Excimer laser monopulse energy real-time detection system and calibration method thereof

Abstract

The invention provides an excimer laser monopulse energy real-time detection system and a calibration method thereof. The excimer laser monopulse energy real-time detection system comprises a real-time energy detection module, an FPGA energy control module, a laser air pressure detection and adjustment module, a power supply voltage pulse width adjustment module and an excimer laser. Comprising the following steps: S1, collecting a monopulse energy value in real time; s2, performing transmission filtering processing on the energy value, and performing optimal estimation on laser monopulse energy data; s3, comparing the energy value with a target energy value, and calculating an energy error; s4, calculating a control signal; s5, adjusting the discharge voltage, the pulse width and the gas pressure to enable the output energy to approach the target value; and S6, repeating the steps. Therefore, the problem that the single pulse energy of the excimer laser cannot be calibrated in real time and at high precision can be solved, the single pulse energy of the excimer laser is always kept within the set precision range under various complex working conditions, and the quality and the stability of laser in skin treatment are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser energy control, and particularly to a real-time detection system for the single-pulse energy of an excimer laser and its calibration method. Background Art

[0002] With its unique wavelength and high-energy characteristics, excimer lasers have a wide range of applications in multiple fields such as medical treatment, industry, scientific research, environmental monitoring, and communication. Its main application scenarios include dermatological treatment, ophthalmic surgery, microfabrication, material processing, spectral analysis, atmospheric monitoring, etc. In the aspect of dermatological treatment, 308nm excimer lasers are mainly used. 308nm excimer laser can effectively induce the apoptosis of T cells and is regarded as the gold standard for the treatment of psoriasis (psoriasis) in the industry.

[0003] However, the output energy of 308nm excimer lasers is easily affected by factors such as changes in the gas composition of the laser cavity, the stability of the discharge power supply, fluctuations in environmental temperature and humidity, gas pressure, and electrode aging, resulting in fluctuations and drifts in the single-pulse energy. Such fluctuations and drifts will affect the treatment dose of patients receiving 308nm laser treatment. In mild cases, the treatment effect cannot be achieved, and in severe cases, it may even cause damage to the patient's skin.

[0004] Currently, most traditional energy calibration methods are static calibrations before the laser starts treatment and cannot real-time monitor and calibrate the changes in the single-pulse energy of the laser during the working process. Common laser energy control methods include open-loop control and simple feedback control. Some real-time monitoring methods, although they can stabilize the energy output to a certain extent, are difficult to achieve high-precision real-time calibration in the scenarios of fast pulses and high-energy fluctuations of excimer lasers. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems in the related art to some extent.

[0006] For this reason, the object of the present invention is to propose a real-time detection system for the single-pulse energy of an excimer laser and its calibration method, which can solve the problem of unable to calibrate the single-pulse energy of an excimer laser in real time and with high precision, ensure that under various complex working conditions, the single-pulse energy of the excimer laser always remains within the set precision range, and improve the quality and stability of the laser in skin treatment.

[0007] To achieve the above object, the present invention provides a real-time detection system for the single-pulse energy of an excimer laser, comprising a real-time energy detection module, an FPGA energy control module, a laser air pressure detection and regulation module, a power supply voltage pulse width regulation module, and an excimer laser; the real-time energy detection module is used for real-time detection of the single-pulse energy of the laser, and real-time quantitative analysis of the laser emission power of the excimer laser; the FPGA energy control module is used for processing and analyzing the collected single-pulse energy data of the laser, and combining with an internal control algorithm, to give corresponding control signals to the laser air pressure detection and regulation module and the power supply voltage pulse width regulation module; the real-time energy detection module is connected to the FPGA energy control module through RS232 communication, and the FPGA energy control module is electrically connected to the laser air pressure detection and regulation module and the power supply voltage pulse width regulation module respectively.

[0008] A calibration method for a real-time detection system of the single-pulse energy of an excimer laser, comprising the following steps: S1. The real-time energy detection module real-time collects the single-pulse energy value E of the excimer laser measured ; S2. Transmit the detected energy value to the FPGA energy control module. The FPGA energy control module performs filtering processing on the collected data, removes abnormal data points generated due to interference factors such as noise, adopts the Kalman filtering algorithm, and through establishing a system state equation and an observation equation, performs optimal estimation on the single-pulse energy data of the laser to obtain the target energy value E target ; S3. The FPGA energy control module compares E measured with the target energy value E target to calculate the energy error e(t) =E target −E measured ; S4. The FPGA energy control module uses an improved PID control algorithm to calculate the control signal , where K p , K i , K d are the proportional, integral, and differential gains respectively; S5. The FPGA energy control module, according to the control signal u(t) , respectively adjusts parameters such as the discharge voltage, pulse width, and gas pressure of the excimer laser through the power supply voltage pulse width regulation module and the air pressure regulation module, so that the output energy approaches the target value; S6. Repeat the above steps, real-time monitor and adjust the single-pulse energy, and ensure the stability and consistency of the energy output.

[0009] In addition, a real-time detection system for the single-pulse energy of an excimer laser and its calibration method proposed above according to the application may also have the following additional technical features: Specifically, the laser gas pressure detection and adjustment module includes a gas pressure detection module and a gas pressure adjustment module. The gas pressure adjustment module includes a gas pressure detection sensor and a gas pressure adjustment solenoid valve for controlling the gas pressure inside the laser.

[0010] Specifically, the power supply voltage pulse width adjustment module includes a voltage regulator and a pulse width regulator for adjusting the output voltage and pulse width of the excimer laser and controlling the output parameters of the laser light source.

[0011] Specifically, a laser power supply is provided on the excimer laser. The laser power supply is electrically connected to the voltage regulator, and the control signal of the voltage regulator is sent to the laser power supply.

[0012] Specifically, the excimer laser is a 308nm excimer laser, and the 308nm excimer laser is electrically connected to the gas pressure adjustment module.

[0013] Compared with the prior art, the present invention has the following advantages: 1. It realizes the real-time acquisition and high-precision real-time calibration of the single-pulse energy of the excimer laser, meeting the high-precision requirements for the single-pulse energy in the field of skin treatment; 2. It realizes the closed-loop control of the single-pulse energy of the excimer laser, introduces an adaptive mechanism, and dynamically adjusts the PID parameters according to the energy fluctuation; 3. It simultaneously adjusts multiple parameters such as the discharge voltage, pulse width, and gas pressure to more precisely control the energy output, improve the control accuracy, the energy fluctuation can be controlled within ±1%, it is applicable to high-frequency pulse scenarios, and the response time is short.

[0014] The additional aspects and advantages of the present invention will be partially given in the following description, partially will become obvious from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the following description of the embodiments in conjunction with the drawings, where: Figure 1 It is a system block diagram of a real-time detection system for the single-pulse energy of an excimer laser and its calibration method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention. On the contrary, the embodiments of the present invention include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0017] A real-time detection system for the single-pulse energy of an excimer laser and its calibration method according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0018] As Figure 1 shown, a real-time detection system for the single-pulse energy of an excimer laser and its calibration method according to an embodiment of the present invention include a real-time energy detection module, an FPGA energy control module, a laser gas pressure detection and adjustment module, a power supply voltage pulse width adjustment module, and an excimer laser.

[0019] Among them, the real-time energy detection module is used for real-time detection of the single-pulse energy of the laser and for real-time quantitative analysis of the laser emission power of the excimer laser.

[0020] The FPGA energy control module is used for processing and analyzing the collected single-pulse energy data of the laser. Combining with the internal control algorithm, it gives the corresponding control signals to the laser gas pressure detection and adjustment module and the power supply voltage pulse width adjustment module.

[0021] The real-time energy detection module is connected to the FPGA energy control module through RS232 communication, and the FPGA energy control module is electrically connected to the laser gas pressure detection and adjustment module and the power supply voltage pulse width adjustment module respectively.

[0022] It should be noted that the FPGA energy control module sequentially sends the control signals to the connected laser gas pressure detection and adjustment module and the power supply voltage pulse width adjustment module. The power supply voltage pulse width adjustment module processes the received control signals and then sends them to the excimer laser to output laser. The laser gas pressure detection and adjustment module is connected to the excimer laser to control the gas pressure of the laser.

[0023] It includes the following steps: S1. The real-time energy detection module real-time collects the single-pulse energy value E of the excimer laser measured ; S2. Transmit the detected energy value to the FPGA energy control module. The FPGA energy control module filters the collected data to remove abnormal data points generated by interference factors such as noise. Using the Kalman filter algorithm, by establishing a system state equation and an observation equation, the single-pulse energy data of the laser is optimally estimated to obtain the target energy value E target ; S3. The FPGA energy control module takes E measured and compares it with the target energy value E target to calculate the energy error e(t) = E target − E measured ; S4. The FPGA energy control module uses an improved PID control algorithm to calculate the control signal , where K p , K i , K d are the proportional, integral, and differential gains respectively; S5. The FPGA energy control module adjusts parameters such as the discharge voltage, pulse width, and gas pressure of the excimer laser respectively through the power supply voltage pulse width adjustment module and the air pressure adjustment module according to the control signal u(t) to make the output energy approach the target value; S6. Repeat the above steps to monitor and adjust the single-pulse energy in real time to ensure the stability and consistency of the energy output.

[0024] It should be noted that the FPGA energy control module can also adopt a sliding average filtering algorithm. After the laser energy is collected, it is converted into an electrical signal through the photoelectric effect. The electrical signal data is preprocessed through the sliding average filtering algorithm to obtain the control signal, achieving the same effect as the PID control algorithm.

[0025] In an embodiment of the present invention, as Figure 1 shown, the laser air pressure detection and adjustment module includes an air pressure detection module and an air pressure adjustment module. Among them, the air pressure adjustment module includes an air pressure detection sensor and an air pressure adjustment solenoid valve for controlling the internal gas pressure of the laser.

[0026] It should be noted that the air pressure adjustment solenoid valve adopts the PA-2001 model, which has the advantages of accurate adjustment and fast response speed, and can immediately respond to the signal of the air pressure adjustment module to adjust the internal gas pressure of the laser.

[0027] In an embodiment of the present invention, as Figure 1 shown, the power supply voltage pulse width adjustment module includes a voltage regulator and a pulse width regulator for adjusting the output voltage and pulse width of the laser power supply, playing a role in controlling the output parameters of the laser light source.

[0028] A laser power supply is provided on the excimer laser, and the laser power supply is electrically connected to the voltage regulator. The control signal of the voltage regulator can be sent to the laser power supply to adjust the voltage.

[0029] The excimer laser is a 308nm excimer laser, which is electrically connected to the air pressure adjustment module to facilitate the control of the gas pressure of the 308nm excimer laser.

[0030] It should be noted that the laser power supply adopts the EL-308-POWER model, which has a reserved program control interface, a more stable output voltage, can receive the adjustment signal of the voltage regulator, quickly responds to change the voltage output, and ensures the effect of real-time calibration.

[0031] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0032] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and deformations to the above embodiments within the scope of the present invention.

Claims

1. A real-time detection system for single pulse energy of excimer laser, characterized in that: It includes a real-time energy detection module, an FPGA energy control module, a laser gas pressure detection and adjustment module, a power supply voltage pulse width adjustment module and an excimer laser; The real-time energy detection module is used for real-time detection of laser single pulse energy and real-time quantitative analysis of the laser emission power of the excimer laser; The FPGA energy control module is used to process and analyze the collected laser single pulse energy data, and in combination with the internal control algorithm, send corresponding control signals to the laser gas pressure detection and adjustment module and the power supply voltage pulse width adjustment module; The real-time energy detection module is connected to the FPGA energy control module via RS232 communication, and the FPGA energy control module is electrically connected to the laser gas pressure detection and regulation module and the power supply voltage pulse width regulation module respectively.

2. The real-time detection system for single pulse energy of excimer laser according to claim 1, characterized in that: The laser gas pressure detection and regulation module comprises a gas pressure detection module and a gas pressure regulation module. The gas pressure regulation module comprises a gas pressure detection sensor and a gas pressure regulation solenoid valve, which are used to control the gas pressure inside the laser.

3. The real-time detection system for single pulse energy of excimer laser according to claim 1, characterized in that: The power supply voltage pulse width adjustment module comprises a voltage regulator and a pulse width regulator, which are used for adjusting the output voltage and pulse width of the excimer laser and controlling the output parameters of the laser light source.

4. The real-time detection system for single pulse energy of excimer laser according to claim 3, characterized in that: The excimer laser is provided with a laser power supply, the laser power supply is electrically connected to a voltage regulator, and a control signal of the voltage regulator is sent to the laser power supply.

5. The real-time detection system for single pulse energy of excimer laser according to claim 2, characterized in that: The excimer laser is a 308nm excimer laser, and the 308nm excimer laser is electrically connected to the gas pressure regulating module.

6. A calibration method for an excimer laser single pulse energy real-time detection system, used for the excimer laser single pulse energy real-time detection system according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Real-time energy detection module collects the single pulse energy value E of the excimer laser in real time measured ; S2, the detected energy value is transmitted to the FPGA energy control module, the FPGA energy control module filters the collected data, removes abnormal data points caused by noise and other interference factors, and uses the Kalman filter algorithm to optimally estimate the laser single pulse energy data by establishing the system state equation and observation equation to obtain the target energy value E. target ; S3, FPGA energy control module will E measured With the target energy value E target Compare and calculate the energy error e(t) =E target −E measured ; S4, FPGA energy control module uses improved PID control algorithm to calculate control signal ,in, K p , K i , K d are proportional, integral and derivative gains respectively; S5, FPGA energy control module according to the control signal u(t) , respectively adjusting the discharge voltage, pulse width and gas pressure of the excimer laser through the power supply voltage pulse width adjustment module and the gas pressure adjustment module, so that the output energy approaches the target value; S6. Repeat the above steps to monitor and adjust the single pulse energy in real time to ensure the stability and consistency of energy output.

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