a control signal to detect a portion of at least one laser pulse generated by at least one laser cavity;
receiving an electrical signal based on the detected portion of the at least one laser pulse;
generating a feedback signal based on the electrical signal;
generating an electric control pulse based on the feedback signal;
generating at least one adjusted laser pulse based on the electric control pulse;
calibrating one or more laser modes based on the feedback signal and at least one spectrum matrix, wherein the spectrum matrix correlates a plurality of frequencies specified on a first axis and a plurality of

Assignees

• Boston Scient Scimed Inc

Inventors

• Yang Baocheng
• Yang Xirong
• Bull Peter
• Cheng Brian
• Xuan Rongwei Jason
• Zhang Jian James
• Hasenberg Thomas Charles
• Pih David

Classifications

• A61B2017/00725

  Calibration or performance testing · CPC title

• A61B2017/0019

  Means for setting or varying the pulse width · CPC title

• A61B2018/20359

  by movable mirrors, e.g. galvanometric · CPC title

• A61B2018/20553

  with special lens or reflector arrangement · CPC title

• H01S3/161

  holmium · CPC title